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)

The roles of inflammation in the malignant progression of tumors during multistep carcinogenesis have been much discussed but remain to be elucidated. To determine the direct contribution of inflammation to colon carcinogenesis, we established a new model of progression of human colonic adenoma cells using a nude mouse; the progression is accelerated by coimplantation of a plastic plate. The FPCK-1-1 cell line, derived from a colonic polyp in a patient with familial adenomatous polyposis, is nontumorigenic when injected subcutaneously into nude mice in a cell suspension of up to 5 x 106 cells per mouse. However implantation of 1 x 10(5) FPCK-1-1 cells attached to a plastic plate induced first acute and then chronic inflammation, and formed progressively growing tumors that were histologically determined as moderately differentiated adenocarcinoma in 65% of mice. Moreover cell lines established from the growing tumors were found to be tumorigenic when injected into mice even without a plastic plate. The tumor arising from the adenoma cells implanted attached to a plastic plate was surrounded by highly proliferating fibrous stroma. This fibrous tissue was considered essential for malignant progression, rather than for attachment to the plastic plate substrate, because the tumors were formed after injection of FPCK-1-1 cells into the fibrous tissue from which the plastic plate had been removed before the cell injection. The conditioned medium (CM) obtained from the fibroblasts derived from a plastic plate-associated stromal tissue was found to contain factors that stimulated growth of FPCK-1-1 cells, but not of the derivative progressor cell lines. The factor was stable to heating and neuraminidase treatment, but labile to trypsin treatment. The main growth-potentiating activity was contained in the fraction larger than 100 kDa. In contrast, the activity to promote FPCK-1-1 cell growth was not present in the CM of subcutaneous fibroblasts from untreated nude mice or the fibroblast cell lines C3H10T 1/2 and NIH3T3. These results demonstrated that inflammation-associated stroma promoted the conversion of colonic adenoma cells to adenocarcinoma cells.
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PMID:Conversion of human colonic adenoma cells to adenocarcinoma cells through inflammation in nude mice. 1109 22

Recently, mast cell tryptase has been identified as another potent proangiogenic factor in tumors, along with fibroblast and vascular endothelial growth factors. Its role has been studied in a number of cancers, including carcinoma of the uterine cervix, with discordant results. Our aim was to study the expression of tryptase and bFGF in mast cells (MCs) during development of neoangiogenesis in premalignant and malignant lesions of the cervix. Biopsy specimens from 21 patients without cancer and from 63 patients with dysplasias and squamous cell carcinomas were used. They were stained with Alcian blue-safranin O (ABSO) and immunostained with specific antibodies against factor VIII, CD105, tryptase, and bFGF. Tryptase-positive mast cells increased with tumor progression and were close to newly formed blood vessels. Vascularization showed a linear increase from dysplasia to invasive cancer. We suggest that MC tryptase may upregulate neoangiogenesis in carcinogenesis of the uterine cervix.
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PMID:The role of mast cell tryptase in neoangiogenesis of premalignant and malignant lesions of the uterine cervix. 1145 36

Prostate specific antigen, the clinical marker for prostate cancer, is a neutral serine protease whose function is to lyse seminal proteins. Recent work by our laboratory has suggested that prostate specific antigen stimulates the generation of reactive oxygen species in prostate cancer cells. Using 2',7'-dichlorofluorescin diacetate, a dye that fluoresces in the presence of hydrogen peroxide or hydroxyl radicals, we found that prostate specific antigen markedly stimulated reactive oxygen species generation in LNCaP cells. The effect was concentration dependent and its specificity was supported by the fact that anti-prostate specific antigen antibodies abolished the response. Since testosterone stimulates the production of prostate specific antigen, we considered that the reactive oxygen species response to testosterone may be linked to prostate specific antigen. We found that the testosterone effect on reactive oxygen species was blocked by flutamide and by anti-prostate specific antigen antibody. Additionally, though PC3 and DU145 could not respond to testosterone, they readily increased reactive oxygen species in response to prostate specific antigen. Focusing on the mechanism of the prostate specific antigen effect, we tested two other serine proteases, trypsin and chymotrypsin, but found no effect on reactive oxygen species in LNCaP cells. Nevertheless, serine protease inhibitors, alpha(1)-antichymotrypsin, alpha(2)-macroglobulin and Bowman-Birk inhibitor, blocked reactive oxygen species generation stimulated by prostate specific antigen. This apparent paradox was investigated with the use of a specific anti-'prostate specific antigen' antibody which recognizes an epitope away from the catalytic site and which does not inhibit protease activity. Despite the lack of inhibition of proteolytic activity, this antibody blocked the effect of prostate specific antigen on reactive oxygen species generation. These findings suggest that although the integrity of the prostate specific antigen molecule is necessary for stimulating reactive oxygen species generation, its proteolytic activity is not. The underlying mechanism is currently under investigation.
Carcinogenesis 2001 Nov
PMID:Testosterone and prostate specific antigen stimulate generation of reactive oxygen species in prostate cancer cells. 1169 38

Several reports suggest that duodenogastroesophageal reflux may produce esophagitis, Barrett's esophagus and esophageal carcinoma. And it is well known that the incidence of adenocarcinoma arising from Barrett's esophagus has been increasing during the past decade. On the other hand, cyclooxygenase-2 and prostaglandins, produced by the catalytic reaction of cyclooxygenase-2, are considered to relate to carcinogenesis of the digestive tract and other malignant tumors. Recent reports suggest that cyclooxygenase-2 is induced in Barrett's esophagus and esophageal carcinoma. The purpose of this study is to investigate the reaction of cyclooxygenase-2 expression and prostaglandinE2 production on normal human esophageal epithelial cells cultured with gastroduodenal components. Normal human esophageal epithelial cells were cultured with chenodeoxycholic acid, trypsin and in acidic condition, individually and with different combinations of these three factors. After culturing, cyclooxygenase-2 expression in the cells and amount of prostglandinE2 in culture media was evaluated by immunoblotting and enzyme-immunoassay, respectively after culturing the cells. Cyclooxygenase-2 expression was up-regulated by bile acid and prostaglandinE2 production was enhanced by bile acid with trypsin, acidic condition or both of these components, without a synergistic effect on cyclooxygenase-2 expression. Production of prostaglandinE2 via these factors was suppressed by the cyclooxygenase-2 selective inhibitor JTE-522. The results suggest that duodenogastroesophageal reflux may induce cyclooxygenase-2 expression and prostaglandinE2 production in esophageal epithelial cells, cyclooxygenase-2 specific inhibitors may have a chemopreventive effect on esophageal carcinoma.
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PMID:Production of prostaglandinE2 via bile acid is enhanced by trypsin and acid in normal human esophageal epithelial cells. 1510 19

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

Tissue kallikreins are members of the S1 family (clan SA) of trypsin-like serine proteases and are present in at least six mammalian orders. In humans, tissue kallikreins (hK) are encoded by 15 structurally similar, steroid hormone-regulated genes (KLK) that colocalize to chromosome 19q13.4, representing the largest cluster of contiguous protease genes in the entire genome. hKs are widely expressed in diverse tissues and implicated in a range of normal physiologic functions from the regulation of blood pressure and electrolyte balance to tissue remodeling, prohormone processing, neural plasticity, and skin desquamation. Several lines of evidence suggest that hKs may be involved in cascade reactions and that cross-talk may exist with proteases of other catalytic classes. The proteolytic activity of hKs is regulated in several ways including zymogen activation, endogenous inhibitors, such as serpins, and via internal (auto)cleavage leading to inactivation. Dysregulated hK expression is associated with multiple diseases, primarily cancer. As a consequence, many kallikreins, in addition to hK3/PSA, have been identified as promising diagnostic and/or prognostic biomarkers for several cancer types, including ovarian, breast, and prostate. Recent data also suggest that hKs may be causally involved in carcinogenesis, particularly in tumor metastasis and invasion, and, thus, may represent attractive drug targets to consider for therapeutic intervention.
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PMID:Human tissue kallikreins: physiologic roles and applications in cancer. 1519 20

Gallbladder carcinoma is one of the most devastating malignant tumors in Japan. An important risk factor for gallbladder carcinoma is pancreaticobiliary maljunction (PBM), which allows reciprocal reflux of bile and pancreatic juice. Protease-activated-receptor-2 (PAR-2), which is activated by trypsin, may be a key molecule in the process of carcinogenesis in the gallbladder epithelium. We investigated the relation between the expression of PAR-2 and clinicopathological findings in gallbladder carcinoma. The study group comprised 58 patients with gallbladder carcinoma. PAR-2 expression was identified by immunohistochemical staining of all tumor specimens. PAR-2 was expressed in cancerous gallbladder epithelium in 37 of 58 patients (64%). PAR-2 expression occurred more frequently in papillary adenocarcinoma (15 of 16 patients, 94%) than in non-papillary types (20 of 42 patients, 48%, p=0.005). Neither lymphatic invasion (p=0.03) nor venous invasion (p=0.009) occurred more frequently in gallbladder carcinoma with PAR-2 than in that without PAR-2. PAR-2 expression was not directly related to PBM (p=0.46). Papillary adenocarcinoma was associated with polypoid growth (p=0.01), PBM (p=0.01), decreased invasion to lymphatic (p=0.007) and venous vessels (p=0.005), lower T-factor (p<0.001), and lower clinical stage (p=0.02). PAR-2 is frequently expressed in papillary adenocarcinoma of the gallbladder. Trypsin may play an important role for carcinogenesis of the gallbladder through PAR-2 signaling.
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PMID:Protease-activating-receptor-2 is frequently expressed in papillary adenocarcinoma of the gallbladder. 1549 86

Ubiquitin-mediated proteolysis plays a central role in controlling intracellular levels of essential regulatory molecules such as p53, cyclins, myc, BRCA1, HIF-1alpha, etc. The Kruppel-like factor 5 (KLF5) transcription factor regulates biological processes involved in carcinogenesis, angiogenesis, and smooth muscle cell differentiation. In carcinogenesis, KLF5's role has been indicated by frequent genetic deletion as well as functional studies. Here we show that KLF5 is an unstable protein with a short half-life. Destruction of KLF5 was prevented by each of the proteasome-specific inhibitors tested but not by an inhibitor for trypsin-like proteases and cysteine proteases or by a lysosome inhibitor in epithelial cells. Furthermore, KLF5 underwent ubiquitination, and deletion of a 56-amino-acid sequence adjacent to a known transactivation domain of KLF5 significantly reduced its ubiquitination and degradation. Interestingly, cancer cells appeared to be more active in KLF5 degradation than untransformed epithelial cells, yet their proteasome activity was not higher. These results suggest that KLF5 protein is degraded at least in part through ubiquitination-proteasome pathway, which may have become hyperactive for KLF5 in cancer cells.
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PMID:Ubiquitin-proteasome degradation of KLF5 transcription factor in cancer and untransformed epithelial cells. 1573 97

The Bowman-Birk inhibitor (BBI), a soybean-derived protease inhibitor with well-characterized ability to inhibit trypsin and chymotrypsin activities, has been shown to be an effective suppressor of carcinogenesis and treated in human phase IIa clinical trial. However, the precise mechanisms by which BBI suppresses carcinogenesis are unknown. In this study, we demonstrated that BBI specifically and potently inhibits the proteasomal chymotrypsin-like activity in vitro and in vivo in MCF7 breast cancer cells. Proteasome inhibition by BBI is associated with accumulation of ubiquitinated proteins and the proteasome substrates, p21Cip1/WAF1 and p27Kip1, accompanied with downregulation of cyclin D1 and cyclin E which could arrest cell cycle at G1/S phase. Moreover, BBI suppressed MCF7 cell growth and had a novel effect on the decrease of phosphorylated extracellular signal-related kinases (ERK1/2). However, BBI was unable to inactivate ERK1/2 in the presence of a phosphatase inhibitor or a transcription inhibitor suggesting the involvement of a specific phosphatase. We found an induction of MAP kinase phosphatase-1 (MKP-1) in dose- and time-dependent manner correlated with dephosphorylation of ERK1/2 in BBI-treated MCF7 cells. In addition, BBI exhibited no inhibitory effects on EGF-stimulated activation of ERK1/2 and Akt. Together, we suggested that BBI abates proteasome function and results in upregulation of MKP-1, which in turn suppresses ERK1/2 activity. Our results support the notion that proteasome inhibition by BBI is a novel mechanism that contributes to prevention of cancer and further provides evidence that soybean products have the potential to advance as chemopreventive agents.
Carcinogenesis 2005 Jul
PMID:Bowman-Birk inhibitor abates proteasome function and suppresses the proliferation of MCF7 breast cancer cells through accumulation of MAP kinase phosphatase-1. 1574 61

Trypsin is involved in colorectal carcinogenesis and promotes proliferation, invasion, and metastasis. Although a well-known pancreatic digestive enzyme, trypsin has also been found in other tissues and various cancers, most importantly of the colorectum. Moreover, colorectal cancers with trypsin expression have a poor prognosis and shorter disease-free survival. Biological understanding of how trypsin causes cancer progression is emerging. It seems to act both directly and indirectly through a 'proteinase-antiproteinase-system', and by activation of other proteinase cascades. Invasion of the basal membrane by cancer cells may be promoted directly by trypsin digestion of type I collagen. Trypsin activates, and is co-expressed with matrix metalloproteinases (MMPs), which are known to facilitate invasion and metastasis. MMP-2, MMP-7, and MMP-9 are co-expressed together with trypsin and seem to be of particular importance in proliferation, progression, and invasion. MMPs may play a role in both conversion from adenoma to carcinoma, and in the initiation of invasion and metastasis. Co-segregation of trypsin and MMPs within the tumour environment is important for the activation of MMPs, and may explain the deleterious effect of trypsin on prognosis in colorectal cancer. Trypsin and proteinase-activated receptor 2 (PAR-2) act together in an autocrine loop that promotes proliferation, invasion, and metastasis through various mechanisms, of which prostaglandin synthesis is important. Stimulated by trypsin, both MMP and PAR-2 may activate the mitogenic MAPK-ERK pathway through activation of the epidermal growth factor receptor. Experimental trypsin inhibition is feasible but not very effective, and trypsin as a target for clinical therapy is unlikely to be successful owing to its universal distribution. However, as the pathways of trypsin and co-activated protein cascades emerge, biological understanding of colorectal carcinogenesis will be further illuminated and may pave the way for prognosticators, predictors, and novel targets of therapy.
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PMID:Trypsin in colorectal cancer: molecular biological mechanisms of proliferation, invasion, and metastasis. 1669 44


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