Expression Of LncRNA MEG3, ANRIL And TUC338in Human Colorectal Cancer

Objective: Many attentions have been paid to newly discovered longnon-coding RNA (lncRNA), which closely related to oncogenesis, thedevelopment of tumor is widely regulated by lncRNA. The goal of this studyis to detect the expression of Maternally imprinted gene expression3(MEG3),Antisense non-coding RNA in the INK4Locus (ANRIL), and Overlappingtranscriptional gene1(TUC338) in human colorectal cancer tissues andnormal tissues adjacent to carcinoma. These lncRNAs involved in oncogenesisby interaction with multiple pathways. By testing the expression of VEGF andthe vessels density in cancer tissues to explore the relationship of lncRNA,VEGF expression differences as well as the angiogenesis in human colorectalcancer.Methods: The colorectal cancer and normal tissues (10cm from tumortissue) were collected from32patients in our Department. We tested therelative expression of MEG3, ANRIL and TUC338genes by real-timequantitative PCR (RT-PCR), respectively.Results:1. The expression of MEG3was decreased in cancer tissues, and ANRILincreased in cancer tissuesThe real-time quantitative RT-PCR analysis showed that theANRIL expression level in cancer tissues of81.25%cases (26/32) was higherthan that in normal tissues. The MEG3expression level in cancer tissues in9.38%cases (3/32) was higher than that of normal ones. By conductingpaired-samples t test, the expression of ANRIL was up-regulated in cancertissues significantly compared with normal tissues (P<0.05), anddown-regulation of MEG3expression in tumors (P<0.05).2. No significant differences of TUC338expression between the cancer and the matched tissuesThe RT-PCR analysis appeared that the TUC338expression levelin cancer tissues of65.63%cases (21/32) was higher than that in normaltissues. The paired-samples t test result showed that no significant differences(P>0.05).3. The correlation between lncRNAs expression and the pathologicfeatures in the colorectal cancerAccording to the real-time quantitative RT-PCR results, we analyzed thecorrelation among the expression of MEG3, ANRIL and TUC338and cancerdifferentiation degree, lymph node invasion, invasion depth and cancerlocation by independent-samples t test, respectively. The results showed thatthere was no significant difference among them (P>0.05), and in which ofTUC338has no statistically relationship with liver metastasis of colorectalcancer(P＞0.05).4. The expression of VEGF in cancer tissuesImmunohistological chemistry results showed that TUC338expressionlevel in cancer tissues of65.63%cases (21/32) was higher than that in normaltissues（P<0.05）, independent-samples t test showed that there were nosignificant differences correlation between VEGF expression and pathologicfeatures (P>0.05).5. Correlation between MEG3expression and VEGF expression level aswell as vessels density.Pearson relationship analysis results showed that there were negativerelationships between MEG3and vessels density(r=-0.352， P <0.05),similarly, negative relationships between MEG3and VEGF（r=-0.297，P <0.05）.Conclusion:1. The expression of MEG3is decreased in cancer tissues, while ANRILincreased in cancer tissues.2. The expressions of MEG3ANRIL TUC338show no statisticallydifferences to pathological features. 3. The expression of VEGF protein in cancer tissue was higher than thatin matched normal tissue, and the MEG3expression negativelycorrelated with expression of VEGF protein.4. Vessels density is significantly higher in the colorectal cancer andnegatively correlated with MEG3expression.