MiR‐324‐5p reduces viability and induces apoptosis in gastric cancer cells through modulating TSPAN8

Objectives The purpose of this study was to further clarify the role and underlying mechanism of miR‐324‐5p in gastric cancer. Methods The expressions of miR‐324‐5p and TSPAN8 as determined by qRT‐PCR or Western blot were compared between the gastric cancer tissues and normal tissues. Human gastric cancer cell line SGC‐7901 was cultured and transfected with miR‐324‐5p mimic/inhibitor or pcDNA‐TSPAN8. The cell survival was assessed by the cell viability and apoptosis. Luciferase reporter gene assays were performed to explore the interaction between miR‐324‐5p and TSPAN8 in SGC‐7901 cells. Key findings MiR‐324‐5p was decreased in human gastric carcinoma tissues (n = 33), but TSPAN8 protein expression was increased in the gastric carcinoma tissues (n = 33). Moreover, miR‐324‐5p inhibited the viability and induced the apoptosis of gastric cancer cells in vitro. TSPAN8 is a functional target of miR‐324‐5p in gastric cancer. MiR‐324‐5p was further confirmed to reduce gastric cancer cell viability and induce apoptosis via downregulating TSPAN8 in SGC‐7901 cells in vitro. Additionally, miR‐324‐5p overexpression markedly inhibited the tumorigenesis of gastric cancer cells in vivo, as shown by the smaller tumour volume compared with the control. Conclusions This study suggested a novel, probable mechanism of miR‐324‐5p in gastric cancer context and revealed that miR‐324‐5p inhibited gastric cancer cell survival by targeting TSPAN8.