gastrin-releasing-peptide and Adenocarcinoma

Topics: Adenocarcinoma; Biomarkers, Tumor; Bombesin; Carcinoma, Small Cell; Gastrin-Releasing Peptide; Humans; In Vitro Techniques; Lung Neoplasms; Peptides; Transforming Growth Factors

Testing for circulating biomarkers in lung cancer is hampered by the insufficient specificity. We aimed to assess the relative diagnostic accuracy of pro-gastrin-releasing peptide (ProGRP) for the differential diagnosis of small cell lung cancer and compare it with more conventional biomarkers.. We enrolled a cohort of 390 patients with a clinical suspicion of lung cancer and for whom a histologic assessment was available. Serum or plasma samples were assessed for ProGRP, carcinoembryonic antigen, CYFRA 21-2, and neuron-specific enolase. The performance of each biomarker in discriminating the small cell lung cancer and squamous cell carcinoma/adenocarcinoma from non-malignant lung disease, and small cell lung cancer from squamous cell carcinoma/adenocarcinoma, was assayed by receiver operating characteristic curve analysis.. At the cut-off levels suggested by the manufacturers, ProGRP and neuron-specific enolase showed an almost identical sensitivity of 55.2% and 55.6%, respectively, in discriminating small cell lung cancer with respect to non-malignant lung disease. In order to quantify the added value of ProGRP to other conventional markers, we ran a multivariable logistic regression analysis, but the results showed that no markers improve the performance of ProGRP.. ProGRP and neuron-specific enolase individually appear more accurate than other conventional biomarkers for small cell lung cancer, but the union of two markers does not increase the accuracy. The very small target group of patients with small cell lung cancer is a limitation of this study, which can explain why ProGRP alone does not show a sensitivity higher than neuron-specific enolase, as reported by other authors.

Topics: Adenocarcinoma; Aged; Antigens, Neoplasm; Biomarkers, Tumor; Carcinoembryonic Antigen; Carcinoma, Non-Small-Cell Lung; Carcinoma, Squamous Cell; Diagnosis, Differential; Female; Follow-Up Studies; Gastrin-Releasing Peptide; Humans; Keratin-19; Lung Neoplasms; Male; Peptide Fragments; Prognosis; Recombinant Proteins; ROC Curve; Small Cell Lung Carcinoma

In prostate cancer (PCa), neuroendocrine cells (NE) have been associated with the progression of the disease due to the secretion of neuropeptides that are capable of diffusing and influence surrounding cells. The GABAergic system is enriched in NE-like cells, and contributes to PCa progression. Additionally, γ-aminobutyric acid (GABA) stimulates the secretion of gastrin-releasing peptide (GRP) in peripheral organs. For the first time, in this study we show the role of GABA and GABA

Topics: Adenocarcinoma; Aged; Cohort Studies; Disease Progression; GABA Agents; gamma-Aminobutyric Acid; Gastrin-Releasing Peptide; Humans; Male; Middle Aged; Neuroendocrine Cells; Prostatic Hyperplasia; Prostatic Neoplasms; Receptors, Androgen; RNA, Small Interfering; Tumor Cells, Cultured

Nerve fibers and neurotransmitters have increasingly been shown to have a role in tumor progression. Gastrin-releasing peptide is a neuropeptide linked to tumor aggressiveness, acting as an autocrine tumor growth factor by binding to its receptor, gastrin-releasing peptide receptor, expressed by many tumors. Although neuropeptides have been previously linked to tumor cell proliferation, more recent studies have uncovered roles for neuropeptides in chemotaxis and metastasis. Understanding the precise roles of such peptides in cancer is crucial to optimizing targeted therapy design. We have previously described that gastrin-releasing peptide acts directly as a chemotactic factor for neutrophils, dependent on PI3K, ERK, and p38. In this study, we investigated roles for gastrin-releasing peptide in lung adenocarcinoma. We asked if gastrin-releasing peptide would act as a proliferative and/or chemotactic stimulus for gastrin-releasing peptide receptor-expressing tumor cells. In A549 cells, a non-small cell lung carcinoma line, the treatment with gastrin-releasing peptide leads to activation of AKT and ERK1/2, and production of reactive oxygen species. Gastrin-releasing peptide induced migration of A549 cells, dependent on gastrin-releasing peptide receptor and PI3K, but not ERK. However, no proliferation was observed in these cells in response to gastrin-releasing peptide, and gastrin-releasing peptide did not promote resistance to treatment with a chemotherapy drug. Our results suggest that, similar to what happens in neutrophils, gastrin-releasing peptide is a migratory, rather than a proliferative, stimulus, for non-small cell lung carcinoma cells, indicating a putative role for gastrin-releasing peptide and gastrin-releasing peptide receptor in metastasis.

Topics: A549 Cells; Adenocarcinoma; Adenocarcinoma of Lung; Antineoplastic Agents; Carcinogenesis; Cell Movement; Cell Proliferation; Drug Resistance, Neoplasm; Gastrin-Releasing Peptide; Humans; Lung Neoplasms; MAP Kinase Signaling System; Oncogene Protein v-akt; Phosphatidylinositol 3-Kinases; Reactive Oxygen Species; Receptors, Bombesin

Numerous studies indicate that androgen receptor splice variants (ARVs) play a critical role in the development of castration-resistant prostate cancer (CRPC), including the resistance to the new generation of inhibitors of androgen receptor (AR) action. Previously, we demonstrated that activation of NF-κB signaling increases ARVs expression in prostate cancer (PC) cells, thereby promoting progression to CRPC. However, it is unclear how NF-κB signaling is activated in CRPC. In this study, we report that long-term treatment with anti-androgens increases a neuroendocrine (NE) hormone - gastrin-releasing peptide (GRP) and its receptor (GRP-R) expression in PC cells. In addition, activation of GRP/GRP-R signaling increases ARVs expression through activating NF-κB signaling. This results in an androgen-dependent tumor progressing to a castrate resistant tumor. The knock-down of AR-V7 restores sensitivity to antiandrogens of PC cells over-expressing the GRP/GRP-R signaling pathway. These findings strongly indicate that the axis of Androgen-Deprivation Therapy (ADT) induces GRP/GRP-R activity, activation NF-κB and increased levels of AR-V7 expression resulting in progression to CRPC. Both prostate adenocarcinoma and small cell NE prostate cancer express GRP-R. Since the GRP-R is clinically targetable by analogue-based approach, this provides a novel therapeutic approach to treat advanced CRPC.

Topics: Adenocarcinoma; Androgen Antagonists; Androgens; Antineoplastic Agents; Cell Line, Tumor; Disease Progression; Gastrin-Releasing Peptide; Gene Expression Regulation, Neoplastic; Genetic Variation; Humans; Male; Prostatic Neoplasms, Castration-Resistant; Receptors, Androgen; Receptors, Bombesin; RNA Splicing; Signal Transduction; Transcription, Genetic

Pancreatic adenocarcinoma is important in oncology because of its high mortality rate. Deaths may be avoided if an early diagnosis could be achieved. Several types of tumors overexpress gastrin-releasing peptide receptors (GRPr), including pancreatic cancer cells. Thus, a radiolabeled peptide derivative of gastrin-releasing peptide (GRP) may be useful as a specific imaging probe. The purpose of the present study was to evaluate the feasibility of using (99m)Tc-HYNIC-βAla-Bombesin(7-14)as an imaging probe for Capan-1 pancreatic adenocarcinoma. Xenographic pancreatic tumor was developed in nude mice and characterized by histopathological analysis. Biodistribution studies and scintigraphic images were carried out in tumor-bearing nude mice. The two methods showed higher uptake by pancreatic tumor when compared to muscle (used as control), and the tumor-to-muscle ratio indicated that (99m)Tc-HYNIC-βAla-Bombesin (7-14)uptake was four-fold higher in tumor cells than in other tissues. Scintigraphic images also showed a clear signal at the tumor site. The present data indicate that (99m)Tc-HYNIC-βAla-Bombesin (7-14) may be useful for the detection of pancreatic adenocarcinoma.

Topics: Adenocarcinoma; Animals; Bombesin; Cell Line, Tumor; Gastrin-Releasing Peptide; Heterografts; Humans; Male; Mice, Nude; Muscles; Organotechnetium Compounds; Pancreatic Neoplasms; Peptide Fragments; Radionuclide Imaging

Gastric cancer cells secrete a variety of proangiogenic molecules, including IL-8 and VEGF. However, factors regulating the expression of proangiogenic genes for gastric cancer remain largely undefined. We investigated the role of HGF-induced activation of GRP and Ets-1 transcription factor in expression of the proangiogenic factor IL-8. The genes associated with angiogenesis induced by HGF were screened using cDNA micro-array technology in two gastric cancer cell lines (NUGC-3 and MKN-28). First, GRP RNA and protein were confirmed to be upregulated. Then, expression of GRP, Ets-1, and IL-8 were further estimated by Western blot analysis. A role for Ets-1 in HGF-induced upregulation of IL-8 was determined by knockdown of Ets-1 with Ets-1 sh-RNA and a chromatin immune precipitation assay. The levels of GRP, Ets-1, and IL-8 were upregulated in cells treated with HGF in a dose-dependent manner. HGF-induced expression of Ets-1 and IL-8 was increased more by GRP treatment and inhibited by pretreatment with an ERK 1/2 inhibitor (PD098059). HGF-induced upregulation of IL-8 was repressed by Ets-1 knockdown. HGF enhanced the binding activity of Ets-1 to the IL-8 promoter in control cells, but not in the Ets-1 shRNA cells. We confirmed the functional role of HGF-induced Ets-1 in activation of the IL-8 promoter by the reporter gene assay. Downregulation of IL-8 also decreased in vitro cell invasion. In conclusion, HGF mediated the GRP induction of IL-8 expression through Ets-1, which thus might serve as a promising target for gastric cancer therapy.

Topics: Adenocarcinoma; Base Sequence; Cell Line, Tumor; Extracellular Signal-Regulated MAP Kinases; Flavonoids; Gastrin-Releasing Peptide; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Genes, fos; Genes, jun; Genes, Reporter; Hepatocyte Growth Factor; Humans; Interleukin-8; MAP Kinase Signaling System; Molecular Sequence Data; Neoplasm Invasiveness; Neoplasm Proteins; Neovascularization, Pathologic; Promoter Regions, Genetic; Proto-Oncogene Protein c-ets-1; RNA, Small Interfering; Stomach Neoplasms

To evaluate five serum tumor markers used alone or in combination for the diagnosis of lung cancer.. The level of five serum tumor markers: NSE, pro-GRP, CYFRA21-1, p53 antibody and CEA was detected by ELISA in 50 healthy adults, 170 lung cancer patients and 60 patients with respiratory infection.. The level of the five serum tumor markers in lung cancer patients was significantly higher than that of healthy adults and patients with respiratory infection (P < 0.01). The level of NSE and pro-GRP in patients with small-cell lung cancer was significantly higher than those of the other subtypes of lung cancer (P < 0.01); The level of CYFRA21-1 in patients with squamous-cell carcinoma was significantly higher than that of other subtypes (P < 0.01). The specificity of p53 antibody was 100% in diagnosing lung cancer and the sensitivity of NSE, pro-GRP was much higher for small-cell lung cancer than for other subtypes (P < 0.01); The same was observed in CYFRA21-1 for the diagnosis of squamous-cell carcinoma (P < 0.01). The sensitivity of the tumor markers in diagnosing lung cancer was significantly enhanced if used in combination (P < 0.01).. These five tumor markers are valuable auxiliary parameters in diagnosing lung cancer. The combination of NSE and pro-GRP is more appropriate than other combinations in diagnosing small-cell lung cancer; the combination of CYFRA21-1, CEA and p53 antibody is the most valuable combination for diagnosing non-small-cell lung cancer. p53 antibody has the highest specificity for diagnosing lung cancer; CYFRA21-1 is the most valuable parameter for diagnosing squamous carcinoma.

Topics: Adenocarcinoma; Antibodies, Neoplasm; Antigens, Neoplasm; Biomarkers, Tumor; Carcinoembryonic Antigen; Carcinoma, Squamous Cell; Female; Gastrin-Releasing Peptide; Humans; Keratin-19; Keratins; Lung Neoplasms; Male; Middle Aged; Phosphopyruvate Hydratase; Tumor Suppressor Protein p53

Gastrin releasing peptide (GRP) is a neuropeptide that has been suggested to play a role in the development of some malignancies. Our aim was: (1) to identify the expression of GRP in cancerous prostate glands, and (2) to correlate its expression to various pathological parameters and to the patient's clinical outcome. Using standard immunohistochemistry, we evaluated GRP expression in both biopsy and radical prostatectomy specimens from 30 patients with prostatic adenocarcinomas. GRP was expressed in 18 radical prostatectomy specimens (60%) and in 15 biopsies (50%). There was an association between positive immunoexpression of GRP, relapse ( P=0.029) and advanced tumor stages (i.e. pT3, pT4) ( P=0.049). In the respective biopsies, GRP immunostatus was similar to that observed in the subsequent radical prostatectomy specimens. GRP immunoexpression may be of some value as a diagnostic and prognostic marker. Patients whose pathology specimens demonstrate GRP immunopositivity should be closely monitored, since they appear to be at higher risk of disease progression and relapse.

Topics: Adenocarcinoma; Aged; Gastrin-Releasing Peptide; Humans; Immunohistochemistry; Male; Prostatic Neoplasms

Little is known about the factors involved in regulating the appearance, or differentiation, of solid tumors including those arising from the colon. We herein demonstrate that the mitogen gastrin-releasing peptide (GRP) is a morphogen, critically important in regulating the differentiation of murine colon cancer. Although epithelial cells lining the mouse colon do not normally express GRP and its receptor (GRP-R), both are aberrantly expressed by all better differentiated cancers in wild-type C57BL/6J mice treated with the carcinogen azoxymethane. Whereas small tumors in both wild-type and GRP-R-deficient (i.e., GRP-R-/-) mice are histologically similar, larger tumors become better differentiated in the former but degenerate into more poorly differentiated mucinous adenocarcinomas in the latter. This alteration in phenotype is attributable to GRP increasing focal adhesion kinase expression in GRP-R-expressing tumors. Consistent with GRP acting as a mitogen, GRP/GRP-R coexpressing tumors in wild-type animals also contain more proliferating cells than those occurring in GRP-R-/- mice. Yet tumors are similarly sized in animals of either genotype receiving azoxymethane for identical times, a finding attributable to the significantly higher number of apoptotic cells detected in GRP/GRP-R coexpressing cancers. Thus, these findings indicate that although GRP is a mitogen, aberrant expression does not result in increased tumor growth. Rather, the mitogenic properties of GRP are subordinate to it acting as a morphogen, where it and its receptor are critically involved in regulating colon cancer histological progression by promoting a well-differentiated phenotype.

Topics: Adenocarcinoma; Animals; Apoptosis; Azoxymethane; Carcinogens; Cell Differentiation; Cell Division; Colonic Neoplasms; Epithelial Cells; Focal Adhesion Kinase 1; Focal Adhesion Protein-Tyrosine Kinases; Gastrin-Releasing Peptide; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitogens; Protein-Tyrosine Kinases; Proto-Oncogene Proteins pp60(c-src); Receptors, Bombesin

The effects of a potent specific gastrin-releasing peptide receptor antagonist, BIM 26226 ([D-F5 Phe6, D-Ala11] bombesin (6-13) OMe), and the long-acting somatostatin analogue, lanreotide (BIM 23014), on the growth of an acinar pancreatic adenocarcinoma growing in the rat or cultured in vitro were investigated. Lewis rats bearing a pancreatic carcinoma transplanted s.c. in the scapular region, were treated with gastrin-releasing peptide (30 microg/kg per day), BIM 26226 (30 and 100 microg/kg per day) and lanreotide (100 microg/kg per day) alone or in combination for 14 successive days. Chronic administration of BIM 26226 and lanreotide significantly inhibited the growth of pancreatic tumours stimulated or not by gastrin-releasing peptide (GRP), as shown by a reduction in tumour volume, protein, ribonucleic acid, amylase and chymotrypsin contents. This effect was more pronounced with 100 microg/kg per day BIM 26226 than with 30 microg/kg per day. However, BIM 26226 and lanreotide, given together, did not exert any additive effect on GRP-treated and -untreated tumours. In cell cultures, both BIM 26226 and lanreotide (10(-6) M) inhibited [3H]thymidine incorporation in tumour cells induced or not by GRP, but no increased effect was observed after combined treatment with both agents. Binding studies showed that BIM 26226 had a high affinity for GRP receptors in tumour cell membranes (IC50 = 6 nM). These results from in vivo and in vitro experiments suggest that BIM 26226 and lanreotide are able to reduce the growth of an experimental acinar pancreatic tumour. Thus, these agents represent interesting steps toward the development of new approaches for treatment of pancreatic carcinomas.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Bombesin; Cell Division; Cell Membrane; Gastrin-Releasing Peptide; Iodine Radioisotopes; Male; Neoplasm Transplantation; Pancreatic Neoplasms; Peptide Fragments; Peptides, Cyclic; Rats; Rats, Inbred Lew; Somatostatin; Thymidine; Tritium; Tumor Cells, Cultured

Neutral endopeptidase (NEP; CALLA, CD10, EC 3.4.24.11) is a cell surface endopeptidase that hydrolyses bioactive peptides, including the bombesin-like peptides, as well as other neuropeptides. Bombesin-like peptides and other neuropeptides are autocrine growth factors for both small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). Low expression of NEP has been reported in SCLC and NSCLC cell lines. NEP inhibition has been shown to increase proliferation in one cell line. To date, NEP expression has not been quantitatively evaluated in normal adult lung, SCLC or NSCLC tumors, paired uninvolved lung from the same patient, or in other pulmonary neoplasms such as mesotheliomas and carcinoids. We examined the expression of NEP in these tissues and human cell lines using immunohistochemistry, flow cytometry, enzyme activity, ELISA, Western blot, and reverse transcription (RT)-PCR. Uninvolved lung tissue from different individuals displayed considerable variation in NEP activity and protein. By immunohistochemistry, NEP expression was detectable in alveolar and airway epithelium, fibroblasts of normal lung, and in mesotheliomas, whereas it was undetectable in most SCLC, adenocarcinoma, squamous cell carcinoma, and carcinoid tumors of the lung. NEP activity and protein levels were lower in all SCLC and adenocarcinoma tumors when compared to adjacent uninvolved lung, often at levels consistent with expression derived from contaminating stroma. NEP expression and activity were reduced or undetectable in most SCLC and lung adenocarcinoma cell lines. NEP mRNA by RT-PCR was not expressed or was in low abundance in the majority of lung cancer cell lines. The majority of lung tumors did not express NEP by RT-PCR as compared with normal adjacent lung. In addition, recombinant NEP abolished, whereas an NEP inhibitor potentiated, the calcium flux generated by neuropeptides in some lung cancer cell lines, demonstrating potential physiological significance for low NEP expression. NEP, therefore, is a signal transduction and possibly a growth modulator for both SCLC and NSCLC, emphasizing the role of neuropeptides in the pathogenesis of the major histological forms of lung cancer.

Topics: Adenocarcinoma; Adult; Base Sequence; Blotting, Western; Bradykinin; Calcium; Carcinoma, Non-Small-Cell Lung; Carcinoma, Small Cell; Carcinoma, Squamous Cell; Cell Line; DNA Primers; Enzyme Inhibitors; Gastrin-Releasing Peptide; Gene Expression; Glycopeptides; Humans; Immunohistochemistry; Lung; Lung Neoplasms; Mesothelioma; Molecular Sequence Data; Neoplasm Metastasis; Neprilysin; Peptides; Polymerase Chain Reaction; Pulmonary Alveoli; Recombinant Proteins; RNA, Messenger; Signal Transduction; Tumor Cells, Cultured

We investigated the effects of bombesin/GRP antagonists RC-3095 and RC-3940-II on the growth of SW-1990 human pancreatic adenocarcinoma cells xenografted into nude mice or cultured in vitro. Nude mice implanted with SW-1990 tumors received s.c. injections of RC-3095 and RC-3940-II or the vehicle (control) for 28 days. Chronic administration of RC-3940-II inhibited the growth of SW-1990 tumors, as shown by a reduction in tumor volume during the treatment and a significant increase in tumor doubling time. RC-3940-II decreased final tumor volume by 57.7% and tumor growth rate by 65%. Final tumor weights in mice treated with RC-3940-II were 75% lower than in controls. Treatment with RC-3095 induced smaller, and not significant, decreases in tumor volume and weight. In cell cultures, both RC-3095 and RC-3940-II effectively inhibited the proliferation of SW-1990 cells, inducing a dose- and time-dependent decrease in the number of cells. RC-3940-II again suppressed in vitro growth of SW-1990 cells more effectively than RC-3095. After 72 hr of culture, RC-3940-II and RC-3095 at 1 microM concentrations decreased cell numbers by 45.7% and 27.7%, respectively. The estimated EC50 value for RC-3940-II was 1 nM. When SW-1990 cells were cultured in the presence of 1 nM and 10 nM RC-3095 for 72 hr, cAMP levels in the incubation medium were decreased to 77.3% and 26.9% of the control value. Our results indicate that bombesin/GRP antagonist RC-3940-II can inhibit the proliferation of SW-1990 human pancreatic adenocarcinoma cells in vivo and in vitro. Our findings also suggest that this effect may involve the intracellular cAMP pathway.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Bombesin; Cell Division; Cyclic AMP; Gastrin-Releasing Peptide; Humans; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Transplantation; Pancreatic Neoplasms; Peptide Fragments; Peptides; 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

Nude mice bearing xenografts of HT-29 human colon cancer cell line were treated for 4 weeks with somatostatin analog (RC-160), bombesin/gastrin releasing peptide (GRP) antagonists (RC-3095 and RC-3440). In three separate experiments somatostatin analog RC-160 (50 micrograms/day) released from microgranules significantly reduced tumor growth. Bombesin/GRP antagonists, RC-3095 and RC-3440 injected subcutaneously (s.c.) twice daily at a dose of 10 micrograms had the greatest and consistently significant inhibitory effect on tumor growth. RC-3095 given once daily s.c. at a dose of 20 micrograms was less effective. RC-3095 also inhibited metastatic tumor growth after intrasplenic injection of HT-29 cells in nude mice. Specific binding sites of somatostatin, bombesin and epidermal growth factor (EGF) were detected on intact HT-29 cells or on the membranes from HT-29 tumor xenografts. The inhibitory effects of bombesin antagonists on tumor growth were consistently linked with a significant down-regulation of EGF receptors. Bombesin/GRP antagonists and somatostatin analogs could be considered for the development of new hormonal therapies for colon cancer.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Bombesin; Colonic Neoplasms; Drug Screening Assays, Antitumor; ErbB Receptors; Gastrin-Releasing Peptide; Gastrins; Growth Hormone; Humans; Insulin-Like Growth Factor I; Liver Neoplasms; Male; Mice; Mice, Nude; Neoplasm Transplantation; Peptide Fragments; Peptides; Radioligand Assay; Somatostatin

This report describes an immunohistopathologic analysis characterizing the incidence, pattern of distribution, and hormonal content of neuroendocrine (NE) cells in human benign prostate and prostatic adenocarcinoma.. Formaldehyde-fixed, paraffin-embedded material from 15 benign prostates, 31 primary prostatic adenocarcinomas, 16 metastatic lesions, 21 primary tumors treated with short-course diethylstilbestrol (DES), and 10 specimens from hormone-refractory patients were examined. NE cells were identified using silver histochemistry and a panel of immunohistochemical NE markers (chromogranin-A, serotonin, neuron-specific enolase), and specific peptide hormone antibodies.. NE cells were identified in all benign prostates. NE cells were identified in 77% of primary untreated adenocarcinomas with no significant differences with respect to pathologic stage. NE cells were found isolated and dispersed in the tumor, composing the minority of malignant cells. Double-labeling and serial section immunohistochemistry demonstrated the coexpression of prostate-specific antigen (PSA) in NE cells. In addition to serotonin, some tumors expressed multiple hormone immunoreactivities. NE cells were identified in 56% of metastatic deposits, with a similar pattern of distribution. In DES-treated cases, NE cells were found consistently in the adjacent benign epithelium, whereas 52% of tumors contained NE cells. Hormone-refractory tumors contained NE cells in 60% of cases.. This analysis demonstrates that a significant proportion of primary and metastatic prostatic adenocarcinomas contain a subpopulation of NE cells, the expression of which does not appear to be suppressed with androgen ablation and does not correlate with pathologic stage. Furthermore, NE cells coexpress PSA, suggesting a common precursor cell of origin. The elaboration of biogenic amines and neuropeptides suggests that NE cells dispersed in prostatic carcinoma may play a paracrine growth-regulatory role.

Topics: Adenocarcinoma; Aged; Aged, 80 and over; Basement Membrane; Calcitonin; Carcinoma; Cell Differentiation; Chromogranin A; Chromogranins; Cytoplasm; Diethylstilbestrol; Gastrin-Releasing Peptide; Gastrins; Humans; Keratins; Lymphatic Metastasis; Male; Middle Aged; Neoplasm Staging; Neurosecretory Systems; Peptides; Prostate; Prostate-Specific Antigen; Prostatic Neoplasms; Seminal Vesicles; Serotonin; Staining and Labeling; Thyrotropin

Palliative methods for treatment of advanced prostatic carcinoma, including those based on luteinizing hormone-releasing hormone (LH-RH) agonists, cannot prevent the ultimate growth of hormone-independent cells, and the duration of disease remission in patients with prostate cancer is limited. New therapeutic approaches combining androgen ablation therapy with other compounds must be explored. Various studies suggest that bombesin or gastrin-releasing peptide (GRP) act as autocrine growth factors and may play a role in the initiation and progression of some cancers, including those of the prostate.. The effects of treatment with bombesin/gastrin-releasing peptide (GRP) receptor antagonist [D-Tpi6, Leu13 psi(CH2NH)Leu14]BN(6-14)(RC-3095), an agonist of LH-RH [D-Lys6]-LH-RH and their combination were investigated in the androgen-dependent Dunning R-3327H rat prostate cancer model. Both analogs were administered by continuous subcutaneous infusion from osmotic minipumps for 7 weeks.. Tumor volumes and weights were significantly reduced by treatment with RC-3095, compared with those of controls. In rats that received [D-Lys6]-LH-RH, there was a greater decrease in tumor weight and volume than that produced by RC-3095, and the weights of testes, ventral prostate, and seminal vesicles also were reduced. The combination of RC-3095 and [D-Lys6]-LH-RH had the greatest inhibitory effect on tumor growth. Histologic parameters demonstrated a significant increase of the ratio of apoptotic to mitotic indices in the groups treated with [D-Lys6]-LH-RH or the combination. Serum LH and testosterone levels were greatly depressed by [D-Lys6]-LH-RH or the combination. Specific high-affinity binding sites for bombesin/GRP, epidermal growth factor (EGF), and insulin-like growth Factor I (IGF-I) were found on the tumor membranes. The concentration of receptors for EGF was significantly reduced by treatment with the bombesin/GRP antagonist RC-3095.. Combination therapy of LH-RH analogs with bombesin antagonists such as RC-3095 might be considered for improvement of hormonal therapy of prostate cancer.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Bombesin; Connective Tissue; ErbB Receptors; Gastrin-Releasing Peptide; Gonadotropin-Releasing Hormone; Male; Mitosis; Peptide Fragments; Peptides; Prostatic Neoplasms; Rats; Rats, Inbred F344; Rats, Inbred Strains; Receptor, IGF Type 1; Receptors, Bombesin; Testosterone; Time Factors

The mammalian gastrin-releasing-peptide (GRP) and its structural amphibian analogue, bombesin, are known to be trophic factors for the normal exocrine pancreas. This work investigates the possible role of GRP in the growth of an acinar pancreatic cancer transplanted to the rat and in primary tumor cell cultures. Moreover, this adenocarcinoma was tested for its content of specific bombesin/GRP receptors by using autoradiographic technics and in vitro binding assays with tumor cells. In Lewis rats bearing the pancreatic carcinoma transplanted s.c. in the scapular region, chronic administration of GRP at the dose 30 micrograms/kg/day for 15 successive days significantly increased the tumor volume, the final tumor weight, and amylase, protein, RNA and DNA contents. Autoradiographic studies showed that tumor tissue was GRP receptor positive with a high density. The biochemical characterization indicated that receptor positive tumor tissue had saturable and high affinity receptors with pharmacological specificity for GRP and its bioactive analogues. In primary tumor cell cultures, GRP increased the incorporation of [3H] thymidine in DNA in a dose- and time-dependent manner. There was a good correlation between the ability of GRP and its COOH terminal analogues to elicit DNA synthesis and their affinity for 125I-GRP binding sites. These results from in vivo and in vitro experiments demonstrated that GRP induces growth of pancreatic carcinoma by acting directly on specific membrane receptors present on the tumor cells.

Topics: Adenocarcinoma; Animals; Cell Division; DNA; Gastrin-Releasing Peptide; Pancreatic Neoplasms; Peptides; Rats; Rats, Inbred Lew; Receptors, Bombesin; Receptors, Neurotransmitter; Tumor Cells, Cultured

Serial changes in serum gastrin level were detected by radioimmunoassay in 58 lung cancer patients before and after operation. In comparing these tests with those of 40 cases of noncancerous thoracic lesions and 151 normal adults, the serum gastrin from lung cancer patients is significantly higher than that of noncancerous thoracic lesions and normal individuals (P less than 0.01). The gastrin level is closely related to stage of cancer, size of primary tumor, presence of lymph node metastasis, and type of histological classification. The serum gastrin was found to decrease gradually after the removal of the tumor and to return to normal on the 14th postoperative day. Those patients whose serum gastrin level can return to normal on the 14th postoperative day will have a good prognosis; if not, their prognosis will be very poor. These results suggest that serum from patients with lung cancer contains a high concentration of gastrin that can help differentiate benign from malignant thoracic lesions and evaluate prognosis of patients with lung cancer. Therefore, the cause of high serum gastrin in patients with lung cancer is likely due to the gastrin-producing property of the lung cancer cells.

Topics: Adenocarcinoma; Adult; Aged; Carcinoma, Small Cell; Carcinoma, Squamous Cell; Female; Gastrin-Releasing Peptide; Gastrins; Humans; Lung Neoplasms; Lymphatic Metastasis; Male; Middle Aged; Neoplasm Staging; Peptides; Postoperative Period; Prognosis; Thoracic Diseases

Levels of gastrin-releasing peptide (GRP) were determined by radioimmunoassay in human normal main and lobar bronchus and parenchymal lung tissue extracts. It was found that the level of GRP differed significantly between all 3 areas. The concentration of GRP was statistically higher in main bronchus (median 6.74 ng/g) compared to both lobar bronchus (median 4.79 ng/g) and parenchymal lung (median 1.73 ng/g), and also statistically higher in lobar bronchus compared to parenchymal lung. Chromatographically, GRP-immunoreactivity in both main and lobar bronchial extracts corresponded to GRP1-27 and GRP18-27, while in lung tissue only one major species was identified which corresponded in retention time to GRP18-27. No significant difference was detected when the levels of GRP in normal lobar bronchus and normal lung tissue were compared to the levels in lobar bronchus and lung taken from patients with lung carcinoma, at a site adjacent to the carcinoma. However, a significant difference was observed between the GRP content of normal main bronchus compared to main bronchus from patients with carcinoma. GRP was measured in 26/56 lung carcinomas examined. The levels ranged from 42,000 ng/g in a carcinoid tumour to 0.18 ng/g in a squamous-cell carcinoma, though only in 6 tumours were the levels outside the range determined for normal pulmonary tissue. Chromatography of selected tumour extracts of different histopathologies showed that there were differences in the GRP products present.

Topics: Adenocarcinoma; Adult; Aged; Carcinoid Tumor; Carcinoma; Carcinoma, Small Cell; Carcinoma, Squamous Cell; Chromatography, High Pressure Liquid; Female; Gastrin-Releasing Peptide; Gastrointestinal Hormones; Humans; Lung; Lung Neoplasms; Male; Middle Aged; Peptides; Radioimmunoassay

Gastrin-releasing peptide (GRP) is now known to be a very common product of small cell lung carcinoma (SCLC). With the aim of investigating the possible role of this peptide as a tumor marker of SCLC, we have developed a sensitive radioimmunoassay system for plasma immunoreactive GRP using immune-affinity chromatography for plasma extraction. Plasma immunoreactive GRP levels in control subjects were determined by using 15 ml of plasma as the starting material (minimum concentration detectable, 0.8 pg/ml). The levels in 10 control subjects were (mean +/- SD) 1.2 +/- 0.27 pg/ml; range, 0.86-1.7 pg/ml. This assay system was applied for the clinical use by using 3 ml of plasma as the starting material (minimum concentration detectable, 4.0 pg/ml). Plasma immunoreactive GRP levels were elevated in SCLC patients at frequencies of 71% in patients with limited disease and 80% in those with extensive disease. Furthermore, a change in the level showed excellent correlation with the therapeutic response. In six patients with complete response who had had elevated levels before treatment, the levels decreased to an undetectable range when the tumor disappeared, and they remained undetectable until 1 month later, when the patients were judged to have achieved complete response. In the partial response group, plasma immunoreactive GRP levels had decreased to an undetectable level in two of three patients, when the patients achieved partial response. In four patients with progressive disease, plasma immunoreactive GRP levels were elevated at the time of the progressive disease judgment, when compared with levels before treatment. The levels in 21 patients with non-SCLC (10 with adenocarcinoma, seven with squamous cell carcinoma and four with large cell carcinoma) were not elevated. These results indicate the plasma immunoreactive GRP level as a useful tumor marker in SCLC patients. It is now believed that GRP can function as an autocrine growth factor for SCLC. The present study suggests that the possible autocrine growth factor could serve as a reliable tumor marker for cancer patients.

Topics: Adenocarcinoma; Biomarkers, Tumor; Carcinoma, Small Cell; Chromatography, Gel; Gastrin-Releasing Peptide; Humans; Lung Neoplasms; Peptides

Twenty-seven cases of surgically resected large cell carcinoma of the lung including nine cases of giant cell carcinoma were examined ultrastructurally and immunohistochemically. Ultrastructurally, of 18 large cell carcinomas other than giant cell carcinoma eight showed characteristic differentiation toward adenocarcinoma, four toward adenosquamous carcinoma, and one each toward squamous cell carcinoma and neuroendocrine cell carcinoma, but the remaining four were undifferentiated. Six of the nine giant cell carcinomas also showed features of adenocarcinoma, two showed features of squamous cell carcinoma, and one was undifferentiated carcinoma. Immunohistochemically, secretory component (SC) was observed in seven of 14 cases with features of adenocarcinoma and two of four cases with features of adenosquamous carcinoma. Carcinomas with only squamous cell differentiation did not stain for SC. Keratin staining was positive in five of the 14 with features of adenocarcinoma, three of the four cases with features of adenosquamous carcinoma and two of the three cases with features of squamous cell carcinoma. The numbers of tumor cells positive for keratin and/or SC were small. One carcinoma with neurosecretory type granules was stained positively for calcitonin. These findings indicate that many large cell carcinomas showed differentiation toward glandular cells and/or squamous cells, and some did not show any differentiation ultrastructurally or immunohistochemically, indicating that the majority of large cell carcinomas are poorly differentiated form of either adenocarcinomas or squamous cell carcinomas.

Topics: Adenocarcinoma; Calcitonin; Carcinoma, Small Cell; Carcinoma, Squamous Cell; Cytoplasmic Granules; Gastrin-Releasing Peptide; Histocytochemistry; Humans; Immunoenzyme Techniques; Keratins; Lung Neoplasms; Peptides; Secretory Component; Staining and Labeling

The cell source of peptide hormone production and the morphological differentiation were investigated in 18 adenocarcinomas of the lung by immunohistochemistry and/or by electron microscopy. These tumors were found by radioimmunoassay of tumor extracts to contain either one or more of 7 peptide hormones, i.e. adrenocorticotropin (ACTH), beta- and gamma-melanocyte stimulating hormones (MSH), somatostatin (SS), vasoactive intestinal polypeptide (VIP), gastrin releasing peptide (GRP) and calcitonin (CT). In a combined adeno- and small cell carcinoma, a considerable number of small tumor cells were positively stained for ACTH, beta- and gamma-MSHs and GRP. In a poorly differentiated adenocarcinoma with mucin and CT production, these products were localized in some single cells. Electron microscopy revealed secretory granules indistinguishable from exocrine or endocrine types. In another mucin-positive adenocarcinoma with high SS and CT contents, some tumor cells were stained for SS and/or CT. Two distinct exocrine and endocrine type secretory granules were found in the same cells. In tumors with 100 ng or less of the peptides/g tissue, most tumor cells were not stained for the peptides but a small number showed morphological endocrine differentiation. In conclusion, a considerable proportion of the adenocarcinomas of the lung may show heterogeneous differentiation in both endocrine and exocrine directions.

Topics: Adenocarcinoma; Adrenocorticotropic Hormone; Calcitonin; Cytoplasmic Granules; Gastrin-Releasing Peptide; Histocytochemistry; Hormones; Humans; Lung Neoplasms; Melanocyte-Stimulating Hormones; Microscopy, Electron; Peptide Biosynthesis; Somatostatin; Vasoactive Intestinal Peptide