Figure 6.

FBXW7-185aa, Encoded by circFBXW7, Inhibited the Proliferation and Metastasis of TNBC Cells through Downregulating c-Myc Expression

(A) Schematic diagram of plasmid construction. The linearized FBXW7-185aa ORF and a FLAG tag were cloned downstream of a cytomegalovirus (CMV) promoter (FBXW7-185aa-FLAG). (B) The expression level of circFBXW7 was measured in BT549 cells after transfection with the FBXW7-185aa-FLAG vector. (C–E) FBXW7-185aa inhibits (C) cell proliferation, as assessed by CCK-8 assays; (D) the colony-forming ability and (E) migration ability were assessed via transwell assays. (F and G) The prooncogenic effect enhanced by sh-circFBXW7 was reversed after cotransfection with miR-197-3p inhibitors and the FBXW7-185aa protein expression plasmid, as evaluated by (F) colony formation assays and (G) transwell assays. (H) FBXW7-185aa-FLAG-overexpressing BT549 cells were cotransfected with sh-FBXW7 or USP28 vectors. The FBXW7-185aa-FLAG, FBXW7, USP28, and c-Myc expression levels were quantified by western blot analysis. (I) The schematic illustrates the biological mechanism of circFBXW7, which sponges miR-197-3p and encodes FBXW7-185aa to suppress TNBC progression through upregulating FBXW7 expression. SD is shown as error bars.