Scrimieri Francesca, Calhoun Eric S, Patel Kalpesh, Gupta Rigu, Huso David L, Hruban Ralph H, Kern Scott E
Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore MD 21287, USA.
Oncotarget. 2011 Jan-Feb;2(1-2):69-75. doi: 10.18632/oncotarget.220.
We found FAM190A transcripts to have internal rearrangements in 40% (19/48) of unselected human cancers. Most of these tumors (84%) had in-frame structures, 94% of which involved deletion of exon 9. The FAM190A gene is located at 4q22.1 in a region of common fragility, FRA4F. Although normally stable in somatic cells, common fragile sites can be hotspots of rearrangement in cancer. The genomic deletion patterns observed at some sites, including FRA4F at 4q22.1, are proposed to be the result of selection for disrupted tumor-suppressor genes. Our evidence, however, indicated additional patterns for FAM190A. We found genomic deletions accounted for some FAM190A in-frame structures, and cases pre-selected for FAM190A genomic deletions had a yet higher prevalence of FAM190A rearrangements. Our evidence of widespread in-frame heterozygous and homozygous rearrangements affecting this gene in tumors of multiple types leads speculation on structural grounds that the mutant forms may retain, provide new, or possibly convey dominant-negative functions. Although a functionally uncharacterized gene, it is evolutionary conserved across vertebrates. In addition to its potential oncogenic role, the in-frame deletions predict the formation of cancer-specific FAM190A peptide sequences (neo-antigens) with potential diagnostic and therapeutic usefulness.
我们发现,在未经筛选的人类癌症中,40%(19/48)存在FAM190A转录本内部重排。这些肿瘤大多(84%)具有读框内结构,其中94%涉及外显子9的缺失。FAM190A基因位于4q22.1的常见脆性区域FRA4F。常见脆性位点虽然在体细胞中通常稳定,但在癌症中可能是重排热点。在包括4q22.1的FRA4F在内的一些位点观察到的基因组缺失模式,被认为是肿瘤抑制基因功能破坏选择的结果。然而,我们的证据表明FAM190A存在其他模式。我们发现基因组缺失导致了一些FAM190A读框内结构,预先选择存在FAM190A基因组缺失的病例中FAM190A重排的发生率更高。我们关于多种类型肿瘤中广泛存在影响该基因的读框内杂合和纯合重排的证据,从结构角度推测突变形式可能保留、提供新功能或可能传递显性负性功能。尽管该基因功能尚未明确,但在脊椎动物中具有进化保守性。除了其潜在的致癌作用外,读框内缺失预示着癌症特异性FAM190A肽序列(新抗原)的形成,具有潜在的诊断和治疗价值。