biostudies-literatureWatabe TJapan Science and Technology Agency9434https://www.ebi.ac.uk/biostudies/studies/S-EPMC9409053biostudies-literatureUnknown23(16)Astatine (²¹¹At) is an alpha-emitter with a better treatment efficacy against differentiated thyroid cancer compared with iodine (¹³¹I), a conventional beta-emitter. However, its therapeutic comparison has not been fully evaluated. In this study, we compared the therapeutic effect between [²¹¹At]NaAt and [¹³¹I]NaI. In vitro analysis of a double-stranded DNA break (DSB) and colony formation assay were performed using K1-NIS cells. The therapeutic effect was compared using K1-NIS xenograft mice administered with [²¹¹At]NaAt (0.4 MBq (n = 7), 0.8 MBq (n = 9), and 1.2 MBq (n = 4)), and [¹³¹I]NaI (1 MBq (n = 4), 3 MBq (n = 4), and 8 MBq (n = 4)). The [²¹¹At]NaAt induced higher numbers of DSBs and had a more reduced colInternational journal of molecular sciencesComparison of the Therapeutic Effects of [²¹¹At]NaAt and [¹³¹I]NaI in an NIS-Expressing Thyroid Cancer Mouse Model.PMC9409053JPMJOP1721Haba HShimosegawa EToyoshima ANakano TKaneda-Nakashima KLiu YSato TWatabe TShinohara AHatazawa JWang YOoe KShirakami YfalseComparison of the Therapeutic Effects of [²¹¹At]NaAt and [¹³¹I]NaI in an NIS-Expressing Thyroid Cancer Mouse Model.Astatine (²¹¹At) is an alpha-emitter with a better treatment efficacy against differentiated thyroid cancer compared with iodine (¹³¹I), a conventional beta-emitter. However, its therapeutic comparison has not been fully evaluated. In this study, we compared the therapeutic effect between [²¹¹At]NaAt and [¹³¹I]NaI. In vitro analysis of a double-stranded DNA break (DSB) and colony formation assay were performed using K1-NIS cells. The therapeutic effect was compared using K1-NIS xenograft mice administered with [²¹¹At]NaAt (0.4 MBq (n = 7), 0.8 MBq (n = 9), and 1.2 MBq (n = 4)), and [¹³¹I]NaI (1 MBq (n = 4), 3 MBq (n = 4), and 8 MBq (n = 4)). The [²¹¹At]NaAt induced higher numbers of DSBs and had a more reduced col2022-01-01T00:00:00Z2022 Aug2025-04-27T02:29:39.503Z2025-02-19T04:38:09.94ZS-EPMC94090533601269810.3390/ijms23169434