Abstract
HOX genes encode transcription factors, which play a key role in morphogenesis and cell differentiation during embryogenesis. Several observations indicate that a deregulated expression of these genes may result in tumor development and progression. Actually, several HOX genes are aberrantly expressed in many tumors and cell lines derived from them. Little is known about the expression of HOX genes in brain tumors. In the present work, we study the relative expression of HOX-D genes (D1, D3, D4, D8, D9, D10, D11, D12, D13) with real-time polymerase chain reaction in a group of 14 pediatric low-grade gliomas. We compare the HOX-D expression level of the 14 tumors with the average expression level of six non-neoplastic human brain tissues. HOX-D1 and HOX-D12 resulted over-expressed in neoplastic samples with respect to non-neoplastic brain parenchyma. Conversely, HOX-D3 was expressed at a lower level in gliomas with respect to non-neoplastic brain. HOX-D4, HOX-D11, and HOX-D13 were never expressed. HOX-D8, HOX-D9, and HOX-D10 were exceptionally expressed in non-neoplastic samples and irregularly expressed in tumors. The observation that all but three HOX-D genes studied are expressed with different pattern in neoplastic and non-neoplastic brain tissue may support the hypothesis that HOX-D genes play a role in the pathogenesis of pediatric low-grade gliomas.