Identification of a 6-cM minimal deletion at 11q23.1-23.2 and exclusion ofPPP2R1B gene as a deletion target in cervical cancer

Previous functional and deletion mapping studies on cervical cancer (CC) ha ve implicated one or more tumor suppressor genes (TSGs) on chromosome 11 at q13 and q22-24 regions. Of these, the 11q22-24 region exhibits frequent al lelic deletions in a variety of solid tumor types, suggesting the presence of critical genes for tumor suppression in this region. However, the precis e region of deletion on 11q is not clearly defined in CC. In an attempt to accurately map the deleted region, we performed an extensive loss of hetero zygosity (LOH) mapping in 58 tumors using 25 polymorphic loci on both the s hort and long arms. The pattern of LOB identified three sites of deletions, two on 11p (p15.11-p15.3 and p12-13), and one on 11q (q23.1-q23.2). The 11 q23.1-q23.2 exhibited highest frequency (60.6%) of deletions, suggesting th at this could be the site of a candidate TSG in CC. The minimal deletion at 11q23.1-23.2 was restricted to a 6-cM region between 123.5 and 129.5 cM ge netic distance on chromosome 11, identifying the site of a potential TSG im portant in the pathogenesis of CC. At least five known genes and 28 UniGene clusters were mapped to the present commonly deleted region. In addition, we have excluded a previously known TSG PPP2R1B at 11q23 as a deletion targ et in CC. The definition of the minimal deletion and the availability of ex pressed sequence resources should facilitate the identification of the cand idate TSG.