CD44^+鼻咽癌细胞的干细胞生物学特性

Stem Cell Biological Characteristics of CD44^+ in Human Nasopharyngeal Carcinoma

目的从人鼻咽癌SUNE-1 5-8F细胞株中分离出CD44+细胞并探讨其生物学特性。方法常规培养SUNE-1 5-8F细胞,采用流式细胞学技术检测SUNE-1 5-8F细胞中CD44+的表达并用流式细胞仪分选CD44+细胞;采用四甲基偶氮唑蓝(MTT)法、克隆形成实验等检测并比较CD44+、CD44-细胞在体外增殖、分化等方面的差异;并用反转录聚合酶链反应(RT-PCR)检测干细胞基因Oct4、Bmi-1的表达。结果 CD44+细胞在鼻咽癌细胞中SUNE-1株所占的比率约为52.5%;新分选的CD44+细胞在无血清培养液和完全培养液中较CD44-及未分选细胞均显示出较强增殖能力;RT-PCR示Bmi-1和Oct4mRNA在CD44+细胞中的表达水平明显高于CD44-细胞。CD44+和CD44-细胞在接受2Gy放射处理后,其平均克隆生成效率分别为(23.44±1.90)%和(7.78±1.17)%(P<0.001);CD44+细胞较CD44-细胞在相同顺铂和多西他赛药物浓度下显示出更高的细胞存活率。结论 CD44+细胞具有类肿瘤干细胞特性,可能是鼻咽癌的重要肿瘤干细胞标志之一。

Objective To separate,expansion,and explore the biological feature of CD44＋ cells from the human nasopharyngeal carcinoma（NPC） SUNE-1 5-8F cell line.Methods Flow cytometry was used to detect the expression of CD44 in SUNE-1 5-8F.Fluorescence-activated Cell Sorting was applied to purify CD44＋ cells.MTT assay or clone formation assay was used to detect the differences of CD44＋ and CD44-cells in proliferation and differentiation ability.The expression of stem cell markers Oct4 and Bmi-1 was examined by reverse transcriptase polymerase chain reaction（RT-PCR）.Results CD44 was positively expressed in about 52.5% of NPC SUNE-1 5-8F cell line.Regardless of serum-free medium and serum medium culture conditions,freshly sorted CD44＋ cells showed stronger proliferative capacity than CD44-and unsorted CD44＋ cells.The expression levels of Bmi-1 and Oct4 mRNA in CD44＋ cells were significantly higher than that in CD44-cells.After 2Gy radiation,the average clone formation efficiency for CD44＋ and CD44-cells was（23.44±1.90）% and（7.78±1.17）%（P0.001）,respectively.After Cisplatin and Docetaxel treatment,CD44＋ cells showed a higher survival rate in the same drug concentration compared with CD44-cells.Conclusion CD44＋ cells have the biological characteristics of tumor stem cell and may be assumed as one of markers of NPC tumor stem cells.