So if you’ve been keeping up with my posts then you have probably realised by now that most of the experiments that I carry out in the lab are for testing how much damaged DNA is present in a cell. And so I thought it would be useful to explain a little bit more about the damage that can happen to DNA and why looking at DNA damage has its advantages.
Damage to DNA can happen naturally in a cell as a result of metabolic processes or can be caused by environmental factors like UV radiation from the sun or X-rays. During the chemical reactions that occur when a cell is metabolising, molecules can be produced called reactive oxygen species that are highly reactive and interfere with the chemical structure of DNA. In a similar way, radiation waves from the environment can also interfere with the structure of DNA, producing damage to the DNA sequence or even the DNA strand itself!
The damage can be relatively minor for example just a single change in the sequence of DNA, or can cause more complex damage if breaks occur in either one or both of the DNA strands. Fortunately, in healthy people, the body’s cells are well-equipped to deal with any damage and there are a fair few repair mechanisms that tackle the damage in a variety of ways. Most damaged DNA is repaired correctly however some repair processes can inadvertently create errors in the DNA sequence, especially if the damage is complicated to repair.
Small errors in the DNA sequence accumulate over time and are a natural part of the ageing process, but if big changes to the DNA are maintained and not successfully removed it can be detrimental to the cell. Often the cell will die or, worse still, pass these errors onto the cells it will divide into and cause diseases such as cancer.
I am interested in looking at how well complex DNA damage like strand breaks are repaired in a cell. This information could give an insight into how much damage cells can withstand and could be very useful to predict how tissues might respond to damage induced by radiotherapy.