FIGURE 3 from Activation of Kras<sup>G12D</sup> in Subset of Alveolar Type II Cells Enhances Cellular Plasticity in Lung Adenocarcinoma

The Kras^G12D-induced upregulation of type I cell markers in double-positive cells requires Notch signaling. A, Representative IF image of lung sections of indicated genotypes stained with GFP (Venus, Notch signaling reporter), Sftpc (red) and Rage (blue) staining in mouse. Note that Sftpc+Rage+ tumor cells express Venus (Notch reporter; marked with yellow arrows). B, Representative FACS density plots showing Notch+ population (left) in wild-type (Sftpc-CreER; CBF-H2B-Venus) versus mutant Kras (Sftpc-CreER; CBF-H2B-Venus; LSL-Kras^G12D) mice. FACS plots on right side display type I and type II population from gated Notch+ population in wild-type and mutant Kras mice. DP, double positive. C, Quantification of type II cells in Notch+ population between wild-type and Kras-mutant mice. D, Quantification of double-positive (type I/II+) cells in Notch+ population between wild-type and Kras-mutant mice. E, Representative IF image of lung sections of indicated genotypes stained with GFP (green), Sftpc (red), and Rage (blue). Note that Sftpc+Rage+ tumor cells (marked with yellow arrows) are visible in Sftpc-CreER; Kras^G12D; Rosa-fGFP mice but absent in GFP+ cells in Sftpc-CreER; LSL-Kras^G12D; DNMaml1 mice. Results shown in A, B, and E are representative of three independent experiments. C and D represent data from three independent experiments. Error bars represent the mean ± SEM values and significance is defined as *, P ≤ 0.05; **, P ≤ 0.01; and ***, P ≤ 0.001.