Biotransformed Soybean Extract Induces Cell Death of Estrogen-Dependent Breast Cancer Cells by Modulation of Apoptotic Proteins

• Published in: Nutrition and cancer Vol. 67; no. 4; pp. 612 - 619
• Main Authors: Stocco, Bianca, Toledo, Karina A, Fumagalli, Helen F, Bianchini, Francine J, Fortes, Vanessa S, Fonseca, Maria José V, Toloi, Maria Regina T
• Format: Journal Article
• Language: English
• Published: United States Routledge 19.05.2015; Taylor & Francis Ltd
• Subjects: Apoptosis; Apoptosis - drug effects; Aspergillus - metabolism; Biotransformation; breast neoplasms; Caspase 3 - genetics; Caspase 3 - metabolism; caspase-3; Cell Death - drug effects; Cell Line, Tumor; Cell Survival - drug effects; cell viability; Cells; Chromatography, High Pressure Liquid; daidzein; DNA; Estrogens; Flow cytometry; fungi; genistein; Genistein - pharmacology; Glycine max - chemistry; Glycine max - microbiology; hormone replacement therapy; Humans; Isoflavones - pharmacology; MCF-7 Cells; necrosis; neoplasm cells; Permeability; phosphatidylserines; Phytoestrogens - pharmacology; Plant Extracts - pharmacology; Proteins; Proto-Oncogene Proteins c-bcl-2 - genetics; Proto-Oncogene Proteins c-bcl-2 - metabolism; soybeans; Tumors; Western blotting
• ISSN: 1532-7914; 0163-5581; 1532-7914
• DOI: 10.1080/01635581.2015.1015744

The process of soybean biotransformation increases the quantity of isoflavones (daidzein and genistein), which besides being considered an alternative to estroprogestive hormone replacement therapy (HRT), are able of hindering the growth and development of tumor cells. We investigated the effects of soybean extract biotransformed by fungus on estrogen-dependent (MCF-7) and nondependent (SK-BR-3) breast cell lines. Cells were treated with different concentrations of biotransformed (BSE) and nonbiotransformed soybean extract (SE), or daidzein (D) and genistein (G) patterns isolated and in combination (D + G). Afterwards, we analyzed cell viability by MTT assay, phosphatidylserine exposure and cell permeability by flow cytometry; expression of apoptotic proteins by Western blotting. BSE promoted reduction in cell viability and increase in DNA degradation in both cell lines. In addition, we verified increase in cell permeability and in the expression of phosphatidylserine, as well as modulation in the expression of apoptotic proteins in MCF-7 cells. The cells did not show any signs of cell death when incubated with the controls (D, G, and D + G). Unknown components found in the BSE induce cell death by apoptosis and necrosis, mainly in MCF-7 cells. These processes depend on the activation of caspase-3 and involve an increase in the expression of proapoptotic molecules.