Effect of inhibition of EBV-encoded latent membrane protein-1 by small interfering RNA on EBV-positive nasopharyngeal carcinoma cell growth.
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 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 G(0)-G(1) 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
Gang
G
Department of Otolaryngology and Head and Neck Surgery, Nanfang Hospital, First Military Medical University, Guangzhou 510515, China. lg@fimmu.com
Li
Xiang-ping
XP
Peng
Ying
Y
Liu
Xiong
X
Li
Xiao-hua
XH
D017209:Apoptosis / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D006801:Humans; D009303:Nasopharyngeal Neoplasms / Q000473:pathology / Q000628:therapy* / Q000821:virology; D012333:RNA, Messenger / Q000032:analysis; D034741:RNA, Small Interfering / Q000494:pharmacology*; D014162:Transfection; D014763:Viral Matrix Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics
C037662:EBV-associated membrane antigen, Epstein-Barr virus; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D014763:Viral Matrix Proteins