Background: Deregulation of Bcl2 pathway is implicated in the pathogenesis of uveal melanoma (UM). Oncolytic adenovirus H101 is the world's first oncolytic viral therapy for cancer approved for clinical use. We aimed to explore a potential synergy of downregulating Bcl2 pathway using a small interfering RNA (siBCL2) combined with H101 therapy on UM cell lines.
Methods: The sensitivity to adenovirus infection was analysed by flow cytometry. PCR, real-time-PCR and western blot were used to detect Bcl2, p53, Bax and fibre expression. Appropriate multiplicity of H101 infection and cell survival rate were measured by a cell counting kit-8 assay. UM cells were stained with Annexin-V and propidium iodide for apoptosis assay and cell cycle distribution.
Results: VUP cells (without elevation of Bcl2) exhibited greater sensitivity to adenovirus infection than OM431 cells (Bcl2 elevated cell line). Bcl2 expression was markedly reduced by siBCL2 or siBCL2 plus H101. Combined treatment with siBCL2 and H101 produced substantial growth inhibition of OM431 cells by enhancing apoptosis and cell cycle arrest through Bax-p53-induced apoptotic pathway.
Conclusions: SiBCL2 and H101 exhibited synergistic cytotoxic effect in Bcl2 elevated UM cell lines and could potentially serve as a novel targeted molecular therapy for UM.