title: Cell adhesion manipulation through single cell assembly for characterization of initial cell-to-cell interaction.
abstract: BACKGROUND
  Cell-to-cell interactions are complex processes that involve physical interactions, chemical binding, and biological signaling pathways. Identification of the functions of special signaling pathway in cell-to-cell interaction from the very first contact will help characterize the mechanism underlying the interaction and advance new drug discovery.
  
  
  METHODS
  This paper reported a case study of characterizing initial interaction between leukemia cancer cells and bone marrow stromal cells, through the use of an optical tweezers-based cell manipulation tool. Optical traps were used to assemble leukemia cells at different positions of the stromal cell layer and enable their interactions by applying a small trapping force to maintain the cell contact for a few minutes. Specific drug was used to inhibit the binding of molecules during receptor-ligand-mediated adhesion.
  
  
  CONCLUSIONS
  Our results showed that the amount of adhesion molecule could affect cell adhesion during the first few minutes contact. We also found that leukemia cancer cells could migrate on the stromal cell layer, which was dependent on the adhesion state and activation triggered by specific chemokine. The reported approaches provided a new opportunity to investigate cell-to-cell interaction through single cell adhesion manipulation.
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong, China. xuegou3-c@my.cityu.edu.hk.
authors.forename: Xue
authors.initials: X
authors.lastname: Gou
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong, China. ranwang7-c@my.cityu.edu.hk.
authors.forename: Ran
authors.initials: R
authors.lastname: Wang
authors.affiliation: Department of Medicine, The University of Hong Kong, Hong Kong, China. stephen_lsy127@me.com.
authors.forename: Stephen S Y
authors.initials: SS
authors.lastname: Lam
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong, China. jdhou2-c@my.cityu.edu.hk.
authors.forename: Jundi
authors.initials: J
authors.lastname: Hou
authors.affiliation: Department of Medicine, The University of Hong Kong, Hong Kong, China. ayhleung@hku.hk.
authors.forename: Anskar Y H
authors.initials: AY
authors.lastname: Leung
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong, China. medsun@cityu.edu.hk.
authors.forename: Dong
authors.initials: D
authors.lastname: Sun
mesh_terms: D002448:Cell Adhesion / Q000502:physiology*; D002450:Cell Communication / Q000502:physiology*; D002460:Cell Line; D002469:Cell Separation / Q000295:instrumentation / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000473:pathology / Q000503:physiopathology*; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000502:physiology*; D008846:Micromanipulation / Q000295:instrumentation* / Q000379:methods; D052898:Optical Tweezers; D013314:Stress, Mechanical