Affiliations: [a] University of Belgrade-Vinča Institute of Nuclear Sciences, Mike Petrovića Alasa, Belgrade, Serbia | [b] Institute for Oncology and Radiology of Serbia, Belgrade, Serbia
Abstract: BACKGROUND: Breast carcinoma is heterogeneous disease.
Understanding the process of invasion and metastasis and the selection of
the therapy for patients with breast carcinomas still remains difficult.
MicroRNAs are powerful gene expression regulators. Because of inconsistent
findings, we have analyzed potential difference in miR-155 levels in three
breast cancer groups. OBJECTIVES: Our goals were to examine miR-155 expression levels in
normal tissue, non-invasive and invasive breast carcinomas, and their
association with standard clinical and pathological parameters and
oncomiR-21, and to investigate the ability of miR-155 to separate invasive
breast carcinomas with non-invasive component from pure invasive. METHODS: In the group of 40 breast tissue samples, relative
expression levels of miR-155 were examined with stem-loop quantitative
real-time PCR using TaqMan technology. RESULTS: The significant difference among four examined groups of
the breast tissue was detected (p = 0.001). In the group of pure invasive
tumors, patients with positive nodal status had significantly higher miR-155
levels (p = 0.046). CONCLUSION: Our results suggest that miR-155 might be involved in
breast cancer pathogenesis and in tumor spreading to the lymph nodes, and
that it might be used as biomarker for additional stratification of patients
with invasive breast carcinomas with non-invasive component.
Keywords: miR-155, , breast cancer, , microRNA expression levels
