title: Identifying a molecular phenotype for bone marrow stromal cells with in vivo bone-forming capacity.
abstract: The ability of bone marrow stromal cells (BMSCs) to differentiate into osteoblasts is being exploited in cell-based therapy for repair of bone defects. However, the phenotype of ex vivo cultured BMSCs predicting their bone-forming capacity is not known. Thus we employed DNA microarrays comparing two human bone marrow stromal cell (hBMSC) populations: One is capable of in vivo heterotopic bone formation (hBMSC-TERT(+Bone)), and the other is not (hBMSC-TERT(-Bone)). Compared with hBMSC-TERT(-Bone), the hBMSC-TERT(+Bone) cells had an increased overrepresentation of extracellular matrix genes (17% versus 5%) and a larger percentage of genes with predicted SP3 transcription factor-binding sites in their promoter region (21% versus 8%). On the other hand, hBMSC-TERT(-Bone) cells expressed a larger number of immune-response-related genes (26% versus 8%). In order to test for the predictive value of these markers, we studied the correlation between their expression levels in six different hBMSC-derived clones and the ability to form bone in vivo. We found a significant correlation for decorin, lysyl oxidase-like 4, natriuretic peptide receptor C, and tetranectin. No significant positive correlation was found for canonical osteoblastic markers Runx2, alkaline phosphatase, collagen type I, osteopontin, and bone sialoprotein. Prospective isolation of four additional hBMSC clones based on their expression levels of the molecular markers correlated with their in vivo bone-formation ability. In conclusion, our data suggest an in vitro molecular signature predictive for hBMSCs' in vivo bone-formation ability. Identifying more of these predictive markers would be very useful in the quality control of osteoblastic cells before use in therapy.
authors.affiliation: Laboratory for Molecular Endocrinology (KMEB), Department of Endocrinology, University Hospital of Odense and Medical Biotechnology Center, University of Southern Denmark, Odense C, Denmark.
authors.forename: Kenneth H
authors.initials: KH
authors.lastname: Larsen
authors.forename: Casper M
authors.initials: CM
authors.lastname: Frederiksen
authors.forename: Jorge S
authors.initials: JS
authors.lastname: Burns
authors.forename: Basem M
authors.initials: BM
authors.lastname: Abdallah
authors.forename: Moustapha
authors.initials: M
authors.lastname: Kassem
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000235:genetics / Q000378:metabolism; D001854:Bone Marrow Cells / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics; D002478:Cells, Cultured; D058575:Decorin; D005109:Extracellular Matrix / Q000235:genetics / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism; D005802:Genes, MHC Class II; D006801:Humans; D037181:Lectins, C-Type / Q000235:genetics / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D010006:Osteoblasts / Q000378:metabolism*; D010012:Osteogenesis / Q000235:genetics*; D010641:Phenotype; D008249:Protein-Lysine 6-Oxidase; D011509:Proteoglycans / Q000235:genetics / Q000378:metabolism; D017461:Receptors, Atrial Natriuretic Factor / Q000235:genetics / Q000378:metabolism; D051705:Sp3 Transcription Factor / Q000235:genetics / Q000378:metabolism; D017154:Stromal Cells / Q000378:metabolism
chemical_list: C546878:DCN protein, human; D058575:Decorin; D016326:Extracellular Matrix Proteins; D037181:Lectins, C-Type; D011509:Proteoglycans; C497121:SP3 protein, human; C048648:tetranectin; D051705:Sp3 Transcription Factor; D000594:Amino Acid Oxidoreductases; C445682:LOXL4 protein, human; D008249:Protein-Lysine 6-Oxidase; D017461:Receptors, Atrial Natriuretic Factor; C073616:atrial natriuretic factor receptor C