Figure 10. Radioiodine therapy after dox withdrawal or PLX4720 treatment in BRAF^V600E-induced thyroid tumors.

Tg-rtTA/tetO-BRAF^V600E mice were pretreated for 1 week with dox, then either fed with regular chow alone (1 week off) or continued on dox for an additional week in the presence of either vehicle or PLX4720 chow. After 2 weeks, all mice were injected with 3 mCi ¹³¹I-iodide, and mice were sacrificed 24 and 72 hours after injection. Representative FFPE sections of thyroid tissues from Tg-rtTA/tetO-BRAF^V600E at (A) 24 hours and (B) 72 hours after ¹³¹I-iodide injection stained as follows: top panels, γH2Ax (green) and DAPI (blue); middle panels, cleaved caspase-3; or bottom panels, TUNEL. Original magnification, ×1000 (top panels); ×400 (middle panels); ×400 (bottom panels). (C–E) Quantification of γH2Ax, cleaved caspase-3, and TUNEL(+) cells at the indicated times. Data are mean ± SEM, and correspond to manual counting of ≥ 3 high-power fields/mouse (n = 3).