Cyclin kinase inhibitor p27 is downregulated in conjunctival melanoma

• Published in: Acta ophthalmologica (Oxford, England) England), 2015-10, Vol.93 (S255), p.n/a
• Main Authors: Moulin, A., Schalenbourg, A., Zografos, L., Nicolas, M.
• Format: Article
• Language: English
• Subjects: Ophthalmology
• ISSN: 1755-375X; 1755-3768
• DOI: 10.1111/j.1755-3768.2015.0660

Purpose As loss of cyclin dependent kinase inhibitors p27 and p21 have been identified in cutaneous melanoma and associated with a poorer prognosis, we decided to assess the expression of p27 and p21 in benign and malignant conjunctival melanocytic proliferations. Methods The expression of p27 and p21 was assessed by immunohistochemistry in 35 conjunctival naevi and 32 conjunctival melanomas. Statistical analysis was performed with JUMP 8.0 software. Immunohistochemistry was evaluated independently by two observers. Results There was a concordance in 94.02% and 92.54% of the cases in the evaluation of the expression of p27 and p21, respectively. Discrepant cases were simultaneously reviewed to achieve complete agreement. There were 13 subepithelial nevi and 22 compound nevi. There were 14 females and 21 males with a mean age was 36.9 ± 3.6 yo (SEM). Nuclear expression of p27 was found in all the nevi. p21 was identified in only 4 nevi (11.4%). The melanoma group was composed of 18 females and 14 males with a mean age of 65.9 ± 3.38 yo (SEM). p27 and p21 were respectively lost in 18 cases (56.25%) and in 24 cases (75%). There was a significant downregulation of p27 in conjunctival melanoma compared to benign conjunctival nevi (p > 0.0001). In the melanomas, there was a correlation between loss of p27 expression and depth of invasion (p = 0.0141) as well as non‐bulbar tumor localization (p = 0.0279). Although the proliferation index was more elevated in melanomas with p27 loss, this was not significant. Conclusions The downregulation of p21 in benign melanocytic proliferations identified in the skin appears also to occur in the conjunctiva. Our results also demonstrate in vivo a significant downregulation of p27 in conjunctival melanoma. Restauration of p27 function in conjunctival melanoma might represent a potential therapeutical option for this tumor.