Label-free quantitative proteomic analysis identifies the oncogenic role of FOXA1 in BaP-transformed 16HBE cells.

Lung cancer has been the leading cause of cancer incidence and mortality in China for years. Benzo[a]pyrene (BaP) is a well-known carcinogen for lung cancer. To understand alternation of key proteins and their role in BaP-induced lung cancer, we compared proteome profiles between BaP-transformed 16HBE cell line T-16HBE-C1 (THBEc1) cells and control using label-free quantitative proteomic analysis. Forkhead box protein A1 (FOXA1) was selected and evaluated for its potential role in BaP-induced carcinogenesis in vitro and in vivo. Relationship between FOXA1 expression and survival of lung cancer patients were examined via The Cancer Genome Atlas (TCGA) database. A total of 183 differentially expressed proteins were identified, with 67 proteins including FOXA1 up-regulated and 116 proteins down-regulated in THBEc1 cells. Differentially expressed proteins mainly functioned in basic cellular metabolism, tumor related pathways and regulation of transcription factors. FOXA1 knockout inhibited colony formation and migration of THBEc1 cells in vitro. FOXA1 knockout inhibited tumor growth and metastasis in BALB/c-nude mice after subcutaneous and tail vein injection of FOXA1 knockout THBEc1 cells, respectively. FOXA1 mRNA expression was higher in tumor tissues for patients with lung squamous cell carcinoma, but not associated with survival of lung cancer patients. Our findings revealed oncogenic role of FOXA1 in BaP-induced lung cancer and improved understanding of mechanism in BaP-induced carcinogenesis.