Fig. 4.

Identification of the PKCβ inhibitor Enzastaurin/LY317615 as a PARPi synergizing agent in breast and ovarian cancer cells. a–e Viability curves following BMN673 treatment with or without the PKCβ inhibitor LY317615 at a constant molar ratio of 1:3 BMN673:LY317615 for 5 days in the breast cancer cells a MDA-MB-231, and b MCF7, and in the ovarian cancer cell lines c ES2 and d BRCA-mutant COV362, as well as in the e non-transformed mammary epithelial cell line MCF10A. f Isobolograms calculated at IC₅₀ values for cancer cell lines demonstrate synergism for all analyzed lines. g Combination indices demonstrate synergism between PARPi and PKCβi in a panel of ovarian and breast cancer cell lines across a range of inhibitor concentrations