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How a Shape-shifting DNA-repair Machine Fights Cancer

Berkeley Lab’s Advanced Light Source reveals inner-workings of essential protein found throughout life.

Maybe you’ve seen the movies or played with toy Transformers, those shape-shifting machines that morph in response to whatever challenge they face. It turns out that DNA-repair machines in your cells use a similar approach to fight cancer and other diseases, according to research led by scientists from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab).

As reported in a pair of new studies, the scientists gained new insights into how a protein complex called Mre11-Rad50 reshapes itself to take on different DNA-repair tasks. (more…)

New Take on Impacts of Low Dose Radiation

By Guest PostDecember 24, 2011Health, Scienceatomic bomb blasts, berkeley lab, biological damage, breast cell line, broken dna, cancer risks, christopher pham, dna damage response, dna repair mechanisms, Environment, epidemiological data, extrapolation, gy of radiation, human breast cells, human tissue, ionizing radiation, Japan, joel swenson, lawrence berkeley national laboratory, levels of ionizing radiation, linear no threshold hypothesis, lnt, low dose radiation, mammogram, mathematical modeling, mcf10a, mina bissell, primary breast epithelial cells, radiation induced foci, rafael gomez sjoberg, repair, rif, standard model, survivors, sylvain costes, teresa neumaier, time lapse imaging, world war II, xray microbeam

*Berkeley Lab Researchers Find Evidence Suggesting Risk May Not Be Proportional to Dose at Low Dose Levels*

Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab), through a combination of time-lapse live imaging and mathematical modeling of a special line of human breast cells, have found evidence to suggest that for low dose levels of ionizing radiation, cancer risks may not be directly proportional to dose. This contradicts the standard model for predicting biological damage from ionizing radiation – the linear-no-threshold hypothesis or LNT – which holds that risk is directly proportional to dose at all levels of irradiation.

“Our data show that at lower doses of ionizing radiation, DNA repair mechanisms work much better than at higher doses,” says Mina Bissell, a world-renowned breast cancer researcher with Berkeley Lab’s Life Sciences Division. “This non-linear DNA damage response casts doubt on the general assumption that any amount of ionizing radiation is harmful and additive.” (more…)

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How a Shape-shifting DNA-repair Machine Fights Cancer

New Take on Impacts of Low Dose Radiation