The Role of Insulin and Insulin-like Growth Factors in the Increased Risk of Cancer in Diabetes

Cancer risk following onset of type 2 diabetes in New Zealanders with impaired glucose tolerance over 25 years: a matched prospective cohort study

BACKGROUND

In people with prediabetes, the link between developing type 2 diabetes (T2D) and cancer risk among those with impaired glucose tolerance (IGT) remains uncertain. We examined this association in IGT individuals from primary care in South and West Auckland, New Zealand, spanning 1994-2019, assessing 5- and 10-year cancer risks.

METHODS

Study cohorts were extracted from the Diabetes Care Support Service in Auckland, New Zealand, linking it with national registries for death, cancer, hospital admissions, pharmaceutical claims, and socioeconomic status. We compared cancer risks in individuals with IGT newly diagnosed with or without T2D within a 1-5-year exposure window. Employing tapered matching and landmark analysis to address potential confounding effects, we formed comparative IGT cohorts. Weighted Cox regression models were then employed to assess the association between T2D onset and 5- and 10-year cancer risks.

RESULTS

The study included 26,794 patients with IGT, with 629 newly diagnosed with T2D within 5 years and 13,007 without such a diagnosis. Those progressing to T2D had similar 5-year cancer risk but significantly higher 10-year risk (HR 1.35; 95% CI 1.09-1.68). This association was stronger in older individuals, the socioeconomically deprived, current smokers, those with worse metabolic measures, and lower renal function. Patients with IGT of NZ European ethnicity had lower 10-year cancer risk.

CONCLUSIONS

T2D diagnosis influences cancer risk in individuals with IGT. Developing risk scores for high-risk IGT individuals and implementing cancer screening and structured diabetes prevention, especially in deprived or minority ethnic populations, is essential.

A Perspective Review on Diet Quality, Excess Adiposity, and Chronic Psychosocial Stress and Implications for Early-Onset Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer worldwide. Although the overall incidence of CRC has been decreasing over the past 40 y, early-onset colorectal cancer (EOCRC), which is defined as a CRC diagnosis in patients aged >50 y has increased. In this Perspective, we highlight and summarize the association between diet quality and excess adiposity, and EOCRC. We also explore chronic psychosocial stress (CPS), a less investigated modifiable risk factor, and EOCRC. We were able to show that a poor-quality diet, characterized by a high intake of sugary beverages and a Western diet pattern (high intake of red and processed meats, refined grains, and foods with added sugars) can promote risk factors associated with EOCRC development, such as an imbalance in the composition and function of the gut microbiome, presence of chronic inflammation, and insulin resistance. Excess adiposity, particularly obesity onset in early adulthood, is a likely contributor of EOCRC. Although the research is sparse examining CPS and CRC/EOCRC, we describe likely pathways linking CPS to tumorigenesis. Although additional research is needed to understand what factors are driving the uptick in EOCRC, managing body weight, improving diet quality, and mitigating psychosocial stress, may play an important role in reducing an individual's risk of EOCRC.

Incidence and risk factors of prostate cancer among the Northern and Eastern parts of the United Arab Emirates population

BACKGROUND

Prostate cancer (PCa) is a prevalent disease worldwide. However, the incidence and patient-specific risk factors of PCa in the Middle East, specifically in the United Arab Emirates, have not been previously reported.

METHODS

We conducted a retrospective cohort study on 2377 men diagnosed with either benign prostatic hyperplasia (BPH) or PCa in the Northern and Eastern regions of the United Arab Emirates, excluding the Western part, which includes Abu Dhabi. The study spanned from January 2012 and December 2021. To calculate the PCa incidence rate, we utilized the world age-standardized incidence rates (W-ASIR) categorized by age groups. Patient-specific risk factors of PCa were identified through a multivariate logistic regression analysis of clinical data.

RESULTS

A total of 247 cases of PCa and 2130 cases of BPH were included in the study. In our cohort, the W-ASIR for PCa was 21.3 per 100,000 men. The incidence of PCa showed an increasing trend with age, with the highest incidence observed among men aged 70 years and older. Accordingly, multivariate analysis revealed that age over 70 was associated with an increased risk of PCa (OR: 2.546, 95% confidence interval [CI]: 1.892-3.425, p < 0.01). On the other hand, preexisting conditions such as hypertension and diabetes mellitus were found to lower the risk of PCa (OR: 0.222, 95% CI: 0.163-0.302, p < 0.001) and (OR: 0.364, 95% CI: 0.205-0.648, p < 0.001), respectively. Additionally, metformin intake was associated with a reduced risk of PCa (OR: 0.385, 95% CI: 0.190-0.782, p = 0.008); while insulin usage increased the risk of PCa (OR: 2.586, 95% CI: 1.539-4.344, p < 0.001). Anti-BPH medications such as phosphodiesterase inhibitors (OR: 0.223, 95% CI: 0.069-0.723, p = 0.012) or 5-α reductase (OR: 0.206, 95% CI: 0.110-0.389, p < 0.000), were found to lower the risk of PCa.

CONCLUSION

The findings underscore the high incidence of PCa in the United Arab Emirates, with age being a significant factor. Furthermore, the study highlights the influence of certain comorbidities and medications on the risk of developing PCa within the United Arab Emirates population.

Brain insulin signaling as a potential mediator of early life adversity effects on physical and mental health

In numerous brain structures, insulin signaling modulates the homeostatic processes, sensitivity to reward pathways, executive function, memory, and cognition. Through human studies and animal models, mounting evidence implicates central insulin signaling in the metabolic, physiological, and psychological consequences of early life adversity. In this review, we describe the consequences of early life adversity in the brain where insulin signaling is a key factor and how insulin may moderate the effects of adversity on psychiatric and cardio-metabolic health outcomes. Further understanding of how early life adversity and insulin signaling impact specific brain regions and mental and physical health outcomes will assist in prevention, diagnosis, and potential intervention following early life adversity.

Transcriptional Profiling of Insulin-like Growth Factor Signaling Components in Embryonic Lung Development and Idiopathic Pulmonary Fibrosis

Insulin-like growth factor (IGF) signaling controls the development and growth of many organs, including the lung. Loss of function of Igf1 or its receptor Igf1r impairs lung development and leads to neonatal respiratory distress in mice. Although many components of the IGF signaling pathway have shown to be dysregulated in idiopathic pulmonary fibrosis (IPF), the expression pattern of such components in different cellular compartments of the developing and/or fibrotic lung has been elusive. In this study, we provide a comprehensive transcriptional profile for such signaling components during embryonic lung development in mice, bleomycin-induced pulmonary fibrosis in mice and in human IPF lung explants. During late gestation, we found that Igf1 is upregulated in parallel to Igf1r downregulation in the lung mesenchyme. Lung tissues derived from bleomycin-treated mice and explanted IPF lungs revealed upregulation of IGF1 in parallel to downregulation of IGF1R, in addition to upregulation of several IGF binding proteins (IGFBPs) in lung fibrosis. Finally, treatment of IPF lung fibroblasts with recombinant IGF1 led to myogenic differentiation. Our data serve as a resource for the transcriptional profile of IGF signaling components and warrant further research on the involvement of this pathway in both lung development and pulmonary disease.

Sodium-Glucose Co-Transporter 2 Inhibitors May Change the Development of Urinary Tract and Hematological Malignancies as Compared With Dipeptidyl Peptidase-4 Inhibitors: Data of the Post-Hoc Analysis of a Nationwide Study

Background

In diabetes mellitus, during the last years, cancer became of equivalent importance as a cardiovascular disease in terms of mortality. In an earlier study, we have analyzed data of the National Health Insurance Fund (NHIF) of Hungary with regards all patients treated with sodium-glucose co-transporter 2 (SGLT2) inhibitors (SGLT2is) vs. those treated with dipeptidyl peptidase-4 (DPP-4) inhibitors (DPP-4is) in a given timeframe. In propensity score-matched groups of SGLT2i- vs. DPP-4i-treated patients, we found a lower incidence of cancer in general. In this post-hoc analysis, we aimed to obtain data on the incidence of site-specific cancer.

Patients and Methods

All patients starting an SGLT2i or a DPP-4i between 2014 and 2017 in Hungary were included; the two groups (SGLT2i vs. DPP-4i) were matched for 54 clinical and demographical parameters. The follow-up period was 639 vs. 696 days, respectively. Patients with a letter “C” International Classification of Diseases, 10th Revision (ICD-10) code have been chosen, and those with a known malignancy within a year before the onset of the study have been excluded from the analysis.

Results

We found a lower risk of urinary tract [HR 0.50 (95% CI: 0.32–0.79) p = 0.0027] and hematological malignancies [HR 0.50 (95% CI: 0.28–0.88) p = 0.0174] in patients treated with SGLT2i vs. those on DPP-4i. Risk of other types of cancer (including lung and larynx, lower gastrointestinal (GI) tract, rectum, pancreas, non-melanoma skin cancers, breast, or prostate) did not differ significantly between the two groups. When plotting absolute risk difference against follow-up time, an early divergence of curves was found in case of prostate, urinary tract, and hematological malignancies, whereas late divergence can be seen in case of cancers of the lung and larynx, the lower GI tract, and the breast.

Conclusions

Urinary tract and hematological malignancies were less frequent in patients treated with SGLT2i vs. DPP-4i. An early vs. late divergence could be observed for different cancer types, which deserves further studies.

Relation between Baseline Coronary Atherosclerotic Status, Cardiovascular Events, and Malignancies in Type 2 Diabetics: A Long-Term Prospective Cohort Study

INTRODUCTION

Coronary artery disease and malignancy occur more frequently in patients with type 2 diabetes. They may share inflammation as a possible common pathogenetic mechanism, but it is unclear whether a clinical correlation exists between them.

METHODS

This prospective cohort study followed 735 asymptomatic diabetics, aged 63.4 ± 5.3 years (mean ± standard deviation) for 12.2 ± 0.6 years after baseline coronary artery calcium scoring and cardiac computed tomography angiography. We examined extent and nature of coronary atherosclerosis and incidence of clinical cardiovascular (CV) events (death or myocardial infarction) and sought a relation to incidence of malignancy and malignancy mortality.

RESULTS

Total mortality was 16.5% (121/735 patients): malignancy was cause of death in 48/121 (39.7%) of these and CV events in 44/121 (36.3%). There was no relation between extent of coronary atherosclerosis and incident malignancy (plaque volume 127 [21, 427] mm3 (median [interquartile range]) for incident malignancy versus 153 [24, 427] mm3 no malignancy, p = 0.71) or death from malignancy (plaque volume 176 [26, 646] versus 144 [22, 411] mm3, p = 0.32). There was also no relation between presence of high-risk plaque and incident malignancy (high-risk plaque in 27.1% with malignancy vs. 21.6% without, p = 0.18) or fatal malignancy (p = 0.16). Incident and fatal malignancy were not related to clinical CV events. Independent predictors of incident and fatal malignancy were age, smoking at baseline, and elevated C-reactive protein.

CONCLUSION

This study found no relation between extent of coronary atherosclerosis or incidence of CV events and malignancy. Malignancy surpassed CV disease as the commonest long-term cause of mortality in middle-aged and older diabetics.

Different response of embryos originating from control and obese mice to insulin in vitro

The aim of the present work was to investigate the impact of maternal obesity on DNA methylation in ovulated oocytes, and to compare the response of in vitro-developing preimplantation embryos originating from control and obese mice to insulin. An intergenerational, diet-induced obesity model was used to produce outbred mice with an increased body weight and body fat. Two-cell and eight-cell embryos recovered from obese and control mice were cultured in a medium supplemented with 1 or 10 ng/ml insulin until blastocyst formation. In the derived blastocysts, cell proliferation, differentiation, and death rates were determined. The results of immunochemical visualization of 5-methylcytosine indicated a slightly higher DNA methylation in ovulated metaphase II oocytes recovered from obese females; however, the difference between groups did not reach statistical significance. Expanded blastocysts developed from embryos provided by control dams showed increased mean cell numbers (two and eight-cell embryos exposed to 10 ng/ml), an increased inner-cell-mass/trophectoderm ratio (two-cell embryos exposed to 1 ng/ml and eight-cell embryos exposed to 10 ng/ml), and a reduced level of apoptosis (two and eight-cell embryos exposed to 10 ng/ml). In contrast, embryos originating from obese mice were significantly less sensitive to insulin; indeed, no difference was recorded in any tested variable between the embryos exposed to insulin and those cultured in insulin-free medium. Real-time RT-PCR analysis showed a significant increase in the amount of insulin receptor transcripts in blastocysts recovered from obese dams. These results suggest that maternal obesity might modulate the mitogenic and antiapoptotic responses of preimplantation embryos to insulin.

NLRP3 as Putative Marker of Ipilimumab-Induced Cardiotoxicity in the Presence of Hyperglycemia in Estrogen-Responsive and Triple-Negative Breast Cancer Cells

Hyperglycemia, obesity and metabolic syndrome are negative prognostic factors in breast cancer patients. Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment, achieving unprecedented efficacy in multiple malignancies. However, ICIs are associated with immune-related adverse events involving cardiotoxicity. We aimed to study if hyperglycemia could affect ipilimumab-induced anticancer efficacy and enhance its cardiotoxicity. Human cardiomyocytes and estrogen-responsive and triple-negative breast cancer cells (MCF-7 and MDA-MB-231 cell lines) were exposed to ipilimumab under high glucose (25 mM); low glucose (5.5 mM); high glucose and co-administration of SGLT-2 inhibitor (empagliflozin); shifting from high glucose to low glucose. Study of cell viability and the expression of new putative biomarkers of cardiotoxicity and resistance to ICIs (NLRP3, MyD88, cytokines) were quantified through ELISA (Cayman Chemical) methods. Hyperglycemia during treatment with ipilimumab increased cardiotoxicity and reduced mortality of breast cancer cells in a manner that is sensitive to NLRP3. Notably, treatment with ipilimumab and empagliflozin under high glucose or shifting from high glucose to low glucose reduced significantly the magnitude of the effects, increasing responsiveness to ipilimumab and reducing cardiotoxicity. To our knowledge, this is the first evidence that hyperglycemia exacerbates ipilimumab-induced cardiotoxicity and decreases its anticancer efficacy in MCF-7 and MDA-MB-231 cells. This study sets the stage for further tests on other breast cancer cell lines and primary cardiomyocytes and for preclinical trials in mice aimed to decrease glucose through nutritional interventions or administration of gliflozines during treatment with ipilimumab.

Maternal undernutrition during pregnancy and lactation affects testicular morphology, the stages of spermatogenic cycle, and the testicular IGF-I system in adult offspring

Maternal undernutrition decreases sperm production in male offspring, possibly through insulin-like growth factor (IGF-I). To test this hypothesis, we fed pregnant Wistar rats ad libitum with a standard diet (CONTROL) or fed 50% of CONTROL intake, either throughout pregnancy (UNP), lactation (UNL, or both (UNPL). After weaning, male offspring (n = 10 per treatment) were fed a standard diet until postnatal day 160, when testes process for histological and molecular analyses. IGF-I immunostaining area and intensity in the testis were greater (P = 0.003) in the UNPL group compared to CONTROL, but lower in the UNP group (P < 0.0001). Levels of IGF-I receptor transcript were lower in the UNPL and UNL groups, compared to CONTROL. There were more Ki-67-positive germ and Sertoli cells, in all underfed groups than in CONTROL. Compared to CONTROL, frequency of spermatogenic cycle stage VII was lower in all underfed groups, and seminiferous tubule diameter was smaller in UNP and UNPL. Plasma FSH concentrations were greater in UNP male offspring compared to all groups (P = 0.05), whereas inhibin B concentrations were greater in UNP (P = 0.01) and UNL (P = 0.003) than in CONTROL or UNPL. Thus, prenatal undernutrition leads to a decrease in testicular IGF-I levels, whereas of pre- and postnatal undernutrition increased testicular IGF-I levels and decreased amounts of IGF-I receptor mRNA in adult offspring. We conclude that maternal undernutrition during pregnancy and lactation leads to long-lasting effects on adult male offspring testicular morphology, spermatogenesis, and IGF-I testicular system.

Alpha-Glucosidase Inhibitor Voglibose Suppresses Azoxymethane-Induced Colonic Preneoplastic Lesions in Diabetic and Obese Mice

Type 2 diabetes mellitus and its related insulin resistance are known to increase the risk of cancer. Anti-diabetic agents can improve insulin resistance and may lead to the suppression of carcinogenesis. This study aimed to investigate the preventive effects of the alpha-glucosidase inhibitor voglibose on the development of azoxymethane-induced colorectal pre-neoplastic lesions in obese and diabetic C57BL/KsJ-db/db mice. The direct effects of voglibose on the proliferation of colorectal cancer cells were also evaluated. Mice were injected with azoxymethane to induce colorectal pre-malignancy and were then administered drinking water with or without voglibose. At the end of the study, the administration of voglibose significantly suppressed the development of colorectal neoplastic lesions. In voglibose-treated mice, serum glucose levels, oxidative stress, as well as mRNA expression of the insulin-like growth factor-1 in the colon mucosa, were reduced. The proliferation of human colorectal cancer cells was not altered by voglibose. These results suggested that voglibose suppressed colorectal carcinogenesis in a diabetes- and obesity-related colorectal cancer model, presumably by improving inflammation via the reduction of oxidative stress and suppressing of the insulin-like growth factor/insulin-like growth factor-1 receptor axis in the colonic mucosa.

Fasting Insulin and Risk of Cancer Related Mortality in Non-diabetic Adults: A Dose-response Meta-analysis of Cohort Studies

BACKGROUND

Insulin is known to have direct and indirect effects on cell cycle progression, proliferation and metastatic activities. We performed a dose-response meta-analysis to investigate the association between hyperinsulinemia and all-cause cancer related mortality.

METHODS

A systematic literature search was conducted on MEDLINE and SCOPUS databases to include all published articles up to January 2019. Combined hazard ratios (HRs) with 95% Confidence Intervals (CIs) were estimated using DerSimonian and Laird random-effects models. A dose-response analysis was also conducted to further explore insulin's relationship with cancer-related mortality.

RESULTS

We identified seven studies, with a total of 23,990 participants, who reported the association between hyperinsulinemia and cancer-related mortality. Results from the eligible studies indicated that higher fasting insulin levels were not associated with an increased risk of cancer mortality (pooled HR: 1.14, 95% CI: 0.99-1.32), however, significant heterogeneity was present (I2 = 60.3%, P heterogeneity = 0.001). A subgroup analysis based on gender demonstrated a significant association between fasting insulin level and cancer mortality in men (pooled HR: 1.92, 95% CI: 1.23-3.01, P heterogeneity = 0.281).

CONCLUSION

This dose-response meta-analysis showed a direct significant association between fasting insulin level and cancer mortality in men.

Dual-targeting nanotherapeutics antagonize hyperinsulinemia-promoted tumor growth via activating cell autophagy

Hyperinsulinemia, a concomitant symptom in type 2 diabetes mellitus (T2DM) promotes the migration, invasion and proliferation of tumors by inhibiting autophagy. Therefore, it is necessary to search for antitumor drugs that can effectively antagonize hyperinsulinemia by promoting autophagy. In this study, dual-targeting modified selenium nanoparticles (u/A-SeNPs) were proposed as a biocompatible tumor chemotherapeutic drug to antagonize high insulin. The modification of chitosan (CS) and grafting targeted peptides (uPA/ACPP) allowed SeNPs to exert better selectivity and higher antitumor activity. The nanotherapeutics entered tumor cells through receptor-mediated endocytosis and produced excessive ROS. Meanwhile, u/A-SeNPs significantly increased the level of autophagy in tumor cells, as detected by monodansylcadaverine (MDC) and mRFP-GFP-LC3. U/A-SeNPs cause mitochondrial fragmentation to induce the cell apoptosis via the synergistic action of overproduced ROS and activated autophagy. In conclusion, this study proposes a feasible method for the synthesis of dual-targeting nanomedicines, and it also provides a new strategy for the application of Se-based nanotherapeutics in tumor therapy under hyperinsulinemia conditions.

The link between the metabolic syndrome and cancer

Since the incidence of the metabolic syndrome is on the rise in the western world, its coherence to cancer is becoming more apparent. In this review we discuss the different potential factors involved in the increase of cancer in the metabolic syndrome including obesity, dyslipidemia and Type 2 Diabetes Mellitus (T2DM) as well as inflammation and hypoxia. We especially focus on the insulin and IGF systems with their intracellular signaling cascades mediated by different receptor subtypes, and suggest that they may play major roles in this process. Understanding the mechanisms involved will be helpful in developing potential therapeutics.