Fig. 7

GBAP1 activates BMP/SMAD signaling under the mediation of miR-22-3p in HCC cells. A Three bioinformatics tools (TargetScan, mirtarbase and microRNA.org) were employed to predict the downstream target candidate of miR-22-3p, and four mRNA candidate NOS1, AGPCR, BMPR1A and AKAP95 were obtained. B and C The expression changes of four mRNAs in Hep3B-anti-miR-22-3p and MHCC97H-miR-22-3p subclones were tested by RT-qPCR. ***P < 0.001 (Student’s t test). D There existed potential binding site between wild type of BMPR1A (BMPR1A -WT) and miR-22-3p, and the mutant type of BMPR1A (BMPR1A-MUT) was established. Double luciferase reporter gene assay revealed that miR-22-3p was able to negatively regulate the luciferase activity of BMPR1A-WT, but had no effect on BMPR1A-MUT. ***P < 0.001 (Student’s t test). E RT-qPCR analysis was performed to analyze BMPR1A expression in HCC tissues (n = 85) and adjacent non-tumor tissues (n = 85). ***P < 0.001 (Student’s t test). F Pearson correlation analysis showed that there existed a negative correlation between BMPR1A and miR-22-3p in HCC tissues (n = 85). G Pearson correlation analysis showed that there existed a positive correlation between GBAP1 and BMPR1A in HCC tissues (n = 85). H and I miR-22-3p expression was negatively regulated by GBAP1 alone, while the effect of GBAP1 alone on miR-22-3p expression was reversed in GBAP1 + miR-22-3p group and shGBAP1#1 + anti-miR-22-3p group. J The KEGG pathway enrichment of GBAP1 based on RNA-seq data were analyzed. The top 10 categories were shown. K and L Western blot was applied to analyze the expression changes of BMPR1A, p-SMAD1/5 and SMAD1 in different co-transfection groups