Effect of inhibition of EBV-encoded latent membrane protein-1 by small interfering RNA on EBV-positive nasopharyngeal carcinoma cell growth

Abstract

Abstract: Objective To evaluate the feasibility of using small interfering RNA (siRNA) for selective inhibiting latent membrane protein-1 (LMP1) expression in Epstein-Barr virus (EBV)-positive nasopharyngeal carcinoma (NPC) cell line C611, and observe the effects of LMP1 gene silencing on the NPC cell growth. Methods Four synthesized double-strand siRNA were respectively transfected into NPC cells, using Oligofectamine^TM reagent. The subsequent changes in LMP1 mRNA level were determined by semi-quantitative reverse transcriptase (RT)-PCR. Flow cytometry and MTT assay were employed to examine the alterations in cell cycle and cell proliferation. Results The most effective sequence was identified among the 4 candidate siRNAs, and its single dose caused nearly 90% loss of LMP1 mRNA in C611 cells, with sustained specific inhibition for 96 h following a re-transfection. LMP1 siRNA treatment resulted in cell cycle arrest at G₀-G₁ phase, accompanied by a reduction of cell proliferation by 33%, whereas EBV-negative NPC cells appeared unaffected. Conclusions EBV-encoded LMP-1 is vulnerable to RNA interference and selective inhibition of LMP1 suppresses the proliferation of EBV-positive NPC cells, a finding that sheds light on the possible use of RNA interference in further investigations of LMP1 and for therapeutic purposes of EBV-related NPC.

LI Gang¹, LI Xiang-ping¹, PENG Ying², LIU Xiong¹, LI Xiao-hua¹. Effect of inhibition of EBV-encoded latent membrane protein-1 by small interfering RNA on EBV-positive nasopharyngeal carcinoma cell growth[J]. Journal of Southern Medical University, 2004, 24(03): 241-246.

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