AXL is crucial for E1A‐enhanced therapeutic efficiency of EGFR tyrosine kinase inhibitors through NFI in breast cancer

AXL which is a chemosensitizer protein for breast cancer cells in response to epidermal growth factor receptor‐tyrosine kinase inhibitor and suppresses tumor growth. The clinical information show nuclear factor I (NFI)‐C and NFI‐X expression correlate with AXL expression in breast cancer patients. Following, we establish serial deletions of AXL promoter to identify regions required for Adenovirus‐5 early region 1A (E1A)‐mediated AXL suppression. All of the NFI family members were extensively studied for their expression and functions in regulating AXL. Moreover, E1A post‐transcriptionally downregulates AXL expression through NFI. NFI‐C and NFI‐X, not NFI‐A and NFI‐B, resulting in cell death in response to EGFR‐TKI. Our finding suggests that NFI‐C and NFI‐X are crucial regulators for AXL and significantly correlated with poor survival of breast cancer patients.