Immunohistochemical features of the human retina and retinoblastoma

Abstract

The immunohistochemical features of 24 retinoblastoma specimens from 22 patients, 15 with unilateral and 7 with bilateral disease, were examined by the labelled streptavidin biotin (LSAB) method and compared with those of specimens from the remaining morphologically normal retina. In the normal retina, S-100 protein, glial fibrillary acidic protein (GFAP) and vimentin were detected in astrocytes and/or Müller cells. Neurofilament protein was seen in axons of the ganglion cells, synaptophysin was present in both plexiform layers, bcl-2 oncoprotein was seen in ganglion cells and bipolar cells, and neuron-specific enolase (NSE) was detected in ganglion cells, bipolar cells and photoreceptor cells and in their cell processes. While retinoblastoma (Rb) protein expression was noted in ganglion cells, bipolar cells, and some photoreceptor cells, p53 protein was not expressed at all. In all retinoblastomas, strong NSE expression and weak bcl-2 expression was observed in almost all tumour cells and synaptophysin was localized in rosette-forming cells, while tumour cells were devoid of S-100, GFAP, vimentin and neurofilament protein. These findings support the view that retinoblastomas are composed of neuron-committed cells. In addition, no Rb protein expression was detected in retinoblastomas, whereas p53 expression was found in 18 cases (75%).

Expression patterns of cyclin D1 and related proteins regulating G1-S phase transition in uveal melanoma and retinoblastoma

“…Uveal melanoma cells, in contrast, demonstrated positivity for both cyclin D1 and pRB in varying percentages, with a positive correlation existing between these two markers (p<0.05), as well as with the growth fraction of the choroidal melanoma (p<0.05). Our data are in agreement with those of previous studies investigating tissue sections for pRB56 57 and cell lines for cyclin D1 55. The absence of pRB and cyclin D1 protein staining in retinoblastoma cells may be explained by the above mentioned second mechanism leading to disruption of the autoregulatory loop between cyclin D1 and pRB.…”

Inhibition of Retinoblastoma In Vitro and In Vivo with Conditionally Replicating Oncolytic Adenovirus H101

“…Dysfunctional tumor suppressor genes such as p53 are the most common genetic lesions identified in human cancers cells, which is why H101 can be used for cancer gene therapy. Although p53 protein is highly expressed in retinoblastoma, 24 the loss of heterozygosity in the VNTR region of intron 1 of p53 is detected in 2 of 10 retinoblastoma cases. 25 Moreover, retinoblastoma has MDMX gene amplifications that inactivate the p53 pathway by reducing steady state amounts of the p53 protein, 18 accounting for the loss of p53 function in patients with retinoblastoma.…”

DicerInactivation Leads to Progressive Functional and Structural Degeneration of the Mouse Retina

“…Photoreceptor rosettes are a common finding in a variety of retinal diseases. In particular, they are found in diabetic retinopathy, retinitis pigmentosa, and ischemia (Lahav et al, 1975;Yuge et al, 1995;Tulvatana et al, 1999). Rosettes have also been reported to result from decreased levels of secreted proteins of the Wnt family, shown to function as organizers of retinal lamination (Nakagawa et al, 2003).…”

“…Rosettes have previously been described in a number of pathological retinal conditions, including retinoblastoma (Yuge et al, 1995), diabetic retinopathy (Lahav et al, 1975), and retinitis pigmentosa (Tulvatana et al, 1999). In these diseases, retinal degeneration and/or abnormal proliferation are present (Lin et al, 2001).…”