Molecular insight into our own DNA is now possible, a field called personal genomics. Such approaches can let us know when we might have cancer-causing alterations in our genes. Well-known examples are the melanoma oncogene BRAF kinase, the breast cancer gene BRCA1 and the prostate specific antigen PSA.
But there is more to cancer and other diseases than our genes. In addition to the DNA code, there is a hidden layer of regulation controlling the activity of genes – while not changing the DNA itself. This field, called epigenetics, is the study of how genes are regulated to express themselves, even though they rely on the same genetic information. A gene is still a gene, but it responds differently to many facets of its chemical environment.
For example, have you thought about why identical twins are different? How it is possible that the lifestyle of our grandparents can affect our lives today? Something beyond our DNA is at work. This is epigenetics.
The hidden layer responsible for fine-tuning alongside our DNA is called epigenomic regulation. Epigenomics is the field of quantifying epigenetic marks on a genome-wide scale, thereby capturing a snapshot of our epigenetic state.
Recently, the systems biology and cancer metabolism lab at UC Merced published discoveries about an epigenetic factor called Jumonji. This factor not only affects how an entire network of cancer genes behaves; it actually takes on the role of a cancer gene, bringing uncontrollable cell growth.
Epigenomics captures how gene activity is controlled
Already, doctors and others who diagnose diseases can, to some degree, use personal genomics tests that integrate our unique genetic makeup into clinical decision-making. However, there is more to our genome than what such tests can reveal.
Epigenetics makes sense of chemical modifications that can switch genes on or off. Importantly, none of these modifications changes the DNA sequence. Alternatively, our own cells use epigenomic regulators to control the activity of genes. If the right chemistry is in place, the right gene products are expressed at the right time.