title: Adipose tissue-derived stem cells promote prostate tumor growth.
abstract: BACKGROUND
  Recent evidence indicates that cancer stem cells play an important role in tumor initiation and maintenance. Additionally, the effect of tissue-resident stem cells located in the surrounding healthy tissue on tumor progression has been demonstrated. While most knowledge has been derived from studies of breast cancer cells, little is known regarding the influence of tissue resident stem cells on the tumor biology of prostate cancer.
  
  
  METHODS
  Twenty male athymic Swiss nu/nu mice (age: 6-8 weeks) were randomized into two treatment groups: (1) subcutaneous injection of 10(6) MDA PCa 118b human prostate cancer cells into the upper back or (2) subcutaneous injection of 10(6) MDA PCa 118b cells mixed directly with 10(5) GFP-labeled human adipose tissue-derived stem cells (hASCs). Tumor growth and volumes over the ensuing 3 weeks were assessed using calipers and micro-computed tomography. Immunohistochemistry was performed to identify engrafted hASCs in tumor sections.
  
  
  RESULTS
  At 3 weeks after injection, the mean tumor volume in the MDA PCa 118b/hASC co-injection group (1019.95 ± 73.49 mm(3)) was significantly higher than that in the MDA PCa 118b-only group (308.70 ± 21.06 mm(3)). Engrafted hASCs exhibited the nuclear marker of proliferation Ki67 and expressed markers for endothelial differentiation, indicating their engraftment in tumor vessels.
  
  
  CONCLUSIONS
  Our study revealed for the first time that ASCs subcutaneously co-injected with prostate cancer cells engraft and promote tumor progression. Further evaluation of the cross-talk between tumor and local tissue-resident stem cells may lead to new strategies for prostate cancer therapy.
authors.affiliation: Department of Molecular Pathology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
authors.forename: Lukas
authors.initials: L
authors.lastname: Prantl
authors.forename: Fabian
authors.initials: F
authors.lastname: Muehlberg
authors.forename: Nora M
authors.initials: NM
authors.lastname: Navone
authors.forename: Yao-Hua
authors.initials: YH
authors.lastname: Song
authors.forename: Jody
authors.initials: J
authors.lastname: Vykoukal
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Logothetis
authors.forename: Eckhard U
authors.initials: EU
authors.lastname: Alt
mesh_terms: D000273:Adipose Tissue / Q000166:cytology*; D000818:Animals; D004195:Disease Models, Animal; D005434:Flow Cytometry; D016130:Immunophenotyping; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation / Q000379:methods; D014411:Neoplastic Stem Cells / Q000166:cytology / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000473:pathology*; D011897:Random Allocation; D014057:Tomography, X-Ray Computed