胃癌相关基因EST片段的筛选与gcI基因克隆  

Screening of gene expressed sequence tags associated to gastric cancer and gene cloning of gcI

作　　者：邢军[1] 赵林胜[1] 徐垚[1] 刘文天[2] 李艳芸[1] 张维铭[1] 

机构地区：[1]天津医科大学实验中心,天津300070 [2]天津医科大学总医院消化科

出　　处：《天津医科大学学报》2005年第4期515-518,共4页Journal of Tianjin Medical University

基　　金：天津市自然科学基金资助(编号:043608511);天津市高等学校科技发展基金资助(编号:20030204)

摘　　要：目的:结合生物信息学手段和实验途径研究mRNA差异显示方法得到的胃癌相关差异表达基因片段的特性。方法:mRNA差异显示技术筛选出的9条胃癌相关基因EST片段,通过国际互联网基因组数据库资源,分别使用BLAST软件将所得到的序列与EST数据库和基因组数据库进行比对分析,获得胃癌表达基因片段的特征信息。应用5'RACE方法延伸序列I,BioEdit软件对延伸的序列进行ORF分析,Northern印迹检测其在各种胃组织中的表达。结果:3条序列与已知基因序列同源,1条序列与CD98A的外显子同源,1条与SPTAN1同源,1条与RPS24同源;显示有3条序列与非编码区长散布核元件LINE区域匹配;3条为新的EST序列,其中1条获得cDNA全长序列,具有完整的读码框,编码120个氨基酸,命名为gcI,定位于染色体10q21-22。Northern验证gcI在胃癌组织中表达上调。结论:利用生物信息学方法对胃癌差异显示序列进行筛选,筛选出3条序列与已知基因同源;3条序列为新EST。对其中1条克隆全长序列,它可能参与了胃癌的发病过程。Objective： To discover differentially expressed genes which studied through the method of mRNA differential display in gastric cancer by bioinformatical tools and experimental approaches. Methotis： Nine differentially expressed cDNA fragments were obtained through fluorescent differential display RT-PCR in gastric cancer, its precancer lesions and normal gastric mucosa tissues. The differential display sequences were searched in EST and nr database on NCBI by basic local alignment search tool BLASTn. The full lengh cDNA of sequence I that had no homologous sequences in databases was cloned with 5＇ RACE, whose ORF was analyzed by software of BioEdit. Northern blot was performed for determining the expression of sequence I. Results： Three differential displayed sequences have homology with known ESTs： the first is human CD9 gene, the second is human SPTAN1 gene, the third is RPS24 gene. The results also indicate that three sequences match to long intersperse nuclear elements（LINE） in noncoding region. One full-lenght cDNA was obtained. Nucleic acid sequence analysis showed it contained a 363 integrate ORF, encoding 120 amino acids. It was named gcI. And gcI is located at human chromosome10q21-22. It is up regulated in gastric cancer tissue. Conclusion： Genes associated with gastric cancer were identifed by bioinformatics techniques. Three known ESTs were obtained and had highly homologous genes. Three unknown ESTs were also obtained, one of which cloned full length might be involved in the process of the gastric carcinogenesis.

关 键 词：胃癌 EST 生物信息学 基因克隆 

分 类 号：Q78[生物学—分子生物学] R730.231[医药卫生—肿瘤]