Evidence for human DNA-mediated transfer of the suppressed phenotype into malignant Chinese hamster cells.

Genetic suppression of the neoplastic phenotype has been demonstrated in somatic cell hybrids between tumor and normal cells. Suppression in whole-cell and microcell hybrids cannot, as yet, be attributed to specific elements defined at the molecular level. To identify a gene capable of suppressing the neoplastic phenotype, we have introduced DNA of normal human cells into tumorigenic Chinese hamster Wg3-h-o cells. Primary and secondary transfectants which exhibit the suppressed phenotype similar to Wg3-h-o x embryonic fibroblast hybrids were selected. The cells require serum growth factors and anchorage for proliferation in vitro and show a reduced tumorigenicity in nude mice. Transferred human DNA segments were molecularly cloned from a secondary transfectant. Indirect evidence suggests that the cloned human DNA is associated with the expression of the suppressed phenotype.