Abstract: Objective To detect the level of miR-150 in side population(SP)and non-side population(NSP)cells of nasopharyngeal carcinoma and to investigate whether miR-150 promoted proliferation and invasion via the Nanog gene. Method miR-150 and Nanog were detected by qRT-PCR in two cell types. An miR-150 inhibitor and miR-150 mimic were used to reduce and upregulate the level of miR-150, respectively, and CCK-8 and Transwell assays were performed to detect cell proliferation and invasion; the change in Nanog was measured by qRT-PCR and western blot analysis. A t-test for independent samples was used to analyze the data. Results The miR-150 level in SP cells(0.99±0.05)was significantly higher than that in NSP cells(0.59±0.02, t=8.06, P<0.000 1)and the level of Nanog in SP cells(0.99±0.47)was significantly higher than that in NSP cells(0.49±0.05, t=7.5, P<0.000 1). The CCK-8 and Transwell assays showed that MiR-150 inhibited proliferation and invasion(114.40±5.14 vs 57.30±4.29, t=8.5, P<0.000 1); western blotting showed that the reduction in MiR-150 decreased the protein expression of Nanog in SP cells(1.01±0.07 vs 0.46±0.03, t=6.85, P=0.000 5). In contrast, the miR-150 mimic group showed significant upregulation of Nanog in NSP cells(0.48±0.04 vs 1.01±0.06, t=6.16, P=0.000 8). Conclusion miR-150 and Nanog were highly expressed in SP cells of nasopharyngeal carcinoma; additionally, miR-150 promoted proliferation and invasion through upregulation of the Nanog gene in nasopharyngeal carcinoma.

Key words: MiR-150, Side population cells, Invasion, Non- side population cells, Proliferation, Nasopharyngeal carcinoma