Circulating exosomal long non‐coding RNAs in patients with acute myocardial infarction

Exosomes are attracting considerable interest in the cardiovascular field as the wide range of their functions is recognized in acute myocardial infarction (AMI). However, the regulatory role of exosomal long non‐coding RNAs (lncRNAs) in AMI remains largely unclear. Exosomes were isolated from the plasma of AMI patients and controls, and the sequencing profiles and twice qRT‐PCR validations of exosomal lncRNAs were performed. A total of 518 differentially expressed lncRNAs were detected over two‐fold change, and 6 kinds of lncRNAs were strikingly elevated in AMI patients with top fold change and were selected to perform subsequent validation. In the two validations, lncRNAs ENST00000556899.1 and ENST00000575985.1 were significantly up‐regulated in AMI patients compared with controls. ROC curve analysis revealed that circulating exosomal lncRNAs ENST00000556899.1 and ENST00000575985.1 yielded the area under the curve values of 0.661 and 0.751 for AMI, respectively. Moreover, ENST00000575985.1 showed more significant relationship with clinical parameters, including inflammatory biomarkers, prognostic indicators and myocardial damage markers. Multivariate logistic model exhibited positive association of ENST00000575985.1 with the risk of heart failure in AMI patients. In summary, our data demonstrated that circulating exosomal lncRNAs ENST00000556899.1 and ENST00000575985.1 are elevated in patients with AMI, functioning as potential biomarkers for predicting the prognosis of pateints with AMI.     

Long non‐coding RNA F11‐AS1 inhibits HBV‐related hepatocellular carcinoma progression by regulating NR1I3 via binding to microRNA‐211‐5p

Long non‐coding RNAs (lncRNAs) could regulate growth and metastasis of hepatocellular carcinoma (HCC). In this study, we aimed to investigate the mechanism of lncRNA F11‐AS1 in hepatitis B virus (HBV)–related HCC. The relation of lncRNA F11‐AS1 expression in HBV‐related HCC tissues to prognosis was analysed in silico. Stably HBV‐expressing HepG2.2.15 cells were established to explore the regulation of lncRNA F11‐AS1 by HBx protein, as well as to study the effects of overexpressed lncRNA F11‐AS1 on proliferation, migration, invasion and apoptosis in vitro. Subsequently, the underlying interactions and roles of lncRNA F11‐AS1/miR‐211‐5p/NR1I3 axis in HBV‐related HCC were investigated. Additionally, the influence of lncRNA F11‐AS1 and miR‐211‐5p on tumour growth and metastasis capacity of HepG2.2.15 cells were studied on tumour‐bearing nude mice. Poor expression of lncRNA F11‐AS1 was correlated with poor prognosis in patients with HBV‐related HCC, and its down‐regulation was caused by the HBx protein. lncRNA F11‐AS1 was proved to up‐regulate the NR1I3 expression by binding to miR‐211‐5p. Overexpression of lncRNA F11‐AS1 reduced the proliferation, migration and invasion, yet induced apoptosis of HepG2.2.15 cells in vitro, which could be abolished by overexpression of miR‐211‐5p. Additionally, either lncRNA F11‐AS1 overexpression or miR‐211‐5p inhibition attenuated the tumour growth and metastasis capacity of HepG2.2.15 cells in vivo. Collectively, lncRNA F11‐AS1 acted as a modulator of miR‐211‐5p to positively regulate the expression of NR1I3, and the lncRNA F11‐AS1/miR‐211‐5p/NR1I3 axis participated in HBV‐related HCC progression via interference with the cellular physiology of HCC.     

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.     

Five key lncRNAs considered as prognostic targets for predicting pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis, and the 5‐year survival rate was only 7.7%. To improve prognosis, a screening biomarker for early diagnosis of pancreatic cancer is in urgent need. Long non‐coding RNA (lncRNA) expression profiles as potential cancer prognostic biomarkers play critical roles in development of tumorigenesis and metastasis of cancer. However, lncRNA signatures in predicting the survival of a patient with PDAC remain unknown. In the current study, we try to identify potential lncRNA biomarkers and their prognostic values in PDAC. LncRNAs expression profiles and corresponding clinical information for 182 cases with PDAC were acquired from The Cancer Genome Atlas (TCGA). A total of 14 470 lncRNA were identified in the cohort, and 175 PDAC patients had clinical variables. We obtained 108 differential expressed lncRNA via R packages. Univariate and multivariate Cox proportional hazards regression, lasso regression was performed to screen the potential prognostic lncRNA. Five lncRNAs have been recognized to significantly correlate with OS. We established a linear prognostic model of five lncRNA (C9orf139, MIR600HG, RP5‐965G21.4, RP11‐436K8.1, and CTC‐327F10.4) and divided patients into high‐ and low‐risk group according to the prognostic index. The five lncRNAs played independent prognostic biomarkers of OS of PDAC patients and the AUC of the ROC curve for the five lncRNAs signatures prediction 5‐year survival was 0.742. In addition, targeted genes of MIR600HG, C9orf139, and CTC‐327F10.4 were explored and functional enrichment was also conducted. These results suggested that this five‐lncRNAs signature could act as potential prognostic biomarkers in the prediction of PDAC patient's survival.     

长链非编码RN在重性抑郁障碍中的作用

重性抑郁障碍(major depression disorder, MDD)是当代社会一种严重的精神性疾病,但目前并不完全明确其发生发展的分子机制。长链非编码RNA(long noncoding RNA, lncRNA)与MDD之间有着密切的联系,目前已知在健康人群与MDD患者之间存在2 000多种差异表达的lncRNAs,如TCONS00019174、ENST00000566208、NONHSAG045500、ENST00000517573、NONHSAT034045和NONHSAT142707等。上述6种lncRNAs在MDD患者外周血中的表达量均显著低于对照组,MDD患者经抗抑郁治疗后,lncRNAs表达量可恢复正常。TCONS00019174可通过激活Wnt-β-catenin途径,使入核的β-catenin蛋白质增加并与其下游分子结合促进转录,发挥抗抑郁作用;高表达的lnc RNA NONHSAG045500可以抑制MDD患者五羟色胺转运体的表达从而产生抗抑郁作用。因此,研究lncRNA在MDD中的表达及作用,将为MDD患者的诊治带来新的契机。     

Exosomal miR‐663b targets Ets2‐repressor factor to promote proliferation and the epithelial–mesenchymal transition of bladder cancer cells

Exosomes circulating in biological fluids have the potential to be utilized as cancer biomarkers and are associated with cancer progression and metastasis. MicroRNA (miR)‐663b has been found to be elevated in plasma from patients with bladder cancer (BC). However, the functional role of exosomal miR‐663b in BC processes remains unknown. Here, we isolated exosomes from plasma and found that the miR‐663b level was elevated in exosomes from plasma of patients with BC compared with healthy controls. Exosomal miR‐663b from BC cells promoted cell proliferation and epithelial–mesenchymal transition. Moreover, exosomal miR‐663b targeted Ets2‐repressor factor and acted as a tumor promoter in BC cells. Taken together, our findings suggested that exosomal miR‐663b is a promising potential biomarker and target for clinical detection and therapy in BC.     

Exosomal long noncoding RNA HOXD-AS1 promotes prostate cancer metastasis via miR-361-5p/FOXM1 axis

Development of distant metastasis is the main cause of deaths in prostate cancer (PCa) patients. Understanding the mechanism of PCa metastasis is of utmost importance to improve its prognosis. The role of exosomal long noncoding RNA (lncRNA) has been reported not yet fully understood in the metastasis of PCa. Here, we discovered an exosomal lncRNA HOXD-AS1 is upregulated in castration resistant prostate cancer (CRPC) cell line derived exosomes and serum exosomes from metastatic PCa patients, which correlated with its tissue expression. Further investigation confirmed exosomal HOXD-AS1 promotes prostate cancer cell metastasis in vitro and in vivo by inducing metastasis associated phenotype. Mechanistically exosomal HOXD-AS1 was internalized directly by PCa cells, acting as competing endogenous RNA (ceRNA) to modulate the miR-361-5p/FOXM1 axis, therefore promoting PCa metastasis. In addition, we found that serum exosomal HOXD-AS1 was upregulated in metastatic PCa patients, especially those with high volume disease. And it is correlated closely with Gleason Score, distant and nodal metastasis, Prostatic specific antigen (PSA) recurrence free survival, and progression free survival (PFS). This sheds a new insight into the regulation of PCa distant metastasis by exosomal HOXD-AS1 mediated miR-361-5p/FOXM1 axis, and provided a promising liquid biopsy biomarker to guide the detection and treatment of metastatic PCa.Subject terms: Bone metastases, Prostate cancer     

LncRNA‐PAGBC acts as a microRNA sponge and promotes gallbladder tumorigenesis

Long noncoding RNAs (lncRNAs) play roles in the development and progression of many cancers; however, the contributions of lncRNAs to human gallbladder cancer (GBC) remain largely unknown. In this study, we identify a group of differentially expressed lncRNAs in human GBC tissues, including prognosis‐associated gallbladder cancer lncRNA (lncRNA‐PAGBC), which we find to be an independent prognostic marker in GBC. Functional analysis indicates that lncRNA‐PAGBC promotes tumour growth and metastasis of GBC cells. More importantly, as a competitive endogenous RNA (ceRNA), lncRNA‐PAGBC competitively binds to the tumour suppressive microRNAs miR‐133b and miR‐511. This competitive role of lncRNA‐PAGBC is required for its ability to promote tumour growth and metastasis and to activate the AKT/mTOR pathway. Moreover, lncRNA‐PAGBC interacts with polyadenylate binding protein cytoplasmic 1 (PABPC1) and is stabilized by this interaction. This work provides novel insight on the molecular pathogenesis of GBC.     

lncRNA‐POIR promotes epithelial–mesenchymal transition and suppresses sorafenib sensitivity simultaneously in hepatocellular carcinoma by sponging miR‐182‐5p

Sorafenib (SOR) resistance remains a major obstacle in the effective treatment of hepatocellular carcinoma (HCC). A number of long noncoding RNAs (lncRNAs) are responsible for this chemoresistance. This study aimed to reveal the essential function of a recently defined lncRNA, lncRNA‐POIR, in the epithelial–mesenchymal transition (EMT) and SOR sensitivity of HCC cells. SOR‐induced cytotoxicity was analyzed via cell counting kit‐8 and ethynyl‐2'‐deoxyuridine incorporation assays, whereas immunoblotting and confocal immunofluorescence were used to determine the expression levels of EMT markers. Furthermore, loss‐ or gain‐of‐function approaches were used to demonstrate the role of lncRNA‐POIR/miR‐182‐5p on EMT and SOR sensitivity in HCC. The direct interaction between lncRNA‐POIR and miR‐182‐5p was verified using a luciferase reporter assay. We found that knockdown of lncRNA‐POIR sensitized HCC cells to SOR and simultaneously reversed EMT. As expected, miR‐182‐5p was confirmed as the downstream target of lncRNA‐POIR. Moreover, miR‐182‐5p overexpression clearly reversed EMT and promoted SOR‐induced cytotoxicity in representative HCC cells, whereas miR‐182‐5p downregulation played a contrasting role; miR‐182‐5p knockdown abolished the modulatory effects of lncRNA‐POIR siRNA on EMT and SOR sensitivity. Together, these pieces of data suggest that lncRNA‐POIR promotes EMT progression and suppresses SOR sensitivity simultaneously by sponging miR‐182‐5p. Thus, we proposed a compelling rationale for the use of lncRNA‐POIR as a promising predictor of SOR response and as a potential therapeutic target for HCC treatment in the future.     

Identification of Serum Monocyte Chemoattractant Protein-1 and Prolactin as Potential Tumor Markers in Hepatocellular Carcinoma

Early diagnosis of hepatocellullar carcinoma (HCC) remains a challenge. The current practice of serum alpha-fetoprotein (AFP) measurement is inadequate. Here we utilized a proteomic approach to identify novel serum biomarkers for distinguishing HCC patients from non-cancer controls. We profiled the serum proteins in a group of 58 resectable HCC patients and 11 non-HCC chronic hepatitis B (HBV) carrier samples from the Singapore General Hospital (SGH) using the RayBio® L-Series 507 Antibody Array and found 113 serum markers that were significantly modulated between HCC and control groups. Selected potential biomarkers from this list were quantified using a multiplex sandwich enzyme-linked immunosorbent assay (ELISA) array in an expanded SGH cohort (126 resectable HCC patients and 115 non-HCC chronic HBV carriers (NC group)), confirming that serum prolactin and monocyte chemoattractant protein-1 (MCP-1) were significantly upregulated in HCC patients. This finding of serum MCP-1 elevation in HCC patients was validated in a separate cohort of serum samples from the Mochtar Riady Institute for Nanotechnology, Indonesia (98 resectable HCC, 101 chronic hepatitis B patients and 100 asymptomatic HBV/HCV carriers) by sandwich ELISA. MCP-1 and prolactin levels were found to correlate with AFP, while MCP-1 also correlated with disease stage. Subsequent receiver operating characteristic (ROC) analysis of AFP, prolactin and MCP-1 in the SGH cohort and comparing their area under the ROC curve (AUC) indicated that neither prolactin nor MCP-1 on their own performed better than AFP. However, the combination of AFP+MCP-1 (AUC, 0.974) had significantly superior discriminative ability than AFP alone (AUC, 0.942; p<0.001). In conclusion, prolactin and MCP-1 are overexpressed in HCC and are conveniently quantifiable in patients’ sera by ELISA. MCP-1 appears to be a promising complementary biomarker for HCC diagnosis and this MCP-1+AFP model should be further evaluated as potential biomarker on a larger scale in patients at-risk of HCC.     

Transcriptional profiling of exosomes derived from plasma of canine with mammary tumor by RNA-seq analysis

Canine mammary tumor (CMT) are the second most common tumor in dogs. Exosomes can act as biomarkers for the early diagnosis of tumors, and also be involved in the pathogenesis and metastasis mechanism of tumors. The expression profile of exosomal RNA revealed that there were a total of 5547 differentially expressed mRNAs, and 196 differentially expressed lncRNAs. GO and KEGG enrichment analysis found that the differentially expressed mRNAs and lncRNA target genes were associated with metabolic processes, DNA replication, cell proliferation, cell junction, and cell adhesion. In conclusion, this study revealed lncRNA and mRNA expression profiles in exosomes derived from plasma of CMT and further annotated their potential functions. The data obtained in this study will also provide valuable resources for understanding lncRNA information in plasma exosomes of dogs with CMT, and contribute to the study of early diagnostic markers and pathogenesis of CMT.     

Overexpression of ZEB2‐AS1 promotes epithelial‐to‐mesenchymal transition and metastasis by stabilizing ZEB2 mRNA in head neck squamous cell carcinoma

The long noncoding RNAs (lncRNAs) have been increasingly appreciated as key players underlying tumourigenesis and hold great potentials as prognostic biomarkers and therapeutic targets. However, their roles in head neck squamous cell carcinoma (HNSCC) have remained incompletely known. Here, we sought to reveal the oncogenic roles and clinical significance of a tumour‐associated lncRNA, zinc finger E‐box binding homeobox 2 antisense RNA 1 (ZEB2‐AS1), in HNSCC. ZEB2‐AS1 was aberrantly overexpressed in a fraction of HNSCC samples. Its overexpression significantly associated with large tumour size, cervical node metastasis and reduced overall and disease‐free survival. Antisense oligonucleotides (ASO)‐mediated ZEB2‐AS1 depletion markedly inhibited cell proliferation, migration and invasion while triggered apoptosis in HNSCC cells in part via modulating ZEB2 mRNA stability. Enforced overexpression of ZEB2 largely attenuated the phenotypic changes resulted from ZEB2‐AS1 inhibition except the impaired cell proliferation. In addition, ZEB2‐AS1 was required for TGF‐β1‐induced epithelial‐mesenchymal transition (EMT) in vitro. Significantly reduced tumour growth and lung metastasis were observed in ZEB2‐AS1‐depleted cells in HNSCC xenograft animal models. Taken together, our findings reveal that overexpression of ZEB2‐AS1 associates with tumour aggressiveness and unfavourable prognosis by serving as a putative oncogenic lncRNA and a novel prognostic biomarker in HNSCC.     

Increased long noncoding RNA LASP1-AS is critical for hepatocellular carcinoma tumorigenesis via upregulating LASP1

Aberrant long noncoding RNAs (lncRNA) have been proved to be associated with the many types of malignant tumors (including hepatocellular carcinoma [HCC]). In this study, a lncRNAs and mRNAs microarray analysis was performed in three pairs of HCC patitents’ tumor. We found lncRNA LIM and SH3 protein 1 antisense (LASP1-AS) and its sense-cognate gene LIM and SH3 protein 1 (LASP1) were upregulated in HCC and both are correlated with poorer prognosis and lower survival of HCC patients. Meanwhile, the expression of LASP1-AS correlated positively with LASP1 expression in HCC tissues. LASP1-AS promoted the proliferation, migration, and invasion abilities of HCC in vitro and vivo by enhancing LASP1 expression. Our study explored lncRNA LASP1-AS as an oncogene in HCC and promoted proliferation and metastasis capabilities of HCC via increasing the expression of its sense-cognate gene LASP1. LncRNA LASP1-AS might be a potential valuable prognostic biomarker and potential therapeutic target of HCC.     

Long non‐coding RNA cardiac hypertrophy‐associated regulator governs cardiac hypertrophy via regulating miR‐20b and the downstream PTEN/AKT pathway

Pathological cardiac hypertrophy (CH) is a key factor leading to heart failure and ultimately sudden death. Long non‐coding RNAs (lncRNAs) are emerging as a new player in gene regulation relevant to a wide spectrum of human disease including cardiac disorders. Here, we characterize the role of a specific lncRNA named cardiac hypertrophy‐associated regulator (CHAR) in CH and delineate the underlying signalling pathway. CHAR was found markedly down‐regulated in both in vivo mouse model of cardiac hypertrophy induced by pressure overload and in vitro cellular model of cardiomyocyte hypertrophy induced by angiotensin II (AngII) insult. CHAR down‐regulation alone was sufficient to induce hypertrophic phenotypes in healthy mice and neonatal rat ventricular cells (NRVCs). Overexpression of CHAR reduced the hypertrophic responses. CHAR was found to act as a competitive endogenous RNA (ceRNA) to down‐regulate miR‐20b that we established as a pro‐hypertrophic miRNA. We experimentally established phosphatase and tensin homolog (PTEN), an anti‐hypertrophic signalling molecule, as a target gene for miR‐20b. We found that miR‐20b induced CH by directly repressing PTEN expression and indirectly increasing AKT activity. Moreover, CHAR overexpression mitigated the repression of PTEN and activation of AKT by miR‐20b, and as such, it abrogated the deleterious effects of miR‐20b on CH. Collectively, this study characterized a new lncRNA CHAR and unravelled a new pro‐hypertrophic signalling pathway: lncRNA‐CHAR/miR‐20b/PTEN/AKT. The findings therefore should improve our understanding of the cellular functionality and pathophysiological role of lncRNAs in the heart.     

The lncRNA ENST00000608794 acts as a competing endogenous RNA to regulate PDK4 expression by sponging miR-15b-5p in dexamethasone induced steatosis

The contribution of ncRNAs, especially long non-coding RNAs (lncRNAs) to drug induced steatosis remains largely unknown. The aim of this study was to investigate the role of lncRNA ENST00000608794 in dexamethasone induced steatosis. We found that ENST00000608794 is expressed at higher levels in dexamethasone treated HepG2 cell, and ENST00000608794 can bind and be regulated by miR-15b-5p. Ectopic expression of ENST00000608794 enhanced steatosis and the protein expression of PDK4 which is a critical gene in lipid metabolism and also is a target of miR-15b-5p. However, the differentiated PDK4 expression between control and ectopic expression of ENST00000608794 was absence in the presence of miR-15b-5p inhibitor. Moreover, in dexamethasone treated HepG2 cell lines, ENST00000608794 increased whether with miR-15b-5p inhibitor treatment or not, while increase of PDK4 expression by dexamethasone was greatly compromised in the presence of miR-15b-5p mimic. Meanwhile, dexamethasone induced steatosis could be ameliorated by silencing ENST00000608794 or expressing miR-15b-5p. Taken together, the results suggested that ENST00000608794 plays an important role in dexamethasone induced steatosis, which was partly mediated by derepressing of PDK4 through competitively binding to miR-15b-5p.     

A panel consisting of three novel circulating lncRNAs,is it a predictive tool for gastric cancer?

Early detection is vital for prolonging 5‐year survival for patients with gastric cancer (GC). Numerous studies indicate that circulating long non‐coding RNAs (lncRNAs) can be used to diagnose malignant tumours. This study aimed to investigate the capacity of novel lncRNAs for diagnosing GC. A lncRNA microarray assay was used to screen differentially expressed lncRNAs between plasma of patients with GC and healthy controls. Plasma samples from 100 patients with healthy controls were used to construct a multiple‐gene panel. An additional 50 pairs of GC patients with healthy controls were used to evaluate the diagnostic accuracy of the panel. Expression levels of lncRNAs were quantified through real‐time polymerase chain reaction. The receiver operating characteristic curve and area under curve (AUC) were used to estimate the diagnostic capacity. We identified three lncRNAs, CTC‐501O10.1, AC100830.4 and RP11‐210K20.5 that were up‐regulated in the plasma of GC patients with AUCs 0.724, 0.730 and 0.737, respectively (P < .01). Based on the logistic regression model, the combined AUC of the three lncRNAs was 0.764. The AUC of the panel was 0.700 in the validation cohort. These findings indicate that plasma lncRNAs can serve as potential biomarkers for detection of GC.     

A novel lncRNA PLK4 up‐regulated by talazoparib represses hepatocellular carcinoma progression by promoting YAP‐mediated cell senescence

A growing number of studies recognize that long non‐coding RNAs (lncRNAs) are essential to mediate multiple tumorigenic processes, including hepatic tumorigenesis. However, the pathological mechanism of lncRNA‐regulated liver cancer cell growth remains poorly understood. In this study, we identified a novel function lncRNA, named polo‐like kinase 4 associated lncRNA (lncRNA PLK4, GenBank Accession No. RP11‐50D9.3), whose expression was dramatically down‐regulated in hepatocellular carcinoma (HCC) tissues and cells. Interestingly, talazoparib, a novel and highly potent poly‐ADP‐ribose polymerase 1/2 (PARP1/2) inhibitor, could increase lncRNA PLK4 expression in HepG2 cells. Importantly, we showed that talazoparib‐induced lncRNA PLK4 could function as a tumour suppressor gene by Yes‐associated protein (YAP) inactivation and induction of cellular senescence to inhibit liver cancer cell viability and growth. In summary, our findings reveal the molecular mechanism of talazoparib‐induced anti‐tumor effect, and suggest a potential clinical use of talazoparib‐targeted lncRNA PLK4/YAP‐dependent cellular senescence for the treatment of HCC.