-
Journal of Translational Medicine Jun 2023Metformin is a well-known anti-diabetic drug that has been repurposed for several emerging applications, including as an anti-cancer agent. It boasts the distinct... (Review)
Review
Metformin is a well-known anti-diabetic drug that has been repurposed for several emerging applications, including as an anti-cancer agent. It boasts the distinct advantages of an excellent safety and tolerability profile and high cost-effectiveness at less than one US dollar per daily dose. Epidemiological evidence reveals that metformin reduces the risk of cancer and decreases cancer-related mortality in patients with diabetes; however, the exact mechanisms are not well understood. Energy metabolism may be central to the mechanism of action. Based on altering whole-body energy metabolism or cellular state, metformin's modes of action can be divided into two broad, non-mutually exclusive categories: "direct effects", which induce a direct effect on cancer cells, independent of blood glucose and insulin levels, and "indirect effects" that arise from systemic metabolic changes depending on blood glucose and insulin levels. In this review, we summarize an updated account of the current knowledge on metformin antitumor action, elaborate on the underlying mechanisms in terms of the hallmarks of cancer, and propose potential applications for repurposing metformin for cancer therapeutics.
Topics: Humans; Metformin; Blood Glucose; Drug Repositioning; Neoplasms; Insulins; Hypoglycemic Agents; Diabetes Mellitus, Type 2
PubMed: 37344841
DOI: 10.1186/s12967-023-04263-8 -
The Lancet. Diabetes & Endocrinology Apr 2023Tackling the mechanisms underlying ageing is desirable to help to extend the duration and improve the quality of life. Life extension has been achieved in animal models... (Review)
Review
Tackling the mechanisms underlying ageing is desirable to help to extend the duration and improve the quality of life. Life extension has been achieved in animal models by suppressing the growth hormone-insulin-like growth factor 1 (IGF-1) axis and also via dietary restriction. Metformin has become the focus of increased interest as a possible anti-ageing drug. There is some overlap in the postulated mechanisms of how these three approaches could produce anti-ageing effects, with convergence on common downstream pathways. In this Review, we draw on evidence from both animal models and human studies to assess the effects of suppression of the growth hormone-IGF-1 axis, dietary restriction, and metformin on ageing.
Topics: Animals; Humans; Growth Hormone; Insulin-Like Growth Factor I; Metformin; Quality of Life; Aging; Human Growth Hormone
PubMed: 36848915
DOI: 10.1016/S2213-8587(23)00001-3 -
Annals of Oncology : Official Journal... Dec 2016Metformin use has been associated with a reduced risk of developing cancer and an improvement in overall cancer survival rates in meta-analyses, but, to date, evidence... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Metformin use has been associated with a reduced risk of developing cancer and an improvement in overall cancer survival rates in meta-analyses, but, to date, evidence to support the use of metformin as an adjuvant therapy in individual cancer types has not been presented.
PATIENTS AND METHODS
We systematically searched research databases, conference abstracts and trial registries for any studies reporting cancer outcomes for individual tumour types in metformin users compared with non-users, and extracted data on patients with early-stage cancer. Studies were assessed for design and quality, and a meta-analysis was conducted to quantify the adjuvant effect of metformin on recurrence-free survival (RFS), overall survival (OS) and cancer-specific survival (CSS), to inform future trial design.
RESULTS
Of 7670 articles screened, 27 eligible studies were identified comprising 24 178 participants, all enrolled in observational studies. In those with early-stage colorectal cancer, metformin use was associated with a significant benefit in all outcomes [RFS hazard ratio (HR) 0.63, 95% confidence interval (CI) 0.47-0.85; OS HR 0.69, CI 0.58-0.83; CSS HR 0.58, CI 0.39-0.86]. For men with early-stage prostate cancer, metformin was associated with significant, or borderline significant, benefits in all outcomes (RFS HR 0.83, CI 0.69-1.00; OS HR 0.82, CI 0.73-0.93; CSS HR 0.58, CI 0.37-0.93); however, there was significant heterogeneity between studies. The data suggest that prostate cancer patients treated with radical radiotherapy may benefit more from metformin (RFS HR 0.45, CI 0.29-0.70). In breast and urothelial cancer, no significant benefits were identified. Sufficient data were not available to conduct analyses on the impact of metformin dose and duration.
CONCLUSIONS
Our findings suggest that metformin could be a useful adjuvant agent, with the greatest benefits seen in colorectal and prostate cancer, particularly in those receiving radical radiotherapy, and randomised, controlled trials which investigate dose and duration, alongside efficacy, are advocated.
Topics: Chemotherapy, Adjuvant; Disease-Free Survival; Humans; Metformin; Neoplasm Staging; Neoplasms
PubMed: 27681864
DOI: 10.1093/annonc/mdw410 -
ACS Nano Feb 2022In view of the lack of a specific drug-sustained release system that is responsive to chronic wounds of the type II diabetic foot, and the demands for frequent movement...
In view of the lack of a specific drug-sustained release system that is responsive to chronic wounds of the type II diabetic foot, and the demands for frequent movement at the foot wound, pH/glucose dual-responsive metformin-released adhesion-enhanced self-healing easy-removable antibacterial antioxidant conductive hemostasis multifunctional phenylboronic acid and benzaldehyde bifunctional polyethylene glycol--poly(glycerol sebacic acid)/dihydrocaffeic acid and l-arginine cografted chitosan (PEGS-PBA-BA/CS-DA-LAG, denoted as PC) hydrogel dressings were constructed based on the double dynamic bond of the Schiff-base and phenylboronate ester. It was further demonstrated that the PC hydrogel promotes wound healing by reducing inflammation and enhancing angiogenesis in a rat type II diabetic foot model. In addition, the addition of metformin (Met) and graphene oxide (GO), as well as their synergy, were confirmed to better promote wound repair . In summary, adhesion-enhanced self-healing multifunctional PC/GO/Met hydrogels with stimuli-responsive metformin release ability and easy removability have shown a promoting effect on the healing of chronic athletic diabetic wounds and provide a local-specific drug dual-response release strategy for the treatment of type II diabetic feet.
Topics: Animals; Bandages; Diabetes Mellitus; Diabetic Foot; Glucose; Hydrogels; Hydrogen-Ion Concentration; Metformin; Rats; Sports; Wound Healing
PubMed: 35099927
DOI: 10.1021/acsnano.1c11040 -
International Journal of Molecular... May 2021Metformin is the first-line treatment for many people with type 2 diabetes mellitus (T2DM) and gestational diabetes mellitus (GDM) to maintain glycaemic control. Recent... (Review)
Review
Metformin is the first-line treatment for many people with type 2 diabetes mellitus (T2DM) and gestational diabetes mellitus (GDM) to maintain glycaemic control. Recent evidence suggests metformin can cross the placenta during pregnancy, thereby exposing the fetus to high concentrations of metformin and potentially restricting placental and fetal growth. Offspring exposed to metformin during gestation are at increased risk of being born small for gestational age (SGA) and show signs of 'catch up' growth and obesity during childhood which increases their risk of future cardiometabolic diseases. The mechanisms by which metformin impacts on the fetal growth and long-term health of the offspring remain to be established. Metformin is associated with maternal vitamin B deficiency and antifolate like activity. Vitamin B and folate balance is vital for one carbon metabolism, which is essential for DNA methylation and purine/pyrimidine synthesis of nucleic acids. Folate:vitamin B imbalance induced by metformin may lead to genomic instability and aberrant gene expression, thus promoting fetal programming. Mitochondrial aerobic respiration may also be affected, thereby inhibiting placental and fetal growth, and suppressing mammalian target of rapamycin (mTOR) activity for cellular nutrient transport. Vitamin supplementation, before or during metformin treatment in pregnancy, could be a promising strategy to improve maternal vitamin B and folate levels and reduce the incidence of SGA births and childhood obesity. Heterogeneous diagnostic and screening criteria for GDM and the transient nature of nutrient biomarkers have led to inconsistencies in clinical study designs to investigate the effects of metformin on folate:vitamin B balance and child development. As rates of diabetes in pregnancy continue to escalate, more women are likely to be prescribed metformin; thus, it is of paramount importance to improve our understanding of metformin's transgenerational effects to develop prophylactic strategies for the prevention of adverse fetal outcomes.
Topics: Carbon; Diabetes Mellitus, Type 2; Diabetes, Gestational; Drug Interactions; Female; Fetal Development; Fetus; Folic Acid; Humans; Metformin; Obesity; Placenta; Pregnancy; Pregnancy Complications; Pregnancy in Diabetics; Vitamin B 12
PubMed: 34071182
DOI: 10.3390/ijms22115759 -
Diabetes Care Jul 2021To determine the longer-term effects of metformin treatment and behavioral weight loss on gut microbiota and short-chain fatty acids (SCFAs). (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
To determine the longer-term effects of metformin treatment and behavioral weight loss on gut microbiota and short-chain fatty acids (SCFAs).
RESEARCH DESIGN AND METHODS
We conducted a 3-parallel-arm, randomized trial. We enrolled overweight/obese adults who had been treated for solid tumors but had no ongoing cancer treatment and randomized them ( = 121) to either ) metformin (up to 2,000 mg), ) coach-directed behavioral weight loss, or ) self-directed care (control) for 12 months. We collected stool and serum at baseline ( = 114), 6 months ( = 109), and 12 months ( = 105). From stool, we extracted microbial DNA and conducted amplicon and metagenomic sequencing. We measured SCFAs and other biochemical parameters from fasting serum.
RESULTS
Of the 121 participants, 79% were female and 46% were Black, and the mean age was 60 years. Only metformin treatment significantly altered microbiota composition. Compared with control, metformin treatment increased amplicon sequence variants for (confirmed as by metagenomic sequencing) and and decreased at both 6 and 12 months and decreased the genus , including and at 12 months. Effects were similar in comparison of the metformin group with the behavioral weight loss group. Metformin versus control also increased butyrate, acetate, and valerate at 6 months (but not at 12 months). Behavioral weight loss versus control did not significantly alter microbiota composition but did increase acetate at 6 months (but not at 12 months). Increases in acetate were associated with decreases in fasting insulin. Additional whole-genome metagenomic sequencing of a subset of the metformin group showed that metformin altered 62 metagenomic functional pathways, including an acetate-producing pathway and three pathways in glucose metabolism.
CONCLUSIONS
Metformin, but not behavioral weight loss, impacted gut microbiota composition at 6 months and 12 months. Both metformin and behavioral weight loss altered circulating SCFAs at 6 months, including increasing acetate, which correlated with lower fasting insulin. Future research is needed to elucidate whether the gut microboime mediates or modifies metformin's health effects.
Topics: Adult; Fatty Acids, Volatile; Feces; Female; Gastrointestinal Microbiome; Humans; Metformin; Middle Aged; Obesity; Weight Loss
PubMed: 34006565
DOI: 10.2337/dc20-2257 -
ELife Jan 2023This study aimed to investigate the protective effect of metformin on trabecular meshwork (TM) and explore its molecular mechanisms in vivo and in vitro. Ocular...
This study aimed to investigate the protective effect of metformin on trabecular meshwork (TM) and explore its molecular mechanisms in vivo and in vitro. Ocular hypertension (OHT) mouse models were induced with dexamethasone and further treated with metformin to determine the intraocular pressure (IOP)-lowering effect. Cultured human TM cells (HTMCs) were pre-stimulated with tert-butyl hydroperoxide (tBHP) to induce oxidative damage and then supplemented with metformin for another 24 hr. The expression of fibrotic markers and integrin/Rho-associated kinase (ROCK) signals, including α-smooth muscle actin (α-SMA), transforming growth factor-β (TGF-β), fibronectin, integrin beta 1, ROCK 1/2, AMP-activated protein kinase, myosin light chain 1, and F-actin were determined by western blotting and immunofluorescence. Reactive oxygen species (ROS) content was analysed using flow cytometry. Transmission electron microscopy was performed to observe microfilaments in HTMCs. It showed that metformin administration reduced the elevated IOP and alleviated the fibrotic activity of aqueous humour outflow in OHT models. Additionally, metformin rearranged the disordered cytoskeleton in the TM both in vivo and in vitro and significantly inhibited ROS production and activated integrin/ROCK signalling induced by tBHP in HTMCs. These results indicated that metformin reduced the elevated IOP in steroid-induced OHT mouse models and exerted its protective effects against oxidative injury by regulating cytoskeleton remodelling through the integrin/ROCK pathway. This study provides new insights into metformin use and preclinical evidence for the potential treatment of primary open-angle glaucoma.
Topics: Mice; Animals; Humans; Trabecular Meshwork; Glaucoma, Open-Angle; Metformin; Reactive Oxygen Species; Integrins; Glaucoma; Ocular Hypertension; Cells, Cultured; Oxidative Stress
PubMed: 36598818
DOI: 10.7554/eLife.81198 -
EMBO Molecular Medicine Dec 2022Metformin, a well-known antidiabetic drug, has been repurposed for cancer treatment; however, recently observed drug resistance and tumor metastasis have questioned its...
Metformin, a well-known antidiabetic drug, has been repurposed for cancer treatment; however, recently observed drug resistance and tumor metastasis have questioned its further application. Here, we found that long-term metformin exposure led to metabolic adaptation of hepatocellular carcinoma (HCC) cells, which was characterized by an obvious epithelial-mesenchymal transition (EMT) phenotype and compensatory elevation of oxidative phosphorylation (OXPHOS). TOMM34, a translocase of the outer mitochondrial membrane, was upregulated to promote tumor metastasis in response to metformin-induced metabolic stress. Mechanistically, TOMM34 interacted with ATP5B to preserve F F -ATPase activity, which conferred mitochondrial OXPHOS and ATP production. This metabolic preference for OXPHOS suggested a large requirement of energy supply by cancer cells to survive and spread in response to therapeutic stress. Notably, disturbing the interaction between TOMM34 and ATP5B using Gboxin, a specific OXPHOS inhibitor, increased sensitivity to metformin and suppressed tumor progression both in vitro and in vivo. Overall, this study demonstrates a molecular link of the TOMM34/ATP5B-ATP synthesis axis during metformin adaptation and provides promising therapeutic targets for metformin sensitization in cancer treatment.
Topics: Humans; Metformin; Carcinoma, Hepatocellular; Liver Neoplasms; Cell Line; Adenosine Triphosphate; Mitochondrial Precursor Protein Import Complex Proteins
PubMed: 36321555
DOI: 10.15252/emmm.202216082 -
Pharmacological Research Mar 2022Metformin is the oldest and most commonly used first-line antidiabetic drug because of its good clinical efficacy, high safety, low cost and easy access. At the same... (Review)
Review
Metformin is the oldest and most commonly used first-line antidiabetic drug because of its good clinical efficacy, high safety, low cost and easy access. At the same time, in recent years, we have found that its role as a therapeutic drug is gradually expanding. A large number of basic studies have shown that metformin may become a promising attractive candidate for drug repurposing. Therefore, it is extremely beneficial to conduct an in-depth discussion on the main mechanism of metformin. As early as the year 1950, studies showed that metformin played a biological role by regulating mitochondria. Then, ground-breaking studies showed that metformin functions by inhibiting complex I in the mitochondrial respiratory chain. Although there are still many controversies about the key molecular targets of metformin, with the emergence of more and more evidence, it gradually came to be concluded that mitochondria play a central role in the application of metformin. Mitochondria are important fulcrums for cell functions. The exact mechanism of action in mitochondria of this pleiotropic anti-hyperglycaemic molecule is still unclear. This review article explores the core role of mitochondria in the pharmacological and toxicological effects of metformin, and summarises the mechanism of action if metformin in mitochondria. It also provides ideas and supporting evidence for the re-development and reuse of metformin as an old drug, as well as new insight into the treatment of human diseases.
Topics: Humans; Hypoglycemic Agents; Metformin; Mitochondria
PubMed: 35124206
DOI: 10.1016/j.phrs.2022.106114 -
Science Advances Sep 2022Ovarian fibrosis is a pathological condition associated with aging and is responsible for a variety of ovarian dysfunctions. Given the known contributions of tissue...
Ovarian fibrosis is a pathological condition associated with aging and is responsible for a variety of ovarian dysfunctions. Given the known contributions of tissue fibrosis to tumorigenesis, it is anticipated that ovarian fibrosis may contribute to ovarian cancer risk. We recently reported that diabetic postmenopausal women using metformin had ovarian collagen abundance and organization that were similar to premenopausal ovaries from nondiabetic women. In this study, we investigated the effects of aging and metformin on mouse ovarian fibrosis at a single-cell level. We discovered that metformin treatment prevented age-associated ovarian fibrosis by modulating the proportion of fibroblasts, myofibroblasts, and immune cells. Senescence-associated secretory phenotype (SASP)-producing fibroblasts increased in aged ovaries, and a unique metformin-responsive subpopulation of macrophages emerged in aged mice treated with metformin. The results demonstrate that metformin can modulate specific populations of immune cells and fibroblasts to prevent age-associated ovarian fibrosis and offers a new strategy to prevent ovarian fibrosis.
Topics: Animals; Female; Fibroblasts; Fibrosis; Humans; Metformin; Mice; Myofibroblasts; Ovary
PubMed: 36054356
DOI: 10.1126/sciadv.abq1475