Abstract
Indirect action of γ-rays on cytotoxicity is, in general, more than 70% of all the lethal effects. In contrast, the action was about 50% in M10 cells, an XRCC4-deficient cell line, as determined by the protective effects of dimethylsulfoxide (DMSO), a radical scavenger. In the present study M10 cells were transfected with XRCC4 cDNA vector using DMRIE-C reagent. The stable transfectants were cloned by the colony formation in the presence of puromycin. These transfectants were confirmed by PCR and Western blot analyses. The protective effects of DMSO against γ-ray-induced cell killing were determined by the colony formation assay. DMSO increased cell survival in both M10 and its parental cell line L5178Y, but less effectively in M10 cells. Transfection of XRCC4 cDNA to M10 entirely restored this decreased radioprotective effects of DMSO to the level of L5178Y.
