PTEN在人脑胶质瘤细胞中的表达及其对细胞增殖的影响  

Expression of PTEN Gene in Human Glioma Cell Lines U251 and SHG-44 and Its Effect on Cell Proliferation

作　　者：李平[1] 钟雪云[1] 秦艳芳[1] 林琛莅[1] 贾晋萍[1] 

机构地区：[1]暨南大学医学院病理教研室,广东广州510632

出　　处：《癌症》2007年第3期247-251,共5页Chinese Journal of Cancer

基　　金：国家科技部重大基础研究前期研究专项(No.2002ccc0400);教育部高等学校博士学科点专项科研基金(No.20040559008);广东省科技厅研究团队项目课题(No.015012)~~

摘　　要：背景与目的:PTEN基因的缺失及突变与多种肿瘤有关,而脑胶质瘤是与PTEN基因变异关系最为密切的恶性肿瘤之一。本研究旨在观察PTEN基因对人脑胶质瘤细胞生物学特性的影响,为PTEN用于胶质瘤基因治疗提供科学的实验依据。方法:(1)应用RT-PCR方法扩增人脑胶质瘤细胞U251、SHG-44中PTEN基因,序列测定分析。(2)采用阳离子聚合物转染试剂,将携带野生型PTEN基因的重组真核表达载体质粒转染至胶质瘤细胞,G418筛选出稳定转染的细胞并扩增培养。通过细胞形态学、细胞生长曲线观察PTEN基因表达对细胞形态和增殖的影响,应用Western blot、免疫细胞化学法检测相关蛋白的表达。结果:(1)胶质瘤细胞U251和SHG-44的PTEN mRNA分别存在着突变型、缺失型两种表达方式。(2)稳定转染的U251和SHG-44细胞株的生长曲线显示细胞增殖明显受抑制,第7天细胞计数分别为未转染对照组细胞数的39.1%、27.8%;Western blot显示稳定转染细胞株有外源性PTEN蛋白的表达;细胞免疫化学法显示胶质纤维酸性蛋白(glial fibrillaryacidic protein,GFAP)表达量增加,从而表现出对细胞形态影响的差异,稳定转染的U251细胞出现向星形细胞分化的特征,SHG-44细胞形态转染前后无明显改变。结论:恢复野生型PTEN基因表达对胶质瘤细胞存在差异性的诱导分化作用。BACKGROUND ＆ OBJECTIVE： Mutation or deletion of PTEN gene is related to a variety of tumors. PTEN gene abnormality is closely related to the tumorigenesis of glioma. This study aimed to investigate the expression of PTEN gene in human glioma cell lines U251 and SHG-44, and explore its effect on cell proliferation. METHODS： The expression of PTEN gene in U251 and SHG-44 cells was detected by reverse transcriptionpolymerase chain reaction （RT-PCR）. The recombinant eukaryotic expression vector containing wild-type PTEN gene was transfected into U251 and SHG- 44 cells by cation polymex. The stably transfected cells were selected by G418 and amplified. Cell morphology was observed under microscope. The effect of PTEN gene on cell proliferation was assessed. The expression of PTEN protein and glial fibrillary acidic protein （GFAP） were detected by Western blot and immunohistochemistry. RESULTS： Point mutation and deletion of PTEN mRNA were observed respectively in U251 and SHG-44 cells. The proliferation rates of U251 and SHG-44 cells were inhibited by 39.1% and 27.8% of control at 7 days after transfection. The expression of PTEN and GFAP were both increased. The stably transfected U251 cells differentiated toward astrocytes, but SHG-44 cells had no obvious morphologic changes. CONCLUSION： Restoring expression of wild-type PTEN could induce differentiation of gtioma cells differently.

关 键 词：PTEN 脑肿瘤 胶质瘤 诱导分化 异质性 

分 类 号：R739.4[医药卫生—肿瘤]