carboxypeptidase-b and Pancreatic-Neoplasms

Gene variants that encode pancreatic enzymes with impaired secretion can induce pancreatic acinar endoplasmic reticulum (ER) stress, cellular injury and pancreatitis. The role of such variants in pancreatic cancer risk has received little attention. We compared the prevalence of ER stress-inducing variants in CPA1 and CPB1 in patients with pancreatic ductal adenocarcinoma (PDAC cases), enrolled in the National Familial Pancreas Tumor Registry, to their prevalence in noncancer controls in the Genome Aggregation Database (gnomAD). Variants of unknown significance were expressed and variants with reduced secretion assessed for ER stress induction. In vitro assessments were compared with software predictions of variant function. Protein variant software was used to assess variants found in only one gnomAD control ("n-of-one" variants). A meta-analysis of prior PDAC case/control studies was also performed. Of the 1385 patients with PDAC, 0.65% were found to harbor an ER stress-inducing variant in CPA1 or CPB1, compared to 0.17% of the 64 026 controls (odds ratio [OR]: 3.80 [1.92-7.51], P = .0001). ER stress-inducing variants in the CPA1 gene were identified in 4 of 1385 PDAC cases vs 77 of 64 026 gnomAD controls (OR: 2.4 [0.88-6.58], P = .087), and variants in CPB1 were detected in 5 of 1385 cases vs 33 of 64 026 controls (OR: 7.02 [2.74-18.01], P = .0001). Meta-analysis demonstrated strong associations for pancreatic cancer and ER-stress inducing variants for both CPA1 (OR: 3.65 [1.58-8.39], P < .023) and CPB1 (OR: 9.51 [3.46-26.15], P < .001). Rare variants in CPB1 and CPA1 that induce ER stress are associated with increased odds of developing pancreatic cancer.

Topics: Carboxypeptidase B; Carboxypeptidases A; Carcinoma, Pancreatic Ductal; Case-Control Studies; Endoplasmic Reticulum Stress; Genetic Predisposition to Disease; Genetic Variation; Humans; Pancreatic Neoplasms; Risk

There is a need to develop methods of early diagnosis for pancreatic cancer. Pancreatic juice is easily collected by endoscopic retrograde cholangiopancreatography and may facilitate diagnosis using molecular markers. The aim of this work was to explore the feasibility of measurement of gene expression in RNA isolated from ductal juice.. Intraoperative sampling of pancreatic juice was undertaken in 27 patients undergoing pancreaticoduodenectomy for suspected tumor. Total RNA was extracted and used as template for poly(adenylic acid) (poly[A]) polymerase chain reaction (PCR) to generate a globally amplified complementary DNA pool representative of all expressed messenger RNAs. Real-time PCR was performed for trefoil factor 2 (TFF2), carboxypeptidase B1 (CPB1), and kallikrein-related peptidase 3 (KLK3) in a subset of samples; all samples were normalized for 3 reference genes (glyceraldehyde-3-phosphate dehydrogenase [GAPDH], PSMB6, and beta-2-microglobulin [B2M]).. The median volume of the pancreatic juice obtained was 1245 microL (range, 50-5000 microL). The RNA integrity number ranged from 1.9 to 10. Reverse transcriptase PCR was positive for pancreas-specific genes (TFF2 and CPB1) and negative for prostatic-specific antigen in all samples.. These results demonstrate that RNA analysis of pancreatic juice is feasible using a combination of poly(A) PCR and real-time PCR. In addition, the poly(A) complementary DNA generated can be probed for multiple genes and is indefinitely renewable, thereby representing a molecular block of importance for future research.

Topics: Adult; Aged; Carboxypeptidase B; Cholangiopancreatography, Endoscopic Retrograde; DNA, Complementary; Early Detection of Cancer; Feasibility Studies; Female; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Genetic Testing; Humans; Intraoperative Care; Male; Middle Aged; Pancreatic Juice; Pancreatic Neoplasms; Pancreaticoduodenectomy; Peptides; Predictive Value of Tests; Prostate-Specific Antigen; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Specimen Handling; Trefoil Factor-2

Pancreas-specific protein (PASP) was compared with serum amylase in 95 episodes of acute pancreatitis with the diagnoses supported by elevated amylase levels. The etiology was typical for Scandinavian countries, with alcohol as the predominant factor, followed by cholelithiasis. PASP values were clearly raised in all patients, except in three cases found to have high salivary-type amylase levels, and one patient with recurrent alcohol pancreatitis. The rise of PASP levels were in general more pronounced than the corresponding amylase elevations, especially in severe pancreatitis. The elevations were generally parallel for the two analytes, but in 41% of the cases PASP levels remained elevated 2-11 days longer than the corresponding amylase levels. PASP was, however, eliminated from the circulation at a rate comparable to that of amylase. The serum range of PASP for 259 healthy subjects was 15-111 micrograms/L with 95% of the values within 16-98 micrograms/L. The upper reference level was set at 100 micrograms/L. PASP levels were also determined for 291 patients with disorders other than acute pancreatitis. Serum levels in patients with renal insufficiency (n = 12), primary biliary cirrhosis (n = 9), and diabetes mellitus (n = 17) were equal to those in healthy subjects. Eight patients of 173 with acute abdominal disorders and no evidence of pancreatitis had elevated PASP levels as well as 4 patients with prostatic carcinoma (n = 28) and 2 patients with benign prostatic hyperplasia (n = 16). PASP values were low in chronic painful pancreatitis (n = 15) and pancreatic cancer (n = 11).

Topics: Acute Disease; Adult; Age Factors; Aged; Amylases; Biomarkers; Carboxypeptidase B; Carboxypeptidases; Chronic Disease; Diabetes Mellitus; Humans; Male; Middle Aged; Pancreatic Neoplasms; Pancreatitis; Prostatic Hyperplasia; Prostatic Neoplasms; Proteins

To clarify the difference in the protein composition of pancreatic juice between patients with pancreatic cancer and normal controls, the proteins of pure pancreatic juice from three cases of cancer of the head of the pancreas and six apparently healthy adults were analyzed by two-dimensional gel electrophoresis (two-DE) followed by silver staining. Two minor proteins of Mr 59,000 and Mr 78,000 present in all the three patients were not detected in the six controls. We have identified the minor proteins with Mr 59,000 and Mr 78,000 as alpha 1-antitrypsin and transferrin, respectively, using Western blotting with anti-alpha 1-antitrypsin and anti-transferrin antibodies. In addition, serum albumin also identified by antibody binding was abundantly present in patients compared to controls. The increase in the amount of serum albumin in the patient was also confirmed by a quantitative analysis using SDS-PAGE and gel densitometry. The data indicate that not only serum albumin but also alpha 1-antitrypsin and transferrin are increased in the pancreatic juice of the patients with pancreatic cancer, as compared with apparently healthy adults. The data also suggests that the analysis of pancreatic juice proteins by two-DE with silver staining is useful for the diagnosis of pancreatic diseases.

Topics: Adenocarcinoma; alpha 1-Antitrypsin; Amylases; Carboxypeptidase B; Carboxypeptidases; Carboxypeptidases A; Densitometry; Electrophoresis; Electrophoresis, Polyacrylamide Gel; Enzyme Precursors; Humans; Lipase; Pancreatic Juice; Pancreatic Neoplasms; Proteins; Serum Albumin; Sodium Dodecyl Sulfate; Staining and Labeling; Transferrin

We have examined the secretogogue responsiveness and the pattern of secretory proteins produced by a transplantable rat pancreatic acinar cell tumor. Dispersed tumor cells were found to discharge secretory proteins in vitro when incubated with hormones that act on four different classes of receptors: carbamylcholine, caerulein, secretin-vasoactive intestinal peptide, and bombesin. With all hormones tested, maximal discharge from tumor cells was only about one-half that of control pancreatic lobules, but occurred at the same dose optima except for secretin, whose dose optimum was 10-fold higher. Biochemical analysis of secretory proteins discharged by the tumor cells was carried out by crossed immunoelectrophoresis and by two-dimensional isoelectric focusing-SDS polyacrylamide gel electrophoresis. To establish a baseline for comparison, secretory proteins from normal rat pancreas were identified according to enzymatic activity and correlated with migration position on two-dimensional gels. Our results indicate that a group of basic polypeptides including proelastase, basic trypsinogen, basic chymotrypsinogen, and ribonuclease, two out of three forms of procarboxypeptidase B, and the major lipase species were greatly reduced or absent in tumor cell secretion. In contrast, the amount of acidic chymotrypsinogen was notably increased compared with normal acinar cells. Although the acinar tumor cells are highly differentiated cytologically and express functional receptors for several classes of pancreatic secretagogues, they show quantitative and qualitative differences when compared with normal pancreas with regard to their production of secretory proteins.

Topics: Amylases; Animals; Carboxypeptidase B; Carboxypeptidases; Chymotrypsin; Hydrolases; Lipase; Neoplasms, Experimental; Pancreas; Pancreatic Elastase; Pancreatic Neoplasms; Rats; Rats, Inbred F344; Ribonucleases; Trypsin

We have previously established that secretory proteins from a rat acinar cell tumor lack two forms of procarboxypeptidase B, are deficient in a major lipase species, and possess markedly reduced amounts of the basic proteins proelastase, basic chymotrypsinogen, basic trypsinogen and ribonuclease (Iwanij, V., and J.D. Jamieson, J. Cell Biol., 95:734-741). Because secretory proteins are markers for acinar cell differentiation, we sought to establish whether the secretory protein profile of the acinar cell tumor is unique to the transformed cell or whether it resembles that of a stage of normal pancreatic development. To this end, we compared the secretory protein pattern from acinar tumor cells with that of rat pancreatic rudiments at days 19-22 of gestation and through day 21 of the postnatal period. Two-dimensional IEF-SDS gel electrophoresis coupled with biosynthetic labeling and fluorography indicates a time-dependent appearance of individual secretory proteins with basic polypeptides, except for amylase, appearing in the terminal stages of differentiation. In comparison, the secretory protein pattern of the acinar tumor cells most closely resembles that of day-19 embryonic pancreatic rudiments. We propose that the cells of the acinar cell tumor may, in part, mirror a stage of normal pancreatic development.

Topics: Amylases; Animals; Carboxypeptidase B; Carboxypeptidases; Cell Differentiation; Chymotrypsinogen; Enzyme Precursors; Hydrolases; Lipase; Pancreas; Pancreatic Elastase; Pancreatic Neoplasms; Rats; Rats, Inbred Strains; Ribonucleases; Trypsinogen