Comparative antitumor activities of 7-N-(p-hydroxyphenyl)mitomycin C (M-83) and mitomycin C.

The antitumor activity of 7-N-(p-hydroxyphenyl)mitomycin C (M-83) against 7 kinds of ascitic tumors and 4 kinds of solid tumors was compared with that of mitomycin C (MMC). M-83 showed more potent activities than MMC against ascites sarcoma 180, fibrosarcoma Meth 1, sarcoma Meth A, melanoma B-16, leukemia P388 and lymphoma EL4, by a single intraperitoneal injection. Furthermore, M-83 gave markedly higher chemotherapeutic ratio than MMC in these tumor systems. M-83 was also markedly effective against solid tumors of sarcoma 180, Meth 1, Meth A and Lewis lung carcinoma, by a single intravenous injection. M-83 gave lower myelo-suppression than MMC at the doses which gave almost equal inhibition on the tumor growth of solid Meth 1. M-83 and MMC significantly inhibited the growth of HeLa S3 cells. Cell growth was observed at 24 hours after addition of 3 X 10(-3) mM of drugs, but no growth was shown thereafter. M-83 inhibited more strongly the incorporation of the radioactive precursor into DNA than that into RNA or protein at the concentration of 3 X 10(-3) mM.