中文摘要：

背景：国内外研究证明乳腺癌干细胞可能是起始乳腺癌生长及辅助治疗后复发和远处转移的根源。目的：观察5-氟尿嘧啶对人乳腺癌MCF7细胞Oct4、Bmi-1表达的影响。方法：应用0.1mg/L5-氟尿嘧啶处理MCF7,RT-PCR检测处理前G0及处理后6代细胞G1～G6中Oct4、Bmi-1 mRNA的表达,免疫细胞化学检测处理前G0、G1～G5中Oct4的表达。结果与结论：5-氟尿嘧啶处理后,Oct4、Bmi-1 mRNA表达水平在G3和G5均较处理前明显增高,OCT4蛋白表达呈现出降低-升高-更高-降低-升高的趋势。提示MCF7中可能存在肿瘤干细胞样细胞;5-氟尿嘧啶可能诱导MCF7中肿瘤干细胞样细胞的数量或比例增加。

英文摘要：

BACKGROUND：Several studies suggest that occurrence and development of breast cancer is a progressional process in which many factors participate,and breast cancer stem cells are thought to be the root cause that may initiate the growth of breast cancer recurrence and far metastasis after neoadjuvant chemotherapy.OBJECTIVE：To investigate the influence of 5-fluorouracil（5-Fu） on the expression of Oct4 and Bmi-1 in human breast cancer cell line MCF7.METHODS：MCF7 was treated with 0.1 mg/L 5-Fu,the expression of Oct4 and Bmi-1 in untreated cells and six generations of treated cells was detected with reverse transcription-polymerase chain reaction,and the expression of Oct4 in untreated cells and five generations of treated cells was detected by immunocytochemistry.RESULTS AND CONCLUSION：After 5-Fu treatment,Oct4 and Bmi-1 mRNA expression in the third and fifth generations of treated cells was significantly increased,and Oct4 protein during first to fifth generations of cells had a certain degree of regularity.These findings suggest that there may be cancer stem cell-like cells in MCF7 and 5-Fu might increase the number of cancer stem cell-like cells in MCF7.