Casein kinase 2 inhibition differentially modulates apoptotic effect of trichostatin A against epithelial ovarian carcinoma cell lines.

Histone deacetylase inhibitors and casein kinase 2 inhibitors have been shown to induce apoptosis. However, the combined effect of casein kinase 2 inhibition on the apoptotic effect of histone deacetylase inhibitor is unknown. We assessed the effect of casein kinase 2 inhibition on the apoptotic effect of trichostatin A in human epithelial carcinoma cell lines with respect to cell death signaling pathways. At concentrations that did not induce cell death, the casein kinase 2 inhibitor 4,5,6,7-tetrabromobenzotriazole inhibited activation of apoptotic proteins and changes in mitochondrial membrane permeability induced by the histone deacetylase inhibitor trichostatin A. These results suggest that casein kinase 2 inhibition may reduce trichostatin A-induced apoptosis in ovarian carcinoma cell lines by suppressing activation of apoptotic proteins and changes in mitochondrial membrane permeability, which both lead to caspase-3 activation. Casein kinase 2 inhibition, which does not induce a cytotoxic effect, may prevent histone deacetylase inhibitor-mediated apoptosis.