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Research Project
As a biochemistry co-op student from in the Zacharewski lab
I am involved in looking at both the effects of ethynyl estradiol
on the changes in gene expression in the mammary tissue and
the effects of 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD) on
the induction of the cyp1a1 and socs-2 promoters.
The first of these projects is to explore the dose related
changes in global gene expression patterns in the mammary tissues
of immature ovariectomized C57BL/6 mice treated with ethynyl
estradiol (EE), a synthetic estrogen. Mice were treated by oral
gavage with 0.1, 1, 10, 100 and 250 µg/kg EE or sesame
oil vehicle and organs were harvested after 24 hours (by Darrell
Boverhof). To assess the relative changes in transcription cDNA
microarrays were performed comparing the treated animals to
the vehicle controls. To further explore the patterns in gene
expression in the mammary gland due to treatment with EE, mice
were treated once or 3x24hr with 0.1mg/kg EE or vehicle and
organs were harvested at 0, 2, 4, 8, 12, 24 or 72 hrs (by Darrell
Boverhof). The levels of transcription of these genes will
be assessed by cDNA microarrays comparing treated animals to
their time-matched vehicles. This is being done under the guidance
of Dr. Jeremy Burt.
The socs-2 gene has been shown to be induced by TCDD in the
mouse liver. I am currently treating mouse Hepa1c1c7 cells with
TCDD that have been transfected with a pgl-basic reporter construct
containing the socs-2 promoter or the cyp1a1 promoter to verify
that TCDD has an effect on the transcription of these genes.
This experiment is also being performed on human lymphoma B
cells (CH12 LX) with the guidance of Darrell
Boverhof.
During my second semester in the Zacharewski lab I will be evaluating the synergistic, additive and/or antagonistic effects of estrogenic mixtures on global gene expression profiles in mouse liver using cDNA microarrays. Specifically I will be examining the effects of genistein (GEN), a phytoestrogen found most commonly in soy products, in mixtures with ethynyl estradiol (EE), an orally active estrogen. The in vivo model system under investigation is the liver tissue of immature, ovariectomized C57BL/6 mice. Mice were dosed with 5 concentrations of EE, GEN, or mixtures of the two in fixed ratios by oral gavage with a typical uterotrophic dosing regimen consisting of one daily dose for three consecutive days and necropsy performed 72 hours after the initial dose. Time matched vehicle control animals were used as reference in the study. Additionally, I will be performing parallel experiments of the above studies in vitro in mouse hepatocyte Hepa1c1c7 cells.
Other projects that I will be involved in will include the characterization of secreted proteins from Hepa1c1c7 cells treated with 2,3,7,8-tetrachlorodibenzodioxin (TCDD) using HPLC and mass spectrometry.
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