circ1662 inhibits SMAD3 expression via YAP1. (A) The top 10 KEGG enrichment analysis of mRNA strongly with YAP1 expression and circ1662 expression in 6 pair colorectal cancer (Pearson correlation coefficient: 0.6-1.0). (B) qPCR anlaysis of ten genes (ACVR2AF, CALM3, EGFR, HK2, MYC, RELA, SGK1, SMAD3, SOCS3, and TGFBR1) screened from the significantly enriched pathways in SW480 transfected circ1662 siRNA. (C) qPCR anlaysis of HK2, SOCS3, RELA and SMAD3 in HCT116 and SW480 transfected circ1662 vector and YAP1 siRNA. (D, E, F) qPCR, Western blot and IF identified SMAD3 mRNA and protein expression level in HCT116 transfected YAP1 siRNA. (G) IHC staining of SMAD3 in metastases from Bala/c mice injected stable overexpressed-circ1662 HCT116 via tail vein. (H) Western blot analysis of SMAD3 expression in HCT116 and SW480 transfected circ1662 siRNA and SMAD3 siRNA. GAPDH is used as an internal reference. (I, J) Transwell assay of HCT116 and SW480 transfected circ1662 siRNA and SMAD3 siRNA. GAPDH is used as an internal reference for performing qPCR. Statistical significance was calculated by Student's t test, *P < 0.05, 0.001 < ** P < 0.01, *** P < 0.001, Mean ± SEM.