Measuring your DNA health

Sometime soon, Sylvain Costes (Ph.D.’99 NE) hopes that annual medical checkups will include a simple blood test to determine levels of DNA damage.

Despite being the foundation of life, DNA is fragile. The list of things assaultive to the body’s basic building blocks is long — radiation, ultraviolet light and toxins, to name a few — and errors occur even during normal cell division. The body continually repairs this damaged DNA, but sometimes, the routine repair process can fail. DNA damage and genetic mutations can lead to serious health problems like cancer, immunological disorders, neurological disorders and premature aging.

Sylvain Costes in the labBerkeley Lab scientists and Exogen Biotechnology co-founders Sylvain Costes (right) and Jonathan Tang have developed a new way for the public to monitor their DNA health. (Photo by Sylvain Costes)

Costes first started studying DNA damage as a nuclear engineering graduate student at Berkeley. His research focused on the effects of cosmic radiation on astronauts. He joined the Lawrence Berkeley National Lab in 2004, where he continues his DNA research as head of the biocomputational modeling and imaging group.

To map DNA damage in tissue or blood samples, Costes uses fluorescent proteins to tag where DNA breaks are being actively repaired. He developed a new technology that automates measurements with a high-throughput microscope and proprietary image analysis software to spot and log DNA breaks. The result is a more accurate count, in a fraction of the time it takes conventional methods.

Costes is interested in a particular kind of DNA damage called double-strand breaks. “DNA double-strand breaks are when the two strands of the DNA are cut, so they can move apart,” says Costes. “This is linked to mutation and chromosome rearrangement, so it’s a big deal. It’s the most dangerous type of DNA damage — that’s why we look at it.”

Along with fellow alum and Berkeley Lab researcher Jonathan Tang (Ph.D.’10 BioE), Costes founded Exogen Biotechnology to translate their technology into an affordable commercial product that the general public can use to monitor personal DNA health. Exogen technology can measure DNA damage levels from tiny blood samples easily collected with an in-home kit.

Costes stresses that their test is very different from genetic testing provided by companies like 23andme, which analyze DNA samples to determine ancestry or identify genetic vulnerabilities to inherited diseases. Exogen is not looking at genetic makeup. Instead, they are looking at a physiological response.

“To me, this will become the cholesterol test of cancer,” says Costes. “Your genetics places you in a certain range, but your lifestyle can change where you are within that range. In contrast to genetic testing, we feel like this test can bring hope — because you have a way to act.”

Exogen tested their new technology in two pilot studies involving a total of 97 adults. They observed a significant increase in the DNA damage with age, with 70-year-olds having twice the number of DNA double-strand breaks compared to 20-year-olds. Individuals with cancer also had higher levels of DNA damage.

“When you age, your lifestyle choices are probably a lot more important,” says Costes. “Testing DNA damage levels could really have an impact for people 50 and above, or for people with poor DNA repair.”

Inspired by the pilot studies, Exogen aims to build a large database of DNA damage levels to better understand the meaning of an elevated level of DNA damage and study how certain factors affect DNA health. For instance, they want to follow a group of people over time to assess how DNA damage correlates with specific diseases or genetic risk and changes in diet.

“Once we have FDA approval, this test will probably join the basic preventive medicine toolkit,” says Costes.