人胰腺癌干细胞差异性基因的表达

Analysis on gene expression profile of human pancreatic cancer stem cells by gene microarray

目的分选、鉴定人胰腺癌干细胞，运用基因芯片技术分析其差异性基因的表达。方法运用流式分选技术分选胰腺癌干细胞（CD24^＋CD44^＋ESA^＋），NOD／SCID鼠移植瘤试验进行肿瘤干细胞特性鉴定。采用Affymetrix U133 plus2．0人类全基因组表达谱芯片对胰腺癌干细胞和非干细胞进行差异基因筛选。结果分选得到人胰腺癌CD24^＋CD44^＋ESA^＋亚群细胞，占所有细胞的0．8％；5×10’个CD24^＋CD44^＋ESA^＋细胞就能成瘤（2／4），而阴性细胞1×10’才能成瘤（1／4）；CD24^＋CD44^＋ESA^＋具有一定的自我更新和分化能力。基因芯片杂交获得6553（11．99％）条差异基因，胰腺癌干细胞中5255（9．61％）条上调表达，1298（2．37％）条下调表达。其中差异基因涉及细胞凋亡、细胞周期、代谢、细胞线粒体结构和耐药等多个方面。结论胰腺癌干细胞具有自身特征性基因表达谱，为进一步从干细胞层面研究胰腺癌发病机制及靶向治疗奠定基础。

Objective To identify and isolate human pancreatic cancer stem cells, and screen gene expression profile of human pancreatic cancer stem cells by gene microarray. Methods Pancreatic cancer stem cells （CD24^＋CD44^＋ESA^＋） were sorted from xenografts by flow cytometry. And the stem-like properties of this subpopulation were assessed by the xenografts model. The differential gene expression between pancreatic cancer stem cells and other pancreatic cancer cells was detected by whole human genome microarray （Affymetrix GeneChip U133 Arrays plus2. 0 ）. Results Human primary pancreatic caner CD24^＋CD44^＋ESA^＋ cells were isolated, and the mean frequency of this subpopulation was 0.8%. 5 × 10^3 CD24^＋CD44^＋ESA^＋ cells developed tumors in 2/4 mice, while 1 × 10^5 negative cells developed tumors in 1/4 mice.CD24^＋CD44^＋ESA^＋ cells also exhibited stem cell-like characteristics of self-renewal and differential properties. We identified 6553 （ 11.99% ） differentially expressed genes, including 5255 （9.61%） up regulated and 1298 （2.37%） down-regulated in human pancreatic cancer stem cells. These differentially expressed genes were mainly involved in cell apoptosis related gene, cell cycle related genes, energy metabolism related genes, mitochondrion related genes, and muhidrug resistance related genes, etc. Conclusion Pancreatic cancer stem cells have special genes expression profile, which may lay a foundatiori for studying the molecular mechanism of stem-like properties and targeted therapy.