GSBS Student Publications


Osteoblast differentiation and skeletal development are regulated by Mdm2-p53 signaling

Publication Date


UMMS Affiliation

Graduate School of Biomedical Sciences; Department of Cancer Biology; Department of Cell Biology; Department of Pathology

Document Type



Life Sciences | Medicine and Health Sciences


Mdm2 is required to negatively regulate p53 activity at the peri-implantation stage of early mouse development. However, the absolute requirement for Mdm2 throughout embryogenesis and in organogenesis is unknown. To explore Mdm2-p53 signaling in osteogenesis, Mdm2-conditional mice were bred with Col3.6-Cre-transgenic mice that express Cre recombinase in osteoblast lineage cells. Mdm2-conditional Col3.6-Cre mice die at birth and display multiple skeletal defects. Osteoblast progenitor cells deleted for Mdm2 have elevated p53 activity, reduced proliferation, reduced levels of the master osteoblast transcriptional regulator Runx2, and reduced differentiation. In contrast, p53-null osteoprogenitor cells have increased proliferation, increased expression of Runx2, increased osteoblast maturation, and increased tumorigenic potential, as mice specifically deleted for p53 in osteoblasts develop osteosarcomas. These results demonstrate that p53 plays a critical role in bone organogenesis and homeostasis by negatively regulating bone development and growth and by suppressing bone neoplasia and that Mdm2-mediated inhibition of p53 function is a prerequisite for Runx2 activation, osteoblast differentiation, and proper skeletal formation.

DOI of Published Version



J Cell Biol. 2006 Mar 13;172(6):909-21. Link to article on publisher's site

Journal/Book/Conference Title

The Journal of cell biology

Related Resources

Link to article in PubMed

PubMed ID