应用基因芯片技术筛选大肠腺瘤-癌序列相关基因的初步研究

Screening of Colorectal Adenoma-carcinoma Sequence Related Genes by Gene chip

目的筛选贯穿于大肠癌发生、发展全过程的基因，探讨大肠腺瘤一癌序列发生的分子机制。方法Trizol法分别提取正常大肠黏膜，大肠腺瘤，DukesA、DukesB和DukesC—D大肠腺癌组织的总RNA，分离纯化mRNA，逆转录得双链cDNA，生物素标记cRNA探针，与Affymetrix U133 PLAS2．0基因芯片（涵盖18400个转录本，代表14500个功能已知的基因）杂交，Gene Scanner3000激光系统扫描，GCOS1．2分析软件读取处理杂交信号。计算机分析，比较5种组织基因表达谱差异。结果分别以大肠腺瘤，Dukes A、Dukes B和DukesC—D大肠腺癌组织与正常大肠黏膜组织的基因表达谱相比后发现在4个组中存在共同表达差异的基因253个，其中表达持续上调基因34个（已知基因29个，未知功能基因5个），表达持续下调基因219个（已知基因196个，未知功能基因23个）。结论大肠癌的发生发展是一个多基因参与的复杂演变过程。这些基因在大肠癌前病变一大肠腺瘤阶段就已经有异常表达，说明正常大肠黏膜细胞恶性转变的潜能在癌前病变阶段就已经存在，并且其作用持续贯穿于大肠癌发生发展的整个过程。因此，对这些基因的进一步研究有助于全面了解大肠腺瘤一癌序列的分子机制，并对大肠癌的早期诊断和及时干预治疗具有指导意义。

Objective To screen genes present in the whole process of colorectal tumor development, and to explore the molecular mechanism underlying the eolorectal adenoma-carcinoma sequence. Methods Affymetrix Human U133 PLAS 2. 0 GeneChip （covering 18400 transcripts, representing 14500 distinct genes） was used to compare different gene expression profiles between normal human colorectal mucosa, eolorectal adenoma, Dukes A, B and C-D eolorectal cancers. Results A total of 253 different ex- pressed genes among eolonrectal adenoma, Dukes A, B and C-D colorectal cancers were identified, among which 34 genes were consistently up-regulated （29 with known function, 5 unknown） , while 219 others were consistently down-regulated （ 196 with known function, 23 unknown）. Conclusion Onset and further tumor development of colorectal cancer is a complex evolutional course which involves numerous genes. These genes are expressed at the precancerous stage-colorectal adenoma, which indicates the potential of malignant transformation from normal colorectal cell into colorectal cancer is already in existence at the precancerosis, and these genes may participate in the whole process of colorectal carcinogenesis. Therefore, further analysis of obtained genes can help to elucidate the molecular pathogenesis of adenoma-cancer sequence, and is of guiding significance in the early diagnosis of colorectal cancer and a timely therapeutic intervention.