Circulating miR-221 and miR-222 as Potential Biomarkers for Screening of Breast Cancer

Abstract

Breast cancer is the second most common cancer in women with approximately 522,000 deaths annually worldwide. microRNAs have recently been studied as potential biomarkers that regulate gene expression and are involved in tumorigenesis. Here we evaluated circulating miR-221 and miR-222 as potential biomarkers for breast cancer by quantitative reverse transcription PCR using blood plasma of 30 healthy controls and 30 breast cancer patients. The TNM stage on circulating miR-221 and miR-222 was also investigated. Circulating miR-221 and miR-222 were significantly up-regulated in breast cancer patients compared to those in healthy controls (P< 0.0022 andP= 0.0058, respectively). Furthermore, the relative expression level of circulating miR-221 in patients with stage III breast cancer was higher than in those with stage I and II. Taken together, we have shown circulating miR-221 and miR-222 could be useful biomarkers for the screening of breast cancer patients.