Tumor microenvironment-derived miRNAs as prognostic markers of breast cancer

Abstract

Aim: To study expression of miRNA derived from tumor microenvironment in patients with breast cancer (BC) as the aspect of tumor-host interaction. Materials and Methods: The expression levels of estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2 (HER2/neu) were analyzed in tissue of BC using immunohistochemical method. Relative expression levels of the miR-155, -320a, and -205 were examined in tissue and sera from BC patients using quantitative reverse transcription polymerase chain reaction. Results: Serum and tissue miR-155, -320a, and -205 levels in patients with BC are of low diagnostic value as such for differentiation of malignant and non-malignant breast neoplasms. Nevertheless, we established the relation of circulating and tissue miR-155, -320a, and -205 to lymph node metastases and basal breast cancer subtype. Conclusions: Changes of miR-155, -320a, and -205 expression in tumor tissue and sera of BC patients provide information about major clinical-pathological characteristics of BC. Key Words: miRNA, breast cancer.