title: Osteoblastic niche supports the growth of quiescent multiple myeloma cells.
abstract: The heterogeneity of multiple myeloma (MM) contributes to variable responses to therapy. In this study, we aim to correlate the heterogeneity of MM to the presence of quiescent cells using the PKH26 dye. We tracked the rare quiescent cells in different niches of the bone marrow by allowing the cells to cycle in vivo. Surprisingly, quiescent PKH(+) MM cells prefer to reside within the osteoblastic niches of the bone marrow (PKH(+)/OS) rather than the vascular (VS) niches or the spleen. These cells (PKH(+)/OS) displayed enhanced stemlike properties by forming colonies in semisolid medium. PKH(+) cells were highly tumorigenic compared with PKH(-) cells and were resistant to a variety of drugs. However, the levels of drug resistance were somewhat similar regardless of where the PKH(+) cells were isolated. Our data indicate that osteoblastic niches support the growth of quiescent PKH(+) cells and allow them to have stemlike functions.
authors.affiliation: Center for Stem Cell and Regenerative Disease, Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases (IMM) University of Texas-Health Science Center at Houston, Houston, TX; and.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Chen
authors.forename: Robert Z
authors.initials: RZ
authors.lastname: Orlowski
authors.forename: Michael
authors.initials: M
authors.lastname: Wang
authors.forename: Larry
authors.initials: L
authors.lastname: Kwak
authors.forename: Nami
authors.initials: N
authors.lastname: McCarty
mesh_terms: D000818:Animals; D059447:Cell Cycle Checkpoints; D049109:Cell Proliferation; D058948:Cell Tracking / Q000379:methods; D006801:Humans; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D009101:Multiple Myeloma / Q000473:pathology*; D014411:Neoplastic Stem Cells / Q000473:pathology*; D009930:Organic Chemicals / Q000032:analysis; D010006:Osteoblasts / Q000473:pathology*; D055153:Stem Cell Niche
chemical_list: D009930:Organic Chemicals; C082445:PKH 2 dye