Preliminary isolation and identifi cation of cancer stem-like cells in colon cancer cell line SW480 / 中国癌症杂志

ABSTRACT

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 indentif ied from corresponding cancer tissue. Our aim was to investigate the content of side population cells in SW480 human colorectal cancer ce11 line and to enrich cancer stem- like 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 ? ow cytometry. SW480 cell line was cultivated in serum- free medium(SFM) supplemented with growth factors and the cancer stem-like cells reforming into ? oating spheres were isolated. The isolated cancer stem-like cells were identifi ed by limited-dilution assay, differentiation assay, self- renewal assay, and alternative cultivation assay. Results:The percentage of SP cells was 1.2% in SW480,In 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 ? oating 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.