Cain's quinolinium (NSC 176319): protection of murine L1210 leukemia cells and bone marrow progenitor cells against mechlorethamine cytotoxicity and its application to combination chemotherapy.

Cain's Quinolinium; quinolinium, 6-amino-1-methyl-4[[[[[[(1-methyl-pyridinium-4-yl)amino]phenyl]amino]carbonyl]phenyl]amino] (NSC 176319), is a chemotherapeutic agent, which is equally cytotoxic in vitro to both murine L1210 leukemia cells and bone marrow progenitor cells. At non-toxic concentrations it equally protects L1210 cells and bone marrow progenitor cells against mechlorethamine cytotoxicity. However, treatment of murine L1210 leukemia bearing mice with the combination of Cain's Quinolinium and mechlorethamine at a mole ratio of 1:1 resulted in 100% long term survivors compared to 50% with Cain's Quinolinium alone or 0% with mechlorethamine alone.