基因表达谱芯片在筛选直肠癌转移相关基因中的应用

目的探讨直肠癌发生淋巴结转移过程中相关基因群的表达和初步功能。方法按一步法抽提人直肠癌原发灶和转移淋巴结组织的RNA,将2000条人类基因PCR产物按微矩阵排列于化学涂层的载玻片上,制成基因芯片;将等量的直肠癌原发灶和转移淋巴结组织总RNA分别逆转录合成荧光分子掺入的cDNA-链做探针,混合后与上述基因芯片杂交,经严格洗片后扫描芯片荧光信号图像,计算机分析后比较两种组织中差异表达的基因。结果在2000条基因中,直肠癌原发灶与转移淋巴结组织间存在差异表达的基因共43条(2.1%),其中上调11条(0.5%),下调32条(1.6%)。表达异常的基因与细胞周期调节、细胞骨架与运动、细胞凋亡、细胞内信号传递、DNA的合成与修复、DNA的结合与转录、蛋白质的翻译合成及免疫功能相关。结论微矩阵基因芯片在筛选直肠癌转移时,相关基因的改变具有快速、高通量、高敏度等特点,直肠癌转移相关基因差异表达谱的分析为预防和控制直肠癌的转移提供了新的思路与线索。

Screening differentially expressed genes between metastatic lymph nodes and primary rectal adenocarcinomas using cDNA microarray

Objective To search for the differentially expressed genes between metastatic lymph nodes and primary rectal adenocarcinomas using cDNA microarray. Methods The PCR products of 2000 human genes were spotted on a chemical material coated glass plate in array. DNA was fixed onto the glass plate after series of treatments. The total RNAs were isolated from metastatic lymph nodes and rectal adenocarcinomas, and reversely transcribed to the cDNAs with the incorporation of fluorescent dUTP to prepare the hybridization probes. The mixed probes were hybridized to the cDNA microarray. After high stringent washing, the cDNA microarray was scanned for fluorescent signals and analyzed for different expression of the target genes between these two tissues. Results Among the 2000 target genes, 43 genes(2.1%)were differentially expressed in metastatic lymph nodes, including 11 genes up regulated (0.5%) and 32 down regulated (1.6%). Conclusions cDNA microarray technique is effective in screening the differentially expressed genes between metastatic lymph nodes and primary rectal adenocarcinomas.