Fig. 3

circKIF4A acts as a sponge for miR-375 a The expression levels of nuclear control (18S), cytoplasmic control (GAPDH) and circKIF4A were detected. b The predicted binding sites of miR-375 within the circKIF4A sequence. c The miR-375 expression in TNBC cell lines. d Luciferase assay of cells cotransfected with miR-375 mimics and wild type or mutant luciferase reporter. e MS2-based RIP assay transfected with MS2bs-circKIF4A, MS2bs-circKIF4Amt or control. f A CCK-8 assay to detect cell proliferation. g A colony formation assay to detect cell colony-forming ability. h The colony formation number was quantified by ImageJ. i A Transwell assay to assess cell migration ability. j The number of invasive was quantified by ImageJ. k A wound-healing assay to detect cell migration ability. l Wound closure was quantified by ImageJ. m-n Immunofluorescence staining for E-cadherin and vimentin. o Xenograft models were established. p Summary of the tumor weights. q Representative image of luciferase signals of lung metastatic nodules. r Representative images of lung metastatic nodules and HE-stained sections. s The number of metastatic nodules was quantified. **P < 0.01