Weinstein Edward J, Bourner Maureen, Head Richard, Zakeri Hamideh, Bauer Christopher, Mazzarella Richard
Department of Oncology Pharmacology, Pharmacia Corporation, 700 Chesterfield Parkway North, St. Louis, MO 63198, USA.
Biochim Biophys Acta. 2003 Apr 17;1637(3):207-16. doi: 10.1016/s0925-4439(03)00035-8.
In a concerted effort to identify biomarkers for lung and colon carcinomas by genome-wide transcriptional profiling, we describe the identification and cloning of one such gene as well as two additional closely related genes. Due to the strong sequence homology to the C. elegans UNC-112 we call this gene URP1, for UNC-112 related protein. We have also isolated the full-length clones for another novel related gene, URP2 and the previously discovered MIG-2 gene. Collectively, these proteins, together with two from Drosophila, appear to form a novel membrane-associated FERM and PH domain-containing protein family. Transcriptional analysis shows that only URP1 is significantly differentially regulated, being over-expressed in 70% of the colon carcinomas and 60% of the lung carcinomas tested. Quantification of URP1 expression by qRT-PCR showed up-regulation of the gene by 60-fold in lung tumors and up to nearly 6-fold in colon tumors. Northern blot analysis of URP1 indicates that normal expression is restricted to neuromuscular tissues. In contrast, the expression of URP2 appears to be confined primarily to tissues of the immune system. SNP analysis of URP1 reveals that it is highly polymorphic, containing seven sites, four of which are in the coding region and one position that results in the interchangeable substitution of glutamic acid and lysine. Finally, we have shown that the genomic structure for all three genes is nearly identical with all encoded by 15 exons although URP1 gene localized to chromosome 20p13, URP2 to 11q12 and MIG-2 to 14q22. This conserved exon structure suggests that all three members probably arose by gene duplication from one ancestral gene. The presence of multiple FERM domains characteristic of cytoplasmic plasma membrane to cytoskeleton linkers and a PH domain typical of membrane-anchored proteins involved in signal transduction suggest an important role for URP1 in tumorigenesis.
为通过全基因组转录谱分析协同鉴定肺癌和结肠癌的生物标志物，我们描述了一个此类基因以及另外两个密切相关基因的鉴定与克隆。由于与秀丽隐杆线虫UNC - 112具有很强的序列同源性，我们将该基因命名为URP1，即UNC - 112相关蛋白。我们还分离出了另一个新的相关基因URP2以及先前发现的MIG - 2基因的全长克隆。总体而言，这些蛋白质与来自果蝇的两种蛋白质似乎形成了一个新的与膜相关的含FERM和PH结构域的蛋白质家族。转录分析表明，只有URP1受到显著差异调节，在70%的测试结肠癌和60%的测试肺癌中过度表达。通过qRT - PCR对URP1表达进行定量分析显示，该基因在肺肿瘤中上调了60倍，在结肠肿瘤中上调了近6倍。URP1的Northern印迹分析表明其正常表达仅限于神经肌肉组织。相比之下，URP2的表达似乎主要局限于免疫系统组织。URP1的SNP分析显示它具有高度多态性，包含七个位点，其中四个位于编码区，一个位点导致谷氨酸和赖氨酸的可互换替代。最后，我们已经表明，尽管URP1基因定位于20号染色体p13，URP2定位于11号染色体q12，MIG - 2定位于14号染色体q22，但这三个基因的基因组结构几乎相同，均由15个外显子编码。这种保守的外显子结构表明这三个成员可能都起源于一个祖先基因的基因复制。细胞质质膜与细胞骨架连接蛋白特有的多个FERM结构域以及参与信号转导的膜锚定蛋白典型的PH结构域的存在，表明URP1在肿瘤发生中起重要作用。
