title: Human bone marrow-derived stem cell proliferation is inhibited by hepatocyte growth factor via increasing the cell cycle inhibitors p53, p21 and p27.
abstract: Human bone marrow-derived stem cells (hMSCs) are a major source of osteoprogenitors. Hepatocyte growth factor (HGF), a glycoprotein constitutively produced by hMSCs, is reported to act on differentiated osteoblasts and also osteoclasts. Moreover, HGF has been shown by us and others to enhance osteoblastic differentiation from hMSCs. Typically, the pro-differentiation effects of HGF have required cooperative action with regulatory factors such as vitamin D or bone matrix material. Here, we have pursued the molecular mechanisms underlying the osteogenic effect of HGF on hMSCs, the principal precursors to bone forming cells. HGF treatment of hMSCs reduced the cell number over time and increased G1/S cell-cycle arrest compared to control (non-treated) cells. RT-qPCR showed treatment with HGF increased gene expression of the cell-cycle inhibitors p53, p21, and p27, possibly explaining the cell growth inhibition and G1 arrest, a step critical to phenotypic differentiation. Transfection of siRNA specific for cMet, the HGF receptor, eliminated the HGF anti-proliferation effect on hMSCs and the HGF-mediated increase in p53, p21, and p27, strongly supporting a role for these cell-cycle inhibitors in HGF's regulation of hMSCs. HGF in combination with a known inducer of osteogenic differentiation, 1,25-dihydroxyvitamin D, significantly increased cell maturation/differentiation as indicated by an increase in several osteoblast markers. Taken together these results demonstrate that HGF significantly enhances hMSC osteoblast differentiation by 1,25-dihydroxyvitamin D.
authors: GRECC and Research Service, Veterans Affairs Medical Center, Miami, FL 33125, USA. KChen@med.miami.edu
authors: Ketian
authors: K
authors: Chen
authors: Carlos
authors: C
authors: Perez-Stable
authors: Gianluca
authors: G
authors: D'Ippolito
authors: Paul C
authors: PC
authors: Schiller
authors: Bernard A
authors: BA
authors: Roos
authors: Guy A
authors: GA
authors: Howard
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D017209:Apoptosis / Q000187:drug effects; D001854:Bone Marrow Cells / Q000166:cytology*; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D016922:Cellular Senescence / Q000187:drug effects; D002648:Child; D002675:Child, Preschool; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism*; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000378:metabolism*; D005260:Female; D017228:Hepatocyte Growth Factor / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010012:Osteogenesis / Q000187:drug effects; D010766:Phosphorylation / Q000187:drug effects; D019859:Proto-Oncogene Proteins c-met / Q000378:metabolism; D016160:Retinoblastoma Protein / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects; D014807:Vitamin D / Q000031:analogs & derivatives / Q000494:pharmacology; D055815:Young Adult
chemical_list: D050759:Cyclin-Dependent Kinase Inhibitor p21; D016160:Retinoblastoma Protein; D016159:Tumor Suppressor Protein p53; D014807:Vitamin D; D050760:Cyclin-Dependent Kinase Inhibitor p27; C097949:1,25-dihydroxyvitamin D; D017228:Hepatocyte Growth Factor; D019859:Proto-Oncogene Proteins c-met