title: Long-term bone marrow cultured stromal cells regulate myeloma tumour growth in vitro: studies with primary tumour cells and LTBMC-dependent cell lines.
abstract: Long-term bone marrow cultured stromal cells (LTBMC) produce IL-6 after contact with tumour cells from multiple myeloma patients. We found that LTBMC could substitute for exogenous IL-6 in the stimulation of bone marrow plasma cells from myeloma patients with active disease in short-term cultures. In addition, tumour cells of some patients with inactive disease, which were unresponsive to exogenous IL-6, were induced to IL-6-dependent growth after LTBMC co-culture. To study the role of LTBMC in myeloma tumour growth in vitro, plasma cell lines UM-2 and UM-3 were selected. UM-2 and UM-3 grew in contact with LTBMC and proliferation was blocked by antibodies against IL-6, IL-6 receptor (IL-6R, gp80, CD126) or the common signal transducing unit, gp130 (CD130). Culture with IL-6 alone or combined with GM-CSF resulted in cell death via apoptosis. The combination of IL-6 with soluble gp80, however, maintained in vitro proliferation of UM-2 and UM-3 cells. These data imply that LTBMC regulate myeloma growth in vitro via production of IL-6, possibly via induction of a functional IL-6 receptor on the tumour cells.
authors.affiliation: Department of Immunology, University Hospital Utrecht, The Netherlands.
authors.forename: A C
authors.initials: AC
authors.lastname: Bloem
authors.forename: T
authors.initials: T
authors.lastname: Lamme
authors.forename: M
authors.initials: M
authors.lastname: de Smet
authors.forename: H
authors.initials: H
authors.lastname: Kok
authors.forename: W
authors.initials: W
authors.lastname: Vooijs
authors.forename: J
authors.initials: J
authors.lastname: Wijdenes
authors.forename: S E
authors.initials: SE
authors.lastname: Boom
authors.forename: H M
authors.initials: HM
authors.lastname: Lokhorst
mesh_terms: D001483:Base Sequence; D001854:Bone Marrow Cells / Q000473:pathology*; D002455:Cell Division; D002478:Cells, Cultured; D051152:Clusterin; D003169:Complement Inactivator Proteins / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism; D006801:Humans; D015850:Interleukin-6 / Q000494:pharmacology; D018832:Molecular Chaperones; D008969:Molecular Sequence Data; D009101:Multiple Myeloma / Q000473:pathology*; D017154:Stromal Cells / Q000473:pathology; D014407:Tumor Cells, Cultured
chemical_list: C495242:CLU protein, human; D051152:Clusterin; D003169:Complement Inactivator Proteins; D006023:Glycoproteins; D015850:Interleukin-6; D018832:Molecular Chaperones