A Long Noncoding RNA ZEB1-AS1 Promotes Tumorigenesis and Predicts Poor Prognosis in Glioma

LncRNA ZEB1-AS1/miR-409-3p/ZEB1 feedback loop is involved in the progression of non-small cell lung cancer

Emerging evidence has illustrated that long noncoding RNA (LncRNA) ZEB1 antisense RNA 1 (ZEB1-AS1) involved in the development of various type of human cancers. However, the role of ZEB1-AS1 in non-small cell lung cancer (NSCLC) is still elusive and poorly understood. The present study aimed to provide functional evidence and elucidate the molecular mechanisms by which the ZEB1-AS1 promotes oncogenesis of NSCLC. Our study found that ZEB1-AS1 was upregulated in NSCLC cells and knockdown of ZEB1-AS1 significantly inhibited cell growth and induced cell apoptosis. Mechanically, miR-409-3p was confirmed as a direct target of ZEB1-AS1 and negatively regulated by ZEB1-AS1 via competing endogenous RNA (ceRNA) mechanism; miR-409-3p inhibited ZEB1 expression by directly binding to the 3'UTR. Importantly, as predicted by JASPAR and further confirmed by luciferase reporter gene and ChIP assays, we found ZEB1 could bind to the promoter region of ZEB1-AS1 to activate its expression. Restoration of ZEB1 could partially abolished the action of ZEB1-AS1 silencing on cell proliferation and apoptosis. Collectively, the results suggested that ZEB1-AS1/miR-409-3p/ZEB1 constitutes a positive feedback loop to promote the tumorigenesis of NSCLC, highlighting the possibility of improving NSCLC treatment by targeting the ZEB1-AS1 signaling pathway.

Long noncoding RNA ZEB1-AS1 promotes the tumorigenesis of glioma cancer cells by modulating the miR-200c/141-ZEB1 axis

Long noncoding RNA Zinc Finger E-box-binding homeobox 1 antisense 1 (ZEB1-AS1) reportedly participates in the tumorigenesis of various cancers. However, the clinical significance and biological functions of ZEB1-AS1 in glioma remain virtually unknown. Here, we show that ZEB1-AS1 expression was higher in glioma tissues and cell lines than in corresponding noncancerous samples and primary normal human astrocytes, respectively. The positive correlation of ZEB1-AS1 expression with the poor prognosis and progressive histological stages of glioma patients was clinically proven. In vitro assays revealed that silencing ZEB1-AS1 inhibited glioma cancer-cell growth and motility. Xenograft experiments confirmed that ZEB1-AS1 depletion attenuated tumor growth and metastasis. Dual-luciferase report assay showed that ZEB1-AS1 directly regulated microRNA-200c/141 (miR-200c/141) in glioma cells, which was confirmed by RNA immunoprecipitation assay. Furthermore, the inhibition of miR-200c/141 partially balanced the inhibition effects of cell proliferation and motility induced by ZEB1-AS1 depletion on U87 cells. Additionally, ZEB1-AS1 can regulate ZEB1 through miR-200c/141. Hence, ZEB1-AS1 directly regulated miR-200c/141 in glioma cells and relieved the inhibition of ZEB1 caused by miR-200c/141. Overall, this study revealed a novel regulatory mechanism between ZEB1-AS1 and the miR-200c/141-ZEB1 axis. The interaction between ZEB1-AS1 and miR-200c/141-ZEB1 axis was involved in the progression of glioma cells. Therefore, targeting this interaction was a promising strategy for glioma treatment.

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.

Long Non-Coding RNAs in Gliomas: From Molecular Pathology to Diagnostic Biomarkers and Therapeutic Targets

Gliomas are the most common malignancies of the central nervous system. Because of tumor localization and the biological behavior of tumor cells, gliomas are characterized by very poor prognosis. Despite significant efforts that have gone into glioma research in recent years, the therapeutic efficacy of available treatment options is still limited, and only a few clinically usable diagnostic biomarkers are available. More and more studies suggest non-coding RNAs to be promising diagnostic biomarkers and therapeutic targets in many cancers, including gliomas. One of the largest groups of these molecules is long non-coding RNAs (lncRNAs). LncRNAs show promising potential because of their unique tissue expression patterns and regulatory functions in cancer cells. Understanding the role of lncRNAs in gliomas may lead to discovery of the novel molecular mechanisms behind glioma biological features. It may also enable development of new solutions to overcome the greatest obstacles in therapy of glioma patients. In this review, we summarize the current knowledge about lncRNAs and their involvement in the molecular pathology of gliomas. A conclusion follows that these RNAs show great potential to serve as powerful diagnostic, prognostic, and predictive biomarkers as well as therapeutic targets.

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.

Over-Expressed FEZF1 Predicts a Poor Prognosis in Glioma and Promotes Glioma Cell Malignant Biological Properties by Regulating Akt-ERK Pathway

FEZ family zinc finger 1 (FEZF1) is an essential transcription factor during olfactory development. In gastrointestinal tumors, FEZF1 plays an oncogenic role through DNA demethylation. However, the role of FEZF1 in the prognosis of human glioma prognosis remains unclear. In this research, we discovered that FEZF1 was significantly increased in glioma tissues in contrast to normal brain tissues (NBTs; P < 0.05). Moreover, the expression of FEZF1 showed a significant correlation with Eastern Cooperative Oncology Group performance status, World Health Organization grade, isocitrate dehydrogenase 1 mutation, over-expression of glial fibrillary acidic protein and 1p19q co-deletion. Furthermore, a high level of FEZF1 in patients with glioma acted as an independent biomarker to predict reduced survival (P = 0.026). In an in vitro experiment, FEZF1 can promote the proliferation, migration, and invasion of glioma cells and inhibit cell apoptosis by activating Akt-ERK pathway. All these findings suggest that FEZF1 acts as a key oncogene and predicts a poor prognosis in glioma.

Increased expression of lncRNA ZEB1-AS1 in non-small cell lung cancer is associated with poor prognosis

BACKGROUND

Dysregulated long non-coding RNAs (lncRNAs) play critical roles in tumorigenesis and tumor progression. The purpose of this study was to investigate the relationship between lncRNA ZEB1-AS1 expression and non-small cell lung cancer (NSCLC) clinicopathological characteristics and prognosis.

METHODS

Expression levels of lncRNA ZEB1-AS1 in 183 NSCLC specimens were determined by quantitative real-time PCR (qRT-PCR). To clarify the clinical significance of lncRNA ZEB1-AS1 in NSCLC, we further explored the relationship between lncRNA ZEB1-AS1 expression and overall survival (OS).

RESULTS

In the present study, we found that lncRNA ZEB1-AS1 was upregulated in NSCLC tissues compared to adjacent non-tumor tissues. In addition, upregulated lncRNA ZEB1-AS1 expression was significantly associated with lymph node metastasis and TNM stage (P<0.05). Furthermore, patients with increased expression of lncRNA ZEB1-AS1 had poor OS (HR=3.202, 95% CI=2.018-5.078, P<0.001). Multivariate Cox proportional hazards model analysis demonstrated that high lncRNA ZEB1-AS1 expression was an independent poor prognostic factor for NSCLC patients.

CONCLUSION

Our study suggests that increased expression of lncRNA ZEB1-AS1 is related to adverse prognosis of NSCLC and may be a new prognostic biomarker and potential therapeutic target for NSCLC intervention.

The lncRNA TP73-AS1 promotes ovarian cancer cell proliferation and metastasis via modulation of MMP2 and MMP9

Ovarian cancer is one of the most common gynecologic malignancy with poor prognosis. Recently, long noncoding RNAs (lncRNAs) have been identified as key regulators in cancer development. The current study investigated the role of lncRNA P73 antisense RNA 1T (TP73-AS1) in ovarian cancer. Quantitative real-time polymerase chain reaction determined the expression levels of TP-73AS1, matrix metallopeptidases (MMPs) messenger RNA. Cell proliferative ability, cell invasion, and migration were CCK-8 and colony formation, and transwell invasion and migration assays, respectively. The protein levels of matrix metallopeptidase 2 (MMP2) and MMP9 were measured by Western blot. TP73-AS1 was upregulated in the ovarian cancer tissues and ovarian cancer cells, and upregulation of TP73-AS1 was associated with poor prognosis. Knockdown of TP73-AS1 significantly suppressed cell proliferation, invasion, and migration of SKOV3 cells, and overexpression of TP73-AS1 promoted cell proliferation, invasion, and migration of OVCA429 cells. In addition, knockdown of TP73-AS1 suppressed the in vivo tumor growth. Tumor metastasis RT² profiler polymerase chain reaction array showed that MMP2 and MMP9 was significantly upregulated by TP73-AS1 overexpression in ovarian cancer cells. TP73-AS1 overexpression enhanced the expression of MMP2 and MMP9 in ovarian cancer cells. Knockdown of MMP2 and MMP9 attenuated the effects of TP73-AS1 overexpression on cell invasion and migration. The clinical data showed that MMP2 and MMP9 were upregulated and positively correlated with TP73-AS1 expression in ovarian cancer tissues. Collectively, our results demonstrated the oncogenic role of TP73-AS1 in ovarian cancer, and targeting TP73-AS1 may represent a novel approach in battling against ovarian cancer.

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.

The utility of long non-coding RNA ZEB1-AS1 as a prognostic biomarker in human solid tumors: A meta-analysis

PURPOSE

This meta-analysis aims to assess the prognostic value of long non-coding RNA ZEB1-AS1 in human solid tumors.

METHODS

We searched the available databases up to January 2018. Pooled hazard ratios (HRs) and the corresponding 95% confidence intervals (CIs) were used to examine the prognostic impact of ZEB1-AS1 on patient survival.

RESULTS

Eight eligible studies with a total of 586 patients were enrolled. A significant association was observed between ZEB1-AS1 overexpression and poor overall survival (OS; HR = 2.195, 95% CI: 1.749-2.755) as well as unfavorable recurrence-free survival (pooled HR = 2.205, 95% CI: 1.486-3.270), and no heterogeneity was found across these studies (p = .962, I² = 0%). Subsequent subgroup analyses showed that cancer type, sample size, follow up months, and HR estimation method did not alter the significant prognostic value of ZEB1-AS1. ZEB1-AS1 expression was indicated to be an independent prognostic factor for tumor OS (pooled HR = 2.177, 95% CI:1.545-3.069). Furthermore, we found that increased ZEB1-AS1 expression was significantly associated with tumor stage [III-IV vs. I-II: odds ratio (OR) = 1.644, 95% CI: 1.201-2.249] and lymph node metastasis (Positive vs. Negative: OR = 2.413, 95% CI: 1.504-3.873).

CONCLUSION

High expression level of ZEB1-AS1 was associated with unfavorable survival outcome for cancer patients, and ZEB1-AS1 could be used as a prognostic predictor for cancers.

Long non-coding RNAs: potential molecular biomarkers for gliomas diagnosis and prognosis

The current grade classification system of gliomas is based on the histopathological features of these tumors and has great significance in defining groups of patients for clinical assessment. However, this classification system is also associated with a number of limitations, and as such, additional clinical assessment criteria are required. Long non-coding RNAs (lncRNAs) play a critical role in cellular functions and are currently regarded as potential biomarkers for glioma diagnosis and prognosis. Therefore, the molecular classification of glioma based on lncRNA expression may provide additional information to assist in the systematic identification of glioma. In the present paper, we review the emerging evidence indicating that specific lncRNAs may have the potential for use as key novel biomarkers and thus provide a powerful tool for the systematic diagnosis of glioma.

Novel lnc RNA regulated by HIF-1 inhibits apoptotic cell death in the renal tubular epithelial cells under hypoxia

Chronic tubulointerstitial hypoxia plays an important role as the final common pathway to end-stage renal disease. HIF-1 (hypoxia-inducible factor-1) is a master transcriptional factor under hypoxia, regulating downstream target genes. Genome-wide analysis of HIF-1 binding sites using high-throughput sequencers has clarified various kinds of downstream targets and made it possible to demonstrate the novel roles of HIF-1. Our aim of this study is to identify novel HIF-1 downstream epigenetic targets which may play important roles in the kidney. Immortalized tubular cell lines (HK2; human kidney-2) and primary cultured cells (RPTEC; renal proximal tubular cell lines) were exposed to 1% hypoxia for 24-72 h. We performed RNA-seq to clarify the expression of mRNA and long non-coding RNA (lncRNA). We also examined ChIP-seq to identify HIF-1 binding sites under hypoxia. RNA-seq identified 44 lncRNAs which are up-regulated under hypoxic condition in both cells. ChIP-seq analysis demonstrated that HIF-1 also binds to the lncRNAs under hypoxia. The expression of novel lncRNA, DARS-AS1 (aspartyl-tRNA synthetase anti-sense 1), is up-regulated only under hypoxia and HIF-1 binds to its promoter region, which includes two hypoxia-responsive elements. Its expression is also up-regulated with cobalt chloride exposure, while it is not under hypoxia when HIF-1 is knocked down by siRNA To clarify the biological roles of DARS-AS1, we measured the activity of caspase 3/7 using anti-sense oligo of DARS-AS1. Knockdown of DARS-AS1 deteriorated apoptotic cell death. In conclusion, we identified the novel lncRNAs regulated by HIF-1 under hypoxia and clarified that DARS-AS1 plays an important role in inhibiting apoptotic cell death in renal tubular cells.

Long non-coding RNAs in glioma progression

Glioma is one of most malignant primary tumors of the brain. However, due to a lack of effective means for diagnosing and treating glioma, the prognosis of glioma patients remains poor. Therefore, understanding the molecular mechanism of glioma progression is essential for effective treatment. Long non-coding RNAs (lncRNAs) are novel regulators of gene expression at the transcriptional, post-transcriptional and epigenetic levels. Recent evidence indicates that lncRNAs may play important roles in regulating the progression of glioma. In this article, we review the expression profile of lncRNAs in glioma and discuss the functions and known mechanisms of several representative lncRNAs in detail, as well as the prospects of lncRNAs as diagnostic and prognostic biomarkers and therapeutic targets.

ZEB1-AS1: A crucial cancer-related long non-coding RNA

Long non-coding RNAs (lncRNAs) recently emerge as a novel class of non-coding RNAs (ncRNAs) with larger than 200 nucleotides in length. Due to lack an obvious open reading frame, lncRNAs have no or limited protein-coding potential. To date, accumulating evidence indicates the vital regulatory function of lncRNAs in pathological processes of human diseases, especially in carcinogenesis and development. Deregulation of lncRNAs not only alters cellular biological behavior, such as proliferation, migration and invasion, but also represents the poor clinical outcomes. Zinc finger E-box binding homeobox 1 antisense 1 (ZEB1-AS1), an outstanding cancer-related lncRNA, is identified as an oncogenic regulator in diverse malignancies. Dysregulation of ZEB1-AS1 has been demonstrated to exhibit a pivotal role in tumorigenesis and progression, suggesting its potential clinical value as a promising biomarker or therapeutic target for cancers. In this review, we make a summary on the current findings regarding the biological functions, underlying mechanisms and clinical significance of ZEB1-AS1 in cancer progression.

Long noncoding RNA ZEB1-AS1 predicts an unfavorable prognosis of non-small lung cancer and regulates epithelial to mesenchymal transition through reducing ZEB1 expression

Long non-coding RNAs (lncRNAs) are critical gene regulators with important roles in a wide variety of biological processes, including tumorigenesis. ZEB1-AS1 was significantly increased in NSCLC tissues and cell lines, and its expression levels were highly associated with aggressive tumor progression and poor prognosis. Down-regulation of ZEB1-AS1 suppresses NSCLC cell proliferation and invasion in vitro, as well as inhibits xenograft tumor growth in vivo. Mechanistically, we found that ZEB1-AS1 down-regulation effectively suppressed EMT process through reducing ZEB1 expression, and the ectopic expression of ZEB1 restored the migratory and invasive abilities of NSCLC cells inhibited by ZEB1-AS1 down-regulation. In conclusion, these findings revealed that ZEB1-AS1 plays regulatory roles in NSCLC and it might become a novel molecular indicator of prognosis and therapeutic target in NSCLC.

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

BACKGROUND

ZEB1-AS1 acts as an oncogene in hepatocellular carcinoma, accelerating tumor growth and promoting metastasis. However, its roles in colorectal cancer (CRC) remain unclear.

METHODS

In this study, we determined the expression of ZEB1-AS1 in CRC tissues by quantitative real-time polymerase chain reaction (qRT-PCR). Additionally, we investigated the relationship between various clinicopathological features of CRC patients and ZEB1-AS1 expression, and evaluated the diagnostic and prognostic value of ZEB1-AS1 in CRC.

RESULTS

We found that ZEB1-AS1 expression was significantly higher in CRC tissues than in adjacent normal colorectal tissues. Moreover, its expression was significantly correlated with tumor size, differentiation degree, TNM grade, metastasis, depth of invasion and Dukes' classification, but not with sex, age, location and organization. In addition, at the optimal cutoff value of 2.340, the values of diagnostic sensitivity and specificity amounted to 63.0% and 90.7%, respectively, with an area under the curve (AUC) of 0.846 (95% CI, 0.797-0.895). Finally, CRC patients of the high ZEB1-AS1 expression group had a poorer prognosis and a significantly lower survival rate than those of the low expression group, and Cox regression analysis indicated that ZEB1-AS1 expression and metastasis were independent predictors of poor prognosis.

CONCLUSIONS

Our data suggest that ZEB1-AS1 has no obvious early diagnostic value, but it may be utilized as a new prognostic biomarker for CRC.

LncRNA ZEB1-AS1 predicts unfavorable prognosis in gastric cancer

OBJECTIVES

LncRNA ZEB1 Antisense 1 (ZEB1-AS1) has been suggested to be an oncogenic role in human hepatocellular carcinoma, osteosarcoma, glioma and esophageal carcinoma progression. However, the clinical significance and biological function of ZEB1-AS1 in gastric cancer is poorly understood.

METHODS

Levels of ZEB1-AS1 expression in gastric cancer tissues and cell lines were detected by qRT-PCR. Loss-of-function and gain-of-function studies were conducted to explore the biological function of ZEB1-AS1 in gastric cancer cells migration, invasion and EMT process. Rescued-function studies were performed to explore the association between ZEB1-AS1 and ZEB1 in gastric cancer cells migration, invasion and EMT process.

RESULTS

ZEB1-AS1 was overexpressed in gastric cancer tissues and cell lines, and correlated with malignant status and prognosis in gastric cancer patients. ZEB1-AS1 regulated gastric cancer cells migration, invasion and EMT process. ZEB1-AS1 positively regulated ZEB1 expression in gastric cancer cells, and had a strongly positive correlation with ZEB1 expression in gastric cancer tissues. Rescued-function studies showed ZEB1 was critical for ZEB1-AS1 induced gastric cancer cells migration, invasion and EMT process.

CONCLUSIONS

ZEB1-AS1 served as oncogenic roles in the regulation of gastric cancer cells migration, invasion and EMT process through modulating ZEB1.

Long noncoding RNA ZEB1-AS1 epigenetically regulates the expressions of ZEB1 and downstream molecules in prostate cancer

Background

Emerging studies show that long noncoding RNAs (lncRNAs) play important roles in carcinogenesis and cancer progression. The lncRNA ZEB1 antisense 1 (ZEB1-AS1) derives from the promoter region of ZEB1 and we still know little about its expressions, roles and mechanisms.

Methods

RACE was used to obtain the sequence of ZEB1-AS1. RNA interference was used to decrease ZEB1-AS1 expression. Adenovirus expression vector was used to increase ZEB1-AS1 expression. CHIP and RIP were used to detect the epigenetic mechanisms by which ZEB1-AS1 regulated ZEB1. CCK8 assay, wound healing assay and transwell assay were used to measure proliferation and migration of prostate cancer cells.

Results

In this study, in prostate cancer cells, we found that RNAi-mediated downregulation of ZEB1-AS1 induced significant ZEB1 inhibition while artificial overexpression of ZEB1-AS1 rescued ZEB1 expression, which means that ZEB1-AS1 promotes ZEB1 expression. Also, ZEB1-AS1 indirectly inhibited miR200c, the well-known target of ZEB1, and upregulated miR200c’s target BMI1. Mechanistically, ZEB1-AS1 bound and recruited histone methyltransferase MLL1 to the promoter region of ZEB1, induced H3K4me3 modification therein, and activated ZEB1 transcription. Biologically, ZEB1-AS1 promoted proliferation and migration of prostate cancer cells.

Conclusions

Collectively, ZEB1-AS1 functions as an oncogene in prostate cancer via epigenetically activating ZEB1 and indirectly regulating downstream molecules of ZEB1.

High expression of long non-coding RNA ZEB1-AS1 promotes colorectal cancer cell proliferation partially by suppressing p15 expression

This study aims to investigate the function of long non-coding RNA ZEB1-AS1, reveal its molecular mechanism in colorectal cancer cell growth, and evaluate its clinical significance in colorectal cancer patients. ZEB1-AS1 has reported in the development of several cancers, but the biological role of it in colorectal cancer has not been discussed. In this report, ZEB1-AS1 expression level was measured with quantitative real-time polymerase chain reaction in 63 pairs of colorectal cancer tissues and paired adjacent non-tumor colorectal tissues. The relationship between ZEB1-AS1 expression and overall survival was analyzed by virtue of Kaplan-Meier analysis. Subsequently, small interfering RNA or lentivirus vector-mediated lncRNA ZEB1-AS1 was transfected into colorectal cancer cell lines. Cell viability and apoptosis were examined. Later, nude mouse transplantation experiment was conducted to evaluate the effect of ZEB1-AS1 on colorectal cancer development in vivo. It turns out that ZEB1-AS1 is upregulated in colorectal cancer tissues and its expression is significantly associated with overall survival rate and recurrence-free survival. Upregulation of ZEB1-AS1 colorectal cancer promotes cell proliferation and inhibits cell apoptosis. In addition, cell cycle inhibitory protein p15 participates in the oncogenic function of ZEB1-AS1. Collectively, ZEB1-AS1 has asignificant effect on colorectal cancer pathological process and serves as a valuable prognostic biomarker for colorectal cancer.

microRNA dependent and independent deregulation of long non-coding RNAs by an oncogenic herpesvirus

Kaposi’s sarcoma (KS) is a highly prevalent cancer in AIDS patients, especially in sub-Saharan Africa. Kaposi’s sarcoma-associated herpesvirus (KSHV) is the etiological agent of KS and other cancers like Primary Effusion Lymphoma (PEL). In KS and PEL, all tumors harbor latent KSHV episomes and express latency-associated viral proteins and microRNAs (miRNAs). The exact molecular mechanisms by which latent KSHV drives tumorigenesis are not completely understood. Recent developments have highlighted the importance of aberrant long non-coding RNA (lncRNA) expression in cancer. Deregulation of lncRNAs by miRNAs is a newly described phenomenon. We hypothesized that KSHV-encoded miRNAs deregulate human lncRNAs to drive tumorigenesis. We performed lncRNA expression profiling of endothelial cells infected with wt and miRNA-deleted KSHV and identified 126 lncRNAs as putative viral miRNA targets. Here we show that KSHV deregulates host lncRNAs in both a miRNA-dependent fashion by direct interaction and in a miRNA-independent fashion through latency-associated proteins. Several lncRNAs that were previously implicated in cancer, including MEG3, ANRIL and UCA1, are deregulated by KSHV. Our results also demonstrate that KSHV-mediated UCA1 deregulation contributes to increased proliferation and migration of endothelial cells.

KS is the most prevalent cancer associated with AIDS in sub-Saharan Africa, and is also common in males not affected by AIDS. KSHV manipulates human cells by targeting protein-coding genes and cell signaling. Here we show that KSHV alters the expression of hundreds of human lncRNAs, a broad class of regulatory molecules involved in a variety of cellular pathways including cell cycle and apoptosis. KSHV uses both latency proteins and miRNAs to target lncRNAs. miRNA-mediated targeting of lncRNAs is a novel regulatory mechanism of gene expression. Given that most herpesviruses encode miRNAs, this mechanism might be a common theme during herpesvirus infections. Understanding lncRNA deregulation by KSHV will help decipher the important molecular mechanisms underlying viral pathogenesis and tumorigenesis.

EMT- and MET-related processes in nonepithelial tumors: importance for disease progression, prognosis, and therapeutic opportunities

The epithelial-to mesenchymal (EMT) process is increasingly recognized for playing a key role in the progression, dissemination, and therapy resistance of epithelial tumors. Accumulating evidence suggests that EMT inducers also lead to a gain in mesenchymal properties and promote malignancy of nonepithelial tumors. In this review, we present and discuss current findings, illustrating the importance of EMT inducers in tumors originating from nonepithelial/mesenchymal tissues, including brain tumors, hematopoietic malignancies, and sarcomas. Among these tumors, the involvement of mesenchymal transition has been most extensively investigated in glioblastoma, providing proof for cell autonomous and microenvironment-derived stimuli that provoke EMT-like processes that regulate stem cell, invasive, and immunogenic properties as well as therapy resistance. The involvement of prominent EMT transcription factor families, such as TWIST, SNAI, and ZEB, in promoting therapy resistance and tumor aggressiveness has also been reported in lymphomas, leukemias, and sarcomas. A reverse process, resembling mesenchymal-to-epithelial transition (MET), seems particularly relevant for sarcomas, where (partial) epithelial differentiation is linked to less aggressive tumors and a better patient prognosis. Overall, a hybrid model in which more stable epithelial and mesenchymal intermediates exist likely extends to the biology of tumors originating from sources other than the epithelium. Deeper investigation and understanding of the EMT/MET machinery in nonepithelial tumors will shed light on the pathogenesis of these tumors, potentially paving the way toward the identification of clinically relevant biomarkers for prognosis and future therapeutic targets.

Interplay Between Long Noncoding RNA ZEB1-AS1 and miR-200s Regulates Osteosarcoma Cell Proliferation and Migration

In our previous study, we found long noncoding RNA ZEB1-AS1 is upregulated and functions as an oncogene in osteosarcoma. MiR-200 family (miR-200s) functions as tumor suppressor via directly targeting ZEB1 in various cancers. In this study, we further investigate the potential interplay between ZEB1-AS1, miR-200s, and ZEB1 in osteosarcoma. Our results showed that ZEB1-AS1 functions as a molecular sponge for miR-200s and relieves the inhibition of ZEB1 caused by miR-200s. ZEB1-AS1 and miR-200s reciprocally negatively regulate each other. MiR-200s are downregulated in osteosarcoma tissues, and negatively correlated with ZEB1-AS1 and ZEB1 expression levels in osteosarcoma. Functional experiments showed that consistent with ZEB1-AS1 depletion, miR-200s overexpression and ZEB1 depletion both inhibit osteosarcoma cell proliferation and migration. Overexpression of miR-200s partially abolished the effects of ZEB1-AS1 on osteosarcoma cell proliferation and migration. Moreover, the combination of ZEB1-AS1 depletion and miR-200s overexpression significantly inhibits osteosarcoma cell proliferation and migration. In conclusion, this study revealed a novel regulatory mechanism between ZEB1-AS1, miR-200s, and ZEB1. The interplay between ZEB1-AS1 and miR-200s contributes to osteosarcoma cell proliferation and migration, and targeting this interplay could be a promising strategy for osteosarcoma treatment. J. Cell. Biochem. 118: 2250-2260, 2017. © 2017 Wiley Periodicals, Inc.

Long Non-Coding RNAs: Key Regulators of Epithelial-Mesenchymal Transition, Tumour Drug Resistance and Cancer Stem Cells

Epithelial mesenchymal transition (EMT), the adoption by epithelial cells of a mesenchymal-like phenotype, is a process co-opted by carcinoma cells in order to initiate invasion and metastasis. In addition, it is becoming clear that is instrumental to both the development of drug resistance by tumour cells and in the generation and maintenance of cancer stem cells. EMT is thus a pivotal process during tumour progression and poses a major barrier to the successful treatment of cancer. Non-coding RNAs (ncRNA) often utilize epigenetic programs to regulate both gene expression and chromatin structure. One type of ncRNA, called long non-coding RNAs (lncRNAs), has become increasingly recognized as being both highly dysregulated in cancer and to play a variety of different roles in tumourigenesis. Indeed, over the last few years, lncRNAs have rapidly emerged as key regulators of EMT in cancer. In this review, we discuss the lncRNAs that have been associated with the EMT process in cancer and the variety of molecular mechanisms and signalling pathways through which they regulate EMT, and finally discuss how these EMT-regulating lncRNAs impact on both anti-cancer drug resistance and the cancer stem cell phenotype.

High expression of long noncoding RNA HULC is a poor predictor of prognosis and regulates cell proliferation in glioma

PURPOSE

Emerging studies show that long noncoding RNAs (lncRNAs) have important roles in carcinogenesis. This study investigated the role of lncRNA highly upregulated in liver cancer (HULC) expression in glioma and its clinical significance in glioma patients.

MATERIALS AND METHODS

HULC expression was detected in glioma tissues and cell lines by using real-time quantitative reverse transcription polymerase chain reactions. Association between HULC levels and clinicopathological factors and patients prognosis was also analyzed. Expression of HULC was restored and knocked down in glioma cell line U87 by using HULC cDNA and siRNA, respectively. CCK-8 and colony formation assays were used to investigate the role of HULC in the regulation of proliferation of glioma cells.

RESULTS

HULC was highly expressed in glioma tissues, being closely related to age and grade of glioma. Univariate survival analysis demonstrated that high HULC levels were significantly associated with overall survival (OS) (hazard ratio [HR], 0.422; 95% confidence interval [CI], 0.220-0.806; P=0.009), and it remained an independent predictor for OS (HR, 0.340; 95% CI, 0.175-0.659; P=0.001) in multivariate Cox regression analysis. Functionally, forced expression of HULC results in increased cell proliferation and colony formation of U87 glioma cell line, whereas knockdown of HULC expression reduced these oncogenic properties of glioma cells.

CONCLUSION

These findings suggest that HULC may play an important role in glioma progression and will be further evaluated as a biomarker for predicting the survival of glioma patients.