不同分化胆管癌间差异表达基因的研究

Differentially expressed genes of cholangiocardnoma tissues

目的 从基因表达水平上探讨不同分化胆管癌及其预后的机理,寻找与胆管癌分化发育相关的基因,从整体上分析不同分化胆管癌差异表达基因的情况,为胆管癌的早期诊断和治疗寻找一些Marker。方法 从高、低分化胆管癌组织中提取总RNA作为比较材料,采用差异显示PCR（DDRT-PCR）技术,将两种组织中差异表达的基因cDNA经PCR扩增,采用反向Northern blot鉴定,以排除假阳性,将有显著差异的PCR产物克隆到质粒载体上,测序并进行同源性比较。结果 得到了9个有显著差异的cDNA片段,其中一个序列分析的结果与LR（Laminin receptor）基因序列高度同源。另有一个序列与EST的大量序列同源。结论 通过对差异显示技术一系列条件的探索和改进,建立了有效的DDRT-PCR法,并在高、低分化胆管癌差异表达基因的研究方面获得了满意结果。

Objective To indentify genes that showed altered expression in cholangiocarcinoma tissues and to identify new molecular markers for differentiation of cholangiocarcinoma. Methods A modified differential display RT - PCR was used. Results This approach identified 32 cDNAs that were preferentially and differentially expressed between well differentiated and poorly differentiated cholangiocarcinoma tissues. When these cDNAs were analyzed by reverse Northern analysis, 3 fragments were reproducibly expressed at well differentiated cholangiocarcinoma tissues and 6 fragments were expressed at poorly differentiated cholangiocarcinoma tissues. Interestingly, Northern blot analysis revealed that one of the genes, LR (laminin receptor), showed significantly increased mRNA levels in poorly differentiated cholangiocarcinoma tissues and normal bile duct epithelium, while the mRNA levels in the well differentiated cholangiocarcinoma tissues was minimal. Blast analysis revealed that this fragment has high sequence identity with many ESTs of NCI CGAP clones (98% identity). Conclusions Differential expression of this LR fragment in cholangiocarcinoma tissues suggests that LR may play an important role in differentiation and carcinomagenesis of cholangiocarcinoma.