Complementation of the tumorigenic phenotype in human cell hybrids.

Several combinations of human tumor cell lines were fused together. Hybrid populations formed from fusions between carcinoma x carcinoma and carcinoma x lymphoblastoid remained highly tumorigenic. However, suppression of tumorigenic potential was seen in carcinoma x sarcoma and carcinoma x melanoma hybrid populations. These results suggest that complementation of the tumorigenic phenotype can occur and that at least 2 different complementation groups may be involved.