'DNA ambulance' can reveal how cancer begins

Toronto, July 24: Researchers have discovered how severely damaged DNA is transported within a cell and how it is repaired - a discovery that can unlock secrets of how cancer operates.

"Scientists knew that severely injured DNA was taken to specialized 'hospitals' in the cell to be repaired, but the big mystery was how it got there," said Karim Mekhail, professor at the University of Toronto.

"We have now discovered the DNA 'ambulance' and the road it takes," he added.

Mekhail discovered this DNA "ambulance", which is a motor protein complex, by using yeast cells.

The team also found that the DNA "hospital", also known as the nuclear pore complex, repairs damaged DNA inaccurately.

This inaccurate fix is important because DNA contains the instructions for all our genetic information.

While the repaired DNA can still replicate, it has irregular cell instructions -- a scenario that could cause cancer.

"This process allows cells to survive an injury, but at a great cost. The cell has a compromised genome but it is stable and can be replicated and that is usually a recipe for disaster," Mekhail noted.

Cancer often occurs when our chromosomes break and are misrepaired.

"This work teaches us that the location of the break within the cell's nucleus has a big impact on the efficiency of repair," the authors concluded.

The research was published in the journal Nature Communications.