Polyethylenimine-mediated PUMA gene delivery to orthotopic oral cancer: suppression of tumor growth through apoptosis induction in situ and prolonged survival.

ABSTRACT

BACKGROUND: PUMA (a p53 up-regulated modulator of apoptosis) is induced by p53 tumor suppressor and other apoptotic stimuli. It was found to be a principal mediator of cell death in response to diverse apoptotic signals, implicating PUMA as a likely tumor suppressor. METHODS: In this study, we examined the efficacy of targeted PUMA gene therapy in human oral cancer (SAS) cells using polyethylenimine (PEI)-mediated transfection for gene delivery. RESULTS: Exogenous expression of PUMA in SAS cells resulted in apoptosis with cytochrome c release, activation of caspase-3 and -9, and cleavage of PARP. Gene delivery of PEI/PUMA in SAS xenografts induced apoptosis and resulted in significant reductions (∼60%) of tumor growth in vivo. Furthermore, we have shown that PEI-mediated PUMA gene therapy prolonged survival of animals with orthotopic SAS oral cancers. CONCLUSIONS: Taken together, these results indicated that PUMA gene therapy via PEI delivery could be a promising method for the treatment of oral squamous cell carcinoma.