Effects of ¹⁸F-FDG on the growth of Lewis lung cancer xenografts in C57BL/6 mice

Model of Lewis lung cancer xenograft in C57BL/6 mouse were set up with 18 mice, which were randomly divided into three groups: high-dose ¹⁸F-FDG group, low-dose ¹⁸F-FDG group and control group. The control was given 0.2 mL saline by intraperitoneal injection 18.5 × 10⁷ Bq and 9.25 × 10⁷ Bq ¹⁸F-FDG in 0.2 mL saline was given intraperitoneally for one time on the 7^th day after Lewis lung cancer cells were inoculated in the high dose ¹⁸F-FDG group and low-dose ¹⁸F-FDG group, respectively. The effects of ¹⁸F-FDG on animals and xenografts were investigated. After 22 days, expression of Bcl-2 and survivin proteins was detected using immunohistochemistry, and apoptotic rate were determined by flow cytometry. The results showed that the inhibition rate and apoptotic rate of xenografts in ¹⁸F-FDG-treated groups were higher than that in control group, and the expression of Bcl-2 and Survivin proteins in ¹⁸F-FDG-treated groups were less than that in control group (P < 0.05). Compared with low-dose ¹⁸F-FDG group, there were more significant differences between the high-dose ¹⁸F-FDG group and control (P < 0.01). It can be suggested that¹⁸F-FDG could effectively inhibit the growth of xenografts. The mechanism may be related to apoptosis caused by the down regulation of bcl-2 and survivin gene expressions in xenografts. (authors)