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 lincRNA‐ROR 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.