American Association for Cancer Research
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FIGURE 1 from Activation of KrasG12D in Subset of Alveolar Type II Cells Enhances Cellular Plasticity in Lung Adenocarcinoma

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posted on 2023-11-24, 14:40 authored by Priyanka Chaudhary, Xia Xu, Guangfang Wang, Jacob P. Hoj, Rishi R. Rampersad, Marie-Liesse Asselin-Labat, Stephanie Ting, William Kim, Pablo Tamayo, Ann Marie Pendergast, Mark W. Onaitis

Activation of KrasG12D transforms type II cells to dual-positive type I and type II expressing cells. A, Experimental outline to compare type I, type II, and double-positive (type I/II+) population between wild-type and KrasG12D-mutant mice. B, Immunofluorescent images showing sections of left lobes of Sftpc-CreER; Rosa26-TdTomato (top) and Sftpc-CreER; LSL-KrasG12D; Rosa26-TdTomato (bottom) mice, 4 weeks after single dose of tamoxifen injection stained with DAPI (blue), Sftpc (green) and Rage (red). Right panel shows higher magnification of boxed area in left panels. Note that many tumor cells are Sftpc+Rage+ (marked with white arrows) in Kras-mutant mice. C, Quantitative analysis of B. D, FACS analysis for comparing type I, type II, and double-positive (type I/II+) population between wild-type and KrasG12D mice. E, Quantitative analysis of D. F, qPCR analysis for comparing the gene expression of some of the type I marker and type II marker genes between double-positive cells and total epithelial cells from Sftpc-CreER; KrasG12D; TdTomato mice. Results shown in B and D are representative of three independent experiments. C, E, and F 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.


HHS | NIH | NCI | National Cancer Institute (NCI)

VA | Veterans Affairs San Diego Healthcare System (VASDHS)



We have previously identified alveolar type II cell as the cell-of-origin of KrasG12D-induced lung adenocarcinoma using cell lineage–specific inducible Cre mouse models. Using gain-of-function and loss-of-function genetic models, we discovered that active Notch signaling and low Sox2 levels dictate the ability of type II cells to proliferate and progress into lung adenocarcinoma upon KrasG12D activation. Here, we examine the phenotype of type II cells after Kras activation and find evidence for proliferation of cells that coexpress type I and type II markers. Three-dimensional organoid culture and transplantation studies determine that these dual-positive cells are highly plastic and tumor initiating in vivo. RNA sequencing analysis reveals that these dual-positive cells are enriched in Ras/MAPK, EGFR, and Notch pathways. Furthermore, the proliferation of these cells requires active Notch signaling and is inhibited by genetic/chemical Sox2 upregulation. Our findings could provide new therapeutic strategies to target KRAS-activated lung adenocarcinomas. Identification of progenitor like tumor-initiating cells in KRAS-mutant lung adenocarcinoma may allow development of novel targeted therapeutics.