title: Spontaneous dormancy of metastatic breast cancer cells in an all human liver microphysiologic system.
abstract: BACKGROUND
  Metastatic outgrowth in breast cancer can occur years after a seeming cure. Existing model systems of dormancy are limited as they do not recapitulate human metastatic dormancy without exogenous manipulations and are unable to query early events of micrometastases.
  
  
  METHODS
  Here, we describe a human ex vivo hepatic microphysiologic system. The system is established with fresh human hepatocytes and non-parenchymal cells (NPCs) creating a microenvironment into which breast cancer cells (MCF7 and MDA-MB-231) are added.
  
  
  RESULTS
  The hepatic tissue maintains function through 15 days as verified by liver-specific protein production and drug metabolism assays. The NPCs form an integral part of the hepatic niche, demonstrated within the system through their participation in differential signalling cascades and cancer cell outcomes. Breast cancer cells intercalate into the hepatic niche without interfering with hepatocyte function. Examination of cancer cells demonstrated that a significant subset enter a quiescent state of dormancy as shown by lack of cell cycling (EdU(-) or Ki67(-)). The presence of NPCs altered the cancer cell fraction entering quiescence, and lead to differential cytokine profiles in the microenvironment effluent.
  
  
  CONCLUSIONS
  These findings establish the liver microphysiologic system as a relevant model for the study of breast cancer metastases and entry into dormancy.
authors.affiliation: Department of Pathology, University of Pittsburgh, S711 Scaife Hall, 3550 Terrace Street, Pittsburgh, PA, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Wheeler
authors.affiliation: Department of Pathology, University of Pittsburgh, S711 Scaife Hall, 3550 Terrace Street, Pittsburgh, PA, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Clark
authors.affiliation: 1] Department of Pathology, University of Pittsburgh, S711 Scaife Hall, 3550 Terrace Street, Pittsburgh, PA, USA [2] Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: D P
authors.initials: DP
authors.lastname: Taylor
authors.affiliation: Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
authors.forename: C L
authors.initials: CL
authors.lastname: Young
authors.affiliation: Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: V C
authors.initials: VC
authors.lastname: Pillai
authors.affiliation: 1] Department of Pathology, University of Pittsburgh, S711 Scaife Hall, 3550 Terrace Street, Pittsburgh, PA, USA [2] Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA [3] McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA [4] University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA.
authors.forename: D B
authors.initials: DB
authors.lastname: Stolz
authors.affiliation: 1] Department of Pathology, University of Pittsburgh, S711 Scaife Hall, 3550 Terrace Street, Pittsburgh, PA, USA [2] Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: R
authors.initials: R
authors.lastname: Venkataramanan
authors.affiliation: Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
authors.forename: D
authors.initials: D
authors.lastname: Lauffenburger
authors.affiliation: Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
authors.forename: L
authors.initials: L
authors.lastname: Griffith
authors.affiliation: 1] Department of Pathology, University of Pittsburgh, S711 Scaife Hall, 3550 Terrace Street, Pittsburgh, PA, USA [2] Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA [3] McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA [4] University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA [5] Pittsburgh VA Medical Center, VA Pittsburgh Healthcare System, Pittsburgh, PA, USA.
authors.forename: A
authors.initials: A
authors.lastname: Wells
mesh_terms: D001943:Breast Neoplasms / Q000473:pathology*; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism / Q000556:secondary*; D009362:Neoplasm Metastasis; D014162:Transfection; D059016:Tumor Microenvironment