CircEPSTI1 Promotes the Proliferation of HER2-Positive Breast Cancer Cells via circEPSTI1/miR-145/ERBB3 Axis

Figure 4

CircEPSTI1 regulates ERBB3 as mir-145 sponge in HER2-positive breast cancer cells. (a) Predicted direct binding sites of hsa-miR-145 within ERBB3 sequences. (b) Luciferase reporter assay was performed and the luciferase activity of cells co‐transfected with miR-145 mimics and luciferase reporter containing EPSTI1 3′UTR (wt) or mutant construct (mut) was tested. (c) The qRT‐PCR was used to determine the expression of ERBB3 in SKBR3 and BT474 cells transfected as described. (d) The expression of ERBB3 determined by western blot (left) and quantified (right). (e) RIP assay measured the enrichment of circEPSTI1, EPSTI1, and miR-145 on Ago2 relative to IgG. (f) RIP assay on Ago2 performed in SKBR3 and BT474 cells transfected as described. (g) qRT‐PCR performed to detect expression of ERBB3 in SKBR3 and BT474 cells transfected. (h) CCK-8 assay evaluated cell proliferation in SKBR3 and BT474 cells transfected. (i) Transwell migration and invasion assays evaluated migration and invasion ability of SKBR3 cells transfected. .

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