Sirtuin1 Expression and Correlation with Histopathological Features in Retinoblastoma

Background: Sirtuin1 (Sirt1) is a member of highly conserved proteins and has been implicated as a tumor promoter as well as a tumor suppressor. One of the mechanisms involves deacetylation of retinoblastoma protein, thereby inhibiting the tumor suppressor function. No study has been reported on the expression of Sirt1 in retinoblastoma. Methods: We assessed the expression of Sirt1 in sections of archived tissue blocks of enucleated and exenterated specimens of retinoblastoma patients by immunohistochemistry. The histopathological features were reviewed and correlated with the expression of Sirt1. The effect of Sirt1 expression on survival was also assessed. Results: Retrospective data of 94 patients revealed that the median age at presentation was 36 months, with a male:female ratio of 1.9: 1. Fifty-one percent of the patients had International Retinoblastoma Staging System (IRSS) stage 1 disease. Of the 94 sections, 89 (95%) expressed Sirt1. Forty-eight percent of the specimens showed grade 3 staining (>75% of the cells), and the intensity was 3+ in 53%. No association between Sirt1 expression and any histopathological feature was noted. Further, Sirt1 expression did not affect the overall and progression-free Received: July 9, 2015 Accepted after revision: August 12, 2015 Published online: September 24, 2015 Dr. Sameer Bakhshi Department of Medical Oncology, Dr. B.R.A. Institute Rotary Cancer Hospital All India Institute of Medical Sciences Room No. 243, Second Floor, Ansari Nagar , New Delhi 110029 (India) E-Mail sambakh @ hotmail.com © 2015 S. Karger AG, Basel 2296–4681/15/0022–0086$39.50/0