Metformin in patients with advanced pancreatic cancer: a double-blind, randomised, placebo-controlled phase 2 trial

Metformin dampens the progression of cholangiofibrosis induced by thioacetamide using deep learning

Purpose

The consistent use of metformin has been linked to a reduced incidence of neoplastic diseases among diabetic populations. As a preventive intervention, metformin may offer a more favorable risk-benefit profile. Here, we explored the efficacy of metformin in the primary prevention of cholangiofibrosis, which can precede the carcinogen-induced development of cholangiocarcinoma (CCA). Our objective was to assess the potential of metformin to act as an intervention prior to the onset of these conditions.

Methods

A rat model of thioacetamide (TAA)-induced cholangiofibrosis was utilized to assess the impact of metformin on the induction process of cholangiocarcinoma (CCA). Liver tissues were harvested and analyzed histologically using light microscopy, complemented by a deep-learning convolutional neural network for enhanced evaluation. Additionally, RNA sequencing (RNA-seq) was performed to investigate the genetic alterations associated with metformin treatment in this TAA-induced cholangiofibrosis model.

Results

In the rat model, the TAA control group exhibited an increased incidence and average count of cholangiofibrosis cases in the liver, with rates of 100 % and an average of 12.0, compared to the metformin-treated group, which showed an incidence of 70 % and an average of 3.3. Notably, the progression from normal cholangioles to cholangiofibrosis was associated with the upregulation of several proteins critical for metabolic processes and the tumor microenvironment. These alterations were significantly mitigated by metformin treatment.

Conclusions

Long-term metformin use may offer protective benefits against cholangiofibrosis, partially by regulating metabolic processes and improving the tumor microenvironment.

Synergistic effects of calcium channel blockers and renin-angiotensin inhibitors with gemcitabine-based chemotherapy on the survival of patients with pancreatic cancer

PURPOSE

Pancreatic cancer remains a significant public health challenge, with poor long-term outcomes due to the lack of effective treatment options. Repurposing commonly used clinical drugs, such as ACE inhibitors, ARBs, CCBs, and metformin, may enhance the efficacy of chemotherapy and offer a promising therapeutic strategy for improving patient outcomes.

METHODS

A retrospective analysis of concomitant treatment with ACE-Is, ARBs, CCBs, and metformin alongside gemcitabine chemotherapy in patients with pancreatic cancer was conducted. Treatment responses were evaluated, with overall survival (OS) estimated using the Kaplan-Meier method. Additionally, the Cox proportional hazards model was employed to assess the impact of these specific agents on patient survival.

RESULTS

4628 patients with various stages of pancreatic cancer were identified in the database between 2007 and 2016. The estimated overall survival (OS) in the analyzed group was 6.9 months (95% CI 6.4-7). The use of any of the analyzed drugs was associated with a significant improvement in mOS of 7.5 months (95% CI 6.8-7.8) vs. 6.7 months (95% CI 6.4-7.0) for patients who did not have additional treatment (p < 0.0001). ARBs, ACE-Is, CCBs, and metformin varied in their effectiveness in prolonging mOS among patients. The longest mOS of 8.9 months (95% CI 7.7-11.6) was observed in patients receiving additional therapy with ARBs, while the shortest mOS of 7.7 months (95% CI 6.5-8.9) was achieved by patients receiving metformin. In the adjusted Cox analysis, metformin was associated with a significantly weaker effect on mOS (p = 0.029). A particularly interesting trend in prolonging 5-year survival was demonstrated by ARBs and CCBs with 14.1% (95% CI 9-22%) and 14.8% (95% CI 11.1-19.6%), respectively, compared to patients not taking these drugs, who achieved a 5-year OS of 3.8% (95% CI 3.2-4.4%).

CONCLUSION

Our results demonstrate a significant positive impact of ARBs, ACE inhibitors, and CCBs on survival in patients with pancreatic cancer treated with gemcitabine. The addition of these inexpensive and relatively safe drugs in patients with additional comorbidities may represent a potential therapeutic option in this indication. However, prospective clinical trials to evaluate the optimal patient population and further studies to determine the potential impact of these agents on chemotherapy are necessary.

An anti-neoplastic tale of metformin through its transport

Metformin is an attractive candidate drug among all the repurposed drugs for cancer. Extensive preclinical and clinical research has evaluated its efficacy in cancer therapy, revealing a mixed outcome in clinical settings. To fully exploit metformin's therapeutic potential, understanding cellular factors relevant to its transport and accumulation in cancer cells needs to be understood. This review highlights the relevance of metformin transporter status towards its anti-cancer potential. Metformin transporters are regulated at pre-transcriptional, transcriptional, and post-translational levels. Moreover, the tumour microenvironment can also influence metformin accumulation in cancer cells. Also, Metformin treatment can regulate its transporters by altering global DNA methylation, protein acetylation, and transcription factors. Importantly, metformin transporters not only influence chemotherapeutic drug toxicity but are also associated with the prognosis and survival of individuals having cancer. Strategic decisions based on the expression and regulation of metformin transporters holds promise for its therapeutic implications and relevance.

Metformin boosts antitumor immunity and improves prognosis in upfront resected pancreatic cancer: an observational study

BACKGROUND

Beyond demographic and immune factors, metabolic considerations, particularly metformin's recognized impact in oncology, warrant exploration in treating pancreatic cancer. This study aimed to investigate the influence of metformin on patient survival and its potential correlation with distinct immune profiles in pancreatic ductal adenocarcinoma (PDAC) tumors.

METHODS

We included 82 upfront resected and 66 gemcitabine-based neoadjuvant chemoradiotherapy (nCRT)-treated patients from the PREOPANC randomized controlled trial (RCT). Transcriptomic NanoString immunoprofiling was performed for a subset of 96 available resected specimens.

RESULTS

Disparities in survival outcomes and immune profiles were apparent between metformin and non-metformin users in upfront resected patients but lacking in nCRT-treated patients. Compared to non-metformin users, upfront resected metformin users showed a higher median overall survival (OS) of 29 vs 14 months and a better 5-year OS rate of 19% vs 5%. Furthermore, metformin use was a favorable prognostic factor for OS in the upfront surgery group (HR = 0.56; 95% CI = 0.32 to 0.99). Transcriptomic data revealed that metformin users significantly underexpressed genes related to pro-tumoral immunity, including monocyte to M2 macrophage polarization and activation. Furthermore, the relative abundance of anti-inflammatory CD163+ MRC1+ M2 macrophages in non-metformin users and immune-activating CD1A+ CD1C+ dendritic cells in metformin users was heightened (P < .001).

CONCLUSION

This study unveils immune profile changes resulting from metformin use in upfront resected pancreatic cancer patients, possibly contributing to prolonged survival outcomes. Specifically, metformin use may decrease the abundance and activity of pro-tumoral M2 macrophages and increase the recruitment and function of tumor-resolving DCs, favoring antitumor immunity.[PREOPANC trial EudraCT: 2012-003181-40].

Five-year recurrence/survival after pancreatoduodenectomy for pancreatic adenocarcinoma: does pre-existing diabetes matter? Results from the Recurrence After Whipple's (RAW) study

BACKGROUND

Diabetes mellitus (DM) has a complex relationship with pancreatic cancer. This study examines the impact of preoperative DM, both recent-onset and pre-existing, on long-term outcomes following pancreatoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC).

METHODS

Data were extracted from the Recurrence After Whipple's (RAW) study, a multi-centre cohort of PD for pancreatic head malignancy (2012-2015). Recurrence and five-year survival rates of patients with DM were compared to those without, and subgroup analysis performed to compare patients with recent-onset DM (less than one year) to patients with established DM.

RESULTS

Out of 758 patients included, 187 (24.7%) had DM, of whom, 47 of the 187 (25.1%) had recent-onset DM. There was no difference in the rate of postoperative pancreatic fistula (DM: 5.9% vs no DM 9.8%; p = 0.11), five-year survival (DM: 24.1% vs no DM: 22.9%; p = 0.77) or five-year recurrence (DM: 71.7% vs no DM: 67.4%; p = 0.32). There was also no difference between patients with recent-onset DM and patients with established DM in postoperative outcomes, recurrence, or survival.

CONCLUSION

We found no difference in five-year recurrence and survival between diabetic patients and those without diabetes. Patients with pre-existing DM should be evaluated for PD on a comparable basis to non-diabetic patients.

Devimistat (CPI-613) With Modified Fluorouarcil, Oxaliplatin, Irinotecan, and Leucovorin (FFX) Versus FFX for Patients With Metastatic Adenocarcinoma of the Pancreas: The Phase III AVENGER 500 Study

PURPOSE

Metastatic pancreatic adenocarcinoma (mPC) remains a difficult-to-treat disease. Fluorouarcil, oxaliplatin, irinotecan, and leucovorin (FFX) is a standard first-line therapy for mPC for patients with a favorable performance status and good organ function. In a phase I study, devimistat (CPI-613) in combination with modified FFX (mFFX) was deemed safe and exhibited promising efficacy in mPC.

METHODS

The AVENGER 500 trial (ClinicalTrials.gov identifier: NCT03504423) is a global, randomized phase III trial conducted at 74 sites across six countries to investigate the efficacy and safety of devimistat in combination with mFFX (experimental arm) compared with standard-dose FFX (control arm) in treatment-naïve patients with mPC. Treatment, administered in once-every-2-weeks cycles until disease progression or intolerable toxicity, included intravenous devimistat at 500 mg/m2 total per day on days 1 and 3 in the experimental arm. The primary end point of the study was overall survival (OS).

RESULTS

Five hundred and twenty-eight patients were randomly assigned (266 in the experimental arm and 262 in the control arm). The median OS was 11.10 months for devimistat plus mFFX versus 11.73 months for FFX (hazard ratio [HR], 0.95 [95% CI, 0.77 to 1.18]; P = .655) and median progression-free survival was 7.8 months versus 8.0 months, respectively (HR, 0.99 [95% CI, 0.76 to 1.29]; P = .94). Grade ≥3 treatment-emergent adverse events with >10% frequency in the devimistat plus mFFX arm versus the FFX arm were neutropenia (29.0% v 34.5%), diarrhea (11.2% v 19.6%), hypokalemia (13.1% v 14.9%), anemia (13.9% v 13.6%), thrombocytopenia (11.6% v 13.6%), and fatigue (10.8% v 11.5%), respectively.

CONCLUSION

Devimistat in combination with mFFX did not improve long- and short-term mPC patient outcomes compared with standard FFX. There were no new toxicity signals with the addition of devimistat.

Identification of 6-Fluorine-Substituted Coumarin Analogues as POLRMT Inhibitors with High Potency and Safety for Treatment of Pancreatic Cancer

Increasing evidence has demonstrated that oxidative phosphorylation (OXPHOS) is closely associated with the progression of pancreatic cancer (PC). Given its central role in mitochondrial transcription, the human mitochondrial RNA polymerase (POLRMT) is a promising target for developing PC treatments. Herein, structure-activity relationship exploration led to the identification of compound S7, which was the first reported POLRMT inhibitor possessing single-digit nanomolar potency of inhibiting PC cells proliferation. Mechanistic studies showed that compound S7 exerted antiproliferative effects without affecting the cell cycle, apoptosis, mitochondrial membrane potential (MMP), or intracellular reactive oxygen species (ROS) levels specifically in MIA PaCa-2 cells. Notably, compound S7 inhibited tumor growth in MIA PaCa-2 xenograft tumor model with a tumor growth inhibition (TGI) rate of 64.52% demonstrating significant improvement compared to the positive control (44.80%). In conclusion, this work enriched SARs of POLRMT inhibitors, and compound S7 deserved further investigations of drug-likeness as a candidate for PC treatment.

Targeting cancer and immune cell metabolism with the complex I inhibitors metformin and IACS-010759

Metformin and IACS-010759 are two distinct antimetabolic agents. Metformin, an established antidiabetic drug, mildly inhibits mitochondrial complex I, while IACS-010759 is a new potent mitochondrial complex I inhibitor. Mitochondria is pivotal in the energy metabolism of cells by providing adenosine triphosphate through oxidative phosphorylation (OXPHOS). Hence, mitochondrial metabolism and OXPHOS become a vulnerability when targeted in cancer cells. Both drugs have promising antitumoral effects in diverse cancers, supported by preclinical in vitro and in vivo studies. We present evidence of their direct impact on cancer cells and their immunomodulatory effects. In clinical studies, while observational epidemiologic studies on metformin were encouraging, actual trial results were not as expected. However, IACS-01075 exhibited major adverse effects, thereby causing a metabolic shift to glycolysis and elevated lactic acid concentrations. Therefore, the future outlook for these two drugs depends on preventive clinical trials for metformin and investigations into the plausible toxic effects on normal cells for IACS-01075.

UCP2 and pancreatic cancer: conscious uncoupling for therapeutic effect

Pancreatic cancer has an exaggerated dependence on mitochondrial metabolism, but methods to specifically target the mitochondria without off target effects in normal tissues that rely on these organelles is a significant challenge. The mitochondrial uncoupling protein 2 (UCP2) has potential as a cancer-specific drug target, and thus, we will review the known biology of UCP2 and discuss its potential role in the pathobiology and future therapy of pancreatic cancer.

Bidirectional relationship between pancreatic cancer and diabetes mellitus: a comprehensive literature review

Pancreatic cancer (PC) is a fatal malignant disease. It is well known that the relationship between PC and type 2 diabetes mellitus (T2DM) is a complicated bidirectional relationship. The most important factors causing increased risks of pancreatic cancer are hyperglycaemia, hyperinsulinemia, pancreatitis, and dyslipidemia. Genetics and the immune system also play an important role in the relationship between diabetes mellitus and pancreatic cancer. The primary contributors to this association involve insulin resistance and inflammatory processes within the tumour microenvironment. The combination of diabetes and obesity can contribute to PC by inducing hyperinsulinemia and influencing leptin and adiponectin levels. Given the heightened incidence of pancreatic cancer in diabetes patients compared to the general population, early screening for pancreatic cancer is recommended. Diabetes negatively impacts the survival of pancreatic cancer patients. Among patients receiving chemotherapy, it reduced their survival. The implementation of a healthy lifestyle, including weight management, serves as an initial preventive measure to mitigate the risk of disease development. The role of anti-diabetic drugs on survival is controversial; however, metformin may have a positive impact, especially in the early stages of cancer, while insulin therapy increases the risk of PC.

Drug repurposing for cancer

In the dynamic landscape of cancer therapeutics, the innovative strategy of drug repurposing emerges as a transformative paradigm, heralding a new era in the fight against malignancies. This book chapter aims to embark on the comprehension of the strategic deployment of approved drugs for repurposing and the meticulous journey of drug repurposing from earlier times to the current era. Moreover, the chapter underscores the multifaceted and complex nature of cancer biology, and the evolving field of cancer drug therapeutics while emphasizing the mandate of drug repurposing to advance cancer therapeutics. Importantly, the narrative explores the latest tools, technologies, and cutting-edge methodologies including high-throughput screening, omics technologies, and artificial intelligence-driven approaches, for shaping and accelerating the pace of drug repurposing to uncover novel cancer therapeutic avenues. The chapter critically assesses the breakthroughs, expanding the repertoire of repurposing drug candidates in cancer, and their major categories. Another focal point of this book chapter is that it addresses the emergence of combination therapies involving repurposed drugs, reflecting a shift towards personalized and synergistic treatment approaches. The expert analysis delves into the intricacies of combinatorial regimens, elucidating their potential to target heterogeneous cancer populations and overcome resistance mechanisms, thereby enhancing treatment efficacy. Therefore, this chapter provides in-depth insights into the potential of repurposing towards bringing the much-needed big leap in the field of cancer therapeutics.

Cancer biology in diabetes update: Focusing on antidiabetic drugs

The association of type 2 diabetes with certain cancer risk has been of great interest for years. However, the effect of diabetic medications on cancer development is not fully understood. Prospective clinical trials have not elucidated the long-term influence of hypoglycemic drugs on cancer incidence and the safety for cancer-bearing patients with diabetes, whereas numerous preclinical studies have shown that antidiabetic drugs could have an impact on carcinogenesis processes beyond the glycemic control effect. Because there is no evidence of the safety profile of antidiabetic agents on cancer biology, careful consideration would be required when prescribing any medicines to patients with diabetes and existing tumor. In this review, we discuss the potential influence of each diabetes therapy in cancer 'initiation', 'promotion' and 'progression'.

Metformin: A Dual-Role Player in Cancer Treatment and Prevention

Cancer continues to pose a significant global health challenge, as evidenced by the increasing incidence rates and high mortality rates, despite the advancements made in chemotherapy. The emergence of chemoresistance further complicates the effectiveness of treatment. However, there is growing interest in the potential of metformin, a commonly prescribed drug for type 2 diabetes mellitus (T2DM), as an adjuvant chemotherapy agent in cancer treatment. Although the precise mechanism of action of metformin in cancer therapy is not fully understood, it has been found to have pleiotropic effects, including the modulation of metabolic pathways, reduction in inflammation, and the regulation of cellular proliferation. This comprehensive review examines the anticancer properties of metformin, drawing insights from various studies conducted in vitro and in vivo, as well as from clinical trials and observational research. This review discusses the mechanisms of action involving both insulin-dependent and independent pathways, shedding light on the potential of metformin as a therapeutic agent for different types of cancer. Despite promising findings, there are challenges that need to be addressed, such as conflicting outcomes in clinical trials, considerations regarding dosing, and the development of resistance. These challenges highlight the importance of further research to fully harness the therapeutic potential of metformin in cancer treatment. The aims of this review are to provide a contemporary understanding of the role of metformin in cancer therapy and identify areas for future exploration in the pursuit of effective anticancer strategies.

Clinical and Preclinical Targeting of Oncogenic Pathways in PDAC: Targeted Therapeutic Approaches for the Deadliest Cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of cancer-related death worldwide. It is commonly diagnosed in advanced stages and therapeutic interventions are typically constrained to systemic chemotherapy, which yields only modest clinical outcomes. In this review, we examine recent developments in targeted therapy tailored to address distinct molecular pathway alteration required for PDAC. Our review delineates the principal signaling pathways and molecular mechanisms implicated in the initiation and progression of PDAC. Subsequently, we provide an overview of prevailing guidelines, ongoing investigations, and prospective research trajectories related to targeted therapeutic interventions, drawing insights from randomized clinical trials and other pertinent studies. This review focus on a comprehensive examination of preclinical and clinical data substantiating the efficacy of these therapeutic modalities, emphasizing the potential of combinatorial regimens and novel therapies to enhance the quality of life for individuals afflicted with PDAC. Lastly, the review delves into the contemporary application and ongoing research endeavors concerning targeted therapy for PDAC. This synthesis serves to bridge the molecular elucidation of PDAC with its clinical implications, the evolution of innovative therapeutic strategies, and the changing landscape of treatment approaches.

Cardiovascular/anti-inflammatory drugs repurposed for treating or preventing cancer: A systematic review and meta-analysis of randomized trials

BACKGROUND

Due to encouraging pre-clinical data and supportive observational studies, there has been growing interest in applying cardiovascular drugs (including aspirin, angiotensin-converting enzyme [ACE] inhibitors, statins, and metformin) approved to treat diseases such as hypertension, hyperlipidemia, and diabetes mellitus to the field of oncology. Moreover, given growing costs with cancer care, these medications have offered a potentially more affordable avenue to treat or prevent recurrence of cancer. We sought to investigate the anti-cancer effects of drugs repurposed from cardiology or anti-inflammatories to treat cancer. We specifically evaluated the following drug classes: HMG-CoA reductase inhibitors (statins), cyclo-oxygenase inhibitors, aspirin, metformin, and both angiotensin receptor blockers (ARBs) and angiotensin-converting enzyme inhibitors. We also included non-steroidal anti-inflammatory drugs (NSAIDs) because they exert a similar mechanism to aspirin by blocking prostaglandins and reducing inflammation that is thought to promote the development of cancer.

METHODS

We performed a systematic literature review using PubMed and Web of Science with search terms including "aspirin," "NSAID," "statin" (including specific statin drug names), "metformin," "ACE inhibitors," and "ARBs" (including specific anti-hypertensive drug names) in combination with "cancer." Searches were limited to human studies published between 2000 and 2023.

MAIN OUTCOMES AND MEASURES

The number and percentage of studies reported positive results and pooled estimates of overall survival, progression-free survival, response, and disease-free survival.

RESULTS

We reviewed 3094 titles and included 67 randomized clinical trials. The most common drugs that were tested were metformin (n = 21; 30.9%), celecoxib (n = 20; 29.4%), and simvastatin (n = 8; 11.8%). There was only one study that tested cardiac glycosides and none that studied ACE inhibitors. The most common tumor types were non-small-cell lung cancer (n = 19; 27.9%); breast (n = 8; 20.6%), colorectal (n = 7; 10.3%), and hepatocellular (n = 6; 8.8%). Most studies were conducted in a phase II trial (n = 38; 55.9%). Most studies were tested in metastatic cancers (n = 49; 72.1%) and in the first-line setting (n = 36; 521.9%). Four studies (5.9%) were stopped early because of difficulty with accrual. The majority of studies did not demonstrate an improvement in either progression-free survival (86.1% of studies testing progression-free survival) or in overall survival (94.3% of studies testing overall survival). Progression-free survival was improved in five studies (7.4%), and overall survival was improved in three studies (4.4%). Overall survival was significantly worse in two studies (3.8% of studies testing overall survival), and progression-free survival was worse in one study (2.8% of studies testing progression-free survival).

CONCLUSIONS AND RELEVANCE

Despite promising pre-clinical and population-based data, cardiovascular drugs and anti-inflammatory medications have overall not demonstrated benefit in the treatment or preventing recurrence of cancer. These findings may help guide future potential clinical trials involving these medications when applied in oncology.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Pancreatic ductal adenocarcinoma chemoresistance: From metabolism reprogramming to novel treatment

ABSTRACT

As pancreatic cancer (PC) is highly malignant, its patients tend to develop metastasis at an early stage and show a poor response to conventional chemotherapies. First-line chemotherapies for PC, according to current guidelines, include fluoropyrimidine- and gemcitabine-based regimens. Accumulating research on drug resistance has shown that biochemical metabolic aberrations in PC, especially those involving glycolysis and glutamine metabolism, are highly associated with chemoresistance. Additionally, lipid metabolism is a major factor in chemoresistance. However, emerging compounds that target these key metabolic pathways have the potential to overcome chemoresistance. This review summarizes how PC develops chemoresistance through aberrations in biochemical metabolism and discusses novel critical targets and pathways within cancer metabolism for new drug research.

Current trends and future prospects of drug repositioning in gastrointestinal oncology

Gastrointestinal (GI) cancers comprise a significant number of cancer cases worldwide and contribute to a high percentage of cancer-related deaths. To improve survival rates of GI cancer patients, it is important to find and implement more effective therapeutic strategies with better prognoses and fewer side effects. The development of new drugs can be a lengthy and expensive process, often involving clinical trials that may fail in the early stages. One strategy to address these challenges is drug repurposing (DR). Drug repurposing is a developmental strategy that involves using existing drugs approved for other diseases and leveraging their safety and pharmacological data to explore their potential use in treating different diseases. In this paper, we outline the existing therapeutic strategies and challenges associated with GI cancers and explore DR as a promising alternative approach. We have presented an extensive review of different DR methodologies, research efforts and examples of repurposed drugs within various GI cancer types, such as colorectal, pancreatic and liver cancers. Our aim is to provide a comprehensive overview of employing the DR approach in GI cancers to inform future research endeavors and clinical trials in this field.

Cuproptosis-related lncRNA scoring system to predict the clinical outcome and immune landscape in pancreatic adenocarcinoma

Cuproptosis is a recently discovered novel programmed cell death pathway that differs from traditional programmed cell death and has an important role in cancer and immune regulation. Long noncoding RNA (lncRNA) is considered new potential prognostic biomarkers in pancreatic adenocarcinoma (PAAD). However, the prognostic role and immune landscape of cuproptosis-related lncRNA in PAAD remain unclear. The transcriptome and clinical data of PAAD were obtained from The Cancer Genome Atlas (TCGA) database. Cuproptosis-related lncRNA was identified using Pearson correlation analysis. The optimal lncRNA was screened by Cox and the Least Absolute Shrinkage and Selection Operator (LASSO) regression mode, and for the construction of risk scoring system. PAAD patients were divided into high- and low-risk groups according to the risk score. Clinicopathological parameter correlation analysis, univariate and multivariate Cox regression, time-dependent receiver operating characteristic (ROC) curves, and nomogram were performed to evaluate the model. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were used to explore differences in biological function between different risk groups. Single-sample gene set enrichment analysis (ssGSEA) and Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data (ESTIMATE) algorithm were used to analyze the differences in tumor immune microenvironment (TIME) in different risk groups of PAAD. Additionally, the Tumor Immune Dysfunction and Exclusion (TIDE) algorithm was used to predict immunotherapy response and identify potential immune beneficiaries. Immune checkpoints and tumor mutation burden (TMB) were also systematically analyzed. Finally, drug sensitivity analysis was used to explore the reactivity of different drugs in high- and low-risk groups to provide a reference for the selection of precise therapeutic drugs. Six cuproptosis-related lncRNAs (AL117335.1, AC044849.1, AL358944.1, ZNF236-DT, Z97832.2, and CASC8) were used to construct risk model. Survival analysis showed that overall survival and progression-free survival in the low-risk group were better than those in the high-risk group, and it is suitable for PAAD patients with different clinical characteristics. Univariate and multifactorial Cox regression analysis showed that risk score was an independent prognostic factor in PAAD patients. ROC analysis showed that the AUC values of the risk score in 1 year, 3 years and 5 years were 0.707,0.762 and 0.880, respectively. Nomogram showed that the total points of PAAD patients at 1 year, 3 years, and 5 years were 0.914,0.648, and 0.543. GO and KEGG analyses indicated that the differential genes in the high- and low-risk groups were associated with tumor proliferation and metastasis and immune regulatory pathway. Immune correlation analysis showed that the amount of pro-inflammatory cells, including CD8+ T cells, was significantly higher in the low-risk group than in the high-risk group, and the expression of immune checkpoint genes, including PD-1 and CTLA-4, was increased in the low-risk group. TIDE analysis suggests that patients in the low-risk group may benefit from immunotherapy. Finally, there was significant variability in multiple chemotherapeutic and targeted drugs across the risk groups, which informs our clinical drug selection. Our cuproptosis-related lncRNA scoring system (CRLss) could predict the clinical outcome and immune landscape of PAAD patients, identify the potential beneficiaries of immunotherapy, and provide a reference for precise therapeutic drug selection.

Carbonized polymer dots derived from metformin and L-arginine for tumor cell membrane- and mitochondria-dual targeting therapy

Metformin has demonstrated antitumor potential in clinical studies; however, achieving optimal antitumor effects requires administering an extremely safe medication dose. To enhance the efficacy and reduce dosage requirements, we propose the creation of large-molecule drugs through the combination of small-molecule drugs. In this study, we developed novel polymer dots, referred to as MA-dots, with sizes of approximately 5 nm, featuring dual targeting capabilities for tumor cell membranes and mitochondria. MA-dots were synthesized using metformin and L-arginine via a rapid microwave-assisted method. Notably, the resulting MA-dots (with a half maximal inhibitory concentration (IC50) of 93.60 μg mL-1) exhibited more than a 12-fold increase in antitumor activity compared to the raw metformin material (IC50 = 1159.00 μg mL-1) over a 24-hour period. In addition, our MA-dots outperformed most metformin-derived nanodrugs in terms of antitumor efficacy. Furthermore, oral gavage treatment with MA-dots led to the suppression of A549 (lung cancer cell lines) tumor growth in vivo. Mechanistic investigations revealed that MA-dots bound to the large neutral amino acid transporter 1 (LAT1) proteins, which are overexpressed in malignant tumor cell membranes. Moreover, these MA-dots accumulated within the mitochondria, leading to increased production of reactive oxygen species (ROS), mitochondrial damage, and disruption of energy metabolism by modulating the 5'-adenosine monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway in tumor cells. This cascade of events triggers cell-cycle arrest and apoptosis. In summary, this study presented a rapid method for fabricating a novel nanoderivative, MA-dots, capable of both tumor targeting and exerting tumor-suppressive effects.

Mechanisms of Regulation of the Expression of miRNAs and lncRNAs by Metformin in Ovarian Cancer

Ovarian cancer (OC) is one of the most lethal gynecological malignancies. The use of biological compounds such as non-coding RNAs (ncRNAs) is being considered as a therapeutic option to improve or complement current treatments since the deregulation of ncRNAs has been implicated in the pathogenesis and progression of OC. Old drugs with antitumoral properties have also been studied in the context of cancer, although their antitumor mechanisms are not fully clear. For instance, the antidiabetic drug metformin has shown pleiotropic effects in several in vitro models of cancer, including OC. Interestingly, metformin has been reported to regulate ncRNAs, which could explain its diverse effects on tumor cells. In this review, we discuss the mechanism of epigenetic regulation described for metformin, with a focus on the evidence of metformin-dependent microRNA (miRNAs) and long non-coding RNA (lncRNAs) regulation in OC.

Metformin use is associated with longer survival in glioblastoma patients with MGMT gene silencing

PURPOSE

New treatments are needed to improve the overall survival of patients with glioblastoma Metformin is known for anti-tumorigenic effects in cancers, including breast and pancreas cancers. In this study, we assessed the association between metformin use and overall survival in glioblastoma patients.

METHODS

We retrospectively studied 241 patients who underwent surgery at diagnosis of glioblastoma between 2014 and 2018. Metformin was used for pre-existing type 2 diabetes mellitus or in the prevention or management of glucocorticoid induced hyperglycemia. Kaplan-Meier curves and log-rank p test were used for univariate analysis. Cox-proportional hazards model was used to generate adjusted hazard ratios for multivariate analysis.

RESULTS

Metformin use was associated with longer survival in patients with tumors that had a methylated O6-methylguanine DNA methyltransferase gene (MGMT) promoter (484 days 95% CI: 56-911 vs. 394 days 95% CI: 249-538, Log-Rank test: 6.5, p = 0.01). Cox regression analysis shows that metformin associates with lower risk of death at 2 years in patients with glioblastoma containing a methylated MGMT promoter (aHR = 0.497, 95% CI 0.26-0.93, p = 0.028).

CONCLUSION

Our findings suggest a survival benefit with metformin use in patients with glioblastomas having methylation of the MGMT promoter.

Exploiting the molecular subtypes and genetic landscape in pancreatic cancer: the quest to find effective drugs

Pancreatic Ductal Adenocarcinoma (PDAC) is a very lethal disease that typically presents at an advanced stage and is non-compliant with most treatments. Recent technologies have helped delineate associated molecular subtypes and genetic variations yielding important insights into the pathophysiology of this disease and having implications for the identification of new therapeutic targets. Drug repurposing has been evaluated as a new paradigm in oncology to accelerate the application of approved or failed target-specific molecules for the treatment of cancer patients. This review focuses on the impact of molecular subtypes on key genomic alterations in PDAC, and the progress made thus far. Importantly, these alterations are discussed in light of the potential role of drug repurposing in PDAC.

Correlations between Demographic, Clinical, and Paraclinical Variables and Outcomes in Patients with KRAS-Mutant or KRAS Wild-Type Metastatic Colorectal Cancer-A Retrospective Study from a Tertiary-Level Center in Romania

Colorectal cancer (CRC) is a significant global public health concern and its characteristics in Eastern Europe are underexplored. In this retrospective study, data of 225 patients with metastatic colorectal cancer (mCRC) from the Colțea Clinical Hospital's Oncology Department in Bucharest were analyzed between 2015 and 2023. They were divided into two groups based on the presence of KRAS mutation. The primary objective of the study was to investigate whether the presence of KRAS mutations influenced the prognosis of mCRC and to identify any demographic, clinical, or paraclinical factors associated with KRAS mutations in stage IV CRC. The overall survival for the entire study population was 29 months. There was a trend towards increased survival in the KRAS wild-type group (31 months) compared to the KRAS-mutant group (26 months), but this difference did not reach statistical significance. We found that lower levels of education, advanced T stage, advanced N stage, and M1 stage at diagnosis negatively impacted prognosis. Real-world data are crucial in shaping public policy strategies to better support patients with metastatic CRC. Understanding the correlations between the demographic, clinical, and paraclinical variables and the outcomes in mCRC patients with KRAS-mutant and KRAS wild-type colorectal cancer is essential for improving patient care and treatment strategies in Romania and beyond.

The Impact of Metformin on Tumor-Infiltrated Immune Cells: Preclinical and Clinical Studies

The tumor microenvironment (TME) plays a pivotal role in the fate of cancer cells, and tumor-infiltrating immune cells have emerged as key players in shaping this complex milieu. Cancer is one of the leading causes of death in the world. The most common standard treatments for cancer are surgery, radiation therapy, and chemotherapeutic drugs. In the last decade, immunotherapy has had a potential effect on the treatment of cancer patients with poor prognoses. One of the immune therapeutic targeted approaches that shows anticancer efficacy is a type 2 diabetes medication, metformin. Beyond its glycemic control properties, studies have revealed intriguing immunomodulatory properties of metformin. Meanwhile, several studies focus on the impact of metformin on tumor-infiltrating immune cells in various tumor models. In several tumor models, metformin can modulate tumor-infiltrated effector immune cells, CD8+, CD4+ T cells, and natural killer (NK) cells, as well as suppressor immune cells, T regulatory cells, tumor-associated macrophages (TAMs), and myeloid-derived suppressor cells (MDSCs). In this review, we discuss the role of metformin in modulating tumor-infiltrating immune cells in different preclinical models and clinical trials. Both preclinical and clinical studies suggest that metformin holds promise as adjunctive therapy in cancer treatment by modulating the immune response within the tumor microenvironment. Nonetheless, both the tumor type and the combined therapy have an impact on the specific targets of metformin in the TME. Further investigations are warranted to elucidate the precise mechanisms underlying the immunomodulatory effects of metformin and to optimize its clinical application in cancer patients.

Bioenergetic alteration in gastrointestinal cancers: The good, the bad and the ugly

Cancer cells exhibit metabolic reprogramming and bioenergetic alteration, utilizing glucose fermentation for energy production, known as the Warburg effect. However, there are a lack of comprehensive reviews summarizing the metabolic reprogramming, bioenergetic alteration, and their oncogenetic links in gastrointestinal (GI) cancers. Furthermore, the efficacy and treatment potential of emerging anticancer drugs targeting these alterations in GI cancers require further evaluation. This review highlights the interplay between aerobic glycolysis, the tricarboxylic acid (TCA) cycle, and oxidative phosphorylation (OXPHOS) in cancer cells, as well as hypotheses on the molecular mechanisms that trigger this alteration. The role of hypoxia-inducible transcription factors, tumor suppressors, and the oncogenetic link between hypoxia-related enzymes, bioenergetic changes, and GI cancer are also discussed. This review emphasizes the potential of targeting bioenergetic regulators for anti-cancer therapy, particularly for GI cancers. Emphasizing the potential of targeting bioenergetic regulators for GI cancer therapy, the review categorizes these regulators into aerobic glycolysis/ lactate biosynthesis/transportation and TCA cycle/coupled OXPHOS. We also detail various anti-cancer drugs and strategies that have produced pre-clinical and/or clinical evidence in treating GI cancers, as well as the challenges posed by these drugs. Here we highlight that understanding dysregulated cancer cell bioenergetics is critical for effective treatments, although the diverse metabolic patterns present challenges for targeted therapies. Further research is needed to comprehend the specific mechanisms of inhibiting bioenergetic enzymes, address side effects, and leverage high-throughput multi-omics and spatial omics to gain insights into cancer cell heterogeneity for targeted bioenergetic therapies.

Extracellular Matrix Collagen I Differentially Regulates the Metabolic Plasticity of Pancreatic Ductal Adenocarcinoma Parenchymal Cell and Cancer Stem Cell

Pancreatic ductal adenocarcinoma (PDAC) has a 5-year survival rate of less than 10 percent largely due to the intense fibrotic desmoplastic reaction, characterized by high levels of extracellular matrix (ECM) collagen I that constitutes a niche for a subset of cancer cells, the cancer stem cells (CSCs). Cancer cells undergo a complex metabolic adaptation characterized by changes in metabolic pathways and biosynthetic processes. The use of the 3D organotypic model in this study allowed us to manipulate the ECM constituents and mimic the progression of PDAC from an early tumor to an ever more advanced tumor stage. To understand the role of desmoplasia on the metabolism of PDAC parenchymal (CPC) and CSC populations, we studied their basic metabolic parameters in organotypic cultures of increasing collagen content to mimic in vivo conditions. We further measured the ability of the bioenergetic modulators (BMs), 2-deoxyglucose, dichloroacetate and phenformin, to modify their metabolic dependence and the therapeutic activity of paclitaxel albumin nanoparticles (NAB-PTX). While all the BMs decreased cell viability and increased cell death in all ECM types, a distinct, collagen I-dependent profile was observed in CSCs. As ECM collagen I content increased (e.g., more aggressive conditions), the CSCs switched from glucose to mostly glutamine metabolism. All three BMs synergistically potentiated the cytotoxicity of NAB-PTX in both cell lines, which, in CSCs, was collagen I-dependent and the strongest when treated with phenformin + NAB-PTX. Metabolic disruption in PDAC can be useful both as monotherapy or combined with conventional drugs to more efficiently block tumor growth.

Diabetes of the Exocrine Pancreas: Implications for Pharmacological Management

Post-pancreatitis diabetes mellitus, pancreatic cancer-related diabetes, and cystic fibrosis-related diabetes are often underappreciated. As a result, a substantial proportion of people with these sub-types of diabetes receive antidiabetic medications that may be suboptimal, if not harmful, in the context of their underlying disease of the exocrine pancreas. The present article delineates both classical (biguanides, insulin, sulfonylureas, α-glucosidase inhibitors, thiazolidinediones, and meglitinides) and newer (glucagon-like peptide-1 receptor agonists, amylin analogs, dipeptidyl peptidase-4 inhibitors, sodium-glucose co-transporter-2 inhibitors, D2 receptor agonists, bile acid sequestrants, and dual glucagon-like peptide-1 receptor and glucose-dependent insulinotropic polypeptide receptor co-agonists) therapies and provides recommendations for managing people with diabetes of the exocrine pancreas based on the most up-to-date clinical evidence. Also, several emerging directions (lipid-enriched pathways, Y4 receptor agonism, glucagon-like peptide-1 and glucagon receptor co-agonism) are presented with a view to informing the process of new drug discovery and development.

Metformin and cancer hallmarks: shedding new lights on therapeutic repurposing

Metformin is a well-known anti-diabetic drug that has been repurposed for several emerging applications, including as an anti-cancer agent. It boasts the distinct advantages of an excellent safety and tolerability profile and high cost-effectiveness at less than one US dollar per daily dose. Epidemiological evidence reveals that metformin reduces the risk of cancer and decreases cancer-related mortality in patients with diabetes; however, the exact mechanisms are not well understood. Energy metabolism may be central to the mechanism of action. Based on altering whole-body energy metabolism or cellular state, metformin's modes of action can be divided into two broad, non-mutually exclusive categories: "direct effects", which induce a direct effect on cancer cells, independent of blood glucose and insulin levels, and "indirect effects" that arise from systemic metabolic changes depending on blood glucose and insulin levels. In this review, we summarize an updated account of the current knowledge on metformin antitumor action, elaborate on the underlying mechanisms in terms of the hallmarks of cancer, and propose potential applications for repurposing metformin for cancer therapeutics.

Low BMI patients with advanced EGFR mutation-positive NSCLC can get a better outcome from metformin plus EGFR-TKI as first-line therapy: A secondary analysis of a phase 2 randomized clinical trial

Background

The synergistic association between metformin and epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) has been confirmed in in vitro studies. It is still controversial which patients can benefit from metformin plus EGFR-TKIs treatment. Body mass index (BMI) was proved to be independently associated with prolonged progression-free survival (PFS) and overall survival (OS). This study aimed to investigate whether BMI is associated with the synergistic effect of metformin and EGFR-TKIs in advanced EGFR mutation (EGFRm)-positive non-small cell lung cancer (NSCLC) among nondiabetic Asian population.

Methods

We performed a post hoc analysis of a prospective, double-blind phase II randomized clinical trial (COAST, NCT01864681), which enrolled 224 patients without diabetes with treatment-naïve stage IIIB-IV EGFRm NSCLC. We stratified patients into those with a high BMI (≥24 kg/m2) and those with a low BMI (<24 kg/m2) to allow an analysis of the difference in PFS and OS between the two groups. The PFS and OS were analyzed using Kaplan-Meier curves, and the differences between groups were compared using log-rank test.

Results

In the univariate analysis, patients who had a high BMI (n = 56) in the gefitinib + metformin group (n = 28) did not have a better PFS (8.84 months vs. 11.67 months; P = 0.351) or OS (15.58 months vs. 24.36 months; P = 0.095) than those in the gefitinib + placebo group (n = 28). Similar results were also observed in the low-BMI groups. Strikingly, in the metformin plus gefitinib group, patients who had low BMI (n = 69) showed significantly better OS than those with high BMI (24.89 months [95% CI, 20.68 months-not reached] vs. 15.58 months [95% CI, 13.78-31.53 months]; P = 0.007), but this difference was not observed in PFS (10.78 months vs. 8.84 months; P = 0.285).

Conclusions

Our study showed that nondiabetic Asian advanced NSCLC patients with EGFR mutations who have low BMI seem to get better OS from metformin plus EGFR-TKI treatment.

Drug Repurposing in Oncology: A Systematic Review of Randomized Controlled Clinical Trials

Quality pharmacological treatment can improve survival in many types of cancer. Drug repurposing offers advantages in comparison with traditional drug development procedures, reducing time and risk. This systematic review identified the most recent randomized controlled clinical trials that focus on drug repurposing in oncology. We found that only a few clinical trials were placebo-controlled or standard-of-care-alone-controlled. Metformin has been studied for potential use in various types of cancer, including prostate, lung, and pancreatic cancer. Other studies assessed the possible use of the antiparasitic agent mebendazole in colorectal cancer and of propranolol in multiple myeloma or, when combined with etodolac, in breast cancer. We were able to identify trials that study the potential use of known antineoplastics in other non-oncological conditions, such as imatinib for severe coronavirus disease in 2019 or a study protocol aiming to assess the possible repurposing of leuprolide for Alzheimer's disease. Major limitations of these clinical trials were the small sample size, the high clinical heterogeneity of the participants regarding the stage of the neoplastic disease, and the lack of accounting for multimorbidity and other baseline clinical characteristics. Drug repurposing possibilities in oncology must be carefully examined with well-designed trials, considering factors that could influence prognosis.

Efficacy of metformin adjunctive therapy as the treatment for non-diabetic patients with advanced non-small cell lung cancer: A Systematic review and Meta-analysis

Background

Currently, the anticancer effects of metformin on different types of lung cancer have been frequently studied. However, the relationship between metformin and prognosis in nondiabetic patients with lung cancer remains controversial. To systematically evaluate the efficacy of metformin adjunctive therapy as the treatment for nondiabetic patients with advanced non-small cell lung cancer (NSCLC) to provide an evidence-based reference for clinical medication.

Materials and Methods

The literatures related to Phase II or III randomized controlled trials (RCTs) of metformin adjunctive therapy in nondiabetic patients with advanced NSCLC, including EMBASE, PubMed, the Cochrane Library, and Scopus database, were retrieved by computer, and the search time ranged from January 2017 to August 2022. The risk of bias assessment tool recommended by Cochrane Systematic Evaluator Manual 5.1.0 was used to evaluate the quality of the RCTs included. Rev Man 5.3 software and STATA15.0 were used for meta-analysis.

Results

A total of 8 studies were included (925 patients). Meta-analysis results showed that there were no significant differences in progression-free survival (PFS) (hazard ratio [HR] = 0.95, 95% confidence interval [CI]: 0.66-1.36, P = 0.77), overall survival (OS) (HR = 0.89, 95% CI: 0.61-1.30, P = 0.55, n =7), objective response rate (ORR) (odds ratio [OR] = 1.37, 95% CI: 0.76-2.46, P = 0.30), and 1-year PFS rate (OR = 0.87, 95% CI: 0.39-1.94, P = 0.73, n = 3). Sensitivity analysis showed that PFS and OS indexes were stable.

Conclusion

Metformin adjunctive therapy can improve the DCR of nondiabetic patients with advanced NSCLC. In addition, the patients cannot obtain a prolonged PFS, OS, 1-year PFS rate, and higher ORR rate.

Is it still worth pursuing the repurposing of metformin as a cancer therapeutic?

Over the past 15 years, there has been great interest in the potential to repurpose the diabetes drug, metformin, as a cancer treatment. However, despite considerable efforts being made to investigate its efficacy in a number of large randomised clinical trials in different tumour types, results have been disappointing to date. This perspective article summarises how interest initially developed in the oncological potential of metformin and the diverse clinical programme of work to date including our contribution to establishing the intra-tumoral pharmacodynamic effects of metformin in the clinic. We also discuss the lessons that can be learnt from this experience and whether a further clinical investigation of metformin in cancer is warranted.

Regulation of metabolism in pancreatic ductal adenocarcinoma via nanotechnology-enabled strategies

Pancreatic ductal adenocarcinoma (PDAC) is a highly fatal malignancy with insidious onset and early distal metastasis. Metabolic reprogramming, the autonomous changes in cellular bioenergetics driven by aberrant genetic events and crosstalk between cancer and non-cancer cells in the desmoplastic microenvironment, is pivotal for the rapid progression of PDAC. As an attractive therapeutic target, nucleoside metabolism is regulated by various anti-metabolic drugs for the clinical treatment of PDAC. Despite various challenges, such as poor drug delivery efficiency and off-target side effects, metabolic modification and intervention are emerging as promising strategies for PDAC therapy, enabled by the rapid development of nanotechnology-based drug delivery strategies. In this review, we discuss the metabolic characteristics of PDAC and highlight how the development of nanomedicine has boosted the development of new therapeutics for PDAC by modulating critical targets in metabolic reprogramming.

A phase II, open-label, non-randomized, prospective study assessing paclitaxel, carboplatin and metformin in the treatment of advanced stage ovarian carcinoma

OBJECTIVE

The purpose of this study was to assess the efficacy and tolerability of a paclitaxel, carboplatin and metformin regimen in the first-line treatment of advanced-stage ovarian, fallopian tube, and primary peritoneal carcinoma.

METHODS

Eligible subjects underwent surgery and 6 cycles of neoadjuvant or adjuvant dose-dense intravenous paclitaxel (80 mg/m²), carboplatin (area under the curve 5 or 6 on Day 1), and oral metformin (850 mg daily). Study participants who completed their primary therapy and attained a clinically defined complete or partial response (PR) were treated with a planned 12 cycles of paclitaxel (135 mg/m² every 21 days) and metformin (850 mg twice daily) maintenance therapy.

RESULTS

Thirty subjects received a median of 6 cycles (range, 5-6) of primary induction chemotherapy and were eligible for response evaluation; twenty-three patients exhibited a complete response, while 3 study patients obtained a PR (an overall response rate of 86.7%). Grade 3-4 hematological toxicity included neutropenia (43.3%), thrombocytopenia (10%) and anemia (36.7%). There was no incidence of grade 3-4 neuropathy although 15 patients (50%) developed grade ≤2 neurotoxicity. Additionally, we observed grade ≤2 diarrhea in 20 (66.7%) subjects. The median progression-free survival was 21 months (range, 3-52) and overall median survival was 35 months (range, 15-61). The subjects also received an aggregate 103 cycles (median, 12; range, 6-12) of maintenance chemotherapy.

CONCLUSION

The study results suggest that the combination of paclitaxel, carboplatin and metformin is associated with moderate efficacy and a reasonable toxicity profile.

Metanalyses on metformin's role in pancreatic cancer suffer from severe bias and low data quality - An umbrella review

AIMS

Discrepancies in the preclinical evidence, retrospective studies, and randomized trials evaluating metformin's role in pancreatic cancer are difficult to disentangle. We aimed to critically and systematically examine the quality and sources of heterogeneity between meta-analyses investigating the association between metformin intake and the prognosis of patients with pancreatic cancer.

MATERIALS AND METHODS

We performed a literature search on PubMed, MEDLINE, Embase, and Scopus on October 31, 2021 to identify meta-analyses investigating the impact of metformin treatment on the prognosis of patients with pancreatic cancer. Meta-analyses quality was assessed using according to the AMSTAR 2 criteria. We assessed bias in individual studies included in the meta-analyses, with particular attention to immortal time bias and quality of reporting.

RESULTS

Eleven meta-analyses describing 24 individual studies were included. All meta-analyses were rated low (n = 5) or critically low (n = 6) quality. Only 4 followed PRISMA reporting guidelines and only in 5 presented data were sufficient to replicate the analyses. Most meta-analyses combined results from clinical trials and retrospective studies (n = 6); patients with different cancer stages (resectable vs advanced) and from studies with different control group definitions. Immortal time bias was present and not accounted for in most (65.2%) of the individual retrospective studies; almost all (n = 9) meta-analyses failed to identify and correct for this source of bias.

CONCLUSIONS

Meta-analyses describing the association of metformin use in patients with pancreatic cancer are plagued by various types of bias inherent in retrospective studies. The quality of evidence linking metformin to decreased pancreatic cancer mortality is generally low.

Mitochondrial Metabolism in Pancreatic Ductal Adenocarcinoma: From Mechanism-Based Perspectives to Therapy

Pancreatic ductal adenocarcinoma (PDAC), the fourteenth most common malignancy, is a major contributor to cancer-related death with the utmost case fatality rate among all malignancies. Functional mitochondria, regardless of their complex ecosystem relative to normal cells, are essential in PDAC progression. Tumor cells' potential to produce ATP as energy, despite retaining the redox potential optimum, and allocating materials for biosynthetic activities that are crucial for cell growth, survival, and proliferation, are assisted by mitochondria. The polyclonal tumor cells with different metabolic profiles may add to carcinogenesis through inter-metabolic coupling. Cancer cells frequently possess alterations in the mitochondrial genome, although they do not hinder metabolism; alternatively, they change bioenergetics. This can further impart retrograde signaling, educate cell signaling, epigenetic modifications, chromatin structures, and transcription machinery, and ultimately satisfy cancer cellular and nuclear demands. To maximize the tumor microenvironment (TME), tumor cells remodel nearby stromal cells and extracellular matrix. These changes initiate polyclonality, which is crucial for growth, stress response, and metastasis. Here, we evaluate all the intrinsic and extrinsic pathways drawn by mitochondria in carcinogenesis, emphasizing the perspectives of mitochondrial metabolism in PDAC progression and treatment.

Structural basis of mammalian respiratory complex I inhibition by medicinal biguanides

The molecular mode of action of biguanides, including the drug metformin, which is widely used in the treatment of diabetes, is incompletely characterized. Here, we define the inhibitory drug-target interaction(s) of a model biguanide with mammalian respiratory complex I by combining cryo-electron microscopy and enzyme kinetics. We interpret these data to explain the selectivity of biguanide binding to different enzyme states. The primary inhibitory site is in an amphipathic region of the quinone-binding channel, and an additional binding site is in a pocket on the intermembrane-space side of the enzyme. An independent local chaotropic interaction, not previously described for any drug, displaces a portion of a key helix in the membrane domain. Our data provide a structural basis for biguanide action and enable the rational design of medicinal biguanides.

Fast Mimicking Diets and Other Innovative Nutritional Interventions to Treat Patients with Breast Cancer

The impact of nutritional patterns on the risk of breast cancer (BC) is well investigated in the oncology literature, including the type of diets and caloric intake. While obesity and elevated body mass index are well-reported critical risk factors of BC occurrence, there is an expanding area of oncology assessing the impact of caloric intake and nutritional patterns in patients with cancer. Caloric restriction and fast mimicking alimentary regimens have been consistently reported to improve survival outcomes based on preclinical models. Moreover, emerging clinical evidence has paved the way for new metabolic approaches for the treatment of BC, in addition to the established therapeutic arsenal or as alternative options. In this chapter, our aim is to discuss the principal strategies of metabolic manipulation through nutritional interventions for patients with BC as an innovative area of cancer therapy.

FDXR drives primary and endocrine-resistant tumor cell growth in ER+ breast cancer via CPT1A-mediated fatty acid oxidation

Background

The majority of breast cancers (BCs) expressing estrogen receptor (ER) have shown endocrine resistance. Our previous study demonstrated that ferredoxin reductase (FDXR) promoted mitochondrial function and ER+ breast tumorigenesis. But the underlying mechanism is not clear.

Methods

Liquid chromatography (LC) tandem mass spectrometry (MS/MS)-based metabolite profiling was utilized to reveal the metabolites regulated by FDXR. RNA microarray was utilized to determine the potential downstream targets of FDXR. Seahorse XF24 analyzer was performed to analyze the FAO-mediated oxygen consumption rate (OCR). Q-PCR and western blotting assays were used to measure expression levels of FDXR and CPT1A. MTS, 2D colony formation and anchorage-independent growth assays were used to evaluate the effects of FDXR or drug treatments on tumor cell growth of primary or endocrine-resistant breast cancer cells.

Results

We found that depletion of FDXR inhibited fatty acid oxidation (FAO) by suppressing CPT1A expression. Endocrine treatment increased the expression levels of both FDXR and CPT1A. Further, we showed that depletion of FDXR or FAO inhibitor etomoxir treatment reduced primary and endocrine-resistant breast cancer cell growth. Therapeutically, combining endocrine therapy with FAO inhibitor etomoxir synergistically inhibits primary and endocrine-resistant breast cancer cell growth.

Discussion

We reveal that the FDXR-CPT1A-FAO signaling axis is essential for primary and endocrine-resistant breast cancer cell growth, thus providing a potential combinatory therapy against endocrine resistance in ER+ breast cancer.

Antitumor Therapy Targeting the Tumor Microenvironment

The development and progression of tumors in human tissues extensively rely on its surrounding environment, that is, tumor microenvironment which includes a variety of cells, molecules, and blood vessels. These components are modified, organized, and integrated to support and facilitate the growth, invasion, and metabolism of tumor cells, suggesting them as potential therapeutic targets in anticancer treatment. An increasing number of pharmacological agents have been developed and clinically applied to target the oncogenic components in the tumor microenvironment, and in this review, we will summarize these pharmacological agents that directly or indirectly target the cellular or molecular components in the tumor microenvironment. However, difficulties and challenges still exist in this field, which will also be reported in this literature.

Anticancer Benefit of Metformin in Patients With Early-Stage Pancreatic Cancer: A Retrospective Cohort Study

Background: Epidemiologic studies have produced conflicting results on the effects of metformin on pancreatic cancer. This study aimed to observe and analyze whether metformin use is associated with better prognosis in pancreatic cancer. Materials and Methods: In this retrospective cohort study, all baseline data were retrieved from The Chinese Medicine Information Retrieval System (https://dc.wzhospital.cn/vpn/index.html) of The First Affiliated Hospital of Wenzhou Medical University. Survival data were collected by follow-up visits and medical records. Overall survival was the primary endpoint, while progression-free survival and disease-free survival were secondary endpoints. Progression or recurrence was assessed with radiologic images. Results: Seventy-six metformin users and 92 metformin nonusers diagnosed with pancreatic cancer from 2012 to 2020 in this hospital were enrolled. The adjusted hazard ratio for overall survival for metformin users was 0.50 (95% confidence interval = 0.33-0.76), where median overall survival was 16.0 months for metformin users versus 11.5 months for metformin nonusers. The protective effect was also found by analyzing progression-free survival (adjusted hazard ratio = 0.39, 95% confidence interval = 0.18-0.86) and disease-free survival (adjusted hazard ratio = 0.30, 95% confidence interval = 0.14-0.68). In the subgroup analysis, metformin use had a statistically significant association with prolongation of survival in stage I to II pancreatic cancer patients (hazard ratio = 0.47, 95% confidence interval = 0.25-0.91), but not for advanced tumor stage (hazard ratio for IV stage = 0.62, 95% confidence interval = 0.33-1.19), after adjustment for other risk factors. Conclusion: Metformin use is related to favorable survival outcomes of pancreatic cancer, especially in early tumor stage.

Prognostic value of metformin in cancers: An updated meta-analysis based on 80 cohort studies

BACKGROUND

Experiments have shown that metformin can inhibit cancer cell growth, but clinical observations have been inconsistent, so we pooled the currently available data to evaluate the impact of metformin on cancer survival and progression.

METHODS

PubMed, web of science, Embase, and Cochrane databases were searched. Pooled hazard ratios (HRs) were identified using a random-effects model to estimate the strength of the association between metformin and survival and progression in cancer patients.

RESULTS

We incorporated 80 articles published from all databases which satisfied the inclusion criterion. It showed that metformin was associated with better overall survival (hazard ratio [HR] = 0. 81; 95% confidence interval [CI]: [0.77-0.85]) and cancer-specific survival (HR = 0.79; 95% CI: [0.73-0.86]), and metformin was associated with progression-free survival (HR = 0.76; 95% CI: [0.66-0.87]). In patients with diabetes mellitus, the HR of overall survival was 0.79(95% CI: [0.75-0.83]), progression-free survival was 0.72(95% CI: [0.60-0.85]), and the cancer-specific survival was 0.76(95% CI: [0.68-0.86]). It was proposed that metformin can improve the prognosis of cancer patients with diabetes mellitus.

CONCLUSION

Based on cohort studies, metformin therapy has potential survival benefits for patients with malignancy, especially with the greatest benefits seen in breast cancer on overall survival, progression-free survival, and cancer-specific survival. And metformin also showed potential benefits in cancer-specific survival in colorectal and prostate cancer.

Metformin in therapeutic applications in human diseases: its mechanism of action and clinical study

Metformin, a biguanide drug, is the most commonly used first-line medication for type 2 diabetes mellites due to its outstanding glucose-lowering ability. After oral administration of 1 g, metformin peaked plasma concentration of approximately 20-30 μM in 3 h, and then it mainly accumulated in the gastrointestinal tract, liver and kidney. Substantial studies have indicated that metformin exerts its beneficial or deleterious effect by multiple mechanisms, apart from AMPK-dependent mechanism, also including several AMPK-independent mechanisms, such as restoring of redox balance, affecting mitochondrial function, modulating gut microbiome and regulating several other signals, such as FBP1, PP2A, FGF21, SIRT1 and mTOR. On the basis of these multiple mechanisms, researchers tried to repurpose this old drug and further explored the possible indications and adverse effects of metformin. Through investigating with clinical studies, researchers concluded that in addition to decreasing cardiovascular events and anti-obesity, metformin is also beneficial for neurodegenerative disease, polycystic ovary syndrome, aging, cancer and COVID-19, however, it also induces some adverse effects, such as gastrointestinal complaints, lactic acidosis, vitamin B12 deficiency, neurodegenerative disease and offspring impairment. Of note, the dose of metformin used in most studies is much higher than its clinically relevant dose, which may cast doubt on the actual effects of metformin on these disease in the clinic. This review summarizes these research developments on the mechanism of action and clinical evidence of metformin and discusses its therapeutic potential and clinical safety.

Mitochondrial DNA Copy Number: Linking Diabetes and Cancer

Recent Advances: Various studies have suggested that mitochondrial DNA copy number (mtDNA-CN), a surrogate biomarker of mitochondrial dysfunction, is an easily quantifiable biomarker for chronic diseases, including diabetes and cancer. However, current knowledge is limited, and the results are controversial. This has been attributed mainly to methodology and study design. Critical Issues: The incidence of diabetes and cancer has increased significantly in recent years. Moreover, type 2 diabetes (T2D) has been shown to be a risk factor for cancer. mtDNA-CN has been associated with both T2D and cancer. However, it is not known whether mtDNA-CN plays any role in the association between T2D and cancer. Significance: In this review, we have discussed mtDNA-CN in diabetes and cancer, and reviewed the literature and methodology used in published studies so far. Based on the literature review, we have speculated how mtDNA-CN may act as a link between diabetes and cancer. Furthermore, we have provided some recommendations for reliable translation of mtDNA-CN as a biomarker. Future Directions: Further research is required to elucidate the role of mtDNA-CN in the association between T2D and cancer. If established, early lifestyle interventions, such as physical activity and diet control that improve mitochondrial function, may help preventing cancer in patients with T2D. Antioxid. Redox Signal. 37, 1168-1190.

The NAMPT Inhibitor FK866 Increases Metformin Sensitivity in Pancreatic Cancer Cells

Pancreatic cancer (pancreatic ductal adenocarcinoma: PDAC) is one of the most aggressive neoplastic diseases. Metformin use has been associated with reduced pancreatic cancer incidence and better survival in diabetics. Metformin has been shown to inhibit PDAC cells growth and survival, both in vitro and in vivo. However, clinical trials using metformin have failed to reduce pancreatic cancer progression in patients, raising important questions about molecular mechanisms that protect tumor cells from the antineoplastic activities of metformin. We confirmed that metformin acts through inhibition of mitochondrial complex I, decreasing the NAD⁺/NADH ratio, and that NAD⁺/NADH homeostasis determines metformin sensitivity in several cancer cell lines. Metabolites that can restore the NAD⁺/NADH ratio caused PDAC cells to be resistant to metformin. In addition, metformin treatment of PDAC cell lines induced a compensatory NAMPT expression, increasing the pool of cellular NAD⁺. The NAMPT inhibitor FK866 sensitized PDAC cells to the antiproliferative effects of metformin in vitro and decreased the cellular NAD⁺ pool. Intriguingly, FK866 combined with metformin increased survival in mice bearing KP4 cell line xenografts, but not in mice with PANC-1 cell line xenografts. Transcriptome analysis revealed that the drug combination reactivated genes in the p53 pathway and oxidative stress, providing new insights about the mechanisms leading to cancer cell death.

Randomised controlled trial: effect of metformin add-on therapy on functional cure in entecavir-treated patients with chronic hepatitis B

INTRODUCTION AND OBJECTIVES

Hepatitis B surface antigen (HBsAg) clearance, indicating functional cure or resolved chronic hepatitis B (CHB), remains difficult to achieve via nucleos(t)ide analogue monotherapy. We investigated whether metformin add-on therapy could help achieve this goal in entecavir-treated patients with hepatitis B e antigen (HBeAg)-negative CHB.

PATIENTS AND METHODS

Patients with HBeAg-negative CHB who met eligibility criteria (entecavir treatment for &gt; 12 months, HBsAg &lt; 1000 IU/mL) were randomly assigned (1:1) to receive 24 weeks of either metformin (1000 mg, oral, once a day) or placebo (oral, once a day) add-on therapy. The group allocation was blinded for both patients and investigators. Efficacy and safety analyses were based on the intention-to-treat set. The primary outcome, serum HBsAg level (IU/mL) at weeks 24 and 36, was analysed using mixed models.

RESULTS

Sixty eligible patients were randomly assigned to the metformin (n = 29) and placebo (n = 31) groups. There was no substantial between-group difference in the HBsAg level at week 24 (adjusted mean difference 0.05, 95% confidence interval -0.04 to 0.13, p = 0.278) or week 36 (0.06, -0.03 to 0.15, p = 0.187), and no significant effect of group-by-time interaction on the HBsAg level throughout the trial (p = 0.814). The occurrence of total adverse events between the two groups was comparable (9 [31.0%] of 29 vs. 5 [16.1%] of 31, p = 0.227) and no patient experienced serious adverse events during the study.

CONCLUSION

Although it was safe, metformin add-on therapy did not accelerate HBsAg clearance in entecavir-treated patients with HBeAg-negative CHB.

Therapeutic targeting of regulatory T cells in cancer

The success of immunotherapy in oncology underscores the vital role of the immune system in cancer development. Regulatory T cells (Tregs) maintain a fine balance between autoimmunity and immune suppression. They have multiple roles in the tumor microenvironment (TME) but act particularly in suppressing T cell activation. This review focuses on the detrimental and sometimes beneficial roles of Tregs in tumors, our current understanding of recruitment and stabilization of Tregs within the TME, and current Treg-targeted therapeutics. Research identifying subpopulations of Tregs and their respective functions and interactions within the complex networks of the TME will be crucial to develop the next generation of immunotherapies. Through these advances, Treg-targeted immunotherapy could have important implications for the future of oncology.

Efficacy of metformin therapy in patients with cancer: a meta-analysis of 22 randomised controlled trials

BACKGROUND

To investigate whether metformin monotherapy or adjunctive therapy improves the prognosis in patients with any type of cancer compared to non-metformin users (age ≥18).

METHODS

Databases (Medline, Embase, and the Cochrane Central Register of Controlled Trials) and clinical trial registries ( ClinicalTrials.gov ; the World Health Organization International Clinical Trials Registry Platform) were screened for randomized, controlled trials (RCT) reporting at least progression-free survival (PFS) and/or overall survival (OS). Main outcome measures included hazard ratios (HR), and combined HRs and 95% confidence intervals (CI) were calculated using random-effects models.

RESULTS

Of the 8419 records screened, 22 RCTs comprising 5943 participants were included. Pooled HRs were not statistically significant in both PFS (HR 0.97, 95% CI 0.82-1.15, I² = 50%) and OS (HR 0.98, 95% CI 0.86-1.13, I² = 33%) for patients with cancer between the metformin and control groups. Subgroup analyses demonstrated that metformin treatment was associated with a marginally significant improvement in PFS in reproductive system cancers (HR 0.86, 95% CI 0.74-1.00) and a significantly worse PFS in digestive system cancers (HR 1.45, 95% CI 1.03-2.04). The PFS or OS was observed consistently across maintenance dose, diabetes exclusion, median follow-up, risk of bias, and combined antitumoral therapies.

CONCLUSION

Metformin treatment was not associated with cancer-related mortality in adults compared with placebo or no treatment. However, metformin implied beneficial effects in the PFS of the patients with reproductive system cancers but was related to a worse PFS in digestive system cancers.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42022324672.

Co-delivery of sorafenib and metformin from amphiphilic polypeptide-based micelles for colon cancer treatment

Colorectal cancer (CRC) is a common clinical disease with a poor prognosis and a high recurrence rate. Chemotherapy is important to inhibit the post-surgical recurrence of CRC patients. But many limitations restrict the further application of chemotherapy. In this study, sorafenib (Sor) and metformin (Met) co-loaded poly(ethylene glycol)-block-poly(L-glutamic acid-co-L-phenylalanine) [mPEG-b-P(Glu-co-Phe)] micelles were developed. The characterizations, drug release, in vivo biodistribution, and pharmacokinetics of the micelles were analyzed. The treatment efficacy of the dual-drug loaded micelles was evaluated in a subcutaneous colon cancer mice model. Sor is a common molecular target agent that can inhibit the mitogen-activated protein kinase (MAPK) pathway to treat solid tumors. Met can also regulate the MAPK pathway and inhibit the expression of the phosphorylated extracellular signal-regulated kinase (p-ERK). Moreover, both Sor and Met play important roles in cell cycle arrest. The integration of these two drugs aims to achieve synergistic effects against colon cancer. The micelles can be targeted to cancer cells and possess longer blood circulation time. The two agents can be released rapidly in the tumor sites. The in vivo study showed that the micelles can prevent tumor progression by inhibiting the expressions of p-ERK and cyclin D1. This study indicated that the Sor/Met-loaded micelles are suitable for CRC treatment.