Fig. 4. circPABPC1 regulates cell adhesion through down-regulating ITGB1.
(A and B) HCC cells with circPABPC1 overexpression (A) or knockdown (B) were analyzed for ITGB1 expression and its downstream signaling by immunoblotting with the indicated antibodies. (C) HCC cells with or without circPABPC1 overexpression were transduced with ITGB1-3xFLAG. ITGB1 expression and FAK activation were determined by Western blot. (D and E) Ectopic expression of ITGB1 rescued circPABPC1-induced phenotypes in trypsin digestion assays (D) and cell adhesion assays (E). OD540nm values were normalized against the control sample (first bar, set to 1.0) in each experiment. *P < 0.05, **P < 0.01, and ***P < 0.001, one-way analysis of variance (ANOVA). n.s., not significant. (F) Depletion of endogenous ITGB1 in HA22T cells by CRISPR-Cas9 eliminated the effect of circPABPC1 knockdown on cell adhesion. Data were analyzed and presented as in (E). (G) Transwell migration assay with the indicated HA22T cells. Representative images of migrated cells (left) and the quantified results (right) are shown (means ± SD, *P < 0.05 and ***P < 0.001, n = 3 biological replicates, one-way ANOVA).