Anti-Diabetic Drugs: Cure or Risk Factors for Cancer?

The antidiabetic drug pioglitazone ameliorates betel-nut-induced carcinogenesis in mice by restoring normal lipid metabolism, reducing oxidative stress, and inducing apoptosis

CONTEXT

Oral administration (2 mg mL-1) of aqueous extract of betel nut (AEBN) for 24 weeks induced oncogenic alterations in the liver of female Swiss Albino mice concomitant with aberrant lipid metabolism, overactivation of Akt/mTOR signaling, and loss of apoptosis.

AIM

This study was designed to investigate the potential of repurposing the antidiabetic drug pioglitazone for alleviating AEBN-induced carcinogenesis.

METHODS

Sera of animals were evaluated for lipid profile and free fatty acid levels. Liver tissues were investigated for oxidative stress, histopathology, and expression of proteins involved in lipid metabolism and oncogenesis by western blotting. Apoptosis was determined using TUNEL assay.

RESULTS

Coadministration of pioglitazone (10 mg kg-1 b.w) with AEBN for 8 weeks restored normal lipid profile and AMPK/ACC signaling, reduced FASN and HMGCR expressions and oxidative stress, and actively induced Akt/mTOR-mediated apoptosis in the liver.

CONCLUSIONS

Pioglitazone can effectively alleviate AEBN-induced carcinogenesis in mice.

Association between diabetes and cancer. Current mechanistic insights into the association and future challenges

Compelling pieces of epidemiological, clinical, and experimental research have demonstrated that Diabetes mellitus (DM) is a major risk factor associated with increased cancer incidence and mortality in many human neoplasms. In the pathophysiology context of DM, many of the main classical actors are relevant elements that can fuel the different steps of the carcinogenesis process. Hyperglycemia, hyperinsulinemia, metabolic inflammation, and dyslipidemia are among the classic contributors to this association. Furthermore, new emerging actors have received particular attention in the last few years, and compelling data support that the microbiome, the epigenetic changes, the reticulum endoplasmic stress, and the increased glycolytic influx also play important roles in promoting the development of many cancer types. The arsenal of glucose-lowering therapeutic agents used for treating diabetes is wide and diverse, and a growing body of data raised during the last two decades has tried to clarify the contribution of therapeutic agents to this association. However, this research area remains controversial, because some anti-diabetic drugs are now considered as either promotors or protecting elements. In the present review, we intend to highlight the compelling epidemiological shreds of evidence that support this association, as well as the mechanistic contributions of many of these potential pathological mechanisms, some controversial points as well as future challenges.

Empagliflozin: a potential anticancer drug

Empagliflozin, a sodium-glucose cotransporter 2 (SGLT2) inhibitor, is a highly effective and well-tolerated antidiabetic drug. In addition to hypoglycemic effects, empagliflozin has many other effects, such as being hypotensive and cardioprotective. It also has anti-inflammatory and antioxidative stress effects in diabetic nephropathy. Several studies have shown that empagliflozin has anticancer effects. SGLT2 is expressed in a variety of cancer cell lines. The SGLT2 inhibitor empagliflozin has significant inhibitory effects on certain types of tumor cells, such as inhibition of proliferation, migration and induction of apoptosis. In conclusion, empagliflozin has promising applications in cancer therapy as a drug for the treatment of diabetes and heart failure. This article provides a brief review of the anticancer effects of empagliflozin.

High burden of diabetes and prediabetes among cancer patients at University of Gondar comprehensive specialized hospital, Northwest Ethiopia

Cancer and diabetes mellitus (DM) are diagnosed within the same individual more frequently and share common risk factors. Although diabetes among cancer patients may result in more aggressive clinical courses of cancer, there is limited evidence about its burden and associated factors. Hence, this study aimed to assess the burden of diabetes and prediabetes among cancer patients and its associated factors. Institution-based cross-sectional study was conducted at the University of Gondar comprehensive specialized hospital from 10 January to 10 March 2021. A systematic random sampling technique was used to select 423 cancer patients. The data was collected using a structured interviewer-administered questionnaire. Prediabetes and diabetes diagnosis was made based on World Health Organization (WHO) criteria. Bi-variable and multivariable binary logistic regression models were fitted to identify factors associated with the outcome. Adjusted Odds Ratio (AOR) with a 95% confidence interval was estimated to show the direction and strength of associations. Variables with a p-value less than 0.05 in the multivariable model were considered significantly associated with the outcome. The final analysis was based on 384 patients with cancer. The proportion of prediabetes and diabetes was 56.8% (95% CI 51.7, 61.7) and 16.7% (95% CI 13.3, 20.8), respectively. Alcohol consumption was found to increase the odds of elevated blood sugar among cancer patients (AOR: 1.96; 95%CI: 1.11, 3.46). The burden of prediabetes and diabetes is alarmingly high among cancer patients. Besides, alcohol consumption was found to increase the odds of having elevated blood sugar among cancer patients. Hence, it is essential to recognize cancer patients are at high risk of having elevated blood sugar and design strategies to integrate diabetes and cancer care.

Metformin: Is it a drug for all reasons and diseases?

Metformin was first used to treat type 2 diabetes in the late 1950s and in 2022 remains the first-choice drug used daily by approximately 150 million people. An accumulation of positive pre-clinical and clinical data has stimulated interest in re-purposing metformin to treat a variety of diseases including COVID-19. In polycystic ovary syndrome metformin improves insulin sensitivity. In type 1 diabetes metformin may help reduce the insulin dose. Meta-analysis and data from pre-clinical and clinical studies link metformin to a reduction in the incidence of cancer. Clinical trials, including MILES (Metformin In Longevity Study), and TAME (Targeting Aging with Metformin), have been designed to determine if metformin can offset aging and extend lifespan. Pre-clinical and clinical data suggest that metformin, via suppression of pro-inflammatory pathways, protection of mitochondria and vascular function, and direct actions on neuronal stem cells, may protect against neurodegenerative diseases. Metformin has also been studied for its anti-bacterial, -viral, -malaria efficacy. Collectively, these data raise the question: Is metformin a drug for all diseases? It remains unclear as to whether all of these putative beneficial effects are secondary to its actions as an anti-hyperglycemic and insulin-sensitizing drug, or result from other cellular actions, including inhibition of mTOR (mammalian target for rapamycin), or direct anti-viral actions. Clarification is also sought as to whether data from ex vivo studies based on the use of high concentrations of metformin can be translated into clinical benefits, or whether they reflect a 'Paracelsus' effect. The environmental impact of metformin, a drug with no known metabolites, is another emerging issue that has been linked to endocrine disruption in fish, and extensive use in T2D has also raised concerns over effects on human reproduction. The objectives for this review are to: 1) evaluate the putative mechanism(s) of action of metformin; 2) analyze the controversial evidence for metformin's effectiveness in the treatment of diseases other than type 2 diabetes; 3) assess the reproducibility of the data, and finally 4) reach an informed conclusion as to whether metformin is a drug for all diseases and reasons. We conclude that the primary clinical benefits of metformin result from its insulin-sensitizing and antihyperglycaemic effects that secondarily contribute to a reduced risk of a number of diseases and thereby enhancing healthspan. However, benefits like improving vascular endothelial function that are independent of effects on glucose homeostasis add to metformin's therapeutic actions.

Retrospective survival analysis in patients with metastatic pancreatic ductal adenocarcinoma with insulin-treated type 2 diabetes mellitus

INTRODUCTION

The association between pancreatic ductal adenocarcinoma (PDAC) and type 2 diabetes mellitus (DM2) has long been evaluated and the role of antidiabetic medications such as metformin has also been investigated. The objective of this study was to examine the association between insulin use and overall survival (OS) in patients with advanced PDAC and DM2.

METHODS

We retrospectively collected data from 164 patients, including an exploratory cohort of 96 patients from Medical Oncology Unit, University Hospital and University of Cagliari, Italy, and a validation cohort of 68 patients from Medical Oncology of Modena University Hospital. Patients had metastatic disease and received a first-line gemcitabine-based chemotherapy and, subsequently, a second-line fluoropyrimidines-based chemotherapy. We performed univariate analysis to evaluate correlation between long-term diabetes and overall survival. Then we performed multivariate analysis, adjusting for sex, metastatic sites, Eastern Cooperative Oncology Group Performance Status, Ca19.9 levels, N/L ratio, and lactate dehydrogenase levels at diagnosis, to confirm the independence of the variable.

RESULTS

In the exploratory cohort, DM2 was significantly associated with higher median OS at univariate analysis (16 vs 10 months; p = 0.004). This result was confirmed by validation cohort (11 months vs 6 months; p = 0.01). In multivariate analysis, insulin-treated patients compared with non diabetic patients showed a significantly increased survival of 4.6 months (p = 0.03).

CONCLUSIONS

Patients with insulin-treated metastatic PDAC showed better OS than non diabetic patients, as demonstrated by both cohorts. The correlation between OS and insulin-treated DM2 should be investigated further through a prospective clinical trial.

Non-cancer to anti-cancer: investigation of human ether-a-go-go-related gene potassium channel inhibitors as potential therapeutics

BACKGROUND

The expression of hERG K⁺ channels is observed in various cancer cells including epithelial, neuronal, leukemic, and connective tissue. The role of hERG potassium channels in regulating the growth and death of cancer cells include cell proliferation, survival, secretion of proangiogenic factors, invasiveness, and metastasis.

METHODS

In the reported study, an attempt has been made to investigate some non-cancer hERG blockers as potential cancer therapeutics using a computational drug repurposing strategy. Preliminary investigation for hERG blockers/non-blockers has identified 26 potential clinically approved compounds for further studies using molecular modeling.

RESULTS

The interactions at the binding pockets have been investigated along with the prioritization based on the binding score. Some of the identified potential hERG inhibitors, i.e., Bromocriptine, Darglitazone, and Troglitazone, have been investigated to derive the mechanism of cancer inhibition.

CONCLUSIONS

The proposed mechanism for anti-cancer properties via hERG blocking for some of the potential compounds is required to be explored using other experimental methodologies. The drug repurposing approach applied to investigate anti-cancer therapeutics may direct to provide a therapeutic solution to late-stage cancer and benefit a significant population of patients.

Potentially Inappropriate Treatments at the End of Life in Nursing Home Residents: Findings From the PACE Cross-Sectional Study in Six European Countries

CONTEXT

Certain treatments are potentially inappropriate when administered to nursing homes residents at the end of life and should be carefully considered. An international comparison of potentially inappropriate treatments allows insight into common issues and country-specific challenges of end-of-life care in nursing homes and helps direct health-care policy in this area.

OBJECTIVES

To estimate the prevalence of potentially inappropriate treatments in the last week of life in nursing home residents and analyze the differences in prevalence between countries.

METHODS

A cross-sectional study of deceased residents in nursing homes (2015) in six European countries: Belgium (Flanders), England, Finland, Italy, The Netherlands, and Poland. Potentially inappropriate treatments included enteral administration of nutrition, parental administration of nutrition, artificial fluids, resuscitation, artificial ventilation, blood transfusion, chemotherapy/radiotherapy, dialysis, surgery, antibiotics, statins, antidiabetics, new oral anticoagulants. Nurses were questioned about whether these treatments were administered in the last week of life.

RESULTS

We included 1384 deceased residents from 322 nursing homes. In most countries, potentially inappropriate treatments were rarely used, with a maximum of 18.3% of residents receiving at least one treatment in Poland. Exceptions were antibiotics in all countries (between 11.3% in Belgium and 45% in Poland), artificial nutrition and hydration in Poland (54.3%) and Italy (41%) and antidiabetics in Poland (19.7%).

CONCLUSION

Although the prevalence of potentially inappropriate treatments in the last week of life was generally low, antibiotics were frequently prescribed in all countries. In Poland and Italy, the prevalence of artificial administration of food/fluids in the last week of life was high, possibly reflecting country differences in legislation, care organization and culture, and the palliative care competences of staff.

Pleiotropic effects of anti-diabetic drugs: A comprehensive review

Diabetes mellitus characterized by hyperglycaemia presents an array of comorbidities such as cardiovascular and renal failure, dyslipidemia, and cognitive impairments. Populations above the age of 60 are in an urgent need of effective therapies to deal with the complications associated with diabetes mellitus. Widely used anti-diabetic drugs have good safety profiles and multiple reports indicate their pleiotropic effects in diabetic patients or models. This review has been written with the objective of identifying the widely-marketed anti-diabetic drugs which can be efficiently repurposed for the treatment of other diseases or disorders. It is an updated, comprehensive review, describing the protective role of various classes of anti-diabetic drugs in mitigating the macro and micro vascular complications of diabetes mellitus, and differentiating these drugs on the basis of their mode of action. Notably, metformin, the anti-diabetic drug most commonly explored for cancer therapy, has also exhibited some antimicrobial effects. Unlike class specific effects, few instances of drug specific effects in managing cardiovascular complications have also been reported. A major drawback is that the pleiotropic effects of anti-diabetic drugs have been mostly investigated only in diabetic patients. Thus, for effective repurposing, more clinical trials devoted to analyse the effects of anti-diabetic drugs in patients irrespective of their diabetic condition, are required.

Metabolism and Immune Modulation in Patients with Solid Tumors: Systematic Review of Preclinical and Clinical Evidence

Several immunotherapy agents are the standard of care of many solid malignancies. Nevertheless, the majority of patients do not benefit from the currently available immunotherapies. It is therefore of paramount importance to identify the prognostic and predictive factors of tumor response/resistance and to design effective therapeutic strategies to overcome primary resistance and improve the efficacy of immunotherapy. The aim of this review is to underline the influence of the tumor and host metabolism on the antitumor immune response and to discuss possible strategies to improve the efficacy of available treatments by targeting the specific metabolic pathways in tumors or immune cells and by modifying patients' nutritional statuses. A systematic search of the Medline and EMBASE databases was carried out to identify scientific papers published until February 2020, which reported original research articles on the influence of tumor or host metabolism on antitumor immune response. The literature data showed the key role of glycolysis and mitochondrial oxidative phosphorylation, arginine, tryptophan, glutamine, lipid metabolism and microbiome on immune cell function. Moreover, specific nutritional behaviors, such as a low dietary intake of vitamin C, low glycemic index and alpha-linolenic acid, eicosapentenoic acid, docosahexaenoic acid, ornithine ketoglutarate, tryptophan and probiotic supplementation were associated with the potential clinical benefits from the currently available immunotherapies.

Recent Developments in Alpha-Glucosidase Inhibitors for Management of Type-2 Diabetes: An Update

The incidence of diabetes has increased globally in recent years and figures of diabetic patients were estimated to rise up to 642 million by 2040. The disorder is accompanied with various complications if not managed at the early stages, and interlinked high mortality rate and morbidity with time. Different classes of drugs are available for the management of type 2 diabetes but were having certain limitations of their safety. Alphaglucosidase is a family of enzyme originated from the pancreas which plays a role in the anabolism of 80-90% of carbohydrate consumed into glucose. This glucose is absorbed into the blood and results in frank postprandial hyperglycemia and worsens the conditions of diabetic patients which precipitate complications. Inhibition of these enzymes helps to prevent postprandial hyperglycemia and the formation of glycated end products. Alphaglucosidase inhibitors are reported to be more important in adequate control of type 2, but marketed drugs have various side effects, such as poor patient compliance and also expensive. This proves the needs for other class of drugs with better efficacy, safety, patient compliance and economic. In this review, we have emphasized the recent advances in the field of new alpha-glucosidase inhibitors with improved safety and pharmacological profile.

Treatment with the anti-diabetic drug metformin ameliorates betel-nut induced carcinogenesis in a murine model

BACKGROUND

Metformin, a widely used anti-diabetic drug has gained enormous attention as an anticancer agent. This study seeks to investigate the efficacy of metformin in ameliorating aqueous extract of betel-nut (AEBN) and arecoline induced carcinogenesis in a murine model.

METHODS

Swiss albino mice were exposed to AEBN (2 mg ml-1) and arecoline (10 μg ml-1) in drinking water for 16 weeks followed by co-administration of metformin (75 mg kg-1 or 150 mg kg-1) for 4 or 8 weeks. Histological changes and oxidative stress were assessed by haematoxylin and eosin staining, TBARS assay and protein carbonylation assay respectively. Lipid profile was determined using an automated analyzer. Expression of total and phosphorylated AMPK, ACC and p53 were determined by immunoblotting.

RESULTS

AEBN and arecoline induced dyslipidemia by downregulating AMPK (Thr-172) and activating ACC (Ser-79); they also downregulated tumor suppressor p53 (Ser-15). Metformin treatment induced AMPK-dependent alleviation of dyslipidemia in a dose and time dependent manner, upregulated p53 (Ser-15), restored tissue architecture and reduced oxidative stress in tissues of AEBN and arecoline treated mice.

CONCLUSION

This study establishes that betel nut induces dyslipidemia through its alkaloid, arecoline by inhibition of AMPK (Thr-172) and activation of ACC (Ser-79) and highlights the therapeutic potential of metformin for treatment of betel-nut induced carcinogenesis, indicating the repurposing of the old drug in a new avenue.

Hyperglycemia-Induced Aberrant Cell Proliferation; A Metabolic Challenge Mediated by Protein O-GlcNAc Modification

Chronic hyperglycemia has been associated with an increased prevalence of pathological conditions including cardiovascular disease, cancer, or various disorders of the immune system. In some cases, these associations may be traced back to a common underlying cause, but more often, hyperglycemia and the disturbance in metabolic balance directly facilitate pathological changes in the regular cellular functions. One such cellular function crucial for every living organism is cell cycle regulation/mitotic activity. Although metabolic challenges have long been recognized to influence cell proliferation, the direct impact of diabetes on cell cycle regulatory elements is a relatively uncharted territory. Among other "nutrient sensing" mechanisms, protein O-linked β-N-acetylglucosamine (O-GlcNAc) modification emerged in recent years as a major contributor to the deleterious effects of hyperglycemia. An increasing amount of evidence suggest that O-GlcNAc may significantly influence the cell cycle and cellular proliferation. In our present review, we summarize the current data available on the direct impact of metabolic changes caused by hyperglycemia in pathological conditions associated with cell cycle disorders. We also review published experimental evidence supporting the hypothesis that O-GlcNAc modification may be one of the missing links between metabolic regulation and cellular proliferation.

Targeting Glucose Metabolism to Enhance Immunotherapy: Emerging Evidence on Intermittent Fasting and Calorie Restriction Mimetics

There is growing interest in harnessing lifestyle and pharmaceutical interventions to boost immune function, reduce tumor growth, and improve cancer treatment efficacy while reducing treatment toxicity. Interventions targeting glucose metabolism are particularly promising, as they have the potential to directly inhibit tumor cell proliferation. However, because anti-tumor immune effector cells also rely on glycolysis to sustain their clonal expansion and function, it remains unclear whether glucose-modulating therapies will support or hinder anti-tumor immunity. In this perspective, we summarize a growing body of literature that evaluates the effects of intermittent fasting, calorie restriction mimetics, and anti-hyperglycemic agents on anti-tumor immunity and immunotherapy outcomes. Based on the limited data currently available, we contend that additional pre-clinical studies and clinical trials are warranted to address the effects of co-administration of anti-hyperglycemic agents or glucose-lowering lifestyle modifications on anti-tumor immunity and cancer treatment outcomes. We stress that there is currently insufficient evidence to provide recommendations regarding these interventions to cancer patients undergoing immunotherapy. However, if found to be safe and effective in clinical trials, interventions targeting glucose metabolism could act as low-cost combinatorial adjuvants for cancer patients receiving immune checkpoint blockade or other immunotherapies.

Cardiovascular safety of oncologic agents: a double-edged sword even in the era of targeted therapies - Part 2

INTRODUCTION

Patients with cancer are subject to the cardiotoxic effects of cancer therapy. Improved cancer treatments lead to more cancer-survivors, who though are exposed to various forms of cardiovascular (CV) disease (CVD) as they age. Aging patients are at increased risk of developing both malignancy and CVD or they may have survived some form of CVD as a result of effective CV treatments. Furthermore, patients with CVD may develop cancer and require treatment (and vice versa), all contributing to increased morbidity and mortality. The prevalence of both malignancy and CVD will increase due to the trend toward a longer lifespan.

AREAS COVERED

In part 2 of this review, the discussion of the CV effects of specific oncology drugs is completed with inclusion of additional immunological agents, current hormonal and other agents. Early detection and monitoring of cardiotoxicity, use of biomarkers and other imaging and diagnostic methods and prevention and treatment options are also discussed.

EXPERT OPINION

As outlined in part 1 of this review, oncologists need to be aware of the CV adverse-effects of their treatments and make careful and expectant clinical decisions, especially in patients with preexisting CVD or CV risk factors. Similarly, cardiologists should consider a detailed previous history of treatment for malignant disease, including prior chemotherapy exposure, dose(s) received, and/or combined modality therapy with chest radiotherapy. Both specialists should collaborate in order to minimize the impact of these two ubiquitous diseases (cancer and CVD) and mitigate the adverse effects of treatment modalities.