Phenotypic Characterization of a Human Immortalized Cranial Periosteal Cell Line

Background/aims: Human cell material for basic research work is limited due to restricted patient numbers and occurring cell senescence during prolonged in vitro cell cultivation. In the present study, we established for the first time a human immortalized cranial periosteal cell line and characterized its phenotype in detail in comparison to that of parental cells.

Methods: For this purpose, human primary cranial periosteal cells were stably transduced with the large T antigen cDNA from polyomavirus SV40 (TAg cells).

Results: The functional activity of the large T antigen was demonstrated by human telomerase gene expression. Whereas TAg cells maintained long-term cell proliferation, immortalization did not compromise their osteogenic differentiation potential. In contrast, TAg cells showed an earlier and stronger mineralization compared to parental cells. Among the analysed stem cell surface markers, CD146 and MSCA-1 (mesenchymal stem cell antigen-1) were shown to be elevated in Tag cells. Gene expression analyses revealed in general higher constitutive m-RNA levels of key factors of osteogenesis than in parental cells.

Conclusion: We conclude that the herein generated cell line represents a suitable cell source for basic science research studying bone biology, the osteogenesis process or biomaterial tests for bone regeneration purposes.