Metformin as a Potential Therapeutic Agent in Breast Cancer: Targeting miR-125a Methylation and Epigenetic Regulation

• Published in: International journal of molecular and cellular medicine Vol. 13; no. 3; pp. 272 - 285
• Main Authors: Ahmadpour, Fatemeh, Igder, Somayeh, Eftekhari Moghadam, Ali Reza, Moradipoodeh, Bahman, Sepahdar, Asma, Mokarram, Pooneh, Fallahi, Jafar, Mohammadzadeh, Ghorban
• Format: Journal Article
• Language: English
• Published: Babol, Iran Babol University of Medical Sciences 01.01.2024
• Subjects: Original
• ISSN: 2251-9637; 2251-9645
• DOI: 10.22088/IJMCM.BUMS.13.3.272

Breast cancer, characterized by genetic diversity and molecular subtypes, presents significant treatment challenges, especially in human epidermal growth factor receptor type 2 (HER2)-positive cases, which are associated with poor prognosis. Metformin, widely known for its antidiabetic effects, has emerged as a promising candidate for cancer therapy. This study investigates the effect of metformin on miR-125a promoter methylation and its subsequent impact on the HER2 signaling pathway in HER2-positive breast cancer cells (SK-BR3). SK-BR3 cells were cultured and treated with various concentrations of metformin to assess its effects on cell viability, DNA methylation, HER2, and DNA Methyltransferase 1 (DNMT1) expression. Molecular analyses focus on the miR-125a signaling pathway modulation, DNA methylation, mRNA expression of DNMT1, and protein level of HER2. Research showed a dose-dependent reduction in cell viability, with IC50 values from 65 mM at 48 hours to 35 mM at 72 hours. Metformin treatment led to demethylation of the miR-125a promoter, which increased miR-125a expression and subsequently reduced HER2 levels. This suggests that metformin exerts its anticancer effects partly by regulation of the miR-125a-HER2 axis. Additionally, metformin inhibited vimentin expression, indicating its potential to interfere with epithelial-mesenchymal transition (EMT) processes. Metformin may serve as a targeted therapeutic agent in HER2-positive breast cancer by modulating the miR-125a-HER2 axis and influencing on the epigenetic and EMT regulation. Further research is warranted to elucidate the therapeutic potential of metformin through these mechanisms.Breast cancer, characterized by genetic diversity and molecular subtypes, presents significant treatment challenges, especially in human epidermal growth factor receptor type 2 (HER2)-positive cases, which are associated with poor prognosis. Metformin, widely known for its antidiabetic effects, has emerged as a promising candidate for cancer therapy. This study investigates the effect of metformin on miR-125a promoter methylation and its subsequent impact on the HER2 signaling pathway in HER2-positive breast cancer cells (SK-BR3). SK-BR3 cells were cultured and treated with various concentrations of metformin to assess its effects on cell viability, DNA methylation, HER2, and DNA Methyltransferase 1 (DNMT1) expression. Molecular analyses focus on the miR-125a signaling pathway modulation, DNA methylation, mRNA expression of DNMT1, and protein level of HER2. Research showed a dose-dependent reduction in cell viability, with IC50 values from 65 mM at 48 hours to 35 mM at 72 hours. Metformin treatment led to demethylation of the miR-125a promoter, which increased miR-125a expression and subsequently reduced HER2 levels. This suggests that metformin exerts its anticancer effects partly by regulation of the miR-125a-HER2 axis. Additionally, metformin inhibited vimentin expression, indicating its potential to interfere with epithelial-mesenchymal transition (EMT) processes. Metformin may serve as a targeted therapeutic agent in HER2-positive breast cancer by modulating the miR-125a-HER2 axis and influencing on the epigenetic and EMT regulation. Further research is warranted to elucidate the therapeutic potential of metformin through these mechanisms.