Short-term treatment with gamma interferon induces stable reversion of ras-transformed mouse fibroblasts.

Persistent revertants have been generated from NIH 3T3 cells transformed by an activated human Ha-ras gene after short-term gamma interferon treatment in the presence of the cardiac aminoglycoside ouabain. Normal fibroblastlike morphology and anchorage dependence are restored in revertants. Tumorigenicity in nude mice is abolished. The revertants continue to express high steady-state levels of the ras oncogene. Partial retransformation of reverted cells is induced after 5-azacytidine treatment or after infection with retrovirus vectors carrying the v-abl, v-fes, v-myc, or v-src oncogene. The revertants resist the transforming activities of the v-Ha-ras and v-mos oncogenes.