I was once again privileged to be invited to an American Association for Cancer Research conference as part of their Survivor<->Scientist Program. This conference, Frontiers in Cancer Prevention Research took place in Washington DC in November. At the AACR conferences, those of us who are survivors and advocates are able to access the great minds of scientists from all over the world who have devoted their lives to searching for a cancer cure. We are also able to meet other survivors and advocates from around the world. We attend sessions and listen to presentations about the latest discoveries in the field from the scientists doing the research. I am inspired when I attend these meetings. I become very hopeful when I see the progress being made against this monster of a disease.
I want to share here what I learned at this most recent conference. This particular conference inspired me to make many personal changes in my own life. I will share here what I learned from attending many of the sessions in a series of blog posts over the next several days.
EPIGENETICS: Epigenetics is a new field in cancer research. While we often hear that cancer is a genetic disease, or find many people who feel that cancer is “in your genes” and therefore unavoidable, in reality only about 10% of cancers result from the genetic defects inherited from our ancestors. In a long term study of identical twins, when one twin had cancer, only 15% of the identical twins developed the cancer. If cancer were a disease inherited in our genes, 100% of identical twins would share a cancer history.
Different genes in our DNA have been discovered that promote cancer or protect against cancer. Some genes can cause unrestricted cell growth characteristic of cancer (this may be helpful when organs are being formed before birth or when tissues are being repaired). Other genes are protective against cancer and destroy cancerous cells before they can metastasize or form tumors. It has been discovered that these genes can be turned on or off, so that a gene protective against cancer no longer protects, or a gene that causes uncontrolled cell growth can be turned on when it shouldn’t be. This occurs because of a biochemical process called methylation. These changes are referred to as epigenetic changes.
In research it has been discovered that the DNA of identical twins becomes less and less similar as the twins age, which accounts for the differences in the appearances and health issues of identical twins as they grow older. When you compare their genetics at birth, they are identical. When you compare their genetics as they age, though, they become genetically very different from each other. I personally worked with two identical twin sisters for a few decades. When I first met them they truly looked identical, now they are no longer identifiable as identical twins, their appearances have changed a lot over the years. I’m not sure if you would even notice a sister resemblance in them now. Epigenetics have caused their genetic expression to become different as they have aged.
The field of epigenetics has implications in the treatment and prevention of cancer. It is believed epigenetic changes occur based on our behavior…that things like smoking and exposure to environmental toxins can cause epigenetic changes that promote cancer or that effectively “handcuff” genes that protect against cancer. Our diet may alter our epigenetics in good or bad ways. This offers great potential for prevention of cancer. It also offers a great potential for cancer treatment. It is much easier to turn genes on and off through epigenetics and demethylation than to correct a mutated gene that is inherited. Currently there is an ongoing clinical trial using drugs that correct epigenetic changes in cancer patients.
To learn more, you can view this link to a NOVA program about epigenetics.
In this NOVA video about epigenetics, two mice who are clones with identical DNA have had certain genes silenced or turned on. They have had epigenetic changes created by scientists. The result is identical twin mice that have totally different body structures and hair color: