Figure 5

PTH increases intracellular calcium and inhibits cell-proliferation in normal and epidermal tumour cell lines. (a,b) Intracellular calcium was monitored for 194 seconds after adding serum-free culture medium of pMSCV (control), Pth ^FVB-GFP and Pth ^MSM-GFP to C5N (a) and B9 (b) cells. C5N is derived from normal mouse keratinocytes. B9 is derived from mouse squamous cell carcinoma cells. The P-values were calculated by two-way ANOVA. Black asterisks indicate pMSCV vs Pth ^FVB. Red asterisks indicate pMSCV vs Pth ^MSM. Blue asterisks indicate Pth ^FVB vs Pth ^MSM (***P < 0.001, **P < 0.01, *P < 0.05). (c,d) Cell proliferation assay after adding secreted PTH-GFP from Pth ^FVB- and Pth ^MSM- transfected NIH-3T3 cells. These collected supernatants were mixed with new DMEM (1:1) and added to 1 × 10³ cells of C5N (c) or B9 (d) seeded on 96 well plates. Proliferation curves represent mean confluence values ± SEM of triplicates. The P-values were calculated by two-way ANOVA. Black asterisks indicate pMSCV vs Pth ^FVB. Red asterisks indicate pMSCV vs Pth ^MSM. Blue asterisks indicate Pth ^FVB vs Pth ^MSM (***P < 0.001, **P < 0.01, *P < 0.05). (a–d) Error bars are standard deviation (SD). Asterisks indicate significant differences.