Title: Osteosarcoma in the Post Genome Era: Preclinical Models and Approaches to Identify Tractable Therapeutic Targets
Authors: Castillo-Tandazo, W
Mutsaers, AJ
Walkley, CR
Issue Year: 2019
Publisher SPRINGER
Series CURRENT OSTEOPOROSIS REPORTS:
Abstract Objective: To investigate the impact of deleting Suppressor of Cytokine Signaling (SOCS)-3 (SOCS3) in chondrocytes during murine skeletal development. Method: Mice with a conditional Socs3 allele (Socs3(fl/fl)) were crossed with a transgenic mouse expressing Cre recombinase under the control of the type II collagen promoter (Col2a1) to generate Socs3(Delta/Delta col2) mice. Skeletal growth was analyzed over the lifespan of Socs3(Delta/Delta col2) mice and controls by detailed histomorphology. Bone size and cortical bone development was evaluated by micro-computed tomography (micro-CT). Growth plate (GP) zone width, chondrocyte proliferation and apoptosis were assessed by immunofluorescence staining for Ki67 and TUNEL. Fibroblast growth factor receptor-3 (FGFR3) signaling in the GP was assessed by immunohistochemistry, while the effect of SOCS3 overexpression on FGFR3-driven pMAPK signaling in HEK293T cells was evaluated by Western blot. Results: Socs3(Delta/Delta col2) mice of both sexes were consistently smaller compared to littermate controls throughout life. This phenotype was due to reduced long bone size, poor cortical bone development, reduced Ki67(+) proliferative chondrocytes and decreased proliferative zone (PZ) width in the GP. Expression of pMAPK, but not pSTAT3, was increased in the GPs of Socs3(Delta/Delta col2) mice relative to littermate controls. Overexpression of FGFR3 in HEK293T cells increased Fibroblast Growth Factor 18 (FGF18)-dependent Mitogen-activated protein kinase (MAPK) phosphorylation, while concomitant expression of SOCS3 reduced FGFR3 expression and abrogated MAPK signaling. Conclusion: Our results suggest a potential role for SOCS3 in GP chondrocyte proliferation by regulating FGFR3-dependent MAPK signaling in response to FGF18. Crown Copyright (C) 2019 Published by Elsevier Ltd on behalf of Osteoarthritis Research Society International. All rights reserved.
URI: https://publications.svi.edu.au/publications/7651
Other Identifiers 10.1007/s11914-019-00534-w
Publication type Review