HIF1α lactylation enhances KIAA1199 transcription to promote angiogenesis and vasculogenic mimicry in prostate cancer

Prostate Cancer (PCa) is one of the most prevalent malignancies in adult males. However, PCa is resistant to multi-kinase inhibitors-based anti-angiogenic therapies, and the mechanism and effective targeting thereof remains unclear. In this study, single-cell and bulk-transcriptomic datasets analysis revealed that KIAA1199, a hyaluronic acid (HA) binding protein, was involved in glycolysis, hypoxia and angiogenesis pathways. Moreover, boosted KIAA1199 expression in PCa tissues was positively correlated with tumor stage, hypoxia-inducible factor (HIF)-1α overexpression, as well as angiogenesis markers. Tube formation, Western blot, enzyme-linked immunosorbent assay, and in vivo tumorigenesis results demonstrated that KIAA1199 silencing significantly inhibited angiogenesis and vasculogenic mimicry (VM), both in vitro and in vivo, by increasing semaphoring-3A (sema3A) expression while decreasing expressions of VEGFA, VE-cadherin, phosphorylated EphA2, and depolymerized HA levels. KIAA1199 overexpression was also found to promote angiogenesis and VM via increasing secretory VEGFA, however, this activity could be reversed by the HA biosynthesis inhibitor 4-methylumbelliferone (4MU). Furthermore, dual-luciferase and ChIP-PCR revealed that HIF1α is the transcriptional enhancer of KIAA1199, while lactate imported to PCa cells by Monocarboxylate Transporter 1 (MCT1) stabilizes HIF1α under normoxia via HIF1α lactylation. Our findings may provide a better understanding of angiogenesis and a promising therapeutic target of PCa.