LncRNA cancer susceptibility 20 regulates the metastasis of human gastric cancer cells via the miR-143-5p/MEMO1 molecular axis

BACKGROUND: Gastric cancer (GC) is considered as one of the most widespread malignancies. Emerging evidence has shown that lncRNAs can function as important oncogenes or tumor suppressors during GC progression. AIM: To investigate the effect and mechanism of lncRNA cancer susceptibility 20 (CASC20) in the proliferation and metastasis of GC cells. METHODS: Data mining and clinical samples were used to evaluate the expression of CASC20 in GC and adjacent tissues. CASC20 was down-regulated in GC cells by short-interfering RNA. Cell proliferation was evaluated by CCK-8 assay, and cell migration and invasion were detected by wound healing and Transwell assays. The expressions of proteins related to epithelial-mesenchymal transition were detected by western blot assay. RESULTS: The expression of CASC20 was increased in GC tumor tissues and various GC cell lines. High CASC20 expression was correlated with a high risk of lymphatic metastasis and poor prognosis in GC patients. In vitro assays showed that silencing CASC20 reduced cell proliferation, migration, and invasion in GC cells. Mechanistic studies revealed that CASC20 exhibits oncogenic functions by regulating MEMO1 expression through competitive endogenous binding to miR-143-5p, leading to induction of epithelial-mesenchymal transition. CONCLUSION: Our findings indicate that CASC20 serves as a tumor promoter by regulating metastasis in GC via the miR-143-5p/MEMO1 axis. CASC20 may be a potential therapeutic target for GC.