FOXF1 promotes angiogenesis and accelerates bevacizumab resistance in colorectal cancer by transcriptionally activating VEGFA

Forkhead box F1 (FOXF1) has been recently implicated in the progression and metastasis of lung cancer and breast cancer. However, the biological functions and underlying mechanisms by which FOXF1 regulates the progression of colorectal cancer (CRC) are largely unknown. As shown in our previous study, FOXF1 is upregulated in 182 CRC tissues, and elevated FOXF1 expression is significantly associated with microvessel density and advanced TNM (T = primary tumour; N = regional lymph nodes; M = distant metastasis) stages. In this study, 43 CRC tissues collected from patients who underwent treatment with first-line standard chemotherapeutic regimens in combination with bevacizumab were used to explore the correlation between FOXF1 expression and resistance to bevacizumab. In addition, FOXF1 regulated angiogenesis by inducing the transcription of vascular endothelial growth factor A1 (VEGFA) in vitro and in vivo. Furthermore, upregulation of FOXF1 enhanced bevacizumab resistance in CRC, and inhibition of VEGFA attenuated angiogenesis and bevacizumab resistance in FOXF1-overexpressing CRC cells. These results suggest that FOXF1 plays critical roles in CRC angiogenesis and bevacizumab resistance by inducing VEGFA transcription and that FOXF1 represents a potentially new therapeutic strategy and biomarker for anti-angiogenic therapy against CRC.