A number of studies have demonstrated the presence of
mitochondrial DNA (
mtDNA) mutations in
cancer cells. In this article, we review mitochondrial genomic aberrations reported in solid
tumors of the breast, colon, stomach, liver, kidney, bladder, head/neck, and lung. The tantalizing association of
tumors with
mtDNA mutations implicates these mutations in the process of
carcinogenesis. Alterations in expression of
mtDNA transcripts in a variety of
cancer types are also reviewed. In solid
tumors, elevated expression of
mtDNA-genes coding for subunits of the mitochondrial electron respiratory chain may reflect mitochondrial adaptation to perturbations in cellular energy requirements. The role of
mtDNA mutations and altered expression of mitochondrial genes in
carcinogenesis is discussed.
Mitochondrial DNA mutations can initiate a cascade of events leading to a continuous increase in the production of
reactive oxygen species (persistent oxidative stress), a condition that probably favors
tumor development.