Nrf2 and HIF1α converge to arsenic-induced metabolic reprogramming and the formation of the cancer stem-like cells

• Published in: Theranostics 2020-01, Vol.10 (9), p.4134-4149
• Main Authors: Bi, Zhuoyue, Zhang, Qian, Fu, Yao, Wadgaonkar, Priya, Zhang, Wenxuan, Almutairy, Bandar, Xu, Liping, Rice, M'Kya, Qiu, Yiran, Thakur, Chitra, Chen, Fei
• Format: Article
• Language: English
• Subjects: Antibodies; Arsenic - toxicity; Cancer; Cell Line; Cellular Reprogramming; Cloning; Contamination; CRISPR; Epithelial-Mesenchymal Transition; Gene Expression Regulation; Genes; Genome editing; Glucose; Glycolysis; Humans; Hypoxia-Inducible Factor 1, alpha Subunit - physiology; Metabolism; Metabolites; Mitochondria - metabolism; Neoplasms - chemically induced; Neoplasms - metabolism; NF-E2-Related Factor 2 - physiology; Outdoor air quality; Proteins; Reactive Oxygen Species - metabolism; Research Paper; Stem cells
• ISSN: 1838-7640; 1838-7640
• DOI: 10.7150/thno.42903

In this report, we demonstrated that inorganic arsenic (iAs) induces generation of the cancer stem-like cells (CSCs) through Nrf2-dependent HIF1α activation, and the subsequent metabolic reprogramming from mitochondrial oxidative phosphorylation to glycolysis in epithelial cells. : Genome-wide ChIP-seq analysis was performed to investigate the global binding of Nrf2 and/or HIF1α on the genome in the cells treated with iAs. Both untargeted metabolomics and UDP- C-glucose flux were applied to determine metabolic reprogramming in the iAs-induced CSCs. The role of Nrf2 on iAs-induced HIF1α and other stemness gene expression was validated by lentiviral transfection of Nrf2 inhibitor Keap1 and CRISPR-Cas9-mediated Nrf2 gene knockout, respectively. : The CSCs induced by iAs exhibit a diminished mitochondrial oxidative phosphorylation and an enhanced glycolysis that is actively shunted to the hexosamine biosynthetic pathway (HBP) and serine/glycine pathway. ChIP-seq data revealed that treatment of the cells with iAs amplified Nrf2 enrichment peaks in intergenic region, promoter and gene body. In contrast, a shift of the HIF1α peaks from distal intergenic region to gene promoter and the first exon was noted. Both Nrf2 and HIF1α are responsible for the iAs-induced expression of the glycolytic genes and the genes important for the stemness of the CSCs. Intriguingly, we also discovered a mutual transcriptional regulation between Nrf2 and HIF1α. Inhibition of Nrf2 by lentiviral infection of Keap1, or knockout of Nrf2 by CRISPR-Cas9 gene editing, not only blocked iAs-induced HIF1α activation, but reduced the expression of the key stemness genes for the formation of CSCs also. : We demonstrated that Nrf2 activation is an initiating signal for iAs-induced HIF1α activation, and Nrf2 and HIF1α played a concerted role on inducing metabolic reprogramming and the CSCs.