CBX7在胃癌干细胞样细胞中的表达及其功能研究  

The expression and function of CBX7 in gastric cancer stem-like cells

作　　者：赵丽琴[1] 郭伟剑[1] 张晓伟[1] 屈晓飞[2] 王小凤[1] 倪苏婕[1] 黄明主[1] 

机构地区：[1]复旦大学附属肿瘤医院肿瘤内科,复旦大学上海医学院肿瘤学系,上海200032 [2]华中科技大学同济医学院附属协和医院肿瘤中心,湖北武汉430022

出　　处：《中国癌症杂志》2013年第2期114-119,共6页China Oncology

基　　金：国家自然科学基金(No:81041074)

摘　　要：背景与目的:色素框同源蛋白7(chromobox protein homolog 7,CBX7)是一种参与调控细胞增殖衰老的转录抑制因子,属于PcG家族成员,其在维持胚胎干细胞自我更新和全能性中发挥重要作用,但CBX7在肿瘤干细胞中的表达和作用鲜见报道。本研究旨在探讨CBX7在胃癌干细胞样细胞中的表达及其对胃癌干细胞相关特性的调节作用。方法:采用无血清悬浮培养法从MKN28胃癌细胞系中分离干细胞样亚群,蛋白质印迹法(Western blot)检测干细胞相关因子Oct4、β-catenin和CBX7蛋白表达。脂质体法将CBX7干扰质粒(CBX7i)和对照质粒(Ctrli)分别转染入MKN28胃癌细胞,转染后荧光显微镜观察转染效率,Western blot检测CBX7下调效果,无血清悬浮培养检测细胞自我更新能力,平板克隆检测细胞克隆增殖能力改变。结果:无血清培养MKN28细胞,极少数细胞能形成干细胞样悬浮球,其高表达Oct4、β-catenin两个干细胞相关因子,且明显高表达PcG家族蛋白CBX7。基因转染下调CBX7表达后,胃癌细胞无血清培养成球率降低,克隆形成率下降。结论:CBX7在胃癌干细胞样细胞中高表达,其在调控胃癌干细胞自我更新和增殖能力中发挥重要作用。Background and purpose： Chromobox protein homolog 7（CBX7） is a PeG family protein that regulates cell proliferation and senescence acting as a transcriptional repressor. It plays an important role in maintaining self-renewal and totipotency of embryonic stem ceils. However, the expression and function of CBX7 in cancer stem cells haven＇t been reported. This study aimed to investigate the expression of CBX7 in gastric cancer stem-like ceils and its function in regulating gastric cancer stem cells＇ properties. Methods： Gastric cancer stem-like cells were seperated from gastric cancer cell line MKN28 via serum-free culture. The expression of stem cell related factors（Oct4, β-catenin） and CBX7 were assayed by Western blot. CBX7 interfering plasmid （CBX7i） and its control plasmid （Ctrli） were respectively tranfected into MKN28 ceils using LipofectamineTM2000. After transfection, a fluorescence microscope was used to observe transfection efficiency, and CBX7 expression level was determined by Western blot. The ability of self- renewal was assayed by serum-flee culture, and anchorage independent growth was analyzed using colony formation assay. Results： A very small number of MKN28 cells could initiate stem-like floating spheres. Cells in these spheres expressed higher level of Oct4, [3-catenin and CBX7 than adherent cells. After the downregulation of CBX7 by gene transfection in MKN28 cells, both the sphere-forming efficiency and the capability of clonogenecity were decreased. Conclusion： CBX7 is highly expressed in gastric cancer stem-like cells. It plays important roles in regulating self- renewal and proliferation of gastric cancer stem ceils.

关 键 词：色素框同源蛋白7 胃癌干细胞 自我更新 细胞增殖 

分 类 号：R735.2[医药卫生—肿瘤]