Figure 2. Hsa_circ_0053063 is highly expressed in BC and acts as an antioncogene in BC cells. (A) qRT-PCR analysis revealed the expression of hsa_circ_0053063 in BC tissues and adjacent normal tissues. (B) Relative expression of hsa_circ_0053063 in BC cell lines compared with normal breast epithelial cell line MCF-10A. (C) qRT-PCR analysis revealed the transfection efficiency of hsa_circ-0053063 specific siRNA. (D–G) Effect of siRNA targeting hsa_circ_0053063 on MTT assays and colony formation in MDA-MB-231 and MDA-MB-468 cells. (H–I) Western blot analysis demonstrated the effect of hsa_circ_0053063 siRNAs on PCNA in MDA-MB-231 and MDA-MB-468 cell lines. (J) qRT-PCR revealed the overexpression efficiency of LV-circ_0053063 in MDA-MB-231 and MDA-MB-468 cell lines. (K–N) Effect of LV-circ_0053063 on proliferation in MDA-MB-231 and MDA-MB-468 cell lines by MTT assay and colony formation assays. (*p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001).