Figure 6.

Adenoviral targeting of survivin to mitochondria inhibits apoptosis. (A) Subcellular localization. INS-1 cells were infected with pAd-MTS, and isolated mitochondrial or cytosolic fractions were analyzed by immunoblotting. The position of endogenous or transduced (HA-MTS) survivin is indicated. (B) Cytoprotection by adenoviral transduction. INS-1 cells transduced with pAd-MTGFP or pAd-MTS were treated with UVB, exposed to serum starvation, or treated with staurosporine, and analyzed for DNA content by flow cytometry. Samples labeled as INS-1 were untreated cultures. The percentage of cells with hypodiploid (apoptotic) DNA content is indicated for each condition tested. (C) Mitochondrial survivin is sufficient for cytoprotection. MCF-7 cells were transduced with pAd-MTGFP, pAd-Survivin, or pAd-MTS, treated with staurosporine, and analyzed for hypodiploid DNA content and immunoblotting of whole cell extracts (W), mitochondrial, or cytosolic fractions. The percentages of cells with hypodiploid (apoptotic) DNA content were 47% (nontransduced cultures, data not shown), 40% (pAd-MTGFP), 25% (pAd-Survivin), and 29% (pAd-MTS).