肺癌中肿瘤抑制基因CEACAM1的选择性拼接与PTB的过表达有关  

Alternating Splicing of Tumor Suppressor Gene CEACAM1 is Correlated with Over-expression of PTB in Lung Cancer

作　　者：袁榴娣[1] 丁洁[1] 李震[1] 

机构地区：[1]东南大学遗传与发育生物学系

出　　处：《肿瘤防治研究》2006年第5期320-323,共4页Cancer Research on Prevention and Treatment

摘　　要：目的研究CEACAM1通过选择性拼接而产生的两种变体在小细胞肺癌及癌旁组织中表达比例不同的调控机制。方法通过Hot-PCR检测小细胞肺癌中CEACAM1的两种产物的表达;Western blot分析PTB在小细胞肺癌组织的表达;用PCR方法获得CEACAM1基因中从内含子5至外显子8长1,606-bp DNA片段插入到真核表达载体pCMV中,构建成CEACAM1迷你基因模型并与PTB基因共转染,PCR法鉴定转染后的产物变化。结果PTB过表达与CEACAML的低表达有明显的相关性。PTB三种变体使CEACAM1L表达下降,其中PTB4对迷你基因的表达产物影响最大。仅转染迷你基因的细胞中CEACAM1L在两条带中所占比例为76.7%,而与PTB三种变体共转染后,比例分别下降至58.3%、64.8%和54%。结论拼接因子PTB与CEACAM1的选择性拼接有关。Objective The possibility of modulating the difference of CEACAM1 splicing pattem between tumor tissues and their corresponding non-malignant lung tissue. Methods Detect the expression pattern of CEACAM1 in non-small cell lung cancer （NSCLC） by Hot-PCR,mini-gene constructs and co-transfection with PTBs. Results The RNA transcript from this mini-gene could be spliced in a cell-specific manner. The exon 7 was predominantly included in H1944, but predominantly excluded in 2213. Over-expression of PTB could ubiquitously alter the ratio of CEACAM1L and CEACAM1S. The amount of CEACAM1L was decreased in a dosagedependent manner. Conclusion We identified polypyrimidine tract binding protein （PTB） as the splicing factor that involves in inclusion / exclusion of CEACAM1 exon 7. A clear correlation was found between over-expression of PTB and the alternative processing of CEACAM1.

关 键 词：CEACAM1 选择性拼接 PTB 迷你基因 

分 类 号：R734.2[医药卫生—肿瘤]