Effects of a podophyllotoxin derivative on tissue culture systems in which human cancer invades normal tissue.

In the search for clinically effective antitumor agents, numerous biologic systems have been con sidered as possible screening devices (4). Some in vestigators have preferred test systems with hu man tumors, with the thought that these may pro vide the greatest possibility of correlation with clinical cancer. Experiments have been conducted with chemical agents and human cancer in several ways, e.g., in the patient, in heterologous animal transplant, and in tissue culture. This report de scribes the development and application of methods in which cancer invades normal tissue in spongematrix tissue culture for the evaluation of chemotherapeutic agents. Tissue culture approaches in experimental med icine have received increased attention recently as an outgrowth of the simplifications of methods, the ready commercial availability of a variety of me dia, the development of many lines of cells derived from human tissue, and, finally, the conclusive demonstration of the usefulness of such technics in the fields of virology and cell nutrition. Of great interest is the approach of Eagle and Foley (3). With almost completely defined nutritional condi tions and with methods that permit quantitative studies on the nutrient as well as on the cell popu lation, they have added potential chemotherapeutic agents to the medium and have observed their toxic effect upon the growth and nutrition of vari ous cell lines. In our work, several lines of cells derived from human cancer,1 when inoculated into cultures of