Fig. 1

MSI2 is upregulated in NSCLC and CAFs and correlates with poor clinical outcomes in patients. A Kaplan–Meier survival curves of lung cancer patients according to the expression of MSI2. B The frequencies of LUSC and LUAD patients following MSI2 expression trend (over- or under-expression) obtained from BioXpress. C Up-regulation of MSI2 is observed in various NSCLC subtypes, including LUSC, LUAD, and LCC when compared with healthy lung tissue. Data are mean ± SD; ^####P < 0.0001 versus normal tissues; ^**P < 0.01 versus LUSC; one-way ANOVA with Tukey’s multiple comparison test. D MSI2 protein level is higher in LUAD than in normal tissues in the CPTAC database. ^*P < 0.05 versus normal tissues; two-tailed Student’s t-test. E Comparison of MSI2 in matched normal and tumor pairs in LUSC and LUAD patients. ^*P < 0.05, ^****P < 0.0001 versus normal tissues; two-tailed Student’s t-test. F–I MSI2 expression according to aggressive clinical outcomes, including relapsed and invasive disease (F and G) and tumor staging (H and I) in the indicated lung cancer patients. Data are mean ± SD; ^*P < 0.05, ^**P < 0.01, ^***P < 0.001 versus normal or not relapsed samples as indicated; ^####P < 0.0001 versus normal tissues; two-tailed Student’s t-test or one-way ANOVA with Tukey’s multiple comparison test. J MSI2 and ACTA2 (encoding α-SMA) expression is higher in IPF/UIP lung tissues than in non-diseased tissues. Data are mean ± SD; ^***P < 0.001, ^****P < 0.0001 versus normal tissues; two-tailed Student’s t-test. K High MSI2 expression in laser-capture-microdissected (LCM) NSCLC stroma (LCM-NSCLCS). ^**P < 0.01 versus paired LCM normal lung parenchyma (LCM-NLP); two-tailed Student’s t-test. Notably, GEO accession numbers of the obtained RNA-seq data were indicated above the plots. L, M Western blot analysis of common CAF markers, including COL11A1, α-SMA, and S100A4 (L) and MSI2 (M), in primary (#1) and immortalized (#2) NSCLC-derived CAFs relative to its matched NFs. β-actin was used as a loading control. Quantitative analysis of MSI2 level after normalization to β-actin and relative to NFs is shown. Data are mean ± SD (n = 3); ^*P < 0.05, ^**P < 0.01 versus NFs; two-tailed Student’s t-test. N Representative immunofluorescence images showing MSI2 expression in CAFs and NFs under the same instrumental setting. Scale bar = 25 μm. Fluorescence intensity of MSI2 relative to NFs is shown. Data are mean ± SD (n ≥ 30 cells per group); ^****P < 0.0001 versus NFs; two-tailed Student’s t-test