Molecular Therapy: Nucleic Acids (Dec 2021)

Essential role of ALKBH5-mediated RNA demethylation modification in bile acid-induced gastric intestinal metaplasia

  • Ben Yue,
  • Ran Cui,
  • Ruizhe Zheng,
  • Weilin Jin,
  • Chenlong Song,
  • Tianshang Bao,
  • Ming Wang,
  • Fengrong Yu,
  • Enhao Zhao

DOI
https://doi.org/10.1016/j.omtn.2021.08.019
Journal volume & issue
Vol. 26
pp. 458 – 472

Abstract

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Bile acid reflux and subsequent caudal-related homeobox 2 (CDX2) activation contribute to gastric intestinal metaplasia (IM), a precursor of gastric cancer; however, the mechanism underlying this phenomenon is unclear. Here, we demonstrate that alkylation repair homolog protein 5 (ALKBH5), a major RNA N6-adenosine demethylase, is required for bile acid-induced gastric IM. Mechanistically, we revealed the N6-methyladenosine (m6A) modification profile in gastric IM for the first time and identified ZNF333 as a novel m6A target of ALKBH5. ALKBH5 was shown to demethylate ZNF333 mRNA, leading to enhanced ZNF333 expression by abolishing m6A-YTHDF2-dependent mRNA degradation. In addition, ALKBH5 activated CDX2 and downstream intestinal markers by targeting the ZNF333/CYLD axis and activating NF-κB signaling. Reciprocally, p65, the key transcription factor of the canonical NF-κB pathway, enhanced the transcription activity of ALKBH5 in the nucleus, thus forming a positive feedforward circuit. Furthermore, ALKBH5 levels were positively correlated with ZNF333 and CDX2 levels in IM tissues, indicating significant clinical relevance. Collectively, our findings suggest that an m6A modification-associated positive feedforward loop between ALKBH5 and NF-κB signaling is involved in generating the IM phenotype of gastric epithelial cells. Targeting the ALKBH5/ZNF333/CYLD/CDX2 axis may be a useful therapeutic strategy for gastric IM in patients with bile regurgitation.

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