title: Long-term in vitro growth of human insulin-secreting insulinoma cells.
abstract: OBJECTIVE
  Long-term in vitro maintenance of human insulin-secreting insulinoma cells.
  
  
  METHODS
  (1) Cell culture of ex vivo-derived insulinoma cell suspensions from 8 individual human donors, using various cell culture medium supplementations; (2) determination of insulin synthesis and secretion using immunocytochemistry and insulin and pro-insulin radioimmunoassays; (3) nestin-immunostaining of long-term in vitro grown insulinoma cell suspensions, and (4) phase-contrast light microscopy for analyzing the in vitro growth characteristics of the insulinoma cells.
  
  
  RESULTS
  (1) Parallel persistence of in vitro insulinoma cell proliferation as well as insulin-synthesizing and -secreting capacity depended on both the co-culture of insulinoma cells with human fibroblasts and the supplementation of the cell culture medium with tissue culture supernatant derived from the rodent pituitary adenoma cell line GH-3; (2) immunostaining for insulin and secretagogin confirmed the neuroendocrine origin of the insulinoma cells grown in vitro; (3) insulin secretion capability persisted up to an observation period of 25 weeks; (4) insulin secretion rates after 6 weeks of in vitro growth ranged from 3.5 to 83.3 muU/ml/h/60,000 cells plated, and (5) after long-term in vitro growth of insulinoma-derived cell suspensions with persistent insulin-secreting capacity, nestin staining was observed predominantly in co-cultured fibroblasts.
  
  
  CONCLUSIONS
  Our data describe for the first time the long-term in vitro culture of insulin-secreting human insulinomas and highlight the importance of beta-cell trophic factors for insulinoma cell growth.
authors.affiliation: Department of Medicine III, Medical University Vienna, Vienna, Austria.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Gartner
authors.forename: Filiz
authors.initials: F
authors.lastname: Koc
authors.forename: Anastasya
authors.initials: A
authors.lastname: Nabokikh
authors.forename: Teodora
authors.initials: T
authors.lastname: Daneva
authors.forename: Bruno
authors.initials: B
authors.lastname: Niederle
authors.forename: Anton
authors.initials: A
authors.lastname: Luger
authors.forename: Ludwig
authors.initials: L
authors.lastname: Wagner
mesh_terms: D000328:Adult; D018929:Cell Culture Techniques / Q000379:methods; D049109:Cell Proliferation; D018920:Coculture Techniques / Q000379:methods; D017077:Culture Media, Conditioned / Q000494:pharmacology; D005260:Female; D005347:Fibroblasts / Q000502:physiology; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000502:physiology*; D007340:Insulinoma / Q000473:pathology*; D007381:Intermediate Filament Proteins / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000378:metabolism; D064231:Nestin; D011863:Radioimmunoassay / Q000379:methods; D013997:Time Factors; D014407:Tumor Cells, Cultured
chemical_list: D017077:Culture Media, Conditioned; D007328:Insulin; D007381:Intermediate Filament Proteins; C577484:NES protein, human; D009419:Nerve Tissue Proteins; D064231:Nestin