title: A negative selection system PowerMag for effective leukocyte depletion and enhanced detection of EpCAM positive and negative circulating tumor cells.
abstract: BACKGROUND
  Circulating tumor cells (CTCs) can be enriched from peripheral blood by leukocyte depletion. In this study, a PowerMag system was designed to enhance leukocyte depletion and CTC detection.
  
  
  METHODS
  The efficiency of PowerMag in leukocyte depletion and recovery of CTCs was evaluated. The cell populations in leukocyte-depleted cell filtrate were characterized by immunofluorescence staining using anti-EpCAM and anti-CD45 antibodies. The suitability of PowerMag in monitoring cancer patient CTCs was assessed by analyzing blood samples collected at baseline and 2 weeks after baseline from the patients with colorectal cancer (CRC, n=24) and head and neck squamous cell carcinoma (HNSCC, n=28).
  
  
  RESULTS
  Only few contaminated CD45(+)-leukocytes were retained in the leukocyte-depleted cell filtrate. The enriched CTCs were viable with a recovery rate of 46-62%. Immunofluorescence staining of the nucleated cells enriched by PowerMag revealed 2 major cell populations EpCAM(+)CD45(-) and EpCAM(-)CD45(-). The number for both cell types was significantly increased in cancer patients when compared to healthy control. After chemotherapy, the number of EpCAM(+)CD45(-) and EpCAM(-)CD45(-) cells was decreased more prominently for CRC and HNSCC patients, respectively.
  
  
  CONCLUSIONS
  PowerMag holds great promise as a platform for leukocyte depletion and CTC detection in a clinical setting.
authors: Graduate Institute of Biomedical Science, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan, ROC.
authors: Hung-Chih
authors: HC
authors: Lin
authors: Hung-Chih
authors: HC
authors: Hsu
authors: Chia-Hsun
authors: CH
authors: Hsieh
authors: Hung-Ming
authors: HM
authors: Wang
authors: Chi-Ya
authors: CY
authors: Huang
authors: Min-Hsien
authors: MH
authors: Wu
authors: Ching-Ping
authors: CP
authors: Tseng
mesh_terms: D000951:Antigens, Neoplasm / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000097:blood / Q000175:diagnosis; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000097:blood / Q000175:diagnosis; D000071858:Epithelial Cell Adhesion Molecule; D005434:Flow Cytometry / Q000295:instrumentation; D006258:Head and Neck Neoplasms / Q000097:blood / Q000175:diagnosis; D006801:Humans; D047589:Leukocyte Reduction Procedures / Q000295:instrumentation / Q000379:methods*; D008280:Magnetics / Q000295:instrumentation; D009360:Neoplastic Cells, Circulating / Q000378:metabolism* / Q000473:pathology*
chemical_list: D000951:Antigens, Neoplasm; D015815:Cell Adhesion Molecules; D000071858:Epithelial Cell Adhesion Molecule