ABSTRACT
Objective To study the effects of internal exposure of 18F-FDG (18F-2-deoxy-2-fiuoroD-glucose) on the protein expressions of P53,XIAP (X-linked inhibitors of apoptosis protein) and GADD (growth arrest and DNA damage)45 in Lewis lung carcinoma,and to explore the possibility of applying 18F-FDG as a radiotherapy drug in vivo.Methods Lewis lung cancer transplanted tumor models were established via subcutaneous injection of 0.2 ml of 2 × 107/ml Lewis lung carcinoma cells at left hind limbs of 48 C57BL/6 mice that were randomly divided into high dose group,low dose group and control group with 16 mice each.After 7 d of cancer cell inoculation,18.5 × 107 Bq and 9.25 × 107 Bq of 18F-FDG in 0.2 ml saline or equal volume of physiological saline was intraperitoneally injected into three group mice,respectively.22 d post inoculation,the protein expressions of P53,XIAP and GADD45 were immuohistochemically detected by using SP approach.Results There was significant difference among the protein expressions in each group (x2 =8.30,16.02,7.68,P ＜0.05).The mean integral optic density of protein expression increased from 0.089 ± 0.033 in control group to 0.315 ± 0.028 in high dose group for P53,and from 0.126 ± 0.023 to 0.383 ±-0.035 for GADD45,but it decreased from 0.422 ± 0.034 to 0.149 ± 0.055 for XIAP.There was significantly difference of these protein expressions in each group (P53:F=5.26,P＜0.05;XIAP:F=4.29,P ＜0.05;GADD45:F=5.98,P ＜0.05).Conclusions 18F-FDG can up-regulate the expressions of P53 and GADD45 proteins and down-regulate the expression of XIAP protein in tumor cells,and it inhibits tumor growth by promoting cell apoptosis in the Lewis lung carcinoma tissue with a P53-dependent manner.