The present study was designed to potentiate the antitumor effects of
cisplatin by combination with
calmodulin antagonists (W-7 and W-5) by using nude mice bearing human ovarian
carcinoma.
Tumor growth in nude mice treated with
W-7 or
W-5 combined with
cisplatin was significantly inhibited, compared to that in nude mice treated with
W-7 alone,
W-5 alone or
cisplatin alone. Although treatment with
cisplatin alone markedly inhibited lytic activity of the spleen cells from
tumor bearing nude mice against the
tumor cells, the inhibitory effect was eliminated by combination with
W-7 or
W-5. There was no significant difference in the survival time among untreated,
cisplatin-treated, W-7-treated and W-5-treated groups. Only when
cisplatin was followed by
W-7 or
W-5, a significant enhancement by
W-7 or
W-5 of the antitumor effect of
cisplatin was observed with respect to inhibition of the
tumor growth as well as prolongation of the survival time.