Francis Collins, the leader of the Human Genome Project, called DNA “the language of God.” If DNA is a language, then one could consider epigenetics the use of that language. Epigenetics studies which genes are turned on or off in our body, and these genes could regulate anything from eye color to height to the ability of your cells to fight off cancer. A type of epigenetic property know as metastable epialleles has the potential to noninvasively detect cancer in patients decades before the cancer develops.
The epigenome remains relatively stable during adult life, but is highly susceptible to environmental triggers in one’s younger years, especially in the prenatal stage. Changes made to the epigenetic switches during this stage are relatively permanent and persist throughout life.
Traditional approaches to detecting cancer involve highly invasive techniques. For example, determining if someone has lung cancer, or a high risk of developing lung cancer, lung tissues must be taken from the patient.
This dilemma brings us to the main topic of this blog: Metastable epialleles. Wow. That is a mouthful. Let’s break these things down a bit. MEs are essentially genes that develop in the early embryo, and their epigenetic light switch is determined early on as well. The most important aspect of MEs is that they are systemic, that is, the same MEs develop in most every type of tissue in the body. Thus they can be detected virtually anywhere that DNA can be found including, you guessed it, your toenail clippings. Other peripherals can be used, including blood and hair follicles, but come on, why use those when you can use toenails?
So here’s why you do. Using your toenail clippings as a source of DNA, you can treat that DNA with a special chemical (bisulfite) that allows you to determine how bright the epigenetic light switches are turned on for each gene. Looking at genes that are known to be correlated with cancer, we can create a predictive model to determine someone’s odds of getting cancer at some point in their life.
So there. Toenail clippings are now at the front lines of the most advance science in the world, so next time you cut your nails make sure to save them for the sake of science.
- How do genes work? http://genetics.thetech.org/about-genetics/how-do-genes-work (accessed 04/03/17), part of The Tech.
- Dolinoy, D.C.; Das, R.; Weidman, J.R.; Jirtle, R.L. Metastable epialleles, imprinting, and the fetal origins of adult diseases. Pediatric Research 2007, 61, 30R-37R.
- Waterland, R.A. et al. Independent genomewide screens identify the tumor suppressor VTRNA2-1 as a human epiallele responsive to periconceptional environment. Genome Biology 2015, 16, 118.