Environmental pollutant may promote obesity
A common environmental pollutant that is known to have a potent effect on gene activity may be promoting obesity, according to Japanese researchers.
Tributyltin is known to affect cell receptors in animals and humans at very low concentrations. Its harmful effect on the liver and the nervous and immune systems of mammals is well documented, however recently scientists have discovered that it also has potent effects on retinoid X receptors (RXRs), cellular components that mediate the biological effects of retinoids (chemical compounds that are chemically related to vitamin A). When activated, RXRs switch on genes that promote the growth of fat cells and switch off those that promote the breakdown of fat (lipolysis). Taisen Iguchi and Yoshinao Katsu, of the Graduate University for Advanced Studies in Japan, write that tributyltin is a potent activator of RXRs, and could thus promote obesity by increasing fat storage.
The authors conclude: The environment may play a significant role in obesity. Since the increase in obesity rates parallels the rapid growth in the use of industrial chemicals over the past 40 years, it is plausible and provocative to associate in utero or chronic lifetime exposure to chemical triggers present in the modern environment with this epidemic.
Eating eggs during pregnancy improves breast cancer outcome of offspring
New research suggests that what a woman eats during pregnancy may offer her offspring protection against breast cancer.
Researchers at Boston University studied female rats whose mothers were given different amounts of choline, a nutrient found in eggs, during pregnancy. The rats were given either no choline, normal amounts of choline, or extra choline during pregnancy, and, after birth, their female offspring were treated with a chemical that causes breast cancer. Whilst all of the female offspring went on to develop breast cancer, the results showed that offspring of the rats that had received extra choline during pregnancy had slow growing tumors whereas the offspring of rats that consumed no choline during pregnancy had fast growing tumors.
Furthermore, multiple genetic and molecular changes detected in the tumors were found to correlate with survival outcomes in humans. For example, the slow growing tumors in the offspring of rats fed extra choline had a genetic pattern similar to those seen in breast cancers of women who are considered to have a good prognosis, whereas the genetic changes that occurred in the fast growing tumors were similar to those seen in women with very aggressive forms of breast cancer that are associated with a poor prognosis.
The authors concluded: Our results suggest a role for adequate maternal choline nutrition during pregnancy in prevention/alleviation of breast cancer in daughters.
Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal, in which the research was published, said: The emerging science of epigenetics has yielded a breakthrough. For the first time, we’ve learned that we might be able to prevent breast cancer as early as a mother’s pregnancy.”