A study of tumor suppressor genes on chromosome 9 in glioblastomas

Objective To locate the deletion regions possibly harboring tumor suppressor genes on chromosome 9 with a view to facilitating the identification of novel tumor suppressor genes in glioblastoma(GMB) .Methods 20 loci on chromosome 9 were examined to detect loss of heterozygosity(LOH) in 21 cases of glioblastoma by PCR based microsatellite polymorphism analy-ses, in which fluorescence-labeled primers and Perkin Elmer 377 DNA Sequencer were applied. Results 66.7%(14/21) infor-mative cases of GBM displayed LOH on chromosome 9, 33.0%(93/282) of informative loci showed LOH in our series, in which the most frequent LOH was observed at locus D9S286(52. 6% ) on 9p21-23 and in the chromosomal region from locus D9S285(43.8%) to D9S157(46.7%) on 9p21. 66.7% of informative cases displayed LOH on 9p and 47.6% on 9q. Conclusions Loss of genetic material on chromosome 9p may play an important role in the molecular genetic pathogenesis of GBM. The chromo-somal regions at D9S286 on 9p21-23 and from D9S285 to D9S157 on 9p21 may harbor several tumor suppressor genes associated with GBM. Besides the well-known TSGs p16 and p15, a novel TSG may be present on the region distal to p16 and p15.