MiR‐5100 increases the cisplatin resistance of the lung cancer stem cells by inhibiting the Rab6

Cisplatin‐based chemotherapy is the most commonly used treatment regimen for lung cancer. Cancer stem cells (CSCs) are postulated to be important promoters of drug resistance. We previously found that miR‐5100 is overexpressed in lung cancer, but it is unknown whether and how miR‐5100 regulates cisplatin resistance. Here, we demonstrated that miR‐5100 was significantly up‐regulated in CD44+CD133+ lung cancer stem cells (LCSCs) compared with non‐CSCs. Additionally, over‐expression of miR‐5100 increased CSC properties, cell growth, and tumor sphere formation in lung cancer cell line A549 or H1299, and that miR‐5100 inhibitor significantly increased sensitivity of LCSCs to cisplatin in vitro. Surprisingly, the combination with miR‐5100 inhibitor significantly decreased the IC50 of LCSCs to cisplatin. Furthermore, miR‐5100 increased CSC properties and cisplatin resistance by inhibiting Rab6, a direct target gene of miR‐5100. We demonstrated that miR‐5100 overexpression increases the cisplatin resistance of the LCSCs through the mitochondrial apoptosis pathway. In conclusion, our results suggest that miR‐5100 increases the cisplatin resistance of the LCSCs by inhibiting the Rab6. This study provides novel insight into the regulation of LCSCs by miRNA.