Evaluation of cisplatin response in three radiation resistant and three radiation sensitive cell lines.

The cisplatin response was studied in three radiation sensitive mutant cell lines each paired with normally responding or radiation resistant cell lines of parental or similar origin. The radiation sensitive cell lines V3 (CHO), AT5BI (human fibroblast) and HT144 (melanoma) also showed reduced or lack of ability to repair sublethal radiation damage. Also, V3 did not repair radiation induced DNA double strand breaks and AT5BI was excision repair deficient. None of these cell lines show any cross sensitivity to cisplatin treatment. Instead the response was more like the paired normally radiation responding cell lines, except for AT5BI which showed cisplatin resistance. Thus the mechanisms causing radiation sensitivity in the three cell lines are not involved in cisplatin sensitivity.