Thiamine protection of murine L1210 leukemia cells against mechlorethamine cytotoxicity and its relation to the choline uptake system.

Thiamine is an inhibitor of choline transport by murine L1210 leukemia cells and a protector of these cells from growth inhibition by mechlorethamine in vitro. Combination chemotherapy of tumor bearing mice with thiamine and mechlorethamine increased the mechlorethamine dosage required for a 50 to 60 percent increase in survival time but did not improve survival over that obtained with mechlorethamine alone.