Fig. 1
MicroRNA profiling in SCLC patient serum identifies miR-1-3p (miR-1) is downregulated in SCLC and validated by DNA-AuNP˗based in situ detection and quantification of serum miR-1. A The clustered heatmap of top differentially expressed genes for microRNAs in the serum samples of 6 healthy donors and 8 SCLC patient samples. The red and blue strips indicate upregulated and downregulated miRNAs. B The volcano plot showed that miR-1 was one of the downregulated miRNAs. C Comparison of log2 fold change expression of miR-1 in the serum samples of 6 healthy donors and 8 SCLC patient samples. D Violin plots comparing the expression profile of miR-1 between normal lung tissues (n = 8) and SCLC tumor tissues (n = 35) in the publicly available gene expression data of human cancers (GSE19945). E Schematic of Au-nanoprobe (DNA-AuNPs) mediated detection of serum miR-1 in the denatured human serum samples. F Violin with point graph representing the quantitative expression of serum miR-1 in the donor (normal control) serum vs SCLC patient serum. p-values are the results of Welch’s t-test. G Representative in situ hybridization of miR-1 on SCLC tissue microarray (BS04116a, US Biomax, Inc., representing the pathology grade tumor tissues of 55 cases/100 cores for SCLC and ten cores for normal lung tissues), stained with RNAscope miR-1 detection probe. H Expression of miR-1 in a panel of human SCLC cell lines analyzed by Taq-man qPCR assay