Researchers found that the DNA repair enzyme MGMT is not constant over the day. When MGMT is active, it repairs the damage that temozolomide (TMZ) makes in tumor DNA. MGMT can be turned off by methylation.
Colleagues at WashU Medicine gave five years of patient biopsy data. The team found morning biopsies were more likely to be scored as methylated. A model by Olivia Walch and colleagues predicts better times for dosing. Next steps include testing chronotherapy with TMZ in clinical settings and studying other time signals.
Difficult words
- enzyme — a protein that speeds up chemical reactions
- repair — to fix something that is broken or damagedrepairs
- methylation — a chemical change that can turn genes off
- biopsy — a medical test where doctors take a tissue samplebiopsies
- model — a simple plan or system that explains results
- chronotherapy — treatment that uses time of day to help medicines work
- tumor — an unusual mass of cells in the body
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- Do you think the time of day can change how medicines work? Why?
- Would you prefer a morning or evening appointment for a biopsy? Why?
- How could a model help doctors choose the best time for a medicine?
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