A collaborative team of international researchers led by Dr. Robert Waterland, PhD, associate professor of pediatrics and nutrition at Baylor College of Medicine (BCM) and the USDA/ARS Children’s Nutrition Research Center at Baylor and Texas Children’s Hospital, has made an important discovery that may lead to significant changes in how the medical establishment views the importance of a woman’s nutritional intake while she is trying to conceive. Their study, entitled, “Independent genome-wide screens identify the tumor suppressor VTRNA2-1 as a human epiallele responsive to periconceptional environment,” which was published in the latest edition of the journal Genome Biology, found that the impact of a mother’s nutritional choices during the time of conception could possibly contribute to her child’s lifetime cancer risk.
- Epigenetics: the study of external or environmental factors that turn genes on and off and affect how cells read genes.
- DNA methylation: is a process in which methyl groups (CH3) are added to DNA resulting in a modification of its function as a genetic code. This process is essential for normal development and is associated with a number of key processes, such as, carcinogenesis.
- Tumor suppressor genes: is a gene that protects a cell from one step on the path to cancer. When this gene mutates to cause a loss or reduction in its function, the cell can progress to cancer, usually in combination with other genetic changes.
About the Study:
This study builds upon Dr. Waterland’s previous research showing that maternal nutritional status during early pregnancy causes persistent and systemic epigenetic changes in human metastable epialleles, special regions of the genome that are highly sensitive to DNA methylation. To investigate whether these epigenetic changes could be a possible result of a woman’s nutritional intake even before conception, the researchers conducted 2 different genome-wide surveys in a population of women in Gambia, where changing seasonal availability of food created a natural experiment in which a comparison could be made amongst women who conceived during times of food abundance versus those in times of famine.
A major finding from both surveys showed that VTRNA2-1, a tumor suppressor gene associated with carcinogenesis, is influenced by a woman’s nutritional intake, and that this influence could contribute to her child’s lifetime cancer risk.
In a BCM press release about the study, Dr. Waterland, stated, “There are around 20,000 genes in the human genome. So for our two groups, taking different approaches, to identify this same gene as the top epiallele was like both of us digging into different sides of a gigantic haystack containing 20,000 needles… and finding the exact same needle.”
Dr. Waterland’s colleague and study co-author, Professor Andrew Prentice at the London School of Hygiene & Tropical Medicine, and head of the MRC International Nutrition Group said, “Our results show that the methylation marks that regulate VTRNA2-1 imprinting are lost in some people, and that this ‘loss of imprinting’ is determined by maternal nutrition around the time of conception. These are large changes in gene methylation that affect a substantial subset of individuals.”
Dr. Waterland and his team plan to conduct future studies investigating the relationship between maternal obesity, the effect of IVF, as well as, environmental contaminants such as pollution or cigarette smoke, on epigenetic variations that may lead to changes in the risk of diseases such as, cancer and auto-immune disorders.
The Children’s Nutrition Research Center is one of six USDA human nutrition research centers conducting scientific investigations designed to provide Americans with a clear understanding of the role of nutrition in maintaining a healthy, active life.
As the first federal nutrition research center to investigate the nutritional needs of pregnant and nursing women and children from conception through adolescence, the CNRC conducts research that helps define guidelines for maternal, infant and childhood nutrition.
The CNRC is operated by Baylor College of Medicine in cooperation with Texas Children’s Hospital and the Agricultural Research Service of the U.S. Department of Agriculture. The center has approximately 50 faculty members conducting nutrition-related research and a total staff of more than 200.
Since its establishment in 1978, center research has generated almost 2,000 scientific publications and continues to provide valuable information for improving the nutritional health of today’s children and that of future generations.