Chemosensitization by monofunctional alkylating agents.

The chemosensitizing ability of model monofunctional alkylating agents with known DNA base alkylating characteristics, that is, methylmethanesulphonate (MMS), ethyl methanesulphonate (EMS) and N-methyl-N-nitrosoguanidine (MNNG) have been investigated. Whereas the alkyl sulphonates chemosensitize V79 cells to cisplatin and melphalan, MNNG does not. The dose response curves show shoulder removal. Drug scheduling and thiourea post-treatment experiments indicate that the effect is likely to be on the initial alkylation rather than completion of crosslink formation from an initial adduct.