Fig. 1: HES1-positive non-neuroendocrine cells in mouse SCLC tumors have features of club epithelial cells.

a Schematic representation of the Rb^fl/fl;p53^fl/fl;p130^fl/fl;Hes1^GFP/+ mouse model of SCLC (TKO;Hes1^GFP/+) in which HES1⁺ non-neuroendocrine SCLC cells generated by Notch pathway activation can be visualized and isolated by GFP^high expression from the Hes1 locus, along with GFP-negative (GFP^neg) neuroendocrine SCLC cells. b Expression of classical markers of the indicated lung epithelial cell types from RNA-seq data in GFP^high cells compared to GFP^neg cells (n = 4). Error bars, log2 fold change estimate ± SE. c Single-cell RT-qPCR analysis (Fluidigm) of GFP^high and GFP^neg SCLC cells (n = 46) isolated from TKO;Hes1^GFP/+ tumors for markers of lung epithelial cells. See Supplementary Fig. 1g for an independent experiment. In this sensitive assay, all GFP^high cells express Scgb1a1, which codes for the club cell marker CC10. d Representative immunofluorescence images for AGER (red) and CC10 (cyan, encoded by Scgb1a1) on a mouse SCLC tumor section (n = 1 experiment, multiple tumors were stained). DAPI stains the DNA in blue. Scale bar, 100 μm. e Representative immunofluorescence images for HES1 (cyan) and CC10 (red) on a mouse SCLC tumor section (n = 2 independent experiments). DAPI stains the DNA in blue. Scale bar, 50 μm. f Quantification (%) of cells that are either HES1⁺, CC10⁺, or HES1⁺ CC10⁺ in n = 3 mouse tumors as in (e). g Representative immunohistochemistry images of HES1, CC10, and RBP-J staining (brown signal) in TKO and TKO;Rbpj^fl/fl tumors (hematoxylin counterstain). Scale bar, 100 μm. h, i Quantification of HES1 staining (h) and CC10 staining (i) in tumor sections from (g) (n = 15 tumors from 3 mice for TKO and 20 tumors from 4 mice for TKO;Rbpj^fl/fl). Unpaired t-test with Welch’s correction, data represented as mean ± s.d. See also Supplementary Figs. 1 and 2 and Supplementary Data 1 and 2. Source data are provided as a Source Data file.