目的 探讨 lncRNA PCAT19 对口腔鳞癌 HSC3 细胞增殖、迁移和侵袭的影响及潜在的分子 机制。方法 收集 45 例口腔鳞癌患者癌组织和癌旁组织，qRT⁃PCR 法检测组织中 PCAT19 和 miR⁃769⁃5p 表达。体外培养HSC3细胞，转染PCAT19小干扰RNA或miR⁃769⁃5p模拟物、或共转染PCAT19小干扰RNA 与 miR⁃769⁃5p 抑制剂后，CCK⁃8 法和单克隆实验检测细胞增殖；划痕实验检测细胞迁移；Transwell 实验检测 细胞侵袭；蛋白质印迹法检测细胞中 E⁃cadherin 和 N⁃cadherin 蛋白表达；双荧光素酶报告基因实验验证 PCAT19和 miR⁃769⁃5p 的调控关系。结果 口腔鳞癌组织中 PCAT19 表达高于癌旁组织，miR⁃769⁃5p 表达 低于癌旁组织（P < 0.05）。干扰PCAT19或过表达miR⁃769⁃5p后，HSC3细胞OD值、克隆形成数、划痕愈合率、 侵袭数、N⁃cadherin 蛋白表达降低，E⁃cadherin 蛋白表达升高（P < 0.05）。PCAT19 靶向负调控 miR⁃769⁃5p。 下调 miR⁃769⁃5p 逆转了干扰 PCAT19 对 HSC3 细胞增殖、迁移和侵袭的影响。结论 PCAT19 在口腔鳞癌 组织中表达上调，干扰PCAT19可能通过靶向上调miR⁃769⁃5p抑制口腔鳞癌HSC3细胞增殖、迁移和侵袭。

Objective To investigate the effect and mechanism of lncRNA PCAT19 on the proliferation， migration and invasion of oral squamous cell carcinoma HSC3 cells. Methods The cancer tissues and adjacent tissues of 45 patients with oral squamous cell carcinoma were collected，and the expression of PCAT19 and miR⁃ 769⁃5p in the tissues was detected by qRT⁃PCR. HSC3 cells were cultured in vitro and transfected with PCAT19 siRNA or miR⁃769⁃5p mimic，or co⁃transfected with PCAT19 siRNA and miR⁃769⁃5p inhibitor. Then cell prolifera⁃ tion was detected by CCK ⁃8 method and clone formation assay. Scratch assay and Transwell assay were used to detect cell migration and invasion，respectively. Western blotting was used to detect the expression of E⁃cadherin and N⁃cadherin protein in the cells. The dual⁃luciferase reporter gene experiment was done to verify the regulatory relationship between PCAT19 and miR ⁃769⁃5p. Results The expression of PCAT19 in the oral squamous cell carcinoma was higher than that in the adjacent tissues，but the expression of miR⁃769⁃5p was lower than that in the adjacent tissue，（P < 0.05）. Interfering with PCAT19 or overexpressing miR⁃769⁃5p decreased the OD value，colony formation number，scratch healing rate，invasion number and the expression of N ⁃cadherin protein in the HSC3 cells（P < 0.05），but promoted the expression of E⁃cadherin protein（P < 0.05）. PCAT19 could target and nega⁃ tively regulate miR ⁃ 769 ⁃ 5p. Downregulation of miR ⁃ 769 ⁃ 5p reversed the effects of interfering with PCAT19 on HSC3 cells proliferation，migration and invasion. Conclusion The expression of PCAT19 is up⁃regulated in oral squamous cell carcinoma tissues，and interfering with PCAT19 may inhibit the proliferation，migration and inva⁃ sion of oral squamous cell carcinoma HSC3 cells by targeting up⁃regulated miR⁃769⁃5p.