Molecular analysis of the putative tumour-suppressor gene EXTL1 in neuroblastoma patients and cell lines

Although neuroblastoma is the most common extracranial solid tumour of childhood, little is known about its aetiology. Together with MYCN amplification and chromosome 17q gain, chromosome 1p deletion is one of the most frequently occurring genetic abnormalities in neuroblastoma. Based upon mapping of deletion breakpoints, putative tumour suppressor gene loci have been assigned to the distal part of the short arm of chromosome 1. Recently, the EXTL1 gene was suggested as a candidate neuroblastoma-suppressor gene and to evaluate this hypothesis, we performed 1p deletion analysis and mutation screening of the EXTL1-coding region on DNA from 22 primary neuroblastomas and 21 neuroblastoma cell lines. Deletions of the chromosome region 1p36.1, including the EXTL1 gene, were detected in several neuroblastoma cell lines and primary tumours. EXTL1 mutation screening resulted in the detection of one unclassified variant (Ser28Cys) but could not provide additional evidence of EXTL1 being involved in the aetiology of neuroblastoma.