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)

In vivo levels of mRNA and the specificity of the extrauterine environment on matrix metalloproteinase (MMP)-3, MMP-2, and tissue inhibitor of matrix metalloproteinase (TIMP)-1 were evaluated in eutopic and ectopic endometrial tissue during the establishment of endometriosis in a rat model. Uteri and endometriotic implants were collected and frozen at 36 h, 2 wk, and 4 wk postsurgery to study in vivo mRNA levels. Intact uteri, uterine tissues implanted in the peritoneum or under the skin, and peritoneal adipose implants were collected at 2 wk, halved, and either frozen or cultured. Gene-specific reverse transcriptase-polymerase chain reaction was performed to detect and quantify MMP-2, MMP-3, and TIMP-1 mRNA levels. The peritoneal endometriotic implants progressed from avascularized implants, to vascularized red lesions, to well-established encapsulated cysts. In vivo, MMP-3 mRNA was detectable at all times in ectopic tissues but not in eutopic uterine tissues, whereas MMP-2 and TIMP-1 were ubiquitously expressed at all times in both tissues. In vitro, only MMP-3 mRNA levels were elevated in endometrial tissues collected from the intact uterine and from under the skin, at levels similar to in vivo endometriotic implant MMP-3. In conclusion, ectopic endometrial MMP-3 may participate in the process of invasion and tissue remodeling that is hypothesized to occur in the pathogenesis of endometriosis.
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PMID:Differential regulation of matrix metalloproteinase-3 gene expression in endometriotic lesions compared with endometrium. 1156 56

Altered expression of matrix metalloproteases (MMPs) and their inhibitors, the tissue inhibitors of matrix metalloproteases (TIMPs), has been demonstrated in various tumour tissues. mRNA expression patterns of MMP-1, MMP-2, MMP-3, MMP-9, MMP-11, MMP-12, MMP-14 and TIMP-1, TIMP-2, TIMP-3 and TIMP-4 were evaluated by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) in 30 renal cell carcinomas (RCC), as well as in the surrounding tissues. Expression of the MMPs was significantly stronger in the carcinomas than in non-malignant tissues. High levels were demonstrated particularly in clear cell RCCs (CC-RCC). Except for MMP-1, MMP expression in the papillary RCCs (P-RCC) was, for most MMPs, significantly lower. Expression of the TIMPs in malignant cells of both subtypes was weak, with the exception of TIMP-4 which was strongly expressed in the P-RCCs and downregulated in the CC-RCCs. The latter was correlated with chromosomal loss of 3p, harbouring the TIMP-4 gene locus. In conclusion, deregulated expression of the MMPs and TIMPs in RCCs differs according to histology, grade, size and cytogenetic characteristics, suggesting that MMP and TIMP expression patterns play an important role for the typical histomorphological features of RCC subtypes and their respective biological behaviour.
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PMID:mRNA expression of matrix metalloproteases and their inhibitors differs in subtypes of renal cell carcinomas. 1157 37

The pathogenesis of pseudomonal keratitis was investigated by focusing on induction and activation of matrix metalloproteinases (MMPs) by pseudomonal virulence factors and proinflammatory cytokines. Corneal lesions and MMP induction in vivo were evaluated in rabbit corneas infected with a clinical isolate of Pseudomonas aeruginosa. Effects of pseudomonal virulence factors [elastase, alkaline protease, exotoxin A and lipopolysaccharide (LPS)], tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta on MMP induction and activation were further examined in vitro in rabbit corneal fibroblasts (RCF) and human fibrosarcoma (HT1080) cells using reverse transcriptase-polymerase chain reaction (RT-PCR), zymography and immunoblotting. Corneal ulcers with typical ring abscesses were observed 12-24 h after infection, and MMPs, particularly MMP-9, were upregulated in infected corneas. Pseudomonal elastase caused the most extensive damage to both cell types. RCF treated with pseudomonal exoproteases or LPS expressed and secreted MMP-9. Exotoxin A had no effect on MMP expression. Both IL-1beta and TNF-alpha augmented MMP-9 expression in HT1080 cells. Pseudomonal elastase proteolytically activated MMP-2 and MMP-9 released from the cells. In conclusion, corneal destruction seen with P. aeruginosa infections may result from enhanced expression of MMPs by corneal stromal cells stimulated with pseudomonal exoproteases and proinflammatory cytokines and the proteolytic activation of MMPs by pseudomonal elastase.
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PMID:Matrix metalloproteinases induction by pseudomonal virulence factors and inflammatory cytokines in vitro. 1174 75

We analyzed the immunohistochemical expression of the metastasis-associated protein, CD44v3, in 46 primary human malignant melanomas (MMs). This is the first time that the v3 splice variant of CD44 was found to be expressed in human melanomas (15 of 46), ranging from 3% to 35% of the cell population in the positive tumors. The expression of CD44v3 was observed in tumors thicker than 1.0 mm, and one-third of these tumors proved to be positive irrespective of the thickness. Patients were followed for a minimum of 61 months. The onset of lymph node or organ metastases occurred not later than 58 months and 60 months, respectively. Of the 15 CD44v3 positive tumors, 14 were observed in the organ metastatic tumor group, comprising the majority of those cases (14 of 21), and this association proved to be statistically significant compared with the non-metastatic (P<0.05) and lymph-node metastatic cases (P<0.01). CD44v3 expression in melanoma was also confirmed at the protein and messenger (mRNA) level in several human melanoma cell lines using flow cytometry and reverse transcriptase polymerase chain reaction analysis. In parallel to CD44v3, MMP-2 expression (determined using immunohistochemistry) was significantly elevated (P<0.05) but only in the organ metastatic group of MM. The 5-year survival of patients having thicker tumors than 1.0 mm (where v3 expression occurred) who had CD44v3+ tumors was significantly lower than those of the negative ones (35.7% versus 68.2%, respectively; P=0.025). Finally, we observed that the CD44v3-expressing tumors were characterized by significantly higher MMP-2 expression than the CD44v3-negative tumors (P<0.001), indicating a possible correlation between CD44v3- and MMP-2-positive phenotype and the organ metastatic potential of MM.
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PMID:Expression of CD44v3 splice variant is associated with the visceral metastatic phenotype of human melanoma. 1176 82

When mouse 3T3-L1 preadipocytes are induced to differentiate into adipocytes, they change from an extended fibroblast-like morphology to a rounded one. This change most likely occurs through extracellular matrix remodelling, a process known to be mediated in part by matrix metalloproteinases (MMPs). In this study, we have shown by semi-quantitative reverse transcriptase-PCR, zymographic and immunoblot analysis that MMP-2, MMP-9 and membrane type 1 (MT1)-MMP are regulated during adipose conversion. To assess the importance of MMPs for adipocytic differentiation we have used MMP-specific inhibitors as well as neutralizing antibodies. Treatment of 3T3-L1 preadipocytes with the broad MMP inhibitor Ilomastat or the more restricted MMP-2 Inhibitor I prevented their differentiation into adipocytes in a dose-dependent manner, as evidenced by absence of triglyceride accumulation. Inhibitor treatment prevented the fibronectin-network degradation, as well as the induction of the genes for peroxisome-proliferator-activated receptor gamma and adipsin, two adipocyte phenotype markers. Inhibitor treatment was effective when applied during the early stages of adipocytic conversion, whereas inhibitor treatment during later stages had little effect. Inhibitor treatment did not inhibit clonal mitotic expansion; nor did it affect the expression pattern of the adipogenic transcription factor CCAAT/enhancer-binding protein beta (C/EBPbeta) or its nuclear translocation. It did, however, markedly reduce C/EBPbeta DNA-binding capacity. Taken together, these results suggest that MMPs, and notably MMP-2 and MMP-9, may be necessary mediators of adipocytic differentiation of 3T3-L1 cells.
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PMID:Involvement of matrix metalloproteinases in the adipose conversion of 3T3-L1 preadipocytes. 1204 38

Tooth germ development is associated with morphological and biochemical changes of the dental papilla and enamel organ. Enzymes with gelatinolytic activities were studied by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and enzymography in tooth germ of newborn to 15-day-old rats. Three major bands with gelatinolytic activity were detected at all periods and characterized as the latent and active forms of MMP-2 using their molecular weight and activity dependent on Zn++ and Ca++ ions as criteria. Expression and activity of MMP-2 increased progressively from 0 to 15 days after birth. Mechanical separation of the tooth germ from 10-day-old rats showed that the gelatinolytic activity was localized mainly in the dental papilla and not the dental organ. These data indicate that the expression and activity of MMP-2 varies during the development and maturation of rat first molar tooth germ.
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PMID:Expression and activity of matrix metalloproteinase-2 (MMP-2) in the development of rat first molar tooth germ. 1223 10

Penta-O-galloyl-beta-D-glucose (5GG) inhibited the invasion of highly metastatic mouse melanoma B16F10 cells in vitro, as demonstrated by transwell assay. Its ability to diminish the activity of matrix metalloproteinase (MMP) was demonstrated by zymographic assay. Our data showed 5GG could diminish the activity of MMP-9 more than that of MMP-2. The effect on MMP-9 was elicited in a dose- and time-dependent manner, with IC50 of 15 microM. Next, we analyzed the amounts of MMP-9 and MMP-2 protein in conditioned media and in the cells. The data indicated MMP-9 proteins were also suppressed by 5GG in the same manner. In accordance with these data above, the results of reverse transcriptase polymerase chain reaction (RT-PCR) and Northern blot analysis showed a reduced level of MMP-9 mRNA. Furthermore, we studied transcription factor binding to MMP-2 and MMP-9 promoter regions by electrophoretic mobility shift assay (EMSA) in the nucleus. The results suggested that the transcription factor binding activities of Activator protein-1 (AP-1) and Sp-1 sites was mainly down-regulated by 5GG in the concentration range of 5-15 microM, but not that of nuclear factor kappaB (NF-kappaB), polioma enhancer activator 3 (PEA-3), and Activator protein-2 (AP-2) sites. The Western blot analysis of AP-1 nuclear protein showed a reduced level of c-Jun but not of c-Fos. In addition, the expression of Sp-1 and c-Jun protein was also suppressed. To elucidate whether the transcriptional activity of AP-1 or Sp-1 sites is more important, we transfected MMP-9/luciferase reporter vector, under MMP-9 promoter control, into the cells. We found that a decreased transcriptional activity of AP-1 sites is sufficient to reduce MMP-9 promoter activity. These results lead us to conclude that 5GG restricts the invasive ability of B16F10 mouse melanoma cells by reducing MMP-9 activity, by suppressing the transcriptional activity of AP-1 sites and the expression of c-Jun protein. The result may provide a potential mechanism for 5GG in cancer chemopreventive action.
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PMID:Penta-O-galloyl-beta-D-glucose inhibits the invasion of mouse melanoma by suppressing metalloproteinase-9 through down-regulation of activator protein-1. 1239 98

OBJECTIVE: To study the expression of matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) in the osteoblasts of SD rats and to assess the change of MMP-2 and TIMP-1 induced by 17beta-estradiol (E2) and progesterone (P), for the purpose of understanding the role of MMP-2 and TIMP-1 in bone resorption. METHODS: The expression and localization of the MMP-2 in cultured rat osteoblasts were observed immunohistochemically, and MMP-2 and TIMP-1 mRNA expression assayed by reverse transcriptase-polymerase chain reaction (RT-PCR) after the cells were treated with E2 and P at varied concentrations. RESULTS: MMP-2 protein expression was observed in cultured rat osteoblats, which was inhibited by E2 treatment. The expression of MMP-2 mRNA decreased as doses of E2 and P increased but TIMP-1 underwent no obvious changes. CONCLUSION: E2 and P can promote the bone formation and slow down the processes of bone matrix degradation and bone resorption by inhibiting the action of MMP-2 in the osteoblasts, and P has the same important effect as estrogen has in the treatment of postmenopausal osteoporosis.
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PMID:Effects of 17beta-estradiol and progesterone on the expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in rat osteoblasts. 1242 69

P450 aromatase catalyzes the conversion of androgens to estrogens and plays a key role in the cell growth of hormone-dependent breast cancer in postmenopausal women. On the other hand, matrix metalloproteinases (MMPs), which can degrade almost all components of the extracellular matrix, play a crucial role in tumor cell invasion and cancer metastasis. In the present study the effect of letrozole on cell proliferation of estrogen receptor (ER)-positive MCF-7 human epithelial breast cancer and MCF-12A human mammary epithelial cells was studied. The effect of letrozole on the in vitro release of MMPs, particularly type IV collagenases (MMP-2 and MMP-9), by the ER-positive MCF-7 cells was also investigated, using a solid-phase method of high sensitivity and accuracy. Using RNA isolates from cell lines MCF-7 and MCF-12A, reverse transcriptase-polymerase chain reaction analysis revealed that only MCF-7 cells express the P450 aromatase gene. Study of the effects of letrozole alone and the hormones 17-beta-estradiol, testosterone and 4-androstene-3, 17-dione in the presence and absence of letrozole on cell growth at the DNA synthesis level showed that letrozole significantly suppressed the endogenous aromatase-induced proliferation of MCF-7 cells. The majority of MMPs secreted by MCF-7 cells were identified in their pro-forms, which was in accordance with the low metastatic potential determined for these cells. After treatment of cells with letrozole (10 nM) for 24 and 48 h, significant inhibition of MMP levels was obtained. Furthermore, concurrent treatment of MCF-7 cells with 17-beta-estradiol in the presence of letrozole significantly suppressed the estradiol-induced stimulation of MMP levels. The data obtained suggest that letrozole is a potent in vitro inhibitor of cell proliferation and of type IV collagenases expressed by ER-positive MCF-7 cells and may be of value for suppressing breast tumor growth and invasiveness.
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PMID:Letrozole as a potent inhibitor of cell proliferation and expression of metalloproteinases (MMP-2 and MMP-9) by human epithelial breast cancer cells. 1256 69

Osteogenic properties of bone cells are a key parameter governing osseointegration of implant devices. In this context, osteoblasts have a central role via extracellular matrix synthesis and remodeling that they regulate through different protease activity. In this study, we have analyzed the expression of two matrix metalloproteinases (MMPs): MMP-2 (72 kDa) and MMP-9 (92 kDa) and their specific tissue inhibitors TIMP-1 and TIMP-2 in primary human osteoblastic cells. The effect of titanium, zirconia, and alumina ceramics on the synthesis of these proteases was assessed using reverse transcriptase-polymerase chain reaction, enzyme-linked immunosorbent assay, and zymographic analysis. Our results showed that osteoblasts express MMP-2 and -9 mRNA. Furthermore, MMP-2 mRNA expression was decreased by titanium and increased by alumina whereas zirconia did not have any significant effect. Conversely, MMP-9 mRNA expression was stimulated by titanium but decreased with zirconia, whereas alumina induced no significant changes. Zymographic analysis has evidenced pro-MMP-2 gelatinolytic activity in all cell populations with time-dependent increase profile; pro-MMP-9, however, was not detected. Enzyme-linked immunosorbent assay data confirmed the production of MMP-2 and very low levels of MMP-9. In addition, TIMP-1 was secreted in 24-h-cultured cells and increased to maximal level at 48-72 h whereas TIMP-2 levels were very low. The interactions between human osteoblasts and the studied biomaterials altered both MMP-2, -9 and TIMP-1expression indicating that biomaterials may influence osseointegration and bone remodeling.
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PMID:Matrix metalloproteinases MMP-2, -9 and tissue inhibitors TIMP-1, -2 expression and secretion by primary human osteoblast cells in response to titanium, zirconia, and alumina ceramics. 1466 Dec 56


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