Krox20 expression in abnormal scars: An immunohistochemical study.

Background: Scars are the end outcome of healing. They are grouped into several types, the common of which are keloids, hypertrophic, and atrophic scars. The role of Krox20 in skin and hair physiology and pathology had emerged. Overexpression of Krox20 was sufficient to stimulate collagen gene expression and myofibroblast differentiation and is necessary for transforming growth factor-β (TGF-β) induced profibrotic responses.

Objective: To investigate the role of Krox20 in abnormal scar pathogenesis. Hopefully, this insight can set the route for newer therapeutic approaches.

Materials And Method: This study was carried out on 30 cases (10 cases of keloids, 10 cases of atrophic scars, and 10 cases with hypertrophic scars [HTS]) and 10 age and gender-matched apparently healthy subjects as a control group. Thirty biopsies were taken from perilesional areas. Evaluation of Krox20 expression was done using standard immunohistochemical technique.

Results: Krox20 was downregulated in epidermis of scar biopsies compared with perilesional and normal skin (p = 0.02) while it was overexpressed in fibroblasts in lesional scar biopsies compared with perilesional and normal skin (p < 0.001). Keloid cases have significantly higher Krox20 expression in fibroblasts compared with HTS cases (p < 0.001). Krox20 had significantly nucleocytoplasmic pattern of staining in scar cases compared with normal skin (p < 0.001).

Conclusion: Krox20 overexpression may have a role in scar pathogenesis through upregulation of multiple genes associated with tissue remodeling and wound healing. This may open an avenue for research for new therapies based on Krox20 inhibition.