Long non-coding RNA DILC as a potentially useful biomarker for the diagnosis and prognosis of colorectal cancer.

OBJECTIVE: LncRNA downregulated in liver cancer stem cells (lnc-DILC) has been implicated as a tumor suppressor in colorectal cancer (CRC). However, the clinical significance of lnc-DILC in CRC patients has not been investigated. In this study, we aimed to explore the diagnostic and prognostic value of lnc-DILC in CRC patients. PATIENTS AND METHODS: The expression of lnc-DILC was measured in 174 paired CRC tissues and adjacent normal tissues using Real Time-Polymerase Chain Reaction (RT-PCR). The correlation of lnc-DILC expression with clinicopathological factors was statistically analyzed by the Chi-square test. Besides, overall survival analysis was carried out with the Kaplan-Meier curve with the log-rank test. Univariate and multivariate analyses were performed to explore the prognostic significance of lnc-DILC expression. RESULTS: We found that lnc-DILC expression was downregulated in CRC tissues compared to their adjacent normal tissues (p<0.01). ROC analyses showed that lnc-DILC levels were reliable in distinguishing patients with CRC from normal colorectal tissues. Then, down-regulation of lnc-DILC was positively associated with aggressive clinical characteristics, including depth of invasion (p=0.018) and advanced TNM stage (p=0.009). Moreover, the Kaplan-Meier analysis demonstrated that overexpression of lnc-DILC was associated with poorer overall survival (p=0.0205) and disease-free survival (p<0.001). Finally, multivariate analyses confirmed that expression of lnc-DILC was an independent prognostic factor in CRC. CONCLUSIONS: Our results firstly suggested that lnc-DILC could be a favorable indicator of prognosis in CRC.