Abstract
The participation of oxidative stress in the mechanism of metformin action in breast cancer remains unclear. We investigated the effects of clinical (6 and 30 μM) and experimental concentrations of metformin (1000 and 5000 μM) in MCF-7 and in MDA-MB-231 cells, verifying cytotoxicity, oxidative stress, DNA damage, and intracellular pathways related to cell growth and survival after 24 h of drug exposure. Clinical concentrations of metformin decreased metabolic activity of MCF-7 cells in the MTT assay, which showed increased oxidative stress and DNA damage, although cell death and impairment in the proliferative capacity were observed only at higher concentrations. The reduction in metabolic activity and proliferation in MDA-MB-231 cells was present only at experimental concentrations after 24 h of drug exposition. Oxidative stress and DNA damage were induced in this cell line at experimental concentrations. The drug decreased cytoplasmic extracellular signal-regulated kinases 1 and 2 (ERK1/2) and AKT and increased nuclear p53 and cytoplasmic transforming growth factor β1 (TGF-β1) in both cell lines. These findings suggest that metformin reduces cell survival by increasing reactive oxygen species, which induce DNA damage and apoptosis. A relationship between the increase in TGF-β1 and p53 levels and the decrease in ERK1/2 and AKT was also observed. These findings suggest the mechanism of action of metformin in both breast cancer cell lineages, whereas cell line specific undergoes redox changes in the cells in which proliferation and survival signaling are modified. Taken together, these results highlight the potential clinical utility of metformin as an adjuvant during the treatment of luminal and triple-negative breast cancer.
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Abbreviations
- ERK1/2:
-
Extracellular signal-regulated kinases 1 and 2
- AKT:
-
Protein kinase B
- TGF-β1:
-
Transforming growth factor β1
- AMPK:
-
Adenosine-5′-monophosphate-activated protein kinase
- mTOR:
-
Mammalian target of rapamycin
- HER-2:
-
Human epidermal growth factor receptor 2
- TNBC:
-
Triple-negative breast cancer
- MTT:
-
2-(3,5-Diphenyltetrazol-2-ium-2-yl)-4,5-dimethyl-1,3-thiazole bromide
- PBS:
-
Phosphate-buffered saline
- EB:
-
Ethidium bromide
- AO:
-
Acridine orange
- MDA:
-
Malondialdehyde
- 8-Oh-dG:
-
8-Hydroxy-2-deoxyguanosine
- ANOVA:
-
Analysis of variance
- SOD:
-
Superoxide dismutase
- OS:
-
Oxidative stress
- ROS:
-
Reactive oxygen species
References
Aksoy S, Sendur MA, Altundag K. Demographic and clinico-pathological characteristics in patients with invasive breast cancer receiving metformin. Med Oncol. 2013;30(2):590–6.
Dowling RJ, Niraula S, Stambolic V, Goodwin PJ. Metformin in cancer: translational challenges. J Mol Endocrinol. 2012;48(3):31–43.
Dowling RJ, Zakikhani M, Fantus IG, Pollak M, Sonenberg N. Metformin inhibits mammalian target of rapamycin-dependent translation initiation in breast cancer cells. Cancer Res. 2007;67(22):10804–12.
Martinez-Outschoorn UE, Goldberg A, Lin Z, Ko Y, Flomenberg N, Wang C, et al. Anti-estrogen resistance in breast cancer is induced by the tumor microenvironment and can be overcome by inhibiting mitochondrial function in epithelial cancer cells. Cancer Biol Ther. 2011;12(10):924–38.
Campagnoli C, Berrino F, Venturelli E, Abbà C, Biglia N, Brucato T, et al. Metformin decreases circulating androgen and estrogen levels in nondiabetic women with breast cancer. Clin Breast Cancer. 2013;13(6):433–8.
Hadad SM, Hardie DG, Appleyard V, Thompson AM. Effects of metformin on breast cancer cell proliferation, the AMPK pathway and the cell cycle. Clin Transl Oncol. 2014;16(8):746–52.
Ishibashi Y, Matsui T, Takeuchi M, Yamagishi S. Metformin inhibits advanced glycation end products (AGEs)-induced growth and VEGF expression in MCF-7 breast cancer cells by suppressing AGEs receptor expression via AMP-activated protein kinase. Horm Metab Res. 2013;45(5):387–90.
Song CW, Lee H, Dings RP, Williams B, Powers J, Santos TD, et al. Metformin kills and radiosensitizes cancer cells and preferentially kills cancer stem cells. Sci Rep. 2012;2:362.
Malki A, Youssef A. Antidiabetic drug metformin induces apoptosis in human MCF breast cancer via targeting ERK signaling. Oncol Res. 2011;19(6):275–85.
Gago-Dominguez M, Jiang X, Castelao JE. Lipid peroxidation, oxidative stress genes and dietary factors in breast cancer protection: a hypothesis. Breast Cancer Res. 2007;9:201–12.
Panis C, Herrera AC, Victorino VJ, Campos FC, Freitas LF, De Rossi T, et al. Oxidative stress and hematological profiles of advanced breast cancer patients subjected to paclitaxel or doxorubicin chemotherapy. Breast Cancer Res Treat. 2012;133(1):89–97.
Queiroz EAIF, Puukila S, Eichler R, Sampaio SC, Forsyth HL, Lees SJ, et al. Metformin induces apoptosis and cell cycle arrest mediated by oxidative stress, AMPK and FOXO3a in MCF-7 breast cancer cells. Plos One. 2014;9(5):e98207.
Ringnér M, Staaf J, Jonsson G. Nonfamilial breast cancer subtypes. Methods Mol Biol. 2013;973:279–95.
Morris GJ, Naidu S, Topham AK, Guiles F, Xu Y, Mccue P, et al. Differences in breast carcinoma characteristics in newly diagnosed African-American and Caucasian patients: a single-institution compilation compared with the National Cancer Institute’s Surveillance, Epidemiology, and End Results database. Cancer. 2007;110(4):876–84.
Barcellos-Hoff MH, Akhurst RJ. Transforming growth factor-β in breast cancer: too much, too late. Breast Cancer Res. 2009;11:202–8.
Luo J, Manning BD, Cantley LC. Targeting the PI3K-Akt pathway in human cancer: rationale and promise. Cancer Cell. 2003;4(4):257–62.
Miller LD, Smeds J, George J, Vega VB, Vergara L, Ploner A, et al. An expression signature for p53 status in human breast cancer predicts mutation status, transcriptional effects, and patient survival. Proc Natl Acad Sci U S A. 2005;102(38):13550–5.
Mosmann T. Rapid colorimetric assay for cellular growth and survival: application to proliferation cytotoxic assays. J Immunol Methods. 1983;65:55–63.
Borenfreund E, Puerner JA. A simple quantitative procedure using monolayer cultures for cytotoxicity assays (HTD/NR-90). J Tissue Cult Methods. 1984;9(1):7–9.
Halliwell B, Gutteridge JMC. Free radical in biology and medicine. 4th ed. New York: Oxford University Press; 2007.
Michaeli A, Feitelson J. Reactivity of singlet oxygen toward amino acids and peptides. Photochem Photobiol. 1994;59:284–98.
Simic MG. Peroxyl radical from oleic acid. In: Simic MG, editor. Autoxidation in food and biological systems. New York: Plenum; 1980. p. 17–26.
Sun Y, Li Y, Wu H, Wu S, Wang YA, Luo D, et al. Effects of an indolocarbazole-derived CDK4 inhibitor on breast cancer cells. J Cancer. 2011;2:36–51.
Aebi H. Catalase in vitro. Methods Enzymol. 1984;105:121–6.
Hu ML. Measurement of protein thiol groups and glutathione in plasma. Methods Enzymol. 1994;233:380–5.
Gonzalez-Flecha B, Llesuy S, Boveris A. Hydroperoxide-initiated chemiluminescence: an assay for oxidative stress in biopsies of heart, liver, and muscle. Free Radic Biol Med. 1991;10(2):93–100.
Victorino VJ, Panis C, Campos FC, Cayres RC, Colado-Simão AN, Oliveira SR, et al. Decreased oxidant profile and increased antioxidant capacity in naturally postmenopausal women. AGE. 2013;35:1411–21.
Tice RR, Agurell E, Anderson D, Burlinson B, Hartmann A, Kobayashi H, et al. Single cell gel/comet assay: guidelines for in vitro and in vivo genetic toxicology testing. Environ Mol Mutagen. 2000;35:206–21.
Hartmann A, Agurell E, Beevers S, Brendler-Schwaab S, Burlinson B, Clay P, et al. Recommendations for conducting the in vivo alkaline comet assay. Mutagenesis. 2003;18(1):45–51.
Wurth R, Barbieri F, Florio T. New molecules and old drugs as emerging approaches to selectively target human glioblastoma cancer stem cells. Biomed Res Int. 2014;2014:126586.
Lee H, Park HJ, Park CS, Oh ET, Choi BH, Williams B, et al. Response of breast cancer cells and cancer stem cells to metformin and hyperthermia alone or combined. PLoS One. 2014;9(2):e87979.
Lin YC, Wu MH, Wei TT, Lin YC, Huang WC, et al. Metformin sensitizes anticancer effect of dasatinib in head and neck squamous cell carcinoma cells through AMPK-dependent ER stress. Oncotarget. 2013;5(1):298–308.
Gonzalez-Ângulo AM, Meric-Bernstam F. Metformin: a therapeutic opportunity in breast cancer. Clin Cancer Res. 2012;16(6):1695–700.
Zhuang Y, Miskimins WK. Metformin induces both caspase-dependent and poly(ADP-ribose) polymerase-dependent cell death in breast cancer cells. Mol Cancer Res. 2011;9(5):603–15.
Hadad SM, Hardie DG, Appleyard V, Thompson AM. Effects of metformin on breast cancer cell proliferation, the AMPK pathway and the cell cycle. Clin Transl Oncol. 2014;16:746–51.
Zordoky BNM, Bark D, Soltys CL, Sung MM, Dyck JRB. The anti-proliferative effect of metformin in triple-negative MDA-MB-231 breast cancer cells is highly dependent on glucose concentration: implications for cancer therapy and prevention. Biochim Biophys Acta. 2014;1840(6):1943–57.
Hasty P, Christy BA. p53 as an intervention target for cancer and aging. Pathobiol Aging Age Relat Dis. 2013;3:22702.
Jin S, Levine AJ. The p53 functional circuit. J Cell Sci. 2001;114:4139–40.
Feng Z, Zhang H, Levine AJ, Jin S. The coordinate regulation of the p53 and mTOR pathways in cells. Proc Natl Acad Sci U S A. 2005;102(23):8204–9.
Santarpia L, Lippman SL, El-Naggar AK. Targeting the MAPK-RAS-RAF signaling pathway in cancer therapy. Expert Opin Ther Targets. 2012;16(1):103–19. doi:10.1517/14728222.2011.645805.
Krstic J, Trivanovic D, Mojsilovic S, Santibanez JF. Transforming growth factor-beta and oxidative stress interplay: implications in tumorigenesis and cancer progression. Oxid Med Cell Longev. 2015;2015(654594):15.
Qi S, den Hartog GJ, Bast A. Superoxide radicals increase transforming growth factor-beta1 and collagen release from human lung fibroblasts via cellular influx through chloride channels. Toxicol Appl Pharmacol. 2009;237(1):111–8.
Acknowledgments
The authors are grateful to J.A. Vargas and P.S.R. Dionízio-Filho, from the Department of General Pathology of the State University of Londrina, for their excellent technical assistance.
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Supplementary Figure 1
Metformin increases nuclear p53 levels and cytoplasmic TGF-β1 levels and reduces cytoplasmic ERK1/2 and AKT in human breast cancer cells. Immunocytochemistry analysis of MCF-7 cells (a) and MDA-MB-231 cells (b) exposed to different metformin concentrations (6, 30, 1000, and 5000 μM) for 24 h. Illustrative panel showing a picture selected for each experimental condition. For the metformin 5000 μM, where the effects were more pronounced, a picture focusing on a single cell was selected (GIF 340 kb).
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Marinello, P.C., da Silva, T.N.X., Panis, C. et al. Mechanism of metformin action in MCF-7 and MDA-MB-231 human breast cancer cells involves oxidative stress generation, DNA damage, and transforming growth factor β1 induction. Tumor Biol. 37, 5337–5346 (2016). https://doi.org/10.1007/s13277-015-4395-x
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DOI: https://doi.org/10.1007/s13277-015-4395-x