FOXA1 prolongs S phase and promotes cancer progression in non‐small cell lung cancer through upregulation of CDC5L and activation of the ERK1/2 and JAK2 pathways

Abstract Non‐small cell lung cancer (NSCLC) causes high mortality worldwide; however, its molecular pathways have not been fully investigated. The relationship between FOXA1 and CDC5L as well as their roles in NSCLC have not been comprehensively studied. Clinical tissues were collected from 78 NSCLC patients for clinical studies. The BEAS‐2B human normal lung epithelial cell line and the A549, Calu‐3, H526 and H2170 human NSCLC cell lines were used for in vitro studies. sh‐FOXA1 and oe‐CDC5L constructs were used to generate knockdown and overexpression models, respectively. The CCK‐8 assay was used to analyze cell viability. The cell cycle and apoptosis were evaluated by flow cytometry analysis. The relationship between FOXA1 and CDC5L was demonstrated using dual‐luciferase and ChIP assays. Gene levels were examined via immunohistochemistry, qRT‐PCR and western blot analysis. FOXA1 levels were increased in NSCLC clinical tissues and cell lines. Depletion of FOXA1 increased the apoptosis rate and increased the proportion of cells in G2/M phase. In addition, we demonstrated that FOXA1 was directly bound to the promoter of CDC5L and that depletion of FOXA1 inhibited CDC5L expression. Overexpression of CDC5L induced ERK1/2 phosphorylation, induced JAK2 phosphorylation, inhibited cell apoptosis, prolonged S phase, and significantly reversed the effects of FOXA1 knockdown on the progression of NSCLC. The present study demonstrated that FOXA1 prolongs S phase and promotes NSCLC progression through upregulation of CDC5L and activation of the ERK1/2 and JAK2 pathways.