Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have previously shown that in the rat osteoblastic osteosarcoma cell line-UMR 106-01-PTH induces maximal collagenase mRNA levels at 4 hours. Since this response to PTH requires de novo protein synthesis, it may be mediated by the combined temporal expression of members of the activator protein-1 (AP-1) gene family. We have demonstrated that maximal mRNA levels of two of the members of this family, c-fos and c-jun, occur 30 min after stimulation by PTH. Phorbol myristate acetate (PMA) elicits a similar increase in c-fos and c-jun mRNAs, but is unable to stimulate transcription of collagenase in these cells. To investigate further the involvement of the AP-1 gene family, we examined PTH and PMA stimulation of jun-B, jun-D, fos B, and fra-1 mRNAs in UMR 106-01 cells. The mRNA for jun-D was abundant under control conditions and showed no variation in response to PTH (10(-8) M). The fos B transcripts were not detected under control conditions, whereas jun-B and fra-1 mRNAs were present at low basal levels. PTH caused an increase in fos B mRNA that reached a maximal 4- to 5-fold plateau between 45 and 60 min. An increase in jun-B mRNA in response to PTH was detectable at 30 min, but reached a maximal 6- to 7-fold increase at 2 hours. After PTH stimulation, the fra-1 transcript showed a 10- to 11-fold peak at 4 hours. PMA (2.6 x 10(-7) M) stimulated fos B mRNA to maximal abundance at 1 hour, similar to PTH. In contrast, PMA caused a maximal increase in jun-B mRNA at 30 min and fra-1 mRNA at 2 hours, which was earlier than the response to PTH. To determine whether an increase in jun-B at the same time as c-fos and c-jun would inhibit collagenase gene transcription, we cotransfected an expression vector for jun-B with a rat collagenase promoter-reporter gene construct. This resulted in a decrease in PTH-stimulation of promoter activity. Thus, it appears that the differential temporal stimulation of the AP-1 genes by PTH and PMA, particularly an increase in jun-B at the same time as c-fos and c-jun, explains the difference seen in their ability to induce transcription of collagenase.
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PMID:Parathyroid hormone versus phorbol ester stimulation of activator protein-1 gene family members in rat osteosarcoma cells. 919 14

Osteosarcoma cells are useful for investigating bone metabolism as malignant counterpart of osteoblasts. In hematogenous metastases of osteosarcoma cells, the cells need to adjust to various changes in pericellular environment. The changes in pericellular environment may change intracellular environment and consequently the secretion of matrix metalloproteinases (MMPs) which destroy extracellular matrices. In this report, a new cell line, KOS-1, derived from human osteoblastic osteosarcoma was established, and we assumed various culture conditions containing ingredients of the extracellular matrix to make a comparative study on MMPs detected from the culture supernatants. A wide spectrum of MMPs, including MMP-1 and -3 which were increased in the presence of interleukin 1 beta, was detected in this cell line. Production of MMP-1, the enzyme which decomposes types I, II, III and X collagen, by the cells, was increased in the presence of type I collagen. MMP-3 (stromelysin-1) which degrades types III and IV collagen, laminin, fibronectin, proteoglycan, etc. was produced more abundantly in the presence of type IV collagen. MMP-2 (72-kd type IV collagenase/gelatinase A) activity was found to be increased in the presence of gelatin and type IV collagen. The MMPs production in cultured osteosarcoma cells was changed depending on the culture conditions. This indicates that the same osteosarocma cells produce different amounts and kinds of enzymes involved in local infiltration and remote metastases and increase the production of the enzymes most required under a specific environment.
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PMID:Establishment of an osteoblastic osteosarcoma cell line and effects of cell culture conditions on secretion of matrix metalloproteinases from the cultured osteosarcoma cells. 1094 49


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