Diagnostic potential of PTEN-targeting miR-214 in the blood of breast cancer patients
MicroRNAs play a role in breast cancer development and progression by post-transcriptional repression of the expression of important genes, such as the tumor suppressor gene phosphatase and tensin homolog (PTEN). The focus of the current study was to examine the diagnostic potential of circulating cell-free microRNAs targeting PTEN in breast cancer. Our analyses were performed on preoperative serum samples of 102 patients with early breast cancer and a subset of 34 postoperative samples, as well as of 32 patients with benign breast disease and 53 healthy women. The relative concentrations of four circulating microRNAs (miR-19a, miR-20a, miR-21, and miR-214) in blood serum were measured by TaqMan MicroRNA assays. Levels of preoperative serum miR-20a and miR-21 were significantly higher in patients with breast cancer and benign disease than in healthy women (p = 0.0001), but only serum miR-214 could discriminate malignant from benign tumors and healthy controls (p = 0.0001) with an area under the curve of 0.878 and 0.883 in ROC analysis, respectively. Moreover, miR-214 levels significantly decreased in the postoperative serum samples (p = 0.0001) as compared to the preoperative samples. The comparison with the clinicopathologic data of the breast cancer patients showed that increased miR-214 levels were associated with a positive lymph node status (p = 0.039). Our data show that circulating, cell-free miR-214 has diagnostic potential in breast cancer as indicator of malignant disease and metastatic spread to regional lymph nodes. Since PTEN is an important target gene of miR-214, this finding could also have potential implications for therapeutic approaches.
KeywordsSerum miRs Tumor progression Lymph node metastasis PTEN
We are grateful to the European Research Council (Advanced Investigators Grant 269081-DISSECT) and the Erich und Gertrud Roggenbuck-Stiftung, Hamburg, for supporting this study. We thank Ms. Carina Roth for their excellent technical assistance.
Conflict of interest
All authors disclose any financial and personal relationships with other people or organizations that could inappropriately influence (bias) their study.
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