Breast cancer gene expression assays

The test system was considerably less sensitive to endosulfan when mouse ER, rather than human ER, was used to mediate (3-gal activity (Ramamoorthy et al. 1997). In similar assays, endosulfan at 10 jM had no effect on (3-gal activity in yeast Saccharomyces) transfected with either the human or rainbow trout ER (Andersen et al. 1999). In addition, no effect was observed on transcriptional activation of HeLa cells transfected with plasmids containing an estrogen receptor as a responsive element (Shelby et al. 1996). Endosulfan also did not induce transient reporter gene expression in MCF-7 human breast cancer cells at an incubation concentration of 2.5 pM (Andersen et al. 1999). Maximum endosulfan-induced ER-mediated luciferase reporter gene expression occurred in vitro in a T47D human breast adenocarcinoma cell line at approximately 10 pM, while 50% expression of luciferase occurred at about 5.9 pM the maximum expression was approximately 59% of the effect from exposure to 0.03 nM estradiol (0.00003 pM) (Legler et al. 1999). Luciferase expression from combined treatment with endosulfan and dieldrin was additive over concentrations ranging from 3 to 8 pM. 

PCBs have been shown to have both estrogenic and anti-estrogenic properties. These properties of some commercial PCB mixtures, PCB congeners, and hydroxylated derivatives of PCB congeners have been assayed by examining uterine variables in immature or ovariectomized female rodents, cell proliferation or gene expression variables in cultured cells including human breast cancer or HeLa cells, and in vitro... 

Cl. Castello, R., Estelles, A., Vazquez, C., et al.. Quantitative real-time reverse transcription-PCR assay for urokinase plasminogen activator, plasminogen activator inhibitor type 1, and tissue metalloproteinase inhibitor type 1 gene expressions in primary breast cancer. Clin. Chem. 48, 1288-1295 (2002). 

Paik S. Development and chnical utility of a 21-gene recurrence score prognostic assay in patients with early breast cancer treated with tamoxifen. Oncologist 2007 12 631-635. Grant GR, Manduchi E, Stoeckert CJ, Jr. Analysis and management of microarray gene expression data. Curr Protoc Mol Biol 2007 Chapter 19 Units 19, 16. 

Kim, C. and Paik, S. 2010. Gene-expression-based prognostic assays for breast cancer. Nat Rev Clin Oncol 7 340-347. 

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