膀胱癌患者尿脱落细胞抑制消减文库的构建及差异基因的初步筛选

目的 应用抑制性消减杂交方法 筛选膀胱移行细胞癌患者与正常人尿脱落细胞差异表达基因.方法 分离膀胱移行细胞癌患者与正常人尿液中总mRNA,用SMART技术反转录成cDNA,经过酶切、接头连接、两轮消减杂交及两轮抑制性PCR,使得差异表达的DNA片段得以富集.PCR产物与T/A载体连接并转化大肠杆菌XL-blue构建差异表达基因的cDNA消减文库.文库扩增后随机挑取克隆进行酶切、测序及同源性分析.结果 PCR鉴定有317个克隆载有主要在200～900bp之间呈随机分布的插入片段,片段插入率达93.2%,证实建库成功.对20个质粒测序结果 经同源性比对分析,其中20个片段源于17个已知基因,1个克隆在GenBank中未检索到与其有相似性的基因序列,表明它们可能为BTCC差异表达的新基因.结论 该消减杂交文库质量町靠,它的成功构建为进一步筛选、克隆膀胱肿瘤差异表达基因提供了依据.也为膀胱肿瘤诊断基因芯片的研究与开发奠定了基础.

Screening differentially expressed genes of urine exfoliated urothelial cells in transitional cell carcinoma by SSH

Objectives To Screening transitional" differentially suppression subtractive eDNA library in transitional cell carcinoma of bladder (BTCC) and normal urine exfoliated urothelial cells. Methods Total mRNA was isolated from BTCC and normal exfoliatod urothelial calls in urine, respectively. Then double-strand eDNA was synthesized and restricted by Hae Ⅲ. eDNA of BTCC was divided into two groups and ligated with either adaptor Ⅰ or adaptor 2. After hybridized twice normal exfoliated urothelial cells eDNA underwent nested PCR, the PCR products were cloned into PGM-T vector and transformed to E. Eoli JM109. Some pesitive clones were randomly picked up, digested, sequenced and homologous analyzed. Results The SSH library contained about 400 positive clones. Random analysis of 384 clones with enzyme restriction showed that 317clones contained cDNA fragments which were mainly between 200～900bp. The inserted rate reached to 82.6%. A subtracted eDNA library of differentially ex-pressed genes was successfully constructed with SSH. Among 20 arbitrary clones were derived from the above 317 clones, No. 243 clone is a previously unknown sequence and the other 17eloues were derived from 19 known genes. Conclusions The quality of the SSH library of BTCC is reliable and its construction would lie the foundation for further screening differentially expressed genes.