title: Side population cells from long-term passage non-small cell lung cancer cells display loss of cancer stem cell-like properties and chemoradioresistance.
abstract: The side population (SP) assay is a widely used method for isolating stem cell-like cells from cancer cell lines and primary cells. The cancer cells used in different laboratories have been passaged for different generations. Emerging evidence revealed that repeated passaging of cell lines for multiple generations frequently leads to change of characteristics. Thus, it is worth investigating the effects of repeated passaging on the biological and functional properties of the enriched SP fraction from early- and late-passage cells. The present study reports that the cancer stem cell (CSC) characteristics, including increased frequency of tumor-initiating and self-renewal capacity, and resistance to the chemotherapy agent doxorubicin and ionizing radiation, was diminished in SP cells from late-passage non-small cell lung cancer (NSCLC) cells. This finding revealed that the SP from long-term passage NSCLC cells was not consistently enriched for stem cell-like cancer cells, and low-passage cell lines and primary cancer cells are therefore recommended in the CSCs field.
authors.affiliation: Department of Radiation Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China.
authors.forename: Hao
authors.initials: H
authors.lastname: Gu
authors.affiliation: Department of Nuclear Medicine, Henan Provincial People's Hospital and The People's Hospital of Zhengzhou University, Zhengzhou, Henan 450003, P.R. China.
authors.forename: Xin-Yu
authors.initials: XY
authors.lastname: Wu
authors.affiliation: Department of Radiation Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China.
authors.forename: Rui-Tai
authors.initials: RT
authors.lastname: Fan
authors.affiliation: Department of Radiation Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Radiation Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China.
authors.forename: You-Zhong
authors.initials: YZ
authors.lastname: Guo
authors.affiliation: Department of Radiation Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China.
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
keywords: cancer stem cell; early passage; late passage; resistance; side population; tumorigenicity