Analysis of new nucleic acid tumor marker in squamous cell carcinoma of the esophagus and establishment of diagnostic method of distant metastasis

本课题组利用由7,600个克隆组成的高密度BAC芯片(日本人基因组BAC文库(Keio BAC文库))，采用比较基因组杂交(CGH)方法建立了诊断系统。这种半定量方法具有高灵敏度、高分辨率、快速、简便等特点，可用于检测基因的扩增和缺失程度。首先，我们对8种来源于食道和外阴鳞状细胞癌(A431)的培养细胞进行了阵列CGH分析。因此，我们检测到了众所周知的基因突变，如EGFR(7p12)或Cyclin D1(11q13)的扩增，这些都是临床上食道癌的恶性因素。与对照组FLEB14-14(前B细胞)相比，EGFR扩增倍数从0.98倍增加到2.5倍，Cyclin D1从0.91倍增加到1.37倍。我们还检测了GFR(7p12)和细胞周期蛋白D1(11q13)的基因扩增情况。此外，我们还在IRB批准下，用BAC微阵列CGH方法分析了50例食道癌的临床资料。最近在3q、7q、11p和11q上发现了基因扩增，这些基因扩增可能是临床重要变化的候选。最后认为需要进一步研究这些新发现的基因与长期临床肿瘤特征之间的关系。

Our group established a diagnostic system by CGH (Comparative Genomic hybridization) method using high-density BAC microarrays consisting of 7,600 clones (Japanese human genome BAC library (Keio BAC library)). This semi-quantitative method can detect degree of gene amplification and deletion with high sensitivity, high resolution, swiftness, and simplicity. At first we performed array CGH analysis on eight kinds of cultured cells derived from squamous cell cancer of the esophagus and the vulva (A431). As a result, we detected well-known gene alterations such as amplification of EGFR (7p12) or cyclinD1(11q13) which are the malignant factors for esophageal cancer clinically. In comparison with FLEB 14-14 (prepro B cell) which was a control, the EGFR amplified 2.5 times from 0.98 times, and cyclinD1 amplified 1.37 times from 0.91 times. As well as GFR (7p12) and cyclinD1(11q13), we detected the gene amplification of the 14q21 lesion. Also, we analyzed clinical materials of 50 esophageal cancer using BAC microarray CGH method under IRB approval. Gene amplifications were newly detected on 3q,7q,11p, and 11q that may be candidates for clinically important changes. Finally it was thought that further examination of relation between these newly detected genes and the long-term clinical oncological characteristic is needed.