miR-30b-5p inhibits cancer progression and enhances cisplatin sensitivity in lung cancer through targeting LRP8.

Accumulated evidence has demonstrated that miRNAs are closely implicated in lung carcinogenesis. Herein, we explored the expression pattern of miR-30b-5p in lung cancer, and aimed to uncover miR-30b-5p roles in lung cancer progression and drug resistance. miR-30b-5p expression profiles in lung cancer tissues and the matched non-tumor tissues were determined by using qPCR. Cell viability, migration, invasion and in vivo tumorigenesis were determined by using the CCK-8, colony formation, wound healing, transwell chambers experiments and tumor xenograft models. RNA immunoprecipitation (RIP) and dual luciferase reporter experiments were applied to evaluate the relationship between miR-30b-5p and LRP8. The results demonstrated that miR-30b-5p showed a low expression profile in lung cancer tissues and cells, and closely linked to poor prognosis and malignant clinical process. Cell viability, migration, invasiveness and tumorigenesis were significantly weakened following miR-30b-5p overexpression in A549 and NCI-H1299 cells, while cell apoptosis rates were increased. In addition, miR-30b-5p was lowly expressed in A549/DDP (a cisplatin drug resistant cell line) as compared with A549 cells, and miR-30b-5p increased A549/DDP cell sensitivity to DDP. However, these above roles of miR-30b-5p were all significantly impaired following the overexpression of LRP8 which was overexpressed in lung cancer tissues. Collectively, this study demonstrated that miR-30b-5p functions as a tumor suppressor in lung cancer, and re-sensitizes lung cancer cells to DDP by targeting LRP8.