Calcium‐sensing receptor activating ERK1/2 and PI3K‐Akt pathways to induce the proliferation of osteosarcoma cells

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 p21(Cip/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.