MiR-324-3p Promotes Gastric Cancer Development By Activating Smad4-mediated Wnt/beta-catenin Signaling Pathway

Background:Emerging evidence suggested that miRNAs can function as oncogenes or tumor suppressors by regulating downstream target genes.miR-324-3p has been reported to function in several carcinomas,but its role in GC(gastric cancer)is still unknown.This study aims to explore the effects of miR-324-3p on the development of GC.Methods:Expression of miR-324-3p was examined in GC cells and tissues by qRT-PCR.Effects of miR-324-3p on GC cells were evaluated by cell vitality assay,colony formation assay,cell migration assay and flow cytometric assay.The dual luciferase assay was used to verify whether miR-324-3p could interact with the potential target genes.Western blot was used to assess the expression level of Smad4 and beta-catenin.Intracellular ATP level was also examined.The tumor xenografts were established using nude mice.Gastric organoid model was made from fresh stomach tissueResults:miR-324-3p was expressed at higher levels in the tumor tissues compared with adjacent normal tissues.Overexpression of miR-324-3p promoted cell growth,migration and decreased apoptosis.miR-324-3p repressed the expression of Smad4 and loss of Smad4 activated Wnt/beta-catenin signaling pathway.Overexpression of Smad4 rescued the effects of miR-324-3p on GC cells.The intracellular ATP level was up-regulated with overexpression of miR-324-3p.miR-324-3p facilitated tumor cell colonization and growth in vivo and contributed to the growth of gastric organoids.Conclusions:The results suggested that miR-324-3p promoted GC through activating Smad4-mediated Wnt/beta-catenin signaling pathway.The miR-324-3p/Smad4/Wnt signaling axis may be a potential therapeutic target to prevent GC progression.