The effect of P-glycoprotein on 18F-FDG uptake in vitro / 中华核医学与分子影像杂志

ABSTRACT

Objective To evaluate the effect of P-gp inhibitors of verapamil (VER) and GF120918 on 18F-FDG uptake in Bcap37 and Bcap37/multidrug resistancce (MDR)1 cell lines in vitro,and to explore the relationship between 18F-FDG uptake and P-gp expression at cellular level.Methods Bcap37 and Bcap37/MDR1 cells were seeded into 6-well plates at a density of 1 × 106 per well.Three days later,37 kBq/ml 18F-FDG,or 37 kBq/ml 18F-FDG + 100 μmoL/L VER,or 37 kBq/ml 18F-FDG + 50 μmol/L GF120918 were added into each well.Mter incubated for 10,30,60 and 120 min at 37 ℃ and in 5％ CO2,the medium was removed and the cells were washed three times with 1 ml ice-cold PBS immediately.The radioactivity of 18 F-FDG was measured using a gamma counter.The uptake of 18F-FDG was expressed as the ratio of 18F-FDG radioactivity in Bcap37 or Bcap37/MDR1 cells and the overall radioactivity added to the cells in each well.The t test was used for statistical analysis.Results 18F-FDG uptake was higher in Bcap37/MDR1 cells than that in Bcap37 cells after incubated for 10 min.The uptake rate was (1.88 ±0.19) ％ in Bcap37/MDR1 cells and (1.37 ± 0.18) ％ in Bcap37 cells (t =7.832,P ＜ 0.05).On the contrary,18 F-FDG uptake was significantly higher in Bcap37 cells than that in Bcap37/MDR1 cells after incubated for 60 and 120 min.The uptake rates were (2.29 ±0.23)％ and (2.34 ±0.15)％ in Bcap37 cells,(1.47 ±0.14)％ and (1.53 ±0.22)％ in Bcap37/MDR1 cells (t =8.437,8.283,both P ＜ 0.05).18 F-FDG uptake was significantly higher with VER or GF120918 in Bcap37/MDR1 cells than that without VER or GF120918 after the incubation of 60 and 120 min (t =9.032,9.243 and 8.765,8.803,all P ＜ 0.05).The uptake rates with VER or GF120918 were (2.45 ±0.21)％ and (2.46 ±0.25)％,(2.50 ±0.24)％ and (2.48 ±0.27)％.There was no significant difference of 18F-FDG uptake in Bcap37 cells with or without VER or GF120918.Conclusions 18F-FDG is a substrate of P-gp at cellular level.P-gp may act as an efflux pump to reduce 18F-FDG uptake in Bcap37/MDR1 cells.The uptake of 18F-FDG can be used to evaluate the function of P-gp in tumor cells.