In the words of Michele Maio, MD, PhD, chair of medical oncology and immunotherapy, Ospedale Santa Maria alle Scotte, Istituto Toscano Tumori, in Siena, Italy, epigenetics is the study of "cellular changes in gene expression." For example, a person could have the DNA necessary to make a certain gene, but if their epigenetic code is not programmed to turn on production of this gene, it is as if the DNA is not even there. Our gene expression is inherited from our parents, and this family connection could also explain why some people have a genetic predisposition for some types of cancer.
Maio stresses the importance of clarifying that epigenetic differences are not the same as a genetic mutation. Rather, methylation of DNA causes certain strands of genetic code to be inactivated (Nature). Fortunately, as research into the mechanics of epigenetics has provided scientists with more information on how to manipulate gene expression, recently cancer experts have been able to utilize epigenetic therapy to uniquely treat cancer patients.
In some cancer patients, uncontrollable cell growth occurs because gene expression for immune cells that recognize cancerous growth is being suppressed. If these necessary regulatory cells are not being produced, cancerous cells will grow uncontrollably, undetected and unregulated. However, using epigenetic therapy to turn expression of these immune cells back on could help the immune system detect and stop cancer cell growth all on its own.
In addition, epigenetic therapy can be used to suppress gene expression of immune cells that instigate cancer cell growth, such as myeloid-derived suppressor cells (MDSCs). Normally, in a healthy individual these cells consist of infection-fighting granulocytes, macrophages, and dendritic cells. However, in a cancerous or other pathological situation, these cells are blocked from differentiating, remain in their immature form, and can contribute to the upregulation of immune suppressors (Nature Reviews Immunology).
Currently, Maio and his team are running clinical trials to test different combinations of immunotherapy and epigenetic therapy with different kinds of cancers to find a perfect match of treatment with which to use on various cancer patients.The future of this combination treatment is bright, but the scientists do have to keep in mind the potential negative side effect of myelotoxicity. Myeloid tissues make blood cells, and overwhelming these tissues with chemicals could harm regular hematopoiesis.
Back in February, John Hopkins Medicine explained how they used epigenetic therapy to fight cancer. As explained by surgeon and oncologist Dr. Malcolm Brock, they transformed cancerous cells into healthy cells to make them easier targets by chemotherapy. Watch the video below to hear Dr. Brock explain how they did this.
Source: EurekAlert and The American Association for Cancer Research