Secretory expression of p53(N15)-Ant following lentivirus-mediated gene transfer induces cell death in human cancer cells.

p53 (N15)-Ant 32-peptide has been considered a novel and effective peptide for cancer therapy. To further enhance its anticancer effect and overcome the limitation of peptide therapy, a recombinant lentivirus was constructed in this study with the following strategies: the secretory expression of therapeutic peptide and lentivirus gene transfer system. The results demonstrated that LV-NT4(Si)-p53 (N15)-Ant could significantly suppress cell growth and induce rapid cell death in MCF-7 (overexpressed wild-type p53), HepG2 (wide-type p53), OVCAR-3 (mutant type p53) and H1299 (null p53) cells in time-dependent manners through successful gene transfer and secretory expression of therapeutic peptide at 48 h post-infection. Transmission electron microscopy and flow cytometric analysis revealed that LV-NT4(Si)-p53 (N15)-Ant could induce two different kinds of cell death (necrosis and apoptosis) by two different mechanisms, since p53 (N15)-Ant peptide has the potential of blocking interaction of mdm-2 with other protein target, and on the other hand, it could form S-shape helix-loop-helix structures, which is able to rapidly disrupt cancer cell membranes. Based on these finding, LV-NT4 (Si)-p53 (N15)-Ant may be a novel recombinant virus because it induces cell death by two different pathways.