[摘要] 目的：探讨circ_0023642 通过调控miR-508-3p/ERBB4 分子轴对胃癌GMC-803 细胞增殖和转移的影响及其作用机制。方法：选取2015 年5 月至2018 年3 月南通市第二人民医院手术切除的31 例胃癌患者癌组织及配对的癌旁组织标本和胃癌细胞系，使用qPCR检测胃癌组织、癌旁组织和细胞系中circ_0023642 和miR-508-3p 的表达情况；WB实验检测MGC-803 细胞中ERBB4、E-cadherin、N-cadherin 和Vimentin 的表达；CCK-8 和Transwell 实验检测调控circ_0023642 和miR-508-3p 的表达对MGC-803 细胞增殖、迁移和侵袭能力的影响；双荧光素酶报告基因验证miR-508-3p 是否能够结合circ_0023642 和ERBB4 的3' UTR。结果：circ_0023642 在胃癌组织和细胞系中的表达水平分别显著高于癌旁组织和正常胃黏膜细胞（P<0.05 或P<0.01），且在MGC-803 细胞中表达水平最高。敲降circ_0023642 后MGC-803 细胞增殖、迁移、侵袭和上皮间质转化（epithelial-mesenchymal transition, EMT）受到明显抑制（均P<0.05 或P<0.01）；circ_0023642 与ERBB4 均可以靶向结合miR-508-3p 的作用位点，并进一步实验证实circ_0023642 通过海绵吸附miR-508-3p 促进MGC-803 细胞增殖、迁移、侵袭和EMT（P<0.05 或P<0.01）。结论：circ_0023642 通过与ERBB4 竞争性结合miR-508-3p 的作用位点，进而促进胃癌MGC-803 细胞增殖和转移，其可作为胃癌临床诊断的标志物。

[Abstract] Objective: To explore the influence of circ_0023642 on the proliferation and metastasis of gastric cancer GMC-803 cells by modulating miR-508-3p/ERBB4 axis. Methods: Cancer tissues and corresponding para-cancer normal tissues from 31 gastric cancer patients, who underwent surgical resection at the Second People's Hospital of Nantong City from May 2015 to March 2018, were collected for this study; meanwhile, gastric cancer cell lines (MGC-803, MKN-45 and MKN-28) were also collected. qPCR was performed to determine the expression levels of circ_0023642 and miR-508-3p in above mentioned tissues and cell lines. WB was applied to measure the expressions of ERBB4, E-cadherin, N-cadherin and Vimentin in MGC-803 cells. CCK-8 assay and Transwell assay were used to evaluate the effects of circ_0023462 and miR-508-3p expression on proliferation, migration and invasion of MGC-803 cells. Dual-luciferase reporter gene was carried out to validate whether miR-508-3p could bind to the 3' UTR of circ_0023642 and ERBB4. Results:Compared with para-cancer tissues or normal gastric mucosal cells, the expression of circ_0023642 was significantly up-regulated in gastric cancer tissues and cells lines, and the expression was highest in MGC-803 cells (P<0.05 or P<0.01). Silencing circ_0023642 dramatically decreased the proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) of MGC-803 cells (P<0.05 or P<0.01). Both circ_0023642 and ERBB4 could target the binding sites of miR-508-3p. Further experiments confirmed that circ_0023642 promoted the proliferation, migration, invasion and EMT of MGC-803 cells by sponging miR-508-3p (P<0.05 or P<0.01).Conclusion: circ_0023642, by competing ERBB4 to bind with miR-508-3p, promotes the proliferation and metastasis of gastric cancer MGC-803 cells, thus could be used as a marker for the clinical diagnosis of gastric cancer.