Molecularly genetic analysis of von Hippel-Lindau associated central nervous system hemangioblastoma

Von Hippel-Lindau (VHL) disease is an autosomal dominant inherited cancer predisposition syndrome, characterized by development of a variety of neoplasms in multiple organs. Central nervous system hemangioblastoma (CHB) is the most common manifestation of VHL disease. The germline mutations in the VHL tumor suppressor gene are responsible for the inherited cancer predisposition syndrome. To expand the VHL mutation data and to investigate the tumorigenesis of VHL-associated CNS hemangioblastoma, 24 CHB tissue samples and blood samples of 14 patients from 10 Chinese VHL families were collected and subjected to molecular genetic analysis. Six distinctive germline mutations were identified, and the 601 G to C (Val130Phe) mutation is reported for the first time. Somatic mutations analysis of the VHL gene in VHL-associated CHB showed that loss of heterozygosity (LOH) occurred in more than half of the cases. In addition, expression of the ZAC1 tumor suppressor gene protein was studied using immunohistochemistry staining in CHB tissues with a specific polyclonal antibody. The ZAC1 protein was lost in all CHB. Our data exhibited high frequency of LOH of ZAC1 gene in VHL-associated CHB, indicating that ZAC1 may have a role in tumorigenesis of VHL-associated CHB.