Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.17 (MMP-3)
 3,419 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Glomerular mesangial cells express matrix metalloproteinase sromelysin in response to the proinflammatory cytokine IL-1 beta. The present study was conducted to identify intracellular machinery involved in this IL-1 action, especially focusing on the role of the TPA response element (TRE) located in the 5'-flanking region of the stromelysin gene. Using transient transfection with a pTRE-LacZ reporter plasmid, we detected no obvious up-regulation of TRE activity in rat mesangial cells following the IL-1 stimulation. However, the basal activity of TRE was found to be essential to the stromelysin induction, since (i) mesangial cells stably expressing a transdominant negative mutant of c-Jun, which effectively suppressed both basal and inducible TRE activity, exhibited the blunted expression of stromelysin in response to IL-1 beta, whereas (ii) transfection with a c-fos antisense gene, which suppressed only the inducible TRE activity, did not affect the stromelysin induction. To seek cooperative pathways required for the IL-1 action, we next focused on protein kinases, the potential regulators of the stromelysin gene. Stimulation of mesangial cells with a protein kinase C (PKC) activator, phorbol 12-myristate 13-acetate (PMA), induced the stromelysin transcript without affecting TRE activity. Depletion of intracellular PKC by high-dose PMA or inhibition of PKC activity with calphostin C suppressed the stromelysin induction by IL-1 beta, suggesting the crucial contribution of a PKC-mediated, but TRE-independent pathway. In contrast, either cAMP inducer forskolin or dibutyryl cAMP suppressed the IL-1-mediated stromelysin expression. An inhibitor of cAMP-dependent protein kinase A (PKA), HA1004, enhanced the IL-1 effect in a dose-dependent manner. Unexpectedly, the inhibitory action of PKA was not through cAMP response element (CRE) but through TRE, because (i) activation of CRE was not induced by IL-1 beta, and (ii) cAMP-mediated activation of PKA suppressed the basal TRE activity. These findings elucidated the unique, binary regulation of stromelysin by IL-1 beta; that is, IL-1 up-regulated the transcript via the PKC-dependent pathway under the cooperation with constitutively active TRE, and this stimulatory effect was in part counterbalanced by the IL-1-inducible PKA which down-regulated the basal TRE activity.
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PMID:Opposite, binary regulatory pathways involved in IL-1-mediated stromelysin gene expression in rat mesangial cells. 887 64

Previously, we reported that growth activation of quiescent 3T3-L1 cells by TPA led to a rapid increase of pro-alpha 2 (I) collagen mRNA and protein, while induction of pro-alpha 2 (I) was not observed in VT-1 cells, a line non-mitogenic in the presence of TPA (26). Here, we further examine the expression of pro-alpha 2 (I) collagen during mitogenic stimulation at the molecular level. In addition to pro-alpha 2 (I) mRNA, TPA treatment increased mRNA production of other collagen family members, pro-alpha 1 (I) and pro-alpha 1 (III) although in reduced amounts relative to pro-alpha 2 (I). In contrast to pro-alpha 2 (I), the mRNA expression profiles of several protooncogenes were regulated in both VT-1 and 3T3-L1 cells. Consistent with increased mRNA levels, TPA treated 3T3-L1 cells produced a matrix abundant in collagen type I protein. In vitro nuclear "run-on" transcription assays demonstrated a 4-fold increase in pro-alpha 2 (I) mRNA that was maximal within 10 min of TPA treatment. Using a chloramphenicol-acetyl transferase (CAT) assay, we identified a TPA sensitive domain within the promoter of the COL1A2 gene. These results establish COL1A2 as an early growth responsive gene, and that its regulation is PKC dependent. Additionally, the increased expression of protooncogenes and transin during TPA stimulation of non-mitogenic VT-1 cells indicated that the regulation of these genes is independent of PKC, indicating the existence of multiple regulatory mechanisms amongst early response genes.
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PMID:The phorbol ester TPA regulates collagen gene expression at the transcriptional level. 890 62

One of the primary antioxidant enzymes, manganese-containing superoxide dismutase (MnSOD), has shown the ability to reverse malignant phenotypes in a variety of human tumor cells that are low or absent in MnSOD expression. We have observed that overexpression of human MnSOD in human breast cancer MCF-7 cells inhibits tumor growth both in vitro and in vivo. The signaling pathway underlying the MnSOD induced tumor suppression is unknown. We demonstrate here that transcriptional and DNA binding ability of AP-1 and NF-kappaB, but not SP-1, were inhibited (by 50%) in the MCF-7 cell line overexpressing MnSOD. When transiently expressing, MnSOD inhibited AP-1 but increased NF-kappaB transactivation, which can be abolished by sodium pyruvate, a hydrogen peroxide scavenger. To analyze the target genes responsible for MnSOD-induced tumor suppression, genes related to tumor growth and responsive to AP-1 or NF-kappaB were analyzed. AP-1 responsive collagenase I, stromelysin I, and NF-kappaB responsive IL-1 and IL-6 were down-regulated in the MnSOD stable transfectants compared to the control cell lines. Since TPA induces differentiation in human breast cancer cells and up-regulates MnSOD gene in HeLa cells, MnSOD expression and AP-1 and NF-kappaB activity were measured under TPA treatment. The results showed that TPA induced endogenous MnSOD expression and inhibited both AP-1 and NF-kappaB. Together, these results suggest that tumor suppression by overexpressing MnSOD is related to a modulation of AP-1 and NF-kappaB, which causes a down-regulation of genes responsible for tumor malignant phenotype.
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PMID:Inhibition of AP-1 and NF-kappaB by manganese-containing superoxide dismutase in human breast cancer cells. 983 61

The aim of the work was to analyze, on a comparative basis, the signaling pathways operating in the regulation of a panel of matrix metalloproteinases (MMP) expressed by human dermal fibroblasts submitted to mechanical stress relaxation by cytochalasin D (CD) and in a retracting collagen gel (RCG). The mRNA steady-state level of MMPs was measured by a quantitative RT-PCR procedure using a synthetic RNA as internal standard. In monolayer, most MMPs were barely detected, except MMP-2. Disruption of the actin stress fibers by CD induced a moderate increase of MMP-2 mRNA and a much larger stimulation of MMP-3, -9, -13 and -14 mRNAs. In RCG, a significant up-regulation of these MMPs was also observed although to a lower extent than in CD-treated monolayers. Among the investigated MMPs, the MMP-8 and -11 were not reproducibly detected. MMP-2 was processed to its active form both by CD and in RCG. The CD-induced up-regulation of gene expression was largely repressed by blocking protein synthesis by cycloheximide for all the MMPs, by inhibiting the tyrosine-kinases of the src family by herbimycin A for all MMPs, except MMP-2, and by inhibiting the TPA-inducible PKC isoforms by bisindoyl maleimide for all MMPs, except MMP-14. The up-regulation induced by stress relaxation in RCG was protein synthesis-dependent for MMP-2 and MMP-13, tyrosine kinases-dependent for MMP-3 and MMP-13, as previously described for MMP-1. Inhibiting TPA-inducible PKC did not affect any MMP in RCG except MMP-13, which was strongly induced. The processing of MMP-2 was tyrosine kinases-dependent but PKC-independent. Inhibitors of the ERK1,2 and p38 MAP kinases pathways diversely affected the MMPs expression. Inhibiting the Rho-kinase activity by Y-27632 was inactive. These results point to the potent regulation operated by the status of the cytoskeleton on the cell phenotype, and to distinct regulatory pathways involved in the control of different MMPs expression.
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PMID:Distinct pathways in the over-expression of matrix metalloproteinases in human fibroblasts by relaxation of mechanical tension. 1169 80

Tumour necrosis factor-alpha (TNF-alpha) deficient mice (TNF-alpha(-/-) mice) are resistant to skin carcinogenesis. Cellular signalling via the transcription factor complex AP-1 is thought to play a key role in tumour promotion. The induction of a specific subset of AP-1 responsive genes thought to be important for tumour development, namely GM-CSF, MMP-9 and MMP-3, was suppressed in TNF-alpha(-/-) compared to wild-type mouse skin in response to the tumour promotor TPA. The differential induction of these genes correlated with a temporal shift in AP-1 activation and c-Jun expression in TNF-alpha(-/-) compared to wild-type epidermis. The major receptor for TPA-induced signalling in basal keratinocytes, PKC alpha, was also differentially regulated in wild-type compared with TNF-alpha(-/-) epidermis. A marked delay in TPA-induced intracellular translocation and downregulation of PKC alpha was observed in TNF-alpha(-/-) epidermis, which correlated with the deregulated TPA-induced AP-1 activation and c-Jun expression. The frequency of DNA adduct formation and c-Ha-ras mutations was the same in wild-type and TNF-alpha(-/-) epidermis after DMBA treatment, suggesting that TNF-alpha was not involved in tumour initiation. These data suggest that the pro-inflammatory cytokine TNF-alpha is a critical mediator of tumour promotion, acting via a PKC alpha- and AP-1-dependent pathway. This may be one mechanism by which chronic inflammation increases susceptibility to cancer.
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PMID:Tumour necrosis factor-alpha mediates tumour promotion via a PKC alpha- and AP-1-dependent pathway. 1210 11

Matrix Metalloproteinases (MMPs) play a crucial role in breast cancer metastasis. We examined the mRNA and protein expression of several MMPs in brain- and bone-seeking clones of MDA-MB-231 breast cancer cells, their transcriptional regulation and their functional role in the metastatic process. MMP mRNA expression was examined using real-time reverse transcription polymerase chain reaction. Protein expression was examined using enzyme linked immunosorbent essay (ELISA). The inducibility of mRNA and protein expression was tested with TPA (phorbol 12-myristate 13-acetate; 50 microM); epidermal growth factor and transforming growth factor beta (20 ng/ml both). Migration and invasion assays were performed with the QCM 96-Well Migration/Invasion Assay (8 microm; Chemicon) over 24 h with or without specific MMPs inhibitors (MMP Inhibitor I Mix (5 microM); MMP-2/MMP-9 Inhibitor III (50 microM); EMD Biosciences). We found significantly higher mRNA expression of MMP-1 and -9 in brain-seeking 231-clones in comparison to -bone and -parental cells. In contrast, the mRNA expression of MMP-3 and -14 was comparable in all cells lines examined and MMP-13 expression was lower in both selective metastatic lines. MMP-2 and -8 were not expressed. ELISA revealed a higher amount of total as well as active MMP-1 and -9 in brain-seeking cells. TPA stimulation showed that MMP-1 and -9 transcription was inducible on the mRNA and protein level in 231-parental but not in 231-brain or -bone. 231-brain showed the highest migration and invasive capacity which could be decreased by the application of MMP-1 and/or MMP-9 inhibitor. Our results indicate functional importance of MMP-1 and -9 overexpression in brain metastasis in an in vitro model.
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PMID:Differential expression of matrix metalloproteinases in brain- and bone-seeking clones of metastatic MDA-MB-231 breast cancer cells. 1685 Jan 7


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