June 2013
Volume 54, Issue 15
Free
ARVO Annual Meeting Abstract  |   June 2013
Role of Apoptotic Regulatory Proteins in Retinoblastoma
Author Affiliations & Notes
  • Lata Singh
    Ocular Pathology, All India Institute of Medical Sciences, New Delhi, India
  • Seema Kashyap
    Ocular Pathology, All India Institute of Medical Sciences, New Delhi, India
  • Neelam Pushker
    Ophthalmology, All India Institute of Medical Sciences, New Delhi, India
  • Seema Sen
    Ocular Pathology, All India Institute of Medical Sciences, New Delhi, India
  • Sameer Bakhshi
    Medical Oncology, IRCH, All India Institute of Medical Sciences, New Delhi, India
  • Anjana Sharma
    Ocular Microbiology, All India Institute of Medical Sciences, New Delhi, India
  • Neeru Saini
    Biochemistry, Institute of Genomics and Integrative Biology, Mall Road, New Delhi, India
  • Jasbir Kaur
    Ocular Biochemistry, All India Institute of Medical Sciences, New Delhi, India
  • Footnotes
    Commercial Relationships Lata Singh, None; Seema Kashyap, None; Neelam Pushker, None; Seema Sen, None; Sameer Bakhshi, None; Anjana Sharma, None; Neeru Saini, None; Jasbir Kaur, None
  • Footnotes
    Support None
Investigative Ophthalmology & Visual Science June 2013, Vol.54, 4987. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Lata Singh, Seema Kashyap, Neelam Pushker, Seema Sen, Sameer Bakhshi, Anjana Sharma, Neeru Saini, Jasbir Kaur; Role of Apoptotic Regulatory Proteins in Retinoblastoma. Invest. Ophthalmol. Vis. Sci. 2013;54(15):4987.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose: Deregulation of apoptosis has been demonstrated in cancer development, proliferation and treatment resistance. Bcl-2 protein family plays a key role in the initiation of the apoptotic pathways. Bax and PUMA are pro-apoptotic proteins whereas Bcl-2 is an anti-apoptotic protein which together influence apoptosis. However, we aim to study the expression of these apoptotic regulatory proteins Bax, PUMA and Bcl-2 in retinoblastoma (Rb) and correlate them with histopathological parameters.

Methods: Prospective analysis of immunohistochemical expression of Bax, PUMA and Bcl-2 proteins in 45 paraffin embedded sections of primary enucleated Rb cases were performed. Their results were validated in fresh tumor tissue by western blotting. Cytoplasmic staining was graded as weak/negative (1+), moderate (2+) and strong (3+). Protein expressions were correlated with tumor differentiation, necrosis, calcification and histopathological high risk factors (HRFs) like massive choroidal invasion, optic nerve invasion, sclera, anterior chamber, iris & ciliary body invasion.

Results: A total of 45 cases were analyzed with a male preponderance (25/45) and their age ranged from 6mths to 8 years. Higher tumor staging (T2aNoMo-T4bNoMo) was found in 25 cases. Poorly differentiated retinoblastoma constituted 71.1% and necrosis and calcification was found in 28/45 (62.5%) and 11/45 (25%) respectively. One or more than one HRFs were found in 55.5%. There were 16 cases with massive choroidal invasion, 27 optic nerve invasion, 7 scleral invasion and 6 iris & ciliary body invasion. Immunohistochemistry showed strong expression of Bax (66.6%) and PUMA (62.2%), whereas no Bcl-2 expression was found in 32/45 (71.1%) cases. The western blotting results correlated with the immunohistochemical expression of Bax (21kDa), PUMA (24kDa) and Bcl-2 (25kDa) proteins. Overexpression of Bax significantly correlated with HRFs (P=0.0274) and poor differentiation (P=0.0163). Similarly, expression of PUMA also correlated with extensive necrosis (p=0.0038) and HRFs (p=0.0007). However, no significant correlation was found with Bcl-2 expression.

Conclusions: Immunohistochemistry and western blotting showed negative correlation between pro-apoptotic and anti-apoptotic proteins in patients with histopathological HRFs. Our findings suggest that these apoptotic regulatory proteins may serve as poor prognostic markers and can be used as a therapeutic target for the treatment of Retinoblastoma.

Keywords: 426 apoptosis/cell death • 703 retinoblastoma • 533 gene/expression  
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×