Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Trypsinogen/trypsin is one of the major serine proteases and is produced by pancreatic acinar cells. Tumor-associated trypsinogen (TAT) has been reported to be produced by several cancer cell lines. The biological roles and activation mechanisms of both TAT and pancreatic acinar trypsinogen (PAT) have not been elucidated in the context of cancer extension, in particular at the stage of invasion and metastasis. In this study, we investigate the roles played by PAT and TAT in pancreatic cancer invasion. In addition, we determined their mechanisms of activation and identified a trypsinogen activity-stimulating factor (TASF) produced by pancreatic cancer cells. TAT expression and high TAT activity were associated with high invasive and liver metastatic potential in SW1990 and CAPAN-2 cells. Moreover, a trypsinogen activating effect and activity prolonging effect was observed in a mixture of these supernatants with trypsinogen. These cells revealed significantly enhanced invasiveness upon invasion assay and in the presence of PAT. TAT and PAT were activated by TASF, active u-PA, produced by pancreatic cancer cells. Activated TAT and PAT can degrade not only ECM proteins but they can also activate other latent proteases. This ECM-protease-network may form a vicious cycle, thereby promoting tumor cell invasion.
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PMID:Identification of a trypsinogen activity stimulating factor produced by pancreatic cancer cells: its role in tumor invasion and metastasis. 1461 60

The protease-activated receptor-2 (PAR-2) is a G protein-coupled receptor that is cleaved and activated by trypsin and tryptase. The purpose of this study was to clarify the role of PAR-2 in proliferation of human pancreatic cancer cells. PAR-2 mRNA and protein expression were detected by RT-PCR and Western blotting in three cell lines, SW1990, Capan-2, and Panc-1. The PAR-2 agonist peptide, SLIGKV (25, 50 micro g/ml) and trypsin (10, 100 ng/ml) significantly increased cell proliferation. Enhancement of MAP kinase also was observed in cancer cells treated with SLIGKV and trypsin. In vivo, subcutaneous xenografted tumors showed significantly enhanced growth after treatment with SLIGKV. Tumor-associated trypsinogen (TAT) mRNA and protein expression was detected in SW1990 and Capan-2, suggesting autocrine trypsin production. PAR-2 activated by trypsin plays an important role in promoting proliferation of pancreatic cancer.
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PMID:A role for protease-activated receptor-2 in pancreatic cancer cell proliferation. 1513 80

Development of pancreatic cancers is clinically so silent in general that at the time of diagnosis, the vast majority of cases are incurable with a very poor prognosis. Therefore, effective preventive approaches against this aggressive disease are urgently required. Experimentally, carcinogenesis process is assumed to consist of at least two stages named initiation and promotion. Using a two-stage model of hamster pancreatic carcinogenesis, we have reported stage-specific inhibitory effects by a number of potent cancer chemopreventive agents. Among them, phenethyl isothiocyanate (PEITC), a constituent of cruciferous vegetables, remarkably blocked the initiation phase of pancreatic as well as lung carcinogenesis in hamsters initiated with N-nitrosobis(2-oxopropyl)amine (BOP). However, PEITC failed to affect both pancreatic and lung carcinogenesis when given during the post-initiation (promotion) phase of carcinogenesis. In contrast, our recent study clearly demonstrated that a cyclooxygenase (COX)-2 inhibitor substantially protects against BOP-induced pancreatic tumors in hamsters in line with decrease in cell proliferative activity of pancreatic ducts when given in the post-initiation phase. Interestingly, trypsin inhibitors inhibited both initiation and post-initiation phases of BOP-induced pancreatic carcinogenesis although they are known to induce hyperplastic acinar lesions in the rat pancreas. Taken together with these data, our review is aimed at looking over mechanistic insights into potent chemopreventive agents against pancreatic cancer.
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PMID:Potent chemopreventive agents against pancreatic cancer. 1518 May 2

Plasma protein profiling with mass spectrometry is currently being evaluated as a diagnostic tool for cancer and other diseases. These experiments consist of three steps: plasma protein fractionation, analysis with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS), and comparisons of the MALDI profiles to develop diagnostic fingerprints using bioinformatic techniques. While preliminary results appear promising in small sample groups, the method is limited by the sensitivity of MALDI-MS for intact proteins, the limited mass range of MALDI-MS, and difficulties associated with isolating individual proteins for identification to validate the diagnostic fingerprint. Here we present an alternative and improved method directed toward diagnostic protein discovery, which incorporates proteolytic peptide profiling, bioinformatic targeting of ion signals, and MALDI tandem mass spectrometry (MS/MS) peptide sequencing, rather than fingerprinting. Pancreatic cancer patients, pancreatitis patients, and controls are used as the model system. Profiling peptides after enzymatic digestion improves sensitivity and extends the accessible protein molecular weight range when compared to intact protein profiling. The first step is to extract and fractionate the proteins from plasma. Each fraction is digested with trypsin and subsequently analyzed by MALDI-MS. Rather than using bioinformatic analysis as a pattern-matching technique, peptides are targeted based on the disease to control peak intensity ratios measured in the averages of all mass spectra in each group and t-tests of the intensity of each individual peak. The targeted peptide ion signals are subsequently identified using MALDI-MS/MS in quadrupole-TOF and tandem-TOF instruments. This study found not only the proteins targeted and identified by a previous protein profiling experiment, but also detected additional proteins. These initial results are consistent with the known biology of pancreatic cancer or pancreatitis, but are not specific to those diseases.
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PMID:Diagnostic protein discovery using proteolytic peptide targeting and identification. 1546 57

Pancreatic tumours are scirrhous, avascular tumours, suggesting that they may produce angiogenesis inhibitors that suppress the growth of the vasculature to the tumour and metastases. We have sought evidence for the angiogenesis inhibitor, endostatin, in normal and cancerous pancreatic tissue. Using Western blotting, we found mature 20 kDa endostatin in cancer tissue but not in normal tissue. Several endostatin-related peptides of higher mol wt were present in both tissues. Extracts from normal tissue were able to degrade exogenous endostatin, whereas extracts from cancer were without effect. Although the exocrine pancreas secretes inactive proenzymes of trypsin, chymotrypsin and elastase, their possible role in this degradation was examined. The trypsin/chymotrypsin inhibitor, Glycine max, did not prevent the degradation of endostatin by normal pancreatic extracts but elastatinal, a specific inhibitor of elastase, reduced the rate of degradation. Extracts of pancreatic tumours did not express any detectable elastase activity, but an elastase (Km 1.1 mM) was expressed by extracts of normal pancreas. We conclude that endostatin is present and stable in pancreatic cancer tissues, which may explain their avascular nature, but that normal pancreatic tissue expresses enzymes, including elastase, which rapidly degrade endostatin. The stability of endostatin may have implications for its therapeutic use.
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PMID:Endostatin expression in pancreatic tissue is modulated by elastase. 1570 75

The purpose of this study was to develop techniques for identifying cancer biomarkers in human serum using differential in-gel electrophoresis (DIGE), and characterizing the protein biomarkers using tandem mass spectrometry (MS/MS). A major problem in profiling protein expression by DIGE comes from the presence of high concentrations of a small number of proteins. Therefore, serum samples were first chromatographed using an immunoaffinity HPLC column (Agilent Technologies), to selectively remove albumin, immunoglobulins, transferrin, haptoglobin, and antitrypsin. Serum samples from three individuals with pancreatic cancer and three individuals without cancer were compared. Serum samples were processed using the immunoaffinity column. Differential protein analysis was performed using DIGE. A total of 56 protein spot-features were found to be significantly increased and 43 significantly decreased in cancer serum samples. These spot features were excised, trypsin digested, and analyzed by MALDI/TOF/TOF (4700 Proteomics Analyzer, Applied Biosystems). We identified 24 unique proteins that were increased and 17 unique proteins that were decreased in cancer serum samples. Western blot analysis confirmed increased levels of several of these proteins in the pancreatic cancer serum samples. In an independent series of serum samples from 20 patients with pancreatic cancer and 14 controls, increased levels of apolipoprotein E, alpha-1-antichymotrypsin, and inter-alpha-trypsin inhibitor were found to be associated with pancreatic cancer. These results suggest that affinity column enrichment and 2-D DIGE can be used to identify numerous proteins differentially expressed in serum from individuals with pancreatic cancer.
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PMID:Characterization of proteins in human pancreatic cancer serum using differential gel electrophoresis and tandem mass spectrometry. 1621 28

Trypsin-like activity is released after stimulation of the exocrine pancreas. We investigated under basal conditions and after stimulation by a meal whether patients suffering from pancreatic disorders differ with respect to plasma trypsin-like activity (PTLA). In 45 subjects (healthy volunteers: n = 18, mild/moderate alcoholic chronic pancreatitis: n = 16, nonjaundice pancreatic cancer n = 7, and calcifying chronic pancreatitis: n = 4), basal and postprandial levels of PTLA were measured over a period of 2 hours. Basal plasma levels were similar in the first 3 groups. After stimulation, healthy volunteers and patients with pancreatic cancer showed significant decreases in trypsin-like activity; however, plasma levels did not decrease in patients with mild/moderate chronic pancreatitis (P < .001). Healthy individuals demonstrate a consistent decrease in postprandial trypsin-like plasma activity. This response is not altered in patients with pancreatic cancer, and it is not seen in patients with mild/moderate alcoholic chronic pancreatitis.
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PMID:Determination of plasma trypsin-like activity in healthy subjects, patients with mild to moderate alcoholic chronic pancreatitis, and patients with nonjaundice pancreatic cancer. 1624 Feb 34

Proteinase-activated receptor-2 (PAR-2) is expressed in various tissues, including cancer lesions. However, the functional consequences of PAR-2 expression in cancer cells, especially in pancreatic cancer cells, are poorly understood. To clarify the biological significance of PAR-2 signaling in pancreatic cancer, we examined the production of growth factors and cytokines, such as IL-6, IL-8, bFGF, TGF-beta1, and VEGF, by specific ELISAs. Two human pancreatic cancer cell lines, SUIT2 and MiaPaCa2, which have been shown to express PAR-2, were stimulated by trypsin and PAR-2 activating peptide (PAR-2AP: SLIGKV-NH2). After 24 h, the culture supernatants were collected and specific ELISAs were performed. Although no significant changes were observed in the release of IL-6, bFGF, TGF-beta1, or VEGF, that of IL-8 was significantly up-regulated by PAR-2 agonists in a dose-dependent manner. In addition, IL-8 receptor expression was found in pancreatic cancer cells and fibroblasts. These results suggest that the PAR-2 signal up-regulates IL-8 release from pancreatic cancer cells. This up-regulated IL-8 has an effect on the pancreatic cancer cells in an autocrine manner and on the fibroblasts in a paracrine manner. Thus, this signal might contribute to tumor progression and characteristic fibrosis in pancreatic cancer.
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PMID:Signal of proteinase-activated receptor-2 contributes to highly malignant potential of human pancreatic cancer by up-regulation of interleukin-8 release. 1652 44

Hereditary pancreatitis is an uncommon autosomal dominant disease secondary to a mutation normally located in the trypsinogen gene, preventing trypsin deactivation. This mutation translates clinically into recurrent attacks of acute pancreatitis and an increased risk of pancreatic cancer. We report a case of acute hereditary pancreatitis due to a trypsinogen mutation that has previously been described in only one family.
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PMID:[Hereditary pancreatitis caused by a new mutation in the trypsinogen gene. Report of a family]. 1675 8

Hereditary chronic pancreatitis (HCP) is a very rare form of early onset chronic pancreatitis. With the exception of the young age at diagnosis and a slower progression, the clinical course, morphological features and laboratory findings of HCP do not differ from those of patients with alcoholic chronic pancreatitis. As well, diagnostic criteria and treatment of HCP resemble that of chronic pancreatitis of other causes. The clinical presentation is highly variable and includes chronic abdominal pain, impairment of endocrine and exocrine pancreatic function, nausea and vomiting, maldigestion, diabetes, pseudocysts, bile duct and duodenal obstruction, and rarely pancreatic cancer. Fortunately, most patients have a mild disease. Mutations in the PRSS1 gene, encoding cationic trypsinogen, play a causative role in chronic pancreatitis. It has been shown that the PRSS1 mutations increase autocatalytic conversion of trypsinogen to active trypsin, and thus probably cause premature, intrapancreatic trypsinogen activation disturbing the intrapancreatic balance of proteases and their inhibitors. Other genes, such as the anionic trypsinogen (PRSS2), the serine protease inhibitor, Kazal type 1 (SPINK1) and the cystic fibrosis transmembrane conductance regulator (CFTR) have been found to be associated with chronic pancreatitis (idiopathic and hereditary) as well. Genetic testing should only be performed in carefully selected patients by direct DNA sequencing and antenatal diagnosis should not be encouraged. Treatment focuses on enzyme and nutritional supplementation, pain management, pancreatic diabetes, and local organ complications, such as pseudocysts, bile duct or duodenal obstruction. The disease course and prognosis of patients with HCP is unpredictable. Pancreatic cancer risk is elevated. Therefore, HCP patients should strongly avoid environmental risk factors for pancreatic cancer.
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PMID:Hereditary chronic pancreatitis. 1720 47


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