Abstract: According to the present invention, there is provided an assay for determining Bax degradation activity in a patient sample. The assay includes a labeled Bax protein which is incubated with a protein extract from the sample and a detector for detecting a signal from the labeled Bax protein, whereby decreased signals compared to a control indicates Bax degradation activity. Also provided by the present invention is a method for assaying a tissue for Bax degradation activity for determining aggressiveness of a tumor, for screening compounds for inhibitors of Bax degradation activity and for determining efficacy of proteasome inhibitors to prevent Bax degradation including the steps of incubating the sample with a labeled Bax protein and detecting the presence of a label generated signal whereby decrease signal compared to a control indicates Bax degradation activity. A method for screening potential proteasome inhibitors and anticancer drugs for efficacy in preventing Bax degradation activity.

Abstract: The present invention relates treatment of tumors using a Bax protein fragment to induce apoptosis. More specifically, the present invention relates to the use of the Bax amino terminus 18 kDa fragment to induce cytochrome c release and apoptosis in cancer cells. Further provided is the method of inducing cell death even in cancer cells overexpressing Bcl-2 oncoprotein. Further provided is a method using Bax/p18 of triggering cytochrome c release, activation of caspase-3, cleavage of poly(ADP-ribose) polymerase, fragmentation of DNA and induction of cell death.

Abstract: According to the present invention, there is provided an assay for determining Bax degradation activity in a patient sample. The assay includes a labeled Bax protein which is incubated with a protein extract from the sample and a detector for detecting a signal from the labeled Bax protein, whereby decreased signals compared to a control indicates Bax degradation activity. Also provided by the present invention is a method for assaying a tissue for Bax degradation activity for determining aggressiveness of a tumor, for screening compounds for inhibitors of Bax degradation activity and for determining efficacy of proteasome inhibitors to prevent Bax degradation including the steps of incubating the sample with a labeled Bax protein and detecting the presence of a label generated signal whereby decrease signal compared to a control indicates Bax degradation activity. A method for screening potential proteasome inhibitors and anticancer drugs for efficacy in preventing Bax degradation activity.

Abstract: The present invention relates treatment of tumors using a Bax protein fragment to induce apoptosis. More specifically, the present invention relates to the use of the Bax amino terminus 18 kDa fragment to induce cytochrome c release and apoptosis in cancer cells. Further provided is the method of inducing cell death even in cancer cells overexpressing Bcl-2 oncoprotein. Further provided is a method using Bax/p18 of triggering cytochrome c release, activation of caspase-3, cleavage of poly(ADP-ribose) polymerase, fragmentation of DNA and induction of cell death. Further provided is a method of introducing Bax/p18 protein into a cancer cell via introducing Bax/p18 cDNA, to cause release of cytochrome c and induction of caspase-3 mediated apoptosis that is not blocked by overexpression of Bcl-2.