Effects of mineral trioxide aggregate (MTA) extracts on mitogen-activated protein kinase activity in human osteosarcoma cell line (U2OS)

Extracellular regulated kinases (ERKs)-1 and -2 are members of the MAPK family of protein kinases involved in the proliferation, differentiation and apoptosis of bone cells. The purpose of the present study investigated the biocompatibility role, and signaling pathways of components of mineral trioxide aggregate (MTA) by culturing human osteosarcoma cell line (U2OS) in the presence of materials. Biocompatibility effects were assessed using the MTT assay for mitochondrial enzyme activity. The statistical analysis of the survival rate was performed using one-way analysis of variance (ANOVA) with p<0.05 shown statistical difference. The signaling pathway of MTA-treated U2OS cells were assessed by the western blotting methods. Dose-dependent and time-dependent tests were conducted. The results showed that the survival rates of the MTA extract experimental groups were higher than that of the control group (p<0.05). ERKs activity was dose-dependent, decreasing as the concentrations of the NITA extract decreased, and was time-dependent, decreasing as the treatment time increased. Suppression of ERK pathway by PD98059 resulted in dose-dependent and time-dependent decreases. The findings suggest that MTA is a biocompatible material to U2OS cells, and the ERK kinase pathway plays a signal transduction role in the MTA treated U2OS cells. (C) 2003 Elsevier Science Ltd. All rights reserved.