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:2.7.7.49 (reverse transcriptase)
31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The purpose of this study was to correlate the presence of matrix metalloproteinase (MMP)-9 and MMP-2 and tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2 mRNAs, detected in serial sections using the reverse transcriptase in situ PCR technique, with prognosis in 23 cases of cervical carcinoma. PCR-amplified MMP and TIMP cDNA were restricted to the invasive cancers cells and the surrounding stromal cells. The ratios of cancer and stromal cells expressing MMP-9 and MMP-2 to those expressing TIMP-1 and TIMP-2 were approximately 1 in those cancers with a good prognosis. This MMP:TIMP ratio in the cancer and stromal cells with a poor prognosis was significantly increased to 5.4 and 3.4 (P < 0.0001), respectively, reflecting a marked reduction in the TIMP detection rate in cancers with a poor prognosis. In cervical cancer cell lines SiHa and HeLa, the MMP:TIMP ratio was also close to 1 and, interestingly, these cell lines are invasive but rarely metastatic in nude mice. These data suggest that the balance of MMP-9 and MMP-2 to TIMP-1 and TIMP-2 expression is an essential factor in the aggressiveness of cervical cancer.
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PMID:Correlation of the in situ detection of polymerase chain reaction-amplified metalloproteinase complementary DNAs and their inhibitors with prognosis in cervical carcinoma. 781 56

The matrix metalloproteinase enzymes have been implicated in tumor invasion and metastasis by a series of correlative immunohistochemical studies. In addition, direct evidence for the role of these enzymes in this pathologic process comes from studies using specific metalloproteinase inhibitors to block tumor invasion and metastasis formation, both in vitro and in vivo. Synthetic oligonucleotide primers for four metalloproteinases (MMP-1, MMP-2, MMP-9, MMP-10) and their tissue inhibitors (TIMP-1, TIMP-2) were selected, synthesized, and optimized in the reverse transcriptase-polymerase chain reaction (RT-PCR) to study the qualitative profile of these enzymes and inhibitors in cultured human tumor cells and tumor tissues. These primers are specific and generate unique amplification products for each appropriate enzyme and inhibitor. Slight enhancement in the amplification of cDNA products was achieved by adding dimethylsulfoxide to the reaction mixture, but commercial enhancement reagents were ineffective. Using this RT-PCR method, cDNA amplification was successful with RNA from as few as 20 cultured tumor cells. The RT-PCR analysis was done on three invasive human colon adenocarcinomas and their paired adjacent normal mucosa. The results show MMP-1 and MMP-2 products in all three tumors, and MMP-2 detected in one of the three normal mucosa samples; TIMP-2 expression was present in two of three patients and awaits quantitative assessment of RT-PCR products.
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PMID:Reverse transcription-polymerase chain reaction phenotyping of metalloproteinases and inhibitors involved in tumor matrix invasion. 826 80

In an attempt to find a potentially useful serum marker in rheumatoid arthritis (RA) which reflects underlying pathogenic mechanisms, we measured the circulating levels of matrix-degrading metalloproteinase-9 (MMP-9), also termed gelatinase B, in sera and synovial fluid (SF) from patients with RA and also quantitated the deposition and local synthesis of MMP-9 in RA synovium. Clinical samples, subjected to gelatin substrate zymography, antigenic immunoassay, and a quantitative substrate degradation assay, revealed elevated 92- and 72-kDa proenzyme forms of MMP-9 and MMP-2 in RA sera and SF compared with healthy controls. Immunostaining on fresh RA synovial specimens revealed MMP-9 within vascular walls in fibroblast-like cells and macrophages; mRNA synthesis was detected using reverse transcriptase in situ PCR. In summary, MMP-9 levels are substantially elevated in the sera and SF from patients with RA. The RA synovium is a source of this MMP-9 production, with abundant mRNA and protein observed within several different type of rheumatoid synovial cells.
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PMID:Markedly elevated serum MMP-9 (gelatinase B) levels in rheumatoid arthritis: a potentially useful laboratory marker. 862 58

Tissue inhibitor of metalloproteinase (TIMP) has been reported to inhibit tumour invasion through an inactivation of matrix metalloproteinase (MMP) both in vitro and in vivo. Among the TIMP family, TIMP-1 possesses not only proteinase inhibitory activity but also a growth-promoting function. However, the significance of the expression of TIMP-1 in human gastric carcinoma tissue has yet to be clarified. In 50 examined cases of gastric carcinoma, 44 (88%) cases showed a higher expression of TIMP-1 mRNA in the biopsy samples from the tumour tissue (T) than in the biopsy samples from the corresponding normal tissue (N), as determined by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR). In a multivariate analysis, the T/N ratio of TIMP-1 mRNA was found to be an independent factor influencing the depth of tumour invasion and was the second most important factor in determining the prognosis of patients. As RT-PCR assay can be performed on biopsy specimens obtained before surgery, an evaluation of the TIMP-1 expression in biopsy specimens by RT-PCR may thus provide useful preoperative information on tumour aggressiveness.
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PMID:Clinical significance of tissue inhibitor of metalloproteinase expression in gastric carcinoma. 927 32

In this study, we addressed the question of whether human bronchial epithelial cells (HBECs) contribute to the regulation of 92-kDa gelatinase activity by secreting tissue inhibitor of metalloproteinase (TIMP)-1. We investigated expression of 92-kDa gelatinase and TIMP-1 in response to lipopolysaccharide (LPS) and to the proinflammatory cytokines interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha. Confluent HBECs from explants were cultured in plastic dishes coated with type I and III collagen. We demonstrated that TIMP-1 was expressed at both the protein and mRNA levels by primary cultures of HBECs. Gelatin zymography of HBEC-conditioned media showed that exposure of HBECs to LPS, IL-1beta, or TNF-alpha induced a twofold increase in the latent form of 92-kDa gelatinase production, as well as its activation. Also, quantitative reverse transcriptase (RT)-polymerase chain reaction (PCR) demonstrated a twofold increase in the 92-kDa mRNA level in response to both cytokines. In contrast, TIMP-1 production evaluated by immunoblotting was unchanged in the presence of LPS and IL-1beta and was clearly decreased in the presence of TNF-alpha. Quantitative RT-PCR demonstrated that TIMP-1 mRNA levels remained unchanged in response to LPS or IL-1beta but decreased by 70% in the presence of TNF-alpha. All of these results strongly suggest that the control mechanisms regulating the expression of 92-kDa gelatinase and TIMP-1 by HBECs in response to inflammatory stimuli are divergent and result in an imbalance between 92-kDa gelatinase and TIMP-1 in favor of the metalloproteinase. Such an imbalance may contribute significantly to acute airway inflammation.
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PMID:Divergent regulation of 92-kDa gelatinase and TIMP-1 by HBECs in response to IL-1beta and TNF-alpha. 935 63

Degradation of the extracellular basement membrane is implicated in atherosclerosis, restenosis after angioplasty, and intimal thickening of vein grafts. Upregulation of metalloproteinase (MMP)-2 and MMP-9 accompanies neointima formation in cholesterol-fed rabbits, in rat and pig models of angioplasty, and in organ cultures of human saphenous veins. MMPs are inhibited by binding to tissue inhibitors of MMPs (TIMPs). Relatively little is known about their regulation in relationship to neointima formation; thus, we investigated TIMP expression in the organ culture model. Qualitative reverse transcriptase-polymerase chain reaction of mRNA extracted from veins showed that TIMP-1, TIMP-2, and TIMP-3 are each expressed before and after culture. Zymography revealed that TIMP-1 was the most abundant TIMP secreted and that its secretion increased dramatically between 0 to 2 and 12 to 14 days of culture. An enzyme-linked immunosorbent assay showed that TIMP-1 secretion increased from 3.2+/-1.5 (mean+/-SE) to 32+/-6 ng/mg wet weight per day (n=5, P<0.01). Immunocytochemical testing localized the increased expression of TIMP-1 to neointimal smooth muscle cells. Although less abundant, TIMP-2 secretion also increased from 0.8+/-0. 3 to 4.7+/-0.2 ng/mg wet weight per day (n=5, P<0.001), and tissue levels increased from 33+/-7 to 150+/-70 ng/mg wet weight (P<0.05). TIMP-2 was also immunolocalized to neointimal smooth muscle cells and their surrounding matrix. TIMP-3 was not secreted but was detected variably and constitutively in tissue extracts (160+/-120 and 170+/-100 ng/mg wet weight [n=9] on days 2 and 14, respectively). TIMP-3 was found in the cells and extracellular matrix of the media and adventitia before culture and to a lesser extent in the neointima after 14 days of culture. Rates of total TIMP secretion on day 14 exceeded those of MMP-2 and MMP-9 (10.6+/-1.9 and 15.6+/-2.3 ng/mg wet weight per day, respectively). Consistent with this, in situ zymography showed that MMP gelatinase activity was highly localized to cell bodies in the media and neointima. Secretion of TIMP-1 and TIMP-2 is greatly increased during neointima formation in human saphenous veins. TIMP-1 is readily released, whereas TIMP-2 remains partially attached and TIMP-3 exclusively attached to the extracellular matrix. Regulation of TIMP expression is therefore an important determinant of net MMP activity during neointima formation, restricting it to the pericellular environment.
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PMID:Expression of tissue inhibitor of metalloproteinase-1, -2, and -3 during neointima formation in organ cultures of human saphenous vein. 997 5

The endothelial cell-derived endothelin-1 (ET-1) is a potent mitogen for endothelial cells, vascular smooth muscle cells, and tumor cells. In this study, we analyzed the role of ET-1 on human umbilical vein endothelial cell (HUVEC) phenotype related to different stages of angiogenesis. ET-1 promoted HUVEC proliferation, migration, and invasion in a dose-dependent manner. The ET(B) receptor (ET(B)R) antagonist, BQ 788, blocked the angiogenic effects induced by ET-1, whereas the ET(A)R antagonist was less effective. ET-1 stimulated matrix metalloproteinase-2 mRNA expression and metalloproteinase-2 production, as determined by reverse transcriptase-polymerase chain reaction and gelatin zymography. Furthermore ET-1 was able to enhance HUVEC differentiation into cord vascular-like structures on Matrigel. When tested in combination with vascular endothelial growth factor (VEGF), ET-1 enhanced VEGF-induced angiogenic-related effects on endothelial cells in vitro. Finally, using the Matrigel plug neovascularization assay in vivo, ET-1 in combination with VEGF stimulated an angiogenic response comparable to that elicited by basic fibroblast growth factor. These findings demonstrated that ET-1 induces angiogenic responses in cultured endothelial cells through ET(B)R and that stimulates neovascularization in vivo in concert with VEGF. ET-1 and its receptors acting as angiogenic regulators might represent new targets for anti-angiogenic therapy.
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PMID:Endothelin-1 induces an angiogenic phenotype in cultured endothelial cells and stimulates neovascularization in vivo. 1107 29

Pericellular proteolysis plays an important role in cell migration and the formation of new capillary structures. The plasminogen activator/plasmin and matrix degrading metalloproteinase (MMP) cascades act together in the remodeling of matrix and cell-matrix contacts. Previously we have shown that the formation of capillary structures by human foreskin microvascular endothelial cells (hMVECs) in a 3-dimensional fibrin matrix requires a functional urokinase-type plasminogen activator receptor (u-PAR). Here we report on the unexpected finding that inhibition of hMVEC-derived MMP activity by BB94 (batimastat) increased the outgrowth of capillary structures in a fibrin matrix. BB94 prevented the release of the u-PA binding domain D1 of u-PAR and thereby increased the number of functional u-PARs on hMVECs without affecting the u-PAR messenger RNA levels. Comparison of various types of protease inhibitors pointed to the prime involvement of MMP activity. Using recombinant MMPs it was shown that MMP-12 activity was able to release the D1 domain of cellularly expressed u-PAR. In addition, the expression of MMP-12 in control and basic fibroblast growth factor/tumor necrosis factor-alpha-stimulated hMVECs was shown by reverse transcriptase-polymerase chain reaction, suggesting that endothelial cell-derived MMP-12 may be involved in angiogenesis-related u-PAR shedding. This new mechanism of u-PAR cleavage provides new insights into the mutual interactions between the MMP and u-PA/plasmin systems. Moreover, it may be helpful in the interpretation of recent data on the use of specific MMP inhibitors in the treatment of several types of cancer.
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PMID:Proteolysis of the urokinase-type plasminogen activator receptor by metalloproteinase-12: implication for angiogenesis in fibrin matrices. 1134 39

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disorder characterized by fibroblast proliferation and extracellular matrix accumulation. However, studies on fibroblast growth rate and collagen synthesis have given contradictory results. Here we analyzed fibroblast growth rate by a formazan-based chromogenic assay; fibroblast apoptosis by in situ end labeling (ISEL) and propidium iodide staining; percent of alpha-smooth muscle actin (alpha-SMA) positive cells by fluorescence-activated cell sorter; and alpha1-(I) collagen, transforming growth factor (TGF)-beta1, collagenase-1, gelatinases A and B, and tissue inhibitor of metalloproteinase (TIMP)-1, -2, -3, and -4 expression by reverse transcriptase/polymerase chain reaction in fibroblasts derived from IPF and control lungs. Growth rate was significantly lower in IPF fibroblasts compared with controls (13.3 +/- 38.5% versus 294.6 +/- 57%, P < 0.0001 at 13 d). Conversely, a significantly higher percentage of apoptotic cells was observed in IPF-derived fibroblasts (ISEL: 31.9 +/- 7.0% versus 15.5 +/- 7.6% from controls; P < 0.008). alpha-SMA analysis revealed a significantly higher percentage of myofibroblasts in IPF samples (62.8 +/- 25.2% versus 14.8 +/- 11.7% from controls; P < 0.01). IPF fibroblasts were characterized by an increase in pro-alpha1-(I) collagen, TGF-beta1, gelatinase B, and all TIMPs' gene expression, whereas collagenase-1 and gelatinase A expression showed no differences. These results suggest that fibroblasts from IPF exhibit a profibrotic secretory phenotype, with lower growth rate and increased spontaneous apoptosis.
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PMID:Fibroblasts from idiopathic pulmonary fibrosis and normal lungs differ in growth rate, apoptosis, and tissue inhibitor of metalloproteinases expression. 1135 Aug 29

The histological diagnosis of hepatocellular carcinoma (HCC) can be complicated by difficulty in differentiation from cholangiocarcinoma and metastatic carcinoma. Immunohistochemical stains currently in use are suboptimal in terms of specificity and sensitivity. Using cDNA array analysis for differential gene expression, we demonstrated a significant increase in mRNA expression level of CD10/CALLA, a type 2 cell-surface metalloproteinase, in HCC, which was subsequently confirmed by reverse transcriptase-polymerase chain reaction and Western blotting analysis. To test the possibility of using CD10/CALLA as a diagnostic marker for HCC, various intrahepatic tumors were studied immunohistochemically using a monoclonal antibody for CD10. A characteristic canalicular-staining pattern was observed in normal hepatocytes and at the apical surface of bile duct epithelial cells. The canalicular expression of CD10 was identified in 9 of 15 HCCs examined (60%), whereas 10 cholangiocarcinomas and 8 of 9 metastatic carcinomas lacked this staining. In three of the six HCCs negative for CD10, the surrounding nonneoplastic liver tissue was also negative, suggesting fixation-associated loss of immunoreactivity. Six HCCs had stronger CD10 staining in tumor cells when compared to the surrounding nonneoplastic tissue. Three cases of benign bile duct adenomas also expressed CD10 at the luminal aspect. One of the MCs showed a diffuse, cytoplasmic staining for CD10, a pattern readily distinguishable from that of HCC. A panel of other immunohistochemical markers were also studied for comparison, including polyclonal anti-carcinoembryonic antigen, cytokeratin (CK) 7, CK20, and alpha-fetoprotein. Our results demonstrate that cDNA arrays can be effectively used to identify new diagnostic markers, and that CD10 is a reliable marker for identifying HCC, particularly when used in conjunction with a panel of immunohistochemical markers (polyclonal anti-carcinoembryonic antigen, CK7, CK20, and alpha-fetoprotein) and in the distinction from cholangiocarcinoma.
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PMID:cDNA arrays and immunohistochemistry identification of CD10/CALLA expression in hepatocellular carcinoma. 1158 69


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