Circulating long noncoding RNA act as potential novel biomarkers for diagnosis and prognosis of non-small cell lung cancer

lncRNAs as potential molecular biomarkers in the clinicopathology and prognosis of cholangiocarcinoma: a systematic review and meta-analysis

Background

Cholangiocarcinoma (CCA) is the second most common fatal primary hepatobiliary malignant carcinoma, characterized by early invasion and extremely poor outcomes. It is therefore necessary to identify a novel biomarker to better diagnose CAA and predict its prognosis. Recently, emerging evidence has revealed that some lncRNAs play an important role in the tumorigenesis and progression of CAA. In order to support this search for novel diagnostic and prognostic biomarkers for CAA, we conducted a meta-analysis to analyze the published association between lncRNA expression and its clinical value in CAA.

Methods

Eligible studies were pooled and analyzed according to our inclusion and exclusion criteria after a comprehensive literature search. Stata 14.0 software was used to analyze the data from relevant studies and to construct a forest plot. Different effect sizes were selected for the meta-analysis.

Results

In total, 24 publications were included in this meta-analysis. After review of their full-text, 16 articles studied the association between lncRNAs and clinicopathological characteristics, 2 discussing diagnosis and 16 discussing prognosis. Our results showed that overexpression of CCAT1 was significantly correlated with tumor stage (I + II vs III + IV) (OR, 4.99; 95% CI 2.77–8.99; P<0.001) and lymph node metastasis in CCA (OR, 4.75; 95% CI 2.65–8.52; P<0.001). Furthermore, elevated CCAT lncRNA family expression predicted a shorter overall survival (HR, 2.09; 95% CI 1.17–3.00; P<0.001), especially CCAT2. Upregulation of CCAT2 was also obviously associated with tumor stage in CCA (OR, 5.29; 95% CI 2.64–10.58; P=0.001).

Conclusion

This is the first meta-analysis to assess the relationship between expression of lncRNAs and the clinical values of patients with CCA. lncRNAs can function as potential molecular biomarkers of the clinicopathology and prognosis of CCA.

Potential clinical application of lncRNAs in non-small cell lung cancer

Lung cancer has been identified as one of the most prevalent and deadly tumors worldwide. In recent years, lncRNAs have been demonstrated to play a significant role in the development of lung cancer. Specifically, lncRNAs act as a regulator of cancer-critical genes, and they regulate the biological behavior of tumors at the transcriptional and posttranscriptional levels. Recent studies have shown that lncRNAs possess great potential in the treatment of non-small cell lung cancer patients because of their roles in diverse cellular processes, such as proliferation, metastasis, stem cell maintenance, and epithelial to mesenchymal transition, and they serve as signaling biomarkers. Compared to other invasive diagnostic methods, detection of lncRNAs may become a very useful noninvasive methodology. Moreover, lncRNAs can serve as potential therapeutic targets in non-small cell lung cancer due to their roles in regulating many signaling pathways associated with lung carcinoma. In this review, we discuss the roles and expression profile of lncRNAs. We also discuss the promising application of lncRNAs as predictors of clinical diagnosis, prognosis, and as potential therapeutic targets, aiming to demonstrate their practical value for clinical treatment.

Diagnostic efficacy of long non-coding RNA in lung cancer: a systematic review and meta-analysis

The detection of long non-coding RNA (lncRNA) is a novel method for lung cancer diagnosis. However, the diagnostic efficacy of lncRNA in different studies is inconsistent. Therefore, we conducted this meta-analysis to elucidate the diagnostic efficacy of lncRNA in identification of lung cancer including small cell lung cancer. The online PubMed, Medline, EMBASE, CNKI and Wanfang literature databases were searched to identify all related articles about the diagnostic efficacy of lncRNA for lung cancer. 28 articles including 3044 patients with lung cancer and 2598 controls were enrolled in our meta-analysis. lncRNA sustained a high diagnostic efficacy, pooled sensitivity of 0.82 (95% CI 0.79 to 0.84), specificity of 0.82 (95% CI 0.78 to 0.84) and area under the curve (AUC) of 0.88 (95% CI 0.85 to 0.91) in identification of patients with lung cancer from controls. Furthermore, the diagnostic efficacy of paralleled lncRNA was better than single lncRNA (sensitivity: 0.86 vs 0.80; specificity: 0.88 vs 0.78; AUC: 0.93 vs 0.86). MALAT1 had a better diagnostic efficacy than GAS5 (AUC: 0.90 vs 0.81; sensitivity: 0.83 vs 0.70; specificity: 0.83 vs 0.78). lncRNA in tissues was observed to achieve lower diagnostic efficacy than that in plasma or serum (AUC: 0.87 vs 0.90 vs 0.90) when stratified by sample types. In summary, our meta-analysis suggests that lncRNA might be a promising biomarker(s) for identifying lung cancer and the combination of lncRNA or with other biomarkers had a better diagnostic efficacy.

Long noncoding RNA Sox2 overlapping transcript (SOX2OT) promotes non-small-cell lung cancer migration and invasion via sponging microRNA 132 (miR-132)

Background

Long noncoding RNA (lncRNA) Sox2 overlapping transcript (SOX2OT) has been reported to be upregulated in various types of cancers, including non-small-cell lung cancer (NSCLC). However, the biological role and underlying mechanism of SOX2OT activity in NSCLC remain largely unknown. This study aims to investigate the function and possible molecular mechanisms of SOX2OT in NSCLC.

Materials and methods

Quantitative real-time polymerase chain reaction was used to detect SOX2OT expression, and cellular proliferation, migration, and invasion were measured using cell counting kit-8, wound healing, and Transwell invasion assays, respectively. Western blotting was used to determine protein expression. Starbase 2.0 and luciferase reporter assay were utilized to identify the molecular target of SOX2OT.

Results

Here, we discovered that SOX2OT was markedly upregulated in NSCLC tissues and cell lines. Knockdown of SOX2OT inhibited the proliferation, migration, invasion, and epithelial–mesenchymal transition (EMT) process in NSCLC cells. Moreover, we explored the regulatory mechanism of SOX2OT and found that SOX2OT directly bound microRNA 132 (miR-132) in NSCLC cells. Importantly, miR-132 inhibition partially reversed the SOX2OT knockdown-mediated inhibitory effect on cell proliferation, migration, invasion, and EMT process. We also found that SOX2OT could regulate zinc finger E-box-binding homeobox 2 (a target of miR-132) expression, which played crucial roles in tumor cell proliferation and invasion.

Conclusion

These findings indicated that SOX2OT was a noncoding oncogene that exerted important regulatory functions in NSCLC via sponging miR-132 and might represent a novel strategy for overcoming this disease.

Effect of lncRNA ANRIL silencing on anoikis and cell cycle in human glioma via microRNA-203a

BACKGROUND

Glioma is a deadly nervous system tumor with a poor prognosis. Although there have been many efforts to overcome glioma, the molecular mechanism of its pathogenesis remains unclear.

METHODS

We used human glioma U251 cells silenced for the oncogenic lncRNA ANRIL or overexpressing the anti-oncogene miR-203a to examine the role of lncRNA ANRIL silencing on anoikis and cell cycle arrest by flow cytometry. Meanwhile, the activity of caspase-3/8/9 was measured by fluorometric assay, the expression of tumor-related genes and activity of AKT signaling pathway was measured by Western blotting, real-time PCR, and dual luciferase reporter gene assay.

RESULTS

lncRNA ANRIL was positively correlated with glioma grade and negatively correlated with miR-203a. lncRNA ANRIL silencing could induce anoikis and cell cycle arrest in G0/G1 phase, while regulating the activity of caspase-3/8/9 and the AKT signaling pathway, and the expression of tumor-related genes in the U251 cell line. miR-203a mimics could partially reverse these functions.

CONCLUSION

We consider that lncRNA ANRIL is a potential therapeutic and diagnostic target for glioma, and miR-203a plays an important role in the biological function of lncRNA ANRIL in glioma.

Long non-coding RNA XIST predicts worse prognosis in digestive system tumors: a systemic review and meta-analysis

Increasing studies are indicating that long non-coding RNA (lncRNA) X-inactive specific transcript (XIST) is associated with the prognosis of cancer patients. However, the results have been disputed. Therefore, we aimed to further explore the prognostic value and clinical significance of XIST in various types of cancers. Then, we focussed our research on the comparison of the predictive value of XIST between digestive system tumors and non-digestive system tumors. We performed a systematic search by looking up PubMed, Embase, Cochrane Library, Web of Science, and Medline (up to 3 January 2018). Fifteen studies which matched our inclusion criteria with a total of 920 patients for overall survival and 867 patients for clinicopathological characteristics were included in this meta-analysis. Pooled hazard ratios (HR) and odds ratios (ORs) with their corresponding 95% confidence intervals (95% CIs) were calculated to summarize the effects. Our results suggested that high expression levels of XIST were associated with unfavorable overall survival in cancer patients (pooled HR = 1.81, 95% CI: 1.45-2.26). Additionally, we found that XIST was more valuable in digestive system tumors (pooled HR = 2.24, 95% CI: 1.73-2.92) than in non-digestive system tumors (pooled HR = 1.22, 95% CI: 0.60-2.45). Furthermore, elevated expression levels of XIST were connected with distant metastasis and tumor stage. XIST was correlated with poor prognosis, which suggested that XIST might serve as a novel predictive biomarker for cancer patients, especially for patients of digestive system tumors.

The prognostic value of long noncoding RNA Sox2ot expression in various cancers: A systematic review and meta-analysis

BACKGROUND

Several investigations have explored the prognostic value of long noncoding RNA Sox2 overlapping transcript (lncRNA Sox2ot) expression in human cancers, however, with inconsistent results. The aim of this study was to evaluate the prognostic role of lncRNA Sox2ot expression in various cancers.

METHODS

PubMed, Web of Science, Embase, and Cochrane Library were comprehensively searched to retrieve relevant studies. The relationships between lncRNA Sox2ot expression and prognostic parameters were detected, including overall survival (OS), tumor differentiation, clinical stage, distant metastasis, lymph node metastasis and so on.

RESULTS

A total of 10 studies involving 943 cancer patients were finally included into the study. High lncRNA Sox2ot expression was significantly related to shorter OS in cancers (HR = 2.06, 95%CI = 1.67-2.55, P < 0.01). The cancer patients with high lncRNA Sox2ot expression tended to have worse tumor differentiation (P = 0.04), advanced clinical stage (P < 0.01), earlier distant metastasis (P < 0.01), and earlier lymph node metastasis (P = 0.01) compared to those with low lncRNA Sox2ot expression. However, there was no distinct correlation between lncRNA Sox2ot expression and age (P = 0.87), gender (P = 0.48), tumor size (P = 0.08), or vascular invasion (P = 0.07).

CONCLUSION

High lncRNA Sox2ot expression was significantly associated with worse OS, advanced clinical stage, worse tumor differentiation, earlier distant metastasis, and earlier lymph node metastasis in various cancers. LncRNA Sox2ot expression might a promising prognostic factor in various cancers.