参与大肠腺瘤癌变过程的信号通路初探

Primary study of signal pathways involved in colorectal adenoma-carcinoma transition

目的了解参与大肠腺瘤癌变这一生物学进程的信号通路。方法分别提取正常大肠黏膜、大肠腺瘤、DukesA、Dukes B和Dukes C-D大肠腺癌组织的总RNA,生物素标记cRNA探针,分别与5张Affymetrix U133PLUS2.0基因芯片(涵盖47000个转录本,38500个功能已知基因)杂交,Gene Scanner3000扫描,GCOS1.2软件处理杂交信号,按大肠腺瘤/正常大肠黏膜、大肠腺癌(包括Dukes A、Dukes B和Dukes C-D大肠腺癌)/大肠腺瘤两组分别筛选表达差异基因。然后应用Pathway V1.0软件对两组表达差异基因中共同上下调的基因进行信号通路分析。结果大肠腺瘤/正常大肠黏膜和大肠腺癌/大肠腺瘤两组分别有2950和742个表达差异基因。其中有463个表达差异基因在两个比较组中均共同表达,而279个表达差异基因是大肠腺癌特异表达的。对463个和279个表达差异基因中的上调基因分别进行信号通路分析,结果显示分别有88个和17个信号通路参与大肠腺瘤癌变这一进程(P<0.05),其中有大部分通路与肿瘤微环境及遗传不稳定性相关。而742个表达差异基因中的282个下调基因属于28个信号通路,这些通路与正常大肠功能的逐步丧失密切相关(P<0.05)。结论大肠癌的发生与发展和浸润转移是多阶段、多基因参与的进程,涉及众多的信号通路。研究结果为系统探索大肠癌发生的分子机制提供了线索,对大肠癌的早期诊断、治疗及预后具有一定的指导意义。

Abstract：Objective Comprehensive understanding of signaling pathways involved in the biological process of colorectal adenoma-carcinoma transition. Methods Total RNA was extracted form tissues of normal human colorectal mucosa,colorectal adenoma,Dukes A,B and C-D colorectal cancer respectively,biotin-labled cRNA target probes were hybridized with Affymetrix Human U133 PLUS 2.0 GeneChip （covering 47 000 transcripts,including 38 500 distinct genes）. Signal images were scanned by gene scanner 3000 and analyzed with GCOS1.2 software. Then compared by colorectal adenoma/normal colorectal mucosa,colorectal adenocarcinoma （including Dukes A,Dukes B and Dukes C-D colorectal adenocarcinoma）/colorectal adenomas,two groups of differentially expressed genes were screened out. Then signaling pathway analysis of common up and down-regulated genes within two differentially expressed genes sets was performed by using pathway V1.0 software. Results There are 2 950 and 742 differentially expressed genes were screened out respectively in colorectal adenoma/normal colorectal mucosa and colorectal adenocarcinoma/adenoma groups. There are 463 differentially expressed genes overlap between the above two groups. While 279 differentially expressed genes are specifically expressed in colorectal adenocarcinoma. Signaling pathway analysis of up-regulated events of 463 and 279 genes individually indicated that there are 88 add 17 signaling pathways involved in the process of colorectal adenoma-carcinoma transition （P〈0.05）,of which the majority of these pathways associated with tumor micro-environment and genetic instability. 282 down-regulated genes of 742 differentially expressed genes are belonging to 28 signaling pathway,these pathways are closely related to the gradual loss of the normal large intestine function （P〈0.05）. Conclusions The whole process of carcinogenesis and progression,invasion and metastasis of colorectal carcinoma involved in multi-stage and multi-gene,as well as numerous signaling pathways. The results provides a guide in exploring the molecular mechanism of colorectal cancer,and have some guiding significance for the early diagnosis,treatment and prognosis of colorectal cancer.