Fig. 1.

Changes in the transcriptome and lung tissue architecture in mice treated with the secretome or with a primary tumour. A Schematic diagram illustrating the s.c. injection of the 143B Luc⁺ cells into the lower flank of mice. Lung tissue was harvested when the primary tumour (PT) reached a maximum volume of 50–60 mm³ (PT-bearing mice, n = 3–5). B Schematic diagram illustrating the preparation and administration schedule of the 143B cell-derived secretome (SCR) in mice. Animals received daily i.p. injections for 1 week (SCR-treated mice, n = 3–5). Lung tissue was harvested at the end of the treatment. C Representative images of H&E at x200 magnification (Scale bar: 20 μm), SEM (Scale bar: 40 μm), and TEM (Scale bars: 1000 and 2000 nm) of lung tissue sections from untreated mice (CTR), SCR-treated or PT-bearing mice. Black arrowheads: exudate of protein, vesicles, and fragments of the surfactant; White arrowheads: mucous granules (produced by peribronchial glands); LB, lamellar bodies; Nu, nucleus; R, red blood cells; Pn II: pneumocytes type II (alveolar cells); Fib: fibrosis. D Venn diagram of differentially expressed genes (DEGs) in lungs for each pairwise comparison: SCR vs. CTR and PT vs. CTR. E KEGG pathway enrichment analysis of DEGs. Circle sizes denote the number of genes included in a group and the colour indicates the p-value. F Bar plots depicting the manually curated common Gene Ontology (GO) terms found for the two comparison groups. Biological process (BP), cellular component (CC), and molecular function (MF) of altered genes reporting the intersections in lungs from SCR vs. CTR and PT vs. CTR. G Representative protein-protein interaction (PPI) network, constructed with the common DEGs, using the STRING database