Newcastle disease virus infection promotes Bax redistribution to mitochondria and cell death in HeLa cells.

BACKGROUND/AIMS Newcastle disease virus (NDV) is an avian paramyxovirus that has gained a lot of interest in cancer viro-therapeutic applications because of its ability to selectively induce apoptosis in human cancer cells. However, the underlying mechanisms by which NDV induces apoptosis in human cancer cells are still not entirely understood. METHODS In this study we examined the effect of a Malaysian velogenic strain of NDV, known as AF2240, on some elements of the intrinsic pathway of apoptosis. RESULTS We show that NDV infection leads to conformational change of Bax protein. This is associated with the translocation of Bax from the cytoplasm to mitochondria and the release of cytochrome c into the cytoplasm. Interestingly, the level of Bcl-2 protein was not affected by NDV treatment. CONCLUSION We have shown that Bax conformational change and subcellular distribution is involved in the intrinsic pathway of apoptosis induced by NDV.