The role of microRNA‐93 regulating angiopoietin2 in the formation of malignant pleural effusion

The biological roles of miRNAs in the development of malignant pleural effusion (MPE) are unclear. In this study, the miRNA microarray analysis was performed in two different prognosis groups of lung adenocarcinoma patients. Expression profiles of miRNAs in MPEs were identified. With the help of quantification PCR, we confirmed the expression differences of miRNAs and further analyzed their biological functions and relative target genes in vitro. The target gene of miR‐93 was estimated by online database, and also, the protein was tested. The target gene and the binding sites of specific miRNA were estimated by online database. The combining capacity of binding sites was verified by luciferase reporter gene assay, and the target gene protein was tested by western blot. We detected 107 miRNAs with expression differences (n = 10) and confirmed significant expression differences in miR‐93 and miR‐146a in two groups of patients (n = 84). By manipulating miR‐93 expression of human lymphatic endothelial cells (HLEC) and human umbilical vein endothelial cells (HUVEC), we discovered that high expression of miR‐93 inhibited migration, proliferation, and angiogenesis. And also, miR‐93 increased not only apoptosis, but also G1 phase cell block. By using luciferase reporter gene assay and western blot, we confirmed that angiopoietin2 (Ang2) was the target of miR‐93. The data showed that miR‐93 has an inhibiting effect on pleural effusion. By targeting Ang2, miR‐93 regulates angiogenesis and lymphangiogenesis and plays a role in pathogenetic mechanism of MPE. MiR‐93/Ang2 may shed light on potential new targets in cancer treatment.