Expression Patterns of Gli-1, Pleckstrin Homology-Like Domain, Family A, Member 1, Transforming Growth Factor-β1/β2, and p63 in Sebaceous and Follicular Tumors

• Published in: Annals of dermatology 2014-12, Vol.26 (6), p.713
• Main Authors: Su Young Jeon, Dae Cheol Kim, Ki Hoon Song, Ki Ho Kim
• Format: Article
• Language: Korean
• Subjects: Follicular tumor; Gli-1; p63; PHLDA-1; Sebaceous tumor; Transforming growth factor-β1
• ISSN: 1013-9087; 2005-3894

Background: Certain epidermal appendage tumors, incl-uding hyperplasias (hamartomas), adenomas, benign epithe-liomas, primordial epitheliomas, and malignant tumors, can exhibit any stage of differentiation. Several molecules associated with tumorigenesis, such as Gli-1, pleckstrin homology-like domain, family A, member 1 (PHLDA-1), transforming growth factor (TGF)-β1, TGF-β2, and p63, are associated with tumor grade and aggressive behavior in follicular and sebaceous tumors in ways that are not well understood. Objective: The aim of this study was to elucidate the expression of Gli-1, PHLDA-1, TGF-β1/β2, and p63 in benign and malignant tumors of the hair and sebaceous glands and to determine their importance in the degree of tumor differentiation. Methods: Immunohistochemistry was performed in follicular and sebaceous tumors using anti-bodies against Gli-1 (sebaceous tumor marker), PHLDA-1 (hair follicle outer root sheath [ORS] cell marker), p63, TGF- β1, and TGF-β2. Results: Gli-1 was expressed in basaloid cells, sebocytes, and sebaceous carcinoma cells, and expression levels decreased as differentiation progressed. PHLDA-1 was expressed in ORS cells and some follicular tumor cells. Expression of p63 was observed in the nuclei of the outermost basaloid cells (seboblasts), poorly differen-tiated sebaceous carcinoma cells, and tumor cells toward the direction of the hair. Remarkably, TGF-β1 was expressed exclusively in the nuclei of benign and malignant follicular (hair) tumors, but not in sebaceous tumors, at levels that correlated with the degree of differentiation. Conclusion: We propose that p63 and/or TGF-β1 are useful for predicting the degree of differentiation and malignant potential of sebaceous and follicular tumors and for distinguishing trichilemmal carcinoma from sebaceous carcinoma. (Ann Dermatol 26(6) 713∼721, 2014)