hes1-protein--human and Pancreatic-Neoplasms

Increasing reports have revealed that dysregulated expression of long non-coding RNAs (lncRNAs) is involved in pancreatic carcinoma progression. This study intends to explore the function and molecular mechanism of lncRNA HLA complex group 11 (HCG11) in pancreatic carcinoma.. The expression profiles of HCG11 in pancreatic carcinoma samples were detected by qPCR. Bioinformatics analysis was applied to detect the associations among HCG11/miR-579-3p/MDM2. The malignant properties of pancreatic carcinoma cells were measured by numerous biological assays. Xenograft model was exploited to detect the effect of HCG11 on tumor growth.. A significant increase of HCG11 was occurred in pancreatic carcinoma samples. Knockdown of HCG11 suppressed the progression of pancreatic carcinoma cells. Bioinformatics analysis revealed that HCG11 upregulated MDM2 expression by competitively targeting miR-579-3p. The rescue assays showed that miR-579-3p reversed cell behaviors caused by HCG11, and MDM2 reversed cell properties induced by miR-579-3p. The Notch1 intracellular domain (NICD) and Hes1 protein levels were increased by overexpression of HCG11/MDM2. The tumor growth was suppressed after depletion of HCG11, followed by suppressing Ki67, PCNA and Vimentin expression, increasing TUNEL-positive cells and E-cadherin expression.. Our observations highlighted that HCG11 contributed to the progression of pancreatic carcinoma by promoting growth and aggressiveness, and inhibiting apoptosis via miR-579-3p/MDM2/Notch/Hes1 axis.

Topics: Animals; Apoptosis; Base Sequence; Cell Line, Tumor; Cell Movement; Cell Proliferation; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Humans; Mice; MicroRNAs; Pancreatic Neoplasms; Proto-Oncogene Proteins c-mdm2; Receptors, Notch; Reproducibility of Results; RNA, Long Noncoding; Signal Transduction; Transcription Factor HES-1; Xenograft Model Antitumor Assays

Emerging evidence indicates that myeloma overexpressed (MYEOV) is an oncogene and plays crucial roles in multiple human cancers. However, its roles in the development of pancreatic ductal adenocarcinoma (PDAC) remain elusive. Here, we provide evidence of essential roles of MYEOV in the development and progression of PDAC. In tumor specimens derived from pancreatic cancer patients, MYEOV was overexpressed and associated with poor prognosis. In addition, MYEOV expression in PDAC was upregulated through promoter hypomethylation. MYEOV depletion impaired metastatic ability and proliferation of PDAC cells both in vitro and in vivo, whereas its overexpression had the opposite effect. Mechanistic investigations revealed that MYEOV interacted with SRY-Box Transcription Factor 9 (SOX9), a well-known oncogenic transcription factor in PDAC. This interaction occurred mainly in the nuclei of PDAC cells and increased transcriptional activity of SOX9. Furthermore, MYEOV promoted the expression of Hairy and enhancer of split homolog-1 (HES1), a SOX9 target gene, by enhancing SOX9 DNA-binding ability to the HES1 enhancer without affecting the protein level and subcellular localization of SOX9. HES1 knockdown partly abrogated the oncogenic effect of MYEOV. Our findings suggest that MYEOV could be a potential prognostic biomarker and therapeutic target for PDAC.

Topics: Aged; Animals; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Cell Movement; Cell Proliferation; Disease Progression; Disease-Free Survival; Enhancer Elements, Genetic; Female; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; Male; Mice; Middle Aged; Pancreas; Pancreatectomy; Pancreatic Neoplasms; Prognosis; Proto-Oncogene Proteins; SOX9 Transcription Factor; Transcription Factor HES-1; Xenograft Model Antitumor Assays

Perturbation of pancreatic acinar cell state can lead to acinar-to-ductal metaplasia (ADM), a precursor lesion to the development of pancreatic ductal adenocarcinoma (PDAC). In the pancreas, Notch signaling is active both during development and in adult cellular differentiation processes. Hes1, a key downstream target of the Notch signaling pathway, is expressed in the centroacinar compartment of the adult pancreas as well as in both preneoplastic and malignant lesions. In this study, we used a murine genetic in vivo approach to ablate Hes1 in pancreatic progenitor cells (Ptf1a

Topics: Acinar Cells; Animals; Carcinogenesis; Carcinoma, Pancreatic Ductal; Cell Differentiation; Cell Plasticity; Ceruletide; Disease Models, Animal; Female; Humans; Male; Metaplasia; Mice; Pancreas; Pancreas, Exocrine; Pancreatic Neoplasms; Pancreatitis; Regeneration; Signal Transduction; Stem Cells; Transcription Factor HES-1

The present study aims to evaluate whether repression of the Numb/Notch signaling pathway affects the radiosensitivity of human pancreatic cancer cell lines. Different doses of X-rays (0, 2, 3, 4, and 5 Gy) were applied to the PANC-1, SW1990, and MIA PaCa-2 human pancreatic cancer cell lines, and the Numb/Notch pathway inhibitor DAPT was added at different doses (0, 1, 3, and 5 μmol/l). MTT assay, colony formation assay, flow cytometry, scratch assay, and Transwell experiments were performed, and qRT-PCR and Western blot were conducted for the detection of Numb expression. Tumorigenicity assay in nude mice was carried out to verify the influence of blocker of the Numb/Notch signaling pathway on the radiosensitivity of xenograft tumors. The MTT assay, colony formation assay and flow cytometry experiments revealed that proliferation decreased as radiation dose increased. The viability of PANC-1 cells at 5 Gy, SW 1990 cells at 4 Gy and 5 Gy, and MIA PaCa-2 cells at 2-5 Gy was significantly lower than that of non-irradiated cells (all P < 0.05). The migration and invasion assays indicated that the PANC-1 cell line was least radiosensitive, while the MIA PaCa-2 cell line was the most radiosensitive. Numb expression significantly increased with increasing radiation dose, whereas the expression of Hes1, Notch1, and Hes5 significantly decreased compared to non-irradiated cells (P < 0.05). Compared to untreated control cells, DAPT dose dependently increased Numb expression and inhibited Notch1, Hes1, and Hes5 expressions at 2 Gy (P < 0.05). Subcutaneous tumorigenicity assay in nude mice demonstrated that DAPT increased the radiosensitivity of PANC-1, SW 1990, and MIA PaCa-2 cells. These findings suggest that Numb/Notch signaling in pancreatic cancer cells is associated with X-ray radiation and that inhibition of the Numb/Notch signaling pathway can enhance radiosensitivity, suggesting that inhibition of the Numb/Notch signaling pathway may serve as a potential target for clinical improvement of the radiosensitivity of pancreatic cancer.

Topics: Animals; Apoptosis; Blotting, Western; Cell Proliferation; Diamines; Gene Expression Regulation, Neoplastic; Humans; Male; Membrane Proteins; Mice; Mice, Inbred BALB C; Mice, Nude; Nerve Tissue Proteins; Pancreatic Neoplasms; Radiation Tolerance; Radiation, Ionizing; Real-Time Polymerase Chain Reaction; Receptors, Notch; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Thiazoles; Transcription Factor HES-1; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

The role of pancreatic stellate cells (PSCs) has been established in many studies. However, the potential mechanism for the chemoresistance induced by PSCs has not been fully elucidated. In the present study, human pancreatic cancer cell lines were directly or indirectly co-cultured with PSCs. The inhibition rate and IC50 values were assessed to determine the ability of chemoresistance. RT-PCR and western blot analysis were used to evaluate Hes 1 and Jagged 1 expression before and after co-culture with PSCs. To determine the relationship between Hes 1 expression and survival in pancreatic cancer patients, Kaplan-Meier survival analysis was performed. PSCs promoted the expression of Hes 1 in both PANC-1 and BxPC-3 cell lines and induced chemoresistance to gemcitabine. A Notch signaling pathway inhibitor (L1790) and Hes 1 siRNA reversed the chemoresistance induced by PSCs. In 72 resected pancreatic cancer patients, high Hes 1 expression was observed in 34 patients with shorter overall and progression-free survival times. In conclusion, Hes 1 is essential for chemoresistance induced by PSCs and is associated with poor prognosis in pancreatic cancer patients. Therapy targeting the Notch signaling pathway may reverse chemoresistance and improve survival in patients with pancreatic cancer.

Topics: Adenocarcinoma; Aged; Animals; Antimetabolites, Antineoplastic; Basic Helix-Loop-Helix Transcription Factors; Cell Line, Tumor; Coculture Techniques; Culture Media, Conditioned; Deoxycytidine; Disease Progression; Disease-Free Survival; Drug Resistance, Neoplasm; Female; Gemcitabine; Gene Expression Regulation, Neoplastic; Homeodomain Proteins; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Neoplasm Proteins; Pancreatic Neoplasms; Pancreatic Stellate Cells; Prognosis; Proportional Hazards Models; Rats; Receptors, Notch; RNA Interference; RNA, Small Interfering; Signal Transduction; Transcription Factor HES-1

Pancreatic cancer remains a lethal disease with limited treatment options. At the time of diagnosis, approximately 80% of these patients present with unresectable tumors caused by either locally advanced lesions or progressive metastatic growth. Therefore, development of novel treatment strategies and new therapeutics is needed. Xanthohumol (XN) has emerged as a potential compound that inhibits various types of cancer, but the molecular mechanism underlying the effects of XN remains unclear. In the present study, we have assessed the efficacy of XN on pancreatic cancer cell lines (AsPC-1, PANC-1, L3.6pl, MiaPaCa-2, 512, and 651) against cell growth in real time and using colony-forming assays. Treatment with XN resulted in reduction in cellular proliferation in a dose- and time-dependent manner. The growth suppression effect of XN in pancreatic cancer cell lines is due to increased apoptosis via the inhibition of the Notch1 signaling pathway, as evidenced by reduction in Notch1, HES-1, and survivin both at mRNA as well as protein levels. Notch1 promoter reporter analysis after XN treatment indicated that XN downregulates Notch promoter activity. Importantly, overexpression of active Notch1 in XN-treated pancreatic cancer cells resulted in negation of growth suppression. Taken together, these findings demonstrate, for the first time, that the growth suppressive effect of XN in pancreatic cancer cells is mainly mediated by Notch1 reduction.

Topics: Antineoplastic Agents; Apoptosis; Basic Helix-Loop-Helix Transcription Factors; Blotting, Western; Cell Line; Cell Line, Tumor; Cell Proliferation; Cell Survival; Dose-Response Relationship, Drug; Flavonoids; Gene Expression Regulation, Neoplastic; Homeodomain Proteins; Humans; Inhibitor of Apoptosis Proteins; Pancreatic Neoplasms; Propiophenones; Receptor, Notch1; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Survivin; Time Factors; Transcription Factor HES-1; Tumor Stem Cell Assay

Routine experiences suggest that cholangiocarcinomas (CCAs) show different clinicopathological behaviors along the biliary tree, and hilar CCA apparently resembles pancreatic duct adenocarcinoma (PDAC). Herein, the backgrounds for these similarities were reviewed. While all cases of PDAC, hilar CCA, intrahepatic CCA (ICCA) and CCA components of combined hepatocellular-cholangiocarcinoma (cHC-CCA) were adenocarcinomas, micropapillary patterns and columnar carcinoma cells were common in PDAC and hilar CCA, and trabecular components and cuboidal carcinoma cells were common in ICCA and CCA components of cHC-CCA. Anterior gradient protein-2 and S100P were frequently expressed in perihilar CCA and PDAC, while neural cell adhesion molecule and luminal epithelial membrane antigen were common in CCA components of c-HC-CCA. Pdx1 and Hes1 were frequently and markedly expressed aberrantly in PDAC and perihilar CCA, although their expression was rare and mild in CCA components in cHC-CCA and ICCA. Hilar CCA showed a similar postoperative prognosis to PDAC but differed from ICCA and cHC-CCA. Taken together, hilar CCA may differ from ICCA and CCA components of cHC-CCA but have a similar development to PDAC. These similarities may be explained by the unique anatomical, embryological and reactive nature of the pancreatobiliary tract. Further studies of these intractable malignancies are warranted.

Topics: Basic Helix-Loop-Helix Transcription Factors; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Biliary Tract; Carcinoma, Pancreatic Ductal; Carrier Proteins; Cholangiocarcinoma; Gene Expression Regulation, Developmental; Homeodomain Proteins; Humans; Immunohistochemistry; Immunophenotyping; Nuclear Proteins; Pancreatic Neoplasms; Trans-Activators; Transcription Factor HES-1

Pancreatic cancer stem cells (CSCs) represent a small subpopulation of pancreatic cancer cells that have the capacity to initiate and propagate tumor formation. However, the mechanisms by which pancreatic CSCs are maintained are not well understood or characterized.. Expression of Notch receptors, ligands, and Notch signaling target genes was quantitated in the CSC and non-CSC populations from 8 primary human pancreatic xenografts. A gamma secretase inhibitor (GSI) that inhibits the Notch pathway and a shRNA targeting the Notch target gene Hes1 were used to assess the role of the Notch pathway in CSC population maintenance and pancreatic tumor growth.. Notch pathway components were found to be upregulated in pancreatic CSCs. Inhibition of the Notch pathway using either a gamma secretase inhibitor or Hes1 shRNA in pancreatic cancer cells reduced the percentage of CSCs and tumorsphere formation. Conversely, activation of the Notch pathway with an exogenous Notch peptide ligand increased the percentage of CSCs as well as tumorsphere formation. In vivo treatment of orthotopic pancreatic tumors in NOD/SCID mice with GSI blocked tumor growth and reduced the CSC population.. The Notch signaling pathway is important in maintaining the pancreatic CSC population and is a potential therapeutic target in pancreatic cancer.

Topics: Animals; Basic Helix-Loop-Helix Transcription Factors; Disease Models, Animal; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Homeodomain Proteins; Humans; Ligands; Mice, Inbred NOD; Mice, SCID; Neoplastic Stem Cells; Pancreatic Neoplasms; Protease Inhibitors; Receptors, Notch; RNA, Small Interfering; Signal Transduction; Spheroids, Cellular; Transcription Factor HES-1; Tumor Cells, Cultured; Up-Regulation

To observe the effect of activation of Notch1 signaling pathway by Notch intracellular domain (NICD) plasmid transfection on pancreatic cancer cell proliferation and explore the underlying mechanism.. The transfection rates were observed under microscope with fluorescence stimulation, and mRNA expression levels of Hes1 were detected by real-time PCR. Cell proliferation changes were evaluated by CCK-8 after NICD and control plasmid transfection in pancreatic cancer cells. Caspase 3 activity was examined using a caspase 3 detection kit.. The transfection rates of NICD plasmid were up to 80% by fluorescence stimulation observation. Hes1 expression was significantly increased after NICD plasmid transfection, suggesting the activation of Notch1 signaling pathway. NICD plasmid transfection significantly promoted cancer cell proliferation compared to control plasmid transfeciton. The activities of caspase 3 were obviously decreased after NICD plasmid transfection in 3 pancreatic cancer cell lines.. Activation of Notch1 signaling pathway by NICD plasmid transfection can promote the proliferation of pancreatic cancer cells by inhibiting the apoptosis pathway.

Topics: Apoptosis; Basic Helix-Loop-Helix Transcription Factors; Caspase 3; Cell Line, Tumor; Cell Proliferation; Homeodomain Proteins; Humans; Pancreatic Neoplasms; Plasmids; Receptor, Notch1; Signal Transduction; Transcription Factor HES-1; Transfection

Activation of the NOTCH receptors relies on their intracellular proteolysis by the gamma-secretase complex. This cleavage liberates the NOTCH intracellular domain (NIC) thereby allowing the translocation of NIC towards the nucleus to assemble into a transcriptional platform. Little information is available regarding the regulatory steps operating on NIC following its release from the transmembrane receptor up to its association with transcriptional partners. Interfering with these regulatory steps might potentially influences the nuclear outcome of NOTCH signalling. Herein, we exploited a reliable model to study the molecular events occurring subsequent to NOTCH1 cleavage. In pancreatic cancer cells, pulse of NOTCH1 activation led to increased expression of NOTCH target genes namely HES1 and c-MYC. We uncovered that, upon its release, the NOTCH1 intracellular domain, NIC1, undergoes a series of post-translational modifications that include phosphorylation. Most interestingly, we found that activation of the MEK/ERK pathway promotes HES1 expression. Inhibition of the gamma-secretase complex prevented the MEK/ERK-induced HES1 expression suggesting a NOTCH-dependent mechanism. Finally, higher levels of NIC1 were found associated with its transcriptional partners [CBF1, Su(H) and LAG-1] (CSL) and MASTERMIND-LIKE 1 (MAML1) upon MEK/ERK activation providing a potential mechanism whereby the MEK/ERK pathway promotes expression of NOTCH target genes. For the first time, our data exposed a signalling pathway, namely the MEK/ERK pathway that positively impacts on NOTCH nuclear outcome.

Topics: Basic Helix-Loop-Helix Transcription Factors; Calcium; Cell Line, Tumor; Extracellular Signal-Regulated MAP Kinases; Gene Expression Regulation, Neoplastic; HEK293 Cells; Homeodomain Proteins; Humans; Intracellular Space; MAP Kinase Signaling System; Mitogen-Activated Protein Kinase Kinases; Pancreatic Neoplasms; Phosphorylation; Protein Structure, Tertiary; Receptor, Notch1; Transcription Factor HES-1

Embryologically, intrahepatic small bile ducts arise from hepatic progenitor cells via ductal plates, whereas the pancreato-extrahepatic biliary progenitor cells expressing the transcription factors PDX1 and HES1 are reportedly involved in the development of the extrahepatic biliary tract and ventral pancreas. The expression of cellular markers characteristic of the different anatomical levels of the biliary tree and pancreas, as well as PDX1 and HES1, was examined in cholangiocarcinoma components of combined hepatocellular cholangiocarcinoma (12 cases), intrahepatic cholangiocarcinoma (21 cases), hilar cholangiocarcinoma (25 cases), and pancreatic ductal adenocarcinoma (18 cases). Anterior gradient protein-2 and S100P were frequently expressed in hilar cholangiocarcinoma and pancreatic ductal adenocarcinoma, whereas neural cell adhesion molecule and luminal expression of epithelial membrane antigen were common in cholangiocarcinoma components of combined hepatocellular cholangiocarcinoma. PDX1 and HES1 were frequently and markedly expressed in pancreatic ductal adenocarcinoma and, to a lesser degree, in hilar cholangiocarcinoma, although their expression was rare and mild in cholangiocarcinoma components in combined hepatocellular cholangiocarcinoma. The expression patterns of these molecules in intrahepatic cholangiocarcinoma were intermediate between those in hilar cholangiocarcinoma and cholangiocarcinoma components of combined hepatocellular cholangiocarcinoma. Pancreatic ductal adenocarcinoma and hilar cholangiocarcinoma had a similar expression of mucin, immunophenotypes, as well as transcription factors. Pancreatic ductal adenocarcinoma and hilar cholangiocarcinoma showed similar postoperative prognosis. In conclusion, the similar expression of phenotypes related to pancreatobiliary anatomy and embryology may in part explain why these 2 types of carcinoma present similar clinicopathologic features. Further studies on the carcinogenesis of these carcinomas based on their similarities are warranted.

Topics: Aged; Basic Helix-Loop-Helix Transcription Factors; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Carcinoma, Pancreatic Ductal; Cholangiocarcinoma; Female; Homeodomain Proteins; Humans; Immunohistochemistry; Klatskin Tumor; Liver Neoplasms; Male; Middle Aged; Mucins; Pancreatic Neoplasms; Trans-Activators; Transcription Factor HES-1

In animal studies, Notch1-signaling pathway plays an important role in the pancreatic embryogenesis by promoting pancreatic progenitor cells self-renewal and exocrine linage development. The persistent activation of Notch pathway could arrest the organ development and keep cells at an undifferentiated stage. Studies have shown that Notch1-signaling pathway is upregulated in invasive pancreatic ductal adenocarcinoma (PDAC). Here we examined the expression pattern of Notch1 and Hes1 in human fetal pancreatic tissues to elucidate the role of Notch1 in human pancreatic embryonic development. We also compared Notch1 expression in tissues from PDAC, chronic pancreatitis and pancreatic intraepithelial neoplasm. Our data show that Notch1/Hes1-signaling pathway is activated during early pancreatic embryogenesis and reaches the highest at birth. After pancreas is fully developed, Notch1/Hes1 pathway is inactivated even though Notch1 protein cell-surface expression is upregulated. We also showed that the expression of both Notch1 and Hes1 are present in 50% (33/66) of PDACs, but not in pancreatic intraepithelial neoplasms. These findings indicate that Notch1 activation is only apparent in late stage of pancreatic carcinogenesis, suggesting that treatment with Notch-signaling inhibitors including γ-secretase should be selectively used for PDACs with confirmed Notch1-signaling activation.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Basic Helix-Loop-Helix Transcription Factors; Carcinoma in Situ; Carcinoma, Pancreatic Ductal; Cell Transformation, Neoplastic; Child; Child, Preschool; Embryonic Development; Female; Fetus; Gene Expression Regulation, Developmental; Gene Expression Regulation, Neoplastic; Homeodomain Proteins; Humans; Infant; Male; Middle Aged; Pancreas; Pancreatic Neoplasms; Pancreatitis, Chronic; Pregnancy; Receptor, Notch1; Signal Transduction; Transcription Factor HES-1

We previously reported that exosomal nanoparticles secreted by human pancreatic tumoral cell lines decrease tumoral cell proliferation through the mitochondria-dependent apoptotic pathway, because of activation of pro-apoptotic phosphatase and tensin homolog deleted on chromosome 10 (PTEN) and of glucose synthase kinase-3beta (GSK-3beta). Interactions between exosomal nanoparticles and cells are thought to involve membrane lipid rafts. However, the underlying mechanism is unknown. Here, we report that the interaction of exosomal nanoparticles with pancreatic cancer cells led to decreased expression of hairy and enhancer-of-split homolog-1 (Hes-1), the intranuclear target of Notch-1 signaling pathway, and to activation of the apoptotic pathway after a cell cycle arrest in G(0)G(1) phase. Strikingly, the expression level of Notch-1 pathway components was critical, because exosomal nanoparticles decreased the proliferation of cells in which these partners are either weakly represented, in differentiated adenocarcinoma cells, or inhibited, in poorly differentiated carcinoma cells, by blocking presenilin in the gamma-secretase complex that regulates the Notch-1 pathway. Overexpression of Notch-1 intracellular domain resulted in the reversion of the cell proliferation inhibition promoted by exosomal nanoparticles. Blocking presenilin unexpectedly resulted in activation of PTEN and GSK-3beta. Conversely, inhibiting either PTEN or GSK-3beta increased Hes-1 expression and partially counteracted the inhibition of proliferation promoted by exosomal nanoparticles, highlighting reciprocal regulations between Notch signaling and PTEN/GSK-3beta. We concluded that interactions of exosomal nanoparticles with target cells, at lipid rafts where Notch-1 pathway partners are localized, hampered the functioning of the Notch-1 survival pathway and activated the apoptotic pathway, which determines tumoral cell fate.

Topics: Adenocarcinoma; Amyloid Precursor Protein Secretases; Apoptosis; Basic Helix-Loop-Helix Transcription Factors; Blotting, Western; Carbamates; Caspase 3; Cell Differentiation; Cell Proliferation; Dipeptides; Exosomes; Flow Cytometry; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Homeodomain Proteins; Humans; Mitochondria; Nanoparticles; Pancreatic Neoplasms; PTEN Phosphohydrolase; Receptors, Notch; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Transcription Factor HES-1; Tumor Cells, Cultured

The Notch signaling cascade plays a vital role in the proliferation and differentiation of cells during pancreatic development. Cell line experiments have suggested the involvement of Notch signaling in pancreatic endocrine tumorigenesis. We investigated the expression of NOTCH1, HES1, HEY1 and ASCL1 in pancreatic endocrine tumors and compared the data to tumor phenotype including hormone production, heredity, and WHO classification. Real-time quantitative PCR and immunohistochemistry were performed on samples of 26 pancreatic endocrine tumors. For comparison, 10 specimens of macroscopically normal pancreas were analyzed using immunohistochemistry. The subcellular localization of proteins was determined. Neither hormone production, nor heredity, or WHO classification was found to be associated with the expression of these proteins. There were discrepancies between mRNA and protein expression levels. All tumors displayed ASCL1 immunoreactivity. HES1 immunoreactivity was lacking altogether in 46% of the tumors, and in the remaining lesions its expression was weak and confined to the cytoplasm. In the nontumorous pancreatic endocrine cells, weak nuclear expression of HES1 as well as of HEY1 and NOTCH1 was observed. There was a significant positive correlation between NOTCH1 and HES1 mRNA levels, but no indication that HES1 was inhibiting ASCL1 transcription was found. No nuclear expression of HES1 was found in the tumors. This lack of nuclear expression of HES1 may contribute to the abundance of ASCL1 and to tumorigenesis in the endocrine pancreas.

Topics: Adult; Aged; Basic Helix-Loop-Helix Transcription Factors; Cell Cycle Proteins; Cell Differentiation; Cell Nucleus; Cell Proliferation; Cell Transformation, Neoplastic; Female; Gene Expression Regulation, Neoplastic; Homeodomain Proteins; Humans; Immunohistochemistry; Male; Middle Aged; Neoplasm Proteins; Pancreatic Neoplasms; Receptor, Notch1; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Transcription Factor HES-1

To evaluate the role of oncogenic RAS mutations in pancreatic tumorigenesis, we directed endogenous expression of KRAS(G12D) to progenitor cells of the mouse pancreas. We find that physiological levels of Kras(G12D) induce ductal lesions that recapitulate the full spectrum of human pancreatic intraepithelial neoplasias (PanINs), putative precursors to invasive pancreatic cancer. The PanINs are highly proliferative, show evidence of histological progression, and activate signaling pathways normally quiescent in ductal epithelium, suggesting potential therapeutic and chemopreventive targets for the cognate human condition. At low frequency, these lesions also progress spontaneously to invasive and metastatic adenocarcinomas, establishing PanINs as definitive precursors to the invasive disease. Finally, mice with PanINs have an identifiable serum proteomic signature, suggesting a means of detecting the preinvasive state in patients.

Topics: Animals; Basic Helix-Loop-Helix Transcription Factors; Carcinoma, Pancreatic Ductal; Cyclooxygenase 2; Genes, ras; Homeodomain Proteins; Humans; Immunohistochemistry; Isoenzymes; Matrix Metalloproteinase 7; Membrane Proteins; Mice; Mutation; Neoplasm Metastasis; Neoplasm Staging; Pancreas; Pancreatic Neoplasms; Prostaglandin-Endoperoxide Synthases; Transcription Factor HES-1