Systemic and tissue microRNAs changes in early phase of breast cancer development.

e13548Background: MicroRNAs (miRs) and their distribution in circulation have been implicated in physiological and pathological processes. Recently, circulating miRs have emerged as potential biomarkers for early detection of cancer. However, their link with breast cancer predisposition remains unclear. In this study we explored the association of miRs with breast cancer susceptibility in terms of systematic (blood circulation) and local (breast tissue) changes. Methods: Plasma and breast tissue specimens, donated by women before a breast cancer diagnosis (labeled pre-cancer), and age-matched healthy controls, were obtained from the Susan G. Komen Tissue Bank at IUSCC. Plasma samples (16 pre-cancer and 16 controls) were processed for miR extraction and RNA sequencing (Illumina NextSeq500). Reads were mapped to miRBase20 to identify known miRs. The analysis of additional samples is underway. Laser microdissection was used to separate breast epithelium, stroma and adipose tissue from frozen tissue biopsies ...