HOXD9 contributes to the Warburg effect and tumor metastasis in non-small cell lung cancer via transcriptional activation of PFKFB3

Warburg effect is associated with the progression of various tumors, leading to the development of drugs targeting the phenomenon. PFKFB3 is an isoform of 6-phosphofructo-2-kinase (PFK2) that modulates the Warburg effect and has been implicated in most common types of cancer, including non-small cell lung cancer (NSCLC). However, the mechanisms underlying the upstream regulation of PFKFB3 in NSCLC remain poorly understood. This study reported that the transcription factor HOXD9 is upregulated in NSCLC patient samples relative to adjacent normal tissue. Elevated HOXD9 levels are primarily associated with poor prognosis in patients with NSCLC. Functionally, HOXD9 knockdown impaired the metastatic capacity of NSCLC cells, whereas its over-expression accelerated the metastasis and invasion of NSCLC cells in an orthotopic tumor mouse model. In addition, HOXD9 promoted metastasis by increasing cellular glycolysis. Further mechanistic studies revealed that HOXD9 directly binds to the promoter region of PFKFB3 to enhance its transcription. The recovery assay confirmed that the capability of HOXD9 to promote NSCLC cells metastasis was significantly weakened upon PFKFB3 inhibition. These data suggest that HOXD9 may exert as a novel biomarker in NSCLC, indicating that blocking the HOXD9/PFKFB3 axis may be a potential therapeutic strategy for NSCLC treatment.