Reactivation of Dihydroorotate Dehydrogenase-Driven Pyrimidine Biosynthesis Restores Tumor Growth of Respiration-Deficient Cancer Cells

Cell Metab. 2019 Feb 5;29(2):399-416.e10. doi: 10.1016/j.cmet.2018.10.014. Epub 2018 Nov 15.

Abstract

Cancer cells without mitochondrial DNA (mtDNA) do not form tumors unless they reconstitute oxidative phosphorylation (OXPHOS) by mitochondria acquired from host stroma. To understand why functional respiration is crucial for tumorigenesis, we used time-resolved analysis of tumor formation by mtDNA-depleted cells and genetic manipulations of OXPHOS. We show that pyrimidine biosynthesis dependent on respiration-linked dihydroorotate dehydrogenase (DHODH) is required to overcome cell-cycle arrest, while mitochondrial ATP generation is dispensable for tumorigenesis. Latent DHODH in mtDNA-deficient cells is fully activated with restoration of complex III/IV activity and coenzyme Q redox-cycling after mitochondrial transfer, or by introduction of an alternative oxidase. Further, deletion of DHODH interferes with tumor formation in cells with fully functional OXPHOS, while disruption of mitochondrial ATP synthase has little effect. Our results show that DHODH-driven pyrimidine biosynthesis is an essential pathway linking respiration to tumorigenesis, pointing to inhibitors of DHODH as potential anti-cancer agents.

Keywords: OXPHOS; cancer; coenzyme Q; dihydroorotate dehydrogenase; mitochondria; pyrimidine biosynthesis; respiration.

Publication types

  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Cell Respiration
  • DNA, Mitochondrial / metabolism*
  • Humans
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Mitochondria / metabolism*
  • Neoplasms / metabolism*
  • Oxidative Phosphorylation
  • Oxidoreductases Acting on CH-CH Group Donors / physiology*
  • Pyrimidines / metabolism*
  • Ubiquinone / metabolism

Substances

  • DNA, Mitochondrial
  • Pyrimidines
  • Ubiquinone
  • Oxidoreductases Acting on CH-CH Group Donors
  • dihydroorotate dehydrogenase
  • pyrimidine