Fig. 1
miRNA expression profiling of LNmets collected by EBUS-TBNA. A Strategy used for miRNA expression profiling of LNmets NSCLC cells (EBUS samples). B Upper panels: bright-field images of three representative primary LNmets cell lines obtained as described in (A). Scale bar, 100 μm. Lower panels: representative confocal analysis of pan-cytokeratins (PanCK) in LNmets cell lines. Pan-cytokeratins (red) identify epithelial cells; DAPI (light blue) visualizes nuclei. Scale bar: 50 μm. C Heat map showing qRT-PCR results of airway cell markers in five individual LN-metastatic cell lines. Two commercial lung cancer cells (LC; yellow) established from LNmets of stage IIIA NSCLC patients (NCI-H2023 and NCI-H1993) were used as positive controls for airway markers expression, while the breast cancer cells (BC; orange) MDA-MB-231 and leukemic cells (LK; magenta) HL-60 were used as negative controls. Data are log2-ratio. D Bar plot showing the number and percentage of miRNAs detected (yellow) or not detected (blue) in EBUS samples. E Violin plot showing expression levels (Cqn) of all miRNAs detected in EBUS samples. F Volcano plot showing differentially expressed miRNAs in chemoresistant (pN2; N = 7) vs. chemosensitive (pN0; N = 5) LNmets. Gray dot, unchanged; blue dot, downregulated (p < 0.05); red dot, upregulated (p < 0.05); statistical significance was calculated using the Mann–Whitney U test. G Hierarchical clustering analysis of differentially expressed miRNAs (N = 16, aka LN-signature) in pN2 vs pN0 LNmets. Data are log2-ratio. LUAD, lung adenocarcinoma; LUSC, lung squamous cell carcinoma