miR-324-3p promotes gastric cancer development by activating Smad4-mediated Wnt/beta-catenin signaling pathway

• DOI: 10.1007/s00535-017-1408-0
• Publication Date: 2017-11-04T16:44:37Z
• Authors: Guang-Li Sun; Zheng Li; Wei-Zhi Wang; Zheng Chen; Lei Zhang; Qing Li; Song Wei; Bo-Wen Li; Jiang-Hao Xu; Liang Chen; Zhong-Yuan He; Kai Ying; Xuan Zhang; Hao Xu; Dian-Cai Zhang; Ze-Kuan Xu
• Keywords: Original Article—Alimentary Tract; Adult; Male; 0301 basic medicine; Mice, Inbred BALB C; Cell Survival; Mice, Nude; Apoptosis; Middle Aged; 3. Good health; Gene Expression Regulation, Neoplastic; MicroRNAs; 03 medical and health sciences; Cell Transformation, Neoplastic; Cell Movement; Animals; Heterografts; Humans; Female; RNA, Neoplasm; Neoplasm Transplantation; Aged; Cell Proliferation; Neoplasm Staging

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 gastric cancer (GC) is still unknown. This study aims to explore the effects of miR-324-3p on the development of GC.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. A gastric organoid model was made from fresh stomach tissue.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 the Wnt/beta-catenin signaling pathway. Overexpression of Smad4 rescued the effects of miR-324-3p on GC cells. The intracellular ATP level was upregulated 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.The results suggested that miR-324-3p promoted GC through activating the 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.