应用显微切割-cDNA PCR-SSH法克隆胃癌前病变相关基因

目的 构建胃异型增生组织cDNA消减文库,初步筛选差异表达基因。方法 手工显微切割取胃异型增生和正常组织,应用cDNAPCR方法对少量组织全转录组扩增后进行双向抑制性消减杂交(suppression subtractive hybridization,SSH),消减后片段与载体连接、克隆、筛选、测序及同源性检索,并用斑点杂交方法验证检测结果。结果 正常和异型增生组织互为tester和driver成功构建了2个cDNA消减文库,分别代表在异型增生组织中表达上调和下调基因,测序的26个克隆中15个为已知基因,3个为已知EST,8个为新的EST,GenBank登录号为BQ164614-BQ164616,BQ291516-BQ291520,其中15个片段经证实在胃异型增生阶段有显著表达差异。结论 利用本室创建的显微切割-cDNA PCR-SSH法成功构建胃异型增生组织cDNA消减文库,初步筛选部分基因,为寻找胃癌发生相关基因提供重要线索。

Cloning associated genes using microdissection-cDNA PCR-SSH in gastric dysplasia

OBJECTIVE: To construct cDNA subtracted libraries from gastric dysplasia and further screen differentially expressed genes. METHODS: Relatively pure dysplasia and normal tissue were procured by manual microdissection, and amplified by cDNA-PCR, which was used to carry on for suppression subtractive hybridization (SSH). Subtracted cDNA fragments were linked with vector, cloned, screened, sequenced, and made homologous search. Differentially expressed fragments were verified by dot hybridization. RESULTS: Two subtracted cDNA libraries were constructed. Among 26 sequenced clones, 15 fragments corresponded to known genes, 3 fragments were known EST and 8 fragments were unknown EST (GenBank BQ164614-BQ164616, BQ291516-BQ291520). Fifteen fragments were verified to be differentially expressed in gastric dysplasia. CONCLUSIONS: Subtracted cDNA libraries from gastric dysplasia are constructed using combination of microdissection-cDNA PCR and SSH setup in our laboratory. Some fragments have been screened and verified to help to search for novel associated genes with gastric carcinogenesis.