MON-250 - The Effects of Cyanidin (Natural Anthocyanin) on the Expression of Estrogen Receptor and Tumor Suppressor Gene BRCA-1 in Breast Cancer Cells

There is growing interest in naturally sourced compounds for their potential therapeutic benefits, especially as treatment options for diseases like breast cancer. Cyanidin (Cy), a naturally occurring Anthocyanin found in red and purple fruits (berries and grapes) and vegetables (cabbage), demonstrates potent antioxidant activity. Recent studies suggest that Cy may also serve as an anti-inflammatory agent, particularly in breast cancer, one of the most diagnosed cancers and a leading cause of cancer-related mortality among women. Despite its therapeutic potential, the biochemical mechanisms and signaling pathways that underlie the beneficial effects of Cy remain poorly understood. This study aims to investigate the effects of Cy on estrogen receptor alpha (ERα) and tumor suppressor genes, such as BRCA1, thereby positioning Cy as a promising candidate for breast cancer research. We examine the effects of Cy, alone and in combination with hormones and anti-hormones, on the expression of ERα and BRCA1 in two breast cancer cell lines, MCF-7 and T-47D. To evaluate the impact of Cy on ERα and BRCA1 expression at both the transcriptional and protein levels, we used Western blotting, cell viability assays, confocal microscopy, and RT-qPCR. To create treatment conditions devoid of endogenous steroids or growth factors, we cultured the cells in a medium containing 5% charcoal-stripped fetal bovine serum (FBS) for six days. For Western blot analyses, cells were exposed to Cy at concentrations ranging from 5 to 31 µM for 24 hours. Increased concentration-dependent expression with Cy was observed in ERα and BRCA1 in both cell lines, similar to controls. In our hormone experiments, we used an optimal concentration of 25 µM Cy, alone and in combination with hormones and anti-hormones. After 24 hours of treatment with Cy, estradiol (E2), and E2 combined with Cy, both ERα and BRCA1 expression decreased relative to controls. The combination of Cy with the anti-hormone ICI led to a notable downregulation of ERα and BRCA1 in T-47D cells, with similar results observed in MCF-7 cells under identical treatment conditions. To analyze Cy’s effects on cell viability in T-47D and MCF-7 cells, image cytometric analysis using propidium iodide staining was conducted. Cells treated for 6 days with 25 μM Cy, along with hormones and anti-hormones, showed reduced proliferation compared to controls in both lines. Cytolocalization studies of ERα revealed no significant changes following Cy treatment. Currently, RT-qPCR experiments are being conducted to clarify further the transcriptional regulation of steroid receptors in relation to tumor suppressor genes. Our findings support accumulating evidence on the molecular effects of Cy, suggesting its role in modulating steroid receptor signaling and tumor suppressor gene function in breast cancer.

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