定位于染色体9p21-22的一个新基因UBAP1的克隆测序及在鼻咽癌中的表达分析

 在染色体 9p2 1 2 2鼻咽癌杂合性丢失 (lossofheterozygosity,LOH)高频区 ,应用EST介导的定位 侯选克隆策略 ,用RT PCR及Northern杂交检测了 2 2个表达序列标记 (expressedsequencetag ,EST)在鼻咽癌细胞株HNE1和原代培养的正常鼻咽上皮细胞中的表达差异 ,并对其中一个在鼻咽癌细胞株HNE1中表达下调的EST检测了在鼻咽癌活检组织中的表达 .用生物信息学方法获得其全长cDNA序列 ,GenBank登录号AF2 2 2 0 4 3.该基因cDNA全长 2 70 1bp ,其开放阅读框 (openreadingframe ,ORF)编码一个含 50 2个氨基酸、分子量为 55kD的碱性蛋白质 ,在蛋白羧基端含有 2个连续的重要UBA功能域 (ubiquitinassociateddomain) ,属于遍在蛋白相关蛋白家族的一个新成员 ,经国际人类基因命名委员会同意 ,将其命名为UBAP1 (ubiquitinassociatedprotein 1 ) .Northern表达分析显示UBAP1在所检测的人组织中广泛表达 ,但在人的心脏、骨骼肌及肝脏中的表达较强 .UBAP1基因在63 2 % ( 1 2 1 9)的鼻咽癌活检组织中表达下调 .UBAP1基因作为一个遍在蛋白相关蛋白家族的新成员 ,结合其在 9p的重要定位信息 ,有必要进一步研究其表达下调参与鼻咽癌发生发展的可能机制 .

Cloning and Sequencing of a Novel Gene,UBAP1,Located on Chromosome 9p21-22 and Its Expression Analysis in Nasopharyngeal Carcinoma

To obtain the novel genes associated with human nasopharyngeal carcinoma (NPC) on chromosome 9p21 22.Twenty two epithelial derived expressed sequence tags(EST) were selected from chromosome 9p21 22 where loss of heterozygosity (LOH) frequently occurs in NPC tissues.And the differential expression pattern of these ESTs were detected in NPC cell line HNE1 and primary culture of normal nasopharyngeal epithelial cell by using RT PCR and Northern blot analysis.One of ESTs,which was substantially down expressed in HNE1 cell line,was further studied for its expression in 5 normal nasopharyngeal and 19 NPC biopsies.Subsequently the corresponding gene sequence for this EST was established by cDNA cloning and bioinformatic methods.The full cDNA sequence and predicted protein of this novel gene was analyzed.This gene is 2.7 kb long,encoding a putative protein of 502 amino acids with a theoretical molecular mass of 55 kD and containing two UBA domains.Analysis of this novel gene shows no significant homology to any reported genes in database of GenBank.So it is a new member of UBA domain protein family and named by UBAP1 for ubiquitin associated protein1(HUGO Gene Nomenclature Committee approved symbol)(GenBank Accession No.AF222043).Northern blot analysis demonstrate a ubiquitious pattern of gene expression in human tissues.It was found to be down expressed in 63.2%(12/19) of NPC biopsies.Clearly,being a new member of UBA protein family and taking its map location into account,a more extensive analysis is warranted to establish whether it may be involved in the development of NPC.