Comparison of Phosphoinositide-Specific Phospholipase C Expression Panels of Human Osteoblasts Versus MG-63 and Saos Osteoblast-Like Cells

A large number of phospholipase C (PLC) enzymes, both mRNA transcripts and proteins, have been detected in osteoblasts, corroborating the importance of calcium regulation in bone tissue. MG-63 and SaOS-2 human osteosarcoma cell lines are actually considered osteoblast-like cells, and are therefore widely used as experimental models for osteoblasts. Our aim was to verify whether MG-63 or SaOS-2 cells might also represent appropriate experimental osteoblast models for signal transduction studies, with special regard to the phosphoinositide (PI) pathway. We analyzed the expression and the subcellular distribution of enzymes related to calcium signal transduction (the PI-specific PLC family), which are known to possess high cell/tissue specificity. The expression of PLC genes was analyzed by performing RT-PCR experiments. The presence of PLC enzymes and their subcellular distribution within the cells was analyzed with immunofluorescence experiments. Osteoblasts, MG-63 cells, and SaOS-2 cells have expression panels similar to those of PLC enzymes. However, slight differences were found in the expression of enzymes belonging to the PLCη subfamily. MG-63 and SaOS-2 osteosarcoma cell lines might not represent appropriate experimental models for studies that aim to analyze signal transduction in osteoblasts.