Herbst Andreas, Helferich Simone, Behrens Andrea, Göke Burkhard, Kolligs Frank T
Department of Medicine II, University of Munich, Germany.
Biochem Biophys Res Commun. 2009 Oct 2;387(4):736-40. doi: 10.1016/j.bbrc.2009.07.102. Epub 2009 Jul 25.
Loss of heterozygosity (LOH) is a hallmark of cancer and the chromosomal regions 5q, 8p, 17p, and 18q are frequently affected by LOH in colorectal cancer. The ITF2 gene is located on chromosome 18q and we have recently demonstrated that expression of the basic helix-loop-helix (bHLH) transcription factor ITF-2B is affected by LOH. Apart from ITF-2B, the ITF2 gene also encodes the isoform ITF-2A that lacks amino-terminal sequences found in ITF-2B. Analysis of ITF-2A expression in micro-dissected colorectal tumor tissue revealed that ITF-2A expression is frequently lost in colorectal cancers, suggesting that loss of ITF-2A provides cancer cells with a growth advantage. Further studies demonstrated that re-expression of ITF-2A in colon cancer cell lines interferes with cell cycle progression. This data support the notion that the ITF2 gene on chromosome 18q is a tumor suppressor gene.
杂合性缺失（LOH）是癌症的一个标志，5q、8p、17p和18q染色体区域在结直肠癌中经常受到LOH的影响。ITF2基因位于18q染色体上，我们最近证明碱性螺旋-环-螺旋（bHLH）转录因子ITF-2B的表达受LOH影响。除了ITF-2B，ITF2基因还编码异构体ITF-2A，其缺乏ITF-2B中发现的氨基末端序列。对显微切割的结直肠肿瘤组织中ITF-2A表达的分析表明，ITF-2A表达在结直肠癌中经常缺失，这表明ITF-2A的缺失为癌细胞提供了生长优势。进一步的研究表明，在结肠癌细胞系中重新表达ITF-2A会干扰细胞周期进程。这些数据支持18q染色体上的ITF2基因是一个肿瘤抑制基因的观点。
