目的：分析miR-19对PTEN及PI3K-Akt通路的调节作用，揭示miR-19和PTEN对子宫内膜癌KLE细胞侵袭、迁移的影响及其机制。方法：收集2017年5月至2020年8月河北医科大学第一医院收治的74例子宫内膜癌患者经手术切除（术前未接受放化疗等治疗）且病理确诊为子宫内膜癌的肿瘤组织及对应癌旁组织，采用qPCR和WB法检测PTEN在子宫内膜癌组织中的表达水平以及转染miR-19模拟物或抑制物对KLE细胞中PTEN表达的影响。通过TargetScan及双荧光素酶报告基因实验预测并验证PTEN是否为miR-19的靶基因，将KLE细胞随机分为对照（NC）组、miR-19模拟物组和miR-19+PTEN组，分别转染阴性对照片段（miR-NC）、miR-19 模拟物或共转染 miR-19 模拟物+PTEN 过表达载体，采用 Transwell 和细胞划痕实验检测 miR-19 和PTEN对KLE细胞迁移和侵袭能力的影响，WB法检测对PI3K-Akt通路相关蛋白表达的影响。结果：子宫内膜癌组织中PTEN的mRNA和蛋白表达水平均明显低于癌旁组织（均P<0.01）。miR-19能与PTEN mRNA的3’-UTR特异性结合，上调miR-19的表达能抑制PTEN的mRNA和蛋白的表达，下调miR-19的表达则出现相反的结果（均P<0.01）。与miR-NC组相比，miR-19 模拟物组的迁移、侵袭细胞数以及划痕愈合率均显著升高（均 P<0.01），而 miR-19+PTEN 组的细胞迁移和侵袭能力以及划痕愈合率较miR-19摸拟物组则明显降低（均P<0.01）；与miR-NC 组相比，miR-19 模拟物组中 PTEN 蛋白的表达明显降低，而p-Akt 308和p-Akt 473蛋白的表达明显升高，Akt蛋白的表达无明显变化（均P<0.01）；而在miR-19+PTEN组中，p-Akt 308和p-Akt 473蛋白的表达均明显低于miR-19模拟物组（均P<0.01）。结论：miR-19可能通过抑制PTEN的表达从而活化PI3K-Akt通路，进而促进子宫内膜癌KLE细胞的迁移和侵袭。

Objective: To analyze the regulatory effects of miR-19 on PTEN and PI3K/Akt signaling pathway, and to reveal the effects of miR-19 and PTEN on invasion and migration of endometrial cancer KLE cells as well as its working mechanism. Methods: Tumor tissues and para-carcerous tissues of 74 patients with endometrial cancer were collected from the First Hospital of Hebei Medical University from May 2017 to August 2020. All patients did not receive radiotherapy or chemotherapy before surgery and were pathologically diagnosed as endometrial cancer. qPCR and WB were used to detect the effects of miR-19 mimics or inhibitors on PTEN expression in KLE cells. TargetScan and Dual-luciferase reporter gene assay were adopted to predict and verify whether PTEN was the target gene of miR-19. KLE cells were randomized into negative control (NC) group (transfected with miR-NC), miR-19 mimic group (transfected with miR-19 mimics) and miR-19+PTEN group (transfected with miR-19 mimics+PTEN overexpression vector).Transwell assay and Scratch assay were used to detect the effects of miR-19 and PTEN on KLE cell migration and invasion. WB was adopted to detect the expression of PI3K/Akt pathway-related proteins.Results: mRNA and protein expression of PTEN was obviously lower in endometrial cancer tissues compared with para-carcerous tissues (P<0.01). miR-19 could specifically bind to 3'-UTR of PTEN.Up-regulation of miR-19 could inhibit mRNA and protein expression of PTEN, and down-regulation of miR-19 showed an opposite result (P<0.01). Compared with miR-NC group, migratory cell count, invasive cell count, and scratch healing rate were significantly increased in miR-19 mimic group (all P<0.01). Compared with miR-19 mimic group, migratory cell count, invasive cell count and scratch healing rate were significantly decreased in miR-19+PTEN group (all P<0.01). WB analysis showed that, comparing with miR[1]NC group, PTEN protein was obviously decreased, while p-Akt 308 and p-Akt 473 protein was obviously elevated in miR-19 mimic group (P<0.01); however, Akt protein maintained unchanged. Additionally, the levels of p-Akt 308 and p-Akt 473 protein were obviously lower in miR-19+PTEN group comparing with miR-19 mimic group (P<0.01). Conclusion: miR-19 may activate PI3K/Akt signal pathway by inhibiting PTEN expression, thereby promoting migration and invasion of endometrial cancer KLE cells.

河北省卫生厅科研基金项目青年科技计划资助（No. 20200126）