Fig. 6

SNHG6 acts as a sponge for miR-214, miR-26a, and miR-26b in the cytoplasm. a Representative FISH images showed the expression of SNHG6 in HCT-116 and HCT-8 cells (red). Nuclei were stained by DAPI (blue). b Relative SNHG6 expression levels in nuclear and cytosolic fractions of HCT-116 and HCT-8 cells. Nuclear controls: U6, cytosolic controls: GAPDH. c The relative expression of candidate microRNAs which could potentially bind to SNHG6 were quantified by qRT-PCR after the biotinylated-SNHG6 pull-down assays in HCT-116 cells. d Dual luciferase reporter assays were conducted with wild-type and mutant-type (putative binding sites for miR-214, miR-26a, or miR-26b were mutated) luciferase report vectors. Left panel, sequence alignment of miR-214, miR-26a, or miR-26b and their predicted binding sites (green) of SNHG6. Predicted microRNA target sequence (blue) in SNHG6 (Luc-SNHG6-wt) and positions of mutated nucleotides (red) in SNHG6 (Luc-SNHG6-mt#1 and Luc-SNHG6-mt#2). e RNA immunoprecipitation with an anti-Ago2 antibody was used to assess endogenous Ago2 binding to RNA, IgG was used as the control. The levels of SNHG6, miR-214, miR-26a, and miR-26b were determined by qRT–PCR and presented as fold enrichment in Ago2 relative to input. f EdU assays showed that overexpression of SNHG6 promotes CRC cells proliferation. Overexpression of miR-214, miR-26a, or miR-26b inhibits cancer cell proliferation. Co-transfecting miR-214, miR-26a, or miR-26b mimics with SNHG6 plasmids abolished the increased proliferation rates. g, h Transwell assays showed that overexpression of SNHG6 promotes CRC cells migration and invasion. Overexpression of miR-214, miR-26a, or miR-26b inhibits CRC cells migration and invasion. Co-transfecting miR-214, miR-26a, or miR-26b mimics with SNHG6 plasmids abolished the increased migration and invasion abilities. Scale bar = 50 μm. *P < 0.05, **P < 0.01, and ***P < 0.001