[摘要] 目的：探讨lncRNA XIST（XIST）通过调控miR-337-3p/HOXC8 分子轴介导胃癌发展进程的分子机制。方法：选取2013 年3 月至2018 年1 月河北省唐山市开滦总医院普通外科手术切除的58 例胃癌组织和对应的癌旁组织标本，以及人胃癌细胞系AGS、MGC803、HGC27 和人胃黏膜细胞GES-1，用qPCR检测胃癌组织和细胞系中XIST 和miR-337-3p 的表达水平。将XIST敲降载体、miR-337-3p mimics/inhibitor 和HOXC8 过表达载体转染进AGS细胞，用CCK-8、Transwell 实验检测AGS细胞的增殖及侵袭能力，用WB检测HOXC8 及上皮钙黏蛋白（E-cadherin）、神经钙黏蛋白（N-cadherin）和波形蛋白（vimentin）的表达水平。用双荧光素酶报告基因验证XIST、miR-337-3p 和HOXC8 的靶向关系。结果：XIST在胃癌组织和细胞系中高表达（均P<0.01）。敲降XIST 显著抑制AGS细胞的增殖、侵袭和EMT（P<0.05 或P<0.01）。XIST 靶向作用miR-337-3p 并下调其表达，HOXC8 是miR-337-3p 的靶基因。敲降XIST 通过靶向上调miR-337-3p 对HOXC8 表达的抑制作用，从而抑制AGS细胞增殖、侵袭和EMT（P<0.05 或P<0.01）。结论：敲降XIST 可抑制AGS 细胞增殖、侵袭和EMT，其作用机制是通过靶向miR-337-3p 并下调HOXC8的表达。

[Abstract] Objective: To investigate the mechanism of lncRNA XIST (XIST) on modulating gastric cancer progression via regulating miR-337-3p/HOXC8 axis. Methods: A total of 58 cases of gastric cancer tissues and corresponding para-cancerous tissues resected from March 2013 to January 2018 in Department of General Surgery, Kailuan General Hospital of Tangshan City were collected for this study; in addition, human gastric cancer cell lines (AGS, MGC803, HGC27) and human gastric mucosal GES-1 cells were also collected. qPCR was used to detect the expressions of XIST and miR-337-3p in above mentioned gastric tissues and cell lines. XIST-knockdown vectors, miR-337-3p mimics, miR-337-3p inhibitor and HOXC8-overexpression vectors were transfected into AGS cells. The proliferation and invasion of AGS cells were detected by CCK-8 and Transwell experiments respectively, and the expression levels of HOXC8, E-cadherin, N-cadherin and vimentin were detected by WB. The targeting relationships between XIST, miR-337-3p and HOXC8 were verified by dual-luciferase reporter gene assay. Results: XIST was up-regulated in gastric cancer tissues and cell lines (all P<0.01). XIST knockdown significantly inhibited proliferation, invasion and EMT of AGS cells (P<0.05 or P<0.01).Moreover, XIST directly interacted with miR-337-3p and down-regulated its expression, while HOXC8 was the target gene of miR-337-3p. Furthermore, XIST knockdown suppressed proliferation, invasion and EMT of AGS cells through up-regulating the inhibitory effect of miR-337-3p on HOXC8 (P<0.05 or P<0.01). Conclusion: XIST knockdown can suppress the proliferation, invasion and EMT of AGS cells, which may be related with down-regulation of HOXC8 by targeting miR-337-3p.