Effect of cisplatin resistance on cellular radiation response.
Cisplatin-resistant tumors of the head and neck are generally resistant to irradiation. To determine whether the association between cisplatin (DDP) resistance and radiation resistance is a cellular phenomenon, we developed DDP-resistant Chinese hamster fibroblasts and studied their response to radiation. DDP resistance did not confer cross resistance to radiation. DDP-resistant cells did not demonstrate altered ability to repair sublethal or potentially lethal radiation damage. However, an isodose concentration of DDP did not inhibit repair of radiation damage in drug-resistant cells as readily as it did in drug-sensitive cells. The results suggest that cross resistance of tumors between DDP and radiation may be a result of the tumor microenvironment, rather than being a cellular phenomenon. Additionally, DDP may not inhibit the repair of radiation damage in DDP-resistant tumors.
D000818:Animals; D002478:Cells, Cultured; D002945:Cisplatin / Q000494:pharmacology*; D006224:Cricetinae; D003412:Cricetulus; D004260:DNA Repair / Q000187:drug effects; D004351:Drug Resistance; D005347:Fibroblasts / Q000528:radiation effects*; D011833:Radiation Injuries, Experimental / Q000517:prevention & control
D002945:Cisplatin