Evaluation of the expression of miR-4270 gene in plasma of breast cancerPatients in northwest of Iran

Introduction & aim: miRNAs are a principle class of short non-coding RNAs which play major roles in the initiation and progression of all types of cancers. The aim of this study was to quantitatively evaluate the expression pattern of miR-4270 in the plasma of patients with invasive ductal carcinoma (IDC), the most common type of aggressive breast cancer in North West of Iran.Methods: fresh blood specimens from 40 women with IDC and 28 healthy women, were obtained. Total RNAs were extracted from plasmas and treated with DNase I, polyA tail was added by an enzymatic reaction and the RNAs were reverse transcripted to cDNA with miRNA cDNA synthesis kit. The expression of miR-4270 and 5s rRNA as internal control was studied by real-time PCR.Results: miR-4270 expression level was significantly upregulated in breast cancer plasmas in relative to the healthy control women (P value=0.00) but the expression of miR-4270 decrease in patients with larger tumor, lymph node invasion, and higher grades. However, this reduction is not significant. The results of plasma specimens yielded area under the ROC curve is 0.5 (AUC) for this gene which implicated the low sensitivity and specificity of miR-4270 to the diagnostic and prognostic biomarker for breast cancer.Conclusion: upregulation of mir-4270 in breast cancer plasma versus normal healthy plasma and its relation to the progression of breast cancer adds a new dimension to more research to help the diagnosis and treatment of breast cancer.