Apoptin (R) induces apoptosis in transformed cells specifically: Potentials for an anti-tumor therapy

Apoptosis is a programmed physiological process for eliminating superfluous , or altered cells. Apoptosis can be induced by many stimuli through differ ent pathways, all of which seem to converge into one evolutionarily conserv ed process. Apoptosis plays an important role in tumor development, and can be exploite d for therapeutic purposes. Many tumor cells have a disabling mutation in t he decision-making machinery for apoptosis, but their execution system may still be intact. This means that tumor cells may die if they are provided w ith an appropriate apoptotic signal. Apoptin, a protein encoded by an avian virus, induces apoptosis in various cultured human tumorigenic and/or transformed cell lines. In such cells, Ap optin induces wild-type p53-independent apoptosis, which is not inhibited b y BCR-ABL or Bcl-2. On the other hand, Apoptin is unable to induce apoptosi s in normal non-transformed human cells. In animal models, Apoptin appears to be a safe and efficient antitumor agen t. The above data imply that Apoptin holds promise as a basis for anti-tumo r therapy.