Upregulation of long noncoding RNA ZEB1-AS1 promotes tumor metastasis and predicts poor prognosis in hepatocellular carcinoma

LncRNA ZEB1-AS1 down-regulation suppresses the proliferation and invasion by inhibiting ZEB1 expression in oesophageal squamous cell carcinoma

Multiple studies have unveiled that long non‐coding RNAs (lncRNAs) play a pivotal role in tumour progression and metastasis. However, the biological role of lncRNA ZEB1‐AS1 in oesophageal squamous cell carcinoma (ESCC) remains under investigation, and thus, the current study was to investigate the functions of ZEB1‐AS1 in proliferation and invasion of ESCC. Here, we discovered that ZEB1‐AS1 and ZEB1 were markedly up‐regulated in ESCC tissues and cells relative to their corresponding normal control. ZEB1‐AS1 and ZEB1 overexpressions were both related to TNM staging and lymph node metastasis as well as poor prognosis in ESCC. The hypomethylation of ZEB1‐AS1 promoter triggered ZEB1‐AS1 overexpression in ESCC tissues and cells. In addition, ZEB1‐AS1 knockdown mediated by siRNA markedly suppressed the proliferation and invasion in vitro in EC9706 and TE1 cells, which was similar with ZEB1 siRNA treatment, coupled with EMT alterations including the up‐regulation of E‐cadherin level as well as the down‐regulation of N‐cadherin and vimentin levels. Notably, ZEB1‐AS1 depletion dramatically down‐regulated ZEB1 expression in EC9706 and TE1 cells, and ZEB1 overexpression obviously reversed the inhibitory effects of proliferation and invasion triggered by ZEB1‐AS1 siRNA. ZEB1‐AS1 shRNA evidently inhibited tumour growth and weight, whereas ZEB1 elevation partly recovered the tumour growth in ESCC EC9706 and TE1 xenografted nude mice. In conclusion, ZEB1‐AS1 overexpression is tightly involved in the development and progression of ESCC, and it exerts the antitumour efficacy by regulating ZEB1 level in ESCC.

Long non-coding RNA linc00645 promotes TGF-β-induced epithelial-mesenchymal transition by regulating miR-205-3p-ZEB1 axis in glioma

Accumulating evidence indicates long noncoding RNAs (lncRNA) play a vital role in tumor progression. However, the role of linc00645-induced accelerated malignant behavior in glioblastoma (GBM) remains unknown. In the present study, linc00645 expression was significantly upregulated in GBM tissues and cell lines. High level of linc00645 was associated with poor overall survival in GBM patients. Knockdown of linc00645 suppressed the proliferation, stemness, migration, invasion, and reversed transforming growth factor (TGF)-β-induced motility of glioma cell lines. Furthermore, linc00645 directly interacted with miR-205-3p and upregulated of miR-205-3p impeded efficiently the increase of ZEB1 induced by linc00645 overexpression. Moreover, knockdown of linc00645 significantly suppressed the progression of glioma cells in vivo. miR-205-3p was a target of linc00645 and linc00645 modulates TGF-β-induced glioma cell migration and invasion via miR-205-3p. Taken together, our findings identified the linc00645/miR-205-3p/ZEB1 signaling axis as a key player in EMT of glioma cells triggered by TGF-β. These data elucidated that linc00645 plays an oncogenic role in glioma and it may serve as a prognostic biomarker and a potential therapeutic target for the treatment of glioma in humans.

Single-cell RNA-seq reveals the invasive trajectory and molecular cascades underlying glioblastoma progression

Glioblastoma (GBM) is the most common and aggressive primary brain tumor, in which GBM stem cells (GSCs) were identified to contribute to aggressive phenotypes and poor prognosis. Yet, how GSCs progress to invasive cells remains largely unexplored. Here, we revealed the cell subpopulations with distinct functional status and the existence of cells with high invasive potential within heterogeneous primary GBM tumors. We reconstructed a branched trajectory by pseudotemporal ordering of single tumor cells, in which the root showed GSC‐like phenotype while the end displayed high invasive activity. Thus, we further determined a path along which GSCs gradually transformed to invasive cells, called the ‘stem‐to‐invasion path’. Along this path, cells showed incremental expression of GBM invasion‐associated signatures and diminishing expression of GBM stem cell markers. These findings were validated in an independent single‐cell data set of GBM. Through analyzing the molecular cascades underlying the path, we identify crucial factors controlling the attainment of invasive potential of tumor cells, including transcription factors and long noncoding RNAs. Our work provides novel insights into GBM progression, especially the attainment of invasive potential in primary tumor cells, and supports the cancer stem cell model, with valuable implications for GBM therapy.

Classification of early and late stage liver hepatocellular carcinoma patients from their genomics and epigenomics profiles

Background

Liver Hepatocellular Carcinoma (LIHC) is one of the major cancers worldwide, responsible for millions of premature deaths every year. Prediction of clinical staging is vital to implement optimal therapeutic strategy and prognostic prediction in cancer patients. However, to date, no method has been developed for predicting the stage of LIHC from the genomic profile of samples.

Methods

The Cancer Genome Atlas (TCGA) dataset of 173 early stage (stage-I), 177 late stage (stage-II, Stage-III and stage-IV) and 50 adjacent normal tissue samples for 60,483 RNA transcripts and 485,577 methylation CpG sites, was extensively analyzed to identify the key transcriptomic expression and methylation-based features using different feature selection techniques. Further, different classification models were developed based on selected key features to categorize different classes of samples implementing different machine learning algorithms.

Results

In the current study, in silico models have been developed for classifying LIHC patients in the early vs. late stage and cancerous vs. normal samples using RNA expression and DNA methylation data. TCGA datasets were extensively analyzed to identify differentially expressed RNA transcripts and methylated CpG sites that can discriminate early vs. late stages and cancer vs. normal samples of LIHC with high precision. Naive Bayes model developed using 51 features that combine 21 CpG methylation sites and 30 RNA transcripts achieved maximum MCC (Matthew’s correlation coefficient) 0.58 with an accuracy of 78.87% on the validation dataset in discrimination of early and late stage. Additionally, the prediction models developed based on 5 RNA transcripts and 5 CpG sites classify LIHC and normal samples with an accuracy of 96–98% and AUC (Area Under the Receiver Operating Characteristic curve) 0.99. Besides, multiclass models also developed for classifying samples in the normal, early and late stage of cancer and achieved an accuracy of 76.54% and AUC of 0.86.

Conclusion

Our study reveals stage prediction of LIHC samples with high accuracy based on the genomics and epigenomics profiling is a challenging task in comparison to the classification of cancerous and normal samples. Comprehensive analysis, differentially expressed RNA transcripts, methylated CpG sites in LIHC samples and prediction models are available from CancerLSP (http://webs.iiitd.edu.in/raghava/cancerlsp/).

Overexpression LINC01082 suppresses the proliferation, migration and invasion of colon cancer

Long non-coding RNAs (lncRNAs) are emerging as pivotal regulators in human cancer. LINC01082 was expressed as decreased in colon cancer by previous lncRNA-seq result and TCGA database, however, the role and function of LINC0182 is not clear in colon cancer. Here, we aimed to explore the role of LINC01082 in colon cancer for exploring the etiopathogenesis of colon cancer. RT-qPCR for LINC01082 expression in tissues (colon cancer vs. their matched adjacent non-cancerous tissues, ANT, n = 39) and cells (colon cancer cells vs. normal colon cells, n = 4) were performed. CCK-8 assay for proliferation of colon cancer, Transwell assay for migration and invasion were carried out in sw480 and sw620 cells. The results revealed that LINC01082 was significantly decreased in tissues and cell lines of colon cancer. Overexpressed LINC01082 significantly suppressed the proliferation ability of colon cancer cells. The migration and invasion of colon cancer cells were also suppressed after LINC01082 overexpression. These findings demonstrated that LINC01082 may act in suppressing the incidence and development of colon cancer via suppressing cell proliferation, migration and invasion, indicating that LINC01082 may act as a new tumor suppressor and may be a promising therapy target for colon cancer.

Decreased Expression of Long Non-Coding RNA GMDS Divergent Transcript (GMDS-DT) is a Potential Biomarker for Poor Prognosis of Hepatocellular Carcinoma

Background

Increasing evidence suggests that long non-coding RNA (lncRNA) is closely related to the development of cancer. The present study investigated the potential predictive value of lncRNA GMDS divergent transcript (GMDS-DT) in the prognosis of patients with hepatocellular carcinoma (HCC) after hepatectomy.

Material/Methods

GMDS-DT was acquired by microarray data in 3 pairs of M1 and M2 macrophage duplicate samples. Real-time polymerase chain reaction (PCR) was performed to evaluate expression levels of GMDS-DT in liver cancer relative to normal tissue of 198 patients. The significance of GMDS-DT in prognosis after hepatectomy was examined via Kaplan-Meier test and Cox regression analysis.

Results

The expression of GMDS-DT in liver cancer tissue was significantly lower than that in adjacent normal liver tissue (P<0.001), and was significantly associated with drinking history and metastasis (both P<0.05). The Kaplan-Meier test suggested that patients with lower expression levels of GMDS-DT in liver cancer tissue had significantly shorter disease-free survival and overall survival times after hepatectomy (P=0.028 and P=0.003, respectively). Cox regression analysis further indicated that GMDS-DT was an independent risk factor for disease-free survival and overall survival times of patients after hepatectomy (P=0.015 and P=0.001, respectively).

Conclusions

LncRNA GMDS-DT might be a potential biomarker for the prognosis of patients with liver cancer after hepatectomy.

Macrophage-associated lncRNA ELMO1-AS1: a novel therapeutic target and prognostic biomarker for hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is a prevalent malignant tumor. Long non-coding RNAs (lncRNAs) have been demonstrated to be abnormally expressed in many tumors and act as crucial regulators in various biological processes. However, the expression and function of the recently identified macrophage-associated lncRNA ELMO1 antisense RNA 1 (ELMO1-AS1) in HCC are unclear.

Methods

The expression of ELMO1-AS1 was determined in HCC tissues and adjacent nontumorous tissues by quantitative real-time polymerase chain reaction (qRT-PCR). The Kaplan-Meier survival analysis and Cox regression analysis were performed to establish the correlation between the expression level and survival of HCC patients in a training set and a validation set, respectively. The overexpression experiments were also conducted to investigate the biological role of ELMO1-AS1 in HCC cells.

Results

We uncovered that ELMO1-AS1 was significantly downregulated in HCC tissues, and high expression of ELMO1-AS1 is correlated with optimistic treatment outcome suggesting its potential as an independent prognostic biomarker for HCC. It was also found that overexpression of ELMO1-AS1 in HCC cells suppressed cell proliferation, migration and invasion and engulfment and cell motility 1 (ELMO1) may be a target of ELMO1-AS1.

Conclusion

Our results suggested that macrophage-associated lncRNA ELMO1-AS1 could be a crucial regulator involved in HCC progression and considered as a potential prognostic biomarker and therapeutic target for HCC.

Whole transcriptome analysis reveals correlation of long noncoding RNA ZEB1-AS1 with invasive profile in melanoma

Melanoma is the deadliest form of skin cancer, and little is known about the impact of deregulated expression of long noncoding RNAs (lncRNAs) in the progression of this cancer. In this study, we explored RNA-Seq data to search for lncRNAs associated with melanoma progression. We found distinct lncRNA gene expression patterns across melanocytes, primary and metastatic melanoma cells. Also, we observed upregulation of the lncRNA ZEB1-AS1 (ZEB1 antisense RNA 1) in melanoma cell lines. Data analysis from The Cancer Genome Atlas (TCGA) confirmed higher ZEB1-AS1 expression in metastatic melanoma and its association with hotspot mutations in BRAF (B-Raf proto-oncogene, serine/threonine kinase) gene and RAS family genes. In addition, a positive correlation between ZEB1-AS1 and ZEB1 (zinc finger E-box binding homeobox 1) gene expression was verified in primary and metastatic melanomas. Using gene expression signatures indicative of invasive or proliferative phenotypes, we found an association between ZEB1-AS1 upregulation and a transcriptional profile for invasiveness. Enrichment analysis of correlated genes demonstrated cancer genes and pathways associated with ZEB1-AS1. We suggest that the lncRNA ZEB1-AS1 could function by activating ZEB1 gene expression, thereby influencing invasiveness and phenotype switching in melanoma, an epithelial-to-mesenchymal transition (EMT)-like process, which the ZEB1 gene has an essential role.

Comprehensive bioinformatics analysis reveals potential lncRNA biomarkers for overall survival in patients with hepatocellular carcinoma: an on-line individual risk calculator based on TCGA cohort

Background

Accumulated evidences have demonstrated that long non-coding RNAs (lncRNAs) are correlated with prognosis of patients with hepatocellular carcinoma. The current study aimed to develop and validate a prognostic lncRNA signature to improve the prediction of overall survival in hepatocellular carcinoma patients.

Methods

The study cohort involved 348 hepatocellular carcinoma patients with lncRNA expression information and overall survival information. Through gene mining approach, the current study established a prognostic lncRNA signature (named LncRNA risk prediction score) for predicting the overall survival of hepatocellular carcinoma patients.

Results

The current study built a predictive nomogram based on ten prognostic lncRNA predictors through Cox regression analysis. In model group, the Harrell’s concordance indexes of LncRNA risk prediction score were 0.811 (95% CI 0.769–0.853) for 1-year overall survival, 0.814 (95% CI 0.772–0.856) for 3-year overall survival and 0.796 (95% CI 0.754–0.838) for 5-year overall survival respectively. In validation cohort, the Harrell’s concordance indexes of LncRNA risk prediction score were 0.779 (95% CI 0.737–0.821), 0.828 (95% CI 0.786–0.870) and 0.796 (95%CI 0.754–0.838) for 1-year survival, 3-year survival and 5-year survival respectively. LncRNA risk prediction score could stratify hepatocellular carcinoma patients into low risk group and high risk group. Further survival curve analysis demonstrated that the overall survival rate of high risk patients was significantly poorer than that of low risk patients (P < 0.001).

Conclusions

In conclusion, the current study developed and validated a prognostic signature to predict the individual mortality risk for hepatocellular carcinoma patients. LncRNA risk prediction score is helpful to identify the patients with high mortality risk and optimize the individualized treatment decision. The web calculator can be used by click the following URL: https://zhangzhiqiao2.shinyapps.io/Smart_cancer_predictive_system_HCC_3/.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0890-2) contains supplementary material, which is available to authorized users.

Current Research Progress on Long Noncoding RNAs Associated with Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the second leading cause of mortality among cancers. It has been found that long noncoding RNAs (lncRNAs) are involved in many human cancers, including liver cancer. It has been identified that carcinogenic and tumor-suppressing lncRNAs are associated with complex processes in liver cancer. These lncRNAs may participate in a variety of pathological and biological activities, such as cell proliferation, apoptosis, invasion, and metastasis. Here, we review the regulation and function of lncRNA in liver cancer and evaluate the potential of lncRNA as a new goal for liver cancer.

A five lncRNA signature for prognosis prediction in hepatocellular carcinoma

This study was conducted to screen prognosis‑​associated long‑noncoding RNAs (lncRNAs) and a prognosis assessment model in hepatocellular carcinoma (HCC). lncRNA‑ and mRNA‑sequencing data of early‑stage HCC samples were downloaded from The Cancer Genome Atlas database. The samples were divided into training set and validation set. Differentially expressed lncRNAs (DELs) between poor prognosis and good prognosis samples were screened with DEseq and edgeR. Cox regression analysis was conducted to identify prognosis‑associated lncRNAs in the training set. A prognosis risk assessment model was established to calculate the risk score for each patient in the training set, and the prognosis prediction function was tested and validated in the validation dataset. The connection between the risk assessment model and clinical features was analyzed. A co‑expression network between lncRNAs and corresponding genes was constructed, and functional enrichment was performed for these genes. A total of 81 DELs were screened between poor and good prognosis samples in the training set, and 43 prognosis‑associated lncRNAs were observed. Of these DELs, five were used to construct the risk assessment model (RP11‑325L7.2, DKFZP434L187, RP11‑100L22.4, DLX2‑AS1 and RP11‑104L21.3). Low‑risk samples exhibited longer survival time compared with the high‑risk samples. The five lncRNAs exhibited significant differences in expression levels between different prognosis groups. Risk score was an independent prognostic factor for HCC. In the entire set, the low‑risk group demonstrated significantly better prognosis compared with the high‑risk group, even across all age, sex and alcohol consumption subgroups. 'Nucleoside‑triphosphatase regulator activity', 'GTPase regulator activity', 'enzyme binding', 'peroxisome proliferator‑activated receptor signaling pathway' and 'fatty acid metabolism' were the most significantly enriched functional terms. The signature lncRNAs screened in this study may have constitute novel strategies and biomarkers that predict the prognosis of HCC, and these may also contribute to a deeper understanding of the mechanisms underlying HCC development.

Identification and validation of a potent multi-mRNA signature for the prediction of early relapse in hepatocellular carcinoma

Early recurrence of hepatocellular carcinoma (HCC) is implicated in poor patient survival and is the major obstacle to improving prognosis. The current staging systems are insufficient for accurate prediction of early recurrence, suggesting that additional indicators for early recurrence are needed. Here, by analyzing the gene expression profiles of 12 Gene Expression Omnibus data sets (n = 1533), we identified 257 differentially expressed genes between HCC and non-tumor tissues. Least absolute shrinkage and selection operator regression model was used to identify a 24-messenger RNA (mRNA)-based signature in discovery cohort GSE14520. With specific risk score formula, patients were divided into high- and low-risk groups. Recurrence-free survival within 2 years (early-RFS) was significantly different between these two groups in discovery cohort [hazard ratio (HR): 7.954, 95% confidence interval (CI): 4.596–13.767, P < 0.001], internal validation cohort (HR: 8.693, 95% CI: 4.029–18.754, P < 0.001) and external validation cohort (HR: 5.982, 95% CI: 3.414–10.480, P < 0.001). Multivariable and subgroup analyses revealed that the 24-mRNA-based classifier was an independent prognostic factor for predicting early relapse of patients with HCC. We further developed a nomogram integrating the 24-mRNA-based signature and clinicopathological risk factors to predict the early-RFS. The 24-mRNA-signature-integrated nomogram showed good discrimination (concordance index: 0.883, 95% CI: 0.836–0.929) and calibration. Decision curve analysis demonstrated that the 24-mRNA-signature-integrated nomogram was clinically useful. In conclusion, our 24-mRNA signature is a powerful tool for early-relapse prediction and will facilitate individual management of HCC patients.

LncRNAs with miRNAs in regulation of gastric, liver, and colorectal cancers: updates in recent years

Long noncoding RNA (lncRNA) is a kind of RNAi molecule composed of hundreds to thousands of nucleotides. There are several major types of functional lncRNAs which participate in some important cellular pathways. LncRNA-RNA interaction controls mRNA translation and degradation or serves as a microRNA (miRNA) sponge for silencing. LncRNA-protein interaction regulates protein activity in transcriptional activation and silencing. LncRNA guide, decoy, and scaffold regulate transcription regulators of enhancer or repressor region of the coding genes for alteration of expression. LncRNA plays a role in cellular responses including the following activities: regulation of chromatin structural modification and gene expression for epigenetic and cell function control, promotion of hematopoiesis and maturation of immunity, cell programming in stem cell and somatic cell development, modulation of pathogen infection, switching glycolysis and lipid metabolism, and initiation of autoimmune diseases. LncRNA, together with miRNA, are considered the critical elements in cancer development. It has been demonstrated that tumorigenesis could be driven by homeostatic imbalance of lncRNA/miRNA/cancer regulatory factors resulting in biochemical and physiological alterations inside the cells. Cancer-driven lncRNAs with other cellular RNAs, epigenetic modulators, or protein effectors may change gene expression level and affect the viability, immortality, and motility of the cells that facilitate cancer cell cycle rearrangement, angiogenesis, proliferation, and metastasis. Molecular medicine will be the future trend for development. LncRNA/miRNA could be one of the potential candidates in this category. Continuous studies in lncRNA functional discrepancy between cancer cells and normal cells and regional and rational genetic differences of lncRNA profiles are critical for clinical research which is beneficial for clinical practice.

Homeobox Genes and Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the sixth most common type of cancer, and is the third leading cause of cancer-related deaths each year. It involves a multi-step progression and is strongly associated with chronic inflammation induced by the intake of environmental toxins and/or viral infections (i.e., hepatitis B and C viruses). Although several genetic dysregulations are considered to be involved in disease progression, the detailed regulatory mechanisms are not well defined. Homeobox genes that encode transcription factors with homeodomains control cell growth, differentiation, and morphogenesis in embryonic development. Recently, more aberrant expressions of Homeobox genes were found in a wide variety of human cancer, including HCC. In this review, we summarize the currently available evidence related to the role of Homeobox genes in the development of HCC. The objective is to determine the roles of this conserved transcription factor family and its potential use as a therapeutic target in future investigations.

LncRNA FOXD2-AS1 accelerates the papillary thyroid cancer progression through regulating the miR-485-5p/KLK7 axis

It has been proved that long noncoding RNAs (lncRNAs) are important modulators in the tumorigenesis and progression of various malignant tumors. Recently, lncRNA FOXD2-AS1 has been reported to be an oncogene in several kinds of human cancers. However, the function of FOXD2-AS1 in papillary thyroid cancer (PTC) has not been well investigated. This study aims to explore the biological role and mechanism of FOXD2-AS1 in PTC. At first, the expression of FOXD2-AS1 was examined in PTC tissues and cell lines with quantitative reverse transcription-polymerase chain reaction (qRT-PCR). FOXD2-AS1 was found to observably upregulated in PTC tissues and cell lines. Kaplan-Meier survival analysis revealed that high expression of FOXD2-AS1 was closely correlated with the unfavorable prognosis of patients with PTC. Based on the TCGA data set, KLK7 was overexpressed in PTC tumor samples. Our experimental data further validated the upregulation of KLK7 in PTC tissues and cell lines. Similarly, high level of KLKF was associated with poor prognosis of patients with PTC. The positive expression association between FOXD2-AS1 and KLK7 was analyzed with Pearson correlation coefficient. Loss-of-function assays revealed that knockdown of FOXD2-AS1 or KLK7 greatly inhibited PTC cell proliferation and migration, while induced cell apoptosis. Results of mechanism experiments suggested that FOXD2-AS1 functioned as a competing endogenous RNA (ceRNA) to enhance the expression of KLK7 by sponging miR-485-5p in PTC. Rescue assays were conducted to verify the function of FOXD2-AS1/miR-485-5p/KLK7 axis in PTC progression.

Prognostic and Therapeutic Implications of Microvascular Invasion in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a morbid condition for which surgical and ablative therapy are the only options for cure. Nonetheless, over half of patients treated with an R0 resection will develop recurrence. Early recurrences within 2 years after resection are thought to be due to the presence of residual microscopic disease, while late recurrences > 2 years after resection are thought to be de novo metachronous HCCs arising in chronically injured liver tissue. Microvascular invasion (MVI) is defined as the presence of micrometastatic HCC emboli within the vessels of the liver, and is a critical determinant of early recurrence and survival. In this review, we summarize the pathogenesis and clinical relevance of MVI, which correlates with adverse biological features, including high grade, large tumor size, and epithelial-mesenchymal transition. Multiple classification schemas have been proposed to capture the heterogeneous features of MVI that are associated with prognosis. However, currently, MVI can only be determined based on surgical specimens, limiting its clinical applicability. Going forward, advances in axial imaging technologies, molecular characterization of biopsy tissue, and novel serum biomarkers hold promise as future methods for non-invasive MVI detection. Ultimately, MVI status may be used to help clinicians determine treatment plans, particularly with respect to surgical intervention, and to provide more accurate prognostication.

Long Noncoding RNA and Epithelial Mesenchymal Transition in Cancer

Epithelial-mesenchymal transition (EMT) is a multistep process that allows epithelial cells to acquire mesenchymal properties. Fundamental in the early stages of embryonic development, this process is aberrantly activated in aggressive cancerous cells to gain motility and invasion capacity, thus promoting metastatic phenotypes. For this reason, EMT is a central topic in cancer research and its regulation by a plethora of mechanisms has been reported. Recently, genomic sequencing and functional genomic studies deepened our knowledge on the fundamental regulatory role of noncoding DNA. A large part of the genome is transcribed in an impressive number of noncoding RNAs. Among these, long noncoding RNAs (lncRNAs) have been reported to control several biological processes affecting gene expression at multiple levels from transcription to protein localization and stability. Up to now, more than 8000 lncRNAs were discovered as selectively expressed in cancer cells. Their elevated number and high expression specificity candidate these molecules as a valuable source of biomarkers and potential therapeutic targets. Rising evidence currently highlights a relevant function of lncRNAs on EMT regulation defining a new layer of involvement of these molecules in cancer biology. In this review we aim to summarize the findings on the role of lncRNAs on EMT regulation and to discuss their prospective potential value as biomarkers and therapeutic targets in cancer.

lncRNA ZEB1-AS1 Mediates Oxidative Low-Density Lipoprotein-Mediated Endothelial Cells Injury by Post-transcriptional Stabilization of NOD2

Oxidized-low density lipoprotein (ox-LDL) can induce injury of endothelial cells, causing atherosclerosis, which is an important initial event in several cardiovascular diseases. Long non-coding RNAs (lncRNAs) have emerged as regulators of diverse biological processes, but their specific biological functions and biochemical mechanisms in ox-LDL-induced endothelial cell injury have not been well investigated. Here, we describe the initial functional analysis of a poorly characterized human lncRNA ZEB1 antisense 1 (ZEB1-AS1). We found that ox-LDL treatment could induce a decreased cell viability and an increased cell apoptosis in endothelial cells, and knockdown of ZEB1-AS1 significantly reversed this effect. Mechanistically, ox-LDL treatment could sequester p53 from binding to ZEB1-AS1 promoter region, causing transcriptional activation and upregulation of ZEB1-AS1. Moreover, enhanced ZEB1-AS1 could upregulate Nucleotide-Binding Oligomerization Domain 2 (NOD2) expression through recruiting leucine-rich pentatricopeptide repeat motif-containing protein (LRPPRC) to stabilize NOD2 mRNA. Experimental data showed that knockdown of NOD2 or LRPPRC dramatically abrogated the functional role of ZEB1-AS1 in ox-LDL-induced endothelial cell injury. In summary, we demonstrated that lncRNA ZEB1-AS1 regulates the ox-LDL-induced endothelial cell injury via an LRPPRC-dependent mRNA stabilization mechanism. Therefore, ZEB1-AS1 may serve as a multi-potency target to overcome endothelial cell injury, atherosclerosis and other cardiovascular diseases.

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.

EGR1-induced upregulation of lncRNA FOXD2-AS1 promotes the progression of hepatocellular carcinoma via epigenetically silencing DKK1 and activating Wnt/β-catenin signaling pathway

Long non-coding RNAs (lncRNAs) are regarded as a group of biomarkers in the initiation and development of various cancers, including hepatocellular carcinoma (HCC). LncRNA FOXD2-AS1 has been studied in human colorectal cancer and glioma as an oncogene. However, the function and mechanism of lncRNA FOXD2-AS1 in hepatocellular carcinoma are marked. In this study, we found that high expression of FOXD2-AS1 predicted poor prognosis of HCC patients in the TCGA database. The dysregulation of FOXD2-AS1 was determined in HCC tissues and cell lines by qRT-PCR. Functionally, silenced FOXD2-AS1 efficiently suppressed HCC progression by regulating cell proliferation, apoptosis, migration and epithelial-mesenchymal transition (EMT). Mechanistically, FOXD2-AS1 was found to be activated by the transcription factor EGR1. Furthermore, FOXD2-AS1 could activate the Wnt/β-catenin signaling pathway. The mechanism contributed to the interaction between FOXD2-AS1 and Wnt/β-catenin signaling pathway was analyzed. It was uncovered that FOXD2-AS1 enhanced the activity of Wnt/β-catenin signaling pathway by epigenetically silencing the inhibitor of Wnt/β-catenin signaling pathway (DKK1). Rescue assays demonstrated that DKK1 and Wnt/β-catenin signaling pathway involved in FOXD2-AS1-mediated HCC progression. In conclusion, our study demonstrated that EGR1-induced upregulation of lncRNA FOXD2-AS1 promotes the progression of hepatocellular carcinoma via epigenetically silencing DKK1 and activating Wnt/β-catenin signaling pathway.

LncRNA ZEB1-AS1 reduces liver cancer cell proliferation by targeting miR-365a-3p

Liver carcinoma is one of the most common malignancies worldwide. Previous studies have demonstrated that long non-coding RNAs (lncRNAs) are crucial mediators that participate in a wide range of molecular processes associated with carcinogenesis. However, little is known about the specific mechanisms that underlie the majority of lncRNAs. Many studies have indicated that lncRNAs affect microRNA (miRNA or miR) activities via physical base-paired binding, therefore serving as competing endogenous RNAs (ceRNAs) that indirectly regulate the expression of miRNA targets. In the current study, it was revealed that lncRNA zinc-finger E-box binding homeobox 1 antisense 1 (ZEB1-AS1) serves as a ceRNA for miR-365a-3p, functioning to positively modulate E2F transcription factor 2 (E2F2) expression in liver cancer cells. Additionally, reverse transcription-quantitative polymerase chain reaction demonstrated that levels of ZEB1-AS1 were abnormally upregulated in liver cancer and this was positively correlated with E2F2 expression. Furthermore, high levels of ZEB1-AS1 exhibited a trend for poor survival in patients with liver cancer. Western blot analysis demonstrated that ZEB1-AS1 silencing could reduce E2F2 expression. EdU staining and flow cytometry analysis indicated that downregulation of ZEB1-AS1 could suppress cell proliferation and decrease the S phase proportion of liver cancer cells, which was effectively reversed by the inhibition of miR-365a-3p. ZEB1-AS1 was also determined to be physically associated with miR-365a-3p, while miR-365a-3p was revealed to target the E2F2 3′UTR for degradation or translational repression. The results also demonstrated that ZEB1-AS1 positively regulates E2F2 expression by competitively binding to miR-365a-3p. It was further revealed to enhance liver cancer cell proliferation. Thus, these results indicate that ZEB1-AS1 is required for liver cancer progression in a ceRNA dependent manner. ZEB1-AS1 may therefore be a potential target for liver cancer intervention.

LncRNA SNHG3 induces EMT and sorafenib resistance by modulating the miR-128/CD151 pathway in hepatocellular carcinoma

Dysregulation of long noncoding RNAs (lncRNAs) plays important roles in carcinogenesis and tumor progression, including hepatocellular carcinoma (HCC). Small nucleolar RNA host gene 3 (SNHG3) has been considered as an lncRNA to be associated with a poor prognosis in patients with HCC. Here, we reported that SNHG3 expression was significantly higher in the highly metastatic HCC (HCCLM3) cells compared with the lowly metastatic HCC cells (Hep3B and PLC/PRF/5). Furthermore, forced expression of SNHG3 promoted cell invasion, epithelial-mesenchymal transition (EMT), and sorafenib resistance in HCC. Moreover, SNHG3 overexpression induced HCC cells EMT via miR-128/CD151 cascade activation. Clinically, our data revealed that increased SNHG3 expression is correlated with poor HCC survival outcomes and sorafenib response. These data suggest that SNHG3 may be a novel therapeutic target and a biomarker for predicting response to sorafenib treatment of HCC.

Long non-coding RNA ZEB1-AS1 regulates miR-200b/FSCN1 signaling and enhances migration and invasion induced by TGF-β1 in bladder cancer cells

Background

The effect of competing endogenous RNA (ceRNA) can regulate gene expression by competitively binding microRNAs. Fascin-1 (FSCN1) plays an important role in the regulation of cellular migration and invasion during tumor progression, but how its regulatory mechanism works through the ceRNA effect is still unclear in bladder cancer (BLCA).

Methods

The role of fascin-1, miR-200b, and ZEB1-AS1 in BLCA was investigated in vitro and in vivo. The interaction between fascin-1, miR-200b, and ZEB1-AS1 was identified using bioinformatics analysis, luciferase activity assays, RNA-binding protein immunoprecipitation (RIP), quantitative PCR, and western blotting. Loss (or gain)-of-function experiments were performed to investigate the biological roles of miR-200b and ZEB1-AS1 on migration, invasion, proliferation, cell apoptosis, and cell cycle.

Results

ZEB1-AS1 functions as a competing endogenous RNA in BLCA to regulate the expression of fascin-1 through miR-200b. Moreover, the oncogenic long non-coding RNA ZEB1-AS1 was highly expressed in BLCA and positively correlated with high tumor grade, high TNM stage, and reduced survival of patients with BLCA. Moreover, ZEB1-AS1 downregulated the expression of miR-200b, promoted migration, invasion, and proliferation, and inhibited apoptosis in BLCA. Furthermore, we found TGF-β1 induced migration and invasion in BLCA by regulating the ZEB1-AS1/miR-200b/FSCN1 axis.

Conclusion

The observations in this study identify an important regulatory mechanism of fascin-1 in BLCA, and the TGF-β1/ZEB1-AS1/miR-200b/FSCN1 axis may serve as a potential target for cancer therapeutic purposes.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1102-6) contains supplementary material, which is available to authorized users.

Bioinformatic analysis of the prognostic value of the lncRNAs encoding snoRNAs in hepatocellular carcinoma

Some lncRNAs can encode small nucleolar RNAs (snoRNAs), called small nucleolar RNA host genes (SNHGs), which exert diverse regulatory effects on cellular processes. In this study, using RNA-seq and survival data in the Cancer Genome Atlas (TCGA)-Liver Hepatocellular Carcinoma (LIHC), we examined the expression profile of some SNHG genes and explored their prognostic value in hepatocellular carcinoma (HCC). Level-3 RNA-sequencing data, the clinicopathological and survival data of patients with primary HCC were downloaded from the UCSC Xena browser (https://xenabrowser.net/), for a secondary analysis. Results showed that SNHG1, GAS5, SNHG3-7 and SNHG10-12 were significantly upregulated in HCC tissues (N = 49) compared with adjacent normal tissues (N = 49). After adjustment for confounding factors, the multivariate analysis confirmed that increased SNHG4 expression was independently associated with shorter OS (HR: 1.319, 95%CI: 1.131-1.537, P < 0.001), while increased GAS5 expression was an independent predictor of shorter RFS (HR: 1.287, 95% CI: 1.027-1.612, P = 0.028). Using the methylation data obtained from the Infinium HumanMethylation450 BeadChip, we found that SNHG4 expression was not likely to be modulated by methylation in HCC. In comparison, the methylation status of 5 CpG sites (cg07177756, cg17025683, cg16290996, cg03044573 and cg06644515) showed a moderately negative correlation (Pearson's r = -0.54, P < 0.001) with GAS5 expression. Based on these findings, we infer that SNHG4 and GAS5 might be valuable prognostic markers in HCC. DNA hypomethylation might play an important role in elevated GAS5 transcription in HCC. © 2018 BioFactors, 45(2):244-252, 2019.

SP1-induced upregulation of long non-coding RNA HCP5 promotes the development of osteosarcoma

Long non-coding RNAs (LncRNAs) are acknowledged as crucial regulators in tumorigenesis and tumor progression. In this study, we explored the mechanism and function of lncRNA HCP5 in osteosarcoma (OS). At first, five lncRNAs were chosen from GeneCard and subjected to qRT-PCR examination. The results indicated that HCP5 was significantly overexpressed in four OS cell lines. Northern blot assay further proved the higher expression of HCP5 in OS cell lines. To identify the biological role of HCP5 in OS, we silenced the expression of HCP5 in U2OS and MG-63 cells which possessed the highest level of HCP5. CCK-8 and colony formation assay revealed the inhibitory effect of HCP5 knockdown on cell proliferation. Cell apoptosis was found to be increased in cells transfected with sh-HCP5#1. Moreover, cell invasion and epithelial-mesenchymal transition (EMT) were reversed by the silencing of HCP5. The results of functional assays showed that HCP5 acted as an oncogene in osteosarcoma. Mechanically, HCP5 was found to be activated by the transcription factor SP1. Finally, rescue assays were conducted to demonstrate the function of SP1/HCP5 axis in osteosarcoma. In conclusion, we confirmed that SP1-induced upregulation of long non-coding RNA HCP5 promotes the development of osteosarcoma.

New Insights into the Role of Epithelial⁻Mesenchymal Transition during Aging

Epithelial–mesenchymal transition (EMT) is a cellular process by which differentiated epithelial cells undergo a phenotypic conversion to a mesenchymal nature. The EMT has been increasingly recognized as an essential process for tissue fibrogenesis during disease and normal aging. Higher levels of EMT proteins in aged tissues support the involvement of EMT as a possible cause and/or consequence of the aging process. Here, we will highlight the existing understanding of EMT supporting the phenotypical alterations that occur during normal aging or pathogenesis, covering the impact of EMT deregulation in tissue homeostasis and stem cell function.

KLF5 and MYC modulated LINC00346 contributes to gastric cancer progression through acting as a competing endogeous RNA and indicates poor outcome

It was found in this study that long intergenic non-protein coding RNA 346 (LINC00346) was an lncRNA aberrantly expressed in gastric cancer (GC) based on multiple Gene Expression Omnibus (GEO) databases of GC cohorts. The LINC00346 gene was recurrently amplified and upregulated in GC, and its expression was positively correlated with poor pathologic stage, large tumor size, and poor prognosis. In addition, the oncogenic transcription factors KLF5 and MYC could bind to the LINC00346 promoter and enhance its expression. Gene Set Enrichment Analysis (GSEA) in the GEO datasets revealed that cell cycle and focal adhesion genes were enriched in patients with high LINC00346 expression. In vitro and in vivo assays of LINC00346 alterations revealed a complex integrated phenotype affecting cell growth, migration and invasion. Strikingly, high-throughput sequencing analysis after LINC00346 alterations highlighted alterations in cell cycle and focal adhesion pathways in GC cells. Mechanistically, argonaute 2 (Ago2) was recruited by LINC00346, which functioned as a molecular sponge for miR-34a-5p by antagonizing its ability to repress CD44, NOTCH1, and AXL protein translation. Taken together, our findings support a model in which the KLF5, MYC/LINC00346/miR-34a-5p cross-talk served as critical effectors in GC tumorigenesis and progression, suggesting a new therapeutic direction in the treatment of GC.

lncRNA ZEB1-AS1 promotes pulmonary fibrosis through ZEB1-mediated epithelial-mesenchymal transition by competitively binding miR-141-3p

Long non-coding RNAs (lncRNAs) have been reported to be involved in various pathophysiological processes in many diseases. However, the role and mechanism of lncRNAs in pulmonary fibrosis have not been explicitly delineated. In the present study, we found that lncRNA ZEB1 antisense RNA 1 (ZEB1-AS1) is upregulated in the lungs of BLM-induced rats and TGF-β1-induced RLE-6TN cells, and positively correlated with the levels of ZEB1, an epithelial-mesenchymal transition (EMT) master regulator. Knockdown of ZEB1-AS1 alleviated BLM-induced fibrogenesis, in vivo, via inhibiting EMT progress. Mechanistically, we identified that ZEB1-AS1 promoted fibrogenesis in RLE-6TN cells and ZEB1-AS1 silencing inhibited TGF-β1-induced fibrogenesis through modulation of miR-141-3p. Further experiments revealed that ZEB1-AS1 acted as competing endogenous RNA (ceRNA) of miR-141-3p: forced expression of ZEB1-AS1 reduced the expression of miR-141-3p to activate Zinc-finger Ebox Binding Homeobox 1 (ZEB1) in RLE-6TN cells. In addition, we found that upregulation of miR-141-3p prevented fibrogenesis by targeting ZEB1. Therefore, our finding suggested lncRNA ZEB1-AS1 as a new profibrotic molecule that acts as a regulator of miR-141-3p/ZEB1 axis during lung fibrosis and demonstrated ZEB1-AS1 as a potential therapeutic target for the prevention and treatment of pulmonary fibrosis.

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.

MicroRNA‑9‑5p downregulates Klf4 and influences the progression of hepatocellular carcinoma via the AKT signaling pathway

Krüppel-like factor 4 (Klf4) is a transcriptional factor involved in the progression of hepatocellular carcinoma (HCC). However, the underlying regulatory mechanisms associated with the Klf4 gene as a tumor suppressor in HCC remain unclear. microRNAs (miRNAs or miRs) are a series of small non-coding RNAs that serve a vital role in regulating gene expression via their influence on protein translation and the associated degradation of mRNA. The mRNA expression levels of the miRNA, miR-9-5p, and Klf4 were measured using reverse transcription-quantitative polymerase chain reaction. The protein expression levels of Klf4, protein kinase B (AKT), phosphorylated (p-)AKT, mechanistic target of rapamycin (mTOR), p-mTOR, B cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein (Bax) were determined by western blot analysis. Dual luciferase reporter assay was used to confirm a direct interaction between miR-9-5p and the 3′-untranslated region (3′-UTR) sequence of Klf4. Cell counting kit-8 assay, wound healing assay, Transwell migration assay and flow cytometric analysis were performed to evaluate the proliferative, migratory and apoptotic capabilities of the HCC cells. In the present study, miR-9-5p was revealed to be overexpressed in HCC as a novel upstream gene of Klf4. miR-9-5p expression was inversely associated with Klf4 expression in clinical samples. Additionally, Kaplan-Meier analysis revealed a markedly poor prognosis of HCC in the miR-9-5p high-expression group. Bioinformatics analysis revealed that miR-9-5p bound directly to the 3′-UTR of Klf4, which reduced the expression levels of Klf4. The miR-9-5p/Klf4 axis promoted HCC proliferation and migration, and inhibited HCC apoptosis. Furthermore, miR-9-5p upregulated the Bcl-2/Bax protein ratio and activated AKT/mTOR signaling. Taken together, these data demonstrated that the miR-9-5p/Klf4 axis was able to promote HCC progression, which may occur via regulation of the AKT signaling pathway, highlighting a potential novel target in HCC treatment.

Role of non-coding RNAs in liver disease progression to hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a tumor with poor prognosis and frequently aggressive. The development of HCC is associated with fibrosis and cirrhosis, which mainly results from nonalcoholic fatty liver disease, excessive alcohol consumption, and viral infections. Non-coding RNAs (ncRNAs) are RNAs transcribed from the genome, but are not translated into proteins. Recently, ncRNAs emerged as key contributors to tumor development and progression because of their abilities to regulate various targets and modulate cell proliferation, differentiation, apoptosis, and development. In this review, we summarize the frequently activated pathways in HCC and discuss the pathological implications of ncRNAs in the context of human liver disease progression, in particular HCC development and progression. This review aims to summarize the role of ncRNA dysregulation in the diseases and discuss the diagnostic and therapeutic potentials of ncRNAs.

lncRNA FEZF1-AS1 Is Associated With Prognosis in Lung Adenocarcinoma and Promotes Cell Proliferation, Migration, and Invasion

Long noncoding RNAs (lncRNAs) have been reported to play important roles in tumorigenesis. In the present study, we demonstrated that lncRNA forebrain embryonic zinc finger protein 1 (FEZF1) antisense RNA1 (FEZF1-AS1) is markedly upregulated in human lung adenocarcinoma (LAD) tissues and cell lines and is associated with poor prognosis. Loss of function revealed that deletion of FEZF1-AS1 expression significantly inhibited the LAD cell proliferation, invasion, and migration. Further studies revealed that downregulation of FEZF1-AS1 reduced mRNA and protein expression of its sense-cognate gene FEZF1 in LAD cells, and vice versa. Correlation analysis indicated that there was a positive correlation between FEZF1-AS1 and FEZF1 expression in LAD tissues. Additionally, rescue assay confirmed that the function of FEZF1-AS1 in LAD was mediated by FEZF1. Our findings suggested that dysregulation of FEZF1-AS1 contributed to the progression of LAD, which might be a potential target for LAD therapy.

Expression of TBX3 in Hepatocellular Carcinoma and Its Clinical Implication

Background

Hepatocellular carcinoma (HCC) is the fifth most common malignancy in China, and China’s annual number of new cases accounts for about 45% of the world total. This research was aimed to study the expression of TBX3 protein in HCC and exploring its clinical significance.

Material/Methods

We collected tumor tissues and adjacent non-tumoral tissues of 174 patients with HCC undergoing surgical resection. The expression of TBX3 protein in different tissues and cell lines in vitro (LO2, HHL-5, MHC97-L, MHC97-H) was detected by immunohistochemistry or Western blotting, and the relationship between TBX3 expression and clinical data of patients with HCC was analyzed.

Results

The expression of TBX3 protein in HCC was significantly correlated with histological grade, tumor size, cancer cell metastasis, hepatitis B surface antigen, and the expression of Ki-67 in tumor tissues (P<0.05), and it was positively correlated with serum AFP level (r=0.766, P<0.05). The expression of TBX3 increased with increased histological grade in HCC (P<0.05). Cox regression analysis showed that the expression of TBX3 protein in HCC was an independent risk factor for prognosis (OR=0.524, 95% CI=0.283–0.964). The 5-year survival rate of patients with HCC that highly expressed TBX3 protein was 20.83%, which was significantly lower than the 40.20% rate in patients with low expression (P<0.05).

Conclusions

The expression of TBX3 in HCC patients undergoing surgical resection is high, and its expression increases with the degree of tumor differentiation. It is related to the metastasis of tumor cells and is positively correlated with the serum level of AFP and may affect the survival time of HCC patients undergoing surgical resection.

Long Stress Induced Non-Coding Transcripts 5 (LSINCT5) Promotes Hepatocellular Carcinoma Progression Through Interaction with High-Mobility Group AT-hook 2 and MiR-4516

Background

Long non-coding RNAs (lncRNAs) have been implicated in various human cancer types. However, the underlying mechanisms involved in hepatocellular carcinoma (HCC) progression remain poorly understood.

Material/Methods

In this study, lncRNA array was used to identify HCC related lncRNAs. RNA immunoprecipitation (RIP) followed mass spectrometry was used to explore lncRNA binding proteins. Western blot, quantitative PCR, tumor sphere formation, migration and viability assay were performed to evaluate the oncogenic role of lncRNAs.

Results

We identified a novel lncRNA named long stress induced non-coding transcripts 5 (LSINCT5) which facilitates HCC progression. LSINCT5 was significantly upregulated in both HCC specimens and cell lines and correlates with poor survival. In vitro experiments showed that LSINCT5 promoted migration and viability of HepG2 and Huh7 cells. The in vivo xenograft mouse model also confirmed an oncogenic role for LSINCT5. RIP in combination with mass spectrometry identified HMGA2 as the LSINCT5 binding partner. LSINCT5 could bind to HMGA2 and decrease proteasome-mediated HMGA2 degradation leading to EMT activation. LSINCT5 also served as a competing endogenous RNA (ceRNA) for miR-4516, resulting in increased STAT3/BclxL expression and attenuated apoptosis.

Conclusions

Our data have collectively established a lncRNA LSINCT5 mediated process during HCC carcinogenesis and might have provided novel insight into therapeutic targeting.

Long non-coding RNA ZEB1-AS1 indicates poor prognosis and promotes melanoma progression through targeting miR-1224-5p

Long non-coding RNAs (lncRNAs) have critical roles in various types of cancer, but their roles in the development of melanoma and the underlying molecular mechanisms remain to be fully elucidated. In the present study, the role of zinc finger E-box binding homeobox 1 antisense RNA 1 (ZEB1-AS1) in melanoma was assessed. The expression levels of ZEB1-AS1 were increased in melanoma cell lines and tumor tissues as indicated by reverse transcription-quantitative polymerase chain reaction analysis. Kaplan-Meier analysis suggested that higher expression of ZEB1-AS1 predicts poor prognosis of melanoma patients. Furthermore, knockdown of ZEB1-AS1 inhibited the proliferation, migration and invasion of melanoma, suggesting a role of ZEB1-AS1 in the development and progression of melanoma. In addition, a luciferase reporter assay confirmed that the expression of miR-1224-5p was directly regulated by ZEB1-AS1. Transfection with miR-1224-5p mimics reduced the levels of ZEB1-AS1 and the proliferation, migration and invasion of melanoma. In conclusion, ZEB1-AS1 enhances the proliferation, migration and invasion of melanoma, at least in part by inhibiting the expression of miR-1224-5p, and its overexpression is associated with poor survival of melanoma patients. In addition, the ZEB1-AS1/miR-1224-5p interaction may be a promising therapeutic target for melanoma treatment.

Evaluation of serum exosomal LncRNA-based biomarker panel for diagnosis and recurrence prediction of bladder cancer

Exosomes are small membrane vesicles released by many cells. These vesicles can mediate cellular communications by transmitting active molecules including long non‐coding RNAs (lncRNAs). In this study, our aim was to identify a panel of lncRNAs in serum exosomes for the diagnosis and recurrence prediction of bladder cancer (BC). The expressions of 11 candidate lncRNAs in exosome were investigated in training set (n = 200) and an independent validation set (n = 320) via quantitative real‐time PCR. A three‐lncRNA panel (PCAT‐1, UBC1 and SNHG16) was finally identified by multivariate logistic regression model to provide high diagnostic accuracy for BC with an area under the receiver‐operating characteristic curve (AUC) of 0.857 and 0.826 in training set and validation set, respectively, which was significantly higher than that of urine cytology. The corresponding AUCs of this panel for patients with Ta, T1 and T2‐T4 were 0.760, 0.827 and 0.878, respectively. In addition, Kaplan‐Meier analysis showed that non‐muscle‐invasive BC (NMIBC) patients with high UBC1 expression had significantly lower recurrence‐free survival (P = 0.01). Multivariate Cox analysis demonstrated that UBC1 was independently associated with tumour recurrence of NMIBC (P = 0.018). Our study suggested that lncRNAs in serum exosomes may serve as considerable diagnostic and prognostic biomarkers of BC.

NOTCH1 regulates the proliferation and migration of bladder cancer cells by cooperating with long non-coding RNA HCG18 and microRNA-34c-5p

In recent years, the NOTCH signaling pathway has been gradually studied in human malignancies. Inactivation of the NOTCH signaling pathway was uncovered to be correlated with the carcinogenesis of bladder cancer (BCa). Nevertheless, the specific molecular mechanism of NOTCH1 (one of the core factors of the NOTCH signaling pathway) is not well elucidated in BCa. This study focused on the mechanism by which NOTCH1 affects the biological behaviors of BCa cells. According to the experimental results of quantitative real-time polymerase chain reaction, NOTCH1 was dysregulated in BCa tissues and cell lines. The prognostic value of NOTCH1 for the patients with BCa was determined using the Kaplan-Meier method. Mechanism investigations revealed that NOTCH1 is a target of miR-34c-5p in BCa. Furthermore, microarray analysis was used to find the dysregulated long noncoding RNAs (lncRNA), which can bind with miR-34c-5p. Mechanism experiments further demonstrated the rationality of the HCG18-miR-34c-5p-NOTCH1 pathway. Functional assays were then applied to validate the inhibitory influences of NOTCH1 on the proliferation and migration of BCa cells. Furthermore, the inhibitory effects of NOTCH1 could be affected by miR-34c-5p or lncRNA HCG18. All findings in this study revealed that NOTCH1 suppresses the BCa progression by cooperating with lncRNA HCG18 and miR-34c-5p.

Long non-coding RNA ARAP1-AS1 promotes the progression of bladder cancer by regulating miR-4735-3p/NOTCH2 axis

Accumulative reports have documented the critical functions of long non-coding RNAs (lncRNAs) in the progression of malignant tumors, including bladder cancer (BCa). LncRNA ARAP1-AS1 was chosen to be the object of this study due to it was significantly upregulated in the BCa samples of TCGA database. qRT-PCR further validated the dysregulation of ARAP1-AS1 in 88 pairs of BCa tissues and six BCa cells. Kaplan Meier analysis was utilized to analyze the prognostic value of ARAP1-AS1 for patients with BCa. To evaluate the oncogenic property of ARAP1-AS1 in bladder cancer, loss-of-function assays were conducted in two BCa cells in which ARAP1-AS1 was expressed highest. Mechanically, ARAP1-AS1 was enriched in the cytoplasm of BCa cells, suggesting that ARAP1-AS1 might act as a ceRNA to regulate gene expression and biological processes in bladder cancer. It was certified that ARAP1-AS1 can bind with miR-4735-3p in BCa cells. Moreover, functional assays supported the hypothesis that miR-4735-3p is a tumor suppressor in BCa. Additionally, NOTCH2 mRNA could be targeted by miR-4735-3p in BCa cells. The results of all mechanism experiments indicated that ARAP1-AS1 regulated miR-4735-3p/NOTCH2 axis in BCa by acting as a ceRNA. All our research findings may bring novel insights into the treatment of bladder cancer.

Electrochemical Assay of the Alpha Fetoprotein-L3 Isoform Ratio To Improve the Diagnostic Accuracy of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is now the major malignant disease with high morbidity and mortality, which seriously endangers human lives and health. Alpha fetoprotein (AFP) assay is a commonly used serological biomarker for clinical diagnosis of HCC, but it lacks specificity. Analysis of its isoform AFP-L3, especially the AFP-L3 ratio in total AFP (AFP-L3%), can significantly improve the specificity for HCC identification. Herein, an electrochemical approach has been first proposed for simple, accurate, and fast determination of AFP-L3% in clinical samples. On the basis of two independent electrochemical signals generated from the synthesized nanoparticles, 4-mercaptophenylboronic acid (MPA)-functionalized copper nanoparticles (MPA-CuNPs) and the Lens culinaris agglutinin (LCA)-functionalized silver nanoparticles (LCA-AgNPs), simultaneous quantification of the AFP-L3 and total AFP in serum sample has been achieved, thus achieving directly the electrochemical assay of AFP-L3%. To be noted, both the assay time and the assay procedure have been significantly compressed when compared to that of available techniques in clinical use. Therefore, with the integration of electrochemical techniques, this new approach for AFP-L3% analysis would be promising for the accurate diagnosis of HCC.

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.

[Expression of long noncoding RNA linc00261 in hepatocellular carcinoma and its association with postoperative outcomes]

OBJECTIVE

To investigate the expression of long noncoding RNA linc00261 in hepatocellular carcinoma (HCC) and its correlation with the clinicopathological features and postoperative outcomes of the patients.

METHODS

Real-time fluorescence quantitative PCR (qRT-PCR) was used to detect the expression of linc00261 in surgical specimens of HCC and adjacent tissues from 74 patients. The correlation of the expression level of linc00261 in HCC with the clinicopathological parameters of the patients was analyzed using Chi-square test. The Cox's proportional hazards regression model was used to assess the value of linc00261 in predicting the prognosis of HCC patients after operation. The expression of linc00261 was also examined in 5 HCC cell lines using qRT-PCR. The HCC cell lines MHCC-LM3 and SNU-449 were transfected with small interfering RNAs targeting linc00261 for linc00261 knockdown, and the changes in the cell proliferation, migration and invasion abilities were observed using CCK-8 assay and Transwell assay.

RESULTS

The expression level of linc00261 in HCC was significantly correlated with AFP (P=0.032), tumor size (P=0.007), microscopic vascular invasion (MVI; P=0.01), and TNM stage (P=002). The patients with lowered expressions of linc00261 in HCC tissues had a significantly shortened tumor-free survival time (P < 0.05), and a lowered expression of linc00261 was identified as an independent risk factor affecting postoperative recurrence-free survival time of the patients (P < 0.05). In HCC cell lines MHCC-LM3 and SNU-449 cells, linc00261 knockdown obviously promoted the cell migration and invasion (P < 0.01) but did not significantly affect cell proliferation (P > 0.05).

CONCLUSIONS

Linc00261 may serve as a new prognostic biomarker for predicting the postoperative outcomes of the patients with HCC.

Systematic analysis of lncRNA-miRNA-mRNA competing endogenous RNA network identifies four-lncRNA signature as a prognostic biomarker for breast cancer

Background

Increasing evidence has underscored the role of long non-coding RNAs (lncRNAs) acting as competing endogenous RNAs (ceRNAs) in the development and progression of tumors. Nevertheless, lncRNA biomarkers in lncRNA-related ceRNA network that can predict the prognosis of breast cancer (BC) are still lacking. The aim of our study was to identify potential lncRNA signatures capable of predicting overall survival (OS) of BC patients.

Methods

The RNA sequencing data and clinical characteristics of BC patients were obtained from the Cancer Genome Atlas database, and differentially expressed lncRNA (DElncRNAs), DEmRNAs, and DEmiRNAs were then identified between BC and normal breast tissue samples. Subsequently, the lncRNA–miRNA–mRNA ceRNA network of BC was established, and the gene oncology enrichment analyses for the DEmRNAs interacting with lncRNAs in the ceRNA network was implemented. Using univariate and multivariate Cox regression analyses, a four-lncRNA signature was developed and used for predicting the survival in BC patients. We applied receiver operating characteristic analysis to assess the performance of our model.

Results

A total of 1061 DElncRNAs, 2150 DEmRNAs, and 82 DEmiRNAs were identified between BC and normal breast tissue samples. A lncRNA–miRNA–mRNA ceRNA network of BC was established, which comprised of 8 DEmiRNAs, 48 DElncRNAs, and 10 DEmRNAs. Further gene oncology enrichment analyses revealed that the DEmRNAs interacting with lncRNAs in the ceRNA network participated in cell leading edge, protease binding, alpha-catenin binding, gamma-catenin binding, and adenylate cyclase binding. A univariate regression analysis of the DElncRNAs revealed 7 lncRNAs (ADAMTS9-AS1, AC061992.1, LINC00536, HOTAIR, AL391421.1, TLR8-AS1 and LINC00491) that were associated with OS of BC patients. A multivariate Cox regression analysis demonstrated that 4 of those lncRNAs (ADAMTS9-AS1, LINC00536, AL391421.1 and LINC00491) had significant prognostic value, and their cumulative risk score indicated that this 4-lncRNA signature independently predicted OS in BC patients. Furthermore, the area under the curve of the 4-lncRNA signature associated with 3-year survival was 0.696.

Conclusions

The current study provides novel insights into the lncRNA-related ceRNA network in BC and the 4 lncRNA biomarkers may be independent prognostic signatures in predicting the survival of BC patients.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1640-2) contains supplementary material, which is available to authorized users.

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.

lncRNA involvement in hepatocellular carcinoma metastasis and prognosis

Eukaryotic lncRNAs are RNA molecules defined to be greater than 200 bp in length that are not translated to a protein and operate through several mechanisms, including participating in chromatin remodeling and methylation, influencing the integrity and stability of proteins and complexes, or acting as a sponge for miRNA inhibition. A number of recent studies have concentrated on the relationship between long non-coding RNAs (lncRNAs) and cancer. Hepatocellular carcinoma (HCC) is the most prevalent histological type of liver tumors, accounting for about 80 % of the cases worldwide. Lack of proper molecular markers for diagnosis of HCC and treatment evaluation is a significant problem. Dysregulated expression of HCC-related lncRNAs such as MEG-3, MALAT1, HULC, HOTAIR, and H19 have been identified and closely related with tumorigenesis, metastasis, prognosis and diagnosis. In this review, we summarized recent highlighted functions and molecular mechanisms of the most extensively studied lncRNAs in the pathophysiology of hepatocellular carcinoma and their potential for serving as probable therapeutic targets.