title: [Isolation and identification of side population cells in human lung adenocarcinoma cell line A549].
abstract: OBJECTIVE
  To isolate and characterize the side population cells (SP cells) in the lung adenocarcinomas cell line A549.
  
  
  METHODS
  The protein expression of ABCG2 in human lung adenocarcinoma cell line A549 was detected by immunohistochemistry. SP and NSP cells in the cell line A549 were isolated by FACS, and their differentiation was analysed. ABCG2 expression in the two cell subsets was detected by RT-PCR. The cell growth curves, cell division indexes, cell cycles, plate clone formation tests, migration and invasion assays, chemotherapeutic susceptibility tests, tests of the intracellular drug levels, and the tumor cell implantation experiments on nude mice were applied to study the biological properties of the two cell subsets. The expression of ABCG2 in the transplanted tumor in nude mice was detected by immunohistochemistry and RT-PCR.
  
  
  RESULTS
  The positive rate of ABCG2 expression in the A549 cells by immunohistochemistry was 2.13%. SP and NSP cells were isolated by FACS. The SP cells could produce both SP and NSP cells, while NSP cells only produced NSP cells. SP cells expressed ABCG2, but NSP cells did not. The proliferation and migration abilities of the two cell subsets were similar, but the invasion and tumorigenic ability of SP cells was significantly higher than that of NSP cells. The susceptibilities to DDP and its intracellular levels of the two cell subsets were similar, but the susceptibilities to 5-FU, VP16, NVB and GEM and their intracellular levels of NSP cells were significantly higher than those of the SP cells.
  
  
  CONCLUSIONS
  SP cells in the human lung adenocarcinomas cell line A549 is enriched with tumor stem cells. An effective way to get lung adenocarcinomas stem cells is to isolate SP cells by FACS.
authors.affiliation: Department of Thoracic Surgery, the Affiliated Tumor Hospital of Guangxi Medical University, Nanning 530021, China. xietong88@126.com
authors.forename: Tong
authors.initials: T
authors.lastname: Xie
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Dan-rong
authors.initials: DR
authors.lastname: Li
authors.forename: Nai-quan
authors.initials: NQ
authors.lastname: Mao
authors.forename: De-seng
authors.initials: DS
authors.lastname: Liu
authors.forename: Chuan-tian
authors.initials: CT
authors.lastname: Zuo
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Ding-ming
authors.initials: DM
authors.lastname: Huang
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D000230:Adenocarcinoma / Q000473:pathology*; D000077192:Adenocarcinoma of Lung; D000818:Animals; D002453:Cell Cycle; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002471:Cell Transformation, Neoplastic / Q000378:metabolism; D005472:Fluorouracil / Q000378:metabolism; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology*; D008819:Mice, Nude; D009363:Neoplasm Proteins / Q000378:metabolism; D009368:Neoplasm Transplantation; D014411:Neoplastic Stem Cells / Q000187:drug effects*; D058985:Side-Population Cells
chemical_list: D018528:ATP-Binding Cassette Transporters; D009363:Neoplasm Proteins; D005472:Fluorouracil