Potential Value of miR-221 as Diagnostic, Prognostic, and Therapeutic Biomarkers for Breast Cancer

Introduction & Aim: Breast cancer entails 10% of all cancers in the world. Among all types of cancers, 30% of women are infected with breast cancer. MicroRNAs (miRNAs) are short non-coding RNAs that regulate gene expression by base pairing with their target messenger RNAs. Dysregulation of miRNAs is involved in the pathological initiation and progression of many human diseases. The aim of the present study was to compare the expression level of miR-221 in normal and neoplastic samples from breast cancer patients by RT-qPCR.Methods: In the present case-control study, 40 samples from patients with breast cancer tumor and 40 patients from non-tumor were collected under the direct supervision of a pathologist specialist due to clinical presentation and laboratory findings. RNA extraction from normal and tumor tissues, cDNA synthesis and RT-qPCR were performed by SYBR®Premix Ex TaqTM II kit. miR-221 expression levels was calculated using ∆∆CT methods. Finally all data were analyzed using t-test.Results: The results of RT-qPCR indicated that the mean relative expression levels of miR-221 in tumor samples compared to normal was down-regulated in breast cancer. This variation in expression of miR-221 related to about 1.5 times in tumor samples compared to healthy group.Conclusion: the results of present study suggest that miR-221 has the potential to be considered as novel diagnostic and prognostic biomarkers for breast cancer. Moreover, expression of miR-221 in different breast cancer subtypes and patient with other blood raises the importance of this molecules as a biomarker for cancer diagnosis and prognosis.

Keywords:

Breast cancer , MicroRNAs , miR-221 , RT-qPCR