CD95 (Fas/APO-1) and p53 signal apoptosis independently in diverse cell types

The tumor suppressor p53 exerts its antioncogenic effects in cells chiefly by regulating their progression through the cell cycle and by inducing cell death. It has been claimed that p53-transduced apoptosis involves the deat h receptor CD95 (Fas/APO-1). We report that thymocytes from mice Lacking fu nctional Fas ligand (gld) show normal sensitivity to apoptosis transduced b y p53, and that hepatocytes from p53(-/-) mice have normal sensitivity to a poptosis triggered through ligation of CD95, p53 and CD95, therefore, funct ion in independent pathways to cell death in these diverse fell types.