neuropeptide-y and Pancreatic-Neoplasms

Currently available data on the involvement of neuropeptide Y (NPY), peptide YY (PYY), and pancreatic polypeptide (PP) and their receptors (YRs) in cancer are updated. The structure and dynamics of YRs and their intracellular signaling pathways are also studied. The roles played by these peptides in 22 different cancer types are reviewed (e.g., breast cancer, colorectal cancer, Ewing sarcoma, liver cancer, melanoma, neuroblastoma, pancreatic cancer, pheochromocytoma, and prostate cancer). YRs could be used as cancer diagnostic markers and therapeutic targets. A high Y1R expression has been correlated with lymph node metastasis, advanced stages, and perineural invasion; an increased Y5R expression with survival and tumor growth; and a high serum NPY level with relapse, metastasis, and poor survival. YRs mediate tumor cell proliferation, migration, invasion, metastasis, and angiogenesis; YR antagonists block the previous actions and promote the death of cancer cells. NPY favors tumor cell growth, migration, and metastasis and promotes angiogenesis in some tumors (e.g., breast cancer, colorectal cancer, neuroblastoma, pancreatic cancer), whereas in others it exerts an antitumor effect (e.g., cholangiocarcinoma, Ewing sarcoma, liver cancer). PYY or its fragments block tumor cell growth, migration, and invasion in breast, colorectal, esophageal, liver, pancreatic, and prostate cancer. Current data show the peptidergic system's high potential for cancer diagnosis, treatment, and support using Y2R/Y5R antagonists and NPY or PYY agonists as promising antitumor therapeutic strategies. Some important research lines to be developed in the future will also be suggested.

Topics: Breast Neoplasms; Colorectal Neoplasms; Humans; Liver Neoplasms; Male; Neoplasm Recurrence, Local; Neuroblastoma; Neuropeptide Y; Pancreatic Neoplasms; Peptide YY; Prostatic Neoplasms; Receptors, Neuropeptide Y; Sarcoma, Ewing

Pancreatic ductal adenocarcinoma (PDAC) is among the most dismal of human malignancies. Neuropeptides have shown to be implicated in angiogenesis, tumor growth, and formation of distant metastases in various solid tumors. In the present study, we used a genetically engineered mouse model of pancreatic cancer to evaluate the impact of neuropeptide Y (NPY) and its receptors 1 (Y1) and 2 (Y2) in preneoplastic lesions and pancreatic cancer as a potential target with antiproliferative properties. In addition, human PDAC tissue was analyzed.. By interbreeding conditional LsL-Trp53. NPY and Y1 expressions were detected in human and murine pancreatic samples, but expression levels were similar in neoplastic and non-neoplastic tissue. Y2 revealed a significant increase of expression in the transgenic mouse model in PanIN lesions and pancreatic cancer compared to control. This holds also true for human samples of pancreatic cancer. Immunohistochemistry of Y2 in murine and human samples of PanINs and pancreatic carcinoma revealed an increased expression in PanIN lesions and pancreatic cancer.. Y2 is strongly overexpressed in pancreatic cancer and may modulate angiogenesis.

Topics: Animals; Carcinoma in Situ; Humans; Immunohistochemistry; Mice; Mice, Inbred C57BL; Mice, Transgenic; Neuropeptide Y; Pancreas; Pancreatic Neoplasms; Receptors, Neuropeptide Y

Accumulating evidence suggests that energy imbalance plays a role in pancreatic carcinogenesis. However, it remains unclear whether single-nucleotide polymorphisms (SNPs) in genes regulating energy homeostasis influence pancreatic cancer risk. We investigated this question in a case-control study conducted from 1994 to 1998.. Patients (n = 173) were ascertained from hospitals in the Twin Cities and Mayo Clinic, Minnesota. Control subjects (n = 476) were identified from the general population and frequency matched to patients by age and sex. Seven SNPs were evaluated in relation to pancreatic cancer using unconditional logistic regression.. After adjustment for confounders, the leucine/proline or proline/proline genotype of the neuropeptide Y (NPY) gene rs16139 was associated with a lower risk than the leucine/leucine genotype (odds ratio, 0.40 [95% confidence interval, 0.15-0.91]). Conversely, an increased risk was observed for the glycine/arginine or arginine/arginine genotype of the adrenoceptor β2, surface (ADRB2) gene rs1042713 as compared with the glycine/glycine genotype (odds ratio, 1.52 [95% confidence interval, 1.01-2.31]).. This study first reveals that SNPs in genes modulating energy intake (NPY) and energy expenditure (ADRB2) altered pancreatic cancer risk. If confirmed by other studies, our findings may shed new light on the etiology and prevention of pancreatic cancer.

Topics: Aged; Case-Control Studies; Energy Metabolism; Female; Gene Frequency; Genetic Predisposition to Disease; Genotype; Ghrelin; Humans; Ion Channels; Leptin; Logistic Models; Male; Middle Aged; Minnesota; Mitochondrial Proteins; Neuropeptide Y; Pancreatic Neoplasms; Polymorphism, Single Nucleotide; Receptors, Adrenergic, beta-2; Receptors, Adrenergic, beta-3; Receptors, Leptin; Risk Factors; Uncoupling Protein 3

Fluorescence microscopy opens new perspectives for the analysis of insulin secretory granule movement. In this study, we examined whether recently developed photoactivatable/photoconvertible proteins are a useful tool for studying this process at the single granule level in insulin-secreting cells after glucose stimulation.. Plasmids were generated for expression of fusion proteins of the granule membrane phosphatase phogrin or the granule cargo protein neuropeptide Y (NPY) with the photoactivatable green fluorescent protein mutant A206K (PA-GFP-A206K), the photoconvertible protein Dendra2 and the fluorescent protein mCherry. Transfected insulin-secreting MIN6 cells were analysed by fluorescence microscopy.. Point-resolved 405 nm light exposure during image acquisition of MIN6 cells transiently transfected with Phogrin-PA-GFP-A206K or NPY-PA-GFP-A206K as well as of stable MIN6-Phogrin-Dendra2 cells resulted in selective visualisation of few granules by green or red fluorescence, respectively. Movement of these granules was analysed by an automated tracking method from confocal 3D image series. The high spatiotemporal resolution facilitated an elongated tracking of single granules. Interestingly, the track speed and track displacement of granules after 1 h starvation and subsequent glucose stimulation was lower in cells pre-cultured for 48 h at 3 mmol/l glucose than in cells pre-cultured at 25 mmol/l glucose.. Targeting of the granule membrane or its cargo with a photoactivatable/photoconvertible protein allows in-depth visualisation and tracking of single insulin granules in dependence upon glucose. This technique may also open the way to elucidating the regulation of granule movement velocity within the pancreatic beta cell with respect to secretory defects in type 2 diabetes.

Topics: Animals; Cell Line, Tumor; Genes, Reporter; Homeostasis; Insulin; Insulin Secretion; Insulinoma; Mice; Neuropeptide Y; Pancreatic Neoplasms; Plasmids; Recombinant Fusion Proteins; Restriction Mapping; Secretory Vesicles

Lactogenic hormones stimulate food intake in rodents, ungulates, and birds. To test the hypothesis that lactogens regulate expression of neuropeptides that control appetite, we used the prolactin (PRL)-responsive rat insulinoma (INS-1) cell line as an experimental paradigm. INS-1 cells express mRNA for neuropeptide Y (NPY) and cocaine- and amphetamine-regulated transcript (CART) but little or no agouti-related peptide or proopiomelanocortin. As in the hypothalamus in vivo, the levels of NPY mRNA in INS-1 cells were increased by glucose deprivation. Conversely, high media glucose concentrations (11 mm) reduced the levels of NPY mRNA and increased levels of CART mRNA. Rat PRL stimulated a 4- to 7-fold increase in NPY mRNA in INS-1 cells (P < 0.001) and reduced by 50-80% the levels of CART mRNA (P < 0.001). The effects of PRL on NPY mRNA were time and dose dependent and potentiated by glucose deprivation or exogenous dexamethasone (Dex). Hormonal induction of NPY mRNA was accompanied by increased secretion of NPY peptide into cellular conditioned media. PRL stimulated a 1.8- to 3.5-fold increase in expression of AMP-activated protein kinase (AMPK), which mediates in part the effects of hypoglycemia on NPY expression in the hypothalamus in vivo. Pharmacological inhibition of AMPK activity blunted slightly the effects of PRL on NPY and CART but reversed entirely the effects of Dex or of PRL plus Dex on CART mRNA. The effects of PRL on NPY, CART, and AMPK mRNA were mirrored by those of other lactogens and somatogens including placental lactogen and GH. Rat PRL and rat GH in combination had no additive or synergistic effects, suggesting that lactogenic and somatogenic hormones regulate neuropeptide gene expression through similar mechanisms. We conclude that lactogens act in concert with glucose deprivation and glucocorticoids to induce NPY expression and inhibit CART. We speculate that the lactogens facilitate food intake in response to fasting or nutrient deprivation, when glucose levels decline and cortisol levels rise.

Topics: AMP-Activated Protein Kinases; Animals; Cell Line, Tumor; Dexamethasone; Drug Interactions; Gene Expression; Glucocorticoids; Glucose; Growth Hormone; Insulin-Secreting Cells; Insulinoma; Multienzyme Complexes; Nerve Tissue Proteins; Neuropeptide Y; Pancreatic Neoplasms; Prolactin; Protein Serine-Threonine Kinases; Rats; RNA, Messenger

We have studied the effects of first and second generation sulphonylureas on the release of insulin and neuropeptide tyrosine (NPY) from hamster insulinoma tumour (HIT T15) cells and isolated rat islets. In the presence of 5.5 mmol/l glucose all sulphonylureas stimulated insulin release from the HIT cells (P<0.01 ANOVA, n> or =4) but only glibenclamide (GLIB, 10 micromol/l) stimulated the release of NPY (mean+/-s.e.m. control 11.1+/-1.3 vs GLIB 28.4+/-4.1 fmol/h per 10(6) cells, P<0001, n=16). In isolated perifused rat islets both glibenclamide (10 micromol/l) (control 3.5+/-0.3 vs GLIB 6. 3+/-0.2 fmol/min per islet, P<0.01, n=6) and tolbutamide (50 micromol/l) (control 4.7+/-0.1 vs TOLB 6.7+/-0.3 fmol/min per islet, P<0.01, n=6) enhanced glucose (8 mmol/l)-stimulated insulin release. However, only glibenclamide stimulated the release of NPY from the islets (control 3.4+/-0.8 vs GLIB 24.5+/-5 attomol/min per islet, P<0.01, n=6). Similar results were obtained in islets isolated from dexamethasonetreated rats. Glibenclamide treatment of HIT cells showed a prompt insulin release (10 min) while NPY secretion was slower (60 min), suggesting that internalization of the sulphonylurea is required to stimulate NPY release. Glibenclamide, the most common oral therapeutic agent in type 2 diabetes mellitus, is associated with release of the autocrine insulin secretion inhibitor, NPY.

Topics: Animals; Blotting, Northern; Cricetinae; Glyburide; Hypoglycemic Agents; Insulin; Insulin Secretion; Insulinoma; Islets of Langerhans; Neuropeptide Y; Pancreatic Neoplasms; Perfusion; Radioimmunoassay; Rats; Stimulation, Chemical; Tolbutamide; Tumor Cells, Cultured

We have isolated a stable, transplantable, and small glucagonoma (MSL-G-AN) associated with abrupt onset of severe anorexia occurring 2-3 wk after subcutaneous transplantation. Before onset of anorexia, food consumption is comparable to untreated controls. Anorexia is followed by adipsia and weight loss, and progresses rapidly in severity, eventually resulting in reduction of food and water intake of 100 and 80%, respectively. During the anorectic phase, the rats eventually become hypoglycemic and hypothermic. The tumor-associated anorexia shows no sex difference, and is not affected by bilateral abdominal vagotomy, indicating a direct central effect. The adipose satiety factor leptin, known to suppress food intake by reducing hypothalamic neuropeptide Y (NPY) levels, was not found to be expressed by the tumor, and circulating leptin levels were reduced twofold in the anorectic phase. A highly significant increase in hypothalamic (arcuate nucleus) NPY mRNA levels was found in anorectic rats compared with control animals. Since elevated hypothalamic NPY is among the most potent stimulators of feeding and a characteristic of most animal models of hyperphagia, we conclude that the MSL-G-AN glucagonoma releases circulating factor(s) that overrides the hypothalamic NPY-ergic system, thereby eliminating the orexigenic effect of NPY. We hypothesize a possible central role of proglucagon-derived peptides in the observed anorexia.

Topics: Animals; Anorexia; Arcuate Nucleus of Hypothalamus; Drinking; Female; Glucagon; Glucagon-Like Peptide 1; Glucagonoma; Male; Neoplasm Transplantation; Neuropeptide Y; Pancreatic Neoplasms; Peptide Fragments; Protein Precursors; Rats; RNA, Messenger; Weight Loss

Neuropeptide Y (NPY) has been shown to inhibit insulin secretion from the islets of Langerhans. We show that insulin secretion in the insulinoma cell line RIN 5AH is inhibited by NPY. 125I-Peptide YY (PYY) saturation and competition-binding studies using NPY fragments and analogues on membranes prepared from this cell line show the presence of a single class of NPY receptor with a Y1 receptor subtype-like profile. Inhibition of insulin secretion in this cell line by NPY fragments and analogues also shows a Y1 receptor-like profile. Both receptor binding and inhibition of insulin secretion showed the same orders of potency with NPY > [Pro34]-NPY > NPY 3-36 >> NPY 13-36. The Y1 receptor antagonist, BIBP 3226, blocks NPY inhibition of insulin secretion from, and inhibits 125I-PYY binding to, RIN 5AH cells. Northern blot analysis using a Y1-receptor specific probe shows that NPY Y1 receptors are expressed by RIN 5AH cells. Y5 receptors are not expressed in this cell line. Neuropeptide Y inhibition of insulin secretion is blocked by incubation with pertussis toxin, implying that the effect is via a G-protein (Gi or Go) coupled receptor. Neuropeptide Y inhibits the activation of adenylyl cyclase by isoprenaline in RIN 5AH cell lysates, and the stimulation of cAMP by glucagon-like peptide-1 (7-36) amide (GLP-1). It also blocks insulin secretion stimulated by GLP-1, but not by dibutyryl cyclic AMP. Hence, we suggest that NPY inhibits insulin secretion from RIN 5AH cells via a Y1 receptor linked through Gi to the inhibition of adenylyl cyclase.

Topics: Adenylyl Cyclase Inhibitors; Adenylyl Cyclases; Animals; Blotting, Northern; Cyclic AMP; Glucagon; Glucagon-Like Peptide 1; Glucose; Insulin; Insulin Secretion; Insulinoma; Iodine Radioisotopes; Isoproterenol; Neuropeptide Y; Pancreatic Neoplasms; Peptide Fragments; Peptide YY; Protein Precursors; Rats; Receptors, Neuropeptide Y; Swine; Tumor Cells, Cultured

Neuropeptide Y (NPY) is a 36 aminoacid peptide known to inhibit glucose-stimulated insulin secretion. NPY has been shown to be synthesized and secreted by rat islets of Langerhans. More recently, we described the presence on NPY within human islets of Langerhans and in several pancreatic endocrine tumors. In this report, we describe the case of a patient presenting with an insulinoma who underwent the surgical resection of the tumor and was studied in vivo and in vitro for NPY production. Using a highly specific and sensitive two-site amplified enzyme-linked immunosorbent assay, we detected high plasma NPY levels in the patient prior to the surgical resection of the tumor which returned to normal after surgery. NPY was secreted from the tumor when kept in primary cell culture. Furthermore, immunohistochemistry of the insulinoma revealed the presence of NPY and its C-flanking peptide together with insulin, chromogranin and neuron specific enolase. It is concluded that elevated circulating NPY levels observed in this patient with an insulinoma reflected in vivo secretion by the tumor and it is hypothesized that NPY could potentially be used as an endocrine marker in patients with suspected insulinoma.

Topics: Aged; Aged, 80 and over; Chromogranins; Female; Humans; Immunoenzyme Techniques; Immunohistochemistry; Insulin; Insulinoma; Neuropeptide Y; Pancreatic Neoplasms; Phosphopyruvate Hydratase; Tumor Cells, Cultured

Neuropeptide Y (NPY) is a 36 amino acid peptide known to inhibit glucose-stimulated insulin secretion. NPY has recently been shown to be synthetized within rat islets of Langerhans and to be secreted in a differentiated rat insulin-secreting cell line, and as to this date the localization of NPY in human endocrine pancreas has not been reported. As NPY shares high amino acid sequence homology with peptide YY (PYY) and pancreatic polypeptide (PP), the polyclonal antibodies raised against these peptides often cross-react with each other. To demonstrate the presence of NPY in the human endocrine pancreas, we used a highly specific monoclonal antibody raised against NPY and another against its C-flanking peptide (CPON). We studied three cases of hyperplasia of Langerhans islets and 11 cases of endocrine tumors of the pancreas. NPY and CPON were detected in all three cases of hyperplasia. For the 11 pancreatic tumors, five and nine of the tumors were positive for the antibodies NPY and CPON, respectively. The two negative tumors for CPON immunoreactivity were differentiated insulinomas, which showed no evidence of other hormonal secretion. In normal Langerhans islet, NPY and CPON immunoreactivities were colocalized in glucagon-producing cells (alpha-cells) and in a few insulin-secreting cell (beta-cells).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Aged; Animals; Antibodies; Carcinoid Tumor; Carcinoma; Cell Line; Female; Humans; Hyperplasia; Immunohistochemistry; Insulin; Insulinoma; Islets of Langerhans; Male; Middle Aged; Neuroendocrine Tumors; Neuropeptide Y; Pancreatic Hormones; Pancreatic Neoplasms; Rats

Sporadic gastrinoma is a pancreatic endocrine tumor whose ontogeny is unknown. The anatomic area where the vast majority of sporadic gastrinomas is found (pancreatic head region) corresponds topographically to the area traversed embryologically by the ventral pancreatic bud. Pancreatic polypeptide (PP), a 36-amino acid hormone, is secreted by pancreatic endocrine cells derived almost exclusively from the ventral pancreatic bud and is proposed as a marker for ventral bud derivation. Based on these observations we postulate that sporadic gastrinomas, found around the head of the pancreas, are derived from ventral bud tissue and should display a high incidence of PP immunoreactivity. Overall, we found PP immunoreactivity in 7 of 14 (50%) gastrinomas. Of those tumors located to the right of the superior mesenteric artery (SMA) (around the head of the pancreas), seven of nine (78%) contained PP, whereas no gastrinoma to the left of the SMA (n = 5) contained PP (p = 0.021; Fisher exact test). Only one other pancreatic endocrine or exocrine tumor, a glucagonoma located to the left of the SMA, stained positively for PP. We conclude that sporadic gastrinomas found around the head of the pancreas (to the right of the SMA) have a high incidence of PP immunoreactivity. These findings are consistent with our hypothesis that sporadic gastrinomas are derived from the ventral pancreatic bud.

Topics: Gastrinoma; Humans; Immunohistochemistry; Mesenteric Artery, Superior; Neuropeptide Y; Pancreatic Neoplasms; Pancreatic Polypeptide

Using an antiserum raised to the C-terminal region of neuropeptide Y (NPY) which does not cross-react with pancreatic polypeptide (PP), immunoreactivity has been detected in two different endocrine tumours of the human pancreas in concentrations permitting isolation and structural analysis. In a clinically-typical gastrinoma, resected from the head of pancreas, the concentration of NPY immunoreactivity was 3.4 nmol/g. Reverse phase HPLC analysis of extracts of this tumour resolved a single immunoreactive peptide coeluting with synthetic human NPY. The molecular mass of the isolated peptide, determined by mass spectroscopy, was 4270 Da, which was in close agreement with that derived from the deduced primary structure of human tumour NPY (4271.7 Da), obtained by gas-phase sequencing. A somatostatinoma, resected from the region of the ampulla of Vater, contained 3.8 nmol/g of NPY immunoreactivity and isolation of this immunoreactive peptide followed by structural analyses, indicated a molecular structure consistent with NPY 3-36. These data suggest that NPY immunoreactivity detected in human pancreatic endocrine tumours is molecularly heterogenous, a finding which may be of relevance in the symptomatology of such tumours as attenuation of the N-terminus of this peptide generates receptor selectivity.

Topics: Adult; Amino Acids; Chromatography, High Pressure Liquid; Gastrinoma; Humans; Male; Middle Aged; Molecular Weight; Neuropeptide Y; Pancreatic Neoplasms; Peptide Fragments; Radioimmunoassay; Somatostatinoma

Neuropeptide-Y (NPY) is a 36-amino acid peptide known to inhibit glucose-stimulated insulin secretion in various animal models in vitro and in vivo. NPY is thought to be one of the mediators of sympathetic action in the pancreas through nerve endings surrounding the islets, and it has recently been shown to be synthesized within the islets of Langerhans. To elucidate the potential role of NPY in the endocrine pancreas, we studied the expression and regulation of NPY secretion in a rat insulinoma cell line (INS-1). NPY mRNA and peptide are highly expressed and secreted by INS-1 cells. NPY levels were determined by a sensitive and specific two-site amplified enzyme-linked immunosorbent assay. Incubation of INS-1 cells with various glucose concentrations did not modify NPY secretion; however, stimulation of adenylate cyclase by forskolin induced a dose- and time-dependent increase in NPY release in the medium. The glucagon-like peptide-I-(7-36) amide (GLP-1), a known gluco-incretin in humans, induced at low concentration (10(-9) M) a similar expression of NPY mRNA and peptide secretion in INS-1 cells. On the other hand, the inhibition of cAMP accumulation by the alpha 2-adrenergic agonist clonidine decreased NPY secretion. In conclusion, 1) high levels of gene expression and secretion of NPY are found in a rat insulinoma cell line (INS-1). 2) Accumulation of cAMP induced by forskolin or a gluco-incretin (GLP-1) induces a further increase in NPY gene expression and release. 3) NPY secretion is not modulated by low or high glucose concentrations in the medium. 4) Induction of NPY, a known inhibitor of insulin secretion, may represent a novel counterregulatory mechanism of insulin secretion, limiting the stimulatory effect of GLP-1 on insulin secretion.

Topics: Adenylyl Cyclases; Animals; Cell Differentiation; Clonidine; Colforsin; Cyclic AMP; Enzyme Activation; Enzyme-Linked Immunosorbent Assay; Gene Expression Regulation, Neoplastic; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Insulin; Insulin Secretion; Insulinoma; Neuropeptide Y; Pancreatic Neoplasms; Peptide Fragments; Protein Kinase C; Rats; Receptors, Neuropeptide Y; Tumor Cells, Cultured

Neuropeptides exert inhibitory effects on pancreatic secretion, but their role in the regulation of growth is unknown. This study was executed to evaluate the effects of PYY and NPY on cell growth and 3H-thymidine incorporation in human (MiaPaCa-2, Capan-2) and hamster (H2T) exocrine pancreatic carcinoma cells in vitro. A significant increase in the number of cells after 96 h of treatment with NPY was observed at 0.01 microM in H2T, 0.1 microM in MiaPCa-2 and at 1 microM in Capan-2 cells. PYY was less potent and did not increase significantly cell growth in MiaPaCa-2, but did at 0.1 microM in Capan-2 and at 1 microM concentration in H2T. Stimulation for 48h with NPY increased 3H-thymidine incorporation significantly at 0.01 microM in all cell lines. With PYY, stimulation of 3H-thymidine incorporation occurred in H2T cells at 0.01 microM. 3H-thymidine incorporation after PYY treatment was significantly increased at 0.1 microM in MiaPaCa-2 and at 1 microM in Capan-2 cells. Receptor studies showed low but definite specific binding of both NPY and PYY in all cell lines. The results suggest that NPY and PYY may have a role in the regulation of growth of exocrine pancreatic carcinoma cells.

Topics: Adenocarcinoma; Cell Division; DNA Replication; DNA, Neoplasm; Humans; Neuropeptide Y; Pancreatic Neoplasms; Peptide YY; Peptides; Stimulation, Chemical; Tumor Cells, Cultured