Antitumor effect of a calmodulin antagonist on the growth of solid sarcoma-180.

A calmodulin antagonist, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), proved to have antitumor activity against solid Sarcoma-180. In particular, intraperitoneal injection of W-7 strongly inhibited the growth of solid Sarcoma-180 in mice given a daily dose, 10 mg/kg for 10 consecutive days. A chlorine deficient analogue, N-(6-aminohexyl)-1-naphthalenesulfonamide (W-5), which interacts weakly with calmodulin, had no antitumor activity against solid Sarcoma-180, in a dose similar to that of W-7. Thus, W-7, a calmodulin antagonist may inhibit the growth of solid Sarcoma-180 by modulation of the Ca2+-calmodulin-dependent processes.