SaOS2 osteosarcoma cells as an in vitro model for studying the transition of human osteoblasts to osteocytes

Matthew Prideaux, Asiri R. Wijenayaka, Duminda D. Kumarasinghe, Renee T. Ormsby, Andreas Evdokiou, David M. Findlay, Gerald J. Atkins

Research output: Contribution to journalArticle

49 Scopus citations


The central importance of osteocytes in regulating bone homeostasis is becoming increasingly apparent. However, the study of these cells has been restricted by the relative paucity of cell line models, especially those of human origin. Therefore, we investigated the extent to which SaOS2 human osteosarcoma cells can differentiate into osteocyte-like cells. During culture under the appropriate mineralising conditions, SaOS2 cells reproducibly synthesised a bone-like mineralised matrix and temporally expressed the mature osteocyte marker genes SOST, DMP1, PHEX and MEPE and down-regulated expression of RUNX2 and COL1A1. SaOS2 cells cultured in 3D collagen gels acquired a dendritic morphology, characteristic of osteocytes, with multiple interconnecting cell processes. These findings suggest that SaOS2 cells have the capacity to differentiate into mature osteocyte-like cells under mineralising conditions. PTH treatment of SaOS2 cells resulted in strong down-regulation of SOST mRNA expression at all time points tested. Interestingly, PTH treatment resulted in the up-regulation of RANKL mRNA expression only at earlier stages of differentiation. These findings suggest that the response to PTH is dependent on the differentiation stage of the osteoblast/osteocyte. Together, our results demonstrate that SaOS2 cells can be used as a human model to investigate responses to osteotropic stimuli throughout differentiation to a mature osteocyte-like stage.

Original languageEnglish (US)
Pages (from-to)183-193
Number of pages11
JournalCalcified Tissue International
Issue number2
StatePublished - Aug 2014



  • Cell culture
  • Differentiation
  • Osteoblast
  • Osteocyte
  • PTH
  • SOST
  • SaOS2

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Orthopedics and Sports Medicine
  • Endocrinology

Cite this

Prideaux, M., Wijenayaka, A. R., Kumarasinghe, D. D., Ormsby, R. T., Evdokiou, A., Findlay, D. M., & Atkins, G. J. (2014). SaOS2 osteosarcoma cells as an in vitro model for studying the transition of human osteoblasts to osteocytes. Calcified Tissue International, 95(2), 183-193.