title: Effective enrichment of prostate cancer stem cells from spheres in a suspension culture system.
abstract: BACKGROUND
  Stem-like prostate cancer cells are also called prostate cancer stem cells (PrCSCs). These rare cells are supposed to be highly tumorigenic and to be involved in maintenance of tumor homeostasis and mediation of tumor metastasis. Methods for sorting PrCSCs are mainly based on sorting cells with the marker (CD133(+)/CD44(+)) or side population cells. However, CD133(+)/CD44(+) cells or side population cells are very rare or even undetectable. The scarcity of approaches for isolation and purification of PrCSCs is the main obstacle to studying PrCSCs.
  
  
  METHODS
  In the present study, suspension culture was used for enrichment of PrCSCs. And PrCSCs were verified by side population technology, drug sensitivity assays, and the molecular marker analysis of prostate cancer stem cell.
  
  
  RESULTS
  PC3 cells survived and formed spheres in nonadherent suspension culture. The percentage of CD44(+)/CD133(+) cells was 18-fold higher in the nonadherent sphere-forming cell population than in the adherent PC3 cell population (13.94% vs. 0.77%, respectively). This side population was increased to 3.1% in the nonadherent population but undetectable in adherent population. Resistance to cisplatin was higher in the nonadherent cells than adherent cells.
  
  
  CONCLUSIONS
  Suspension culture can be used to enrich for PrCSCs. This approach will aid prostate stem cell biology research and facilitate identification of novel therapeutic agents for prostate cancer.
authors.affiliation: Center of Medical Research, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Xinlan
authors.initials: X
authors.lastname: Fan
authors.forename: Shanying
authors.initials: S
authors.lastname: Liu
authors.forename: Fang
authors.initials: F
authors.lastname: Su
authors.forename: Qiuhui
authors.initials: Q
authors.lastname: Pan
authors.forename: Tianxin
authors.initials: T
authors.lastname: Lin
mesh_terms: D000071916:AC133 Antigen; D015703:Antigens, CD / Q000096:biosynthesis; D000970:Antineoplastic Agents / Q000494:pharmacology; D018929:Cell Culture Techniques; D045744:Cell Line, Tumor; D002469:Cell Separation; D002945:Cisplatin / Q000494:pharmacology; D019008:Drug Resistance, Neoplasm; D004354:Drug Screening Assays, Antitumor / Q000379:methods; D005434:Flow Cytometry / Q000379:methods; D006023:Glycoproteins / Q000096:biosynthesis; D006801:Humans; D018960:Hyaluronan Receptors / Q000096:biosynthesis; D008297:Male; D014411:Neoplastic Stem Cells / Q000473:pathology*; D010455:Peptides; D011471:Prostatic Neoplasms / Q000473:pathology*; D058985:Side-Population Cells / Q000166:cytology
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D000970:Antineoplastic Agents; D006023:Glycoproteins; D018960:Hyaluronan Receptors; C000606023:PROM1 protein, human; D010455:Peptides; D002945:Cisplatin