Circ_0003356 suppresses gastric cancer growth through targeting the miR-668-3p/SOCS3 axis

Wei-Dong Li; Hai-Tao Wang; Yue-Ming Huang; Bo-Hao Cheng; Li-Jun Xiang; Xin-Hao Zhou; Qing-Yan Deng; Zhi-Gang Guo; Zhi-Feng Yang; Zhi-Fen Guan; Yao Wang

doi:10.4251/wjgo.v15.i5.787

Circ_0003356 suppresses gastric cancer growth through targeting the miR-668-3p/SOCS3 axis

World J Gastrointest Oncol. 2023 May 15;15(5):787-809. doi: 10.4251/wjgo.v15.i5.787.

Authors

Affiliations

¹ Department of Gastrointestinal Surgery, Zhongshan City People's Hospital, Zhongshan 528403, Guangdong Province, China.
² Department of Gastrointestinal Surgery, Zhongshan City People's Hospital, Zhongshan 528403, Guangdong Province, China. wangyao8065@163.com.

Abstract

Background: Circular RNAs (circRNAs) have attracted extensive attention as therapeutic targets in gastric cancer (GC). Circ_0003356 is known to be downregulated in GC tissues, but its cellular function and mechanisms remain undefined.

Aim: To investigate the role of circ_0003356 in GC at the molecular and cellular level.

Methods: Circ_0003356, miR-668-3p, and SOCS3 expression were assessed via quantitative real time-polymerase chain reaction (qRT-PCR). Wound healing, EdU, CCK-8, flow cytometry and transwell assays were used to analyze the migration, proliferation, viability, apoptosis and invasion of GC cells. The subcellular localization of circ_0003356 was monitored using fluorescence in situ hybridization. The interaction of circ_0003356 with miR-668-3p was confirmed using RIP-qRT-PCR, RNA pull-down, and dual luciferase reporter assays. We observed protein levels of genes via western blot. We injected AGS cells into the upper back of mice and performed immunohistochemistry staining for examining E-cadherin, N-cadherin, Ki67, and SOCS3 expressions. TUNEL staining was performed for the assessment of apoptosis in mouse tumor tissues.

Results: Circ_0003356 and SOCS3 expression was downregulated in GC cells, whilst miR-668-3p was upregulated. Exogenous circ_0003356 expression and miR-668-3p silencing suppressed the migration, viability, proliferation, epithelial to mesenchy-mal transition (EMT) and invasion of GC cells and enhanced apoptosis. Circ_0003356 overexpression impaired tumor growth in xenograft mice. Targeting of miR-668-3p by circ_0003356 was confirmed through binding assays and SOCS3 was identified as a downstream target of miR-668-3p. The impacts of circ_0003356 on cell proliferation, apoptosis, migration, invasion and EMT were reversed by miR-668-3p up-regulation or SOCS3 down-regulation in GC cells.

Conclusion: Circ_0003356 impaired GC development through its interaction with the miR-668-3p/SOCS3 axis.

Keywords: Circ_0003356; Epithelial-mesenchymal transition; Gastric cancer; Invasion; Migration; Proliferation.