OBJECTIVETo investigate the effect of RNA interference (RNAi) targeting NRP-1 gene on the growth and proliferation of nasopharyngeal carcinoma (NPC) CNE-2Z cells.

METHODSShort hairpin RNA (shRNA) plasmids targeting NRP-1 were designed and synthesized. These plasmids were respectively transfected into human NPC CNE-2Z cells and xenograft tumors in nude mice. The expressions of Fluorescein-labeled plasmids in NPC CNE-2Z cells and xenograft tumors were observed by fluorescence microscopy. Cell proliferation was detected by MTT assay. The inhibitory effects on target genes were evaluated with RT-PCR and Western blotting, respectively. The inhibitory effect of plasmids with the most effective sequence on xenograft tumors in nude mice was observed.

RESULTSCNE-2Z cell proliferation was significantly inhibited by NRP-1/shRNA silencing. RT-PCR showed NRP-1 mRNA expression was significantly decreased. Western blotting demonstrated the NRP-1/shRNA silencing can effectively inhibit the expression of target proteins in CNE-2Z cells. After six weeks, there were significant differences in the mean tumor volumes in nude mice between plasmid group and negative control group [(0.599±0.002) vs (1.141±0.013) cm(3), P<0.05] or blank control group [(0.599±0.002) vs (1.165±0.308) cm(3), P<0.05], and the inhibitory rate of tumor growth was 48.6%.

CONCLUSIONRNA interference targeting NRP-1 can remarkably inhibit the growth of CNE-2Z cells in vitro and in vivo.