Effect of diabetes mellitus on levels of insulin-like growth factors and their carrier proteins in Guerin’s carcinoma and it’s perifocal tissue in rats

Purpose of the study. Diabetes mellitus (DM) is considered an independent risk factor for higher cancer incidence and death rates. The system of insulin-like growth factors and their carrier proteins (IGF and IGFBP) and hyperglycemia create favorable conditions for the proliferation and metastasis of cancer cells.Materials and methods. Outbred male and female rats were divided into groups (n = 8 each): controls - with Guerin's carcinoma; main group - Guerin's carcinoma growing in presence of DM. Experimental DM was reproduces in animals by the single intraperitoneal alloxan injection (150 mg/kg body weight). After 10 days of the carcinoma growth, levels of IGF and IGFBP in the tumor and in it's perifocal area were measured using ELISA.Results. DM in females upregulated levels of glucose both in the tumor and in perifocal tissues by 1.8 (p < 0.05) and 8.1 times, respectively, but caused opposite changes in IGF-I - it's increase by 6.3 times in the tumor and decrease by 3.2 times in the perifocal area; as a result, such tumors with small primary nodes were more "aggressive" and actively metastasized. In males, induced DM downregulated levels of glucose, IGF-II and IGFBP2 in the carcinoma by 8.4, 3.1 and 1.7 (p < 0.05) times, respectively, and increased levels of IGF-I and IGFBP2 by 1.4 and 1.3 times (p < 0.05) in the perifocal area without changing glucose levels; as a result, tumor volumes exceeded the values in the standard growth, without metastasizing into visceral organs.Conclusion. We revealed gender differences in changing levels of glucose and IGF both in the tumor and in it's perifocal tissue in rats with Guerin's carcinoma growing in presence of DM; these differences could determine different tumor growth dynamics in male and female rats.

Concentrations of Insulin-like Growth Factors and Insulin-like Growth Factor-Binding Proteins and Respective Gene Expressions in Children before and after Hematopoietic Stem Cell Transplantation

Insulin-like growth factors (IGF-1 and IGF-2) and insulin-like growth factor-binding proteins (IGFBP-1 to -7) are involved in the regulation of cell proliferation and differentiation and may be associated with various metabolic parameters. The aim of our study was to compare levels of IGFs and IGFBPs and the expressions of their genes in children before and after hematopoietic stem cell transplantation (HSCT) to assess their potential as markers of late metabolic complications of HSCT. We also conducted additional comparisons with healthy controls and of correlations of IGF and IGFBP levels with anthropometric and biochemical parameters. We analyzed 19 children treated with HSCT and 21 healthy controls. We found no significant differences in the levels of IGFs and IGFBPs and expressions of their genes before and after HSCT, while IGF and IGFBP levels were significantly lower in children treated with HSCT compared with controls. We conclude that our results did not reveal significant differences between the levels of IGFs and IGFBPs before and after HSCT, which would make them obvious candidates for markers of late complications of the procedure in children. However, due to the very low number of patients this conclusion must be taken with caution and may be altered by further research.

Diabetes mellitus and cancer: a system of insulin-like growth factors

Diabetes mellitus and malignant tumors are among the most common and complex diseases. Epidemiological studies have shown a strong relationship between these pathologies. The causality of this relationship has not yet been unambiguously established, but a number of probable biological mechanisms have been proposed to explain it through the effects of hyperglycemia, hyperinsulinemia on the process of oncogenesis. An important role in this is played by the axis of insulin-like growth factors, their receptors and binding proteins (IGF / IGFR / IGFBP). The review provides data on the structural elements of the insulin / IGF / IGFR / IGFBP signaling axis and their internal relationships in diabetes mellitus and in the development of malignant tumors. Significant changes in the axis that occur during the formation of the diabetic environment prepare the background, which, under certain conditions, can lead to the stimulation or inhibition of tumor development. The considered signaling system, playing a significant role in the physiology of normal cells, often functions as a decisive factor in the survival of tumor cells, providing fine context-dependent regulation of many cellular processes associated with oncogenesis. However, despite many years of in-depth studies of the pathogenesis of diabetes mellitus and malignant tumors, the molecular mechanisms of the relationship between these pathologies are still largely unclear, and the internal heterogeneity of pathologies complicates research and interpretation of the results, leaving many questions.

Effects of COVID-19, diabetes mellitus, and cardiovascular diseases on insulin receptor substrate-1 amount in the blood plasma of patients

Insulin receptor substrate (IRS) is a key adapter protein mediating effects of insulin and insulin-like growth factors (IGF) in cells. IRS-1 is a member of the insulin receptor substrate family, which is associated with tumor initiation and progression. The aim of the study is to determine the level of IRS-1 in the blood of patients (n = 81) with diabetes mellitus and COVID-19. IRS-1 was determined with enzyme-linked immunosorbent assay (ELISA) (Elabscience, USA). The measurements were performed at an optical wavelength of 450 nm. The level of IRS-1 in the blood plasma of patients with COVID-19 was much (from 3.5 to more than 6 times) higher than that in the blood of healthy people. The IRS-1 amounts in COVID-19 patients with diabetes and diabetes + CVD were significantly higher than in patients with COVID-19 without concomitant diseases. The level of IRS-1 in blood plasma may be one of the promising markers of COVID-19.

Role of insulin and insulin-like growth factor I receptor expression in the pathogenesis of genital endometriosis

BACKGROUND: Growth factors play an important role in the pathogenesis of genital endometriosis. Insulin and insulin-like growth factors are involved in mitosis and differentiation in the endometrium during the menstrual cycle and early pregnancy, and are likely to indirectly affect the invasion of the endometrium during retrograde menstruation and the development of pain syndrome in endometriosis. However, the available literature data on insulin-like growth factors and insulin in the endometrium and endometrioid heterotopies in patients with genital endometriosis are scarse and contradictory. AIM: The aim of this study was to investigate the expression of insulin receptors and insulin-like growth factor I receptors in the eutopic endometrium and endometrioid heterotopies of patients with genital endometriosis. MATERIALS AND METHODS: This cross-sectional study included immunohistochemical analysis of surgical material obtained from two groups of women in the proliferative phase of the menstrual cycle: patients with endometriosis who received surgical treatment (endometrium and endometrioid heterotopies) and patients without endometriosis who were examined due to infertility (endometrium). The study also included investigation of carbohydrate metabolism (glucose tolerance test) and determination of blood serum insulin-like growth factor I, insulin and sex hormone levels. The material was stained to detect the expression of insulin receptors and insulin-like growth factor I receptors. Then, the relative area and optical density of the receptor expression were determined and the obtained data were analyzed statistically. RESULTS: We analyzed the examination results of 131 women matched in age and weight and height characteristics: 101 patients with genital endometriosis and 30 patients in the control group. Carbohydrate metabolism was characterized by a 2.1-fold increase in glucose-stimulated insulin secretion in patients with genital endometriosis compared with the control subjects. The blood level of insulin-like growth factor I did not differ in the study groups. Statistically significant differences in receptor expression were obtained between the groups. In the endometrium of patients with genital endometriosis, the optical density of insulin receptors was lower (p = 0.007) and the expression of insulin-like growth factor I receptors higher (p = 0.002) compared to the endometrium of the control subjects. The median values of insulin receptor expression in endometrioid heterotopies were decreased compared to the endometrium of the control group (p 0.001). The expression of insulin-like growth factor I receptors in endometrioid heterotopies was reduced compared to the endometrium of the same patients (p 0.001). CONCLUSIONS: The data obtained indicate significant features in the functioning of the insulin / insulin-like growth factor I system in patients with genital endometriosis: glucose-stimulated insulin secretion and relative endometrial insulin resistance due to the decreased expression of insulin receptors and the increased expression of insulin-like growth factor I receptors in the endometrium.

Targeting Adipokines in Obesity-Related Tumors

Obesity, a global epidemic, is an independent risk factor for the occurrence and development of a variety of tumorigenesis, such as breast cancer, pancreatic cancer, ovarian cancer and colorectal cancer. Adipocytes are important endocrine cells in the tumor microenvironment of obesity-related tumors, which can secrete a variety of adipokines (such as leptin, adiponectin, estrogen, resistin, MIF and MCP-1, etc.), among which leptin, adiponectin and estrogen are the most in-depth and valuable ones. These adipokines are closely related to tumorigenesis and the progression of tumors. In recent years, more and more studies have shown that under chronic inflammatory conditions such as obesity, adipocytes secrete more adipokines to promote the tumorigenesis and development of tumors. However, it is worth noting that although adiponectin is also secreted by adipocytes, it has an anti-tumor effect, and can cross-talk with other adipokines (such as leptin and estrogen) and insulin to play an anti-tumor effect together. In addition, obesity is the main cause of insulin resistance, which can lead to the increase of the expression levels of insulin and insulin-like growth factor (IGF). As important regulators of blood glucose and lipid metabolism, insulin and IGF also play an important role in the progress of obesity related tumors. In view of the important role of adipokines secreted by adipocytes and insulin/IGF in tumors, this article not only elaborates leptin, adiponectin and estrogen secreted by adipocytes and their mechanism of action in the development of obesity- related tumors, but also introduces the relationship between insulin/IGF, a regulator of lipid metabolism, and obesity related tumors. At the same time, it briefly describes the cancer-promoting mechanism of resistin, MIF and MCP-1 in obesity-related tumors, and finally summarizes the specific treatment opinions and measures for various adipokines and insulin/insulin-like growth factors in recent years.