Two really interesting studies crossed my desk this week. The first looked at new insights of behavioral epigenetics
, the study of changes in the DNA and how they impact physiological issues in our lives.
takes the case of nurture vs. nature to a whole new level by examining not only how our early environment may impact us as we grow up, but also how experiences of our grandparents may influence us not only physically but also in ways more connected to who we are.
The two scientists who have been studying this area both come from McGill University in Montreal. Moshe Szyf, a molecular biologist and geneticist, and Michael Meaney, a neurobiologist, began to explore changes to the DNA back in the early '90s. Already understood, especially for those of us with cancer, is that people can be born with a DNA mutation that results in cancer -- or they can acquire the mutation from some kind of exposure during their lifetime.
These two guys took that idea a step farther and asked whether, in the same way that we are born with genetic mutations from generations past that can result in physical issues, what if the result of events in the lives of our ancestors, such as traumatic experiences, could also be passed on in the family DNA.
What if in addition to physical issues we could acquire psychological and behavioral
tendencies as well?
For example, when I learned a decade ago that they had identified a gene for alcoholism
, I wasn't surprised. I had only to look at my father's family to see the thread of alcoholism that warned me away from using alcohol to cope. But what if there was a tendency toward depression that drove that alcohol issue that I never saw? Could that tendency be passed on too?
I like to think it was my mother's resiliency that balanced that out in my life and kept me from searching for self medication.
What these two researchers are looking at is the impact of life experiences and whether "how" we respond to issues and how we "cope" with life could also be something that is inherited based on events that may have happened before we were born. That sounds like what my dad used to call "character."
My father's mother, who raised five children in the shadow of my alcoholic grandfather, was the kind of woman who told the kids not to play in the front yard on Friday, knowing their father would probably come down the hill in the car in a payday alcoholic stupor. She was a frontier woman who moved her brood across the country for a better life and remained a loving and giving woman to the end. Did her loving personality, which my mother also had, give me an ability to bounce back time and time again. And was it my mother's mother, who ran the Philadelphia draft board way before women did that kind of thing, give me some of my drive to succeed?
It all makes sense when we look at what we already know from other sociological studies about the impact early life has on children, specifically where they grow up and the kind of nurturing they receive, will have a direct impact on their success – or inability to succeed.
When we hear stories of those who have overcome their beginnings, they attribute it to a person who believed in them. This research would say it may have been the character of the person, whose DNA they received, as well as their nurturing. It's an interesting idea.
The second study
looked at social stress and its impact on the development of breast cancer. Researchers looked at genes in fat cells in mammary glands of mice that had been given a genetically altered mouse model of triple-negative breast cancer. One part of the group was raised in isolation with no social support, an established model of chronic stress, and compared to those raised in small groups.
All the mice developed triple-negative breast tumors, but those that had been isolated developed much larger tumors. The reason, it seemed, was because those mice that were socially isolated at birth had fat cells that secreted substances that caused nearby precancerous epithelial cells to proliferate more rapidly, which accelerated the development of breast cancer.
The researchers were surprised to find no difference in circulating hormones between the two groups, but the fat cells in the mammary glands of the stressed mice had significant increases in the expression of three genes that are crucial to the use of glucose, the primary source of cellular energy. The increase in metabolic activity of the stressed group resulted in a cascade effect of the release of chemicals that resulted in the proliferation of epithelial cells in the mammary gland.
What would happen in human tissue is still to be explored, and I would like to see how immune function might ameliorate some of those insults.
These studies seem to say that where we come from, indeed the fabric of who we are and how we were treated as infants could impact us in ways not considered before.
What do you think?