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

Abstract

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.

Long non‑coding RNA XIST predicting advanced clinical parameters in cancer: A Meta‑Analysis and case series study in a single institution (Review)

“…Mao et al (21) identified 15 eligible studies containing 1,209 patients for inclusion in their meta-analysis; they observed that increased lncRNA-XIST expression levels in cancer tissues were associated with a poorer overall survival. In the study conducted by Liu et al (22), 15 studies with a total of 920 patients were included in the meta-analysis, and the results suggested that high lncRNA-XIST expression levels were associated with distant metastasis, tumor stage and poor prognosis. However, a number of contrasting studies were published concerning the role of lncRNA-XIST in cancer: In a recent study by Du et al (18), lncRNA-XIST served as a tumor suppressor in prostate cancer, its expression correlating with prognosis and tumor stage.…”

“…Also, the association between lncRNA-XIST expression and the survival rates of patients was not determined. However, recent studies revealed that high expression levels were correlated with decreased overall and disease-free survival (20,22,58). The subgroup analysis did not identify a source of heterogeneity, although significant heterogeneity in distant metastasis, tumor size and stage was observed.…”

“…However, the majority of the data described so far is limited by discrete outcomes and small sample sizes. In recent years, several meta-analyses were conducted to evaluate the prognostic value of lncRNA-XIST in patients with cancer, and it was identified that the expression level of XIST was associated with overall survival, lymph node metastasis, distant metastasis and tumor stage (20–22). However, following these meta-analyses, a number of studies concerning XIST and cancer were published, with some describing contradicting conclusions (23,24).…”

MiR-7 reduces the BCSC subset by inhibiting XIST to modulate the miR-92b/Slug/ESA axis and inhibit tumor growth

“…Next, we observed that miR-7 could directly regulate RELA expression, as confirmed by the luciferase reporter assay. Since CD44 is tightly associated with the BCSC phenotype [10,16,34], we hypothesized that miR-7 decreased the BCSC subset mainly by targeting RELA to inhibit CD44 expression. Our findings agreed with a recent report by Cantley et al, which reported a targeted relationship between miR-7 and the NF-κB subunit RELA and miR-7 inhibition of RELA expression could impact the proliferation, invasion, and apoptosis of non-small cell lung cancer cells.…”

LncRNA NORAD as a Novel Predictor of Lymph Node Metastasis and Prognosis in Solid Tumors: A Systematic Review and Meta-Analysis

“… 29 , 30 Many studies have reported that several lncRNAs could be used as prognostic biomarkers in human cancers, such as MALAT1, GAS5, XIST, and BLACAT1. 31 - 34 LncRNA NORAD is a novel identified lncRNA, located on Chr20q11.23. Lee et al first discovered that lncRNA NORAD could maintain genomic stability in human cells.…”