Long Non-Coding RNA (lncRNA) X-Inactive Specific Transcript (XIST) Plays a Critical Role in Predicting Clinical Prognosis and Progression of Colorectal Cancer.

BACKGROUND Long non-coding RNAs (lncRNAs) participate in all cancer biology processes of cells. Although functions and associated mechanisms of lncRNAs have been proven in colorectal cancer (CRC), the roles of lncRNA X-inactive specific transcript (XIST) have not been clearly investigated in CRC. MATERIAL AND METHODS Expression of XIST was detected by quantitative real-time PCR (qRT-PCR) assay in CRC cell lines and 196 clinical samples. Correlations between XIST expression and CRC clinicopathological features were analyzed. Log-rank test and Kaplan-Meier test were performed to assess and compare the prognoses of patients with higher and lower expression of XIST. The multivariate Cox regression and univariate Cox regression were conducted to evaluate the risk factors for prognosis of CRC. RESULTS lncRNA XIST was upregulated in CRC cells lines and tissues (p<0.05). Statistical analysis found high XIST expression was correlated with larger tumor size, N1, M1, and topography lymph node metastasis (TNM) III+IV stage of CRC. Moreover, higher expression of XIST could predict poor progression-free survival (PFS) and poor overall survival (OS) of CRC patients. The M1 stage and high expression of XIST were proven to be independent risk factors for poor prognosis (p<0.05). CONCLUSIONS XIST is upregulated in CRC and is significantly correlated with CRC clinical progression. lncRNA XIST overexpression predict poor PFS and poor OS for CRC patients. lncRNA XIST can be an independent risk factor for CRC prognosis, and could be a potential therapeutic target and prognostic biomarker for CRC patients.

Prognosis and Clinicopathology of CXCR4 in Colorectal Cancer Patients: a Meta-analysis.

The chemokine receptor 4 (CXCR4) has been widely used in diagnosis and prognosis of colorectal cancer (CRC). However, there is no current consensus on the impact of CXCR4 on CRC patients. The purpose of this study was to evaluate the prognostic and clinicopathological importance of CXCR4 in CRC patients. Databases, such as PubMed, Cochrane library, CBM and EMBASE updated to 2014 were searched to include eligible articles. We analysed correlations between CXCR4 expression and clinicopathological features and overall survival (OS). A total of 1, 055 CRC patients from twelve studies were included in the study. The pooled odds ratios (ORs) which indicated CXCR4 expression was likely to be associated with TNM stage (OR=0.43, CI=0.34-0.55, P<0.00001), lymph node status (OR=2.23, CI=1.23-4.05, P=0.008) and vascular invasion (OR=2.21, CI=1.11-4.39, P=0.02). Poor overall survival of CRC cancer was found to be significantly related to CXCR4 overexpression (hazard ratio (HR) 1.36 CI=1.17-1.59, P<0.0001), whereas combined ORs revealed that CXCR4 expression had no correlation with gender or differentiation. Based on the published studies, CXCR4 overexpression in patients with CRC indicates poor survival outcome and clinicopathological factors.