Mesothelial Cell HIF1α Expression Is Metabolically Downregulated by Metformin to Prevent Oncogenic Tumor-Stromal Crosstalk

Cell Rep. 2019 Dec 17;29(12):4086-4098.e6. doi: 10.1016/j.celrep.2019.11.079.


The tumor microenvironment (TME) plays a pivotal role in cancer progression, and, in ovarian cancer (OvCa), the primary TME is the omentum. Here, we show that the diabetes drug metformin alters mesothelial cells in the omental microenvironment. Metformin interrupts bidirectional signaling between tumor and mesothelial cells by blocking OvCa cell TGF-β signaling and mesothelial cell production of CCL2 and IL-8. Inhibition of tumor-stromal crosstalk by metformin is caused by the reduced expression of the tricarboxylic acid (TCA) enzyme succinyl CoA ligase (SUCLG2). Through repressing this TCA enzyme and its metabolite, succinate, metformin activated prolyl hydroxylases (PHDs), resulting in the degradation of hypoxia-inducible factor 1α (HIF1α) in mesothelial cells. Disruption of HIF1α-driven IL-8 signaling in mesothelial cells by metformin results in reduced OvCa invasion in an organotypic 3D model. These findings indicate that tumor-promoting signaling between mesothelial and OvCa cells in the TME can be targeted using metformin.

Keywords: HIF1; IL-8; SUCLG2; TGF; mesothelial cells; metformin; omental metastasis; ovarian cancer; succinate; tumor microenvironment.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Carcinogenesis / drug effects*
  • Carcinogenesis / metabolism
  • Carcinogenesis / pathology
  • Female
  • Humans
  • Hypoglycemic Agents / pharmacology
  • Hypoxia-Inducible Factor 1, alpha Subunit / genetics
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism*
  • Metformin / pharmacology*
  • Mice, Inbred C57BL
  • Ovarian Neoplasms / drug therapy*
  • Ovarian Neoplasms / metabolism
  • Ovarian Neoplasms / pathology
  • Prolyl Hydroxylases / genetics
  • Prolyl Hydroxylases / metabolism
  • Stromal Cells / drug effects*
  • Stromal Cells / pathology
  • Succinate-CoA Ligases / genetics
  • Succinate-CoA Ligases / metabolism
  • Tumor Cells, Cultured
  • Tumor Microenvironment / drug effects*


  • HIF1A protein, human
  • Hypoglycemic Agents
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Metformin
  • Prolyl Hydroxylases
  • Succinate-CoA Ligases