CACNA1C and Familial prostate cancer: To address this question, the expression of calcium channels CACNA1-C, -D, -G, and -H, which are activated by membrane potential and the transient receptor potential (TRP) channels TRPM-7, which respond to magnesium and TRPV-6 which is constitutively active, was measured in the normal PWR-1E prostate cells, the hormone-responsive LNCaP prostate cancer cells, and the castration-resistant VCaP and 22RV1 prostate cancer cells (Figure 4).