Blockade of T-type Ca(2+) channels inhibits human ovarian cancer cell proliferation.

Regulation of Ca(2+) channels has been implicated in the progression of tumor cells. We report here that T-type Ca(2+) channel expression in human ovarian cancer tissues is greatly increased compared to normal ovarian tissues. Blockade of T-type Ca(2+) channel with NNC 55-0396, mibefradil, or by specifically knocking down the expression of these proteins with siRNA-Ca(v)3.1/3.2 suppressed the proliferation of two ovarian cancer cell lines and increased G0/G1 phase distribution in the cell cycle. Furthermore, NNC 55-0396 slowed ovarian cancer formation in nude mice. Therefore the function of T-type Ca(2+) channels is important for the proliferation of human ovarian cancer cells.