The Ca²⁺Channel Antagonists Mibefradil and Pimozide Inhibit Cell Growth via Different Cytotoxic Mechanisms

We show that mitogenic cells expressing T-type Ca²⁺channels (T-channels) are more sensitive to the antiproliferative effects of the drugs pimozide and mibefradil than cells without significant T-channel expression. The growth of Y79 and WERI-Rb1 retinoblastoma cells, as well as MCF7 breast cancer epithelial cells, all of which express T-channel current and mRNA for T-channel subunits, is inhibited by pimozide and mibefradil with...