Close homologue of L1 sensitizes lung cancer cells to cisplatin and paclitaxel via inhibition Akt pathway

Drug resistance is a serious promble during chemotherapy in lung cancer, which may lead to tumor relapse and further progression. CHL1 was a tumor suppressor in most malignancies, and it was found downregulated in NSCLC cisplatin-resistant cells H460. Thus, in this study, we investigated the role and mechanism of chemoresistance by CHL1 in lung cancer. Human lung adenocarcinoma cell lines A549 and its cisplatin resistant cells (A549/DDP) and paclitaxel resistant cells (A549/PTX) were applied in this research. CHL1 was found obvious downregulation in A549/DDP and A549/PTX cells versus A549 cells. Suppression of CHL1 in A549 cells, promoted cell survival rate and clone formation, decreased cell apoptosis when treated with or without DDP and PTX, respectively. While excessive CHL1 expression in A549/DDP and A549/PTX cells, the results were opposite. Moreover, CHL1 knockdown mediating chemoresistance was reversed by Akt inhibitor SC66 in A549 cells. In summary, overexpression of CHL1 reversed chemoresistance to cisplatin and PTX via suppressing Akt pathway in lung cancer, it was suggested that CHL1 maybe as a potential target for overcome chemoresistance in lung cancer.