Rethinking the Relationship between Insulin and Cancer

Diabetes and obesity: the role of stress in the development of cancer

Diabesity is a condition where an individual has both diabetes and obesity, which can lead to severe complications including cardiovascular disease, a leading cause of mortality. Recently, cancer has become a leading cause of excess hospitalizations, and both diabetes and obesity are associated with a higher risk of developing several types of cancer. In this review, we propose that chronic stress significantly increases this association. Managing diabetes and obesity is challenging as they both cause significant distress. The relationship between stress and cancer is interconnected, with anxiety and depression being common in cancer patients. Cancer diagnosis and treatment can cause lasting changes in the body's neuroendocrine system, with stress causing an excessive release of catecholamines and prostaglandins in patients undergoing cancer surgery, which promotes the spread of cancer to other parts of the body. Furthermore, stress could significantly increase the risk of cancer in patients with diabetes, obesity, or both.

Effect of a Phytochemical-Rich Olive-Derived Extract on Anthropometric, Hematological, and Metabolic Parameters

BACKGROUND

Extra virgin olive oil is a fundamental component of the Mediterranean diet. It contains several molecules that sustain human well-being by modulating cellular metabolism and exerting antioxidant, anti-inflammatory, and anti-ageing effects to protect normal tissues, and it can exert anti-angiogenic and pro-apoptotic effects on cancer cells. Metabolites found in different parts of the olive tree, including leaves, also possess properties that might help in cancer prevention and promote wellness in aging. Olive mill wastewater (OMWW), a liquid residue produced during olive oil extraction, represents an environmental issue. However, it is rich in phytochemicals with potential beneficial properties. Dietary supplements based on OMWW can be produced for nutritional supplementation with advantages to the ecology.

PURPOSE

This work aims to measure hematochemical, anthropometric, and metabolomic parameters in volunteers taking an OMWW dietary supplement, Oliphenolia® (OMWW-OL).

METHODS

The supplementation of OMWW-OL 25 mL twice daily for 30 days was tested on a pilot cohort of volunteers with characteristics close to metabolic syndrome. Hematochemical, anthropometric, serum biomarkers and serum metabolomic parameters were analyzed before the intervention, at 30 days, and 30 days after stopping consumption.

RESULTS

A total of 29 volunteers were enrolled, and 23 completed the study. The participants' parameters at baseline were measured, and then twice daily at 30 days of treatment and 30 days after assumption discontinuation. Although treatment was with an olive derivative, their weight did not increase. Their body mass index, instead of augmenting, slightly decreased, particularly in the women. Also, hydration increased, especially in the women, while blood pressure, glycemia, and insulin decreased. Cholesterol, high-density lipoproteins, and triglycerides were stable, and LDL levels decreased, while vitamin D levels, alongside calcium, perceptibly increased. Albumin also increased. All the values were in support of an equilibrium, with no damaging effects. By mass spectrometry analysis, we also found favorable changes in the vitamin D/histamine and homocysteine/methionine ratios, an increase in a new metabolite of unknown formula, and the vitamin D/unknown metabolite ratio.

CONCLUSIONS

Supplementation of OMWW-OL has no detrimental effects and might imply the beneficial modulation of several biological parameters. Although this is a small pilot study, with limited potency, it preliminarily suggests that the OMWW extract use could be potentially valuable for people at risk of metabolic syndrome. Some of these parameters could also be relevant in supporting healthy ageing and in cancer prevention.

Lactobacillus Firm-5-derived succinate prevents honeybees from having diabetes-like symptoms

The gut microbiome plays an important role in honeybee hormonal regulation and growth, but the underlying mechanisms are poorly understood. Here, we showed that the depletion of gut bacteria resulted in reduced expression of insulin-like peptide gene (ilp) in the head, accompanied by metabolic syndromes resembling those of Type 1 diabetes in humans: hyperglycemia, impaired lipid storage, and decreased metabolism. These symptoms were alleviated by gut bacterial inoculation. Gut metabolite profiling revealed that succinate, produced by Lactobacillus Firm-5, played deterministic roles in activating ilp gene expression and in regulating metabolism in honeybees. Notably, we demonstrated that succinate modulates host ilp gene expression through stimulating gut gluconeogenesis, a mechanism resembling that of humans. This study presents evidence for the role of gut metabolite in modulating host metabolism and contributes to the understanding of the interactions between gut microbiome and bee hosts.

Metformin and its potential influence on cell fate decision between apoptosis and senescence in cancer, with a special emphasis on glioblastoma

Despite reaching enormous achievements in therapeutic approaches worldwide, GBM still remains the most incurable malignancy among various cancers. It emphasizes the necessity of adjuvant therapies from the perspectives of both patients and healthcare providers. Therefore, most emerging studies have focused on various complementary and adjuvant therapies. Among them, metabolic therapy has received special attention, and metformin has been considered as a treatment in various types of cancer, including GBM. It is clearly evident that reaching efficient approaches without a comprehensive evaluation of the key mechanisms is not possible. Among the studied mechanisms, one of the more challenging ones is the effect of metformin on apoptosis and senescence. Moreover, metformin is well known as an insulin sensitizer. However, if insulin signaling is facilitated in the tumor microenvironment, it may result in tumor growth. Therefore, to partially resolve some paradoxical issues, we conducted a narrative review of related studies to address the following questions as comprehensively as possible: 1) Does the improvement of cellular insulin function resulting from metformin have detrimental or beneficial effects on GBM cells? 2) If these effects are detrimental to GBM cells, which is more important: apoptosis or senescence? 3) What determines the cellular decision between apoptosis and senescence?

Associations between Diabetes Mellitus and Selected Cancers

Cancer is one of the major causes of mortality and is the second leading cause of death. Diabetes mellitus is a serious and growing problem worldwide, and its prevalence continues to grow; it is the 12th leading cause of death. An association between diabetes mellitus and cancer has been suggested for more than 100 years. Diabetes is a common disease diagnosed among patients with cancer, and evidence indicates that approximately 8-18% of patients with cancer have diabetes, with investigations suggesting an association between diabetes and some particular cancers, increasing the risk for developing cancers such as pancreatic, liver, colon, breast, stomach, and a few others. Breast and colorectal cancers have increased from 20% to 30% and there is a 97% increased risk of intrahepatic cholangiocarcinoma or endometrial cancer. On the other hand, a number of cancers and cancer therapies increase the risk of diabetes mellitus. Complications due to diabetes in patients with cancer may influence the choice of cancer therapy. Unfortunately, the mechanisms of the associations between diabetes mellitus and cancer are still unknown. The aim of this review is to summarize the association of diabetes mellitus with selected cancers and update the evidence on the underlying mechanisms of this association.

Prognostic value of oxidative phosphorylation-related genes in hepatocellular carcinoma

PURPOSE

Hepatocellular carcinoma (HCC) is the most prevalent malignancies worldwide. Recently, oxidative phosphorylation (OXPHOS) has received extensive concern as an emerging target in antitumor therapy. However, the OXPHOS-involved underlying genes and clinical utilization in HCC remain worth exploring. The present research aimed to create an OXPHOS-relevant signature in HCC.

PATIENTS AND METHODS

In this study, the prognostic signature genes linked with OXPHOS were identified, and prognostic models were built using least absolute shrinkage and selection operator (LASSO) cox regression analysis. Furthermore, the combination study of immune microenvironment and signature genes looked into the involvement of immune cells in signature-based genes in HCC. Following that, chemotherapeutic drug sensitivity and immunotherapy analysis was implemented to predict clinical efficacy in HCC patients. Finally, clinical samples were collected to measure the expression of OXPHOS-related signature genes.

RESULTS

Following a series of screens, six prognostic signature genes related with OXPHOS were identified: MRPS23, MPV17, MAPK3, IGF2BP2, CDK5, and IDH2, on which a risk model was built. The findings revealed a significant drop in the survival rate of HCC patients as their risk score increased. Meanwhile, independent prognostic study demonstrated that the risk score could accurately identify HCC patients. Immuno-microenvironmental correlation research suggested that the prognostic characteristics could serve as a reference index for both immunotherapy and chemotherapy. Finally, RT-qPCR exhibited a trend in signature gene expression that was consistent with the results.

CONCLUSION

In this study, a total of six prognostic genes associated with OXPHOS were selected and a prognostic model was constructed, providing an essential reference for the study of OXPHOS in HCC.

Sensitive and label-free SPR biosensing platforms for high-throughput screening of plasma membrane receptors interactions with insulin-like targets of hypoglycaemic activity

Progress in medical sciences aims for tailored therapy of civilization diseases like diabetes. Preclinical screening of new medicines superior to insulin should include the verification of their affinity to the membrane receptors naturally stimulated by this hormone: insulin receptor isoforms A and B and insulin-like growth factor receptor. Considering that the affinity constants obtained using different experimental conditions are incomparable, it is essential to develop a robust and reliable method to analyze these interactions. The versatile SPR platform developed in this study enables the evaluation of the bioactivity of hypoglycaemic molecules. Thanks to the comprehensive characterization of miscellaneous aspects of the analytical platform, including the design of the SPR biosensor receptor layer, ensuring interaction specificity, as well as the quality control of the standards used (human insulin, HI; long-acting insulin analog: glargine, Gla), the feasibility of the method of equilibrium and kinetic constants determination for insulin-like targets was confirmed. SPR assays constructed in the direct format using IR-A, IR-B, and IGF1-R receptor proteins show high sensitivities and low detection limits towards insulin and glargine detection in the range of 18.3-53.3 nM with no signs of mass transport limitations. The improved analytical performance and stability of SPR biosensors favor the acquisition of good-quality kinetic data, while preservation of receptors activity after binding to long-chain carboxymethyldextran, combined with spontaneous regeneration, results in stability and long shelf life of the biosensor, which makes it useful for label-free insulin analogs biosensing and thus extensive screening in diabetic drugs discovery.

The role of IGF/IGF-1R signaling in the regulation of cancer stem cells

Cancer stem cells (CSCs) are a group of tumor cells with high tumorigenic ability and self-renewal potential similar to those of normal stem cells. CSCs are the key "seeds" for tumor development, metastasis, and recurrence. A better insight into the key mechanisms underlying CSC survival improves the efficiency of cancer therapy via specific targeting of CSCs. Insulin-like growth factor (IGF)/IGF-1 receptor (IGF-1R) signaling plays an important role in the maintenance of cancer stemness. However, the effect of IGF/IGF-1R signaling on stemness and CSCs and the underlying mechanisms are still controversial. Based on the similarity between CSCs and normal stem cells, this review discusses emerging data on the functions of IGF/IGF-1R signaling in normal stem cells and CSCs and dissects the underlying mechanisms by which IGF/IGF-1R signaling is involved in CSCs. On the other hand, this review highlighted the role of IGF/IGF-1R signaling blockade in multiple CSCs as a potential strategy to improve CSC-based therapy.

Arginase-induced cell death pathways and metabolic changes in cancer cells are not altered by insulin

Arginine, a semi-essential amino acid, is critical for cell growth. Typically, de novo synthesis of arginine is sufficient to support cellular processes, however, it becomes vital for cancer cells that are unable to synthesise arginine due to enzyme deficiencies. Targeting this need, arginine depletion with enzymes such as arginase (ARG) has emerged as a potential cancer therapeutic strategy. Studies have proposed using high dose insulin to induce a state of hypoaminoacidaemia in the body, thereby further reducing circulating arginine levels. However, the mitogenic and metabolic properties of insulin could potentially counteract the therapeutic effects of ARG. Our study examined the combined impact of insulin and ARG on breast, lung, and ovarian cell lines, focusing on cell proliferation, metabolism, apoptosis, and autophagy. Our results showed that the influence of insulin on ARG uptake varied between cell lines but failed to promote the proliferation of ARG-treated cells or aid recovery post-ARG treatment. Moreover, insulin was largely ineffective in altering ARG-induced metabolic changes and did not prevent apoptosis. In vitro, at least, these findings imply that insulin does not offer a growth or survival benefit to cancer cells being treated with ARG.

Changes in Cells Associated with Insulin Resistance

Insulin is a polypeptide hormone synthesized and secreted by pancreatic β-cells. It plays an important role as a metabolic hormone. Insulin influences the metabolism of glucose, regulating plasma glucose levels and stimulating glucose storage in organs such as the liver, muscles and adipose tissue. It is involved in fat metabolism, increasing the storage of triglycerides and decreasing lipolysis. Ketone body metabolism also depends on insulin action, as insulin reduces ketone body concentrations and influences protein metabolism. It increases nitrogen retention, facilitates the transport of amino acids into cells and increases the synthesis of proteins. Insulin also inhibits protein breakdown and is involved in cellular growth and proliferation. On the other hand, defects in the intracellular signaling pathways of insulin may cause several disturbances in human metabolism, resulting in several chronic diseases. Insulin resistance, also known as impaired insulin sensitivity, is due to the decreased reaction of insulin signaling for glucose levels, seen when glucose use in response to an adequate concentration of insulin is impaired. Insulin resistance may cause, for example, increased plasma insulin levels. That state, called hyperinsulinemia, impairs metabolic processes and is observed in patients with type 2 diabetes mellitus and obesity. Hyperinsulinemia may increase the risk of initiation, progression and metastasis of several cancers and may cause poor cancer outcomes. Insulin resistance is a health problem worldwide; therefore, mechanisms of insulin resistance, causes and types of insulin resistance and strategies against insulin resistance are described in this review. Attention is also paid to factors that are associated with the development of insulin resistance, the main and characteristic symptoms of particular syndromes, plus other aspects of severe insulin resistance. This review mainly focuses on the description and analysis of changes in cells due to insulin resistance.

Insulin Resistance: The Increased Risk of Cancers

Insulin resistance, also known as impaired insulin sensitivity, is the result of a decreased reaction of insulin signaling to blood glucose levels. This state is observed when muscle cells, adipose tissue, and liver cells, improperly respond to a particular concentration of insulin. Insulin resistance and related increased plasma insulin levels (hyperinsulinemia) may cause metabolic impairments, which are pathological states observed in obesity and type 2 diabetes mellitus. Observations of cancer patients confirm that hyperinsulinemia is a major factor influencing obesity, type 2 diabetes, and cancer. Obesity and diabetes have been reported as risks of the initiation, progression, and metastasis of several cancers. However, both of the aforementioned pathologies may independently and additionally increase the cancer risk. The state of metabolic disorders observed in cancer patients is associated with poor outcomes of cancer treatment. For example, patients suffering from metabolic disorders have higher cancer recurrence rates and their overall survival is reduced. In these associations between insulin resistance and cancer risk, an overview of the various pathogenic mechanisms that play a role in the development of cancer is discussed.

Safety and glycemic control with insulin degludec use in clinical practice: results from a 3-year Japanese post-marketing surveillance study

Introduction

Insulin degludec (degludec) is a basal insulin with a long duration of action. This post-marketing surveillance study monitored safety and glycemic control during use of degludec for 3 years in normal clinical practice in Japan.

Materials and methods

This multicenter, open-label, observational study included patients with diabetes receiving degludec in Japan between 2013 and 2019. The primary outcome was incidence of adverse events occurring over 3 years of treatment. The pre-specified, secondary outcomes were severe hypoglycemic episodes and changes in HbA1c and fasting plasma glucose levels.

Results

Of 4167 patients enrolled, 4022 were included in the safety assessments and 3918 in the assessments of glycemic control. Mean age was 58.9 years; 74.1% of patients had type 2 diabetes, and mean HbA1c at baseline was 8.7%. Adverse events and serious adverse events were observed in 19.1% and 8.9% of patients, respectively. Cardiac disorders and neoplasms were reported in 2.0% and 1.8% of patients, respectively, with the majority of these incidents reported as serious adverse events. Adverse drug reactions were seen in 8.0% of patients, mainly hypoglycemia. Hypoglycemic events were observed in 5.6% of patients, and severe hypoglycemic events in 1.7%. No serious allergic or injection-site reactions were seen. Respective changes (from baseline to 3 years' observation) in HbA1c and fasting plasma glucose levels were - 0.55% and - 36.3 mg/dL, and 19.6% of patients reached HbA1c < 7.0%.

Conclusions

Using degludec for 3 years in normal clinical practice had a good safety and tolerability profile. Improvements in glycemic control were also seen.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13340-023-00657-7.

Risk of thyroid cancer associated with glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors in patients with type 2 diabetes: A population-based cohort study

AIMS

To determine the potential association between the use of either glucagon-like peptide-1 receptor agonists (GLP-1RAs) or dipeptidyl peptidase-4 (DPP-4) inhibitors, and the risk of thyroid cancer in individuals with type 2 diabetes.

MATERIALS AND METHODS

This population-based cohort study used claims data from the Korean National Health Insurance Database, 2014-2020. Two distinct cohorts were established to compare each incretin-based drug with sodium-glucose cotransporter-2 (SGLT2) inhibitors, chosen as active comparators because of their previous non-association with thyroid cancer, and their common usage as add-on therapy to metformin along with GLP-1RAs and DPP-4 inhibitors. The first cohort included 21 722 new users of GLP-1RAs and 326 993 new users of SGLT2 inhibitors, whereas the second cohort included 904 300 DPP-4 inhibitor new users and 112 017 SGLT2 inhibitor new users. The outcome was the time to incident thyroid cancer. Weighted Cox proportional models were used to estimate hazard ratios of thyroid cancer incidence associated with incretin-based drugs of interest.

RESULTS

The use of GLP-1RAs was not associated with an increased risk of thyroid cancer (weighted hazard ratio 0.98, 95% confidence interval 0.62-1.53) compared with that of SGLT2 inhibitors. Using DPP-4 inhibitors was also not associated with an increased risk of thyroid cancer (0.95, 0.79-1.14) compared with that of SGLT2 inhibitors. No significant effect modifications were observed across subgroup analyses. Sensitivity analyses, including alternative outcome definition analysis of medullary thyroid cancer, were consistent with the primary analysis results.

CONCLUSIONS

GLP-1RAs and DPP-4 inhibitors were not associated with an increased risk of thyroid cancer in individuals with type 2 diabetes.

Duration of Type 2 Diabetes and Incidence of Cancer: An Observational Study in England

OBJECTIVE

To investigate the association between duration of type 2 diabetes and cancer incidence.

RESEARCH DESIGN AND METHODS

In the Clinical Practice Research Datalink database, we identified 130,764 individuals with type 2 diabetes aged ≥35 years at diagnosis who were linked to hospital and mortality records. We used sex-stratified Royston-Parmar models with two timescales to estimate incidence rates of all cancers, the four commonest cancers in the U.K. (colorectal, lung, prostate, breast), and the obesity-related cancers (e.g., liver, ovary) between 1 January 1998 and 14 January 2019, by age and diabetes duration.

RESULTS

During 1,089,923 person-years, 18,977 incident cancers occurred. At the same age, rates of all cancers in men and women did not vary across durations ranging from diagnosis to 20 years; conversely, for any duration, there was a strong, positive association between age and cancer rates. In men, the rate ratio (95% CI) comparing 20 with 5 years of duration was 1.18 (0.82-1.69) at 60 years of age and 0.90 (0.75-1.08) at 80 years; corresponding ratios in women were 1.07 (0.71-1.63) and 0.84 (0.66-1.05). This pattern was observed also for the four commonest cancers. For obesity-related cancers, although rates were generally higher in individuals with a higher BMI, there was no association with duration at any level of BMI.

CONCLUSIONS

In this study, we did not find evidence of an association between duration of type 2 diabetes and risk of cancer, with the higher risk observed for longer durations related to ageing.

Association of Phosphorylated Pyruvate Dehydrogenase with Pyruvate Kinase M2 Promotes PKM2 Stability in Response to Insulin

Insulin is a crucial signalling molecule that primarily functions to reduce blood glucose levels through cellular uptake of glucose. In addition to its role in glucose homeostasis, insulin has been shown to regulate cell proliferation. Specifically, insulin enhances the phosphorylation of pyruvate dehydrogenase E1α (PDHA1) at the Ser293 residue and promotes the proliferation of HepG2 hepatocellular carcinoma cells. Furthermore, we previously observed that p-Ser293 PDHA1 bound with pyruvate kinase M2 (PKM2) as confirmed by coimmunoprecipitation. In this study, we used an in silico analysis to predict the structural conformation of the two binding proteins. However, the function of the protein complex remained unclear. To investigate further, we treated cells with si-PDHA1 and si-PKM2, which led to a reduction in PKM2 and p-Ser293 PDHA1 levels, respectively. Additionally, we found that the PDHA S293A dephospho-mimic reduced PKM2 levels and its associated enzyme activity. Treatment with MG132 and leupeptin impeded the PDHA1 S293A-mediated PKM2 reduction. These results suggest that the association between p-PDHA1 and PKM2 promotes their stability and protects them from protein degradation. Of interest, we observed that p-PDHA1 and PKM2 were localized in the nucleus in liver cancer patients. Under insulin stimulation, the knockdown of both PDHA1 and PKM2 led to a reduction in the expression of common genes, including KDMB1. These findings suggest that p-PDHA1 and PKM2 play a regulatory role in these proteins' expression and induce tumorigenesis in response to insulin.

Recent onset diabetes is associated with better survival in pancreatic ductal adenocarcinoma-An analysis of preoperative symptoms within the DGAV StuDoQ|Pancreas Registry

BACKGROUND

This multicenter study analyzed the relationship between preoperative symptoms and postsurgical outcomes utilizing the German national DGAV StuDoQ|Pancreas database.

METHODS

This retrospective study included 2,643 pancreatic ductal adenocarcinoma patients undergoing pancreatic head resection from 2013-2017 within the German pancreatic surgery registry (DGAV StuDoQ|Pancreas). The association of preoperative symptoms with overall survival was analyzed using Kaplan-Meier and Cox regression analysis.

RESULTS

Preoperative symptoms were common, with 2,380 of 2,643 (90%) patients presenting with any one or more of the following symptoms: jaundice (40%), biliary obstruction treated with biliary stent (41%), pain (37%), weight loss (29%), nausea (18%), diabetes (31%), emesis (6%), and recent onset diabetes (5%). Patients were separated into 3 groups: no symptoms (n = 293), symptoms (n = 2,229), and recent onset diabetes (n = 121). The 3 groups differed in body mass index and nodal staging, where patients with recent onset diabetes had the highest values (body mass index: no symptoms: 24.5 kg/m2, symptoms: 25.1 kg/m2; recent-onset diabetes: 26.3 kg/m2, P = .007), (no symptoms: N1: 55%, N2: 10%; symptoms: N1: 53%, N2: 17%; recent-onset diabetes: N1: 56%, N2: 16%, P = .023). Other pathological characteristics, carbohydrate antigen 19-9 levels, and adjuvant chemotherapy receival did not differ between the groups. Interestingly, recent-onset diabetes was associated with better survival compared with the other groups (Median overall survival: 28 months [no symptoms at all], 22 months [symptoms] versus not reached [recent onset diabetes group], and 5-year overall survival rates of 28%, 11%, and 57%, respectively [log rank, P = .013]). Multivariable analysis revealed that recent-onset diabetes and preoperative symptoms were independently associated with overall survival (recent-onset diabetes, relative risk 0.052 P = .027, >5 symptoms relative risk 3.66, P < .001).

CONCLUSION

Pancreatic ductal adenocarcinoma symptoms occured in up to 90% of patients with resectable pancreatic ductal adenocarcinoma. In addition, PDAC symptoms were associated with overall survival and might identify unique pancreatic ductal adenocarcinoma subtypes.

The Association of Empirical Dietary Index for Hyperinsulinemia with the Risk of Cancer and Cancer Mortality: A Meta-analysis of Observational Studies

This meta-analysis aimed to assess the association between the empirical dietary index for hyperinsulinemia (EDIH) and cancer mortality risk. We performed a comprehensive search across the online literature up to November 2022 databases. Then, hazard ratio (H.R.) and 95% confidence intervals (CI) were extracted. A total of 14 and seven cohort studies that reported H.R. for the risk of cancer incidence and cancer mortality respectively were included. The pooled H.R. (95% CI) of the association between EDIH and cancer incidence was 1.13 (1.05-1.23) in overall meta-analyses, 1.15 (1.08-1.22) in female subgroups, 1.27 (1.14-1.41) in digestive cancer subgroups, and 1.15 (1.07-1.24) in breast cancer subgroups. Also, the pooled H.R. (95% CI) of the association between EDIH and incidence of cancer mortality was 1.19 (1.13-1.26) in overall meta-analyses, 1.23 (1.13-1.34) in males, 1.18(1.10-1.28) in females, and 1.20 (1.13-1.27) in studies conducted on all cancers as an outcome. Our findings revealed that a higher EDIH was significantly associated with an increased risk of cancer incidence, particularly in females, digestive cancers, and breast cancer. Also, a higher EDIH score was related to a higher risk of cancer mortality overall in both male and female subgroups and with all cancers.

Out of the cycle: Impact of cell cycle aberrations on cancer metabolism and metastasis

The use of cell cycle inhibitors has necessitated a better understanding of the cell cycle in tumor biology to optimize the therapeutic approach. Cell cycle aberrations are common in cancers, and it is increasingly acknowledged that these aberrations exert oncogenic effects beyond the cell cycle. Multiple facets such as cancer metabolism, immunity and metastasis are also affected, all of which are beyond the effect of cell proliferation alone. This review comprehensively summarized the important recent findings and advances in these interrelated processes. In cancer metabolism, cell cycle regulators can modulate various pathways in aerobic glycolysis, glucose uptake and gluconeogenesis, mainly through transcriptional regulation and kinase activities. Amino acid metabolism is also regulated through cell cycle progression. On cancer metastasis, metabolic plasticity, immune evasion, tumor microenvironment adaptation and metastatic site colonization are intricately related to the cell cycle, with distinct regulatory mechanisms at each step of invasion and dissemination. Throughout the synthesis of current understanding, knowledge gaps and limitations in the literature are also highlighted, as are new therapeutic approaches such as combinational therapy and challenges in tackling emerging targeted therapy resistance. A greater understanding of how the cell cycle modulates diverse aspects of cancer biology can hopefully shed light on identifying new molecular targets by harnessing the vast potential of the cell cycle.

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

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

Association of metformin, aspirin, and cancer incidence with mortality risk in adults with diabetes

BACKGROUND

Metformin and aspirin are commonly co-prescribed to people with diabetes. Metformin may prevent cancer, but in older people (over 70 years), aspirin has been found to increase cancer mortality. This study examined whether metformin reduces cancer mortality and incidence in older people with diabetes; it used randomization to 100 mg aspirin or placebo in the ASPirin in Reducing Events in the Elderly (ASPREE) trial to quantify aspirin's impact on metformin users.

METHODS

Analysis included community-dwelling ASPREE participants (aged ≥70 years, or ≥65 years for members of US minority populations) with diabetes. Diabetes was defined as a fasting blood glucose level greater than 125 mg/dL, self-report of diabetes, or antidiabetic medication use. Cox proportional hazards regression models were used to analyze the association of metformin and a metformin-aspirin interaction with cancer incidence and mortality, with adjustment for confounders.

RESULTS

Of 2045 participants with diabetes at enrollment, 965 were concurrently using metformin. Metformin was associated with a reduced cancer incidence risk (adjusted hazard ratio [HR] = 0.68, 95% confidence interval [CI] = 0.51 to 0.90), but no conclusive benefit for cancer mortality (adjusted HR = 0.72, 95% CI = 0.43 to 1.19). Metformin users randomized to aspirin had greater risk of cancer mortality compared with placebo (HR = 2.53, 95% CI = 1.18 to 5.43), but no effect was seen for cancer incidence (HR = 1.11, 95% CI = 0.75 to 1.64). The possible effect modification of aspirin on cancer mortality, however, was not statistically significant (interaction P = .11).

CONCLUSIONS

In community-dwelling older adults with diabetes, metformin use was associated with reduced cancer incidence. Increased cancer mortality risk in metformin users randomized to aspirin warrants further investigation.

ASPREE TRIAL REGISTRATION

ClinicalTrials.gov ID NCT01038583.

Body Mass Index and Cancer Risk: An Umbrella Review of Meta-Analyses of Observational Studies

Increasing evidence indicates that obesity is a risk factor for various tumors. We aimed to clarify the evidence for an association between body mass index (BMI) and cancer risk based on existing systematic reviews and meta-analyses. Eighteen studies were included in this umbrella review after searching PubMed, Embase and Web of science. The results revealed that underweight was inversely associated with the incidence of brain tumors and positively related to the risk of esophageal and lung cancer. Overweight enhances the incidence of brain tumors, kidney cancer, endometrial cancer, ovarian cancer, multiple myeloma, bladder cancer and liver cancer. Obesity was related to the increased incidence of brain tumors, cervical cancer, kidney cancer, endometrial cancer, esophageal cancer, gastric cancer, ovarian cancer, multiple myeloma, gallbladder cancer, bladder cancer, colorectal cancer, liver cancer, thyroid cancer and Hodgkin's lymphoma. Moreover, dose-response analysis was conducted by 10 studies, and the results demonstrated that each 5 Kg/m² increase in BMI was associated with a 1.01- to 1.13-fold increased risk of general brain tumors, multiple myeloma, bladder cancer, pancreatic cancer, breast cancer, and non-Hodgkin's lymphoma. Every 1 Kg/m² increase in BMI was linked to 6% and 4% increases in the risk of kidney cancer and gallbladder cancer, respectively.

Associations between serum glucose, insulin, insulin resistance and the risk of incident primary liver cancer or chronic liver disease mortality: a nested case-control study

BACKGROUND

To evaluate the associations between pre-diagnostic levels of serum insulin, glucose and insulin resistance (HOMA-IR) and future risk of incident primary liver cancer (PLC) or chronic liver disease (CLD)-related mortality.

METHODS

We used a nested case-control design to evaluate subjects over 22 years of follow-up. Glucose, insulin, and three markers of hepatitis B virus (HBV) and hepatitis C virus were measured in fasting baseline serum from 119 incident PLCs, 157 CLD-death cases and 512 matched controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression to estimate the associations between insulin, glucose, HOMA-IR and the risk of PLC or CLD death.

RESULTS

Compared with the lowest quartile of insulin, multivariable adjusted models showed that subjects in the highest quartile had elevated odds of developing PLC (ORQ4/Q1 = 2.42, 95% CI = 1.26-4.75, Ptrend = 0.007), particularly in HBV-positive subjects (Pinteraction = 0.040), and of CLD death (ORQ4/Q1 = 1.80, 95% CI = 1.02-3.21, Ptrend = 0.018). For glucose, in the HBV-positive group, subjects in the fourth quartile had an increased risk of PLC (ORQ4/Q1 = 2.18, 95% CI = 1.07-4.60, Ptrend = 0.009), and of CLD mortality (ORQ4/Q1 = 1.75, 95% CI = 0.95-3.28, Ptrend = 0.019). Subjects with the highest HOMA-IR values had a threefold risk of developing PLC (ORQ4/Q1 = 2.94, 95% CI = 1.54-5.87, Ptrend = 0.001), and a twofold risk of CLD death (ORQ4/Q1 = 2.20, 95% CI = 1.25-3.94, Ptrend = 0.005).

CONCLUSIONS

We found that serum insulin and HOMA-IR could potentially be risk factors for PLC or CLD death.

Protein Disulfide Isomerases Function as the Missing Link Between Diabetes and Cancer

Significance: Diabetes has long been recognized as an independent risk factor for cancer, but there is insufficient mechanistic understanding of biological mediators that bridge two disorders together. Understanding the pathogenic association between diabetes and cancer has become the focus of many studies, and findings are potentially valuable for the development of effective preventive or therapeutic strategies for both disorders. Recent Advances: A summary of literature reveals a possible connection between diabetes and cancer through the family of protein disulfide isomerase (PDI). Historical as well as the most recent findings on the structure, biochemistry, and biology of the PDI family were summarized in this review. Critical Issues: PDIs in general function as redox enzymes and protein chaperones to control the quality of proteins by correcting or otherwise eliminating misfolded proteins in conditions of oxidative stress and endoplasmic reticulum stress, respectively. However, individual members of the PDI family may contribute uniquely to the pathogenesis of diabetes and cancer. Studies of exemplary members such as protein disulfide isomerase-associated (PDIA) 1, PDIA6, and PDIA15 were reviewed to highlight their contributions in the pathogenesis of diabetes and cancer and how they can be potential links bridging the two disorders through the cross talk of signaling pathways. Future Directions: Apparently ubiquitous presence of the PDIs creates difficulties and challenges for scientific community to develop targeted therapeutics for the treatment of diabetes and cancer simultaneously. Understanding molecular contribution of individual PDI in the context of specific disease may provide some insights into the development of mechanism-based target-directed therapeutics. Antioxid. Redox Signal. 37, 1191-1205.

The Insulin-like Growth Factor Signaling Pathway in Breast Cancer: An Elusive Therapeutic Target

In this review, we provide an overview of the role of the insulin-like growth factor (IGF) signaling pathway in breast cancer and discuss its potential as a therapeutic target. The IGF pathway ligands, IGF-1 and IGF-2, and their receptors, primarily IGF-1R, are important for normal mammary gland biology, and dysregulation of their expression and function drives breast cancer risk and progression through activation of downstream signaling effectors, often in a subtype-dependent manner. The IGF signaling pathway has also been implicated in resistance to current therapeutic strategies, including ER and HER2 targeting drugs. Unfortunately, efforts to target IGF signaling for the treatment of breast cancer have been unsuccessful, due to a number of factors, most significantly the adverse effects of disrupting IGF signaling on normal glucose metabolism. We highlight here the recent discoveries that provide enthusiasm for continuing efforts to target IGF signaling for the treatment of breast cancer patients.

The Association of Metformin, Other Antidiabetic Medications and Statins on the Prognosis of Rectal Cancer in Patients with Type 2 Diabetes: A Retrospective Cohort Study

Metformin and statin use have been associated with an improved prognosis for colorectal cancer in persons with type 2 diabetes (T2D). Data regarding rectal cancer (RC) have been inconclusive; therefore, we investigated the issue with high-quality data and a robust study design. We identified 1271 eligible patients with T2D and incident RC between 1998 and 2011 from the Diabetes in Finland (FinDM) database. Cox models were fitted for cause-specific mortality rates to obtain adjusted estimates of the hazard ratios (HR) with 95% confidence intervals (CI) in relation to use of antidiabetic medication (ADM) and statins before the RC diagnosis and for post-diagnostic use in a time-dependent exposure manner. No sufficient evidence was found for either pre- or post-diagnostic metformin use and RC mortality (HR 0.96, 95% CI 0.67–1.38, and 0.70, 95% CI 0.45–1.10, respectively) when compared to other oral ADMs. Both pre- and post-diagnostic statin use appeared to be inversely associated with mortality from RC (HR 0.77 95% CI 0.63–0.94, and 0.57, 95% CI 0.42–0.78, respectively). Our study was inconclusive as to the association of metformin use with the prognosis of RC, but statin use was found to predict reduced mortality, both from RC and from other causes of death in persons with T2D.

Diabetes and Risks of Right-Sided and Left-Sided Colon Cancer: A Meta-Analysis of Prospective Cohorts

Background and Aims

Diabetes is associated with an increased risk of colon cancer (CC). Epidemiologic studies previously reported a higher risk for right-sided colon cancer (RCC) compare to left-sided colon cancer (LCC), although data are conflicting. We performed a meta-analysis to investigate this issue.

Methods

We systematically searched the PubMed, EMBASE, Web of Science and Cochrane Library database for prospective cohort studies published up to June 2021. Studies were included if they reported site-specific estimates of the relative risk (RR) between diabetes and the risks of RCC and LCC. Random effects meta-analyses with inverse variance weighting were used to estimate the pooled site-specific RRs and the RCC-to-LCC ratio of RRs (RRRs).

Results

Data from 10 prospective cohort studies, representing 1,642,823 individuals (mainly white) and 17,624 CC patients, were included in the analysis. Diabetes was associated with an increased risk of both RCC (RR =1.35, 95% CI = 1.24-1.47) and LCC (RR = 1.18, 95% CI = 1.08-1.28). After adjusting for major risk factors, individuals with diabetes had a greater risk for RCC than for LCC (RRR = 1.13, 95% CI = 1.02-1.26), with no significant heterogeneity between studies (I² = 0%).

Conclusions

This meta-analysis indicates that diabetes is associated with a higher risk for RCC than for LCC. Our findings suggest that colonoscopic surveillance in diabetic patients with careful examination of the right colon is warranted.

Impacts of nutritive and bioactive compounds on cancer development and therapy

For persons who survive with progressive cancer, nutritional therapy and exercise may be significant factors to improve the health condition and life quality of cancer patients. Nutritional therapy and medications are essential to managing progressive cancer. Cancer survivors, as well as cancer patients, are mostly extremely encouraged to search for knowledge about the selection of diet, exercise, and dietary supplements to recover as well as maintain their treatment consequences, living quality, and survival of patients. A healthy diet plays an important role in cancer treatment. Different articles are studied to collect information and knowledge about the use of nutrients in cancer treatment as well as cancer prevention. The report deliberates nutrition and exercise strategies during the range of cancer care, emphasizing significant concerns during treatment of cancer and for patients of advanced cancer, but concentrating mostly on the requirements of the population of persons who are healthy or who have constant disease following their repossession from management. It also deliberates choice nutrition and exercise problems such as dietary supplements, food care, food selections, and weight; problems interrelated to designated cancer sites, and common questions about diet, and cancer survival. Decrease the side effects of medicines both during and after treatment.

Insulin-Degrading Enzyme, an Under-Estimated Potential Target to Treat Cancer?

Insulin-degrading enzyme (IDE) is a multifunctional protease due to the variety of its substrates, its various cellular locations, its conservation between species and its many non-proteolytic functions. Numerous studies have successfully demonstrated its implication in two main therapeutic areas: metabolic and neuronal diseases. In recent years, several reports have underlined the overexpression of this enzyme in different cancers. Still, the exact role of IDE in the physiopathology of cancer remains to be elucidated. Known as the main enzyme responsible for the degradation of insulin, an essential growth factor for healthy cells and cancer cells, IDE has also been shown to behave like a chaperone and interact with the proteasome. The pharmacological modulation of IDE (siRNA, chemical compounds, etc.) has demonstrated interesting results in cancer models. All these results point towards IDE as a potential target in cancer. In this review, we will discuss evidence of links between IDE and cancer development or resistance, IDE's functions, catalytic or non-catalytic, in the context of cell proliferation, cancer development and the impact of the pharmacomodulation of IDE via cancer therapeutics.

New Discoveries and Ambiguities of Nrf2 and ATF3 Signaling in Environmental Arsenic-Induced Carcinogenesis

Environment exposure to arsenic had been linked to increased incidents of human cancers. In cellular and animal experimental systems, arsenic has been shown to be highly capable of activating several signaling pathways that play critical roles in cell growth regulation, malignant transformation and the stemness of cancer stem-like cells. Emerging evidence indicates certain oncogenic properties of the Nrf2 transcription factor that can be activated by arsenic and many other environmental hazards. In human bronchial epithelial cells, our most recent data suggested that arsenic-activated Nrf2 signaling fosters metabolic reprogramming of the cells through shifting mitochondrial TCA cycle to cytosolic glycolysis, and some of the metabolites in glycolysis shunt the hexosamine biosynthesis and serine-glycine pathways important for the energy metabolism of the cancer cells. In the current report, we further demonstrated direct regulation of oncogenic signals by arsenic-activated Nrf2 and connection of Nrf2 with ATF3 stress transcription factor. Meanwhile, we also highlighted some unanswered questions on the molecular characteristics of the Nrf2 protein, which warrants further collaborative efforts among scientists for understanding the important role of Nrf2 in human cancers either associated or not to environmental arsenic exposure.

Insulin Resistance and Cancer: In Search for a Causal Link

Insulin resistance (IR) is a condition which refers to individuals whose cells and tissues become insensitive to the peptide hormone, insulin. Over the recent years, a wealth of data has made it clear that a synergistic relationship exists between IR, type 2 diabetes mellitus, and cancer. Although the underlying mechanism(s) for this association remain unclear, it is well established that hyperinsulinemia, a hallmark of IR, may play a role in tumorigenesis. On the other hand, IR is strongly associated with visceral adiposity dysfunction and systemic inflammation, two conditions which favor the establishment of a pro-tumorigenic environment. Similarly, epigenetic modifications, such as DNA methylation, histone modifications, and non-coding RNA, in IR states, have been often associated with tumorigenesis in numerous types of human cancer. In addition to these observations, it is also broadly accepted that gut microbiota may play an intriguing role in the development of IR-related diseases, including type 2 diabetes and cancer, whereas potential chemopreventive properties have been attributed to some of the most commonly used antidiabetic medications. Herein we provide a concise overview of the most recent literature in this field and discuss how different but interrelated molecular pathways may impact on tumor development.

Effect of Basal Metabolic Rate on Cancer: A Mendelian Randomization Study

Background: Basal metabolic rate is associated with cancer, but these observations are open to confounding. Limited evidence from Mendelian randomization studies exists, with inconclusive results. Moreover, whether basal metabolic rate has a similar role in cancer for men and women independent of insulin-like growth factor 1 increasing cancer risk has not been investigated.

Methods: We conducted a two-sample Mendelian randomization study using summary data from the UK Biobank to estimate the causal effect of basal metabolic rate on cancer. Overall and sex-specific analysis and multiple sensitivity analyses were performed including multivariable Mendelian randomization to control for insulin-like growth factor 1.

Results: We obtained 782 genetic variants strongly (p-value < 5 × 10^–8) and independently (r² < 0.01) predicting basal metabolic rate. Genetically predicted higher basal metabolic rate was associated with an increase in cancer risk overall (odds ratio, 1.06; 95% confidence interval, 1.02–1.10) with similar estimates by sex (odds ratio for men, 1.07; 95% confidence interval, 1.002–1.14; odds ratio for women, 1.06; 95% confidence interval, 0.995–1.12). Sensitivity analyses including adjustment for insulin-like growth factor 1 showed directionally consistent results.

Conclusion: Higher basal metabolic rate might increase cancer risk. Basal metabolic rate as a potential modifiable target of cancer prevention warrants further study.

Regulatory effect of insulin on the structure, function and metabolism of Na+/K+-ATPase (Review)

Na⁺/K⁺-ATPase is an ancient enzyme, the role of which is to maintain Na⁺ and K⁺ gradients across cell membranes, thus preserving intracellular ion homeostasis. The regulation of Na⁺/K⁺-ATPase is affected by several regulatory factors through a number of pathways, with hormones serving important short-term and long-term regulatory functions. Na⁺/K⁺-ATPase can also be degraded through activation of the ubiquitin proteasome and autophagy-lysosomal pathways, thereby affecting its abundance and enzymatic activity. As regards the regulatory effect of insulin, it has been found to upregulate the relative abundance of Na⁺/K⁺-ATPase and restore the transport efficiency in multiple in vitro and in vivo experiments. Therefore, elucidating the role of insulin in the regulation Na⁺/K⁺-ATPase may help uncover new drug targets for the treatment of related diseases. The aim of the present study was to review the structure and function of Na⁺/K⁺-ATPase and to discuss the possible mechanisms through which it may be regulated by insulin, in order to investigate the possibility of designing new therapies for related diseases.

Identification of genetic variants for blood insulin level in sex-stratified Korean population and evaluation of the causal relationship between blood insulin level and polycystic ovary syndrome

BACKGROUND

Blood insulin level is an important risk factor for numerous disorders. Individual blood insulin level is known to be substantially influenced by genetic factors. Several genetic association studies identified a number of genetic variants for blood insulin level, but none of them was from a sex-stratified population.

OBJECTIVE

This study aimed to identify male- and female-specific genetic variants related to blood insulin level and to evaluate the causal relationship between blood insulin level and polycystic ovary syndrome (PCOS) that is likely caused by high insulin in Korean women.

METHODS

A genome-wide association study was conducted to identify genetic variants influencing blood insulin level in males (N = 4183) and females (N = 4659) in the Korean population. Two-sample Mendelian randomization (MR) analysis was used to investigate the causal effects of the insulin variants identified from GWAS on PCOS in Korean women. Genetic association data for PCOS were obtained from a PCOS study cohort (946 cases, 976 controls) in Ewha Womans University Hospital.

RESULTS

GWAS linear regression analysis identified 13 female-specific SNPs and 13 male-specific SNPs showing suggestive associations (P < 10^-5) with blood insulin level. The results from two-sample MR analysis using the GWAS variants for PCOS indicated that genetically determined insulin level was not associated with the risk of PCOS in Korean women.

CONCLUSION

This study identified sex-specific genetic variants showing associations with insulin for the first time in East Asian populations. In addition, MR analysis using variants discovered from Korean women revealed that genetically determined high level of insulin is not the cause of PCOS.

Role of metformin and other metabolic drugs in the prevention and therapy of endocrine-related cancers

Metabolic syndrome is associated with chronic diseases, including type 2 diabetes, cardiovascular diseases, and cancer. This review summarizes the current evidence on the antitumor effects of some relevant drugs currently used to manage metabolic-related pathologies (i.e. insulin and its analogs, metformin, statins, etc.) in endocrine-related cancers including breast cancer, prostate cancer, pituitary cancer, ovarian cancer, and neuroendocrine neoplasms. Although current evidence does not provide a clear antitumor role of several of these drugs, metformin seems to be a promising chemopreventive and adjuvant agent in cancer management, modulating tumor cell metabolism and microenvironment, through both AMP-activated protein kinase-dependent and -independent mechanisms. Moreover, its combination with statins might represent a promising therapeutic strategy to tackle the progression of endocrine-related tumors. However, further studies are needed to endorse the clinical relevance of these drugs as adjuvants for cancer chemotherapy.

Western diet leads to aging-related tumorigenesis via activation of the inflammatory, UPR, and EMT pathways

Among the principal causative factors for the development of complications related to aging is a diet rich in fats and sugars, also known as the Western diet. This diet advocates numerous changes that might increase the susceptibility to initiate cancer and/or to create a tissue microenvironment more conducive to the growth of malignant cells, thus favoring the progression of cancer and metastasis. Hypercaloric diets in general lead to oxidative stress generating reactive oxygen species and induce endoplasmic reticulum stress. Our results demonstrate that mice bearing tumors fed with a Western diet presented bigger tumor mass with increased insulin sensitivity in these tissues. Several markers of insulin signaling, such as AKT phosphorylation and mTOR pathway, are promoted in tumors of Western diet-fed animals. This process is associated with increased macrophage infiltration, activation of unfolded protein response pathway, and initiation of epithelial-mesenchymal transition (EMT) process in these tumor tissues. Summing up, we propose that the Western diet accelerates the aging-related processes favoring tumor development.

Tumor apelin and obesity are associated with reduced neoadjuvant chemotherapy response in a cohort of breast cancer patients

Obesity is a known factor increasing the risk of developing breast cancer and reducing disease free survival. In addition to these well-documented effects, recent studies have shown that obesity is also affecting response to chemotherapy. Among the multiple dysregulations associated with obesity, increased level of the apelin adipokine has been recently shown to be directly involved in the association between obesity and increased breast cancer progression. In this study, we analyzed in a retrospective cohort of 62 breast cancer patients the impact of obesity and tumoral apelin expression on response to neoadjuvant chemotherapy. In the multivariate logistic regression, obesity and high tumoral apelin expression were associated with a reduced response to NAC in our cohort. However, obesity and high tumoral apelin expression were not correlated, suggesting that those two parameters could be independently associated with reduced NAC response. These findings should be confirmed in independent cohorts.

Exercise-A Panacea of Metabolic Dysregulation in Cancer: Physiological and Molecular Insights

Metabolic dysfunction is a comorbidity of many types of cancers. Disruption of glucose metabolism is of concern, as it is associated with higher cancer recurrence rates and reduced survival. Current evidence suggests many health benefits from exercise during and after cancer treatment, yet only a limited number of studies have addressed the effect of exercise on cancer-associated disruption of metabolism. In this review, we draw on studies in cells, rodents, and humans to describe the metabolic dysfunctions observed in cancer and the tissues involved. We discuss how the known effects of acute exercise and exercise training observed in healthy subjects could have a positive outcome on mechanisms in people with cancer, namely: insulin resistance, hyperlipidemia, mitochondrial dysfunction, inflammation, and cachexia. Finally, we compile the current limited knowledge of how exercise corrects metabolic control in cancer and identify unanswered questions for future research.

Relationship between type 2 diabetes mellitus and markers of cutaneous melanoma aggressiveness: an observational multicentric study in 443 patients with melanoma

BACKGROUND

Some studies have suggested a relationship between type 2 diabetes mellitus (T2DM) and increased incidence of melanoma. Efforts are under way to identify preventable and treatable factors associated with greater melanoma aggressiveness, but no studies to date have examined the relationship between T2DM and the aggressiveness of cutaneous melanoma at diagnosis.

OBJECTIVES

To explore potential associations between T2DM, glycaemic control and metformin treatment and the aggressiveness of cutaneous melanoma.

METHODS

We conducted a cross-sectional multicentric study in 443 patients diagnosed with cutaneous melanoma. At diagnosis, all patients completed a standardized protocol, and a fasting blood sample was extracted to analyse their glucose levels, glycated haemoglobin concentration and markers of systemic inflammation. Melanoma characteristics and aggressiveness factors [Breslow thickness, ulceration, tumour mitotic rate (TMR), sentinel lymph node (SLN) involvement and tumour stage] were also recorded.

RESULTS

The mean (SD) age of the patients was 55·98 (15·3) years and 50·6% were male. The median Breslow thickness was 0·85 mm. In total, 48 (10·8%) patients were diagnosed with T2DM and this finding was associated with a Breslow thickness > 2 mm [odds ratio (OR) 2·6, 95% confidence interval (CI) 1·4-4·9; P = 0·004)] and > 4 mm (OR 3·6, 95% CI 1·7-7·9; P = 0·001), TMR > 5 per mm² (OR 4·5, 95% CI 1·4-13·7; P = 0·009), SLN involvement (OR 2·3, 95% CI 1-5·7; P = 0·038) and tumour stages III-IV (vs. I-II) (OR 3·4, 95% CI 1·6-7·4; P = 0·002), after adjusting for age, sex, obesity, alcohol intake and smoking habits. No significant associations emerged between glycated haemoglobin levels, metformin treatment and melanoma aggressiveness.

CONCLUSIONS

T2DM, rather than glycaemic control and metformin treatment, is associated with increased cutaneous melanoma aggressiveness at diagnosis.

Nuclear receptors: Lipid and hormone sensors with essential roles in the control of cancer development

Nuclear receptors (NRs) are a superfamily of ligand-activated transcription factors that act as biological sensors and use a combination of mechanisms to modulate positively and negatively gene expression in a spatial and temporal manner. The highly orchestrated biological actions of several NRs influence the proliferation, differentiation, and apoptosis of many different cell types. Synthetic ligands for several NRs have been the focus of extensive drug discovery efforts for cancer intervention. This review summarizes the roles in tumour growth and metastasis of several relevant NR family members, namely androgen receptor (AR), estrogen receptor (ER), glucocorticoid receptor (GR), thyroid hormone receptor (TR), retinoic acid receptors (RARs), retinoid X receptors (RXRs), peroxisome proliferator-activated receptors (PPARs), and liver X receptors (LXRs). These studies are key to develop improved therapeutic agents based on novel modes of action with reduced side effects and overcoming resistance.