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Analysis of the aryl hydrocarbon receptor and a truncated form (AHR C[upper case symbol for greek Delta]Δ553) in cancer cells

The aryl hydrocarbon receptor (AhR) is a ligand-activated bHLH-PAS protein that binds its partner, the aryl hydrocarbon receptor nuclear translocator (Arnt), in the nucleus to initiate the expression of proteins involved with detoxification. Published work suggests cross-talk between both proteins and cellular pathways involving the transcription factors, HIF -1 , ER, and NFKB, whose activity is typically upregulated in cancer. This thesis focuses on using a truncated form of AhR, AhR CΔ553, which is thought to act as a dominant-negative to sequester Arnt from its other binding partners. To test this hypothesis, we transfected HeLa cells with AhR CΔ553 fused to pEGFP or a vector under a tetracycline-inducible promoter. Stable cell lines expressing pEGFP-AhR CΔ553 have been generated and confirmed to have nuclear localization. We were also interested in confirming endogenous localization patterns of AhR and Arnt to study the role of p23 in the nuclear translocation of AhR. While we were successful in showing AhR translocating to the nucleus in treated MCF-7 cells, we couldn't clearly see nuclear AhR in Hepalclc7 cells, the cell line with knockdown levels of p23. To compare DNA damage generated in Jm·kat and Hepalclc7 cells, we looked for reactive oxygen species (ROS) production and quantified DNA damage after exposure to benzo[a]pyrene (B[a]P) and some of its derivatives. Hepalclc7 cells were prone to a wide variety of DNA damage, but Jurkat cells did not appear to undergo damage specifically through ROS production. Finally, we wanted to confirm apoptosis in HeLa cells after being cocultured with Trichomonas vaginalis. The G3 lab strain was more aggressive than Tl , but Parp, and apoptotic marker, was not observed in HeLa cells, suggesting that experimental conditions need to be further optimized.

Identiferoai:union.ndltd.org:pacific.edu/oai:scholarlycommons.pacific.edu:uop_etds-1792
Date01 January 2011
CreatorsChow, Marilynn
PublisherScholarly Commons
Source SetsUniversity of the Pacific
Detected LanguageEnglish
Typetext
Formatapplication/pdf
SourceUniversity of the Pacific Theses and Dissertations

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