Figure 1

A 25-miRNA expression signature discriminating between triple-negative breast cancers and adjacent normal tissues. (A) The global miRNA expression portrait from each sample was investigated using principal component analysis. Each data point in the principal component plot is composed of gene expression data of 707 mature miRNAs from a sample. Triple-negative breast cancers are shown in red and adjacent normal tissues are shown in blue. (B) Hierarchical clustering analysis of triple-negative breast cancers (red) and adjacent normal tissues (green) was performed using the 25 differentially expressed miRNAs. Each row represents the normalized gene expression data of a miRNA and each column represents a tissue sample. The dendrogram depicts similarities in the gene expression profiles among the samples. (C) Triple-negative breast cancers (red) and adjacent normal tissues (blue) are clearly separated into two groups in the principal component analysis using the gene expression data of the 25 differentially expressed miRNAs.