title: Bone marrow stromal cells from myeloma patients support the growth of myeloma stem cells.
abstract: It has been well documented that bone marrow stromal cells (BMSCs) of multiple myeloma patients play a pivotal role in supporting the growth of mature myeloma cells. With evolving concepts concerning the presence of myeloma stem (initiating) cells, we aimed this investigation to specifically address the supportive role of BMSCs for myeloma stem cell growth in vitro and in vivo. BMSC lines were derived from myeloma or control patients (myeloma or control BMSCs). Myeloma stem cells of the RPMI 8226 myeloma cell line were recognized through the identification of "side populations" (SP) with Hoechst dye staining. SP cells formed more colonies when grown on myeloma BMSC than on control BMSC. Additionally, higher percentages of SP cells were observed when grown on myeloma BMSCs than on control BMSCs. In the mouse model, SP cells inoculated with myeloma BMSCs grew faster than those inoculated with control BMSCs. Of note, SP cells demonstrated an increased expression of CD184 (CXCR4) compared with non-SP cells. The expression of CD184 in SP cells was further increased when they were cultured with myeloma BMSCs. CD184(+) SP cells formed more colonies than CD184(-) SP cells. Treatment with AMD 3100, an inhibitor of CD184, reduced colony formation by CD184(+) SP cells when co-cultured with myeloma BMSCs. This was associated with the decreased activation of ERK, a downstream target of activated CD184, in myeloma cells. These findings indicate that the myeloma BMSCs create a microenvironment supportive of myeloma stem cells via, at least partially, the CXCR4 signaling pathway.
authors.affiliation: Department of Pathology, The Methodist Hospital and The Methodist Hospital Research Institute, Houston, Texas 77030, USA.
authors.forename: Yongdong
authors.initials: Y
authors.lastname: Feng
authors.forename: Jianguo
authors.initials: J
authors.lastname: Wen
authors.forename: Perez
authors.initials: P
authors.lastname: Mike
authors.forename: Dong Soon
authors.initials: DS
authors.lastname: Choi
authors.forename: Camellia
authors.initials: C
authors.lastname: Eshoa
authors.forename: Zheng-Zheng
authors.initials: ZZ
authors.lastname: Shi
authors.forename: Youli
authors.initials: Y
authors.lastname: Zu
authors.forename: Chung-Che
authors.initials: CC
authors.lastname: Chang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D001596:Benzylamines; D001854:Bone Marrow Cells / Q000473:pathology / Q000502:physiology*; D016022:Case-Control Studies; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D000080027:Cyclams; D006571:Heterocyclic Compounds / Q000494:pharmacology; D006801:Humans; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D008822:Mice, Transgenic; D008875:Middle Aged; D009101:Multiple Myeloma / Q000473:pathology*; D014411:Neoplastic Stem Cells / Q000473:pathology / Q000502:physiology*; D017154:Stromal Cells / Q000473:pathology / Q000502:physiology*; D059016:Tumor Microenvironment / Q000502:physiology; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D001596:Benzylamines; D000080027:Cyclams; D006571:Heterocyclic Compounds; C088327:plerixafor