Expression of SP7, RUNX1, DLX5, and CTNNB1 in Human Mesenchymal Stem Cells Cultured on Xenogeneic Bone Substitute as Compared With Machined Titanium

PURPOSE: The aim of this research was to investigate the gene expression profile of 4 transcription factors in human mesenchymal stem cells (hMSC) cultured with a xenogeneic bone substitute and a support of machined titanium. MATERIAL AND METHODS: In vitro studies were performed on hMSC cells, which grew in contact with cortical porcine bone and machined titanium disks for 10 days. RNA quantification for genes DLX5, CTNNB1, RUNX1, and SP7 was assessed by quantitative real-time polymerase chain reaction. For cells supported by titanium, immunocytochemistry of osteocalcin (OC) was also performed. RESULTS: In the osteoblast-induced cells (OIC), DLX5, CTNNB1, and RUNX1 were significantly upregulated (+2.38-, +3.51-, and +7.08-fold, respectively), whereas SP7 was downregulated (-26.32-fold). None of the genes seemed to be upregulated or downregulated by the corticocancellous porcine bone. In cells grown on titanium support, DLX5 and RUNX1 were respectively upregulated (+3.12-fold) and downregulated (-2.14-fold). For titanium support, the presence of both catenin beta-1 and OC was verified. CONCLUSION: The 2 genes RUNX1 and SP7 resulted differently expressed in cells cultured on metallic supports if compared with the expression recorded for OIC. An induction of the osteogenic phenotype was observed when cells were cultured on machined titanium, but not on xenogeneic material