Figure 7

PDCD4 regulated the expression of miR-184 via PI3K/AKT/JNK pathway in NPC. (a) siRNAs were used to suppress the C-JUN expression by western blot examination. (b) Knocking down C-JUN expression by siRNA stimulated the expression of miR-184 in NPC SUNE1 and 5-8F cells. (c) From mock and pcDNA3.1-C-JUN-transfected SUNE1 cells was immunoprecipitated with anti-C-JUN and a normal rabbit IgG. The AP-1 binding sites on the immunoprecipitated DNA was determined by quantitative RT-PCR. Amplification of input chromatin (input) before immunoprecipitation was served as positive controls for chromatin extraction and PCR amplification. Chromatin immunoprecipitation using a non-specific antibody (normal human IgG) served as negative controls. QPCR analysis indicated that C-Jun could bind more miR-184 promoter region than that in control group in NPC SUNE1 cells. (d) Suppressing the expression of PI3K by its specific inhibitor Ly294002 (50 nM) reduced pPI3K, pAKT and C-JUN expression in NPC SUNE1 and 5-8F cells, but did not induce AKT expression change. (e) Knocking down JNK1 suppressed the expression of C-Jun in NPC SUNE1 and 5-8F cells. (f) Specific inhibition of JNK1 by siRNA decreased the expression of JNK and C-Jun in NPC cells. Data are presented as mean±S.D. of three independent experiments (*P<0.05)