The TRPV6
calcium channel is known to be up-regulated in various
tumors. The efforts to target the
TRPV6 channel in vivo are still ongoing to propose an effective
therapy against
cancer. Here, we report the generation of two
antibodies raised against extracellular
epitopes corresponding to the extracellular loop between S1 and S2 (rb79) and the pore region (rb82). These
antibodies generated a complex biphasic response with the transient activation of the
TRPV6 channel. Store-operated
calcium entry was consequently potentiated in the
prostate cancer cell line LNCaP upon the treatment. Both rb79 and rb82
antibodies significantly decreased cell survival rate in a dose-dependent manner as compared to the control
antibodies of the same isotype. This decrease was due to the enhanced cell death via apoptosis revealed using a sub-G1 peak in a cell cycle assay, TUNEL assay, and a Hoechst staining, having no effects in the PC3Mtrpv6-/- cell line. Moreover, all TUNEL-positive cells had TRPV6 membrane staining as compared to the control antibody treatment where TRPV6-positive cells were all TUNEL negative. These data clearly demonstrate that
TRPV6 channel targeting using rb79 and rb82
antibodies is fatal and may be successfully used in the anticancer
therapies.