RNAi silencing targeting LMP 2 A enhances the radiosensitivity of nasopharyngeal carcinoma cell line C 666-1

Latent membrane protein 2A (LMP2A) is found to play an important role in development of nasopharyngeal carcinoma (NPC), to which the main current approach was radiotherapy. However, the role of silencing LMP2A in the radiosensitivity of NPC cells has not been clarified. In this study, we inhibited LMP2A expression by lentivirusmediated RNAi, to explore the effects of silencing LMP2A on the radiosensitivity of NPC cell line C666-1. A lentivirusmediated RNAi technology was employed to specifically knock down the LMP2A gene in C666-1 cells, whose expression was detected by Western blotting. Clonogenic survival assay and flow cytometry were performed to evaluate the clonogenic cell survival, cell cycle distribution and apoptosis of C666-1 cells after irradiation. We successfully construct a highly efficient and stable lentivirus vector, which efficiently down-regulates the expression of LMP2A gene in the infected cell line C666-1. Down-regulation of LMP2A significantly decreases the radiobiological parameters (SF2, D0, Dq), and the specific down-regulation arrests cells in G0/G1 phase of cell cycle and increases cell apoptosis after irradiation. Our findings suggest that lentivirus-mediated RNAi silencing targeting LMP2A enhanced the radiosensitivity of NPC cell line C666-1, and LMP2A may be a potential target for radiotherapy in treatment of NPC.