基于铜死亡相关lncRNAs的胰腺癌预后模型构建与验证

目的研究铜死亡相关lncRNAs在胰腺癌(PAAD)患者中的预后预测价值,并进一步构建预后预测模型。方法从TCGA数据库中下载胰腺癌患者的转录组测序数据和相应临床信息,通过Pearson相关性分析筛选与预后相关的铜死亡相关lncRNAs,先后利用单因素Cox回归和Lasso回归分析并进一步构建预后模型。根据模型的风险评分中位数,将所有患者分为高风险组和低风险组。通过Kaplan-Meier生存分析、亚组分析、ROC曲线分析及一致性指数分析评估模型的预后预测价值,并利用单因素和多因素回归分析验证模型的独立性。对高、低风险组的差异表达基因进行GO及KEGG功能富集分析,并对高、低风险组患者进行肿瘤突变负荷(TMB)分析、免疫治疗反应预测以及药物敏感性分析。结果通过Pearson相关性分析,确定了127个铜死亡相关的lncRNAs,先后利用单因素Cox回归分析及Lasso回归分析构建了一个基于6个铜死亡相关lncRNAs的预后预测模型。根据模型计算结果将PAAD患者队列分成高风险组和低风险组,Kaplan-Meier生存分析表明低风险组患者的生存时间要长于高风险组(P<0.05)。ROC曲线证明了该模型对胰腺癌患者预后的预测性能良好:1、3、5年ROC曲线下面积分别为0.687、0.753、0.771;基因功能富集分析表明,高、低风险组差异表达基因主要富集于免疫相关通路。此外,高风险组患者的TMB值明显大于低风险组,而TIDE评分明显低于低风险组。最后,通过药物敏感性分析发现不同组的胰腺癌患者对特定药物的敏感性存在统计学差异,对临床用药具有一定的指导意义。结论本研究基于铜死亡相关lncRNAs成功构建了一个PAAD患者预后模型,可精准预测PAAD患者的预后,并为患者的临床药物治疗选择提供个性化指导。

Non-coding RNAs in acute ischemic stroke:from brain to periphery

Acute ischemic stroke is a clinical emergency and a condition with high morbidity,mortality,and disability.Accurate predictive,diagnostic,and prognostic biomarkers and effective therapeutic targets for acute ischemic stroke remain undetermined.With innovations in high-throughput gene sequencing analysis,many aberrantly expressed non-coding RNAs(ncRNAs)in the brain and peripheral blood after acute ischemic stroke have been found in clinical samples and experimental models.Differentially expressed ncRNAs in the post-stroke brain were demonstrated to play vital roles in pathological processes,leading to neuroprotection or deterioration,thus ncRNAs can serve as therapeutic targets in acute ischemic stroke.Moreover,distinctly expressed ncRNAs in the peripheral blood can be used as biomarkers for acute ischemic stroke prediction,diagnosis,and prognosis.In particular,ncRNAs in peripheral immune cells were recently shown to be involved in the peripheral and brain immune response after acute ischemic stroke.In this review,we consolidate the latest progress of research into the roles of ncRNAs(microRNAs,long ncRNAs,and circular RNAs)in the pathological processes of acute ischemic stroke–induced brain damage,as well as the potential of these ncRNAs to act as biomarkers for acute ischemic stroke prediction,diagnosis,and prognosis.Findings from this review will provide novel ideas for the clinical application of ncRNAs in acute ischemic stroke.

Long Non-coding RNA PCED1B Antisense RNA 1 Promotes Cell Proliferation and Invasion in Hepatocellular Carcinoma by Regulating the MicroRNA-34a/CD44 Axis

Objective This study aimed to examine the role of long non-coding RNA PCED1B antisense RNA 1(PCED1B-AS1)in the development of hepatocellular carcinoma(HCC).Methods A total of 62 pairs of HCC tissues and adjacent non-tumor tissues were obtained from 62 HCC patients.The interactions of PCED1B-AS1 and microRNA-34a(miR-34a)were detected by dual luciferase activity assay and RNA pull-down assay.The RNA expression levels of PCED1B-AS1,miR-34a and CD44 were detected by RT-qPCR,and the protein expression level of CD44 was determined by Western blotting.The cell proliferation was detected by cell proliferation assay,and the cell invasion and migration by transwell invasion assay.The HCC tumor growth after PCED1B-AS1 was downregulated was determined by in vivo animal study.Results PCED1B-AS1 was highly expressed in HCC tissues,which was associated with poor survival of HCC patients.Furthermore,PCED1B-AS1 interacted with miR-34a in HCC cells,but they did not regulate the expression of each other.Additionally,PCED1B-AS1 increased the expression level of CD44,which was targeted by miR-34a.The cell proliferation and invasion assay revealed that miR-34a inhibited the proliferation and invasion of HCC in vitro,while CD44 exhibited the opposite effects.Furthermore,PCED1B-AS1 suppressed the role of miR-34a.Moreover,the knockdown of PCED1B-AS1 repressed the HCC tumor growth in nude mice in vivo.Conclusion PCED1B-AS1 may play an oncogenic role by regulating the miR-34a/CD44 axis in HCC.

Long non-coding RNA GATA6-AS1 is mediated by N6-methyladenosine methylation and inhibits the proliferation and metastasis of gastric cancer

BACKGROUND Through experimental research on the biological function of GATA6-AS1,it was confirmed that GATA6-AS1 can inhibit the proliferation,invasion,and migration of gastric cancer cells,suggesting that GATA6-AS1 plays a role as an anti-oncogene in the occurrence and development of gastric cancer.Further experi-ments confirmed that the overexpression of fat mass and obesity-associated protein(FTO)inhibited the expression of GATA6-AS1,thereby promoting the occurrence and development of gastric cancer.AIM To investigate the effects of GATA6-AS1 on the proliferation,invasion and migration of gastric cancer cells and its mechanism of action.METHODS We used bioinformatics methods to analyze the Cancer Genome Atlas(https://portal.gdc.cancer.gov/.The Cancer Genome Atlas)and download expression data for GATA6-AS1 in gastric cancer tissue and normal tissue.We also constructed a GATA6-AS1 lentivirus overexpression vector which was transfected into gastric cancer cells to investigate its effects on proliferation,migration and invasion,and thereby clarify the expression of GATA6-AS1 in gastric cancer and its biological role in the genesis and development of gastric cancer.Next,we used a database(http://starbase.sysu.edu.cn/starbase2/)to analysis GATA6-AS1 whether by m6A methylation modify regulation and predict the methyltransferases that may methylate GATA6-AS1.Furthermore,RNA immunoprecipitation experiments confirmed that GATA6-AS1 was able to bind to the m6A methylation modification enzyme.These data allowed us to clarify the ability of m6A methylase to influence the action of GATA6-AS1 and its role in the occurrence and development of gastric cancer.RESULTS Low expression levels of GATA6-AS1 were detected in gastric cancer.We also determined the effects of GATA6-AS1 overexpression on the biological function of gastric cancer cells.GATA6-AS1 had strong binding ability with the m6A demethylase FTO,which was expressed at high levels in gastric cancer and negatively correlated with the expression of GATA6-AS1.Following transfection with siRNA to knock down the expression of FTO,the expression levels of GATA6-AS1 were up-regulated.Finally,the proliferation,migration and invasion of gastric cancer cells were all inhibited following the knockdown of FTO expression.CONCLUSION During the occurrence and development of gastric cancer,the overexpression of FTO may inhibit the expression of GATA6-AS1,thus promoting the proliferation and metastasis of gastric cancer.

Involvement of long non-coding RNAs in pear fruit senescence under high-and low-temperature conditions

Pear fruit senescence under high-and low-temperature conditions has been reported to be mediated by microRNAs.Long non-coding RNAs(lncRNAs),which can function as competing endogenous RNAs that interact with microRNAs,may also be involved in temperature-affected fruit senescence.Based on the transcriptome and microRNA sequencings,in this study,3330 lncRNAs were isolated from Pyrus pyrifolia fruit.Of these lncRNAs,2060 and 537 were responsive to high-and low-temperature conditions,respectively.Of these differentially expressed lncRNAs,82 and 24 correlated to the mRNAs involved in fruit senescence under high-and low-temperature conditions,respectively.Moreover,three lncRNAs were predicted to be competing endogenous RNAs(ceRNAs)that interact with the microRNAs involved in fruit senescence,while one and two ceRNAs were involved in fruit senescence under high-and low-temperature conditions,respectively.A dual-luciferase assay showed that the interaction of an lncRNA with a microRNA disrupts the action of the microRNA on the expression of its target mRNA(s).Furthermore,four alternative splicing-derived lncRNAs interacted with miR172i homologies(Novel_88 and Novel_69)to relieve the repressed expression of their target and produce an miR172i precursor.Correlation analysis of microRNA expression suggested that Novel_69 is likely involved in the cleavage of the pre-miR172i hairpin to generate mature miR172i.Taken together,lncRNAs are involved in pear fruit senescence under high-or low-temperature conditions through ceRNAs and the production of microRNA.

Expression profile of long non-coding RNAs in the intestine of black rockfish Sebastes schlegelii in response to Edwardsiella tarda infection

Long non-coding RNAs(lncRNAs)are a class of transcripts longer than 200 bp,which have been emerged as essential regulators in numerous biological processes.Black rockfish(Sebastes schlegelii)is an economic fish that widely cultured in the coastal areas of China,Japan,and South Korea.With the expansion of aquacultural scale,various pathogens have threatened its industry and reduced its economic values.It has been reported that lncRNA were involved in the immune response and metabolic pathway in teleost,while no study is available on identification and functional analysis of lncRNAs in black rockfish so far.Herein,this study was performed to identify lncRNAs in the intestine of black rockfish after Edwardsiella tarda infection.In our results,a total of 9311 lncRNAs were identified through highthroughput sequencing,and 102 lncRNAs were significantly regulated following challenge,which were predicted to target 3348 mRNAs.Results of Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analyses of the se target genes showed they were function in catalytic activity,hydrolase activity,defense response and peptidase activity,which involved in metabolic pathways and immune related pathways.In addition,47 lncRNAs and 8 differentially expressed mRNAs(DEmRNAs)showed co-expression at two or more infection time points with metabolism and immunity functions.Moreover,real-time quantitative PCR(qRT-PCR)was performed to verify the reliability of sequencing gene expression analysis results.This research laid the foundation for further investigation of the regulatory roles of lncRNAs in the intestinal immune response of black rockfish.

Identification and Characterization of Long Non-Coding RNAs Involved in Sex-Related Gene Regulation in Kelp Saccharina japonica

Long non-coding RNAs(lncRNAs)regulate a variety of biological processes,including sexual reproduction and differentiation.Saccharina japonica,a commercially important brown alga in China,shows remarkable sexual dimorphism in haploid gametophytes.The sex of Saccharina japonica gametophytes is determined by UV sexual system.However,no results have been reported on the lncRNAs involved in the sex-related gene regulation of S.japonica.This study identified a number of lncRNAs and assessed their expression levels in male and female gametophytes.Among them,a total of 405 lncRNAs and 211 mRNAs showed differential expressions.Furthermore,the functions of target genes of differentially expressed lncRNAs(DELs)differed from those of differentially expressed genes(DEGs),suggesting that lncRNA may interact with other functional proteins,in addition to DEGs,to involve sex regulation in S.japonica.There were 32 and 90 potential cis-regulatory and trans-regulatory interactions between DELsDEGs,respectively.Five of these lncRNAs(LNC_002974,LNC_021059,LNC_038466,LNC_051584,and LNC_027400)interacted with putative male sex determination region(SDR)genes,suggesting that they act as regulators in gametophytes'sex regulation potentially.Findings from this study contribute to our understanding of the roles of lncRNAs in sex differentiation and lay the foundation for functional studies of candidate lncRNAs in the future.

Bioinformatics Analysis and Experimental Verification of Prognostic and Biological Significance of Autophagy-Related Long Non-Coding RNAs in Gastric Carcinoma

Background:Long non-coding RNAs(lncRNAs)play a vital role in autophagy modulation and tumor progression.However,the key lncRNAs and their functions in gastric cancer(GC)remain largely unknown.Methods:A bioinformatic analysis of GC patients’gene expression profiling data from the Cancer Genome Atlas database was performed to identify autophagy-related lncRNAs that are associated with predictive risk.Through Cox regression and Lasso regression analyses,the autophagy-related lncRNAs that are associated with prognosis were identified,and a novel prognostic model for GC was established.The model was then used to evaluate the clinical features and predictive risk of individuals with GC.By using two datasets,GSE 62254(n=300)and GSE 15459(n=192),from Gene Expression Omnibus,its effectiveness was verified.Gene set enrichment analysis according to hallmark and Kyoto Encyclopedia of Genes and Genomes were used to determine the possible biological roles of these lncRNAs.Furthermore,the HOXD antisense growth-associated long non-coding RNA(HAGLR)mechanism in GC was discovered through in vitro and in vivo experiments.Results:Six lncRNAs associated with autophagy in GC were identified,and a new prognostic risk model based on these lncRNAs was established.The six-lncRNA signature was significantly associated with adverse clinicopathological features and found to be an independent GC prognostic factor.The model was proven to be effective and robust by GSE62254 and GSE15459.According to gene set enrichment analysis,the six lncRNAs appeared to be tightly linked to autophagy-related and cancer-related mechanisms.HAGLR was also found to promote tumor growth by enhancing autophagy signaling in GC.Conclusion:A novel prognostic model integrating HAGLR that can effectively evaluate and predict the prognostic risk of GC patients was established.The results indicated that HAGLR promotes gastric cancer progression by enhancing autophagy and is anticipated to be a potential new target for the treatment of gastric cancer.

The Dual Role of Non-coding RNAs in the Development of Periodontitis

This review aims to sum up how Non-coding RNAs(ncRNAs)regulate the development of periodontitis and provides a new perspective for understanding the pathogenesis of periodontitis.We explored the ncRNA's dual role in the development of periodontitis by summarizing evidence from previous in vivo and in vitro studies as well as clinical samples.In our review,the downregulation of 18 miRNAs,22 lncRNAs and 10 circRNAs demonstrates protective roles in periodontitis.In contrast,the expression of other 11 miRNAs,7 lncRNAs and 6 circRNAs are upregulated in periodontitis,which promote the progression of periodontitis.These dysregulated ncRNAs exert their protective or destructive roles by mainly influencing cell proliferation,differentiation and apoptosis via cross-talking with various molecules or signaling pathways.Our findings suggested which and how ncRNAs promote or delay the progression of periodontitis,which may greatly contribute to diagnose and therapy development of periodontitis based on ncRNAs in the future.

Non-coding RNAs:The potential biomarker or therapeutic target in hepatic ischemia-reperfusion injury

Hepatic ischemia-reperfusion injury(HIRI)is the major complication of liver surgery and liver transplantation,that may increase the postoperative morbidity,mortality,tumor progression,and metastasis.The underlying mechanisms have been extensively investigated in recent years.Among these,oxidative stress,inflammatory responses,immunoreactions,and cell death are the most studied.Non-coding RNAs(ncRNAs)are defined as the RNAs that do not encode proteins,but can regulate gene expressions.In recent years,ncRNAs have emerged as research hotspots for various diseases.During the progression of HIRI,ncRNAs are differentially expressed,while these dysregulations of ncRNAs,in turn,have been verified to be related to the above pathological processes involved in HIRI.ncRNAs mainly contain microRNAs,long ncRNAs,and circular RNAs,some of which have been reported as biomarkers for early diagnosis or assessment of liver damage severity,and as therapeutic targets to attenuate HIRI.Here,we briefly summarize the common pathophysiology of HIRI,describe the current knowledge of ncRNAs involved in HIRI in animal and human studies,and discuss the potential of ncRNA-targeted therapeutic strategies.Given the scarcity of clinical trials,there is still a long way to go from pre-clinical to clinical application,and further studies are needed to uncover their potential as therapeutic targets.

Roles of lncRNAs in pancreatic ductal adenocarcinoma: Diagnosis,treatment, and the development of drug resistance

Background: Pancreatic ductal adenocarcinoma(PDAC) is one of the most lethal cancers, primarily due to its late diagnosis, high propensity to metastasis, and the development of resistance to chemo-/radiotherapy. Accumulating evidence suggests that long non-coding RNAs(lnc RNAs) are intimately involved in the treatment resistance of pancreatic cancer cells via interacting with critical signaling pathways and may serve as potential diagnostic/prognostic markers or therapeutic targets in PDAC. Data sources: We carried out a systematic review on lnc RNAs-based research in the context of pancreatic cancer and presented an overview of the updated information regarding the molecular mechanisms underlying lnc RNAs-modulated pancreatic cancer progression and drug resistance, together with their potential value in diagnosis, prognosis, and treatment of PDAC. Literature mining was performed in Pub Med with the following keywords: long non-coding RNA, pancreatic ductal adenocarcinoma, pancreatic cancer up to January 2022. Publications relevant to the roles of lnc RNAs in diagnosis, prognosis, drug resistance, and therapy of PDAC were collected and systematically reviewed. Results: Lnc RNAs, such as HOTAIR, HOTTIP, and PVT1, play essential roles in regulating pancreatic cancer cell proliferation, invasion, migration, and drug resistance, thus may serve as potential diagnostic/prognostic markers or therapeutic targets in PDAC. They participate in tumorigenesis mainly by targeting mi RNAs, interacting with signaling molecules, and involving in the epithelial-mesenchymal transition process. Conclusions: The functional lnc RNAs play essential roles in pancreatic cancer cell proliferation, invasion, migration, and drug resistance and have potential values in diagnosis, prognostic prediction, and treatment of PDAC.

Construction of a prognostic signature of m7G-related lncRNAs in bladder cancer:a bioinformatics analysis

Background:N7-methylguanosine(m7G)-related plays an important role in the occurrence and development of tumors,and some recent studies have pointed out that long non-coding RNA is involved in the occurrence and development of various cancers.However,there is no literature on how m7G-related lncRNAs predict the prognosis of bladder cancer.The purpose of this study was to develop a predictive feature based on long non-coding RNA(lncRNAs)associated with m7G to predict the prognosis of patients with bladder cancer.Methods:We obtained the RNA transcriptome data and clinical data of bladder cancer patients through the cancer genome atlas database,and obtained the lncRNAs related to m7G by co-expression analysis and Cox regression analysis.Then the signature was evaluated by receiver operating characteristic curve and nomogram,and single sample gene set concentration analysis was used to study the correlation between the predictive model and tumor immune microenvironment in high-risk and low-risk groups.Results:We got a total of 5 m7G related lncRNA(MAFG-DT,AP003352.1,AC242842.1,AC024060.1,FAM111A-DT),which may be related to the prognosis of patients with bladder cancer.For predicting 1-,3-and 5-year survival rates,the area under the receiver operating characteristic curve was 0.757 and 0.722 and 0.739,respectively.Kaplan-Meier analysis showed that the prognosis of bladder cancer patients in high risk group was worse than that in low risk group.Immunoassay showed that the immune function of patients with bladder cancer in high risk group was more active.Conclusion:Prognostic markers based on m7G-related lncRNAs can be used to independently predict the prognosis of patients with bladder cancer and provide therapeutic targets for future clinical treatment.

LncRNA NORAD通过miR-513b-5p/GREM1轴调节颅内动脉瘤血管平滑肌细胞增殖、迁移、侵袭和凋亡的作用机制

目的:探讨长链非编码RNA DNA损伤诱导的非编码RNA(LncRNA NORAD)通过miR-513b-5p/GREM1轴调节颅内动脉瘤血管平滑肌细胞(VSMC)增殖、迁移、侵袭和凋亡的机制。方法:采用实时荧光定量聚合酶链式反应(PCR)法检测人颅内动脉瘤组织和正常组织中LncRNA NORAD、miR-513b-5p及GREM1表达。体外分离培养人VSMC,随机分为对照组、LncRNA NORAD siRNA组、miR-513b-5p mimics组、共转染(LncRNA NORAD siRNA+miR-513b-5p inhibitor)组、共转染阴性对照(LncRNA NORAD siRNA阴性对照+miR-513b-5p inhibitor阴性对照)组,分组转染后,采用实时荧光定量PCR法检测各组细胞LncRNA NORAD、miR-513b-5p及GREM1 mRNA表达;采用细胞计数试剂盒(CCK-8)和免疫荧光染色检测各组细胞增殖情况;采用Hoechst 33342染色和免疫荧光染色检测各组细胞凋亡情况;采用细胞划痕实验和Transwell实验检测各组细胞迁移、侵袭情况;采用免疫印记实验检测各组细胞上皮间充质转化(EMT)标志蛋白神经钙黏素(N-cadherin)、E-钙黏素(E-cadherin)、波形蛋白(Vimentin)表达;采用双荧光素酶报告实验分析VSMC中LncRNA NORAD对miR-513b-5p、miR-513b-5p对GREM1的靶向调控。结果:与正常组织比较,颅内动脉瘤组织LncRNA NORAD、GREM1 mRNA表达明显升高(P<0.05),miR-513b-5p表达明显降低(P<0.05)。与对照组比较,LncRNA NORAD siRNA组、miR-513b-5p mimics组细胞GREM1 mRNA表达、增殖率、Ki67阳性率、迁移率、侵袭数及N-cadherin、Vimentin蛋白表达降低(P<0.05),miR-513b-5p表达、凋亡率及Bax/Bcl-2、E-cadherin蛋白表达升高(P<0.05);共转染阴性对照组各指标差异无统计学意义(P>0.05)。与LncRNA NORAD siRNA组比较,共转染组细胞GREM1 mRNA表达、增殖率、Ki67阳性率、迁移率、侵袭数及N-cadherin、Vimentin蛋白表达升高(P<0.05),miR-513b-5p表达、凋亡率及Bax/Bcl-2、E-cadherin蛋白表达降低(P<0.05)。结论:敲低LncRNA NORAD可通过上调miR-513b-5p表达而降低GREM1表达,从而抑制VSMC增殖与侵袭迁移,并促使其凋亡。

参芪复方对糖尿病GK大鼠肝脏组织mRNA、lncRNA表达谱的影响

目的应用全转录组测序与实时聚合酶链锁反应(Real-time polymerase chain reaction,RT-qPCR)技术,探索参芪复方调控糖尿病GK大鼠肝脏信使RNA(messenger RNA,mRNA)、长链非编码RNA(long non-coding RNA,lncRNA)表达谱的机制研究。方法采用高脂高糖饲料建立2型糖尿病模型,将GK大鼠随机分为模型组、参芪复方组和西药组。另将10只Wistar大鼠设为空白组,予普通饲料喂养。参芪复方组大鼠予参芪复方浸膏灌胃,西药组予西格列汀混悬液灌胃,模型组及空白组灌服生理盐水。干预12周,每周检测空腹血糖(fasting blood glucose,FBG)。运用HE染色法观察大鼠肝脏组织病理形态,在空白组、模型组和参芪复方组中每组随机选取4只大鼠进行全转录组测序,构建mRNA、lncRNA差异表达谱,分析差异基因生物学功能,并进行RT-qPCR验证。结果与空白组相比,糖尿病GK大鼠FBG显著升高(P<0.05),模型组大鼠肝脏可见肝细胞排列紊乱,边界模糊,出现弥漫空泡状改变,呈中度脂肪变性,伴见炎性浸润、弥漫水肿;与模型组相比,参芪复方组大鼠FBG在12周时明显降低(P<0.05),肝脏组织排列较整齐,脂质沉积、细胞水肿及炎细胞浸润明显减轻。全转录组结果显示,与空白组相比,模型组大鼠mRNA、lncRNA表达谱存在显著差异,决定了糖尿病大鼠生理病理上的差异表现。参芪复方可广泛调控mRNA、lncRNA的差异表达,富集分析显示参芪复方通过调控多条内分泌系统及代谢过程相关信号通路改善糖尿病,包括胰岛素分泌、非酒精性脂肪性肝病、胆固醇代谢、鞘脂代谢、胰岛素抵抗等信号通路。RT-qPCR结果显示,基因Irf1、Trim30、Tmcc3、Insig1与转录组结果一致,转录组准确性较高。结论参芪复方发挥调节血糖及改善肝脏脂质沉积、水肿的作用,可能与广泛调控mRNA、lncRNA的差异表达有关。

Diagnostic and prognostic potential of tissue and circulating long non-coding RNAs in colorectal tumors

Long non-coding RNAs(lncRNAs)are members of the non-protein coding RNA family longer than 200 nucleotides.They participate in the regulation of gene and protein expression influencing apoptosis,cell proliferation and immune responses,thereby playing a critical role in the development and progression of various cancers,including colorectal cancer(CRC).As CRC is one of the most frequently diagnosed malignancies worldwide with high mortality,its screening and early detection are crucial,so the identification of disease-specific biomarkers is necessary.LncRNAs are promising candidates as they are involved in carcinogenesis,and certain lncRNAs(e.g.,CCAT1,CRNDE,CRCAL1-4)show altered expression in adenomas,making them potential early diagnostic markers.In addition to being useful as tissue-specific markers,analysis of circulating lncRNAs(e.g.,CCAT1,CCAT2,BLACAT1,CRNDE,NEAT1,UCA1)in peripheral blood offers the possibility to establish minimally invasive,liquid biopsy-based diagnostic tests.This review article aims to describe the origin,structure,and functions of lncRNAs and to discuss their contribution to CRC development.Moreover,our purpose is to summarise lncRNAs showing altered expression levels during tumor formation in both colon tissue and plasma/serum samples and to demonstrate their clinical implications as diagnostic or prognostic biomarkers for CRC.

Circulating micro RNAs and long non-coding RNAs in gastric cancer diagnosis:An update and review

Gastric cancer(GC) is the fourth most common cancer and the third leading cause of cancer mortality worldwide. Micro RNAs(mi RNAs) and long non-coding RNAs(lnc RNAs) are the most popular non-coding RNAs in cancer research. To date,the roles of mi RNAs and lnc RNAs have been extensively studied in GC,suggesting that mi RNAs and lnc RNAs represent a vital component of tumor biology. Furthermore,circulating mi RNAs and lnc RNAs are found to be dysregulated in patients with GC compared with healthy individuals. Circulating mi RNAs and lnc RNAs may function as promising biomarkers to improve the early detection of GC. Multiple possibilities for mi RNA secretion have been elucidated,including active secretion by microvesicles,exosomes,apoptotic bodies,highdensity lipoproteins and protein complexes as well as passive leakage from cells. However,the mechanism underlying lnc RNA secretion and the functions of circulating mi RNAs and lnc RNAs have not been fully illuminated. Concurrently,to standardize results of global investigations of circulating mi RNAs and lnc RNAs biomarker studies,several recommendations for preanalytic considerations are put forward. In this review,we summarize the known circulating mi RNAs and lnc RNAs for GC diagnosis. The possible mechanism of mi RNA and lnc RNA secretion as well as methodologies for identification of circulating mi RNAs and lnc RNAs are also discussed. The topics covered here highlight new insights into GC diagnosis and screening.

Behind the curtain of non-coding RNAs; long non-coding RNAs regulating hepatocarcinogenesis

Hepatocellular carcinoma(HCC) is one of the most common and aggressive cancers worldwide. HCC is the fifth common malignancy in the world and the second leading cause of cancer death in Asia. Long non-coding RNAs(lncRNAs) are RNAs with a length greater than 200 nucleotides that do not encode proteins. lncRNAs can regulate gene expression and protein synthesis in several ways by interacting with DNA, RNA and proteins in a sequence specific manner. They could regulate cellular and developmental processes through either gene inhibition or gene activation. Many studies have shown that dysregulation of lncRNAs is related to many human diseases such as cardiovascular diseases, genetic disorders, neurological diseases, immune mediated disorders and cancers. However, the study of lncRNAs is challenging as they are poorly conserved between species, their expression levels aren't as high as that of m RNAs and have great interpatient variations. The study of lncRNAs expression in cancers have been a breakthrough as it unveils potential biomarkers and drug targets for cancer therapy and helps understand the mechanism of pathogenesis. This review discusses many long non-coding RNAs and their contribution in HCC, their role in development, metastasis, and prognosis of HCC and how to regulate and target these lncRNAs as a therapeutic tool in HCC treatment in the future.

Long non-coding RNAs in stem cells and cancer

An overwhelming majority of the transcribed genome encodes for non-coding RNA(ncR NA) sequences. Deep sequencing of the transcriptome has uncovered tens of thousands of long ncR NA(lncR NA) sequences. However, little is known regarding the possible functions for a vast majority of these sequences. Among those lncR NAs whose function has been experimentally validated, most serve as regulators of gene expression. LncR NAs have been found to be critical to development and homeostasis and they have been implicated in several pathologies including cancer. Here, we examine the functions and underlying mechanisms of lnc RNAs in stem cells and in cancer biology, areas linked by the actions of lncR NAs.

Expression Profile of Altered Long Non-coding RNAs in Patients with HBV-associated Hepatocellular Carcinoma

In China, hepatitis B virus （HBV） infection is the major cause of hepatocellular carcinoma （HCC）, which is called HBV-related HCC （HBV-HCC）, but the pathogenesis has not been clearly elu- cidated. Long non-coding RNAs （lncRNAs） have been paid increasing attention to, as an important regulatory molecule involved in many biological processes, as well as a variety of diseases. This study examined lncRNA that might play an important role in HBV-HCC pathogenesis by conducting lncRNA and mRNA profile comparison between HBV-HCC and normal liver tissues. The differentially ex- pressed lncRNA and mRNA profiles between HBV-HCC and normal liver tissues were analyzed by mi- croarrays. The potential protein-encoding gene regulated by lncRNA, and the biological function （gene ontology, pathway analysis） of the target gene were investigated. The results showed that the expression levels of lncRNA and mRNA in HBV-HCC tissues were different from those in normal liver tissues. As compared with normal liver tissue, 837 （4.30%） lncRNAs exhibited more than two-fold change （P〈0.05）; 325 were up-regulated, and 512 were down-regulated; 991 （5.70%） mRNAs exhibited more than 2-fold change （P〈0.05）; 733 were up-regulated and 258 were down-regulated in HBV-HCC tissue. Besides, there were 7 lncRNAs with above 10-fold elevation, 6 lncRNAs with above 10-fold decrease, 18 mRNAs with above 10-fold elevation and 11 mRNAs with above 10-fold decrease. 444 （53.05%） lncRNAs had their corresponding mRNAs, some of which were adjacent to lncRNAs. The biological analysis showed that the target gene of differentially expressed lncRNAs took part in the important bio- logical regulatory function. Target gene-related pathway analysis revealed the pathways in carcinoma and mitogen-activated protein kinase （MAPK） signaling pathways significantly changed in the HBV-HCC tissues as compared with normal liver tissues （P〈0.05）. It was suggested that as compared with normal liver tissues, the expression of lncRNAs in HBV-HCC tissues changed significantly, and lncRNAs played a key role in the pathogenesis of HBV-HCC probably by mainly regulating the carci- noma-related signaling pathway and MAPK signaling pathways.

Long non-coding RNAs era in liver cancer

Hepatocellular carcinoma(HCC) is one of the most common malignancies leading to high mortality rates in the general population and the sixth most common cancer worldwide. HCC is characterized by deregulation of multiple genes and signalling pathways. These genetic effects can involve both protein coding genes as well as non-coding RNA genes. Long noncoding RNAs(lnc RNAs) are transcripts longer than 200 nt, constituting a subpopulation of nc RNAs. Their biological effects are not well understood comparedto small non-coding RNA(micro RNAs), but they have been recently recognized to exert a crucial role in the regulation of gene expression and modulation of signalling pathways. Notably, several studies indicated that lnc RNAs contribute to the pathogenesis and progression of HCC. Investigating the molecular mechanisms underlying lnc RNAs expression opens potential applications in diagnosis and treatment of liver disease. This editorial provides three examples(MALAT-1 metastasis associated lung adenocarcinoma transcript, HULC highly upregulated in liver cancer and HOTAIR HOX transcript antisense intergenic RNA) of well-known lnc RNAs upregulated in HCC, whose mechanisms of action are known, and for which therapeutic applications are delineated. Targeting of lnc RNAs using several approaches(siR NA-mediated silencing or changing their secondary structure) offers new possibility to treat HCC.