FIG. 8.

Inhibition of PKCδ by rottlerin abrogates DNA damage-induced expression of topoisomerase IIα. (A and B) MOLT-4 cells were pretreated with or without rottlerin for 1 h followed by treatment with ara-C (A) or cisplatin (CDDP) (B) for the indicated periods. Cell lysates were subjected to immunoblot (IB) analysis with anti-topoisomerase IIα (anti-TopoIIα) or anti-PKCδ. DMSO, dimethyl sulfoxide. (C) U-937 cells were treated and analyzed as described above for panel A. (D) MOLT-4 cells were left untreated or treated with ara-C for 4 h in the presence or absence of rottlerin. Total RNA was subjected to RT-PCR analysis using primer sets for topoisomerase IIα (TopoIIα) or β-actin. (E) 293T/GFP-TopoIIα cells were left untreated or treated with rottlerin for 1 h followed by treatment with ara-C for 4 h. Cell lysates were subjected to immunoblot analysis with anti-topoisomerase IIα or anti-PKCδ.