LAUSR

Our results showed that the expression of calcium‐sensing receptor (CaSR) and the concentration of intracellular calcium were enhanced in the osteosarcoma cells MG‐63 compared with in the normal osteoblasts hFOB1.19. GdCl3 (CaSR agonist) significantly increased the proliferation rate of MG‐63 cells, the expression of PCNA and Cyclin D1 and decreased the expression of p21Cip/WAF‐1. The effect of NPS2390 (CaSR antagonist) on the above indicators was opposite to GdCl3. In addition, GdCl3 up‐regulated the phosphorylation of ERK1/2, PI3K and Akt and the proliferation rate of MG‐63 cells. However, these effects of GdCl3 were cancelled by LY294002 (a PI3K inhibitor) or PD98059 (an ERK1/2 inhibitor). Our results demonstrate that activation of CaSR promotes osteosarcoma cell multiplication by up‐regulating ERK1/2 and PI3K‐Akt pathways.