Mechanism Research Of FOX-A1 Involved In Docetaxel Chemoresistance Of Human Lung Adenocarcinoma

Objective:To study the role of transcription factor FOX-A1 in docetaxel resistance in human lung adenocarcinoma and its mechanism..Methods:Real-time RT-PCR and Western blot were used to detect the gene expression of important members of the FOX family in human lung adenocarcinoma cell lines SPC-A1 and H1299 and docetaxel-resistant cell lines SPC-A1/DTX and H1299/DTX.Tissue samples of 52 advanced lung adenocarcinoma patients were examined to analyze the expression of FOX-A1 and their relationship with docetaxel resistance and clinical prognosis.Cloning formation experiments,Transwell experiments,CCK-8 experiment and in vivo xenograft experiments were performed to analyze the role of FOX-A1 in docetaxel resistance of lung adenocarcinoma cells.Chromatin immunoprecipitation(ChIP)and dual luciferase reporter assay to identify the target gene of FOX-A1.To investigate the effects of SOX5 on EMT,migration,invasion and apoptosis of docetaxel-resistant lung adenocarcinoma cells.Detection the expression of SOX5 in lung adenocarcinoma cells and tissues using Real-time RT-PCR.The relationship between SOX5 expression and clinical prognosis,FOX-A1 expression,and docetaxel resistance was analyzed statistically.Results:The expression of FOX-A1 was significantly up-regulated in the docetaxel-resistant cell lines SPC-A1/DTX and H1299/DTX.FOX-A1 was up-regulated in the human lung adenocarcinoma group compared with normal tissues,and its expression was significantly up-regulated in lung adenocarcinoma tissues of patients with docetaxel resistance.Statistical analysis showed that the expression of FOX-A1 was associated with poor prognosis in patients with lung adenocarcinoma.Multivariate Cox regression analysis suggested that FOX-A1 is an independent poor prognostic factor for PFS and OS.Knockdown of FOX-A1 expression in docetaxel-resistant lung adenocarcinoma cells inhibits cell clonal formation,migration and invasion,induces apoptosis,and reverses EMT.Inhibition of FOX-A1 enhances the sensitivity of DTX-resistant lung adenocarcinoma cells to DTX chemotherapy in vivo and vitro.SOX5 was identified as a new and direct target of FOX-A1 via ChIP and dual luciferase reporter assay.Knockdown of SOX5 in docetaxel-resistant lung adenocarcinoma cells inhibits cell clonal formation,migration and invasion,induces apoptosis,and reverses EMT.SOX5 is upregulated in lung cancer tissue compared to normal lung tissue and is significantly upregulated in lung cancer tissues of docetaxel resistant patients.Kaplan-Meier analysis showed that high expression of SOX5 was significantly associated with shorter PFS and OS.Linear regression analysis showed a statistically positive correlation between SOX5 and FOX-A1 expression.Conclusion:The current data revealed a new FOX-A1/SOX5 signaling axis that regulated the chemosensitivity of docetaxel-resistant lung adenocarcinoma cells and represented a novel therapeutic target for chemosensitizing docetaxel-resistant lung adenocarcinoma.