title: Detection and characterization of side population in Ewing's sarcoma SK-ES-1 cells in vitro.
abstract: Dye exclusion is a valuable technique to isolate cancer stem cells (CSCs) based on an ability of stem cell to efflux fluorescent DNA-binding dye, especially for tumors without unique surface markers. It has been proven that side population (SP) cells that exclude Hoechst 33342 dye are enriched with stem-like cells in several cancer cell lines. In this study, we isolated and characterized SP cells from human Ewing's sarcoma cell line SK-ES-1 in vitro. SP cells were detected in SK-ES-1 and comprised 1.2% of total cell population. Only SP cells had the capacity to regenerate both SP and non-SP cells. The proliferation rates were similar between SP and non-SP cells. However, the clonogenicity and invasiveness of SP cells were significantly higher than that of non-SP cells. Further characterization of this SP phenotype presented other properties. SP cells exhibited increased multi-drug resistance and the ATP binding cassette protein (ABC) transporters were up-regulated in SP population. These findings suggest that SP cells derived from Ewing's sarcoma play the critical role in tumor metastasis and recurrence and might be an ideal target for clinical therapy.
authors.affiliation: Institute of Orthopaedics and Traumatology of PLA of China, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, PR China.
authors.forename: Min
authors.initials: M
authors.lastname: Yang
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.forename: Ming
authors.initials: M
authors.lastname: Yan
authors.forename: Zhengxu
authors.initials: Z
authors.lastname: Ye
authors.forename: Wei
authors.initials: W
authors.lastname: Liang
authors.forename: Zhuojing
authors.initials: Z
authors.lastname: Luo
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000096:biosynthesis; D000970:Antineoplastic Agents / Q000494:pharmacology; D001562:Benzimidazoles / Q000378:metabolism; D001859:Bone Neoplasms / Q000473:pathology*; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002469:Cell Separation / Q000379:methods; D002999:Clone Cells / Q000378:metabolism / Q000473:pathology; D019008:Drug Resistance, Neoplasm; D005456:Fluorescent Dyes / Q000378:metabolism; D006801:Humans; D009363:Neoplasm Proteins / Q000096:biosynthesis; D014411:Neoplastic Stem Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D012333:RNA, Messenger / Q000096:biosynthesis; D012038:Regeneration; D012512:Sarcoma, Ewing / Q000473:pathology*
chemical_list: C513055:ABCB1 protein, human; C116614:ABCG2 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D000970:Antineoplastic Agents; D001562:Benzimidazoles; D005456:Fluorescent Dyes; D009363:Neoplasm Proteins; D012333:RNA, Messenger; C017807:bisbenzimide ethoxide trihydrochloride