Increased expression of the long noncoding RNA CRNDE-h indicates a poor prognosis in colorectal cancer, and is positively correlated with IRX5 mRNA expression

Background: The long noncoding RNA (lncRNA) colorectal neoplasia differentially expressed - h (CRNDE-h) plays important roles in the early stages of human development and cancer progression. We investigated the expression and clinical significance of lncRNA CRNDE-h in colorectal cancer (CRC). Methods: The expression level of lncRNA CRNDE-h was analyzed in 142 CRC tissues and 142 paired adjacent nontumorous tissues, along with 21 inflammatory bowel diseases, 69 hyperplastic polyp, and 73 colorectal adenoma samples, using quantitative real-time polymerase chain reaction. The association between lncRNA CRNDE-h, and Iroquois homeobox protein 5 (IRX5) mRNA was examined in the same 142 CRC tissues. Results: We found that lncRNA CRNDE-h level was elevated in the CRC and adenoma groups compared with the other groups (all at P<0.001). In CRC, upregulation of lncRNA CRNDE-h was significantly correlated with large tumor size, positive regional lymph node metastasis, and distant metastasis (all at P<0.05). Area under the curve for lncRNA CRNDE-h showed diagnostic capability for distinguishing CRC from other groups. Patients with CRC with high lncRNA CRNDE-h expression level had poorer overall survival than those with low lncRNA CRNDE-h expression (log-rank test, P<0.001). Further, multivariable Cox regression analysis suggested that increased expression of lncRNA CRNDE-h was an independent prognostic indicator for CRC (hazard ratio [HR]=2.173; 95% confidence interval [CI], 1.282-3.684, P=0.004). Furthermore, lncRNA CRNDE-h expression was positively correlated with IRX5 mRNA in CRC tissues. Conclusions: Our data offers convincing evidence for the first time that lncRNA CRNDE-h is associated with adverse clinical characteristics and poor prognosis, which suggests that it might play an important role in CRC development and progression and might have clinical potential as a useful prognostic predictor.