Combination therapy with radiation and mitomycin C: preliminary results with EMT6 tumor cells in vitro and in vivo

EMT6 tumor cells in vitro and in vivo were used to examine the cytoxicity and metabolism of mitomycin C, a bioreductive alkylating agent, and to study the use of this drug in combination with radiation. Mitomycin C was active against both aerobic and hypoxic cells in vitro. The drug did not alter the D0's of the radiation dose-response curves of aerated or hypoxic cells when present during irradiation in vitro or in vivo. Preliminary experiments suggested that mitomycin C may be preferentially metabolized by and toxic to chronically hypoxic cells in vitro. In vivo, mitomycin C reached and was toxic to the cells of solid tumors, including some hypoxic tumor cells