microRNA-27b inhibits cell proliferation and invasion in bladder cancer by targeting engrailed-2.

 Bladder cancer is considered a malignant tumour characterised by great heterogeneity. Engrailed-2 may be a gene implicated in bladder cancer. Bioinformatics analysis found base pair complementation between microRNA-27b and engrailed-2. This study aimed to investigate the reciprocal association between microRNA-27b and engrailed-2 in bladder cancer.

 The microRNA-27b and the proteins of engrailed-2 in the tissues and cells of the bladder were detected. The processes of apoptosis, proliferation, invasion, and migration of tumour cells were evaluated. The co-action between microRNA-27b and engrailed-2 was detected by a luciferase reporter system. Finally, the interaction between microRNA-27b and engrailed-2 was further verified in vivo.

 The study found that the expression level of microRNA-27b is lower in bladder cancer tissues and cells than that in neighbouring ordinary tissues, whereas the opposite outcome was observed regarding the expression level of engrailed-2. Furthermore, microRNA-27b expression level is not significantly linked to the age of patients with bladder cancer; however, it is significantly associated with the clinicopathological grade of bladder cancer. Notably, engrailed-2 is negatively regulated by microRNA-27b. Transfection with microRNA-27b was associated with a significant reduction in the activity of bladder cancer cells and promoted apoptosis, while engrailed-2 restoration effectively reversed the above effects of microRNA-27b on bladder cancer in vitro and in vivo.

 In conclusion, engrailed-2 is engaged in the development and process of bladder cancer through the negative mediation of microRNA-27b; additionally, microRNA-27b/engrailed-2 could form a signalling pathway with a significant effect on the process of bladder cancer.

Bioscience reports. 2020 Dec 22 [Epub ahead of print]

Yunfei Li, Qilin Duan, Lu Gan, Wei Li, Jianggen Yang, Guixiao Huang

Third Affiliated Hospital of Shenzhen University, Shenzhen, China., Clinical Medical Research Center, First Affiliated Hospital of South University of Science and Technology of China, Shenzhen, China.