Figure 5

SNHG20 interacted with EZH2, and regulated P21 expression in NSCLC cells. (a) SNHG20 expression levels in the cytoplasm or nucleus of SPC-A1 and A549 cells were detected by qRT-PCR. GAPDH was used as a cytosol marker and U1 was used as a nuclear marker. (b) RNA immunoprecipitation experiments were performed in SPC-A1 and A549 cells and the coprecipitated RNA was subjected to qRT-PCR for SNHG20. SNHG20 RNA expression levels are presented as fold enrichment in EZH2 and SUZ12 immunoprecipitates relative to that of IgG. (c) The expression of p15, p16, P21 and p27 was determined using qRT-PCR after knockdown of SNHG20. (d) Western blot analysis was conducted to detect the level of P21 protein in SPC-A1 and A549 cells transfected with si-SNHG20. (e–g) qRT-PCR and western blot assays were used to detect EZH2 and P21 mRNA and protein levels in SPC-A1 and A549 cells transfected with si-EZH2. (h) ChIP-qRT-PCR of EZH2 occupancy and H3K27me3 binding to the P21 promoter in SPC-A1 and A549 cells treated with si-SNHG20 (48 h) or si-NC; IgG as a negative control. (i) Analysis of the relationship between SNHG20 expression and P21 mRNA levels (DCt value) in NSCLC patient tissue from GEO. Values are shown as the mean (S.D.) from three independent experiments. *P<0.05, **P<0.01