The Regulation of Tumor Suppressor Protein, p53, and Estrogen Receptor (ERá) by Resveratrol in Breast Cancer Cells

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 355-388-Sex Hormone Receptor Action & Reaction
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-380
Lisa Shammas*, Amy Elizabeth Siebert, Maria S Yonan, Nada Sitto, Omar Atcho, Michelle Nguyen, Meghan Quigley, Bryan Allender and Sumi Dinda
Oakland University, Rochester, MI
Resveratrol (Res) is a natural antioxidant abundantly found in grapes, peanuts, and berries and is known to possess anti-tumorgenic properties. Recently, this compound has become increasingly popular in cancer research; however, there is a noticeable lack of studies focused on the effects of resveratrol on the specific mechanism of tumor suppressors.  Previous studies from our lab have shown the tumor suppressor protein p53 and estrogen receptor (ERα) to be possible molecular targets for Res. The anti-estrogenic effects of Res were analyzed on the expression of ERα and p53 in this study. This was done in conjunction with hormonal and anti-hormonal treatments, as well as Bisphenol A (BPA). In order to deplete any endogenous steroids or effectors, breast cancer cells were cultured in medium containing 5% charcoal-stripped fetal bovine serum for six days. For 24h, the cells were treated with 60μM Res – the determined optimum after a concentration study of Res from 1 to 100μM. Protein was extracted, quantified, and subjected to SDS-PAGE and Western Blot analysis. Res caused a decrease in the levels of cellular p53 as well as in ERα, as compared to the control. Additionally, T47D cell proliferation was enumerated after Res treatments. Increasing concentrations of this compound caused a four-fold decrease in the number of cells as compared to estradiol. Res, in conjunction with ICI, caused a downregulation of both p53 and ERα, as compared to the control. Downregulation of p53 and upregulation of ERα were seen with the addition of Res with both the SERM Raloxifene, and the anti-estrogen ZK. The results of immunofluorescence, performed using laser scanning confocal microscopy, depicted levels of p53 and ERα that correlate with the Western Blot expression. Previously, our lab has shown that BPA has estrogen-like effects on p53 and ERα. When Res was combined with BPA, there was a downregulation of both the tumor suppressor p53 as well as the estrogen receptor; treatments of BPA alone did not produce this effect. These observed effects on cell proliferation and regulation of p53 and ERα by Resveratrol may lead to further understanding of the relationship between tumor suppressor proteins and steroid receptors in breast cancer cells.

Nothing to Disclose: LS, AES, MSY, NS, OA, MN, MQ, BA, SD

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