Aberrant E-cadherin, β-catenin, and glial fibrillary acidic protein (GFAP) expression in canine choroid plexus tumors

Abstract

Abstract.Expression of E-cadherin and β-catenin has been widely studied in various human and canine epithelial tumors and has been correlated with dedifferentiation, invasiveness, and metastasis. Choroid plexus tumors (CPTs) are of epithelial origin, and the most important prognostic factor in human medicine is the tumor grade. Limited information is available regarding E-cadherin and β-catenin expression in human CPTs, and no information is found in the veterinary literature. In the current study, 42 canine CPTs (19 choroid plexus papillomas and 23 choroid plexus carcinomas) were retrospectively reviewed, and the intensity and cellular staining pattern of E-cadherin and β-catenin were correlated with histological features, paying special attention to grade, invasion, and metastasis. In addition, cytokeratin and glial fibrillary acidic protein (GFAP) antibodies were evaluated as markers for canine CPTs. It was found that loss of E-cadherin and β-catenin expression was uncommon in canine CPTs. Rather, membranous expression of both molecules was increased in CPTs compared to normal choroid plexus (NCP), regardless of tumor grade. Additionally, aberrant cytoplasmic or nuclear expression of both E-cadherin and β-catenin was often observed in CPTs. GFAP was frequently expressed in CPTs in contrast to NCP. None of these parameters were correlated with malignancy, and therefore, do not appear to be useful for prognostic information. Nevertheless, a panel of antibodies including E-cadherin and GFAP might be useful to support the diagnosis of CPTs and help to differentiate them from other tumors, such as ependymomas and metastatic epithelial tumors.

E-cadherin, N-cadherin Expression and Histologic Characterization of Canine Choroid Plexus Tumors

“…12 However, based on histologic criteria more recently, Westworth et al did not meet criteria for atypical CPPs and identified CPCs in up to 64% of cases in dogs. 14 In the same way, atypical CPPs were not identified by Nentwig et al 10 In the current study a high number of neoplasms were classified as atypical CPPs. Certainly contributing to this result is the fact that in the human classification system, (1) the role of the peripheral infiltration is downsized, and (2) the presence of necrotic areas is no longer assumed as an unquestionable index of malignancy.…”

“…However, these efforts have produced contradictory results. 10,12,14 Normal adult choroid plexus strongly expresses E-cadherin 5 and N-cadherin 9 as adhesion molecules. E-cadherin is found mainly in the epithelia, where it promotes tight cell-cell associations known as adherens junctions.…”

“…10 Several studies indicated that a non-tissue-specific expression of N-cadherin in tumors plays a crucial role in cell migration, invasion, and metastasis, as part of the epithelial-tomesenchymal transition. 15 In this study, NCCPs appear to constitutively express N-cadherin, with a mixed membranous and cytoplasmic pattern.…”

Kir7.1 immunoreactivity in canine choroid plexus tumors

“…9 Furthermore, diagnosis of brain biopsies, which may lack overall architecture and histologic pattern, can be difficult. Although CPTs arise from the choroid plexus epithelium, cytokeratin immunoreactivity in canine tumors has been reported to be variable with at least 1 study indicating only a small number of cases immunoreactive to wide-spectrum cytokeratin; however, immunoreactivity of these are either variably or not specific to CPTs.…”

“…Although CPTs arise from the choroid plexus epithelium, cytokeratin immunoreactivity in canine tumors has been reported to be variable with at least 1 study indicating only a small number of cases immunoreactive to wide-spectrum cytokeratin; however, immunoreactivity of these are either variably or not specific to CPTs. 3,5,9 In human samples of CPTs, tissue microarray analysis has identified several candidate genes that are specific to choroid plexus and allow for differentiation from metastatic carcinomas. 2 One of these diagnostic markers is the inward rectifier potassium (K + ) channel Kir7.1, also known as inward rectifier potassium channel 13 or potassium inwardly rectifying channel, subfamily J, member 13.…”