人胰腺癌干细胞对吉西他滨的敏感性及其分子机制研究

Sensitivity of Human Pancreatic Cancer Stem Cells to Gemcitabine and Molecular Mechanism

目的检测人胰腺癌干细胞对吉西他滨的敏感性,分析其差异性基因的表达,初步阐明其耐药分子机制。方法运用流式技术从人原代胰腺癌和细胞系SW1990中分选CD24+CD44+ESA+细胞,行NOD/SCID鼠移植瘤实验验证其肿瘤干细胞特性;运用吉西他滨进行体内、外干预,检测胰腺癌干细胞凋亡和表达率变化情况。采用人类全基因组表达谱AffymetrixU133plus2.0芯片对胰腺癌干细胞和非干细胞进行差异基因筛选。结果人原代胰腺癌和细胞系SW1990中分选到CD24+CD44+ESA+(0.8%)和CD24+CD44+(3.6%)细胞,移植瘤实验证实其为胰腺癌干细胞。肿瘤干细胞凋亡率及表达率检测提示胰腺癌干细胞对吉西他滨显著耐药。与胰腺癌非干细胞比对,基因表达谱芯片筛查到胰腺癌干细胞820条差异基因,其中上调表达281个,下调表达539个。结论胰腺癌干细胞对吉西他滨耐药,具有特征性基因表达谱,为阐明胰腺癌多药耐药机制及靶向治疗奠定基础。

Objective To study the sensitivity of human pancreatic cancer stem cells to gemcitabine and screen the gene expression profile by gene microarray to clarify the multi-drug resistance mechanism of pancreatic cancer stem cells.Methods CD24^＋CD44^＋ESA^＋ cells were sorted from xenografts and SW1990 cell line by flow cytometry.The stem-like properties of this subpopulation were assessed by the xenografts model.Pancreatic cancer cells were interfered with gemcitabine in vivo and in vitro,and apoptosis rate and rate of pancreatic cancer stem cells were detected.The differential gene expression between pancreatic cancer stem cells and other pancreatic cancer cells was detected by whole human genome microarray（Affymetrix Gene Chip U133 Arrays plus2.0）.Results CD24^＋CD44^＋ESA^＋ cells（0.8%）and CD24^＋CD44^＋ cells（3.6%）were isolated in human pancreatic cancer xenografts and SW1990,respectively.Xenograft experiments confirmed that the sub-group had the characteristics of cancer stem cells.Detection of apoptosis rate and the rate of pancreatic cancer stem cells indicated that this sub-population was significantly resistant to gemcitabine.820 differentially expressed genes were identified,including 281 up-regulated and 539 down-regulated in human pancreatic cancer stem cells by CDNA microarray screening.Conclusion Pancreatic cancer stem cells were significantly resistant to gemcitabine,and have special genes expression profile,which may lay a foundation for studying the molecular mechanism of stem-like properties and targeted therapy.