鼻咽癌肿瘤干细胞样细胞亚群的分离及初步鉴定*

摘要

Objective: The present study aimed to isolate and characterize a cancer stem cell-like sphere-forming cell subpopula-tion. Methods: By using a spheroid culture stem cell-conditioned medium, we isolated a subgroup of cancer stem-like cells from naso-pharyngeal cancer cell lines. Chemotherapy resistance was analyzed by using methyl thiazolyl tetrazolium, and clone-forming capabili-ty was determined by using softer agar clone formation assay. Finally, we verified the expression of the stemness-specific gene andβ-catenin by using immunocytochemistry staining and RT-PCR. Results: The lower-differentiated nasopharyngeal cancer lines con-tained more sphere-forming cells, whereas sphere-forming cells were not observed in the high differentiated nasopharyngeal cancer line CNE-1. Compared with CNE-2, CNE-2S (sphere-forming cells derived from CNE-2) exhibited higher chemotherapy resistance and clone-forming ability. Interestingly, the stemness genes BMI-1, ABCG2, and ALDH1 exhibited higher expression in CNE-2S than in CNE-2. β-catenin, a vital transcription factor of the WNT pathway related to stem cells, exhibited higher expression in CNE-2s cellular nucleus and plasma than in CNE-2. Conclusion: We isolated a subgroup of stem-like nasopharyngeal cancer sphere-forming cells. This discovery paves the way for the development of therapeutic strategies aimed at eradicating tumorigenic subpopulations in nasopharyn-geal cancer.%　　目的：分离和鉴定具有肿瘤干细胞特性的鼻咽癌球形成细胞亚群。方法：利用无血清干细胞球悬浮培养技术从不同分化程度鼻咽癌细胞株中分离成球细胞，然后利用MTT法，软琼脂克隆形成实验，分别评价成球细胞的耐药性、克隆形成能力，最后利用 RT-PCR 和免疫荧光细胞技术分析干性基因及 Wnt 信号通路关键转录因子β-catenin 在成球及未成球细胞中的表达情况。结果：低分化鼻咽癌细胞含有较高成球细胞，而高分化细胞株CNE-1中未见成球细胞。与CNE-2相比较，CNE-2S（来源于CNE-2的成球细胞）具有较强的抗肿瘤药物耐药性、克隆形成能力、高表达干性基因，且β-catenin 在胞浆和核内都呈高表达。结论：本研究分离到干细胞样鼻咽癌成球细胞亚群，为最终靶向杀灭鼻咽癌肿瘤干细胞提供了可能。