Complementation analysis of testis tumor cells.

Testis tumors are cured using cisplatin-based chemotherapy in over 80% of patients, and sensitivity to cisplatin is retained by testis tumor cells in vitro. The aim of this study was to use complementation analysis to determine how many genes control sensitivity to cisplatin in testis tumor cells. Four testis tumor cell lines were transfected with pSV2NEO and pBABE plasmids, conferring G418 and puromycin resistance, respectively. Self-crosses were generated to control for gene dosage, and the parentage of the hybrids was confirmed by PCR amplification of VNTR regions. Karyotyping confirmed that all the hybrids retained at least 88% of the combined number of chromosomes of the two parental cell lines. Cisplatin sensitivity was measured by clonogenic assay and complementation was not observed. This finding provides evidence that there is a single common mechanism controlling cisplatin sensitivity in testis tumor cells.