Expression of Gene rrg Is Associated with Reversion of NIH 3Tt3 Transformed by LTR-c-H- ras

A partial complementary DNA was isolated for a gene (rrg) that is normally expressed in mouse NIH 3T3 cells, but is down-regulated after cellular transformation by long terminal repeat (LTR)-activated c-H-ras (LTR-c-H-ras). This gene was reexpressed in a nontumorigenic persistent revertant cell line created by prolonged treatment of the transformed cells with mouse interferon alpha/beta. Persistent revertants stably transfected with rrg complementary DNA antisense expression vectors appeared transformed, had decreased amounts of rrg messenger RNA, and were tumorigenic in nude mice. Stable transfection with sense constructs did not alter the normal morphology, message level, or nontumorigenicity of the persistent revertant cell line.