ASSESSMENT OF CIRCULATING miRNA LEVELS IN BREAST CANCER PATIENTS DEPENDING ON CLINICAL CHARACTERISTICS AND CHEMOTHERAPY.

Abstract

Breast cancer (BC) stands out as the most prevalent cancer in women. The levels of miRNA expression before and after chemotherapy are considered a potential indicator for the prognosis of the disease. To study blood plasma miRNA levels in BC patients and to assess their correlation with the menopausal status, disease stage, and molecular BC subtype. Blood plasma levels of 6 miRNAs (miRNA-25, miRNA-27, miRNA-155, miRNA-200, miRNA-335, and miRNA-497) were studied in 70 BC patients and 18 healthy individuals using RT-PCR. miRNA-25, miRNA-335, and miRNA-497 levels were significantly higher in BC patients, while a tendency toward a decrease in the miRNA-27 and miRNA-335 levels in premenopausal patients and high miRNA-27 levels in menopausal patients was established. After neoadjuvant chemotherapy, a decrease in the miRNA-25 and miRNA-335 levels was registered. The results indicated that miRNA-25, miRNA-27, miRNA-335, and miRNA-497 deserve attention as markers for assessing the efficacy of treatment of BC patients.