<p>Role of insulin-like growth factor-1 in skin tags: a clinical, genetic and immunohistochemical study in a sample of Egyptian patients</p>

Abstract

Background: Skin tags (STs) are benign connective tissue neoplasms, in which insulin-like growth factor −1 (IGF-1) has a mitogenic and antiapoptotic activity. Purpose: We aimed to study for the first time, the possible role of IGF-1 (CA) 19 and rs6214 gene polymorphisms, and its tissue immunoreactivity in the pathogenesis of STs. Patients and methods: This case–control study included 40 ST patients and 20 controls. We searched for (CA) 19 single-nucleotide polymorphism (SNP) using conversional PCR and for rs6214 gene polymorphism using real-time PCR. IGF-1 tissue immunoreactivity was investigated using polyclonal IGF-1 antibody. Results: IGF-1 immunoreactivity showed significantly strong upregulation in epidermis ( p =0.002) and dermal components (endothelial cells [ p =0.038] and fibroblasts [ p =0.004]) of excised STs than control skin. TT and CT rs6214 genotypes and its T allele were significantly associated with STs ( p =0.006 and P =0.002, respectively). Also (<192 bp) and 192–194 bp (CA) 19 genotypes were significantly predominant in ST patients than controls ( p =0.013). These 4 genotypes were significantly associated with development of multiple STs and epidermal IGF-1 tissue immunoreactivity in studied patients. Conclusions: IGF-1 (CA) 19 and rs6214 gene polymorphisms may contribute to a predisposition of STs in Egyptian patients, the role of which could be mediated through local upregulation of IGF-1 in cutaneous tissues.

Introduction of a novel quantitative scoring system for acanthosis nigricans and its validation in a pilot study

“…Pathogenesis of AN and skin tags remain incompletely understood. Clinical association with metabolic syndrome, such as obesity, hyperinsulinemia, and insulin resistance, is frequently observed 13,14 . Genetic mutations described in severe extensive AN may include the insulin receptor gene, fibroblast growth factor receptor (FGFR)2, and FGFR3 gene, and phosphatase and tensin homolog gene.…”

“…Genetic mutations described in severe extensive AN may include the insulin receptor gene, fibroblast growth factor receptor (FGFR)2, and FGFR3 gene, and phosphatase and tensin homolog gene. A significant upregulation of IGF‐1 immunoreactivity has been demonstrated in the epidermis and fibroblasts of excised skin tags as compared with the control skin 14 . It is proposed that interactions among insulin, IGF‐1, androgens, and growth factors play a pivotal role in regulation of the proliferation, differentiation, and apoptosis of keratinocytes and fibroblasts in the diseased state 13,14 …”

“…Clinical association with metabolic syndrome, such as obesity, hyperinsulinemia, and insulin resistance, is frequently observed. 13,14 Genetic mutations described in severe extensive AN may include the insulin receptor gene, fibroblast growth factor receptor (FGFR)2, and FGFR3 gene, and phosphatase and tensin homolog gene. A significant upregulation of IGF-1 immunoreactivity has been demonstrated in the epidermis and fibroblasts of excised skin tags as compared with the control skin.…”

“…A significant upregulation of IGF-1 immunoreactivity has been demonstrated in the epidermis and fibroblasts of excised skin tags as compared with the control skin. 14 It is proposed that interactions among insulin, IGF-1, androgens, and growth factors play a pivotal role in regulation of the proliferation, differentiation, and apoptosis of keratinocytes and fibroblasts in the diseased state. 13,14 No biological markers can reflect the severity of AN or skin tags, while only a few scoring systems are intended to assess the severity of AN.…”

“…14 It is proposed that interactions among insulin, IGF-1, androgens, and growth factors play a pivotal role in regulation of the proliferation, differentiation, and apoptosis of keratinocytes and fibroblasts in the diseased state. 13,14 No biological markers can reflect the severity of AN or skin tags, while only a few scoring systems are intended to assess the severity of AN. 2,3,15 The current study was aimed to develop a scale combining AN and skin tags and to validate this new scoring system in a large Turkish population, especially regarding its association with obesity, type II DM, and the relevant risk factors, such as prediabetes, overweight, age 45 years or older, positive family history (one parent, brother, or sister) of type 2 diabetes, past history of gestational diabetes or giving birth to a baby weighing more than 9 pounds, and nonalcoholic fatty liver disease.…”