Knockdown of long non-coding RNA CCAT2 suppressed proliferation and migration of glioma cells

Long non-coding RNA XIST exerts oncogenic functions in human glioma by targeting miR-137

Long non-coding RNA (lncRNA) X inactivate-specific transcript (XIST) acts as an important regulator in tumor progression. However, its expression and the underlying mechanism in glioma remain unclear. The aim of this study was to explore the potential function of XIST in glioma progression. In the present study, our data showed that the expression of XIST was significantly up-regulated in glioma tissues and enhanced the proliferation of glioma cells. The expression of miR-137 was significantly decreased in glioma tissues. Further correlation analysis demonstrated that there was a negative correlation between XIST expression and miR-137 expression. Bioinformatics prediction and luciferase reporter assays demonstrated that miR-137 could directly bind to XIST and negatively regulated the expression of miR-137. Additionally, our data further showed that XIST could up-regulate the expression of miR-137 targeted gene Rac1 through acting as an endogenous sponge of miR-137. In addition, we found that Rac1 inhibition or miR-137 overexpression could suppress glioma cells proliferation induced by XIST overexpression. Thus, a novel XIST-miR-137-Rac1 pathway regulatory axis in glioma pathogenesis was revealed in the present study. Overall, our study indicated that XIST could be a potential therapeutic target in the treatment of glioma.

Long noncoding RNA CCAT2 can predict metastasis and a poor prognosis: A meta-analysis

BACKGROUND

Colon cancer associated transcript 2 (CCAT2), a novel long non-coding RNA (lncRNA), plays a key role in tumorigenesis. This meta-analysis systematically summarizes the relationship between CCAT2 and cancers.

METHODS

A comprehensive, computerized literature search was conducted in PubMed, Cochrane library, Chinese National Knowledge Infrastructure, and Chinese Wan Fang database. Odds ratios (ORs), hazard ratios (HRs) and their 95% confidence interval (95% CI) were calculated to assess the effect size. A total of 9 studies were enrolled in this meta-analysis, which was performed by Revman5.3 software and Stata12.0.

RESULTS

Our meta-analysis indicates that patients with elevated expression of CCAT2 are prone to developing distant metastasis (DM) (OR=12.42; 95% CI=5.77-26.74; P < 0.00001), which is associated with a tendency for lymph nodes metastasis (LNM) (OR=3.60 95% CI=1.65-7.87, P=0.001). Further analyses reveal that patients with high CCAT2 expression have poorer overall survival (OS) (HR=1.53, 95% CI=1.15-2.02, P=0.003, random-effects) and progression-free survival (PFS) (HR=2.88, 95% CI=1.81-4.56, P < 0.00001, fixed-effects).

CONCLUSIONS

Therefore, CCAT2 may be a potential novel biomarker for indicating clinical outcomes of human cancers.

CCAT2: A novel oncogenic long non-coding RNA in human cancers

Colon cancer-associated transcript 2 (CCAT2) was originally identified as an oncogenic long non-coding RNA in colorectal cancer. Since its discovery, the oncogenic role of CCAT2 has been increasingly demonstrated in human cancers. In this connection, CCAT2 upregulation is frequently reported and very often associated with tumour progression and poor clinical outcomes. Functionally, knockdown of CCAT2 could induce cancer cell apoptosis and suppress cell proliferation and invasiveness, suggesting that CCAT2 might be a therapeutic target. The present review summarized current literature concerning the expression and functional role of CCAT2 in human malignancies.