title: Sirtuin1 Expression and Correlation with Histopathological Features in Retinoblastoma.
abstract: 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 survival.
  
  
  CONCLUSIONS
  Sirt1 was expressed in most of the retinoblastoma samples. However, the degree of Sirt1 expression was not associated with any high-risk histopathological feature or survival.
authors.affiliation: Departments of Medical Oncology, New Delhi, India; Dr. B.R.A. Institute Rotary Cancer Hospital, New Delhi, India; All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Atul
authors.initials: A
authors.lastname: Batra
authors.affiliation: Departments of Ocular Pathology, New Delhi, India; All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Seema
authors.initials: S
authors.lastname: Kashyap
authors.affiliation: Departments of Ocular Pathology, New Delhi, India; All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Lata
authors.initials: L
authors.lastname: Singh
authors.affiliation: Departments of Medical Oncology, New Delhi, India; Dr. B.R.A. Institute Rotary Cancer Hospital, New Delhi, India; All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Sameer
authors.initials: S
authors.lastname: Bakhshi
keywords: Histopathology; Retinoblastoma; Sirtuin1