title: Persistence of side population cells with high drug efflux capacity in pancreatic cancer.
abstract: OBJECTIVE
  To investigate the persistence of side population (SP) cells in pancreatic cancer and their role and mechanism in the drug resistance.
  
  
  METHODS
  The presentation of side population cells in pancreatic cancer cell line PANC-1 and its proportion change when cultured with Gemcitabine, was detected by Hoechst 33342 staining and FACS analysis. The expression of ABCB1 and ABCG2 was detected by real-time PCR in either SP cells or non-SP cells.
  
  
  RESULTS
  SP cells do exist in PANC-1, with a median of 3.3% and a range of 2.1-8.7%. After cultured with Gemcitabine for 3 d, the proportion of SP cells increased significantly (3.8% +/- 1.9%, 10.7% +/- 3.7%, t = 4.616, P = 0.001 < 0.05). ABCB1 and ABCG2 expressed at higher concentrations in SP as compared with non-SP cells (ABCB1: 1.15 +/- 0.72, 5.82 +/- 1.16, t = 10.839, P = 0.000 < 0.05; ABCG2: 1.16 +/- 0.75, 5.48 +/- 0.94, t = 11.305, P = 0.000 < 0.05), which may contribute to the efflux of fluorescent staining and drug resistance.
  
  
  CONCLUSIONS
  SP cells with inherently high resistance to chemotherapeutic agents do exist in pancreatic cancers, which may be candidate cancer stem cells contributing to the relapse of the tumor.
authors.affiliation: Institute of Pancreatic Surgery, Union Hospital, Huazhong University of Science and Technology, 1277 Jiefang Ave, Wuhan 430022, Hubei Province, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhou
authors.forename: Chun-You
authors.initials: CY
authors.lastname: Wang
authors.forename: Tao
authors.initials: T
authors.lastname: Liu
authors.forename: Bin
authors.initials: B
authors.lastname: Wu
authors.forename: Feng
authors.initials: F
authors.lastname: Zhou
authors.forename: Jiong-Xin
authors.initials: JX
authors.lastname: Xiong
authors.forename: He-Shui
authors.initials: HS
authors.lastname: Wu
authors.forename: Jing
authors.initials: J
authors.lastname: Tao
authors.forename: Gang
authors.initials: G
authors.lastname: Zhao
authors.forename: Ming
authors.initials: M
authors.lastname: Yang
authors.forename: Shan-Miao
authors.initials: SM
authors.lastname: Gou
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism; D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism; D000964:Antimetabolites, Antineoplastic / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D048430:Cell Shape; D003841:Deoxycytidine / Q000031:analogs & derivatives / Q000378:metabolism; D019008:Drug Resistance, Neoplasm; D006801:Humans; D014411:Neoplastic Stem Cells / Q000166:cytology / Q000502:physiology*; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000473:pathology; D000093542:Gemcitabine
chemical_list: C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D018528:ATP-Binding Cassette Transporters; D000964:Antimetabolites, Antineoplastic; D014408:Biomarkers, Tumor; C073119:TAP1 protein, human; D003841:Deoxycytidine; D000093542:Gemcitabine