Establishment of a tumor cell line and its use for an agar-free colony-forming assay.

The establishment of a spontaneously transformed tumorigenic human fibrosarcoma line derived from the ovary of a breast cancer patient (NO-15) is described. This tumor cell line has been characterized by tumor growth in nude mice. The cells form colonies without the usually recommended agar technique and are sensitive to cis-dichlorodiammineplatinum(II) (cis-DDP), daunorubicin (DR) and bleomycin (BLM), three well-known chemotherapeutic agents. The cells were incubated in the presence of drugs using three different methods. These agents proved to be noncytotoxic to monolayers treated for three hours. Conversely dose-dependent cytotoxicity was seen in suspension cultures treated for three hours. Optimal correlation between the three methods for the evaluation of cytotoxicity was seen in monolayers exposed to these agents for 24 hours. The results of three different methods to evaluate drug efficacy (number of colonies, growth rate and 3H-thymidine incorporation) were in good correlation. The incorporation of the radiolabeled tracer into cellular DNA is advantageous for its rapidity and quantitative reproducibility.