Long noncoding RNA ZEB1-AS1 expression predicts progression and poor prognosis of colorectal cancer

A review on the role of ZEB1-AS1 in human disorders

ZEB1 Antisense RNA 1 (ZEB1-AS1) is a type of RNA characterized as long non-coding RNA (lncRNA). This lncRNA has important regulatory roles on its related gene, Zinc Finger E-Box Binding Homeobox 1 (ZEB1). In addition, role of ZEB1-AS1 has been approved in diverse malignancies such as colorectal cancer, breast cancer, glioma, hepatocellular carcinoma and gastric cancer. ZEB1-AS1 serves as a sponge for a number of microRNAs, namely miR-577, miR-335-5p, miR-101, miR-505-3p, miR-455-3p, miR-205, miR-23a, miR-365a-3p, miR-302b, miR-299-3p, miR-133a-3p, miR-200a, miR-200c, miR-342-3p, miR-214, miR-149-3p and miR-1224-5p. In addition to malignant conditions, ZEB1-AS1 has functional role in non-malignant conditions like diabetic nephropathy, diabetic lung, arthrosclerosis, Chlamydia trachomatis infection, pulmonary fibrosis and ischemic stroke. This review outlines different molecular mechanisms of ZEB1-AS1 in a variety of disorders and highlights its importance in their pathogenesis.

LncRNAs in colorectal cancer: Biomarkers to therapeutic targets

Colorectal cancer (CRC) is the third leading cause of cancer-related death in men and women worldwide. As early detection is associated with lower mortality, novel biomarkers are urgently needed for timely diagnosis and appropriate management of patients to achieve the best therapeutic response. Long noncoding RNAs (lncRNAs) have been reported to play essential roles in CRC progression. Accordingly, the regulatory roles of lncRNAs should be better understood in general and for identifying diagnostic, prognostic and predictive biomarkers in CRC specifically. In this review, the latest advances on the potential diagnostic and prognostic lncRNAs as biomarkers in CRC samples were highlighted, Current knowledge on dysregulated lncRNAs and their potential molecular mechanisms were summarized. The potential therapeutic implications and challenges for future and ongoing research in the field were also discussed. Finally, novel insights on the underlying mechanisms of lncRNAs were examined as to their potential role as biomarkers and therapeutic targets in CRC. This review may be used to design future studies and advanced investigations on lncRNAs as biomarkers for the diagnosis, prognosis and therapy in CRC.

Identification of prognostic immune-related lncRNA signature predicting the overall survival for colorectal cancer

Long non-coding RNA (lncRNA) is an important regulator of gene expression and serves a fundamental role in immune regulation. The present study aimed to develop a novel immune-related lncRNA signature to assess the prognosis of patients with colorectal cancer (CRC). Transcriptome data and clinical information of patients with CRC were downloaded from The Cancer Genome Atlas (TCGA) and UCSC Xena platforms. Immune-related mRNAs were extracted from the Molecular Signatures Database (MSigDB), and the immune-related lncRNAs were identified based on correlation analysis. Then, univariate, Lasso and multivariate Cox regression were applied to construct an immune-related lncRNA signature, and CRC patients were divided into high- and low-risk groups according to the median risk score. Finally, we evaluated the signature from the perspectives of clinical outcome, clinicopathological parameters, tumor-infiltrating immune cells (TIICs), immune status, tumor mutation burden (TMB) and immunotherapy responsiveness. In total, 272 immune-related lncRNAs were identified, five of which were applied to construct an immune-related lncRNA signature. The signature divided patients with CRC into low- and high-risk groups, the prognosis of patients in the high-risk group were significantly poorer than those in low-risk group, and the results were further confirmed in external validation cohort. Furthermore, the high-risk group showed aggressive clinicopathological characteristics, specific TIIC and immune function status, and low sensitivity to immunotherapy. The immune-related lncRNA signature could be exploited as a promising biomarker for predicting the prognosis and immune status of patients with CRC.

Glycosyltransferase-related long non-coding RNA signature predicts the prognosis of colon adenocarcinoma

Purpose

Colon adenocarcinoma (COAD) is the most common type of colorectal cancer (CRC) and is associated with poor prognosis. Emerging evidence has demonstrated that glycosylation by long noncoding RNAs (lncRNAs) was associated with COAD progression. To date, however, the prognostic values of glycosyltransferase (GT)-related lncRNAs in COAD are still largely unknown.

Methods

We obtained the expression matrix of mRNAs and lncRNAs in COAD from The Cancer Genome Atlas (TCGA) database. Then, the univariate Cox regression analysis was conducted to identify 33 prognostic GT-related lncRNAs. Subsequently, LASSO and multivariate Cox regression analysis were performed, and 7 of 33 GT-related lncRNAs were selected to conduct a risk model. Gene set enrichment analysis (GSEA) was used to analyze gene signaling pathway enrichment of the risk model. ImmuCellAI, an online tool for estimating the abundance of immune cells, and correlation analysis were used to explore the tumor-infiltrating immune cells in COAD. Finally, the expression levels of seven lncRNAs were detected in colorectal cancer cell lines by reverse transcription-quantitative polymerase chain reaction (RT-qPCR).

Results

A total of 1,140 GT-related lncRNAs were identified, and 7 COAD-specific GT-related lncRNAs (LINC02381, MIR210HG, AC009237.14, AC105219.1, ZEB1-AS1, AC002310.1, and AC020558.2) were selected to conduct a risk model. Patients were divided into high- and low-risk groups based on the median of risk score. The prognosis of the high-risk group was worse than that of the low-risk group, indicating the good reliability and specificity of our risk model. Additionally, a nomogram based on the risk score and clinical traits was built to help clinical decisions. GSEA showed that the risk model was significantly enriched in metabolism-related pathways. Immune infiltration analysis revealed that five types of immune cells were significantly different between groups, and two types of immune cells were negatively correlated with the risk score. Besides, we found that the expression levels of these seven lncRNAs in tumor cells were significantly higher than those in normal cells, which verified the feasibility of the risk model.

Conclusion

The efficient risk model based on seven GT-related lncRNAs has prognostic potential for COAD, which may be novel biomarkers and therapeutic targets for COAD patients.

Regulatory Roles of Noncoding RNAs in the Progression of Gastrointestinal Cancers and Health Disparities

Annually, more than a million individuals are diagnosed with gastrointestinal (GI) cancers worldwide. With the advancements in radio- and chemotherapy and surgery, the survival rates for GI cancer patients have improved in recent years. However, the prognosis for advanced-stage GI cancers remains poor. Site-specific GI cancers share a few common risk factors; however, they are largely distinct in their etiologies and descriptive epidemiologic profiles. A large number of mutations or copy number changes associated with carcinogenesis are commonly found in noncoding DNA regions, which transcribe several noncoding RNAs (ncRNAs) that are implicated to regulate cancer initiation, metastasis, and drug resistance. In this review, we summarize the regulatory functions of ncRNAs in GI cancer development, progression, chemoresistance, and health disparities. We also highlight the potential roles of ncRNAs as therapeutic targets and biomarkers, mainly focusing on their ethnicity-/race-specific prognostic value, and discuss the prospects of genome-wide association studies (GWAS) to investigate the contribution of ncRNAs in GI tumorigenesis.

Identification and Validation of an Endoplasmic Reticulum Stress-Related lncRNA Signature for Colon Adenocarcinoma Patients

Purpose

Methods

Results

Conclusion

Long noncoding RNAs as diagnostic biomarkers for the early detection of digestive tract cancers: a systematic review and meta-analysis

BACKGROUND

long noncoding RNAs (lncRNAs) have attracted attention recently. However, many inconsistencies frequently appeared for the early diagnosis of digestive tract cancers (DTCs). We performed this meta-analysis to describe the diagnostic performance of lncRNAs in the discrimination of DTCs.

METHODS

data were extracted from PubMed, Web of Science, Embase, and Cochrane Library. Their quality was evaluated using the revised Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). Such parameters as sensitivity and specificity were included for pooled analyses. The STATA 12.0 and Meta-Disc 1.4 software packages were used to perform the statistical analysis.

RESULTS

sixty-nine papers were included in this meta-analysis. The pooled analysis of DTCs showed that lncRNAs had a sensitivity of 0.78 and a specificity of 0.80. The area under the summary ROC curve (AUC) was 0.86. For gastric cancer (GC), the pooled sensitivity and specificity were 0.77 (95 % CI: 0.72-0.81) and 0.75 (95 % CI: 0.71-0.79), respectively, and the AUC was 0.83. For colorectal cancer (CRC), these three parameters were 0.82 (95 % CI: 0.76-0.86), 0.84 (95 % CI: 0.79-0.88), and 0.90, respectively. For esophageal cancer (EC) sensitivity was 0.74 (95 % CI: 0.67-0.80) and specificity reached 0.86 (95 % CI: 0.72-0.93), with an AUC of 0.82.

CONCLUSIONS

LncRNAs show potential diagnostic value for discrimination between DTCs.

The Emerging Landscape of Long Non-Coding RNAs in Colorectal Cancer Metastasis

Colorectal cancer (CRC) is one of the most common gastrointestinal cancers, with extremely high rates of morbidity and mortality. The main cause of death in CRC is distant metastasis; it affects patient prognosis and survival and is one of the key challenges in the treatment of CRC. Long non-coding RNAs (lncRNAs) are a group of non-coding RNA molecules with more than 200 nucleotides. Abnormal lncRNA expression is closely related to the occurrence and progression of several diseases, including cancer. Recent studies have shown that numerous lncRNAs play pivotal roles in the CRC metastasis, and reversing the expression of these lncRNAs through artificial means can reduce the malignant phenotype of metastatic CRC to some extent. This review summarizes the major mechanisms of lncRNAs in CRC metastasis and proposes lncRNAs as potential therapeutic targets for CRC and molecular markers for early diagnosis.

Long noncoding RNA ZEB1-AS1 affects paclitaxel and cisplatin resistance by regulating MMP19 in epithelial ovarian cancer cells

PURPOSE

The long noncoding RNA (lncRNA) ZEB1-AS1 is reported overexpressed in sensitive ovarian cancer cells A2780 compared with paclitaxel (PTX)-and cisplatin (DDP)- resistant. However, the function and mechanism of ZEB1-AS1 in EOC cells still unknown.

METHODS

We used quantitative real-time PCR (qPCR) to detect ZEB1-AS1 expression in A2780 and A2780/R cells. A combination of siRNA, plasmids, CCK8 and flow cytometry was used to detect the effect of ZEB1-AS1 on ovarian cancer cell A2780 PTX and DDP resistance. Transcriptome sequencing, qPCR, and western blot were used for further mechanistic studies.

RESULTS

ZEB1-AS1 depletion using siRNA in chemosensitive A2780 cells significantly increased PTX and DDP resistance. In contrast, ZEB1-AS1 overexpression in PTX- and DDP-resistant A2780/resistant (A2780/R) cells reversed the observed drug resistance. Thus, ZEB1-AS1 plays an important role in PTX and DDP resistance in EOC cells. However, quantitative real-time PCR (qPCR) and western blot results suggested that ZEB1-AS1 did not regulate chemoresistance through regulation of ZEB1 protein. We used sequencing to detect mRNA expression changes in A2780 cells after ZEB1-AS1 silencing. The results indicated that MMP19 was the likely downstream factor of ZEB1-AS1. We further examined whether ZEB1-AS1 played an important role in chemoresistance by silencing MMP19 in ZEB1-AS1-overexpressing cells. CCK8 assay results suggested that MMP19 knockdown promoted ZEB1-AS1-induced chemoresistance to PTX and DDP in A2780 cells.

CONCLUSION

This study is the first to reveal that ZEB1-AS1 plays a pivotal role in cancer chemoresistance.

Construction and Characterization of a Synergistic lncRNA-miRNA Network Reveals a Crucial and Prognostic Role of lncRNAs in Colon Cancer

Non-coding RNAs such as long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been found to be indispensable factors in carcinogenesis and cancer development. Numerous studies have explored the regulatory functions of these molecules and identified the synergistic interactions among lncRNAs or miRNAs, while those between lncRNAs and miRNAs remain to be investigated. In this study, we constructed and characterized an lncRNA–miRNA synergistic network following a four-step approach by integrating the regulatory pairs and expression profiles. The synergistic interactions with more shared regulatory mRNAs were found to have higher interactional intensity. Through the analysis of nodes in the network, we found that lncRNAs played roles that are more central and had similar synergistic interactions with their neighbors when compared with miRNAs. In addition, known colon adenocarcinoma (COAD)-related RNAs were found to be enriched in this synergistic network, with higher degrees, betweenness, and closeness. Finally, we proposed a risk score model to predict the clinical outcome for COAD patients based on two prognostic hub lncRNAs, MEG3 and ZEB1-AS1. Moreover, the hierarchical networks of these two lncRNAs could contribute to the understanding of the biological mechanism of tumorigenesis. For each lncRNA–miRNA interaction in the hub-related subnetwork and two hierarchical networks, we performed RNAup method to evaluate their binding energy. Our results identified two important lncRNAs with prognostic roles in colon cancer and dissected their regulatory mechanism involving synergistic interaction with miRNAs.

Clinical value of long noncoding RNA ZEB1 anti-sense1 in cancer patients: A meta-analysis

BACKGROUND

The high expression of long noncoding RNA ZEB1 anti-sense1 (ZEB1-AS1) has been reported in several types of cancer. However, most studies investigating this phenomenon were either case reports or used small patient samples. The objective of this meta-analysis was to clarify the potential clinical values of ZEB1-AS1 in various cancers.

MATERIALS AND METHODS

The PubMed-MEDLINE, Web of Science, and EMBASE databases were searched, using systematic search terms, to find relevant research reports on this subject. The combined hazards ratios (HRs) and corresponding 95% confidence intervals (CIs) were calculated to explore the association between ZEB1-AS1 expression and overall survival (OS). The combined odd ratios (ORs) were calculated to evaluate the association between ZEB1-AS1 expression and pathological parameters. Data analysis was conducted in R software version 3.4.2. and Stata version 12.0 (College Station, TX: Stata Corp LP).

RESULTS

Ten studies including 963 cancer patients were selected as suitable for this study. The pooled hazards ratio (HR) indicated that high ZEB1-AS1 expression was strongly associated with poor OS (pooled HR = 2.26, 95% CI: 1.80-2.85, P < .0001) in the Chinese cancer patients. Also, a high expression of ZEB1-AS1 was related to metastasis (pooled HR = 3.38, 95% CI: 1.91-6.00, P < .0001), and advanced tumor stage (pooled HR = 0.48, 95% CI: 0.29-0.81, P = .005). The up-regulation of ZEB1-AS1 was not significantly associated with histological differentiation (P = .39), sex (P = .001), and age (P = .372) of cancer patients.

CONCLUSION

The high expression of ZEB1-AS1 significantly predicted poor OS, poor metastasis, and high tumor stage in cancer patients, demonstrating that high ZEB1-AS1 expression may serve as a biomarker of poor prognosis in the Chinese cancer patients.

Long noncoding RNA PRKCQ-AS1 promotes CRC cell proliferation and migration via modulating miR-1287-5p/YBX1 axis

Colorectal cancer (CRC) brings more than 600 000 deaths every year around the globe, making itself the third most frequently occurred carcinoma. The great progress human achieved in diagnosis and treatment of various cancers has failed to reverse this trend. Fortunately, growing evidence has implied the relationship between lncRNAs and cancer progression. Long noncoding RNA (lncRNA) PRKCQ-AS1 was heightened in CRC cells and tissues and related with dismal prognosis of CRC patients. Knockdown of PRKCQ-AS1 would induce a decrease in proliferative and migrating ability of CRC cells. Also, PRKCQ-AS1 enriched in cytoplasm of CRC cells and negatively regulated miR-1287-5p level. More important, PRKCQ-AS1 could bind to argonaute 2 and function in the RNA-induced silencing complex with miR-1287-5p. Therefore, PRKCQ-AS1 was a competing endogenous RNA for miR-1287-5p. Subsequently, it was validated that miR-1287-5p could suppress the proliferative and migratory functions in CRC. Furthermore, PRKCQ-AS1 could upregulate the mRNA and protein level of YBX1 targeted by miR-1287-5p. And YBX1 expression was elevated in CRC cells and tissues. Rescue assays in vitro and in vivo showed that overexpression of YBX1 could partly offset the effect of CRC progression induced by knocking down PRKCQ-AS1, demonstrating PRKCQ-AS1 mediating CRC progression via miR-1287-5p/YBX1 pathway.

Long non‑coding RNA ZEB1‑AS1 predicts a poor prognosis and promotes cancer progression through the miR‑200a/ZEB1 signaling pathway in intrahepatic cholangiocarcinoma

Emerging evidence suggests that long non‑coding RNAs (lncRNAs) play pivotal roles in cancer progression, including in intrahepatic cholangiocarcinoma (IHCC). The overexpression of lncRNA ZEB1 antisense 1 (ZEB1‑AS1) has been discovered in several types of cancer; however, the clinical significance and functional role of ZEB1‑AS1 in IHCC have not yet been determined. In the present study, ZEB1‑AS1 was found to be upregulated in IHCC cell lines and tissues. A high ZEB1‑AS1 expression was associated with clinical progression and a poor survival of patients with IHCC, and was identified as an independent risk factor for a poor prognosis. In addition, ZEB1‑AS1 promoted the proliferation and metastasis of IHCC cells both in vitro and in vivo. ZEB1‑AS1 was demonstrated to increase the expression of ZEB1 by sponging miR‑200a and to thereby accelerate epithelial‑mesenchymal transition (EMT). On the whole, the findings of the present study demonstrate that ZEB1‑AS1 promotes proliferation and metastasis in IHCC, and induces EMT through the miR‑200a/ZEB1 signaling pathway. ZEB1‑AS1 may thus be a promising prognostic biomarker and essential therapeutic target for IHCC.

Long noncoding RNA ZEB1-AS1 acts as a Sponge of miR-141-3p to Inhibit Cell Proliferation in Colorectal Cancer

Evidence shows that long noncoding RNAs (lncRNAs) play key roles in various cancers, including colorectal cancer. In this current study, we found that the expression of ZEB1-AS1 in colorectal cancer tissues and cell lines was significantly upregulated, and positively correlated with advanced stage of colorectal cancer. Kaplan-Meier assays also indicated that the expression of ZEB1-AS1 was correlated with poor prognosis in patients with colorectal cancer. Knocking down of ZEB1-AS1 inhibited the proliferation of colorectal cancer cells. Subcellular fractionation analyses suggested that ZEB1-AS1 was majorly distributed in cytoplasm of SW480 and LOVO cells. Thus, ZEB1-AS1 might act as a competing endogenous RNA. MicroRNA array analysis suggested that miR-141-3p was significantly downregulated in CRC tissues, which was further verified by RT-qPCR. The results of luciferase reporter assay proved that miR-141-3p was a target of ZEB1-AS1. Functionally, miR-141-3p inhibitor reversed the anti-proliferation effect of sh-ZEB1-AS1 on colorectal cancer cells. Collectively, ZEB1-AS1 may contribute to colorectal cancer cell proliferation by sponging miR-141-3p.

LncRNAs as Regulators of Autophagy and Drug Resistance in Colorectal Cancer

Colorectal cancer (CRC) is a common malignancy with 1. 8 million cases in 2018. Autophagy helps to maintain an adequate cancer microenvironment in order to provide nutritional supplement under adverse conditions such as starvation and hypoxia. Additionally, most of the cases of CRC are unresponsive to chemotherapy, representing a significant challenge for cancer therapy. Recently, autophagy induced by therapy has been shown as a unique mechanism of resistance to anticancer drugs. In this regard, long non-coding RNAs (lncRNAs) analysis are important for cancer detection, progression, diagnosis, therapy response, and prognostic values. With increasing development of quantitative detection techniques, lncRNAs derived from patients' non-invasive samples (i.e., blood, stools, and urine) has become into a novel approach in precision oncology. Tumorspecific GAS5, HOTAIR, H19, and MALAT are novels CRC related lncRNAs detected in patients. Nonetheless, the effect and mechanism of lncRNAs in cancer autophagy and chemoresistance have not been extensively characterized. Chemoresistance and autophagy are relevant for cancer treatment and lncRNAs play a pivotal role in resistance acquisition for several drugs. LncRNAs such as HAGLROS, KCNQ1OT1, and H19 are examples of lncRNAs related to chemoresistance leaded by autophagy. Finally, clinical implications of lncRNAs in CRC are relevant, since they have been associated with tumor differentiation, tumor size, histological grade, histological types, Dukes staging, degree of differentiation, lymph node metastasis, distant metastasis, recurrent free survival, and overall survival (OS).

Effect of lncRNA ZEB1-AS1 on proliferation, invasion and apoptosis of glioma U87 cells

This study aimed to investigate the effect of LncRNA ZEB1-AS1 on the proliferation, invasion and apoptosis of human glioma U87 cells. U87 glioma cells were divided into three groups. The Si group was transfected with LncRNA ZEB1-AS1 specific SiRNA. The NC group was transfected with non-specific scramble siRNA, and untransfected glioma cells were used as the blank group. After 48 h of transfection, the proliferation of U87 cells was detected by MTT assay, apoptosis of U87 cells was detected by flow cytometry, and Transwell invasion assay was used to detect cell invasion. The expression of LncZEB1-AS1 in Si group was significantly lower than that in the NC and blank groups (P<0.01). There was no statistical difference in the OD 490 between the three groups at 24 h (P>0.05). At 48 h, the Si group was significantly lower than the NC group and the blank group (P<0.01). After 48 h, the three groups showed a gradually increasing trend, but at all the time points, the Si group was always lower than the NC and blank groups (P<0.01). The OD values of the blank and NC groups were significantly higher than the same group at the previous time point (P<0.01). The OD values of Si group at 48 and 96 h were significantly higher than those at the previous time point (P <0.05). Although there was an upward trend between 72 and 48 h, the difference was not significant (P>0.05). Flow cytometry detected apoptosis in each group and found that the apoptosis rate in the Si group was significantly higher than that in the NC and blank groups (P<0.01). Inhibition of LncRNA ZEB1-AS1 can inhibit the proliferation and invasion of glioma U87 cells and promote apoptosis. LncRNA ZEB1-AS1 is expected to become a new target for the treatment of glioma.

Prognostic value of long non-coding RNA ZEB1-AS1 in Chinese cancer patients: A Meta-analysis

BACKGROUND

Aberrant expression of long non-coding RNA Zinc finger E-box binding homeobox 1 antisense 1 (lncRNA ZEB1-AS1) can be detected in numerous malignancies. Therefore, a meta-analysis had been carried out in this study, aiming to examine the prognostic value of lncRNA ZEB1-AS1 in malignancies.

METHODS

Electronic databases, such as PubMed, OVID as well as Web of Science, had been systemically retrieved from inception to February 14th, 2019. Besides, the hazard ratios (HRs), together with the corresponding 95% confidence intervals (CIs), had also been analyzed for determining the association of lncRNA ZEB1-AS1 expression with the overall survival (OS) and recurrence-free survival (RFS). In addition, the pooled odds ratios (ORs) would also be computed using the Stata SE12.0 software for evaluating the relationship of lncRNA ZEB1-AS1 expression with pathological factors.

RESULTS

A total of 21 original studies involving 1801 cancer patients had been enrolled into the current meta-analysis. As suggested by the pooled HR, high expression of lncRNA ZEB1-AS1 had displayed marked correlation with OS (HR = 2.16, 95% CI: 1.89-2.47) among cancer patients, and no significant heterogeneity was detected. Additionally, high expression of lncRNA ZEB1-AS1 was also markedly associated with RFS among cancer patients (pooled HR = 2.55, 95% CI: 1.61-4.03). Besides, the expression of lncRNA ZEB1-AS1 had displayed marked correlation with poor histological grade (PHG) (OR = 2.86, 95% CI: 2.11-3.87), high tumor stage (HTS) (OR = 3.81, 95% CI: 2.72-5.34) as well as lymph node metastasis (LNM) (OR = 3.33, 95% CI: 2.47-4.49). Additionally, no distinct asymmetry had been detected for RFS, PHG as well as HTS based on Begg funnel plot.

CONCLUSIONS

Taken together, high expression of lncRNA ZEB1-AS1 can predict the dismal OS, RFS, LNM, PHG, and HTS, indicating that lncRNA ZEB1-AS1 can be potentially used as a new biomarker to predict the dismal prognosis for cancer patients.

ZEB1-AS1 initiates a miRNA-mediated ceRNA network to facilitate gastric cancer progression

Background

Currently, cancer-related competing endogenous RNA (ceRNA) networks are attracting significant interest. As long noncoding RNA ZEB1-AS1 has been reported to function as an oncogene due to sponging microRNAs (miRNAs) in several cancers, we hypothesized that it could interact with specific miRNAs to form regulatory networks and facilitate the growth of gastric cancer (GC).

Methods

MiRNAs interacting with ZEB1-AS1 were screened for and selected by bioinformatics analysis. Overexpression or repression of ZEB1-AS1 was performed to determine whether it could regulate selected miRNAs. Quantitative real-time polymerase chain reactions (qPCR) validated the expression profiles of ZEB1-AS1 and miR-149-3p in GC cell lines and tissue. Statistical analysis determined the clinical significance of ZEB1-AS1 in relation to miR-149-3p. Cell counting, wound healing and transwell assays were performed to assess cell proliferation, migration and invasion. A luciferase reporter assay was utilized to confirm the putative miR-149-3p-binding sites in ZEB1-AS1.

Results

Briefly, bioinformatics analysis inferred that ZEB1-AS1 interacts with miR-204, miR-610, and miR-149. Gain- or loss-of function assays suggested that ZEB1-AS1 negatively regulates miR-149-3p, miR-204-5p and miR-610 in GC cells. Validated by qPCR, ZEB1-AS1 was up-regulated and miR-149-3p down-regulated in GC cells and tissue. Data analyses indicated that ZEB1-AS1 and miR-149-3p are associated with the independent diagnosis and prognosis of GC. Functional assays support the theory that miR-149-3p hinders GC proliferation, migration and invasion, whereas its overexpression abrogates the corresponding effects induced by ZEB1-AS1. Lastly, dissection of the molecular mechanisms involved indicated that ZEB1-AS1 can regulate GC partly via a ZEB1-AS1/miR-149-3p axis.

Conclusions

ZEB1-AS1 can interact with specific miRNAs, forming a miRNA-mediated ceRNA network and promoting GC progress, partly through a ZEB1-AS1/miR-149-3p axis.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0742-0) contains supplementary material, which is available to authorized users.

Long Noncoding RNAs Serve as Potential Diagnostic Biomarkers for Colorectal Cancer

Background: Mounting evidence has indicated that long noncoding RNAs (lncRNAs) are promising candidates for tumor diagnosis and prognosis. Nonetheless, the significance of lncRNAs in colorectal cancer (CRC) diagnosis remains to be clarified. Here, we performed a comprehensive meta-analysis to evaluate the utility of lncRNAs as diagnostic indicators for CRC. Materials and Methods: Pertinent studies were searched using PubMed, PMC, Web of Science, Cochrane, and EMBASE database up to September 2018. Study quality was assessed with the Quality Assessment for Studies of Diagnostic Accuracy-2. Subgroup analyses by sample size and publication year were conducted. Threshold effect and meta-regression were performed to find the origin of heterogeneity. Statistical analyses were conducted using Stata and Meta-Disc. Results: A total of 19 studies with 3,114 individuals were enrolled in the current analysis. The overall sensitivity and specificity of lncRNAs in the diagnosis of CRC were 0.83 [95% confidence interval (CI): 0.76-0.87] and 0.84 (95% CI: 0.77-0.89), respectively. The pooled positive likelihood ratio was 5.11 (95% CI: 3.57-7.31), and the pooled negative likelihood ratio was 0.21 (95% CI: 0.15-0.28). The overall area under the curve was 0.90 (95% CI: 0.87-0.92), with a diagnostic odds ratio of 24.57 (95% CI: 14.67-41.17). Conclusions: The accuracy of lncRNAs for CRC diagnosis is high, and lncRNAs could be functioned as promising candidates for CRC diagnosis.

Long non-coding RNA ZEB1-AS1 promotes cell invasion and epithelial to mesenchymal transition through inducing ZEB1 expression in cervical cancer

Background

Long non-coding RNAs (lncRNAs) play important roles in cancer initiation and development. The purpose of the present study was to determine the functions and mechanisms of lncRNA ZEB1-AS1 in human cervical cancer (CC).

Methods

A total of 106 pairs of CC tissues and adjacent normal epithelial tissues were collected from CC patients who underwent resection. Three human CC cell lines (HeLa, C33A and SiHa) and a normal cervical cell line Crl-2614 and were transfected with human ZEB1-AS1 cDNA, or empty vector as the control. Then, cells were transfected with ZEB1-AS1-specific small interfering RNA (si-ZEB1-AS1), ZEB1-specific siRNA (si-ZEB1) or negative siRNA control (si-NC). The transfection efficiency was confirmed by RT-qPCR analysis. qPCR was applied to determine the qualification of RNA. Cell proliferation was investigated by MTT assay. The apoptosis rate of cells was detected by flow cytometer. Cell invasion was detected by transwell assay. Western blot was applied to determine the expression of proteins. CC xenografts in 12 male BALB/c athymic nude mice were established. And the tumor volumes were measured by vernier caliper.

Results

We found that ZEB1-AS1 expression was remarkably increased in human CC tissue samples and cell lines, and its expression levels were closely associated with poor prognosis of CC patients. Moreover, we found that knockdown of ZEB1-AS1 inhibited the proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) of CC cells in vitro and suppressed CC xenograft tumor growth in vivo. Mechanistically, we found that knockdown of ZEB1-AS1 significantly inhibited ZEB1 expression, and knockdown of ZEB1 could rescue the effects of ZEB1-AS1 overexpression in CC cells.

Conclusion

In conclusion, our findings indicated that ZEB1-AS1 serves an oncogenic role in CC, which might become a potential prognostic indicator and therapeutic target in CC.

The prognostic value of long noncoding RNA ZEB1-AS1 on clinical outcomes in human cancer

Background: Although growing evidence have demonstrated that long non-coding RNA ZEB1-AS1 was aberrantly expressed in various types of cancers and can be used as a prognostic marker in cancer, the results remain inconclusive. Therefore, we performed this meta-analysis to evaluate the prognostic value of ZEB1-AS1 in human cancer.

Methods: A literature survey was conducted for all eligible studies by searching the following online databases: PubMed and Embase. The pooled odds ratios (ORs) or hazard ratios (HRs) with a 95 % confidence interval (95 % Cl) were computed to demonstrate its prognostic value.

Results: A total of 14 studies with 1096 individuals were included to evaluate the association of ZEB1-AS1 with clinicopathological features and overall survival (OS). In the pooled analyses stratified by clinicopathological features, ZEB1-AS1 expression was significantly related to depth of tumor (OR=2.92, 95% CI 1.22-7.02), poor histological differentiation (OR=2.72, 95% CI: 1.92-3.86), lymph node metastasis (OR=3.93, 95% CI: 2.65-5.84), distant metastasis (OR=5.34, 95% CI: 2.85-10.02) and tumor stage (OR=2.46, 95% CI 1.42-4.24), but not to tumor size (OR=1.25, 95% CI 0.79-1.96). Altered ZEB1-AS1 expression was found to be an indicator of worse prognosis in OS (HR = 1.94, 95% CI: 1. 66-2.22) among tumor patients.

Conclusions: High ZEB1-AS1expression was associated poor clinical outcome and it can serve as a novel predictive biomarker in various cancers.

The lncRNA ZEB1-AS1 sponges miR-181a-5p to promote colorectal cancer cell proliferation by regulating Wnt/β-catenin signaling

Long noncoding RNAs (lncRNAs) are important regulators of the biological functions and underlying molecular mechanisms of colorectal cancer (CRC). However, the role of the lncRNA ZEB1-AS1 in CRC is not thoroughly understood. In this study, we found that ZEB1-AS1 was markedly upregulated in CRC. ZEB1-AS1 knockdown significantly suppressed CRC cell proliferation and induced apoptosis, whereas enhanced expression of ZEB1-AS1 had the opposite effect. Bioinformatics analysis identified miR-181a-5p as a candidate target of ZEB1-AS1. Moreover, we found an inverse correlation between ZEB1-AS1 and miR-181a-5p expression in CRC tissue. Inhibition of miR-181a-5p significantly upregulated ZEB1-AS1, whereas overexpression of miR-181a-5p had the opposite effect, suggesting that ZEB1-AS1 is negatively regulated by miR-181a-5p. Using luciferase reporter and RIP assays, we found that miR-181a-5p directly targets ZEB1-AS1. Importantly, ZEB1-AS1 may act as an endogenous 'sponge' to regulate miRNA targets by competing for miR-181a-5p binding. In summary, our findings provide the evidence supporting the role of ZEB1-AS1 as an oncogene in CRC. Our study also demonstrates that miR-181a-5p targets not only protein-coding genes but also the lncRNA ZEB1-AS1.

The significant prognostic value of ZEB1-AS1 up-regulation in patients with cancer

Zinc finger E-box binding homeobox 1 antisense 1 (ZEB1-AS1) is a long non-coding RNA, which has found to unregulated in various kinds of cancer. This meta-analysis was conducted to demonstrate the association between ZEB1-AS1 expression levels and clinical outcome or prognosis of cancer patients.10 studies with 783 cancer patients were included in this meta-analysis by retrieving 5 databases (PubMed Central, EMBASE, Cochrane Library, Wiley Online Library and Medline).The result showed that overexpression of ZEB1-AS1 is significantly correlated with poor OS (Hazard ratio, HR=2.45, 95% confidence interval, CI: 1.89-3.16). ZEB1-AS1 expression levels were also associated with clinicopathological parameters including lymph node metastasis (Yes vs. No; OR=4.00, 95%CI: 2.23-7.17, P<0.00001), histologic differentiation (Moderate + poor vs. Well; OR=2.72, 95% CI: 1.69-4.37, p<0.0001), tumor metastasis and invasion (Yes vs. No; OR =2.52, 95%CI: 1.12-5.68, P=0.03) and TNM stage (III+IV vs. I+II; OR=2.76, 95 %CI 1.46-5.21, P=0.002). However, ZEB1-AS1 expression was not significantly associated with patients' gender (Male vs. Female; OR=1.20, 95% CI: 0.87-1.66; P=0.27).This meta-analysis indicated the potential value of ZEB1-AS1 as a biomarker for predicting a poor prognosis in patients with cancer.

Long non-coding RNA PVT1 as a novel potential biomarker for predicting the prognosis of colorectal cancer

BACKGROUND

Long non-coding RNA (lncRNA) plays a very important role in the occurrence and development of various tumors, and is a potential biomarker for cancer diagnosis and prognosis. The purpose of this study was to investigate the relationship between the expression of lncRNA plasmacytoma variant translocation 1 (PVT1) and the prognostic significance in patients with colorectal cancer.

METHODS

The expression of PVT1 was measured by real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) in cancerous and adjacent tissues of 210 colorectal cancer patients. The disease-free survival and overall survival of colorectal cancer patients were evaluated by Kaplan-Meier analysis, and univariate and multivariate analysis were performed by Cox proportional-hazards model.

RESULTS

Our results revealed that PVT1 expression in cancer tissues of colorectal cancer was significantly higher than that of adjacent tissues (P<0.001). High PVT1 expression was increased by 51.4% (108/210), which was significantly correlated with the tumor differentiation, the depth of invasion, the stage of tumor, node, metastasis (TNM), and lymphatic metastasis. The Kaplan-Meier analysis showed that high PVT1 expression resulted in a shorter disease-free survival (Log-rank test P<0.001) and overall survival (Log-rank test P<0.001) compared with the low PVT1 expression group in colorectal cancer patients, whether at TNM I/II stage or at TNM III/IV stage. A multivariate Cox regression analysis demonstrated that high PVT1 expression was an independent predictor of poor prognosis in colorectal cancer patients.

CONCLUSIONS

Our results suggest that high PVT1 expression might be a potential biomarker for assessing tumor recurrence and prognosis in colorectal cancer patients.