linc-UBC1 physically associates with polycomb repressive complex 2 (PRC2) and acts as a negative prognostic factor for lymph node metastasis and survival in bladder cancer

Long non-coding RNAs: regulators of autophagy and potential biomarkers in therapy resistance and urological cancers

The non-coding RNAs (ncRNAs) comprise a large part of human genome that mainly do not code for proteins. Although ncRNAs were first believed to be non-functional, the more investigations highlighted tthe possibility of ncRNAs in controlling vital biological processes. The length of long non-coding RNAs (lncRNAs) exceeds 200 nucleotidesand can be present in nucleus and cytoplasm. LncRNAs do not translate to proteins and they have been implicated in the regulation of tumorigenesis. On the other hand, One way cells die is by a process called autophagy, which breaks down proteins and other components in the cytoplasm., while the aberrant activation of autophagy allegedly involved in the pathogenesis of diseases. The autophagy exerts anti-cancer activity in pre-cancerous lesions, while it has oncogenic function in advanced stages of cancers. The current overview focuses on the connection between lncRNAs and autophagy in urological cancers is discussed. Notably, one possible role for lncRNAs is as diagnostic and prognostic variablesin urological cancers. The proliferation, metastasis, apoptosis and therapy response in prostate, bladder and renal cancers are regulated by lncRNAs. The changes in autophagy levels can also influence the apoptosis, proliferation and therapy response in urological tumors. Since lncRNAs have modulatory functions, they can affect autophagy mechanism to determine progression of urological cancers.

The prognostic significance of LncRNA BLACAT1 overexpression in various tumors: a meta-analysis

Objective

Recent studies have revealed increasing evidence that the long non-coding RNA bladder cancer associated transcript 1 (LncRNA BLACAT1) plays an essential role in the emergence of different malignancies. This meta-analysis aimed to evaluate the prognostic significance of LncRNA BLACAT1 in various cancers.

Methods

Six electronic databases (PubMed, Embase, Medline, Web of Science, China National Knowledge Infrastructure (CNKI), and the Chinese WanFang database) were comprehensively searched for relevant studies. The analysis of overall survival (OS) and clinicopathological characteristics was conducted.

Results

Nineteen studies with 1,559 patients were eventually eligible to be included in this meta-analysis. High expression level of LncRNA BLACAT1 was identified to be linked with shorter OS (HR: 2.02, 95% CI: 1.66-2.46, p < 0.001) and PFS (HR: 2.424, 95% CI: 1.827-3.020, p < 0.001) in cancer patients as opposed to low expression levels. Subgroup analysis showed that analysis model (multivariate or univariate), cut-off value (mean or median), sample size (more or fewer than 100), and cancer type had little effect on OS in multiple tumors. Moreover, high LncRNA BLACAT1 expression was associated with positive lymph node metastasis (HR: 2.29, 95% CI: 1.66-3.16, p < 0.00001), advanced clinical stage (HR: 2.29, 95% CI: 1.65-3.19, p < 0.00001) and worse differentiation status (HR: 0.58, 95% CI: 0.37-0.92, p = 0.02), compared to low LncRNA BLACAT1 expression.

Conclusion

The findings highlight that high LncRNA BLACAT1 expression might be detrimental and induce a worse prognosis for cancer patients.

Clinical significance of small nuclear ribonucleoprotein U1 subunit 70 in patients with hepatocellular carcinoma

Background & Aims

Small nuclear ribonucleoprotein U1 subunit 70 (SNRNP70) as one of the components of the U1 small nuclear ribonucleoprotein (snRNP) is rarely reported in cancers. This study aims to estimate the application potential of SNRNP70 in hepatocellular carcinoma (HCC) clinical practice.

Methods

Based on the TCGA database and cohort of HCC patients, we investigated the expression patterns and prognostic value of SNRNP70 in HCC. Then, the combination of SNRNP70 and alpha-fetoprotein (AFP) in 278 HCC cases was analyzed. Next, western blotting and immunohistochemistry were used to detect the expression of SNRNP70 in nucleus and cytoplasm. Finally, Cell Counting Kit-8 (CCK-8) and scratch wound healing assays were used to detect the effect of SNRNP70 on the proliferation and migration of HCC cells.

Results

SNRNP70 was highly expressed in HCC. Its expression was increasingly high during the progression of HCC and was positively related to immune infiltration cells. Higher SNRNP70 expression indicated a poor outcome of HCC patients. In addition, nuclear SNRNP70/AFP combination could be a prognostic biomarker for overall survival and recurrence. Cell experiments confirmed that knockdown of SNRNP70 inhibited the proliferation and migration of HCC cells.

Conclusion

SNRNP70 may be a new biomarker for HCC progression and HCC diagnosis as well as prognosis. SNRNP70 combined with serum AFP may indicate the prognosis and recurrence status of HCC patients after operation.

Identification of necroptosis-related long non-coding RNAs prognostic signature and the crucial lncRNA in bladder cancer

BACKGROUND

Research on the relationships between long non-coding RNAs (lncRNAs) and cancer is attractive and has progressed very rapidly. Necroptosis-related biomarkers can potentially be used for predicting the prognosis of cancer patients. This study aimed to establish a necroptosis-related lncRNA (NPlncRNA) signature to predict the prognosis of patients with bladder cancer (BCa).

METHODS

First, NPlncRNAs were identified using Pearson correlation analysis and machine learning algorithms, including SVM-RFE, least absolute shrinkage and selection operator (LASSO) regression, and random forest. The prognostic NPlncRNA signature was constructed using univariate and multivariate Cox regression analyses and the diagnostic efficacy and clinically predictive efficiency were evaluated and validated. The biological functions of the signature were analysed using gene set enrichment analysis (GSEA) and functional enrichment analysis. We further integrated the RNA-seq dataset (GSE133624) with our outcomes to reveal the crucial NPlncRNA that was functionally verified by assessing cell viability, proliferation, and apoptosis in BCa cells.

RESULTS

The prognostic NPlncRNAs signature was composed of PTOV1-AS2, AC083862.2, MAFG-DT, AC074117.1, AL049840.3, and AC078778.1, and a risk score based on this signature was proven to be an independent prognostic factor for the BCa patients, indicated by poor overall survival (OS) of patients in the high-risk group. Additionally, the NPlncRNAs signature had a higher diagnostic validity than that of other clinicopathological variables, with a greater area under the receptor operating characteristic and concordance index curves. A nomogram established by integrating clinical variables and risk score confirmed that the signature can accurately predict the OS of patients and has high clinical practicability. Functional enrichment analysis and GSEA revealed that some cancer-related and necroptosis-related pathways were enriched in high-risk groups. The crucial NPlncRNA MAFG-DT was associated with poor prognosis and was highly expressed in BCa cells. MAFG-DT silencing notably inhibited proliferation and enhanced apoptosis of BCa cells.

CONCLUSIONS

A novel prognostic NPlncRNAs signature was identified in BCa in this study, which provides potential therapeutic targets among which MAFG-DT plays critical roles in the tumorigenesis of BCa.

Lnc-ing epigenetic mechanisms with autophagy and cancer drug resistance

Long noncoding RNAs (lncRNAs) comprise a diverse class of RNA molecules that regulate various physiological processes and have been reported to be involved in several human pathologies ranging from neurodegenerative disease to cancer. Therapeutic resistance is a major hurdle for cancer treatment. Over the past decade, several studies has emerged on the role of lncRNAs in cancer drug resistance and many trials have been conducted employing them. LncRNAs also regulate different cell death pathways thereby maintaining a fine balance of cell survival and death. Autophagy is a complex cell-killing mechanism that has both cytoprotective and cytotoxic roles. Similarly, autophagy can lead to the induction of both chemosensitization and chemoresistance in cancer cells upon therapeutic intervention. Recently the role of lncRNAs in the regulation of autophagy has also surfaced. Thus, lncRNAs can be used in cancer therapeutics to alleviate the challenges of chemoresistance by targeting the autophagosomal axis. In this chapter, we discuss about the role of lncRNAs in autophagy-mediated cancer drug resistance and its implication in targeted cancer therapy.

Urinary BLACAT1 as a non-invasive biomarker for bladder cancer

BACKGROUND

Bladder cancer (BC) is recorded as the fifth most common cancer worldwide with high morbidity and mortality. The most urgent problem in BCs is the high recurrence rate as two-thirds of non-muscle-invasive bladder cancer (NMIBC) will develop into muscle-invasive bladder cancer (MIBC), which retains a feature of rapid progress and metastasis. In addition, only a limited number of biomarkers are available for diagnosing BC compared to other cancers. Hence, finding sensitive and specific biomarkers for predicting the diagnosis and prognosis of patients with BC is critically needed. Therefore, this study aimed to determine the expression and clinical significance of urinary lncRNA BLACAT1 as a non-invasively diagnostic and prognostic biomarker to detect and differentiate BCs stages.

METHODS AND RESULTS

The expression levels of urinary BLACAT1 were detected by qRT-PCR assay in seventy (70) BC patients with different TNM grades (T0-T3) and twelve (12) healthy subjects as control. BLACAT1 was downregulated in superficial stages (T0 = 0.09 ± 0.02 and T1 = 0.5 ± 0.1) compared to healthy control. Furthermore, in the invasive stages, its levels started to elevate in the T2 stage (1.2 ± 0. 2), and higher levels were detected in the T3 stage with a mean value of (5.2 ± 0.6). This elevation was positively correlated with disease progression. Therefore, BLACAT1 can differentiate between metastatic and non-metastatic stages of BCs. Furthermore, its predictive values are not like to be influenced by schistosomal infection.

CONCLUSIONS

Upregulation of BLACAT1 in invasive stages predicted an unfavorable prognosis for patients with BCs, as it contributes to the migration and metastasis of BCs. Therefore, we can conclude that urinary BLACAT1 may be considered a non-invasive promising metastatic biomarker for BCs.

An Integrated Bioinformatics Analysis towards the Identification of Diagnostic, Prognostic, and Predictive Key Biomarkers for Urinary Bladder Cancer

Simple Summary

Bladder cancer is evidently a challenge as far as its prognosis and treatment are concerned. The investigation of potential biomarkers and therapeutic targets is indispensable and still in progress. Most studies attempt to identify differential signatures between distinct molecular tumor subtypes. Therefore, keeping in mind the heterogeneity of urinary bladder tumors, we attempted to identify a consensus gene-related signature between the common expression profile of bladder cancer and control samples. In the quest for substantive features, we were able to identify key hub genes, whose signatures could hold diagnostic, prognostic, or therapeutic significance, but, primarily, could contribute to a better understanding of urinary bladder cancer biology.

Abstract

Bladder cancer (BCa) is one of the most prevalent cancers worldwide and accounts for high morbidity and mortality. This study intended to elucidate potential key biomarkers related to the occurrence, development, and prognosis of BCa through an integrated bioinformatics analysis. In this context, a systematic meta-analysis, integrating 18 microarray gene expression datasets from the GEO repository into a merged meta-dataset, identified 815 robust differentially expressed genes (DEGs). The key hub genes resulted from DEG-based protein–protein interaction and weighted gene co-expression network analyses were screened for their differential expression in urine and blood plasma samples of BCa patients. Subsequently, they were tested for their prognostic value, and a three-gene signature model, including COL3A1, FOXM1, and PLK4, was built. In addition, they were tested for their predictive value regarding muscle-invasive BCa patients’ response to neoadjuvant chemotherapy. A six-gene signature model, including ANXA5, CD44, NCAM1, SPP1, CDCA8, and KIF14, was developed. In conclusion, this study identified nine key biomarker genes, namely ANXA5, CDT1, COL3A1, SPP1, VEGFA, CDCA8, HJURP, TOP2A, and COL6A1, which were differentially expressed in urine or blood of BCa patients, held a prognostic or predictive value, and were immunohistochemically validated. These biomarkers may be of significance as prognostic and therapeutic targets for BCa.

Comprehensive analysis of autophagy related long non-coding RNAs in prognosis, immunity, and treatment of muscular invasive bladder cancer

To predict disease outcome in muscle-invasive bladder cancer (MIBC), we constructed a prognostic autophagy-related (PAR) lncRNA signature. Comprehensive bioinformatics analyses were performed using data from TCGA and GTEx databases. Univariate Cox, and least absolute shrinkage and selection operator regression analyses were also performed, based on differentially expressed genes, to identify PAR-related lncRNAs to establish the signature. Furthermore, the Kaplan–Meier OS curve and receiver operating characteristic curve analyses were performed and a nomogram was constructed, all of which together confirmed the strong predictive ability of the constructed signature. Patients with MIBC were then divided into high- and low-risk groups. Gene enrichment and immune infiltration analyses revealed the potential mechanisms in MIBC. We also further evaluated the signature of molecules related to immune checkpoints and the sensitivity toward chemotherapeutic agents and antitumor-targeted drugs to find better treatment prescriptions. We identified a number of PAR-related lncRNA signatures, including HCP5, AC024060.1, NEAT1, AC105942.1, XIST, MAFG-DT, and NR2F1-AS1, which could be valuable prognostic tools to develop more efficient, individualized drug therapies for MIBC patients.

Long noncoding RNA AK023096 interacts with hnRNP-K and contributes to the maintenance of self-renewal in bladder cancer stem-like cells

LncRNA contribution to self-renewal of bladder cancer stem-like cells (CSLCs) remains largely unknown. We investigated the expression profile and biological function of lncRNAs in urothelial CSLCs by microarray analysis. Among these, lncRNA-AK023096 was identified as potentially playing a role in maintaining self-renewal of CSLCs. Knockdown of this transcript inhibited spheroid formation and tumor formation. We found that AK023096 mediates recruitment of hnRNP-K to SOX2 promoter and increases H3K4 trimethylation status on SOX2 promoter, leading to a robust change in SOX2 mRNA and protein levels. Moreover, AK023096 expression in primary tumors was found to be a powerful predictor of recurrence following transurethral resection in patients with nonmuscle-invasive bladder cancer, highlighting the critical role of lncRNA in the bladder cancer regulatory network.

lncRNA ADAMTS9-AS1 promotes bladder cancer cell invasion, migration, and inhibits apoptosis and autophagy through PI3K/AKT/mTOR signaling pathway

Bladder cancer is the most common cancer in the urinary system which has threatened lives. Increasing evidence has shown that lncRNAs were expressed in cancer cells as a biomarker and might regulate cancer cell development and progression. It was reported that ADAMTS9-AS1 plays a suppressive role in tumor cell growth and proliferation in prostate cancer. However, it remains unclear whether ADAMTS9-AS1 influences the function of bladder cancer cells. In this study, we detected that ADAMTS9-AS1 is highly expressed in bladder cancer. We observed that the up-regulation of ADAMTS9-AS1 promoted cell proliferation, migration and invasion, and reduced the apoptosis and autophagy of 5637 and T42 cell lines. Meanwhile, the down-regulation of ADAMTS9-AS1 increased the apoptosis and autophagy, and suppressed their proliferation, migration and invasion. Interestingly, the up-regulation of ADAMTS9-AS1 was accompanied by the activation of PI3K/AKT/mTOR signaling pathway, while the down-regulation of ADAMTS9-AS1 lead to an opposite effect. Together, these results demonstrated that ADAMTS9-AS1 promotes bladder cancer cell invasion and migration, and negatively regulates bladder cancer cell apoptosis and autophagy, which might be through PI3K/AKT/mTOR signaling pathway. Targeting ADAMTS9-AS1 might become a potential therapeutic approach in treating bladder cancer.

Role of hypermethylated-lncRNAs in the prognosis of bladder cancer patients

OBJECTIVE

To explore the hypermethylated long non-coding (lnc)RNAs involved in bladder carcinogenesis and prognosis.

METHODS

Reduced representation bisulfite sequencing and RNA sequencing were performed on five paired tumor and adjacent normal tissue samples from bladder cancer patients. The differentially methylated regions around transcription start sites and differentially expressed genes, including lncRNAs, were analyzed. Correlations between DNA methylation modifications and the expression of lncRNAs were examined. Survival analysis was surveyed on the GEPIA web server.

RESULTS

We identified 19,560 hypomethylated and 68,781 hypermethylated differentially methylated regions around transcription start sites in bladder cancer tissues. In total, 2321 differentially expressed genes were found in bladder tumors, among which, 367 were upregulated and 1954 were downregulated. There were 141 downregulated genes involving eight lncRNAs that were consistently hypermethylated, while 24 upregulated genes were consistently hypomethylated. Survival analysis demonstrated that hypermethylation of lncRNAs LINC00683 and MSC-AS1 were associated with poor overall survival in bladder cancer patients.

CONCLUSION

Some lncRNAs are controlled by DNA methylation in bladder cancer and they might be important factors in bladder carcinogenesis. Hypermethylated lncRNAs including LINC00683 and MSC-AS1 have the potential to be prognostic biomarkers for bladder cancer.

Role of Long Non-coding RNAs on Bladder Cancer

Bladder cancer (BC) is the most common malignant tumor in the urinary system, and its early diagnosis is conducive to improving clinical prognosis and prolonging overall survival time. However, few biomarkers with high sensitivity and specificity are used as diagnostic markers for BC. Multiple long non-coding RNAs (lncRNAs) are abnormally expressed in BC, and play key roles in tumorigenesis, progression and prognosis of BC. In this review, we summarize the expression, function, molecular mechanisms and the clinical significance of lncRNAs on bladder cancer. There are more than 100 dysregulated lncRNAs in BC, which are involved in the regulation of proliferation, cell cycle, apoptosis, migration, invasion, metabolism and drug resistance of BC. Meanwhile, the molecular mechanisms of lncRNAs in BC was explored, including lncRNAs interacting with DNA, RNA and proteins. Additionally, the abnormal expression of thirty-six lncRNAs is closely associated with multiple clinical characteristics of BC, including tumor size, metastasis, invasion, and drug sensitivity or resistance of BC. Furthermore, we summarize some potential diagnostic and prognostic biomarkers of lncRNA for BC. This review provides promising novel biomarkers in early diagnosis, prognosis and monitoring of BC based on lncRNAs.

LncRNA BLACAT1 Accelerates Non-small Cell Lung Cancer Through Up-Regulating the Activation of Sonic Hedgehog Pathway

Recently, increasing evidence has displayed that lncRNAs can exhibit crucial function in cancer progression, including lung cancer. LncRNA bladder cancer-associated transcript 1 (BLACAT1) is reported to participate in various cancers. The aim of our current study was to investigate the function of BLACAT1 in non-small cell lung cancer progression and study the functional pathway. Here, we reported BLACAT1 was significantly up-regulated in lung cancer tissues in comparison to the adjacent normal tissues, which suggested BLACAT1 might act as an oncogene in lung cancer. Then, A549 and PC9 cells were infected with BLACAT1 overexpression plasmid and shRNA. As shown, we proved up-regulation of BLACAT1 greatly induced the growth of non-small cell lung cancer cells. Reversely, knockdown of BLACAT1 reduced A549 and PC9 cell proliferation, migration and invasion. Sonic hedgehog (shh) signaling is able to exert a significant role in carcinogenesis, including lung cancer. Currently, we proved that up-regulation of BLACAT1 activated shh signaling pathway, via inducing shh, Gli-1 and Smo expression. shh pathway inhibitor GANT-61 reversed the effect of overexpression of BLACAT1 on non-small cell lung cancer. Moreover, we manifested that loss of BLACAT1 remarkably reduced the in vivo growth and metastasis of A549 cells via enhancing infiltrating CD3+ T cells. In conclusion, our research revealed a critical role of BLACAT1 in the modulation of non-small cell lung cancer via modulating shh pathway.

LncRNA DANCR regulates lymphatic metastasis of bladder cancer via the miR-335/VEGF-C axis

Background

Substantial evidence indicate that long non-coding RNA (lncRNA) and microRNA (miRNA) act as key role in bladder cancer. Differentiation antagonistic ncRNA (DANCR) could be used as a biomarker in the occurrence and development of cancer. This study aims to explore the mechanism of DANCR/miR-335/VEGF-C axis affecting lymphatic metastasis of bladder cancer.

Methods

qRT-PCR detects the expression of DANCR in bladder cancer cell lines (SW780, 5637, T24, UM-UC-3) and normal bladder cell lines (SV-HUC-1), and selects T24 cell lines for subsequent experiments. The expression levels of DANCR, miR-335 and VEGF were measured by qRT-PCR, and the dual luciferase reporter gene verified the targeted regulation of DANCR on miR-335 and miR-335 on VEGF. CCK-8, Transwell and Wound healing assay detect the proliferation, invasion and migration ability of bladder cancer cells, Endothelial cell adhesion assay and Western blot further prove the lymphatic metastasis of bladder cancer.

Results

In this study, DANCR was highly expressed in bladder cancer cell lines. Transfection of si-DANCR significantly inhibits the proliferation, migration, invasion and lymphatic metastasis of bladder cancer cells. Dual luciferase assay confirmed that DANCR targets miR-335/VEGF-C. Transfection of miR-335 mimic promotes the proliferation, migration, invasion and lymphatic metastasis of bladder cancer cells, overexpression of DANCR eliminates the promotion of miR-335 mimic on bladder cancer cells. Further experiments proved that inhibition of miR-335 and overexpression of VEGF-C can reverse the inhibitory effect of silencing DANCR on bladder cancer cells.

Conclusions

In bladder cancer, DARCR plays an important role, which regulates the proliferation, migration, invasion and lymphatic metastasis of bladder cancer cells through the miR-335/VEGF-C molecular axis.

Lymphatic metastasis of bladder cancer: Molecular mechanisms, diagnosis and targeted therapy

Bladder cancer is the most common and lethal cancer of the urinary system. Lymphatic metastasis is the primary and main metastatic type of bladder cancer, leading to an extremely poor prognosis in patients. Therefore, a better understanding of molecular mechanisms may provide potential targets for the diagnosis and treatment of lymphatic metastasis in bladder cancer. Herein, we summarize the current knowledge of molecular mechanisms of the lymphatic metastasis in bladder cancer, including lymphangiogenesis and its regulators, noncoding RNAs, and microenvironment-associated molecules. Novel radiomics and genomics approaches have substantially improved the preoperative diagnostic accuracy of lymph node metastasis in patients with bladder cancer. Newly discovered targets may lead to promising therapeutic strategies for clinical intervention in lymphatic metastasis of bladder cancer. More basic and translational studies need to be conducted to further clarify the molecular mechanisms, and identify predictive markers and therapeutic targets of lymphatic metastasis for bladder cancer patients.

Crosstalk of long non-coding RNAs and EMT: Searching the missing pieces of an incomplete puzzle for lung cancer therapy

BACKGROUND

Lung cancer is considered to be the first place among the cancer-related deaths worldwide and demands novel strategies in the treatment of this life-threatening disorder. The aim of this review is to explore regulation of epithelial-to-mesenchymal transition (EMT) by long non-coding RNAs (lncRNAs) in lung cancer.

INTRODUCTION

LncRNAs can be considered as potential factors for targeting in cancer therapy, since they regulate a bunch of biological processes, e.g. cell proliferation, differentiation and apoptosis. The abnormal expression of lncRNAs occurs in different cancer cells. On the other hand, epithelial-to-mesenchymal transition (EMT) is a critical mechanism participating in migration and metastasis of cancer cells.

METHOD

Different databases including Googlescholar, Pubmed and Sciencedirect were used for collecting articles using keywords such as "LncRNA", "EMT", and "Lung cancer".

RESULT

There are tumor-suppressing lncRNAs that can suppress EMT and metastasis of lung cancer cells. Expression of such lncRNAs undergoes down-regulation in lung cancer progression and restoring their expression is of importance in suppressing lung cancer migration. There are tumor-promoting lncRNAs triggering EMT in lung cancer and enhancing their migration.

CONCLUSION

LncRNAs are potential regulators of EMT in lung cancer, and targeting them, both pharmacologically and genetically, can be of importance in controlling migration of lung cancer cells.

Long-Chain Noncoding RNA ADAMTS9-AS2 Regulates Proliferation, Migration, and Apoptosis in Bladder Cancer Cells Through Regulating miR-182-5p

The long-chain noncoding RNA ADAMTS9-AS2 functions as a tumor suppressor gene in many cancers. However, the underlying mechanism remains to be fully elucidated in bladder cancer (BC). ADAMTS9-AS2 exhibited a lower expression level in BC samples and cell lines. In addition, overexpression of ADAMTS9-AS2 obviously suppressed proliferation and migration, and induced apoptosis of T24 cells, while transfection with the ADAMTS9-AS2 inhibitor had opposite results in 5637 cells. Furthermore, miR-182-5p was the target microRNA of ADAMTS9-AS2 and was negatively correlated with ADAMTS9-AS2 expression. Upregulation of miR-182-5p reversed the effects of ADAMTS9-AS2 overexpression on biological function in T24 cells. ADAMTS9-AS2 was a tumor suppressor that inhibited BC cell proliferation and induced cellular apoptosis by targeting miR-182-5p, and it could be a promising target for BC treatment.

A systematic review and meta-analysis of long noncoding RNA linc-UBC1 expression and prognosis and clinicopathological phenotypes in human cancers

According to previous studies, linc-UBC1 is abnormally expressed in various human tumours. Nonetheless, the clinical significance and mechanism of linc-UBC1 in cancer remains unclear. In our present analysis, we wanted to explore the specific role of linc-UBC1 in malignant tumours by integrating all of the relevant literature and subsequently elucidating the relationship between linc-UBC1 expression level and clinical characteristics of cancers. An elaborate database search of PubMed, Embase, Wanfang Data, Web of Science, Ovid, Medline, Cochrane Library and PMC was carried out up to 8 August 2019. We further applied the pooled odds ratio (OR) and hazard ratio (HR) to evaluate OS. After filtering by strict criteria, 11 studies containing 1017 cases were included in this analysis. Our results implied that high expression of linc-UBC1 was obviously related to poor OS in cancer (HR =1.735, 95% 1.348-2.235, p < .001 random effects model). Analogously, the data revealed that high expression of linc-UBC1 was highly correlated with lymph node metastasis (OR = 2.912, 95% CI: 2.056-4.125, p < .001 fix effects model) and high tumour stage (OR = 2.678, 95% CI: 1.859-3.857, p < .001 fix effects model). In summary, linc-UBC1 overexpression is associated with poor OS and advanced tumour stage and could be used as a novel prognostic biomarker in various cancers.

LINC00460 Enhances Bladder Carcinoma Cell Proliferation and Migration by Modulating miR-612/FOXK1 Axis

INTRODUCTION

LincRNA (long intergenic noncoding RNA) has been indicated as a mediator in tumorigenesis of bladder carcinoma. This study was performed to evaluate the role of LINC00460 in bladder carcinoma progression.

METHODS

Expression levels of LINC00460 in bladder carcinoma tissues and cell lines were analyzed via qRT-PCR. MTT, EdU (5-ethynyl-2'-deoxyuridine) staining, and colony formation assays were utilized to evaluate cell viability and proliferation. The wound healing assay was performed to evaluate bladder cancer cell migration, and the transwell assay was used to evaluate cell invasion. The microRNA (miRNA) target of LINC00460 and the corresponding target gene were validated via the dual luciferase activity assay. The tumorigenic function of LINC00460 was determined via establishment of a xenotransplanted tumor model.

RESULTS

LINC00460 was elevated in bladder carcinoma tissues and cell lines. Elevated LINC00460 was associated with shorter overall survival of bladder carcinoma patients. Overexpression of LINC00460 promoted cell viability, proliferation, invasion, and migration, while silencing of LINC00460 indicated the opposite effect on bladder carcinoma progression. LINC00460 could directly bind to miR-612 and inhibit miR-612 expression. Moreover, LINC00460 expression was negatively correlated with miR-612 in patients with bladder carcinoma. FOXK1 (Forkhead Box K1) was identified as the target of miR-612 and upregulated in patients with bladder carcinoma. Overexpression of FOXK1 attenuated interference of LINC00460-inhibited bladder carcinoma progression. Knockdown of LINC00460 suppressed in vivo bladder carcinoma growth.

CONCLUSIONS

LINC00460 promoted bladder carcinoma progression via sponging miR-612 to facilitate FOXK1 expression, suggesting that LINC00460 might have the potential of being explored as a therapeutic target for treatment of bladder carcinoma.

Regulating Methylation at H3K27: A Trick or Treat for Cancer Cell Plasticity

Properly timed addition and removal of histone 3 lysine 27 tri-methylation (H3K27me3) is critical for enabling proper differentiation throughout all stages of development and, likewise, can guide carcinoma cells into altered differentiation states which correspond to poor prognoses and treatment evasion. In early embryonic stages, H3K27me3 is invoked to silence genes and restrict cell fate. Not surprisingly, mutation or altered functionality in the enzymes that regulate this pathway results in aberrant methylation or demethylation that can lead to malignancy. Likewise, changes in expression or activity of these enzymes impact cellular plasticity, metastasis, and treatment evasion. This review focuses on current knowledge regarding methylation and de-methylation of H3K27 in cancer initiation and cancer cell plasticity.

LncRNAs: Potential Novel Prognostic and Diagnostic Biomarkers in Colorectal Cancer

BACKGROUND

Long non-coding RNAs (lncRNAs), a type of regulatory RNAs, play a key role in numerous cellular pathways. Ectopic expression of this group of non-coding RNAs has been specified to be involved in numerous diseases. Moreover, the role of lncRNAs in the initiation and development of cancers including colorectal cancer (CRC) has been acknowledged.

OBJECTIVE

In the present review, the role of lncRNAs as prognostic and diagnostic biomarkers in CRC as well as the molecular mechanisms of their contribution to development of CRC has been addressed.

RESULTS

The presented studies have indicated the ectopic expression of various lncRNAs in CRC. Some lncRNAs which were considered as tumor suppressors were downregulated in the colorectal cancerous tissues compared with healthy controls; however, some with oncogenic effects were upregulated. LncRNAs contribute to tumor development via various molecular mechanisms such as epigenetically controlling the expression of target genes, interacting with miRNAs as their sponge, etc. Conclusion: LncRNAs that have been recognized as prognostic biomarkers may pave the way for clinical management to offer adjuvant treatments for patients with CRC.

Long Non-Coding RNA BLACAT1 in Human Cancers

Long non-coding RNAs (lncRNAs) are a cluster of RNAs with more than 200 nucleotides in length, which lack protein-coding capacity. They are important regulators of numerous cellular processes, including gene transcription, translation, and posttranslational modification, especially in tumor initiation and progression. Aberrant expression of lncRNA bladder cancer-associated transcript 1 (BLACAT1) has been reported in various human cancers and was usually associated with unfavorable prognosis. Previous studies have revealed that dysregulation of BLACAT1 could promote the proliferation and metastasis of cancer cells. In this review, we summarize the present understanding of the functions and underlying mechanisms of BLACAT1 in the occurrence and development of various human cancers and discuss the roles of this lncRNA in cancers, including its promising application as a prognostic biomarker or a novel therapeutic target for malignancies.

Down-regulation of lncRNA BLACAT1 inhibits ovarian cancer progression by suppressing the Wnt/β-catenin signaling pathway via regulating miR-519d-3p

Ovarian cancer has the highest mortality in gynecologic malignancies. LncRNA BLACAT1 serves crucial functions in various cancers, but its role in ovarian cancer has not been investigated. In this article, our team explored the role and the potential regulatory mechanism of BLACAT1 in ovarian cancer. Quantitative RT-PCR showed that BLACAT1 was aberrantly up-regulated in ovarian cancer tissues compared with normal tissues. In vitro, BLACAT1 knockdown induced cell cycle arrest and inhibited the proliferation, migration and invasion of ovarian cancer cells using flow cytometry, MTT and EdU assays, wound healing assay and transwell assay, respectively. Luciferase assay verified the binding relationship between microRNA-519d-3p and lncRNA BLACAT1, and BLACAT1 negatively regulated the expression of miR-519d-3p. We also found that miR-519d-3p overexpression could inhibit ovarian cancer cells proliferation, migration and invasion. Further, Western blot demonstrated that the expression of RPS15A and nuclear β-catenin expression was markedly reduced by BLACAT1 knockdown, and cytoplasmic β-catenin level was not obviously affected. In vivo, BLACAT1 knockdown inhibited the tumor growth, and immunohistochemistry showed that ki67 expression was decreased by BLACAT1 suppression. Inhibition of BLACAT1 was sufficient to down-regulate the expression of RPS15A and nuclear β-catenin but did not cause an obvious change in cytoplasmic β-catenin expression. Taken together, BLACAT1 knockdown inhibited the progression of ovarian cancer by suppressing the Wnt/β-catenin signaling pathway via regulating miR-519d-3p. Our work provided a proper understanding of the critical roles of BLACAT1 in ovarian cancer.

Long non-coding RNA in bladder cancer

Bladder cancer (BC) is the ninth most common malignant disease and ranks fourteenth in cancer mortality worldwide. Moreover, among cancers, the incidence and mortality of BC in males increased to the 6th and 9th place, respectively. The overall survival (OS) declines dramatically as the cancer progresses, especially when urothelial cells transition from noninvasive to invasive. It is well known that epithelial cells can acquire invasive properties and a propensity to metastasize through the epithelial-to-mesenchymal transition (EMT) process in tumourigenesis and progression. However, the potential molecular mechanisms and key pathways are still unclear. As the sequencing technology advances, long non-coding RNAs (lncRNAs) have been proven to play an important role in regulating biological processes and cellular pathways. Here, we reviewed important lncRNAs, such as H19, UCA1 and MALAT1, that participate in the malignant phenotype of BC and regulate EMT signalling networks in the invasion-metastasis cascade during BC development. We further discuss MALAT1, PCAT-1 and SPRY4-IT1, and also urine and blood exosomal H19 and PTENP as potential noninvasive biomarkers. Moreover, antisense oligonucleotides (ASOs) and a double-stranded DNA plasmid (BC-819) have been designed for use in preclinical cancer models and clinical trials in patients. Therefore, the results of investigations have gradually prompted the utility of lncRNAs.

Mechanism of long noncoding RNAs as transcriptional regulators in cancer

Dysregulation of gene expression, often interpreted by gene transcription as an endpoint response, is tightly associated with human cancer. Long noncoding RNAs (lncRNAs), derived from the noncoding elements in the genome and appeared no less than 200nt in length, have emerged as a novel class of pivotal regulatory component. Recently, great attention has been paid to the cancer-related lncRNAs and growing evidence have shown that lncRNAs act as key transcriptional regulators in cancer cells through diverse mechanisms. Here, we focus on the nucleus-expressed lncRNAs and summarize their molecular mechanisms in transcriptional control during tumorigenesis and cancer metastasis. Six major mechanisms will be discussed in this review: association with transcriptional factor, modulating DNA methylation or histone modification enzyme, influencing on chromatin remodelling complex, facilitating chromosomal looping, interaction with RNA polymerase and direct association with promoter.

LncRNAs act as prognostic biomarkers in bladder carcinoma: A meta-analysis

Background and purpose

Increasing studies have shown that different kinds of lncRNAs play key role in the development of multiple carcinomas. Therefore, we conducted a meta-analysis to investigate an association between the expression level of lncRNAs and the prognosis of bladder cancer (death or other clinical outcomes).

Methods

A systematic literature search was performed by using PubMed. Twenty-four studies were included in the meta-analysis based on the inclusion and exclusion criteria. In total, there are 1652 independent participants.

Results

The result showed that high expression levels of lncRNAs were demonstrated to be associated with poor overall survival (OS) (HR = 2.33, 95%CI: 1.51–2.39, p < 0.01) in bladder carcinoma, but there was no significant correlation between lncRNAs level and recurrence-free survival (RFS) (pooled HR = 1.57, 95%CI 0.69–3.56, p = 0.284), and progression-free survival (PFS) (pooled HR = 1.37, 95%CI 0.79–2.38, p = 0.269). Additionally, increased lncRNAs expression was found to be moderately correlated with tumor stage and progression (II/III/IV vs. I, OR = 3.20, 95%CI: 1.72–5.98, p < 0.001). In addition, elevated lncRNAs expression predicted lymph node metastasis (LNM) significantly (pooled OR = 2.29, 95 % CI 1.33–3.95, p < 0.01). No significant heterogeneity was observed among studies except lymph node metastasis.

Conclusion

In conclusion, high expression levels of lncRNAs were demonstrated to be associated with poor OS and positive LNM, and lncRNAs might be potential prognostic markers in bladder cancer.

Communication Of Cancer Cells And Lymphatic Vessels In Cancer: Focus On Bladder Cancer

Bladder cancer is one of the most commonly diagnosed cancers worldwide and causes the highest lifetime treatment costs per patient. Bladder cancer is most likely to metastasize through lymphatic ducts, and once the lymph nodes are involved, the prognosis is poorly and finitely improved by current modalities. The underlying metastatic mechanism for bladder cancer is thus becoming a research focus to date. To identify relevant published data, an online search of the PubMed/Medline archives was performed to locate original articles and review articles regarding lymphangiogenesis and lymphatic metastasis in urinary bladder cancer (UBC), and was limited to articles in English published between 1998 and 2018. A further search of the clinical trials.gov search engine was conducted to identify both trials with results available and those with results not yet available. Herein, we summarized the unique mechanisms and biomarkers involved in the malignant progression of bladder cancer as well as their emerging roles in therapeutics, and that current data suggests that lymphangiogenesis and lymph node invasion are important prognostic factors for UBC. The growing knowledge about their roles in bladder cancers provides the basis for novel therapeutic strategies. In addition, more basic and clinical research needs to be conducted in order to identify further accurate predictive molecules and relevant mechanisms.

LINC00628 suppresses migration and invasion of hepatocellular carcinoma by its conserved region interacting with the promoter of VEGFA

Accumulated evidence revealed that numerous long noncoding RNAs (lncRNAs) have been found to be involved in the development and progression of hepatocellular carcinoma (HCC). LINC00628, a member of lncRNAs, has been reported to act as a tumor suppressor in gastric cancer and breast cancer. However, its potential role in HCC still remains unknown. Herein, we characterized the function of LINC00628 in HCC. Our investigation has revealed that LINC00628 were dramatically decreased in HCC tissues and cells, and inhibited the migration and invasion of HCC cells in vitro and in vivo. Moreover, LINC00628 exerted its tumor suppressive function by repressing the vascular endothelial growth factor A (VEGFA) promoter activity. A highly conserved region element in LINC00628 was identified by a cross-species comparative analysis, which is required for LINC00628 exerted its function. Dual-luciferase reporter assay showed that the conserved sequence mediated the interaction with a specific region of VEGFA promoter, resulting in a decrease of VEGFA expression. In conclusion, our results demonstrated that LINC00628 could function as a tumor suppressor in HCC via its conserved sequence elements interacting with a particular region of VEGFA promoter, suggesting that LINC00628 may serve as a novel promising target for diagnosis and therapy in HCC.

Long noncoding RNAs in bladder cancer prognosis: A meta-analysis

BACKGROUND

Numerous studies have demonstrated the involvement of long non-coding RNAs (lncRNAs) in the tumorigenesis of bladder cancer (BC). The aim of this study was to investigate the possible correlations between the specific lncRNAs and the clinical outcomes in bladder cancer patients.

METHODS

We systematically searched the PubMed, EMBASE and the Cochrane Library databases for studies published up to October 15, 2018, and retrieved the suitable articles. Pooled odds ratios (ORs), hazard ratios (HRs) and 95% confidence intervals (95% CIs) were obtained by using fixed-effect or random-effect model.

RESULTS

Up-regulation of lncRNAs predicted unfavorable overall survival (OS) (HR: 2.01, 95%CI: 1.66-2.44, P < 0.001) and recurrence-free survival (RFS) (HR: 2.05, 95%CI: 1.43-2.94, P < 0.001) in BC patients, and the high expression of lncRNAs was significantly associated with distant metastasis (DM) (OR: 8.16, 95%CI: 4.45-14.99, P < 0.001).

CONCLUSION

Abnormal expression of relevant lncRNAs are potential novel markers for predicting the clinical outcomes of BC.

LncRNA BLACAT1 May Serve as a Prognostic Predictor in Cancer: Evidence from a Meta-Analysis

Background

As a newly discovered lncRNA, bladder cancer-associated transcript 1 (BLACAT1) has been reported to correlate with poor clinical outcomes in several different cancers. This study aimed to evaluate its generalized predictive value for cancer prognosis.

Materials and Methods

We thoroughly searched PubMed, Embase, and Web of Science databases for eligible studies published until November 11, 2018, in which the relationship between BLACAT1 expression and cancer prognosis was explored. The analyses were performed using Review Manager Version 5.3 and Stata SE 12.0. The primary endpoints included overall survival (OS), pathological characteristics (TNM stage and tumor grade), lymph node metastasis (LNM), and distant metastasis.

Results

Ten studies containing 861 patients with 7 different cancerous diseases were eventually included. The results demonstrated that patients with high lncRNA BLACAT1 expression had a significantly shorter OS (HR: 1.82, 95% CI: 1.44-2.30, p < 0.00001) than patients with low lncRNA BLACAT1 expression. Moreover, elevated BLACAT1 expression was significantly associated with advanced TNM stage (OR: 2.29, 95% CI: 1.15-4.56, p = 0.005), high tumor grade (OR: 1.67, 95% CI: 1.11-2.53, p = 0.01), and lymph node metastasis (OR: 2.53, 95% CI: 1.80-3.57, p < 0.00001). Meanwhile, the expression of BLACAT1 had no significant association with age (p = 0.92), gender (p = 0.55), and smoking (p = 0.62).

Conclusion

High expression of lncRNA BLACAT1 may predict a poor prognosis in OS, TNM stage, tumor grade, and LNM. Its predictive roles were not significantly affected by age, gender, or smoking. Therefore, lncRNA BLACAT1 may serve as a promising predictor in cancer prognosis.

BLACAT1 predicts poor prognosis and serves as oncogenic lncRNA in small-cell lung cancer

Bladder cancer-associated transcript 1 (BLACAT1) is a novel identified long noncoding RNA (lncRNA) in bladder cancer, and has been suggested to function as an oncogenic lncRNA in several types of human cancer. However, its involvement in the progression of small-cell lung cancer (SCLC) remained unknown. The aim of our study was to investigate the clinical value and biological function in SCLC. In our results, BLACAT1 expression was increased in SCLC tissues and cell lines compared with paired adjacent normal tissues and bronchial epithelial cell lines, respectively. In addition, BLACAT1 high-expression was obviously associated with advanced clinical stage, large tumor size, more lymph node metastasis, present distant metastasis, and poor prognosis. Furthermore, multivariate analysis indicated that high-expression of BLACAT1 acted as an independent poor prognostic factor for overall survival in SCLC cases. The loss-of-function studies suggested that of BLACAT1 suppressed SCLC cell proliferation, migration, and invasion, and induced G0/G1 phase arrest. In conclusion, BLACAT1 is associated with the malignant status and prognosis in patients with SCLC, and functions as an oncogenic lncRNA in regulating cell proliferation and motility, suggesting BLACAT1 may act as a potential target for SCLC prevention and treatment.

Knockdown of long non-coding RNA linc-ITGB1 inhibits cancer stemness and epithelial-mesenchymal transition by reducing the expression of Snail in non-small cell lung cancer

BACKGROUND

The main cause of death in patients with non-small cell lung cancer (NSCLC) is the progression of cancer metastasis, which can be attributed to multiple factors, such as cancer stem cells (CSCs) and epithelial-mesenchymal transition (EMT). Long non-coding RNAs (lncRNAs) play important roles in the regulation of the cell cycle, cell proliferation, immune responses, and metastasis in cancers, but the potential roles and mechanisms of lincRNAs in CSC-like properties of cancer have not yet been elucidated.

METHODS

Human NSCLC cell lines (A549 and H1299), highly metastatic cell lines (L9981 and 95D), and their corresponding low-metastatic cell lines (NL9980 and 95C) were subject to quantitative real-time PCR and Western blot, transwell invasion, colony formation, and wound healing assays.

RESULTS

Linc-ITGB1 was greatly upregulated in CSC spheres. Linc-ITGB1 knockdown markedly inhibited CSC formation and the expression of stemness-associated genes, such as Sox2, Nanog, Oct-4, c-Myc, and CD133. Depletion of linc-ITGB1 expression also inhibited the in vitro invasive and migratory potential of cells, and further analysis indicated that linc-ITGB1 knockdown increased the expression of the epithelial marker E-cadherin and downregulated the mesenchymal markers vimentin and fibronectin. The EMT-related transcription factor Snail mediated these effects of linc-ITGB1 in NSCLC, and overexpression of Snail significantly reversed the inhibitory effects of linc-ITGB1 depletion.

CONCLUSION

Overall, our study demonstrated that linc-ITGB1 promoted NSCLC cell EMT and cancer stemness by regulating Snail expression.

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.

Downregulation of long noncoding RNA FENDRR predicts poor prognosis in renal cell carcinoma

Long noncoding RNA FOXF1 adjacent non-coding developmental regulatory RNA (FENDRR) dysregulation associates with multiple types of human cancer. However, the biological functions of FENDRR in renal cell carcinoma are unresolved. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to determine the expression level of FENDRR in renal cell carcinoma tissues. An RNA interference assay and ectopic expression experiments were conducted to evaluate the effects of FENDRR on cell proliferation, migration, invasion and colony formation in vitro. RNA immunoprecipitation was conducted to identify proteins associated with FENDRR. It was observed that FENDRR is frequently downregulated in renal cell carcinoma and overexpression of FENDRR attenuated proliferation, migration, invasion and colony growth of renal carcinoma cells. Conversely, knockdown of FENDRR promotes proliferation and invasiveness of renal carcinoma cells. Downregulation of FENDRR associates with poor prognosis of renal cell carcinoma. Mechanistically, it was identified that FENDRR may bind to Polycomb Repressive Complex 2 and lysin methyltransferase 2A histone modifying complexes. In summary, FENDRR acts as an tumor suppressor in renal cell carcinoma and may serve as a candidate target for gene therapy.

LncRNA as a diagnostic and prognostic biomarker in bladder cancer: a systematic review and meta-analysis

Background

Bladder cancer is one of the most common urinary malignancies, and has a high recurrence rate and poor outcomes. In order to identify novel diagnostic and prognostic biomarkers for bladder cancer, we conducted a meta-analysis to analyze the association between long non-coding RNA (lncRNA) expression and survival in bladder cancer.

Materials and methods

We searched literature from databases using our inclusion and exclusion criteria. STATA 14.0 software was used to analyze the data from collected studies and to construct the forest plots. A different effect size was selected for each meta-analysis.

Results

After selection, 30 articles were found to be eligible. The present meta-analysis contains data from 13 articles about clinicopathological characteristics, six articles about diagnosis, and 16 articles about prognosis. In the present study, we found that many lncRNAs could function as potential diagnostic and prognostic markers in bladder cancer. Among these findings, UCA1 was expected to be a diagnostic biomarker for bladder cancer, while the aberrant expression of HOTAIR and GAS5 was associated with poor disease-free survival/recurrence-free survival/disease-specific survival.

Conclusion

Overall, the present study is the first meta-analysis to assess the association between expression of lncRNAs and clinical value in patients with bladder cancer. LncRNAs hold promise as novel diagnostic and prognostic markers in bladder cancer.

Identification of oncogenic long noncoding RNA SNHG12 and DUXAP8 in human bladder cancer through a comprehensive profiling analysis

Bladder cancer is a common urological malignancies world-wide. Recently, a growing number of evidence have highlighted the importance of long noncoding RNAs (lncRNAs) in multiple cancers development and progression. However, the expression pattern of lncRNAs in bladder cancer and their underlying function remain poorly understood. To identify lncRNAs profile alterations and uncover valuable lncRNA candidates for bladder cancer diagnostic, we conducted a comprehensively lncRNAs profiling analyses and explored their clinical relevance using The Cancer Genome Atlas (TCGA) data and three independent microarray profiling data from the Gene Expression Omnibus (GEO). After annotation and analyses of these data, we found that lots of lncRNAs were dysregulated in bladder specimen when compared with normal control specimen. In addition, we found that differential expression of these lncRNAs is accompanied by genomic variations, including genome loci copy number deletion or amplification. Importantly, a part of these lncRNAs are related to bladder cancer patients outcome, such as SNHG10, SNHG12 and LINC00115. Finally, we validated two of these lncRNAs' (DUXAP8 and SNHG12) function in bladder cancer cells by down-regulating their expression with siRNAs, and found that down-regulation of DUXAP8 and SNHG12 could inhibit bladder cancer cells proliferation in vitro. In summary, this study demonstrated that a lot of lncRNAs are dysregulated in bladder cancer, and might provide useful lncRNAs resource for potential prognostic or diagnostic markers for this disease.

Long non-coding RNAs as emerging regulators of epithelial to mesenchymal transition in gynecologic cancers

Gynecologic cancer is a vital global healthcare issue with high rates of mortality and morbidity. Tumor metastasis attributes to most of the death suffering from solid tumors. The epithelial-mesenchymal transition (EMT) plays a pivotal role in initiating metastasis. Long non-coding RNAs (lncRNAs), a well-known group of non-coding RNAs, and a prominent topic in life science research, are misregulated in many malignancies and some are EMT-associated. In the case of gynecologic cancers, several EMT-associated lncRNAs have been identified and found to be implicated in cancer aggressiveness and progression. Mechanically, these lncRNAs participate in the EMT-related metastatic process in multiple ways including interaction with polycomb repressive complex 2 (PRC2), regulation of EMT signaling networks, mediation of EMT-transcription factors (EMT-TFs) and EMT markers, and cooperation with microRNAs (miRNAs). Further studies on these EMT-associated lncRNAs and identification of more relevant lncRNAs are imperative for the lncRNAs-based clinical management of high rate of metastasis in patients with gynecologic cancers.

The Nefarious Nexus of Noncoding RNAs in Cancer

The past decade has witnessed enormous progress, and has seen the noncoding RNAs (ncRNAs) turn from the so-called dark matter RNA to critical functional molecules, influencing most physiological processes in development and disease contexts. Many ncRNAs interact with each other and are part of networks that influence the cell transcriptome and proteome and consequently the outcome of biological processes. The regulatory circuits controlled by ncRNAs have become increasingly more relevant in cancer. Further understanding of these complex network interactions and how ncRNAs are regulated, is paving the way for the identification of better therapeutic strategies in cancer.

Clinical Values of Long Non-coding RNAs in Bladder Cancer: A Systematic Review

Background: Increasing evidence shows that dysregulated expression of long non-coding RNAs (lncRNAs) can serve as diagnostic or prognostic markers in bladder cancer. The aim of this study was to evaluate the clinical values of dysregulated lncRNAs in bladder cancer.

Methods: Eligible studies were systematically searched in PubMed, Embase, and Web of Science databases from inception to December 2017. Odds ratios (OR) were calculated to investigate the correlation between lncRNAs and clinicopathological parameters. Pooled hazard ratios (HR) and 95% confidence interval (CI) were calculated to explore the prognostic value of lncRNAs in bladder cancer. Pooled diagnostic parameters were also calculated to estimate the performance of lncRNAs in diagnosing bladder cancer. All statistical analyses were performed by using STATA 13.1 program.

Results: A total of 37 relevant studies were included to the present systematic review according to the inclusion and exclusion criteria, including 26 on clinicopathological parameters, 19 on prognosis, and 7 on diagnosis. For clinicopathological parameters, MALAT1 expression was significantly associated with lymph node metastasis (OR = 2.731; 95% CI: 1.409–5.292; p = 0.003), and high-level expression of XIST was related to larger tumor size (OR = 2.473; 95% CI: 1.159–5.276; p = 0.019) and higher TNM stage (OR = 0.400; 95% CI, 0.184–0.868; p = 0.020). For the prognostic values, the most significant association was observed between increased expressions of SPRY4-IT1 and poor overall survival (OS) (HR = 3.716; 95% CI: 2.084–6.719; p < 0.001); high MALAT1 expression was significantly associated with poor OS (HR = 1.611; 95% CI: 1.076–2.412; p = 0.020). For the diagnostic values, UCA1 expression profile achieved a combined AUC of 0.92, with sensitivity of 0.84 and specificity of 0.89 in distinguishing patients with bladder cancer from non-cancerous controls.

Conclusions: In summary, systematic review elaborated that abnormal lncRNAs expression can serve as potential markers for prognostic evaluation in bladder cancer patients. In addition, the diagnostic meta-analysis concluded that abnormally expressed UCA1 can function as potential diagnostic markers for bladder cancer.

Functional and therapeutic significance of EZH2 in urological cancers

The enhancer of zeste homolog 2 (EZH2) is a core subunit of the polycomb repressor complex 2 (PRC2), which is overexpressed in numerous cancers and mutated in several others. Notably, EZH2 acts not only a critical epigenetic repressor through its role in histone methylation, it is also an activator of gene expression, acting through multiple signaling pathways in distinct cancer types. Increasing evidence suggests that EZH2 is an oncogene and is central to initiation, growth and progression of urological cancers. In this review, we highlight the critical role of EZH2 as a master regulator of tumorigenesis in the prostate, bladder and the kidney through epigenetic control of transcription as well as a modulation of various critical signaling pathways. We also discuss the promise and challenges for EZH2 inhibitors as future anticancer therapeutics, some of which are currently in clinical trials.

Long noncoding RNAs in gastric cancer carcinogenesis and metastasis

Recent studies of the human transcriptome, most prominently by the ENCyclopedia Of DNA Elements project, have revealed an unexpected number of noncoding RNAs (ncRNAs). Long noncoding RNAs (lncRNAs) are typically referred to a heterogeneous group of polyadenylated long ncRNAs, with a length of > 200 nt. LncRNAs constitute an integral part of tumor biology, with many lncRNAs discovered to be aberrantly expressed in various cancer types. They are involved in many aspects of cancer pathogenesis from its initiation to progression, metastasis and treatment response. Gastric cancer (GC) is the third leading cause of cancer death worldwide. Despite the current improvements of life expectancy and survival rate, most of the patients are diagnosed when their cancer has been progressed to advanced stages. Therefore, unraveling the molecular mechanisms of GC to find early-stage biomarkers is urgent. As the list of lncRNAs with deregulated expression in GC is steadily expanding, these molecules offer a source for developing GC-specific biomarkers. In this review, we will present and discuss those lncRNAs whose expression has been shown to be deregulated in GC.

Identification of a serum circulating lncRNA panel for the diagnosis and recurrence prediction of bladder cancer

Accumulating evidence indicates that long non-coding RNAs (lncRNAs) play important roles in tumorigenesis and progression. We aimed to identify a panel of lncRNAs for the diagnosis and recurrence prediction in bladder cancer (BC). The expression of 13 candidate lncRNAs was investigated in 80 BC and matched adjacent normal tissues via quantitative real-time PCR. The differentially expressed lncRNAs were then analyzed in 240 serum samples (training set) and three lncRNAs (MEG3, SNHG16 and MALAT1) showed differential expression. A logistic regression model was constructed using the training set and validated in an independent cohort of 200 serum samples (validation set). The AUC of the three-lncRNA panel was 0.865 for the training and 0.828 for the validation set. The diagnostic performance of the lncRNA panel for Ta, T1, and T2-T4 were 0.778, 0.805, and 0.880, which were significantly higher than those of urine cytology (0.548, 0.604, and 0.682, respectively). Moreover, we determined that low expression of MEG3 was associated with poor recurrence-free survival by Kaplan-Meier analysis (p = 0.028), univariate Cox analysis (p = 0.033) and multivariate Cox analysis (p = 0.046). In conclusion, our results identified a three-lncRNA panel for BC diagnosis and a recurrence-independent prognostic factor, MEG3.

Long noncoding RNA BLACAT1 modulates ABCB1 to promote oxaliplatin resistance of gastric cancer via sponging miR-361

Long non-coding RNAs (lncRNAs) have emerged as novel gene regulators in multiple tumorigenesis and chemoresistance. However, their potential roles and molecular mechanisms in gastric cancer chemoresistance remain unclear. In present study, our team investigated the role and potential regulatory mechanism of lncRNA s bladder cancer associated transcript-1 (BLACAT1) in the gastric cancer chemoresistance. Results showed that BLACAT1 expression was up-regulated in the oxaliplatin (OXA) resistant gastric cancer tissue and cells compared with OXA-sensitive tissue and parental cell lines. In vitro, BLACAT1 knockdown decreased the expression levels of drug resistance related genes and ABCB1 protein. Besides, BLACAT1 knockdown significantly promoted apoptosis and down-regulated the invasion and the IC50 value of oxaliplatin. In vivo, BLACAT1 knockdown suppressed the tumor growth of gastric cancer cells. Bioinformatics tools and luciferase assay indicated that miR-361 both targeted 3?-UTR of BLACAT1 and ABCB1mRNA, suggesting the BLACAT1/miR-361/ABCB1 regulatory pathway. In summary, our results conclude that BLACAT1 accelerates the oxaliplatin-resistance of gastric cancer via promoting ABCB1 protein expression by targeting miR-361, providing a novel insight for the chemoresistance of gastric cancer.

Long noncoding RNA BLACAT2 promotes bladder cancer-associated lymphangiogenesis and lymphatic metastasis

The prognosis for bladder cancer patients with lymph node (LN) metastasis is dismal and only minimally improved by current treatment modalities. Elucidation of the molecular mechanisms that underlie LN metastasis may provide clinical therapeutic strategies for LN-metastatic bladder cancer. Here, we report that a long noncoding RNA LINC00958, which we have termed bladder cancer-associated transcript 2 (BLACAT2), was markedly upregulated in LN-metastatic bladder cancer and correlated with LN metastasis. Overexpression of BLACAT2 promoted bladder cancer-associated lymphangiogenesis and lymphatic metastasis in both cultured bladder cancer cell lines and mouse models. Furthermore, we demonstrate that BLACAT2 epigenetically upregulated VEGF-C expression by directly associating with WDR5, a core subunit of human H3K4 methyltransferase complexes. Importantly, administration of an anti-VEGF-C antibody inhibited LN metastasis in BLACAT2-overexpressing bladder cancer. Taken together, these findings uncover a molecular mechanism in the lymphatic metastasis of bladder cancer and indicate that BLACAT2 may represent a target for clinical intervention in LN-metastatic bladder cancer.

LncRNA CCND2-AS1 promotes proliferation, migration, and invasion in papillary thyroid carcinoma

In decades, a lot of long non-coding RNAs (LncRNAs) have been proven to exert influences on tumorigenesis in vitro and in vivo. Many lncRNAs have been reported as effective therapeutic targets and biomarkers in various cancers. However, whether LncRNAs are associated with the progression of PTC remains largely unknown. In this study, we measured the expression of CCND2-AS1 in PTC cell lines by quantitative real-time polymerase chain reaction (qRT-PCR).We found that CCND2-AS1 expression was significantly over-expressed in PTC cell lines compared to normal thyroid epithelial cells. Gain-and loss-of-function experiments were performed to investigate the role of CCND2-AS1 in PTC cells. In vitro experiments, we proved that CCND2-AS1 knockdown in TPC1 significantly suppressed cell proliferation, migration, and invasion, while CCND2-AS1 overexpression in BCPAP had the opposite effects. Meanwhile, we also found that CCND2-AS1 could regulate N-cadherin and Vimentin expression, which may influence invasion and migration. Our findings indicate that the lncRNA CCND2-AS1 is a gene associated with PTC and might become a potential therapeutic target.

Long noncoding RNA BLACAT1 promotes cell proliferation and invasion in human cervical cancer

Cervical cancer is one of the leading causes of mortality in females worldwide. Predisposition to distant metastasis has reduced the prognosis of this malignancy, thus the identification of a novel agent for metastatic cervical cancer is required. Long noncoding RNAs (LncRNAs) have been reported to serve significant roles in human tumorigenesis. The present study aimed to investigate the effects of a newly discovered LncRNA bladder cancer associated transcript 1 (non-protein coding) (BLACAT1) on cell proliferation and metastasis in cervical cancer. A total of 100 patients with cervical cancer were included, and tumor tissues as well as the adjacent non-cancerous counterparts were collected for reverse transcription-quantitative polymerase chain reaction analysis. It was demonstrated that BLACAT1 was highly expressed in human cervical cancer tissues and cell lines. The knockdown of BLACAT1 with specific short hairpin RNA reduced colony formation rates in ME180 and C33A cells. Cell cycle and cell proliferation assays revealed that depletion of BLACAT1 in ME180, and C33A cells arrested the cell cycle at the G0/G1 phase and inhibited cell proliferation. Transwell assays demonstrated that the knockdown of BLACAT1 inhibited cell migration and invasion in ME180, and C33A cells. Moreover, wound-healing assays supported the aformentioned observations. Western blot analysis showed that the knockdown of BLACAT1 in ME180 and C33A cells decreased the protein levels of cyclin B1, cell division cycle 25C, and N-cadherin, while increasing the protein level of E-cadherin. These findings indicated the oncogenic potential of BLACAT1 in cervical cancer, which may provide novel insights for the clinical diagnosis and treatment of cervical cancer.

LncRNA Expression Signature in Prediction of the Prognosis of Lung Adenocarcinoma

OBJECTIVE

To determine if lncRNA expression can be used for the prognoses of patients diagnosed with lung adenocarcinoma (LUAD) patients.

METHODS

The Cancer Genome Atlas database was used to identify 409 LUAD patients for whom there were both, gene expression data and relevant clinical information available. LncRNAs were then selected from the expression data through record linkage between the National Center for Biotechnology Information (NCBI) and Ensemble databases. lncRNAs with significantly different expression levels between normal and tumor tissues were screened, and those whose levels correlated with a positive LUAD prognosis were identified. Based on the expression of the selected lncRNAs, an unsupervised learning method was used to cluster these patients into two groups, and survival analyses were performed to assess the overall survival (OS) between the two groups. Receiver operating characteristic curves were used to calculate the specificity and sensitivity of the models based on the presence of these lncRNAs, and the model was tested with another dataset from the Gene Expression Omnibus.

RESULTS

A total of 151 lncRNAs were found to be differentially expressed between tumor and normal tissues (permutation p-values <0.05) based on the Cancer Genome Atlas dataset, and 20 lncRNAs were associated with OS. Two lncRNAs (DKFZP434 L187 and LOC285548) were correlated with LUAD. All patients with high expression of these two lncRNAs from the two datasets exhibited poor OS compared with those with low expression (p < 0.05).

CONCLUSIONS

The expression of DKFZP434 L187 and LOC285548 may have prognostic value for the OS of LUAD patients.