Induction and characterization of de novo methylation by benzo[A]pyrene in the cancer cell lines MCF-7 and MDA-MB-231

Citation data:

Page: 54

Publication Year:
2005
Usage 2
Abstract Views 2
Repository URL:
https://scholarlycommons.pacific.edu/uop_etds/609
Author(s):
Kozina, Vladimir Joseph
Tags:
University of the Pacific Dissertations;Breast Cancer;DNA Methylation;Carcinogenesis Molecular aspects; Life Sciences
thesis / dissertation description
The experiments presented were designed to test the hypothesis that the well-known carcinogen, benzo[a]pyrene has epigenetic effects, specifically the ability to alter cytosine methylation patterns. MCF-7 and MDA-MB-231 human breast cancer cells were treated for a period of sixty days with 100 nM benzo[a]pyrene. The methylation status of two genes, Ecadherin and GSTP 1 were examined using methyl-specific PCR and Southern blot analysis. After sixty days, no detectable change in methylation was observed. Evidence exists that de novo methylation is a consequence of transcriptional inactivity. Benzo[a]pyrene can contribute to transcriptional repression by sequestering the transcription factor, Spl. To test this hypothesis in our system, MCF-7 cells were transiently transfected with a reporter construct containing Sp 1 sites. These experiments demonstrated an 8.4 fold increase in reporter gene activity over a promoterless control plasmid; however, a difference could not be established between benzo[a]pyrene-treated and untreated cells.