Fig. 1: SCLC liver metastases present significantly reduced MHC-I expression compared to primary lesions.
a Schematic of the initial analysis of publicly available scRNA-seq data from SCLC primary tumors and metastases10, followed by validation through the analysis of matched SCLC samples from primary tumors and liver metastases in human and murine context. Created in BioRender. Meder, L. (2025) https://BioRender.com/z2ehzfh. b UMAP of B2M expression in publicly available scRNA-seq data from SCLC primary tumors and metastases (21 biospecimens, 19 patients)10. c Expression of B2M in primary (n = 9) and metastatic (n = 12) SCLC patient samples in scRNA-seq data10 (two-sided Mann–Whitney test). The center line represents the median, box bounds represent Q1 and Q3 percentiles and whiskers extend to the minimum and maximum values. For primary: Min = 0, Q1 = 3.4412, Median = 5.2901, Q3 = 6.0248, Max = 8.8348, n = 26,043 cells. For metastasis: Min = 0, Q1 = 2.1763, Median = 3.0322, Q3 = 3.8150, Max = 7.5308, n = 28,270 cells. d Representative images of matched patient samples (n = 6 patients) from primary and liver metastases. Images were taken at 20× magnification. Scale bars, 60 µm. e Expression of MHC-I on patient samples quantified by H-score analysis on IHC with Qupath software (two-sided, paired Student’s t-test; n = 6 patients). Clinicopathologic characteristics are listed in the Supplementary Data 10. f Exemplary histograms and corresponding quantification of MHC-I surface expression determined by flow cytometry in matched samples from primary and liver metastasis in Rb1/Trp53-depleted autochthonous mouse model (two-sided, paired Student’s t-test; n = 10 mice). *p < 0.05, ***p < 0.001. Source data are provided as a Source Data file. Icons created in BioRender. Meder, L. (2025) https://BioRender.com/z2ehzfh.
