Proteomics of Retinoblastoma: A Pilot Study

Abstract

Purpose: : Various proteins are abnormally expressed in tumor cells. The study of the differential protein expression in tumors, in comparison with normal cells, implicates target molecules for the clinical management of cancers. Here our objective has been to identify and analyze differentially expressed proteins in retinoblastoma (RB) and normal human adult retina.

Methods: : RB tumor samples and human donor adult retinas were collected, and histologically examined. The tissues were homogenized and proteins were separated by two-dimensional gel electrophoresis (2DE). Differential spots were assessed using PDQuest software (Biorad) analysis. The protein spots were subjected to in-gel trypsin digestion, and subsequently identified by matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry (MALDI-TOF-TOF).

Results: : The expression of nearly 52 proteins was found to be altered in retinoblastoma in comparison with normal retina. Importantly, we observed about 50 fold increased expression of apolipoprotein and about 43 fold increased expression of transferrin in RB compared to the adult retinas. It may be cited here that apolipoprotein A1 and transferrin have been described as biomarkers in few other cancers. Retinoblastoma and normal retinal samples have yielded interesting expression patterns in other proteins too, such as alpha-enolase, carbonic anhydrase, phosphatidylethanolamine-binding protein, guanine nucleotide binding protein, alpha-crystallin A and gamma enolase.

Keywords: retina • proteomics • retinoblastoma