Picture every cell carrying a passport with its age written inside. But sometimes a cell grows old faster than the years go by. Scientists have learned to read that "passport" from chemical marks on DNA. These marks are called methylation.
Researchers examined 5528 tissue samples across eight types of cancer. They used seven different ways of counting a cell's age. In almost every case, tumors turned out to be "older" than healthy tissues. Only in uterine cancer was it the other way around: the diseased cells looked younger.
Now scientists want to test these marks on other data and figure out why uterine cancer behaves differently. If all goes well, doctors will be able to spot the disease earlier with a simple test.
The Horvath clock, created in 2013, uses just 353 CpG sites, yet it works in almost all human tissues, including brain, liver, and lungs.
In the series "Altered Carbon," biological age and body condition can be changed, and in reality epigenetic clocks allow us to estimate how much cells are "older" than their passport age, which vaguely resembles the idea of biological monitoring from science fiction.
Not published on arXiv. Here are its page, the PDF and the formalization: you can check it yourself, not only read our account.