Mitochondrial Mutations in Cancer Progression: Causative, Bystanders, or Modifiers of Tumorigenesis?

Mitochondrial DNA encodes genes that are de facto metabolic enzymes and are currently emerging as pivotal players in the origin, progression, and outcome of human cancers. We here revise the multifaceted implications of mitochondrial mutations on the metabolic reprogramming cancer cells must undergo to adapt and proliferate. The sources of such mutations and the processes that govern their positive selection are described, along with the consequences that a deranged respiratory metabolism may have on the remodeling that follows oncogenes activation or tumor suppressors ablation. Ultimately, we dwell on the peculiar features of oncocytic tumors, one of the most relevant yet mysterious models to functionally investigate the role of mitochondrial mutations in cancer.