DNA repair genes amaze me. I see, in my mind’s eye, little railroad engines with sidecars chugging along down your DNA, comparing the two sides and somehow knowing which genes have mutations, like de novo (newly arising) breaks in your DNA. In virtually all diseases, from cancer to autism, genetics is involved, and in theory, anything that helps repair your genes would be vital.
In January, I blogged on these repair genes; a blog with more questions than answers. Here were some of the questions:
- How many DNA repair genes does vitamin D control?
- Do the repair proteins they increase all have different mechanisms of action in repairing DNA?
- When activated vitamin D stimulates these DNA repair genes, is the increase profound or only minimal?
- Do these DNA repair proteins repair small inherited mutations or only the ongoing DNA damage we suffer from living on Earth?
- What happens if you give pharmacological (large) doses of vitamin D to people suffering from a genetic disease like fragile X syndrome? Would the vitamin D make the DNA less fragile?
I wish I could tell you a more recent paper has answered all these questions, but it may have answered a few.
Ting HJ, Yasmin-Karim S, Yan SJ, Hsu JW, Lin TH, Zeng W, Messing J, Sheu TJ, Bao BY, Li WX, Messing E, Lee YF. A Positive Feedback Signaling Loop between ATM and the Vitamin D Receptor Is Critical for Cancer Chemoprevention by Vitamin D. Cancer Res. 2012 Feb 15;72(4):958-68. Epub 2011 Dec 29.
This is a test tube study using the latest genetic techniques, a study I was barely able to read, much less fully understand. One thing I did understand is a major problem humans have with their DNA, something called “double stranded breaks” (DSB), which I infer is exactly what it sounds. Instead of just one strand of our DNA breaking in response to oxidant toxins, or radiation, or other DNA enemies, both — not just one, but two DNA strands – break, and we are essentially in trouble.
What does vitamin D do for these double stranded breaks?
According to the investigators of this study, “Together, our results suggested that activated vitamin D protects cells from insults through inducing DNA repair genes’s expression to promote the repair of double stranded breaks.” They went on to say, “Overall, our efforts support the role of vitamin D in guarding genomic integrity through regulation of genes involved in anti-oxidation and DNA repair.”
Now, I have even more questions and I know researchers are eagerly trying to find the answers.