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

Abstract

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.

Keywords

• сахарный диабет
• карцинома герена
• igf
• igfbp
• крысы
• самцы
• самки