A novel long non-coding RNA WASIR2 regulates MEX3A expression by sponging miR-374b-5p and promotes lung adenocarcinoma progression

Background Long noncoding RNAs (lncRNAs) have been reported to play important roles in the progression of lung adenocarcinoma (LUAD). However, the expressions and function of lncRNA WASIR2 remain largely unknown in LUAD. Methods Differential expression of WASIR2, miR-374b-5p and MEX3A between LUAD tumor tissues and normal tissues were analyzed according to The Cancer Genome Atlas (TCGA) database, GEPIA online tool and our own clinical specimens. Kaplan-Meier survival analysis was performed to investigate their prognostic value in LUAD. CCK8 assay was performed to evaluate the cell proliferation ability. Transwell assay was used to evaluate cell migration and invasion. Furthermore, a luciferase reporter assay was performed to explore the target of WASIR2. Results WASIR2 expression was significantly upregulated in LUAD tumor tissues. Upregulated expression of WASIR2 was correlated with poor overall survival. Gain-of and loss-of function assays showed that overexpression of WASIR2 promoted tumor cell proliferation, migration and invasion, while silencing of WASIR2 inhibited these effects. Mechanistically, WASIR2 upregulated the expression of MEX3A by directly binding to miR-374b-5p. Rescue assays showed that miR-374b-5p could reverse the effects of WASIR2 on cell proliferation, migration and invasion. Conclusion Together, our study demonstrated that WASIR2 could promote the progression of lung adenocarcinoma through upregulating MEX3A expression by sponging miR-374b-5p. This study provides novel evidence that WASIR2 could be viewed as a prognostic factor and therapeutic target in LUAD.