Figure 3.

circOMA1 acts as sponge of miR-1276. (A) Subcellular fraction analysis of the location of circOMA1 in BC cells. (B) Ago2 RNA-protein immunoprecipitation assay was used for the detection of circOMA1 in BC cells expressing Flag-Ago2 or Flag-tag. (C) RNA pull-down assay was used for the detection of circOMA1 using a circOMA1-specific probe in BC cells. (D) Relative expression of circOMA1 putative binding miRNAs was examined by reverse transcription-quantitative PCR analysis using a circOMA1-specific probe. (E) Predictive binding sites between circOMA1 and miR-1276; relative luciferase activity was assessed in BC cells co-transfected with wt or mut luciferase reporters and miR-1276 mimics or corresponding NC. (F) BC cells were transfected with sh-NC or sh-circOMA1, and the expression of miR-1276 was assessed. (G) BC cells were transfected with pcDNA3.1 or pcDNA.circOMA1, and the expression of miR-1276 was assessed. (H) Expression of miR-1276 was assessed in BC tissues and adjacent normal tissues. (I) Correlation between the expression of miR-1276 and circOMA1 was analyzed in BC tissues. (J) BC cells were transfected as indicated and the expression levels of miR-1276 were measured. (K) BC cells were transfected as indicated and cell proliferation was measured by Cell Counting Kit-8 assay at different time points. *P<0.05, **P<0.01 vs. NC group. (L) BC cells were transfected as indicated and cellular migration was assessed (magnification, ×100). (M) BC cells were transfected as indicated and cellular invasion was assessed (magnification, ×100). (N) BC cells were transfected as indicated and cellular apoptosis was assessed. Data are presented as the mean ± SD. Experiments were performed at least three times. *P<0.05, **P<0.01. BC, breast cancer; circ/circRNA, circular RNA; sh, short hairpin RNA; NC, negative control; miR, microRNA; mut, mutant; wt, wild-type; OD, optical density; PI, propidium iodide; FITC, fluorescein isothiocyanate.