OBJECTIVETo investigate the influnce of receptor activity modifying protein 1(RAMP-1) overexpression on enhancing effect of calcitonin gene-related peptide on MG-63 cells proliferation.

METHODSCultured MG-63 osteoblasts in exponential phase of growth were randomly divided into three groups: RAMP-1 overexpression group, empty vector control group and negative control group. RAMP-1 eukaryotic expression vector was constructed and stably transfected into MG-63 cells. Realtime-polymerase chain reaction, Western blotting and immunofluroescence were used respectively to detect the expression of calcitonin receptor-like receptor (CRLR) in the cells and its distribution on cell membrane. The status of proliferation was detected respectively at 0, 24, 48, 72, 96 h by cell counting kit-8 (CCK-8) and cells were collected to analyze their cycle respectively at 0, 8, 16, 24 h by flow cytometry.

RESULTSCRLR protein and mRNA expression levels of MG-63 cells in RAMP-1 overexpression group were significantly higher than the other two groups (P < 0.05). The A value of RAMP-1 overexpression group at 24, 48, 72, 96 h were 0.628 ± 0.175, 0.896 ± 0.592, 1.055 ± 0.004, 1.179 ± 0.618, respectively, which were significantly higher than that of the other two groups (P < 0.05). The difference was most pronounced at 72 h. S-phase fraction of RAMP-1 overexpression group was (1.25 ± 0.13)%, (68.79 ± 0.56)%, (64.49 ± 1.59)%, (57.82 ± 0.75)%, respectively, which were significantly higher than the other two groups (P < 0.05). The difference was most pronounced at 8 h.

CONCLUSIONSRAMP-1 overexpression can promote CRLR distribution on MG-63 cell membrane and enhance CGRP's promotion effect on MG-63 cell proliferation.