MOLECULAR MARKERS OF HUMAN LIVER CANCER-NOVEL GENES DIFFERENTIALLY EXPRESSED

我们先前已经证明粗面内质网(RER)来自 肝细胞系可提供完整和丰富的分泌蛋白mRNA(参见 项目编号Z01CP05739-01 LMO)。这种信使核糖核酸被用作化验的一部分。 系统来确定哪些3‘cDNA片段(如果有)是由 差异显示对应于分泌的蛋白质。 在20个差异表达的cdna片段中，有一个是新发现的。 通过数据库序列分析，与一种分泌型蛋白质相对应 通过RER组分提取的RNA Northern分析。我们用的是5‘RAPID 扩增cDNA末端(RACE)聚合酶链式反应(PCR) 从胎盘mRNA中克隆出整个3.7kb的mRNA，这是唯一的 表达这一新克隆的健康组织。该基因包含一种 前导肽序列、一个脯氨酸重复序列和七个潜在的 根据计算机分析，跨膜结构域。其他19个 差异表达克隆包含六个完整的新基因，一个 组蛋白相关基因、转录因子和核浆 RER定位阴性的蛋白质，根据 前面讨论过的化验。我们目前正专注于我们推定的 用于蛋白表达、抗体产生的细胞表面蛋白克隆 和患者血清/组织筛查以确定其诊断/ 预后/治疗意义。

We have previously shown that rough endoplasmic reticulum (RER) from liver cell lines can give intact and enriched secretory protein mRNA (See project #Z01CP05739-01 LMO). Such mRNA was used as part of an assay system to determine which, if any, 3' cDNA fragments cloned by differential display correspond to secreted proteins. Out of 20 differentially expressed cDNA fragments, one was found novel by database sequence analysis and corresponding to a secretory protein by RER fraction-extracted RNA Northern analysis. We used 5' rapid amplification of cDNA ends (RACE) polymerase chain reaction (PCR) to clone the entire 3.7 kb mRNA from placenta mRNA, which was the only healthy tissue that expressed this novel clone. This gene contains a leader peptide sequence, a proline repeat, and seven potential membrane-spanning domains, according to computer analysis. The other 19 differentially expressed clones contain six complete novel genes, a histone-related gene, a transcriptional factor, and nuclear cytosolic proteins which are negative for RER localization, according to the previously discussed assay. We are currently focusing on our putative cell surface protein clone for protein expression, antibody production and patient sera/tissue screening to determine its diagnostic/ prognostic/therapeutic significance.