摘要
目的:进一步精细限定鼻咽癌9p21-22区域等位基因杂合性丢失的频率和范围,筛选和克隆其共同缺失区内鼻咽癌相关的候选抑瘤基因。方法:应用11个定位于 9p21-22区域的高密度微卫星位点,检测 25例低分化鼻咽癌患者的杂合性丢失,确定其共同缺失区;用RT-PCR和Northern筛出在鼻咽癌细胞株HNE1和鼻咽癌活检组织中表达下调的、定位于共同缺失区内的 3’末端ESTs(Express Sequence Tags);采用 RACE技术和生物信息学资源克隆出候选EST的全长cDNA。结果: 25例患者中有17例(68%)存在一个或多个位点的杂合性丢失,其中D9s161(35.0%,7/20),D9S1678(31.5%,6/19),D9S263(3.3%,6/18)和D9S1853(33.3%,7/21)四个紧邻位点的丢失频率相对较高,并发现六位患者在该四个位点表现为连续性缺失;筛选D9S161-D9S1853区域内25个代表新基因的3’末端ESTs序列,发现一个EST(dbEST:208825)在鼻咽癌细胞株HNE1及73%(11/15)的活检组织中表达降低, Multiple Tissue Nort
Objectives: To further refine the extent of deletion on chromosome gp21-22 in nasopharyngeal carcinoma (NPC) and clone a new putative tumor suppressor gene associated with NPC. Methods: Loss of heterozygosity (LOH) on chromosome 9p21 -22 was analyzed in 25 paired blood and tumor samples by using 11 high-density microsatellite polymorphic markers; the expression of 3' end express sequence tags (ESTs) localized with in common deletion region was investigated tri NPC cell line HNE1, primary culture nasopharyngeal epithelial cells and BPC biopsies by using differential RT-PCR and Northern hybridization. Rapid amplification of cDNA ends (RACE) and bioinformatic data were used to clone putative EST, full-length cDNA. Results: Seventeen of 25 cases (68%) showed LOH at one or more loci. Higher frequencies of LOH were found at four loci: D9S161 (35. 0% ), D9S1678 (31.5% ), D9S263 (33. 3% ) and D9S1853 (33.3% ), where 6 cases had a contiguous stretch of allelic loss; 25 ESTs localized within D9S161 - D9S1853 were investigated and one EST (dbESI: 208825) was downexpressed in NPC cell line HNE1 and in 73% (11 / 15) NPC biopsies. Multiple tissue blot revealed that this putative EST hybridized to two different size transcripts (approximately 2.4 kb) and 3.5 kb) in fetal heart and brain tissues. A near full-length cDNA of 2.4 kb transcript of this EST was cloned(named NAG-6 gene) and there is no significant homology with any known genes. Conclusions: The minimal common region of deletion might he defined between D9S161 and D9S1853 (estimated about 2.7 cM in extent) at 9p21.1, the new gene NAG-6 located in this region may be a putative tumor suppressor gene associated with NPC.
出处
《癌症》
SCIE
CAS
CSCD
北大核心
2000年第1期6-9,共4页
Chinese Journal of Cancer
基金
国家863项目!(102-10-01-05)
973重大项目("疾病基因组学"理论和技术体系的建立鼻咽癌子项目)资助
关键词
鼻咽肿瘤
染色体
9p21-22
杂合性丢失
克隆
Nasopharyngeal carcinoma
Chromosome 9p21-22
Loss of heterozygosity
Gene cloning
Tumor suppressor gene