Effects of N,N'-bis(2-chloroethyl)-N-nitrosourea and 2-[3-(2-chloroethyl)-3-nitrosoureido]-2-deoxy-D-glucopyranose upon the proliferation, DNA synthesis, and viability of cultured sensitive and resistant L1210 cells.

The effects of N,N'-bis(2-chloroethyl)-N-nitrosourea and chlorozotocin upon the proliferation, DNA synthesis, and viability of cultured cells of a sensitive line of L1210 leukemia, a line partially resistant to N,N'-bis(2-chloroethyl)-N-nitrosourea, and a line resistant to cyclophosphamide were determined. The results indicate that neither the effect upon proliferation nor the effect upon DNA synthesis is a good predictor of the extent of cell kill. The similarity of the effects of N,N'-bis(2-chloroethyl)-N-nitrosourea upon these two parameters for the three cell lines indicates that the sensitive and resistant cells are affected to approximately the same extent, but more of the resistant cells survive. Additional studies are required to seek the reasons for this differential survival.