The micro RNA expression of 5 nomal breast tissues and 15 breast cancer tissues

MicroRNAs (miRNAs) are short non-coding RNAs that regulate the function of target genes at the post-transcriptional phase. MiRNAs are considered to play roles in the development, progression and metastasis of cancer. Recent studies have indicated that particular miRNA signatures are correlated with tumor aggressiveness, response to drug therapy, and patient outcome in breast cancer. In the present research, we would like to evaluate the morphological and biological characters of breast cancer stratified by miRNAs signature. The frozen tissue samples from 5 normal breast tissue and 15 invasive breast cancer diagnosed at Gunma University were initially retrieved, and the statuses of ER and HER2 were assessed and the intrinsic subtypes of these breast cancers decided (ER-positive/HER2-negative: 5 cases; HER2-positive/ER-negative: 5 cases; triple negative: 5 cases).