LncRNA RP3-340N1.2 affects the progression of lung adenocarcinoma cell lines by targeting miR-134-5p

We found lncRNA RP3-340N1.2 is highly expressed in LUAD and relatived with the progression of LUAD through high-throughput sequencing. Our results showed that the expression level of RP3-340N1.2 was upregulated significantly in three LUAD cell lines (A549, NCI_x001E_H1299, and NCI-H1975) and lentivirus-mediated knockdown of RP3-340N1.2 inhibited the differentiation, proliferation, migration, invasion, cell cycle, and other biological processes of tumor cells significantly. Bioinformatic software predicted the downstream target of RP3-340N1.2, which was verified using dual luciferase assays and other methods. We found that RP3-340N1.2 can competitively bind miR-134-5p in LUAD, and this microRNA has a significant regulatory effect on the expression of epidermal growth factor receptor (EGFR), which leads to increased migration and invasion of LUAD cells. This discovery provided a possible mechanism by which RP3-340N1.2 participates in the development of LUAD. In conclusion, our results showed that lncRNA RP3_x001E_340N1.2 regulates the expression of EGFR indirectly by targeting miR-134-5p and promotes the progression of LUAD. Therefore, RP3-340N1.2 may become a valuable biomarker and therapeutic target in LUAD. Overall design: Examination of lncRNAs in lung adenocarcinoma cell lines.