[Effect of rAAV-mediated RNA interference against EB virus-encoded latent membrane protein 1 on nasopharyngeal carcinoma cell proliferation and metastasis in nude mice].
OBJECTIVE
To study the role of Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP-1) in nasopharyngeal carcinoma (NPC) cell growth and metastasis in vivo by recombinant adeno-associated virus (rAAV)-mediated RNA interference (RNAi).


METHODS
Specific small hairpin RNA (shRNA) targeting EBV-LMP-1 gene was designed and synthesized to construct two rAAV vectors rAAV-shRNA-LMP-1 and rAAV-EGFP. The multiplicity of infection (MOI) was confirmed using different titers of rAAV-EGFP to transfect the NPC cell line C666-1. The C666-1 cells were transfected by rAAV-shRNA-LMP-1 at the optimal MOI titer and the inhibition efficiency of the target gene expression was determined with RT-PCR. The C666-1 cells with RNAi of LMP-1 gene were injected into nude mouse liver via laparotomy to establish the animal model of hepatic and lung metastases of NPC cells. The metastases of the C666-1 cells in the liver and lungs were observed to assess the effect of LMP-1 gene silencing on the tumorigenic and metastatic potentials of the cells in vivo.


RESULTS
The transfection efficiency of 5 x 10(4) virus genome/cell rAAV-EGFP exceeded 95%. The expression of the target gene was suppressed by over 90% as shown by RT-PCR after transfection with rAAV-shRNA-LMP-1 at 5 x 10(4) virus genome/cell. Animal experiments showed that compared with rAAV-EGFP, rAAV-shRNA-LMP-1 transfection did not reduce the primary tumor volume implanted into the liver, but significantly inhibited the intrahepatic and lung metastases of the NPC cells.


CONCLUSIONS
LMP-1 expression can be suppressed effectively by rAAV-mediated RNAi, and LMP-1 suppression does not obviously affect the tumor cell growth but can inhibit their metastasis in vivo.
Liu
Xiong
X
Department of Otolaryngology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China. liux1218@ 126.com
Liu
Xiong
X
Li
Gang
G
Zhang
Bao
B
Wang
Lu
L
Li
Xiao-hua
XH
Li
Xiang-ping
XP
D000818:Animals; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D004274:DNA, Recombinant / Q000235:genetics*; D000229:Dependovirus / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D004854:Herpesvirus 4, Human / Q000235:genetics*; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009303:Nasopharyngeal Neoplasms / Q000235:genetics* / Q000473:pathology*; D009362:Neoplasm Metastasis; D034622:RNA Interference; D014763:Viral Matrix Proteins / Q000235:genetics*
D004274:DNA, Recombinant; C037662:EBV-associated membrane antigen, Epstein-Barr virus; D014763:Viral Matrix Proteins