Respiratory competent mitochondria in human ovarian and peritoneal cancer.
Level 5 - mechanism / opinion, no new human data
Bench research evaluating isolated mitochondria from human tissue samples
PubMed 21211574 · doi:10.1016/j.mito.2010.12.015
What was done
Mitochondria were isolated from human ovarian and peritoneal cancer tissues to determine oxidative phosphorylation (OXPHOS) competence. Investigators assessed mitochondrial membrane potential, ATP biosynthesis, oxygen consumption, and the specific activities of succinate, malate, and glutamate dehydrogenases.
What was found
The abstract provides no raw numbers or sample sizes. Intact tumor mitochondria showed substantive OXPHOS activity regarding membrane potential, ATP generation, and oxygen consumption. Dehydrogenase activities were comparable to literature-reported values for human skeletal muscle, heart, and liver, but the rate of ATP biosynthesis was one order of magnitude lower than human skeletal muscle.
Why it matters
This study demonstrates that human ovarian and peritoneal cancers retain functional TCA cycle enzymes and respiratory-competent mitochondria, challenging the concept that cancer cells universally suffer from intrinsically defective respiration.
Limits
Sample size is not reported in the abstract. The study relies on historical literature values for normal tissue comparisons rather than concurrent or patient-matched normal control tissues, and quantitative measurements with variance are omitted.
Cited by
- contradicts Every major cancer has damaged mitochondria and insufficient oxidative phosphorylation, rendering them dependent on fermentation of glucose and glutamine.