ヒト骨肉腫由来骨芽細胞様細胞株におけるコラゲナーゼ遺伝子の発現

抄録

The regulation of collagenase gene expression in the human osteosarcoma-derived osteoblastic cell lines MG-63, U2-OS and human fibloblast cell line IMR-90 was investigated by Northern blot analysis.
Exposure of quiescent MG-63, U2-OS and IMR-90 cells to 12-0-tetradecanoyl-phorbol-13-acetate (TPA) and 10-0 fetal calf serum (FCS) resulted in the induction of mRNA encoding collagenase.
Epidermal growth factor (EGF) induced collagenase mRNA in the IMR-90 cell but not in the MG-63 and U2-OS cells. In the IMR-90 and MG-63 cells, EGF stimulated the transcription of the c-fos and c-jun genes encoding the transcriptional factors which interact directly with the promoter region of the human collagenase gene. Parathyroid hormone and 1, 25-dihydroxyvitamin D₃ did not increase the collagenase mRNA level in both osteosarcoma cells.
Recombinant interleukin-1β (rIL-1β) induced collagenase and c-jun but no t c-fos mRNA in the MG-63 cell. The induction by rIL-1β was blocked by cycloheximide and dexamethasone. Transforming growth factorβ 1 blocked the FCS-induced collagenase gene expression but partially inhibited the rIL-1β-induced gene expression in the MG-63 cell.
These results suggest that the collagenase activity is regulated not only by post-translational modification but also at the transcriptional level by the various factors in bone.