Yang Kun, Tang Hai, Ding Mantang, Guo Yijun, Kai Kai, Xiao Jun, Shen Yu, Miao Shuai, Zhou Renyuan
Department of Urology, Jing'an District Centre Hospital of Shanghai (Huashan Hospital Fudan University Jing'an Branch) Shanghai, China.
Int J Clin Exp Pathol. 2019 Mar 1;12(3):843-850. eCollection 2019.
MAPK kinase 1 (MEK1) plays an important role in regulating cell proliferation and apoptosis through activation of the ERK/MAPK signaling pathway. It was found that the expression of miR-195 in bladder cancer was abnormally decreased, suggesting that miR-195 may affect the development of bladder cancer. In this study, we examined the expression of miR-195 and MEK1 in bladder cancer tissues and analyzed the relationship between miR-195 and MEK1 in cell proliferation and apoptosis in bladder cancer cells.
The expression of MEK1 in bladder cancer tissues was detected by western blot, and the expression levels of miR-195 and MEK1 mRNA were detected by qRT-PCR. Log Rank test was used to compare the survival and prognosis of patients with low and high expression of miR-195 and MEK1 by using the median expression of miR-195 and MEK1. Bioinformatics analysis and double luciferase reporter gene test were used to verify the relationship between miR-195 and MEK1. Bladder cancer BIU-87 and 5637 cells were cultured in vitro and divided into two groups: miR-NC group and miR-195 mimic group. The expression of MEK1 and p-MEK1 protein was detected by western blot, apoptosis was detected by flow cytometry, and cell proliferation was detected by EdU staining.
Compared with normal bladder tissue, expression of miR-195 in bladder cancer tissue was significantly decreased, while the expression of MEK1 mRNA and protein was significantly increased. The prognosis of patients with low expression of miR-195 was worse than those with high expression of miR-195. The prognosis of patients with low expression of MEK1 was better than those with high expression of MEK1. Bioinformatics analysis showed that there was a target complementary binding site between miR-195 and MEK1. Double luciferase reporter gene experiments confirmed that there was a target regulatory relationship between miR-195 and MEK1. miR-195 mimic transfection could significantly down-regulate the expression of MEK1 and p-MEK1 proteins in BIU-87 and 5637 cells, weaken cell proliferation, and increase cell apoptosis.
Overexpression of miR-195 can inhibit the proliferation of bladder cancer cells by inhibiting MEK1, which provides further evidence for developing therapy against bladder cancer.
丝裂原活化蛋白激酶激酶1（MEK1）通过激活ERK/MAPK信号通路在调节细胞增殖和凋亡中起重要作用。研究发现，miR-195在膀胱癌中的表达异常降低，提示miR-195可能影响膀胱癌的发生发展。本研究检测了miR-195和MEK1在膀胱癌组织中的表达，并分析了miR-195与MEK1在膀胱癌细胞增殖和凋亡中的关系。
采用蛋白质免疫印迹法检测膀胱癌组织中MEK1的表达，采用实时荧光定量PCR检测miR-195和MEK1 mRNA的表达水平。通过Log Rank检验，以miR-195和MEK1的中位表达为界，比较miR-195和MEK1低表达与高表达患者的生存及预后情况。采用生物信息学分析和双荧光素酶报告基因实验验证miR-195与MEK1之间的关系。体外培养膀胱癌BIU-87和5637细胞，分为两组：miR-NC组和miR-195模拟物组。采用蛋白质免疫印迹法检测MEK1和p-MEK1蛋白的表达，采用流式细胞术检测细胞凋亡，采用EdU染色检测细胞增殖。
与正常膀胱组织相比，膀胱癌组织中miR-195的表达显著降低，而MEK1 mRNA和蛋白的表达显著升高。miR-195低表达患者的预后较miR-195高表达患者差。MEK1低表达患者的预后较MEK1高表达患者好。生物信息学分析显示miR-195与MEK1之间存在靶标互补结合位点。双荧光素酶报告基因实验证实miR-195与MEK1之间存在靶标调控关系。miR-195模拟物转染可显著下调BIU-87和5637细胞中MEK1和p-MEK1蛋白的表达，减弱细胞增殖，并增加细胞凋亡。
miR-195过表达可通过抑制MEK1抑制膀胱癌细胞增殖，为膀胱癌治疗提供了进一步的证据。
