B2基因结构及其在结直肠癌中的表达  

Study of B2 gene structure and its expression in colorectal cancer

作　　者：邵丽娜[1] 黄琼[1] 罗敏捷[1] 来茂德[1] 

机构地区：[1]浙江大学医学院病理与法医研究所,杭州310031

出　　处：《中华病理学杂志》2003年第1期14-19,共6页Chinese Journal of Pathology

基　　金：国家自然科学基金资助项目 ( 30 2 0 0 333)

摘　　要：目的　明确B2基因与胰岛素样生长因子结合蛋白 相关蛋白 1(insulin likegrowthfactorbindingproteinrelatedprotein 1,IGFBP rP1)基因在结构上的关系以及其在结直肠肿瘤中的表达改变。方法　用 5′RACE(rapidamplificationofcDNAend)技术获得B2全长 ,用半定量逆转录 聚合酶链反应(RT PCR)法和免疫组织化学SP法检测 76例结直肠癌组织和配对的正常黏膜以及 6个结肠癌细胞系(SW480 ,SW1116,SW62 0 ,HCT8,CoLo2 0 5和LoVo)中B2的表达水平。结果　获得的B2基因全长 112 5bp ,与IGFBP rP1一致性为 112 2 / 112 5。mRNA水平上 ,B2 /IGFBP rP1的表达水平从正常 癌旁 腺瘤 腺癌逐步递增 (P <0 0 5 )。除SW480外 ,其余 5个细胞系中均无该基因的表达。蛋白水平上 ,腺癌与正常黏膜之间B2 /IGFBP rP1的表达阳性率差异有显著意义 (P <0 0 1)。B2 /IGFBP rP1在侵袭前沿肿瘤细胞中高表达的病例 ,发生淋巴结转移概率较高 ,肿瘤的浸润深度较深 ,B2 /IGFBP rP1的阳性程度也较高 (P <0 0 5 )。结论　B2与IGFBP rP1是同一个基因 ;B2 /IGFBP rP1的表达改变可能与结直肠肿瘤的发生、发展有关 ;高表达B2 /IGFBPObjective To get a complete cDNA sequence of B2 and evaluate the correlation on structure and expression between B2 and insulin like growth factor binding protein related protein 1 (IGFBP-rP1) in colorectal carcinomas, paired normal tissues, adenomas, tissues adjacent to the tumor, and colorectal carcinoma cell lines. Methods 5′RACE (rapid amplification of cDNA end) was applied to get the sequence of the 5′ end of B2. Semi-quantitative RT-PCR and immunohistochemistry were used to detect the expression of B2 in colorectal cancer tissues and cell lines (SW480, SW1116, SW620, HCT8, CoLo205 and LoVo). Results A sequence of 1 125 bp was obtained by combining the sequence from 5′RACE product and the known sequence of B2. It shared 1 122/1 125 identities with IGFBP-rP1. At the level of mRNA, the expression of B2/IGFBP-rP1 was high in colorectal carcinomas, moderate in adenomas and tissues adjacent to tumor, low in normal tissues (P<0.05). Five cell lines except SW480 showed no expression of B2/IGFBP-rP1. A significant difference was obtaind in the immunoreactivity of B2/ IGFBP-rP1 between normal tissue and cancer (P<0.05). In 28.9%(22/76) samples, cancer cells locating at the invasive front of cancer nest had a stronger staining of B2/IGFBP-rP1 than those surrounding the lumen. These samples had also an increased frequency of lymph node metastases, increased depth of invasion and a stronger staining of B2/IGFBP-rP1 than in other samples (P<0.05). Conclusions B2 is the same gene as IGFBP-rP1. Overexpression of B2/IGFBP-rP1 may play an important role in the initiation and promotion of colorectal cancer. Its overexpression in invading tumor cells may be linking with an increased potential of invasion.

关 键 词：B2基因 结直肠癌 基因结构 RT-PCR 免疫组织化学SP法 淋巴结转移 肿瘤侵袭 

分 类 号：R735.3[医药卫生—肿瘤]