The response of human lymphoma cells in vitro to bleomycin and 1,3-bis(2-chloroethyl)-1-nitrosourea.

Abstract

Asynchronous human lymphoma cells treated with 1,3-bis(2-chloroethyl)-1-nitrosourea exhibited a broad-shouldered, threshold-type survival curve similar to that obtained after X-irradiation, suggesting that damage must be accumulated before killing effect is expressed. The sensitivity of the lymphoma cells to bleomycin was expressed as a biphasic dose-response survival curve, suggesting the involvement of sensitive and less sensitive fractions of cells. A 1000-fold reduction in survival was observed following treatment with bleomycin for the duration of one cell cycle.