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Ong, A. J. S.

Publications and source records attributed to Ong, A. J. S..

2 recordsLinked to original sources

NRF2 co-opts the SWI/SNF complex to drive liver cell plasticity

Nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor that plays a role in the regulation of redox homeostasis and cellular metabolism. Activating mutations in the NRF2 pathway have been identified in approximately 15% of liver cancer patients. However, the mechanisms by which NRF2 promotes liver tumorigenesis are poorly understood. Employing a transgenic zebrafish model with hepatocyte-specific, inducible expression of a clinically relevant constitutively active NRF2 mutant (NRF2T80K), we show that constitutive activation of NRF2 drives hepatocyte to cholangiocyte transdifferentiation. Importantly, we demonstrate that NRF2 affects liver cell plasticity in a cell-autonomous, evolutionarily conserved, and reversible manner. Utilizing an epigenetic-focused chemical screen, the BRG1/BRM inhibitor FHD-286 was identified as a potent suppressor of NRF2-driven transdifferentiation. Overall, our study reveals a novel role for NRF2 in the regulation of liver cell plasticity during tumour initiation and identifies a therapeutic approach to overcome the oncogenic activity of NRF2.

cancer biology↗

A Multi-omic approach reveals iron availability influences hepatocyte cell fate

Recent evidence has highlighted the importance of employing culture media designed to emulate the metabolic environment Here, we utilize the physiological medium Plasmax to examine the impact of nutrient availability on the human hepatocyte cell line, HepG2. Incubation of HepG2 cells in Plasmax suppressed a transcriptional program driven by Hepatocyte Nuclear Factor 4 (HNF4A), a master regulator of hepatocyte identity. Given that HepG2 cells were originally isolated from a patient with hepatoblastoma, this suggests reversion to the native state in physiological media. Importantly, exclusion of iron from Plasmax reinstated the HNF4A-driven transcriptional program. These studies suggest a relationship between iron availability and the fidelity of hepatocyte cell fate and highlight the importance of more faithfully recapitulating in vivo metabolite availability in vitro.

cell biology↗