APOPTIN-INDUCED APOPTOSIS - POTENTIAL FOR ANTITUMOR THERAPY

Cytotoxic anticancer agents often exert their effect by inducing apopt osis. Many tumors, however, are resistant to chemotherapy. This is due to lack of expression of certain genes essential in mediating the apo ptotic signal, such as p53, or to over-expression of apoptosis inhibit ors, such as bcl-2 or bcr-abl. Apoptin, a small protein derived from a n avian virus, induces a p53-independent, bcr-abl-insensitive, and bcl -2-stimulated apoptosis in various human tumor cells. Interestingly, a poptin does not induce apoptosis in normal diploid cells. These featur es make apoptin a promising antitumor agent. Strategies for anti-cance r therapy based on viral vectors expressing apoptin are under developm ent.