结肠癌细胞系SW480肿瘤干细胞相关亚群初步分离、鉴定

Preliminary isolation and identifi cation of cancer stem-like cells in colon cancer cell line SW480

背景与目的:肿瘤干细胞学说的提出为认识肿瘤提供了新的思路,越来越多种肿瘤的干细胞得到了分离鉴定;本实验旨在检测结直肠癌细胞系SW480中侧群细胞(side population, SP)亚群,通过无血清培养基初步分离SW480肿瘤干细胞相关亚群。方法:采用流式细胞术检测结直肠癌细胞系SW480中的SP细胞含量,添加表皮生长因子20μg/L、碱性成纤维生长因子10μg/L的无血清培养基(SFM)培养SW480,初步分离,富集肿瘤干细胞样亚群,有限稀释实验,诱导分化,传代更新,含血清/无血清培养基交替培养证实肿瘤干细胞相关亚群。结果:SW480细胞系中SP细胞含量为1.2%;SW480细胞中0.54%～0.62%的细胞能在无血清培养基中存活、增殖并形成悬浮肿瘤细胞球;在SFM中加入血清可促使肿瘤干细胞相关细胞分化;肿瘤干细胞相关细胞可以连续传代,并可交替培养于含10%小牛血清培养基(SSM)和SFM中。结论:结直肠癌细胞系SW480中含SP细胞,SW480中的肿瘤干细胞相关亚群可通过无血清培养基初步富集。

Background and purpose： The theory of cancer stem cell offers us a new thought about tumors, more and more kinds of cancer stem cell were isolated and indentified from corresponding cancer tissue. Our aim was to investigate the content of side population cells in SW480 human coloreetal cancer cell line and to enrich cancer stemlike cells in SW480 through serum-free medium （SFM） culture. Methods： The percentage of side population cells in human colorectal cancer cell line SW480 was detected with flow cytometry. SW480 cell line was cultivated in serumfree medium（SFM） supplemented with growth factors and the cancer stem-like cells reforming into floating spheres were isolated. The isolated cancer stem-like cells were identified by limited-dilution assay, differentiation assay, selfrenewal assay, and alternative cultivation assay. Results： The percentage of SP cells was 1.2% in SW4803n the absence of serum, a minority （0.54%-0.62%） of cancer stem-like cells in SW480 cells survived, proliferated and formed into the suspended tumor cell spheres. SW480 cancer stem-like cells possessed proliferative, self-renewal and differentiation potential, which were responsible for the floating tumor clone. Serum addition into SFM resulted in the proliferation of cancer stem-like cells; after several generations and alternated cultivation in SSM and SFM, cancer stem-like cells maintained their characteristics. Conclusions： SW480 cell line contains a tiny minority of SP cells with stem cell properties.The cancer stem-like cells in SW480 line can be maintained in SFM using a floating culture method.