Hypoxia‐induced HIF1α targets in melanocytes reveal a molecular profile associated with poor melanoma prognosis

SK Loftus, LL Baxter, JC Cronin, TD Fufa… - Pigment cell & …, 2017 - Wiley Online Library
SK Loftus, LL Baxter, JC Cronin, TD Fufa, NISC Comparative Sequencing Program…
Pigment cell & melanoma research, 2017Wiley Online Library
Hypoxia and HIF 1α signaling direct tissue‐specific gene responses regulating tumor
progression, invasion, and metastasis. By integrating HIF 1α knockdown and hypoxia‐
induced gene expression changes, this study identifies a melanocyte‐specific, HIF 1α‐
dependent/hypoxia‐responsive gene expression signature. Integration of these gene
expression changes with HIF 1α Ch IP‐Seq analysis identifies 81 HIF 1α direct target genes
in melanocytes. The expression levels for 10 of the HIF 1α direct targets–GAPDH, PKM …
Summary
Hypoxia and HIF1α signaling direct tissue‐specific gene responses regulating tumor progression, invasion, and metastasis. By integrating HIF1α knockdown and hypoxia‐induced gene expression changes, this study identifies a melanocyte‐specific, HIF1α‐dependent/hypoxia‐responsive gene expression signature. Integration of these gene expression changes with HIF1α ChIP‐Seq analysis identifies 81 HIF1α direct target genes in melanocytes. The expression levels for 10 of the HIF1α direct targets – GAPDH, PKM, PPAT, DARS, DTWD1, SEH1L, ZNF292, RLF, AGTRAP, and GPC6 – are significantly correlated with reduced time of disease‐free status in melanoma by logistic regression (Pvalue = 0.0013) and ROC curve analysis (AUC = 0.826, P‐value < 0.0001). This HIF1α‐regulated profile defines a melanocyte‐specific response under hypoxia, and demonstrates the role of HIF1α as an invasive cell state gatekeeper in regulating cellular metabolism, chromatin and transcriptional regulation, vascularization, and invasion.
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