Figure 1.

Smad4^KO BRAF^V600E tumor organoids have invasive capability in 3D environment. (A) Representative images of organoids cultured in BME R1. Adjacent normal and tumor organoids were derived from Smad4^KO BRAF^V600E/+ Villin^Cre-ERT2 mice 3–6 months post-tamoxifen injection. Tumor organoids have capability to migrate through Matrigel and develop projections which connect neighboring organoids. Scale bars = 0.5 mm. (B) Tumor organoids with RosaGFP expression reveal that projections are cellular. Scale bars = 0.5 mm (C) Capability to develop projections is unique to tumor organoids (* = p-value < 0.05, Student’s t-test). (D) Smad4^KO BRAF^V600E/+ Villin^Cre-ERT2 Rosa-GFP tumor organoids transplanted into NOD.CB17-Prkdc^scid mice colon for 2 months revealed invasive capability (white arrows). Scale bars = 0.5 mm (E) Smad4^KO BRAF^V6000E/+ β-catenin^gof Villin^Cre-ERT2 organoids developed similar invasive behavior as Smad4^KO BRAF^V600E/+ tumor organoids (red arrows). (F) Capability to form projections was highest in Smad4^KO BRAF^V600E Ctnnb1^Exon3 Villin^Cre-ERT2 organoids (* = p-value < 0.05, Student’s t-test).