m6A demethylase ALKBH5 inhibits pancreatic cancer tumorigenesis by decreasing WIF-1 RNA methylation and mediating Wnt signaling

Mol Cancer. 2020 Jan 6;19(1):3. doi: 10.1186/s12943-019-1128-6.


Background: Pancreatic cancer is one of the most lethal types of cancer with extremely poor diagnosis and prognosis, and chemo-resistance remains a major challenge. The dynamic and reversible N6-methyladenosine (m6A) RNA modification has emerged as a new layer of epigenetic gene regulation.

Methods: qRT-PCR and IHC were applied to examine ALKBH5 levels in normal and pancreatic cancer tissues. Cancer cell proliferation and chemo-resistance were evaluated by clonogenic formation, chemosensitivity detection, and Western blotting assays. m6A-seq was performed to identify target genes. We evaluated the inhibitory effect of ALKBH5 in both in vivo and in vitro models.

Results: Here, we show that m6A demethylase ALKBH5 is downregulated in gemcitabine-treated patient-derived xenograft (PDX) model and its overexpression sensitized pancreatic ductal adenocarcinoma (PDAC) cells to chemotherapy. Decreased ALKBH5 levels predicts poor clinical outcome in PDAC and multiple other cancers. Furthermore, silencing ALKBH5 remarkably increases PDAC cell proliferation, migration, and invasion both in vitro and in vivo, whereas its overexpression causes the opposite effects. Global m6A profile revealed altered expression of certain ALKBH5 target genes, including Wnt inhibitory factor 1 (WIF-1), which is correlated with WIF-1 transactivation and mediation of the Wnt pathway.

Conclusions: Our work uncovers the tumor suppressive and chemo-sensitizing function for ALKBH5, which provides insight into critical roles of m6A methylation in PDAC.

Keywords: ALKBH5; Chemo-resistance; Pancreatic cancer; WIF-1; Wnt; m6A methylation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics*
  • AlkB Homolog 5, RNA Demethylase / genetics
  • AlkB Homolog 5, RNA Demethylase / metabolism*
  • Animals
  • Apoptosis
  • Biomarkers, Tumor / genetics
  • Biomarkers, Tumor / metabolism*
  • Carcinoma, Pancreatic Ductal / genetics
  • Carcinoma, Pancreatic Ductal / metabolism
  • Carcinoma, Pancreatic Ductal / pathology
  • Carcinoma, Pancreatic Ductal / prevention & control*
  • Cell Movement
  • Cell Proliferation
  • DNA Methylation*
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Mice
  • Mice, Nude
  • Pancreatic Neoplasms / genetics
  • Pancreatic Neoplasms / metabolism
  • Pancreatic Neoplasms / pathology
  • Pancreatic Neoplasms / prevention & control*
  • Tumor Cells, Cultured
  • Wnt Signaling Pathway*
  • Xenograft Model Antitumor Assays


  • Adaptor Proteins, Signal Transducing
  • Biomarkers, Tumor
  • WIF1 protein, human
  • ALKBH5 protein, human
  • AlkB Homolog 5, RNA Demethylase