Glebov Oleg K, Rodriguez Luz M, Soballe Peter, DeNobile John, Cliatt Janet, Nakahara Kenneth, Kirsch Ilan R
Genetics Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA.
Cancer Epidemiol Biomarkers Prev. 2006 Nov;15(11):2253-62. doi: 10.1158/1055-9965.EPI-05-0694.
Aberrant crypt foci (ACF) are considered the earliest identifiable preneoplastic colonic lesions; thus, a greater understanding of the nature of genetic changes underlying the transformation of normal colonic mucosa (NM) into ACF may provide insight into the mechanisms of carcinogenesis. ACF were identified by indigo carmine spraying onto colonic mucosa during colonoscopy and isolated as standard pinch biopsies of the mucosal areas containing the ACF. RNAs isolated from ACF and matched NM biopsies from the ascending and descending colons of 13 patients were analyzed on arrays containing 9128 cDNAs. Thirty-four differentially expressed (P < 0.001) genes were found in a paired comparison of the ACF and NM samples, and 25 of 26 matched pairs of ACF and NM could be correctly classified in leave-one-out cross-validation. Differential expression for seven of eight genes was confirmed by real-time reverse transcription-PCR. Furthermore, ACF and NM samples, including six pairs of ACF and NM samples that had not previously been analyzed by array hybridization, can be correctly classified on the basis of the overexpression in ACF of three selected genes (REG4, SRPN-B5, and TRIM29) evaluated by real-time reverse transcription-PCR. In a separate analysis of 13 biopsy pairs from either ascending or descending colon, ACF and NM samples could also be correctly classified by the gene expression patterns. Analysis of gene expression differences in ACF from the ascending and descending colon versus NM samples indicates that ACF from these distinct colonic locations are converging toward similar gene expression profiles and losing differences in gene expression characteristic of NM from the ascending versus descending colon.
异常隐窝灶（ACF）被认为是最早可识别的结肠肿瘤前病变；因此，深入了解正常结肠黏膜（NM）转变为ACF背后的基因变化本质，可能有助于深入了解致癌机制。在结肠镜检查期间，通过向结肠黏膜喷洒靛胭脂来识别ACF，并将其作为包含ACF的黏膜区域的标准钳取活检样本进行分离。对从13名患者升结肠和降结肠的ACF以及匹配的NM活检样本中分离出的RNA，在包含9128个cDNA的阵列上进行分析。在ACF和NM样本的配对比较中发现了34个差异表达（P < 0.001）基因，并且在留一法交叉验证中，26对匹配的ACF和NM样本中有25对能够被正确分类。通过实时逆转录 - PCR证实了8个基因中的7个基因的差异表达。此外，基于实时逆转录 - PCR评估的三个选定基因（REG4、SRPN - B5和TRIM29）在ACF中的过表达，ACF和NM样本（包括之前未通过阵列杂交分析的6对ACF和NM样本）能够被正确分类。在对来自升结肠或降结肠的13对活检样本的单独分析中，ACF和NM样本也可以通过基因表达模式被正确分类。对升结肠和降结肠的ACF与NM样本之间基因表达差异的分析表明，来自这些不同结肠部位的ACF正趋向于相似的基因表达谱，并失去升结肠与降结肠NM所特有的基因表达差异。
