肝癌组织差异表达基因cDNA序列的筛选与鉴定

目的：筛选并鉴定肝癌组织特异表达基因。方法：通过菌落原位杂交技术筛选用抑制消减杂交法构建肝癌与癌旁肝组织差异表达基因消减cDNA文库，用PCR方法进一步筛选出有插入片段的阳性克隆，将阳性克隆进行DNA测序和同源性比较分析，用Northern印迹方法对新的cDNA序列进行初步鉴定。结果：从消减文库中随机挑取的100个白色克隆中筛选出13个阳性克隆，DNA测序获得11个不同的cDNA序列；同源性比较分析表明，6个cDNA片段与在基因高度同源，5个cDNA片段为新的序列。其长度大于300bp的3个新序列，Norther印迹证实它都来源于肝癌组织。结论：用抑制消减杂交方法构建的肝癌差异表达基因消减cDNA文库富含肝癌特异表达基因，经验证的3个新的cDNA序列可能为肝癌特异的基因序列。

Screening and identification for cDNA of differentially expressed genes in human primary hepatocellular carcinoma

Objective Screening and identification of differentially expressed genes in human primary hepatocellular carcinoma(HCC). Methods The differentially expressed genes subtracted cDNA library of HCC constructed by suppression subtractive hybridization(SSH) technique was screened by colony in situ hybridization, then the positive clones were further screened with PCR amplification. The positive clones were sequenced and analyzed for homology in the Genbank databases with Basic Local Alignment Search Tool(BLAST). The novel cDNA sequences were analyzed by Northern blot analysis. Results Thirteen positive clones were obtained, and 11 cDNA sequences were identified. Sequences of 11 cDNA showed that 6 cDNA were homologous with the genes published in Genbank and 5 cDNA were unknown genes. Northern blot indicated that 3 novel cDNA(>300 bp) were only expressed in HCC. Conclusion The subtracted cDNA library constructed by SSH technique contains differentially expressed genes of HCC. Three novel cDNA sequences might be differentially expressed genes of HCC. Further screening the library and gaining the whole gene sequence may lay a foundation for identifying differentially expressed genes in HCC.