The article explores the impact of genetic research, epigenetics research and their applications for cancer treatments.
While epigenetics research is relativity new, applications in genetic medicine are the future, and the future is now. Following the introduction of the $1000 genome project in the 1990s, not only has the cost of sequencing decreased drastically, but the overall utilization of genetic sequencing has also become more commonplace in healthcare.1 Molecular testing has provided clinicians a better understanding of an individual patient’s health across the clinical laboratory industry, but is DNA the only characteristic at play when it comes to hereditary characteristics and diseases?
The study of epigenetics takes a look at the hereditary impact of physical traits that impact, but aren’t necessarily reflected in the physical genetic code.2 Essentially, the term refers to the environment surrounding DNA and its physical impact on how it functions at the cellular level. Although this is not a new discovery by any stretch of the imagination, the concept has received renewed interest and attention due to its potential role in and impact on cancers.2
“In the past five years, and especially in the past year or two, several groundbreaking studies have focued fresh attention on epigenetics,” wrote Weinhold.3 “Interest has been enhanced as it has become clear that understanding epigenetics and epigenomics—the genome-wide distribution of epigenetic changes—will be essential in work related to many other topics requiring a thorough understanding of all aspects of genetics.”
Chromatin and DNA Methylation
According to Johns Hopkins Medicine, chromatin is a “Combination of DNA and proteins, mainly histones” that are essential to control gene expression in cells.2 Chromatin allows allow genetic codes to both fit and function appropriately within respective cells. Like any other bodily function, epigenetic process can be both positive and negative. One of these processes, DNA methylation, has been linked to several diseases and disorders.3 The DNA methylation process impairs chromatin and results in malfunctioning and potentially cancerous cells.2
Unlike chemotherapy, which simply aims to kill the cancerous cells, or mutating tumor suppression genes, epigenetic therapies are based on the idea that changing the environment surrounding a cell can change how it functions.2 For the most part, cancerous cells behave similarly to embryonic cells with the exception that they continue to divide—forming a tumor.2 By targeting tumor suppression genes and manipulating their surrounding environmental factors, epigenetic therapies could be able to stop these cells from replicating and simply act as normal, non-cancerous cells.4
“The reversible nature of the profound epigenetic changes that occur in cancer has led to the possibility of ‘epigenetic therapy’ as a treatment option,” wrote Shikhar et al.4 “The aim of epigenetic therapy is to reverse the casual epigenetic aberrations that occur in cancer, leading to the restoration of a ‘normal epigenome.’”
Similar to how immunotherapies work by manipulating the body’s T-cells to fight cancer, epigenetic therapies work by reprograming cancer cells to function properly.2,5 There are many potential benefits to this process. Unlike chemotherapy, which does a lot of internal harm to both cancerous and non-cancerous cells alike, epigenetic therapies would pose significantly less risk to normal cells and gene expression beyond the targeted area. As such, it would require lower dosages to remain effective.
On the other side of the coin, however, this is still a novel concept. The long-term implications of epigenetic therapy remain to be seen, so the limitations lie more in what we do not know. Non-cancerous cells may not sustain the same level of damage as seen in chemotherapy, but there is still a risk of toxicity. Despite this, Shikhar et all noted that, since the therapy would be focused on dividing cancer cells, the adverse effects to normal cells would be relatively limited.5
As researchers and scientists develop a broader understanding of genetic information in the human body, they are also discovering that, not only does DNA impact bodily functions, but those same functions can also affect the DNA. Like many other fields within the medical laboratory, the role of molecular data in clinical decision making continues to evolve. With it, new treatment methods are presented.
The Molecular Edge is a bimonthly column exploring advances in molecular diagnostics, sponsored by Roche.
References
- Hayden EC. Technology: The $1,000 genome.
- The Sidney Kimmel Comprehensive Cancer Center. Johns Hopkins Medicine. What is epigenetics?
- Weinhold B. Epigenetics: The science of change. Available at:
- Shikhar S, Kelly TK, Jones PA. Epigenetics in cancer.
- Cancer Treatment Centers of America. What is immunotherapy?
