Immunohistochemical localization of β-catenin in medulloblastoma

Abstract

ObjectivesThe aim of this study was to explore the relationship between immunohistochemical expression of β-catenin and the relevant clinicopathological features of medulloblastoma in Egyptian patients.BackgroundMedulloblastoma is a small round blue cell malignancy of the cerebellum and is a major cause of morbidity and mortality in pediatric oncology. Identification of the signaling pathways involved in the pathogenesis of medulloblastoma represents a key challenge for medulloblastoma management. The wingless (WNT)-signaling pathway has been reported to be responsible for 15% of sporadic medulloblastoma. β-Catenin represents the downstream effector of the WNT pathway. Activation of the WNT-signaling pathway results in stabilization of β-catenin and its translocation from the cytoplasm to the nucleus where it regulates the related genes.Patients and methodsThis retrospective study was conducted on 49 tissue specimens of medulloblastoma patients for evaluation of immunohistochemical expression of β-catenin.ResultsNone of the studied medulloblastoma patients showed nuclear localization of β-catenin. However, 29 patients exhibited cytoplasmic staining and 20 patients were absolutely negative. No statistically significant difference was found when comparing patients with cytoplasmic β-catenin expression and negative patients with the studied parameters. In addition, the H-score value of patients with cytoplasmic β-catenin did not show significant relationship with the studied clinicopathologic parameters.ConclusionIn view of the absence of nuclear localization of β-catenin, we could conclude that β-catenin does not play a role in the pathogenesis in all evaluated medulloblastoma patients. However, a large-scale study is recommended to elicit the exact role of the WNT-signaling pathway through dysregulation of components other than β-catenin.