DMBT1, a new member of the SRCR superfamily, on chromosome 10q25.3-26.1 is deleted in malignant brain tumours

Loss of sequences from human chromosome 10q has been associated with the progression of human cancer. Medulloblastoma and glioblastoma multiforme ave the most common malignant brain tumours in children and adults, respectively. In glioblastoma multiforme, the most aggressive form, 80% of the tumours show loss of 10q. We have used representational difference analysis to identify a homozygous deletion at 10q25.3-26.1 in a medulloblastoma cell line and have cloned a novel gene, DMBT1, spanning this deletion. DMBT1 shows homology to the scavenger receptor cysteine-rich (SRCR) superfamily. Intragenic homozygous deletions have been detected in 2/20 medulloblastomas and in 9/39 glioblastomas mutliformes. Lack of DMBT1 expression has been demonstrated in 4/5 brain-tumour cell lines. We suggest that DMBT1 is a putative tumour-suppressor gene implicated in the carcinogenesis of medulloblastoma and glioblastoma multiforme.