title: Mammosphere cells from high-passage MCF7 cell line show variable loss of tumorigenicity and radioresistance.
abstract: Mammosphere culture of cancer cell lines is an important approach used for enrichment of stem-like cancer cells (SLCs), but over-subcultured cell lines have been experimentally shown to change properties over time. It remains unclear if mammosphere cells (MSs) derived from high-passage cancer cell lines retain the tumorigenicity and radioresistance seen in MSs from primary or low-passage cell lines. In this study, we report that mammospheres derived from MCF-7 sublines after different passage numbers were consistently enriched for CD44+/CD24(-/low) cells but were not consistently enriched for tumorigenic and radioresistant cells. The tumorigenicity and radioresistance of MSs were associated with their sphere-forming ability, proliferation ability in vitro, and intracellular reactive oxygen species (ROS) levels. The radioresistant MSs showed significant cell cycle arrest in G2/M phase after X-ray irradiation and expressed higher ataxia telangiectasia mutated (ATM) mRNA levels. These results suggest that MSs from high-passage cancer cell lines were not consistently enriched for stem-like cancer cells with higher tumorigenicity and enhanced radioresistance.
authors: Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, PR China.
authors: Guozhu
authors: G
authors: Xie
authors: Junfang
authors: J
authors: Zhan
authors: Yunhong
authors: Y
authors: Tian
authors: Ying
authors: Y
authors: Liu
authors: Zhixian
authors: Z
authors: Chen
authors: Chen
authors: C
authors: Ren
authors: Quanquan
authors: Q
authors: Sun
authors: Jianping
authors: J
authors: Lian
authors: Longhua
authors: L
authors: Chen
authors: Jian
authors: J
authors: Ruan
authors: Changsheng
authors: C
authors: Ye
authors: Aimin
authors: A
authors: Sun
authors: Yawei
authors: Y
authors: Yuan
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology* / Q000532:radiotherapy*; D051927:CD24 Antigen / Q000378:metabolism; D059447:Cell Cycle Checkpoints / Q000235:genetics; D002455:Cell Division / Q000235:genetics; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D016195:G2 Phase / Q000235:genetics; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D014411:Neoplastic Stem Cells / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics; D011836:Radiation Tolerance; D017382:Reactive Oxygen Species / Q000378:metabolism; D018874:Spheroids, Cellular; D013684:Telangiectasis / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D014965:X-Rays
chemical_list: D051927:CD24 Antigen; D018960:Hyaluronan Receptors; D012333:RNA, Messenger; D017382:Reactive Oxygen Species