Figure 1 from Tumor Cell Plasticity and Stromal Microenvironment Distinguish Papillary and Follicular Growth Patterns in a Mouse Model of BRAFV600E-Induced Thyroid Cancer

Comparison of tamoxifen-induced and noninduced thyroid tumorigenesis in Tg-CreER^T2;Braf^CA/+ mice. Representative images of histology and IHC staining of Tg and CRE recombinase. A and B, Thyroid lobe of wild-type (WT) animals. Normal follicular tissue (A) and uniform accumulation of Tg in follicle lumina (B). C–E, General neoplastic changes in the thyroid of Tg-CreER^T2;Braf^CA/+ mice injected with Tam after weaning. Gross lobe enlargement (A) and loss of Tg expression in cells (D and E); E shows the high power of the boxed area in D. Of note, the follicle lumina is largely empty of Tg. F and G, Heterogeneous neoplastic alterations due to spontaneous Braf^CA activation in Tg-CreER^T2;Braf^CA/+ mice devoid of Tam injections. Loss of Tg expression in neoplastic cells and preserved Tg expression in nonneoplastic follicles (F and G). F shows the high power of the boxed area in G. Arrowheads indicate Tg⁺ cells. H–J, Loss of CRE expression in neoplastic cells; J shows the high power of the boxed area in I. Asterisks (in H) mark CRE-negative neoplastic follicles. Arrows (in H and I) indicate residual CRE⁺ cells. Tam, tamoxifen; f, follicle; inj, injection. Bars: 500 (A–D and F), 100 (G–I), and 50 (E and J) μm.