title: Unique characteristics of human mesenchymal stromal/progenitor cells pre-activated in 3-dimensional cultures under different conditions.
abstract: OBJECTIVE
  Human mesenchymal stromal cells (MSCs) are being used in clinical trials, but the best protocol to prepare the cells for administration to patients remains unclear. We previously demonstrated that MSCs could be pre-activated to express therapeutic factors by culturing the cells in 3 dimensions (3D). We compared the activation of MSCs in 3D in fetal bovine serum containing medium and in multiple xeno-free media formulations.
  
  
  METHODS
  MSC aggregation and sphere formation was studied with the use of hanging drop cultures with medium containing fetal bovine serum or with various commercially available stem cell media with or without human serum albumin (HSA). Activation of MSCs was studied with the use of gene expression and protein secretion measurements and with functional studies with the use of macrophages and cancer cells.
  
  
  RESULTS
  MSCs did not condense into tight spheroids and express a full complement of therapeutic genes in α-minimum essential medium or several commercial stem-cell media. However, we identified a chemically defined xeno-free media, which, when supplemented with HSA from blood or recombinant HSA, resulted in compact spheres with high cell viability, together with high expression of anti-inflammatory (prostaglandin E2, TSG-6 TNF-alpha induced gene/protein 6) and anti-cancer molecules (TRAIL TNF-related apoptosis-inducing ligand, interleukin-24). Furthermore, spheres cultured in this medium showed potent anti-inflammatory effects in a lipopolysaccharide-stimulated macrophage system and suppressed the growth of prostate cancer cells by promoting cell-cycle arrest and cell death.
  
  
  CONCLUSIONS
  We demonstrated that cell activation in 3D depends critically on the culture medium. The conditions developed in the present study for 3D culture of MSCs should be useful in further research on MSCs and their potential therapeutic applications.
authors.affiliation: Institute for Regenerative Medicine, Texas A&M University Health Science Center College of Medicine at Scott & White, Temple, TX, USA.
authors.forename: Joni H
authors.initials: JH
authors.lastname: Ylostalo
authors.affiliation: Institute for Regenerative Medicine, Texas A&M University Health Science Center College of Medicine at Scott & White, Temple, TX, USA.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Bartosh
authors.affiliation: Institute for Regenerative Medicine, Texas A&M University Health Science Center College of Medicine at Scott & White, Temple, TX, USA.
authors.forename: April
authors.initials: A
authors.lastname: Tiblow
authors.affiliation: Institute for Regenerative Medicine, Texas A&M University Health Science Center College of Medicine at Scott & White, Temple, TX, USA. Electronic address: prockop@medicine.tamhsc.edu.
authors.forename: Darwin J
authors.initials: DJ
authors.lastname: Prockop
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D003470:Culture Media / Q000737:chemistry*; D015232:Dinoprostone / Q000096:biosynthesis; D006801:Humans; D066298:In Vitro Techniques / Q000379:methods*; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D012709:Serum Albumin / Q000737:chemistry; D018874:Spheroids, Cellular / Q000166:cytology / Q000187:drug effects
chemical_list: D003470:Culture Media; D012709:Serum Albumin; D015232:Dinoprostone
keywords: 3D; MSC; pre-activation; sphere; stem cell; xeno-free