@misc{oai:repo.qst.go.jp:00070473,
 author = {Takahara, Noriko and Kiyono, Yasushi and Yoshii, Yukie and Fujibayashi, Yasuhisa and et.al and 高原 典子 and 清野 泰 and 吉井 幸恵 and 藤林 康久},
 month = {Jun},
 note = {Objectives: We have recently developed the radiobromine-labeled 5-bromo 4'-thio-2'-deoxyuridine (BTdU) as an imaigng agent for tumor proliferation. The aim of this study was to evaluate the potential usefulness of radiobromine-labeled BTdU as an imaging agent for detecting the early therapeutic effects of 5-fluorouracil (5-FU) compared with 3H-FLT uptake. 
\nMethods: The radiolabeling of BTdU with 77Br was achieved by a destannylation reaction of tributylstannyl precursor. 3H-FLT was commerically available. The cells of human renal cacinoma cell line, ACHN, were treated with various concentrations of 5-FU (0.01-300 µM). At 36 hr after 5-FU addition, double tracer cell uptake studies were performed. 2.0x10-2 MBq of 77Br-BTdU and 3.7x10-2 MBq of 3H-FLT were simaltaneously added to the cells and incubated for 15min, 30min, 60min. After 3 times washing, cells were lysed, and then the radioactivity and protein content were measured. 
\nResults: The radiochemical yield of 77Br-BTdU was about 40% and the radiochemical purity was more than 99%. Uptakes of 77Br-BTdU and 3H-FLT were increased with time. There was not significant differences between the uptake of 77Br-BTdU and that of 3H-FLT in control group at 60min (77Br-BTdU: 18.5 +- 2.0,3H-FLT: 20.3 +- 2.7 %ID/mg protein). Compared with control the uptake of 77Br-BTdU was significantlty decreased from 0.3 µM of 5-FU (One-way ANOVA with a post hoc Dunnett's Multiple Comparison Test). However, the uptake of 3H-FLT was significantly decreased from 300 µM of 5-FU. These results suggest that 77Br-BTdU could detect the earlier effect of 5-FU compared with 3H-FLT. 
\nConclusions: Radiobromine-labeled BTdU is potentially useful as an imaging agent for detecting the early therapeutic effects of anticancer therapy with 5-FU in patients with renal cell carcinoma, SNM 2011 Annual Meeting},
 title = {Evaluation of radiobromine-labeled 5-bromo-4'-thio-2'-deoxyuridine uptake in ACHN cells after treatment with 5-fluorouracil: comparison with 3H-FLT uptake.},
 year = {2011}
}