For the first time ever, researchers in New Zealand have shown that mitochondrial DNA can move between cells in an animal tumor. It's an extraordinary finding that could lead to an entirely new field of synthetic biology and the treatment of hundreds of diseases.
Top image: The dark field image on the left highlights the transfer of fluorescent mitochondria. The bright field on the right has sufficient light to see the connecting nanotube. Caption and image: Malaghan Institute
The discovery could have major implications for the field of synthetic biology and the treatment of diseases caused by defective mitochondrial DNA. As reported in the New Zealand Herald, the discovery offers new avenues for targeting debilitating brain and muscle diseases in which defective genes are replaced with custom-designed, or synthetic, mitochondrial DNA.
Unrelated to nuclear DNA, mitochondrial DNA encodes our genetic profile and encodes key proteins within mitochondria that convert energy from food into energy that's crucial for brain and muscle function. Prior to the new study, scientists thought these genes stayed within cells, except during reproduction.
But experiments conducted by a team led by professor Mike Berridge from the Malaghan Institute have shown this isn't the case. As reported in the NZH:
A Kiwi-led research team demonstrated the movement of mitochondrial DNA between cells in an animal tumour. After mitochondrial DNA was removed from breast cancers and melanomas in mice, replacement mitochondrial DNA naturally shifted from surrounding normal tissue. After adopting the new DNA, the cancer cells went on to form tumours that spread to other parts of the body.
[...] It's a leap in the science of cellular biology, and could boost the understanding of human diseases other than cancer, since defective mitochondrial DNA accounts for about 200 diseases and is implicated in many more.
As noted by Berridge in a release, "This appears to be a basic physiological mechanism in the body that no one has seen before because they lacked the exploratory tools. Whether this new phenomenon is important in tumour formation is still unclear, but we are interested in pursuing the research to see if the transfer occurs more widely in the body. Preliminary evidence indicates it may be a common occurrence in the brain."