title: Human Adipose-Derived Mesenchymal Stromal Cells May Promote Breast Cancer Progression and Metastatic Spread.
abstract: BACKGROUND
  Stem cell-enriched fat grafting has been proposed as a potential therapy for reconstructive, restorative, or enhancement-related procedures of the breast. Its role in postoncologic breast reconstruction is still emerging, with concerns about safety. The authors investigated the dose-dependent interaction between human adipose-derived mesenchymal stromal cells (AD-MSCs) and human breast cancer cell (BCC) lines [MDA-MB-231 (MDA) and MCF-7 (MCF)] focusing on tumor microenvironment, tumor growth, and metastatic spread.
  
  
  METHODS
  Adipose-derived mesenchymal stromal cell influence on viability and factor expression [regulated on activation, normal T cell expressed and secreted (RANTES), tumor necrosis factor-α, and eotaxin) of breast cancer cells was studied in vitro using direct and indirect co-culture systems. Groups were formed according to adipose-derived mesenchymal stromal cell-to-cancer cell number ratio [MDA/MCF only, AD-MSC/(MDA/MCF), and AD-MSC/(MDA/MCF)]. A humanized orthotopic murine cancer model was used to evaluate breast cancer progression and metastasis (n = 10/group). Cells were injected into the mammary pad in different ratios and animals were monitored over 42 days. Microdialysis was performed to analyze RANTES levels in the tumor microenvironment (days 21 and 42). Primary and metastatic tumors were weighed and analyzed for oncogene, growth factor, and metastatic marker expression.
  
  
  RESULTS
  MDA cell viability increased from 45.5 percent to 95.5 percent in presence of adipose-derived mesenchymal stromal cells in vitro. In vivo, animals with AD-MSC showed increased mean tumor weight (MDA, p < 0.01; MCF versus controls, p < 0.05) and metastatic occurrence (40 percent in MDA; 30 percent in MCF versus 0 percent in controls). Cytokine analysis revealed switching of MCF tumor phenotype to a more malignant type in the presence of adipose-derived mesenchymal stromal cells.
  
  
  CONCLUSIONS
  Human adipose-derived mesenchymal stromal cells may promote progression and metastatic spread in breast cancer through a switch to a more malignant phenotype with worse prognosis.
authors.affiliation: Zurich and Bern, Switzerland; and Pittsburgh, Pa. From the Department of Plastic Surgery and Hand Surgery and the Center for Clinical Research, Laboratory for Urologic Tissue Engineering and Stem Cell Therapy, University Hospital Zurich; the Department of Clinical Research, Mammary Gland Biology and Carcinogenesis, University of Bern; and the Department of Plastic Surgery, University of Pittsburgh Medical Center, University of Pittsburgh.
authors.forename: Pranitha
authors.initials: P
authors.lastname: Kamat
authors.forename: Riccardo
authors.initials: R
authors.lastname: Schweizer
authors.forename: Philip
authors.initials: P
authors.lastname: Kaenel
authors.forename: Souzan
authors.initials: S
authors.lastname: Salemi
authors.forename: Maurizio
authors.initials: M
authors.lastname: Calcagni
authors.forename: Pietro
authors.initials: P
authors.lastname: Giovanoli
authors.forename: Vijay S
authors.initials: VS
authors.lastname: Gorantla
authors.forename: Daniel
authors.initials: D
authors.lastname: Eberli
authors.forename: Anne-Catherine
authors.initials: AC
authors.lastname: Andres
authors.forename: Jan A
authors.initials: JA
authors.lastname: Plock
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D000818:Animals; D001943:Breast Neoplasms / Q000473:pathology*; D002470:Cell Survival; D018450:Disease Progression; D005260:Female; D006801:Humans; D061986:MCF-7 Cells; D008325:Mammary Neoplasms, Experimental / Q000473:pathology*; D045164:Mesenchymal Stem Cell Transplantation / Q000009:adverse effects*; D051379:Mice; D009362:Neoplasm Metastasis; D009368:Neoplasm Transplantation; D047368:Tumor Burden; D059016:Tumor Microenvironment