pd-114-721 and Sarcoma-180

The antitumor activity of a new antibiotic, kazusamycin, against various murine tumors was studied by various treatment schedules. Single, intermittent, and successive injections of the antibiotic were almost equally effective against Ehrlich carcinoma, IMC carcinoma and sarcoma 180 tumor, but successive injections showed more efficacy than the other schedules against Meth A fibrosarcoma and Lewis lung carcinoma. Interestingly, there was no clear dose response for the efficacy of kazusamycin on murine tumors. When HeLa cells were exposed to kazusamycin for 72 hours in vitro, the IC50 value was about 1 ng/ml, however the cytotoxicity of the antibiotic depended on the incubation time.

Topics: Animals; Antibiotics, Antineoplastic; Carcinoma, Ehrlich Tumor; Cell Survival; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Fatty Acids, Unsaturated; HeLa Cells; Melanoma; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Neoplasms, Experimental; Sarcoma 180

A new antibiotic kazusamycin, was isolated from the culture broth of Streptomyces sp. No. 81-484, which shows antitumor activity against experimental murine tumors. This antibiotic did not possess antibacterial activity against Gram-positive and Gram-negative bacteria, but showed strong cytotoxic activity against HeLa cells in vitro. The chemical and physico-chemical properties of kazusamycin suggest that the molecular formula of this antibiotic is C33H48O7 (MW 556).

Topics: Animals; Antibiotics, Antineoplastic; Fatty Acids, Unsaturated; Fermentation; HeLa Cells; Leukemia P388; Magnetic Resonance Spectroscopy; Mice; Microbial Sensitivity Tests; Sarcoma 180; Streptomyces