Tumor promoter phorbol-12-myristate-13-acetate induces poly(ADP)-ribosylation in fibroblasts.

Abstract

The tumor promoter phorbol-12-myristate-13-acetate (PMA) causes an increase in poly(ADP)-ribosylation in mouse and human fibroblasts via the intermediate formation of active O2. In contrast to poly(ADP)-ribosylation induced by the methylating agent N-methyl-N''-nitro-N-nitrosoguanidine, de novo RNA and protein synthesis are required and the accumulation of the polymer occurs in the absence of detectable DNA strand breakage. A mechanism for PMA-induced modulation of chromatin structure and gene expression is suggested.