Kinetics of circulating levels of miR-195, miR-155 and miR-21 in patients with breast cancer undergoing mastectomy

Abstract

Background: MicroRNAs are small RNA molecules that negatively regulate the expression of the majority of proteins, mainly at the post-transcriptional level. Being stable in the circulation and resistant to storage handling, they are potentially promising biomarkers.

Materials and methods: We measured RNA levels of three microRNAs with tumorigenic or angiogenic potential (miR-155, miR-195, and miR-21) in blood samples taken from patients with early breast cancer, both preoperatively and postoperatively.

Results: We found that persistently elevated postoperative levels of miR-195 were detected only in patients who developed early tumor relapse and that miR-155 levels tended to increase three days postoperatively (p=0.05) and fell below baseline one month post-surgery (p<0.05). We had no major findings for miR-21.

Conclusion: The results of this pilot study indicate a possible involvement of miR-155 in surgery-induced angiogenesis and potential prognostic significance of high postoperative levels of circulating miR-195 in patients with breast cancer.

Keywords: Breast cancer; biomarkers; miR-155; miR-195; miR-21.