Experimental Chemotherapy Studies. v. the Collateral Sensitivity to Alkylating Agents of Several Antimetabolite-resistant Ascites Tumors in Mice.

Although the phenomenon of acquired resistance has come to play a major role in studies of mechanism of ac tion and in the design of new chemotherapeutic agents, the development of knowledge about collateral sensitivity has received far less attention. Yet this feature of the complex changes which accompany conversion to drug resistance is potentially of importance to chemotherapy, as well as to an understanding of the biochemical and physiological phenomena which underlie resistance (7). As part of a general program concerned with the mech anism of action of alkylating agents, we have examined the patterns of resistance and sensitivity of a number of murine neoplasms and their antimetabolite-resistant sublines.