• The Breast Cancer and the Environment Research Center
• Genomic Basis of Reproductive History in Breast Cancer
• Breast Cancer Therapy by Differentiation Gene Activation
• Estrogens and Breast Cancer
• Biomarkers of Exposure
• Biomarkers of Breast Cancer Prevention
• Epigenetic Control of Estrogen Induced Cell Transformation
• Prevention Trial in the use of r-hCG in Women of High Risk of Developing Breast Cancer
• Circadian Rhythm and Mammary Gland Development
• Fox Chase Cancer Center Breast Cancer Tissue Resources
• Characterization and Validation of Genomic Expression Signature of Pregnancy
• Epigenetic And Chromatin Remodeling Studies

Biomarkers of Exposure

The objective of this project is to determine whether genomic changes induced in the mammary gland of rats exposed to endocrine disruptors are also expressed in the blood and the buccal mucosa of the same animal. The rationale of this protocol is based on the need to translate this approach to humans in which exposure could be evaluated in the blood and buccal mucosa as a reflection on their effect in the breast tissue.

In this project it is our goal to develop sensitive and reproducible genomic and proteomic technologies for identification of biomarkers of exposure in girls (and rats as a model system) exposed to the environmental chemicals bisphenol A, phthalates (butyl benzyl phthalate (BBP) and/or di-2-ethylhexyl phthalate (DEHP)) and genistein, all which are measurable in the population and suspected to alter susceptibility for biochemical insult.  For this purpose we will use a two pronged approach – humans and animals –  for sourcing blood plasma/serum, buffy coat, and buccal mucosa. In the human studies, we will target girls who have elevated levels of one of the environmental chemicals selected, as determined by urine concentrations performed prospectively in the prepubertal period. For the animal studies, we will treat rats acutely and sub-chronically with the same compounds. (Figure 1: Click to see).

Figure 1: Lactating Sprague Dawley Rats were gavaged on days 2-20 postpartum with 0.25 and 250 mg DEHP/Kg BW to effect lactational exposure of the offspring. Rats were sacrificed at 21, 35 and 50 days postpartum.

In both humans and rats we will identify genomic and proteomic biomarkers and chemical blood levels as a means of comparing patterns of response to environmental chemicals across species. The exposure period will be (pre)pubertal, using biological fluids from girls to assess for changes in the onset of puberty as a consequence of exposure to these chemicals. These girls are part of ongoing U01 studies of the Breast Cancer and Environment Research Centers whereby puberty is being evaluated, and chemicals and their metabolites are being measured from the blood via the CDC. These samples are being/will be collected at time of puberty, defined as breast and pubic hair development in girls and vaginal opening in rats.

Our specific aims are:

1. To use state of the art technology to measure genomic biomarkers of exposure from blood serum and buffy coat, and buccal swabs from pubertal girls and rats exposed to bisphenol A, BBP and/or DEHP and genistein. Initially, genomic biomarkers will be identified via microarrays to identify differentially regulated genes following exposure of rats and girls to these chemicals. This will be followed by the use of low density arrays specifically designed to provide reliable and relatively quick identification of biomarkers of exposure in rodents and clinical samples.
   
2. To develop sensitive and reproducible methods to measure protein biomarkers of exposure in blood serum/plasma of girls and rats at time of puberty that are expressing high and low levels of bisphenol A, BBP and/or DEHP and genistein as indicative of exposure to these compounds. Initial studies will use 2-D gels and MALDI-TOF while developing more sensitive technology for biomarker identification via liquid chromatography and MS-TOF-TOF. This study is a consortium between the FCCC and the University of Alabama at Birmingham and the University of Cincinnati.

Main Publications Generated from this Project

• López, R., Russo, P., Pereira, J.S., Lamartiniere, C. and Russo, J. Optimal Protocol for RNA Purification from Rat Mammary Gland, Whole Blood, and Buccal Mucosa for Microarray Analyses. Proceeding of the GEI Exposure Biology, Organized by the NIEHS, Hyatt Regency Hotel, Bethesda, MS. January 24-25-2008.
• López, R., Russo, P., Pereira, J.S., Lamartiniere, C.  Biro, F. and Russo, J. RNA Purification from Human Whole Blood and Buccal Mucosa for Microarray Analyses. Proceeding of the GEI Exposure Biology, Organized by the NIEHS, Hyatt Regency Hotel, Bethesda, MS. January 24-25-2008.
• Lamartiniere, C.  Biro, F. and Russo, J Genomic and Proteomic Biomarkers of Biological Responses to Exposure (1U01ES016003-01) Proceeding of the GEI Exposure Biology, Organized by the NIEHS, Hyatt Regency Hotel, Bethesda, MS. January 24-25-2008.