[The effect of calmodulin antagonist on the anticancer effect of vinblastine]

Calmodulin exists in all eukaryotic cells. It functions as the intracellular receptor of Ca, regulates various cellular physiological processes. We studied the effect of calmodulin antagonist W-7 on the anti-cancer effects of vinblastine. With the method that calmodulin can activate cyclic nucleotide PDE, we found that W-7 can significantly reduce the calmodulin level of MGC803 cell (P < 0.05). W-7 could not only increase the uptaking and accumulating of -3H-Vinblastine in MGC803 cells (P < 0.05), but also decrease the IC50 of Vinblastine (from 12.0 +/- 0.03 nmol to 5.27 +/- 0.02 nmol) in MGC803 cells. It is indicated that calmodulin antagonist W-7 can enhance the anticancer effect of vinblastine.