Detection and analysis of circulating large intergenic non-coding RNA regulator of reprogramming in plasma for breast cancer.

Background: Previous studies have indicated that large intergenic non-coding RNA regulator of reprogramming (lincRNA-ROR) plays an important role in regulating tumor carcinogenesis and metastasis; however, whether circulating lincRNA-ROR could function as a potential biomarker for breast cancer (BC) diagnosis and monitoring is unknown. This study was conducted to investigate circulating lincRNA-ROR in plasma as a potential biomarker for BC diagnosis and monitoring. Methods: We performed reverse transcription-quantitative-PCR to examine lincRNA-ROR expression levels in cell lines, 24 pairs of BC tissue samples, and 94 plasma samples from BC patients. Potential correlations between plasma lincRNA-ROR levels and clinicopathological characteristics were analyzed. A receiver operating characteristic curve was calculated to evaluate the diagnostic values for BC. Pearson correlation analysis of lincRNA-ROR in plasma samples and the corresponding tissues of the same patients was performed to explore tumor monitoring values. Results: LincRNA-ROR expression was significantly increased in BC cell lines, tissues, and plasma (all P < 0.01). Plasma lincRNA-ROR levels were associated with estrogen receptors (P = 0.042) and lymph node metastasis (P = 0.046). The area under the receiver operating characteristic curve of plasma lincRNA-ROR was 0.844 (sensitivity 80.0%, specificity 56.7%), which was higher than carcinoembryonic and carbohydrate antigen 15-3 values. Moreover, plasma lincRNAROR levels were decreased in postoperative compared to preoperative samples (P < 0.0001). Plasma lincRNA-ROR levels moderately correlated with the corresponding tissue level in the same patients (r(2) = 0.638, P < 0.0001). Conclusion: Plasma lincRNA-ROR may be a potential biomarker for BC diagnosis and a dynamic monitor.