Cancer cell-driven HIF-1alpha activation enhances the motility of cancer-associated fibroblasts in the lung tumor microenvironment

Cancer-associated fibroblasts (CAFs) display significant phenotypic heterogeneity driven by dynamic interactions within the tumor microenvironment. To investigate motility-driven CAF heterogeneity, we utilized a 3D culture system and the photoconvertible fluorescent protein Dendra2, to isolate ‘motile' and ‘static' CAF subpopulations. Transcriptomic analyses revealed that motile CAFs upregulated hypoxia- and glycolysis-related genes, which are downstream targets of HIF-1alpha. In line with these findings, HIF-1alpha activation enhanced CAF motility, while the knockdown of its downstream targets, ALDOA and LDHA, significantly reduced CAF motility. Notably, mesenchymal-like lung cancer cells enhanced both HIF-1alpha activity and motility in CAFs through secretory factors. Using mass spectrometry, we identified ceruloplasmin (CP) as a key secretory protein from these lung cancer cells, whose transcription was regulated by the EMT-inducing transcription factor ZEB1. Functionally, CP knockdown abolished the ability of lung cancer cells to promote CAF motility in vitro and to metastasize in vivo. Collectively, these findings demonstrate a novel mechanism where lung cancer cell-secreted CP facilitates HIF-1alpha signaling in CAFs, thereby driving their motility and promoting metastasis.