Possible involvement of protein kinase C in proliferation and differentiation of osteoblast‐like cells

Abstract

In cloned osteoblast‐like cells, MC3T3‐E1, 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA), a protein kinase C activating phorbol ester, and 1‐oleoyl‐2‐acetylglycerol (OAG), a specific activator for protein kinase C, stimulated DNA synthesis in a dose‐dependent manner. Both TPA and OAG acted synergistically with insulin‐like growth factor I to stimulate DNA synthesis. TPA as well as OAG suppressed the increase in alkaline phosphatase activity of MC3T3‐E1 cells induced by parathyroid hormone. These results suggest that protein kinase C is involved in the process which directs osteoblast‐like cells toward proliferation.