Anticancer activity of metformin: a systematic review of the literature

Gynotoxic Effects of Chemotherapy and Potential Protective Mechanisms

Chemotherapy is one of the leading cancer treatments. Unfortunately, its use can contribute to several side effects, including gynotoxic effects in women. Ovarian reserve suppression and estrogen deficiency result in reduced quality of life for cancer patients and are frequently the cause of infertility and early menopause. Classic alkylating cytostatics are among the most toxic chemotherapeutics in this regard. They cause DNA damage in ovarian follicles and the cells they contain, and they can also induce oxidative stress or affect numerous signaling pathways. In vitro tests, animal models, and a few studies among women have investigated the effects of various agents on the protection of the ovarian reserve during classic chemotherapy. In this review article, we focused on the possible beneficial effects of selected hormones (anti-Müllerian hormone, ghrelin, luteinizing hormone, melatonin), agents affecting the activity of apoptotic pathways and modulating gene expression (C1P, S1P, microRNA), and several natural (quercetin, rapamycin, resveratrol) and synthetic compounds (bortezomib, dexrazoxane, goserelin, gonadoliberin analogs, imatinib, metformin, tamoxifen) in preventing gynotoxic effects induced by commonly used cytostatics. The presented line of research appears to provide a promising strategy for protecting and/or improving the ovarian reserve in the studied group of cancer patients. However, well-designed clinical trials are needed to unequivocally assess the effects of these agents on improving hormonal function and fertility in women treated with ovotoxic anticancer drugs.

Metformin for endometrial hyperplasia

BACKGROUND

Endometrial cancer is one of the most common gynaecological cancers in the world. Rates of endometrial cancer are rising, in part because of rising obesity rates. Endometrial hyperplasia is a precancerous condition in women that can lead to endometrial cancer if left untreated. Endometrial hyperplasia occurs more commonly than endometrial cancer. Progesterone tablets that are currently used to treat women with endometrial hyperplasia are associated with adverse effects in up to 84% of women. A levonorgestrel intrauterine device may improve compliance, but it is invasive, is not acceptable to all women, and is associated with irregular vaginal bleeding in 82% of cases. Therefore, an alternative treatment for women with endometrial hyperplasia is needed. Metformin, a drug that is often used to treat people with diabetes, has been shown, in some human studies, to reverse endometrial hyperplasia. However, the effectiveness and safety of metformin for treatment of endometrial hyperplasia remain uncertain. This is an update of a review first published in 2017.

OBJECTIVES

To determine the effectiveness and safety of metformin in treating women with endometrial hyperplasia.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility Specialised Register, CENTRAL, MEDLINE, PubMed, Embase, Google Scholar, OpenGrey, LILACS, and two trials registers from inception to 5 September 2022. We searched the bibliographies of all relevant studies, and contacted experts in the field for any additional trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and cross-over trials comparing metformin (used alone or in combination with other medical therapies) versus placebo, no treatment, any conventional medical treatment, or any other active intervention for women with histologically confirmed endometrial hyperplasia of any type.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for eligibility, extracted data from included studies, assessed the risk of bias in the included studies, and assessed the certainty of the evidence for each outcome. We resolved disagreements by discussion or by deferring to a third review author. When study details were missing, review authors contacted the study authors. The primary outcome of this review was regression of endometrial hyperplasia histology (with or without atypia) towards normal histology.

MAIN RESULTS

We included seven RCTs, in which a total of 387 women took part. In the comparison, Metformin plus megestrol versus megestrol alone, we rated the certainty of the evidence as low for the outcome, regression of endometrial hyperplasia. We rated the quality of the evidence as very low for the rest of the outcomes, in all three comparisons. Although there was a low risk of selection bias, there was a high risk of bias in the blinding of personnel and outcome assessment (performance bias and detection bias) in many studies. This update identified four new RCTs and six ongoing RCTs. Metformin versus megestrol We are uncertain whether metformin increases the regression of endometrial hyperplasia towards normal histology over megestrol (odds ratio (OR) 4.89, 95% confidence interval (CI) 1.56 to 15.32; P = 0.006; 2 RCTs, 83 participants; I² = 7%; very low-certainty evidence). This evidence suggests that if the rate of regression with megestrol is 61%, the rate of regression with metformin would be between 71% and 96%. It is unresolved whether metformin results in different rates of abnormal uterine bleeding or hysterectomy compared to megestrol. No study in this comparison reported progression of hyperplasia to endometrial cancer, recurrence of endometrial hyperplasia, health-related quality of life, or adverse effects during treatment. Metformin plus megestrol versus megestrol monotherapy The combination of metformin and megestrol may enhance the regression of endometrial hyperplasia towards normal histology more than megestrol alone (OR 3.27, 95% CI 1.65 to 6.51; P = 0.0007; 4 RCTs, 258 participants; I² = 0%, low-certainty evidence). This suggests that if the rate of regression with megestrol monotherapy is 54%, the rate of regression with the addition of metformin would be between 66% and 84%. In one study, 3/8 (37.5%) of participants who took metformin had nausea that settled without further treatment. It is unresolved whether the combination of metformin and megestrol results in different rates of recurrence of endometrial hyperplasia, progression of endometrial hyperplasia to endometrial cancer, or hysterectomy compared to megestrol monotherapy. No study in this comparison reported abnormal uterine bleeding, or health-related quality of life. Metformin plus levonorgestrel (intrauterine system) versus levonorgestrel (intrauterine system) monotherapy We are uncertain whether there is a difference between groups in the regression of endometrial hyperplasia towards normal histology (OR 0.29, 95% CI 0.01 to 7.56; 1 RCT, 46 participants; very low-certainty evidence). This evidence suggests that if the rate of regression with levonorgestrel monotherapy is 96%, the rate of regression with the addition of metformin would be between 73% and 100%. It is unresolved whether the combination of metformin and levonorgestrel results in different rates of abnormal uterine bleeding, hysterectomy, or the development of adverse effects during treatment compared to levonorgestrel monotherapy. No study in this comparison reported recurrence of endometrial hyperplasia, progression of hyperplasia to endometrial cancer, or health-related quality of life.

AUTHORS' CONCLUSIONS

Review authors found insufficient evidence to either support or refute the use of metformin, specifically megestrol acetate, given alone or in combination with standard therapy, for the treatment of women with endometrial hyperplasia. Robustly designed and adequately powered randomised controlled trials, yielding long-term outcome data are still needed to address this clinical question.

Statin use as a moderator on the association between metformin and breast cancer risk in women with type 2 diabetes mellitus

INTRODUCTION

Metformin and statins are considered as potential agents for prevention of breast cancer, however, existing evidence does not uniformly substantiate this claim, and the data is scarce concerning their interaction in relation to breast cancer risk. This study aims to investigate whether the effect of metformin on breast cancer incidence varied by statin use among women with type 2 diabetes mellitus (T2DM).

METHODS

This study included women with T2DM, without a history of cancers, and followed up for more than one year from the Zwolle Outpatient Diabetes project Integrating Available Care (ZODIAC) for the period 1998-2014. The dataset was structured using a person-time approach, where the cumulative medication usage was annually updated for each person. The extended Cox proportional hazards models were employed, reporting adjusted hazard ratios (HR) with 95% confidence intervals (CI).

RESULTS

During a median follow-up of 5 years, 515 of 29,498 women received a breast cancer diagnosis. Each additional year of metformin or statins use corresponded to a decrease in breast cancer incidence, while the magnitude attenuated over time. Noteworthily, statin use modified the effect of metformin on breast cancer incidence. For instance, after 5 years of follow-up, one-year increase of metformin use among women who used statins for 3 years was linked to a substantially reduced breast cancer risk (HR, 95% CI: 0.88, 0.84-0.93), however, there was no significant decrease in risk for those non-statins users (HR, 95% CI: 0.96, 0.89-1.04).

CONCLUSIONS

Extending metformin or statin usage by one year conferred breast cancer protection in women with T2DM. Enhanced protective effect of metformin was observed among those who also use statins. These results suggest the potential of combined metformin and statin therapy as promising breast cancer prevention strategies.

Metformin Loaded Zein Polymeric Nanoparticles to Augment Antitumor Activity against Ehrlich Carcinoma via Activation of AMPK Pathway: D-Optimal Design Optimization, In Vitro Characterization, and In Vivo Study

Metformin (MET), an antidiabetic drug, is emerging as a promising anticancer agent. This study was initiated to investigate the antitumor effects and potential molecular targets of MET in mice bearing solid Ehrlich carcinoma (SEC) as a model of breast cancer (BC) and to explore the potential of zein nanoparticles (ZNs) as a carrier for improving the anticancer effect of MET. ZNs were fabricated through ethanol injection followed by probe sonication method. The optimum ZN formulation (ZN8) was spherical and contained 5 mg zein and 30 mg sodium deoxycholate with a small particle size and high entrapment efficiency percentage and zeta potential. A stability study showed that ZN8 was stable for up to three months. In vitro release profiles proved the sustained effect of ZN8 compared to the MET solution. Treatment of SEC-bearing mice with ZN8 produced a more pronounced anticancer effect which was mediated by upregulation of P53 and miRNA-543 as well as downregulation of NF-κB and miRNA-191-5p gene expression. Furthermore, ZN8 produced a marked elevation in pAMPK and caspase-3 levels as well as a significant decrease in cyclin D1, COX-2, and PGE2 levels. The acquired findings verified the potency of MET-loaded ZNs as a treatment approach for BC.

Role of SGLT2 Inhibitors, DPP-4 Inhibitors, and Metformin in Pancreatic Cancer Prevention

Pancreatic carcinoma is a highly aggressive tumor that usually presents when it has already metastasized. Therapeutic options for cure remain scarce and rely on combination chemotherapy with limited sustainability. Diabetes is considered an important risk factor for the development of pancreatic cancer due to the production of proinflammatory cytokines, which result in increased cell proliferation. More than half of patients diagnosed with pancreatic cancer eventually develop diabetes due to the destruction of insulin-producing cells. The interlinkage of both diseases might identify a possible preventative strategy for reducing the incidence of pancreatic carcinoma. This study reviewed the recent literature on the association between pancreatic cancer risk and SGLT2 inhibitors, GLP-1 RA, DPP-4 inhibitors, and biguanides. There are mixed data regarding the relationship between GLP-1 RA and DPP-4 inhibitors and pancreatic cancer, with some trials suggesting that they might increase the risk. In contrast, studies have mostly revealed that SGLT2 inhibitors have an antiproliferative effect on various tumors, such as liver, pancreatic, prostate, bowel, lung, and breast carcinoma, which might be due to their mechanism of blockage of reabsorption of glucose by cells, lowering the amount of available glucose for the growth of tumor cells. Metformin, the first-line agent for diabetes, has also been shown to be associated with decreasing pancreatic cancer risk and improving prognosis in those who already have the disease. Dedicated trials are needed to further delineate the association of antidiabetic drugs with the risk of pancreatic cancer in the general population, as previous studies have mostly focused on diabetic patients.

Ianus Bifrons: The Two Faces of Metformin

The ancient Roman god Ianus was a mysterious divinity with two opposite faces, one looking at the past and the other looking to the future. Likewise, metformin is an "old" drug, with one side looking at the metabolic role and the other looking at the anti-proliferative mechanism; therefore, it represents a typical and ideal bridge between diabetes and cancer. Metformin (1,1-dimethylbiguanidine hydrochloride) is a drug that has long been in use for the treatment of type 2 diabetes mellitus, but recently evidence is growing about its potential use in other metabolic conditions and in proliferative-associated diseases. The aim of this paper is to retrace, from a historical perspective, the knowledge of this molecule, shedding light on the subcellular mechanisms of action involved in metabolism as well as cellular and tissue growth. The intra-tumoral pharmacodynamic effects of metformin and its possible role in the management of different neoplasms are evaluated and debated. The etymology of the name Ianus is probably from the Latin term ianua, which means door. How many new doors will this old drug be able to open?

The mechanisms of action of metformin on head and neck cancer in the pre-clinical setting: a scoping review

This scoping review identifies the mechanistic pathways of metformin when used to treat head and neck cancer cells, in the pre-clinical setting. Understanding the underlying mechanisms will inform future experimental designs exploring metformin as a potential adjuvant for head and neck cancer. This scoping review was conducted according to the Joanna-Briggs Institute framework. A structured search identified 1288 studies, of which 52 studies fulfilled the eligibility screen. The studies are presented in themes addressing hallmarks of cancer. Most of the studies demonstrated encouraging anti-proliferative effects in vitro and reduced tumor weight and volume in animal models. However, a few studies have cautioned the use of metformin which supported cancer cell growth under certain conditions.

Paclitaxel-loaded niosomes in combination with metformin: development, characterization and anticancer potentials

Aim: This study aims to assess the efficacy of free and niosomes-loaded paclitaxel combined with the anti-diabetic drug metformin. Methods: Paclitaxel was successfully encapsulated in all niosome formulations, using microfluidic mixing, with a maximum encapsulation efficiency of 11.9%. Results: The half maximal inhibitory concentration (IC50) for free paclitaxel in T47D cells was significantly reduced from 0.2 to 0.048 mg/ml when combined with metformin 40 mg. The IC50 of paclitaxel was significantly reduced when loaded in niosomes to less than 0.06 mg/ml alone or with metformin. Conclusion: Paclitaxel combination (free or loaded into niosomes) with metformin significantly improved the anticancer efficacy of paclitaxel, which can serve as a method to reduce the paclitaxel dose and its associated side effects.

Metformin Hydrochloride Loaded Mucoadhesive Microspheres and Nanoparticles for Anti-Hyperglycemic and Anticancer Effects Using Factorial Experimental Design

Background

Metformin hydrochloride (HCl) microspheres and nanoparticles were formulated to enhance bioavailability and minimize side effects through sustained action and optimized drug-release characteristics. Initially, the same formulation design with different ratios of metformin HCl and Eudragit RSPO was used to formulate four batches of microspheres and nanoparticles using solvent evaporation and nanoprecipitation methods, respectively.

Methods

The produced formulations were evaluated based on particle size and shape (particle size distribution (PSD), scanning electron microscope (SEM)), incompatibility (differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR)), drug release pattern, permeation behavior, in vivo hypoglycemic effects, and in vitro anticancer potential.

Results

Compatibility studies concluded that there was minimal interaction between metformin HCl and the polymer, whereas SEM images revealed smoother, more spherical nanoparticles than microspheres. Drug release from the formulations was primarily controlled by the non-Fickian diffusion process, except for A1 and A4 by Fickian, and B3 by Super case II. Korsmeyer-Peppas was the best-fit model for the maximum formulations. The best formulations of microspheres and nanoparticles, based on greater drug release, drug entrapment, and compatibility characteristics, were attributed to the study of drug permeation by non-everted intestinal sacs, in vivo anti-hyperglycemic activity, and in vitro anticancer activity.

Conclusion

This study suggests that the proposed metformin HCl formulation can dramatically reduce hyperglycemic conditions and may also have anticancer potential.

The cubosome-based nanoplatforms in cancer therapy: Seeking new paradigms for cancer theranostics

Lyotropic liquid crystals are self-assembled, non-lamellar, and mesophase nanostructured materials that have garnered significant attention as drug carriers. Cubosomes, a subtype of lyotropic liquid crystalline nanoparticles, possess three-dimensional structures that display bicontinuous cubic liquid-crystalline patterns. These patterns are formed through the self-organization of unsaturated monoglycerides (amphphilic lipids such as glyceryl monooleate or phytantriol), followed by stabilization using steric polymers (poloxamers). Owing to their bicontinuous structure and steric polymer-based stabilization, cubosomes have been demonstrated to possess greater entrapment efficiency for hydrophobic drugs compared to liposomes, while also exhibiting high stability. In the past decade, there has been significant interest in cubosomes due to their ability to deliver therapeutic and contrast agents for cancer treatment and imaging with minimal side effects, establishing them as a safe and effective approach. Concerning these advantages, the present review elaborates on the general aspects, composition, and preparation techniques of cubosomes, followed by explanations of their mechanisms of drug loading and release patterns. Furthermore, the review provides meticulous discussions on the use of cubosomes in the treatment and imaging of various types of cancer, culminating in the enumeration of patents related to cubosome-based drug delivery systems.

Cytotoxicity and reversal effect of sertraline, fluoxetine, and citalopram on MRP1- and MRP7-mediated MDR

Cancer is one of the leading causes of death worldwide, and the development of resistance to chemotherapy drugs is a major challenge in treating malignancies. In recent years, researchers have focused on understanding the mechanisms of multidrug resistance (MDR) in cancer cells and have identified the overexpression of ATP-binding cassette (ABC) transporters, including ABCC1/MRP1 and ABCC10/MRP7, as a key factor in the development of MDR. In this study, we aimed to investigate whether three drugs (sertraline, fluoxetine, and citalopram) from the selective serotonin reuptake inhibitor (SSRI) family, commonly used as antidepressants, could be repurposed as inhibitors of MRP1 and MRP7 transporters and reverse MDR in cancer cells. Using a combination of in silico predictions and in vitro validations, we analyzed the interaction of MRP1 and MRP7 with the drugs and evaluated their ability to hinder cell resistance. We used computational tools to identify and analyze the binding site of these three molecules and determine their binding energy. Subsequently, we conducted experimental assays to assess cell viability when treated with various standard chemotherapies, both with and without the presence of SSRI inhibitors. Our results show that all three SSRI drugs exhibited inhibitory/reversal effects in the presence of chemotherapies on both MRP1-overexpressed cells and MRP7-overexpressed cells, suggesting that these medications have the potential to be repurposed to target MDR in cancer cells. These findings may open the door to using FDA-approved medications in combination therapy protocols to treat highly resistant malignancies and improve the efficacy of chemotherapy treatment. Our research highlights the importance of investigating and repurposing existing drugs to overcome MDR in cancer treatment.

The impact of cellular environment on in vitro drug screening

There are various reasons for drug failure in the developmental stage including toxicity, adverse effects and inefficacy. This is likely due to the differences in drug behavior between a simple and controlled cell culture system to that of a more complex whole organism environment. While the use of human phenotypical cells relevant to the condition may provide more accurate screening results, they are susceptible to producing false positives as cells are continuously influenced by constant chemical and physical interaction with the surrounding microenvironment. Therefore, several microenvironmental and pharmacomechanical aspects must be factored in during tissue culture drug screening.

Research Progress of Metformin in the Treatment of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies and has a high mortality, posing a great threat to both human physical and mental health. With the advancement of scientific research, a variety of cancer therapies have been used for OSCC treatment. However, the prognosis of OSCC shows no significant improvement. Metformin has been recognized as the first-line drug for the treatment of diabetes, and recent studies have shown that metformin has a remarkable suppressive effect on tumor progression. Metformin can not only affect the energy metabolism of tumor cells but also play an antitumor role by modulating the tumor microenvironment and cancer stem cells. In this review, the molecular mechanism of metformin and its anticancer mechanism in OSCC are summarized. In addition, this article summarizes the side effects of metformin and the future prospects of its application in the treatment of OSCC.

Repurposing drugs targeting metabolic diseases for cancer therapeutics

Hurdles in the identification of new drugs for cancer treatment have made drug repurposing an increasingly appealing alternative. The approach involves the use of old drugs for new therapeutic purposes. It is cost-effective and facilitates rapid clinical translation. Given that cancer is also considered a metabolic disease, drugs for metabolic disorders are being actively repurposed for cancer therapeutics. In this review, we discuss the repurposing of such drugs approved for two major metabolic diseases, diabetes and cardiovascular disease (CVD), which have shown potential as anti-cancer treatment. We also highlight the current understanding of the cancer signaling pathways that these drugs target.

The Effect of Different Glucose Concentrations on the Antiproliferative Activity of Metformin in MCF-7 Breast Cancer Cells

The glucose-lowering drug metformin has been reported to have anticancer properties through unknown mechanisms. Other unknown factors that may influence its anticancer potential include the glycemic status of the patient. Therefore, the objective of this study is to determine the effect of different glucose environments on the antiproliferative potency and the cellular mechanism of action of metformin. Human breast cancer cells, MCF-7, were incubated in low, normal, elevated, and high glucose environments and treated with metformin. The antiproliferative potential of metformin and its effect on protein expression as well as its ability to induce cellular apoptosis and autophagy under different glucose environments, were determined using different molecular techniques. Metformin significantly inhibited cellular proliferation in a time- and glucose-concentration-dependent manner. In comparison to elevated glucose, low normal glucose alone induced a significant level of autophagy that was further increased in the presence of metformin. While glucose concentration did not appear to have an effect on the antiproliferative potency of metformin, the cellular basis of action was shown to be glucose-dependent. The antiproliferative mechanism of action of metformin in elevated and low normal glucose environments is mTOR-dependent, whereas, in the high glucose environment, the antiproliferative mechanism is independent of mTOR. This is the first study to report that both the antiproliferative potency and the cellular mechanism of action aredependent on the concentration of glucose.

Poly(2-Hydroxyethyl Methacrylate) Hydrogel-Based Microneedles for Metformin Release

The release of metformin, a drug used in the treatment of cancer and diabetes, from poly(2-hydroxyethyl methacrylate), pHEMA, hydrogel-based microneedle patches is demonstrated in vitro. Tuning the composition of the pHEMA hydrogels enables preparation of robust microneedle patches with mechanical properties such that they would penetrate skin (insertion force of a single microneedle to be ≈40 N). Swelling experiments conducted at 20, 35, and 60 °C show temperature-dependent degrees of swelling and diffusion kinetics. Drug release from the pHEMA hydrogel-based microneedles is fitted to various models (e.g., zero order, first order, second order). Such pHEMA microneedles have potential application for transdermal delivery of metformin for the treatment of aging, cancer, diabetes, etc.

Type 2 Diabetes Mellitus and Efficacy Outcomes from Immune Checkpoint Blockade in Patients with Cancer

PURPOSE

No evidence exists as to whether type 2 diabetes mellitus (T2DM) impairs clinical outcome from immune checkpoint inhibitors (ICI) in patients with solid tumors.

EXPERIMENTAL DESIGN

In a large cohort of ICI recipients treated at 21 institutions from June 2014 to June 2020, we studied whether patients on glucose-lowering medications (GLM) for T2DM had shorter overall survival (OS) and progression-free survival (PFS). We used targeted transcriptomics in a subset of patients to explore differences in the tumor microenvironment (TME) of patients with or without diabetes.

RESULTS

A total of 1,395 patients were included. Primary tumors included non-small cell lung cancer (NSCLC; 54.7%), melanoma (24.7%), renal cell (15.0%), and other carcinomas (5.6%). After multivariable analysis, patients on GLM (n = 226, 16.2%) displayed an increased risk of death [HR, 1.29; 95% confidence interval (CI),1.07-1.56] and disease progression/death (HR, 1.21; 95% CI, 1.03-1.43) independent of number of GLM received. We matched 92 metformin-exposed patients with 363 controls and 78 patients on other oral GLM or insulin with 299 control patients. Exposure to metformin, but not other GLM, was associated with an increased risk of death (HR, 1.53; 95% CI, 1.16-2.03) and disease progression/death (HR, 1.34; 95% CI, 1.04-1.72). Patients with T2DM with higher pretreatment glycemia had higher neutrophil-to-lymphocyte ratio (P = 0.04), while exploratory tumoral transcriptomic profiling in a subset of patients (n = 22) revealed differential regulation of innate and adaptive immune pathways in patients with T2DM.

CONCLUSIONS

In this study, patients on GLM experienced worse outcomes from immunotherapy, independent of baseline features. Prospective studies are warranted to clarify the relative impact of metformin over a preexisting diagnosis of T2DM in influencing poorer outcomes in this population.

Repurposing of Chronically Used Drugs in Cancer Therapy: A Chance to Grasp

Despite the advancement in drug discovery for cancer therapy, drug repurposing remains an exceptional opportunistic strategy. This approach offers many advantages (faster, safer, and cheaper drugs) typically needed to overcome increased challenges, i.e., side effects, resistance, and costs associated with cancer therapy. However, not all drug classes suit a patient's condition or long-time use. For that, repurposing chronically used medications is more appealing. This review highlights the importance of repurposing anti-diabetic and anti-hypertensive drugs in the global fight against human malignancies. Extensive searches of all available evidence (up to 30 March 2023) on the anti-cancer activities of anti-diabetic and anti-hypertensive agents are obtained from multiple resources (PubMed, Google Scholar, ClinicalTrials.gov, Drug Bank database, ReDo database, and the National Institutes of Health). Interestingly, more than 92 clinical trials are evaluating the anti-cancer activity of 14 anti-diabetic and anti-hypertensive drugs against more than 15 cancer types. Moreover, some of these agents have reached Phase IV evaluations, suggesting promising official release as anti-cancer medications. This comprehensive review provides current updates on different anti-diabetic and anti-hypertensive classes possessing anti-cancer activities with the available evidence about their mechanism(s) and stage of development and evaluation. Hence, it serves researchers and clinicians interested in anti-cancer drug discovery and cancer management.

Metformin Induces a Caspase 3-Unrelated Apoptosis in Human Colorectal Cancer Cell Lines HCT116 and SW620

Purpose

To study the effects of metformin on the proliferation and growth of human colorectal cancer cell lines HCT116 and SW620.

Materials and Methods

The antiproliferative effect of metformin was assayed using an MTS reagent and its ability to inhibit colony formation was demonstrated using a clonogenic assay. Flow cytometry using YO-PRO-1/PI was performed to examine the effects of metformin on apoptosis and cell death of HCT116 and SW620. Caspase 3 activities were measured in caspase-3 activity tests using a caspase-3 activity kit. Furthermore, Western blots were performed with anti-PARP1, anti-caspase 3, and anti-cleaved caspase 3 to confirm whether caspase activation was present or not.

Results

Both MTS proliferation assays and clonogenic assays showed that metformin inhibited the proliferation and growth of HCT116 and SW620 cells in a concentration-dependent manner. Flow cytometric analysis identified early apoptosis and metformin-induced cell death in both cell lines. However, caspase 3 activity could not be detected. Cleavage of both PARP1 and pro-caspase 3 was not observed in the Western blot, confirming the absence of caspase 3 activations.

Conclusion

This present study suggests a caspase 3-unrelated apoptosis mechanism of metformin-induced cell death in human colorectal cancer cell lines HCT116 and SW620.

The antiproliferative potential and mechanism of action of metformin in MCF-7 cells

Aim

The current study aimed to investigate the potential antiproliferative activity of metformin, the effective concentration range, and the mechanism of action.

Materials & methods

Human breast cancer cells, MCF-7 were treated with a serial dilution of metformin (10-150 μM) for 24 and 48 h. Potential antiproliferative activity of metformin and its ability in inducing cellular apoptosis and autophagy were also investigated.

Results

Metformin inhibited MCF-7 proliferation in a concentration and time dependent manner, with 80 μM as the most effective concentration. Compared with nontreated cells, metformin induced significant levels of autophagy and apoptosis, which were confirmed by the reduction of mTOR and BCL-2 protein expression.

Conclusion

The study confirms the antiproliferative activity of metformin, which may likely occur through AMPK signaling pathway.

Changes in the expression of cancer- and metastasis-related genes and proteins after metformin treatment under different metabolic conditions in endometrial cancer cells

Research question

Hyperinsulinemia and elevated estrogen levels are known risk factors for endometrial cancer (EC) development and are associated with obesity, type 2 diabetes mellitus (T2DM), insulin resistance, among others. Metformin, an insulin-sensitizing drug, displays anti-tumor effects in cancer patients, including EC, but the mechanism of action is still not completely understood. In the present study, the effects of metformin on gene and protein expression were investigated in pre- and postmenopausal EC in vitro models in order to identify candidates that are potentially involved in the drug's anti-cancer mechanism.

Design

After treating the cells with metformin (0.1 and 1.0 mmol/L), changes in the expression of >160 cancer- and metastasis-related gene transcripts were evaluated with RNA arrays. A total of 19 genes and 7 proteins were selected for a follow-up expression analysis, including further treatment conditions, in order to evaluate the influence of hyperinsulinemia and hyperglycemia on metformin-induced effects.

Results

Changes in the expression of BCL2L11, CDH1, CDKN1A, COL1A1, PTEN, MMP9 and TIMP2 were analyzed on gene and protein level. The consequences resulting from the detected expression changes as well as the influence of varying environmental influences are discussed in detail. With the presented data, we contribute to a better understanding of the direct anti-cancer activity of metformin as well as its underlying mechanism of action in EC cells.

Conclusions

Although further research will be necessary to confirm the data, the influence of different environmental settings on metformin-induced effects could be highlighted with the presented data. Additionally, gene and protein regulation were not similar in the pre- and postmenopausal in vitro models.

Beta-adrenergic receptor blocker propranolol triggers anti-tumor immunity and enhances irinotecan therapy in mice colorectal cancer

Colorectal cancer (CRC) stands as the second leading cause of cancer-related deaths worldwide with limited available medicines. While drug repurposing comes as a promising strategy for cancer treatment, we discovered that propranolol (Prop), a non-selective β1 and β2 adrenergic receptor blocker, significantly inhibited the development of subcutaneous CT26 CRC and AOM/DSS-induced CRC models. The RNA-seq analysis highlighted the activated immune pathways after Prop treatment, with GO analysis enriched in T-cell differentiation, leukocyte-mediated immunity, regulation of leukocyte-mediated cytotoxicity, and interferon-gamma production. Routine analyses of blood revealed a decrease in neutrophil to lymphocyte ratio, a biomarker of systemic inflammation, and a prognostic indicator in the Prop-treated groups in both CRC models. Analysis of the tumor-infiltrating immune cells exhibited that Prop regressed the exhaustion of CD4⁺ and CD8⁺ T cells in the CT26-derived graft models, which was further corroborated in the AOM/DSS-induced models. Furthermore, bioinformatic analysis fitted well with the experimental data, showing that β2 adrenergic receptor (ADRB2) was positively correlated with T-cell exhaustion signature in various tumors. The in vitro experiment showed no direct effect of Prop on CT26 cell viability, while T cells were activated with significantly-upregulated production of IFN-γ and Granzyme B. Consistently, Prop was unable to restrain CT26 tumor growth in nude mice. At last, the combination of Prop and the chemotherapeutic drug Irinotecan acted out the strongest inhibition in CT26 tumor progress. Collectively, we repurpose Prop as a promising and economical therapeutic drug for CRC treatment and highlight T-cell as its target.

Metformin Use Is Associated With Lower Mortality in Veterans With Diabetes Hospitalized With Pneumonia

BACKGROUND

Recent studies suggest that metformin use may be associated with improved infectious disease-related outcomes, whereas other papers suggest potentially worse outcomes in serious bacterial infections. Our purpose was to examine the association of prior outpatient prescription of metformin on 30- and 90-day mortality for older veterans with pre-existing diabetes hospitalized with pneumonia.

METHODS

We conducted a retrospective cohort study using national Department of Veterans Affairs data of patients ≥65 years with a prior history of diabetes who were hospitalized with pneumonia over a 10-year period (fiscal years 2002-2012.) For our primary analysis, we created a propensity score and matched metformin users to nonusers 1:1.

RESULTS

We identified 34 759 patients who met the inclusion criteria, 20.3% of whom were prescribed metformin. Unadjusted 30-day mortality was 9.6% for those who received metformin versus 13.9% in nonusers (P < .003), and 90-day mortality was 15.8% for those who received metformin versus 23.0% for nonusers (P < .0001). For the propensity score model, we matched 6899 metformin users to 6899 nonusers. After propensity matching, both 30-day (relative risk [RR]: .86; 95% confidence interval [CI]: .78-.95) and 90-day (RR: .85; 95% CI: .79-.92) mortality was significantly lower for metformin users.

CONCLUSIONS

Prior receipt of metformin was associated with significantly lower mortality after adjusting for potential confounders. Additional research is needed to examine the safety and potential benefits of metformin use in patients with respiratory infections.

The Association between Metformin and the Cancer-Specific Mortality Rate in Nasopharyngeal Cancer Patients: Real-World Evidence

Objectives: Nasopharyngeal cancer is a common cancer in East and South Asia. The radiotherapy and chemotherapy regimen has advanced in recent years. However, many patients still suffer from local recurrence and distant metastasis; thus, identifying medication that can be combined with standard treatment to improve the treatment outcomes in nasopharyngeal cancer patients is an unmet need. Methods: We included nasopharyngeal cancer patients from the Taiwan National Health Insurance Database (NHIRD). The primary endpoint was set as the cancer-specific mortality rate. Metformin cohorts and non-Metformin cohorts were matched by sex, age, and the year of the index date. Propensity score matching with a ratio of 1:1 was applied. Results: A total of 6078 subjects were included in the study, with 3039 patients in each group. Male participants outnumbered female participants. Most of the patients were aged 50 to 64; the mean age was 60.4 ± 10.4 years in Metformin non-users, and that of Metformin users was 59.9 ± 10.5 years. Metformin users had a lower risk of death due to nasopharyngeal cancer (adjusted HR = 0.80; 95% CI = 0.71, 0.90) than controls. Conclusions: We concluded that Metformin might be effective at reducing the cancer-specific mortality rate in nasopharyngeal cancer patients. Further randomized control trials should be completed.

Metformin May Alter the Metabolic Reprogramming in Cancer Cells by Disrupting the L-Arginine Metabolism: A Preliminary Computational Study

Metabolic reprogramming in cancer is considered to be one of the most important hallmarks to drive proliferation, angiogenesis, and invasion. AMP-activated protein kinase activation is one of the established mechanisms for metformin’s anti-cancer actions. However, it has been suggested that metformin may exert antitumoral effects by the modulation of other master regulators of cellular energy. Here, based on structural and physicochemical criteria, we tested the hypothesis that metformin may act as an antagonist of L-arginine metabolism and other related metabolic pathways. First, we created a database containing different L-arginine-related metabolites and biguanides. After that, comparisons of structural and physicochemical properties were performed employing different cheminformatic tools. Finally, we performed molecular docking simulations using AutoDock 4.2 to compare the affinities and binding modes of biguanides and L-arginine-related metabolites against their corresponding targets. Our results showed that biguanides, especially metformin and buformin, exhibited a moderate-to-high similarity to the metabolites belonging to the urea cycle, polyamine metabolism, and creatine biosynthesis. The predicted affinities and binding modes for biguanides displayed good concordance with those obtained for some L-arginine-related metabolites, including L-arginine and creatine. In conclusion, metabolic reprogramming in cancer cells by metformin and biguanides may be also driven by metabolic disruption of L-arginine and structurally related compounds.

Metformin: new applications for an old drug

Metformin is a biguanide, evolved as one of the most widely used medicines. The applications of this component include but are not limited to reducing blood glucose, weight loss, and polycystic ovary syndrome. Studies about other probable indications have emerged, indicating that this agent can also be utilized for other purposes. In this review, applications of metformin are noticed based on the current evidence. Metformin commonly is used as an off-label drug in non-alcoholic fatty liver disease (NAFLD), but it worsens inflammation and should not be used for this purpose, according to the latest research. Metformin decreased the risk of death in patients with liver cirrhosis. It is an effective agent in the prevention and improvement of survival in patients suffering hepatocellular carcinoma. There is evidence of the beneficial effects of metformin in colorectal cancer, early-stage prostate cancer, breast cancer, urothelial cancer, blood cancer, melanoma, and bone cancer, suggesting metformin as a potent anti-tumor agent. Metformin shows neuroprotective effects and provides a potential therapeutic benefit for mild cognitive impairment and Alzheimer's disease (AD). It also has been shown to improve mental function and reduce the incidence of dementia. Another condition that metformin has been shown to slow the progression of is Duchenne muscular dystrophy. Regarding infectious diseases, tuberculosis (TB) and coronavirus disease (COVID-19) are among the conditions suggested to be affected by metformin. The beneficial effects of metformin in cardiovascular diseases were also reported in the literature. Concerning renal function, studies showed that daily oral administration of metformin could ameliorate kidney fibrosis and normalize kidney structure and function. This study reviewed the clinical and preclinical evidence about the possible benefits of metformin based on recent studies. Numerous questions like whether these probable indications of metformin can be observed in non-diabetics, need to be described by future basic experiments and clinical studies.

Tuberous Sclerosis, Type II Diabetes Mellitus and the PI3K/AKT/mTOR Signaling Pathways-Case Report and Literature Review

Tuberous sclerosis complex (TSC) is a rare autosomal dominant neurocutaneous syndrome. It is manifested mainly in cutaneous lesions, epilepsy and the emergence of hamartomas in several tissues and organs. The disease sets in due to mutations in two tumor suppressor genes: TSC1 and TSC2. The authors present the case of a 33-year-old female patient registered with the Bihor County Regional Center of Medical Genetics (RCMG) since 2021 with a TSC diagnosis. She was diagnosed with epilepsy at eight months old. At 18 years old she was diagnosed with tuberous sclerosis and was referred to the neurology department. Since 2013 she has been registered with the department for diabetes and nutritional diseases with a type 2 diabetes mellitus (T2DM) diagnosis. The clinical examination revealed: growth delay, obesity, facial angiofibromas, sebaceous adenomas, depigmented macules, papillomatous tumorlets in the thorax (bilateral) and neck, periungual fibroma in both lower limbs, frequent convulsive seizures; on a biological level, high glycemia and glycated hemoglobin levels. Brain MRI displayed a distinctive TS aspect with five bilateral hamartomatous subependymal nodules associating cortical/subcortical tubers with the frontal, temporal and occipital distribution. Molecular diagnosis showed a pathogenic variant in the TSC1 gene, exon 13, c.1270A>T (p. Arg424*). Current treatment targets diabetes (Metformin, Gliclazide and the GLP-1 analog semaglutide) and epilepsy (Carbamazepine and Clonazepam). This case report presents a rare association between type 2 diabetes mellitus and Tuberous Sclerosis Complex. We suggest that the diabetes medication Metformin may have positive effects on both the progression of the tumor associated with TSC and the seizures specific to TSC and we assume that the association of TSC and T2DM in the presented cases is accidental, as there are no similar cases reported in the literature.

Metformin Therapy and Breast Cancer Incidence in the Ha'il Region

BACKGROUND

Metformin is a drug used to treat patients with type 2 diabetes, especially those who suffer from obesity. It is also used in the treatment of women with polycystic ovary syndrome (PCOS). This disease is related to insulin resistance and multiplied blood sugar ranges. Furthermore, it has been established that the use of metformin improves the menstrual cycles and ovulation rates of these women.

METHODS

A structured questionnaire was conducted to determine the prevalence of breast cancer among women using metformin in the Ha'il region.

RESULT

The incidence of breast cancer among women using metformin in the Ha'il region is very low. Thus, it can be said that breast cancer cases declined among diabetics taking metformin. This means that metformin use is associated with a lower risk of breast cancer in women with type 2 diabetes, even in cases where these women have a family history of breast cancer.

CONCLUSIONS

According to previous findings, metformin has been linked to lower breast cancer risk in women with type 2 diabetes. Furthermore, the findings of this study corroborate the literature on this subject by indicating that there is a substantial connection between metformin use and a lower risk of breast cancer in women with type 2 diabetes. However, further in vitro and in vivo experiments are crucial to investigate the protective effect of metformin against breast cancer and to confirm our findings.

Targeted Delivery of Metformin Against Lung Cancer Cells Via Hyaluronan-Modified Mesoporous Silica Nanoparticles

Metformin (Metf), a biguanide widely used to manage type 2 diabetes mellitus, has recently entered the spotlight as a hopeful anti-tumor agent. In this work, because of the hyaluronic acid (HA) capability to specifically target CD44 receptors over-expressed on the surface of non-small lung cancer cells, a tumor-targeted drug delivery nanocarrier-based HA-coated mesoporous silica nanoparticles (MSNs) have been used for active targeting and efficient delivery of Metf. For this purpose, the synthesized MSNs-HA were characterized using BET, FE-EM, DLS, and FTIR. Confocal microscopy was applied to show the enhanced cellular uptake of the FITC-labelled MSNs-HA compared to MSNs without HA coating. MTT and qPCR results also revealed superior cytotoxicity and pro-apoptotic effects of Metf-loaded MSNs-HA (Metf@MSNs-HA) against the A549 lung cancer cells compared to the free Metf and MSNs@Metf due to the efficient CD44-targeting capability and delivery of Metf@MSNs-HA. Besides, it was demonstrated that Metf@MSNs-HA could effectively trigger the AMP-activated protein kinase α (AMPKα) pathway and inhibit the mammalian target rapamycin (mTOR), increasing the growth suppression. In conclusion, this preliminary work disclosed the great potential of Metf@MSNs-HA in targeted therapy of lung cancer cells.

Cell cycle exits and U-turns: Quiescence as multiple reversible forms of arrest

Cell proliferation control is essential during development and for maintaining adult tissues. Loss of that control promotes not only oncogenesis when cells proliferate inappropriately but also developmental abnormalities or degeneration when cells fail to proliferate when and where needed. To ensure that cells are produced at the right place and time, an intricate balance of pro-proliferative and anti-proliferative signals impacts the probability that cells undergo cell cycle exit to quiescence, or G₀ phase. This brief review describes recent advances in our understanding of how and when quiescence is initiated and maintained in mammalian cells. We highlight the growing appreciation for quiescence as a collection of context-dependent distinct states.

Metformin use and mortality in Asian, diabetic patients with prostate cancer on androgen deprivation therapy: A population-based study

BACKGROUND

This study aims to examine the associations between metformin use concurrent with androgen deprivation therapy (ADT) and mortality risks in Asian, diabetic patients with prostate cancer (PCa).

METHODS

This study identified diabetic adults with PCa receiving any ADT attending public hospitals in Hong Kong between December 1999 and March 2021 retrospectively, with follow-up until September 2021. Patients with <6 months of medical castration without subsequent bilateral orchidectomy, <6 months of concurrent metformin use and ADT, or missing baseline HbA1c were excluded. Metformin users had ≥180 days of concurrent metformin use and ADT, while non-users had no concurrent metformin use and ADT or never used metformin. The primary outcome was PCa-related mortality. The secondary outcome was all-cause mortality. The study used inverse probability treatment weighting to balance covariates.

RESULTS

The analyzed cohort consisted of 1971 patients (1284 metformin users and 687 non-users; mean age 76.2 ± 7.8 years). Over a mean follow-up of 4.1 ± 3.2 years, metformin users had significantly lower risks of PCa-related mortality (weighted hazard ratio [wHR]: 0.49 [95% confidence interval, CI:  0.39-0.61], p < 0.001) and all-cause mortality (wHR 0.53 [0.46-0.61], p < 0.001), independent of diabetic control or status of chronic kidney disease. Such effects appeared stronger in patients with less advanced PCa, which is reflected by the absence of androgen receptor antagonist or chemotherapy use (p value for interaction: 0.017 for PCa-related mortality; 0.048 for all-cause mortality).

CONCLUSIONS

Metformin use concurrent with ADT was associated with lower risks of mortality in Asian, diabetic patients with PCa.

Targeting the "hallmarks of aging" to slow aging and treat age-related disease: fact or fiction?

Aging is a major risk factor for a number of chronic diseases, including neurodegenerative and cerebrovascular disorders. Aging processes have therefore been discussed as potential targets for the development of novel and broadly effective preventatives or therapeutics for age-related diseases, including those affecting the brain. Mechanisms thought to contribute to aging have been summarized under the term the "hallmarks of aging" and include a loss of proteostasis, mitochondrial dysfunction, altered nutrient sensing, telomere attrition, genomic instability, cellular senescence, stem cell exhaustion, epigenetic alterations and altered intercellular communication. We here examine key claims about the "hallmarks of aging". Our analysis reveals important weaknesses that preclude strong and definitive conclusions concerning a possible role of these processes in shaping organismal aging rate. Significant ambiguity arises from the overreliance on lifespan as a proxy marker for aging, the use of models with unclear relevance for organismal aging, and the use of study designs that do not allow to properly estimate intervention effects on aging rate. We also discuss future research directions that should be taken to clarify if and to what extent putative aging regulators do in fact interact with aging. These include multidimensional analytical frameworks as well as designs that facilitate the proper assessment of intervention effects on aging rate.

Metformin and bladder cancer: Drug repurposing as a potential tool for novel therapy: A review

Bladder cancer (BC) is a common type of cancer worldwide. Currently, the gold standard treatment is transurethral resection of bladder tumor (TUR-Bt) accompanied by intravesical Bacillus Calmette-Guérin (BCG) instillation for patients with middle-to-high-risk non-muscle-invasive bladder cancer (NMIBC). However, intravesical BCG therapy fails in almost 50% of high risk cases, leading to NMIBC persistence or early recurrence. In these patients, the gold standard remains radical cystectomy; however, it can seriously affect the patients' quality of life. Moreover, for patients with muscle-invasive bladder cancer (MIBC), the 5-year survival rate after radical cystectomy with neoadjuvant chemotherapy remains low. Recent discoveries have paved the way for a new era in BC treatment. Metformin is the most widely used oral hypoglycemic drug in clinical practice, being mostly used in the treatment of type 2 diabetes. Epidemiological studies have demonstrated that metformin exerts a potentially positive effect on reducing the incidence and mortality of cancer; therefore, a increasing number of studies have investigated the potential anticancer effects of metformin and its mechanisms of action. This review aims to summarize the evidence for the role of metformin in bladder cancer therapy, including how metformin mediates bladder cancer cell apoptosis.

Metformin: Activation of 5′ AMP-activated protein kinase and its emerging potential beyond anti-hyperglycemic action

Metformin is a plant-based drug belonging to the class of biguanides and is known to treat type-2 diabetes mellitus (T2DM). The drug, combined with controlling blood glucose levels, improves the body’s response to insulin. In addition, trials have identified the cardioprotective potential of metformin in the diabetic population receiving the drug. Activation of 5′ AMP-activated protein kinase (AMPK) is the major pathway for these potential beneficial effects of metformin. Historically, much emphasis has been placed on the potential indications of metformin beyond its anti-diabetic use. This review aims to appraise other potential uses of metformin primarily mediated by the activation of AMPK. We also discuss various mechanisms, other than AMPK activation, by which metformin could produce beneficial effects for different conditions. Databases including PubMed/MEDLINE and Embase were searched for literature relevant to the review’s objective. Reports from both research and review articles were considered. We found that metformin has diverse effects on the human body systems. It has been shown to exert anti-inflammatory, antioxidant, cardioprotective, metabolic, neuroprotective, anti-cancer, and antimicrobial effects and has now even been identified as effective against SARS-CoV-2. Above all, the AMPK pathway has been recognized as responsible for metformin’s efficiency and effectiveness. Owing to its extensive potential, it has the capability to become a part of treatment regimens for diseases apart from T2DM.

Milk Exosomal microRNAs: Postnatal Promoters of β Cell Proliferation but Potential Inducers of β Cell De-Differentiation in Adult Life

Pancreatic β cell expansion and functional maturation during the birth-to-weaning period is driven by epigenetic programs primarily triggered by growth factors, hormones, and nutrients provided by human milk. As shown recently, exosomes derived from various origins interact with β cells. This review elucidates the potential role of milk-derived exosomes (MEX) and their microRNAs (miRs) on pancreatic β cell programming during the postnatal period of lactation as well as during continuous cow milk exposure of adult humans to bovine MEX. Mechanistic evidence suggests that MEX miRs stimulate mTORC1/c-MYC-dependent postnatal β cell proliferation and glycolysis, but attenuate β cell differentiation, mitochondrial function, and insulin synthesis and secretion. MEX miR content is negatively affected by maternal obesity, gestational diabetes, psychological stress, caesarean delivery, and is completely absent in infant formula. Weaning-related disappearance of MEX miRs may be the critical event switching β cells from proliferation to TGF-β/AMPK-mediated cell differentiation, whereas continued exposure of adult humans to bovine MEX miRs via intake of pasteurized cow milk may reverse β cell differentiation, promoting β cell de-differentiation. Whereas MEX miR signaling supports postnatal β cell proliferation (diabetes prevention), persistent bovine MEX exposure after the lactation period may de-differentiate β cells back to the postnatal phenotype (diabetes induction).

High Expression of ACOT2 Predicts Worse Overall Survival and Abnormal Lipid Metabolism: A Potential Target for Acute Myeloid Leukemia

Acyl-CoA thioesterase (ACOT) plays a considerable role in lipid metabolism, which is closely related to the occurrence and development of cancer, nevertheless, its role has not been fully elucidated in acute myeloid leukemia (AML). To explore the role of ACOT2 in AML and to provide a potential therapeutic target for AML, the expression pattern of ACOT was investigated based on the TNMplot, Gene Expression Profiling Interactive Analysis (GEPIA), and Cancer Cell Line Encyclopedia (CCLE) database, and diagnostic value, prognostic value, and clinical phenotype of ACOT were explored based on data from The Cancer Genome Atlas (TCGA). Functional annotation and enrichment analysis of the common targets between ACOT2 coexpressed and AML-related genes were further performed by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA) analyses. The protein-protein interaction (PPI) network of ACOT2 coexpressed genes and functional ACOT2-related metabolites association network were constructed based on GeneMANIA and Human Metabolome Database. Among ACOTs, ACOT2 was highly expressed in AML compared to normal control subjects according to TNMplot, GEPIA, and CCLE database, which was significantly associated with poor overall survival (OS) in AML ( $P=0.003$ ). Moreover, ACOT2 exhibited excellent diagnostic efficiency for AML (AUC: 1.000) and related to French-American-British (FAB) classification and cytogenetics. GO, KEGG, and GSEA analyses of 71 common targets between ACOT2 coexpressed and AML-related genes revealed that ACOT2 is closely related to ACOT1, ACOT4, enoyl-acyl carrier protein reductase, mitochondrial (MECR), puromycin-sensitive aminopeptidase (NPEPPS), SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1 (SMARCB1), and long-chain fatty acid-CoA ligase 1 (ACSL1) in PPI network, and plays a significant role in lipid metabolism, that is, involved in fatty acid elongation and biosynthesis of unsaturated fatty acids. Collectively, the increase of ACOT2 may be an important characteristic of worse OS and abnormal lipid metabolism, suggesting that ACOT2 may become a potential therapeutic target for AML.

Pharmacokinetic-Pharmacometabolomic Approach in Early-Phase Clinical Trials: A Way Forward for Targeted Therapy in Type 2 Diabetes

Pharmacometabolomics in early phase clinical trials demonstrate the metabolic profiles of a subject responding to a drug treatment in a controlled environment, whereas pharmacokinetics measure the drug plasma concentration in human circulation. Application of the personalized peak plasma concentration from pharmacokinetics in pharmacometabolomic studies provides insights into drugs’ pharmacological effects through dysregulation of metabolic pathways or pharmacodynamic biomarkers. This proof-of-concept study integrates personalized pharmacokinetic and pharmacometabolomic approaches to determine the predictive pharmacodynamic response of human metabolic pathways for type 2 diabetes. In this study, we use metformin as a model drug. Metformin is a first-line glucose-lowering agent; however, the variation of metabolites that potentially affect the efficacy and safety profile remains inconclusive. Seventeen healthy subjects were given a single dose of 1000 mg of metformin under fasting conditions. Fifteen sampling time-points were collected and analyzed using the validated bioanalytical LCMS method for metformin quantification in plasma. The individualized peak-concentration plasma samples determined from the pharmacokinetic parameters calculated using Matlab Simbiology were further analyzed with pre-dose plasma samples using an untargeted metabolomic approach. Pharmacometabolomic data processing and statistical analysis were performed using MetaboAnalyst with a functional meta-analysis peaks-to-pathway approach to identify dysregulated human metabolic pathways. The validated metformin calibration ranged from 80.4 to 2010 ng/mL for accuracy, precision, stability and others. The median and IQR for Cmax was 1248 (849–1391) ng/mL; AUC_0-infinity was 9510 (7314–10,411) ng·h/mL, and Tmax was 2.5 (2.5–3.0) h. The individualized Cmax pharmacokinetics guided the untargeted pharmacometabolomics of metformin, suggesting a series of provisional predictive human metabolic pathways, which include arginine and proline metabolism, branched-chain amino acid (BCAA) metabolism, glutathione metabolism and others that are associated with metformin’s pharmacological effects of increasing insulin sensitivity and lipid metabolism. Integration of pharmacokinetic and pharmacometabolomic approaches in early-phase clinical trials may pave a pathway for developing targeted therapy. This could further reduce variability in a controlled trial environment and aid in identifying surrogates for drug response pathways, increasing the prediction of responders for dose selection in phase II clinical trials.

Extra-Glycemic Effects of Anti-Diabetic Medications: Two Birds with One Stone?

The world is suffering from a rapid increase in the number of people with diabetes due to the increased prevalence of obesity and lengthened life span. Since the development of insulin thanks to the efforts of Prof. Banting and Dr. Best in 1922, for which they won the Nobel Prize, remarkable developments in anti-diabetic medications have dramatically lengthened the lifespan of patients with diabetes. However, the control rate of hyperglycemia in patients with diabetes remains unsatisfactory, since glycemic control requires both medication and lifestyle modifications to slow the deterioration of pancreatic beta-cell function and prevent diabetic complications. From the initial "triumvirate" to the "ominous octet," and now the "egregious eleven," the number of organs recognized as being involved in hyperglycemia and diabetes has increased with the development of anti-diabetic medications. Recent unexpected results from outcome trials of anti-diabetic medications have enabled anti-diabetic medications to be indicated for the prevention of chronic kidney disease and heart failure, even in patients without diabetes. In this review, I would like to summarize the extra-glycemic effects of anti-diabetic medications.

Implementation of QbD Approach to the Analytical Method Development and Validation for the Estimation of Metformin Hydrochloride in Tablet Dosage Forms by HPLC

The current studies entail quality by design (QbD)-enabled development of a simple, rapid, precise, accurate, and cost-effective high-performance liquid chromatographic method for estimation of metformin hydrochloride (M-HCl). Design of experiments (DoE) was applied for multivariate optimization of the experimental conditions of the HPLC method. Risk assessment was performed to identify the critical method parameters (CMPs) using Ishikawa diagram. The factor screening studies were performed using a two-factor three-levels design. Two independent factors, buffer pH and mobile phase composition, were used to design mathematical models. Central composite design (CCD) was used to study the response surface methodology and to study in depth the effects of these independent factors, thus evaluating the critical analytical attributes (CAAs), namely, retention time, peak area, and symmetry factor as the parameters of method robustness. Desirability function was used to simultaneously optimize the CAAs. The optimized and predicted data from contour diagram consisted of 0.02 M acetate buffer pH = 3/methanol in a ratio of 70/30 (v/v) as the mobile phase with a flow rate 1 mL/min. The separation was made on a Thermoscientific ODS Hypersyl^TM chromatographic column (250 × 4.6 mm, 5 μm) with oven temperature 35 °C and UV detection at 235 nm. The optimized assay conditions were validated according to ICH guidelines. Hence, the results clearly showed that QbD approach could be successfully applied to optimize HPLC method for estimation of M-HCl. The method was applied both for the evaluation of M-HCl content in tablets, and for in vitro dissolution studies of M-HCl from conventional and prolonged-release tablets.

In Vitro and In Ovo Evaluation of the Potential Hepatoprotective Effect of Metformin

Background and Objectives: Metformin is currently the leading drug of choice for treating type 2 diabetes mellitus, being one of the most widely used drugs worldwide. The beneficial effects of Metformin, however, extend far beyond the reduction of blood glucose. Therefore, this study aimed to evaluate Metformin's effects both in vitro and in ovo. Materials and Methods: Metformin has been tested in five different concentrations in human hepatocytes -HepaRG, in terms of cell viability, morphology, structure and number of nuclei and mitochondria, as well as the effect on cell migration. Through the application of HET-CAM, the biocompatibility and potential anti-irritant, as well as protective effects on the vascular plexus were also assessed. Results: According to the results obtained, Metformin increases cell viability without causing morphological changes to cells, mitochondria, or nuclei. Metformin displayed an anti-irritant activity rather than causing irritation at the level of the vascular plexus. Conclusions: In conclusion, Metformin enhances cell viability and proliferation and, has a protective effect on the vascular plexus. Nonetheless, more studies are required to clarify the mechanism of hepatoprotective effect of metformin.

Development and evaluation of core-shell nanocarrier system for enhancing the cytotoxicity of doxorubicin/ metformin combination against breast cancer cell line

Breast cancer is the most invasive and life-threatening cancer in women. The treatment options are usually a combination of mastectomy, radiation therapy, hormonal therapy and chemotherapy. As a standard practice, doxorubicin (DOX) is one of the commonly used drugs for breast cancer treatment. However, DOX is known to have many harmful adverse effects including its cardiotoxicity. Hence, recent reports used metformin (MET), an anti-diabetic drug, as an adjuvant therapy to decrease the severity of DOX's adverse effects and to improve its ultimate therapeutic outcome. The current study is aimed at co-loading and enhancing the encapsulation efficiency of the hydrophilic DOX and MET in poly(lactic-co-glycolic acid) (PLGA) nanocapsules (NCs) with oil core for breast cancer treatment. The NCs were developed by single emulsification-solvent diffusion technique, and were optimized through using two types of oils, pluronics and PLGA (50:50) of different molecular weights followed by various physicochemical characterizations. The obtained DOX/MET-loaded NCs showed the size and polydispersity index (PDI) of 203.0 ± 3.4 nm and 0.081 ± 0.03, respectively with a surface charge of -2.15 ± 0.2 mV. The entrapment efficiency of DOX and MET were about 93.7% ± 2.9 and 70% ± 1.6, respectively. The developed PLGA core-shell NCs successfully sustained the DOX/MET release for more than 30 days. The in-vitro results showed a significant enhancement in DOX cytotoxic effect as well as a duplication in its apoptotic effect upon addition of MET for both free DOX/MET combination and DOX/MET-loaded PLGA NCs against MCF-7. Besides, flow cytometry demonstrated that the DOX/MET-loaded NCs possess their antitumor effect by preventing DNA replication and cell division. This study provides a promising facile, rapid and reproducible single emulsification-solvent diffusion technique for improving the encapsulation and release of hydrophilic drugs in nanocapsules for biomedical applications.

Drug repurposing to overcome microbial resistance

Infections are a growing global threat, and the number of resistant species of microbial pathogens is alarming. However, the rapid development of cross-resistant or multidrug-resistant strains and the development of so-called 'superbugs' are in stark contrast to the number of newly launched anti-infectives on the market. In this review, I summarize the causes of antimicrobial resistance, briefly discuss different approaches to the discovery and development of new anti-infective drugs, and focus on drug repurposing strategy, which is discussed from all possible perspectives. A comprehensive overview of drugs of other indications tested for their in vitro antimicrobial activity to support existing anti-infective therapeutics is provided, including several critical remarks on this strategy of repurposing non-antibiotics to antibacterial drugs.

Biological Properties of Transition Metal Complexes with Metformin and Its Analogues

Metformin is a widely prescribed medication for the treatment and management of type 2 diabetes. It belongs to a class of biguanides, which are characterized by a wide range of diverse biological properties, including anticancer, antimicrobial, antimalarial, cardioprotective and other activities. It is known that biguanides serve as excellent N-donor bidentate ligands and readily form complexes with virtually all transition metals. Recent evidence suggests that the mechanism of action of metformin and its analogues is linked to their metal-binding properties. These findings prompted us to summarize the existing data on the synthetic strategies and biological properties of various metal complexes with metformin and its analogues. We demonstrated that coordination of biologically active biguanides to various metal centers often resulted in an improved pharmacological profile, including reduced drug resistance as well as a wider spectrum of activity. In addition, coordination to the redox-active metal centers, such as Au(III), allowed for various activatable strategies, leading to the selective activation of the prodrugs and reduced off-target toxicity.

Management Strategies for Hyperglycemia Associated with the α-Selective PI3K Inhibitor Alpelisib for the Treatment of Breast Cancer

Alpelisib is an α-selective phosphatidylinositol 3-kinase inhibitor used for treating hormone receptor-positive (HR+), human epidermal growth receptor 2-negative (HER2-), PIK3CA-mutated locally advanced or metastatic breast cancer following disease progression on or after endocrine therapy. Hyperglycemia is an on-target effect of alpelisib affecting approximately 60% of treated patients, and sometimes necessitating dose reductions, treatment interruptions, or discontinuation of alpelisib. Early detection of hyperglycemia and timely intervention have a key role in achieving optimal glycemic control and maintaining alpelisib dose intensity to optimize the benefit of this drug. A glycemic support program implemented by an endocrinology-oncology collaborative team may be very useful in this regard. Lifestyle modifications, mainly comprising a reduced-carbohydrate diet, and a designated stepwise, personalized antihyperglycemic regimen, based on metformin, sodium-glucose co-transporter 2 inhibitors, and pioglitazone, are the main tools required to address the insulin-resistant hyperglycemia induced by alpelisib. In this report, based on the consensus of 14 oncologists and seven endocrinologists, we provide guidance for hyperglycemia management strategies before, during, and after alpelisib therapy for HR+, HER2-, PIK3CA-mutated breast cancer, with a focus on a proactive, multidisciplinary approach.

Factors influencing the anticancer effects of metformin on breast cancer outcomes: a systematic review and meta-analysis

INTRODUCTION

Several clinical trials have attempted to find evidence that supports the use of metformin as an anticancer treatment. However, the observed effects on various breast cancer (BC) outcomes have been heterogeneous.

AREAS COVERED

Based on the outcomes of previous clinical trials, this review discusses the patients' characteristics, cancer intrinsic subtypes, cancer stage, and anticancer treatments that may influence the anticancer effect of metformin on BC outcomes. Additionally, the safety and tolerability of metformin addition to various anticancer regimens are reviewed.

EXPERT OPINION

Metformin is a challenging anticancer agent in BC cohorts, besides being safe and well-tolerated at antidiabetic doses. Survival benefits of metformin have been observed in BC patients with: hormone receptor-positive, human epidermal growth factor receptor-2 overexpression, and high insulin like growth factor-1 receptor expression on the tumor surface. Moreover, patients with diabetes receiving metformin experienced better survival outcomes compared to diabetic patients not receiving metformin. Additionally, metformin has anti-proliferative activity in patients with BC who have high insulin resistance and high body mass index. Besides, metformin has been shown to decrease metastatic events, and enhance the level of metabolic- and insulin-related biomarkers associated with carcinogenesis. Finally, most adverse events following metformin treatment were low-grade GIT toxicities.