Systematic review and meta-analysis of the utility of long non-coding RNA GAS5 as a diagnostic and prognostic cancer biomarker

Clinicopathological and prognostic value of long non-coding RNA CCAT1 expression in patients with digestive system cancer

Colon cancer associated transcript-1 (CCAT1) is known to play an important role in numerous types of human cancer, including bladder, prostate and ovarian cancer. However, a consistent perspective has not been established in digestive system cancer (DSC). To explore the prognostic value of CCAT1 in patients with DSC, a meta-analysis was performed. A systematic search of PubMed, Embase, Web of Science, China National Knowledge Infrastructure, Chinese Biological Medical Literature database, Cochrane Library and WanFang database was applied to select eligible articles. Pooled odds ratios (ORs) or hazard ratios (HRs) with corresponding 95% confidence intervals (CIs) were calculated to estimate the effects of CCAT1 on pathological or clinical features. A total of 1,719 patients from 12 eligible articles were enrolled in the meta-analysis. The results revealed that elevated CCAT1 expression was significantly related to larger tumor size (OR, 1.81; 95% CI, 1.31-2.48), poorer differentiation (OR, 0.45; 95% CI, 0.31-0.64), earlier lymph node metastasis (OR, 3.14; 95% CI, 2.34-4.22) and advanced TNM stage (OR, 3.08; 95% CI, 2.07-4.59). In addition, high CCAT1 expression predicted a poorer outcome for overall survival rate (HR, 2.37; 95% CI, 2.11-2.67) and recurrence-free survival rate (HR, 2.16, 95% CI, 1.31-3.57). High expression levels of CCAT1 were therefore related to unfavorable clinical outcomes of patients with DSC. These results demonstrated that CCAT1 could serve as a prognostic predictor in human DSC.

Noncoding RNome as Enabling Biomarkers for Precision Health

Noncoding RNAs (ncRNAs), in the form of structural, catalytic or regulatory RNAs, have emerged to be critical effectors of many biological processes. With the advent of new technologies, we have begun to appreciate how intracellular and circulatory ncRNAs elegantly choreograph the regulation of gene expression and protein function(s) in the cell. Armed with this knowledge, the clinical utility of ncRNAs as biomarkers has been recently tested in a wide range of human diseases. In this review, we examine how critical factors govern the success of interrogating ncRNA biomarker expression in liquid biopsies and tissues to enhance our current clinical management of human diseases, particularly in the context of cancer. We also discuss strategies to overcome key challenges that preclude ncRNAs from becoming standard-of-care clinical biomarkers, including sample pre-analytics standardization, data cross-validation with closer attention to discordant findings, as well as correlation with clinical outcomes. Although harnessing multi-modal information from disease-associated noncoding RNome (ncRNome) in biofluids or in tissues using artificial intelligence or machine learning is at the nascent stage, it will undoubtedly fuel the community adoption of precision population health.

Silencing of LncRNA KCNQ1OT1 confers an inhibitory effect on renal fibrosis through repressing miR-124-3p activity

LncRNA have been increasingly shown that plays pivotal roles in the development of various diseases, including renal fibrosis. Nevertheless, the pathological function of Long non-coding RNA KCNQ1OT1 (KCNQ1OT1) in the renal fibrosis remains obscure. Unilateral ureteral obstruction (UUO) was used to induce renal fibrosis. We detected the expression levels of KCNQ1OT1 in the TGF-β1-induced HK-2 cells via RT-qPCR analysis. The functions of KCNQ1OT1 on the progression of renal fibrosis were examined by CCK-8, EdU, dual-luciferase reporter, and immunofluorescence analyses. In the present study, we found that sh-KCNQ1OT1 obviously attenuated UUO-induced renal fibrosis. Moreover, production of extracellular matrix (ECM), including α-SMA and Fibronectin levels, was significantly increased in kidney and HK-2 cells after UUO or TGF-β stimulation. Knockdown of KCNQ1OT1 inhibited cell proliferation and inhibits the α-SMA and Fibronectin expression of TGF-β1-induced HK-2 cells. In addition, bioinformatics analysis and dual-luciferase reporter assay indicated that miR-124-3p was a target gene of KCNQ1OT1. Mechanistically, silencing miR-124-3p abolished the repressive effects of KCNQ1OT1 on TGF-β1-induced HK-2 cells. In conclusion, KCNQ1OT1 knockdown plays an anti-fibrotic effect through promotion of miR-124-3p expression in renal fibrosis, which provides a promising therapeutic target for the treatment of renal fibrosis.

LncRNA OIP5-AS1 accelerates intervertebral disc degeneration by targeting miR-25-3p

It is obvious that epigenetic processes influence the evolution of intervertebral disc degeneration (IDD). However, its molecular mechanisms are poorly understood. Long noncoding RNAs (lncRNAs) have been validated to exert vital roles in IDD. Therefore, we tested the hypothesis that OIP5-AS1, a potential regulator of IDD, modulates IDD progression. RT-PCR was utilized to detect levels of OIP5-AS1, miR-25-3p, Collagen II and Aggrecan in IDD tissues and nucleus pulposus cells (NPCs). Immunofluorescence assay measured Collagen II expression. CCK-8, EdU, and flow cytometry estimated the levels of proliferation and apoptosis. Proteins were assessed via Western blot. The binding affinity of OIP5-AS1 with miR-25-3p was investigated by luciferase reporter assay. Enzyme-linked immunosorbent assay (ELISA) analyzed the levels of inflammatory factors. OIP5-AS1 was high expressed in IDD tissues and its expression gradually promoted with the increasing of Pfirrmann scores. The cell morphology of NPCs changed into spindle-shaped, and Collagen II expression was low. After OIP5-AS1 was silenced, cell proliferation was boosted whereas both apoptosis and extracellular matrix (ECM) degradation were restrained. In LPS-activated NPCs, OIP5-AS1 depletion also suppressed inflammation response. Further, miR-25-3p was a target of OIP5-AS1. The effects of OIP5-AS1 silence on proliferation, apoptosis, and ECM degradation were reversed upon miR-25-3p downregulation. Moreover, the inhibitory impact of OIP5-AS1 knockdown on the inflammation of LPS-treated NPCs was rescued with miR-25-3p inference. In general, lncRNA OIP5-AS1 exerted its effects in IDD by targeting miR-25-3p, implying the usage of OIP5-AS1/miR-25-3p as a novel regulatory axis for the molecular targets of IDD therapy.

The Effect of lncRNA SNHG3 Overexpression on Lung Adenocarcinoma by Regulating the Expression of miR-890

The lncRNA small nucleolar host gene 3 (SNHG3) was discovered to play an important role in the occurrence and development of lung adenocarcinoma (LUAD). However, the underlying molecular mechanism of SNHG3 in LUAD remains unclear. In the present study, SNHG3 expression levels in LUAD tissues and cell lines were analyzed using reverse transcription-quantitative PCR. The effects of SNHG3 on the proliferation, apoptosis, migration, and invasion of LUAD cells were determined using Cell Counting Kit-8, colony formation, flow cytometry, wound healing, and Transwell chamber assays, respectively. The specific underlying mechanism of SNHG3 in LUAD was investigated using bioinformatics analysis and a dual luciferase reporter assay. The results revealed that SNHG3 expression levels were downregulated in LUAD tissues and cell lines. Functionally, SNHG3 overexpression suppressed the proliferation, migration, and invasion of LUAD cells, while promoting apoptosis. Mechanistically, microRNA- (miR-) 890 was identified as a potential target of SNHG3, and its expression was negatively regulated by SNHG3. Notably, SNHG3 was found to promote LUAD progression by targeting miR-890. In conclusion, the findings of the present study revealed that lncRNA SNHG3 promoted the occurrence and progression of LUAD by regulating miR-890 expression.

Long non‑coding RNA SNHG3 promotes the development of non‑small cell lung cancer via the miR‑1343‑3p/NFIX pathway

The aim of the present study was to identify the function of long non‑coding RNA (lncRNA) small nucleolar RNA host gene 3 (SNHG3) and examine its effects on non‑small cell lung cancer (NSCLC). A series of in vitro experiments were employed to evaluate the effects of SNHG3 on the progression of NSCLC, including Cell Counting Kit‑8, 5‑Ethynyl‑2'‑deoxyuridine, flow cytometry, wound healing, Transwell, western blotting and reverse transcription‑quantitative PCR assays. Bioinformatics analyses and a luciferase reporter assay were performed to identify the target gene of SNHG3 and microRNA (miR)‑1343‑3p. Finally, recuse experiments were conducted to verify the effect of SNHG3 and its target gene on proliferation, apoptosis, migration and invasion. The findings indicated that lncRNA SNHG3 was highly expressed in NSCLC tissues and cell lines. Knockdown of lncRNA SNHG3 inhibited cell proliferation, migration and invasion, and accelerated cell apoptosis in NSCLC cell lines. The results of the bioinformatics analysis and the luciferase reporter assay indicated that lncRNA SNHG3 directly bound to miR‑1343‑3p and that it could downregulate the expression levels of miR‑1343‑3p to promote the progression of NSCLC. Rescue experiments indicated that lncRNA SNHG3 increased nuclear factor IX (NFIX) expression by sequestering miR‑1343‑3p in NSCLC. These results suggested that the SNHG3/miR‑1343‑3p/NFIX axis may serve as a novel prognostic biomarker and therapeutic target for NSCLC.

Long Non-coding RNA RUNDC3A-AS1 Promotes Lung Metastasis of Thyroid Cancer via Targeting the miR-182-5p/ADAM9

Long non-coding RNAs (lncRNAs) have been identified as influential indicators in variety of malignancies. Among which, LncRNA RUNDC3A-AS1 is reported to upregulate in thyroid cancer. However, the expression pattern and the pathological function of lncRNA RUNDC3A-AS1 in thyroid cancer is unclear. In this study, we examined the expression levels of lncRNA RUNDC3A-AS1 in the thyroid cancer tissues and cell lines via RT-qPCR analysis. The effects of RUNDC3A-AS1 on thyroid cancer cell metastasis were detected by transwell chamber assay, scratch assay in vitro and lung metastasis model in vivo. The results indicated that RUNDC3A-AS1 was highly expressed in the thyroid cancer tissues and cell lines. Functionally, knockdown of RUNDC3A-AS1 could repress the migration and invasion of thyroid cancer cells in vitro, and inhibit thyroid cancer metastasis to lung in vivo. Mechanistically, RUNDC3A-AS1 served as an inhibitor of miR-182-5p in tumor tissues and cell lines. RUNDC3A-AS1 inhibited the expression of miR-182-5p to increase the expression level of ADAM9, thus further aggravating the malignancy of thyroid cancer. Therefore, the RUNDC3A-AS1/miR-182-5p/ADAM9 axis may be a potential therapeutic target for the treatment of thyroid cancer metastasis.

Long non-coding RNA LINC00488 facilitates thyroid cancer cell progression through miR-376a-3p/PON2

Objective: Long non-coding RNAs (lncRNAs) recently have been identified as influential indicators in a variety of malignancies. The aim of the present study was to identify a functional lncRNA LINC00488 and its effects on thyroid cancer in the view of cell proliferation and apoptosis.

Methods: In order to evaluate the effects of LINC00488 on the cellular process of thyroid cancer, we performed a series of in vitro experiments, including cell counting kit-8 (CCK-8) assay, EdU (5-ethynyl-2′-deoxyuridine) assay, flow cytometry, transwell chamber assay, Western blot and RT-qPCR. The target gene of LINC00488 was then identified by bioinformatics analysis (DIANA and TargetScan). Finally, a series of rescue experiments was conducted to validate the effect of LINC00488 and its target genes on proliferation, migration, invasion and apoptosis of thyroid cancer.

Results: Our findings revealed that LINC00488 was highly expressed in thyroid cancer cell lines (BCPAP, BHP5-16, TPC-1 and CGTH-W3) and promoted the proliferation, migration and invasion, while inhibited the apoptosis of thyroid cancer cells (BCPAP and TPC-1). The results of bioinformatics analysis and dual luciferase reporter gene assay showed that LINC00488 could directly bind to miR-376a-3p and down-regulated the expression level of miR-376a-3p. In addition, Paraoxonase-2 (PON2) was a target gene of miR-376a-3p and negatively regulated by miR-376a-3p. Rescue experiment indicated that LINC00488 might enhance PON2 expression by sponging miR-376a-3p in thyroid cancer.

Conclusion: Taken together, our study revealed that lncRNA LINC00488 acted as an oncogenic gene in the progression of thyroid cancer via regulating miR-376a-3p/PON2 axis, which indicated that LINC00488-miR-376a-3p-PON2 axis could serve as novel biomarkers or potential targets for the treatment of thyroid cancer.

Long Non-Coding RNA MAPK8IP1P2 Inhibits Lymphatic Metastasis of Thyroid Cancer by Activating Hippo Signaling via Sponging miR-146b-3p

The principal issue derived from thyroid cancer is its high propensity to metastasize to the lymph node. Aberrant exprssion of long non-coding RNAs have been extensively reported to be significantly correlated with lymphatic metastasis of thyroid cancer. However, the clinical significance and functional role of lncRNA-MAPK8IP1P2 in lymphatic metastasis of thyroid cancer remain unclear. Here, we reported that MAPK8IP1P2 was downregulated in thyroid cancer tissues with lymphatic metastasis. Upregulating MAPK8IP1P2 inhibited, while silencing MAPK8IP1P2 enhanced anoikis resistance in vitro and lymphatic metastasis of thyroid cancer cells in vivo. Mechanistically, MAPK8IP1P2 activated Hippo signaling by sponging miR-146b-3p to disrupt the inhibitory effect of miR-146b-3p on NF2, RASSF1, and RASSF5 expression, which further inhibited anoikis resistance and lymphatic metastasis in thyroid cancer. Importantly, miR-146b-3p mimics reversed the inhibitory effect of MAPK8IP1P2 overexpression on anoikis resistance of thyroid cancer cells. In conclusion, our findings suggest that MAPK8IP1P2 may serve as a potential biomarker to predict lymphatic metastasis in thyroid cancer, or a potential therapeutic target in lymphatic metastatic thyroid cancer.

LncRNA RP11-395G23.3 suppresses the endometrial cancer progression via regulating microRNA-205-5p/PTEN axis

The focal point of this research was the functional role of RP11-395G23.3 in endometrial cancer (EC). The expression of RP11-395G23.3, microRNA (miRNA)-205-5p, and their target proteins were detected by quantitative real-time polymerase chain reaction and western-blot analyses. Flow cytometry and proliferation, Transwell, and wound healing assays were used to detect the effects of RP11-395G23.3 and miRNA-205-5p on tumor cell migration and proliferation in vitro. RP11-395G23.3 expression was negatively related to miRNA-205-5p, but positively related to phosphatase and tensin homolog (PTEN) expression in human EC tissues. We discovered that low RP11-395G23.3 expression was significantly related to advanced histological grade and lymphovascular space invasion in EC patients. In addition, overexpression of RP11-395G23.3 significantly inhibited the proliferation, invasion, migration, and induced apoptosis of Ishikawa and HEC-1A cells in vitro. Our results also showed that RP11-395G23.3 could directly bind to miRNA-205-5p through its miRNA response elements and eliminate the inhibitory effect of targeting gene PTEN, thus leading to the signaling pathway of phosphatidylinositol-3-kinase/AKT inactivation. We demonstrated for the first time that RP11-395G23.3 may inhibit the development and pathogenesis of EC by acting as a sponge for miRNA-205-5p and increasing PTEN expression. RP11-395G23.3 may be a target for the diagnosis and treatment of EC.

LncRNA GAS5-AS1 inhibits glioma proliferation, migration, and invasion via miR-106b-5p/TUSC2 axis

Glioma is one of the most common malignant tumors and shows a high metastasis rate and poor prognosis. Abnormal expression of long non-coding RNAs (lncRNAs) contributes to various human tumors including gliomas. This study aimed to investigate the regulatory role of the antisense RNA of growth arrest special 5 (GAS5-AS1), a novel lncRNA, in gliomas. Expression of GAS5-AS1 and microRNA-106b-5p (miR-106b-5p) in glioma tissues and cells was detected by quantitative reverse transcription PCR, northern blotting, or fluorescent in situ hybridization. Cell proliferation, migration, and invasion were analyzed by CCK-8 and Transwell assays. BALB/c nude mice were used to establish a glioma xenograft animal model by subcutaneous injection of U251 cells transfected with small interfering RNA targeting GAS5-AS1. A dual-luciferase reporter assay was conducted to confirm the targeting relationship between GAS5-AS1 and miR-106b-5p. GAS5-AS1 expression was downregulated in glioma tissues and cells, and upregulation of GAS5-AS1 expression inhibited glioma cell proliferation, migration, and invasion. GAS5-AS1 expression was correlated with the glioma tumor grade. In nude mice, upregulation of GAS5-AS1 markedly suppressed glioma tumor growth. GAS5-AS1 overexpression significantly increased the miR-106b-5p level in glioma cells, and GAS5-AS1 expression was negatively related to miR-106b-5p expression in glioma tissues. Overexpression of miR-106b-5p reversed the inhibitory effects of GAS5-AS1 upregulation on glioma cell proliferation and metastasis, while restoration of TUSC2 rescued the proliferation and invasion of glioma cells transfected with miR-106b-5p mimics. In summary, lncRNA GAS5-AS1 inhibited glioma proliferation, migration, and invasion by sponging miR-106b-5p and regulating the expression of TUSC2. Our results suggest GAS5-AS1 as a novel target for the treatment and prognosis prediction of gliomas.

Effect of eleutheroside B1 on non‑coding RNAs and protein profiles of influenza A virus‑infected A549 cells

Influenza viruses often pose a serious threat to animals and human health. In an attempt to explore the potential of herbal medicine as a treatment for influenza virus infection, eleutheroside B1, a coumarin compound extracted from herba sarcandrae, was identified, which exhibited antiviral and anti-inflammatory activities against influenza A virus. In this study, high-throughput RNA sequencing and isobaric tags for relative and absolute quantification (iTRAQ) assays were performed to determine alterations in the non-coding RNA (ncRNA) transcriptome and proteomics. Bioinformatics and target prediction analyses were used to decipher the potential roles of altered ncRNAs in the function of eleutheroside B1. Furthermore, long ncRNA (lncRNA) and mRNA co-expressing networks were constructed to analyze the biological functions by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. The analysis of RNA sequencing data revealed that 5 differentially expressed ncRNAs were upregulated and 3 ncRNAs were downregulated in the A549 cells infected with A/PR8/34/H1N1, with or without eleutheroside B1 treatment (PR8+eleu and PR8, respectively). Nuclear paraspeckle assembly transcript 1 (NEAT1) was differentially expressed between the PR8 and A549 cell groups. GO and KEGG pathway analyses indicated that eleutheroside B1 took advantage of the host cell biological processes and molecular function for its antiviral and anti-inflammatory activities, as well as for regulating cytokine-cytokine receptor interaction in the immune system, consistent with previous findings. The results of the iTRAQ assays indicated that L antigen family member 3 (LAGE3) protein, essential for tRNA processing, tRNA metabolic processes and ncRNA processing, was down-regulated in the PR8+eleu compared with the PR8 group. In the present study, these comprehensive, large-scale data analysis enhanced the understanding of multiple aspects of the transcriptome and proteomics that are involved in the antiviral and anti-inflammatory activities of eleutheroside B1. These findings demonstrate the potential of eleutheroside B1 for use in the prevention and treatment of influenza A virus-mediated infections.

Developmental changes of rRNA ribose methylations in the mouse

A sequencing-based profiling method (RiboMeth-seq) for ribose methylations was used to study methylation patterns in mouse adult tissues and during development. In contrast to previous reports based on studies of human cancer cell lines, almost all methylation sites were close to fully methylated in adult tissues. A subset of sites was differentially modified in developing tissues compared to their adult counterparts and showed clear developmental dynamics. This provides the first evidence for ribosome heterogeneity at the level of rRNA modifications during mouse development. In a prominent example, the expression levels of SNORD78 during development appeared to be regulated by alternative splicing of the Gas5 host-gene and to correlate with the methylation level of its target site at LSU-G4593. The results are discussed in the context of the specialized ribosome hypothesis.

Up-regulated lncRNA GAS5 promotes chemosensitivity and apoptosis of triple-negative breast cancer cells

Up to accomplishment of this study, the role of long non-coding RNAs (lncRNAs) in breast cancer has been investigated in several researches. Nevertheless, its association with the chemosensitivity of cancer was little known. Therefore, this study is focused on lncRNA GAS5 and its influence in the chemosensitivity of triple-negative breast cancer (TNBC). Expression of GAS5 in TNBC tissues and cells was detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and its methylation was evaluated using methylation-specific polymerase chain reaction (MSP). Moreover, in order to define the contributory role of GAS5 in TNBC, GAS5 expression, proliferation, and apoptosis of TNBC cells were detected by a series of experiment. Finally, the effects of GAS5 in vivo were investigated by measuring tumor formation in nude mice. GAS5 was poorly expressed in TNBC tissues and cells, which could regulate the progression of TNBC. The methylation of CpG island in the promoter region of GAS5 in MDA-MB-231 and MDA-MB-468 cells was decreased, while GAS5 expression in cells was increased. Overexpressed GAS5 reduced the inhibitory concentration (IC50) value and the cell proliferation of TNBC, and promoted their apoptosis, so as to delay the progression of TNBC. Our study provides evidence that up-regulated GAS5 suppressed the progression of TNBC and promoted chemosensitivity and apoptosis of TNBC cells. Thus, GAS5 may be a potential candidate for the treatment of TNBC.

LncRNA FOXD2-AS1 Functions as a Competing Endogenous RNA to Regulate TERT Expression by Sponging miR-7-5p in Thyroid Cancer

Long non-coding RNA FOXD2 Adjacent Opposite Strand RNA 1 (FOXD2-AS1) has been widely reported to be implicated in the progression and recurrence of several cancers. The clinical significance and functional role of FOXD2-AS1 in thyroid carcinoma remain unknown. FOXD2-AS1 expression was evaluated by analyzing thyroid cancer RNA sequencing dataset from The Cancer Genome Atlas (TCGA). In vitro and in vivo assays were performed to assess the biological roles of FOXD2-AS1 in thyroid cancer cells. Western blot, luciferase, immunoprecipitation (IP), and RNA immunoprecipitation (RIP) assays were used to identify the underlying miRNA and mRNA target mediating the biological roles of FOXD2-AS1 in thyroid cancer cells. FOXD2-AS1 was upregulated in thyroid carcinoma tissues and cells. High expression of FOXD2-AS1 significantly correlated with clinical stage, recurrence of thyroid carcinoma. Silencing FOXD2-AS1 inhibited cancer stem cell-like phenotypes and attenuates the anoikis resistance in vitro. Downregulating FOXD2-AS1 represses the tumorigenesis of thyroid carcinoma cells in vivo. FOXD2-AS1 acts as a competitive endogenous RNA (ceRNA) for miR-7-5p, up-regulating the expression of telomerase reverse transcriptase (TERT), which further promotes the cancer stem cells features and anoikis resistance in thyroid cancer cells. Our findings indicate that FOXD2-AS1 functions as an oncogenic regulator in the development of thyroid cancer, contributing to early recurrence of thyroid cancer.

Long noncoding RNA X-inactive specific transcript as a prognostic factor in cancer patients: A meta-analysis based on retrospective studies

BACKGROUND/AIMS

Emerging evidence showed the long noncoding RNA X-inactive specific transcript (lncRNA XIST) may play a crucial role in various cancers. However, its prognostic value in cancer patients remains controversial. Therefore, we performed an in-depth meta-analysis to investigate the potential clinical value of lncRNA XIST as a prognostic marker for cancer patients.

METHODS

A comprehensive literature search was performed from PubMed, Embase and the Cochrane Central Search Library by January 2018. Pooled hazard ratios (HRs) or odds ratios (ORs) with 95% confidence interval (95% Cl) were calculated to evaluate the prognosis as well as clinicopathological parameters of XIST, respectively.

RESULTS

A total of 18 retrospective studies with 1351 cancer patients were included. Current meta-analysis revealed that elevated lncRNA XIST expression was associated with poor overall survival (OS) (HR = 2.14, 95% CI = 1.26-3.64; P = .005) and disease free survival (DFS) (HR = 4.52, 95% CI = 1.42-14.37; P = .011). The clinicopathological parameters analysis demonstrated that increased XIST expression was significantly associated with tumor size (OR = 2.93, 95% CI = 2.24-3.84; P < .001), clinical stage (OR = 2.73, 95% CI = 1.62-4.58; P < .001) and lymph node metastasis (OR = 2.44, 95% CI = 1.74-3.42; P < .001). In addition, subgroup analysis based on cancer type revealed that lncRNA XIST expression correlated with distant metastasis in digestive cancer (OR = 2.90, 95% CI = 1.80-4.68; P < .001).

CONCLUSION

The current meta-analysis results indicated lncRNA XIST expression level could serve as a prognostic predictor and biomarker in multiple cancers.

Loss of GAS5 tumour suppressor lncRNA: an independent molecular cancer biomarker for short-term relapse and progression in bladder cancer patients

Background

Bladder cancer (BlCa) heterogeneity and the lack of personalised prognosis lead to patients’ highly variable treatment outcomes. Here, we have analysed the utility of the GAS5 tumour-suppressor lncRNA in improving BlCa prognosis.

Methods

GAS5 was quantified in a screening cohort of 176 patients. Hedegaard et al. (2016) (n = 476) and TCGA provisional (n = 413) were used as validation cohorts. Survival analysis was performed using recurrence and progression for NMIBC, or death for MIBC. Internal validation was performed by bootstrap analysis, and decision curve analysis was used to evaluate the clinical benefit on disease prognosis.

Results

GAS5 levels were significantly downregulated in BlCa and associated with invasive high-grade tumours, and high EORTC-risk NMIBC patients. GAS5 loss was strongly and independently correlated with higher risk for NMIBC early relapse (HR = 2.680, p = 0.011) and progression (HR = 6.362, p = 0.035). Hedegaard et al. and TCGA validation cohorts’ analysis clearly confirmed the association of GAS5 loss with NMIBC worse prognosis. Finally, multivariate models incorporating GAS5 with disease established markers resulted in higher clinical benefit for NMIBC prognosis.

Conclusions

GAS5 loss is associated with adverse outcome of NMIBC and results in improved positive prediction of NMIBC patients at higher risk for short-term relapse and progression, supporting personalised prognosis and treatment decisions.

Prognostic value of lncRNA ROR expression in various cancers: a meta-analysis

Background: There is a dispute on the prognostic value of long non-coding RNA regulator of reprogramming (lncRNA ROR) in cancers. The purpose of the present study was to evaluate the prognostic significance of lncRNA ROR expression in human cancers. Methods: PubMed, Embase, and Cochrane Library were searched to look for relevant studies. The meta-analyses of prognostic and clinicopathological parameters (CPs) were conducted. Results: A total of ten studies were finally included into the meta-analysis. High lncRNA ROR expression was significantly associated with shorter overall survival (hazard ratio [HR] = 2.88, 95% confidence interval [CI] = 2.16-3.84, P<0.01) and disease-free survival (HR = 3.25, 95% CI = 2.30-4.60, P<0.01) compared with low lncRNA ROR expression. Besides, high lncRNA ROR expression was obviously related to more advanced clinical stage (P<0.01), earlier tumor metastasis (P=0.02), lymph node metastasis (P<0.01), and vascular invasion (P<0.01) compared with low lncRNA ROR expression. However, there was no significant correlation between lncRNA ROR expression and other CPs, including age (P=0.18), gender (P=0.33), tumor size (P=0.25), or tumor differentiation (P=0.13). Conclusion: High lncRNA ROR expression was associated with worse prognosis in cancers. LncRNA ROR expression could serve as an unfavorable prognostic factor in various cancers.

Integrative Bioinformatics Analysis Reveals Potential Long Non-Coding RNA Biomarkers and Analysis of Function in Non-Smoking Females with Lung Cancer

BACKGROUND Lung cancer is the most lethal cancer worldwide. The aim of this study was to identify the tumor-related lncRNAs and explore their functions in female non-smokers with lung cancer. MATERIAL AND METHODS The gene expression microarray datasets GSE19804, GSE31210, and GSE31548 were downloaded from the Gene Expression Omnibus database. The differentially-expressed lncRNAs between non-smoking female lung cancer samples and non-tumor lung tissues were identified using GEO2R. RESULTS In total, 25, 40, and 15 differentially-expressed lncRNAs were obtained from GSE19804, GSE31210, and GSE31548 datasets (|logFC| >1, adj. P<0.05), respectively. Eight lncRNAs were screened out in all 3 datasets. Of these, 5 lncRNAs were up-regulated and 3 lncRNAs were down-regulated in lung cancer tissues compared to non-tumor lung tissues. Then, the target miRNAs of aberrantly expressed lncRNAs and target mRNAs corresponding to miRNAs were predicted. Subsequently, the ceRNA network with 8 key lncRNAs, 20 miRNAs, and 38 mRNAs were constructed. Functional and pathway enrichment analysis showed these target genes were mainly enriched in biological processes associated with protein binding, nucleus, metal ion binding, regulation of transcription from RNA polymerase II promoter, nucleic acid binding, cell differentiation, microRNAs in cancer, and the hippo signaling pathway. Survival analysis of these lncRNAs revealed that low LINC00968 (P=0.0067) and TBX5-AS1 (P=0.0028) expression were associated with unfavorable prognosis in never-smoking female lung cancer patients. CONCLUSIONS The present study promotes understanding of the molecular mechanism of the pathogenesis of non-smoking female lung cancer and provides potential biomarkers for diagnosis and treatment.

Long non-coding RNA GAS5 is induced by interferons and plays an antitumor role in esophageal squamous cell carcinoma

The long non-coding RNA GAS5 has been reported as a tumor suppressor in many cancers. However, its functions and mechanisms remain largely unknown in esophageal squamous cell carcinoma (ESCC). In this study, we found that GAS5 was over-expressed in ESCC tissue compared with that in normal esophageal tissue in a public database. Functional studies showed that GAS5 could inhibit ESCC cell proliferation, migration and invasion in vitro. Further analysis revealed that GAS5 was regulated by interferon (IFN) responses via the JAK-STAT pathway. Moreover, as an IFN-stimulated gene (ISG), GAS5 was a positive regulator of IFN responses. The feedback loop between GAS5 and the IFN signaling pathway plays an important antitumor role in ESCC, thus providing novel potential therapeutic targets.

Non-coding RNAs: long non-coding RNAs and microRNAs in endocrine-related cancers

The human genome is 'pervasively transcribed' leading to a complex array of non-coding RNAs (ncRNAs) that far outnumber coding mRNAs. ncRNAs have regulatory roles in transcription and post-transcriptional processes as well numerous cellular functions that remain to be fully described. Best characterized of the 'expanding universe' of ncRNAs are the ~22 nucleotide microRNAs (miRNAs) that base-pair to target mRNA's 3' untranslated region within the RNA-induced silencing complex (RISC) and block translation and may stimulate mRNA transcript degradation. Long non-coding RNAs (lncRNAs) are classified as >200 nucleotides in length, but range up to several kb and are heterogeneous in genomic origin and function. lncRNAs fold into structures that interact with DNA, RNA and proteins to regulate chromatin dynamics, protein complex assembly, transcription, telomere biology and splicing. Some lncRNAs act as sponges for miRNAs and decoys for proteins. Nuclear-encoded lncRNAs can be taken up by mitochondria and lncRNAs are transcribed from mtDNA. Both miRNAs and lncRNAs are dysregulated in endocrine cancers. This review provides an overview on the current understanding of the regulation and function of selected lncRNAs and miRNAs, and their interaction, in endocrine-related cancers: breast, prostate, endometrial and thyroid.

LncRNA Gas5 acts as a ceRNA to regulate PTEN expression by sponging miR-222-3p in papillary thyroid carcinoma

Accumulating evidence demonstrates that the long non-coding RNA Growth Arrest-Specific 5 (Gas5) has practical significance in cancer progression and metastasis. However, its role and function in papillary thyroid carcinoma (PTC) remains unknown. In this study, we aimed to explore the potential involvement of Gas5 in papillary thyroid carcinogenesis and to highlight the emerging roles of ceRNAs in the biological regulation of PTC cells. The results suggested that Gas5 was markedly downregulated in both PTC tissues and PTC cell lines. Over-expression of Gas5 remarkably suppressed PTC cells proliferation in vitro and inhibited the growth of tumor cells in vivo likewise. Furthermore, Gas5 was identified as a target of miR-222-3p which was aberrantly high in PTC cells. Enhanced expression of miR-222-3p promoted the proliferation of PTC cells while knocking down miR-222-3p could inhibit it. The advanced effects of miR-222-3p on the proliferation of PTC cells could be partly reversed by the upregulation of Gas5 expression. Furthermore, we validated that Gas5 increased the protein level of the PTEN, one of miR-222-3p’s targets, which further activated PTEN/AKT pathway. Taken together, our study identified a tumor suppressive role of Gas5 in PTC cells acting as a ceRNA, effectively becoming a sink for miR-222-3p, modulating the expression of PTEN, which lead to PTEN/AKT pathway activation and proliferation suppression. This finding may offer a new potential therapeutic strategy for PTC.