NITROSOUREA-INDUCED SISTER CHROMATID EXCHANGES AND CORRELATION TO CELL-SURVIVAL IN 9L RAT-BRAIN TUMOR-CELLS

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  • 1 January 1983
    • journal article
    • research article
    • Vol. 43  (2) , 473-475
Abstract
The ability of various nitrosoureas to induce sister chromatid exchanges (SCEs) in 9L rat brain tumor cells was investigated. Treatment of cells for 1 h with the alkylating and cross-linking agents 1,3-bis(2-chloroethyl)-1-nitrosourea or chlorozotocin produced concentration-dependent increases in SCEs; elevations above controls were detected at concentrations of 1 .mu.M or more. Above 0.25 mM, the alkylating agent ethylnitrosourea produced a dose-dependent increase in SCEs. Treatment with the carbamoylating agent 1,3-bis(trans-4-hydroxycyclohexyl)-1-nitrosourea did not induce SCEs. The maximum drug concentration at which SCEs are readily scored kills approximately 50% of cells. When accurate cell survival data in this dose range were obtained, a direct correlation between nitrosourea-induced cell kill, measured by a colony-forming efficiency assay, and SCE induction was found. Analysis of the levels of SCE production may provide information about the efficacy of antineoplastic drugs.