Fig. 6

PIK3R1 is a direct target of miR-198. a mRNA microarray data of the top 20 upregulated genes in SGC7901CDDP, BGC823CDDP, SGC7901 and BGC823 cells are presented as heatmaps. b Venn diagram showing 4 genes that are putative miR-198 targets computationally predicted by four algorithms (miRanda, RNAhybrid, miRWalk and TargetScan) among the top 20 upregulated genes. c Schematic of PIK3R1 3’UTR wild-type (WT) and mutant (Mut) luciferase reporter vectors is shown. d The relative luciferase activities were analyzed in 293 T cells cotransfected with miR-198 mimics or miR-NC and luciferase reporter vectors PIK3R1 3’UTR (WT) or PIK3R1 3’UTR (Mut). e & f The expression of PIK3R1 was analyzed using RT-qPCR in tissues of cohort 1 (E) and in SGC7901CDDP, BGC823CDDP, SGC7901 and BGC823 cells (F). g The expression of PIK3R1 was analyzed using western blot in SGC7901CDDP, BGC823CDDP, SGC7901 and BGC823 cells. h & i The expression of PIK3R1 was analyzed by RT-qPCR (G) and western blot (H). SGC7901CDDP and BGC823CDDP cells were transfected with miR-198 mimic or cotransfected with the indicated vectors. j The IC50 of miR-198 was analyzed by the CCK8 assay. SGC7901CDDP cells were transfected with miR-198 mimic alone or cotransfected with the indicated vectors upon CDDP exposure (6 μM) for 48 h. k The apoptosis rates of SGC7901CDDP cells transfected with miR-198 mimic alone or cotransfected with the indicated vectors upon CDDP exposure (6 μM) for 48 h. The results are presented as the mean ± SEM. *P < 0.05, **P < 0.01