251
|
|
252
|
Quinn BJ, Kitagawa H, Memmott RM, Gills JJ, Dennis PA. Repositioning metformin for cancer prevention and treatment. Trends Endocrinol Metab 2013; 24:469-80. [PMID: 23773243 DOI: 10.1016/j.tem.2013.05.004] [Citation(s) in RCA: 216] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 05/07/2013] [Accepted: 05/16/2013] [Indexed: 12/19/2022]
Abstract
Metformin is the most commonly prescribed drug for type 2 diabetes (T2DM). Retrospective studies show that metformin is associated with decreased cancer risk. This historical correlation has driven vigorous research campaigns to determine the anticancer mechanisms of metformin. Consolidating the preclinical data is a challenge because unanswered questions remain concerning relevant mechanisms, bioavailability, and genetic factors that confer metformin sensitivity. Perhaps the most important unanswered question is whether metformin has activity against cancer in non-diabetics. In this review we highlight the proposed mechanisms of metformin action in cancer and discuss ongoing clinical trials with metformin in cancer. Improved understanding of these issues will increase the chances for successful application of metformin as an inexpensive, well-tolerated, and effective anticancer agent.
Collapse
Affiliation(s)
- Brendan J Quinn
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
| | | | | | | | | |
Collapse
|
253
|
Anisimov VN, Bartke A. The key role of growth hormone-insulin-IGF-1 signaling in aging and cancer. Crit Rev Oncol Hematol 2013; 87:201-23. [PMID: 23434537 PMCID: PMC4095988 DOI: 10.1016/j.critrevonc.2013.01.005] [Citation(s) in RCA: 149] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Revised: 12/22/2012] [Accepted: 01/18/2013] [Indexed: 12/14/2022] Open
Abstract
Studies in mammals have led to the suggestion that hyperglycemia and hyperinsulinemia are important factors in aging. GH/Insulin/insulin-like growth factor-1 (IGF-1) signaling molecules that have been linked to longevity include daf-2 and InR and their homologues in mammals, and inactivation of the corresponding genes increases lifespan in nematodes, fruit flies and mice. The life-prolonging effects of caloric restriction are likely related to decreasing IGF-1 levels. Evidence has emerged that antidiabetic drugs are promising candidates for both lifespan extension and prevention of cancer. Thus, antidiabetic drugs postpone spontaneous carcinogenesis in mice and rats, as well as chemical and radiation carcinogenesis in mice, rats and hamsters. Furthermore, metformin seems to decrease the risk for cancer in diabetic patients.
Collapse
Affiliation(s)
- Vladimir N Anisimov
- Department of Carcinogenesis and Oncogerontology, N.N. Petrov Research Institute of Oncology, St. Petersburg, Russia.
| | | |
Collapse
|
254
|
Pernemalm M, De Petris L, Branca RM, Forshed J, Kanter L, Soria JC, Girard P, Validire P, Pawitan Y, van den Oord J, Lazar V, Påhlman S, Lewensohn R, Lehtiö J. Quantitative proteomics profiling of primary lung adenocarcinoma tumors reveals functional perturbations in tumor metabolism. J Proteome Res 2013; 12:3934-43. [PMID: 23902561 DOI: 10.1021/pr4002096] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In this study, we have analyzed human primary lung adenocarcinoma tumors using global mass spectrometry to elucidate the biological mechanisms behind relapse post surgery. In total, we identified over 3000 proteins with high confidence. Supervised multivariate analysis was used to select 132 proteins separating the prognostic groups. Based on in-depth bioinformatics analysis, we hypothesized that the tumors with poor prognosis had a higher glycolytic activity and HIF activation. By measuring the bioenergetic cellular index of the tumors, we could detect a higher dependency of glycolysis among the tumors with poor prognosis. Further, we could also detect an up-regulation of HIF1α mRNA expression in tumors with early relapse. Finally, we selected three proteins that were upregulated in the poor prognosis group (cathepsin D, ENO1, and VDAC1) to confirm that the proteins indeed originated from the tumor and not from a stromal or inflammatory component. Overall, these findings show how in-depth analysis of clinical material can lead to an increased understanding of the molecular mechanisms behind tumor progression.
Collapse
Affiliation(s)
- Maria Pernemalm
- Cancer Proteomics Mass Spectrometry, Department of Oncology-Pathology, Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
255
|
Morgillo F, Sasso FC, Della Corte CM, Festino L, Manzo A, Martinelli E, Troiani T, Capuano A, Ciardiello F. Metformin in lung cancer: rationale for a combination therapy. Expert Opin Investig Drugs 2013; 22:1401-9. [PMID: 23937224 DOI: 10.1517/13543784.2013.828691] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
INTRODUCTION Metformin is a widely used antidiabetic drug, which also displays significant growth inhibitory and proapoptotic effects in several cancer models, including lung cancer, alone or in combination with chemotherapeutic drugs. AREAS COVERED The role of metformin as a chemopreventive drug in lung cancer is still an object of debate as epidemiological studies have shown contrasting results. More preclinical data support its role as an adjuvant drug in the treatment of lung cancer, in combination with chemotherapy or targeted molecular drugs, although the complete mechanism of action of metformin is still unclear, and potentially may exert unexpected effects with contradictory clinical implications. EXPERT OPINION Future perspective studies are required in nonsmall-cell lung cancer (NSCLC) patients to better investigate the effect of metformin action on the RAS/RAF/MAPK pathway and the best context in which to use metformin in combination with molecularly targeted agents.
Collapse
Affiliation(s)
- Floriana Morgillo
- Oncologia Medica, Medicina Interna , Via S. Pansini 5, 80131 Napoli , Italia
| | | | | | | | | | | | | | | | | |
Collapse
|
256
|
Blagosklonny MV. Common drugs and treatments for cancer and age-related diseases: revitalizing answers to NCI's provocative questions. Oncotarget 2013; 3:1711-24. [PMID: 23565531 PMCID: PMC3681506 DOI: 10.18632/oncotarget.890] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
In 2011, The National Cancer Institute (NCI) has announced 24 provocative questions on cancer. Some of these questions have been already answered in “NCI's provocative questions on cancer: some answers to ignite discussion” (published in Oncotarget, 2011, 2: 1352.) The questions included “Why do many cancer cells die when suddenly deprived of a protein encoded by an oncogene?” “Can we extend patient survival by using approaches that keep tumors static?” “Why are some disseminated cancers cured by chemotherapy alone?” “Can we develop methods to rapidly test interventions for cancer treatment or prevention?” “Can we use our knowledge of aging to enhance prevention or treatment of cancer?” “What is the mechanism by which some drugs commonly and chronically used for other indications protect against cancer?” “How does obesity contribute to cancer risk?” I devoted a single subchapter to each the answer. As expected, the provocative questions were very diverse and numerous. Now I choose and combine, as a single problem, only three last questions, all related to common mechanisms and treatment of age-related diseases including obesity and cancer. Can we use common existing drugs for cancer prevention and treatment? Can we use some targeted “cancer-selective” agents for other diseases and … aging itself.
Collapse
Affiliation(s)
- Mikhail V Blagosklonny
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY, USA.
| |
Collapse
|
257
|
Marzbani E, Inatsuka C, Lu H, Disis ML. The invisible arm of immunity in common cancer chemoprevention agents. Cancer Prev Res (Phila) 2013; 6:764-73. [PMID: 23918793 PMCID: PMC3773490 DOI: 10.1158/1940-6207.capr-13-0036] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Immunoprevention refers to a strategy of preventing pathogen-associated and spontaneous cancers through the use of vaccines, antibodies, and immune modulators. Immune modulators function by enhancing the endogenous ability of the immune system to monitor for malignancy, so-called "immunosurveillance." There is growing evidence that many of the most promising cancer chemoprevention agents including aspirin, COX-2 inhibitors, aromatase inhibitors, and bisphosphonates mediate their effects, in part, by enhancing immunosurveillance and reversing the immune evasive mechanisms that premalignant lesions use. In the following review, we introduce critical components of the human immune surveillance system-dendritic cells, T cells, and immune suppressive cells-and discuss the emerging data suggesting that common chemoprevention agents may modulate the function of these immunologic cells.
Collapse
Affiliation(s)
- Edmond Marzbani
- Tumor Vaccine Group, University of Washington, Box 358050, Seattle, WA 98109, USA.
| | | | | | | |
Collapse
|
258
|
Muaddi H, Chowdhury S, Vellanki R, Zamiara P, Koritzinsky M. Contributions of AMPK and p53 dependent signaling to radiation response in the presence of metformin. Radiother Oncol 2013; 108:446-50. [PMID: 23891087 DOI: 10.1016/j.radonc.2013.06.014] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2013] [Revised: 06/08/2013] [Accepted: 06/11/2013] [Indexed: 11/25/2022]
Abstract
BACKGROUND AND PURPOSE Metformin is commonly prescribed to treat type 2 diabetes, and has additional potential as a cancer prophylactic and therapeutic. Metformin activates AMPK that in turn can launch a p53-dependent metabolic checkpoint. Possible interactions between metformin and radiation are poorly understood. Since radiation-induced signaling also involves AMPK and p53, we investigated their importance in mediating responses to metformin and radiation. MATERIALS AND METHODS A549 cells, HCT116 cells wildtype or knockout for p53 or MEFs wildtype or double knockout for AMPKα1 and α2 were irradiated in the presence or absence of metformin. The impact of metformin on oxygen consumption and proliferation rates was determined, as well as clonogenic radiation survival. RESULTS Metformin resulted in moderate radiation protection in all cell lines, irrespective of AMPK and p53. Loss of AMPK sensitized cells to the anti-proliferative effects of metformin, while loss of p53 promoted both the growth inhibitory and toxic effects of metformin. Consequently, overall cell death after radiation was similar with and without metformin irrespective of AMPK or p53 genotype. CONCLUSIONS The anti-proliferative activity of metformin may confer benefit in combination with radiotherapy, and this benefit is intensified upon loss of AMPK or p53 signaling.
Collapse
Affiliation(s)
- Hala Muaddi
- Ontario Cancer Institute and Campbell Family Institute for Cancer Research, Princess Margaret Cancer Centre, University Health Network, Toronto, Canada; Faculty of Medicine, University of Toronto, Canada
| | | | | | | | | |
Collapse
|
259
|
Lin HC, Kachingwe BH, Lin HL, Cheng HW, Uang YS, Wang LH. Effects of metformin dose on cancer risk reduction in patients with type 2 diabetes mellitus: a 6-year follow-up study. Pharmacotherapy 2013; 34:36-45. [PMID: 23864581 DOI: 10.1002/phar.1334] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
STUDY OBJECTIVE To explore the effects of metformin dose on cancer risk reduction in patients with type 2 diabetes. DESIGN Population-based cohort study. DATA SOURCE National Health Insurance program Longitudinal Health Insurance Database. PATIENTS A total of 65,754 age- and gender-matched patients without diabetes and no previous cancer diagnosis were extracted from the database. MEASUREMENTS AND MAIN RESULTS We compared cancer risk among the subjects who had no diabetes, had type 2 diabetes but were not on diabetes drugs, used metformin only, used antidiabetic drugs other than metformin, or used metformin in combination with other antidiabetic drugs. Our results revealed dose-dependent effects of metformin on cancer risk and cancer onset times. A significant decrease in cancer risk was found in the monotherapy group who received more than 360 defined daily doses (DDDs) of metformin (hazard ratio [HR] 0.40, 95% confidence interval [CI] 0.24-0.66). The greatest decrease in cancer risk was observed in patients who took more than 1080 DDDs (HR 0.27, 95% CI 0.09-0.84). Significantly greater dose-dependent effects were seen in patients who used metformin in combination with other antidiabetic drugs. CONCLUSION The magnitude of cancer risk reduction and prolonged cancer onset times produced by metformin in patients with type 2 diabetes depended on the dose of metformin, regardless of whether metformin was used alone or combined with other antidiabetic drugs.
Collapse
Affiliation(s)
- Hsiu-Chen Lin
- Department of Pediatrics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Laboratory Medicine, Taipei Medical University Hospital, Taipei, Taiwan
| | | | | | | | | | | |
Collapse
|
260
|
Kim I, He YY. Targeting the AMP-Activated Protein Kinase for Cancer Prevention and Therapy. Front Oncol 2013; 3:175. [PMID: 23875169 PMCID: PMC3711071 DOI: 10.3389/fonc.2013.00175] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 06/21/2013] [Indexed: 12/25/2022] Open
Abstract
Despite the advances in biomedical research and clinical applications, cancer remains a leading cause of death worldwide. Given the limitations of conventional chemotherapeutics, including serious toxicities and reduced quality of life for patients, the development of safe and efficacious alternatives with known mechanism of action is much needed. Prevention of cancer through dietary intervention may hold promise and has been investigated extensively in the recent years. AMP-activated protein kinase (AMPK) is an energy sensor that plays a key role in the regulation of protein and lipid metabolism in response to changes in fuel availability. When activated, AMPK promotes energy-producing catabolic pathways while inhibiting anabolic pathways, such as cell growth and proliferation – thereby antagonizing carcinogenesis. Other anti-cancer effects of AMPK may include promoting autophagy and DNA repair upon UVB damage. In the last decade, interest in AMPK has grown extensively as it emerged as an attractive target molecule for cancer prevention and treatment. Among the latest developments is the activation of AMPK by naturally occurring dietary constituents and plant products – termed phytochemicals. Owing to their efficacy and safety, phytochemicals are considered as an alternative to the conventional harmful chemotherapy. The rising popularity of using phytochemicals for cancer prevention and therapy is supported by a substantial progress in identifying the molecular pathways involved, including AMPK. In this article, we review the recent progress in this budding field that suggests AMPK as a new molecular target in the prevention and treatment of cancer by phytochemicals.
Collapse
Affiliation(s)
- Inyoung Kim
- Pritzker School of Medicine, University of Chicago , Chicago, IL , USA
| | | |
Collapse
|
261
|
Abstract
OBJECTIVE Pancreatic ductal adenocarcinoma is a devastating disease, with an overall 5-year survival rate of only 3% to 5%. As the current therapies offer very limited survival benefits, novel therapeutic strategies are urgently required to treat this disease. Here, we determined whether metformin administration inhibits the growth of PANC-1 and MiaPaCa-2 tumor xenografts in vivo. METHODS Different xenograft models, including orthotopic implantation, were used to determine whether intraperitoneal or oral administration of metformin inhibits the growth of pancreatic cancer in vivo. RESULTS We demonstrate that metformin given once daily intraperitoneally at various doses (50-250 mg/kg) to nude mice inhibited the growth of PANC-1 xenografts in a dose-dependent manner. A significant effect of metformin was obtained at 50 mg/kg and maximal effect at 200 mg/kg. Metformin administration also caused a significant reduction in the phosphorylation of ribosomal S6 protein and ERK in these xenografts. Metformin also inhibited the growth of pancreatic cancer xenografts when administered orally (2.5 mg/mL) either before or after tumor implantation. Importantly, oral administration of metformin also inhibited the growth of MiaPaCa-2 tumors xenografted orthotopically. CONCLUSIONS The studies presented here provide further evidence indicating that metformin offers a potential novel approach for pancreatic ductal adenocarcinoma prevention and therapy.
Collapse
|
262
|
Sant'Anna JR, Yajima JPRS, Rosada LJ, Franco CCS, Prioli AJ, Della-Rosa VA, Mathias PCF, Castro-Prado MAA. Metformin's performance in in vitro and in vivo genetic toxicology studies. Exp Biol Med (Maywood) 2013; 238:803-10. [PMID: 23788173 DOI: 10.1177/1535370213480744] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Metformin is a hypoglycemiant drug prescribed for the treatment and control of the type 2 diabetes mellitus. Recently, the potential efficacy of this antidiabetic drug as an anticancer agent has been demonstrated in various mammalian cancer cells. This report evaluates the mutagenic as well as the recombinogenic potentials of the metformin drug in therapeutically relevant plasma concentrations (12.5 µM, 25.0 µM or 50.0 µM). Since the loss of heterozygosity is a process associated with carcinogenesis, the recombinogenic potential of such a drug was evaluated by the homozygotization assay using a heterozygous diploid strain of Aspergillus nidulans. The homozigotization indices (HI) for the genetic markers from the metformin-treated diploids were not statistically different from the negative control (non-treated diploids). For the first time, this indicated a lack of recombinogenic activity of the antidiabetic drug. The mutagenic potential of the metformin drug was evaluated by the chromosome aberrations and the micronuclei tests in human lymphocytes cultures. The metformin drug did not show any significant increase either in the numerical or in the structural chromosome aberrations and did not affect significantly the mitotic index when compared to the negative control. In the in vitro micronucleus test, the drug did not increase the number of micronuclei or nuclear buds when compared with the negative control. The data in this study suggest that the metformin drug is not a secondary cancer inducer, since it has neither showed recombinogenic nor mutagenic activities when used in pharmacological concentrations.
Collapse
Affiliation(s)
- Juliane R Sant'Anna
- Laboratório de Genética de Microorganismos e Mutagênese, Departamento de Biotecnologia, Genética e Biologia Celular, Universidade Estadual de Maringá, 87020-900, Maringá, PR, Brazil
| | | | | | | | | | | | | | | |
Collapse
|
263
|
Quinn BJ, Dallos M, Kitagawa H, Kunnumakkara AB, Memmott RM, Hollander MC, Gills JJ, Dennis PA. Inhibition of lung tumorigenesis by metformin is associated with decreased plasma IGF-I and diminished receptor tyrosine kinase signaling. Cancer Prev Res (Phila) 2013; 6:801-10. [PMID: 23771523 DOI: 10.1158/1940-6207.capr-13-0058-t] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Metformin is the most commonly prescribed drug for type II diabetes and is associated with decreased cancer risk. Previously, we showed that metformin prevented tobacco carcinogen (NNK)-induced lung tumorigenesis in a non-diabetic mouse model, which was associated with decreased IGF-I/insulin receptor signaling but not activation of AMPK in lung tissues, as well as decreased circulating levels of IGF-I and insulin. Here, we used liver IGF-I-deficient (LID) mice to determine the importance of IGF-I in NNK-induced lung tumorigenesis and chemoprevention by metformin. LID mice had decreased lung tumor multiplicity and burden compared with wild-type (WT) mice. Metformin further decreased lung tumorigenesis in LID mice without affecting IGF-I levels, suggesting that metformin can act through IGF-I-independent mechanisms. In lung tissues, metformin decreased phosphorylation of multiple receptor tyrosine kinases (RTK) as well as levels of GTP-bound Ras independently of AMPK. Metformin also diminished plasma levels of several cognate ligands for these RTKs. Tissue distribution studies using [(14)C]-metformin showed that uptake of metformin was high in liver but four-fold lower in lungs, suggesting that the suppression of RTK activation by metformin occurs predominantly via systemic, indirect effects. Systemic inhibition of circulating growth factors and local RTK signaling are new AMPK-independent mechanisms of action of metformin that could underlie its ability to prevent tobacco carcinogen-induced lung tumorigenesis.
Collapse
Affiliation(s)
- Brendan J Quinn
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
| | | | | | | | | | | | | | | |
Collapse
|
264
|
Abstract
The high rate of negative clinical trials and failed drug development programs calls into question the use of preclinical testing as currently practiced. An important issue for the in vitro testing of agents that have advanced into the clinic is the use of clinically irrelevant concentrations in reports making claims for anticancer activity, as illustrated by publications for sorafenib, vorinostat, and metformin. For sorafenib, high protein binding leads to a dichotomy between concentrations active in the 10% serum conditions commonly used for in vitro testing and concentrations active in plasma. Failure to recognize this distinction leads to inappropriate claims of activity for sorafenib based on the micromolar concentrations commonly used for in vitro testing in low serum conditions. For vorinostat and metformin, results using in vitro concentrations higher than those achievable in patients are reported despite the availability of publications describing human pharmacokinetic data for each agent. We encourage journal editors and reviewers to pay greater attention to clinically relevant concentrations when considering reports that include in vitro testing of agents for which human pharmacokinetic data are available. Steps taken to more carefully scrutinize activity claims based on in vitro results can help direct researchers away from clinically irrelevant lines of research and toward lines of research that are more likely to lead to positive clinical trials and to improved treatments for patients with cancer.
Collapse
Affiliation(s)
- Malcolm A Smith
- Cancer Therapy Evaluation Program, National Cancer Institute, Bethesda, Maryland 20892, USA.
| | | |
Collapse
|
265
|
Moiseeva O, Deschênes‐Simard X, St‐Germain E, Igelmann S, Huot G, Cadar AE, Bourdeau V, Pollak MN, Ferbeyre G. Metformin inhibits the senescence-associated secretory phenotype by interfering with IKK/NF-κB activation. Aging Cell 2013; 12:489-98. [PMID: 23521863 DOI: 10.1111/acel.12075] [Citation(s) in RCA: 457] [Impact Index Per Article: 38.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/09/2013] [Indexed: 12/23/2022] Open
Abstract
We show that the antidiabetic drug metformin inhibits the expression of genes coding for multiple inflammatory cytokines seen during cellular senescence. Conditioned medium (CM) from senescent cells stimulates the growth of prostate cancer cells but treatment of senescent cells with metformin inhibited this effect. Bioinformatic analysis of genes downregulated by metformin suggests that the drug blocks the activity of the transcription factor NF-κB. In agreement, metformin prevented the translocation of NF-κB to the nucleus and inhibited the phosphorylation of IκB and IKKα/β, events required for activation of the NF-κB pathway. These effects were not dependent on AMPK activation or on the context of cellular senescence, as metformin inhibited the NF-κB pathway stimulated by lipopolysaccharide (LPS) in ampk null fibroblasts and in macrophages. Taken together, our results provide a novel mechanism for the antiaging and antineoplastic effects of metformin reported in animal models and in diabetic patients taking this drug.
Collapse
Affiliation(s)
- Olga Moiseeva
- Département de Biochimie Université de Montréal Pavillon Roger‐Gaudry 2900 boul. Édouard MontpetitMontréal QC H3C 3J7Canada
| | - Xavier Deschênes‐Simard
- Département de Biochimie Université de Montréal Pavillon Roger‐Gaudry 2900 boul. Édouard MontpetitMontréal QC H3C 3J7Canada
| | - Emmanuelle St‐Germain
- Département de Biochimie Université de Montréal Pavillon Roger‐Gaudry 2900 boul. Édouard MontpetitMontréal QC H3C 3J7Canada
| | - Sebastian Igelmann
- Département de Biochimie Université de Montréal Pavillon Roger‐Gaudry 2900 boul. Édouard MontpetitMontréal QC H3C 3J7Canada
| | - Geneviève Huot
- Département de Biochimie Université de Montréal Pavillon Roger‐Gaudry 2900 boul. Édouard MontpetitMontréal QC H3C 3J7Canada
| | - Alexandra E. Cadar
- Département de Biochimie Université de Montréal Pavillon Roger‐Gaudry 2900 boul. Édouard MontpetitMontréal QC H3C 3J7Canada
| | - Véronique Bourdeau
- Département de Biochimie Université de Montréal Pavillon Roger‐Gaudry 2900 boul. Édouard MontpetitMontréal QC H3C 3J7Canada
| | - Michael N. Pollak
- Division of Experimental Medicine McGill University and Segal Cancer Centre of Jewish General Hospital 3755 Côte Ste Catherine Montréal QC H3T 1E2Canada
| | - Gerardo Ferbeyre
- Département de Biochimie Université de Montréal Pavillon Roger‐Gaudry 2900 boul. Édouard MontpetitMontréal QC H3C 3J7Canada
| |
Collapse
|
266
|
Abstract
Lung cancer is the leading cause of cancer death worldwide, making it an attractive disease for chemoprevention. Although avoidance of tobacco use and smoking cessation will have the greatest impact on lung cancer development, chemoprevention could prove to be very effective, particularly in former smokers. Chemoprevention is the use of agents to reverse or inhibit carcinogenesis and has been successfully applied to other common malignancies. Despite prior studies in lung cancer chemoprevention failing to identify effective agents, we now have the ability to identify high-risk populations, and our understanding of lung tumour and premalignant biology continues to advance. There are distinct histological lesions that can be reproducibly graded as precursors of non-small-cell lung cancer and similar precursor lesions exist for adenocarcinoma. These premalignant lesions are being targeted by chemopreventive agents in current trials and will continue to be studied in the future. In addition, biomarkers that predict risk and response to targeted agents are being investigated and validated. In this Review, we discuss the principles of chemoprevention, data from preclinical models, completed clinical trials and observational studies, and describe new treatments for novel targeted pathways and future chemopreventive efforts.
Collapse
Affiliation(s)
- Robert L Keith
- Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, VA Eastern Colorado Healthcare System, University of Colorado Denver School of Medicine, 1055 Clermont Street, Box 151, Denver, CO 80220, USA. robert.keith@ ucdenver.edu
| | | |
Collapse
|
267
|
Morgillo F, Sasso FC, Della Corte CM, Vitagliano D, D'Aiuto E, Troiani T, Martinelli E, De Vita F, Orditura M, De Palma R, Ciardiello F. Synergistic effects of metformin treatment in combination with gefitinib, a selective EGFR tyrosine kinase inhibitor, in LKB1 wild-type NSCLC cell lines. Clin Cancer Res 2013; 19:3508-19. [PMID: 23695170 DOI: 10.1158/1078-0432.ccr-12-2777] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE EGF receptor (EGFR) tyrosine kinase inhibitors (TKI) have been found to be effective against lung cancer, but clinical resistance to these agents has developed as their usage has increased. Metformin is a widely used antidiabetic drug and also displays significant growth-inhibitory and proapoptotic effects in several cancer models, alone or in combination with chemotherapeutic drugs. EXPERIMENTAL DESIGN The effects of gefitinib, a selective EGFR-TKI, and metformin on a panel of non-small cell lung cancer (NSCLC) cell lines were assessed by using MTT, bromide assay, flow cytometry, anchorage-independent growth, coimmunoprecipitation, and Western blot analysis. RESULTS The combination of metformin with gefitinib induced a strong antiproliferative and proapoptotic effect in NSCLC cell lines that harbored wild-type LKB1 gene. Treatment with metformin as single agent, however, induced an activation and phosphorylation of mitogen-activated protein kinase (MAPK) through an increased C-RAF/B-RAF heterodimerization. The inhibition of EGFR phosphorylation and of downstream signaling by adding gefitinib to metformin treatment abrogated this phenomenon and induced a strong apoptotic effect in vitro and in vivo. CONCLUSIONS Metformin and gefitinib are synergistic in LKB1 wild-type NSCLC cells. However, further studies are required to investigate better the effect of metformin action on the RAS/RAF/MAPK pathway and the best context in which to use metformin in combination with molecular targeted agents.
Collapse
Affiliation(s)
- Floriana Morgillo
- Oncologia Medica, Dipartimento Medico-Chirurgico di Internistica Clinica e Sperimentale F. Magrassi e A. Lanzara, Seconda Università degli Studi di Napoli, Naples, Italy.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
268
|
Karnevi E, Said K, Andersson R, Rosendahl AH. Metformin-mediated growth inhibition involves suppression of the IGF-I receptor signalling pathway in human pancreatic cancer cells. BMC Cancer 2013; 13:235. [PMID: 23663483 PMCID: PMC3661399 DOI: 10.1186/1471-2407-13-235] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 04/30/2013] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Epidemiological studies have shown direct associations between type 2 diabetes and obesity, both conditions associated with hyperglycaemia and hyperinsulinemia, and the risk of pancreatic cancer. Up to 80% of pancreatic cancer patients present with either new-onset type 2 diabetes or impaired glucose tolerance at the time of diagnosis. Recent population studies indicate that the incidence of pancreatic cancer is reduced among diabetics taking metformin. In this study, the effects of exposure of pancreatic cancer cells to high glucose levels on their growth and response to metformin were investigated. METHODS The human pancreatic cancer cell lines AsPC-1, BxPC-3, PANC-1 and MIAPaCa-2 were grown in normal (5 mM) or high (25 mM) glucose conditions, with or without metformin. The influence by metformin on proliferation, apoptosis and the AMPK and IGF-IR signalling pathways were evaluated in vitro. RESULTS Metformin significantly reduced the proliferation of pancreatic cancer cells under normal glucose conditions. Hyperglycaemia however, protected against the metformin-induced growth inhibition. The anti-proliferative actions of metformin were associated with an activation of AMP-activated protein kinase AMPKThr172 together with an inhibition of the insulin/insulin-like growth factor-I (IGF-I) receptor activation and downstream signalling mediators IRS-1 and phosphorylated Akt. Furthermore, exposure to metformin during normal glucose conditions led to increased apoptosis as measured by poly(ADP-ribose) polymerase (PARP) cleavage. In contrast, exposure to high glucose levels promoted a more robust IGF-I response and Akt activation which correlated to stimulated AMPKSer485 phosphorylation and impaired AMPKThr172 phosphorylation, resulting in reduced anti-proliferative and apoptotic effects by metformin. CONCLUSION Our results indicate that metformin has direct anti-tumour activities in pancreatic cancer cells involving AMPKThr172 activation and suppression of the insulin/IGF signalling pathways. However, hyperglycaemic conditions enhance the insulin/IGF-I responses resulting in an altered AMPK activation profile and prevent metformin from fully switching off the growth promoting signals in pancreatic cancer cells.
Collapse
Affiliation(s)
- Emelie Karnevi
- Department of Surgery, Clinical Sciences Lund, Skåne University Hospital and Lund University, Lund SE-221 84, Sweden
| | - Katarzyna Said
- Department of Surgery, Clinical Sciences Lund, Skåne University Hospital and Lund University, Lund SE-221 84, Sweden
| | - Roland Andersson
- Department of Surgery, Clinical Sciences Lund, Skåne University Hospital and Lund University, Lund SE-221 84, Sweden
| | - Ann H Rosendahl
- Department of Surgery, Clinical Sciences Lund, Skåne University Hospital and Lund University, Lund SE-221 84, Sweden
| |
Collapse
|
269
|
Monteiro LS, Delgado ML, Ricardo S, Garcez F, Amaral BD, Warnakulasuriya S, Lopes C. Phosphorylated mammalian target of rapamycin is associated with an adverse outcome in oral squamous cell carcinoma. Oral Surg Oral Med Oral Pathol Oral Radiol 2013; 115:638-45. [DOI: 10.1016/j.oooo.2013.01.022] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 01/18/2013] [Accepted: 01/23/2013] [Indexed: 10/26/2022]
|
270
|
Loubière C, Dirat B, Tanti JF, Bost F. [New perspectives for metformin in cancer therapy]. ANNALES D'ENDOCRINOLOGIE 2013; 74:130-6. [PMID: 23587351 DOI: 10.1016/j.ando.2013.02.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Cancer and type II diabetes are two diseases that appear to be associated. In fact, diabetes increases the incidence of several cancers (colon, endometrium, rectum and breast). Retrospective epidemiological studies show that metformin, a drug commonly used in type II diabetes, has antitumor properties. Therefore, many experimental studies (in vivo and in vitro) have been initiated in recent years to understand the cellular and molecular mechanisms that may explain the protective effects of metformin against cancer. Two main mode of action have been proposed. The first, indirect, involves the decrease of insulinemia. The second, via a direct action on cells, results in the regulation of the activated AMPK kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway, which plays a central role in many cellular processes such as energy metabolism, protein synthesis, autophagy and apoptosis. Here, we review recent results concerning the antitumor action of metformin: epidemiological, metabolic, cellular and molecular levels. Ongoing experimental and clinical trials should help us better understand the mechanisms of action of metformin and allow us to determine whether the drug can be used in the treatment of cancer.
Collapse
Affiliation(s)
- Camille Loubière
- Inserm U1065, centre méditerranéen de médecine moléculaire, équipe « physiopathologie cellulaire et moléculaire de l'obésité et du diabète », 06204 Nice, France
| | | | | | | |
Collapse
|
271
|
Shackelford DB, Abt E, Gerken L, Vasquez DS, Seki A, Leblanc M, Wei L, Fishbein MC, Czernin J, Mischel PS, Shaw RJ. LKB1 inactivation dictates therapeutic response of non-small cell lung cancer to the metabolism drug phenformin. Cancer Cell 2013; 23:143-58. [PMID: 23352126 PMCID: PMC3579627 DOI: 10.1016/j.ccr.2012.12.008] [Citation(s) in RCA: 478] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 10/07/2012] [Accepted: 12/20/2012] [Indexed: 01/09/2023]
Abstract
The LKB1 (also called STK11) tumor suppressor is mutationally inactivated in ∼20% of non-small cell lung cancers (NSCLC). LKB1 is the major upstream kinase activating the energy-sensing kinase AMPK, making LKB1-deficient cells unable to appropriately sense metabolic stress. We tested the therapeutic potential of metabolic drugs in NSCLC and identified phenformin, a mitochondrial inhibitor and analog of the diabetes therapeutic metformin, as selectively inducing apoptosis in LKB1-deficient NSCLC cells. Therapeutic trials in Kras-dependent mouse models of NSCLC revealed that tumors with Kras and Lkb1 mutations, but not those with Kras and p53 mutations, showed selective response to phenformin as a single agent, resulting in prolonged survival. This study suggests phenformin as a cancer metabolism-based therapeutic to selectively target LKB1-deficient tumors.
Collapse
Affiliation(s)
- David B. Shackelford
- Molecular and Cell Biology Laboratory, Dulbecco Center for Cancer Research, The Salk Institute for Biological Studies, La Jolla, CA 92037
- Molecular and Medical Pharmacology, David Geffen UCLA School of Medicine, Los Angeles, CA 90095.
- Pulmonary and Critical Care Medicine, David Geffen UCLA School of Medicine, Los Angeles, CA 90095.
- Correspondence: ,
| | - Evan Abt
- Molecular and Medical Pharmacology, David Geffen UCLA School of Medicine, Los Angeles, CA 90095.
- Pulmonary and Critical Care Medicine, David Geffen UCLA School of Medicine, Los Angeles, CA 90095.
| | - Laurie Gerken
- Molecular and Cell Biology Laboratory, Dulbecco Center for Cancer Research, The Salk Institute for Biological Studies, La Jolla, CA 92037
| | - Debbie S. Vasquez
- Molecular and Cell Biology Laboratory, Dulbecco Center for Cancer Research, The Salk Institute for Biological Studies, La Jolla, CA 92037
| | - Atsuko Seki
- Department of Pathology and Laboratory Medicine, David Geffen UCLA School of Medicine, Los Angeles, CA 90095.
| | - Mathias Leblanc
- Molecular and Cell Biology Laboratory, Dulbecco Center for Cancer Research, The Salk Institute for Biological Studies, La Jolla, CA 92037
| | - Liu Wei
- Molecular and Medical Pharmacology, David Geffen UCLA School of Medicine, Los Angeles, CA 90095.
| | - Michael C. Fishbein
- Department of Pathology and Laboratory Medicine, David Geffen UCLA School of Medicine, Los Angeles, CA 90095.
| | - Johannes Czernin
- Molecular and Medical Pharmacology, David Geffen UCLA School of Medicine, Los Angeles, CA 90095.
| | - Paul S. Mischel
- Department of Pathology and Laboratory Medicine, David Geffen UCLA School of Medicine, Los Angeles, CA 90095.
- Molecular and Medical Pharmacology, David Geffen UCLA School of Medicine, Los Angeles, CA 90095.
| | - Reuben J. Shaw
- Molecular and Cell Biology Laboratory, Dulbecco Center for Cancer Research, The Salk Institute for Biological Studies, La Jolla, CA 92037
- Howard Hughes Medical Institute, Dulbecco Center for Cancer Research, The Salk Institute for Biological Studies, La Jolla, CA 92037
- Correspondence: ,
| |
Collapse
|
272
|
Smiechowski BB, Azoulay L, Yin H, Pollak MN, Suissa S. The use of metformin and the incidence of lung cancer in patients with type 2 diabetes. Diabetes Care 2013; 36:124-9. [PMID: 22923670 PMCID: PMC3526233 DOI: 10.2337/dc12-0740] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Observational studies have associated metformin use with a decreased risk of lung cancer incidence in patients with type 2 diabetes, but the studies had important methodological shortcomings. The objective of this study was to determine whether metformin use is associated with a decreased risk of lung cancer in patients with type 2 diabetes, while avoiding previous biases. RESEARCH DESIGN AND METHODS Using the U.K. General Practice Research Database, we assembled a cohort of patients newly treated with oral hypoglycemic agents (OHAs) between 1988 and 2009. A nested case-control analysis was conducted, where case subjects with lung cancer occurring during follow-up were matched with up to 10 control subjects for age, sex, calendar time, and duration of follow-up. Conditional logistic regression was used to estimate adjusted rate ratios of lung cancer associated with ever use of metformin, along with measures of duration and cumulative dose. Models were adjusted for potential confounders, which included smoking. RESULTS The cohort included 115,923 new users of OHAs, with 1,061 patients diagnosed with lung cancer during follow-up (rate 2.0/1,000 person-years). Metformin use was not associated with a decreased rate of lung cancer (rate ratio 0.94 [95% CI 0.76-1.17]). No dose-response was observed by number of prescriptions received, cumulative duration of use, and dose. CONCLUSIONS Metformin use is not associated with a decreased risk of lung cancer in patients with type 2 diabetes. The decreased risk reported in other observational studies is likely due to bias from methodological shortcomings. Nonetheless, greater consideration should be given to clarify inconsistencies between experimental models and population studies.
Collapse
Affiliation(s)
- Brielan B Smiechowski
- Centre for Clinical Epidemiology, Lady Davis Institute, Jewish General Hospital, Montreal, Quebec, Canada
| | | | | | | | | |
Collapse
|
273
|
Trouillas P, Marchetti C, Bonnefont-Rousselot D, Lazzaroni R, Jore D, Gardès-Albert M, Collin F. Mechanism of one-electron oxidation of metformin in aqueous solution. Phys Chem Chem Phys 2013; 15:9871-8. [DOI: 10.1039/c3cp50602a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
274
|
Korsse SE, Peppelenbosch MP, van Veelen W. Targeting LKB1 signaling in cancer. Biochim Biophys Acta Rev Cancer 2012; 1835:194-210. [PMID: 23287572 DOI: 10.1016/j.bbcan.2012.12.006] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 12/18/2012] [Accepted: 12/20/2012] [Indexed: 12/13/2022]
Abstract
The serine/threonine kinase LKB1 is a master kinase involved in cellular responses such as energy metabolism, cell polarity and cell growth. LKB1 regulates these crucial cellular responses mainly via AMPK/mTOR signaling. Germ-line mutations in LKB1 are associated with the predisposition of the Peutz-Jeghers syndrome in which patients develop gastrointestinal hamartomas and have an enormously increased risk for developing gastrointestinal, breast and gynecological cancers. In addition, somatic inactivation of LKB1 has been associated with sporadic cancers such as lung cancer. The exact mechanisms of LKB1-mediated tumor suppression remain so far unidentified; however, the inability to activate AMPK and the resulting mTOR hyperactivation has been detected in PJS-associated lesions. Therefore, targeting LKB1 in cancer is now mainly focusing on the activation of AMPK and inactivation of mTOR. Preclinical in vitro and in vivo studies show encouraging results regarding these approaches, which have even progressed to the initiation of a few clinical trials. In this review, we describe the functions, regulation and downstream signaling of LKB1, and its role in hereditary and sporadic cancers. In addition, we provide an overview of several AMPK activators, mTOR inhibitors and additional mechanisms to target LKB1 signaling, and describe the effect of these compounds on cancer cells. Overall, we will explain the current strategies attempting to find a way of treating LKB1-associated cancer.
Collapse
Affiliation(s)
- S E Korsse
- Dept. of Gastroenterology and Hepatology, Erasmus Medical University Center, Rotterdam, The Netherlands
| | | | | |
Collapse
|
275
|
Würth R, Pattarozzi A, Gatti M, Bajetto A, Corsaro A, Parodi A, Sirito R, Massollo M, Marini C, Zona G, Fenoglio D, Sambuceti G, Filaci G, Daga A, Barbieri F, Florio T. Metformin selectively affects human glioblastoma tumor-initiating cell viability: A role for metformin-induced inhibition of Akt. Cell Cycle 2012; 12:145-56. [PMID: 23255107 DOI: 10.4161/cc.23050] [Citation(s) in RCA: 150] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Cancer stem cell theory postulates that a small population of tumor-initiating cells is responsible for the development, progression and recurrence of several malignancies, including glioblastoma. In this perspective, tumor-initiating cells represent the most relevant target to obtain effective cancer treatment. Metformin, a first-line drug for type II diabetes, was reported to possess anticancer properties affecting the survival of cancer stem cells in breast cancer models. We report that metformin treatment reduced the proliferation rate of tumor-initiating cell-enriched cultures isolated from four human glioblastomas. Metformin also impairs tumor-initiating cell spherogenesis, indicating a direct effect on self-renewal mechanisms. Interestingly, analyzing by FACS the antiproliferative effects of metformin on CD133-expressing subpopulation, a component of glioblastoma cancer stem cells, a higher reduction of proliferation was observed as compared with CD133-negative cells, suggesting a certain degree of cancer stem cell selectivity in its effects. In fact, glioblastoma cell differentiation strongly reduced sensitivity to metformin treatment. Metformin effects in tumor-initiating cell-enriched cultures were associated with a powerful inhibition of Akt-dependent cell survival pathway, while this pathway was not affected in differentiated cells. The specificity of metformin antiproliferative effects toward glioblastoma tumor-initiating cells was confirmed by the lack of significant inhibition of normal human stem cells (umbilical cord-derived mesenchymal stem cells) in vitro proliferation after metformin exposure. Altogether, these data clearly suggest that metformin exerts antiproliferative activity on glioblastoma cells, showing a higher specificity toward tumor-initiating cells, and that the inhibition of Akt pathway may represent a possible intracellular target of this effect.
Collapse
Affiliation(s)
- Roberto Würth
- Department of Internal Medicine, University of Genova, Genoa, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
276
|
Tseng SC, Huang YC, Chen HJ, Chiu HC, Huang YJ, Wo TY, Weng SH, Lin YW. Metformin-mediated downregulation of p38 mitogen-activated protein kinase-dependent excision repair cross-complementing 1 decreases DNA repair capacity and sensitizes human lung cancer cells to paclitaxel. Biochem Pharmacol 2012; 85:583-94. [PMID: 23228696 DOI: 10.1016/j.bcp.2012.12.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 12/03/2012] [Accepted: 12/03/2012] [Indexed: 10/27/2022]
Abstract
Metformin, an extensively used and well-tolerated drug for treating individuals with type 2 diabetes, has recently gained significant attention as an anticancer drug. On the other hand, paclitaxel (Taxol) is a new antineoplastic drug that has shown promise in the treatment of non-small cell lung cancer (NSCLC). High expression levels of excision repair cross-complementary 1 (ERCC1) in cancers have been positively associated with the DNA repair capacity and a poor prognosis in NSCLC patients treated with platinum-containing chemotherapy. In this current study, paclitaxel was found to increase phosphorylation of mitogen-activated protein kinase (MAPK) kinase 3/6 (MKK3/6)-p38 MAPK as well as protein and mRNA levels of ERCC1 in H1650 and H1703 cells. Moreover, paclitaxel-induced ERCC1 protein and mRNA levels significantly decreased via the downregulation of p38 activity by either a p38 MAPK inhibitor SB202190 or p38 knockdown with specific small interfering RNA (siRNA). Specific inhibition of ERCC1 with siRNA was found to enhance the paclitaxel-induced cytotoxic effect and growth inhibition. Furthermore, metformin was able to not only decrease the paclitaxel-induced p38 MAPK-mediated ERCC1 expression, but also augment the cytotoxic effect induced by paclitaxel. Finally, expression of constitutive activate MKK6 or HA-p38 MAPK vectors in lung cancer cells was able to abrogate ERCC1 downregulation by metformin and paclitaxel as well as cell viability and DNA repair capacity. Overall, our results suggest that inhibition of the p38 MAPK signaling by metformin coupled with paclitaxel therapy in human NSCLC cells may be a clinically useful combination, which however will require further validation.
Collapse
Affiliation(s)
- Sheng-Chieh Tseng
- Molecular Oncology Laboratory, Department of Biochemical Science and Technology, National Chiayi University, 300 Syuefu Road, Chiayi 600, Taiwan
| | | | | | | | | | | | | | | |
Collapse
|
277
|
Luo Q, Hu D, Hu S, Yan M, Sun Z, Chen F. In vitro and in vivo anti-tumor effect of metformin as a novel therapeutic agent in human oral squamous cell carcinoma. BMC Cancer 2012; 12:517. [PMID: 23151022 PMCID: PMC3518152 DOI: 10.1186/1471-2407-12-517] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 11/11/2012] [Indexed: 01/29/2023] Open
Abstract
Background Metformin, which is widely used as an antidiabetic agent, has recently been reported to reduce cancer risk and improve prognosis in certain malignancies. However, the specific mechanisms underlying the effect of metformin on the development and progression of several cancers including oral squamous cell carcinoma (OSCC) remain unclear. In the present study, we investigated the effects of metformin on OSCC cells in vitro and in vivo. Methods OSCC cells treated with or without metformin were counted using a hemocytometer. The clonogenic ability of OSCC cells after metformin treatment was determined by colony formation assay. Cell cycle progression and apoptosis were assessed by flow cytometry, and the activation of related signaling pathways was examined by immunoblotting. The in vivo anti-tumor effect of metformin was examined using a xenograft mouse model. Immunohistochemistry and TUNEL staining were used to determine the expression of cyclin D1 and the presence of apoptotic cells in tumors from mice treated with or without metformin. Results Metformin inhibited proliferation in the OSCC cell lines CAL27, WSU-HN6 and SCC25 in a time- and dose-dependent manner, and significantly reduced the colony formation of OSCC cells in vitro. Metformin induced an apparent cell cycle arrest at the G0/G1 phase, which was accompanied by an obvious activation of the AMP kinase pathway and a strongly decreased activation of mammalian target of rapamycin and S6 kinase. Metformin treatment led to a remarkable decrease of cyclin D1, cyclin-dependent kinase (CDK) 4 and CDK6 protein levels and phosphorylation of retinoblastoma protein, but did not affect p21 or p27 protein expression in OSCC cells. In addition, metformin induced apoptosis in OSCC cells, significantly down-regulating the anti-apoptotic proteins Bcl-2 and Bcl-xL and up-regulating the pro-apoptotic protein Bax. Metformin also markedly reduced the expression of cyclin D1 and increased the numbers of apoptotic cells in vivo, thus inhibiting the growth of OSCC xenografts. Conclusions Our data suggested that metformin could be a potential candidate for the development of new treatment strategies for human OSCC.
Collapse
Affiliation(s)
- Qingqiong Luo
- Department of Clinical Laboratories, Ninth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 639 Zhizaoju Road, Shanghai, 200011, China
| | | | | | | | | | | |
Collapse
|
278
|
Sova H, Puistola U, Morin-Papunen L, Karihtala P. Metformin decreases serum 8-hydroxy-2'-deoxyguanosine levels in polycystic ovary syndrome. Fertil Steril 2012; 99:593-8. [PMID: 23122829 DOI: 10.1016/j.fertnstert.2012.10.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 09/23/2012] [Accepted: 10/08/2012] [Indexed: 12/20/2022]
Abstract
OBJECTIVE To learn whether metformin treatment affects oxidative stress as measured by serum concentrations of 8-hydroxy-2'-deoxyguanosine (8-OHdG). DESIGN Double-blind, randomized, placebo-controlled trial. SETTING University outpatient clinic. PATIENT(S) The study cohort consisted of 50 obese women (body mass index [BMI] ≥ 27 kg/m(2)) and 60 nonobese patients (BMI <27 kg/m(2)), mean age was 27.7 ± 4.0 SD years. INTERVENTION(S) Randomization to receive metformin or placebo for 3 months. MAIN OUTCOME MEASURE(S) Serum levels of 8-OHdG before and after medical treatment. RESULT(S) The levels of 8-OHdG were equal at baseline in the placebo and metformin groups. Obese women had higher baseline serum concentrations of 8-OHdG. Levels of 8-OHdG were statistically significantly reduced with metformin treatment, especially in obese patients with polycystic ovary syndrome. This study was a secondary subanalysis of a previously conducted prospective multicenter, randomized, placebo-controlled study on the effects of metformin on miscarriage, pregnancy, and miscarriage rates. CONCLUSION(S) Metformin treatment, compared with placebo, statistically significantly decreased 8-OHdG levels in women with polycystic ovary syndrome. CLINICAL TRIAL REGISTRATION NUMBER NCT00994812.
Collapse
Affiliation(s)
- Henri Sova
- Department of Oncology and Radiotherapy, Oulu University Hospital and University of Oulu, Oulu, Finland.
| | | | | | | |
Collapse
|
279
|
Mirrakhimov AE. Chronic obstructive pulmonary disease and glucose metabolism: a bitter sweet symphony. Cardiovasc Diabetol 2012; 11:132. [PMID: 23101436 PMCID: PMC3499352 DOI: 10.1186/1475-2840-11-132] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 10/04/2012] [Indexed: 01/05/2023] Open
Abstract
Chronic obstructive pulmonary disease, metabolic syndrome and diabetes mellitus are common and underdiagnosed medical conditions. It was predicted that chronic obstructive pulmonary disease will be the third leading cause of death worldwide by 2020. The healthcare burden of this disease is even greater if we consider the significant impact of chronic obstructive pulmonary disease on the cardiovascular morbidity and mortality. Chronic obstructive pulmonary disease may be considered as a novel risk factor for new onset type 2 diabetes mellitus via multiple pathophysiological alterations such as: inflammation and oxidative stress, insulin resistance, weight gain and alterations in metabolism of adipokines. On the other hand, diabetes may act as an independent factor, negatively affecting pulmonary structure and function. Diabetes is associated with an increased risk of pulmonary infections, disease exacerbations and worsened COPD outcomes. On the top of that, coexistent OSA may increase the risk for type 2 DM in some individuals. The current scientific data necessitate a greater outlook on chronic obstructive pulmonary disease and chronic obstructive pulmonary disease may be viewed as a risk factor for the new onset type 2 diabetes mellitus. Conversely, both types of diabetes mellitus should be viewed as strong contributing factors for the development of obstructive lung disease. Such approach can potentially improve the outcomes and medical control for both conditions, and, thus, decrease the healthcare burden of these major medical problems.
Collapse
MESH Headings
- Adipokines/blood
- Adult
- Aged
- Animals
- Blood Glucose/metabolism
- Comorbidity
- Diabetes Mellitus, Type 2/blood
- Diabetes Mellitus, Type 2/diagnosis
- Diabetes Mellitus, Type 2/epidemiology
- Diabetes Mellitus, Type 2/physiopathology
- Diabetes Mellitus, Type 2/therapy
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/physiopathology
- Female
- Humans
- Inflammation Mediators/blood
- Lung/metabolism
- Lung/physiopathology
- Male
- Middle Aged
- Oxidative Stress
- Prognosis
- Pulmonary Disease, Chronic Obstructive/blood
- Pulmonary Disease, Chronic Obstructive/diagnosis
- Pulmonary Disease, Chronic Obstructive/epidemiology
- Pulmonary Disease, Chronic Obstructive/physiopathology
- Pulmonary Disease, Chronic Obstructive/therapy
- Risk Factors
Collapse
Affiliation(s)
- Aibek E Mirrakhimov
- Kyrgyz State Medical Academy named by I,K, Akhunbaev, Akhunbaev street 92, Bishkek 720020, Kyrgyzstan.
| |
Collapse
|
280
|
Ito K, Colley T, Mercado N. Geroprotectors as a novel therapeutic strategy for COPD, an accelerating aging disease. Int J Chron Obstruct Pulmon Dis 2012; 7:641-52. [PMID: 23055713 PMCID: PMC3459652 DOI: 10.2147/copd.s28250] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Chronic obstructive pulmonary disease (COPD) progresses very slowly and the majority of patients are therefore elderly. COPD is characterized by an abnormal persistent inflammatory response to noxious environmental stimuli and there are increasing evidences for a close relationship between premature aging and chronic inflammatory diseases. Thus, COPD is considered to be a disease of an accelerating aging. In this review, we collected the evidence for roles of aging on pathogenesis of COPD and considered future therapeutic strategy for COPD based on this senescence hypothesis. Since calorie restriction has been proved to extend lifespan, many efforts were made to clarify the molecular mechanism of aging. Aging is defined as the progressive decline of homeostasis that occurs after the reproductive phase of life is complete, leading to an increasing risk of disease or death due to impaired DNA repair after damage by oxidative stress or telomere shortening as a result of repeated cell division. During aging, pulmonary function progressively deteriorates; innate immunity is impaired and pulmonary inflammation increases, accompanied by structural changes, such as an enlargement of airspaces. Noxious environmental gases, such as cigarette smoke, may worsen these aging-related events in the lung or accelerate aging of the lung due to reduction in anti-aging molecules and/or stimulation of aging molecules. Aging signaling are complex but conserved in divert species, such as worm, fruit fry, rodent and humans. Especially the insulin like growth factor (IGF-1) signaling was well documented. Geroprotectors are therapeutics that affect the root cause of aging and age-related diseases, and thus prolong the life-span of animals. Most of geroprotectors such as melatonin, metformin, rapamycin and resveratrol are anti-oxidant or anti-aging molecule regulators. Therefore, geroprotection for the lung might be an attractive approach for the treatment of COPD by preventing premature aging of lung.
Collapse
Affiliation(s)
- Kazuhiro Ito
- Airways Disease Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom.
| | | | | |
Collapse
|
281
|
The effect of metformin and thiazolidinedione use on lung cancer in diabetics. BMC Cancer 2012; 12:410. [PMID: 22978440 PMCID: PMC3517374 DOI: 10.1186/1471-2407-12-410] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Accepted: 09/10/2012] [Indexed: 11/24/2022] Open
Abstract
Background Metformin and the thiazolidinediones (TZDs) may have a protective effect against the development of lung cancer. Methods Patients with diabetes mellitus (DM) were identified from the electronic medical records of the Cleveland Clinic. Diabetics with lung cancer were identified then verified by direct review of their records. Control subjects were matched with cancer subjects 1:1 by date of birth, sex, and smoking history. The frequency and duration of diabetic medication use was compared between the groups. The cancer characteristics were compared between those with lung cancer who had and had not been using metformin and/or a TZD. Results 93,939 patients were identified as having DM. 522 lung cancers in 507 patients were confirmed. The matched control group was more likely to have used metformin and/or a TZD (61.0% vs. 41.2%, p < 0.001 for any use; 55.5% vs. 24.6%, p < 0.001 for >24 months vs. 0–12 months). In the group with lung cancer, those who had used metformin alone had a different histology distribution than those who received neither metformin nor a TZD, were more likely to present with metastatic disease (40.8% vs. 28.2%, p = 0.013), and had a shorter survival from the time of diagnosis (HR 1.47, p < 0.005). Conclusions The use of metformin and/or the TZDs is associated with a lower likelihood of developing lung cancer in diabetic patients. Diabetics who develop lung cancer while receiving metformin may have a more aggressive cancer phenotype.
Collapse
|
282
|
Bodmer M, Becker C, Jick SS, Meier CR. Metformin does not alter the risk of lung cancer: a case-control analysis. Lung Cancer 2012; 78:133-7. [PMID: 22959242 DOI: 10.1016/j.lungcan.2012.08.010] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Revised: 06/24/2012] [Accepted: 08/15/2012] [Indexed: 11/16/2022]
Abstract
BACKGROUND Metformin use has been linked to a decreased cancer risk. We explored the association between use of metformin or other antidiabetic drugs and the risk of lung cancer. METHODS We assessed the association between metformin, and other antidiabetic drugs and lung cancer using a case-control analysis in the UK-based General Practice Research Database (GPRD). Cases were people with an incident diagnosis of lung cancer. Up to 6 controls per case were matched on age, sex, calendar time, general practice, and number of years of active history in the GPRD. The contribution of potential confounders including tuberculosis, chronic obstructive pulmonary disease (COPD), diabetes mellitus, and co-morbid conditions to diabetes was evaluated in univariate models, and final results were adjusted for BMI and smoking. RESULTS Long-term use (≥40 prescriptions) of metformin was not associated with an altered risk of lung cancer (adj. OR 1.21, 95% CI 0.97-1.50. Long-term use of sulfonylureas was linked to a marginally decreased risk of lung cancer (adj. OR 0.74, 95% CI 0.60-0.90. This risk decrease was observed in men (adj. OR 0.64, 95% CI 0.50-0.83) but not in women (adj. OR 0.97, 95% CI 0.69-1.37) and this risk decrease was not statistically significant in an analysis restricted to diabetic patients only (adj. OR. 0.82, 95% CI 0.65-1.02). Long-term use of insulin was associated with a slightly increased risk of lung cancer (adj. OR 1.33, 95% CI 1.04-1.71); however, no consistent trend across duration strata was observed. CONCLUSION Metformin did not decrease the risk of lung cancer.
Collapse
Affiliation(s)
- Michael Bodmer
- Basel Pharmacoepidemiology Unit, Division of Clinical Pharmacy and Epidemiology, Department of Pharmaceutical Sciences, University of Basel, Switzerland.
| | | | | | | |
Collapse
|
283
|
Chaudhary SC, Kurundkar D, Elmets CA, Kopelovich L, Athar M. Metformin, an antidiabetic agent reduces growth of cutaneous squamous cell carcinoma by targeting mTOR signaling pathway. Photochem Photobiol 2012; 88:1149-56. [PMID: 22540890 PMCID: PMC3476735 DOI: 10.1111/j.1751-1097.2012.01165.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The biguanide metformin is widely used for the treatment of Type-II diabetes. Its antiproliferative and pro-apoptotic effects in various tumor cells suggest its potential candidacy for cancer chemoprevention. Herein, we report that metformin significantly inhibited human epidermoid A431 tumor xenograft growth in nu/nu mice, which was associated with a significant reduction in proliferative biomarkers PCNA and cyclins D1/B1. This tumor growth reduction was accompanied by the enhanced apoptotic cell death and an increase in Bax:Bcl2 ratio. The mechanism by which metformin manifests antitumor effects appears to be dependent on the inhibition of nuclear factor kappa B (NFkB) and mTOR signaling pathways. Decreased phosphorylation of NFkB inhibitory protein IKBα together with reduced enhancement of NFkB transcriptional target proteins, iNOS/COX-2 were observed. In addition, a decrease in the activation of ERK/p38-driven MAP kinase signaling was seen. Similarly, AKT signaling activation as assessed by the diminished phosphorylation at Ser473 with a concomitant decrease in mTOR signaling pathway was also noted as phosphorylation of mTOR regulatory proteins p70S6K and 4E-BP-1 was significantly reduced. Consistently, decreased phosphorylation of GSK3β, which is carried out by AKT kinases was also observed. These results suggest that metformin blocks SCC growth by dampening NFkB and mTOR signaling pathways.
Collapse
Affiliation(s)
- Sandeep C. Chaudhary
- Department of Dermatology, University of Alabama at Birmingham, 1530 3 Avenue South, VH 509, Birmingham, AL 35294-0019
| | - Deepali Kurundkar
- Department of Dermatology, University of Alabama at Birmingham, 1530 3 Avenue South, VH 509, Birmingham, AL 35294-0019
| | - Craig A. Elmets
- Department of Dermatology, University of Alabama at Birmingham, 1530 3 Avenue South, VH 509, Birmingham, AL 35294-0019
| | - Levy Kopelovich
- Division of Cancer Prevention, National Cancer Institute, 6130 Executive Blvd, Suite 2114, Bethesda, MD 20892
| | - Mohammad Athar
- Department of Dermatology, University of Alabama at Birmingham, 1530 3 Avenue South, VH 509, Birmingham, AL 35294-0019
| |
Collapse
|
284
|
Abstract
OBJECTIVE A retrospective cohort study, using a population-based reimbursement database, was conducted for investigating the relationship between diabetes and colon cancer and assessing whether metformin had a protective effect. METHODS Overall, 493,704 men and 502,139 women, covered by the National Health Insurance, without colon cancer were followed from 2003 to 2005. Cox regression evaluated the adjusted relative risk (RR), considering confounders and detection examinations. RESULTS Even though diabetes patients had a significantly higher probability of receiving examinations that could lead to the detection of colon cancer, they had a significantly higher risk (24%) of this cancer after adjustment. Metformin users had a significantly lower risk (27%) of colon cancer. While comparing patients with diabetes for <1, 1-3, and ≥ 3 years to nondiabetes individuals, the adjusted RR (95% confidence interval) was 1.308 (1.020-1.679), 1.087 (0.900-1.313), and 1.185 (1.055-1.330) respectively. The higher risk among those with diabetes for <1 year suggested a possible reverse causality or a link with prediabetes. However, diabetes still might play some role in the development of colon cancer in those with diabetes for ≥ 3 years. The duration of metformin use showed an inverse trend, with a significant RR of 0.643 (0.490-0.845) in users for ≥ 3 years, when compared with nonusers. In addition, metformin may reduce colon cancer risk associated with chronic obstructive pulmonary disease (a surrogate for smoking). CONCLUSIONS Following adjustment for potential detection bias and other covariates, diabetes remains a significant risk factor for colon cancer. Metformin may protect against colon cancer.
Collapse
Affiliation(s)
- Chin-Hsiao Tseng
- Department of Internal Medicine, National Taiwan University College of Medicine, Taipei, Taiwan.
| |
Collapse
|
285
|
Qu Z, Zhang Y, Liao M, Chen Y, Zhao J, Pan Y. In vitro and in vivo antitumoral action of metformin on hepatocellular carcinoma. Hepatol Res 2012; 42:922-33. [PMID: 22524458 DOI: 10.1111/j.1872-034x.2012.01007.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
AIMS Metformin is a biguanide that has been widely used to treat type 2 diabetes. Several studies have shown that metformin is also effective in treating cancer, including hepatocellular carcinoma (HCC). The objective of this study was to evaluate the antitumor effects of metformin in HCC, and to investigate the potential molecular target(s) of metformin-mediated antitumor activity. METHODS The antiproliferative effects of metformin were assessed in human HCC cell lines and normal human liver cells at various concentrations. Orthotopic xenograft tumors were established in athymic nude mice, and tumor growth was monitored after metformin treatment. Western blot analysis and cell cycle regulation were performed to determine the involvement of various mediators of apoptosis. RESULTS Metformin specifically inhibited the growth of HCC cells without affecting the growth of normal liver cells both in vitro and in vivo. Metformin caused cell cycle arrest in HCC cells, which resulted in caspase-3 activation. Livin levels decreased in a dose-dependent manner upon metformin treatment. Metformin activated 5'-adenosine monophosphate-activated protein kinase, inhibited the mammalian target of rapamycin pathway and downregulated Livin protein expression. CONCLUSION Our findings indicate that metformin is effective at initiating apoptosis and inhibiting key survival signaling pathways in HCC cells. These data provide a foundation for further studies to evaluate metformin in the clinic either as a single agent or in combination with other first-line agents as a treatment option for HCC.
Collapse
Affiliation(s)
- Zhan Qu
- National Hepatobiliary & Enteric Surgery Research Center, Central South University, Changsha, Hunan, China
| | | | | | | | | | | |
Collapse
|
286
|
Pollak MN. Investigating metformin for cancer prevention and treatment: the end of the beginning. Cancer Discov 2012; 2:778-90. [PMID: 22926251 DOI: 10.1158/2159-8290.cd-12-0263] [Citation(s) in RCA: 402] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
UNLABELLED Laboratory research and pharmacoepidemiology are providing converging evidence that the widely used antidiabetic drug metformin has antineoplastic activity, but there are caveats. Although population studies suggest that metformin exposure is associated with reduced cancer risk and/or improved prognosis, these data are mostly retrospective and nonrandomized. Laboratory models show antineoplastic activity, but metformin concentrations used in many experiments exceed those achieved with conventional doses used for diabetes treatment. Ongoing translational research should be useful in guiding design of clinical trials, not only to evaluate metformin at conventional antidiabetic doses, where reduction of elevated insulin levels may contribute to antineoplastic activity for certain subsets of patients, but also to explore more aggressive dosing of biguanides, which may lead to reprogramming of energy metabolism in a manner that could provide important opportunities for synthetic lethality through rational drug combinations or in the context of genetic lesions associated with hypersensitivity to energetic stress. SIGNIFICANCE There are tantalizing clues that justify the investigation of antineoplastic activities of biguanides. The complexity of their biologic effects requires further translational research to guide clinical trial design.
Collapse
Affiliation(s)
- Michael N Pollak
- Department of Oncology, McGill University, Montreal, Quebec, Canada.
| |
Collapse
|
287
|
Goodwin PJ, Stambolic V. Obesity and insulin resistance in breast cancer--chemoprevention strategies with a focus on metformin. Breast 2012; 20 Suppl 3:S31-5. [PMID: 22015290 DOI: 10.1016/s0960-9776(11)70291-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Obesity and insulin resistance have been associated with breast cancer risk, and breast cancer outcomes. Recent research has focused on insulin as a potential biologic mediator of these effects given frequent expression of insulin/IGF-1 receptors on breast cancer cells which, when activated, can stimulate signaling through PI3K and Ras-Raf signaling pathways to enhance proliferation. Metformin, a commonly used diabetes drug, lowers insulin in non-breast diabetic cancer patients, likely by reducing hepatic gluconeogenesis; it also appears to have potential insulin independent direct effects on tumor cells which are mediated by activation of AMPK with downstream inhibition of mTOR. There is growing epidemiologic, clinical and preclinical (in vitro and in vivo) evidence in keeping with anticancer effects of metformin in breast and other cancers. This has led to the hypothesis that metformin may be effective in breast cancer prevention and treatment. Clinical studies in the neoadjuvant and adjuvant settings are ongoing; additional Phase 2 trials in the metastatic setting and proof of principle studies in the prevention setting are planned.
Collapse
Affiliation(s)
- Pamela J Goodwin
- Department of Medicine, Division of Clinical Epidemiology at the Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Princess Margaret Hospital, University of Toronto; Mount Sinai Hospital, 1284-600 University Avenue, Toronto, Ontario M5G 1X5, Canada.
| | | |
Collapse
|
288
|
Bost F, Ben-Sahra I, Tanti JF. Prevention of mutagenesis: new potential mechanisms of metformin action in neoplastic cells. Cancer Prev Res (Phila) 2012; 5:503-6. [PMID: 22491515 DOI: 10.1158/1940-6207.capr-12-0085] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Several experimental and epidemiologic studies have shown that the antidiabetes drug metformin has antitumor properties. The report by Algire and colleagues in this issue of the journal (beginning on page 536) shows for the first time that metformin reduces mutagenesis induced by reactive oxygen species. This report offers new perspectives on metformin in cancer prevention and provides a new mechanism for the reduction of cancer risk in diabetic patients treated with this drug.
Collapse
Affiliation(s)
- Frédéric Bost
- INSERM U1065, Centre Méditerranéen de Médecine Moléculaire, Team Cellular and molecular physiophathology of obesity and diabetes, and University of Nice Sophia-Antipolis, Faculty of Medicine, Nice, France.
| | | | | |
Collapse
|
289
|
Patel H, Younis RH, Ord RA, Basile JR, Schneider A. Differential expression of organic cation transporter OCT-3 in oral premalignant and malignant lesions: potential implications in the antineoplastic effects of metformin. J Oral Pathol Med 2012; 42:250-6. [PMID: 22861817 DOI: 10.1111/j.1600-0714.2012.01196.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/12/2012] [Indexed: 01/01/2023]
Abstract
BACKGROUND Recent evidence indicates that metformin, a biguanide used as first-line treatment for type 2 diabetes, prevents the conversion of carcinogen-induced oral dysplasias into head and neck squamous cell carcinomas (HNSCC), most likely by inhibiting mammalian target of rapamycin complex 1 (mTORC1) oncogenic signaling. Whether metformin acts directly at the primary tumor site or indirectly by modulating hormonal secretion from extratumoral organs remains unknown. As organic cation transporters (OCT) belonging to the solute carrier 22A gene family, including OCT-1, OCT-2, and OCT-3, mediate metformin uptake and activity, it is critical to define what role they play in the antineoplastic activity of metformin. METHODS Immunohistochemical and immunoblotting techniques were used in normal, dysplastic and HNSCC tissues, and HNSCC cell lines, respectively, to determine OCTs expression levels. RESULTS We report that only OCT-3 was highly expressed in a number of HNSCC cell lines, oral epithelial dysplasias, and well to moderately differentiated HNSCC. Indeed, inhibition of OCT-3 expression and activity in HNSCC cells prevented metformin-induced AMP-activated protein kinase activation and mTORC1 pathway inhibition. Moreover, in oral dysplasias, high OCT-3 expression localized to epithelial compartments where mTORC1 signaling was also upregulated suggestive of a potential local effect of metformin. CONCLUSIONS The concept of using metformin as a chemopreventive agent to control head and neck carcinogenesis is promising. Further work is warranted to elucidate largely unexplored mechanisms of metformin uptake and pharmacologic action that may ultimately influence the selection of the most suitable patients who can benefit from metformin in head and neck cancer chemoprevention.
Collapse
Affiliation(s)
- Harsh Patel
- Department of Oncology and Diagnostic Sciences, University of Maryland School of Dentistry, Baltimore, MD, USA
| | | | | | | | | |
Collapse
|
290
|
Bonanni B, Puntoni M, Cazzaniga M, Pruneri G, Serrano D, Guerrieri-Gonzaga A, Gennari A, Trabacca MS, Galimberti V, Veronesi P, Johansson H, Aristarco V, Bassi F, Luini A, Lazzeroni M, Varricchio C, Viale G, Bruzzi P, DeCensi A. Dual Effect of Metformin on Breast Cancer Proliferation in a Randomized Presurgical Trial. J Clin Oncol 2012; 30:2593-600. [DOI: 10.1200/jco.2011.39.3769] [Citation(s) in RCA: 197] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Purpose Metformin is associated with reduced breast cancer risk in observational studies in patients with diabetes, but clinical evidence for antitumor activity is unclear. The change in Ki-67 between pretreatment biopsy and post-treatment surgical specimen has prognostic value and may predict antitumor activity in breast cancer. Patients and Methods After tumor biopsy, we randomly allocated 200 nondiabetic women with operable breast cancer to either metformin 850 mg/twice per day (n = 100) or placebo (n = 100). The primary outcome measure was the difference between arms in Ki-67 after 4 weeks adjusted for baseline values. Results Overall, the metformin effect on Ki-67 change relative to placebo was not statistically significant, with a mean proportional increase of 4.0% (95% CI, −5.6% to 14.4%) 4 weeks apart. However, there was a different drug effect depending on insulin resistance (homeostasis model assessment [HOMA] index > 2.8, fasting glucose [mmol/L] × insulin [mU/L]/22.5; Pinteraction = .045), with a nonsignificant mean proportional decrease in Ki-67 of 10.5% (95% CI, −26.1% to 8.4%) in women with HOMA more than 2.8 and a nonsignificant increase of 11.1% (95% CI, −0.6% to 24.2%) with HOMA less than or equal to 2.8. A different effect of metformin according to HOMA index was noted also in luminal B tumors (Pinteraction = .05). Similar trends to drug effect modifications were observed according to body mass index (P = .143), waist/hip girth-ratio (P = .058), moderate alcohol consumption (P = .005), and C-reactive protein (P = .080). Conclusion Metformin before surgery did not significantly affect Ki-67 overall, but showed significantly different effects according to insulin resistance, particularly in luminal B tumors. Our findings warrant further studies of metformin in breast cancer with careful consideration to the metabolic characteristics of the study population.
Collapse
Affiliation(s)
- Bernardo Bonanni
- Bernardo Bonanni, Massimiliano Cazzaniga, Giancarlo Pruneri, Davide Serrano, Aliana Guerrieri-Gonzaga, Viviana Galimberti, Paolo Veronesi, Harriet Johansson, Valentina Aristarco, Fabio Bassi, Alberto Luini, Matteo Lazzeroni, Clara Varricchio, Giuseppe Viale, and Andrea DeCensi, European Institute of Oncology; Giancarlo Pruneri, Paolo Veronesi, and Giuseppe Viale, University of Milan, Milan; Matteo Puntoni, Alessandra Gennari, Maria Stella Trabacca, and Andrea DeCensi, E.O. Ospedali Galliera; and Paolo
| | - Matteo Puntoni
- Bernardo Bonanni, Massimiliano Cazzaniga, Giancarlo Pruneri, Davide Serrano, Aliana Guerrieri-Gonzaga, Viviana Galimberti, Paolo Veronesi, Harriet Johansson, Valentina Aristarco, Fabio Bassi, Alberto Luini, Matteo Lazzeroni, Clara Varricchio, Giuseppe Viale, and Andrea DeCensi, European Institute of Oncology; Giancarlo Pruneri, Paolo Veronesi, and Giuseppe Viale, University of Milan, Milan; Matteo Puntoni, Alessandra Gennari, Maria Stella Trabacca, and Andrea DeCensi, E.O. Ospedali Galliera; and Paolo
| | - Massimiliano Cazzaniga
- Bernardo Bonanni, Massimiliano Cazzaniga, Giancarlo Pruneri, Davide Serrano, Aliana Guerrieri-Gonzaga, Viviana Galimberti, Paolo Veronesi, Harriet Johansson, Valentina Aristarco, Fabio Bassi, Alberto Luini, Matteo Lazzeroni, Clara Varricchio, Giuseppe Viale, and Andrea DeCensi, European Institute of Oncology; Giancarlo Pruneri, Paolo Veronesi, and Giuseppe Viale, University of Milan, Milan; Matteo Puntoni, Alessandra Gennari, Maria Stella Trabacca, and Andrea DeCensi, E.O. Ospedali Galliera; and Paolo
| | - Giancarlo Pruneri
- Bernardo Bonanni, Massimiliano Cazzaniga, Giancarlo Pruneri, Davide Serrano, Aliana Guerrieri-Gonzaga, Viviana Galimberti, Paolo Veronesi, Harriet Johansson, Valentina Aristarco, Fabio Bassi, Alberto Luini, Matteo Lazzeroni, Clara Varricchio, Giuseppe Viale, and Andrea DeCensi, European Institute of Oncology; Giancarlo Pruneri, Paolo Veronesi, and Giuseppe Viale, University of Milan, Milan; Matteo Puntoni, Alessandra Gennari, Maria Stella Trabacca, and Andrea DeCensi, E.O. Ospedali Galliera; and Paolo
| | - Davide Serrano
- Bernardo Bonanni, Massimiliano Cazzaniga, Giancarlo Pruneri, Davide Serrano, Aliana Guerrieri-Gonzaga, Viviana Galimberti, Paolo Veronesi, Harriet Johansson, Valentina Aristarco, Fabio Bassi, Alberto Luini, Matteo Lazzeroni, Clara Varricchio, Giuseppe Viale, and Andrea DeCensi, European Institute of Oncology; Giancarlo Pruneri, Paolo Veronesi, and Giuseppe Viale, University of Milan, Milan; Matteo Puntoni, Alessandra Gennari, Maria Stella Trabacca, and Andrea DeCensi, E.O. Ospedali Galliera; and Paolo
| | - Aliana Guerrieri-Gonzaga
- Bernardo Bonanni, Massimiliano Cazzaniga, Giancarlo Pruneri, Davide Serrano, Aliana Guerrieri-Gonzaga, Viviana Galimberti, Paolo Veronesi, Harriet Johansson, Valentina Aristarco, Fabio Bassi, Alberto Luini, Matteo Lazzeroni, Clara Varricchio, Giuseppe Viale, and Andrea DeCensi, European Institute of Oncology; Giancarlo Pruneri, Paolo Veronesi, and Giuseppe Viale, University of Milan, Milan; Matteo Puntoni, Alessandra Gennari, Maria Stella Trabacca, and Andrea DeCensi, E.O. Ospedali Galliera; and Paolo
| | - Alessandra Gennari
- Bernardo Bonanni, Massimiliano Cazzaniga, Giancarlo Pruneri, Davide Serrano, Aliana Guerrieri-Gonzaga, Viviana Galimberti, Paolo Veronesi, Harriet Johansson, Valentina Aristarco, Fabio Bassi, Alberto Luini, Matteo Lazzeroni, Clara Varricchio, Giuseppe Viale, and Andrea DeCensi, European Institute of Oncology; Giancarlo Pruneri, Paolo Veronesi, and Giuseppe Viale, University of Milan, Milan; Matteo Puntoni, Alessandra Gennari, Maria Stella Trabacca, and Andrea DeCensi, E.O. Ospedali Galliera; and Paolo
| | - Maria Stella Trabacca
- Bernardo Bonanni, Massimiliano Cazzaniga, Giancarlo Pruneri, Davide Serrano, Aliana Guerrieri-Gonzaga, Viviana Galimberti, Paolo Veronesi, Harriet Johansson, Valentina Aristarco, Fabio Bassi, Alberto Luini, Matteo Lazzeroni, Clara Varricchio, Giuseppe Viale, and Andrea DeCensi, European Institute of Oncology; Giancarlo Pruneri, Paolo Veronesi, and Giuseppe Viale, University of Milan, Milan; Matteo Puntoni, Alessandra Gennari, Maria Stella Trabacca, and Andrea DeCensi, E.O. Ospedali Galliera; and Paolo
| | - Viviana Galimberti
- Bernardo Bonanni, Massimiliano Cazzaniga, Giancarlo Pruneri, Davide Serrano, Aliana Guerrieri-Gonzaga, Viviana Galimberti, Paolo Veronesi, Harriet Johansson, Valentina Aristarco, Fabio Bassi, Alberto Luini, Matteo Lazzeroni, Clara Varricchio, Giuseppe Viale, and Andrea DeCensi, European Institute of Oncology; Giancarlo Pruneri, Paolo Veronesi, and Giuseppe Viale, University of Milan, Milan; Matteo Puntoni, Alessandra Gennari, Maria Stella Trabacca, and Andrea DeCensi, E.O. Ospedali Galliera; and Paolo
| | - Paolo Veronesi
- Bernardo Bonanni, Massimiliano Cazzaniga, Giancarlo Pruneri, Davide Serrano, Aliana Guerrieri-Gonzaga, Viviana Galimberti, Paolo Veronesi, Harriet Johansson, Valentina Aristarco, Fabio Bassi, Alberto Luini, Matteo Lazzeroni, Clara Varricchio, Giuseppe Viale, and Andrea DeCensi, European Institute of Oncology; Giancarlo Pruneri, Paolo Veronesi, and Giuseppe Viale, University of Milan, Milan; Matteo Puntoni, Alessandra Gennari, Maria Stella Trabacca, and Andrea DeCensi, E.O. Ospedali Galliera; and Paolo
| | - Harriet Johansson
- Bernardo Bonanni, Massimiliano Cazzaniga, Giancarlo Pruneri, Davide Serrano, Aliana Guerrieri-Gonzaga, Viviana Galimberti, Paolo Veronesi, Harriet Johansson, Valentina Aristarco, Fabio Bassi, Alberto Luini, Matteo Lazzeroni, Clara Varricchio, Giuseppe Viale, and Andrea DeCensi, European Institute of Oncology; Giancarlo Pruneri, Paolo Veronesi, and Giuseppe Viale, University of Milan, Milan; Matteo Puntoni, Alessandra Gennari, Maria Stella Trabacca, and Andrea DeCensi, E.O. Ospedali Galliera; and Paolo
| | - Valentina Aristarco
- Bernardo Bonanni, Massimiliano Cazzaniga, Giancarlo Pruneri, Davide Serrano, Aliana Guerrieri-Gonzaga, Viviana Galimberti, Paolo Veronesi, Harriet Johansson, Valentina Aristarco, Fabio Bassi, Alberto Luini, Matteo Lazzeroni, Clara Varricchio, Giuseppe Viale, and Andrea DeCensi, European Institute of Oncology; Giancarlo Pruneri, Paolo Veronesi, and Giuseppe Viale, University of Milan, Milan; Matteo Puntoni, Alessandra Gennari, Maria Stella Trabacca, and Andrea DeCensi, E.O. Ospedali Galliera; and Paolo
| | - Fabio Bassi
- Bernardo Bonanni, Massimiliano Cazzaniga, Giancarlo Pruneri, Davide Serrano, Aliana Guerrieri-Gonzaga, Viviana Galimberti, Paolo Veronesi, Harriet Johansson, Valentina Aristarco, Fabio Bassi, Alberto Luini, Matteo Lazzeroni, Clara Varricchio, Giuseppe Viale, and Andrea DeCensi, European Institute of Oncology; Giancarlo Pruneri, Paolo Veronesi, and Giuseppe Viale, University of Milan, Milan; Matteo Puntoni, Alessandra Gennari, Maria Stella Trabacca, and Andrea DeCensi, E.O. Ospedali Galliera; and Paolo
| | - Alberto Luini
- Bernardo Bonanni, Massimiliano Cazzaniga, Giancarlo Pruneri, Davide Serrano, Aliana Guerrieri-Gonzaga, Viviana Galimberti, Paolo Veronesi, Harriet Johansson, Valentina Aristarco, Fabio Bassi, Alberto Luini, Matteo Lazzeroni, Clara Varricchio, Giuseppe Viale, and Andrea DeCensi, European Institute of Oncology; Giancarlo Pruneri, Paolo Veronesi, and Giuseppe Viale, University of Milan, Milan; Matteo Puntoni, Alessandra Gennari, Maria Stella Trabacca, and Andrea DeCensi, E.O. Ospedali Galliera; and Paolo
| | - Matteo Lazzeroni
- Bernardo Bonanni, Massimiliano Cazzaniga, Giancarlo Pruneri, Davide Serrano, Aliana Guerrieri-Gonzaga, Viviana Galimberti, Paolo Veronesi, Harriet Johansson, Valentina Aristarco, Fabio Bassi, Alberto Luini, Matteo Lazzeroni, Clara Varricchio, Giuseppe Viale, and Andrea DeCensi, European Institute of Oncology; Giancarlo Pruneri, Paolo Veronesi, and Giuseppe Viale, University of Milan, Milan; Matteo Puntoni, Alessandra Gennari, Maria Stella Trabacca, and Andrea DeCensi, E.O. Ospedali Galliera; and Paolo
| | - Clara Varricchio
- Bernardo Bonanni, Massimiliano Cazzaniga, Giancarlo Pruneri, Davide Serrano, Aliana Guerrieri-Gonzaga, Viviana Galimberti, Paolo Veronesi, Harriet Johansson, Valentina Aristarco, Fabio Bassi, Alberto Luini, Matteo Lazzeroni, Clara Varricchio, Giuseppe Viale, and Andrea DeCensi, European Institute of Oncology; Giancarlo Pruneri, Paolo Veronesi, and Giuseppe Viale, University of Milan, Milan; Matteo Puntoni, Alessandra Gennari, Maria Stella Trabacca, and Andrea DeCensi, E.O. Ospedali Galliera; and Paolo
| | - Giuseppe Viale
- Bernardo Bonanni, Massimiliano Cazzaniga, Giancarlo Pruneri, Davide Serrano, Aliana Guerrieri-Gonzaga, Viviana Galimberti, Paolo Veronesi, Harriet Johansson, Valentina Aristarco, Fabio Bassi, Alberto Luini, Matteo Lazzeroni, Clara Varricchio, Giuseppe Viale, and Andrea DeCensi, European Institute of Oncology; Giancarlo Pruneri, Paolo Veronesi, and Giuseppe Viale, University of Milan, Milan; Matteo Puntoni, Alessandra Gennari, Maria Stella Trabacca, and Andrea DeCensi, E.O. Ospedali Galliera; and Paolo
| | - Paolo Bruzzi
- Bernardo Bonanni, Massimiliano Cazzaniga, Giancarlo Pruneri, Davide Serrano, Aliana Guerrieri-Gonzaga, Viviana Galimberti, Paolo Veronesi, Harriet Johansson, Valentina Aristarco, Fabio Bassi, Alberto Luini, Matteo Lazzeroni, Clara Varricchio, Giuseppe Viale, and Andrea DeCensi, European Institute of Oncology; Giancarlo Pruneri, Paolo Veronesi, and Giuseppe Viale, University of Milan, Milan; Matteo Puntoni, Alessandra Gennari, Maria Stella Trabacca, and Andrea DeCensi, E.O. Ospedali Galliera; and Paolo
| | - Andrea DeCensi
- Bernardo Bonanni, Massimiliano Cazzaniga, Giancarlo Pruneri, Davide Serrano, Aliana Guerrieri-Gonzaga, Viviana Galimberti, Paolo Veronesi, Harriet Johansson, Valentina Aristarco, Fabio Bassi, Alberto Luini, Matteo Lazzeroni, Clara Varricchio, Giuseppe Viale, and Andrea DeCensi, European Institute of Oncology; Giancarlo Pruneri, Paolo Veronesi, and Giuseppe Viale, University of Milan, Milan; Matteo Puntoni, Alessandra Gennari, Maria Stella Trabacca, and Andrea DeCensi, E.O. Ospedali Galliera; and Paolo
| |
Collapse
|
291
|
Abstract
National Cancer Institute has announced 24 provocative questions on cancer. Here I try to answer some of them by linking the dots of existing knowledge.
Collapse
Affiliation(s)
- Mikhail V Blagosklonny
- Department of Cell Stress Biology, Roswell Park Cancer Institute, BLSC, L3-312, Elm and Carlton Streets, Buffalo, NY 14263, USA.
| |
Collapse
|
292
|
Del Barco S, Vazquez-Martin A, Cufí S, Oliveras-Ferraros C, Bosch-Barrera J, Joven J, Martin-Castillo B, Menendez JA. Metformin: multi-faceted protection against cancer. Oncotarget 2012; 2:896-917. [PMID: 22203527 PMCID: PMC3282095 DOI: 10.18632/oncotarget.387] [Citation(s) in RCA: 238] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The biguanide metformin, a widely used drug for the treatment of type 2 diabetes, may exert cancer chemopreventive effects by suppressing the transformative and hyperproliferative processes that initiate carcinogenesis. Metformin's molecular targets in cancer cells (e.g., mTOR, HER2) are similar to those currently being used for directed cancer therapy. However, metformin is nontoxic and might be extremely useful for enhancing treatment efficacy of mechanism-based and biologically targeted drugs. Here, we first revisit the epidemiological, preclinical, and clinical evidence from the last 5 years showing that metformin is a promising candidate for oncology therapeutics. Second, the anticancer effects of metformin by both direct (insulin-independent) and indirect (insulin-dependent) mechanisms are discussed in terms of metformin-targeted processes and the ontogenesis of cancer stem cells (CSC), including Epithelial-to-Mesenchymal Transition (EMT) and microRNAs-regulated dedifferentiation of CSCs. Finally, we present preliminary evidence that metformin may regulate cellular senescence, an innate safeguard against cellular immortalization. There are two main lines of evidence that suggest that metformin's primary target is the immortalizing step during tumorigenesis. First, metformin activates intracellular DNA damage response checkpoints. Second, metformin attenuates the anti-senescence effects of the ATP-generating glycolytic metabotype-the Warburg effect-, which is required for self-renewal and proliferation of CSCs. If metformin therapy presents an intrinsic barrier against tumorigenesis by lowering the threshold for stress-induced senescence, metformin therapeutic strategies may be pivotal for therapeutic intervention for cancer. Current and future clinical trials will elucidate whether metformin has the potential to be used in preventive and treatment settings as an adjuvant to current cancer therapeutics.
Collapse
Affiliation(s)
- Sonia Del Barco
- Medical Oncology, Catalan Institute of Oncology, Girona, Catalonia, Spain
| | | | | | | | | | | | | | | |
Collapse
|
293
|
Abstract
The abnormal BCR-ABL oncoprotein is a constitutively active tyrosine kinase driving aberrant proliferation of transformed hematopoietic cells. BCR-ABL regulates activation of many mitogenic and pro-survival pathways, including the PI 3'K/AKT/mTOR pathway that controls various effectors and regulates initiation of mRNA translation in mammalian cells. Although tyrosine kinase inhibitors (TKIs) that target the ABL kinase domain have remarkable clinical activity and have dramatically changed the natural history of Ph+ leukemias, resistance to these agents also develops via a wide range of mechanisms. Efforts to target the PI3'K/AKT/mTOR signaling pathway using kinase inhibitors have been the focus of extensive ongoing investigations by several research groups. Here we review the effects of activation of the AMPK kinase, which regulates downstream targeting and inhibition of mTOR. The potential for future clinical-translational applications of AMPK activators such as AICAR, metformin and resveratrol for the treatment of chronic myelogenous leukemia (CML) and Ph+ acute lymphoblastic leukemia (ALL) are discussed.
Collapse
|
294
|
Xiao X, He Q, Lu C, Werle KD, Zhao RX, Chen J, Davis BC, Cui R, Liang J, Xu ZX. Metformin impairs the growth of liver kinase B1-intact cervical cancer cells. Gynecol Oncol 2012; 127:249-55. [PMID: 22735790 DOI: 10.1016/j.ygyno.2012.06.032] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 06/15/2012] [Accepted: 06/19/2012] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Metformin is one of the most widely used drugs for the treatment of type 2 diabetes. Recent investigations demonstrated that application of metformin reduces cancer risk. The present study aimed to determine the role of liver kinase B1 (LKB1) in the response of cervical cancer cells to metformin. METHODS LKB1 expression and the integrity of LKB1-AMPK signaling were determined with immunoblot in 6 cervical cancer cell lines. Cellular sensitivity to metformin was analyzed with MTT assay. RESULTS Metformin inhibited growth of cervical cancer cells, C33A, Me180, and CaSki, but was less effective against HeLa, HT-3, and MS751 cells. Analyzing the expression status and the integrity of LKB1-AMPK-mTOR signaling, we found that cervical cancer cells sensitive to metformin were LKB1 intact and exerted an integral AMPK-mTOR signaling response after the treatment. Ectopic expression of LKB1 with stable transduction system or inducible expression construct in endogenous LKB1 deficient cells improved the activation of AMPK, promoted the inhibition of mTOR, and prompted the sensitivity of cells to metformin. In contrast, knock-down of LKB1 compromised cellular response to metformin. Our further investigation demonstrated that metformin could induce both apoptosis and autophagy in cervical cancer cells when LKB1 is expressed. CONCLUSIONS Metformin is a potential drug for the treatment of cervical cancers, in particular to those with intact LKB1 expression. Administration of cell metabolism agonists may enhance LKB1 tumor suppression, inhibit cell growth, and reduce tumor cell viability via the activation of LKB1-AMPK signaling.
Collapse
Affiliation(s)
- Xuxian Xiao
- Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
295
|
Metformin: an emerging new therapeutic option for targeting cancer stem cells and metastasis. JOURNAL OF ONCOLOGY 2012; 2012:928127. [PMID: 22701483 PMCID: PMC3373168 DOI: 10.1155/2012/928127] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 03/05/2012] [Indexed: 12/13/2022]
Abstract
Metastasis is an intricate process by which a small number of cancer cells from the primary tumor site undergo numerous alterations, which enables them to form secondary tumors at another and often multiple sites in the host. Transition of a cancer cell from epithelial to mesenchymal phenotype is thought to be the first step in the progression of metastasis. Recently, the recognition of cancer stem cells has added to the perplexity in understanding metastasis, as studies suggest cancer stem cells to be the originators of metastasis. All current and investigative drugs have been unable to prevent or reverse metastasis, as a result of which most metastatic cancers are incurable. A potential drug that can be considered is metformin, an oral hypoglycemic drug. In this review we discuss the potential of metformin in targeting both epithelial to mesenchymal transition and cancer stem cells in combating cancer metastases.
Collapse
|
296
|
Targeting metabolism for cancer treatment and prevention: metformin, an old drug with multi-faceted effects. Oncogene 2012; 32:1475-87. [PMID: 22665053 DOI: 10.1038/onc.2012.181] [Citation(s) in RCA: 175] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Understanding the complexity of cancer and of the underlying regulatory networks provides a new paradigm that tackles cancer development and treatment through a system biology approach, contemporarily acting on various intersecting pathways. Cancer cell metabolism is an old pathogenetic issue that has recently gained new interest as target for therapeutic approaches. More than 70 years ago, Warburg discovered that malignant cells generally have altered metabolism with high rates of glucose uptake and increased glycolysis, even under aerobic condition. Observational studies have provided evidence that impaired metabolism, obesity, hyperglycemia and hyperinsulinemia may have a role in cancer development, progression and prognosis, and actually diabetic and obese patients have increased cancer risk. On the other hand, caloric restriction has been shown to prolong life span and reduce cancer incidence in several animal models, having an impact on different metabolic pathways. Metformin, an antidiabetic drug widely used for over 40 years, mimics caloric restriction acting on cell metabolism at multiple levels, reducing all energy-consuming processes in the cells, including cell proliferation. By overviewing molecular mechanisms of action, epidemiological evidences, experimental data in tumor models and early clinical study results, this review provides information supporting the promising use of metformin in cancer prevention and treatment.
Collapse
|
297
|
Abstract
The anti-diabetic drug metformin is rapidly emerging as a potential anti-cancer agent. Metformin, effective in treating type 2 diabetes and the insulin resistance syndromes, improves insulin resistance by reducing hepatic gluconeogenesis and by enhancing glucose uptake by skeletal muscle. Epidemiological studies have consistently associated metformin use with decreased cancer incidence and cancer-related mortality. Furthermore, numerous preclinical and clinical studies have demonstrated anti-cancer effects of metformin, leading to an explosion of interest in evaluating this agent in human cancer. The effects of metformin on circulating insulin levels indicate a potential efficacy towards cancers associated with hyperinsulinaemia; however, metformin may also directly inhibit tumour growth. In this review, we describe the mechanism of action of metformin and summarise the epidemiological, clinical and preclinical evidence supporting a role for metformin in the treatment of cancer. In addition, the challenges associated with translating preclinical results into therapeutic benefit in the clinical setting will be discussed.
Collapse
Affiliation(s)
- Ryan J O Dowling
- Division of Signalling Biology, Ontario Cancer Institute, University Health Network, Toronto, Ontario, Canada M5G 2M9
| | | | | | | |
Collapse
|
298
|
Role of phosphatidylinositol-3-kinase pathway in head and neck squamous cell carcinoma. JOURNAL OF ONCOLOGY 2012; 2012:450179. [PMID: 22666248 PMCID: PMC3362130 DOI: 10.1155/2012/450179] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Accepted: 03/14/2012] [Indexed: 01/04/2023]
Abstract
Activation of the phosphatidylinositol-3-kinase (PI3K) pathway is one of the most frequently observed molecular alterations in many human malignancies, including head and neck squamous cell carcinoma (HNSCC). A growing body of evidence demonstrates the prime importance of the PI3K pathway at each stage of tumorigenesis, that is, tumor initiation, progression, recurrence, and metastasis. Expectedly, targeting the PI3K pathway yields some promising results in both preclinical studies and clinical trials for certain cancer patients. However, there are still many questions that need to be answered, given the complexity of this pathway and the existence of its multiple feedback loops and interactions with other signaling pathways. In this paper, we will summarize recent advances in the understanding of the PI3K pathway role in human malignancies, with an emphasis on HNSCC, and discuss the clinical applications and future direction of this field.
Collapse
|
299
|
Vakana E, Altman JK, Platanias LC. Targeting AMPK in the treatment of malignancies. J Cell Biochem 2012; 113:404-9. [PMID: 21928327 DOI: 10.1002/jcb.23369] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The AMPK pathway is a metabolic stress-related and energy censor pathway which plays important regulatory roles in normal and malignant cells. This cellular cascade controls generation of signals for initiation of mRNA translation via the mTOR pathway and exhibits regulatory roles on the initiation of autophagy. AMPK activators have been shown to suppress mTOR activity and to negatively control malignant transformation and cell proliferation of diverse malignant cell types. Such properties of AMPK inducers have generated substantial interest for the use of AMPK targeting compounds as antineoplastic agents and have provoked extensive research efforts to better define and classify the mechanisms controlling AMPK activity and its functional consequences in malignant cells.
Collapse
Affiliation(s)
- Eliza Vakana
- Robert H. Lurie Comprehensive Cancer Center and Division of Hematology/Oncology, Northwestern University Medical School and Jesse Brown VA Medical Center, Chicago, Illinois 60611, USA
| | | | | |
Collapse
|
300
|
Song CW, Lee H, Dings RPM, Williams B, Powers J, Santos TD, Choi BH, Park HJ. Metformin kills and radiosensitizes cancer cells and preferentially kills cancer stem cells. Sci Rep 2012; 2:362. [PMID: 22500211 PMCID: PMC3324825 DOI: 10.1038/srep00362] [Citation(s) in RCA: 228] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Accepted: 03/02/2012] [Indexed: 12/24/2022] Open
Abstract
The anti-cancer effects of metformin, the most widely used drug for type 2 diabetes, alone or in combination with ionizing radiation were studied with MCF-7 human breast cancer cells and FSaII mouse fibrosarcoma cells. Clinically achievable concentrations of metformin caused significant clonogenic death in cancer cells. Importantly, metformin was preferentially cytotoxic to cancer stem cells relative to non-cancer stem cells. Metformin increased the radiosensitivity of cancer cells in vitro, and significantly enhanced the radiation-induced growth delay of FSaII tumors (s.c.) in the legs of C3H mice. Both metformin and ionizing radiation activated AMPK leading to inactivation of mTOR and suppression of its downstream effectors such as S6K1 and 4EBP1, a crucial signaling pathway for proliferation and survival of cancer cells, in vitro as well as in the in vivo tumors. Conclusion: Metformin kills and radiosensitizes cancer cells and eradicates radioresistant cancer stem cells by activating AMPK and suppressing mTOR.
Collapse
Affiliation(s)
- Chang W Song
- Radiobiology Laboratory, Department of Therapeutic Radiology-Radiation Oncology, University of Minnesota Medical School, Minneapolis, MN, U.S.A
| | | | | | | | | | | | | | | |
Collapse
|