ABSTRACT
Alterations of mitochondrial structure and function in tumor cells allow cell survival and proliferation under hypoxic and acidic microenvironment. The effect of normal mitochondria on tumor initiation and development remains unknown. In this study, mice were euthanized by rapid cervical dislocation for isolation of hepatic mitochondria, which were injected intravenously to melanoma-bearing mice. This animal experiment had been approved by Southwest University Experiment Animal Ethics Review Committee. The results showed that exogenous mitochondria can significantly inhibit the growth of melanoma. Mitochondria isolated from the liver of young mice had more potent anti-melanoma effect than those isolated from aging mice. The average volume of tumors decreased significantly from 1.35 cm3 to 0.34 cm3, and the average mass of tumors decreased significantly from 0.63 g to 0.22 g. This anti-tumor mechanism might be associated with induction of mitophagy and cell necrosis after the exogenous mitochondria entering the melanoma cells. As mitotherapy can clinically improve somatic cell survival for treatment of pediatric patients with myocardial ischemia, the observed anti-tumor effect of exogenous mitochondria provides a hope for selective tumor treatment.