OTX1 and OTX2 genes in medulloblastomas.

OBJECTIVE: To study the prevalence of OTX1 and OTX2 gene expression in 60 medulloblastoma specimen samples and to establish correlations between gene expression and clinical and histopathological aspects. METHODS: We performed a retrospective analysis of 60 patients with a diagnosis of medulloblastoma at the Clinicas Hospital of the School of Medicine, University of Sao Paulo, and the Cancer Hospital of Barretos. We created a database of the 60 patients containing information on the gene expression of OTX1 and OTX2 (obtained using realtime polymerase chain reaction) and clinical and epidemiological data. Statistical tests were performed to verify potential correlations of clinicopathological data and follow-up aspects with gene expression. RESULTS: The OTX1 gene was expressed in 52% of the study population. Expression varied with age (higher in adults), location (predominantly by hemisphere), and histological type (desmoplastic). The OTX2 gene was expressed in 62% of the study population. Expression varied with age (higher in younger age groups), location (predominantly vermis), and histological type (classic and anaplastic). A statistical correlation between OTX2 gene expression and the development of leptomeningeal metastases was observed. CONCLUSIONS: The relative expression of OTX1 and OTX2 was dependent on patient age, tumor location, and histological variant. In addition, OTX2 expression might be a predictive factor for leptomeningeal metastases of medulloblastoma. The OTX pathway should be consider as an important venue for medulloblastomas development.