MicroRNA expression profiling of human breast cancer identifies new markers of tumour subtype

MicroRNAs (miRNAs), a class of short non-coding RNAs, often act post-transcriptionally to inhibit gene expression. We used a bead-based flow cytometric profiling method to obtain miRNA expression data for 93 primary human breast tumours, 21 cell lines and five normal breast samples. Of 309 human miRNAs assayed we identify 133 miRNAs expressed in human breast and breast tumours. We used mRNA expression profiling to classify the breast tumours into Luminal A, Luminal B, Basal-like, HER2+/ER- and Normal-like. A number of miRNAs are differentially expressed between these molecular tumour subtypes and individual miRNAs are associated with clinicopathological factors. Furthermore, we find that miRNAs could classify basal versus luminal tumour subtypes in an independent data set. Keywords = miRNA Keywords = microRNA Keywords = normal Keywords = tumour Keywords = cell line Keywords = breast Keywords = cancer Keywords: Bead-based flow cytometric profiling miRNA expression data for 93 primary human breast tumours, 21 cell lines and five normal breast samples