Epigenetics is the study of how heritability affects gene expression. Epigenetics began as a combination of genetics and embryology over 50 years ago. One of the first experiments performed was conducted by Conrad Waddington who observed how stress affected fruit flies and their characteristics. The environment that Waddington had placed the fruit flies in ultimately changed their physical appearance. Waddington was also the man who named the field after the idea of epigenesis and genetics.
Epigenetics has been focused around DNA methylation which is a systematic method of gene expression. In October of 2000, the Human Epigenome Project (HEP) began. Many people have heard of the Human Genome Project (HGP) which ended in the early 2000’s which gave us the ‘blueprints’ of human life, but HEP aims to give us the directions on how to use the blueprints. The study of epigenetics and HEP is giving light to a whole new side of modern medicine that could provide many breakthroughs in today’s diseases and disabilities.
DNA methylation, histones, and the chromatin structure are all genetic markers that play a huge role in epigenetics. DNA methylation is the process that allows genes to be expressed or not. The process itself has a methyl group that binds to a cytosine. The methyl group that is added is the “light switch” that determines if the gene is turned on or turned off. Histones are tightly packaged proteins that DNA wraps itself around. Histones are a huge component of chromatin because once the DNA has wrapped itself around the histones and tightly compacted itself, it becomes chromatin as a whole.
Because of these systems, there are ‘predictive markers’ which allow us to tag specific parts of the genome and determine possibilities of faults in the DNA sequence that could cause someone to be at risk of something. These genetic markers are what’s leading the HEP to map the methylation sites of a human. Because of these errors in methylation, histones, or chromatin structure, many diseases or disabilities have affected people. These errors that have been found can be very difficult to pin point. If we could find the exact location of the error, we could learn a lot more about the disease or disability itself.
In todays world of modern medicine, there is a lot that is yet to be discovered in terms of epigenetics. Feinberg 2008, claims that cancer was the first known epigenetic mechanism of human disease. He continues to describe that there was a widespread loss of DNA methylation that was observed in colorectal cancers. This observation led to many other discoveries about methylation sites and disease that correlate with them. Age related disease, memory related disease, cancer, and many other types of diseases have been linked to epigenetics. Age related diseases has been a big one. A study has been conducted that has tested epigenetic factors as compared to the lifespan of mice (Cell Press 2016).
This study showed that epigenetics might be more relevant in the aging process than we originally thought. This experiment also claims that the aging process is ‘malleable’ and therefore we can change it based on the factors and environment we put ourselves in. Nutrition and exercise have been shown to be big influences in aging as well as stress. The aging process is known to be linked with lifestyle, but when genes are added to the mixture, it imposes a new thought. How can external factors change your gene expression?
Epigenetics is showing the connection between the external factors and the expression of genes. As the gap in the bridge is being closed between the two and their relatedness, epigenetics will be able to show us how exactly we can improve our lifespan. Modern medicine is playing a huge role in these diseases, and one of them is gene therapy through epigenetics. Scientists are trying to use stem cells to treat patients. In the mouse experiment mentioned above, they used adult stem cells and turned them into induced pluripotent stem (iPS) pluripotent stem cells (Cell Press 2016). This being done, they used those cells in the mice to reprogram the other cells. Epigenetics is showing a promising future for medicine and an alternative way of treating diseases.
Epigenetic therapy has been introduced to the medical world and is making strides. “The first successful drugs developed as epigenetic agents were DNA methyltransferase inhibitors… [the] drug aim at reversing gene silencing and demonstrate antitumor activity in vitro and in vivo” (Boumber 2011). This means that the drug would theoretically silence the cancer gene that continuously makes cancer grow. If it is possible that they will find a drug that can target cancer cells and make them stop mitosis, then cancer could be defeated and finally cured. Epigenetic therapy has so many possibilities out there and cancer is just the tip of the iceberg.
Environmental factors play a huge role in epigenetics and can cause many things to go awry. Studies have shown there is a strong link between our outside environment and our genes. One study shows that there is a link between such factors and type 2 diabetes (Ling 2009). Another study has shown that environmental factors can play a role in diseases such as Parkinson’s, Alzheimer’s, and ALS (Migliore 2008).
Migliore says that factors such as pesticides, metals, head injuries, lifestyles, and diet can severely impact the risk of someone having such a disease. Environmental factors are not just the environment someone was raised in, but also the environment that they create for themselves. This can include sports they played in high school, to the food they ate, to the love that they receive or lack thereof. The setting in which someone has been in can force methylation in their DNA to change. Stress can also be a huge factor when it comes to gene expression and therefore the risk someone is at for a multitude of diseases.
People who undergo a lot of stress in their daily lives are at a higher risk. Stress can come from work, family, friends, or any of the surrounding elements of someone’s environment. Epigenetics is not something most people would tie to the environment they live in or could even imagine that the way they live life could potentially put them at a higher risk for any disease or disability in terms of genetics.
New technologies are having a big hand in epigenetic advancements. One piece of technology that has been developed is the assisted reproductive technology (ART). This piece of technology helps families have children through in vitro fertilization. In the practice of ART, both the egg and the sperm cells are manipulated in the lab to make sure that the offspring will have a smaller chance of coming out with a disease of any sort (Niemitz 2008). ART has helped several families have healthy babies because of the ability to pick and choose the cells that are used and that will be fertilized.
Another piece of technology that was previously mentioned has to do with cancer. This would, once again, turn off the gene in cancer cells that cause rapid mitosis and make the cells constantly grow and divide. Epigenetic therapy has set out to change the world of scientific technology. Cancer treatments will have gone from years of radiation and chemotherapy to gene therapy. In patients that have early detections of Parkinson’s and Alzheimer’s, their lives will be changed so they may never have to experience the horrible pains of the mentioned diseases. Epigenetic therapy including gene splicing and gene reprogramming is the future of technology.
Gene therapy has driven a lot of controversy over the subject for people’s moral beliefs. Some people say that gene therapy could be used for the wrong reasons and be used to change people based on their physical appearance and what they want to look like. There is also the issue of where you draw the line on disorders and disabilities. Is someone with scoliosis deserving of gene therapy? Or is that too miniscule. There are so many moral questions surrounding the topic that makes it even hard to get the legal aspect of it all involved, too (Genetics Home Reference 2018).
Many argue that by performing gene therapy, they would be playing God. There is also the argument that any natural selection would be removed and the environment would almost only consist of artificial selection. The society in which gene therapy was more prevalent could also be less accepting of anyone that is different in the slightest (Hunt 2008). Overall, there are many questions that must be taken into consideration before gene therapy does become any everyday part of modern medicine. There are people out there who will want to abuse the powers of gene therapy, but there are also the people that will only want to help someone in dire need.
Epigenetics overall has given light to how the future of medicine is changing. There are many key factors that play a role in how someone’s epigenome is determined and what genes are expressed at what time in someone’s life. This can be due to environmental factors or even their genetics that they inherited from a family member such as their mother or their father. When it comes to having families, there are so many options available for families that are worried about their child having a disease or defect with assisted reproductive technologies with the help of in vitro fertilization.
Epigenetics is also helping with the fight against cancer as well as the fight against other horrible diseases (Alzheimer’s, Parkinson’s, etc). With the new ideas of gene therapy, there has been a lot of controversy regarding ‘playing God’ as well as moral dilemmas within specific situations. Overall, epigenetics is a rising new field with the Human Epigenome Project and is expected to lead to many new breakthroughs.