Tiffany Holland

 Introduction: In recent years there has been an emergence of research investigating dietary isoflavones and its potential anti-breast cancer effects. Isoflavones are found in foods such as soy and legumes¹. Previous studies have suggested that isoflavones, especially genistein and daidzein, may play a role in breast cancer development, progression and metastasis. However, results of these studies vary and are often contradictory in its findings, raising the possibility that genistein and daidzein have varying effects depending on breast cancer type^2,3. Methods: Breast cancer cell lines T47D and MCF-7 were treated with genistein. Reactive oxygen species (ROS) levels was measured using Epix XL flow cytometer. PCR was completed for proteins SIRT1 and UCP2. Daidzein and R and S isomers of equol were added to highly metastatic receptor negative (ER-) breast cancer cell-line MDA-MB-231 in vitro using Matrigel invasion assay. Results: MCF-7 cells undergo cell proliferation and apoptosis inhibition when treated with genistein. SIRT1 and UCP2 proteins, markers of oxidative stress and ROS respectively, remained unchanged in the MCF-7 cell line. Conversely, T47D cells demonstrated antiproliferative effects, proapoptotic effects and increased mitochondrial functionality when treated with genistein. SIRT1 and UCP2 proteins increased in the T47D cell line ^2,3 . Daidzein, R and S-equol were all found to down-regulate matrix metalloproteinase-2, thereby inhibiting the invasion and metastasis of MDA-MD-231 human breast cancer cells. Conclusion: Overall, genistein had proapoptotic and antiproliferative effects in T47D cells, and apoptotic inhibitory and proliferative effects in MCF-7 breast cancer cells. These studies support the notion that isoflavones play varying roles depending on breast cancer type. Both genistein and daidzein appear to have potential anti-breast cancer effects. However, their anti-breast cancer effects are highly dependent on breast cancer type. In some instances, it may actually expediate breast cancer development. Dietary isoflavones have therapeutic potential, but further research is necessary to identify conditions in which isoflavones are beneficial.

1. Li Y, Li S, Meng X, Gan RY, Zhang JJ, Li HB. Dietary Natural Products for Prevention and Treatment of Breast Cancer. Nutrients. 2017;9(7):728.
2. Nadal-Serrano M, Pons DG, Sastre-Serra J, Blanquer-Rosselló M, Roca P, Oliver J. Genistein modulates oxidative stress in breast cancer cell lines according to ERα/ERβ ratio: Effects on mitochondrial functionality, sirtuins, uncoupling protein 2 and antioxidant enzymes. Int J Biochem Cell Biol. 2013; 45(9):2045-51.
3. Pons DG, Nadal-Serrano M, Blanquer-Rossello MM, Sastre-Serra J, Oliver J, Roca P. Genistein modulates proliferation and mitochondrial functionality in breast cancer cells depending on ERalpha/ERbeta ratio. J Cell Biochem. 2014; 115(5): 949-58.