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

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.

Keywords:

• skin tags
• insulin growth factor-1
• gene polymorphism
• immunohistochemistry

Acknowledgments

The authors are grateful to administrative and technical staffs at Dermatology Clinic, Biochemistry and Pathology Departments, Faculty of Medicine, Menoufia University, Egypt, who kindly helped throughout this study.

Disclosure

The authors report no conflicts of interest in this work.