epidermal-growth-factor and Pancreatic-Neoplasms

Pancreatic adenocarcinoma (PDAC) is a disease with a high incidence and a dreary prognosis. Its lack of symptomatology and late diagnosis contribute to the dearth and inefficiency of therapeutic schemes. Studies show that overexpressed epidermal growth factor receptor (EGFR) is a common occurrence, linking this to the progression of pancreatic cancer, although the association between its expression and the survival rate is rather controversial. EGFR-targeted therapy has not shown the results expected, leaving at hand more questions than answers; clearly, there is a need for a better understanding of the molecular pathways involved. Nanoparticles have been used in trying to improve the efficacy of antitumor treatment; thus, using EGFR's ligand, EGF, for nanoconjugation, showed promising results in increasing the cellular uptake mechanisms and apoptosis of the targeted cells.

Topics: Adenocarcinoma; Animals; Apoptosis; Epidermal Growth Factor; ErbB Receptors; Humans; Molecular Targeted Therapy; Nanoparticles; Pancreatic Neoplasms

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) constitute a heterogeneous group of tumours associated with variable clinical presentations, growth rates, and prognoses. To improve the management of GEP-NENs, the WHO developed a classification system that enables tumours to be graded based on markers of cell proliferation in biopsy specimens. Indeed, histopathology has been a mainstay in the diagnosis of GEP-NENs, and the WHO grading system facilitates therapeutic decision-making; however, considerable intratumoural heterogeneity, predominantly comprising regional variations in proliferation rates, complicates the evaluation of tumour biology. The use of molecular imaging modalities to delineate the most-aggressive cell populations is becoming more widespread. In addition, molecular profiling is increasingly undertaken in the clinical setting, and genomic studies have revealed a number of chromosomal alterations in GEP-NENs, although the 'drivers' of neoplastic development have not been identified. Thus, our molecular understanding of GEP-NENs remains insufficient to inform on patient prognosis or selection for treatments, and the WHO classification continues to form the basis for management of this disease. Nevertheless, our increasing understanding of the molecular genetics and biology of GEP-NENs has begun to expose flaws in the WHO classification. We describe the current understanding of the molecular characteristics of GEP-NENs, and discuss how advances in molecular profiling measurements, including assays of circulating mRNAs, are likely to influence the management of these tumours.

Topics: Biomarkers, Tumor; Clinical Trials as Topic; DNA Methylation; Epidermal Growth Factor; Gastrointestinal Neoplasms; Gene Expression Regulation, Neoplastic; Genes, Neoplasm; Humans; Mutation; Neoplasm Proteins; Neovascularization, Pathologic; Neuroendocrine Tumors; Pancreatic Neoplasms; Phenotype; Phosphatidylinositol 3-Kinases; Receptors, Somatostatin; Signal Transduction; Somatomedins; TOR Serine-Threonine Kinases; Vascular Endothelial Growth Factor A

The aim of palliative chemotherapy is to increase survival whilst maintaining optimal quality of life for the individual patient. While the best use of traditional chemotherapeutical agents continues to be explored, the introduction of targeted therapies has significantly broadened the therapeutic options. Yet it is interesting to note that the results of current trials did not always confirm the underlying molecular concepts. Recent data have suggested that altered pathways underlie the development of cancer, not just altered genes. Thus an effective therapeutic agent will have to target pathophysiologically relevant signalling networks, rather than individual proteins. This review presents current concepts and problems of cancer treatment, highlighting results from recent clinical trials of colorectal and pancreatic cancer patients and to discuss the current understanding of the underlying mechanisms.

Topics: Antineoplastic Combined Chemotherapy Protocols; Biomarkers, Tumor; Colorectal Neoplasms; Disease-Free Survival; DNA Mutational Analysis; Drug Delivery Systems; Epidermal Growth Factor; ErbB Receptors; Gastrointestinal Neoplasms; Gene Expression Regulation, Neoplastic; Genes, ras; Humans; Pancreatic Neoplasms; Precision Medicine; Signal Transduction; Vascular Endothelial Growth Factor Receptor-2

Patients with metastatic pancreatic cancer have poor prognosis and short survival due to lack of effective therapy and aggressiveness of the disease. Pancreatic cancer has widespread chromosomal instability, including a high rate of translocations and deletions. Upregulated EGF signaling and mutation of K-RAS are found in most pancreatic cancers. Therefore, inhibitors that target EGF receptor, K-RAS, RAF, MEK, mTOR, VEGF and PDGF, for example, have been evaluated in patients with pancreatic cancer. Although significant activities of these inhibitors have not been observed in the majority of pancreatic cancer patients, an enormous amount of experience and knowledge has been obtained from recent clinical trials. With a better inhibitor or combination of inhibitors, and improvement in the selection of patients for available inhibitors, better therapy for pancreatic cancer is on the horizon.

Topics: Epidermal Growth Factor; Humans; Neoplasm Metastasis; Neovascularization, Pathologic; Pancreatic Neoplasms; Signal Transduction

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Cytokines; Epidermal Growth Factor; Gene Expression Regulation, Neoplastic; Genes, Neoplasm; Humans; Mutation; NF-kappa B; Pancreatic Neoplasms; Phosphatidylinositol 3-Kinases; Prostaglandin-Endoperoxide Synthases; Proto-Oncogene Proteins c-akt; Signal Transduction; Vascular Endothelial Growth Factor A

Pancreatic cancer remains a treatment-refractory cancer. Standard therapy for metastatic cancer is gemcitabine chemotherapy, with a median survival of 5-6 months. The epidermal growth factor receptor (EGFR) is commonly expressed in pancreatic cancer and has been evaluated as a therapeutic target. A Phase III trial of gemcitabine with or without the EGFR inhibitor, erlotinib, demonstrated a modest but significant prolongation of survival with the addition of erlotinib. A Phase II trial of gemcitabine with the anti-EGFR antibody cetuximab resulted in a 1-year survival of 32%. A Phase III trial of gemcitabine with or without cetuximab and a randomized Phase II trial of the Murren regimen with or without cetuximab are completed; results for both are anticipated in 2007. A Phase I trial of gemcitabine with the EGFR/Her-2 inhibitor, lapatinib, is completed. Improved patient selection and rational combination of targeted therapies will be necessary to optimize the management of patients with this tragic disease.

Topics: Animals; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antimetabolites, Antineoplastic; Antineoplastic Combined Chemotherapy Protocols; Cetuximab; Deoxycytidine; Epidermal Growth Factor; Erlotinib Hydrochloride; Gemcitabine; Humans; Lapatinib; Organoplatinum Compounds; Oxaliplatin; Pancreatic Neoplasms; Protein Kinase Inhibitors; Quinazolines; Receptor, ErbB-2; Signal Transduction; Treatment Outcome

Pancreas cancer is a highly aggressive and rapidly fatal disease. The current standard of care for advanced disease improves survival modestly at best and provides palliation for a minority of patients. The need for new therapies is undisputed. This article describes new therapeutic strategies currently under investigation and discusses possible reasons that others have failed. New potential targets in the treatment of this formidable disease are suggested based on recent findings.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Epidermal Growth Factor; ErbB Receptors; Genes, Tumor Suppressor; Humans; Immunotherapy; Macrophages; Matrix Metalloproteinase Inhibitors; Pancreatic Neoplasms; Proto-Oncogene Proteins; Proto-Oncogene Proteins p21(ras); ras Proteins; Serine Endopeptidases; Signal Transduction

Pancreatic ductal adenocarcinoma (PDA) is arguably the most lethal malignancy in the United States. Despite the identification of many molecular alterations in PDA, this information has not translated into effective therapeutic strategies to date. A recent report in Cancer Cell (Fernandez-Zapico et al, Cancer Cell 2005, 7:39-49) reveals an unexpected role for the hematopoietic-specific RhoGEF VAV1 in pancreatic tumorigenesis, where ectopic expression of VAV1 as a result of promoter demethylation was identified in the majority of established cell lines and PDA tissue samples. Importantly, VAV1 expression was functionally required for optimal proliferation, transformation and survival of pancreatic cancer cell lines. This study provides the first evidence of VAV1 promoter demethylation as an event in cancer progression, suggesting that aberrant signaling pathways driven by VAV1 are potential therapeutic targets in PDA.

Topics: Animals; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cell Transformation, Neoplastic; DNA Methylation; Enzyme Activation; Epidermal Growth Factor; Humans; Mice; Pancreatic Neoplasms; Promoter Regions, Genetic; Proto-Oncogene Proteins c-vav; rac1 GTP-Binding Protein; RNA Interference; RNA, Messenger; Signal Transduction

A large number of data derived from molecular analyses support the hypothesis that human cancer is a genetic disease and a distinct subset of genes have been found to be genetically changed in most tumors. Molecular alterations in pancreatic cancer include: (1) oncogenes such as K-ras, c-myc, c-fos, and c-erbB-2; (2) tumor suppressor genes such as p53, p16, DPC4/SMAD4, and DCC; and (3) growth factors such as EGF, FGF, HGF, PDGF, VEGF, TGF-beta. Genetic alterations of K-ras and p53 are common in human pancreatic cancer, but the occurrence of pancreatic cancer is a multi-step phenomenon in which the accumulation of genetic changes is extremely important.

Topics: Epidermal Growth Factor; Fibroblast Growth Factors; Genes, myc; Genes, p16; Genes, p53; Genes, ras; Genes, Tumor Suppressor; Growth Substances; Humans; Oncogenes; Pancreatic Neoplasms

Despite advances in our understanding of the molecular and genetic basis of pancreatic cancer, the disease remains a clinical challenge. Gemcitabine, the standard chemotherapy for pancreatic cancer, offers modest improvement of tumor-related symptoms and marginal advantage of survival. New approaches, alone and in combination with gemcitabine, are being developed to combat this cancer. In this article we review the current status of investigations into several classes of agents: matrix metalloproteinase inhibitors; farnesyl transferase inhibitors; epidermal growth factor receptor inhibitors, including monoclonal antibodies and tyrosine kinase inhibitors; cyclooxygenase-2 inhibitors, and others. The scientific rationale, mechanism of action, and clinical trial data for these novel agents are discussed.

Topics: Adenocarcinoma; Angiogenesis Inhibitors; Antimetabolites, Antineoplastic; Antineoplastic Combined Chemotherapy Protocols; Cysteine Endopeptidases; Deoxycytidine; Epidermal Growth Factor; Gemcitabine; Humans; Hydroxamic Acids; Matrix Metalloproteinase Inhibitors; Metalloendopeptidases; Multienzyme Complexes; Pancreatic Neoplasms; Proteasome Endopeptidase Complex; Protein-Tyrosine Kinases; RNA, Antisense

Pancreatic cancer ranks fifth as a cause of cancer-related death in the world with an overall 5-year survival rate of less than 1% and a median survival of less than a year after tumour detection. Most of these patients have already metastases at the time of diagnosis. The oncologic strategies such as chemotherapy, radiotherapy, antihormonal modalities or the systemic use of specific monoclonal antibodies have not achieved a significant improvement in the survival of pancreatic cancer patients. Recent studies suggest that alterations in molecular pathways, particularly in growth factor mediated mechanisms, that regulate cell proliferation and differentiation play a pivotal role in the pathogenesis of this cancer. The molecular knowledge regarding changes in the expression of growth factors in pancreatic cancer has the potential to improve diagnostic and therapeutic treatment strategies in the near future.

Topics: Animals; Epidermal Growth Factor; Fibroblast Growth Factors; Growth Substances; Humans; Neoplasm Invasiveness; Neoplasm Metastasis; Nerve Growth Factor; Pancreatic Neoplasms; Platelet-Derived Growth Factor; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

Topics: Epidermal Growth Factor; Fibroblast Growth Factors; Growth Substances; Humans; Pancreatic Neoplasms; RNA, Messenger; Transforming Growth Factors

A case of pancreatic carcinoma associated with the Leser-Trélat sign is reported. A 53-yr-old male had complained of mild epigastric discomfort and back pain accompanied by seborrheic keratoses, which had increased in size and number over the previous 6 mo. A tumor was detected in the head of the pancreas and macroscopically curatively resected. His skin lesions diminished after surgery, but progressed again when the tumor recurred. Immunohistology for EGF showed a low level in the pancreatic carcinoma cells but a higher EGF content was recognized in the hyperkeratinized portions of the seborrheic keratoses. Of 130 underlying malignancies described in the 125 reported patients with the Leser-Trélat sign, neoplasms of the gastrointestinal tract were most common, comprising 47.7% of the total. The present case is the third case showing an association between a pancreatic carcinoma and the Leser-Trélat sign, but the first case for which the tumor of the pancreas was diagnosed in an early stage and resected surgically, as a result of the suggestive nature of this sign.

Topics: Adenocarcinoma; Epidermal Growth Factor; Humans; Immunohistochemistry; Keratosis, Seborrheic; Male; Middle Aged; Pancreatic Neoplasms; Tomography, X-Ray Computed

Pancreatic cancer is one of the most frequent carcinomas of the human gastrointestinal tract. despite considerable progress in diagnosis, its prognosis has remained unchanged during the last years. Up to now, there is no possibility to screen patients for pancreatic carcinomas, and the symptoms of the disease are uncharacteristic and often misleading. Surgical treatment, with resection of the tumor is the only chance for cure, but for experienced pancreatic surgeons, an advanced tumor stage at the time of operation is a common finding. Large studies reveal the poor prognosis of the disease. Only 20-30% of all patients suffering from pancreatic cancer can be operated with curative intention. In 80-85% of all cases, the tumor has spread into peripancreatic lymph nodes. Thus, mean 5-years survival rates of 3 to 5% are commonly reported, and the median survival time after establishment of diagnosis is 4-6 months. Improvements in surgical technique and postoperative patient's care have led to an impressive decrease in the formerly considerable morbidity and mortality after pancreatic resection. If the tumor can be resected at an early stage and the regional lymph nodes are not involved, median 5-years survival rates of 20-40% are commonly reported. Further approaches include more radical surgical procedures with dissection of the entire peripancreatic region and resection of the upper abdominal blood vessels. Whether this new technique or a combination of operation, radiation and chemotherapy will improve the prognosis of the disease remains unclear. Large clinical trials are necessary to prove these assumptions.

Topics: Epidermal Growth Factor; Humans; Neoplasm Staging; Pancreatectomy; Pancreatic Neoplasms; Pancreaticoduodenectomy; Prognosis; Transforming Growth Factors

The efficacy of erlotinib, the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, has been demonstrated in patients with non-small cell lung cancer (NSCLC) and pancreatic cancer (PC). In the present study, we evaluated the effect of epidermal growth factor (EGF) ointment on erlotinib-related skin effects (ERSEs).. This was an open-label, non-comparative, multicenter, phase II trial. The patients included those diagnosed with NSCLC or PC who were treated with erlotinib. The effectiveness of the ointment was defined as follows: (1) grade 2, 3, or 4 ERSEs downgraded to ≤ grade 1 or (2) grade 3 or 4 ERSEs downgraded to grade 2 and persisted for at least 2 weeks.. Fifty-two patients from seven institutes in Korea were enrolled with informed consent. The final assessment included 46 patients (30 males, 16 females). According to the definition of effectiveness, the EGF ointment was effective in 36 (69.2%) intention to treat patients. There were no statistically significant differences in the effectiveness of the EGF ointment by gender (p = 0.465), age (p = 0.547), tumor type (p = 0.085), erlotinib dosage (p = 0.117), and number of prior chemotherapy sessions (p = 0.547). The grading for the average National Cancer Institute's Common Terminology Criteria for Adverse Events (NCI-CTCAE) rating of rash/acne and itching improved from 2.02 ± 0.83 to 1.13 ± 0.89 and 1.52 ± 0.84 to 0.67 ± 0.90, respectively (p < 0.001). The most common reason for discontinuing the study was progression of cancer (37%).. Based on the results, the EGF ointment is effective for ERSEs, regardless of gender, age, type of tumor, and dosage of erlotinib. The EGF ointment evenly improved all kinds of symptoms of ERSEs.. ClinicalTrials.gov identifier: NCT01593995.

Topics: Aged; Antineoplastic Agents; Carcinoma, Non-Small-Cell Lung; Dermatologic Agents; Disease Progression; Disease-Free Survival; Drug Eruptions; Epidermal Growth Factor; Erlotinib Hydrochloride; Female; Humans; Lung Neoplasms; Male; Middle Aged; Ointments; Pancreatic Neoplasms; Protein Kinase Inhibitors; Republic of Korea; Treatment Outcome

A sustained increase in the mortality of pancreatic cancer (PC) and sudden metastasis-related mortality is a cause for concern. Aberrant expression of epidermal growth factor (EGF) receptor (EGFR) is noted in several cases of PC metastasis. The present study is aimed at analyzing the expression of EGFR in PC and its relevance to the progression of PC. Despite the number of studies that have shown the benefits of plumbagin on PC cells, its role on cancer stem cells remains largely unknown. To this end, the study used an EGF micro-environment to make cancer stem cells in vitro and ascertained the role of plumbagin in mitigating the actions of EGF. The kaplan-meier (KM) plot indicated reduced overall survival (OS) analysis in PC patients with high EGFR than low EGFR expression. Plumbagin pre-treatment significantly prevented EGF-induced survival, epithelial-to-mesenchymal transition (EMT), clonogenesis, migration, matrix metalloproteinase -2 (MMP-2) gene expression and its secretion, and matrix protein hyaluron production in PANC-1 cells. The computational studies indicate the greater affinity of plumbagin with different domains of EGFR than gefitinib. Several hallmarks of resistance and migration due to EGF are effectively attenuated by plumbagin. Collectively, these results warrant investigating the actions of plumbagin in a pre-clinical study to substantiate these findings.

Topics: Cell Line, Tumor; Epidermal Growth Factor; ErbB Receptors; Humans; Naphthoquinones; Pancreatic Neoplasms

Girdin, an actin‑binding protein, is reportedly involved in the invasion and angiogenesis of various cancers. It has been suggested that the flavonoid Scutellarin (SCU) inhibits Girdin signaling. In the present study, the function and therapeutic applications of Girdin in pancreatic cancer (PaCa) were investigated. Immunohistochemical staining of Girdin in resected PaCa specimens from the Department of Gastroenterological Surgery, Nagoya City University Graduate School of Medical Science showed that high Girdin expression was associated with poor overall survival and relapse‑free survival, as well as with T factor, indicating invasion into the surrounding tissues. On the other hand, Girdin was highly expressed in almost all PaCa cell lines, and the migration ability of Girdin‑knockdown cell lines was decreased even under epidermal growth factor (EGF) stimulation. In addition, SCU suppressed PaCa cell migration by inhibiting the phosphorylation of Girdin. The expression and production of vascular endothelial growth factor A (VEGF‑A) was significantly decreased in Girdin‑knockdown cell lines. Furthermore, in Matrigel tube formation assays performed using culture supernatant, the lumen‑forming ability of vascular endothelial cells was also decreased in Girdin‑knockdown cell lines. However, SCU treatment did not significantly alter the expression or production of VEGF‑A. These results suggested that Girdin is involved in EGF signaling‑mediated migration of PaCa cells, that SCU inhibits PaCa invasion by suppressing Girdin activity, and that Girdin is also involved in angiogenesis via an activation pathway different from the action site of SCU. Girdin may be a prognostic biomarker, and the development of a novel molecular‑targeted drugs for Girdin may improve the prognosis of PaCa in the future.

Topics: Cell Line, Tumor; Cell Movement; Cell Proliferation; Endothelial Cells; Epidermal Growth Factor; Humans; Microfilament Proteins; Pancreatic Neoplasms; Vascular Endothelial Growth Factor A; Vesicular Transport Proteins

Recent studies have shown that amphoteric regulatory protein (AREG), a member of the epidermal growth factor (EGF) family, is expressed in many cancers and is an independent prognostic indicator for patients with pancreatic cancer, but whether AREG is regulated at the epigenetic level to promote the development of pancreatic cancer (PC) has not been elucidated. Our results support the notion that AREG is overexpressed in pancreatic cancer tissues and cell lines. Functionally, the deletion of AREG impedes pancreatic cancer (PC) cell proliferation, migration, and invasion. In addition, we identified and validated that methyltransferase-like 3 (METTL3) induced the m

Topics: Amphiregulin; Epidermal Growth Factor; Epithelial-Mesenchymal Transition; Humans; Methyltransferases; MicroRNAs; Pancreatic Neoplasms

Isoform-specific functions of Numb in the development of cancers, especially in the initiation of epithelial-to-mesenchymal transition (EMT) remains controversial. We study the specific function of Numb-PRRL isoform in activated EMT of pancreatic ductal adenocarcinoma (PC), which is distinguished from our previous studies that only focused on the total Numb protein. Numb-PRRL isoform was specifically overexpressed and silenced in PC cells combining with TGF-β1 and EGF stimulus. We systematically explored the potential effect of Numb-PRRL in the activated EMT of PC in vitro and in vivo. The total Numb protein was overexpressed in the normal pancreatic duct and well-differentiated PC by IHC. However, Numb-PRRS isoform but not Numb-PRRL showed dominant expression in PC tissues. Numb-PRRL overexpression promoted TGF-β1-induced EMT in PANC-1 and Miapaca-2 cells. TGF-β1-induced EMT-like cell morphology, cell invasion, and migration were enhanced in Numb-PRRL overexpressing groups following the increase of N-cadherin, Vimentin, Smad2/3, Snail1, Snail2, and cleaved-Notch1 and the decrease of E-cadherin. Numb-PRRL overexpression activated TGFβ1-Smad2/3-Snail1 signaling was significantly reversed by the Notch1 inhibitor RO4929097. Conversely, Numb-PRRL silencing inhibited EGF-induced EMT in AsPC-1 and BxPC-3 cells following the activation of EGFR-ERK/MAPK signaling via phosphorylating EGFR at tyrosine 1045. In vivo, Numb-PRRL overexpression or silencing promoted or inhibited subcutaneous tumor size and distant liver metastases via regulating EMT and Snail signaling, respectively. Numb-PRRL promotes TGF-β1- and EGF-induced EMT in PC by regulating TGF-β1-Smad2/3-Snail and EGF-induced EGFR-ERK/MAPK signaling.

Topics: Cell Line, Tumor; Cell Movement; Epidermal Growth Factor; Epithelial-Mesenchymal Transition; ErbB Receptors; Humans; Membrane Proteins; Nerve Tissue Proteins; Pancreatic Neoplasms; Transforming Growth Factor beta1

Pancreatic neuroendocrine tumors (NETs) are rare and account for about 7% of all cancers occurring in the pancreas. The epidermal growth factor family of receptors and their ligands play an important role in the growth and progression of tumors but their role in PNET development remains unknown. We hypothesized that functional single nucleotide polymorphisms (SNPs) in the EGF, EGFR, and HER2 genes might affect individual susceptibility to PNETs development and invasion like it was shown for various other tumors.. We genotyped 68 patients with unresectable PNETs and 300 controls to evaluate the association between EGF, EGFR, and HER2 polymorphisms and susceptibility to PNETs and presence of metastases.. Genotype analysis of three SNPs EGF +61A/G (rs4444903), EGFR +1562 G/A (rs11543848), and HER2 +1963 A/G (rs1136201) showed that carriers of EGFR +1562 AG genotype and AA/AG EGF +61/HER2 +1963 genotype combination are at risk of developing PNET. Furthermore, EGFR +1562 AA genotype could be associated with the susceptibility to insulinoma development.. Our results suggest involvement of EGFR signaling pathway in etiology of PNET development.

Topics: Epidermal Growth Factor; ErbB Receptors; Genes, erbB-2; Genetic Predisposition to Disease; Humans; Neuroectodermal Tumors, Primitive; Neuroendocrine Tumors; Pancreatic Neoplasms; Polymorphism, Single Nucleotide; Receptor, ErbB-2

Oncogenic RAS proteins are important for driving tumour formation, and for maintenance of the transformed phenotype, and thus their relevance as a cancer therapeutic target is undeniable. We focused here on obtaining peptidomimetics, which have good pharmacological properties, to block Ras-effector interaction. Computational analysis was used to identify hot spots of RAS relevant for these interactions and to screen a library of peptidomimetics. Nine compounds were synthesized and assayed for their activity as RAS inhibitors in cultured cells. Most of them induced a reduction in ERK and AKT activation by EGF, a marker of RAS activity. The most potent inhibitor disrupted Raf and PI3K interaction with oncogenic KRAS, corroborating its mechanism of action as an inhibitor of protein-protein interactions, and thus validating our computational methodology. Most interestingly, improvement of one of the compounds allowed us to obtain a peptidomimetic that decreased the survival of pancreatic cancer cell lines harbouring oncogenic KRAS.

Topics: Cell Line, Tumor; Epidermal Growth Factor; Humans; Pancreatic Neoplasms; Peptidomimetics; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins p21(ras); Signal Transduction

Pancreatic ductal adenocarcinoma (PDAC) is the deadliest cancer mainly owing to its proclivity to early metastasis and the lack of effective targeted therapeutic drugs. Hence, understanding the molecular mechanisms underlying early invasion and metastasis by PDAC is imperative for improving patient outcomes. The present study identified that upregulation of TSPAN8 expression in PDAC facilitates metastasis in vivo and in vitro. We found SOX9 as a key transcriptional regulator of TSPAN8 expression in response to EGF stimulation. SOX9 modulation was sufficient to positively regulate endogenous expression of TSPAN8, with concomitant in vitro phenotypic changes such as loss of cell-matrix adherence and increased invasion. Moreover, increased SOX9 and TSPAN8 levels were shown to correlate in human pancreatic cancer specimens and downregulated in vitro by EGFR tyrosine kinase inhibitors. High expression of SOX9 and TSPAN8 has been associated with tumor stage, poor prognosis and poor patient survival in PDAC. In conclusion, this study highlights the importance of the EGF-SOX9-TSPAN8 signaling cascade in the control of PDAC invasion and implies that TSPAN8 may be a promising novel therapeutic target for the treatment of PDAC.

Topics: Biomarkers, Tumor; Cell Movement; Disease Progression; Disease Susceptibility; Epidermal Growth Factor; Gene Expression Regulation, Neoplastic; Humans; Neoplasm Metastasis; Neoplasm Staging; Pancreatic Neoplasms; Prognosis; Promoter Regions, Genetic; Protein Binding; SOX9 Transcription Factor; Tetraspanins

The relationship between diabetes mellitus and pancreatic cancer is complex. Diabetes has been postulated to be both an independent risk factor and a consequence of pancreatic cancer. Our previous study confirmed that curcumin plays a vital role in inhibiting the epithelial-mesenchymal transition of pancreatic cancer cells. However, whether curcumin attenuates hyperglycemia-induced cancer invasive and migratory abilities and the underlying mechanisms are not yet well understood. As high glucose is able to induce the expression of epidermal growth factor (EGF), which is intimately related with tumor progression, the aim of this study was to evaluate whether curcumin could influence the high glucose-induced EGF/EGFR pathway and the biological activity of pancreatic cancer cells. Human pancreatic cancer BxPC-3 cells were exposed to high glucose or EGF, with or without curcumin, LY 294002 (an Akt inhibitor) or PD 98059 (an ERK inhibitor). MTT, Transwell invasion and wound healing assays were used to detect the proliferation, invasion and migration potential of cancer cells. The activation of p-EGFR, p-ERK and p-Akt was determined by western blot analysis. The expression levels of uPA and E-cadherin were examined using qRT-PCR and western blot analysis. The results showed that high glucose could not only promote the proliferation, invasion and migration of pancreatic cancer cells, but also induce the expression of EGF and activation of EGFR, ERK and Akt. These effects of high glucose were counter-balanced by curcumin. EGF-induced proliferative, invasive and migratory abilities of BxPC-3 cells were abrogated by curcumin, LY 294002 and PD 98059. In addition, EGF-modulated activation of EGFR, ERK and Akt, as well as the expression of uPA and E-cadherin were inhibited by curcumin. Taken together, the present study indicates that curcumin suppresses hyperglycemia-driven EGF-induced invasion and migration of pancreatic cancer cells by inhibiting the EGF/EGFR signaling pathway and its downstream signaling molecules including ERK and Akt. Curcumin is a potential anticancer agent for pancreatic cancer.

Topics: Antineoplastic Agents; Cell Line, Tumor; Cell Movement; Cell Proliferation; Chromones; Curcumin; Epidermal Growth Factor; ErbB Receptors; Extracellular Signal-Regulated MAP Kinases; Flavonoids; Glucose; Humans; Hyperglycemia; Morpholines; Neoplasm Invasiveness; Pancreatic Neoplasms; Proto-Oncogene Proteins c-akt; Signal Transduction

It is well-known that the activation status of the P53, signal transducer and activator of transcription (Stat)3 and nuclear factor (NF)‑κB signaling pathways determines the radiosensitivity of cancer cells. However, the function of these pathways in radiosensitive vs radioresistant cancer cells remains elusive. The present study demonstrated that adaptive expression of epidermal growth factor (EGF) following exposure to ionizing radiation (IR) may induce radiosensitization of pancreatic cancer (PC) cells through induction of the cyclin D1/P53/poly(ADP‑ribose) polymerase pathway. By contrast, adaptively expressed interleukin (IL)‑6 and insulin‑like growth factor (IGF)‑1 may promote radioresistance of PC cells, likely through activation of the Stat3 and NF‑κB pathways. In addition, cyclin D1 and survivin, which are specifically expressed in the G1/S and G2/M phase of the cell cycle, respectively, are mutually exclusive in radiosensitive and radioresistant PC cells, while Bcl‑2 and Bcl‑xL expression does not differ between radiosensitive and radioresistant PC cells. Therefore, adaptively expressed EGF and IL‑6/IGF‑1 may alter these pathways to promote the radiosensitivity of PC cancers. The findings of the present study highlight potential makers for the evaluation of radiosensitivity and enable the development of effective regimens for cancer radiotherapy.

Topics: Apoptosis; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Cyclin D1; Epidermal Growth Factor; Gene Expression Regulation, Neoplastic; Humans; Pancreatic Neoplasms; Poly (ADP-Ribose) Polymerase-1; Radiation Tolerance; Signal Transduction; Tumor Suppressor Protein p53; Up-Regulation

Pancreatic cancer typically spreads rapidly and has poor survival rates. Here, we report that the calcium-activated chloride channel TMEM16A is a biomarker for pancreatic cancer with a poor prognosis. TMEM16A is up-regulated in 75% of cases of pancreatic cancer and high levels of TMEM16A expression are correlated with low patient survival probability. TMEM16A up-regulation is associated with the ligand-dependent EGFR signaling pathway. In vitro, TMEM16A is required for EGF-induced store-operated calcium entry essential for pancreatic cancer cell migration. TMEM16A also has a profound impact on phosphoproteome remodeling upon EGF stimulation. Moreover, molecular actors identified in this TMEM16A-dependent EGFR-induced calcium signaling pathway form a gene set that makes it possible not only to distinguish neuro-endocrine tumors from other forms of pancreatic cancer, but also to subdivide the latter into three clusters with distinct genetic profiles that could reflect their molecular underpinning.

Topics: Anoctamin-1; Biomarkers, Tumor; Calcium Signaling; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Cell Movement; Datasets as Topic; Diagnosis, Differential; Epidermal Growth Factor; ErbB Receptors; HEK293 Cells; Humans; Neoplasm Proteins; Pancreas; Pancreatic Neoplasms; Prognosis; RNA-Seq; RNA, Small Interfering; Survival Rate; Up-Regulation

The purpose of this project was to investigate the expression and clinical significance of epidermal growth factor (EGF) and the transforming growth factor-α (TGF-α) in the occurrence and development of chronic pancreatitis and pancreatic cancer.. We recruited 31 patients with chronic pancreatitis, 42 with pancreatic cancer, and 20 with normal pancreas in our hospital. Chronic pancreatitis, pancreatic cancer, and normal pancreas expressed EGF and TGF-α mRNAs as well as EGF and TGF-α proteins.. Immunofluorescence showed that EGF and TGF-α were expressed in chronic pancreatitis and pancreatic cancer, but the expression levels for both proteins were higher in pancreatic cancer. Variance analysis indicated that the differences in the expression levels of EGF and TGF-α in chronic pancreatitis, pancreatic cancer, and normal pancreas were statistically significant. The abnormally elevated expression of EGF and TGF-α are closely associated with the occurrence and development of chronic pancreatitis and pancreatic cancer.. EGF and TGF-α have important research value as indicators to assess the progression of these conditions and provide a new basis for the clinical diagnosis.

Topics: Adult; Aged; Biomarkers; Biomarkers, Tumor; Disease Progression; Epidermal Growth Factor; Female; Humans; Male; Middle Aged; Pancreatic Neoplasms; Pancreatitis, Chronic; Transforming Growth Factor alpha

Pancreatic cancer is one of the most malignant cancers with a high mortality rate. Some types of pancreatic cancer cells overexpress epidermal growth factor receptor (EGFR), which is a potential target for anticancer agents. In this study, we examined the effect of epidermal growth factor (EGF)-conjugated liposomes containing curcumin (EGF-LP-Cur) on three different EGFR-expressed human pancreatic cancer cell lines, BxPC-3, Panc-1 and Mia Paca-2. We have demonstrated that it is feasible to prepare liposomal vesicles of EGF-LP-Cur and that it is stable in the liquid vehicle at ambient conditions for three weeks. In addition, the formulation of curcumin had higher cytotoxicity on BxPC-3 than on any other cells. It is also shown that the cellular uptake of curcumin on BxPC-3, which is essential for the cytotoxicity, is associated with EGFR-mediated mechanism of action. In summary, our results have showed that targeting EGFR with EGF-conjugated curcumin liposomes enhanced the antitumor activity of curcumin against human pancreatic cancer cells.

Topics: Adenocarcinoma; Antineoplastic Agents; Curcumin; Epidermal Growth Factor; Humans; Liposomes; Pancreatic Neoplasms

Targeted cancer therapy provides the basis for the arrest of tumor growth in aggressive pancreatic carcinoma; however, a number of protein-based targeted toxins lack efficacy due to insufficient endosomal escape after being endocytosed. Therefore, we tested a fusion protein of the ribosome-inactivating protein dianthin and human epidermal growth factor in combination with a glycosylated triterpene (SO1861) that serves as an endosomal escape enhancer. In vitro investigations with the pancreatic carcinoma cell lines BxPC-3 and MIA PaCa-2 revealed no significant differences to off-target cells in the half maximal inhibitory concentration (IC

Topics: Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Cell Line, Tumor; Epidermal Growth Factor; Humans; Mice, Nude; Pancreas; Pancreatic Neoplasms; Recombinant Fusion Proteins; Ribosome Inactivating Proteins; Saponins

Our previous study showed that Calreticulin (CRT) promoted the development of pancreatic cancer (PC) through ERK/MAPK pathway. We next investigate whether CRT promotes EGF-induced epithelial-mesenchymal transition (EMT) in PC via Integrin/EGFR-ERK/MAPK signaling, which has not been reported yet to our knowledge. EGF simultaneously induced EMT and activated Integrin/EGFR-ERK/MAPK signaling pathway in 3 PC cells. However, CRT silencing significantly inhibited EGF function, including inhibiting EGF-induced EMT-like cell morphology, EGF-enhanced cell invasion and migration, and EGF induced the decrease of E-cadherin, ZO-1, and β-catenin and the increase of the key proteins in Integrin/EGFR-ERK/MAPK signaling (pEGFR-tyr1173, Fibronectin, Integrinβ1, c-Myc and pERK). Conversely, CRT overexpression rescued the change of EMT-related proteins induced by EGF in CRT silencing PC cells. Additionally, CRT was co-stained with pEGFR1173 (with EGF), Fibronectin and Integrinβ1 by IF under confocal microscopy and was co-immunoprecipitated with Fibronectin, Integrinβ1 and c-Myc in both PC cells, all of which indicating a close interaction of CRT with Integrin/EGFR-ERK/MAPK signaling pathway in PC. In vivo, CRT silencing inhibited subcutaneous tumor growth and liver metastasis of pancreatic tumor. A positive relationship of CRT with Fibronectin, Integrinβ1, c-Myc and pERK and a negative association of CRT with E-cad was also observed in vivo and clinical samples. Meanwhile, overexpression of the above proteins was closely associated with multiple aggressive clinicopathological characteristics and the poor prognosis of PC patients. CRT promotes EGF-induced EMT in PC cells via Integrin/EGFR-ERK/MAPK signaling pathway, which would be a promising therapy target for PC.

Topics: Animals; Calreticulin; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Epidermal Growth Factor; Epithelial-Mesenchymal Transition; Heterografts; Humans; Integrins; MAP Kinase Signaling System; Mice; Mice, Inbred BALB C; Mice, Nude; Pancreatic Neoplasms; Transfection

Epidermal growth factor (EGF) receptor (EGFR/HER1) is overexpressed in human pancreatic cancers. However, anti-EGFR therapy does not exhibit significant therapeutic activity with oncogenic K-ras mutation. We sought to assess the signaling relationship between EGFR and mutant K-ras, which is commonly detected in pancreatic cancer.. Pancreatic cancer cells harboring mutated K-ras were treated with EGF to assess signaling from EGFR to mitogen-activated protein kinase (MAPK) pathway. The role of Ras family of proteins in transducing EGFR signals was assessed using short interfering RNA. Other components of MAPK and PI3K (phosphoinositide 3-kinase) pathways were examined for their roles in EGFR signaling.. First, EGF signaling in pancreatic cancer cells occurs selectively through HER1. Second, knockdown of all Ras isoforms failed to block EGF-mediated phosphorylation of extracellular signal-regulated kinase (ERK). Inhibition of Raf was observed to partially abrogate ERK phosphorylation, whereas MEK inhibition resulted in complete attenuation of EGF-mediated ERK phosphorylation. Finally, inhibition of phosphoinositide 3-kinase/AKT and CDC42/PAK pathways did not block EGFR signaling.. Our study results demonstrate that EGFR-mediated signaling in mutant K-ras pancreatic cancer cells does not follow canonical MAPK signaling. Our novel findings suggest the existence of alternate signaling pathways to downstream MAPK in the presence of mutant K-ras.

Topics: Cell Line, Tumor; Epidermal Growth Factor; ErbB Receptors; Extracellular Signal-Regulated MAP Kinases; Humans; Immunoblotting; MAP Kinase Signaling System; Mutation; Pancreatic Neoplasms; Phosphorylation; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins p21(ras); RNA Interference; Signal Transduction

N-MYC downstream-regulated gene-1 (NDRG1) is a potent growth and metastasis suppressor that acts through its inhibitory effects on a wide variety of cellular signaling pathways, including the TGF-β pathway, protein kinase B (AKT)/PI3K pathway, RAS, etc. To investigate the hypothesis that its multiple effects could be regulated by a common upstream effector, the role of NDRG1 on the epidermal growth factor receptor (EGFR) and other members of the ErbB family, namely human epidermal growth factor receptor 2 (HER2) and human epidermal growth factor receptor 3 (HER3), was examined. We demonstrate that NDRG1 markedly decreased the expression and activation of EGFR, HER2, and HER3 in response to the epidermal growth factor (EGF) ligand, while also inhibiting formation of the EGFR/HER2 and HER2/HER3 heterodimers. In addition, NDRG1 also decreased activation of the downstream MAPKK in response to EGF. Moreover, novel anti-tumor agents of the di-2-pyridylketone class of thiosemicarbazones, namely di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone and di-2-pyridylketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone, which markedly up-regulate NDRG1, were found to inhibit EGFR, HER2, and HER3 expression and phosphorylation in cancer cells. However, the mechanism involved appeared dependent on NDRG1 for di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone, but was independent of this metastasis suppressor for di-2-pyridylketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone. This observation demonstrates that small structural changes in thiosemicarbazones result in marked alterations in molecular targeting. Collectively, these results reveal a mechanism for the extensive downstream effects on cellular signaling attributed to NDRG1. Furthermore, this study identifies a novel approach for the treatment of tumors resistant to traditional EGFR inhibitors.

Topics: Animals; Antineoplastic Agents; Cell Cycle Proteins; Cell Line, Tumor; Colonic Neoplasms; Epidermal Growth Factor; ErbB Receptors; Female; Gene Expression Regulation, Neoplastic; Humans; Intracellular Signaling Peptides and Proteins; MAP Kinase Signaling System; Mice, Nude; Pancreatic Neoplasms; Pyridines; Random Allocation; Receptor, ErbB-2; Receptor, ErbB-3; Recombinant Proteins; RNA Interference; Thiosemicarbazones; Tumor Burden; Xenograft Model Antitumor Assays

Pancreatic ductal adenocarcinoma (PDAC) is one of the most potent and perilous diseases known, with a median survival rate of 3-5 months due to the combination of only advanced stage diagnosis and ineffective therapeutic options. Metformin (1,1-Dimethylbiguanide hydrochloride), the leading drug used for type 2 diabetes mellitus, emerges as a potential therapy for PDAC and other human cancers. Metformin exerts its anticancer action via a variety of adenosine monophosphate (AMP)-activated protein kinase (AMPK)- dependent and/or AMPK-independent mechanisms. We present data here showing that metformin downregulated pancreatic transcription factor pancreatic duodenal homeobox-1 (PDX-1), suggesting a potential novel mechanism by which metformin exerts its anticancer action. Metformin inhibited PDX-1 expression at both protein and mRNA levels and PDX-1 transactivity as well in PDAC cells. Extracellular signal-regulated kinase (ERK) was identified as a PDX-1-interacting protein by antibody array screening in GFP-PDX-1 stable HEK293 cells. Co-transfection of ERK1 with PDX-1 resulted in an enhanced PDX-1 expression in HEK293 cells in a dose-dependent manner. Immunoprecipitation/Western blotting analysis confirmed the ERK-PDX-1 interaction in PANC-1 cells stimulated by epidermal growth factor (EGF). EGF induced an enhanced PDX-1 expression in PANC-1 cells and this stimulation was inhibited by MEK inhibitor PD0325901. Metformin inhibited EGF-stimulated PDX-1 expression with an accompanied inhibition of ERK kinase activation in PANC- 1 cells. Taken together, our studies show that PDX-1 is a potential novel target for metformin in PDAC cells and that metformin may exert its anticancer action in PDAC by down-regulating PDX-1 via a mechanism involving inhibition of ERK signaling.

Topics: Adenocarcinoma; Carcinoma, Pancreatic Ductal; Cell Line; Cell Line, Tumor; Diabetes Mellitus, Type 2; Down-Regulation; Epidermal Growth Factor; Extracellular Signal-Regulated MAP Kinases; Genes, Homeobox; HEK293 Cells; Homeodomain Proteins; Humans; MAP Kinase Signaling System; Metformin; Pancreas; Pancreatic Neoplasms; Protein Kinase Inhibitors; Signal Transduction; Trans-Activators

The development of pancreatic cancer requires the acquisition of oncogenic KRas mutations and upregulation of growth factor signaling, but the relationship between these is not well established. Here, we show that mutant KRas alters mitochondrial metabolism in pancreatic acinar cells, resulting in increased generation of mitochondrial reactive oxygen species (mROS). Mitochondrial ROS then drives the dedifferentiation of acinar cells to a duct-like progenitor phenotype and progression to PanIN. This is mediated via the ROS-receptive kinase protein kinase D1 and the transcription factors NF-κB1 and NF-κB2, which upregulate expression of the epidermal growth factor, its ligands, and their sheddase ADAM17. In vivo, interception of KRas-mediated generation of mROS reduced the formation of pre-neoplastic lesions. Hence, our data provide insight into how oncogenic KRas interacts with growth factor signaling to induce the formation of pancreatic cancer.

Topics: Acinar Cells; ADAM17 Protein; Animals; Cells, Cultured; Epidermal Growth Factor; ErbB Receptors; Humans; Ligands; Mice; Mitochondria; Mutagenesis, Site-Directed; NF-kappa B p52 Subunit; Oxidative Stress; Pancreatic Neoplasms; Precancerous Conditions; Protein Kinase C; Proto-Oncogene Proteins p21(ras); Reactive Oxygen Species; RNA Interference; Signal Transduction; Up-Regulation

Epidermal Growth Factor (EGF) receptor overexpression, KRAS, TP53, CDKN2A and SMAD4 mutations characterize pancreatic ductal adenocarcinoma. This mutational landscape might influence cancer cells response to EGF, Transforming Growth Factor β1 (TGFβ1) and stromal inflammatory calcium binding proteins S100A8/A9. We investigated whether chronic exposure to EGF modifies in a SMAD4-dependent manner pancreatic cancer cell signalling, proliferation and invasion in response to EGF, TGFβ1 and S100A8/A9. BxPC3, homozigously deleted (HD) for SMAD4, and BxPC3-SMAD4+ cells were or not stimulated with EGF (100 ng/mL) for three days. EGF pre-treated and non pretreated cells were stimulated with a single dose of EGF (100 ng/mL), TGFβ1 (0,02 ng/mL), S100A8/A9 (10 nM). Signalling pathways (Reverse Phase Protein Array and western blot), cell migration (Matrigel) and cell proliferation (XTT) were evaluated. SMAD4 HD constitutively activated ERK and Wnt/β-catenin, while inhibiting PI3K/AKT pathways. These effects were antagonized by chronic EGF, which increased p-BAD (anti-apoptotic) in response to combined TGFβ1 and S100A8/A9 stimulation. SMAD4 HD underlied the inhibition of NF-κB and PI3K/AKT in response to TGFβ1 and S100A8/A9, which also induced cell migration. Chronic EGF exposure enhanced cell migration of both BxPC3 and BxPC3-SMAD4+, rendering the cells less sensitive to the other inflammatory stimuli. In conclusion, SMAD4 HD is associated with the constitutive activation of the ERK and Wnt/β-catenin signalling pathways, and favors the EGF-induced activation of multiple signalling pathways critical to cancer proliferation and invasion. TGFβ1 and S100A8/A9 mainly inhibit NF-κB and PI3K/AKT pathways and, when combined, sinergize with EGF in enhancing anti-apoptotic p-BAD in a SMAD4-dependent manner.

Topics: Adenocarcinoma; Apoptosis; Calgranulin A; Calgranulin B; Cell Line, Tumor; Cell Movement; Critical Pathways; Epidermal Growth Factor; Humans; Neoplasm Invasiveness; NF-kappa B; Pancreatic Neoplasms; Phosphoinositide-3 Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Smad4 Protein; Transforming Growth Factor beta1

The Hedgehog signaling pathway and its key target effector Gli1 are linked closely to the development of the epithelial to mesenchymal transition (EMT) in many cancers. The definite function of Gli1 in regulating the EMT of pancreatic cancer (PC), however, is still unclear.. At the cell and tissue levels, we investigated the role of Gli1 in the initiation of EMT in PC with and without external stimulus treatments.. The immunohistochemistry results showed that Gli1 was associated positively with MMP9 but not with E-cad or Vimentin. Gli1 expression was associated positively with tumor T (P = .025) and Union for International Cancer Control stage (P = .032), whereas MMP9 expression was associated positively with lymph node metastasis (P = .017) and Union for International Cancer Control stage (P = .006). Furthermore, patients with Gli1 and MMP9 coexpression had poor overall survival (P = .015). Silencing of Gli1 alone without external stimulus had no effect on EMT but inhibited transforming growth factor-beta1 (TGFβ1)- and epidermal growth factor (EGF)-induced EMT in PANC-1, AsPC-1, and BxPC-3 PC cell lines, along with the inhibition of TGFβ1- and EGF-induced EMT-like cell morphology and invasion, down-regulation of E-cad, and up-regulation of MMP9 and Vimentin in those 3 cell lines, respectively.. Gli1 silencing alone has no effect on EMT initiation; however, it exerts a protumor role in the aggressive invasion of PC cells by promoting TGFβ1- and EGF-induced EMT.

Topics: Cadherins; Cell Line, Tumor; Epidermal Growth Factor; Epithelial-Mesenchymal Transition; Gene Silencing; Humans; Matrix Metalloproteinase 9; Neoplasm Invasiveness; Pancreatic Neoplasms; Survival Analysis; Transcription Factors; Transforming Growth Factor beta1; Tumor Cells, Cultured; Vimentin; Zinc Finger Protein GLI1

Pancreatic cancer is one of the most dangerous cancers and is associated with a grave prognosis. Despite increased knowledge of the complex signaling networks responsible for progression of pancreatic cancer, many challenging therapies have fallen short of expectations. In this study, we examined the anti-migratory effect of quercetin 3-O-glucoside in epidermal growth factor-induced cell migration by inhibiting EGF receptor (EGFR) signaling in several human pancreatic cancer cell lines. Treatment with quercetin, quercetin 3-O-glucoside, and quercetin 7-O-glucoside differentially suppressed epidermal growth factor-induced migration activity of human pancreatic cancer cells. In particular, quercetin 3-O-glucoside strongly inhibited the infiltration activity of pancreatic cancer cells in a dose-dependent manner. Furthermore, quercetin 3-O-glucoside exerted the anti-migratory effect even at a relatively low dose compared with other forms of quercetin. The anti-tumor effects of quercetin 3-O-glucoside were mediated by selectively inhibiting the EGFR-mediated FAK, AKT, MEK1/2, and ERK1/2 signaling pathway. Combinatorial treatment with quercetin 3-O-glucoside plus gemcitabine showed the synergistic anti-migratory effect on epidermal growth factor-induced cell migration in human pancreatic cancer cell lines. These results suggest that quercetin 3-O-glucoside has potential for anti-metastatic therapy in human pancreatic cancer.

Topics: Apoptosis; Cell Line, Tumor; Cell Movement; Epidermal Growth Factor; ErbB Receptors; Flavonoids; Glucosides; Humans; MAP Kinase Signaling System; Pancreatic Neoplasms; Phosphorylation; Quercetin

Increased microRNA-10b (miR-10b) expression in the cancer cells in pancreatic ductal adenocarcinoma (PDAC) is a marker of disease aggressiveness. In the present study, we determined that plasma miR-10b levels are significantly increased in PDAC patients by comparison with normal controls. By gene profiling, we identified potential targets downregulated by miR-10b, including Tat-interacting protein 30 (TIP30). Immunoblotting and luciferase reporter assays confirmed that TIP30 was a direct miR-10b target. Downregulation of TIP30 by miR-10b or siRNA-mediated silencing of TIP30 enhanced epidermal growth factor (EGF)-dependent invasion. The actions of miR-10b were abrogated by expressing a modified TIP30 cDNA resistant to miR-10b. EGF-induced EGF receptor (EGFR) tyrosine phosphorylation and extracellular signal-regulated kinase phosphorylation were enhanced by miR-10b, and these effects were mimicked by TIP30 silencing. The actions of EGF in the presence of miR-10b were blocked by EGFR kinase inhibition with erlotinib and by dual inhibition of PI3K (phosphatidylinositol 3'-kinase) and MEK. Moreover, miR-10b, EGF and transforming growth factor-beta (TGF-β) combined to markedly increase cell invasion, and this effect was blocked by the combination of erlotinib and SB505124, a type I TGF-β receptor inhibitor. miR-10b also enhanced the stimulatory effects of EGF and TGF-β on cell migration and epithelial-mesenchymal transition (EMT) and decreased the expression of RAP2A, EPHB2, KLF4 and NF1. Moreover, miR-10b overexpression accelerated pancreatic cancer cell (PCC) proliferation and tumor growth in an orthotopic model. Thus, plasma miR-10b levels may serve as a diagnostic marker in PDAC, whereas intra-tumoral miR-10b promotes PCC proliferation and invasion by suppressing TIP30, which enhances EGFR signaling, facilitates EGF-TGF-β cross-talk and enhances the expression of EMT-promoting genes, whereas decreasing the expression of several metastasis-suppressing genes. Therefore, therapeutic targeting of miR-10b in PDAC may interrupt growth-promoting deleterious EGF-TGF-β interactions and antagonize the metastatic process at various levels.

Topics: Acetyltransferases; Animals; Antineoplastic Agents; Base Sequence; Binding Sites; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Epidermal Growth Factor; Erlotinib Hydrochloride; Gene Expression; Gene Expression Regulation, Neoplastic; Humans; Kruppel-Like Factor 4; Male; Mice; Mice, Nude; MicroRNAs; Neoplasm Invasiveness; Neoplasm Transplantation; Pancreatic Neoplasms; Quinazolines; RNA Interference; Signal Transduction; Transcription Factors; Transforming Growth Factor beta

Elevated CARMA3 expression has been reported to be involved in tumor progression of several cancer types. In the present study, we examined the expression pattern of CARMA3 protein and its biological roles in human pancreatic carcinoma. Using immunohistochemistry, we checked CARMA3 protein expression in 95 pancreatic ductal carcinoma specimens. We found that CARMA3 was overexpressed in 34 of 95 (35.8 %) specimens. A significant association was observed between CARMA3 overexpression with histological grade (p=0.0099) and nodal status (p=0.0126). To further explore its biological roles, we knocked down CARMA3 expression in CAPAN2 cell line using small interfering RNA (siRNA). MTT growth assay, wound healing assay, and Transwell assay showed that CARMA3 depletion inhibited cell proliferation, migration, and invasion. We also showed that CARMA3 depletion inhibited EGF-induced nuclear factor-kappaB (NF-κB) activation and its target genes' expression. The effect of CARMA3 depletion on NF-κB signaling was significantly reduced in Bcl10-depleted cells. In conclusion, CARMA3 is overexpressed in pancreatic cancer and regulates malignant cell growth, invasion, and NF-κB signaling, which was dependent on its association with Bcl10.

Topics: Adaptor Proteins, Signal Transducing; Adult; Aged; B-Cell CLL-Lymphoma 10 Protein; CARD Signaling Adaptor Proteins; Cell Line, Tumor; Cell Movement; Cell Proliferation; Epidermal Growth Factor; Female; Humans; Male; Middle Aged; Neoplasm Invasiveness; NF-kappa B; Pancreatic Neoplasms; Signal Transduction

A functional vacuolar adenosine triphosphatase (v-ATPase) complex regulates canonical Wnt/β-catenin signaling. The goal of this study was to identify the distribution of the v-ATPase in human and murine models of pancreatic intraepithelial neoplasms (PanINs) and assess its role in Wnt/β-catenin signaling.. We evaluated the immunolabeling pattern of the v-ATPase in human PanIN specimens and murine PanIN-1 and PanIN-2 lesions obtained from Ptf1a(Cre/+); LSL-Kras(G12D) mice. Wnt/β-catenin signaling was interrogated in primary PanIN cells by examining the phosphorylated levels of its surface coreceptor, low-density lipoprotein receptor-related protein-6 (LRP6), and its intracellular effector, nonphosphorylated β-catenin. The response of primary PanIN cells to epidermal growth factor (EGF) was assessed in the absence and presence of the v-ATPase inhibitor, concanamycin.. In advanced (PanIN-2), but not early (PanIN-1), lesions, the v-ATPase assumed a polarized phenotype. Blocking the v-ATPase disrupted Wnt/β-catenin signaling in primary PanIN cells despite significantly higher levels of the total and activated Wnt cell surface coreceptor, LRP6. Vacuolar adenosine triphosphatase blockade significantly decreased the total and activated levels of EGF receptor, a determinant of PanIN progression. The activation of EGF receptor and its intracellular mediator, p44/42 mitogen-activated protein kinase, was also reduced by v-ATPase blockade. This led to diminished proliferation in response to EGF ligand.. The v-ATPase regulates Wnt/β-catenin and EGF receptor signaling in PanINs.

Topics: Adenocarcinoma in Situ; Alcian Blue; Animals; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Cell Polarity; Disease Progression; Epidermal Growth Factor; ErbB Receptors; Humans; Islets of Langerhans; Low Density Lipoprotein Receptor-Related Protein-6; Membrane Proteins; Mice; Mice, Mutant Strains; Mitogen-Activated Protein Kinase 3; Neoplasm Grading; Neoplasm Proteins; Pancreatic Neoplasms; Protein Transport; Staining and Labeling; Vacuolar Proton-Translocating ATPases; Wnt Signaling Pathway

MUC1 is a large cell surface mucin glycoprotein that plays diverse roles in both normal and tumor cell biology. These roles include mucosal hydration and protection, inhibition of embryo implantation, protection of tumor cells from the immune system and reduction of cytotoxic drug uptake. Similarly, the EGFR family of cell surface receptors drives many normal developmental processes as well as various aspects of tumor growth and gene expression. EGFR family members have been demonstrated to form complexes with MUC1 in various cellular contexts. Nonetheless, the role that EGFR activation plays in modulating MUC1 levels has not been considered. In this study, we demonstrate that activated EGFR drives high level MUC1 expression in multiple cell lines of uterine adenocarcinoma and pancreatic cancer origins. In some cells, addition of exogenous EGFR ligands (EGF or HB-EGF) elevates MUC1 levels while addition of the EGFR tyrosine kinase inhibitor, AG1478, reduces MUC1 levels. The thiazolidinedione, rosiglitazone, previously shown to reduce progesterone-stimulated MUC1 expression, also blocks EGFR ligand-driven MUC1 expression. This activity was observed at relatively high rosiglitazone concentrations (above 10 µM) and appeared to be largely PPARγ independent indicating a novel utility of this drug to reduce mucin-expression in various tumor settings. Collectively, these data demonstrate that: (1) activation of EGFR stimulates MUC1 expression in multiple cellular contexts and (2) it may be possible to develop useful interventions to reduce MUC1 expression as a complementary strategy for tumor therapy.

Topics: Blotting, Western; Cell Line, Tumor; Epidermal Growth Factor; ErbB Receptors; Female; Gene Expression; Humans; Mucin-1; Pancreatic Neoplasms; Quinazolines; Rosiglitazone; Thiazolidinediones; Tyrphostins; Uterine Neoplasms

Epidermal growth factor (EGF)-induced EGFR tyrosine kinase receptor activation in cancer cell survival responses has become a strategic molecular-targeting clinical therapeutic intent, but the failures of these targeted approaches in the clinical setting demand alternate strategies. Here, we uncover a novel neuraminidase-1 (Neu1) and matrix metalloproteinase-9 (MMP-9) cross-talk in alliance with GPCR neuromedin B, which is essential for EGF-induced receptor activation and cellular signaling. Neu1 and MMP-9 form a complex with EGFR on the cell surface. Tamiflu (oseltamivir phosphate), anti-Neu1 antibodies, broad range MMP inhibitor galardin (GM6001), neuromedin B GPCR specific antagonist BIM-23127, the selective inhibitor of whole heterotrimeric G-protein complex BIM-46174 and MMP-9 specific inhibitor dose-dependently inhibited Neu1 activity associated with EGF stimulated 3T3-hEGFR cells. Tamiflu, anti-Neu1 antibodies and MMP9i attenuated EGFR phosphorylation associated with EGF-stimulated cells. Preclinical data provide the proof-of-evidence for a therapeutic targeting of Neu1 with Tamiflu in impeding human pancreatic cancer growth and metastatic spread in heterotopic xenografts of eGFP-MiaPaCa-2 tumors growing in RAGxCγ double mutant mice. Tamiflu-treated cohort exhibited a reduction of phosphorylation of EGFR-Tyr1173, Stat1-Tyr701, Akt-Thr308, PDGFRα-Tyr754 and NFκBp65-Ser311 but an increase in phospho-Smad2-Ser465/467 and -VEGFR2-Tyr1175 in the tumor lysates from the xenografts of human eGFP-MiaPaCa-2 tumor-bearing mice. The findings identify a novel promising alternate therapeutic treatment of human pancreatic cancer.

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Enzyme Inhibitors; Epidermal Growth Factor; ErbB Receptors; Humans; Male; Matrix Metalloproteinase 9; Mice; Neoplasm Metastasis; Neuraminidase; NIH 3T3 Cells; Oseltamivir; Pancreas; Pancreatic Neoplasms; Signal Transduction

Foregut neuroendocrine tumors [NETs] usually pursuit a benign course, but some show aggressive behavior. The treatment of patients with advanced NETs is marginally effective and new approaches are needed. In other tumors, transactivation of the EGF receptor (EGFR) by growth factors, gastrointestinal (GI) hormones and lipids can stimulate growth, which has led to new treatments. Recent studies show a direct correlation between NET malignancy and EGFR expression, EGFR inhibition decreases basal NET growth and an autocrine growth effect exerted by GI hormones, for some NETs. To determine if GI hormones can stimulate NET growth by inducing transactivation of EGFR, we examined the ability of EGF, TGFα and various GI hormones to stimulate growth of the human foregut carcinoid,BON, the somatostatinoma QGP-1 and the rat islet tumor,Rin-14B-cell lines. The EGFR tyrosine-kinase inhibitor, AG1478 strongly inhibited EGF and the GI hormones stimulated cell growth, both in BON and QGP-1 cells. In all the three neuroendocrine cell lines studied, we found EGF, TGFα and the other growth-stimulating GI hormones increased Tyr(1068) EGFR phosphorylation. In BON cells, both the GI hormones neurotensin and a bombesin analogue caused a time- and dose-dependent increase in EGFR phosphorylation, which was strongly inhibited by AG1478. Moreover, we found this stimulated phosphorylation was dependent on Src kinases, PKCs, matrix metalloproteinase activation and the generation of reactive oxygen species. These results raise the possibility that disruption of this signaling cascade by either EGFR inhibition alone or combined with receptor antagonists may be a novel therapeutic approach for treatment of foregut NETs/PETs.

Topics: Adenoma, Islet Cell; Animals; Blotting, Western; Cell Proliferation; Epidermal Growth Factor; ErbB Receptors; Gastrointestinal Hormones; Humans; Neuroendocrine Tumors; Pancreatic Neoplasms; Phosphorylation; Rats; Reactive Oxygen Species; Signal Transduction; Somatostatinoma; Transcriptional Activation; Transforming Growth Factor alpha; Tumor Cells, Cultured; Tyrosine

Perioperative blood transfusion in pancreatic cancer patients is linked to decreased survival; however, a causal mechanism has not been determined. Previously we have shown that the plasma fraction of stored packed red blood cells (pRBCs) promotes pancreas cancer progression and associated morbidity. We hypothesize these untoward effects will be mitigated by use of a hemoglobin-based oxygen carrier (HBOC).. Cytokines and growth factors were measured in the plasma fraction from stored pRBCs and in an HBOC via cytokine array followed by formal enzyme-linked immunosorbent assay (ELISA). In an immunocompetent murine model, pancreas cancer progression was determined in vivo by bioluminescence, tumor weight, and number of metastases.. Elevated levels of epidermal growth factor (EGF), platelet-derived growth factor BB (PDGF-BB), and regulated upon activation, normal T cell expressed and secreted (RANTES) were present in the plasma fraction of stored pRBCs, but were not found in the HBOC. Intravenous delivery of plasma fraction to mice with pancreatic cancer resulted in increased bioluminescence activity compared with mice that received HBOC. Metastatic events and pancreatic primary tumor weights were significantly higher in animals receiving plasma fraction from stored pRBCs compared with animals receiving HBOC.. Intravenous receipt of the acellular plasma fraction of stored pRBCs promotes pancreatic cancer progression in an immunocompetent mouse model. These untoward events are mitigated by use of an HBOC.

Topics: Analysis of Variance; Animals; Becaplermin; Blood Substitutes; Chemokine CCL5; Cytokines; Disease Progression; Epidermal Growth Factor; Erythrocyte Transfusion; Hemoglobins; Humans; Mice; Neoplasm Metastasis; Pancreatic Neoplasms; Plasma; Protein Array Analysis; Proto-Oncogene Proteins c-sis

Cellular receptor targeted imaging agents present the potential to target extracellular molecular expression in cancerous lesions; however, the image contrast in vivo does not reflect the magnitude of overexpression expected from in vitro data. Here, the in vivo delivery and binding kinetics of epidermal growth factor receptor (EGFR) was determined for normal pancreas and AsPC-1 orthotopic pancreatic tumors known to overexpress EGFR.. EGFR in orthotopic xenograft AsPC-1 tumors was targeted with epidermal growth factor (EGF) conjugated with IRDye800CW. The transfer rate constants (k(e), K₁₂, k₂₁, k₂₃, and k₃₂) associated with a three-compartment model describing the vascular delivery, leakage rate and binding of targeted agents were determined experimentally. The plasma excretion rate, k (e), was determined from extracted blood plasma samples. K₁₂, k₂₁, and k₃₂ were determined from ex vivo tissue washing studies at time points ≥ 24 h. The measured in vivo uptake of IRDye800CW-EGF and a non-targeted tracer dye, IRDye700DX-carboxylate, injected simultaneously was used to determined k₂₃.. The vascular exchange of IRDye800CW-EGF in the orthotopic tumor (K₁₂ and k₂₁) was higher than in the AsPC-1 tumor as compared to normal pancreas, suggesting that more targeted agent can be taken up in tumor tissue. However, the cellular associated (binding) rate constant (k₂₃) was slightly lower for AsPC-1 pancreatic tumor (4.1 × 10(-4) s(-1)) than the normal pancreas (5.5 × 10(-4) s(-1)), implying that less binding is occurring.. Higher vascular delivery but low cellular association in the AsPC-1 tumor compared to the normal pancreas may be indicative of low receptor density due to low cellular content. This attribute of the AsPC-1 tumor may indicate one contributing cause of the difficulty in treating pancreatic tumors with cellular targeted agents.

Topics: Animals; Blood Vessels; Cell Line, Tumor; Drug Delivery Systems; Epidermal Growth Factor; ErbB Receptors; Fluorescence; Fluorescent Dyes; Humans; Kinetics; Male; Mice; Models, Biological; Pancreas; Pancreatic Neoplasms; Protein Binding; Xenograft Model Antitumor Assays

Single-walled carbon nanotubes (SWCNTs) were covalently linked to epidermal growth factor (EGF) proteins through an esterification process that was found to be responsible for the docking of SWCNTs on the human pancreatic cancer cells (PANC-1) surface, thus providing a mechanism for the enhanced delivery and internalization of the nanotubes. Micro Raman spectroscopy and enzyme-linked immunosorbent assay were used to evaluate the delivery process and kinetics of the SWCNTs. In vitro studies indicated that the delivery kinetics of SWCNT-EGF conjugates, at a concentration of 85 µg ml(-1), to the PANC-1 cell surfaces was significant in the first 30 min of incubation, but reached a plateau with time in accordance with the establishment of equilibrium between the association and the dissociation of EGF with the cell receptors. SWCNT-EGF conjugates could act as strong thermal ablation agents and could induce higher percentages of cellular death compared with the nontargeted SWCNTs alone.

Topics: Cell Line, Tumor; Drug Delivery Systems; Enzyme-Linked Immunosorbent Assay; Epidermal Growth Factor; Humans; Nanotubes, Carbon; Pancreatic Neoplasms; Spectrum Analysis, Raman

The objective was to test a bispecific ligand-directed toxin (BLT), with reduced immunogenicity for enhanced efficacy in targeting orthotopic pancreatic cancer in vivo.. A new BLT was created in which both human epidermal growth factor (EGF) and interleukin 4 cytokines were cloned onto the same single chain molecule with deimmunized pseudomonas exotoxin (dEGF4KDEL). Key amino acids dictating B-cell generation of neutralizing antitoxin antibodies were mutated. Bioassays were used to determine whether mutation reduced potency, and enzyme-linked immunosorbent assay studies were performed to determine whether antitoxin antibodies were reduced. A genetically altered luciferase MIA PaCa-2 xenograft model was used to image in real time and determine effects on systemic malignant human cancer. Bispecific ligand-directed toxins targeting B cells were used as specificity controls.. Deimmunized EGF4KDEL was significantly effective after systemic injection against established orthotopic MIA PaCa-2 pancreatic cancer and selectively prevented metastasis. Mutagenesis significantly reduced antitoxin levels in vivo with no apparent activity loss in vitro. The drug was effective against 3 human pancreatic cancer lines in vitro, MIA PaCa-2, SW1990, and S2VP10.. Despite the metastatic nature of the MIA PaCa-2 orthotopic tumor xenografted in nude mice, high percentages of tumors responded to extended dEGFKDEL treatment resulting in significant anticancer effects and disease-free survivors.

Topics: Amino Acid Sequence; Animals; Antibodies, Bispecific; Antineoplastic Agents; Cell Line, Tumor; Epidermal Growth Factor; Exotoxins; Humans; Immunotoxins; Interleukin-4; Ligands; Male; Mice; Mice, Nude; Mutation; Pancreatic Neoplasms; Pseudomonas; Time Factors; Tumor Burden; Xenograft Model Antitumor Assays

Pancreatic carcinoma is one of the most malignant and aggressive cancers. Increased motility and invasiveness of pancreatic cancer cells are believed to be associated with epithelial-to-mesenchymal transition (EMT). However, the molecular basis of EMT in pancreatic cancer cells is poorly understood. In this study, we examined the relationship between Jun dimerization protein 2 (JDP2), which is an AP-1 inhibitor, and EMT in human pancreatic carcinoma cells. We demonstrated that transforming growth factor-β1 (TGF-β1) promoted epidermal growth factor (EGF)-induced EMT in co-treated human pancreatic BxPC3 cells and that JDP2 overexpression reversed the EMT that was induced by co-treatment with TGF-β1 and EGF. These results suggest that EGF plays a principal role in EMT through its association with TGF-β1 in human pancreatic BxPC3 cells and that JDP2 may be a molecular target for pancreatic carcinoma intervention.

Topics: Cadherins; Cell Line, Tumor; Cell Movement; Epidermal Growth Factor; Epithelial-Mesenchymal Transition; Gene Expression Regulation, Neoplastic; Humans; Pancreatic Neoplasms; Repressor Proteins; Transforming Growth Factor beta1; Vimentin

Receptor tyrosine kinases and integrins play an essential role in tumor cell invasion and metastasis. We previously showed that EGF and other growth factors induce human carcinoma cell invasion and metastasis mediated by integrin αvβ5 that is prevented by Src blockade. MUC1, a transmembrane glycoprotein, is expressed in most epithelial tumors as a heterodimer consisting of an extracellular and a transmembrane subunit. The MUC1 cytoplasmic domain of the transmembrane subunit (MUC1.CD) translocates to the nucleus where it promotes the transcription of a metastatic gene signature associated with epithelial to mesenchymal transition. Here, we demonstrate a requirement for MUC1 in carcinoma cell metastasis dependent on EGFR and Src without affecting primary tumor growth. EGF stimulates Src-dependent MUC1 cleavage and nuclear localization leading to the expression of genes linked to metastasis. Moreover, expression of MUC1.CD results in its nuclear localization and is sufficient for transcription of the metastatic gene signature and tumor cell metastasis. These results demonstrate that EGFR and Src activity contribute to carcinoma cell invasion and metastasis mediated by integrin αvβ5 in part by promoting proteolytic cleavage of MUC1 and highlight the ability of MUC1.CD to promote metastasis in a context-dependent manner. Our findings may have implications for the use and future design of targeted therapies in cancers known to express EGFR, Src, or MUC1.

Topics: Animals; Carcinoma; Cell Line, Tumor; Chick Embryo; CSK Tyrosine-Protein Kinase; Epidermal Growth Factor; Epithelial-Mesenchymal Transition; ErbB Receptors; Gene Expression Regulation, Neoplastic; Humans; Mucin-1; Neoplasm Invasiveness; Neoplasm Metastasis; Pancreatic Neoplasms; Protein-Tyrosine Kinases; Receptors, Vitronectin; Signal Transduction; src-Family Kinases

Adenoid cystic carcinoma (ACC) is a relatively rare epithelial tumour of the salivary glands in the maxillofacial region. About 40-60% of the patients develop distant metastases, which have been documented most commonly in the lung but also in brain, bone, liver, thyroid, spleen and pancreatic gland.. A 55-year-old women with intraosseous ACC in the mandible mimicking apical periodontitis following curative resection and radiotherapy is presented. Three years later, multiple lung metastases were observed followed by chemotherapy. Five years after curative resection, the patient presented simultaneously with new expansive soft tissue in the pancreas and mammary gland as well as in the kidney found to be metastatic ACC. No case has been reported to date on the manifestation of distant metastases of intraosseous ACC in the breast and the kidney as described by these observations. Metastatic mammary gland ACC stained positive for epithelial growth factor receptor (EGFR) but was negative for HER-2/neu and Cyclooxygenase-2 (COX-2) expression.

Topics: Alveolar Bone Loss; Breast Neoplasms; Carcinoma, Adenoid Cystic; Cyclooxygenase 2; Diagnosis, Differential; Diagnostic Errors; Epidermal Growth Factor; Female; Humans; Hyperbaric Oxygenation; Kidney Neoplasms; Mandibular Neoplasms; Middle Aged; Osteomyelitis; Pancreatic Neoplasms; Periapical Periodontitis; Receptor, ErbB-2; Salivary Gland Neoplasms

Aquaporin (AQP) water channels are expressed in high-grade tumor cells of different tissue origins. In this study, we investigated whether AQP3 is expressed in cultured MPC-83 pancreatic cancer cells, whether AQP3 enhances cell migration and the signal pathway mechanism involved. MPC-83 pancreatic cancer cells were pre-treated and treated with EGF at different time points and then analyzed using western blotting. Results showed that epidermal growth factor (EGF) induced the phosphorylation of the EGF receptor (EGFR) and extracellular signal-regulated kinase (ERK), which peaked at 5 min after EGF treatment. EGFR and ERK phosphorylation induced by EGF were inhibited by PD153035 (EGFR tyrosine kinase inhibitor) and U0126 (ERK inhibitor), respectively. EGF increased the activity of AQP3 in a dose- and time-dependent manner in MPC-83 pancreatic cancer cells, which peaked at 24 h after treatment. The activity of AQP3 and cell migration were inhibited by PD153035, U0126 and CuSO4 (AQP3 water transport inhibitor). EGFR/ERK pathway-mediated AQP3 activation and cell migration were stimulated by EGF in cultured MPC-83 pancreatic cancer cells in vitro and this cell signaling pathway is inhibited by the EGFR and ERK inhibitors, which may be used as potential therapeutic targets in the treatment of pancreatic cancer.

Topics: Antineoplastic Agents; Aquaporin 3; Butadienes; Cell Line, Tumor; Cell Movement; Enzyme Inhibitors; Epidermal Growth Factor; ErbB Receptors; Extracellular Signal-Regulated MAP Kinases; Humans; Nitriles; Pancreatic Neoplasms; Phosphorylation; Quinazolines; Up-Regulation

To investigate the regulation of epithelium growth factor receptor (EGFR), pan-Ras, and extracellular regulated protein kinase (ERK) with both a ras homologue member I (ARHI) suppression and epithelium growth factor (EGF) stimulation.. After identification and implication, the constructed plasmid pIRES2-EGFP-ARHI was transfected into Panc-1. The untransfected cell was also explored as controls. The growth curve was drawn to indicate the proliferation effect of ARHI. EGFR-ELISA was performed to investigate the expression of EGFR. Western blot analysis was used to investigate the expression of protein MAPK/ERK1/2, pan-Ras in Panc-1.. The proliferation rate of Panc-1 was inhibited by ARHI compared with both empty plasmid and untransfected cell. The amount of EGFR was parallel in both transfected and untransfected cell but affected by EGF stimulation. The amount of pan-Ras was decreased after ARHI transfection. The optimum concentration of EGF effect on P-ERK was 50 ng/ml.. Both ARHI and EGF play roles in the EGF-EGFR-Ras-Raf-MAPK/ERK1/2 pathway.

Topics: Cell Proliferation; Epidermal Growth Factor; ErbB Receptors; Humans; Mitogen-Activated Protein Kinase 3; Pancreatic Neoplasms; ras Proteins; rho GTP-Binding Proteins; Signal Transduction; Transfection; Tumor Cells, Cultured

The authors previously reported that neutrophil gelatinase-associated lipocalin (NGAL) overexpression significantly blocked invasion and angiogenesis of pancreatic ductal adenocarcinoma (PDAC). They also demonstrated a loss of NGAL expression in the advanced stages of PDAC. However, little is known regarding the mechanisms of NGAL regulation in PDAC. Because the epidermal growth factor (EGF)-EGF receptor (EGFR) axis is up-regulated significantly in PDAC, they examined EGF-mediated NGAL regulation in these cells.. The NGAL-positive cell lines AsPC-1 and BxPC-3 were used as a model system. Quantitative real-time polymerase chain reaction (RT-PCR), Western blot analysis, and immunofluorescence studies were used to investigate EGF-mediated effects on NGAL expression. E-cadherin expression was manipulated using lentiviral overexpression or small hairpin RNA constructs. NGAL promoter activity was assessed by luciferase-reporter assay and electrophoretic mobility shift assay.. NGAL expression was positively associated with tumor differentiation and was down-regulated significantly after EGF treatment along with a concomitant reduction of E-cadherin expression in PDAC cells. E-cadherin down-regulation was partly through the EGFR-dependent mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) (MEK-ERK) signaling pathway. In addition, E-cadherin down-regulation reduced NGAL expression in PDAC cells, whereas overexpression of E-cadherin led to increased NGAL expression and partly rescued the inhibition of NGAL expression by EGF. Furthermore, EGF, in part through E-cadherin, reduced NGAL promoter activity by blocking nuclear factor κB (NF-κB) activation.. The current study demonstrated for the first time that EGF potently blocked NGAL expression in PDAC cells. This effect was mediated in part through activation of the EGFR-MEK-ERK signaling pathway, which, in turn, down-regulated E-cadherin with a subsequent reduction in NF-κB activation. These findings illustrate a novel mechanism by which EGF regulates NGAL expression in PDAC.

Topics: Acute-Phase Proteins; Cadherins; Cell Line, Tumor; Epidermal Growth Factor; Extracellular Signal-Regulated MAP Kinases; Gene Expression Regulation, Neoplastic; Humans; Lipocalin-2; Lipocalins; Neoplasm Grading; Neoplasm Staging; NF-kappa B; Pancreatic Neoplasms; Proto-Oncogene Proteins; Signal Transduction

MUC1 is overexpressed and aberrantly glycosylated in more than 60% of pancreatic ductal adenocarcinomas. The functional role of MUC1 in pancreatic cancer has yet to be fully elucidated due to a dearth of appropriate models. In this study, we have generated mouse models that spontaneously develop pancreatic ductal adenocarcinoma (KC), which are either Muc1-null (KCKO) or express human MUC1 (KCM). We show that KCKO mice have significantly slower tumor progression and rates of secondary metastasis, compared with both KC and KCM. Cell lines derived from KCKO tumors have significantly less tumorigenic capacity compared with cells from KCM tumors. Therefore, mice with KCKO tumors had a significant survival benefit compared with mice with KCM tumors. In vitro, KCKO cells have reduced proliferation and invasion and failed to respond to epidermal growth factor, platelet-derived growth factor, or matrix metalloproteinase 9. Further, significantly less KCKO cells entered the G(2)-M phase of the cell cycle compared with the KCM cells. Proteomics and Western blotting analysis revealed a complete loss of cdc-25c expression, phosphorylation of mitogen-activated protein kinase (MAPK), as well as a significant decrease in nestin and tubulin-α2 chain expression in KCKO cells. Treatment with a MEK1/2 inhibitor, U0126, abrogated the enhanced proliferation of the KCM cells but had minimal effect on KCKO cells, suggesting that MUC1 is necessary for MAPK activity and oncogenic signaling. This is the first study to utilize a Muc1-null PDA mouse to fully elucidate the oncogenic role of MUC1, both in vivo and in vitro.

Topics: Animals; Butadienes; Carcinoma, Pancreatic Ductal; Cell Cycle; Cell Growth Processes; Epidermal Growth Factor; Humans; Intermediate Filament Proteins; Matrix Metalloproteinase 9; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitogen-Activated Protein Kinases; Mucin-1; Neoplasm Metastasis; Nerve Tissue Proteins; Nestin; Nitriles; Pancreatic Neoplasms; Platelet-Derived Growth Factor; Protein Kinase Inhibitors; Tubulin

Transforming Growth Factor-β (TGF-β) exerts cell type-specific and context-dependent effects. Understanding the intrinsic effects of TGF-β on cancer cells in pancreatic ductal adenocarcinoma (PDAC) is a prerequisite for rationalized clinical implementation of TGF-β targeting therapies. Since the tumor microenvironment can affect how cancer cell respond to TGF-β, we employed a novel three-dimensional (3D) culturing system to recapitulate stromal and extracellular matrix interactions. We show here that TGF-β stimulates growth of human and murine pancreatic cancer cell lines (PCCs) when embedded in a 3% collagen IV/laminin-rich gelatinous medium (Matrigel™) over a solidified layer of soft agar. Moreover, in this novel 3D model, concomitant treatment with TGF-β1 and epidermal growth factor (EGF) enhanced PCC growth to a greater extent than either growth factor alone, and conferred increased chemoresistance to cytotoxic compounds. These cooperative growth-stimulatory effects were blocked by pharmacological inhibition of TGF-β type I receptor with SB431542 or the EGF receptor with erlotinib. Co-incubation with SB431542 and erlotinib enhanced the efficacy of gemcitabine and cisplatin in PCCs and in primary cell cultures established from pancreata of genetically-engineered mouse models of PDAC. These findings suggest that concomitant inhibition of TGF-β and EGF signaling may represent an effective therapeutic strategy in PDAC, and that this 3D culturing system could be utilized to test ex vivo the therapeutic response of pancreatic tumor biopsies from PDAC patients, thereby providing a functional assay to facilitate personalized targeted therapies.

Topics: Animals; Benzamides; Carcinoma, Pancreatic Ductal; Cell Culture Techniques; Cell Line, Tumor; Cell Proliferation; Cisplatin; Culture Media; Deoxycytidine; Dioxoles; Drug Resistance, Neoplasm; Epidermal Growth Factor; ErbB Receptors; Erlotinib Hydrochloride; Extracellular Matrix; Gemcitabine; Humans; Mice; Mice, Transgenic; Pancreatic Neoplasms; Quinazolines; Receptors, Transforming Growth Factor beta; Transforming Growth Factor beta; Transforming Growth Factor beta1; Tumor Microenvironment

Rho-associated coiled-coil containing protein kinase (Rho-kinase/ROCK) is involved in various cellular functions including cell proliferation, and is generally considered to be oncogenic, while some studies show that ROCK functions as a negative regulator of cancer progression. As a result, the precise role of ROCK remains controversial. We have previously reported that Rho-kinase/ROCK negatively regulates epidermal growth factor (EGF)-induced cell proliferation in SW480 colon cancer cells. In the present study, we investigated the role of ROCK in EGF receptor (EGFR) signaling in the pancreatic cancer cell lines, Panc1, KP3 and AsPc1.. In these cells, Y27632, a specific ROCK inhibitor, enhanced EGF-induced BrdU incorporation. The blockade of EGF stimulation utilizing anti-EGFR-neutralizing antibodies suppressed Panc1 cell proliferation. EGF induced RhoA activity, as well as the phosphorylation of cofilin and myosin light chain (MLC), both targets of ROCK signaling, and Y27632 suppressed both of these processes, indicating that the phosphorylation of cofilin and MLC by EGF occurs through ROCK in Panc1 cells. EGF-induced phosphorylation of EGFR at tyrosine residues was augmented when the cells were pretreated with Y27632 or were subjected to gene silencing using ROCK-siRNA. We also obtained similar results using transforming growth factor-α. In addition, EGF-induced phosphorylation of p44/p42 mitogen-activated protein kinase and Akt were also enhanced by Y27632 or ROCK-siRNA. Moreover, an immunofluorescence microscope study revealed that pretreatment with Y27632 delayed EGF-induced internalization of EGFR. Taken together, these data indicate that ROCK functions to switch off EGFR signaling by promoting the internalization of the EGFR.. While EGF first stimulates the activation of the EGFR and subsequently increases cancer cell proliferation, EGF concurrently induces the activation of ROCK, which then turns off the activated EGFR pathway via a negative feedback system.

Topics: Amides; Antibodies, Neutralizing; Carcinoma; Cell Line, Tumor; Cell Proliferation; Drug Evaluation, Preclinical; Enzyme Activation; Epidermal Growth Factor; ErbB Receptors; Humans; Pancreatic Neoplasms; Protein Kinase Inhibitors; Pyridines; rho-Associated Kinases; Up-Regulation

The utility of circulating angiogenic cytokines (CAC) as biomarkers in pancreatic cancer has not been clarified yet. We investigated the expression and prognostic associations of seven CAC in patients with pancreatic cancer.. Serum samples were collected preoperatively in patients undergoing surgery for localized pancreatic cancer (n = 74), metastatic pancreatic cancer (n = 24) or chronic pancreatitis (n = 20) and in healthy controls (n = 48). Quantitative enzyme-linked immunosorbent assays and multiplex protein arrays were used to determine circulating levels of VEGF, VEGFR-1, PlGF, PDGF-AA, PDGF-BB, Ang-1 and EGF. Multivariate analyses on cancer-specific survival were performed with a Cox proportional hazards model.. VEGF (p < 0.0001), PDGF-AA (p < 0.0001), Ang-1 (p = 0.002) and EGF (p < 0.0001) were differentially expressed in patients with pancreatic cancer compared to healthy controls. The presence of lymph node metastases was associated with increased levels of all CAC except for PlGF, whereas there were only minor associations of CAC with other clinicopathologic variables. The multivariate model including the entire angiogenic panel revealed high levels of circulating PDGF-AA (hazard ratio 4.58; 95% confidence interval 1.43 - 14.69) as predictor of poor cancer-specific survival, whereas high levels of PDGF-BB (0.15; 0.15 - 0.88), Ang-1 (0.30; 0.10 - 0.93) and VEGF (0.24; 0.09 - 0.57) were associated with a favorable prognosis.. Circulating levels of certain angiogenic cytokines correlate with patients' prognosis after resection for pancreatic cancer, if a panel of several CAC is considered simultaneously. These data should be considered in future studies evaluating angiogenic factors as prognostic biomarkers and therapeutic targets in patients with pancreatic cancer.

Topics: Aged; Angiogenic Proteins; Angiotensin I; Becaplermin; Carcinoma, Pancreatic Ductal; Cytokines; Epidermal Growth Factor; Female; Gene Expression Regulation, Neoplastic; Humans; Kaplan-Meier Estimate; Male; Membrane Proteins; Middle Aged; Neoplasm Proteins; Pancreatic Neoplasms; Platelet-Derived Growth Factor; Prognosis; Proportional Hazards Models; Proto-Oncogene Proteins c-sis; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-1

Pancreatic ductal adenocarcinoma (PDAC) is highly resistant to current chemotherapy regimens, in part due to alterations in the p53 tumor suppressor pathway. p53 homolog p63 is a transcription factor essential for the development and differentiation of epithelial surfaces. However its function in cancer is controversial and its role in PDAC is not known. We discovered that ΔNp63α was the predominantly expressed p63 variant in pancreatic cancer cell lines. ΔNp63α protein and mRNA levels were high in T3M4, BxPC3 and COLO-357 pancreatic cancer cells and low in ASPC-1 and PANC-1 cells. Overexpression of ΔNp63α in PANC-1 cells and shRNA-mediated knockdown in T3M4 cells indicated that ΔNp63α promoted anchorage-dependent and -independent growth, motility and invasion, and enhanced resistance to cisplatin-induced apoptosis. Epidermal growth factor receptor (EGFR) signaling pathways contribute to the biological aggressiveness of PDAC, and we found that the motogenic effects of ΔNp63α were augmented in presence of EGF. Ectopic expression of ΔNp63α resulted in upregulation of EGFR and β1-integrin in PANC-1 cells. Conversely, ΔNp63α knockdown had an opposite effect in T3M4 cells. ΔNp63α potentiated EGF-mediated activation of ERK, Akt and JNK signaling. Chromatin immunoprecipitation and functional reporter assays demonstrated that ΔNp63α activated EGFR transcription. 14-3-3σ transcription was also positively regulated by ΔNp63α and we have previously shown that 14-3-3σ contributes to chemoresistance in pancreatic cancer cell lines. Conversely, shRNA-mediated knockdown of 14-3-3σ led to abrogation of the ΔNp63α effects on cell proliferation and invasion. Thus, p53 homolog ΔNp63α enhances the oncogenic potential of pancreatic cancer cells through trans-activation of EGFR and 14-3-3σ.

Topics: 14-3-3 Proteins; Animals; Biomarkers, Tumor; Cell Adhesion; Cell Line, Tumor; Cell Movement; Cell Proliferation; Drug Resistance, Neoplasm; Epidermal Growth Factor; ErbB Receptors; Exonucleases; Exoribonucleases; Gene Expression Regulation, Neoplastic; HEK293 Cells; Humans; Mice; Neoplasm Invasiveness; Pancreatic Neoplasms; Protein Isoforms; Signal Transduction; Trans-Activators; Transcription Factors; Tumor Suppressor Protein p53; Tumor Suppressor Proteins; Up-Regulation

Multiple lines of evidence suggest that a large portion of pancreatic cancer patients suffer from either hyperglycemia or diabetes, both of which are characterized by high blood glucose level. However, the underlying biological mechanism of this phenomenon is largely unknown. In the present study, we demonstrated that the proliferative ability of two human pancreatic cancer cell lines, BxPC-3 and Panc-1, was upregulated by high glucose in a concentration-dependent manner. Furthermore, the promoting effect of high glucose levels on EGF transcription and secretion but not its receptors in these PC cell lines was detected by using an EGF-neutralizing antibody and RT-PCR. In addition, the EGFR transactivation is induced by high glucose levels in concentration- and time-dependent manners in PC cells in the presence of the EGF-neutralizing antibody. These results suggest that high glucose promotes pancreatic cancer cell proliferation via the induction of EGF expression and transactivation of EGFR. Our findings may provide new insight on the links between high glucose level and PC in terms of the molecular mechanism and reveal a novel therapeutic strategy for PC patients who simultaneously suffer from either diabetes or hyperglycemia.

Topics: Cell Line, Tumor; Cell Proliferation; Diabetes Mellitus; Epidermal Growth Factor; ErbB Receptors; Gene Expression Regulation, Neoplastic; Glucose; Humans; Hyperglycemia; Pancreatic Neoplasms; Transcriptional Activation

Biologicals targeting epidermal growth factor (EGF) and interleukin 13 receptors not only react with overexpressed markers on cancer cells but also react with receptors on normal cells. Because we developed novel bispecific ligand-directed toxins synthesized by cloning EGF and interleukin 13 on the same molecule with toxin, our objective was to determine whether we could block normal receptors while still targeting receptors overexpressed on cancer cells, thereby decreasing toxicity while maintaining efficacy.. A method, toxicity blocking (ToxBloc), was developed in which a bolus intraperitoneal dose of recombinant EGF13 (without toxin) was given to mice approximately 15 to 20 minutes before DTEGF13. Experiments were then performed to determine whether the maximal tolerated dose (MTD) was reduced and whether we were still able to eliminate progression of aggressive human, metastatic, pancreatic cancer induced by orthotopic injection (OT) in nude mice.. ToxBloc permitted us to safely exceed the DTEGF13 maximal tolerated dose by 15-fold. This approach permitted repetitive high dosing with the bispecific ligand-directed toxin resulting in tumor regression (P < 0.01). Tumor effects were documented using a tumor imaging model in which OT tumor growth was monitored noninvasively in real time. ToxBloc was selective because other bispecific peptides did not block.. ToxBloc represents a new method of drug delivery and a potential solution to the problem of toxicity.

Topics: Animals; Cell Line, Tumor; Cell Proliferation; Diphtheria Toxin; Dose-Response Relationship, Drug; Drug Delivery Systems; Epidermal Growth Factor; Green Fluorescent Proteins; Humans; Interleukin-13; Male; Mice; Mice, Nude; Pancreatic Neoplasms; Recombinant Fusion Proteins; Time Factors; Treatment Outcome; Xenograft Model Antitumor Assays

Human cervical cancer oncoprotein 1 (HCCR-1), reported as a negative regulator of p53, is over-expressed in a variety of human cancers. However, it is yet unknown whether HCCR-1 plays any role in pancreatic cancer development. The aim of this study was to investigate the effect of epidermal growth factor on the expression of HCCR in pancreatic cancer cells, and to explore if PI3K/Akt/mTOR signaling pathway mediated this expression.. A polyclonal antibody against HCCR protein was raised by immunizing Balb/c mice with the purified recombinant protein pMBPc-HCCR. Tissue samples were constructed on a tissue chip, and the expression of HCCR was investigated by immunohistochemistry assay and Western blotting. Pancreatic cell line, PANC-1 cells were stably transfected with plasmids containing sense-HCCR-1 fragment and HCCR siRNA fragment. MTT and transwell assay were used to investigate the proliferation and invasion of stable tansfectants. The specific inhibitor of PI3K and mTOR was used to see if PI3K/mTOR signal transduction was involved in the induction of HCCR gene expression. A Luciferase assay was used to see if Akt can enhance the HCCR promoter activity.. HCCR was up-regulated in pancreatic tumor tissues (mean Allred score 4.51+/-1.549 vs. 2.87+/-2.193, P<0.01), especially with high expression in poorly differentiated pancreatic cancer. The growth of cells decreased in HCCR-1 siRNA transfected cells compared with vector transfectants. The number of invasion cells was significantly lower in HCCR-1 siRNA transfected cells (24.4+/-9.9) than that in vector transfectants (49.1+/-15.4). Treatment of PANC-1 cells with epidermal growth factor increased HCCR protein level in a dose- and time-dependent manner. However, application of LY294002 and rapamycin caused a dramatic reduction of epidermal growth factor-induced HCCR expression. Over-expression of exogenous constitutively active Akt increased the HCCR promoter activity; in contrast, dominant negative Akt decreased the promoter activity.. EGF-induced HCCR-1 over-expression is mediated by PI3K/AKT/mTOR signaling which plays a pivotal role in pancreatic tumor progression, suggesting that HCCR-1 could be a potential target for cancer therapeutics.

Topics: Animals; Antibodies; Blotting, Western; Cell Line, Tumor; Cell Movement; Cell Proliferation; Chromones; Epidermal Growth Factor; Humans; Immunohistochemistry; Intracellular Signaling Peptides and Proteins; Mice; Mice, Inbred BALB C; Morpholines; Neoplasm Invasiveness; Pancreatic Neoplasms; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Promoter Regions, Genetic; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Recombinant Proteins; RNA Interference; Signal Transduction; Sirolimus; Time Factors; Tissue Array Analysis; TOR Serine-Threonine Kinases; Transfection; Up-Regulation

To date, EGF 61*A/G, TGF-β1 -509*T/C and TNF-α -308*A/G gene polymorphisms have been not been analysed in pancreatic carcinoma. This study investigated the frequency of these gene polymorphisms among patients with cancer of the pancreatic head.. A total of 73 pancreatic head cancer patients and 117 cancer-free healthy people were recruited at the Surgical Department of the University Hospital Mannheim. Genomic DNA was isolated from peripheral blood and gene polymorphisms were analysed by PCR-RFLP.. The distribution of EGF 61*G/G homozygotes among pancreatic head cancer patients was more frequent than that in the control group (24.7% vs 11.1%, odds ratio (OR) = 2.618, 95% confidence interval (CI) = 1.195-5.738). In addition, the frequency of the G allele in the pancreatic head cancer patient group was also higher than that in the control group (45.9% vs. 33.3%, OR = 1.696, 95% CI = 1.110-2.592). No difference was found for the TGF-β1 -509 and TNF-α -308 genotypes among pancreatic head cancer patients and healthy controls.. The frequencies of the EGF 61*G/G genotype and G allele are significantly increased among patients with pancreatic head cancer. TGF-β1-509*T/C and TNF-α -308*A/G gene polymorphisms are not related to this cancer entity.

Topics: Adult; Aged; Aged, 80 and over; Case-Control Studies; Epidermal Growth Factor; Female; Humans; Male; Middle Aged; Pancreatic Neoplasms; Polymerase Chain Reaction; Polymorphism, Single Nucleotide; Transforming Growth Factor beta1; Tumor Necrosis Factor-alpha

Human Cripto-1, a membrane-bound protein, plays an important role during early embryogenesis and has oncogenic properties, including cell transformation and enhancement of invasion. Cripto-1 is up-regulated in various malignant tissues and premalignant lesions. However, Cripto-1 expression in intraductal papillary mucinous neoplasms (IPMNs) has yet to be reported. This study aimed to investigate Cripto-1 expression in IPMNs and evaluate the expression patterns according to the histological grade or phenotypic subclassification. Cripto-1 expression was evaluated by immunohistochemistry using 37 IPMN tissue samples and real-time RT-PCR analysis of seven frozen samples. Cripto-1 was up-regulated in 59.5% of IPMNs. Cripto-1 was positively stained in 3 of 4 (75%) adenomas, 12 of 19 (63.2%) borderline neoplasms, 5 of 11 (45.5%) non-invasive carcinomas and 2 of 3 (66.7%) invasive carcinomas. There was no correlation between Cripto-1 overexpression and the histological grade (P>0.05). Cripto-1 expression was significantly increased in pancreatobiliary- (4/5, 80%) and gastric-type (13/19, 68.4.2%) IPMNs compared with those of the intestinal type (2/10, 20%; P<0.01). Cripto-1 mRNA expression was higher in gastric- and pancreatobiliary-type IPMNs than in intestinal ones, supporting the immunohistochemical results. It is concluded that Cripto-1 overexpression is involved in the tumorigenesis of gastric- and pancreatobiliary-type IPMNs.

Topics: Adenocarcinoma, Mucinous; Adenocarcinoma, Papillary; Adult; Aged; Biomarkers, Tumor; Carcinoma, Pancreatic Ductal; Epidermal Growth Factor; Female; Gene Expression; GPI-Linked Proteins; Humans; Immunohistochemistry; Intercellular Signaling Peptides and Proteins; Male; Membrane Glycoproteins; Middle Aged; Neoplasm Proteins; Pancreatic Neoplasms; Reverse Transcriptase Polymerase Chain Reaction

Cancer metastasis involves tumor cells invading the surrounding tissue. Remodeling of tissue barriers depends on the ability of tumor cells to degrade the surrounding collagen matrix and then migrate through the matrix defects. Epidermal growth factor (EGF) has been shown to regulate tumor cell invasion through activation of matrix metalloproteinase-2 (MMP-2) in various tumor cell types. In the present study, we investigated the role of MMP-2 and the signaling pathway involved in EGF-promoted invasion by human pancreatic cancer cells PANC-1. Using specific inhibitors, we found that EGF stimulation of these tumor cells induced secretion and activation of the collagenase MMP-2, which was required for EGF-stimulated basement membrane degradation and cell invasion. Our results also indicate that signaling events downstream of EGF receptor involved PI3K- and Src-dependent activation of Rac1, which mediated the NADPH-generated reactive oxygen species responsible for MMP-2 secretion and activation.

Topics: Cell Line, Tumor; Enzyme Activation; Epidermal Growth Factor; Humans; Matrix Metalloproteinase 2; Matrix Metalloproteinase Inhibitors; NADP; Neoplasm Invasiveness; Pancreatic Neoplasms; Phosphatidylinositol 3-Kinases; rac1 GTP-Binding Protein; Reactive Oxygen Species; src-Family Kinases

Malignant ascites from pancreatic cancer patients has been reported to stimulate migration of pancreatic cancer cells through lysophosphatidic acid (LPA) and LPA(1) receptors. Indeed, ascites- and LPA-induced migration was inhibited by Ki16425, an LPA(1) and LPA(3) antagonist, in Panc-1 cells. Unexpectedly, however, in the presence of Ki16425, ascites and LPA inhibited cell migration in response to epidermal growth factor (EGF). The inhibitory migratory response to ascites and LPA was also observed in the cells treated with pertussis toxin (PTX), a G(i) protein inhibitor, and attenuated by a small interfering RNA (siRNA) specific to the LPA(2) receptor. The inhibitory LPA action was reversed by the regulators of G-protein signaling domain of p115RhoGEF, dominant-negative RhoA or C3 toxin. Indeed, LPA activated RhoA, which was attenuated by the siRNA against the LPA(2) receptor. Moreover, LP-105, an LPA(2) agonist, also inhibited EGF-induced migration in the PTX-treated cells. A similar inhibitory migration response through LPA(2) receptors was also observed in YAPC-PD, BxPC-3, CFPAC-1 and PK-1 pancreatic cancer cell lines. LPA also inhibited the invasion of Panc-1 cells in the PTX-treated cells in the in vitro Matrigel invasion assay. We conclude that LPA(2) receptors are coupled to the G(12/13) protein/Rho-signaling pathway, leading to the inhibition of EGF-induced migration and invasion of pancreatic cancer cells.

Topics: Ascites; Cell Line, Tumor; Cell Movement; Collagen; Drug Combinations; Epidermal Growth Factor; GTP-Binding Protein alpha Subunits, Gi-Go; Humans; Isoxazoles; Laminin; Lysophospholipids; Neoplasm Invasiveness; Pancreatic Neoplasms; Pertussis Toxin; Propionates; Proteoglycans; Receptors, Lysophosphatidic Acid; rhoA GTP-Binding Protein; RNA, Small Interfering

Tyrosine kinase receptors and integrins play essential roles in tumor cell invasion and metastasis. Previously, we showed that epidermal growth factor (EGF) stimulation of pancreatic carcinoma cells led to invasion and metastasis that was blocked by antagonists of integrin alpha(v)beta(5). Here, we show that EGF stimulates metastasis of carcinoma cells via a Src-dependent phosphorylation of p130 CAS leading to activation of Rap1, a small GTPase involved in integrin activation. Specifically, EGF receptor (EGFR)-induced Src activity leads to phosphorylation of a region within the CAS substrate domain, which is essential for Rap1 and alpha(v)beta(5) activation. This pathway induces alpha(v)beta(5)-mediated invasion and metastasis in vivo yet does not influence primary tumor growth or activation of other integrins on these cells. These findings show cross-talk between a tyrosine kinase receptor and an integrin involved in carcinoma cell invasion and metastasis and may explain in part how inhibitors of EGFR affect malignant disease.

Topics: Animals; Carcinoma; Cell Movement; Chick Embryo; DNA Primers; Epidermal Growth Factor; ErbB Receptors; Gene Knockdown Techniques; Humans; Inverted Repeat Sequences; Lung; Lung Neoplasms; Mutation; Neoplasm Invasiveness; Neoplasm Metastasis; Pancreatic Neoplasms; Polymerase Chain Reaction; Receptor Cross-Talk; Receptors, Vitronectin; RNA, Neoplasm; Tumor Cells, Cultured

This work evaluated SU11248 (sunitinib) as a potential therapeutic agent, alone or in combination with the cytotoxic agent gemcitabine or radiotherapy in a murine model of pancreatic cancer. Panc02 cells were injected subcutaneously into HsdOla/MF1 mice (n=222). Treatment was administered during 1 week: sunitinib (SUN), gemcitabine (GEM), radiotherapy (RT), RT+SUN and GEM+SUN. Mice were sacrificed 14 days after treatment. The effect on microvessel density (MVD) was measured by CD31 staining. Apoptosis (sFAS, cleaved caspase-3) and proangiogenic proteins (VEGF, PlGF, EGF) were measured with ELISA and immunohistochemistry. At day 14, tumors in all groups increased significantly despite treatment. Only after RT/SUN treatment tumor growth slowed down, although the accretion was still significant (P=0.033). Highest levels of apoptosis were seen in GEM/SUN, RT/SUN and RT treated mice (respectively P<0.001, P<0.01 and P<0.05 compared to placebo). MVD was lowest in RT/SUN treated mice [compared to placebo (P<0.05), GEM (P<0.05) and GEM/SUN (P<0.01)]. Highest VEGF levels were seen after RT and RT/SUN treatment [vs. placebo (P<0.001) and vs. other treatments (P<0.01 for all comparisons)]. GEM and SUN in monotherapy lead to an up-regulation of PlGF and EGF, respectively. In conclusion, the combination treatments RT/SUN and GEM/SUN result in a more potent anti-angiogenic and antitumor effect when compared to either treatment alone. Multitargeted angiogenesis inhibitor therapy with sunitinib combined with either radiotherapy or gemcitabine may be a novel approach for human pancreatic cancer.

Topics: Angiogenesis Inhibitors; Animals; Antimetabolites, Antineoplastic; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Caspase 3; Cell Line, Tumor; Chemotherapy, Adjuvant; Deoxycytidine; Epidermal Growth Factor; fas Receptor; Gemcitabine; Indoles; Male; Mice; Microvessels; Neovascularization, Pathologic; Pancreatic Neoplasms; Placenta Growth Factor; Pregnancy Proteins; Protein Kinase Inhibitors; Pyrroles; Radiotherapy, Adjuvant; Sunitinib; Time Factors; Vascular Endothelial Growth Factor A

Epidermal growth factor family members: EGF, EGFR and the c-erbB-2(HER-2/neu) are involved in the growth of pancreatic ductal carcinoma, its invasiveness and metastases. Similarly, proteins regulating apoptosis can influence the development of pancreatic cancer. The aim of our study was to assess the expressions of EGF, EGFR, c-erbB-2, Bax and Bcl-xL in comparison with anatomo-clinical parameters. We also analyzed the relationship between the epidermal growth factors and apoptosis-regulating proteins.. The levels of these proteins were determined immunohistochemically in 29 pancreatic ductal carcinoma cases.. We found no correlation of EGF, EGFR, c-erbB-2, Bax and Bcl-xL with age and gender of patients, or histological type and grade of malignancy (G). However, we observed a very strong correlation between EGF, EGFR, Bax, Bcl-xL and lymph node metastases (p=0.000, p=0.001, p=0.008, p=0.012, respectively) and between EGF, EGFR and distant metastases (p=0.002, p=0.008, respectively). Moreover, we found a correlation between Bcl-xL and c-erbB-2 (p=0.030) and between EGF and Bax (p=0.041).. These investigations seem to suggest that both epidermal growth factors (EGF, EGFR) and apoptosis-regulating proteins (Bax and Bcl-xL) play an essential role in lymph node involvement. Moreover EGF and EGFR are involved in distant metastases. The apoptosis markers appear to cooperate with epidermal growth factor proteins in the process of tumor spread.

Topics: Adult; Aged; Apoptosis; bcl-2-Associated X Protein; bcl-X Protein; Biomarkers, Tumor; Carcinoma, Pancreatic Ductal; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Male; Middle Aged; Pancreatic Neoplasms; Proto-Oncogene Proteins c-bcl-2

Little is known about the factors that enable the mobilisation of human mesenchymal stem cells (MSC) from the bone marrow into the blood stream and their recruitment to and retention in the tumour. We found specific migration of MSC towards growth factors present in pancreatic tumours, such as PDGF, EGF, VEGF and specific inhibitors Glivec, Erbitux and Avastin interfered with migration. Within a few hours, MSC migrated into spheroids consisting of pancreatic cancer cells, fibroblasts and endothelial cells as measured by time-lapse microscopy. Supernatant from subconfluent MSC increased sprouting of HUVEC due to VEGF production by MSC itself as demonstrated by RT-PCR and ELISA. Only few MSCs were differentiated into endothelial cells in vitro, whereas in vivo differentiation was not observed. Lentiviral GFP-marked MSCs, injected in nude mice xenografted with orthotopic pancreatic tumours, preferentially migrated into the tumours as observed by FACS analysis of green fluorescent cells. By immunofluorescence and intravital microscopic studies, we found the interaction of MSC with the endothelium of blood vessels. Mesenchymal stem cells supported tumour angiogenesis in vivo, that is CD31(+) vessel density was increased after the transfer of MSC compared with siVEGF-MSC. Our data demonstrate the migration of MSC toward tumour vessels and suggest a supportive role in angiogenesis.

Topics: Actins; Angiogenesis Inhibitors; Animals; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antineoplastic Agents; Benzamides; Bevacizumab; Cell Differentiation; Cell Movement; Cell Proliferation; Cells, Cultured; Cetuximab; Endothelium, Vascular; Epidermal Growth Factor; Fibroblasts; Humans; Imatinib Mesylate; Lentivirus; Male; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice; Mice, Nude; Muscle, Smooth; Neovascularization, Pathologic; Pancreatic Neoplasms; Piperazines; Platelet-Derived Growth Factor; Pyrimidines; Spheroids, Cellular; Transplantation, Heterologous; Umbilical Veins; Vascular Endothelial Growth Factor A

The expression of epidermal growth factor receptors in normal and tumor cells of the pancreas, the type and incidence of EGFR gene polymorphism were studied. EGFR gene expression in pancreatic adenocarcinoma cells significantly surpassed that in normal pancreatic cells. On the other hand, AA genome and A allele polymorphism in the EGF gene nucleotide pair G-A 61 is a significant risk factor for pancreatic cancer. The effect of AG-1478 preparation (a new-generation inhibitor of EGFR) on apoptosis and cell proliferation in pancreatic cancer was evaluated. This preparation is not inferior to 5FU by its apoptotic effect and significantly reduces cell proliferation, its antiproliferative effect being 1.5 times higher than that of 5FU.

Topics: Antineoplastic Agents; Apoptosis; Carcinoma; Cell Proliferation; Drug Evaluation, Preclinical; Epidermal Growth Factor; ErbB Receptors; Fluorouracil; Gene Frequency; Genetic Predisposition to Disease; Humans; Pancreatic Neoplasms; Polymorphism, Restriction Fragment Length; Polymorphism, Single Nucleotide; Quinazolines; Time Factors; Tumor Cells, Cultured; Tyrphostins

The EGF family of ligands and receptors plays an important role in the pathogenesis of pancreatic ductal adenocarcinoma (PDAC) and contributes to its aggressiveness. A number of molecular approaches have been developed to block these pathways, and studies have already proven the clinical benefit of this concept in PDAC. In the present study, we sought to determine the potential role of heregulins (HRGs), a family of EGF-like growth factors, in PDAC. Quantitative RT-PCR analysis revealed that HRGs as well as its signaling ErbB receptors were present in 4 of 4 human pancreatic cancer cell lines (PCCL). HRG-beta1 stimulated the growth of 3 of 4 PCCL, whereas HRG-alpha1 inhibited cell growth in 3 of 4 cell lines. Responses towards HRGs could in part be predicted by ErbB2 and ErbB3 expression levels. HRGs induced phosphorylation of different ErbB receptors as well as activation of MAPK, p38MAPK, JNK and PI3K in a cell- and ligand-specific manner. In vivo, HRG was upregulated in pancreatic cancer tissues and localized predominantly in the cancer cells. High HRG-beta levels but not HRG-alpha levels were associated with decreased patient survival. In conclusion, HRG is expressed by pancreatic cancer cells and influences pancreatic cancer cell growth and patient survival.

Topics: Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Enzyme Activation; Epidermal Growth Factor; ErbB Receptors; Gene Expression Regulation, Neoplastic; Humans; Immunoblotting; JNK Mitogen-Activated Protein Kinases; Nerve Tissue Proteins; Neuregulin-1; p38 Mitogen-Activated Protein Kinases; Pancreatic Neoplasms; Phosphatidylinositol 3-Kinases; Phosphorylation; Receptor, ErbB-2; Receptor, ErbB-3; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Survival Analysis

Tissue plasminogen activator (tPA) is the major activator of plasminogen in plasma. This serine protease is overexpressed by exocrine pancreas tumour cells, where it promotes tumour cell proliferation, growth, and invasion. Here we have explored the signalling pathways used by tPA to activate the proliferation of pancreatic cancer cells.. Transcriptional profiling on cDNA micro arrays was used to analyse the pattern of gene expression in response to tPA compared to the response to epidermal growth factor (EGF) and platelet derived growth factor (PDGF). Results were confirmed using different biochemical assays in which specific kinase inhibitors or RNA interference were used.. Transcriptional profiling showed that tPA modulates the expression of a set of genes commonly regulated by EGF, but distinct from the major set of genes modulated by PDGF. This suggested that tPA and EGF share common signalling pathways, a conclusion supported by further experimental evidence. Firstly, we found that tPA induced a rapid and transient phosphorylation of the EGFR. Secondly, specific EGFR kinase inhibitors, but not PDGFR kinase inhibitors, abolished the tPA induced phosphorylation of the ERK1/2 kinases and cell proliferation. The mitogenic activity of tPA was also inhibited by siRNA depletion of EGFR, thus confirming the involvement of this receptor in tPA triggered signalling. Thirdly, we show that the signalling and mitogenic effects of tPA require its proteolytic activity, the activity of the metalloprotease-9 and active hb-EGF.. Our results suggest that tPA induces proliferation by triggering a proteolytic cascade that sequentially activates plasmin, metalloprotease-9 (MMP-9) and hb-EGF. These events are required to activate the EGFR signalling pathway and cell proliferation.

Topics: Cell Division; Cell Line, Tumor; Enzyme Activation; Epidermal Growth Factor; ErbB Receptors; Extracellular Signal-Regulated MAP Kinases; Fibrinolysin; Fibrinolytic Agents; Gene Expression Regulation; Heparin-binding EGF-like Growth Factor; Humans; Intercellular Signaling Peptides and Proteins; Matrix Metalloproteinase 9; Metalloproteases; Pancreatic Neoplasms; Platelet-Derived Growth Factor; RNA Interference; RNA, Small Interfering; Signal Transduction; Tissue Plasminogen Activator; Transcription, Genetic

Epidermal growth factor receptor (EGFR) expression does not predict response to anti-EGFR therapy with erlotinib in pancreatic cancer patients. In the absence of known pancreatic cancer EGFR activating mutations, we sought to identify alternative factors, such as increased gene copy number (genomic gain) and ligand overexpression, which could be associated with aberrant EGFR pathway activation and improved response to targeted therapy.. EGFR gene copy number was analyzed by fluorescence in situ hybridization in nine pancreatic cancer cell lines and 31 pancreatic cancer surgical specimens. In vitro effects of erlotinib on tumor cell proliferation were tested. Tumor specimen EGFR expression levels were measured by reverse transcriptase-polymerase chain reaction. Expression of stimulating ligand (EGF), phosphorylated receptor (p-EGFR), and activated downstream adaptor proteins (p-Akt and p-ERK), were evaluated by immunohistochemistry and immunoblotting.. Pancreatic cancer EGFR genomic gain, in the form of high polysomy, was present in four of nine cell lines and in 10/24 (42%) of patients. Twenty-four patients (77%) expressed EGFR transcript, and of those, half displayed p-EGFR (35% of all patients). A majority of patients demonstrated downstream EGFR pathway activation, with 65% expressing p-Akt and 84% expressing p-ERK. EGFR-expressing tumors also expressed EGF, with exclusive tumor cell localization, suggesting autocrine stimulation of the EGFR pathway. EGF expression level was significantly greater in patients with increased EGFR gene copy number (P = 0.016).. Increased EGFR gene copy number and elevated EGF levels are present in a significant proportion of pancreatic cancer patients, and this may reflect increased EGFR pathway dependence with improved sensitivity to EGFR-targeted therapy.

Topics: Aged; Aged, 80 and over; Cell Line, Tumor; Cell Proliferation; Child, Preschool; Epidermal Growth Factor; ErbB Receptors; Erlotinib Hydrochloride; Extracellular Signal-Regulated MAP Kinases; Female; Gene Dosage; Gene Expression Regulation, Neoplastic; Humans; Infant; Kaplan-Meier Estimate; Male; Middle Aged; Pancreatic Neoplasms; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Quinazolines; Signal Transduction

To determine the effect of EGF on the invasiveness of pancreatic cancer cells and its related regulatory mechanism.. The effects of EGF on the proliferation, adhesion and invasion of pancreatic cancer cells were detected by WST-1 proliferation assay, adhesion assay and invasive assay. The expression of uPA was assayed by Western blot and RT-PCR. The activity of NF-kappaB was examined by EMSA.. EGF significantly increased the invasiveness of pancreatic cancer cells but did not affect cell proliferation or adhesion. Increased invasiveness was associated with the induction of uPA at both mRNA and protein levels. Furthermore, EGF stimulated the NF-kappaB binding activity, and pretreatment of cells with a NF-kappaB inhibitor, pyrrolidine dithiocarbamate, markedly attenuated EGF-induced NF-kappaB activation. Subsequently, the EGF-induced uPA expression and invasiveness were also inhibited by NF-kappaB inhibitor.. Our findings indicated that NF-kappaB-mediated up-regulation of uPA expression is responsible for EGF-induced invasiveness in pancreatic cancer cells, and implicate that such anti-NF-kappaB therapy with NF-kappaB inhibitors may contribute to the reduction of invasiveness of pancreatic cancer.

Topics: Cell Adhesion; Cell Line, Tumor; Cell Proliferation; Epidermal Growth Factor; Gene Expression Regulation, Neoplastic; Humans; Neoplasm Invasiveness; NF-kappa B; Pancreatic Neoplasms; Protein Binding; Pyrrolidines; RNA, Messenger; Thiocarbamates; Up-Regulation; Urokinase-Type Plasminogen Activator

Overexpression of epidermal growth factor (EGF) and EGF receptor has been associated with progression and invasive phenotype in pancreatic cancer. However, the underlying molecular mechanism by which EGF worked in pancreatic cancer cells has been poorly understood. In this study, we determined the effect of EGF on the invasiveness and the related regulatory mechanism in two pancreatic cancer cell lines NOR-P1 and KP4.. Invasion assay was performed to examine the invasiveness of tumor cells induced by EGF, and the expression of matrix metalloproteinase (MMP)-9, MMP-2, and plasminogen activator (uPA) was determined by reverse transcription-polymerase chain reaction and Western blot. Gelatin zymography was used to detect the activities of MMP-9 and MMP-2, and the nuclear factor-kappaB (NF-kappaB) binding activity was determined by electrophoretic mobility shift assay (EMSA).. EGF significantly increased the invasiveness of both cell lines but did not affect cell proliferation or adhesion. Increased invasiveness was associated with the induction of MMP-9 and uPA at both mRNA and protein levels. Furthermore, EGF stimulated NF-kappaB binding activity. Moreover, pretreatment of cells with NF-kappaB inhibitors, pyrrolidine dithiocarbamate or ibuprofen, markedly attenuated EGF-induced NF-kappaB activation. Subsequently, the EGF-induced MMP-9 and uPA expression and MMP-9 activity, as well as cell invasiveness, were also inhibited by these NF-kappaB inhibitors.. Our findings indicated that NF-kappaB-mediated MMP-9 and uPA induction was responsible for EGF-induced invasiveness in these pancreatic cancer cell lines and implicate that such anti-NF-kappaB therapy as the use of NF-kappaB inhibitors may contribute to the reduction of invasiveness of pancreatic cancer.

Topics: Cell Adhesion; Cell Division; Cell Line, Tumor; Epidermal Growth Factor; Humans; Matrix Metalloproteinases; Neoplasm Invasiveness; NF-kappa B; Pancreatic Neoplasms; Peptide Hydrolases

Cells form transient, circular dorsal ruffles or "waves" in response to stimulation of receptor tyrosine kinases, including epidermal growth factor receptor (EGFR) or platelet-derived growth factor receptor. These dynamic structures progress inward on the dorsal surface and disappear, occurring concomitantly with a marked reorganization of F-actin. The cellular function of these structures is largely unknown. Here we show that EGF-induced waves selectively sequester and internalize approximately 50% of ligand-bound EGFR from the cell surface. This process requires receptor phosphorylation, active phosphatidylinositol 3-kinase, and dynamin 2, although clathrin-coated pits or caveolae are not required. Epithelial and fibroblast cells stimulated with EGF sequestered EGFR rapidly into waves that subsequently generated numerous receptor-positive tubular-vesicular structures. Electron microscopy confirmed that waves formed along the dorsal membrane surface and extended numerous tubules into the cytoplasm. These findings characterize a structure that selectively sequesters large numbers of activated EGFR for their subsequent internalization, independent of traditional endocytic mechanisms such as clathrin pits or caveolae.

Topics: Amino Acid Sequence; Animals; Chlorocebus aethiops; COS Cells; Endocytosis; Epidermal Growth Factor; ErbB Receptors; Fibroblasts; HeLa Cells; Humans; Mice; Molecular Sequence Data; Pancreatic Neoplasms; Phosphatidylinositol 3-Kinases; Phosphorylation

A number of small GTPases are involved in cancer cell proliferation, migration and invasion, acting as molecular switches that cycle between GTP- and GDP-bound states. GTPase-activating proteins (GAPs) have been established as a major class of negative regulators of Rho GTPase signaling. To investigate the biological function of p190 RhoGAP toward RhoA in cancer cell invasion and metastasis, we generated a chimera made of the RhoGAP domain of p190 and the C-terminus of RhoA (p190-RhoA chimera), and transfected it into human pancreatic cancer cells, AsPC-1. Epidermal growth factor (EGF)-induced activation of RhoA, as well as RhoB and RhoC, to a lesser extent, was significantly inhibited in p190-RhoA chimera-transfected AsPC-1 cells compared with that of control cells (mock-infected), when assessed by pull-down assay for GTP-bound RhoA, RhoB, and RhoC, respectively. EGF-induced invasion of p190-RhoA chimera transfectants was significantly inhibited compared with that of mock-infected cells in a modified Boyden chamber assay. Furthermore, the mice injected intrasplenically with AsPC-1 cells that overexpressed the p190-RhoA chimera had a marked reduction in the number and size of metastatic nodules in the liver. These data suggest that the inhibitory action of p190 RhoGAP toward RhoA offers a novel approach to the treatment of invasion and metastasis of cancer cells.

Topics: Animals; Blotting, Western; Carrier Proteins; Cell Line, Tumor; Chimera; DNA-Binding Proteins; Enzyme Activation; Epidermal Growth Factor; GTPase-Activating Proteins; Guanine Nucleotide Exchange Factors; Humans; Mice; Mitogen-Activated Protein Kinases; Neoplasm Invasiveness; Neoplasm Transplantation; Neoplasms, Experimental; Pancreatic Neoplasms; Repressor Proteins; rho GTP-Binding Proteins; Transfection

Herein, we show that the hematopoietic-specific GEF VAV1 is ectopically expressed in primary pancreatic adenocarcinomas due to demethylation of the gene promoter. Interestingly, VAV1-positive tumors had a worse survival rate compared to VAV1-negative tumors. Surprisingly, even in the presence of oncogenic KRAS, VAV1 RNAi abrogates neoplastic cellular proliferation in vitro and in vivo, thus identifying Vav1 as a growth-stimulatory protein in this disease. Vav1 acts synergistically with the EGF receptor to stimulate pancreatic tumor cell proliferation. Mechanistically, the effects of Vav1 require its GEF activity and the activation of Rac1, PAK1, and NF-kappaB and involve cyclin D1 upregulation. Thus, the discovery of prooncogenic pathways regulated by Vav1 makes it an attractive target for therapeutic intervention.

Topics: Adenocarcinoma; Animals; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Cell Transformation, Neoplastic; Cyclin D1; DNA Methylation; Epidermal Growth Factor; Humans; Male; Mice; Mice, Nude; p21-Activated Kinases; Pancreatic Neoplasms; Promoter Regions, Genetic; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-vav; rac1 GTP-Binding Protein; Recombinant Fusion Proteins; Signal Transduction; Survival Rate

The human pancreatic cancer cell line (SW 1990) was exposed to 0.2 microg/ml of octreotide, galanin or serotonin as single, double or triple combinations. The tumor cells were checked at 3, 6 and 12 hours. In order to determine the number of viable cancer cells, the MTT-assay was used. Proliferation, apoptosis and the expression of epidermal growth factor were detected with immunohistochemistry using the avidin-biotin complex method. In addition, apoptosis was also detected with (TUNEL) method. The primary antibodies used were proliferating cell nuclear antigen (PCNA), anti-poly (ADP-ribose) polymerase (PARP) and anti-human epidermal growth factor. Single treatment with octreotide or serotonin reduced, the number of viable cells and the proliferation index at all observation times. Galanin increased the number of viable cells and the proliferation index. Whereas double treatments containing octreotide reduced the number of viable cells, those containing galanin increased the number. The effect of single, double or triple treatment on the apoptotic index obtained with both TUNEL method and PARP expression varied depending on the combination and the observation time. Octreotide did not affect the tumor cell expression of EGF. Galanin and serotonin, on the other hand, increased the expression of EGF. Whereas triple combination increased the expression of EGF after 6 h, all the other double combinations decreased this expression. It has been concluded that treatment with a combination of octreotide and serotonin may be useful in clinical settings.

Topics: Antineoplastic Agents; Antineoplastic Agents, Hormonal; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cell Survival; Drug Therapy, Combination; Epidermal Growth Factor; Galanin; Humans; Octreotide; Pancreatic Neoplasms; Poly(ADP-ribose) Polymerases; Proliferating Cell Nuclear Antigen; Serotonin

Pancreatic adenocarcinoma is a highly invasive neoplasm. Epidermal growth factor (EGF) and its receptor are over expressed in pancreatic cancer, and expression correlates with invasion and metastasis. We hypothesized that EGF receptor and integrin signalling pathways interact in mediating cellular adhesion and invasion in pancreatic cancer, and that invasiveness correlates temporally with detachment from extracellular matrix.. We tested this hypothesis by investigating the role of EGF in mediating adhesion to and invasion through collagen I and Matrigel in the metastatic pancreatic adenocarcinoma cell line Capan-1. Adhesion and invasion were measured using in vitro assays of fluorescently-labeled cells. Adhesion and invasion assays were also performed in the primary pancreatic adenocarcinoma cell line MIA PaCa-2.. EGF inhibited adhesion to collagen I and Matrigel in Capan-1 cells. The loss of adhesion was reversed by AG825, an inhibitor of erbB2 receptor signalling and by wortmannin, a PI3K inhibitor, but not by the protein synthesis inhibitor cycloheximide. EGF stimulated invasion through collagen I and Matrigel at concentrations and time courses similar to those mediating detachment from these extracellular matrix components. Adhesion to collagen I was different in MIA PaCa-2 cells, with no significant change elicited following EGF treatment, whereas treatment with the EGF family member heregulin-alpha elicited a marked increase in adhesion. Invasion through Matrigel in response to EGF, however, was similar to that observed in Capan-1 cells.. An inverse relationship exists between adhesion and invasion capabilities in Capan-1 cells but not in MIA PaCa-2 cells. EGF receptor signalling involving the erbB2 and PI3K pathways plays a role in mediating these events in Capan-1 cells.

Topics: Biocompatible Materials; Cell Adhesion; Cell Line, Tumor; Collagen; Collagen Type I; Dose-Response Relationship, Drug; Drug Combinations; Epidermal Growth Factor; ErbB Receptors; Humans; Integrin alpha2; Integrin beta1; Laminin; Neoplasm Invasiveness; Pancreatic Neoplasms; Phosphatidylinositol 3-Kinases; Proteoglycans; Receptor, ErbB-2; Signal Transduction; Time Factors

Dysregulation of the epidermal growth factor receptor (EGFR) signaling network has been frequently reported in pancreatic cancer. Inhibition of EGFR was associated with antitumor effects in both in vitro and in vivo studies of pancreatic cancer. We have previously reported the isolation and characterization of an EGFR-related protein (ERRP), which seems to be a negative regulator of EGFR. In the present investigation, we tested our hypothesis whether recombinant ERRP could be an effective inhibitor of growth of BxPC3 pancreatic cancer cells. Cell growth and apoptosis were measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and apoptosis ELISA assay, respectively, in the presence and absence of recombinant ERRP in BxPC3 cells. To evaluate activation of EGFR and its downstream signaling events, levels of phospho-EGFR, phospho-AKT, and phospho-extracellular signal-regulated kinase (phospho-ERK) were determined by Western blot analysis. NF-kappaB activity was measured by electrophoretic mobility shift assay. Our data show, for the first time, that ERRP inhibits the growth of BxPC3 cells in a dose- and time-dependent manner. The EGF or transforming growth factor (TGF)-alpha-induced stimulation of cell growth and activation of EGFR was also inhibited by ERRP. These changes were accompanied by a concomitant attenuation of activation of mitogen-activated protein (MAP) kinases, AKT, and NF-kappaB. ERRP also induced apoptosis as evidenced by increased poly(ADP-ribose) polymerase cleavage and reduction in procaspase3. From these results, we conclude that ERRP is a potent inhibitor of growth of BxPC-3 pancreatic cancer cells, which could be due to attenuation of EGFR cellular signaling processes. We also suggest that ERRP could be a potential therapeutic agent for pancreatic cancer.

Topics: Apoptosis; Caspase 3; Caspases; Cell Growth Processes; Cell Line, Tumor; Dose-Response Relationship, Drug; Drug Administration Schedule; Epidermal Growth Factor; ErbB Receptors; Glycoproteins; Humans; NF-kappa B; Pancreatic Neoplasms; Phosphorylation; Poly(ADP-ribose) Polymerases; Recombinant Proteins; Transforming Growth Factor alpha

Multiple signaling proteins may be aberrantly activated and/or overexpressed in pancreatic tumors, including the nonreceptor protein tyrosine kinase Src. The goal of this study was to determine the role of Src in regulating VEGF expression and angiogenic potential in pancreatic cancer cell lines.. Src activity was inhibited using the Src family kinase selective inhibitor PP2, and c-Src expression was down-regulated via siRNA. The activities of downstream signaling molecules phosphatidyl inositol 3'-kinase (PI3K) and p38 mitogen-activated protein kinase (MAPK) were disrupted via selective inhibitors. In vivo angiogenesis was assessed through the use of a gel-foam assay.. Inhibition of Src activity or expression decreases both constitutive and EGF-induced VEGF production. Both the PI3K/Akt and p38 MAPK pathways are activated in a Src family kinase-dependent fashion on EGF-R activation and are important for EGF-mediated VEGF production in pancreatic cancer cells. Additionally, media from Src-inhibited L3.6pl cells fail to promote angiogenesis into gel foams implanted subcutaneously into mice, whereas media from control cells promote a robust angiogenic response.. Src activity contributes to constitutive and EGF-induced VEGF expression and angiogenic potential in pancreatic cancer cells. Therefore, Src may be a viable target for antiangiogenesis therapy in pancreatic cancer.

Topics: Animals; Cell Line, Tumor; CSK Tyrosine-Protein Kinase; Epidermal Growth Factor; Female; Humans; MAP Kinase Signaling System; Mice; Mice, Inbred C3H; Neovascularization, Pathologic; p38 Mitogen-Activated Protein Kinases; Pancreatic Neoplasms; Phosphatidylinositol 3-Kinases; Protein-Tyrosine Kinases; Proto-Oncogene Proteins c-akt; RNA, Small Interfering; src-Family Kinases; Vascular Endothelial Growth Factor A

Pancreatic cystic neoplasms and ductal adenocarcinoma manifest diverse clinical features and prognoses, which might be related to cellular distribution of ezrin modulated through various trophic molecules.. Laboratory investigation and retrospective analysis.. Medical school-affiliated university hospital.. Patients with solid pseudopapillary tumor (SPT) (n = 12), mucinous cystic neoplasm (MCN) (n = 18), intraductal papillary mucinous tumor (IPMT) (n = 18), and ductal adenocarcinoma (PA) (n = 73) of the pancreas were studied. Expression of epidermal growth factor (EGF) and its receptor (EGFR) and ezrin were determined using immunohistochemistry. Epidermal growth factor receptor and ezrin expression in sodium butyrate (SB)-treated PA cell line PANC-1 was determined using immunocytochemistry. Messenger RNA expression of ezrin in the PANC-1 cell line treated with SB was determined using reverse transcriptase-polymerase chain reaction. Multivariate analysis of survival of patients with PA was performed.. None of 12 SPTs displayed synchronous expression of EGF and EGFR, while all 3 malignant SPTs displayed membranous ezrin expression. One of 18 MCNs displayed synchronous expression of EGF and EGFR, while 4 of 6 borderline malignant and 8 of 8 malignant MCNs displayed membranous ezrin expression. Two of 4 borderline malignant and 11 of 11 malignant IPMTs displayed synchronous expression of EGF and EGFR, and all borderline malignant and malignant IPMTs displayed membranous ezrin expression. Less differentiated PA displayed EGF, EGFR, and membranous ezrin expression more frequently compared with more differentiated PA. Epidermal growth factor receptor expression of PANC-1 cells decreased in an SB dose dependent manner, in which PANC-1 cells became more differentiated and membranous ezrin expression of PANC-1 cells decreased correspondingly. Messenger RNA expression of ezrin in PANC-1 cells also decreased in an SB dose dependent manner. Patients with PA with membranous ezrin expression had a poorer prognosis compared with those without (P = .02).. Membranous translocation of ezrin might play a role during malignant transformation of SPT, MCN, IPMT, and PA, which are either dependent on (IPMT and PA) or independent of (SPT and MCN) the EGF-EGFR pathway. Membranous ezrin expression represents a prognostic factor for PA.

Topics: Adenocarcinoma, Mucinous; Adolescent; Adult; Aged; Biomarkers, Tumor; Carcinoma, Pancreatic Ductal; Cytoskeletal Proteins; Disease Progression; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Immunoenzyme Techniques; Male; Middle Aged; Multivariate Analysis; Pancreatic Neoplasms; Phosphoproteins; Prognosis; Proportional Hazards Models; Retrospective Studies; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Survival Rate

Cytokines and growth factors in malignant ascites are thought to modulate a variety of cellular activities of cancer cells and normal host cells. The motility of cancer cells is an especially important activity for invasion and metastasis. Here, we examined the components in ascites, which are responsible for cell motility, from patients and cancer cell-injected mice. Ascites remarkably stimulated the migration of pancreatic cancer cells. This response was inhibited or abolished by pertussis toxin, monoglyceride lipase, an enzyme hydrolyzing lysophosphatidic acid (LPA), and Ki16425 and VPC12249, antagonists for LPA receptors (LPA1 and LPA3), but not by an LPA3-selective antagonist. These agents also inhibited the response to LPA but not to the epidermal growth factor. In malignant ascites, LPA is present at a high level, which can explain the migration activity, and the fractionation study of ascites by lipid extraction and subsequent thin-layer chromatography indicated LPA as an active component. A significant level of LPA1 receptor mRNA is expressed in pancreatic cancer cells with high migration activity to ascites but not in cells with low migration activity. Small interfering RNA against LPA1 receptors specifically inhibited the receptor mRNA expression and abolished the migration response to ascites. These results suggest that LPA is a critical component of ascites for the motility of pancreatic cancer cells and LPA1 receptors may mediate this activity. LPA receptor antagonists including Ki16425 are potential therapeutic drugs against the migration and invasion of cancer cells.

Topics: Adult; Animals; Ascites; Blotting, Northern; Cell Adhesion; Cell Division; Cell Line, Tumor; Cell Movement; Chromatography, Thin Layer; Dose-Response Relationship, Drug; Epidermal Growth Factor; Female; Humans; Isoxazoles; Lipids; Lysophospholipids; Male; Mice; Mice, Inbred BALB C; Middle Aged; Monoacylglycerol Lipases; Neoplasm Invasiveness; Neoplasm Metastasis; Neoplasm Transplantation; Pancreatic Neoplasms; Pertussis Toxin; Propionates; Receptors, G-Protein-Coupled; Receptors, Lysophosphatidic Acid; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Time Factors; Transfection

Hypoxia, frequently found in the center of solid tumor, is associated with resistance to chemotherapy by activation of signaling pathways that regulate cell pro-liferation, angiogenesis, and apoptosis. We determined whether hypoxia can increase the resistance of human pancreatic carcinoma cells to gemcitabine-induced apoptosis by activation of phosphatidylinositol 3'-kinase (PI3K)/Akt, MEK/mitogen-activated protein kinase (extracellular signal-regulated kinase) [MAPK(Erk) kinase (MEK)], and nuclear factor kappa B (NF-kappa B) signaling pathways.. We evaluated the phosphorylation of Akt and MAPK(Erk), DNA binding activity of NF-kappa B, and apoptosis induced by gemcitabine in L3.6pl human pancreatic cancer cells under normoxic and hypoxic conditions. We then examined the effects of the PI3K inhibitor LY294002, MEK inhibitor U0126, and the epidermal growth factor receptor tyrosine kinase inhibitor PKI 166 on these signaling pathways and induction of apoptosis.. Hypoxic conditions increased phosphorylation of Akt and MAPK(Erk) and NF-kappa B DNA binding activity in L3.6pl cells. The activation of Akt and NF-kappa B was prevented by LY294002, whereas the activity of MAPK(Erk), but not NF-kappa B, was inhibited by U0126. The increased activation of Akt, NF-kappa B, and MAPK(Erk) was inhibited by PKI 166. Under hypoxic conditions, L3.6pl cells were resistant to apoptosis induced by gemcitabine. The addition of LY294002 or PKI 166 abrogated cell resistance to gemcitabine, whereas U0126 only partially decreased this resistance.. These data demonstrate that hypoxia can induce resistance of pancreatic cancer cells to gemcitabine mainly through the PI3K/Akt/NF-kappa B pathways and partially through the MAPK(Erk) signaling pathway. Because PKI 166 prevented the activation of PI3K/Akt/NF-kappa B and MAPK(Erk) pathways, the combination of this tyrosine kinase inhibitor with gemcitabine should be an effective therapy for pancreatic cancer.

Topics: Antimetabolites, Antineoplastic; Antineoplastic Agents; Apoptosis; Blotting, Western; Butadienes; Cell Division; Cell Line, Tumor; Chromones; Deoxycytidine; Dose-Response Relationship, Drug; Enzyme Inhibitors; Epidermal Growth Factor; ErbB Receptors; Gemcitabine; Humans; Hypoxia; Mitogen-Activated Protein Kinases; Morpholines; Neovascularization, Pathologic; NF-kappa B; Nitriles; Oxygen; Pancreatic Neoplasms; Phosphatidylinositol 3-Kinases; Phosphorylation; Protein-Tyrosine Kinases; Pyrimidines; Pyrroles; Signal Transduction; Sp1 Transcription Factor; Time Factors; Tyrosine

In both pancreatic cancer and chronic pancreatitis, there is enhanced expression of mitogenic growth factors and their tyrosine kinase receptors, which have the capacity to activate mitogen-activated protein kinase (MAPK). In view of the important role of MAPK kinase phosphatase (MKP)-1 in the regulation of MAPK activation, the expression and functional role of MKP-1 was analyzed.. Pancreatic tissues were analyzed by Northern blotting, Western blotting, and immunohistochemistry. Pancreatic cancer cells were transfected with a full-length MKP-1 antisense construct. Growth characteristics and tumorigenicity in vivo and the effects of mitogenic growth factors on cell growth and MAPK activation were determined in transfected and control cells.. MKP-1 messenger RNA (mRNA) levels were increased in pancreatic cancer and chronic pancreatitis (CP) tissues. Moderate to strong MKP-1 immunoreactivity was present in the cancer cells, ductal cells of pancreatic intraepithelial neoplasia, and in tubular complexes in CP. Down-regulation of MKP-1 resulted in decreased anchorage-dependent and -independent growth of pancreatic cancer cells, and decreased tumorigenicity in a nude mouse tumor model. MKP-1 down-regulation led to decreased proliferation and sustained MAPK activation in response to mitogens.. Suppression of MKP-1 expression reduces the tumorigenicity of pancreatic cancer cells in vivo, suggesting that MKP-1 contributes to enhanced mitogenic signaling in pancreatic cancer cells.

Topics: Adolescent; Adult; Aged; Cell Cycle Proteins; Chronic Disease; Down-Regulation; Dual Specificity Phosphatase 1; Epidermal Growth Factor; Female; Gene Expression Regulation, Enzymologic; Humans; Immediate-Early Proteins; JNK Mitogen-Activated Protein Kinases; Male; Middle Aged; Mitogen-Activated Protein Kinases; Pancreas; Pancreatic Neoplasms; Pancreatitis; Phosphoprotein Phosphatases; Phosphorylation; Protein Phosphatase 1; Protein Tyrosine Phosphatases; RNA, Messenger; Transfection; Tumor Cells, Cultured

Pancreatic cancer remains a devastating disease, with 95% of all patients diagnosed with the disease dying within 2 years. The combined therapy using Erbitux, gemcitabine, and radiation caused complete tumor regression using a nude mouse model inoculated with pancreatic MiaPaCa-2 cells but only a delay in tumor growth with BxPC-3. We investigated the effect of prolonged Erbitux treatment to the sensitivity to gemcitabine and/or radiation and the epidermal growth factor receptor (EGFR) signal transduction pathway.. MiaPaCa-2 and BxPC-3 cells were cultured with or without Erbitux for 6 weeks. Cells were then treated with gemcitabine and/or radiation, harvested 48 h after treatment, and counted. Differences in EGFR expression after exposure to Erbitux were analyzed by FACS. Internalization rates of EGFR induced by Erbitux on these cell lines were determined using 125I-EGF binding assay after removal of Erbitux by acidic wash. Cell lysates were harvested after cells were stimulated with EGF, FGF, or IGF-1 respectively, and EGFR was immunoprecipitated using Erbitux. Samples were separated using SDS-PAGE and transferred to PVDF membrane. The membranes were probed with antibody against human growth factor receptor binding protein (Grb2) to detect the association of this Ras-MAPK upstream adaptor protein to EGFR. Cell lysates were also separated with SDS-PAGE and probed with rabbit anti-human PARP after samples were transferred to PVDF membrane. Expression of BAX and Bcl-(XL) were probed in the cells treated with or without Erbitux.. Proliferation assays indicated that prolonged exposure to Erbitux increased the sensitivities of MiaPaCa-2 to gemcitabine and radiation therapy (41 +/- 16% vs 52 +/- 9% for gemcitation, 28 +/- 9 vs 39 +/- 9% for combination; P = 0.015) but not for BxPC-3. FACS analysis showed that the expressed EGFR level decreased by about 42% on MiaPaCa 2 whereas no loss was seen on BxPC-3. Expression of BAX was upregulated on MiaPaCa-2. Poly (ADP-ribose) polymerase cleavage indicated the killing was mediated by apoptosis. Immunoblots showed that Grb2 was co-immunoprecipitated with EGFR after EGF stimulation. Incubation with Erbitux blocked Grb2 binding in MiaPaCa-2 but not BxPC 3. FGF transactivated EGFR down stream Ras-MAPK in the presence or absence of Erbitux. Internalization of EGFR induced by Erbitux did not differ between MiaPaCa-2 and BxPC-3.. 1) Association of Grb2 to EGFR in BxPC-3 induced by EGF in the presence of Erbitux indicates an alternate pathway of Ras-MAPK activation, which may be related with the tumor resistance to treatment; 2) transactivation of EGFR downstream Ras-MAPK pathway by FGF contributes the resistance to treatment; and 3) downregulation of EGFR may increase the response to therapy.

Topics: Adaptor Proteins, Signal Transducing; Adenocarcinoma; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Apoptosis; bcl-2-Associated X Protein; bcl-X Protein; Cell Division; Cetuximab; Cobalt Radioisotopes; Deoxycytidine; Electrophoresis, Polyacrylamide Gel; Epidermal Growth Factor; ErbB Receptors; Flow Cytometry; Gemcitabine; Gene Expression Regulation, Neoplastic; GRB2 Adaptor Protein; Humans; Immunosorbent Techniques; Iodine Radioisotopes; Mitogen-Activated Protein Kinases; Pancreatic Neoplasms; Proteins; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-bcl-2; Tumor Cells, Cultured

It was recently shown that neuropilin-1 (NRP-1), which was described originally as a receptor for the semaphorins/collapsins (ligands involved in neuronal guidance), is a coreceptor for vascular endothelial growth factor (VEGF) and increases the affinity of specific isoforms of VEGF to its receptor, VEGF-R2.. The authors investigated the expression and regulation of NRP-1 in human pancreatic adenocarcinoma specimens and cell lines.. Immunohistochemical analysis revealed that NRP-1 was expressed in 12 of 12 human pancreatic adenocarcinoma specimens but was absent in nonmalignant pancreatic tissue. Northern blot analysis revealed NRP-1 mRNA expression in 8 of 11 human pancreatic adenocarcinoma cell lines. NRP-1 mRNA expression was increased by epidermal growth factor (EGF) but not by tumor necrosis factor alpha in several of the human pancreatic adenocarcinoma cell lines studied. Treating human Panc-48 adenocarcinoma cells with EGF activated Akt and Erk but not P-38. Blockade of the phosphatidylinositol-3 kinase (PI-3K)/Akt, mitogen-activated protein kinase (MAPK)/Erk, or P-38 pathways abrogated EGF-induced NRP-1 expression. Finally, EGF receptor blockade in vivo led to a decrease in NRP-1 expression in an orthotopic model of human pancreatic carcinoma.. NRP-1 is expressed in most human pancreatic adenocarcinomas and cell lines but not in nonmalignant pancreatic tissue. EGF regulates NRP-1 expression through the PI-3K/Akt and MAPK/Erk signaling pathways, and blockade of the EGF receptor is associated with decreased expression of NRP-1 in vivo. NRP-1 may act as a coreceptor for VEGF in pancreatic carcinoma, as it does in other tumor systems, thereby enhancing angiogenesis and the effect of VEGF on the growth of pancreatic adenocarcinoma.

Topics: Adenocarcinoma; Blotting, Northern; Dose-Response Relationship, Drug; Epidermal Growth Factor; Humans; Immunohistochemistry; Keratins; Mitogen-Activated Protein Kinases; Neuropilin-1; Pancreas; Pancreatic Neoplasms; Phosphatidylinositol 3-Kinases; Receptors, Vascular Endothelial Growth Factor; RNA, Messenger; Signal Transduction; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha

Pancreatic carcinoma still has the highest mortality rate in comparison to any other malignancy. Major reasons are late detection of disease, highly aggressive tumor growth and the early formation of metastases. Thus, novel effective therapies are urgently needed to improve the outcome of the patients. Overexpression of the epidermal growth factor receptor (EGFR) and its ligands has been implicated in the oncogenesis of pancreatic carcinoma and associated with an unfavorable prognosis. Consequently, the EGFR represents a specific target antigen suitable for immunotherapy. We generated a recombinant immunotoxin by fusing the anti-EGFR single chain fragment 425(scFv) to a truncated mutant of Pseudomonas Exotoxin A (ETA'). Using the expression vector pBM1.1, functional 425(scFv)-ETA' was periplasmically expressed under osmotic stress conditions in the presence of compatible solutes. The 72 kDa His10-tagged fusion protein was purified by a combination of metal-ion affinity and molecular size chromatography. Binding activity and specificity of the immunotoxin to the EGFR-positive pancreatic carcinoma cell line L3.6pl was confirmed by flow cytometry and ELISA. Finally, 425(scFv)-ETA' showed significant toxicity toward this cell line reaching 50% inhibition of cell proliferation at a concentration (IC50) of 7.5 ng/ml. This is the first report documenting the specific cytotoxicity of a recombinant immunotoxin towards metastatic pancreatic carcinoma cells, suggesting that EGFR-specific antibody toxins may become valuable therapeutic reagents for the treatment of pancreatic carcinoma.

Topics: Carcinoma; Cell Division; Cell Line, Tumor; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Epidermal Growth Factor; Escherichia coli; Flow Cytometry; Humans; Immunoglobulin Variable Region; Immunotherapy; Immunotoxins; Inhibitory Concentration 50; Ligands; Models, Genetic; Mutation; Neoplasm Metastasis; Pancreatic Neoplasms; Plasmids; Prognosis; Recombinant Fusion Proteins; Recombinant Proteins; Single-Chain Antibodies

The epidermal growth factor (EGF) receptor (EGFR) family consists of four transmembrane tyrosine kinases that undergo homodimerization and heterodimerization. Pancreatic cancers overexpress these receptors. To examine the effects of EGFR blockade on pancreatic cancer cell mitogenesis in relation to activation of specific signaling pathways, four pancreatic cancer cell lines were infected with an adenoviral vector encoding a truncated EGFR (AdtrEGFR), and activation of signaling was assessed with the mitogen-activated protein kinase (MAPK) kinase inhibitors PD98059 and U0126, the p38 MAPK inhibitor SB203580, and the c-Jun NH2-terminal kinase inhibitor SP600125. In all four cell lines, AdtrEGFR markedly attenuated EGF and heparin-binding EGF-dependent cell growth, EGFR family tyrosine phosphorylation, and phosphorylation of MAPK, c-Jun NH2-terminal kinase, p38 MAPK, and activating transcription factor 2. AdtrEGFR did not alter fibroblast growth factor 2 actions on mitogenesis. In ASPC-1, PANC-1, and T3M4 cells, PD98059 and U0126 inhibited MAPK kinase activation but not EGF-stimulated mitogenesis, whereas SB203580 inhibited EGF-stimulated mitogenesis, p38 MAPK activation, and MAPK-activated protein kinase 2 activation, without attenuating the mitogenic effect of insulin-like growth factor 1. In contrast, in COLO-357 cells, PD98059, and U0126, but not SB203580, inhibited EGF-stimulated mitogenesis, whereas SP600125 did not alter the mitogenic actions of EGF in any of the cell lines. Thus, EGF promotes proliferation via the MAPK in COLO-357 cells but via p38 MAPK in ASPC-1, PANC-1, and T3M4 cells, and whereas EGFR activation leads to the activation of all four members of the EGFR family in these cells, downstream signaling is efficiently blocked by AdtrEGFR.

Topics: Adenoviridae; Cell Division; Enzyme Inhibitors; Epidermal Growth Factor; ErbB Receptors; Genetic Vectors; Heparin-binding EGF-like Growth Factor; Humans; Intercellular Signaling Peptides and Proteins; MAP Kinase Signaling System; Pancreatic Neoplasms; Phosphorylation; Tumor Cells, Cultured

The pancreatic cystic neoplasms, including solid pseudopapillary tumour (SPT), mucinous cystic neoplasm (MCN), and intraductal papillary mucin producing tumour (IPMT), have their characteristic clinicopathological features. A systematic investigation of oestrogen receptor (OR), progesterone receptor (PR), trefoil factor 1(TFF1), and epidermal growth factor and its receptor (EGF and EGFR) expressed in pancreatic cystic neoplasms and pancreatic ductal adenocarcinoma was determined to elucidate their corresponding sex and age predilection, cell origin, and pathway of malignant transformation.. Surgical specimens of SPT (n=10), MCN (n=12), IPMT (n=10), and ductal adenocarcinoma (n=20) were studied. The expression of OR, PR, TFF1, EGF, and EGFR were each determined in each disease entity using monoclonal antibodies by immunohistochemical method. The results were correlated with the clinicopathological data.. PR was expressed in all 10 SPT, whereas OR was expressed in none of 10 SPT. TFF1 was not or weakly expressed in SPT. Although EGF was strongly expressed in seven of 10 SPT, synchronous expression of EGF and its receptor was expressed in none of 10 SPT. Of the 12 MCN, six had PR expression in the stroma cells but not in the neoplastic epithelium, seven had a moderate or strong expression of TFF1, and 10 had no or weak EGFR expression, irrespective of their benigneity or malignancy. Synchronous expression of EGF and EGFR was observed in only one of 12 MCN. Among 10 IPMT, TFF1 and EGFR were moderately or strongly expressed in all six malignancies, whereas TFF1 and EGFR were not or weakly expressed in three of four benigneity. Of 20 ductal adenocarcinomas, TFF1 and EGFR were moderately or strongly expressed in 16 and 12, respectively. Synchronous expression of EGF and EGFR was observed in six of 10 IPMT and nine of 20 ductal adenocarcinoma, respectively.. PR was uniquely expressed in SPT, and OR and PR were expressed in stroma of MCN, reflecting their sex and age predilection. TFF1 expression was related to EGFR such as in IPMT and ductal adenocarcinoma, not related to EGFR such as in MCN, and not related to hormonal receptors such as in SPT. EGF and its receptor might play a part in the malignant transformation of IPMT and ductal adenocarcinoma, but not of SPT and MCN.

Topics: Adult; Aged; Cystadenocarcinoma, Mucinous; Epidermal Growth Factor; ErbB Receptors; Female; Growth Substances; Humans; Immunohistochemistry; Male; Middle Aged; Neoplasm Proteins; Pancreatic Neoplasms; Peptides; Proteins; Receptors, Cell Surface; Receptors, Estrogen; Receptors, Progesterone; Trefoil Factor-1; Tumor Suppressor Proteins

CD97 expression is related closely to the dedifferentiation and tumor stage in thyroid carcinomas. We systematically examined the role of CD97 and its closest relative, EMR2, in normal and malignant gastric, esophageal, and pancreatic tissue. The normal tissues were EMR2-, whereas CD97 was expressed slightly in the parietal cells of gastric mucosa and in exocrine pancreatic cells. Interestingly, intralobular and interlobular pancreatic ducts were CD97+. All tumors were EMR2-. CD97 was expressed by 44 of 50 gastric, 14 of 18 pancreatic, and 10 of 13 esophageal carcinomas. Of the 44 gastric cancers, 27 showed disseminated or scattered tumor cells at the invasion front with stronger CD97 expression than tumor cells located in solid tumor formations. There was no correlation between CD97 levels in the tumors or soluble CD97 in the serum samples and the clinicopathologic features of the patients. Taken together, significant numbers of gastric, esophageal, and pancreatic carcinomas are CD97+, whereas its homolog, EMR2, does not have any role in such tumors.

Topics: Aged; Antigens, CD; Biomarkers, Tumor; Carcinoma; Epidermal Growth Factor; Esophageal Neoplasms; Female; Humans; Immunohistochemistry; Male; Membrane Glycoproteins; Middle Aged; Pancreatic Neoplasms; Receptors, G-Protein-Coupled; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Neoplasm; Stomach Neoplasms; Tumor Cells, Cultured

Inhibition of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase blocks the mevalonate metabolic pathway, which is necessary for the isoprenylation of a number of small guanosine triphosphatases. We examined the effects of HMG-CoA reductase inhibitors, fluvastatin and lovastatin, on human pancreatic cancer cell invasion in vitro and experimental liver metastasis in vivo.. Cell invasion was studied in a modified Boyden chamber assay. The translocation of RhoA was assessed by immunoblotting. Experimental liver metastases were induced in nude mice by intrasplenic inoculation of ASPC-1 human pancreatic cancer cells.. Fluvastatin and lovastatin inhibited the in vitro cancer cell invasion induced by epidermal growth factor (EGF) in a manner sensitive to C3 transferase, a specific inhibitor of Rho. Treatment of ASPC-1 cells with fluvastatin markedly attenuated the EGF-induced translocation of RhoA from the cytosol to the membrane fraction and caused cell rounding. The effects of fluvastatin could be reversed by the addition of all-trans-geranylgeraniol. Administration of fluvastatin to nude mice reduced both metastatic tumor formation in the liver and the growth of established liver metastases at doses recommended for the treatment of hypercholesterolemia in humans.. HMG-CoA reductase inhibitors can be antimetastatic agents with the potential for useful clinical applications.

Topics: Adenocarcinoma; Animals; Cell Division; Cell Membrane; Cytosol; Epidermal Growth Factor; Fatty Acids, Monounsaturated; Fluvastatin; Humans; Hydroxymethylglutaryl CoA Reductases; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypercholesterolemia; Indoles; Liver Neoplasms, Experimental; Lovastatin; Mice; Mice, Nude; Neoplasm Invasiveness; Pancreatic Neoplasms; rhoA GTP-Binding Protein; Tumor Cells, Cultured

Somatostatin, or its structural analog SMS 201-995 (SMS), is recognized to exert a growth-inhibitory action in rat pancreas, but the cellular mechanisms are not completely understood. This study was undertaken to evaluate the effect of SMS on p42/p44 MAP kinases and phosphatidylinositol 3-kinase activation and to analyze expression of some cell cycle regulatory proteins in relation to pancreatic acinar cell proliferation in vivo (rat pancreas), as well as in the well-established tumoral cell line AR4-2J. We herein report that: 1) SMS inhibits caerulein-induced pancreatic weight and DNA content and abolishes epidermal growth factor (EGF)-stimulated AR4-2J proliferation; 2) SMS only moderately reduces the stimulatory effect of caerulein on p42/p44 MAP kinase activities in pancreas and has no effect on EGF-stimulated MAP kinase activities in AR4-2J cells; 3) SMS repressed caerulein-induced Akt activity in normal pancreas; 4) SMS has a strong inhibitory action on cyclin E expression induced by caerulein in pancreas and EGF in AR4-2J cells and as expected, the resulting cyclin E-associated cyclin-dependent kinase (cdk)2 activity, as well as pRb phosphorylation, are blunted by SMS treatment in both models; and 5) SMS suppresses mitogen-induced p27(Kip1) down-regulation, as well as marginally induces p21(Cip) expression. Thus, our data suggest that somatostatin-induced growth arrest is mediated by inhibition of phosphatidylinositol 3-kinase pathway and by enhanced expression of p21(Cip) and p27(Kip1), leading to repression of pRb phosphorylation and cyclin E-cdk2 complex activity.

Topics: Animals; Cell Cycle; Cell Division; Cell Line; Ceruletide; Enzyme Activation; Epidermal Growth Factor; Male; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinases; Octreotide; Pancreas; Pancreatic Neoplasms; Phosphorylation; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Rats; Rats, Sprague-Dawley; Somatostatin; Tumor Cells, Cultured

In-vitro and in-vivo studies have shown that autocrine growth factors and receptors are frequently expressed in human malignancies. Few of these studies, however, provide evidence that the identified autocrine pathway is functional. In this study, a functional autocrine growth pathway in pancreatic cancer has been identified using an in-vitro cell culture system. When pancreatic cancer cells were grown without change of medium, proliferation was greater than when either medium was replaced frequently (HPAF, CAPAN-2, PANC-1 or SW1990) or cells were grown in the presence of the EGF receptor tyrosine kinase inhibitor AG1478 or the MEK inhibitor PD098059 (HPAF or CAPAN-2). Activity of extracellular-regulated kinases (ERK) 1 and 2 and c- jun and c- fos mRNA levels were significantly elevated in CAPAN-2 cells cultured continuously in serum-free medium. Collectively, the observations indicate that the EGF receptor and the ERK MAP kinase pathway mediate autocrine signals. In contrast to previous reports, the GRP and IGF-I receptors were shown not to be required for autocrine effects on pancreatic cancer cell proliferation. Autocrine stimulation of the EGF receptor can contribute to sustained mitogenic activity and proliferation of pancreatic cancer cells.

Topics: Cell Division; Culture Media, Serum-Free; Enzyme Activation; Enzyme Inhibitors; Epidermal Growth Factor; ErbB Receptors; Flavonoids; Gastrin-Releasing Peptide; Gene Expression Regulation, Neoplastic; Humans; Insulin-Like Growth Factor I; MAP Kinase Signaling System; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinases; Pancreatic Neoplasms; Quinazolines; Substrate Specificity; Transcription Factor AP-1; Tumor Cells, Cultured; Tyrphostins

Overexpression of autocrine growth factors and their receptors has been reported in many human cancers. The study of autocrine-regulated pathways using in vitro culture systems can be hindered by the presence of fetal bovine serum in culture medium. A human pancreatic cancer cell line (HPAF) was slowly weaned from its dependence on fetal bovine serum and subsequently maintained in serum-free conditions. Growth factor secretion studies showed that production of autocrine growth factors such as transforming growth factor alpha, gastrin-releasing peptide, and insulin-like growth factor I from weaned cells increased three times compared with nonweaned cells (p < 0.01). The epidermal growth factor and gastrin-releasing peptide receptor densities were also increased in weaned cells (2 times and 2.5 times, respectively, p < 0.05). The proliferation of weaned cells cultured continuously in the same medium was significantly greater than of nonweaned cells (p < 0.05). Collectively, these data indicate that weaned pancreatic cancer cells can proliferate in the absence of serum by up-regulating autocrine pathways.

Topics: Binding, Competitive; Bombesin; Cell Division; Culture Media, Conditioned; Culture Media, Serum-Free; Epidermal Growth Factor; ErbB Receptors; Gastrin-Releasing Peptide; Growth Substances; Humans; Insulin-Like Growth Factor I; Pancreatic Neoplasms; Receptors, Bombesin; RNA, Messenger; Transforming Growth Factor alpha; Tumor Cells, Cultured

Topics: Cell Division; Cell Line; Emulsions; Epidermal Growth Factor; Fatty Acids, Omega-3; Humans; Membrane Proteins; Pancreatic Neoplasms; Phosphorylation; Signal Transduction; Tumor Cells, Cultured

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors prevent the conversion of HMG-CoA to mevalonate and thereby inhibit the synthesis of other products derived from this metabolite. This includes a number of small prenylated GTPases involved in cell growth, motility, and invasion. We studied the effect of HMG-CoA reductase inhibitors (fluvastatin and lovastatin) on in vitro invasion of human pancreatic cancer PANC-1 cells. Epidermal growth factor (EGF) induced a dose-dependent increase of PANC-1 cell invasion in a modified Boyden chamber assay. Stimulation of cancer cells with EGF induced translocation of RhoA from the cytosol to the membrane fraction and actin stress fiber assembly. Furthermore, Clostridium botulinum C3 transferase, a specific inhibitor of Rho, inhibited the ability of EGF to promote invasion, indicating that EGF-induced cancer cell invasion is regulated by Rho signaling. Treatment of PANC-1 cells with fluvastatin markedly attenuated EGF-induced translocation of RhoA from the cytosol to the membrane fraction and actin stress fiber assembly, whereas it did not inhibit the tyrosine phosphorylation of EGF receptor and c-erbB-2. The induction of cancer cell invasion by EGF was inhibited by the addition of fluvastatin or lovastatin in a dose-dependent manner. The effects of fluvastatin or lovastatin on cell morphology and invasion were reversed by the addition of all-trans-geranylgeraniol but not by the addition of all-trans-farnesol. These results suggest that HMG-CoA reductase inhibitors affect RhoA activation by preventing geranylgeranylation, which results in inhibition of EGF-induced invasiveness of human pancreatic cancer cells.

Topics: Actins; ADP Ribose Transferases; Botulinum Toxins; Cell Membrane; Cytoskeleton; Cytosol; Epidermal Growth Factor; Fatty Acids, Monounsaturated; Fluvastatin; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Indoles; Neoplasm Invasiveness; Pancreatic Neoplasms; rhoA GTP-Binding Protein; Tumor Cells, Cultured

The human mucin gene MUC4 encodes a large transmembrane mucin that is thought to play important roles in tumor cell biology and that is overexpressed in human pancreatic carcinomas. In this report, we describe the structure and functional activity of the 5'-flanking region, including 1.0 kilobase of the promoter. The long 5'-untranslated region (2.7 kilobases) is characterized by a high content of GC in its 3'-end. The first TATA box was located at -2672/-2668. Multiple transcription start sites and a high density of putative binding sites for Sp1 (GC and CACCC boxes), AP-1/-2/-4, cAMP-responsive element-binding protein, GATA, GR, and STAT transcription factors were found within the 5'-flanking region. Transcriptional activity of the promoter was assessed using pGL3-luciferase deletion mutants in two MUC4-expressing (CAPAN-1 and CAPAN-2) and one nonexpressing (PANC-1) pancreatic cancer cell line. Two highly active fragments (-219/-1 and -2781/-2572) that drive MUC4 transcription in CAPAN-1 and CAPAN-2 cells were identified. Gel retardation assays indicated that Sp1 and Sp3 bind to cognate cis-elements found in the 5'-flanking region and that Sp1 transactivates, whereas Sp3 inhibits the GC-rich region (-464/-1) in CAPAN-2 cells. Activation of protein kinase C with phorbol ester and treatment of cells with epidermal growth factor and transforming growth factor-alpha resulted in up-regulation of the promoter. Tumor necrosis factor-alpha and interferon (IFN)-gamma inflammatory cytokines had no or mild effect on MUC4 transcriptional activity when used alone. However, a very strong synergistic effect (10-12-fold activation) between IFN-gamma and tumor necrosis factor-alpha or IFN-gamma and transforming growth factor-alpha was obtained in CAPAN-2 cells. Altogether these results demonstrate that the 5'-flanking region of MUC4 contains epithelial cell-specific, positive, and negative regulatory cis-elements, that Sp1/Sp3 are important regulators of MUC4 basal expression, and that its regulation in pancreatic cancer cells involves complex interplay between several signaling pathways.

Topics: 5' Untranslated Regions; Base Sequence; Cloning, Molecular; DNA-Binding Proteins; Epidermal Growth Factor; Gene Expression Regulation, Neoplastic; Humans; Interferon-gamma; Molecular Sequence Data; Mucin-4; Mucins; Pancreatic Neoplasms; Promoter Regions, Genetic; Protein Kinase C; Sp1 Transcription Factor; Sp3 Transcription Factor; TATA Box; Transcription Factors; Transcription, Genetic; Transforming Growth Factor alpha; Tumor Cells, Cultured

Mutation of the K-ras gene is thought to be an early and important event in pancreatic carcinogenesis. In order to study the role of this molecular alteration in the transition from the normal to the neoplastic pancreatic cell, bovine pancreatic duct cells were first immortalized by SV40 large T antigen (Ag) complementary (c)DNA transfection and then transfected with a mutated K-ras gene. As did primary duct cells, the immortalized duct cells (more than 100 passages) expressed cytokeratins, carbonic anhydrase type-II, cystic fibrosis transmembrane conductance regulator (CFTR), and multidrug resistance (mdr). They grew as a single layer after transplantation under plastic domes and formed three-dimensional structures resembling ducts when grown on Matrigel. Cell growth was stimulated by insulin, epidermal growth factor (EGF), transforming growth factor (TGF)-alpha, but cells did not respond to gastrin and CCK-8. They did not form colonies in soft agar nor did they form tumors in nude mice. Immortalized cells transfected with mutated K-ras acquired the ability to form tumors after orthotopic injection into the nude mouse pancreas. It is concluded that SV 40 immortalized bovine pancreatic

Topics: Animals; Antigens, Polyomavirus Transforming; Biomarkers; Cattle; Cell Division; Cell Line, Transformed; Cell Transformation, Neoplastic; Clone Cells; DNA, Complementary; Epidermal Growth Factor; Epithelial Cells; Fluorescent Antibody Technique, Indirect; Genes, ras; Insulin; Mice; Mice, Nude; Mutation; Pancreatic Ducts; Pancreatic Neoplasms; Polymerase Chain Reaction; RNA, Viral; Transfection; Transforming Growth Factor alpha

Previous studies demonstrated that heparin-binding epidermal growth factor-like growth factor (HB-EGF) contributes to carcinogenesis and carcinoma progression. In this study, we investigated its expression in human pancreatic adenocarcinoma.. We immunohistochemically investigated the expression of HB-EGF in 40 cases of pancreatic adenocarcinoma.. HB-EGF was only occasionally and faintly expressed in normal and hyperplastic pancreas duct epithelia. In pancreatic adenocarcinoma, 22 (55.0%) of the 40 cases were classified as positive for HB-EGF. Its expression was more frequently observed in cases with a low Ki-67 labeling index, well differentiated. early stage, small size, without lymph node metastasis and low EGF-R expression.. These results suggest that HB-EGF mainly plays a role in early phase of the progression of pancreatic adenocarcinoma.

Topics: Adenocarcinoma; Aged; Epidermal Growth Factor; ErbB Receptors; Female; Heparin-binding EGF-like Growth Factor; Humans; Hyperplasia; Immunohistochemistry; Intercellular Signaling Peptides and Proteins; Ki-67 Antigen; Male; Middle Aged; Pancreas; Pancreatic Neoplasms; Reference Values

AstraZeneca is developing ZD-1839, an inhibitor of epidermal growth factor receptor 1 (EGFR1) tyrosine kinase, for potential treatment of cancers which overexpress EGF receptors, including non-small cell lung cancer (NSCLC) and pancreatic cancer [196279], [270898]. Phase III studies had started by August 2000 [349551], [350295], [353050], [377656], with first results being expected at the 2001 meetings of the American Association for Cancer Research (AACR) and the American Society for Clinical Oncology (ASCO). The US FDA has issued ZD-1839 with Fast Track status [350295], [353050]. In September 2000, the company expected global NDA filing to take place at the end of 2001, with launch in the next four to five years [383469]. In January 1999, ABN Amro predicted sales of US $25 million in 2004 rising to $82 million in 2005 [316250]. In March 1999, Lehman Brothers predicted a 30% probability that the drug would reach worldwide markets and be launched onto the market in 2004 [336599]. In June 2000, Deutsche Bank predicted sales of US $8 million in 2002, rising to $100 million in 2003 [374500]. In September 2000, analysts Merrill Lynch predicted a launch in 2002 with sales estimated at UK 50 million pounds, rising to 360 million pounds in 2004, while in December 2000, the analysts predicted a filing date in the fourth quarter of 2001 [383742], [396280]. Also in December 2000, Lehman Brothers predicted a filing date late in 2001, and a possible Fast Track review. They also estimated peak sales of US $1 billion [394606].

Topics: Anemia; Animals; Antineoplastic Agents; Carcinoma, Non-Small-Cell Lung; Clinical Trials, Phase I as Topic; Diarrhea; Disease Models, Animal; Drug Evaluation, Preclinical; Drug Tolerance; Drugs, Investigational; Economics, Pharmaceutical; Epidermal Growth Factor; ErbB Receptors; Gefitinib; Humans; Lung Neoplasms; Nausea; Pancreatic Neoplasms; Quinazolines; Tumor Cells, Cultured

We recently showed that cyclin D1 is overexpressed in human pancreatic carcinoma cells, and that this overexpression correlates significantly with a poor prognosis.. To assess the interrelations of epidermal growth factor (EGF), EGF receptor (EGFR), and cyclin D1 in human pancreatic carcinoma.. In pancreatic carcinoma cell lines (BxPC-3, AsPC-1), cell cycle analysis revealed an increase in cells in the S/G1 phase between 18 and 30 hours after stimulation with 50 ng/mL EGF. Cyclin D1 mRNA increased after 2 hours, corresponding to an increase in cyclin D1 protein, with the maximum level between 7.5 and 10 hours after stimulation, as demonstrated by Western blot analysis. We performed immunohistochemical analysis on 61 adenocarcinoma tissues for the expression of EGF, EGFR, and cyclin D1 and demonstrated an overexpression in the tumor cells in 51%, 54%, and 62.3%, respectively, whereas normal human pancreas stained negative for all of the three factors. Interestingly, EGF and EGFR expression correlated significantly with the cyclin D1 expression in human pancreatic tumor cells (p < 0.001 and p < 0.01, respectively).. These results demonstrate that cyclin D1 overexpression in the tumor cells of pancreatic carcinoma tissue is at least partly dependent on the mitogenic effects of EGF signaling through the EGFR.

Topics: Blotting, Western; Cell Cycle; Cell Division; Cyclin D1; Epidermal Growth Factor; ErbB Receptors; G1 Phase; Gene Expression; Humans; Immunohistochemistry; Kinetics; Pancreatic Neoplasms; Prognosis; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; S Phase; Tumor Cells, Cultured

Betacellulin (BTC) was identified in mouse pancreatic beta cell tumors as a member of the epidermal growth factor (EGF) family, and was found to bind and activate the EGF receptor. BTC is also expressed in some human malignancies and may have an important role in tumor growth progression. We examined whether BTC and EGF have a growth stimulatory effect on human pancreatic cancer cell lines both in vitro and in vivo. We also investigated the BTC expression and autonomous induction of BTC in pancreatic cancer cells. in vitro, both BTC and EGF had almost the same proliferative effect on Panc-1, MIA PaCa-2 and AsPC-1. in vivo, in a Panc-1 inoculated athymic mice model, BTC-treated tumors grew approximately five times larger than in control. Immunocytochemistry showed that BTC expression occurred in three pancreatic cancer cell lines, with MIA PaCa-2 showing the strongest intensity. Semi-quantitative RT-PCR of MIA Paca-2 showed that mRNA levels of BTC gradually increased after treatment with 1 nM BTC. Immunocytochemistry also demonstrated that the intensity of BTC-like immunoreactivity was increased when treated with 1 nM BTC but was reduced after treatment with 100 nM of AG1478, an EGF receptor tyrosine kinase inhibitor. BTC has thus a significant growth stimulatory effect on pancreatic cancer cells and might function as an autocrine and paracrine growth factor. BTC expression in pancreatic cancer cells is, at least in part, controlled by an auto-induction mechanism.

Topics: Animals; Betacellulin; Cell Division; Epidermal Growth Factor; ErbB Receptors; Growth Substances; Humans; Immunohistochemistry; Intercellular Signaling Peptides and Proteins; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Transplantation; Pancreatic Neoplasms; Recombinant Proteins; Reverse Transcriptase Polymerase Chain Reaction; Tumor Cells, Cultured

Both epidermal growth factor receptor (EGF-R) signaling mechanisms and angiogenesis have been evaluated as independent targets for therapy of human pancreatic carcinoma, but a link between the two processes has been identified only recently. This study evaluated whether EGF-R blockade therapy with anti-EGF-R antibody C225 inhibits pancreatic carcinoma growth and metastasis in an orthotopic nude mouse model via tumor-mediated angiogenesis and whether gemcitabine potentiates this effect. In vitro treatment of human pancreatic carcinoma L3.6pl cells with C225 inhibited EGF-R autophosphorylation, producing a maximum of 20% cytostasis. Treatment with C225 plus gemcitabine resulted in additive cytotoxic effects that increased with increasing gemcitabine concentrations. Dose-dependent decreases in expression of the angiogenic factors vascular endothelial growth factor and interleukin 8 (but not basic fibroblast growth factor) were observed in the C225-treated cells (mRNA and protein levels). In L3.6pl tumors established in the pancreas of nude mice, systemic therapy with C225 alone and C225 in combination with gemcitabine resulted in growth inhibition, tumor regression, and abrogation of metastasis; median tumor volume was reduced from 538 to 0.3 and to 0 mm3, respectively. Gemcitabine treatment alone reduced median tumor volume from 538 to 152 mm3. Liver metastases were present in 50% of the controls, 30% of the gemcitabine-treated animals, and 20% of C225-treated animals. No macroscopically visible liver metastases were observed in the combination treatment group. As early as 11 days after C225 treatment, the median percentage of proliferating cell nuclear antigen-positive cells was substantially reduced compared with gemcitabine treatment alone (26% versus 73%, respectively) versus controls (92%), correlating with in vivo blockade of EGF-R activation. Similarly after 11 days treatment, production of vascular endothelial growth factor and interleukin 8 was significantly lower in C225 and C225 plus gemcitabine-treated tumors versus gemcitabine-treated and control tumors. Significant differences in microvessel density were observed 18 days after C225 or combination treatments (but not gemcitabine alone) in direct correlation with the difference in percentage of apoptotic endothelial cells, as visualized by double immunofluorescence microscopy. These experiments indicate that therapeutic strategies targeting EGF-R have a significant antitumor effect on human L3.6

Topics: Animals; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Cell Division; Cetuximab; Deoxycytidine; Endothelial Growth Factors; Epidermal Growth Factor; ErbB Receptors; Fluorescent Antibody Technique; Gemcitabine; Humans; Immunohistochemistry; In Situ Nick-End Labeling; Interleukin-8; Lymphokines; Male; Mice; Mice, Nude; Neoplasm Metastasis; Neoplasm Transplantation; Neovascularization, Pathologic; Pancreas; Pancreatic Neoplasms; Phosphorylation; Platelet Endothelial Cell Adhesion Molecule-1; Proliferating Cell Nuclear Antigen; Transplantation, Heterologous; Tumor Cells, Cultured; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

Human ductal adenocarcinoma of the pancreas frequently carry activating point mutations in the K-ras protooncogene. We have analysed the activity of the Ras-Raf-MEK-MAPK cascade in the human pancreatic carcinoma cell line PANC-1 carrying an activating K-ras mutation. Serum-starved cells and cells grown in medium with serum did not show constitutively activated c-Raf, MEK-1, or p42 MAPK. Stimulation of cells with epidermal growth factor (EGF) or fetal calf serum (FCS) resulted in activation of N-Ras, but not K-Ras, as well as activation of c-Raf, MEK-1, and p42 MAPK. Preincubation of serum-starved cells with MEK-1 inhibitor PD98059 abolished EGF- and FCS-induced MAPK activation, identifying MEK as the upstream activator of MAPK. PANC-1 cells exhibited marked serum-dependence of anchorage-dependent and -independent cell growth as well as cell migration. EGF, alone or in combination with insulin and transferrin, did not induce cell proliferation of serum-starved PANC-1 cells, indicating that activation of MAPK alone was not sufficient to induce cell proliferation. FCS-induced DNA synthesis was inhibited by 40% by the MEK-1 inhibitor. On the other hand, treatment with either FCS or EGF alone resulted in marked, MEK-dependent increase of directed cell migration. Collectively, our results show that the activating K-ras mutation in PANC-1 cells does not result in constitutively increased Raf-MEK-MAPK signaling. Signal transduction via the Ras-Raf-MEK-MAPK cascade is maintained in these cells and is required for growth factor-induced cell proliferation and directed cell migration. Oncogene (2000).

Topics: Base Sequence; Cell Division; Cell Movement; DNA Primers; Enzyme Activation; Epidermal Growth Factor; Genes, ras; Humans; Mitogen-Activated Protein Kinases; Pancreatic Neoplasms; Reverse Transcriptase Polymerase Chain Reaction; Tumor Cells, Cultured

Epiregulin belongs to the epidermal growth factor (EGF) family of polypeptides. Previous studies have underscored the important role of the EGF family of ligands and receptors in the pathology of pancreatic ductal adenocarcinoma (PDAC) and chronic pancreatitis (CP). It is not known, however, whether epiregulin may also have a role in these diseases. Therefore, in the present study we investigated the expression and function of epiregulin in five pancreatic cancer cell lines and in PDAC and CP tissue samples. Epiregulin mRNA was present at high (MIA-PaCa-2 cells) or moderate levels (ASPC-1, CAPAN-1, and T3M4) in most cells, but was below detection levels in PANC-1 cells. All the cell lines exhibited a dose-dependent increase in growth in response to recombinant human epiregulin. Epiregulin mRNA levels were increased 2.1-fold in PDAC samples (P < 0.01) and 1.7-fold in CP samples (P < 0.01), when compared with the normal controls. There was no correlation between epiregulin mRNA levels and tumor stage or grade. By in situ hybridization, a moderate to intense epiregulin mRNA signal was present in most pancreatic cancer cells in PDAC. In contrast, only a weak (normal pancreas) to moderate (CP) signals were present in the ductal and acinar cells in CP. These findings suggest that epiregulin may contribute to the pathobiology of PDAC, and may also have a role in CP.

Topics: Adenocarcinoma; Blotting, Northern; Cell Division; Epidermal Growth Factor; Epiregulin; Humans; In Situ Hybridization; Pancreatic Neoplasms; RNA, Messenger; Up-Regulation

The human MUC4 gene is not expressed in normal pancreas; however, its dysregulation results in high levels of expression in pancreatic tumors. To investigate the tumor-associated expression, MUC4 cDNA was cloned from a human pancreatic tumor cell line cDNA expression library using a polyclonal antibody raised against human deglycosylated mucin and RT-PCR. Pancreatic MUC4 cDNA shows differences in 12 amino acid residues in the non-tandem repeat coding region with no structural rearrangement as compared with tracheal MUC4. The full-length MUC4 cDNA includes a leader sequence, a serine and threonine rich non-tandem repeat region, a central large tandem repeat domain containing 48 bp repetitive units, regions rich in potential N-glycosylation sites, two cysteine-rich domains, EGF-like domains, and a transmembrane domain. We also report the presence of a new EGF-like domain in MUC4 cDNA, located in the cysteine-rich region upstream from the first EGF-like domain. Four distinct splice events were identified in the region downstream of the central tandem repeat domain that generate three new MUC4 cDNA sequences (sv4, sv9, and sv10). The deduced amino acid sequences of two of these variants lack the transmembrane domain. Furthermore, two unique forms of MUC4 (MUC4/Y and MUC4/X) generated as a result of alternative splicing lack the salient feature of mucins, the tandem repeat domain. A high degree of polymorphism in the central tandem repeat region of MUC4 was observed in various pancreatic adenocarcinoma cell lines, with allele sizes ranging from 23.5 to 10.0 kb. MUC4 mRNA expression was higher in differentiated cell lines, with no detectable expression in poorly differentiated pancreatic tumor cell lines.

Topics: Alternative Splicing; Amino Acid Sequence; Blotting, Northern; DNA, Complementary; Epidermal Growth Factor; Genetic Variation; Humans; Molecular Sequence Data; Mucin-4; Mucins; Pancreatic Neoplasms; Protein Structure, Tertiary; Reverse Transcriptase Polymerase Chain Reaction; Tumor Cells, Cultured

In the present study, we show that 2-(2-hydroxyethylsulfaryl)-3-methyl-1,4-naphthoquinone, or CPD 5, is a potent growth inhibitor for pancreas cancer cell lines (ID(50): 21.4 +/- 3.8, 31.8 +/- 2.7 and 55.2 +/- 4.5 microM for MiaPaCa, Panc-1 and BxPc3, respectively). It induced protein tyrosine phosphor-ylation of hepatocyte growth factor (HGF) receptor (c-Met) or epidermal growth factor receptor (EGFR), which increased progressively to a maximum level at 30 min in Panc-1 cells. The receptor phosphorylation by CPD 5 was indicated to be functional, since these receptors were found to bind with Grb2 or SOS1 protein. CPD 5 was also suggested to induce phosphorylation of external signal-regulated kinase (ERK). EGF induced cell proliferation through ERK phosphorylation, since U0126, which is an inhibitor of ERK phosphorylation, abrogated the increase of cyclin D1 by EGF. HGF increased the amount of p27 protein, suggesting that it is associated with cell differentiation. By contrast, U0126 reduced CPD 5-induced cell death. On two-dimensional electrophoresis, we found an extra type of phospho-ERK, and this was completely and selectively abolished by U0126. These results suggest that ERK phosphorylation, especially the extra spot on two-dimensional gel, is critically associated with CPD 5-mediated cell death.

Topics: Antineoplastic Agents; Cell Death; Cell Division; Cyclin D1; Epidermal Growth Factor; ErbB Receptors; Hepatocyte Growth Factor; Humans; Microfilament Proteins; Mitogen-Activated Protein Kinases; Muscle Proteins; Naphthoquinones; Pancreatic Neoplasms; Phosphorylation; Proto-Oncogene Proteins c-met; Tumor Cells, Cultured; Vitamin K

The pancreas harbors growth factors such as the epidermal growth factor (EGF) family. The physiological and pathophysiological roles of growth factors in normal pancreas remain unsettled. Human pancreatic cancer overexpresses the EGF receptor, and the ligands EGF and transforming growth factor alpha (TGF-alpha). The aim of the present experiments was to study the effect of TGF-alpha in a pancreatic cancer cell line and in normal mouse pancreas.. The LN-36 cell line, established from a pancreatic duct cell adenocarcinoma, was incubated with TGF-alpha or EGF. The effect of an EGF receptor-specific, tyrosine kinase inhibitor (tyrphostin B56) with or without growth factors was also studied. The cell number was measured with the XTT-colorimetric method. TGF-alpha, the tyrphostins A25, B48, and B56, were in separate experiments infused during 1 wk to normal female mice by subcutaneous (sc) minipumps.. The LN-36 cell line responded to TGF-alpha and EGF with increased cell number; +61% with 10(-10) M TGF-alpha and +34% with 10(-9) M EGF. Tyrphostin B56 at a concentration of 10(-5) M reduced the cell number by 76%, but when incubated together with growth factors the reduction was only 44% with TGF-alpha, and 39% with EGF. Infusion of TGF-alpha increased mouse pancreatic wet weight and protein content but was without effect on DNA synthesis, measured as incorporation of tritiated thymidine. Infusion of three different tyrphostins did not influence mice pancreas.. The results support the role of TGF-alpha to maintain growth of pancreatic cancer cells by the EGF receptor. Infusion of TGF-alpha induced hypertrophy in normal mouse pancreas.

Topics: Animals; Cell Count; Dose-Response Relationship, Drug; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Hypertrophy; Mice; Pancreas; Pancreatic Neoplasms; Transforming Growth Factor alpha; Tumor Cells, Cultured; Tyrphostins

Somatostatin (SS-14) and its structural analogue SMS 201-995 (SMS) are recognized as physiological inhibitors of multiple organs and tissue functions through specific membrane receptors (sst1-sst5). The effects of SS-14 and SMS in the growth control of the pancreatic cancer cell lines MIA PaCa-2 and PANC-1 were investigated to identify and clarify the intracellular events involved. In PANC-1 cells, SS-14 and SMS caused inhibition of their basal growth, and that stimulated by epidermal growth factor, with a maximal effect at 0.1-1 microM. To understand the inhibitory mechanisms, we investigated the effects of SS-14 and SMS on phosphotyrosine phosphatase (PTPase) activity and, more specifically, that of tyrosine phosphatase SHP-1 (PTP1C). SS-14 and SMS caused significant increases in total cellular PTPase activity, and particularly SHP-1, with maximal activation within 1 min. Inhibition of membrane tyrosine kinase and p42 MAP kinase activities was also observed, in response to SS-14 and SMS. In MIA PaCa-2 cells, SS-14 and SMS were associated with a positive growth response at 1-10 nM, after 4 days of culture in serum-free medium. Total cellular PTPase activity was slightly increased, but SHP-1 activity could not be detected; its absence in this cell line was confirmed by Western blot. Membrane tyrosine kinase activities were significantly increased by SS-14 and SMS at concentrations needed for maximal growth. p44/p42, which are constitutively active in this cell line, and p38 activities were not affected by somatostatin. In conclusion, somatostatin can exert different effects on human pancreatic cancer cell growth, depending upon the presence or absence of SHP-1. This enzyme can play a key role in the control of cell proliferation, and its cellular presence may determine the therapeutic potential of somatostatin in the control of cancer cell growth.

Topics: Calcium-Calmodulin-Dependent Protein Kinases; Cell Division; Epidermal Growth Factor; Fibroblasts; Humans; Intracellular Signaling Peptides and Proteins; Liver; Pancreas; Pancreatic Neoplasms; Protein Tyrosine Phosphatase, Non-Receptor Type 11; Protein Tyrosine Phosphatase, Non-Receptor Type 6; Protein Tyrosine Phosphatases; Protein-Tyrosine Kinases; Receptors, Somatostatin; Skin; Somatostatin; Tumor Cells, Cultured

CTGF is an immediate early growth responsive gene that has been shown to be a downstream mediator of TGFbeta actions in fibroblasts and vascular endothelial cells. In the present study hCTGF was isolated as immediate early target gene of EGF/TGFalpha in human pancreatic cancer cells by suppression hybridization. CTGF transcripts were found in 13/15 pancreatic cancer cell lines incubated with 10% serum. In 3/7 pancreatic cancer cell lines EGF/TGFalpha induced a significant rise of CTGF transcript levels peaking 1-2 h after the start of treatment. TGFbeta increased CTGF transcript levels in 2/7 pancreatic cancer cell lines after 4 h of treatment and this elevation was sustained after 24 h. Only treatment with TGFbeta was accompanied by a parallel induction of collagen type I transcription. 15/19 human pancreatic cancer tissues were shown to overexpress high levels of CTGF transcripts. CTGF transcript levels in pancreatic cancer tissues and nude mouse xenograft tumors showed a good correlation to the degree of fibrosis. In situ hybridization and the nude mouse experiments revealed that in pancreatic cancer tissues, fibroblasts are the predominant site of CTGF transcription, whereas the tumor cells appear to contribute to a lesser extent. We conclude that CTGF may be of paramount importance for the development of the characteristic desmoplastic reaction in pancreatic cancer tissues.

Topics: Animals; Collagen; Connective Tissue Growth Factor; Epidermal Growth Factor; Fibroblasts; Growth Substances; Humans; Immediate-Early Proteins; In Situ Hybridization; Intercellular Signaling Peptides and Proteins; Mice; Mice, Nude; Neoplasm Proteins; Pancreatic Neoplasms; Time Factors; Transcription, Genetic; Transforming Growth Factor alpha; Transforming Growth Factor beta; Transplantation, Heterologous; Tumor Cells, Cultured

A serious insulin resistance characterizes pancreatic cancer-associated diabetes mellitus. Elsewhere, we demonstrated that MIA PaCa2 cultured cells secrete a soluble factor responsible for reduced glucose tolerance induced in SCID mice. The intracellular mechanism of insulin resistance was investigated in isolated and perfused rat hepatocytes incubated with MIA PaCa2 conditioned medium. Lactate production was reduced compared to hepatocytes incubated with control medium while 1,2-DAG was increased and PKC was activated in the hepatocytes incubated with MIA PaCa2 conditioned medium. This behavior was not reproduced treating the hepatocytes with the growth factors EGF, interleukin Ibeta, interleukin-6, and TGF-beta1. In an attempt to make a biochemical identification of the hypothesized tumor associated-diabetogenic factors we observed a low molecular weight protein in the conditioned medium, absent in the nonconditioned one, that may be responsible for the described behaviors.

Topics: Animals; Biological Factors; Cell Membrane; Cells, Cultured; Culture Media, Conditioned; Cytosol; Diglycerides; Epidermal Growth Factor; Glucose; Humans; Insulin Resistance; Interleukins; Lactic Acid; Liver; Male; Molecular Weight; Pancreatic Neoplasms; Perfusion; Protein Kinase C; Rats; Rats, Wistar; Transforming Growth Factor beta; Tumor Cells, Cultured

p22/PACAP response gene-1 (PRG1) is a novel rat early response gene expressed during induction of proliferation and stress response. In humans, a homolog of p22/PRG1, designated IEX-1/DIF-2, exists, yet the exact function of this gene remains elusive. To characterize the expression of p22/PRG1 in human cancers, we analyzed the expression of p22/PRG1 in the human pancreatic carcinoma cell lines 818-4, PT45, and PancTu1. Serum or growth factors, like epidermal growth factor (EGF) and hepatocyte growth factor (HGF), rapidly and transiently induced transcription of p22/PRG1 in these cells, correlating with the mitogenic response. Treatment with TNF-alpha was followed by a rapid increase of p22/PRG1 messenger RNA (mRNA) levels in PT45 and Panc-Tul cells, which proliferate in the presence of TNF-alpha, but not in 818-4 cells, which are growth-inhibited when treated with TNF-alpha. Our findings suggest that human p22/PRG1 is expressed in various pancreatic carcinoma cells as a growth-associated early response gene.

Topics: Cell Division; Epidermal Growth Factor; Gene Expression; Hepatocyte Growth Factor; Humans; Kinetics; Neuropeptides; Pancreatic Neoplasms; Pituitary Adenylate Cyclase-Activating Polypeptide; Response Elements; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Transcription, Genetic; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha

Constitutively active Ras proteins, their regulatory components, and overexpressed tyrosine kinase receptors that activate Ras, are frequently associated with cell transformation in human tumors. This suggests that functional Ras antagonists may have anti-tumor activity. Studies in rodent fibroblasts have shown that S-trans, transfarnesylthiosalicylic acid (FTS) acts as a rather specific nontoxic Ras antagonist, dislodging Ras from its membrane anchorage domains and accelerating its degradation. FTS is not a farnesyltransferase inhibitor, and does not affect Ras maturation. Here we demonstrate that FTS also acts as a functional Ras antagonist in human pancreatic cell lines that express activated K-Ras (Panc-1 and MiaPaCa-2). In Panc-1 cells, FTS at a concentration of 25-100 microM reduced the amount of Ras in a dose-dependent manner and interfered with serum-dependent and epidermal growth factor-stimulated ERK activation, thus inhibiting both anchorage-dependent and anchorage-independent growth of Panc-1 cells in vitro. FTS also inhibited tumor growth in Panc-1 xenografted nude mice, apparently without systemic toxicity. Daily FTS treatment (5 mg/kg intraperitoneally) in mice with tumors (mean volume 0.07 cm3) markedly decreased tumor growth (after treatment for 18 days, tumor volume had increased by only 23+/-30-fold in the FTS-treated group and by 127+/-66-fold in controls). These findings suggest that FTS represents a new class of functional Ras antagonists with potential therapeutic value.

Topics: Animals; Antineoplastic Agents; Calcium-Calmodulin-Dependent Protein Kinases; Dose-Response Relationship, Drug; Enzyme Activation; Epidermal Growth Factor; Farnesol; Humans; Mice; Mice, Nude; Pancreatic Neoplasms; ras Proteins; Salicylates; Tumor Cells, Cultured

The results of this study show that routine measurements of epidermal growth factor (EGF) and epidermal growth factor receptor (EGF-R) cannot improve screening for pancreatic cancer despite the frequently present tissue overexpression. Both values fail to reveal this malignancy in a serum test. Patients with chronic pancreatitis exhibit no or very low concentrations of EGF. In cases where preoperative diagnosis is difficult the noninvasive EGF and EGF-R serum measurements may be helpful in discriminating between pancreatic cancer and chronic pancreatitis.. EGF and EGF-R are frequently overexpressed in the tissue of patients suffering from ductal pancreatic cancer and to lesser degree in patients with chronic pancreatitis. The aim of this study was to determine the value of serum measurements in these patients to detect malignant pancreatic disease. In cases of pancreatic cancer, the tissue expression of EGF and EGF-R was evaluated by immunohistochemistry.. Thirty-five patients with chronic pancreatitis and 31 patients with pancreatic cancer were evaluated; 71 patients admitted for routine surgery (hernia repair, cholecystectomy, goiter surgery) served as controls.. EGF and EGF-R values were not significantly different in pancreatic cancer as compared to controls and did not correlate with other tumor markers (CA 19-9, carcinoembryonic antigen [CEA], tumor polypeptide antigen [TPA]) or with the stage of the disease. Fourteen patients (67%) with pancreatic cancer displayed tissue overexpression for EGF and 11 patients for EGF-R (52%). These patients, however, also failed to exhibit any significant pathological changes in serum concentration. In chronic pancreatitis, EGF and EGF-R were significantly decreased as compared to pancreatic cancer and controls. This was an unexpected finding. There was a positive correlation to clinical exocrine insufficiency.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Case-Control Studies; Chronic Disease; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Immunohistochemistry; Male; Middle Aged; Pancreatic Neoplasms; Pancreatitis

The implication of MAP kinases in the proliferation control of pancreatic cancer cells is still unknown. This study was undertaken to examine the contribution of the p44/p42 and p38 MAP kinases in the mitogenic response to epidermal growth factor (EGF) and bombesin in human pancreatic cancer cells, MIA PaCa-2 and PANC-1. Data indicate that EGF and bombesin stimulated growth of both cell lines. In MIA PaCa-2 cells, EGF and bombesin stimulated the in gel activation of p38 while p44/p42 kinases exhibited high basal activity and no response to stimuli. Growth and p38 activation were inhibited by genistein, wortmannin, PD98059 and SB203580, specific inhibitors of tyrosine kinase, phosphatidylinositol 3-kinase, MEK-1 and p38 kinases, respectively. In PANC-1 cells, EGF and bombesin stimulated p42 in gel activation; p44 remained highly activated and unresponsive to stimuli and p38 did not respond. Stimulated growth and p42 activation were inhibited by genistein, wortmannin and PD98059. Estimation of MAPK activities with a specific anti-active MAP kinase antibody indicated, however, that EGF increased the intensity of the bands corresponding to p42 and p44 MAP kinases in both cell lines, indicating that the mitogenic factor can regulate MAP kinase activity. Data also pointed out that ATP is sufficient to increase MAP kinase activity within the in gel assay technique and may thus explain the discrepancies existing between the in gel assay data and those obtained with the anti-active MAP kinase antibody.

Topics: Adenosine Triphosphate; Bombesin; Calcium-Calmodulin-Dependent Protein Kinases; Cell Division; Enzyme Activation; Epidermal Growth Factor; Humans; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinases; p38 Mitogen-Activated Protein Kinases; Pancreatic Neoplasms; Phosphorylation; Tumor Cells, Cultured

Cyclooxygenase (COX)-2 mRNA and protein expression were found to be frequently elevated in human pancreatic adenocarcinomas and cell lines derived from such tumors. Immunohistochemistry demonstrated cytoplasmic COX-2 expression in 14 of 21 (67%) pancreatic carcinomas. The level of COX-2 mRNA was found to be elevated in carcinomas, relative to histologically normal pancreas from a healthy individual, as assessed by reverse transcription-PCR. COX-2 protein expression was detected by the Western blot assay in three of five pancreatic carcinoma cell lines (BxPC-3, Capan-1, and MDAPanc-3), whereas COX-1 protein was detected in two of the five cell lines (BxPC-3 and Capan-1). Increased levels of COX-2 mRNA were found in four of five cell lines, and only in PANC-1 cells was the low level of transcript comparable to that in the normal pancreas. The level of COX-2 mRNA was positively correlated with the differentiation status of the tumor of origin for each cell line, COX-2 protein expression was up-regulated by epidermal growth factor when the cells were grown in absence of serum. Finally, two nonsteroidal anti-inflammatory drugs, sulindac sulfide and NS398, produced a dose-dependent inhibition of cell proliferation in all pancreatic cell lines tested. No correlation was found between the level of COX-2 or COX-1 expression and the extent of growth inhibition. Treatment of BxPC-3 cells with sulindac sulfide and NS398 resulted in an induction of COX-2 expression. Our findings indicate that COX-2 up-regulation is a frequent event in pancreatic cancers and suggest that nonsteroidal anti-inflammatory drugs may be useful in the chemoprevention and therapy of pancreatic carcinoma.

Topics: Adenocarcinoma; Anti-Inflammatory Agents, Non-Steroidal; Cell Division; Cyclooxygenase 1; Cyclooxygenase 2; Epidermal Growth Factor; Humans; Isoenzymes; Membrane Proteins; Nitrobenzenes; Pancreatic Neoplasms; Prostaglandin-Endoperoxide Synthases; RNA, Messenger; Sulfonamides; Sulindac; Tumor Cells, Cultured

It is suggested that interleukin-1beta-converting enzyme (ICE) and ICE-related proteases play an important role in programmed cell death (apoptosis). We investigated ICE expression in the human pancreatic carcinoma cell line AsPC-1 after stimulation with epidermal growth factor and found a time-dependent expression of active ICE induced by epidermal growth factor. Interestingly, ICE expression does not lead to apoptosis. Cell cycle analyses revealed that acetyl-Tyr-Val-Ala-Asp-chloromethylketone-specific and acetyl-Ala-Ala-Val-Ala-Leu-Leu-Pro-Ala-Val-Leu-Leu-Ala-Leu-Leu-Ala-Pro-T yr-Val-Ala-Asp-aldehyde-specific cell-permeable inhibitors of ICE significantly reduced the proliferation of AsPC-1 cells, which suggested a positive influence of ICE on the proliferation in human pancreatic carcinoma cells.

Topics: Apoptosis; Caspase 1; Cell Cycle; Cell Division; Epidermal Growth Factor; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Humans; Pancreatic Neoplasms; Reverse Transcriptase Polymerase Chain Reaction; Tumor Cells, Cultured

Variations in cancer cell adhesion to extracellular matrix (ECM) proteins might underlie an enhanced metastatic potential. ECM binding is mediated by cell-adhesion molecules, the membrane expression of which might be influenced by soluble mediators, such as cytokines. The aims of our study were to ascertain whether epidermal growth factor (EGF), transforming growth factor beta1 (TGF-beta1), interleukin 1alpha (IL-1alpha), or interleukin 1beta (IL-1beta) can modify MIA PaCa 2 (pancreatic cancer cell line) and CAPAN-1 (metastatic pancreatic cancer cell line) adhesion to fibronectin, laminin, or type I collagen, and whether these cytokines can shift the membrane expression of the hyaluronic acid receptor (CD44). EGF significantly enhanced MIA PaCa 2, but not CAPAN-1, adhesion to fibronectin, laminin, and type I collagen. TGF-beta1 reduced MIA PaCa 2 adhesion to type I collagen, but enhanced CAPAN-1 adhesion to fibronectin and laminin. IL-1alpha was found to enhance MIA PaCa 2 adhesion to fibronectin, while reducing adhesion to type I collagen, whereas IL-1beta reduced the adhesion to laminin. IL-1alpha enhanced CAPAN-1 adhesion to laminin in a dose-dependent manner; IL-1beta slightly increased the adhesion of these cells to laminin at low dosage, and to type I collagen at high dosage. Both IL-1alpha and IL-1beta reduced CD44 membrane expression of MIA PaCa 2, while TGF-beta1 increased the percentage of CD44-positive CAPAN-1 cells. We suggest that the effects on cell adhesion induced by different cytokines depend on the status of the target pancreatic cancer cell. EGF and, in part, IL-1alpha can favor nonmetastatic pancreatic cancer cell adhesion to ECM, possibly favoring tumor spread. Metastatic cells seem to lose the responsiveness to EGF, while becoming hyperresponsive to IL-1alpha. TGF-beta1 might exert an antidiffusive effect on primary, and a prodiffusive effect on metastatic pancreatic cancer cells. Only IL-1alpha, IL-1beta, and TGF-beta1 seem to influence CD44 membrane expression. All the results presented in this study were obtained in vitro, and in vivo studies are needed to verify whether the studied cytokines can favor or counteract pancreatic cancer spread.

Topics: Cell Adhesion; Cell Membrane; Cytokines; Epidermal Growth Factor; Extracellular Matrix Proteins; Fibronectins; Humans; Hyaluronan Receptors; Interleukin-1; Laminin; Liver Neoplasms; Pancreatic Ducts; Pancreatic Neoplasms; Transforming Growth Factor beta; Tumor Cells, Cultured

Cyclin D1 belongs to a family of protein kinases that have been implicated in cell cycle regulation. Recent studies have demonstrated that elevated cyclin D1 levels correlate with decreased survival in human pancreatic cancer. In this study we expressed in a stable manner a cyclin D1 antisense cDNA construct in PANC-1 human pancreatic cancer cells. Expression of the antisense construct caused a decrease in cyclin D1 mRNA and protein levels and in cyclin D1-associated kinase activity. Antisense expressing clones displayed significantly increased doubling times, decreased anchorage-dependent and -independent basal growth, and complete loss of tumorigenicity in nude mice. EGF, FGF-2, and IGF-I enhanced mitogen-activated protein kinase activity in antisense expressing clones, but failed to stimulate their proliferation. In contrast, all three growth factors were mitogenic in parental cells. Furthermore, the inhibitory effect of cisplatinum on cell proliferation was enhanced markedly in the antisense expressing clones. These findings indicate that cyclin D1 overexpression contributes to abnormal growth and tumorigenicity in human pancreatic cancer and to the resistance of pancreatic cancer to chemotherapeutic agents.

Topics: Animals; Antineoplastic Agents; Antisense Elements (Genetics); Cisplatin; Cyclin D1; DNA, Complementary; Epidermal Growth Factor; Female; Fibroblast Growth Factor 2; Humans; Mice; Mice, Nude; Pancreatic Neoplasms; Transfection; Tumor Cells, Cultured

This new animal cell line may be a useful model to study the effect of growth factors on malignant cell proliferation and differentiation in both in vivo and in vitro systems.. We established a new pancreatic cancer cell line from pancreatic cancer in the hamster (HPC) induced by N-nitrosobis(2-oxopropyl)amine (BOP) and characterized its morphological, pathological, and biological patterns.. Cells grew rapidly, with a doubling time of 22.5 h. Chromosome number ranged from 33 to 144, and flow cytometric analysis showed two peaks of DNA distribution as a proliferative pattern. Ultrastructural analyses using transmission and scanning electron microscopy of HPC cells revealed desmosomes and loose interdigitation, with pseudopods and microvilli on the cell surface. The overexpression of epidermal growth factor (EGF) receptors on HPC cells was shown by immunohistochemistry. Binding characteristics and biological activity of EGF and type alpha transforming growth factor (TGF-alpha) were studied. TGF-alpha stimulated DNA synthesis in a dose-dependent manner, whereas EGF was without effect. Scatchard analysis of 125I-EGF binding data at pH 7.4 indicated the presence of two orders of binding sites, where that of 125I-TGF-alpha showed only a single order. Regarding the effect of pH on 125I-EGF or 125I-TGF-alpha dissociation, one-half maximal dissociation of 125I-EGF or 125I-TGF-alpha occurred at pH 6.0 or 6.5, respectively. Characteristics of the EGF receptor are similar to those of cultured human pancreatic cancer cells.

Topics: Animals; Cricetinae; Epidermal Growth Factor; ErbB Receptors; Flow Cytometry; Humans; Hydrogen-Ion Concentration; Male; Mesocricetus; Microscopy, Electron; Pancreatic Neoplasms; Transforming Growth Factor alpha; Tumor Cells, Cultured

Epidermal growth factor (EGF) and its receptor (EGFR) are involved in many aspects of the development of carcinomas, including tumor cell growth, vascularization, invasiveness, and metastasis. Because EGFR has been found to be overexpressed in many tumors of epithelial origin, it is a potential target for antitumor therapy. Here we report that potato carboxypeptidase inhibitor (PCI), a 39-amino acid protease inhibitor with three disulfide bridges, is an antagonist of human EGF. It competed with EGF for binding to EGFR and inhibited EGFR activation and cell proliferation induced by this growth factor. PCI suppressed the growth of several human pancreatic adenocarcinoma cell lines, both in vitro and in nude mice. PCI has a special disulfide scaffold called a T-knot that is also present in several growth factors including EGF and transforming growth factor alpha. PCI shows structural similarities with these factors, a fact that can explain the antagonistic effect of the former. This is the first reported example of an antagonistic analogue of human EGF.

Topics: Animals; Cell Cycle; Cell Division; Computer Simulation; Epidermal Growth Factor; Humans; Mice; Mice, Nude; Neoplasm Transplantation; Pancreatic Neoplasms; Plant Proteins; Protease Inhibitors; Tumor Cells, Cultured

We investigated the expression of interleukin 1beta-converting enzyme (ICE; caspase-1) in human adenocarcinomas of the pancreas. Immunohistochemistry and Western blot analyses revealed an overexpression of ICE in 71 and 80% of tumor cells, respectively. Also, on a mRNA level, ICE mRNA was overexpressed in 45% of the cases, as compared to normal pancreatic tissue. Interestingly, the overexpression of ICE in tumor cells correlated significantly with the overexpression of cyclin D1, epidermal growth factor, and epidermal growth factor receptor (P < 0.0005, P < 0.05, and P < 0.002, respectively), which are involved in cell cycle progression and proliferation in human pancreatic carcinoma. This is the first report concerning ICE expression in human carcinomas; however, the exact mechanism underlying these close correlations warrant further research.

Topics: Adenocarcinoma; Adult; Aged; Blotting, Western; Caspase 1; Cyclin D1; Cysteine Endopeptidases; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Immunohistochemistry; Male; Middle Aged; Neoplasm Proteins; Pancreas; Pancreatic Neoplasms; RNA, Messenger

Heparan sulfate proteoglycans (HSPGs) play diverse roles in cell recognition, growth, and adhesion. In vitro studies suggest that cell-surface HSPGs act as coreceptors for heparin-binding mitogenic growth factors. Here we show that the glycosylphosphatidylinositol- (GPI-) anchored HSPG glypican-1 is strongly expressed in human pancreatic cancer, both by the cancer cells and the adjacent fibroblasts, whereas expression of glypican-1 is low in the normal pancreas and in chronic pancreatitis. Treatment of two pancreatic cancer cell lines, which express glypican-1, with the enzyme phosphoinositide-specific phospholipase-C (PI-PLC) abrogated their mitogenic responses to two heparin-binding growth factors that are commonly overexpressed in pancreatic cancer: fibroblast growth factor 2 (FGF2) and heparin-binding EGF-like growth factor (HB-EGF). PI-PLC did not alter the response to the non-heparin-binding growth factors EGF and IGF-1. Stable expression of a form of glypican-1 engineered to possess a transmembrane domain instead of a GPI anchor conferred resistance to the inhibitory effects of PI-PLC on growth factor responsiveness. Furthermore, transfection of a glypican-1 antisense construct attenuated glypican-1 protein levels and the mitogenic response to FGF2 and HB-EGF. We propose that glypican-1 plays an essential role in the responses of pancreatic cancer cells to certain mitogenic stimuli, that it is relatively unique in relation to other HSPGs, and that its expression by pancreatic cancer cells may be of importance in the pathobiology of this disorder.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Amino Acid Sequence; Cell Membrane; Epidermal Growth Factor; Female; Fibroblast Growth Factor 2; Gene Expression; Glycosylphosphatidylinositols; Growth Substances; Heparan Sulfate Proteoglycans; Heparin-binding EGF-like Growth Factor; Humans; Immunoenzyme Techniques; In Situ Hybridization; Insulin-Like Growth Factor I; Intercellular Signaling Peptides and Proteins; Male; Middle Aged; Molecular Sequence Data; Pancreatic Neoplasms; Tumor Cells, Cultured

Epidermal growth factor (EGF) increased the cell number of the two pancreatic cancer cell lines, MiaPaCa-2 and LN-36, in vitro. A blockade of the EGF-R tyrosine kinase with tyrphostin was more efficient in reducing the cell number than inhibiting receptor antibodies. IGF-1 increased the cell number, and blockade of the IGF-1-R initially decreased the cell number that later was followed by an increase in LN-36.. The receptors and ligands of EGF and insulin-like growth factor-1 (IGF-1) are overexpressed in pancreatic cancer tissue. The aim of the present experiments was to study the effects of EGF and IGF-1 on the cell number in two pancreatic cancer cell lines.. MiaPaCa-2 cells were grown in 0.2% fetal calf serum (FCS) and the newly established LN-36 cells in serum-free medium (SFM). The cell number was measured with the XTT method. The effects of EGF and IGF-1 were studied in combination with inhibiting receptor antibodies and an EGF-R-specific tyrosine kinase inhibitor, tyrphostin B56.. MiaPaCa-2 responded with increased cell number to stimulation with EGF, and at 10(-8) M or higher concentrations a dose-response pattern was seen. Administration of B56 to MiaPaCa-2 decreased the cell number by 87%. The inhibiting EGF-R-Ab only inhibited EGF-induced increase in cell number. IGF-1 doubled the cell number of MiaPaCa-2 and increased the cell growth induced by EGF. The inhibiting IGF-1-R-Ab reduced the cell number by 10%. The LN-36 cell line responded to EGF with an increased cell number with a maximum at 5 x 10(-9) M after 96 h. B56 reduced the cell number by 90% at 10(-5) M, with less effect during stimulation with EGF. In contrast to B56, the inhibiting EGF-R-Ab in the same experiment did not reduce the cell number. LN-36 responded to IGF-1 with an increased cell number, but EGF-stimulated growth was not influenced. The inhibiting IGF-1-R-Ab reduced the cell number and suppressed the IGF-1 stimulated increase after 24 h and later it induced an increased cell number.

Topics: Antibodies; Cell Count; Enzyme Inhibitors; Epidermal Growth Factor; ErbB Receptors; Humans; Insulin-Like Growth Factor I; Pancreatic Neoplasms; Receptor, IGF Type 1; Tumor Cells, Cultured; Tyrphostins

The study of zinc finger proteins has revealed their potential to act as oncogenes or tumor suppressors. Here we report the molecular, biochemical, and functional characterization of KS1 (KRAB/zinc finger suppressor protein 1), a novel, ubiquitously expressed zinc finger gene initially isolated from a rat pancreas library. KS1 contains 10 C2H2 zinc fingers, a KRAB-A/B motif, and an ID sequence that has been shown previously to participate in growth factor-regulated gene expression. Northern blot analysis using pancreatic cell lines demonstrates that KS1 mRNA is inducible by serum and epidermal growth factor, suggesting a role for this gene in cell growth regulation. Biochemical analysis reveals that KS1 is a nuclear protein containing two transcriptional repressor domains, R1 and R2. R1 corresponds to the KRAB-A motif, whereas R2 represents a novel sequence. Transformation assays using NIH3T3 cells demonstrate that KS1 suppresses transformation by the potent oncogenes Ha-ras, Galpha12, and Galpha13. Deletion of the R1/ KRAB-A domain does not modify the transformation suppressive activity of KS1, whereas deletion of R2 abolishes this function. Thus, KS1 is a novel growth factor-inducible zinc finger transcriptional repressor protein with the potential to protect against neoplastic transformation induced by several oncogenes.

Topics: 3T3 Cells; Amino Acid Sequence; Animals; Base Sequence; Cell Nucleus; Cell Transformation, Neoplastic; DNA-Binding Proteins; Epidermal Growth Factor; Gene Expression Regulation; Gene Library; Genes; Genes, ras; Genes, Tumor Suppressor; Genes, Wilms Tumor; Kruppel-Like Transcription Factors; Mice; Molecular Sequence Data; Multigene Family; Neoplasm Proteins; Nuclear Proteins; Pancreas; Pancreatic Neoplasms; Protein Conformation; Rats; Repressor Proteins; Sequence Alignment; Sequence Homology, Amino Acid; Transcription Factors; Transcription, Genetic; Tumor Cells, Cultured; Zinc Fingers

Elevated levels of the growth factor pS2 protein in the cyst fluids of mucinous cystic tumors correlate with earlier observations using immunohistochemical techniques showing that pS2 protein is expressed by these tumors. The markedly elevated levels of pS2 protein compared to normal plasma values suggest that this growth factor may be important in the pathogenesis of pancreatic mucinous cystic tumors.. Cystic lesions of the pancreas include inflammatory pseudocysts, serous cystadenomas, and mucinous cystic tumors, some of which are malignant. Previous studies using immunohistochemical techniques have shown that virtually all pancreatic mucinous tumors express pS2 protein. pS2 protein is a growth factor that is believed to be important in the normal process of inflammation and repair. We measured pS2 protein and other growth factors in pancreatic cyst fluids to assess their potential pathophysiologic and diagnostic significance.. Levels of pS2 protein were measured in 54 pancreatic cyst fluids by radioimmunoassay. The growth factors, epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), and insulin-like growth factors I and II (IGF-I, IGF-II) were measured in 22 cyst fluids using commercial immunoassays.. Mucinous cysts exhibited significantly higher levels of cyst fluid pS2 protein than nonmucinous lesions, including pseudocysts and serous cystadenomas (median: 78,303 pg/mL; range: 218-361,176 pg/mL vs median: 886 pg/mL; range: 0-14,206 pg/mL; p = 0.0001). The level of pS2 in mucinous tumors was markedly higher than plasma values (median: 392 pg/mL). Levels of pS2 protein in malignant mucinous lesions tended to be higher than those in benign mucinous cysts, but this difference was not statistically significant (median: 88,817 vs 64,350 pg/mL; p = 0.159). Levels of other growth factors, including EGF, TGF-alpha, IGF-I, and IGF-II, did not discriminate among the different cyst types, and the values were within normal plasma ranges.

Topics: Cyst Fluid; Cystadenocarcinoma, Mucinous; Cystadenoma, Mucinous; Cystadenoma, Serous; Epidermal Growth Factor; Humans; Insulin-Like Growth Factor I; Insulin-Like Growth Factor II; Pancreatic Cyst; Pancreatic Neoplasms; Pancreatic Pseudocyst; Proteins; Transforming Growth Factor alpha; Trefoil Factor-1; Tumor Suppressor Proteins

Our experiments were designed to identify initial biochemical and biological changes that occur during pancreatic carcinogenesis. TAKA-1, an immortal hamster pancreatic ductal cell line, was treated in vitro for up to 11 weeks with the pancreatic carcinogen N-nitorosobis(2-oxopropyl)amine (BOP). These treated cells were designated TAKA-1 + BOP. The growth of TAKA-1 and TAKA-1 + BOP cell lines was investigated in soft agar and in hamsters intradermally. The resulting tumor from TAKA-1 + BOP was re-cultured in vitro and designated TAKA-1 + BOP-T. Mutation of c-K-ras and p53 oncogenes, chromosomal changes, expression of transforming growth factor alpha (TGF-alpha) and epidermal growth factor (EGF) receptor and several biochemical markers were examined in all cell lines. TAKA-1 + BOP but not TAKA-1 cells grew in soft agar and produced an invasive tumor in vivo. However, there were no differences in cell growth rate, DNA flow cytometry, or immunohistochemical findings between the non-transformed and transformed cells. TAKA-1, TAKA-1 + BOP and TAKA-1 + BOP-T cells all expressed mRNA of TGF-alpha and EGF receptor in a comparable pattern. DNA sequence analysis following polymerase chain reaction showed that neither TAKA-1 nor TAKA-1 + BOP cells has a mutation of c-K-ras or p53. Karyotype analysis demonstrated that TAKA-1 + BOP cells had more chromosomal abnormalities compared with TAKA-1 cells. Mutation of c-K-ras and p53 was not essential for carcinogenesis in hamster pancreatic ductal cells in vitro. In conclusion, immortality of the TAKA-1 cells caused expression of TGF-alpha to the same extent as in malignant cells. Chromosomal and ultrastructural patterns were the only differences detected between the non-transformed and BOP-transformed cells.

Topics: Amino Acid Sequence; Animals; Base Sequence; Carcinogens; Cell Division; Cell Line; Cell Transformation, Neoplastic; Cricetinae; Epidermal Growth Factor; ErbB Receptors; Genes, p53; Genes, ras; Karyotyping; Keratins; Kinetics; Mice; Microscopy, Electron; Molecular Sequence Data; Mutagenesis; Nitrosamines; Pancreatic Ducts; Pancreatic Neoplasms; Rats; Sequence Alignment; Transforming Growth Factor alpha

Using immunohistochemistry, Northern blotting and a semi-quantitative PCR technique, epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha) and epidermal growth factor receptor (EGFR) expression were studied in the pancreas of N-nitrosobis(2-oxopropyl)-amine (BOP)-treated hamsters. After initiation pancreatic carcinogenesis was modulated by a high fat diet or by injections with the cholecystokinin analogue caerulein. Autopsies were performed 6 and 12 months after the last injection with BOP. Immunohistochemistry revealed a weak expression of TGF-alpha in nomal acinar cells and a stronger expression in ductular and centro-acinar cells. Over-expression of TGF-alpha was observed in advanced putative preneoplastic lesions (classified as borderline lesions) and in ductular adenocarcinomas. EGFR immunoreactivity was present only in ductular adenocarcinomas. EGF peptide expression was observed both in acinar and ductular normal and tumorous cells and the level of expression did not change significantly during carcinogenesis. Moreover, the post-initiation treatments did not cause differences in EGF, TGF-alpha or EGFR peptide or mRNA levels, except for a significantly lower expression of TGF-alpha mRNA in hamsters fed a high fat diet when compared with those fed a low fat diet. TGF-alpha mRNA levels increased, whereas EGF mRNA levels decreased significantly in total pancreatic homogenates of BOP-treated hamsters in comparison with untreated controls. Also, in ductular adenocarcinomas TGF-alpha and EGFR (but not EGF) mRNA levels were significantly higher than in normal pancreatic homogenates. In pancreatic homogenates obtained 6 months after the last BOP injection, these differences were less pronounced in comparison with those obtained after 12 months. The present results indicate that TGF-alpha (but not EGF) might act in a paracrine or autocrine manner in pancreatic tumours in BOP-treated hamsters via simultaneously expressed EGFR. However, TGF-alpha, EGF and EGFR do not seem to be involved in the modulating effects of a high fat diet or caerulein treatment on pancreatic carcinogenesis in BOP-treated hamsters.

Topics: Adenocarcinoma; Animals; Blotting, Northern; Body Weight; Carcinogens; Cricetinae; Epidermal Growth Factor; ErbB Receptors; Immunohistochemistry; Mesocricetus; Nitrosamines; Organ Size; Pancreas; Pancreatic Neoplasms; Polymerase Chain Reaction; Transforming Growth Factor alpha

Glycine-extended gastrin (gastrin-Gly) stimulates proliferation of AR4-2J pancreatic tumor cell line through a specific receptor, different from the gastrin-cholecystokinin B receptor. Our purpose was to determine whether AR4-2J cells produced gastrin-Gly and then whether the peptide was involved in an autocrine loop. First, proliferation of AR4-2J cells in serum-free medium was inhibited by a gastrin anti-sense oligodeoxynucleotide phosphorothioate and by antibodies specific for gastrin-Gly. In contrast, antibodies specific for alpha-amidated gastrin were without effect. By using RT-PCR, we have shown that AR4-2J cells expressed gastrin mRNA. The presence of gastrin-Gly, but not alpha-amidated gastrin, in serum-free media was detected by radioimmunoanalysis. Gel chromatography revealed that the predominant molecular forms secreted were glycine-extended gastrin-34 and gastrin- 17. Furthermore, epidermal growth factor (EGF), a stimulator of gastrin gene transcription, modulates gastrin-Gly secretion by AR4-2J. These data together suggest that gastrin-Gly is an autocrine growth factor for AR4-2J cells and that it participates with EGF in the regulation of AR4-2J-cell proliferation.

Topics: Amino Acid Sequence; Animals; Antibodies; Cell Division; Epidermal Growth Factor; Gastrins; Gene Expression; Humans; Molecular Sequence Data; Oligonucleotides, Antisense; Pancreatic Neoplasms; Rats; Stimulation, Chemical; Thionucleotides; Tumor Cells, Cultured

Somatostatin inhibits proliferation of many solid tumors. The current study examines whether inhibition of the growth of pancreatic cancer by the somatostatin analog, octreotide, requires tumor expression of somatostatin receptors.. We studied five human pancreatic cancer cell lines, Capan-1, Capan-2, CAV, MIA PaCa-2, and Panc-1. Solid tumors were established in nude mice (n = 20/cell line) by flank injection of tumor cells. Subcutaneous octreotide (500 micrograms/kg/day) was administered by osmotic pumps to 10 of the animals in each group, and the other 10 received control infusions of saline solution. On day 36, the tumors were excised and weighed. Plasma levels of the putative trophic peptides cholecystokinin, epidermal growth factor (EGF), insulin-like growth factor-1 (IGF-1), and insulin were assessed by radioimmunoassay. Each of the five cell lines was assayed for the presence of cell surface somatostatin receptors by using whole cell competitive binding assays with 125I-somatostatin. Expression of the somatostatin receptor subtype-2 (SSR2) gene was determined with reverse transcriptase-polymerase chain reactions. Southern blot hybridization was used to assess the presence of the SSR2 gene.. Octreotide inhibited tumor growth in the MIA PaCa-2 group (512 +/- 75 mg control versus 285 +/- 71 mg treated; p < 0.05) but had no significant effect on tumor weight in the other four cell lines. Plasma levels of cholecystokinin, epidermal growth factor, insulin-like growth factor-1, and insulin were not altered by chronic octreotide infusion. Cell surface somatostatin receptors and SSR2 gene expression were detected only in the MIA PaCa-2 tumors. The gene for the SSR2 receptor was found in all five tumor lines.. Octreotide-mediated inhibition of pancreatic cancer growth is dependent on expression of somatostatin receptors. The expression of somatostatin receptors should be considered in the design and interpretation of clinical trials with somatostatin analogs for treatment of pancreatic cancer.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents, Hormonal; Base Sequence; Binding, Competitive; Blotting, Southern; Cell Division; Cholecystokinin; DNA, Neoplasm; Epidermal Growth Factor; Gene Expression Regulation, Neoplastic; Humans; Insulin; Insulin-Like Growth Factor I; Mice; Mice, Nude; Molecular Sequence Data; Octreotide; Pancreatic Neoplasms; Peptides; Polymerase Chain Reaction; Receptors, Somatostatin; Tumor Cells, Cultured

The epidermal growth factor (EGF) signal transduction pathway, frequently activated in pancreatic cancer, is an important regulator of cellular growth and transformation. This study examined whether activation of the cyclic adenosine monophosphate protein kinase A pathway may inhibit the EGF signal transduction pathway in pancreatic cancer cell lines.. Human pancreatic cancer lines BxPC-3 and AsPC-1 were stimulated with EGF, forskolin, or both. Forskolin is a compound that increases cyclic adenosine monophosphate levels. Assays of cell lines were then obtained for cellular growth (MTT assay), anchorage-independent growth (soft agar), and EGF-induced mitogen-activated protein kinase activation as measured by an in-gel kinase assay.. Treatment with forskolin resulted in inhibition of EGF-induced activation of mitogen-activated protein kinase activity (BxPC-3 78% inhibition and AsPC-1 70% inhibition, p < 0.005), diminished cellular proliferation (BxPC-3 92% inhibition and AsPC-1 86% inhibition, p < 0.001), and formation of colonies in soft agar (BxPC-3 98% inhibition and AsPC-1 76% inhibition, p < 0.001). Forskolin did not inhibit EGF receptor autophosphorylation or tyrosine kinase signaling in response to EGF.. Forskolin-induced inhibition of mitogen-activated protein kinase is associated with diminished pancreatic cancer cell proliferation in vitro. Use of strategies to increase cyclic adenosine monophosphate levels may have therapeutic application in pancreatic cancer.

Topics: Adenocarcinoma; Calcium-Calmodulin-Dependent Protein Kinases; Cell Culture Techniques; Cell Division; Cyclic AMP; Epidermal Growth Factor; ErbB Receptors; Humans; Pancreatic Neoplasms; Phosphorylation; Phosphotyrosine; Signal Transduction; Tumor Cells, Cultured

The Ras protein is involved in tyrosine kinase signal transduction pathway steps such as EGFR signalling. Most human pancreatic carcinomas harbor a point mutation of K-ras oncogene and overexpress transforming TGF-alpha. We studied how K-ras gene mutation could influence the EGFR signal transduction mechanism and the autonomous proliferation of pancreatic carcinoma cells, using PANC-1 human pancreatic carcinoma line and W1-38 normal human fibroblast cell line as a control. PANC-1 cells responded to neither EGF nor exogenous TGF-alpha, although anti-TGF-alpha MAb suppressed their growth. Expression of TGF-alpha mRNA was detected only in PANC-1 cells, which confirmed EGFR being within an autocrine loop. Ras protein and MAP kinase were constitutively activated in PANC-1 cells so that the cells did not respond to treatment with staurosporine or herbimycin A, and exhibited slight response to EGF stimulation. PANC-1 cells harbored K-ras gene mutation in codon 12. In contrast, EGF stimulation induced an elevation of GTP-bound ratio to Ras protein and an activation of MAP kinase with accelerated growth in W1-38 cells. From these findings, we concluded that K-ras gene mutation possibly plays an important role in the autonomous proliferation of PANC-1 pancreatic carcinoma cells, and that an autocrine loop represented by TGF-alpha and EGFR may further accelerate the growth of PANC-1 cells.

Topics: Antibodies, Monoclonal; Base Sequence; Calcium-Calmodulin-Dependent Protein Kinases; Enzyme Activation; Enzyme Inhibitors; Epidermal Growth Factor; ErbB Receptors; Genes, ras; Guanine Nucleotides; Humans; Molecular Sequence Data; Mutation; Pancreatic Neoplasms; Phosphotyrosine; ras Proteins; RNA, Messenger; Signal Transduction; Transforming Growth Factor alpha; Tumor Cells, Cultured

Tumor spread may be favored by a reduced production and/or an enhanced degradation of extracellular matrix components (collagen, fibronectin, laminin). Most tumor cell behavior, from growth to spread, may be regulated by cytokines, the exact roles of which, however, are not yet fully understood. We here evaluate the effects of some cytokines (epidermal growth factor, transforming growth factor-beta 1, interleukin-1 alpha, and interleukin-1 beta) on both cell growth and the production of the aminoterminal peptide of type III procollagen, the urokinase plasminogen activator, and the plasminogen activator inhibitor-1 in neoplastic cell lines originating in the pancreas and colon. Cells were stimulated daily with the above cytokines and the aminoterminal peptide of type III procollagen, urokinase plasminogen activator, and plasminogen activator inhibitor-1 were measured in the conditioned media. Epidermal growth factor stimulated cell growth of both cell lines. Transforming growth factor-beta 1 counteracted cell proliferation and stimulated type III procollagen and plasminogen activator inhibitor-1 production only in the colon cancer cell line. Interleukin-1 alpha slightly stimulated cell growth, but inhibited plasminogen activator inhibitor-1 production in both cell lines; interleukin-1 beta did not affect cell growth, but stimulated plasminogen activator inhibitor-1 production by the colon cancer cell line. Our findings suggest that transforming growth factor-beta 1 and interleukin-1 beta may have an antidiffusive effect. These results confirm that cytokine-producing cells have a potential role in stimulating or counteracting tumor growth and spread and also confirm the pivotal role of host-tumor interactions in determining the outcome of a particular neoplasia.

Topics: Cell Division; Collagen; Colonic Neoplasms; Cytokines; Dose-Response Relationship, Drug; Epidermal Growth Factor; Humans; Interleukin-1; Pancreatic Neoplasms; Plasminogen Activator Inhibitor 1; Serine Proteinase Inhibitors; Transforming Growth Factor beta; Tumor Cells, Cultured; Urokinase-Type Plasminogen Activator

Intracellular signaling by an increase in [Ca2+]i was observed in pancreatic AR42J cells in response to agonists whose receptors are G-protein coupled including cholecystokinin (CCK), bombesin, carbachol, substance P, pituitary adenylate cyclase activating peptide (PACAP), bradykinin, ATP, calcitonin gene related peptide (CGRP), and in response to growth factors EGF and FGF whose receptors are tyrosine kinases. The response to growth factors was smaller both in magnitude and in the percentage of cells responding but was independent of extracellular Ca2+. CCK and carbachol induced sizeable increases in inositol phosphates while growth factors did not. The responses to both carbachol and EGF, however, were blocked by the phospholipase C inhibitor U73122. The tyrosine kinase inhibitor, genestein, blocked the response to EGF but not that to CCK. These data are consistent with two types of signaling mechanisms in AR42J cells. Secretagogues act on receptors which couple through G proteins to induce a large amount of inositol phosphate production and subsequent intracellular Ca2+ mobilization. Growth factors act on receptors which signal through tyrosine kinase activity and in this cell type produced limited amounts of inositol phosphate and a smaller increase in intracellular Ca2+.

Topics: Adenosine Triphosphate; Animals; Binding Sites; Bombesin; Bradykinin; Calcitonin Gene-Related Peptide; Calcium; Carbachol; Cholecystokinin; Epidermal Growth Factor; Estrenes; Fibroblast Growth Factors; GTP-Binding Proteins; Hydrolysis; Inositol Phosphates; Neuropeptides; Neurotransmitter Agents; Pancreas; Pancreatic Neoplasms; Pituitary Adenylate Cyclase-Activating Polypeptide; Protein-Tyrosine Kinases; Pyrrolidinones; Rats; Receptors, Neuropeptide; Substance P; Tumor Cells, Cultured; Type C Phospholipases

Expression of transforming growth factor-alpha (TGF-alpha) and epidermal growth factor (EGF) was studied in normal pancreatic tissue and in (pre)neoplastic pancreatic lesions of azaserine-treated rats. They were given either a low fat, high fiber (low caloric) diet, to inhibit carcinogenesis, or a low fat diet combined with injections of the cholecystokinin analog caerulein to enhance carcinogenesis. The control groups, maintained on a low fat diet, were injected with azaserine or were not treated at all. Autopsy was performed at 6 and 15 months after the last azaserine injection. After both 6 and 15 months immunohistochemistry revealed a weak expression of EGF and TGF-alpha peptides in the acinar cells, and a stronger expression in the ductular and centroacinar cells. TGF-alpha peptide expression was reduced in both putative preneoplastic and neoplastic acinar cell lesions, but no differences in EGF peptide expression were observed between the various stages of exocrine pancreatic carcinogenesis. After 16 months an increase in TGF-alpha mRNA due to treatment with azaserine was detected by semi-quantitative PCR in total pancreatic homogenates, whereas EGF mRNA expression had decreased. TGF-alpha mRNA levels in macroscopically isolated tumors were significantly lower, but EGF mRNA levels were significantly higher, than in total pancreatic homogenates from azaserine-treated rats. Furthermore, EGF and TGF-alpha mRNA levels in isolated tumors did not differ significantly from mRNA levels in non-carcinogen-treated rats. Neither with immunohistochemistry nor with PCR were differences in EGF or TGF-alpha expression observed due to either inhibition or stimulation of carcinogenesis. It is concluded that putative preneoplastic acinar cell lesions induced in rat pancreas by azaserine may develop into acinar adenocarcinomas independently of TGF-alpha and EGF. The results suggest involvement of these growth factors at the early stage of the carcinogenic process, during the initiation of normal acinar cells into putative preneoplastic cells. However, modulation of azaserine-induced pancreatic carcinogenesis by cholecystokinin or a low fat, high fiber (caloric restricted) diet appeared not to be regulated by EGF or TGF-alpha.

Topics: Animals; Azaserine; Base Sequence; Body Weight; Carcinogens; Ceruletide; Cocarcinogenesis; Diet, Fat-Restricted; Dietary Fiber; Drug Synergism; Energy Intake; Epidermal Growth Factor; Immunohistochemistry; Male; Molecular Sequence Data; Organ Size; Pancreas; Pancreatic Neoplasms; Polymerase Chain Reaction; Rats; Rats, Wistar; RNA, Messenger; Transforming Growth Factor alpha

The effects of hormones and synthetic analogues have been examined on the growth of 2 human pancreatic cancer cell lines, MiaPaCa2 a well-established cell line and PANI which was derived in our own laboratories from a tumour specimen. The hormones/growth factors included gastrin (G-17), epidermal growth factor (EGF) and bombesin, while the synthetic analogues used were a gastrin receptor antagonist (CR 1718), a somatostatin analogue (RC-160) and a bombesin receptor antagonist (ICI 216,140). Cell proliferation was assessed by the [75Se]selenomethionine uptake method which has been shown to correlate with cell counts. The effect of each hormone or growth factor on growth was expressed as a percentage of the untreated control. There were 5 replicates in each experiment, and each one was repeated at least 3 times. In vitro growth of both cell lines was unaffected by gastrin, bombesin or the respective antagonists (CR1718 and ICI 216140). The somatostatin analogue RC-160 also had no effect on basal growth. Significant growth stimulation of both MiaPaCa2 and PANI was seen with epidermal growth factor. We tested the hypothesis that somatostatin analogues may inhibit EGF-stimulated growth on both MiaPaCa2, a somatostatin receptor positive cell line, and on PANI which is negative for somatostatin receptors. RC-160 did not inhibit EGF-stimulated growth of either MiaPaCA2 or PANI. Both cell lines were established in vivo as xenografts in nude mice. The effect of RC-160 on tumour growth was measured. RC-160 inhibited the growth of MiaPaCa2, the somatostatin receptor-positive cell line, but not of PANI.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Cell Division; Epidermal Growth Factor; Gastrointestinal Hormones; Humans; In Vitro Techniques; Mice; Mice, Nude; Neoplasm Transplantation; Pancreatic Neoplasms; Receptors, Cholecystokinin; Somatostatin; Transplantation, Heterologous; Tumor Cells, Cultured

We compared morphological, biological and molecular biological patterns of a newly established, spontaneously immortalized pancreatic ductal cell line, TAKA-1, with a hamster pancreatic ductal adenocarcinoma cell line, PC-1. PC-1 cells grew in a monolayer on plastic tissue culture flasks, whereas TAKA-1 cells required type I collagen gel matrix to propagate. The growth rate and argyrophilic nuclear organizer region (Ag-NOR) counts were greater in PC-1 cells than in TAKA-1 cells. More TAKA-1 cells were in G0/G1 and less were in the S cell cycle phase than PC-1 cells. Karyotypically, the consistent change in TAKA-1 cells was an abnormal no. 3 chromosome, whereas additional chromosomal abnormalities were found in PC-1 cells. Ultrastructurally, TAKA-1 cells formed ductal structures and were composed of two types of cells, as in the normal hamster pancreatic ducts, whereas PC-1 cells were pleomorphic, showed evidence for loss of differentiation and contained intracytoplasmic lumens. Unlike the PC-1, TAKA-1 cells did not show a point mutation at codon 12 in the c-Ki-ras oncogene and did not grow in soft agar. Receptor binding assay showed specific epidermal growth factor binding to both cell lines, but secretin binding only to TAKA-1 cells. Both cells produced and released transforming growth factor-alpha in serum-free medium. Both cell lines expressed blood group A antigen, carbonic anhydrase, coexpressed cytokeratin and vimentin, and reacted with tomato and Phaseolus vulgaris leucoagglutinin (L-PHA) lectins. The results demonstrate that chromosomal abnormalities, cell cycle patterns, expression of cytokeratin 18, lectin bindings and the c-Ki-ras mutation are the features that distinguish the benign from the malignant pancreatic ductal cells in Syrian hamster.

Topics: Adenocarcinoma; Animals; Base Sequence; Cell Adhesion; Cell Cycle; Cell Division; Cell Line; Cholecystokinin; Cricetinae; Epidermal Growth Factor; Flow Cytometry; Gastrin-Releasing Peptide; Genes, ras; Immunohistochemistry; Karyotyping; Kinetics; Light; Mesocricetus; Microscopy; Microscopy, Electron; Molecular Sequence Data; Pancreas; Pancreatic Ducts; Pancreatic Neoplasms; Peptides; Point Mutation; Secretin; Tumor Cells, Cultured

A 150 bp epidermal growth factor (EGF) cDNA fragment and a 1024 bp epidermal growth factor receptor (EGFR) cDNA fragment were inserted into 5.05 kb pBabe-puro retroviral vectors between BamH I and EcoR I sites in 3'-5' and/or 5'-3' orientation. The vectors were ligated with EGF and EGFR fragments by T-4 Ligase. The recombinant retroviral vectors were then packaged with packaging cell line PA317 through calcium phosphate mediated transfection. The viral supernatant of transfected PA317 cell lines were used to infect the human pancreatic carcinoma cell line PC-7. The resultant transformant cell lines: PC-7/AS-EGF, PC-7/S-EGFR, PC-7/AS-EGFR and PC-7/pBabe were tested for their endogenous EGF and EGFR mRNA expressions, cell growth rate, 3H-TdR incorporation rate, soft agar colony formation and tumorigenicity in nude mice. The results showed that there were noticeable inhibitions of cell growth, 3H-TdR incorporation rate, soft agar colony formation and tumorigenicity in nude mice in PC-7/AS-EGF and PC-7/AS-EGFR transformant cell lines. The endogenous EGF mRNA expression was blocked in PC-7/AS-EGF cell line and the endogenous EGFR mRNA was significantly down-regulated in PC-7/AS-EGFR cell line.

Topics: Adenocarcinoma; Animals; Cell Division; DNA, Antisense; DNA, Recombinant; Epidermal Growth Factor; ErbB Receptors; Female; Gene Expression; Genetic Vectors; Humans; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Middle Aged; Pancreatic Neoplasms; Retroviridae; Tumor Cells, Cultured

FG human pancreatic carcinoma cells adhere to vitronectin using integrin alpha v beta 5 yet are unable to migrate on this ligand whereas they readily migrate on collagen in an alpha 2 beta 1-dependent manner. We report here that epidermal growth factor receptor (EGFR) activation leads to de novo alpha v beta 5-dependent FG cell migration on vitronectin. The EGFR specific tyrosine kinase inhibitor tyrphostin 25 selectively prevents EGFR autophosphorylation thereby preventing the EGF-induced FG cell migration response on vitronectin without affecting constitutive migration on collagen. Protein kinase C (PKC) activation also leads to alpha v beta 5-directed motility on vitronectin; however, this is not blocked by tyrosine kinase inhibitors. In this case, PKC activation appears to be associated with and downstream of EGFR signaling since calphostin C, an inhibitor of PKC, blocks FG cell migration on vitronectin induced by either PKC or EGF. These findings represent the first report implicating a receptor tyrosine kinase in a specific integrin mediated cell motility event independent of adhesion.

Topics: Cell Adhesion; Cell Line; Cell Movement; Enzyme Activation; Epidermal Growth Factor; ErbB Receptors; Flow Cytometry; Genistein; Glycoproteins; Humans; Insulin-Like Growth Factor I; Integrins; Isoflavones; Kinetics; Naphthalenes; Nitriles; Pancreatic Neoplasms; Phosphotyrosine; Polycyclic Compounds; Protein Kinase C; Receptor Protein-Tyrosine Kinases; Receptor, IGF Type 1; Receptors, Vitronectin; Signal Transduction; Tetradecanoylphorbol Acetate; Tumor Cells, Cultured; Tyrosine; Tyrphostins; Vitronectin

Soybean trypsin inhibitor was added to the primary cell culture for establishing a novel moderately differentiated human pancreatic adenocarcinoma cell line, PC-7. The PC-7 cell line was confirmed to be a malignant human pancreatic adenocarcinoma by morphological and biological studies. Chromosomal analysis and DNA content of PC-7 determined by flow cytometry showed a hypodiploid karyotypic pattern. Cultured PC-7 cells were inoculated into the back of athymic nude mice to create a transplanted tumor model. The effects of epidermal growth factor (EGF) and anti-EGF antiserum on PC-7 transplanted tumor were observed by injecting EGF or anti-EGF at the periphery of the solid tumors. In comparing to the control group, the tumor weights of the EGF group and the anti-EGF group were 138% and 67% respectively. Histological and electron microscopic studies higher mitotic rate in the EGF group and a lower rate in the anti-EGF group compared to the control. The results indicate that EGF stimulated and anti-EGF partially inhibited the growth of transplanted PC-7 solid tumors in athymic nude mice.

Topics: Adenocarcinoma; Animals; Epidermal Growth Factor; Humans; Immune Sera; Immunization, Passive; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Middle Aged; Neoplasm Transplantation; Pancreatic Neoplasms; Tumor Cells, Cultured

AR42J, a rat pancreatic cell line expressing receptors for both gastrin and epidermal growth factor (EGF), has been used to examine the effect of the gastrin receptor antagonist CR2093 on basal, gastrin-17 (G17), EGF and transforming growth factor (TGF)-alpha stimulated growth in vitro. In serum-free conditions, CR2093 reduced the basal growth of AR42J at a concentration known to displace physiological levels of G17 from gastrin receptors and this effect was reversed by G17 at 1 x 10(-9) M. Alone, G17 had little effect on growth, but EGF and TGF-alpha stimulated growth to 181 and 176% of control values, respectively, and marked synergy was observed when G17 was used in combination with both EGF (212%) and TGF-alpha (259%). When CR2093 was added, the synergistic effects of the G17/EGF and G17/TGF-alpha combinations were reduced to basal levels. In addition, CR2093 inhibited the growth stimulation induced by EGF and TGF-alpha alone. When the ability of CR2093 to bind to EGF receptors was assessed in a ligand binding assay, it was found that the antagonist displaced up to 23% of labeled EGF. Thus CR2093 has potent inhibitory effects on the basal growth of AR42J which can be reversed by G17. It can also inhibit type 1 growth factor-stimulated growth, but although this action may in part be related to the antagonist's ability to inhibit binding to the EGF receptor, other mechanisms may be involved.

Topics: Amino Acids; Animals; Cell Division; Coloring Agents; Epidermal Growth Factor; Gastrins; Growth Inhibitors; Growth Substances; Humans; Iodine Radioisotopes; Pancreatic Neoplasms; Rats; Receptors, Cholecystokinin; Tetrazolium Salts; Thiazoles; Transforming Growth Factor alpha; Tumor Cells, Cultured

The expression of mRNA for epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), EGF receptor (EGFR) and c-erbB-2 genes and the immunoreactivity to these gene products were examined in 3 newly established human pancreatic carcinoma cell lines and their corresponding in vivo tumor lines using the Northern blot technique and the immunohistochemical method. All 3 cell lines expressed TGF-alpha, EGFR and 2 of the 3 lines expressed EGF and c-erbB-2 mRNAs. The immunohistochemical study showed immunoreactivity to EGF, TGF-alpha and EGFR in all these 3 cell lines and their corresponding in vivo tumor lines. These results indicate that the autocrine loop of EGF and/or TGF-alpha/EGFR in pancreatic carcinoma cells may be one of the important reasons for the uncontrolled growth of the pancreatic carcinoma. The c-erbB-2 overexpression in some of the cell lines may also contribute to the carcinogenesis or progression of this cancer.

Topics: Animals; Epidermal Growth Factor; ErbB Receptors; Gene Expression Regulation, Neoplastic; Humans; Immunoenzyme Techniques; In Vitro Techniques; Mice; Mice, Nude; Pancreatic Neoplasms; Receptor, ErbB-2; RNA, Messenger; Transforming Growth Factor alpha; Tumor Cells, Cultured

Interactions between growth factor receptor systems may be important in the regulation of cell growth. The proliferation of pancreatic tumor AR42J cells has been shown to be stimulated by Epidermal growth factor (EGF) and gastrin and inhibited by somatostatin. To analyze the interaction between these different peptides, we explored the influence of EGF and gastrin on the somatostatin receptors. Treatment of AR42J cells with 10 nM EGF or gastrin for 24 hr increased specific binding of [125I] Tyr3SMS to 131 and 147% of that in control cells, respectively. The effect of peptides on [125I]Tyr3SMS binding was time- and dose-dependent, with half-maximal effect at 0.2 +/- 0.03 nM EGF and 0.3 +/- 0.15 nM gastrin. Scatchard plots revealed an increase in somatostatin receptor number of 27 and 80% after 48 hr of treatment with EGF and gastrin, respectively, without any change in receptor affinity. The increase in somatostatin receptor density was accompanied by the enhancement of biological responses to somatostatin. In cells pretreated with EGF or gastrin, the potency of somatostatin for inhibiting vasoactive intestinal peptide-stimulated cAMP content was increased 2-fold as that of somatostatin analog, SMS, for inhibiting cell proliferation. Furthermore, the efficiency of SMS as antiproliferative agent was greatly increased. Vasoactive intestinal peptide or forskolin did not modify [125I]Tyr3SMS binding of control or treated cells. The phorbol ester 12-O-tetradecanoyl phorbol 13-acetate (TPA) did not affect [125I]Tyr3SMS binding. On the other hand, cycloheximide completely blocked the increase in [125I]Tyr3SMS binding induced by EGF and gastrin.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Base Sequence; Cell Division; Cyclic AMP; Cycloheximide; DNA Primers; Epidermal Growth Factor; Gastrins; Molecular Sequence Data; Octreotide; Pancreatic Neoplasms; Protein Kinase C; Receptors, Somatostatin; RNA, Messenger; Tumor Cells, Cultured; Up-Regulation

Heparin-binding EGF-like growth factor (HB-EGF) is a polypeptide with an apparent molecular weight of 22 kilodalton that is related to epidermal growth factor (EGF) and that binds and activates the EGF receptor. We examined HB-EGF biological action and expression in human pancreatic cancer cell lines, and compared HB-EGF expression in normal and cancerous pancreatic tissues. HB-EGF enhanced the growth of human pancreatic cancer cells in a dose-dependent manner. Several cell lines expressed HB-EGF mRNA transcripts, and the transcript level was enhanced by HB-EGF, as well as by 12-O-tetradecanoylphorbol-13-acetate and transforming growth factor-alpha (TGF-alpha). By comparison with the normal pancreas, HB-EGF mRNA levels were increased in human pancreatic cancer tissues. These findings suggest that HB-EGF may participate in aberrant autocrine and paracrine activation of the EGF receptor, thereby contributing to pancreatic cancer cell growth.

Topics: Blotting, Northern; Epidermal Growth Factor; Heparin; Heparin-binding EGF-like Growth Factor; Humans; Intercellular Signaling Peptides and Proteins; Pancreatic Neoplasms; RNA, Messenger; Tetradecanoylphorbol Acetate; Tumor Cells, Cultured

The expression of cripto gene product was examined immunohistochemically in 45 surgically resected pancreatic tumors, including 32 invasive ductal carcinomas, 4 intraductal papillary adenocarcinomas, 4 intraductal papillary adenomas, 2 mucinous cystadenomas, 2 islet cell tumors, and one solid and cystic tumor, and compared with that in 32 areas of accompanying chronic pancreatitis present in the cases of invasive ductal carcinomas and 5 non-tumorous areas of pancreas without pancreatitis. All pancreatic ductal tumors including adenomas and carcinomas showed positive staining with no difference in terms of staining intensity among intraductal tumors and invasive carcinomas with or without mucin hypersecretion. Islet cell tumors were positively stained but the solid and cystic tumor was negative. Duct epithelial cells and acinar cells were negative but islet cells were positive in the pancreas tissues without pancreatitis. Cells arranged in duct-like structures in areas of accompanying chronic pancreatitis were positively stained. The results suggest that cripto expression might be associated with a growth advantage of tumor cells and also with differentiation to form duct-like structures.

Topics: Biomarkers, Tumor; Carcinoma; Carcinoma, Islet Cell; Cell Transformation, Neoplastic; Cystadenoma, Mucinous; Epidermal Growth Factor; Gene Expression; GPI-Linked Proteins; Humans; Intercellular Signaling Peptides and Proteins; Islets of Langerhans; Membrane Glycoproteins; Neoplasm Proteins; Pancreatic Ducts; Pancreatic Neoplasms; Pancreatitis

Cripto is a 188 amino-acid protein containing a central segment that shares amino-acid sequence homology with epidermal growth factor (EGF) and transforming growth factor alpha (TGF-alpha). The EGF receptor, EGF and TGF-alpha are expressed in the normal human pancreas, and are over-expressed in human pancreatic cancer. Therefore, in the present study we sought to determine whether cripto is found in the normal human pancreas and whether its expression is altered in pancreatic cancer. Because chronic pancreatitis (CP) is associated with interstitial fibrosis similar to that observed in pancreatic cancer, we also examined cripto expression in pancreatic tissues from patients with CP. In the normal pancreas, cripto immunoreactivity was found at moderate levels in most ductal cells and was present very faintly in a rare acinar cell. In 26 of 58 pancreatic cancers, cripto immunoreactivity was present in many cancer cells. Its presence was associated with advanced tumor stage, but not with shorter post-operative survival. Cripto was also present in acinar and ductal cells adjacent to the cancer cells, and in many ductal atrophic acinar cells in the CP samples. Northern blot analysis revealed a marked increase in cripto mRNA levels in the cancer and CP samples. By densitometry, there was a 11- and 4-fold increase in cripto mRNA levels in pancreatic cancer and CP respectively. Southern blot analysis did not reveal an increase in gene copies encoding cripto either in cancer or in CP. These findings indicate that cripto expression may contribute to disease progression in pancreatic cancer, and implicate cripto in the histopathological alterations that occur in the pancreas both in cancer and in CP.

Topics: Adolescent; Adult; Aged; Biomarkers, Tumor; Blotting, Northern; Blotting, Southern; Chronic Disease; Epidermal Growth Factor; Female; GPI-Linked Proteins; Humans; Immunohistochemistry; Intercellular Signaling Peptides and Proteins; Male; Membrane Glycoproteins; Middle Aged; Neoplasm Proteins; Pancreas; Pancreatic Neoplasms; Pancreatitis

Using immunohistochemical and Northern blot hybridization techniques, the expression of epidermal growth factor (EGF) and its mRNA was studied in 3 human pancreatic carcinoma cell lines and their in vivo tumor lines. 2 out of 3 cell lines (PC-2 and PC-3) showed strong immunoreaction with EGF antiserum whereas PC-1 was stained weakly. Northern blot exhibited expression of EGF mRNA in PC-2 and PC-3. No EGF mRNA was detected in PC-1. The detectable levels of EGF protein and EGF mRNA in this study and EGF receptor mRNA in our previous study, indicated the presence of autocrine cycle in human pancreatic carcinoma cell lines. The autostimulation of growth factor to cancer cells and overexpression of growth factor receptors may be the main mechanism of uncontrolled growth of cancer cells.

Topics: Animals; Blotting, Northern; Epidermal Growth Factor; Humans; Immunohistochemistry; Mice; Mice, Nude; Neoplasm Transplantation; Pancreatic Neoplasms; RNA, Messenger; Tumor Cells, Cultured

Pancreatic cancer cell lines overexpress epidermal growth factor (EGF) receptors and also have the capacity to produce transforming growth factor alpha (TGF alpha), the alternate agonist of the EGF receptor. The purpose of this study was to determine if TGF alpha had a trophic effect on the growth of pancreatic cancer in vivo. Syrian golden hamsters were inoculated with 50,000 H2T hamster ductal pancreatic cancer cells. The hamsters were then randomised to three equal groups: the groups received either saline (control), EGF, or TGF alpha, each by intraperitoneal injection, three times a day. Treatment continued for seven weeks, and each week the hamsters were weighed and tumour areas were measured. The hamsters were then killed, and the tumours were excised, weighed, and extracted for assay of DNA content as a measure of cellularity. From week four onwards both EGF and TGF alpha significantly stimulated tumour growth. Although tumour weights were not significantly different, tumour DNA content had nearly doubled after exposure to both EGF and TGF alpha. It is concluded that like EGF, TGF alpha can stimulate pancreatic cancer growth in vivo, and this may in part explain the aggressive nature of these cancers in clinical practice.

Topics: Animals; Body Weight; Cricetinae; DNA, Neoplasm; Epidermal Growth Factor; Injections, Intraperitoneal; Mesocricetus; Pancreatic Neoplasms; Random Allocation; Transforming Growth Factor alpha; Tumor Cells, Cultured

Tyrphostins are a group of low molecular weight synthetic inhibitors of protein tyrosine kinases (PTK). The intracellular domains of the receptors for epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), insulin-like growth factor 1 (IGF-1) possess PTK activity. Since EGF, TGF-alpha and IGF-1 are considered to play an important role in the proliferation of pancreatic cancer cells, we studied the effects of tyrphostins on the growth of three human pancreatic cancer cell lines (MiaPaCa-2, Panc-1 and CAV). The tyrphostins AG17, T23 and T47 all inhibited EGF and serum-stimulated DNA synthesis. AG17 was found to be the most potent of these agents and caused a dose-dependent but reversible inhibition of cell growth. Furthermore using an immunoblotting procedure we also found AG17 to inhibit EGF-induced tyrosine phosphorylation in the MiaPaCa-2 cell line. Tyrosine kinase inhibitors may prove to be useful agents for the treatment of pancreatic cancer.

Topics: Catechols; Cell Division; DNA, Neoplasm; Dose-Response Relationship, Drug; Epidermal Growth Factor; Humans; Immunoblotting; Nitriles; Pancreatic Ducts; Pancreatic Neoplasms; Phenols; Phosphorylation; Platelet-Derived Growth Factor; Protein-Tyrosine Kinases; Tumor Cells, Cultured; Tyrosine; Tyrphostins

The effects of cholera toxin (CT) and 8-chloro-cAMP (8-Cl-cAMP) on cell growth were investigated using two human pancreatic carcinoma cell lines (MIA PaCa-2, Panc-1). CT, which catalyses the ADP ribosylation of Gs, suppresses the proliferation of MIA PaCa-2(PC) cells. CT at the low dose of 0.1 pg ml-1 was inhibitory of PC cell growth, and the maximum suppression (70%) was achieved at a CT concentration of 100 pg ml-1. This phenomenon was reversible. The production of cAMP by CT (100 pg ml-1) in PC cells was enhanced 320-fold compared with the control. In addition, cAMP analogues (8-Cl-cAMP, 8-Br-cAMP) and forskolin decreased the growth rate of PC cells in a dose-dependent manner. These results support the view that CT suppresses PC cell growth by stimulating cAMP production. Conversely, Panc-1 cells were far less sensitive to CT in cell growth and cAMP production. 8-Cl-cAMP was also less effective on Panc-1 cell growth. The binding of an insulin-like growth factor (IGF)-I and transforming growth factor (TGF)-alpha, which has been shown to stimulate PC cell growth in an autocrine manner, to PC cells was not modified in cells treated with CT or 8-Cl-cAMP. The results suggest that the inhibitory actions of these substances do not occur at the level of the receptor for IGF-I or EGF/TGF-alpha. We have previously shown that phorbol esters, which decrease the binding of TGF-alpha to PC cells, has an anti-proliferative activity on these tumour cells. Inhibited cell growth by maximum suppressive dose of CT or 8-Cl-cAMP was further inhibited by TPA. In addition, an oncogene product of K-ras which is commonly activated in pancreatic cancer, was increased by CT and 8-Cl-cAMP. It is concluded that CT and 8-Cl-cAMP inhibit PC cell growth, presumably in a similar manner, and their mechanism(s) of action may be different from that of TPA. The anti-proliferative effect of CT or 8-Cl-cAMP was enhanced by TPA, implying that the combination of these substances results in increased inhibition of the PC cell growth.

Topics: 8-Bromo Cyclic Adenosine Monophosphate; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Cell Division; Cholera Toxin; Colforsin; Cyclic AMP; Drug Synergism; Epidermal Growth Factor; Humans; Immunologic Factors; Insulin-Like Growth Factor I; Pancreatic Neoplasms; Proto-Oncogene Proteins p21(ras); Tetradecanoylphorbol Acetate; Tumor Cells, Cultured

Female Syrian golden hamsters with N-nitroso-bis (2-oxopropyl) amine (BOP)-induced pancreatic cancers were treated for 2 months with bombesin/gastrin-releasing peptide (GRP) antagonist D-Tpi6,Leu13 psi(CH2NH)Leu14 bombesin(6-14) (RC-3095). Bombesin and GRP(14-27) were also administered alone and in combination with the antagonist RC-3095. RC-3095 exerted a dose-dependent inhibitory effect on growth of pancreatic cancers. The number of animals with pancreatic cancers was significantly lower in the group treated with 60 micrograms/day of RC-3095 and the weight of tumorous pancreata was reduced. Administration of bombesin or GRP alone did not stimulate the growth of pancreatic tumors and, in fact, had a slightly suppressive effect on cancers which was significant only in Experiment I. Bombesin and GRP (14-27) given together with RC-3095 did not nullify the inhibitory effect of the antagonist on pancreatic cancer growth. Actually, a greater inhibition of pancreatic tumors was observed after administration of RC-3095 together with bombesin or GRP, than with RC-3095 alone. The mechanism of action of bombesin, GRP, and bombesin antagonists on pancreatic cancers appears to be complex. The inhibitory effect of bombesin antagonists on pancreatic cancer growth was accompanied by a decrease in the binding capacity of EGF receptors in tumor membranes. Administration of bombesin also caused a down-regulation of EGF receptors and the greatest decrease in binding capacity of EGF receptors was observed after treatment with RC-3095 in combination with GRP. Inhibition of pancreatic cancer can thus be tentatively explained by some common pathways in the action of bombesin, GRP and their antagonists, that could be mediated by interference with EGF-receptor mechanisms.

Topics: Animals; Body Weight; Bombesin; Carcinoma; Cricetinae; Dose-Response Relationship, Drug; Down-Regulation; Epidermal Growth Factor; ErbB Receptors; Female; Gastrin-Releasing Peptide; Gastrins; Growth Hormone; Insulin-Like Growth Factor I; Mesocricetus; Nitrosamines; Pancreatic Neoplasms; Peptide Fragments; Peptides; Receptors, Bombesin; Receptors, Neurotransmitter

Exogenous administration of epidermal growth factor (EGF) enhances tumor growth of H2T, a hamster pancreatic cancer that is inoculated in the cheek pouch. The effect of endogenous EGF on tumor growth, however, is not known. The main source of EGF in the body is the submandibular glands. This study examined the influence of submandibular gland resection (SMx) on H2T tumor growth in the cheek pouch and compared it to the growth in SC tissue. Bilateral SMx or sham operation was performed on male Syrian golden hamsters. In 30 hamsters (n = 15 for each operation group), 5 x 10(4) and 5 x 10(5) H2T cells were inoculated in the bilateral cheek pouches and intrascapular SC tissue, respectively (Exp. 1). In another 30 hamsters (n = 15 for each operation group), 5 x 10(5) and 1 x 10(6) H2T cells were inoculated at the same sites (Exp. 2). Two longest perpendicular diameters of the tumor were measured once a week for 12 wk (Exp. 1) or 8 wk (Exp. 2), and the tumor area was calculated. The tumor area in the cheek pouch became significantly smaller in the SMx group than the sham-operated group after the 8th wk (Exp. 1) or the 7th wk (Exp. 2). On the other hand, the tumor area in the SC tissue did not show any difference between groups through the experiments.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Cheek; Cricetinae; Epidermal Growth Factor; Male; Mesocricetus; Mouth Neoplasms; Neoplasm Transplantation; Pancreatic Neoplasms; Skin Neoplasms; Submandibular Gland

Betacellulin, a member of the epidermal growth factor family, has been identified in the conditioned medium of cell lines derived from mouse pancreatic beta cell tumors. Betacellulin is a 32-kilodalton glycoprotein that appears to be processed from a larger transmembrane precursor by proteolytic cleavage. The carboxyl-terminal domain of betacellulin has 50 percent sequence similarity with that of rat transforming growth factor alpha. Betacellulin is a potent mitogen for retinal pigment epithelial cells and vascular smooth muscle cells.

Topics: 3T3 Cells; Amino Acid Sequence; Animals; Base Sequence; Betacellulin; Cell Division; Cells, Cultured; DNA Replication; Endothelium, Vascular; Epidermal Growth Factor; ErbB Receptors; Growth Substances; Humans; Intercellular Signaling Peptides and Proteins; Islets of Langerhans; Kinetics; Mice; Molecular Sequence Data; Muscle, Smooth, Vascular; Oligodeoxyribonucleotides; Pancreatic Neoplasms; Pigment Epithelium of Eye; Polymerase Chain Reaction; Protein Precursors; Rats; Recombinant Proteins; Sequence Homology, Amino Acid; Thymidine; Transforming Growth Factor alpha

In the present work the effects of the novel neuropeptide Pituitary Adenylate Cyclase Activating Peptide (PACAP) on both AR4-2J cell growth and the modulation of ornithine decarboxylase activity were investigated. Both PACAP38 and the amidated form PACAP27 caused a concentration-dependent stimulation of AR4-2J cell growth; the maximal increase was seen at 1 nmol/L (30% above control, P less than 0.01) with a half-maximal effect at 0.01 nmol/L. Ornithine decarboxylase activity was also increased by PACAP in a dose-dependent manner, reaching half-maximal stimulation at 0.5 nmol/L. The addition of 1 nmol/L of somatostatin analog SMS 201-995 totally suppressed PACAP-stimulated AR4-2J cell growth. Vasoactive intestinal polypeptide (3 mumol/L) and 8-bromo-cyclic adenosine monophosphate (1 mmol/L) had no effect on cell proliferation. Treatment of cells by pertussis toxin (25 ng.mL-1.day-1) suppressed PACAP-stimulated AR4-2J cell growth but enhanced PACAP-induced stimulation of adenylate cyclase activity. It was concluded that PACAP stimulates AR4-2J cell proliferation by a mechanism that seems independent of cyclic adenosine monophosphate production. The mitogenic effect of PACAP depends on a pertussis toxin-sensitive G protein and is associated with an increase of ornithine decarboxylase activity.

Topics: Adenylate Cyclase Toxin; Adenylyl Cyclases; Animals; Cell Count; Cell Division; Cyclic AMP; Dose-Response Relationship, Drug; Epidermal Growth Factor; Insulin; Neuropeptides; Octreotide; Ornithine Decarboxylase; Pancreatic Neoplasms; Pertussis Toxin; Pituitary Adenylate Cyclase-Activating Polypeptide; Rats; Tumor Cells, Cultured; Vasoactive Intestinal Peptide; Virulence Factors, Bordetella

The expressions of epidermal growth factors (EGF), epidermal growth factor receptors (EGFR), and the c-erbB-2 oncoprotein were immunohistochemically examined in 25 cases of human pancreatic carcinoma and epineoplastic pancreatitis and in 10 non-cancerous/non-inflammatory pancreatic tissues. The positive rates of EGF, EGFR, and the c-erbB-2 oncoprotein in cancer tissues were 72%, 36%, and 28%, respectively. EGF was stained mainly in the cytoplasm and partly on the surfaces of the cancer cells. EGFR and the c-erbB-2 oncoprotein were stained mainly on the surfaces of the cancer cells and partly in the cytoplasm. The expressions of these 3 products correlated significantly with tumor invasion into the anterior and posterior areas surrounding the pancreas. In the EGF, EGFR, and c-erbB-2 positive cancer tissues, some stromal cells, that is fibroblasts and endothelial cells, were also positive. In the adjacent pancreatic tissues with inflammation, these products were noted in some ductal cells, acinar cells, fibroblasts and endothelial cells. No distinct staining was detected in non-cancerous/non-inflammatory tissues. The survival period for patients who tested positive for these three proteins was statistically shorter than for those who tested negative. These results suggest that the coexpression of EGF and EGFR and the expression of the c-erbB-2 oncoprotein are related to the existence of the invasion of human pancreatic cancer. Furthermore, an immunohistochemical examination of these three products is useful in forming a prognosis for pancreatic cancer patients.

Topics: Epidermal Growth Factor; ErbB Receptors; Female; Humans; Immunohistochemistry; Lymphatic Metastasis; Male; Neoplasm Invasiveness; Oncogene Proteins v-erbB; Pancreas; Pancreatic Neoplasms; Pancreatitis; Prognosis; Retroviridae Proteins, Oncogenic

The in vivo administration of somatostatin (SS) or its analogues is capable of suppressing the growth of pancreatic cancer in experimental animals. We examined the effects of SS-14 and its analogue RC-160 on the in vitro growth of two human pancreatic cancer cell lines MiaPaCa-2 and Panc-1 stimulated with epidermal growth factor (EGF) or insulin-like growth factor 1 (IGF-1). Neither SS-14 nor RC-160 inhibited the growth of either cell line. In contrast RC-160 did inhibit the EGF-stimulated growth of a rat pancreatic cancer cell line AR42J. Binding studies with 125I-Tyr11 somatostatin revealed the presence of a single class of high affinity binding sites with a Kd of 0.20 +/- 0.05 nM and a Bmax of 2.1 +/- 0.26 pmoles mg-1 protein on AR42J but not displaceable binding was observed on MiaPaCa-2 or Panc-1. We conclude that lack of receptors accounts for the failure of SS-14 and RC-160 to influence the growth of human pancreatic cancer in vitro. These results, taken together with other findings, lead us to question the therapeutic efficacy of somatostatin and its analogues as mono-therapy in the treatment of human pancreatic cancer.

Topics: Animals; Carcinoma, Intraductal, Noninfiltrating; Epidermal Growth Factor; Humans; Insulin-Like Growth Factor I; Pancreatic Neoplasms; Rats; Receptors, Neurotransmitter; Receptors, Somatostatin; Somatostatin; Tumor Cells, Cultured

Exogenous epidermal growth factor (or somatostatin) can stimulate (or inhibit) proliferation of pancreatic cancer cells, with a corresponding decrease (or increase) of the saturation index of the cell membrane and up-regulation (or down-regulation) of insulin receptor expression. By measuring the saturation index and insulin receptor numbers on the cell membrane it may be possible to evaluate the curative effects of treatment on pancreatic cancer at an early time.

Topics: Cell Division; Cell Membrane; Epidermal Growth Factor; Humans; Oleic Acids; Pancreatic Neoplasms; Receptor, Insulin; Somatostatin; Stearic Acids; Tumor Cells, Cultured

The epidermal growth factor (EGF) receptor is activated by both EGF and transforming growth factor-alpha (TGF-alpha). Using immunohistochemical and immunoblotting techniques we now report that the EGF receptor, EGF, and TGF-alpha are found in both pancreatic acini and ducts in the normal human pancreas, and that all three proteins are expressed at higher levels in human pancreatic cancer tissues. Using in situ hybridization techniques, we also report that the mRNA encoding the EGF receptor, EGF, and TGF-alpha colocalize with their respective proteins. Northern blot analysis of total RNA indicates that, by comparison with the normal pancreas, the pancreatic tumors exhibit a 3-, 15-, and 10-fold increase in the mRNA levels encoding the EGF receptor, EGF, and TGF-alpha, respectively. Furthermore, by in situ hybridization, there is a marked increase in these mRNA moieties within the tumor mass. These findings suggest that EGF and TGF-alpha may participate in the regulation of normal pancreatic exocrine function, and that overexpression of the EGF receptor and its two principal ligands may contribute to the pathophysiological processes that occur in human pancreatic cancer.

Topics: Adult; Aged; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Male; Middle Aged; Pancreas; Pancreatic Neoplasms; RNA, Messenger; Transforming Growth Factor alpha

In this study, 3 human pancreatic adenocarcinoma cell lines (PC-1, PC-2 and PC-3) and 3 other human cancer cell lines (adenocarcinoma of lung, LETP; gastric carcinoma, SGL7901; and breast carcinoma, BCP37) were investigated by adding EGF, anti-EGF antiserum and anti-EGFR monoclonal antibody into culture medium. EGF was found to exert a mild stimulating effect on the growth of PC-1 and LETP cells, but had no effect on the other 4 cell lines. Anti-EGF and anti-EGFR antibodies inhibited the proliferation of PC-1, LETP and SGL7901 cells. No significant effect on the other 3 cell lines was seen. By using the Northern blot technique, expression of EGFR mRNA was identified in all 6 cell lines. There were 3 bands (10.5 kb, 5.8 kb and 2.8 kb) of EGFR mRNA in all cell lines except for LETP, in which the 10.5 kb band was absent. The results indicate that the effect of EGF on the growth of cancer cells is very complicated and may involve an unknown regulatory mechanism of cancer cell growth. EGF may exert stimulating or inhibiting effects on cancer cell proliferation, or it may have no effect at all, even though the EGFR gene was expressed in these cell lines.

Topics: Adenocarcinoma; Antibodies, Monoclonal; Cell Division; Epidermal Growth Factor; ErbB Receptors; Humans; Immune Sera; Lung Neoplasms; Pancreatic Neoplasms; RNA, Messenger; Stomach Neoplasms; Tumor Cells, Cultured

Analogues of somatostatin (SS) and luteinizing hormone-releasing hormone (LH-RH) activate tyrosine phosphatases in MIA PaCa-2 human pancreatic cancer cell line membranes and inhibit growth. We compared the substrates phosphorylated by epidermal growth factor (EGF) to those dephosphorylated by the SS analogue RC-160 (D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH2) and [D-Trp6]LH-RH in cancer cell lines such as MIA PaCa-2 (human pancreatic cancer), HCPC (hamster cheek pouch carcinoma), A-549 (human lung cancer), HT-29 (human colon cancer), and R3230AC (breast cancer). EGF phosphorylated proteins of 170, 65, and 60 kDa and analogues of SS and LH-RH promoted the dephosphorylation of these proteins in MIA PaCa-2 and HCPC cell lines. The EGF receptor is 170 kDa. pp60src (60 kDa) is known to be a substrate for EGF receptor. The LH-RH receptor is also 60 kDa. The effects of RC-160 and [D-Trp6]LH-RH were quantitatively different. Examinations of HT-29, A-549, and R3230AC cancer cell lines revealed no phosphorylation by EGF or dephosphorylation by RC-160 and [D-Trp6]LH-RH. In addition to the 170-, 65-, and 60-kDa proteins, 35-kDa proteins were also phosphorylated in some cancer cell lines. This work demonstrates that analogues of SS and LH-RH can reverse the effects of EGF biochemically as well as functionally.

Topics: Amino Acid Sequence; Animals; Antineoplastic Agents; Autoradiography; Breast Neoplasms; Cell Line; Colonic Neoplasms; Epidermal Growth Factor; Gonadotropin-Releasing Hormone; Humans; Kinetics; Lung Neoplasms; Membrane Proteins; Molecular Sequence Data; Pancreatic Neoplasms; Phosphorus Radioisotopes; Phosphorylation; Protein Kinases; Protein-Tyrosine Kinases; Somatostatin; Triptorelin Pamoate; Tyrosine

Overexpression of the epidermal growth factor receptor (EGFR) has been reported as an important molecular abnormality in human pancreatic cancer. There is in vitro evidence that simultaneous overproduction of one of its ligands, transforming growth factor alpha (TGF-alpha), might result in an autocrine loop with an increased proliferation signal. We analysed by immunocytochemical staining a retrospective series of human pancreatic cancers, chronic pancreatitis, and normal fetal and adult pancreatic tissues for the presence of TGF-alpha and epidermal growth factor (EGF). Ductal epithelial cells showed TGF-alpha immunoreactivity in both normal tissue and chronic pancreatitis, and 95 per cent of tumours showed strong immunoreactivity. In contrast, EGF immunoreactivity was not found in normal pancreas, but was expressed in 12 per cent of pancreatic carcinomas. Well-defined areas of EGF immunoreactivity in exocrine ducts showing reactive changes in pancreatitis might represent a benign response to tissue damage similar to that previously described in the gastric mucosa.

Topics: Adenocarcinoma; Chronic Disease; Epidermal Growth Factor; ErbB Receptors; Fetus; Humans; Immunoenzyme Techniques; Pancreas; Pancreatic Neoplasms; Pancreatitis; Staining and Labeling; Transforming Growth Factor alpha

Cultured human pancreatic cancer cells produce a number of growth factors, including transforming growth factor-alpha (TGF-alpha). These cells also overexpress the epidermal growth factor (EGF) receptor and exhibit a parallel increase in EGF receptor mRNA levels. TGF-alpha, which binds to the EGF receptor, is more potent than EGF in enhancing the anchorage-independent growth of several pancreatic cancer cell lines, including T3M4 cells. In contrast, EGF is more efficient than TGF-alpha with respect to EGF receptor downregulation and tyrosine phosphorylation in T3M4 cells. Further, T3M4 cells recycle EGF, but markedly degrade TGF-alpha. It is suggested that the production of multiple growth factors, the overexpression of the EGF receptor, the recycling of EGF, and the attenuated ability of TGF-alpha to downregulate the EGF receptor combine to enhance the growth advantage of human pancreatic cancer cells.

Topics: Epidermal Growth Factor; ErbB Receptors; Growth Substances; Humans; Pancreatic Neoplasms; Transforming Growth Factor alpha; Tumor Cells, Cultured

We studied the effects of hormonal manipulation by orchiectomy, alone or in combination with the aromatase inhibitor aminoglutethimide (AGT), and by luteinizing hormone-releasing hormone agonist (LH-RH-A) (goserelin) treatment on the development of early putative (pre)neoplastic lesions induced in the pancreas of rats and hamsters by azaserine and N-nitrosobis(2-oxopropyl)amine respectively. Treatment of the animals started 1 week after the last injection with carcinogen and continued for 4 months. Orchiectomy caused a significant inhibition of growth of acidophilic atypical acinar cell nodules in the rat model, whereas surgical castration did not show an effect in the hamster model. In rats, but not in hamsters, orchiectomy resulted in a significant decrease in body weight and in absolute, but not relative pancreatic weight. Treatment of the animals with AGT or goserelin did not cause a significant effect on the development of either putative preneoplastic acinar lesions in rat pancreas or early ductular lesions in hamster pancreas. Hamsters showed clearly higher plasma epidermal growth factor (EGF) and insulin-like growth factor 1 (IGF-1) concentrations than rats, while plasma testosterone levels were significantly lower. Plasma EGF and IGF-1 levels decreased with increasing age in both control and treatment groups. Compared to controls there were no clear unequivocal effects of treatment on EGF, IGF-1 and gastrin levels. Plasma testosterone levels decreased by orchiectomy and LH-RH-A treatment. In rats hormone-induced effects on food intake and altered nutritional status might be important with respect to the development of carcinogen-induced preneoplastic pancreatic lesions.

Topics: Aminoglutethimide; Animals; Azaserine; Body Weight; Buserelin; Carcinogens; Cricetinae; Epidermal Growth Factor; Gastrins; Goserelin; Male; Mesocricetus; Nitrosamines; Orchiectomy; Organ Size; Pancreatic Neoplasms; Precancerous Conditions; Rats; Rats, Inbred Strains; Somatomedins; Testosterone

Cultured human pancreatic cancer cells produce transforming growth factor-alpha (TGF-alpha), a potent mitogenic polypeptide. In the present study, we investigated the regulation of TGF-alpha mRNA expression in T3M4 human pancreatic carcinoma cells. TGF-alpha mRNA levels were quantitated by densitometric analysis of autoradiographs obtained following hybridization of size-fractionated cytoplasmic RNA with 32P-labeled cRNA coding for human TGF-alpha. There was a twofold increase in TGF-alpha mRNA levels at 2 h following addition of either epidermal growth factor (EGF) or TGF-alpha. However, TGF-alpha mRNA levels declined to near basal levels by 10 h. At 2 h, one-half maximal stimulation of TGF-alpha mRNA levels occurred at 1 nM and maximal stimulation at 4 nM of either EGF or TGF-alpha. The transcriptional inhibitor actinomycin D (Act D) and the phorbol ester, 12-O-tetradecanoyl-phorbol-13-acetate (TPA), mimicked the actions of EGF and TGF-alpha. These findings indicate that the regulation of TGF-alpha mRNA expression in T3M4 cells is complex, and is mediated, in part, via the EGF receptor.

Topics: Dactinomycin; Epidermal Growth Factor; Gene Expression Regulation, Neoplastic; Humans; Nucleic Acid Hybridization; Pancreatic Neoplasms; RNA, Messenger; RNA, Neoplasm; Tetradecanoylphorbol Acetate; Transforming Growth Factor alpha; Tumor Cells, Cultured

The binding characteristics and biological activities of epidermal growth factor (EGF) and transforming growth factor alpha (TGF-alpha) were studied in T3M4 human pancreatic cancer cells. Scatchard analysis of 125I-EGF binding data at pH 7.4 indicated the presence of two orders of binding sites: a high-affinity site (Kd = 0.58 nM; 25,300 sites/cell) and a low-affinity site (Kd = 7.0 nM; 484,000 sites/cell). At pH 8.5, there was a decrease in the number of high-affinity sites. In contrast, only a single order of high-affinity sites was detected with 125I-TGF-alpha at either pH 7.4 (Kd = 0.57 nM; 100,200 sites/cell) or pH 8.5 (Kd = 0.70 nM; 230,400 sites/cell). The two ligands bound to the same receptor, as determined in cross-linking experiments and in competitive binding assays performed in the presence of an anti-EGF receptor antibody that allows for EGF binding. Phosphoamino acid analysis of the immunoprecipitated EGF receptor indicated that EGF exerted a greater effect than TGF-alpha on tyrosine phosphorylation of the receptor. EGF and TGF-alpha also exhibited different potencies with respect to their effects on inositol 1,4,5-trisphosphate generation and exerted divergent effects on the kinetics of inositol 1,4,5-trisphosphate formation. These findings point to dissimilar interactions of EGF and TGF-alpha with the EGF receptor in T3M4 cells, which may lead to differential activation of signal transduction pathways by these ligands.

Topics: Epidermal Growth Factor; ErbB Receptors; Humans; Hydrogen-Ion Concentration; Inositol 1,4,5-Trisphosphate; Iodine Radioisotopes; Pancreatic Neoplasms; Phosphorylation; Statistics as Topic; Transforming Growth Factor alpha; Tumor Cells, Cultured; Tyrosine

Hematopoietic growth factors have recently been well characterized by complementary DNA cloning. For human epidermal growth factor, granulocyte-macrophage colony-stimulating factor recombinant proteins have been expressed in Escherichia coli. To reduce the toxic side effects of chemotherapy on the bone marrow, recombinant human granulocyte-macrophage colony-stimulating factor and recombinant human interleukin 3 were applied to patients suffering of gastrointestinal cancers. To determine the influence of recombinant human granulocyte-macrophage colony-stimulating factor and recombinant human interleukin 3 on human pancreas and gastric cancer cell cells in vitro, a sensitive microculture test system was established that allows precise quantification of proliferation. A more than twofold enhancement of proliferation was observed by interleukin 3 and granulocyte-macrophage colony-stimulating factor in two of two cell cultures derived from gastric carcinoma cells, while two of nine cultures from pancreas carcinoma cells have shown enhanced cell growth in the presence of recombinant human interleukin 3 or recombinant human granulocyte-macrophage colony-stimulating factor. In comparison, recombinant human epidermal growth factor increased cell growth in two of two gastric and in five of nine pancreas carcinoma cultures. In general, 1-10 ng/mL of the growth factors yielded the highest growth rate, but even 1-pg amounts produced increased cell growth. Expression of messenger RNA for granulocyte-macrophage colony-stimulating factor, interleukin 3, and the oncogene HER2/neu remained undetectable in all of the tested cell lines, while the various abundance of messenger RNA for the epidermal growth factor receptor was different in each cell line. The reported results imply that the hematopoietic growth factors interleukin 3 and granulocyte-macrophage colony-stimulating factor influence cellular growth of pancreas and gastric carcinoma cells by a paracrine mechanism and may possess a more general regulatory function than originally anticipated.

Topics: Animals; Cell Division; Epidermal Growth Factor; Granulocyte-Macrophage Colony-Stimulating Factor; Interleukin-3; Mice; Pancreatic Neoplasms; RNA, Messenger; Stomach Neoplasms; Tumor Cells, Cultured

UCVA-1 cells, derived from human pancreas adenocarcinoma, have a high number of epidermal growth factor (EGF) receptors (1.0 x 10(6) per cell) but their growth is not inhibited by EGF, unlike other EGF receptor-hyperproducing tumour cells. In UCVA-1 cells EGF activates neither the phosphatidylinositol turnover nor protein kinase C. EGF, however, enhances the phosphorylation of EGF receptors at specific tyrosine residues, indicating that the EGF receptor kinase is active and subject to autophosphorylation. Downmodulation of EGF receptors by 12-O-tetradecanoylphorbol 13-acetate (TPA) is also observed. Using an anti-phosphotyrosine antibody several phosphoproteins, including EGF receptors, were immunoprecipitated from UCVA-1 cell lysates, whereas more than 20 phosphoproteins were detected in other EGF receptor-hyperproducing tumour cells (NA), indicating that tyrosine-phosphorylation of endogenous substrates by EGF receptor kinase is significantly reduced in UCVA-1 cells. Thus, non-responsiveness of UCVA-1 cells to EGF is correlated with the reduced tyrosine phosphorylation.

Topics: Carcinoma, Squamous Cell; Cell Division; Down-Regulation; Epidermal Growth Factor; ErbB Receptors; Humans; Pancreatic Neoplasms; Peptide Mapping; Phosphatidylinositols; Phosphoproteins; Phosphorylation; Protein-Tyrosine Kinases; Tetradecanoylphorbol Acetate; Tumor Cells, Cultured; Tyrosine

Several studies have reported effects of gastrointestinal regulatory peptides on growth of experimentally induced pancreatic neoplasms and human cancer cell lines. The growth of human pancreatic cancer lines PANC-1 and MIA PaCa-2 was characterized in vitro, and the effects of cholecystokinin, bombesin, insulin, epidermal growth factor, secretin, vasoactive intestinal peptide, and somatostatin were determined. Fetal bovine serum was required for initiation of growth in both cell lines. Growth effects of peptides were determined by incubating cells with peptides in serum-free medium after a 72-h preincubation in 10% serum-supplemented medium alone. Epidermal growth factor (3.4 x 10(-9) M) and insulin (10(-6) M) significantly (p less than 0.001) increased growth of both cell lines as determined by increases in deoxyribonucleic acid and protein. Bombesin, secretin, vasoactive intestinal peptide, and somatostatin (all 10(-8) M) did not affect growth of either cell line. Neither cholecystokinin-8 nor [Thr4, Nle7] cholecystokinin-9 altered growth in concentrations from 10(-12)-10(-6) M. Anchorage-dependent clonogenic growth of both cell lines was also not altered by cholecystokinin-8. Cholecystokinin added to cultures was degraded by separate effects of serum and cells. Addition of cholecystokinin-8 to cultures every 8 h maintained cholecystokinin levels but did not alter cell growth. These data support roles for epidermal growth factor and insulin as growth factors for human pancreatic cancer cell lines.

Topics: Blood; Carcinoma; Cell Division; Cholecystokinin; Clone Cells; Culture Media; DNA, Neoplasm; Epidermal Growth Factor; Gastrointestinal Hormones; Humans; Insulin; Neoplasm Proteins; Pancreatic Neoplasms; Tumor Cells, Cultured

We investigated immunohistochemical expressions of the epidermal growth factor (EGF) and the epidermal growth factor receptor (EGFR) in 25 cases of pancreatic carcinoma, including 13 cases of metastatic lymph nodes. EGF and EGFR were stained mainly in the cytoplasm and on the surface of some pancreatic carcinoma cells, with positive rates of 18/25 (72%) and 9/25 (36%) respectively. In all cases EGFR was noted only when EGF was also detected. EGF and EGFR were stained frequently in differentiated types. In metastatic lymph nodes, EGF and EGFR were found in 54% and 15% respectively, and they were detected only when they were also noted in the same patient's primary lesions. EGF and EGFR were found more frequently in Stages III and IV than in Stage II. These results emphasize that EGF and EGFR may promote both the proliferation and the differentiation of human pancreatic carcinoma cells, as in other sites.

Topics: Adult; Aged; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Immunohistochemistry; Male; Middle Aged; Pancreatic Neoplasms

The existence of different classes of EGF receptors in human pancreatic cancer cells has yet not been determined. EGF binding to two cancer cell lines (CAPAN-1 and MIA PaCa-2) was studied. Two classes of EGF binding sites were characterized. The first class of EGF binding sites demonstrated a high affinity and low capacity for EGF, with a Kd of 0.25 +/- 0.11 nM, close to the concentration of EGF suggested to be present in human pancreatic juice. The second class of EGF binding sites had a lower affinity and a higher capacity for EGF, with Kd of 1.78 +/- 0.61 nM. The total number of EGF binding sites was about 40,000/cell. Treatment of the cells with a phorbol ester, TPA, caused a complete loss of the high affinity binding sites and also caused a decrease in the concentration of the lower affinity binding sites present on the cells. Interestingly, with the increasing age of the cells, the concentration of both the high and low affinity EGF binding sites was significantly decreased. In the presence or absence of fetal calf serum, EGF, at concentrations higher than 1.10(-10)M, exerted a dose-dependent mitogenic effect on the growth of the pancreatic cancer cells in culture. These data demonstrate the existence of two classes of binding sites for EGF on some human pancreatic cancer cells and a possible role of EGF in the growth of pancreatic tumors.

Topics: Cell Division; Cell Survival; Epidermal Growth Factor; ErbB Receptors; Humans; Pancreatic Neoplasms; Tetradecanoylphorbol Acetate; Tumor Cells, Cultured

The role of epidermal growth factor (EGF) in oncogenesis and progression of malignant tumors is a subject of vast interest. In this study, radioimmunoassay and radioreceptor assay of EGF were established. EGF contents in malignant and benign pancreatic tumors, in normal pancreas tissue, and in culture media of a human pancreatic carcinoma cell line were determined. EGF receptor binding studies were performed. It was shown that EGF contents in pancreatic carcinomas were significantly higher than those in normal pancreas or benign pancreatic tumors. EGF was also detected in the culture medium of a pancreatic carcinoma cell line. The binding of 125I-EGF to the pancreatic carcinoma cells was time and temperature dependent, reversible, competitive, and specific. Scatchard analysis showed that the dissociation constant of EGF receptor was 2.1 X 10(-9) M, number of binding sites was 1.3 X 10(5) cell. These results indicate that there is an over-expression of EGF/EGF receptors in pancreatic carcinomas, and that an autocrine regulatory mechanism may exist in the growth-promoting effect of EGF on tumor cells.

Topics: Epidermal Growth Factor; ErbB Receptors; Humans; Iodine Radioisotopes; Pancreatic Neoplasms; Radioimmunoassay; Radioligand Assay; Temperature

Pancreatic carcinoma is usually a fatal disease with most patients dying of metastases. We have developed several pancreatic carcinoma cell lines that have varying metastatic abilities in a splenic injection/liver metastasis model. Epidermal growth factor (EGF) is a mitogen to most cell types with increased levels of EGF receptor. The parent cell line (COLO-357) of the pancreatic carcinoma cell lines used in this study has been shown to have a high number of EGF receptors per cell. We studied the relationship between the mitogenic responsiveness to EGF and the metastatic rate of each of the cell lines. Three of the six cell lines were significantly stimulated by EGF as determined by an increase in cell number over the course of 4 days, and three of the cell lines were not. There was no correlation between metastatic rate and EGF responsiveness. Further work will be needed to determine if there is any relationship between growth factors and their receptors and tumor metastasis with these pancreatic cancer cell lines.

Topics: Animals; Cell Division; Epidermal Growth Factor; ErbB Receptors; Humans; Mice; Mice, Nude; Neoplasm Metastasis; Neoplasm Transplantation; Pancreatic Neoplasms; Tumor Cells, Cultured

Information about the mechanism of beta-cell growth and regeneration may be obtained by studies of insulinoma cells. In the present study the growth and function of the rat insulinoma cell lines RINm5F and 5AH were evaluated by addition of serum, hormones, and growth factors. It was found that transferrin is the only obligatory factor whereas growth hormone, epidermal growth factor, fibroblast growth factor, and TRH had modulating effects. A heat-labile heparin binding serum factor which stimulated thymidine incorporation but not cell proliferation was demonstrated in human serum. Measurements of insulin mRNA content showed that the insulinoma cells only contained about 2% of that of normal rat beta-cells. These results are discussed in relation to the role of growth factors, oncogenes, and differentiation in the growth and regeneration of beta-cells.

Topics: Adenoma, Islet Cell; Animals; Cell Division; Cell Line, Transformed; Cell Transformation, Neoplastic; Epidermal Growth Factor; Fibroblast Growth Factors; Growth Hormone; Insulin; Insulinoma; Islets of Langerhans; Pancreas; Pancreatic Neoplasms; Rats; Regeneration; RNA, Messenger; Thymidine; Thyrotropin-Releasing Hormone; Transferrin; Tumor Cells, Cultured

Somatostatin has been demonstrated to negatively regulate pancreatic growth in vivo. In this study we used the AR4-2J rat pancreatic acinar tumor cell line to investigate the effect of a stable somatostatin analog, SMS 201-995 (SMS) on cell proliferation. SMS induced an antiproliferative effect on both serum or epidermal growth factor (EGF)-induced cell proliferation; exposure of the cells for 48 h to SMS caused a slight inhibition of serum-induced proliferation (maximal inhibition, 26%) and abolished the growth-promoting effect of EGF. Maximal effect was observed with 10 nM SMS, and half-maximal (IC50) effect with 0.06-0.1 nM SMS. Binding studies with an iodinated derivative of SMS, [125I-Tyr3]SMS, revealed the presence of a single class of high affinity binding sites on AR4-2J plasma membranes with an equilibrium dissociation constant of 0.2 +/- 0.03 nM and a binding site number of 1.1 +/- 0.07 pmol/mg protein. Addition of the nonhydrolyzable GTP analog, guanosine 5-[gamma-thio] triphosphate (GTP gamma S), increased the rate of dissociation of the specifically bound peptide in agreement with the coupling of somatostatin receptors with a GTP-binding regulatory protein. The good agreement between the IC50 for SMS inhibition of cell proliferation and the apparent Kd for binding indicates that the characterized binding sites are the somatostatin receptors that mediate the antiproliferative effect of SMS. When cells were grown in serum-free medium EGF stimulated AR4-2J cell proliferation with half-maximal (ED50) and maximal effects at 0.6 and 10 nM EGF, respectively. This stimulatory effect of EGF was mediated by specific receptors, since binding studies with [125I]EGF indicated that AR4-2J cells contained a single class of EGF receptors (13,000 sites/cell), with an affinity constant for [125I]EGF (Kd = 0.9 +/- 0.09 nM) close to the ED50 for EGF stimulation of cell growth. To examine if SMS-induced growth inhibition involved a cAMP-dependent mechanism we first studied the effect of SMS on cAMP production. SMS had no effect on basal cAMP, but completely inhibited VIP-stimulated cAMP production with an IC50 of 0.2 nM. Pertussis toxin, which is known to abolish the inhibitory effect of somatostatin on adenylate cyclase activity in AR4-2J cells, did not reverse the ability of SMS to inhibit cell proliferation as well as EGF-induced cell proliferation. These data indicate that the antiproliferative effect of SMS does not involve the GTP-binding protein-mediated n

Topics: Adenylate Cyclase Toxin; Animals; Cell Division; Cell Line; Cyclic AMP; DNA Replication; Epidermal Growth Factor; ErbB Receptors; GTP-Binding Proteins; Kinetics; Octreotide; Pancreatic Neoplasms; Pertussis Toxin; Receptors, Neurotransmitter; Receptors, Somatostatin; Somatostatin; Thymidine; Virulence Factors, Bordetella

T3M4 human pancreatic carcinoma cells avidly bound and internalized 125I-labeled epidermal growth factor (EGF) but did not readily degrade the ligand. Pulse-chase experiments in which the cell-bound radioactivity was allowed to dissociate into the incubation medium in the presence of unlabeled EGF indicated that the majority of the released 125I-EGF consisted of intact EGF and a slightly processed species that readily bound to the cell. Omission of unlabeled EGF during the chase period markedly decreased the amount of radioactivity in the incubation medium, mainly as a result of the rebinding of EGF to the cells. In contrast, T3M4 cells readily degraded 125I-labeled transforming growth factor-alpha (TGF-alpha), and the released radiolabeled products did not rebind to the cells. Both ligands were released from T3M4 cells under acidic conditions, complete dissociation occurring at a pH of 4.5 for EGF, and a pH of 6.5 for TGF-alpha. A 431 human epidermoid carcinoma cells and ASPC-1 human pancreatic carcinoma cells also failed to extensively degrade 125I-EGF, whereas Rat-1 fibroblasts markedly degraded the growth factor. As in the case of T3M4 cells, ASPC-1 cells extensively degraded 125I-TGF-alpha. Degradation of either ligand was blocked by the lysosomotropic compound methylamine in all the tested cell lines. Immunoprecipitation of the EGF receptor with specific polyclonal antibodies and Western blot analysis revealed the anticipated 170-kDa protein in T3M4 cells. Both EGF and TGF-alpha enhanced EGF receptor degradation, but TGF-alpha was less effective than EGF. These findings indicate that in certain cell types EGF and TGF-alpha may be differentially processed.

Topics: Animals; Binding, Competitive; Carcinoma; Cell Line; Epidermal Growth Factor; ErbB Receptors; Humans; Iodine Radioisotopes; Kinetics; Mice; Pancreatic Neoplasms; Transforming Growth Factors; Tumor Cells, Cultured

Topics: Epidermal Growth Factor; ErbB Receptors; Humans; Pancreatic Neoplasms

The incidence of Syrian golden hamsters with pancreatic cancer induced by subcutaneous injections of N-nitroso-bis(2-oxopropyl)amine for 19 weeks (each 10 mg/kg) increased from 44% to 75% (p=0.016) when epidermal growth factor was also administered from week 5 through week 8 (5 mug energy three days for injections). Epidermal growth factor increased pancreatic weight and body weight. The incidence of animals with bronchial cancer doubled. Epidermal growth factor could be a cocarcinogen as a result of its mitogenic activity.

Topics: Animals; Bronchial Neoplasms; Carcinogens; Cocarcinogenesis; Cricetinae; Epidermal Growth Factor; Female; Mesocricetus; Nitrosamines; Pancreatic Neoplasms

Previous work showed that cultured human pancreatic cancer cells overexpress the epidermal growth factor (EGF) receptor. In the present study, we sought to determine whether some of these cell lines produce transforming growth factor alpha (TGF-alpha). Utilizing a radiolabeled TGF-alpha cDNA in hybridization experiments, we determined that ASPC-1, T3M4, PANC-1, COLO-357, and MIA PaCa-2 cell lines expressed TGF-alpha mRNA. Serum-free medium conditioned by T3M4 and ASPC-1 cells contained significant amounts of TGF-alpha protein. Although unlabeled TGF-alpha readily competed with 125I-labeled EGF for binding, each cell line exhibited lower surface binding and internalization of 125I-labeled TGF-alpha as compared to 125I-labeled EGF. Both TGF-alpha and EGF significantly enhanced the anchorage-independent growth of PANC-1, T3M4, and ASPC-1 cells. However, TGF-alpha was 10- to 100-fold more potent than EGF. These findings suggest that the concomitant overexpression of EGF receptors and production of TGF-alpha may represent an efficient mechanism for certain cancer cells to obtain a growth advantage.

Topics: Cell Division; Cell Line; Epidermal Growth Factor; ErbB Receptors; Humans; Kinetics; Neoplasm Proteins; Nucleic Acid Hybridization; Pancreatic Neoplasms; Peptide Biosynthesis; Peptides; Transforming Growth Factors

The peptide somatostatin (SRIF) is secreted by delta cells of the endocrine pancreas and inhibits the secretion of insulin from pancreatic beta cells. We have previously shown that [125I-Tyr11]SRIF binds to specific, high affinity receptors on RINm5F insulinoma cells and that these receptors mediate the action of SRIF to inhibit insulin release. In the present study we investigated the processing of receptor-bound [125I-Tyr11]SRIF in this clonal cell line. Surface-bound and internalized peptides were distinguished by the ability of an acid/salt solution (0.2 M acetic acid, 0.5 M NaCl, pH 2.5) to dissociate only exposed ligand-receptor complexes. Surprisingly, greater than 80% of saturably bound [125I-Tyr11]SRIF was removed by this acid wash independent of the time or temperature of the binding incubation. In contrast, the processing of receptor-bound [125I]EGF (epidermal growth factor) in RINm5F cells was markedly temperature-dependent. Although over 90% of saturably bound [125I]EGF was dissociated by acid after a 4 degrees C binding incubation, less than 10% was removed by acid treatment after 37 degrees C binding. The radioactivity released upon dissociation of receptor-bound [125I-Tyr11]SRIF was analyzed by high performance liquid chromatography and shown to consist of a mixture of intact peptide (40%) and [125I]tyrosine (60%). However, neither the rate of [125I-Tyr11]SRIF dissociation nor its degradation were affected by NH4Cl, methylamine, or leupeptin at concentrations which inhibited the lysosomal degradation of [125I] EGF. Of 11 other protease inhibitors tested, only the metalloendoprotease inhibitor, phosphoramidon, substantially reduced the degradation of receptor-bound [125I-Tyr11]SRIF. These data indicate that, unlike [125I] EGF, receptor-bound [125I-Tyr11]SRIF is not rapidly internalized by RINm5F cells and is degraded by a nonlysosomal process which may involve a metalloendoprotease.

Topics: Adenoma, Islet Cell; Ammonium Chloride; Animals; Cells, Cultured; Deoxyglucose; Epidermal Growth Factor; Glycopeptides; Insulinoma; Iodine Radioisotopes; Lysosomes; Methylamines; Pancreatic Neoplasms; Protease Inhibitors; Rats; Receptors, Cell Surface; Receptors, Somatostatin; Somatostatin; Temperature

The effects of epidermal growth factor (EGF) and somatostatin-14 (SS) on growth of Mia PaCa-2 cells in cell culture were examined. EGF had no effect on cell growth in sera containing media but significantly increased growth in sera-free media. The effect of EGF was complete within 18 h. SS added with EGF entirely eliminated the growth stimulation of EGF. SS added to cells in culture with sera inhibited their growth as well.

Topics: Cell Division; Cell Line; Epidermal Growth Factor; ErbB Receptors; Humans; Neoplasms, Hormone-Dependent; Pancreatic Neoplasms; Somatostatin

Because epidermal growth factor (EGF) is rapidly bound and internalized into rat pancreas, stimulates uptake of tritiated thymidine, and increases pancreatic weight, a cocarcinogenic effect on pancreatic cancer seemed likely. Pancreatic adenocarcinomas were induced in 70 female Syrian hamsters by 19 weekly s.c. injections of N-nitrosobis(2-oxopropyl)amine (BOP) (10 mg/kg). From Wk 5 through Wk 8 of BOP injections, additional s.c. injections of EGF (5 micrograms every 3 days for 10 injections) were given to 45 animals, while 25 received saline solution. An additional group of 10 received EGF alone, and another 10 animals received saline solution alone (controls). Eleven wk later, the mean body weight of EGF-treated animals increased by 29% as compared with that of controls, and their mean pancreatic weight relative to body weight increased by 44% as compared with controls. The mean body weight of EGF + BOP-treated animals increased by 10%, and their pancreatic weight relative to body weight increased by 22% as compared with that of animals treated with BOP alone. The incidence of pancreatic cancer in the EGF + BOP-treated animals was 75% versus 44% in those treated with BOP alone (P = 0.016). No tumors developed in either animals treated with EGF alone or control animals. EGF augments pancreatic carcinogenesis induced by BOP. The incidence of bronchial carcinomas doubles.

Topics: Adenocarcinoma; Animals; Body Weight; Bronchial Neoplasms; Carcinogens; Cocarcinogenesis; Cricetinae; Epidermal Growth Factor; ErbB Receptors; Female; Mesocricetus; Nitrosamines; Oncogenes; Pancreatic Neoplasms; Receptors, Cell Surface; Receptors, Platelet-Derived Growth Factor

Recently, the gene for the epidermal growth factor (EGF) receptor has been mapped to chromosome 7p, the short arm of chromosome 7 [Shimizu, N., Kondo, I., Gamou, M. A., Behzadian, A. & Shimizu, Y. (1984) Somatic Cell Mol. Genet. 10, 45-53]. Utilizing EGF binding in saturation studies, karyology, and cDNA hybridization experiments, we have sought to determine whether there is a correlation between dosage or alteration of chromosome 7 and enhanced expression of EGF receptor in cultured human pancreatic carcinoma cells. Saturation binding studies with 125I-labeled EGF were performed at 4 degrees C with four established human pancreatic cancer cell lines: T3M4, PANC-1, COLO 357, and UACC-462. Analysis of binding data revealed enhanced numbers of EGF receptors in all four cell lines. Chromosome banding analysis revealed clonal structural alterations of chromosome 7p in the cell lines T3M4, PANC-1, and COLO 357, whereas UACC-462 displayed multiple copies of chromosome 7. Hybridization studies using a radiolabeled EGF receptor cDNA probe failed to demonstrate DNA sequence amplification in any cell line but confirmed the presence of EGF receptor mRNA in these cells in approximate proportion to EGF receptor number. Our results suggest that enhanced expression of EGF receptor in human pancreatic cancer can be associated with either structural or numerical alterations of chromosome 7.

Topics: Cell Line; Chromosome Deletion; Chromosomes, Human, 6-12 and X; DNA, Neoplasm; Epidermal Growth Factor; ErbB Receptors; Humans; Pancreatic Neoplasms; Receptors, Cell Surface; Translocation, Genetic

A membrane receptor and a cytosolic receptor for somatostatin were found in a human undifferentiated pancreatic cancer cell line (MIA PaCa-2). Binding of somatostatin to this membrane receptor activates dephosphorylation of a phosphotyrosyl-membrane protein whose phosphorylation was promoted by epidermal growth factor (EGF). Vanadate, a purported inhibitor of dephosphorylation, interferes with the action of somatostatin. These findings suggest a possible biochemical mechanism by which somatostatin may inhibit the growth of human pancreatic cancers.

Topics: Cell Line; Epidermal Growth Factor; Humans; Membrane Proteins; Pancreatic Neoplasms; Phosphoprotein Phosphatases; Phosphoproteins; Phosphorylation; Receptors, Cell Surface; Receptors, Somatostatin; Somatostatin; Vanadates; Vanadium

The binding of 125I-labeled epidermal growth factor (EGF) was studied in Panc-I human pancreatic carcinoma cells. At 37 degrees C, binding was rapid and associated with marked endocytosis of the ligand. Bound EGF was sequentially converted to a number of more acidic species as follows: pI 4.55 to pI 4.2, to pI 4.35, to pI 4.0. EGF internalization and processing were blocked at 4 degrees C. EGF did not alter cell growth when Panc-I cells were incubated in the presence of 2 to 10% serum. In contrast, when the serum concentration was lowered to 0.1%, EGF significantly enhanced cell replication after 6 days of culture.

Topics: Autoradiography; Cell Division; Cells, Cultured; DNA, Neoplasm; Epidermal Growth Factor; ErbB Receptors; Humans; Isoelectric Focusing; Pancreatic Neoplasms; Protein Processing, Post-Translational; Radioligand Assay; Receptors, Cell Surface

PANC-1 human pancreatic carcinoma cells readily bound and internalized 125I-labeled epidermal growth factor (EGF). Bound 125I-labeled EGF was then partially processed to a number of high molecular weight acidic species. Percoll gradient centrifugation of cell homogenates indicated that the majority of 125I activity localized to several intracellular vesicular compartments. Both intact EGF and its processed species were subsequently released into the incubation medium. A major portion of the released radioactivity was capable of rebinding to the cell. Only a small amount of bound 125I-labeled EGF was degraded to low molecular weight products, and this degradation was completely blocked by methylamine. This lysosomotropic compound did not arrest either the generation or the extrusion of the major high molecular weight species of processed EGF (pI 4.2). These findings suggest that in PANC-1 cells, bound EGF undergoes only limited processing. Both intact EGF and its major processed species bypass the cellular degradative pathways, are slowly released from the cell, and then rebind to the cell.

Topics: Biological Transport; Carcinoma; Cell Line; Culture Media; Endocytosis; Epidermal Growth Factor; ErbB Receptors; Exocytosis; Humans; Isoelectric Point; Lysosomes; Molecular Weight; Pancreatic Neoplasms; Peptide Fragments; Receptors, Cell Surface

EGF binding capacity was examined in 9 different human cell lines which were derived from colon, rectum and pancreas tumors. Among these cell lines, a pancreatic carcinoma cell line, UCVA-1, was found to possess a high number (0.9 X 10(6)/cell) of EGF receptors. This number is comparable to that of EGF receptors in human vulva epidermoid carcinoma A431 cells (2 X 10(6)/cell). However, it was found that, unlike A431 cells, the growth of UCVA-1 cells, in serum-containing and serum-free conditions, was not inhibited by EGF. The UCVA-1 cells have EGF receptor of Mr = 170 K and of two affinity types: Kd1 = 72 X 10(-9) M and Kd2 = 2 X 10(-8) M. The EGF receptors in UCVA-1 cells are less susceptible to proteolytic cleavage than those in A431 cells. In UCVA-1 cells, EGF is apparently processed via a receptor-mediated endocytosis. The UCVA-1 cell membrane contained EGF-stimulated protein kinase as was found in A431 cells. The stimulation of phosphorylation by EGF was only approximately 20% in UCVA-1 while it was over 100% in A431. When angiotensin II was used as a substrate, the relative activity of EGF-dependent tyrosine-specific protein phosphorylation was approximately 8 times less in UCVA-1 cell membrane. The EGF-stimulated phosphorylation was mostly on EGF receptors for both cell lines. However, several other components (Mr = 100 K, 80 K, 72 K and 65 K) were readily detected in A431 cells. These observations indicate that the EGF receptor/protein kinase relation differs in these two cell lines and suggests that it may be related to the growth-inhibitory effect of EGF seen in A431.

Topics: Carcinoma, Squamous Cell; Cell Line; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Kinetics; Pancreatic Neoplasms; Phosphoproteins; Phosphorylation; Protein Kinases; Receptors, Cell Surface; Vulvar Neoplasms