RESUMO
OBJECTIVE: We study the adhesion molecules on the surface of SO-Rb50 retinoblastoma cell line. METHODS: The distribution of proteoglycans in the retinoblastoma SO-Rb50 cell line was analyzed by histochem-electron microscopy, using Colloidal Iron in combination with a series of enzyme digestions. In addition, immunohistochemistry was performed using a panel of specific antibodies including neuron specific enolase (NSE), glial fibrillary acidic protein (GFAP), S-100 protein, fibronectin, laminin, and collagen IV. RESULTS: Immunohistochemical stains showed the most marked cytoplasmic reactivity of SO-Rb50 cells with anti-NSE and anti-S100. The cells member and surface was postive with anti-NSE. No reactivity was noted with antibodies against laminin, GFAP, and collagen IV. After incubated with colloidal iron solution, three types of colloidal iron-positive stained material could be distinguished based on differences in shape, size, electron density: (1) electron dense particles, (2) the larger colloidal iron-positive filaments, (3) the smaller colloidal iron-positive filaments, which were observed present on the tumor cells surface and in the extracellular matrix. CONCLUSION: We think that the cell surface proteoglycans is the main component of adhesion molecules of retinoblastoma, which may play a central role in mediating tumor cell adhesion to extracellular matrix and adjacent host cell.