Background: Gemcitabine is the first-line drug for nonsmall cell lung cancer, and 18F-fluorodeoxyglucose. (18F-FDG) and 18F-fluorothymidine. (18F-FLT) are positron emission tomography. (PET) imaging agents. The aim of this study was to explore the effect of gemcitabine on the uptake of 18F-FDG and 18F-FLT in A549 cells and the animal tumor model.
Materials and methods: The inhibitory effects of gemcitabine on cell growth were determined by tetrazolium blue method, and uptake rates of 18F-FDG and 18F-FLT were determined under the same conditions. The adenocarcinoma-bearing nude mice before and after gemcitabine treatments were performed microPET imaging with 18F-FDG and 18F-FLT. Hematoxylin and eosin staining and immunohistochemical analysis of tumor specimens were conducted.
Results: After the administration of gemcitabine, positive correlations were observed between inhibition of 18F-FDG or 18F.FLT uptake and cell growth. (r = 0.957 or 0.981, P < 0.01). SUVmax values by 18F-FDG in the tumor, before and after administration of gemcitabine at the dose of 60 mmol/L, revealed an increase by. (35.83 ± 10.58) %. After administration of 120 mmol/L gemcitabine, the SUVmax values decreased by (12.37 ± 7.33) %. The SUVmax values by 18F-FLT at the dose of 60 mmol/L gemcitabine revealed a decrease by (56.47 ± 10.83) %. Pathological staining showed obvious vasodilation and invasion of lymphocytes and plasma cells at the dose of 60 mmol/L, and the expression of glucose transporter protein-1, Ki-67 and proliferating cell nuclear antigen in tumor cells were inhibited.
Conclusion: 18F-FLT imaging can assess the proliferation of tumor cells and 18F-FDG imaging can reflect the changes of the tumor microenvironment after administration of gemcitabine.