Proliferative and signaling activities of insulin analogues in endometrial cancer cells

Risk of Endometrial Cancer in Women with Diabetes: A Population-Based Retrospective Cohort Study

The aim of this study was to examine the association between type 2 diabetes (T2DM), use of glucose-lowering medications and endometrial cancer (EC) risk.

METHODS

The risk of EC incidence among women with T2DM in Lithuania was assessed using a retrospective cohort study design. Female patients who were registered with T2DM between 1 January 2000 and 31 December 2012 were identified in the National Health Insurance Fund database. EC cases (ICD-10 code C54) were identified from the Lithuanian Cancer Registry. Standardized incidence ratios (SIRs) were calculated by dividing the observed numbers of EC among patients with T2DM by the expected number of EC, calculated using national rates.

RESULTS

A total of 77,708 diabetic women were included in the analysis, and 995 cases of EC were identified. A significantly increased EC risk in diabetic women was found as compared to the general population (SIR = 1.69, 95% CI 1.59-1.80). The greatest EC risk was found among younger patients at T2DM diagnosis, and the risk declined gradually with increasing age but persisted in being significantly increased among all age groups. The risk for EC increased with increasing duration of diabetes, and the highest EC risk was observed more than 10 years after T2DM diagnosis. A significantly higher EC risk than expected from the general population was found in all patient groups by glucose-lowering medication combinations. The lowest EC risk was observed in diabetic women who were users of "oral only" (without metformin) (SIR = 1.42, 95% CI 1.10-1.83) and "metformin only" (SIR = 1.69, 95% CI 1.49-1.92) medications. A two times greater EC risk was observed among the remaining glucose-lowering medication categories. In contrast, use of insulin only was not related to a higher EC incidence risk (SIR = 0.45, 95% CI 0.23-0.86); however, the risk estimation was based on nine cases.

CONCLUSIONS

Our study shows a significantly increased EC risk in diabetic women as compared to the general population. In this study, a significantly higher EC risk was found in all patient groups by glucose-lowering medication combinations, except for insulin only users.

Dexmedetomidine alleviates insulin resistance in hepatocytes by reducing endoplasmic reticulum stress

PURPOSE

Dexmedetomidine (DEX) stabilizes intraoperative blood glucose levels and reduces insulin resistance (IR), a common perioperative complication. However, the molecular mechanisms underlying these effects remain unclear. Since endoplasmic reticulum stress (ERS) is a mechanism of IR, this study sought to examine whether DEX can effectively alleviate IR by reducing ERS.

METHODS

HepG2 and LO2 cells were treated with different concentrations of insulin. The glucose content assay and Cell Counting Kit-8 (CCK-8) were then employed to determine the optimal insulin concentration capable of inducing IR without affecting cell viability. Insulin-resistant hepatocytes were cultured with different concentrations of DEX for 24 h, and the glucose concentration in the supernatant was measured. ERS was assessed by qPCR and western blotting. The latter was also used to quantify the expression of phosphorylated protein kinase B (p-AKT), phosphoenolpyruvate carboxykinase (PEPCK), and glucose 6 phosphatase (G6Pase), which are key proteins involved in the action of insulin.

RESULTS

After 48-h of culturing with 10 μg/mL insulin, glucose consumption in hepatocytes was found to be reduced. IR hepatocytes cultured with 10, 100, or 1000 ng/ml DEX for 24 h showed a concentration-dependent increase in glucose consumption. Elevated mRNA and protein levels of ERS markers binding immunoglobulin protein (BIP) and ER protein 29 (ERp29), were reversed by DEX treatment. Moreover, reduced p-AKT and increased PEPCK and G6Pase protein levels in IR hepatocytes were also restored following DEX treatment.

CONCLUSION

DEX may alleviate IR in hepatocytes by reducing ERS serving to restore insulin action via the IRS-1/PI3K/AKT pathway.

Patient-derived organoids from endometrial disease capture clinical heterogeneity and are amenable to drug screening

Endometrial disorders represent a major gynaecological burden. Current research models fail to recapitulate the nature and heterogeneity of these diseases, thereby hampering scientific and clinical progress. Here we developed long-term expandable organoids from a broad spectrum of endometrial pathologies. Organoids from endometriosis show disease-associated traits and cancer-linked mutations. Endometrial cancer-derived organoids accurately capture cancer subtypes, replicate the mutational landscape of the tumours and display patient-specific drug responses. Organoids were also established from precancerous pathologies encompassing endometrial hyperplasia and Lynch syndrome, and inherited gene mutations were maintained. Endometrial disease organoids reproduced the original lesion when transplanted in vivo. In summary, we developed multiple organoid models that capture endometrial disease diversity and will provide powerful research models and drug screening and discovery tools.

Clinical value screening, prognostic significance and key pathway identification of miR-204-5p in endometrial carcinoma: A study based on the Cancer Genome Atlas (TCGA), and bioinformatics analysis

BACKGROUND

Endometrial carcinoma is one of the common carcinomas in the female reproductive system. It is reported that miR-204-5p is down-regulated in endometrial carcinoma. However, the mechanism and key pathways of miR-204-5p in endometrial carcinoma have not been clarified.

MATERIAL/METHODS

We evaluated the expression profiles and prognostic value of miR-204-5p expression in endometrial carcinoma by using bioinformatics analysis of a public dataset from TCGA. Drug of endometrial carcinoma from DrugBank, GO analysis, KEGG analysis, PPI network, mutation, as well as assessment of the prognostic significance were performed to the overlapping target genes of miR-204-5p in endometrial carcinoma. The relative expression levels of miR-204-5p target genes in endometrial carcinoma, including SF3B1, FBXW7, SPOP, and BRD4, were assessed by real-time quantitative polymerase chain reaction (RT-qPCR).

RESULTS

First, through DrugBank website, we obtained target drugs for endometrial carcinoma. MiR-204-5p expression was found to be lower in the endometrial carcinoma tissues than in adjacent normal tissues from TCGA. Next, we identified 143 genes as potential targets of miR-204-5p. Then, through GO enrichment analysis, KEGG signaling pathway and PPI analysis, we revealed the key networks in endometrial carcinoma. Next, mutation and assessment of the prognostic significance of endometrial carcinoma were obtained. At last, in endometrial carcinoma, the relative expression of SF3B1 and BRD4 increased, and the relative expression of FBXW7 decreased.

CONCLUSIONS

MiR-204-5p is down-regulated in endometrial carcinoma and affects the prognostic significance of endometrial carcinoma, which might play an important role in the tumorigenesis of endometrial carcinoma.

Effect of insulin on thyroid cell proliferation, tumor cell migration, and potentially related mechanisms

BACKGROUND

Diabetes has recently been identified as a risk factor for a variety of cancers, possibly due to hyperinsulinemia or exogenous insulin use. Thyroid cancer is the most common endocrine malignancy, and its incidence has been exponentially increasing worldwide at an alarming rate. The aim of this study was to establish whether insulin use affects thyroid cancer development and progression, specifically cell proliferation and migration in vitro.

METHODS

In this study, we investigated the effects of the insulin agents most commonly used in the clinic, regular human insulin (HI) and insulin glargine (IG), on the proliferation and migration of thyroid cells.

RESULTS

Both HI and IG affected the thyroid cells in a dose-dependent manner and at high concentrations significantly promoted thyroid cell proliferation and tumor cell migration. The promoting effect might be elicited by activation of the insulin receptor and insulin-like growth factor-1 receptor and through the downstream Akt-signaling pathway, which inhibits the activity of the tumor-suppressor FoxO3a. In particular, MAPK-signaling cascades were activated in papillary thyroid carcinoma cell-1 cells but not in follicular rat thyroid-5 cells.

CONCLUSION

The in vitro evidence demonstrated that HI and IG can promote thyroid cell proliferation and tumor cell migration at supraphysiological concentrations, but the effect was not significant at low concentrations. Whether high-dose insulins could affect diabetic patients with thyroid cancer or undetected (pre)cancerous lesions needs further in vivo study.

ABBREVIATIONS

HI: human regular insulin; IG: insulin glargine; IR: insulin receptor; IGF-1R: insulin-like growth factor-1 receptor; Akt: protein kinase B (PKB); MAPK: mitogen-activated protein kinase; FoxO3a: the forkhead box-containing protein: class O 3a.

Characterisation of insulin analogues therapeutically available to patients

The structure and function of clinical dosage insulin and its analogues were assessed. This included ‘native insulins’ (human recombinant, bovine, porcine), ‘fast-acting analogues’ (aspart, glulisine, lispro) and ‘slow-acting analogues’ (glargine, detemir, degludec). Analytical ultracentrifugation, both sedimentation velocity and equilibrium experiments, were employed to yield distributions of both molar mass and sedimentation coefficient of all nine insulins. Size exclusion chromatography, coupled to multi-angle light scattering, was also used to explore the function of these analogues. On ultracentrifugation analysis, the insulins under investigation were found to be in numerous conformational states, however the majority of insulins were present in a primarily hexameric conformation. This was true for all native insulins and two fast-acting analogues. However, glargine was present as a dimer, detemir was a multi-hexameric system, degludec was a dodecamer (di-hexamer) and glulisine was present as a dimer-hexamer-dihexamer system. However, size-exclusion chromatography showed that the two hexameric fast-acting analogues (aspart and lispro) dissociated into monomers and dimers due to the lack of zinc in the mobile phase. This comprehensive study is the first time all nine insulins have been characterised in this way, the first time that insulin detemir have been studied using analytical ultracentrifugation and the first time that insulins aspart and glulisine have been studied using sedimentation equilibrium. The structure and function of these clinically administered insulins is of critical importance and this research adds novel data to an otherwise complex functional physiological protein.

Linking type 2 diabetes and gynecological cancer: an introductory overview

Type 2 diabetes (T2D) is a chronic disease with a growing prevalence and a leading cause of death in many countries. Several epidemiological studies observed an association between T2D and increased risk of many types of cancer, such as gynecologic neoplasms (endometrial, cervical, ovarian and vulvar cancer). Insulin resistance, chronic inflammation and high free ovarian steroid hormones are considered the possible mechanisms behind this complex relationship. A higher risk of endometrial cancer was observed in T2D, even though this association largely attenuated after adjusting for obesity. A clear relationship between the incidence of cervical cancer (CC) and T2D has still not be determined; however T2D might have an impact on prognosis in patients with CC. To date, studies on the association between T2D and ovarian cancer (OC) are limited. The effect of pre-existing diabetes on cancer-specific mortality has been evaluated in several studies, with less clear results. Other epidemiological and experimental studies focused on the potential role of diabetes medications, mainly metformin, in cancer development in women. The correct understanding of the link between T2D and gynecologic cancer risk and mortality is currently imperative to possibly modify screening and diagnostic-therapeutic protocols in the future.

Genome-Wide Analyses Identify Filamin-A As a Novel Downstream Target for Insulin and IGF1 Action

Insulin analogs were developed to improve diabetes therapy. However, certain modifications introduced into the insulin molecule were shown to enhance their affinity to the insulin-like growth factor-1 receptor (IGF1R). Most tumors, including endometrial cancers, express high levels of IGF1R. The present study was aimed at identifying the entire set of genes that are differentially activated by insulin glargine or detemir, in comparison to insulin and IGF1, in Type 1 and Type 2 endometrial cancer cell lines (ECC-1 and USPC-1, respectively). Global gene expression analyses demonstrated a ligand-dependent upregulated expression of filamin-A (FLNA), a gene that encodes an actin filament cross-linking protein, in both endometrial cancer cell types. Silencing experiments linked to migration assays confirmed the role of FLNA in cell growth and motility. Our data suggest that the activation of distinct sets of genes by glargine may lead to stimulation of specific pathways or, alternatively, may provide additive effects, different from those classically induced by insulin. Given that metastases are probably the main factor contributing to tumor invasiveness, the identification of FLNA as a downstream target for insulin-like hormones may be of translational relevance in oncology. Clinical studies in endometrial cancer may add further relevant information regarding the possible differential actions of insulin analogs with respect to native insulin.

Glargine and degludec: Solution behaviour of higher dose synthetic insulins

Single, double and triple doses of the synthetic insulins glargine and degludec currently used in patient therapy are characterised using macromolecular hydrodynamic techniques (dynamic light scattering and analytical ultracentrifugation) in an attempt to provide the basis for improved personalised insulin profiling in patients with diabetes. Using dynamic light scattering and sedimentation velocity in the analytical ultracentrifuge glargine was shown to be primarily dimeric under solvent conditions used in current formulations whereas degludec behaved as a dihexamer with evidence of further association of the hexamers ("multi-hexamerisation"). Further analysis by sedimentation equilibrium showed that degludec exhibited reversible interaction between mono- and-di-hexamer forms. Unlike glargine, degludec showed strong thermodynamic non-ideality, but this was suppressed by the addition of salt. With such large injectable doses of synthetic insulins remaining in the physiological system for extended periods of time, in some case 24-40 hours, double and triple dose insulins may impact adversely on personalised insulin profiling in patients with diabetes.

Expression of CD133 in endometrial cancer cells and its implications

Cancer stem cells are an attractive therapeutic target for cancer. The present study examined stem cell characteristics of CD133+ cells isolated from endometrial cancer. Phenotypic characteristics, proliferation, migration, anchorage-independent growth, chemoresistance, gene expression profile and tumorigenicity of CD133+ tumor cells were assessed. Primary tumor exhibited immunoreactivity for CD133. Endometrial CD133+ tumor cells enhanced proliferation rate, colony formation, chemotaxis migration ability, and chemoresistance to cisplatin, paclitaxel, and doxorubicin than CD133- cells. CD133+ cells expressed more cancer stem cells markers such as EpCAM, aldehyde dehydrogenase 1 and insulin-like growth factor-1 receptor than CD133- cells. Moreover, CD133+ cells also increased expression of embryonic stem cell markers including oct4, nanog, sox2, and cmyc than CD133- cells. Finally, CD133+ tumor cells could generate xenograft but not CD133- tumor cells. CD133 and Ki67 were extensively expressed in the xenograft. In conclusion, endometrial CD133+ tumor cells displayed cancer stem cell characteristics and might represent a valuable tool for identifying endometrial cancer stem cells and hence a potential therapeutic target.