Mitochondria – cellular structures known as the “power plants” of the cell – are inherited exclusively from the mother. These organelles contain their own DNA (mtDNA), which is highly vulnerable to damage by environmental insults – for example radiation exposure to the ovaries during treatment for childhood cancer.
Because such damage could be passed on to the offspring of female cancer survivors, John Boice, Jr., professor of medicine, and colleagues evaluated mtDNA of 18 mothers who had been treated for cancer as children and their 26 children.
They reported in the May 15 Mutation Research that nine of the 18 families had at least one child who inherited mutated mtDNA. However, there was no significant difference in the number of single nucleotide polymorphisms (mutations in a single “letter” of the DNA code) between mother and child, and radiation dose to the mothers’ ovaries was not linked to mtDNA mutations in offspring.
The results suggest that radiation therapy in female children does not affect mitochondrial mutation rate, and therefore may not increase future cancer risk in the offspring of those survivors.
The research was funded by a grant from the National Cancer Institute (CA104666) of the National Institutes of Health.