Comparison of bleomycin and peplomycin toxicity on clonogenic tumor cells from various human tumors.

The cytotoxic effect of bleomycin and peplomycin was compared using a methylcellulose monolayer assay for the cultivation of human tumor cells. In 3 out of 4 samples from human malignant melanomas peplomycin proved to be more cytotoxic than bleomycin. Peplomycin was more cytotoxic than bleomycin in 1 of 5 myosarcoma samples, whereas 2 samples from squamous cell carcinomas of the lung showed identical dose response curves. In 1 carcinoma of the gall bladder peplomycin was more toxic than bleomycin.