Combined identification of long non-coding RNA CCAT1 and HOTAIR in serum as an effective screening for colorectal carcinoma.

Long non-coding RNAs (lncRNAs) CCAT1 and HOTAIR have been shown to play an important regulatory role in cancer biology, and CCAT1 and HOTAIR are upregulated in several cancers, however, its value in the diagnosis of colorectal cancer (CRC) is unclear. Therefore, the aim of this study is to evaluate the clinical significance of plasma CCAT1 and HOTAIR as a biomarker in the screening of CRC. In our study, we found that the levels of HOTAIR (P < 0.05) and CCAT1 (P < 0.05) were significantly higher in plasma of CRC patients than that of the healthy control. Moreover, the levels of lincRNA-p21 (P < 0.05) were obviously decreased in plasma of CRC patients as compared to those of healthy control. There was highly correlated for CCAT1 (R = 0.752, mean differences = -0.06 ± 1.20), HOTAIR (R = 0.739, mean differences = -0.26 ± 0.76) and lincRNA-p21 (R = 0.848, mean differences = -0.41 ± 0.89) in plasma and serum. By receiver operating characteristic curve (ROC) analysis, plasma CCAT1 provided the higher diagnostic performance for detection of CRC (the area under the ROC curve (AUC), 0.836; P < 0.001; sensitivity, 75.7%; specificity, 85.3%). Moreover, CCAT1 combining with HOTAIR could provide a more effective diagnosis performance (AUC, 0.954, P < 0.001, sensitivity, 84.3%; specificity, 80.2%). Most importantly, this combination was effective to detect CRC at an early stage (85%). In conclusion, our results demonstrated that increased plasma HOTAIR and CCAT1 could be used as a predictive biomarker for CRC screening, and that combination of HOTAIR and CCAT1 had a higher positive diagnostic rate of CRC than HOTAIR or CCAT1 alone.