Metformin inhibits mammalian target of rapamycin-dependent translation initiation in breast cancer cells

Metformin: Its salutary effects beyond diabetes mellitus

Metformin, an oral hypoglycemic agent, is commonly used in patients with type II diabetes mellitus. Studies have shown its use is associated with a reduction in major cardiovascular events (MACE) in patients with type 2 diabetes such as hospitalization for acute myocardial infarction, stroke, transient ischemic attack, or cardiovascular death. There is also a suggestion that metformin may have effects beyond those relating to lowering of blood sugar. The goal of this review is to assess the effects of metformin in coronary artery disease (CAD), but more importantly, its effects on disease states other than CAD.

Insights into targeting LKB1 in tumorigenesis

Genetic alterations to serine-threonine kinase 11 (STK11) have been implicated in Peutz-Jeghers syndrome and tumorigenesis. Further exploration of the context-specific roles of liver kinase B1 (LKB1; encoded by STK11) observed that it regulates AMP-activated protein kinase (AMPK) and AMPK-related kinases. Given that both migration and proliferation are enhanced with the loss of LKB1 activity combined with the prevalence of STK11 genetic alterations in cancer biopsies, LKB1 was marked as a tumor suppressor. However, the role of LKB1 in tumorigenesis is paradoxical as LKB1 activates autophagy and reactive oxygen species scavenging while dampening anoikis, which contribute to cancer cell survival. Due to the pro-tumorigenic properties of LKB1, targeting LKB1 pathways is now relevant for cancer treatment. With the recent successes of targeting LKB1 signaling in research and clinical settings, and enhanced cytotoxicity of chemical compounds in LKB1-deficient tumors, there is now a need for LKB1 inhibitors. However, validating LKB1 inhibitors is challenging as LKB1 adaptor proteins, nucleocytoplasmic shuttling, and splice variants all manipulate LKB1 activity. Furthermore, STE-20-related kinase adaptor protein (STRAD) and mouse protein 25 dictate LKB1 cellular localization and kinase activity. For these reasons, prior to assessing the efficacy and potency of pharmacological candidates, the functional status of LKB1 needs to be defined. Therefore, to improve the understanding of LKB1 in physiology and oncology, this review highlights the role of LKB1 in tumorigenesis and addresses the therapeutic relevancy of LKB1 inhibitors.

Unraveling molecular interconnections and identifying potential therapeutic targets of significance in obesity-cancer link

Obesity, a global health concern, is associated with severe health issues like type 2 diabetes, heart disease, and respiratory complications. It also increases the risk of various cancers, including melanoma, endometrial, prostate, pancreatic, esophageal adenocarcinoma, colorectal carcinoma, renal adenocarcinoma, and pre-and post-menopausal breast cancer. Obesity-induced cellular changes, such as impaired CD8+ T cell function, dyslipidemia, hypercholesterolemia, insulin resistance, mild hyperglycemia, and fluctuating levels of leptin, resistin, adiponectin, and IL-6, contribute to cancer development by promoting inflammation and creating a tumor-promoting microenvironment rich in adipocytes. Adipocytes release leptin, a pro-inflammatory substance that stimulates cancer cell proliferation, inflammation, and invasion, altering the tumor cell metabolic pathway. Adiponectin, an insulin-sensitizing adipokine, is typically downregulated in obese individuals. It has antiproliferative, proapoptotic, and antiangiogenic properties, making it a potential cancer treatment. This narrative review offers a comprehensive examination of the molecular interconnections between obesity and cancer, drawing on an extensive, though non-systematic, survey of the recent literature. This approach allows us to integrate and synthesize findings from various studies, offering a cohesive perspective on emerging themes and potential therapeutic targets. The review explores the metabolic disturbances, cellular alterations, inflammatory responses, and shifts in the tumor microenvironment that contribute to the obesity-cancer link. Finally, it discusses potential therapeutic strategies aimed at disrupting these connections, offering valuable insights into future research directions and the development of targeted interventions.

A phase I study of temsirolimus in combination with metformin in patients with advanced or recurrent endometrial cancer

INTRODUCTION

Molecular alterations in the PI3K/AKT and Ras/Raf/MEK/ERK pathways are frequently observed in patients with endometrial cancers. However, mTOR inhibitors, such as temsirolimus, have modest clinical benefits. In addition to inducing metabolic changes in cells, metformin activates AMPK, which in turn inhibits the mTOR pathway. In this phase 1 clinical trial we hypothesized that combining metformin with temsirolimus would potentiate the antitumor activity against advanced or recurrent endometrial cancer.

METHODS

The dose-expansion cohort used a Simon Minimax two-stage design. The objectives of the endometrial cancer expansion cohort were to evaluate the clinical tumor response, as indicated by the objective response and clinical benefit rates, as well as an ongoing safety assessment of the combination treatment.

RESULTS

Forty patients were enrolled in this study. The most common treatment-related adverse events (reported in 32 patients) were hypertriglyceridemia (n = 14), diarrhea (n = 13), mucositis (n = 13), anorexia (n = 12), and anemia (n = 10). The grade 3 adverse events were 2 instances each of anemia and thrombocytopenia and 1 instance each of mucositis, fatigue, weight loss, hypokalemia, hypophosphatemia, and increased aspartate aminotransferase and alanine transaminase levels. Among the 33 patients evaluable for response, objective response was seen in two (6 %; both partial responses), and 13 (39 %) patients had stable disease, including 11 for ≥4 months, representing a clinical benefit rate of 39 %.

CONCLUSIONS

The results of this single-center clinical trial showed that, in patients with advanced or recurrent endometrial cancer, metformin can be safely added to temsirolimus providing limited response without added safety concerns.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01529593.

Metformin Impairs Linsitinib Anti-Tumor Effect on Ovarian Cancer Cell Lines

Ovarian cancer (OC) remains one of the leading causes of cancer-related mortality among women. Targeting the insulin-like growth factor 1 (IGF-1) signaling pathway has emerged as a promising therapeutic strategy. Linsitinib, an IGF-1 receptor (IGF-1R) inhibitor, has shown potential in disrupting this pathway. Additionally, metformin, commonly used in the treatment of type 2 diabetes, has been studied for its anti-cancer properties due to its ability to inhibit metabolic pathways that intersect with IGF-1 signaling, making it a candidate for combination therapy in cancer treatments. This study explores the anti-cancer effects of linsitinib and metformin on OVCAR3 cells by the suppression of the IGF-1 signaling pathway by siRNA-mediated IGF-1 gene silencing. The goal is to evaluate their efficacy as therapeutic agents and to emphasize the critical role of this pathway in OC cell proliferation. Cellular viability was evaluated by resazurin-based assay, and apoptosis was assessed by flux cytometry. The results of this study indicate that the combination of linsitinib and metformin exhibits an antagonistic effect (obtained by SynergyFinder 2.0 Software), reducing their anti-neoplastic efficacy in OC cell lines. Statistical analyses were performed using ordinary one-way or two-way ANOVA, followed by Tukey's or Šídák's multiple comparison tests. While linsitinib shows promise as a therapeutic option for OC, further research is needed to identify agents that could synergize with it to enhance its therapeutic efficacy, like the combination with standard chemotherapy in OC (carboplatin and paclitaxel).

Electroporation enhances cell death in 3D scaffold-based MDA-MB-231 cells treated with metformin

Triple-negative breast cancer (TNBC), the most aggressive subtype of breast cancer lacks estrogen, progesterone, and HER2 receptors and hence, is therapeutically challenging. Towards this, we studied an alternate therapy by repurposing metformin (FDA-approved type-2 diabetic drug with anticancer properties) in a 3D-scaffold culture, with electrical pulses. 3D cell culture was used to simulate the tumor microenvironment more closely and MDA-MB-231, human TNBC cells, treated with both 5 mM metformin (Met) and 8 electrical pulses at 2500 V/cm, 10 µs (EP1) and 800 V/cm, 100 µs (EP2) at 1 Hz were studied in 3D and 2D. They were characterized using cell viability, reactive oxygen species (ROS), glucose uptake, and lactate production assays at 24 h. Cell viability, as low as 20 % was obtained with EP1 + 5 mM Met. They exhibited 1.65-fold lower cell viability than 2D with EP1 + 5 mM Met. ROS levels indicated a 2-fold increase in oxidative stress for EP1 + 5 mM Met, while the glucose uptake was limited to only 9 %. No significant change in the lactate production indicated glycolytic arrest and a non-conducive environment for MDA-MB-231 growth. Our results indicate that 3D cell culture, with a more realistic tumor environment that enhances cell death using metformin and electrical pulses could be a promising approach for TNBC therapeutic intervention studies.

Antidiabetic and Antihyperlipidemic Activities and Molecular Mechanisms of Phyllanthus emblica L. Extract in Mice on a High-Fat Diet

We planned to explore the protective activities of extract of Phyllanthus emblica L. (EPE) on insulin resistance and metabolic disorders including hyperlipidemia, visceral obesity, and renal dysfunction in high-fat diet (HFD)-progressed T2DM mice. Mice treatments included 7 weeks of HFD induction followed by EPE, fenofibrate (Feno), or metformin (Metf) treatment daily for another 4-week HFD in HFD-fed mice. Finally, we harvested blood to analyze some tests on circulating glycemia and blood lipid levels. Western blotting analysis was performed on target gene expressions in peripheral tissues. The present findings indicated that EPE treatment reversed the HFD-induced increases in blood glucose, glycosylated HbA1C, and insulin levels. Our findings proved that treatment with EPE in HFD mice effectively controls hyperglycemia and hyperinsulinemia. Our results showed that EPE reduced blood lipid levels, including a reduction in blood triglyceride (TG), total cholesterol (TC), and free fatty acid (FFA); moreover, EPE reduced blood leptin levels and enhanced adiponectin concentrations. EPE treatment in HFD mice reduced BUN and creatinine in both blood and urine and lowered albumin levels in urine; moreover, EPE decreased circulating concentrations of inflammatory NLR family pyrin domain containing 3 (NLRP3) and kidney injury molecule-1 (KIM-1). These results indicated that EPE displayed antihyperglycemic and antihyperlipidemic activities but alleviated renal dysfunction in HFD mice. The histology examinations indicated that EPE treatment decreased adipose hypertrophy and hepatic ballooning, thus contributing to amelioration of lipid accumulation. EPE treatment decreased visceral fat amounts and led to improved systemic insulin resistance. For target gene expression levels, EPE enhanced AMP-activated protein kinase (AMPK) phosphorylation expressions both in livers and skeletal muscles and elevated the muscular membrane glucose transporter 4 (GLUT4) expressions. Treatment with EPE reduced hepatic glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK) expressions to suppress glucose production in the livers and decreased phosphorylation of glycogen synthase kinase 3β (GSK3β) expressions to affect hepatic glycogen synthesis, thus convergently contributing to an antidiabetic effect and improving insulin resistance. The mechanism of the antihyperlipidemic activity of EPE involved a decrease in the hepatic phosphorylation of mammalian target of rapamycin complex C1 (mTORC1) and p70 S6 kinase 1 (S6K1) expressions to improve insulin resistance but also a reduction in hepatic sterol regulatory element binding protein (SREBP)-1c expressions, and suppression of ACC activity, thus resulting in the decreased fatty acid synthesis but elevated hepatic peroxisome proliferator-activated receptor (PPAR) α and SREBP-2 expressions, resulting in lowering TG and TC concentrations. Our results demonstrated that EPE improves insulin resistance and ameliorates hyperlipidemia in HFD mice.

Knowledge mapping of metformin use on cancers: a bibliometric analysis (2013-2023)

There is substantial evidence from clinical and preclinical studies suggesting an association between metformin use and a reduced risk of cancer. However, the effects of metformin use on cancers have not yet been subjected to bibliometric analysis. The goal of this study was to explore the potential effects of metformin use on cancers and to conduct a comprehensive assessment of research hotspots related to the use of metformin on cancers. The results of the literature analysis were visualized using various tools such as Adobe Illustrator CC 2018, VOSviewer, CiteSpace, and the R package "bibliometric." The average annual publications from 2013 to 2023 was 372. In terms of journals and co-cited journals, a total of 1,064 journals published 1958 papers, and Oncotarget published the highest number of papers (n = 153, 7.81%), while Cancer Research (Co-citation = 5,125) was the most frequently cited journal. A total of 25,665 authors participated in the research on metformin use on cancers. Metformin has demonstrated improved outcomes in various types of cancer, including breast cancer (BC), lung cancer (LC), colorectal cancer (CRC), prostate cancer (PC), and pancreatic cancer. This bibliometric analysis reviews the current literature on the clinical data on metformin use on cancers and describes the preclinical evidence illustrating the potential mechanisms of metformin use on various cancers directly or indirectly.

Metformin in Chemoprevention of Lung Cancer: A Retrospective Population-Based Cohort Study in Lithuania

Background and Objectives: This study aimed to evaluate the potential chemopreventive effect of antidiabetic medications, specifically metformin and pioglitazone, on lung cancer in patients with type 2 diabetes mellitus (T2DM). Additionally, the potential dose-response relationship for metformin use was analyzed. Methods: We conducted a retrospective cohort study utilizing comprehensive national health insurance and cancer registry databases to gather a large cohort of T2DM patients. Cox proportional hazards regression models were used to assess the risk of lung cancer across different antidiabetic medication groups, adjusting for potential confounders such as age and gender. A dose-response analysis was conducted for metformin users. Results: Our results indicated that metformin users had a significantly lower lung cancer risk than the reference group (HR = 0.69, 95% CI [0.55-0.86], p = 0.001). The risk reduction increased with higher cumulative metformin doses: a metformin cumulative dose between 1,370,000 and 2,976,000 had an HR of 0.61 (95% CI [0.49-0.75], p < 0.001) vs. cumulative metformin dose >2,976,000 which had an HR of 0.35 (95% CI [0.21-0.59], p < 0.001). No significant association between pioglitazone use and the risk of lung cancer was found (HR = 1.00, 95% CI [0.25-4.02]). Conclusions: This study shows that metformin may have a dose-dependent chemopreventive effect against lung cancer in T2DM, while the impact of pioglitazone remains unclear and requires further investigation.

Pancreatic Cancer: A Review of Risk Factors

Pancreatic adenocarcinoma is one of the most lethal types of gastrointestinal cancer despite the latest medical advances. Its incidence has continuously increased in recent years in developed countries. The location of the pancreas can result in the initial symptoms of neoplasia being overlooked, which can lead to a delayed diagnosis and a subsequent reduction in the spectrum of available therapeutic options. The role of modifiable risk factors in pancreatic cancer has been extensively studied in recent years, with smoking and alcohol consumption identified as key contributors. However, the few screening programs that have been developed focus exclusively on genetic factors, without considering the potential impact of modifiable factors on disease occurrence. Thus, fully understanding and detecting the risk factors for pancreatic cancer represents an important step in the prevention and early diagnosis of this type of neoplasia. This review reports the available evidence on different risk factors and identifies the areas that could benefit the most from additional studies.

Complex Interplay between DNA Damage and Autophagy in Disease and Therapy

Cancer, a multifactorial disease characterized by uncontrolled cellular proliferation, remains a global health challenge with significant morbidity and mortality. Genomic and molecular aberrations, coupled with environmental factors, contribute to its heterogeneity and complexity. Chemotherapeutic agents like doxorubicin (Dox) have shown efficacy against various cancers but are hindered by dose-dependent cytotoxicity, particularly on vital organs like the heart and brain. Autophagy, a cellular process involved in self-degradation and recycling, emerges as a promising therapeutic target in cancer therapy and neurodegenerative diseases. Dysregulation of autophagy contributes to cancer progression and drug resistance, while its modulation holds the potential to enhance treatment outcomes and mitigate adverse effects. Additionally, emerging evidence suggests a potential link between autophagy, DNA damage, and caretaker breast cancer genes BRCA1/2, highlighting the interplay between DNA repair mechanisms and cellular homeostasis. This review explores the intricate relationship between cancer, Dox-induced cytotoxicity, autophagy modulation, and the potential implications of autophagy in DNA damage repair pathways, particularly in the context of BRCA1/2 mutations.

A doxycycline-loaded microfiber of poly-metformin/PCL for eradicating melanoma stem cells

Nowadays, electrospun fibrous mats are used as drug delivery systems for loading of potential drugs in order to kill cancer cells. In the study, a skin patch for treating melanoma cancer after surgery was made using polycaprolactone and polymetformin microfibers that were loaded with doxycycline (PolyMet/PCL@DOX), an anti-cancer stem cell agent. The morphology, structure, mechanical characteristics, swelling, and porosity of the electrospun microfibers were examined. Drug release andanticancereffectiveness of PolyMet/PCL@DOXwas evaluated against A375 melanoma cancer stem cells using the MTS, Flow cytometry, colony formation and CD44 expression assays. Scanning electron microscopy (SEM) verified the micro fibrous structure with a diameter of about 2.31 µm. The porosity and swelling percentages for microfibers was 73.5 % and 2.9 %, respectively. The tensile strength at the breaking point was equal to 3.84 MPa. The IC50 of PolyMet/PCL@DOX was 7.4 μg/mL. The survival rate of A375 cells after 72 h of PolyMet/PCL@DOX treatment was 43.9 %. The colony formation capacity of A375 cells decreased after PolyMet/PCL@DOX treatment. The level of CD44 expression in the PolyMet/PCL@DOX group decreased compared to the control group. Generally, PolyMet/PCL@DOX microfibers can be a promising candidate as a patch after surgery to eradicate cancer stem cells, effectively.

Metformin administration in prevention of colorectal polyps in type 2 diabetes mellitus patients

BACKGROUND

Colorectal polyps are frequently observed in patients with type 2 diabetes mellitus (DM), posing a significant risk for colorectal cancer. Metformin, a widely prescribed biguanidine drug for type 2 DM, has been suggested to have potential chemoprophylactic effects against various cancers.

AIM

To explore the correlation between colorectal polyps and metformin use in type 2 DM patients.

METHODS

Type 2 DM patients were categorized into polyp and non-polyp groups. Following this, all patients were categorized into the type 2 DM-metformin, type 2 DM-non-metformin, and non-type 2 DM groups. Based on the baseline colonoscopy results, we performed pairwise comparisons of the incidence of colorectal polyps among the three groups. Additionally, we analyzed the relationship between colorectal polyps and the duration of metformin use and between the size and number of polyps and metformin use. Simultaneously, we focused on the specific pathological types of polyps and analyzed their relationship with metformin use. Finally, we compared the incidence of polyps between metformin and non-metformin groups according to the interval colonoscopy results.

RESULTS

The rate of metformin use in patients with colorectal polyps was 0.502 times that of patients without colorectal polyps [odds ratio (OR) = 0.502, 95% confidence interval (CI): 0.365-0.689; P < 0.001]. The incidence of colorectal polyps did not differ significantly between the type 2 DM-metformin and non-type 2 DM groups (P > 0.05). Furthermore, the correlations between the duration of metformin use and the incidence of colorectal polyps and between the size and number of polyps and metformin use were not statistically significant (P > 0.05). Metformin use did not affect the incidence of colorectal polyps during interval colonoscopy (P > 0.05).

CONCLUSION

Metformin use and colorectal polyp incidence in type 2 DM patients showed a negative correlation, independent of the hypoglycemic effect of metformin.

Comprehensive Evaluation of a Levonorgestrel Intrauterine Device (LNG-IUD), Metformin, and Liraglutide for Fertility Preservation in Endometrial Cancer: Protocol for a Randomized Clinical Trial

Endometrial cancer is a leading gynecological malignancy, with obesity being a significant risk factor due to increased estrogen production in body fat. Current treatments often involve hysterectomy, which precludes fertility, thus highlighting the need for fertility-preserving options. This study aims to evaluate the combined efficacy of a levonorgestrel intrauterine device (LNG-IUD), metformin, and liraglutide for treating women with endometrial hyperplasia or early stage endometrial cancer while preserving fertility. The study will enroll 264 women aged 18-45 with a BMI > 30 who desire uterine preservation. Participants will be randomized into three groups: LNG-IUD alone, LNG-IUD plus metformin, and LNG-IUD plus metformin and liraglutide. Primary outcomes will include complete pathological remission, while secondary outcomes will assess histological changes, glucose, insulin levels, and weight changes over a 12-month period. This study protocol hypothesizes that LNG-IUD combined with metformin and liraglutide may potentially lead to higher regression rates of endometrial hyperplasia (EH) and early stage endometrial cancer (EC) compared to LNG-IUD alone. Furthermore, the protocol anticipates that these combination therapies will demonstrate good tolerability with minimal adverse effects, suggesting the potential benefit of integrating metabolic interventions with LNG-IUD to enhance treatment efficacy while preserving fertility in women with EH and EC.

Bridging the gap: exploring the causal relationship between metformin and tumors

Objective

Numerous studies have reported that metformin can reduce the risk of tumor development. However, some of the results of these studies are conflicting, necessitating a more reliable evaluation.

Methods

We conducted a Mendelian randomization phenome-wide association study (MR-PheWAS) of tumors to explore the causal relationship between metformin and tumors. Two cohorts of patients taking metformin were obtained from the UK Biobank. Complete phenotype data of the tumors were obtained from FinnGen_R10. We elucidated the causal relationship using a two-sample Mendelian randomization (MR) analysis. More importantly, we conducted a meta-analysis to ensure relatively unbiased results. In the MR analysis, we used the inverse-variance weighted (IVW) method as the main outcome indicator. Subsequently, two cohorts were integrated for the meta-analysis. Finally, we investigated the mechanisms through mediational MR analysis.

Results

MR analysis revealed that metformin might have a causal relationship with 13 tumor-associated phenotypes in the training cohort. Four phenotypes were validated in the testing cohort. In the training and testing cohorts, metformin exhibited a protective effect against brain meningiomas and malignant neoplasms of the breast (HER-positive), oral cavity, tonsils, and the base of the tongue. Intriguingly, after integrating the results of the two cohorts for the meta-analysis, 12 results were statistically significant. Mediational MR analysis suggested that the effects of metformin on brain meningiomas may be weakened by the presence of the family Oxalobacteraceae.

Conclusion

Metformin exhibits potential preventive and therapeutic effects on four types of tumors: brain meningioma, malignant neoplasms of the breast (HER-positive), oral cavity and tonsils, and the base of the tongue. Large randomized controlled trials are required to confirm these findings.

LKB1 biology: assessing the therapeutic relevancy of LKB1 inhibitors

Liver Kinase B1 (LKB1), encoded by Serine-Threonine Kinase 11 (STK11), is a master kinase that regulates cell migration, polarity, proliferation, and metabolism through downstream adenosine monophosphate-activated protein kinase (AMPK) and AMPK-related kinase signalling. Since genetic screens identified STK11 mutations in Peutz-Jeghers Syndrome, STK11 mutants have been implicated in tumourigenesis labelling it as a tumour suppressor. In support of this, several compounds reduce tumour burden through upregulating LKB1 signalling, and LKB1-AMPK agonists are cytotoxic to tumour cells. However, in certain contexts, its role in cancer is paradoxical as LKB1 promotes tumour cell survival by mediating resistance against metabolic and oxidative stressors. LKB1 deficiency has also enhanced the selectivity and cytotoxicity of several cancer therapies. Taken together, there is a need to develop LKB1-specific pharmacological compounds, but prior to developing LKB1 inhibitors, further work is needed to understand LKB1 activity and regulation. However, investigating LKB1 activity is strenuous as cell/tissue type, mutations to the LKB1 signalling pathway, STE-20-related kinase adaptor protein (STRAD) binding, Mouse protein 25-STRAD binding, splicing variants, nucleocytoplasmic shuttling, post-translational modifications, and kinase conformation impact the functional status of LKB1. For these reasons, guidelines to standardize experimental strategies to study LKB1 activity, associate proteins, spliced isoforms, post-translational modifications, and regulation are of upmost importance to the development of LKB1-specific therapies. Therefore, to assess the therapeutic relevancy of LKB1 inhibitors, this review summarizes the importance of LKB1 in cell physiology, highlights contributors to LKB1 activation, and outlines the benefits and risks associated with targeting LKB1.

Metformin treatment of juvenile mice alters aging-related developmental and metabolic phenotypes in sex-dependent and sex-independent manners

Metformin has attracted increasing interest for its potential benefits in extending healthspan and longevity. This study examined the effects of early-life metformin treatment on the development and metabolism of C57BL/6 J (B6) mice, with metformin administered to juvenile mice from 15 to 56 days of age. Metformin treatment led to decreased body weight in both sexes (P < 0.05, t-test). At 9 weeks of age, mice were euthanized and organ weights were recorded. The relative weight of retroperitoneal fat was decreased in females, while relative weights of perigonadal and retroperitoneal fat were decreased, and relative liver weight was increased in males (P < 0.05, t-test). Glucose and insulin tolerance tests (GTT and ITT) were conducted at the age of 7 weeks. ANOVA revealed a significant impairment in insulin sensitivity by the treatment, and a significantly interactive effect on glucose tolerance between sex and treatment, underscoring a disparity in GTT between sexes in response to the treatment. Metformin treatment reduced circulating insulin levels in fasting and non-fasting conditions for male mice, with no significant alterations observed in female mice. qRT-PCR analysis of glucose metabolism-related genes (Akt2, Glut2, Glut4, Irs1, Nrip1, Pi3k, Pi3kca, Pkca) in the liver and skeletal muscle reveals metformin-induced sex- and organ-specific effects on gene expression. Comparison with previous studies in heterogeneous UM-HET3 mice receiving the same treatment suggests that genetic differences may contribute to variability in the effects of metformin treatment on development and metabolism. These findings indicate that early-life metformin treatment affects development and metabolism in both sex- and genetics-dependent manners.

Advances in Anti-Cancer Drug Development: Metformin as Anti-Angiogenic Supplemental Treatment for Glioblastoma

According to the WHO 2016 classification, glioblastoma is the most prevalent primary tumor in the adult central nervous system (CNS) and is categorized as grade IV. With an average lifespan of about 15 months from diagnosis, glioblastoma has a poor prognosis and presents a significant treatment challenge. Aberrant angiogenesis, which promotes tumor neovascularization and is a prospective target for molecular target treatment, is one of its unique and aggressive characteristics. Recently, the existence of glioma stem cells (GSCs) within the tumor, which are tolerant to chemotherapy and radiation, has been linked to the highly aggressive form of glioblastoma. Anti-angiogenic medications have not significantly improved overall survival (OS), despite various preclinical investigations and clinical trials demonstrating encouraging results. This suggests the need to discover new treatment options. Glioblastoma is one of the numerous cancers for which metformin, an anti-hyperglycemic medication belonging to the Biguanides family, is used as first-line therapy for type 2 diabetes mellitus (T2DM), and it has shown both in vitro and in vivo anti-tumoral activity. Based on these findings, the medication has been repurposed, which has shown the inhibition of many oncopromoter mechanisms and, as a result, identified the molecular pathways involved. Metformin inhibits cancer cell growth by blocking the LKB1/AMPK/mTOR/S6K1 pathway, leading to selective cell death in GSCs and inhibiting the proliferation of CD133+ cells. It has minimal impact on differentiated glioblastoma cells and normal human stem cells. The systematic retrieval of information was performed on PubMed. A total of 106 articles were found in a search on metformin for glioblastoma. Out of these six articles were Meta-analyses, Randomized Controlled Trials, clinical trials, and Systematic Reviews. The rest were Literature review articles. These articles were from the years 2011 to 2024. Appropriate studies were isolated, and important information from each of them was understood and entered into a database from which the information was used in this article. The clinical trials on metformin use in the treatment of glioblastoma were searched on clinicaltrials.gov. In this article, we examine and evaluate metformin's possible anti-tumoral effects on glioblastoma, determining whether or not it may appropriately function as an anti-angiogenic substance and be safely added to the treatment and management of glioblastoma patients.

Clinical outcomes with metformin use in diabetic patients with compensated cirrhosis: a systematic review and meta-analysis

BACKGROUND

Previous studies have demonstrated a beneficial effect of metformin in patients with cirrhosis, but no improvement in liver histology.

AIM

To investigate the impact of metformin on mortality and hepatic decompensation in people with diabetes with compensated cirrhosis.

METHODS

Medline, Embase and Cochrane databases were searched from inception to February 2023 for studies reporting results regarding the impact of metformin on all-cause mortality and hepatic decompensation in people with diabetes with compensated cirrhosis. The risk of bias was assessed by ROBINS-I Cochrane tool. R software 4.3.1 was used for all analyses.

RESULTS

Six observational studies were included in the final analysis. Metformin use was associated with reduced all-cause mortality or liver transplantation [hazard ratio (HR): 0.55; 95% confidence interval (CI) 0.37-0.82], while no benefit was shown in the prevention of hepatic decompensation (HR: 0.97; 95% CI: 0.77-1.22). In the subgroup analysis, metformin use was associated with reduced all-cause mortality or liver transplantation (HR: 0.50; 95% CI 0.38-0.65) in patients with metabolic-associated steatohepatitis cirrhosis, while two studies reported no survival benefit in patients with cirrhosis due to hepatitis C (HR: 0.39; 95% CI 0.12-1.20).

CONCLUSION

Metformin use is associated with reduced all-cause mortality, but not with the prevention of hepatic decompensation in people with diabetes with compensated cirrhosis. The mortality benefit is most likely driven by better diabetes and cardiovascular health control.

Metformin prevents mandibular bone loss in a mouse model of accelerated aging by correcting dysregulated AMPK-mTOR signaling and osteoclast differentiation

Background

Age-related mandibular osteoporosis frequently causes loose teeth, difficulty eating, and disfiguration in elders. Bmi1-/- mice displaying accelerated skeletal aging represent a useful model for testing interventions against premature jaw bone loss. As an anti-aging agent, metformin may ameliorate molecular dysfunction driving osteoporosis pathogenesis. We explored the mechanisms of mandibular osteopenia in Bmi1-/- mice and prevention by metformin treatment.

Methods

Three mouse groups were utilized: wild-type controls, untreated Bmi1-/-, and Bmi1-/- receiving 1 g/kg metformin diet. Mandibular bone phenotype was assessed by X-ray, micro-CT, histology, and immunohistochemistry. AMPK-mTOR pathway analysis, senescence markers, osteoblast and osteoclast gene expression were evaluated in jaw tissue. Osteoclast differentiation capacity and associated signaling molecules were examined in cultured Bmi1-/- bone marrow mononuclear cells ± metformin.

Results

Bmi1 loss reduced mandible bone density concomitant with decreased AMPK activity, increased mTOR signaling and cellular senescence in jaw tissue versus wild-type controls. This was accompanied by impaired osteoblast function and upregulated osteoclastogenesis markers. Metformin administration normalized AMPK-mTOR balance, oxidative stress and senescence signaling to significantly improve mandibular bone architecture in Bmi1-/- mice. In culture, metformin attenuated excessive osteoclast differentiation from Bmi1-/- marrow precursors by correcting dysregulated AMPK-mTOR-p53 pathway activity and suppressing novel pro-osteoclastogenic factor Stfa1.

Conclusions

Our study newly demonstrates metformin prevents accelerated jaw bone loss in a premature aging murine model by rectifying molecular dysfunction in cellular energy sensors, redox state, senescence and osteoclastogenesis pathways. Targeting such age-associated mechanisms contributing to osteoporosis pathogenesis may help maintain oral health and aesthetics in the growing elderly population.

Translational potential

The pronounced mandibular osteopenia exhibited in Bmi1-/- mice represents an accelerated model of jaw bone deterioration observed during human aging. Our finding that metformin preserves mandibular bone integrity in this progeroid model has important clinical implications. As an inexpensive oral medication already widely used to manage diabetes, metformin holds translational promise for mitigating age-related osteoporosis. The mandible is essential for chewing, swallowing, speech and facial structure, but progressively loses bone mass and strength with advancing age, significantly impacting seniors' nutrition, physical function and self-image. Our results suggest metformin's ability to rectify cellular energy imbalance, oxidative stress and osteoclast overactivity may help maintain jaw bone health into old age. Further research is still needed given metformin's multifaceted biology and bone regulation by diverse pathways. However, this preclinical study provides a strong rationale for clinical trials specifically examining mandibular outcomes in elderly subjects receiving standard metformin treatment for diabetes or prediabetes. Determining if metformin supplementation can prevent or delay oral disability and disfigurement from senescent jaw bone loss in the growing aged population represents an important public health priority. In summary, our mechanistic findings in a genetic mouse model indicate metformin merits investigation in rigorous human studies for alleviating morbidity associated with age-related mandibular osteoporosis.

View on Metformin: Antidiabetic and Pleiotropic Effects, Pharmacokinetics, Side Effects, and Sex-Related Differences

Metformin is a synthetic biguanide used as an antidiabetic drug in type 2 diabetes mellitus, achieved by studying the bioactive metabolites of Galega officinalis L. It is also used off-label for various other diseases, such as subclinical diabetes, obesity, polycystic ovary syndrome, etc. In addition, metformin is proposed as an add-on therapy for several conditions, including autoimmune diseases, neurodegenerative diseases, and cancer. Although metformin has been used for many decades, it is still the subject of many pharmacodynamic and pharmacokinetic studies in light of its extensive use. Metformin acts at the mitochondrial level by inhibiting the respiratory chain, thus increasing the AMP/ATP ratio and, subsequently, activating the AMP-activated protein kinase. However, several other mechanisms have been proposed, including binding to presenilin enhancer 2, increasing GLP1 release, and modification of microRNA expression. Regarding its pharmacokinetics, after oral administration, metformin is absorbed, distributed, and eliminated, mainly through the renal route, using transporters for cationic solutes, since it exists as an ionic molecule at physiological pH. In this review, particular consideration has been paid to literature data from the last 10 years, deepening the study of clinical trials inherent to new uses of metformin, the differences in effectiveness and safety observed between the sexes, and the unwanted side effects. For this last objective, metformin safety was also evaluated using both VigiBase and EudraVigilance, respectively, the WHO and European databases of the reported adverse drug reactions, to assess the extent of metformin side effects in real-life use.

Beneficial Effect of Metformin on the Five-Year Survival in about 40,000 Patients with Head and Neck Cancer

INTRODUCTION

Even in times of new therapy regimes, the overall survival of patients with head and neck cancer remains low. Since the previous studies showed the beneficial effect of metformin medication on the survival of patients with cancer, our objective was to investigate if-and in which way-metformin medication affects the overall survival of patients with head and neck cancer.

METHODS

Clinical data pertaining to patients diagnosed with head and neck cancer (International Classification of Diseases 10 codes C00-C14, C31, and C32) were retrospectively retrieved from the TriNetX network (TriNetX, Cambridge, MA, USA). The initial cohort extracted from the network was stratified into two groups: patients on metformin medication (cohort I), and individuals not on metformin medication (cohort II). The matching criteria included age, gender, BMI, type 2 diabetes, and risk factors, such as nicotine and alcohol abuse/dependence. Kaplan-Meier analysis, risk analysis, and the calculation of odds and hazard ratios were conducted. Additionally, the Hemoglobin A1c values were subject to analysis.

RESULTS

Following matching, each cohort comprised 20,416 patients. Cohort I exhibited a higher five-year survival rate at 75.3%, in contrast to cohort II, which registered a rate of 69.8%. The odds ratio was 0.79 (95% CI = 0.75-0.83), and the hazard ratio was 0.78 (95% CI = 0.75-0.82).

CONCLUSION

Metformin medication may correlate with improved five-year survival rates in patients with head and neck cancer. Since potentially influencing factors such as comorbidities and the initial tumor stage were not available, the results of our retrospectively conducted study must be interpreted with caution.

Systematic Investigation of Dose-Dependent Protein Thermal Stability Changes to Uncover the Mechanisms of the Pleiotropic Effects of Metformin

Metformin is a widely used drug to treat type II diabetes. Beyond lowering blood sugar, it has been reported to have pleiotropic effects such as suppressing cancer growth and attenuating cell oxidative stress and inflammation. However, the underlying mechanisms of these effects remain to be explored. Here, we systematically study the thermal stability changes of proteins in liver cells (HepG2) induced by a wide dosage range of metformin by using the proteome integral solubility alteration (PISA) assay. The current results demonstrate that, besides the most accepted target of metformin (complex I), low concentrations of metformin (such as 0.2 μM) stabilize the complex IV subunits, suggesting its important role in the sugar-lowering effect. Low-dose metformin also results in stability alterations of ribosomal proteins, correlating with its inhibitive effect on cell proliferation. We further find that low-concentration metformin impacts mitochondrial cargo and vesicle transport, while high-concentration metformin affects cell redox responses and cell membrane protein sorting. This study provides mechanistic insights into the molecular mechanisms of lowering blood sugar and the pleiotropic effects of metformin.

Chemopreventive and Biological Strategies in the Management of Oral Potentially Malignant and Malignant Disorders

Oral potentially malignant disorders (OPMD) and oral squamous cell carcinoma (OSCC) represent a significant global health burden due to their potential for malignant transformation and the challenges associated with their diagnosis and treatment. Chemoprevention, an innovative approach aimed at halting or reversing the neoplastic process before full malignancy, has emerged as a promising avenue for mitigating the impact of OPMD and OSCC. The pivotal role of chemopreventive strategies is underscored by the need for effective interventions that go beyond traditional therapies. In this regard, chemopreventive agents offer a unique opportunity to intercept disease progression by targeting the molecular pathways implicated in carcinogenesis. Natural compounds, such as curcumin, green tea polyphenols, and resveratrol, exhibit anti-inflammatory, antioxidant, and anti-cancer properties that could make them potential candidates for curtailing the transformation of OPMD to OSCC. Moreover, targeted therapies directed at specific molecular alterations hold promise in disrupting the signaling cascades driving OSCC growth. Immunomodulatory agents, like immune checkpoint inhibitors, are gaining attention for their potential to harness the body's immune response against early malignancies, thus impeding OSCC advancement. Additionally, nutritional interventions and topical formulations of chemopreventive agents offer localized strategies for preventing carcinogenesis in the oral cavity. The challenge lies in optimizing these strategies for efficacy, safety, and patient compliance. This review presents an up to date on the dynamic interplay between molecular insights, clinical interventions, and the broader goal of reducing the burden of oral malignancies. As research progresses, the synergy between early diagnosis, non-invasive biomarker identification, and chemopreventive therapy is poised to reshape the landscape of OPMD and OSCC management, offering a glimpse of a future where these diseases are no longer insurmountable challenges but rather preventable and manageable conditions.

Overexpression of Glutathione S-Transferases in Human Diseases: Drug Targets and Therapeutic Implications

Glutathione S-transferases (GSTs) are a major class of phase II metabolic enzymes. Besides their essential role in detoxification, GSTs also exert diverse biological activities in the occurrence and development of various diseases. In the past few decades, much research interest has been paid to exploring the mechanisms of GST overexpression in tumor drug resistance. Correspondingly, many GST inhibitors have been developed and applied, solely or in combination with chemotherapeutic drugs, for the treatment of multi-drug resistant tumors. Moreover, novel roles of GSTs in other diseases, such as pulmonary fibrosis and neurodegenerative diseases, have been recognized in recent years, although the exact regulatory mechanisms remain to be elucidated. This review, firstly summarizes the roles of GSTs and their overexpression in the above-mentioned diseases with emphasis on the modulation of cell signaling pathways and protein functions. Secondly, specific GST inhibitors currently in pre-clinical development and in clinical stages are inventoried. Lastly, applications of GST inhibitors in targeting cell signaling pathways and intracellular biological processes are discussed, and the potential for disease treatment is prospected. Taken together, this review is expected to provide new insights into the interconnection between GST overexpression and human diseases, which may assist future drug discovery targeting GSTs.

Targeting cancer metabolic pathways for improving chemotherapy and immunotherapy

Recent discoveries in cancer metabolism have revealed promising metabolic targets to modulate cancer progression, drug response, and anti-cancer immunity. Combination therapy, consisting of metabolic inhibitors and chemotherapeutic or immunotherapeutic agents, offers new opportunities for improved cancer therapy. However, it also presents challenges due to the complexity of cancer metabolic pathways and the metabolic interactions between tumor cells and immune cells. Many studies have been published demonstrating potential synergy between novel inhibitors of metabolism and chemo/immunotherapy, yet our understanding of the underlying mechanisms remains limited. Here, we review the current strategies of altering the metabolic pathways of cancer to improve the anti-cancer effects of chemo/immunotherapy. We also note the need to differentiate the effect of metabolic inhibition on cancer cells and immune cells and highlight nanotechnology as an emerging solution. Improving our understanding of the complexity of the metabolic pathways in different cell populations and the anti-cancer effects of chemo/immunotherapy will aid in the discovery of novel strategies that effectively restrict cancer growth and augment the anti-cancer effects of chemo/immunotherapy.

Multifaceted role of mTOR (mammalian target of rapamycin) signaling pathway in human health and disease

The mammalian target of rapamycin (mTOR) is a protein kinase that controls cellular metabolism, catabolism, immune responses, autophagy, survival, proliferation, and migration, to maintain cellular homeostasis. The mTOR signaling cascade consists of two distinct multi-subunit complexes named mTOR complex 1/2 (mTORC1/2). mTOR catalyzes the phosphorylation of several critical proteins like AKT, protein kinase C, insulin growth factor receptor (IGF-1R), 4E binding protein 1 (4E-BP1), ribosomal protein S6 kinase (S6K), transcription factor EB (TFEB), sterol-responsive element-binding proteins (SREBPs), Lipin-1, and Unc-51-like autophagy-activating kinases. mTOR signaling plays a central role in regulating translation, lipid synthesis, nucleotide synthesis, biogenesis of lysosomes, nutrient sensing, and growth factor signaling. The emerging pieces of evidence have revealed that the constitutive activation of the mTOR pathway due to mutations/amplification/deletion in either mTOR and its complexes (mTORC1 and mTORC2) or upstream targets is responsible for aging, neurological diseases, and human malignancies. Here, we provide the detailed structure of mTOR, its complexes, and the comprehensive role of upstream regulators, as well as downstream effectors of mTOR signaling cascades in the metabolism, biogenesis of biomolecules, immune responses, and autophagy. Additionally, we summarize the potential of long noncoding RNAs (lncRNAs) as an important modulator of mTOR signaling. Importantly, we have highlighted the potential of mTOR signaling in aging, neurological disorders, human cancers, cancer stem cells, and drug resistance. Here, we discuss the developments for the therapeutic targeting of mTOR signaling with improved anticancer efficacy for the benefit of cancer patients in clinics.

Cancer Metabolism as a Therapeutic Target and Review of Interventions

Cancer is amenable to low-cost treatments, given that it has a significant metabolic component, which can be affected through diet and lifestyle change at minimal cost. The Warburg hypothesis states that cancer cells have an altered cell metabolism towards anaerobic glycolysis. Given this metabolic reprogramming in cancer cells, it is possible to target cancers metabolically by depriving them of glucose. In addition to dietary and lifestyle modifications which work on tumors metabolically, there are a panoply of nutritional supplements and repurposed drugs associated with cancer prevention and better treatment outcomes. These interventions and their evidentiary basis are covered in the latter half of this review to guide future cancer treatment.

Clinical potentials of metformin in cancer therapy

Diabetes is a prevalent metabolic disorder that results in several comorbidities including cancer. Cancer becomes the most severe complication of diabetes patients. Growing evidence proved that impaired glucose homeostasis is an independent risk factor for the occurrence of various types of cancers including liver, pancreatic, gastric (stomach), colorectal, kidney, and breast cancers, and influences cancer prognosis. Diabetes mellitus and cancer have a bidirectional relationship, thus there is a need to look for drugs that can be beneficial in treating both diseases. Therefore, more research is focusing on evaluating the role of antihyperglycemic agents in the treatment of various types of cancers. Metformin, an FDA-approved first-line antihyperglycemic agent can be used as a monotherapy or as an adjuvant to chemotherapeutic agents in the treatment of various types of cancer. However, the exact mechanism of metformin as an anticancer agent is still unknown, the majority of the described putative mechanisms focus on promoting the activity of the AMP-activated protein kinase (AMPK) pathway. This review article thus gives insights into the prognosis of cancer in diabetes patients and aims to explore the possible mechanism of action of metformin in the prevention and treatment of cancer.

Transcriptomics-inferred dynamics of SARS-CoV-2 interactions with host epithelial cells

Virus-host interactions can reveal potentially effective and selective therapeutic targets for treating infection. Here, we performed an integrated analysis of the dynamics of virus replication and the host cell transcriptional response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection using human Caco-2 colon cancer cells as a model. Time-resolved RNA sequencing revealed that, upon infection, cells immediately transcriptionally activated genes associated with inflammatory pathways that mediate the antiviral response, which was followed by an increase in the expression of genes involved in ribosome and mitochondria function, thus suggesting rapid alterations in protein production and cellular energy supply. At later stages, between 24 and 48 hours after infection, the expression of genes involved in metabolic processes-in particular, those related to xenobiotic metabolism-was decreased. Mathematical modeling incorporating SARS-CoV-2 replication suggested that SARS-CoV-2 proteins inhibited the host antiviral response and that virus transcripts exceeded the translation capacity of the host cells. Targeting kinase-dependent pathways that exhibited increases in transcription in host cells was as effective as a virus-targeted inhibitor at repressing viral replication. Our findings in this model system delineate a sequence of SARS-CoV-2 virus-host interactions that may facilitate the identification of druggable host pathways to suppress infection.

Extracellular Vesicles-Derived Hybrid Nanoplatforms for Amplified CD47 Blockade-Based Cancer Immunotherapy

Immunomodulation of tumor-associated macrophages (TAMs) into tumor-inhibiting M1-like phenotype is a promising but challenging strategy. Cleverly, tumor cells overexpress CD47, a "don't eat me" signal that ligates with the signal regulatory protein alpha (SIRPα) on macrophages to escape phagocytosis. Thus, effective re-education of TAMs into the "eat me" type and blocking the CD47-SIRPα signaling play pivotal roles in tumor immunotherapy. Herein, it is reported that hybrid nanovesicles (hEL-RS17) derived from extracellular vesicles of M1 macrophages and decorated with RS17 peptide, an antitumor peptide that specifically binds to CD47 on tumor cells and blocks CD47-SIRPα signaling, can actively target tumor cells and remodel TAM phenotypes. Consequently, more M1-like TAMs infiltrate into tumor tissue to phagocytize more tumor cells due to CD47 blockade. By further co-encapsulating chemotherapeutic agent shikonin, photosensitizer IR820, and immunomodulator polymetformin in hEL-RS17, an enhanced antitumor effect is obtained due to the combinational treatment modality and close synergy among each component. Upon laser irradiation, the designed SPI@hEL-RS17 nanoparticles exert potent antitumor efficacy against both 4T1 breast tumor and B16F10 melanoma models, which not only suppresses primary tumor growth but also inhibits lung metastasis and prevents tumor recurrence, exhibiting great potential in boosting CD47 blockade-based antitumor immunotherapy.

Prognostic role of metformin in diabetes mellitus type 2 patients with hepatocellular carcinoma: A systematic review and meta-analysis

BACKGROUND

Hepatocellular carcinoma (HCC) is among the commonest malignancies associated with significant cancer-related death. The identification of chemo-preventive agents following HCC treatments with the potential to lower the risk of HCC adverse course is intriguing. Metformin, a first-line agent used in the treatment of type 2 diabetes mellitus (T2DM), has been associated with inhibition of HCC growth.

AIM

To determine whether metformin can prevent adverse events (i.e., death, tumor progression, and recurrence) after any HCC treatment in T2DM patients.

METHODS

A systematic review of the published literature was undertaken focused on the role of metformin on outcomes in patients with T2DM and HCC receiving any tumor therapy. A search of the PubMed and Cochrane Central Register of Con-trolled Trials Databases was conducted.

RESULTS

A total of 13 studies (n = 14886 patients) were included in this review. With regard to the risk of death, a decreased risk was reported in cases receiving metformin, although this decrease was not statistically significant [odds ratio (OR) = 0.89, P = 0.42]. When only patients treated with curative strategies were considered, a more marked correlation between metformin and favorable cases was reported (OR = 0.70, P = 0.068). When analyzing palliative treatment, there was no statistical significance in terms of the correlation between metformin and favorable cases (OR = 0.74, P = 0.66). As for the risks of progressive disease and recurrence, no obvious correlation between metformin use and reduced risk was reported. When sub-analyses were performed for patients from different regions, the results for patients from Eastern countries showed a tendency for decreased risk of death in T2DM cases receiving metformin (OR = 0.69, P = 0.17), but the same was not seen in patients from Western countries (OR = 1.19, P = 0.31).

CONCLUSION

Metformin failed to show a marked impact in preventing adverse effects after HCC treatment. A trend was reported in T2DM cases receiving curative therapies in relation to the risk of death, especially in patients from Eastern regions. Great heterogeneity was reported among the different studies. Further large studies are required to definitively clarify the real impact of metformin as a chemopreventive agent for HCC.

Metformin promotes cGAS/STING signaling pathway activation by blocking AKT phosphorylation in gastric cancer

The cGAS/STING signaling pathway plays a pivotal role in regulating innate immunity. Emerging novel drugs aim to regulate the anti-tumor immune response by activating innate immunity. The anti-diabetic drug metformin has been reported to exhibit anti-cancer effect against various types of cancer. However, the role of metformin in regulating the cGAS/STING signaling pathway in gastric cancer remains unknown. In our study, we first used bioinformatic analysis to detect that metformin is closely related to tumor immunity in multiple tumors. Next, we validated the function of metformin in activating the cGAS/STING signaling pathway in gastric cancer cell lines. In addition, KEGG pathway enrichment analysis showed that metformin is negatively correlated with the PI3K/AKT signaling pathway in gastric cancer. We further verified that metformin activates the cGAS/STING signaling pathway by blocking AKT phosphorylation. Moreover, we found that metformin regulates the AKT signaling pathway by mediating the transcription factor SOX2. Thus, our study indicates that metformin activates the cGAS/STING signaling pathway by suppressing SOX2/AKT and has promising potential in gastric cancer immunotherapy.

Amino acid homeostasis is a target of metformin therapy

OBJECTIVE

Unexplained changes in regulation of branched chain amino acids (BCAA) during diabetes therapy with metformin have been known for years. Here we have investigated mechanisms underlying this effect.

METHODS

We used cellular approaches, including single gene/protein measurements, as well as systems-level proteomics. Findings were then cross-validated with electronic health records and other data from human material.

RESULTS

In cell studies, we observed diminished uptake/incorporation of amino acids following metformin treatment of liver cells and cardiac myocytes. Supplementation of media with amino acids attenuated known effects of the drug, including on glucose production, providing a possible explanation for discrepancies between effective doses in vivo and in vitro observed in most studies. Data-Independent Acquisition proteomics identified that SNAT2, which mediates tertiary control of BCAA uptake, was the most strongly suppressed amino acid transporter in liver cells following metformin treatment. Other transporters were affected to a lesser extent. In humans, metformin attenuated increased risk of left ventricular hypertrophy due to the AA allele of KLF15, which is an inducer of BCAA catabolism. In plasma from a double-blind placebo-controlled trial in nondiabetic heart failure (trial registration: NCT00473876), metformin caused selective accumulation of plasma BCAA and glutamine, consistent with the effects in cells.

CONCLUSIONS

Metformin restricts tertiary control of BCAA cellular uptake. We conclude that modulation of amino acid homeostasis contributes to therapeutic actions of the drug.

Metformin-Induced Receptor Turnover Alters Antibody Accumulation in HER-Expressing Tumors

Metformin has effects beyond its antihyperglycemic properties, including altering the localization of membrane receptors in cancer cells. Metformin decreases human epidermal growth factor receptor (HER) membrane density. Depletion of cell-surface HER decreases antibody-tumor binding for imaging and therapeutic approaches. Here, we used HER-targeted PET to annotate antibody-tumor binding in mice treated with metformin. Methods: Small-animal PET annotated antibody binding in HER-expressing xenografts on administration of an acute versus a daily dose schedule of metformin. Analyses at the protein level in the total, membrane, and internalized cell extracts were performed to determine receptor endocytosis, HER surface and internalized protein levels, and HER phosphorylation. Results: At 24 h after injection of radiolabeled anti-HER antibodies, control tumors had higher antibody accumulation than tumors treated with an acute dose of metformin. These differences were temporal, and by 72 h, tumor uptake in acute cohorts was similar to uptake in control. Additional PET imaging revealed a sustained decrease in tumor uptake on daily metformin treatment compared with control and acute metformin cohorts. The effects of metformin on membrane HER were reversible, and after its removal, antibody-tumor binding was restored. The time- and dose-dependent effects of metformin-induced HER depletion observed preclinically were validated with immunofluorescence, fractionation, and protein analysis cell assays. Conclusion: The findings that metformin decreases cell-surface HER receptors and reduces antibody-tumor binding may have significant implications for the use of antibodies targeting these receptors in cancer treatment and molecular imaging.

Advanced nano-therapeutic delivery of metformin: potential anti-cancer effect against human colon cancer cells through inhibition of GPR75 expression

The high incidence rate coupled with significant mortality makes colorectal cancer one of the most prevalent and devastating cancers worldwide. Research is currently underway to explore new forms of treatment that could potentially maximize treatment outcomes while minimizing the side effects associated with conventional chemotherapy. Metformin, a natural biguanide drug, has anti-cancer properties that can inhibit the growth and proliferation of cancer cells. However, due to its short half-life and low bioavailability, the efficacy of Metf as an anti-cancer agent is limited. The purpose of this research is to assess the potency of PEGylated niosomes as a nano-delivery system for Metf, with the aim of increasing its anti-cancer effects on CaCo2 colorectal cancer cells through the effect on the expression of genes, including GPR75, hTERT, Bax, Bcl2, and Cyclin D1. Metf-loaded niosomal NPs (N-Metf) were synthesized using the thin-film hydration method and then characterized using SEM, FTIR, AFM, and DLS techniques. The release pattern of the drug from the nanoparticles (NPS) was determined using the dialysis membrane method. Furthermore, the cytotoxic effect of the metformin-loaded PEGylated niosome on the CaCo2 cell line was evaluated by the MTT test. Additionally, an apoptosis assay was conducted to assess the effect of free Metf and Metf-loaded NPS on the programmed death of the CaCo2 cells, and the impact on the cell cycle was studied through a cell cycle test. Finally, the expression levels of hTERT, Cyclin D1, BCL2, GPR75, and BAX genes were assessed in the presence of free Metf and Metf-loaded NPs by RT-PCR. Characterization experiments showed successful loading of metformin into PEGylated niosomes. The results of cytotoxicity evaluation showed that Metf-NPs had more cytotoxicity than free Metf in a dose-dependent manner. Furthermore, nuclear fragmentation and the percentage of apoptotic cells induced by Metf-NPs were significantly higher than those induced by free Metf. Additionally, Metf-NPs were found to induce more cell cycle arrest at the sub-G1 checkpoint than free Metf did. Compared with Metf-treated cells, the mRNA expression levels of GPR75, Cyclin D1, and hTERT were significantly changed in cells treated with Metf-NPs. Ultimately, it is hypothesized the nano-encapsulation of Metf into PEGylated niosomal NPs could be a worthwhile drug delivery system to enhance its effectiveness in treating colorectal cancer cells.

Efficacy and safety of metformin in combination with chemotherapy in cancer patients without diabetes: systematic review and meta-analysis

Background

The results of a meta-analysis of retrospective studies suggest that the use of metformin in cancer patients may prolong progression-free disease survival and overall survival. However, the studies included in the meta-analysis did not strictly distinguish between patients with or without type 2 diabetes mellitus. Therefore, further studies are needed to assess whether the use of adjuvant chemotherapy with metformin in cancer patients without diabetes improves prognosis.

Method

Systematic searches of Embase, Pubmed, and The Cochrane library were performed for the subject terms metformin and neoplasm and for free words. Data related to PFS, OS were extracted according to inclusion exclusion criteria. The data were combined and meta-analysis was performed using Review Manager 5.4 to confirm the efficacy and safety of metformin administration.

Results

There were 3228 publications retrieved from the database and a total of 13 publications with 955 patients were included in the meta-analysis after screening. All included studies were randomised controlled trials. Metformin combined with adjuvant chemotherapy did not improve progression-free survival (HR=1,95CI 0.79-1.25), overall survival (HR=0.91,95% CI 0.69-1.20) and did not improve objective disease response rates in patients. There was no significant difference in grade 3-4 adverse reactions compared to placebo.

Conclusion

In this meta-analysis of randomised controlled trial studies, we found that chemotherapy in combination with metformin in cancer patients without diabetes did not prolong progression-free survival and overall survival and improved disease control in patients, although there was no significant difference in terms of safety. More high-quality randomised controlled trials are needed in the future to confirm the in vivo anti-tumour activity and survival benefit of metformin.

The development and benefits of metformin in various diseases

Metformin has been used for the treatment of type II diabetes mellitus for decades due to its safety, low cost, and outstanding hypoglycemic effect clinically. The mechanisms underlying these benefits are complex and still not fully understood. Inhibition of mitochondrial respiratory-chain complex I is the most described downstream mechanism of metformin, leading to reduced ATP production and activation of AMP-activated protein kinase (AMPK). Meanwhile, many novel targets of metformin have been gradually discovered. In recent years, multiple pre-clinical and clinical studies are committed to extend the indications of metformin in addition to diabetes. Herein, we summarized the benefits of metformin in four types of diseases, including metabolic associated diseases, cancer, aging and age-related diseases, neurological disorders. We comprehensively discussed the pharmacokinetic properties and the mechanisms of action, treatment strategies, the clinical application, the potential risk of metformin in various diseases. This review provides a brief summary of the benefits and concerns of metformin, aiming to interest scientists to consider and explore the common and specific mechanisms and guiding for the further research. Although there have been countless studies of metformin, longitudinal research in each field is still much warranted.

A triple-drug combination induces apoptosis in cervical cancer-derived cell lines

Introduction

Cervical cancer is a worldwide health problem due to the number of deaths caused by this neoplasm. In particular, in 2020, 30,000 deaths of this type of tumor were reported in Latin America. Treatments used to manage patients diagnosed in the early stages have excellent results as measured by different clinical outcomes. Existing first-line treatments are not enough to avoid cancer recurrence, progression, or metastasis in locally advanced and advanced stages. Therefore, there is a need to continue with the proposal of new therapies. Drug repositioning is a strategy to explore known medicines as treatments for other diseases. In this scenario, drugs used in other pathologies that have antitumor activity, such as metformin and sodium oxamate, are analyzed.

Methods

In this research, we combined the drugs metformin and sodium oxamate with doxorubicin (named triple therapy or TT) based on their mechanism of action and previous investigation of our group against three CC cell lines.

Results

Through flow cytometry, Western blot, and protein microarray experiments, we found TT-induced apoptosis on HeLa, CaSki, and SiHa through the caspase 3 intrinsic pathway, including the critical proapoptotic proteins BAD, BAX, cytochrome-C, and p21. In addition, mTOR and S6K phosphorylated proteins were inhibited in the three cell lines. Also, we show an anti-migratory activity of the TT, suggesting other targets of the drug combination in the late CC stages.

Discussion

These results, together with our former studies, conclude that TT inhibits the mTOR pathway leading to cell death by apoptosis. Our work provides new evidence of TT against cervical cancer as a promising antineoplastic therapy.

Defining regorafenib as a senomorphic drug: therapeutic potential in the age-related lung disease emphysema

Senescence, a hallmark of aging, is a factor in age-related diseases (ARDs). Therefore, targeting senescence is widely regarded as a practicable method for modulating the effects of aging and ARDs. Here, we report the identification of regorafenib, an inhibitor of multiple receptor tyrosine kinases, as a senescence-attenuating drug. We identified regorafenib by screening an FDA-approved drug library. Treatment with regorafenib at a sublethal dose resulted in effective attenuation of the phenotypes of βPIX knockdown- and doxorubicin-induced senescence and replicative senescence in IMR-90 cells; cell cycle arrest, and increased SA-β-Gal staining and senescence-associated secretory phenotypes, particularly increasing the secretion of interleukin 6 (IL-6) and IL-8. Consistent with this result, slower progression of βPIX depletion-induced senescence was observed in the lungs of mice after treatment with regorafenib. Mechanistically, the results of proteomics analysis in diverse types of senescence indicated that growth differentiation factor 15 and plasminogen activator inhibitor-1 are shared targets of regorafenib. Analysis of arrays for phospho-receptors and kinases identified several receptor tyrosine kinases, including platelet-derived growth factor receptor α and discoidin domain receptor 2, as additional targets of regorafenib and revealed AKT/mTOR, ERK/RSK, and JAK/STAT3 signaling as the major effector pathways. Finally, treatment with regorafenib resulted in attenuation of senescence and amelioration of porcine pancreatic elastase-induced emphysema in mice. Based on these results, regorafenib can be defined as a novel senomorphic drug, suggesting its therapeutic potential in pulmonary emphysema.

An injectable and pH-responsive hyaluronic acid hydrogel as metformin carrier for prevention of breast cancer recurrence

To achieve the pH-responsive release of metformin in tumor acidic microenvironment, we prepared OHA-Met by covalently grafting metformin (Met) onto oxidized hyaluronic acid (OHA) through imine bonds, and then prepared carboxymethyl chitosan (CMCS)/OHA-Met drug loaded hydrogels. The CMCS/OHA-Met hydrogels showed the in-situ injection performance. At pH = 7.4, the cumulative release rate of metformin from CMCS/OHA-Met20 hydrogel was 42.7 ± 2.6 % in 6 h, and the release tended to balance after 72 h. At pH = 5.5, the release kept constant and the cumulative release rate was 79.3 ± 4.7 % at 6 h, showing good pH-responsive behavior. Metformin induced apoptosis of MCF-7 cells through the caspase 3/PARP pathway. CMCS/OHA-Met20 hydrogel could effectively kill MCF-7 cells, while reducing the cytotoxicity of free metformin to L929 cells. In vivo breast cancer recurrence experiments showed CMCS/OHA-Met20 hydrogel could achieve local injection and pH-responsive smart drug delivery at the tumor resection site, inhibiting breast cancer recurrence. Compared with direct administration, CMCS/OHA-Met20 hydrogel reduced the metformin dosage, frequency of administration and systemic side effects.

A phase I trial of metformin in combination with vincristine, irinotecan, and temozolomide in children with relapsed or refractory solid and central nervous system tumors: A report from the national pediatric cancer foundation

BACKGROUND

Patients with relapsed and refractory solid and central nervous system (CNS) tumors have poor outcomes and need novel therapeutic options. Vincristine, irinotecan, and temozolomide (VIT) is a common chemotherapy regimen in relapsed pediatric tumors with an established toxicity profile. Metformin shows preclinical anti-cancer activity through multiple pathways.

METHODS

The objective of this Phase I trial was to establish the maximum tolerated dose (MTD) and recommended Phase II dose (RP2D) of metformin in combination with VIT in children with relapsed and refractory solid and CNS tumors. A 3 + 3 design was used to test the addition of metformin at five dose levels (666, 999, 1333, 1666, and 2000 mg/m² /day). Therapy toxicity, pharmacokinetics, and radiologic response to treatment were evaluated.

RESULTS

Twenty-six patients (median age 13 years, range 2-18 years) were enrolled with 22 evaluable for toxicity. The most common diagnoses were Ewing sarcoma (n = 8), rhabdomyosarcoma (n = 3) and atypical teratoid/rhabdoid tumor (n = 3). The MTD was exceeded at Dose Level 5 due to two dose-limiting toxicities; both were Grade 3 diarrhea requiring prolonged hospitalization and intravenous fluids. The MTD was not determined due to study closure with less than six patients enrolled at Dose Level 4. Frequently observed toxicities were gastrointestinal (most notably diarrhea) and hematologic. Amongst 16 patients evaluable for best overall response, there was one complete response (Ewing sarcoma), three partial responses (Ewing sarcoma, glioblastoma multiforme, and alveolar rhabdomyosarcoma), and five patients with stable disease.

CONCLUSIONS

The MTD of VIT with metformin was not determined due to premature study closure. We recommend an RP2D of Dose Level 4, 1666 mg/m² /day. Radiographic responses were seen in multiple tumor types. Further evaluation for efficacy could be investigated in a Phase II trial.

Metabolic and Metabolomic Effects of Metformin in Murine Model of Pulmonary Adenoma Formation

Epidemiologic studies of diabetic patients treated with metformin identified significantly lower incidences of cancer. From this, there is growing interest in the use of metformin to treat and prevent cancer. Studies have investigated chemopreventive mechanisms including alterations in calorie intake, cancer metabolism, and cell signaling. Repurposing the drug is challenging due to its metabolic effects and non-uniform effects on different types of cancer. In our previously published studies, we observed that benzo[a]pyrene treated mice receiving metformin significantly reduced lung adenomas; however, mice had reduced weight gain. In this study, we compared chemoprevention diets with and without metformin to evaluate the effects of diet vs. effects of metformin. We also performed tandem mass spectrometry on mouse serum to assess metabolomic alterations associated with metformin treatment. In metformin cohorts, the rate of weight gain was reduced, but weights did not vary between diets. There was no weight difference between diets without metformin. Interestingly, caloric intake was increased in metformin treated mice. Metabolomic analysis revealed metabolite alterations consistent with metformin treatment. Based on these results, we conclude that previous reductions in lung adenomas may have been occurred from anticancer effects of metformin rather than a potentially toxic effect such as calorie restriction.

Use of Antihyperglycemic Drugs and Risk of Cancer in Patients with Diabetes

PURPOSE OF REVIEW

Diabetes is associated with an increased risk for several types of cancer. Therefore, use of antihyperglycemic medications to lower blood glucose may modify cancer risk. Here we review available data on the link between the most common classes of antihyperglycemic agents and cancer risk among patients with diabetes.

RECENT FINDINGS

A database search was conducted between February 2022 and June 2022 on PubMed and Embase for systematic reviews and meta-analyses investigating the association between antihyperglycemic agents and risk of cancer. Use of biguanides such as metformin is associated with 20-30% lower risk for all cancer incidence, and somewhat greater benefit for cancer-related mortality. Alpha-glucosidase inhibitors, e.g., acarbose, have not been consistently associated with cancer. Similarly, no consistent effects have been reported for thiazolidinediones, but the relationship with cancer seems to depend on the type of drug, dose, and duration of treatment. Exposure to various types of incretin-based therapies (glucagon-like peptide-1 agonists and dipeptidyl peptidase-4 inhibitors) has not been found to significantly modify cancer risk. Inhibitors of sodium glucose cotransporter-2 may raise risk for bladder cancer and reduce risk for gastrointestinal cancer. Use of insulin and insulin analogs is associated with a significant increase in total cancer risk by almost 50% compared to other antihyperglycemic drugs. Likewise, insulin secretagogues like sulfonylureas have generally been linked to greater risk for cancer by ~ 20%, although these associations may be agent-specific and dose-dependent. Current evidence suggests that the risk of cancer associated with the use of antihyperglycemic medications among patients with diabetes depends on the class of drug and type of agent, dosage, and duration of treatment. More research is needed to delineate the mechanisms by which these agents affect the process of carcinogenesis.

The Potential Therapeutic Impact of Metformin in Glioblastoma Multiforme

In terms of frequency and aggressiveness, glioblastoma multiforme (GBM) is undoubtedly the most frequent and fatal primary brain tumor. Despite advances in clinical management, the response to current treatments is dismal, with a 2-year survival rate varying between 6 and 12 percent. Metformin, a derivative of biguanide widely used in treating type 2 diabetes, has been shown to extend the lifespan of patients with various malignancies. There is limited evidence available on the long-term survival of GBM patients who have taken metformin. This research examined the literature to assess the connection between metformin's anticancer properties and GBM development. Clinical findings, together with the preclinical data from animal models and cell lines, are included in the present review. This comprehensive review covers not only the association of hyperactivation of the AMPK pathway with the anticancer activity of metformin but also other mechanisms underpinning its role in apoptosis, cell proliferation, metastasis, as well as its chemo-radio-sensitizing behavior against GBM. Current challenges and future directions for developments and applications of metformin-based therapeutics are also discussed.

Endogenous drivers of altered immune cell metabolism

Dysregulated metabolism has long been recognized as a feature of many metabolic disorders. However, recent studies demonstrating that metabolic reprogramming occurs in immune cells have led to a growing interest in the relationship between metabolic rewiring and immune-mediated disease pathogeneses. It is clear now that immune cell subsets engage in different metabolic pathways depending on their activation and/or maturation state. As a result, it may be possible to modulate metabolic reprogramming for clinical benefit. In this review, we provide an overview of immune cell metabolism with focus on endogenous drivers of metabolic reprogramming given their link to a number of immune-mediated disorders.

Respiratory Complex I dysfunction in cancer: from a maze of cellular adaptive responses to potential therapeutic strategies

Mitochondria act as key organelles in cellular bioenergetics and biosynthetic processes producing signals that regulate different molecular networks for proliferation and cell death. This ability is also preserved in pathologic contexts such as tumorigenesis, during which bioenergetic changes and metabolic reprogramming confer flexibility favoring cancer cell survival in a hostile microenvironment. Although different studies epitomize mitochondrial dysfunction as a protumorigenic hit, genetic ablation or pharmacological inhibition of respiratory complex I causing a severe impairment is associated with a low-proliferative phenotype. In this scenario, it must be considered that despite the initial delay in growth, cancer cells may become able to resume proliferation exploiting molecular mechanisms to overcome growth arrest. Here, we highlight the current knowledge on molecular responses activated by complex I-defective cancer cells to bypass physiological control systems and to re-adapt their fitness during microenvironment changes. Such adaptive mechanisms could reveal possible novel molecular players in synthetic lethality with complex I impairment, thus providing new synergistic strategies for mitochondrial-based anticancer therapy.

Levonorgestrel-releasing intrauterine device plus metformin, or megestrol acetate plus metformin for fertility-sparing treatment of atypical endometrial hyperplasia and early endometrial carcinoma: a prospective, randomized, blind-endpoint design trial protocol

Background

Endometrial adenocarcinoma (EC) is the fifth most common cancer in women worldwide, standard treatment for EC includes hysterectomy, but it results in the loss of reproductive function. Thus, conservative treatment for these patients is strongly demanded, progestin therapy is widely accepted as the main fertility-sparing treatment for young women with endometrial hyperplasia with atypia (EHA) and well-differentiated endometrioid endometrial cancer. This trial will investigate the effectiveness of conservative treatment for obese women with early-stage EC.

Method and design

This will be an open-label, 2-armed, randomized, phase-II single-center trial of LNG-IUD plus metformin or megestrol acetate (MA) plus metformin. A total of 88 participants will be randomly assigned into 2 treatment arms in a 1:1 ratio. Clinical, laboratory, ultrasound and radiology data, will be collected at baseline, and then at 3, 6, 9, 12, 18, and 24 months. EC biomarkers will be collected at baseline. The primary aim is to determine the efficacy of a levonorgestrel-releasing intrauterine device (LNG-IUD) plus metformin, or megestrol acetate (MA) plus metformin in achieving pathological complete response (pCR) at 12 months, as well as post-treatment pregnancy outcomes and recurrence rate. The secondary aims are to predict the response to an LNG-IUD plus metformin and MA plus metformin via clinical, blood, and tissue predictive biomarkers.

Conclusions

Prospective evidence for conservative treatment of EC is limited. New methods to achieve better CR rates with fewer side effects are needed. This trial will investigate the effectiveness of LNG-IUD plus metformin, and MA plus metformin, in obese women with early-stage EC, providing a non-surgical treatment option for these patients.

Trial registration ChiCTR2200055624. The trial was registered at http://www.chictr.org.cn/listbycreater.aspx on January 15, 2022

Endometrial adenocarcinoma (EC) is the fifth most common cancer in women worldwide, and up to 90% of EC patients are obese. Standard treatment for EC includes hysterectomy, but it leads to loss of reproductive function. This trial will investigate the effectiveness of non-surgical treatment for obese women with early-stage EC. There is limited prospective evidence for the conservative treatment of EC. New methods to achieve better CR rates with fewer side effects are needed. In this trial, patients with early-stage EC will be randomly assigned in a 1:1 ratio to receive treatment with a levonorgestrel-releasing intrauterine device (LNG-IUD) plus metformin, or megestrol acetate (MA) plus metformin. The primary aims are to determine the effectiveness of the 2 treatments to achieve a pathological complete response (pCR) at 12 months, pregnancy outcomes, and recurrence rate. The secondary aims are to predict the response to the 2 treatments using clinical data and blood and tissue predictive biomarkers. If the trial results indicate the treatments are effective, they may significantly reduce the incidence of adverse events in obese EC patients receiving current treatments, and preserve fertility; thereby improving patients’ quality of life and reducing healthcare costs.

Hypothesis-generating proteome perturbation to identify NEU-4438 and acoziborole modes of action in the African Trypanosome

NEU-4438 is a lead for the development of drugs against Trypanosoma brucei, which causes human African trypanosomiasis. Optimized with phenotypic screening, targets of NEU-4438 are unknown. Herein, we present a cell perturbome workflow that compares NEU-4438's molecular modes of action to those of SCYX-7158 (acoziborole). Following a 6 h perturbation of trypanosomes, NEU-4438 and acoziborole reduced steady-state amounts of 68 and 92 unique proteins, respectively. After analysis of proteomes, hypotheses formulated for modes of action were tested: Acoziborole and NEU-4438 have different modes of action. Whereas NEU-4438 prevented DNA biosynthesis and basal body maturation, acoziborole destabilized CPSF3 and other proteins, inhibited polypeptide translation, and reduced endocytosis of haptoglobin-hemoglobin. These data point to CPSF3-independent modes of action for acoziborole. In case of polypharmacology, the cell-perturbome workflow elucidates modes of action because it is target-agnostic. Finally, the workflow can be used in any cell that is amenable to proteomic and molecular biology experiments.

Zebrafish Avatars of rectal cancer patients validate the radiosensitive effect of metformin

Neoadjuvant chemoradiation (nCRT) followed by surgery represents the standard of care in patients with locally advanced rectal cancer. Increasing radiotherapy (RT) doses and chemotherapy cycles with 5FU have been associated with increased rates of complete response, however these strategies imply significant toxicity. In the last years, epidemiologic findings have demonstrated that metformin is associated with significantly higher rates of pathological complete response to nCRT. Also, pre-clinical studies using cell lines provide evidence for the radiosensitive effect of metformin. However, no studies have been performed using rectal cancer patient samples to test this radiosensitive effect of metformin and compared it to the standard 5FU. Here, we designed an experimental study to compare both radiosensitizers in the zebrafish xenograft model (zAvatar), using rectal cancer surgical specimens and diagnostic biopsies. Patient zAvatars confirmed that metformin has indeed a powerful in vivo radiosensitizer effect, similar to 5FU. Our work confirms that metformin constitutes a promising less toxic alternative to the standard 5FU, which could be game changing in elderly/frail patients to optimize tumor regression.