To explore the mechanism of miR-202-5p targeting the expression of PIK3CA and mediating the activation of PI3K/Akt/mTOR signaling pathway on the proliferation, invasion, and epithelial–mesenchymal transition (EMT) of cervical cancer. The objects of study were 105 cases of cervical cancer and their corresponding normal tissues. qRT-PCR was used to detect the expression of miR-202-5p and PIK3CA in adjacent normal tissue and cervical cancer tissue. Dual luciferase reporter assay was used to verify the targeting relationship between miR-202-5p and PIK3CA gene. Human cervical cancer cell lines HPV-16E6, SiHa, HeLa, and CaSki were purchased for our cell experiments. The expression levels of PIK3CA in the cells were detected by qRT-PCR. The cell line with higher expression levels was selected to complete the follow-up experiment. The cultured cells were transfected and divided into the miR-202-5p mimic NC group, miR-202-5p mimic group, miR-202-5p inhibitor NC group, miR-202-5p inhibitor group, siRNA-PIK3CA NC group, siRNA-PIK3CA group, miR-202-5p inhibitor NC + siRNA-PIK3CA NC group, miR-202-5p inhibitor + siRNA-PIK3CA NC group, and miR-202-5p inhibitor + siRNA-PIK3CA group. QRT-PCR was used to detect the expression of miR-202-5p. Western blot and qRT-PCR were applied to detect the mRNA and protein expression levels of related pathway proteins (PIK3CA, PI3K, PTEN, p-Akt1, and p-mTOR) and epithelial–mesenchymal transition-related factors (N-cadherin, E-cadherin, and vimentin). Cell proliferation was detected by plate colony formation assay. Transwell assay was used to detect the invasion ability of each group. When compared with the adjacent tissues, PIK3CA mRNA expression level was significantly increased and miR-202-5p expression level was significantly decreased in cervical cancer tissues (all P < 0.05). PIK3CA was a target gene of miR-202-5p. The mRNA expression level of PIK3CA in SiHa cervical cancer cells was significantly higher than that in CaSki, HeLa, and HPV-16E6 cells (all P < 0.05), and SiHa cervical cancer cells were selected to complete the follow-up experiments. When compared with the corresponding NC group, the expression of miR-202-5p in miR-202-5p mimic group was increased. In addition, the mRNA and protein expression levels of E-cadherin and PTEN in miR-202-5p mimic and siRNA-PIK3CA groups were increased, and the protein expression of p-Akt1 and p-mTOR was decreased, and also, the mRNA and protein expression levels of PIK3CA, PI3K, N-cadherin, and vimentin were decreased (all P < 0.05); in miR-202-5p inhibitor group, the expression levels of miR-202-5p, E-cadherin, and PTEN decreased, the protein expression of p-Akt1 and p-mTOR increased, and the mRNA and protein expression of PIK3CA, PI3K, N-cadherin, and vimentin increased in miR-202-5p inhibitor group (all P < 0.05); in miR-202-5p inhibitor + siRNA-PIK3CA group, the expression of miR-202-5p decreased (P < 0.05), but the mRNA and protein expression of PIK3CA, PI3K, p-Akt1, p-mTOR, N-cadherin, E-cadherin, and vimentin had no significant changes (all P > 0.05). When compared with the corresponding NC group, the number of cell clones in miR-202-5p mimic group and siRNA-PIK3CA group was decreased, and the invasion ability of miR-202-5p inhibitor group was increased, and the invasion ability was enhanced (all P < 0.05); miR-202-5p inhibitor + siRNA-PIK3CA group showed no significant change in the number of cell clones and the rate of invasion (P > 0.05). In conclusion, the overexpression of miR-202-5p can suppress PIK3CA gene expression and the activation of PI3K/Akt/mTOR signaling pathway to suppress the proliferation, invasion, and EMT of cervical cancer.

探讨miR-202-5p靶向PIK3CA表达介导PI3K/Akt/mTOR信号通路激活对宫颈癌增殖、侵袭和上皮-间质转化(EMT)的作用机制。研究对象为105例宫颈癌及其相应的正常组织。qRT-PCR检测邻近正常组织和宫颈癌组织中miR-202-5p和PIK3CA的表达。双荧光素酶报告基因检测用于验证 miR-202-5p 和 PIK3CA 基因之间的靶向关系。我们购买了人宫颈癌细胞系 HPV-16E6、SiHa、HeLa 和 CaSki 用于我们的细胞实验。通过qRT-PCR检测细胞中PIK3CA的表达水平。选择表达水平较高的细胞系完成后续实验。将培养的细胞转染并分为miR-202-5p mimic NC组、miR-202-5p mimic组、miR-202-5p inhibitor NC组、miR-202-5p inhibitor组、siRNA-PIK3CA NC组、siRNA -PIK3CA组、miR-202-5p抑制剂NC+siRNA-PIK3CA NC组、miR-202-5p抑制剂+siRNA-PIK3CA NC组、miR-202-5p抑制剂+siRNA-PIK3CA组。QRT-PCR用于检测miR-202-5p的表达。Western blot 和 qRT-PCR 用于检测相关通路蛋白（PIK3CA、PI3K、PTEN、p-Akt1 和 p-mTOR）和上皮间质转化相关因子（N-cadherin、E -钙粘蛋白和波形蛋白）。通过平板集落形成测定法检测细胞增殖。Transwell法检测各组的侵袭能力。与邻近组织相比，P  < 0.05)。PIK3CA 是 miR-202-5p 的靶基因。PIK3CA在SiHa宫颈癌细胞中的mRNA表达水平显着高于CaSki、HeLa和HPV-16E6细胞（均P  < 0.05），并选择SiHa宫颈癌细胞完成后续实验。与相应的NC组相比，miR-202-5p模拟组中miR-202-5p的表达增加。此外，miR-202-5p mimic和siRNA-PIK3CA组E-cadherin和PTEN的mRNA和蛋白表达水平升高，p-Akt1和p-mTOR蛋白表达降低，mRNA PIK3CA、PI3K、N-cadherin 和 vimentin 的蛋白表达水平降低（所有P < 0.05); miR-202-5p抑制剂组miR-202-5p、E-cadherin、PTEN表达水平降低，p-Akt1、p-mTOR蛋白表达升高，PIK3CA、PI3K mRNA和蛋白表达升高、N-cadherin、vimentin 在 miR-202-5p 抑制剂组增加（均P  < 0.05）；miR-202-5p inhibitor + siRNA-PIK3CA组，miR-202-5p表达降低（P  < 0.05），但PIK3CA、PI3K、p-Akt1、p-mTOR、N-cadherin mRNA和蛋白表达降低、E-cadherin 和波形蛋白没有显着变化（所有P > 0.05)。与相应的NC组相比，miR-202-5p mimic组和siRNA-PIK3CA组细胞克隆数减少，miR-202-5p inhibitor组侵袭能力增强，侵袭能力增强（所有P  < 0.05）；miR-202-5p抑制剂+siRNA-PIK3CA组细胞克隆数和侵袭率无明显变化（P  > 0.05）。综上所述，miR-202-5p过表达可抑制PIK3CA基因表达，激活PI3K/Akt/mTOR信号通路，从而抑制宫颈癌的增殖、侵袭和EMT。