Environmental Factor, November 2009, National Institute of Environmental Health Sciences
Editorial Recognizes NIEHS-Funded Research
By Laura Hall
A University of Southern California (USC) study on prenatal tobacco smoke (PTS) exposure and DNA methylation partially funded by NIEHS has been commended for the quality of the research. First author, Carrie Breton, ScD., is a USC assistant professor in the NIEHS-supported Southern California Environmental Health Science Center(http://hydra.usc.edu/scehsc/default.asp) (SCEHS). Second author, Hyang-Min Byun of the USC Department of Hematology, was an equal contributor.
"The results from Breton and colleagues provide a framework for further studies," wrote Seif Shaheen, Ph.D., and Ian Adcock, Ph.D., internationally recognized scientists of the National Heart and Lung Institute at the Imperial College London, in an American Journal of Respiratory and Critical Care Medicine editorial. They affirmed the need for epidemiological studies examining the effects of environmental exposures during prenatal and postnatal development to incorporate epigenetic analyses as Breton's study did.
Breton has received NIEHS support for much of her career. Her mentors see Breton as a rising star in epidemiology research. Director of Community Outreach and Education in the SCEHS Andrea Hricko declared, "I take some pride in Carrie's trajectory with our Center, since she was the first person we hired to work in the NIEHS Outreach Program a year after she finished her undergraduate education at Amherst."
While pursuing her master of public health degree, Breton worked under another NIEHS grantee, Beate Ritz, M.D., Ph.D., professor and vice chair of the Epidemiology Department at the University of California, Los Angeles (UCLA). Ritz is a member of the SCEHSC, the Center for Occupational Health, and co-directs the NIEHS-funded UCLA Center for Gene-Environment Studies of Parkinson's Disease.
Senior scientist, Frank Gilliland, M.D., Ph.D., director of the SCEHS said, "As Dr. Breton's primary mentor at USC, I have seen how NIEHS support and careful nuturing has led to her independence as a researcher and member of our faculty." He added that Breton has "demonstrated the ability to successfully direct research projects, all of which have resulted in original, quality scientific proposals."
Mentor John Peters, M.D., ScD., deputy director of the SCEHS who has known Breton for over 10 years said he has "witnessed her transition from budding young investigator to the independent faculty researcher she is today." He added, "Her strong foundation in epidemiologic principles, coupled with her dedication to environmental epidemiology and public health, promises a bright future for her forthcoming contributions to environmental health sciences."
In the PTS study, DNA from buccal scrapings of a subset of kindergarten and first grade children enrolled in the Children's Health Study was screened for global and gene-specific DNA methylation patterns. DNA methylation is an epigenetic factor that can prevent DNA and RNA replication machinery from accessing the DNA template. The result is that proteins that are coded for in the methylated genes are prevented from being made. These methylation patterns can persist for the life of the individual and be inherited by the next generation with no alteration of the DNA sequence.
PTS exposure has been shown to increase the risk of diseases such as asthma later in the child's life. How this association occurs is not well understood. Breton's study rationale was that the mechanism for this association could be alterations in DNA methylation. The study showed that children exposed to PTS have differences in global and gene-specific DNA methylation.
Editorial citation: Seif O. Shaheen and Ian M. Adcock.(http://ajrccm.atsjournals.org/cgi/content/full/180/8/690?ct=ct) 2009. The Developmental Origins of Asthma: Does Epigenetics Hold the Key? Am J Respir Crit Care Med 180(8):690-691.
Citation: Breton CV, Byun H-M, Wenten M, Pan F, Yang A, Gilliland FD.(http://www.ncbi.nlm.nih.gov/pubmed/19498054?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum) 2009. Prenatal tobacco smoke exposure affects global and gene-specific DNA methylation. Am J Respir Crit Care Med 180(5):462-467.
(Laura Hall is a biologist in the NIEHS Laboratory of Pharmacology currently on detail as a writer for the Environmental Factor.)