title: Establishment of a human colorectal cancer cell line P6C with stem cell properties and resistance to chemotherapeutic drugs.
abstract: OBJECTIVE
  Cancer stem cells have the capacity to initiate and sustain tumor growth. In this study, we established a CD44(+) colorectal cancer stem cell line with particular emphasis on its self-renewal capacity, enhanced tumor initiation and drug resistance.
  
  
  METHODS
  Fresh colon cancer and paired normal colon tissues were collected from 13 patients who had not received chemotherapy or radiotherapy prior to surgery. Among the 6 single-cell derived clones, only the P6C cell line was cultured for more than 20 passages in serial culture and formed holoclones with high efficiency, and then the stemness gene expression, colony formation, tumorigenicity and drug sensitivities of the P6C cell line were examined.
  
  
  RESULTS
  Stemness proteins, including c-Myc, Oct3/4, Nanog, Lgr5, and SOX2, were highly expressed in the P6C cell line. Oct3/4-positive P6C cells mostly generated holoclones through symmetric division, while a small number of P6C cells generated meroclones through asymmetric division. P6C cells stably expressed CD44 and possessed a high capacity to form tumor spheres. A single cell-derived sphere was capable of generating xenograft tumors in nude mice. Compared to SW480 and HCT116 colorectal cancer cells, P6C cells were highly resistant to Camptothecin and 5-fluorouracil, the commonly used chemotherapeutic agents to treat colorectal cancers.
  
  
  CONCLUSIONS
  We established a colorectal cancer stem cell line P6C with a high tumorigenic capacity and the characteristics of normal stem cells. It will benefit the mechanistic studies on cancer stem cells and the development of drugs that specifically target the cancer stem cells.
authors.affiliation: Tianjin Key Laboratory of Protein Sciences, College of Life Sciences, Nankai University, Tianjin 300071, China.
authors.forename: Guan-hua
authors.initials: GH
authors.lastname: Rao
authors.forename: Hong-min
authors.initials: HM
authors.lastname: Liu
authors.forename: Bao-wei
authors.initials: BW
authors.lastname: Li
authors.forename: Jia-jie
authors.initials: JJ
authors.lastname: Hao
authors.forename: Yan-lei
authors.initials: YL
authors.lastname: Yang
authors.forename: Ming-rong
authors.initials: MR
authors.lastname: Wang
authors.forename: Xiao-hui
authors.initials: XH
authors.lastname: Wang
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Hai-jing
authors.initials: HJ
authors.lastname: Jin
authors.forename: Lei
authors.initials: L
authors.lastname: Du
authors.forename: Quan
authors.initials: Q
authors.lastname: Chen
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002166:Camptothecin / Q000494:pharmacology; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D015195:Drug Design; D019008:Drug Resistance, Neoplasm; D005260:Female; D005472:Fluorouracil / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic; D045325:HCT116 Cells; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008875:Middle Aged; D058990:Molecular Targeted Therapy; D014411:Neoplastic Stem Cells / Q000378:metabolism*; D023041:Xenograft Model Antitumor Assays / Q000379:methods
chemical_list: D000970:Antineoplastic Agents; D018960:Hyaluronan Receptors; D005472:Fluorouracil; D002166:Camptothecin