CELL-DEATH SUFFERS A TKO

The cytokine interferon-gamma (IFN-gamma), initiates both cell cycle a rrest and cell death in certain cell lines. Through a novel strategy o f cell transfection with episomal vectors expressing antisense cDNAs, Deiss et al.((1,2)) have demonstrated that it is possible to isolate g enes that are required for the initiation of cell death by the cytokin e IFN-gamma. This approach, referred to as TKO, for Technical Knock Ou t, has identified several genes whose activity appears to be essential for the induction of apoptosis by IFN-gamma in HeLa cells. interestin gly these genes appear to mediate IFN-gamma-induced apoptosis in HeLa cells, but their inhibition by antisense does not ameliorate the anti- proliferative effects of lFN-gamma in these cells. The clever strategy employed by these authors holds promise for others who wish to isolat e genes required for other differentiative processes in cultured cell lines.