Kras突变小鼠胰腺癌前病变PanIN细胞的生物学特性  

The biological features of pancreatic intraepithelial neoplasia arising from endogenous activated Kras

作　　者：王立夫[1] David A.Tuveson 

机构地区：[1]上海交通大学医学院附属瑞金医院消化内科 [2]Department of Cancer Biology and Medicine,Abramson Cancer Research Instituteat the University of Pennsylvania,Pennsylvania 19104,USA

出　　处：《中国癌症杂志》2006年第8期651-657,共7页China Oncology

摘　　要：背景与目的:胰腺腺管内上皮瘤(pancreatic intraepithelial neoplasia,PanIN)是近几年提出的新术语,目前对其缺乏足够认识。在首次建立小鼠PanIN细胞系的基础上探索Kras突变小鼠PanIN细胞的生物学特性。方法:通过免疫组化分析基因打靶KrasG12D突变小鼠PanIN组织,分离和建立LoxP-Stop-LoxP-KrasG12D;Pdx1-Cre产生的小鼠PanIN细胞系,鉴定其体外贴壁依赖性生长及在软琼脂半固体培养基中集落形成,对PanIN细胞中抑癌基因Tp53、Smad4、p16进行突变分析。结果:KrasG12D激活突变产生了各期小鼠胰腺癌前病变-胰腺腺管内上皮瘤(Pa-nIN);PanIN细胞的胞浆和核中的磷酸化MAPK染色强阳性和高表达,EGFR、Her-2/Neu、和β-Catenin在PanIN细胞中也表现了高表达,Tp53在早期PanIN细胞和Smad4在各期PanIN细胞中的表达无异常;PanIN细胞在体外培养中的增殖速度与原发胰腺癌相似,并且能在软琼脂中形成光学显微镜下所见的集落,随着培养时间的延长而集落增大;PanIN细胞中除可检测到KrasG12D突变外无p16、Tp53、Smad4突变或缺失。结论:单纯Kras的激活突变足以启动PanIN,是胰腺癌发生的早期主要分子遗传学改变事件,PanIN细胞已在一定程度上具备了恶性转化的肿瘤细胞的生物学特性。Background and purpose： Pancreatic intraepithelial neoplasia （PanIN） is a new nomenclature and classification system for pancreatic duct lesions. The biologic feature of PanIN is not well identified. Based on the first established PanIN cell line, the biological features of PanIN arising from endogenous Kras^G12D were studied in this paper. Methods： The mouse strain with Pdx1-Cre was bred to LoxP-Stop-LoxP-Kras^G12D to generate the mouse with genotypes： LoxP- Stop-LoxP -Kras^G12D; Pdx1-Cre. The phenotypes of the strains were studied by histology and immunohistochemistry. The anchorage-dependent, anchorage-independent growth and gene mutation analyses of the first established PanIN cell line were carried out. Results： These strains generated PanIN with high expression levels of activated Kras, EGFR, Her-2/Neu and （ - Catenin. Tp53 expression level in early PanIN and Smad4 expression level in all stages of PanIN were normal. PanIN cells showed in vitro anchorage-dependent growth as well as pancreatic ductal adenocarcinoma. Interestingly, PanIN cells showed anchorage-independent growth in soft agar. Moreover, no Tp53, p16 and Smad4 mutation were detected except for Kras^G12D in PanIN cells. Conclusions： Endogenous activated Kras^G12D is enough to initiate PanIN and is an early event of the molecular genetics in the development of pancreatic ductal adenocarcinoma, and PanIN cells shows the malignant biological features.

关 键 词：Kras突变 PANIN 胰腺癌 基因打靶 

分 类 号：R73-3[医药卫生—肿瘤]