INHIBITION OF BONE-MARROW METASTASIS BY CALMODULIN ANTAGONISTS IN MICE WITH C-1300 NEUROBLASTOMA

The antitumor effect of calmodulin (CaM) antagonists against neuroblas toma (NB) was examined. A total of 10(5) cells of C-1300 NE were inocu lated intravenously into 8-week-old female mice to produce liver and b one marrow metastases. The effects of CaM antagonists, such as trifluo perazine, tamoxifen, melittin, or chlorpromazine, were tested in the t reatment of distant metastasis. Liver metastases, where CaM content wa s low, were not affected by CaM antagonists. However, intraperitoneal injection of CaM antagonists 14 days after tumor cell inoculation inhi bited the bone marrow metastases, where CaM content was high. These fi ndings raise the possibility that CaM antagonists may have clinical va lue for the treatment of bone marrow metastases of NE.