[Anticancer drug induced sister chromatid exchange and correlation to cell survival in human brain tumor cells]

Sister chromatid exchanges (SCEs) induced by four anticancer drugs, 3-(4-amino-2-methyl-5-pyrimidyl) methyl-1-(2-chloroethyl)-1-nitrosourea (ACNU), 1-3-bis (2-chloroethyl)-1-nitrosourea (BCNU), nitrogen mustard (HN2), cis-diamminedichloroplatinum (II) (cis-Pt) were examined on five cell lines derived from human malignant glioma biopsy specimens, and compared to results obtained with colony-forming efficiency (CFE) assay. Treatment of the five cell lines with these four drugs produced concentration-dependent increases in SCEs. Treatment with ACNU induced the most SCEs in SF-126 cells decreasing in SF-268 cells followed by SF-210 cells, SF-295 cells, and the least SCEs in SF-188 cells. The results of the SCE assay with BCNU in these cell lines were similar with ones with ACNU. In contrast to results obtained with nitrosoureas, the most SCEs were induced in SF-188 cells and the least were induced in SF-126 cells by the treatment of HN2. The frequency of SCEs induced with cis-Pt was almost similar in the five cell lines. The number of SCEs induced by the treatment of ACNU, BCNU, HN2 and cis-Pt in five cells lines showed a good correlation with cytotoxicity measured by CFE assays, and induction of SCEs occurred at much lower concentrations of these anticancer drugs than those required to induced cell kill. These results suggest that measurement of induced SCEs in human brain tumor cells treated with some anticancer drugs provide a more sensitive indicator of drug action than CFE assay and that SCE assays may be a useful method of the in vitro sensitivity test to some anticancer drugs.