Myeloma cells inhibit non-canonical wnt co-receptor ror2 expression in human bone marrow osteoprogenitor cells: effect of wnt5a/ror2 pathway activation on the osteogenic differentiation impairment induced by myeloma cells

• Published in: Leukemia Vol. 27; no. 2; pp. 451 - 463
• Main Authors: Bolzoni, M, Donofrio, G, Storti, P, Guasco, D, Toscani, D, Lazzaretti, M, Bonomini, S, Agnelli, L, Capocefalo, A, Dalla Palma, B, Neri, A, Nicolini, F, Lisignoli, G, Russo, F, Colla, S, Aversa, F, Giuliani, N
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.02.2013; Nature Publishing Group
• Subjects: 631/136/532/1360; 631/80/86; 692/699/67/1990/804; Animal experimentation; Animals; Biomarkers, Tumor - genetics; Biomarkers, Tumor - metabolism; Biomedical materials; Blotting, Western; Bone diseases; Bone growth; Bone marrow; Bone Marrow Cells - cytology; Bone Marrow Cells - metabolism; Cancer Research; Case-Control Studies; Cell culture; Cell Differentiation; Cell growth; Cell Proliferation; Cellular signal transduction; Coculture Techniques; Critical Care Medicine; Culture; Differentiation (biology); Flow Cytometry; Gene expression; Gene Expression Profiling; Hematology; Humans; Intensive; Internal Medicine; Kinases; Leukemia; Medicine; Medicine & Public Health; Mesenchymal Stromal Cells - cytology; Mesenchymal Stromal Cells - metabolism; Mesenchyme; Mice; Multiple myeloma; Multiple Myeloma - genetics; Multiple Myeloma - metabolism; Multiple Myeloma - pathology; Oligonucleotide Array Sequence Analysis; Oncology; original-article; Osteoblastogenesis; Osteoblasts - cytology; Osteoblasts - metabolism; Osteogenesis; Osteoprogenitor cells; Physiological aspects; Proto-Oncogene Proteins - antagonists & inhibitors; Proto-Oncogene Proteins - genetics; Proto-Oncogene Proteins - metabolism; Real-Time Polymerase Chain Reaction; Receptor Tyrosine Kinase-like Orphan Receptors - genetics; Receptor Tyrosine Kinase-like Orphan Receptors - metabolism; Receptors; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - genetics; RNA, Small Interfering - genetics; Signal Transduction; Signaling; siRNA; Stem Cells - cytology; Stem Cells - metabolism; Stromal cells; Wnt protein; Wnt Proteins - antagonists & inhibitors; Wnt Proteins - genetics; Wnt Proteins - metabolism; Wnt-5a Protein; United States > US; Italy; microenvironment; multiple myeloma; non-canonical Wnt signaling; mesenchymal cells
• ISSN: 0887-6924; 1476-5551
• DOI: 10.1038/leu.2012.190

Multiple myeloma (MM) is characterized by the impaired osteogenic differentiation of human mesenchymal stromal cells (hMSCs). Canonical Wnt signaling is critical for the regulation of bone formation, however, recent evidence suggests that the non-canonical Wnt agonist Wnt5a stimulates human osteoblastogenesis through its co-receptor Ror2. The effects of MM cells on non-canonical Wnt signaling and the effect of the activation of this pathway on MM-induced osteoblast exhaustion are not known and were investigated in this study. We found that the osteogenic differentiation of bone marrow hMSCs toward osteoprogenitor cells (PreOB) significantly increased Ror2 expression, and that MM cells inhibit Ror2 expression by PreOB in co-culture by inhibiting the non-canonical Wnt5a signaling. The activation of the non-canonical Wnt pathway in hMSCs by means of Wnt5a treatment and the overexpression of Wnt5 or Ror2 by lentiviral vectors increased the osteogenic differentiation of hMSCs and blunted the inhibitory effect of MM in co-culture. Consistently, Wnt5a inhibition by specific small interfering RNA reduced the hMSC expression of osteogenic markers. Our findings demonstrate that the Wnt5a/Ror2 pathway is involved in the pathophysiology of MM-induced bone disease and that the activation of the non-canonical Wnt5a/Ror2 pathway in hMSCs increases osteogenic differentiation and may counterbalance the inhibitory effect of MM cells.