【摘要】 在先前确定了鼻咽癌 9p2 1 2 2区域的一个最小共同缺失区内的基础上 ,为了筛选和克隆鼻咽癌相关的候选抑瘤基因 ,应用EST介导的定位候选克隆策略 ,用RT PCR及Northern杂交检测了 2 2个表达序列标签 (expressedsequencetag ,EST)在鼻咽癌细胞株HNE 1和原代培养的正常鼻咽上皮细胞中的表达水平 ,发现其中一个ESTw5 6 112在鼻咽癌细胞株HNE 1中的表达显著下调 ,RNA印迹显示其代表一转录本为 2 .7kb的基因。进一步运用cDNA测序和RACE方法克隆了该EST代表的基因全长cDNA ,Genbank登录号AF2 2 2 0 43,同时结合生物信息学方法克隆了该基因在小鼠中的同源基因 ,Genbank登录AF2 75 5 49。该基因cDNA全长 2 .7kb ,编码由 5 0 2个氨基酸组成的、分子质量为 5 5kD的蛋白质。数据库分析显示该基因编码的蛋白质羧基段含有两个重要的泛肽相关结构域 (UBAdomain) ,属于泛肽相关蛋白家族的一个新成员 ,因此征得国际人类基因组命名委员会同意 ,将其命名为UBAP1基因。运用Northern杂交和RT PCR方法检测发现UBAP1基因在所检测的人和小鼠的组织中广泛表达。采用RT PCR和直接测序的方法 ,未能发现UBAP1基因编码区在鼻咽癌细胞株HNE 1和 10例鼻咽癌活检标本中存在突变。UBAP1基因作为一个泛肽相关蛋白家族的新成员 ,有可能参与?更多还原

【Abstract】 The 9p21 22 region shows loss of heterozygosity in up to 60% of human nasopharyngeal carcinomas (NPC), indicating the presence of a tumor suppressor gene in this region. We have identified a novel minimal common deletion region at 9p21 22. Twenty two epithelial derived expressed sequence tags(ESTs) in this critical region were systematically screened by differential RT PCR to investigate the expression patterns in NPC cell line HNE1 and primary cultures of normal nasopharyngeal epithelial cells. One of these ESTs was found down expressed in HNE1, whose differential expression was confirmed by Northern blot. Subsequently the corresponding gene sequence for this EST was established by cDNA cloning and RACE procedures (GenBank Accession No.AF222043). Furthermore, a mouse homologue of this gene was identified (GenBank Accession No.AF275549). This gene is 2.7 kb long and contains two UBA domains. It is a new member of UBA domain protein family, encoding a putative protein of 502 amino acids with a theoretical molecular mass of 55 kD, so we have named this gene UBAP1 for ubiquitin associated protein 1 (HUGO Gene Nomenclature Committee approved symbol). Northern blot and RT PCR analysis demonstrated a ubiquitous pattern of gene expression in human and mouse tissues. Direct sequencing analysis of the coding region of hUBAP1 following RT PCR failed to reveal any mutations in a preliminary screening of NPC cell line HNE1 and primary nasopharyngeal carcinomas samples. However, more detailed analysis is to be performed to reveal if fine mutations of this gene are present in NPC.更多还原