Stories about: DNA damage

Breaking down brain disease one DNA break at a time

DNA breaks are depicted in this artistic renderingCells throughout the human body are constantly being damaged as a part of natural life, normal cellular processes, UV and chemical exposure and environmental factors — resulting in what are called DNA double-strand breaks. Thankfully, to prevent the accumulation of DNA damage that could eventually lead to cell dysfunction, cancer or death, the healthy human body has developed ways of locating and repairing the damage.

Unfortunately, these DNA repair mechanisms themselves are not impervious to genetic errors. Genetic mutations that disrupt DNA repair can contribute to devastating disease.

Across the early-stage progenitor cells that give rise to the human brain’s 80 billion neuronal cells, genomic alterations impacting DNA repair processes have been linked to neuropsychiatric disorders and the childhood brain cancer medulloblastoma. But until now, it was not known exactly which disruptions in DNA repair were involved.

A Boston Children’s Hospital team led by Frederick Alt, PhD, has finally changed that.

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‘Hotspots’ for DNA breakage in neurons may promote brain genetic diversity, disease

DNA breakage brain
DNA breaks in certain genes may help brains evolve, but also can cause disease (Constantin Ciprian/Shutterstock)

As organs go, the brain seems to harbor an abundance of somatic mutations — genetic variants that arise after conception and affect only some of our neurons. In a recent study in Science, researchers found about 1,500 variants in each of neurons they sampled.

New research revealing the propensity of DNA to break in certain spots backs up the idea of a genetically diverse brain. Reported in Cell last month, it also suggests a new avenue for thinking about brain development, brain tumors and neurodevelopmental/psychiatric diseases.

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Predicting cancer drug response: One or two genes don’t always tell the story

Measuring the total amount of DNA damage within a tumor’s cells could help doctors predict its vulnerability to drugs like cisplatin. (Haukeland universitetssjukehus/Flickr)

Drugs like cisplatin that break DNA are some of the strongest weapons we have against breast, ovarian and other cancers. The problem, common to every form of chemotherapy, is that cisplatin doesn’t work for everyone. Given the potential side effects that go along with the drug—including vomiting, hearing loss and muscle cramps, just to name a few—the decision to give it to a patient becomes something of a gamble: Does the benefit outweigh the risk?

There are tests that examine individual genes and which can give doctors a limited view as to which tumors might respond best to cisplatin. But a multicenter team co-led by Zoltan Szallasi, MD, of Boston Children’s Hospital’s Informatics Program (CHIP), thinks they may have a solution that looks beyond individual genes to see which tumors might succumb to cisplatin and other drugs like it.

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