title: Hormone-deprived serum impairs angiogenic properties in human endothelial cells regardless of estrogens.
abstract: OBJECTIVE
  In vitro studies on hormone biological activities are commonly performed on cells cultured in nominally hormone-free media consisting of phenol-red-free media supplemented with charcoal-stripped (CS) serum. These media are largely used in almost all cell types, including endothelial cells (ECs).
  
  
  METHODS
  Cell number and metabolic activity were measured with standard methods. Angiogenesis was evaluated in a three-dimensional spheroid sprouting assay.
  
  
  RESULTS
  When we compared human umbilical vein ECs (HUVECs) cultured in standard conditions (199 medium supplemented with normal serum) with HUVECs grown in the hormone-free medium (phenol-red-free 199 medium supplemented with CS serum), we found that cells stop to grow in the absence of hormones. Notably, neither 17-β2 estradiol nor dihydrotestosterone reversed this inhibition. Moreover, the presence of the CS serum was sufficient to abrogate the ability of HUVECs to sprout in a three-dimensional spheroid assay, thus affecting a functional property of ECs.
  
  
  CONCLUSIONS
  Our results suggest that one or possibly more substances removed by stripping procedure from serum and different from sex hormones are crucial for the maintenance of in vitro ECs distinctive properties. Therefore, caution should be used when ECs are studied in media containing the CS serum.
authors.affiliation: a Department of Medical Biotechnology and Translational Medicine , Università degli Studi di Milano , Milano , Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Vanetti
authors.affiliation: a Department of Medical Biotechnology and Translational Medicine , Università degli Studi di Milano , Milano , Italy.
authors.forename: Lucia M
authors.initials: LM
authors.lastname: Vicentini
authors.affiliation: a Department of Medical Biotechnology and Translational Medicine , Università degli Studi di Milano , Milano , Italy.
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Cattaneo
mesh_terms: D001681:Biological Assay / Q000592:standards*; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000378:metabolism*; D004967:Estrogens / Q000378:metabolism*; D006801:Humans; D018919:Neovascularization, Physiologic / Q000502:physiology*; D014471:Umbilical Veins
chemical_list: D004967:Estrogens
keywords: Cell growth; endothelial cells; hormone-deprived serum; in vitro angiogenesis; sex steroids