Long non-coding RNA CARLo-5 expression is associated with disease progression and predicts outcome in hepatocellular carcinoma patients. Clin Exp Med. 2017;17:33-43. [PMID: 26433964 DOI: 10.1007/s10238-015-0395-9]

The role of long non-coding RNA in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a prevalent liver malignancy with complex etiology and generally poor prognosis. Recently, long non-coding RNAs (lncRNAs), non-protein-coding RNA molecules exceeding 200 nucleotides, have emerged as pivotal players in HCC, influencing its initiation, progression, invasion, and metastasis. These lncRNAs modulate gene expression at epigenetic, transcriptional, and post-transcriptional levels, actively participating in the pathological and physiological processes of HCC. Understanding the intricate relationship between lncRNAs and HCC is important for improving prognosis and reducing mortality. This review summarizes advancements in elucidating the role of lncRNAs in HCC pathogenesis.

Clinicopathological and prognostic value of long non-coding RNA CCAT1 expression in patients with digestive system cancer

Colon cancer associated transcript-1 (CCAT1) is known to play an important role in numerous types of human cancer, including bladder, prostate and ovarian cancer. However, a consistent perspective has not been established in digestive system cancer (DSC). To explore the prognostic value of CCAT1 in patients with DSC, a meta-analysis was performed. A systematic search of PubMed, Embase, Web of Science, China National Knowledge Infrastructure, Chinese Biological Medical Literature database, Cochrane Library and WanFang database was applied to select eligible articles. Pooled odds ratios (ORs) or hazard ratios (HRs) with corresponding 95% confidence intervals (CIs) were calculated to estimate the effects of CCAT1 on pathological or clinical features. A total of 1,719 patients from 12 eligible articles were enrolled in the meta-analysis. The results revealed that elevated CCAT1 expression was significantly related to larger tumor size (OR, 1.81; 95% CI, 1.31-2.48), poorer differentiation (OR, 0.45; 95% CI, 0.31-0.64), earlier lymph node metastasis (OR, 3.14; 95% CI, 2.34-4.22) and advanced TNM stage (OR, 3.08; 95% CI, 2.07-4.59). In addition, high CCAT1 expression predicted a poorer outcome for overall survival rate (HR, 2.37; 95% CI, 2.11-2.67) and recurrence-free survival rate (HR, 2.16, 95% CI, 1.31-3.57). High expression levels of CCAT1 were therefore related to unfavorable clinical outcomes of patients with DSC. These results demonstrated that CCAT1 could serve as a prognostic predictor in human DSC.

LncRNA FGD5-AS1 enhances the proliferation and stemness of hepatocellular carcinoma cells through targeting miR-223 and regulating the expression of ECT2 and FAT1

AIM

Hepatocellular carcinoma (HCC) is common and causes many deaths worldwide. The aim of this study is to explore the mechanism by which long non-coding RNA FGD5-AS1 regulates HCC cell proliferation and stemness.

METHODS

Tumor and normal adjacent tissues were harvested from HCC patients. Real-time quantitative reverse transcription-PCR was applied to examine the expression of FGD5-AS1, miR-223, Epithelial cell transforming sequence 2 (ECT2) and FAT1. The protein levels of ECT2, FAT1, proliferating cell nuclear antigen (PCNA), OCT4, CD133 and CD90 were analyzed by western blot. The localization of FGD5-AS1 was examined by Fluorescence in situ hybridization. Cell proliferation was analyzed with CCK-8 and colony formation assays. Spheroid formation was used for analyzing cell stemness. Gene interaction was examined by RNA immunoprecipitation and luciferase activity assays. A subcutaneous xenograft mouse model was established to analyze HCC growth and stemness in vivo. Immunohistochemistry staining was used to analyze the expression PCNA and OCT4 in subcutaneous tumors.

RESULTS

FGD5-AS1 was upregulated in HCC and its high expression indicated poor prognosis of patients. High expression of FGD5-AS1 enhanced HCC cell proliferation and stemness. Knockdown of FGD5-AS1 restrained tumor growth and stemness in mice. FGD5-AS1 directly sponged miR-223 and promoted the expression of ECT2 and FAT1 in HCC. Both knockdown of miR-223 and overexpression of ECT2 and FAT1 reversed FGD5-AS1 silencing-mediated suppression of HCC cell proliferation and stemness.

CONCLUSION

FGD5-AS1 directly sponged miR-223 and promoted the expression of ECT2 and FAT1 in HCC, thus enhancing HCC cell proliferation and stemness. Our study identifies potential prognostic biomarkers and therapeutic targets for HCC.

Involvement of the circular RNA/microRNA/glucose-6-phosphate dehydrogenase axis in the pathological mechanism of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related death worldwide with high mortality. The incidence of HCC is increasing in China. Abnormal activation of glucose-6-phosphate dehydrogenase (G6PD) exists in all malignant tumors, including HCC, and is closely related to the development of HCC. In addition, the differential expression of non-coding RNAs is closely related to the development of HCC. This systematic review focuses on the relationship between G6PD, HCC, and non-coding RNA, which form the basis for the circRNA/miRNA/G6PD axis in HCC. The circular RNA (circRNA)/microRNA (miRNA)/G6PD axis is involved in development of HCC. We proposed that non-coding RNA molecules of the circRNA/miRNA/G6PD axis may be novel biomarkers for the pathological diagnosis, prognosis, and targeted therapy of HCC.

The Association between Long Noncoding RNA over Expression and Poor Prognosis of Liver Cancer: A Meta-Analysis

BACKGROUND

Long noncoding RNA (lncRNA) is considered to be a mediator of carcinogenesis, which may be associated with liver cancer survival. However, the relationship remains inconclusive. Meta-analysis was conducted to analytically review the association between the lncRNA expression level and clinicopathological characteristics and prognostic value of hepatic carcinoma.

MATERIALS AND METHODS

Four databases including Embase, PubMed, Web of Science, and the Cochrane Library were searched to collect studies about the relation between lncRNA overexpression and prognosis of liver cancer, dating from the earliest records of these databases to March 2021. Two researchers independently screened the data and literature to perform a stringent evaluation of the quality of material involved in the study. Meta-analysis was performed by Stata 16.0 software on 42 case-control studies with 6293 samples.

RESULTS

The outcomes of meta-analysis are presented as follows: lncRNA overexpression patients had later TNM stage (OR = 0.36, 95% CI (0.31, 0.41), P < 0.001), lower histological grade (OR = 0.56, 95%CI (0.49, 0.65), P < 0.001), more vascular invasion (OR = 2.02, 95% CI (1.74, 2.35), P < 0.001), bigger tumor size (OR = 2.28, 95% CI (2.00, 2.60), P < 0.001), more severe liver cirrhosis (OR = 1.39, 95% CI(0.1.16, 1.66), P < 0.001), more likely to metastasize (OR = 1.80, 95%CI(1.49, 2.18), P < 0.001), and more tumor numbers (OR = 0.72, 95% CI (0.62, 0.84), P < 0.05). lncRNA over expression patients had shorter OS (HR = 2.32, 95 CI% (2.08, 2.59), P < 0.01, RFS (HR = 2.19, 95 CI% (1.72, 2.78), P < 0.01), and DFS (HR = 2.01, 95 CI% (1.57, 2.57), P < 0.01).

CONCLUSIONS

Overexposure of lncRNA is a poor prognostic feature for patients with hepatic carcinoma. The scope of our study was limited because of a lack of relevant research and the poor representativeness and varying quality of the studies involved in the current meta-analysis. Our conclusion still requires higher studies for further validation. This trial is clinically registered with CRD4201920620.

The Association between Long Noncoding RNA over Expression and Poor Prognosis of Liver Cancer: A Meta-Analysis

Background

Long noncoding RNA (lncRNA) is considered to be a mediator of carcinogenesis, which may be associated with liver cancer survival. However, the relationship remains inconclusive. Meta-analysis was conducted to analytically review the association between the lncRNA expression level and clinicopathological characteristics and prognostic value of hepatic carcinoma.

Materials and Methods

Four databases including Embase, PubMed, Web of Science, and the Cochrane Library were searched to collect studies about the relation between lncRNA overexpression and prognosis of liver cancer, dating from the earliest records of these databases to March 2021. Two researchers independently screened the data and literature to perform a stringent evaluation of the quality of material involved in the study. Meta-analysis was performed by Stata 16.0 software on 42 case-control studies with 6293 samples.

Results

The outcomes of meta-analysis are presented as follows: lncRNA overexpression patients had later TNM stage (OR = 0.36, 95% CI (0.31, 0.41), P < 0.001), lower histological grade (OR = 0.56, 95%CI (0.49, 0.65), P < 0.001), more vascular invasion (OR = 2.02, 95% CI (1.74, 2.35), P < 0.001), bigger tumor size (OR = 2.28, 95% CI (2.00, 2.60), P < 0.001), more severe liver cirrhosis (OR = 1.39, 95% CI(0.1.16, 1.66), P < 0.001), more likely to metastasize (OR = 1.80, 95%CI(1.49, 2.18), P < 0.001), and more tumor numbers (OR = 0.72, 95% CI (0.62, 0.84), P < 0.05). lncRNA over expression patients had shorter OS (HR = 2.32, 95 CI% (2.08, 2.59), P < 0.01, RFS (HR = 2.19, 95 CI% (1.72, 2.78), P < 0.01), and DFS (HR = 2.01, 95 CI% (1.57, 2.57), P < 0.01).

Conclusions

Overexposure of lncRNA is a poor prognostic feature for patients with hepatic carcinoma. The scope of our study was limited because of a lack of relevant research and the poor representativeness and varying quality of the studies involved in the current meta-analysis. Our conclusion still requires higher studies for further validation. This trial is clinically registered with CRD4201920620.

Long noncoding RNA ZFPM2-AS1 promotes the proliferation, migration, and invasion of hepatocellular carcinoma cells by regulating the miR-576-3p/HIF-1α axis

Long noncoding RNA (LncRNA) zinc finger protein multitype 2 antisense RNA 1 (ZFPM2-AS1) is highly expressed in a variety of tumors and is involved in promoting the malignant biological behaviors of cancer cells. However, the mechanism of ZFPM2-AS1 in the progression of hepatocellular carcinoma (HCC) remains to be explored. The ZFPM2-AS1 expression in HCC was measured by quantitative real-time PCR (qRT-PCR); cell counting kit-8, 5-bromo-2'-deoxyuridine (BrdU), and transwell assays were used to confirm the biological functions of ZFPM2-AS1 in regulating the malignant biological behaviors of HCC cells; the luciferase reporter gene assay was employed to detect whether ZFPM2-AS1 could bind to microRNA (miR)-576-3p; the regulatory relationship between ZFPM2-AS1 and miR-576-3p was probed by qRT-PCR; the effects of ZFPM2-AS1 and miR-576-3p on the expression of hypoxia-inducible factor 1α (HIF-1α) were detected by qRT-PCR and Western blot. The expression of ZFPM2-AS1 in HCC tissues, compared with that in normal liver tissues, was significantly upregulated. Knockdown of ZFPM2-AS1 markedly inhibited HCC cell proliferation, migration, and invasion while the overexpression of ZFPM2-AS1 worked oppositely. miR-576-3p could reverse the effects of ZFPM2-AS1 on the biological behaviors of HCC cells. Besides, ZFPM2-AS1 could bind to miR-576-3p and positively regulate the expression of HIF-1α, a target gene of miR-576-3p, by adsorbing miR-576-3p. ZFPM2-AS1 is abnormally highly expressed in HCC and facilitates proliferation, migration, and invasion of HCC cells by adsorbing miR-576-3p and upregulating HIF-1α expression.

Long Noncoding RNA MIR100HG Knockdown Attenuates Hepatocellular Carcinoma Progression by Regulating MicroRNA-146b-5p/Chromobox 6

PURPOSE

Hepatocellular carcinoma (HCC) accounts for approximately ninety percent of primary liver cancer. This study attempted to investigate the effects of the long noncoding RNA MIR100HG (MIR100HG) in HCC and the underlying molecular mechanism.

MATERIALS AND METHODS

qRT-PCR was implemented to analyze the expression of MIR100HG, microRNA-146b-5p (miR-146b-5p), and Chromobox 6 (CBX6). The correlation between MIR100HG and clinicopathological features of HCC patients was assessed. Additionally, the effects of MIR100HG knockdown on HCC cell viability, migration, and invasion were explored. The interactions among MIR100HG, miR-146b-5p, and CBX6 were confirmed. Furthermore, rescue experiments were conducted to investigate whether MIR100HG knockdown modulates HCC cell behaviors through modulating the miR-146b-5p/CBX6 axis.

RESULTS

The expression of MIR100HG and CBX6 was enhanced, while miR-146b-5p was inhibited in HCC cells. High MIR100HG expression was positively associated with the TNM tumor stage and Edmondson-Steiner grading in HCC patients. MIR100HG knockdown considerably reduced the HCC cell viability, migration, and invasion. In addition, MIR100HG directly targeted miR-146b-5p, and miR-146b-5p directly targeted CBX6 in HCC cells. Moreover, miR-146b-5p suppression or CBX6 elevation evidently rescued the suppressed viability, migration, and invasion of HCC cells caused by MIR100HG knockdown.

CONCLUSIONS

Knockdown of MIR100HG inhibited the viability, migration, and invasion of HCC cells by targeting the miR-146b-5p/CBX6 axis, offering a potential therapeutic target for HCC therapy.

The Impact of Long Non-Coding RNAs in the Pathogenesis of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is among the utmost deadly human malignancies. This type of cancer has been associated with several environmental, viral, and lifestyle risk factors. Among the epigenetic factors which contribute in the pathogenesis of HCC is dysregulation of long non-coding RNAs (lncRNAs). These transcripts modulate expression of several tumor suppressor genes and oncogenes and alter the activity of cancer-related signaling axes. Several lncRNAs such as NEAT1, MALAT1, ANRIL, and SNHG1 have been up-regulated in HCC samples. On the other hand, a number of so-called tumor suppressor lncRNAs namely CASS2 and MEG3 are down-regulated in HCC. The interaction between lncRNAs and miRNAs regulate expression of a number of mRNA coding genes which are involved in the pathogenesis of HCC. H19/miR-15b/CDC42, H19/miR-326/TWIST1, NEAT1/miR-485/STAT3, MALAT1/miR-124-3p/Slug, MALAT1/miR-195/EGFR, MALAT1/miR-22/SNAI1, and ANRIL/miR-144/PBX3 axes are among functional axes in the pathobiology of HCC. Some genetic polymorphisms within non-coding regions of the genome have been associated with risk of HCC in certain populations. In the current paper, we describe the recent finding about the impact of lncRNAs in HCC.

Effect of long noncoding RNAs on epithelial-mesenchymal transition in A549 cells and fibrotic human lungs

Long noncoding RNAs (LncRNAs) regulate epithelial-mesenchymal transition (EMT). EMT involves myofibroblast differentiation and pulmonary fibrosis (PF). We aimed to determine the expression profiles of HOTAIR, CARLo-5, and CD99P1 LncRNAs in EMT-mediated myofibroblast differentiation in A549 cells and fibrotic human lungs and to explain their roles. A group of A549s was stimulated with transforming growth factor β (TGF-β; 5 ng/ml) to induce EMT. The remaining A549s were incubated with 20 μM FH535 after 24 h of TGF-β treatment to inhibit EMT. A549s were collected at 0, 24, 36, and 48 h. Expressions of three LncRNAs and protein/genes related to EMT, myofibroblast differentiation, and PF were assayed by quantitative reverse-transcription polymerase chain reaction and Western blot analysis in A549s and fibrotic human lungs. The targets of three LncRNAs were investigated by bioinformatics methods. TGF-β stimulation resulted in increased expressions of three LncRNAs, ACTA2, COL1A1, SNAI1, CTNNB1, TCF4, LEF1, α-SMA, and active-β-catenin, and decreased E-cadherin at 24, 36, and 48 h in A549s. FH535 treatment regressed these alterations. But it increased HOTAIR expression at 36 h and did not increase E-cadherin at 48 h. Fibrotic human lungs were characterized by increased expressions of HOTAIR, CARLo-5, CD99P1, and miR-214, decreased expressions of miR-148b, miR-218-1, miR-7-1, and the presence of CARLo-5 and CD99P1 in HDAC1-LncRNAs coprecipitation products, but not HOTAIR. Bioinformatic analysis showed the interactions of three LncRNAs with both proteins and at least 13 microRNAs related to EMT and PF. In conclusion, HOTAIR, CARLo-5, and CD99P1 can regulate EMT-mediated myofibroblast differentiation through interacting with proteins and miRNAs associated with EMT and PF. These LncRNAs can be considered as potential targets to decrease EMT for treating PF.

Potential diagnostic and prognostic value and regulatory relationship of long noncoding RNA CCAT1 and miR-130a-3p in clear cell renal cell carcinoma

Background

MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs) could interact with each other to play a vital role in the pathogenesis of cancers. We aimed to examine the expression profile, clinical significance and regulatory relationship of miR-130a-3p and its predicted interactive lncRNA in clear cell renal cell carcinoma (ccRCC).

Methods

Bioinformatics analysis was used to predict lncRNAs binding with miR-130a-3p. qRT-PCR was employed to detect the expression levels of miR-130a-3p and the miRNA-targeted lncRNA, and their clinical values in ccRCC were clarified. The lncRNA sponge potential of miR-130a-3p was assessed through dual-luciferase reporter assay and the biological effects of them were observed.

Results

Colon cancer associated transcript 1 (CCAT1) directly interacted with miR-130a-3p and negatively regulated miR-130a-3p expression. CCAT1 was upregulated and miR-130a-3p was downregulated in ccRCC cell line and tissues (all P < 0.05). High CCAT1 and low miR-130a-3p expression was correlated with larger tumor size and advanced TNM stage in ccRCC patients. High CCAT1 level suggested a poor survival prognosis. There was a negative association between CCAT1 and miR-130a-3p expression (r = − 0.373, P = 0.010). MiR-130a-3p mimic and si-CCAT1 inhibited ccRCC cell proliferation and invasion, and induced apoptosis.

Conclusions

CCAT1/miR-130a-3p axis may have potential to serve as a novel diagnostic and prognostic target of ccRCC patients.

The prognostic significance of long non-coding RNAs in hepatocellular carcinoma: An updated meta-analysis

BACKGROUND

Recently, many studies have demonstrated that long non-coding RNAs (lncRNAs) are abnormally expressed in hepatocellular carcinoma (HCC) and may serve as a potential molecular biomarker to evaluate the prognosis of hepatocellular carcinoma. Therefore, we accomplished a meta-analysis built on current studies to assess the prognostic value of lncRNAs in hepatocellular carcinoma.

METHODS

The PubMed database was carefully searched to collect all eligible studies until February 20, 2019. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) of the overall survival, relapse-free survival, and progression-free survival were calculated to evaluate the prognostic significance of lncRNAs expression in hepatocellular carcinoma using Stata12.0 software. Heterogeneity, sensitivity analysis, and publication bias were also evaluated.

RESULTS

The results showed that the expression level of lncRNAs was significantly correlated with clinical outcomes. Abnormally expressed lncRNAs predicted poor overall survival (HR=2.19, 95% CI: 1.99-2.42, P<0.001; I²=44.7%, P=0.005), relapse-free survival (HR=2.68, 95% CI: 1.74-4.14, P<0.001; I²=0.0%, P=0.763) and progression-free survival of hepatocellular carcinoma patients (HR=2.44, 95% CI: 1.53-3.89, P<0.001; I²=0.0%, P=0.336). Statistical significance was also noted in subgroup meta-analyses that were stratified by follow-up time, cutoff value, and quality score. Moreover, the pooled results indicated that lncRNAs expression was significantly associated with tumor size (HR=1.48, 95% CI: 1.24-1.79), tumor number (HR=1.34, 95% CI: 1.08-1.66), and tumor node metastasis stage (HR=2.10, 95% CI: 1.48-2.99), but not liver cirrhosis and tumor differentiation (P>0.05).

CONCLUSIONS

This meta-analysis indicates that lncRNAs are strongly associated with prognosis in hepatocellular carcinoma and may serve as a promising indicator for prognostic evaluation of patients with hepatocellular carcinoma. But larger clinical studies are needed to verify its feasibility.

Lung Carcinoma Cells Secrete Exosomal MALAT1 to Inhibit Dendritic Cell Phagocytosis, Inflammatory Response, Costimulatory Molecule Expression and Promote Dendritic Cell Autophagy via AKT/mTOR Pathway

Objective

To investigate the potential mechanism underlying the effect of lung carcinoma cell-derived exosomes on dendritic cell function.

Materials and Methods

C57BL/6 (B6) mice were randomly divided into five groups: control, dendritic cell (DC), DC-NC, DC-siMALAT1, and siMALAT1. Tumor cell proliferation was measured by Ki-67 staining. LLC cells were divided into control, NC, and si-MALAT1 groups, and exosomes secreted by each group were labeled as PEX, PEXN, and PEX-si, respectively. Exosomes and autophagic vacuoles were observed by transmission electron microscopy. MALAT1 expression in LLC, A549, and Beas-2b cells was examined by RT-PCR. The expression of IFN-γ, IL-12, IL-10, and TGF-β was observed by Elisa assay. Flow cytometry was used to observe the phagocytic function of DCs, costimulatory molecule expression, and T cell proliferation and differentiation. The protein expression of p-AKT, AKT, p-mTOR, mTOR, ALIX, TSG101, and CD63 was detected by Western blot.

Results

Compared with Beas-2b cells, MALAT1 expression was significantly increased in both LLC and A549 cells and in their secreted exosomes, and LLC cells showed the highest expression of MALAT1 (P < 0.05). Tumor cell proliferation and tumor volume were significantly decreased in the siMALAT1 and DC-siMALAT1 groups compared to those in the control group. DC phagocytosis, inflammatory response, costimulatory molecule expression, and T cell proliferation in the siMALAT1 and PEX-si groups were significantly enhanced (P < 0.05), while DC autophagy and T cell differentiation were reduced (P < 0.05). The levels of p-AKT, AKT, p-mTOR, and mTOR in the PEX and PEXN groups were increased compared with those in the control group, while those in the siMALAT1 and PEX-si groups were significantly decreased (P < 0.05).

Conclusion

Inhibition of MALAT1 expression in LLC-derived exosomes promoted DC function and T cell proliferation and suppressed DC autophagy and T cell differentiation, suggesting that MALAT1 inhibition may be a potential strategy for the clinical treatment of lung cancer.

Role of long noncoding RNA-mediated competing endogenous RNA regulatory network in hepatocellular carcinoma

Long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) are noncoding RNAs (ncRNAs) that occupy over 90% of the human genome, and their main function is to directly or indirectly regulate messenger RNA (mRNA) expression and participate in the tumorigenesis and progression of malignances. In particular, some lncRNAs can interact with miRNAs as competing endogenous RNAs (ceRNAs) to modulate mRNA expression. Accordingly, these RNA molecules are interrelated and coordinate to form a dynamic lncRNA-mediated ceRNA regulatory network. Mounting evidence has revealed that lncRNAs that act as ceRNAs are closely related to tumorigenesis. To date, numerous studies have established many different regulatory networks in hepatocellular carcinoma (HCC), and perturbations in these ceRNA interactions may result in the initiation and progression of HCC. Herein, we emphasize recent advances concerning the biological function of lncRNAs as ceRNAs in HCC, with the aim of elucidating the molecular mechanism underlying these HCC-related RNA molecules and providing novel insights into the diagnosis and treatment of HCC.

Clinical significance of serum miR-768-3p in HBV-related hepatocellular carcinoma and its potential mechanism

The purpose of this study was to reveal the clinical diagnostic and prognostic value of miR-768-3p in HBV-related HCC and to investigate its effect on the biological function of HCC. Quantitative real-time polymerase chain reaction was used to detect the expression level of miR-768-3p in subjects' serum. The receiver operating characteristics curve (ROC) evaluated the diagnostic value of miR-768-3p in patients. A Chi-square test was used to analyze the relationship between miR-768-3p and clinical data of patients. Kaplan-Meier survival and Cox regression analysis assessed the prognostic value of miR-768-3p in HCC. Finally, CCK-8 and Transwell assays were used to demonstrate the effect of miR-768-3p on HBV-related HCC function. Serum miR-768-3p was significantly lower in HCC patients than in healthy controls and chronic hepatitis B (CHB) patients. ROC curve suggested that serum miR-768-3p has an important diagnostic value for HBV-related HCC and can significantly differentiate HCC patients from healthy controls, and it can also diagnose HCC patients from CHB patients. Cox analysis confirmed that miR-768-3p was an independent risk factor. Low expression of miR-768-3p was associated with Tumor, Node, Metastasis stage, Barcelona Clinic Liver Cancer stage, and poor prognosis in HCC patients. Finally, cell function experiments confirmed that high expression of miR-768-3p could inhibit cell proliferation, migration, and invasion. All experiments confirmed that miR-768-3p can inhibit the proliferation, migration, and invasion of HBV-related HCC cells, and the low expression of miR-768-3p can be used as a potential diagnostic and prognostic biomarker for HBV-related HCC.

Six long noncoding RNAs as potentially biomarkers involved in competitive endogenous RNA of hepatocellular carcinoma

To investigate lncRNAs acting as competing endogenous RNAs (ceRNAs) involved in oncogenesis and progression of HCC. Different expressed lncRNAs, microRNAs, and mRNAs (DElncRNAs, DEmiRNAs, DEmRNAs), downloaded from The Cancer Genome Atlas (TCGA) database, were identified by edgeR package. CeRNA network was constructed based on miRcode, TargetScan, and miRTarBase. Target DEmRNAs were annotated by KEGG pathway and GO analysis. Negatively correlated lncRNA-miRNA pairs were analyzed by Pearson correlation coefficient, simultaneously, overall survival (OS) were evaluated. The expression of these lncRNAs were examined in HCC cell lines and tissues through qRT-PCR. 1070 DElncRNAs, 147 DEmiRNAs and 1993 DEmRNAs were acquired. CeRNA network was successfully established, including 27 lncRNAs, 5 miRNAs, and 30 mRNAs significantly correlated with OS. The DEmRNAs were significantly enriched in "Cell Cycle" and "pathways in cancer". Six lncRNAs and 2 miRNAs were negatively correlated. These lncRNAs were validated by qRT-PCR. These observations will provide a novel perspective to elucidate HCC pathogenesis.

Long non-coding RNAs in non-small cell lung cancer: functions and distinctions from other malignancies

Lung cancer leads to the most cancer-related death in the world. It was shown from the increasing evidences that long non-coding RNAs (lncRNAs) are emerging as molecules for diagnosis, prognosis and even therapy of lung cancer and other malignancies. The biological functions or involved signaling pathways of lncRNAs are always found to be inconsistent among different types of malignancies. However, no available literature has systemically summarized differences in the functions and underlying molecular mechanisms of lncRNAs between lung cancer and other cancers. In this review, the biological functions and molecular mechanisms of lncRNAs in lung cancer were introduced. Furthermore, their functional differences between lung cancer and other malignancies were discussed. Finally, their potential clinical applications in future lung cancer therapy were focused on.

The Long Noncoding RNA LINC00908 Facilitates Hepatocellular Carcinoma Progression Via Interaction With Sox-4

Background

The hepatocellular carcinoma (HCC) is a highly aggressive and common malignancy worldwide. Accumulating evidence has demonstrated a pivotal role of long noncoding RNAs (lncRNAs) in various tumors. However, the function of intergenic lncRNA LINC00908 is still unknown in HCC.

Methods

The RT-qPCR method was used to quantify the expression of LINC00908. Migration and viability assay were performed to evaluate the in vitro effect and xenograft tumor model was used to measure the in vivo effect. Immunoblot was used to identify the association of LINC00908 with Sox-4 and the stability of Sox-4.

Results

We found a novel lncRNA related to HCC. LINC00908 is highly expressed in tumorous tissues and cell lines compared with normal ones. High LINC00908 expression correlated with advanced TNM stages, tumor size and metastasis. LINC00908 promoted the migration and viability of HCC cells. The in vivo xenograft tumor growth and proliferation were also enhanced by LINC00908 overexpression and inhibited by LINC00908 silence. LINC00908 physically interacted with Sox-4, and the association between LINC00908 and Sox-4 increased the stability of Sox-4 by reducing proteasomal degradation.

Conclusion

Taken together, our current work has identified a novel lncRNA LINC00908 which is critically involved in HCC progression. The LINC00908-Sox-4 axis might provide a new and potential target for pharmaceutical therapies.

Identification of diagnostic long non‑coding RNA biomarkers in patients with hepatocellular carcinoma

Liver cancer is a leading cause of cancer-associated mortality worldwide. Hepatocellular carcinoma (HCC) is the most common subtype of liver cancer. The aim of the present study was to identify long non-coding RNA (lncRNAs) as diagnostic biomarkers for HCC. The lncRNA and mRNA expression profiles of a large group of patients with HCC were obtained from The Cancer Genome Atlas. The differentially expressed lncRNAs (DElncRNAs) and the differentially expressed mRNAs (DEmRNAs) were identified by bioinformatics analysis. Using feature selection procedure and a classification model, the optimal diagnostic lncRNA biomarkers for HCC were identified. Classification models, including random forests, decision tree and support vector machine (SVM), were established to distinguish between HCC and normal tissues. DEmRNAs co-expressed with the lncRNAs were considered as targets of DElncRNAs. Functional annotation of DEmRNAs co-expressed with these lncRNAs biomarkers was performed. Receiver operating characteristic curve analysis of lncRNAs biomarkers was conducted. A total of 3,177 lncRNAs and 15,183 mRNAs between HCC and normal tissues were obtained. RP11-486O12.2, RP11-863K10.7, LINC01093 and RP11-273G15.2 were identified as optimal diagnostic lncRNA biomarkers for HCC that were co-expressed with 273, 69, 76 and 1 DEmRNAs, respectively. The area under the curve values of the random forest model, decision tree model and SVM model were 0.992, 0.927 and 0.992, and the specificity and sensitivity of the three models were 100.0 and 95.6, 92.0 and 98.3 and 98.0 and 97.2%, respectively. ‘PPAR signaling pathway’ and ‘retinol metabolism’ were two significantly enriched target pathways of DElncRNAs. The present study identified four DElncRNAs, including RP11-486O12.2, RP11-863K10.7, LINC01093 and RP11-273G15.2, as potential diagnostic biomarkers of HCC. Functional annotation of target DEmRNAs provided novel evidence for examining the precise roles of lncRNA in HCC.

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

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

Pivotal prognostic and diagnostic role of the long non‑coding RNA colon cancer‑associated transcript 1 expression in human cancer (Review)

Long non‑coding RNAs (lncRNAs) have been classically defined as regulatory RNA members >200 nucleotides in length, without detectable open‑reading frames to encode proteins. Previous studies have demonstrated that lncRNAs serve critical roles in multiple cancer types. Colon cancer‑associated transcript 1 (CCAT1), a novel cancer‑associated lncRNA, is significantly overexpressed in a number of malignancies. Functionally, as an oncogenic lncRNA, CCAT1 is involved in proliferation, migration, cell cycle progression, apoptosis, chemoresistance and other biological processes of cancer cells through complex regulation mechanisms in the cytoplasm or nucleus. In clinical applications, CCAT1 is additionally positively associated with histological differentiation, tumour node metastasis stage, vascular invasion, overall survival and recurrence‑free survival, which demonstrates its important role as a diagnostic and prognostic marker in cancer. The present review summarises the current research progress of the oncogenic potential and clinical uses of CCAT1 in various human cancer types.

Analyses of changes in myocardial long non-coding RNA and mRNA profiles after severe hemorrhagic shock and resuscitation via RNA sequencing in a rat model

Background

Ischemia–reperfusion injury has been proven to induce organ dysfunction and death, although the mechanism is not fully understood. Long non-coding RNAs (lncRNAs) have drawn wide attention with their important roles in the gene expression of some biological processes and diseases, including myocardial ischemia–reperfusion (I/R) injury. In this paper, a total of 26 Sprague–Dawley (SD) rats were randomized into two groups: sham and ischemia–reperfusion (I/R) injury. Hemorrhagic shock was induced by removing 45% of the estimated total blood volume followed by reinfusion of shed blood. High-throughput RNA sequencing was used to analyze differentially expressed (DE) lncRNAs and messenger RNAs (mRNAs) in the heart tissue 4 h after reperfusion. Myocardial function was also evaluated.

Results

After resuscitation, the decline of myocardial function of shocked animals, expressed by cardiac output, ejection fraction, and myocardial performance index (MPI), was significant (p < 0.05). DE lncRNAs and mRNAs were identified by absolute value of fold change ≥ 2 and the false discovery rate ≤ 0.001. In rats from the I/R injury group, 851 lncRNAs and 1015 mRNAs were significantly up-regulated while 1533 lncRNAs and 1702 m RNAs were significantly down-regulated when compared to the sham group. Among the DE lncRNAs, we found 12 location-associated with some known apoptosis-related protein-coding genes which were up-regulated or down-regulated accordingly, including STAT3 and Il1r1. Real time PCR assays confirmed that the expression levels of five location-associated lncRNAs (NONRATT006032.2, NONRATT006033.2, NONRATT006034.2, NONRATT006035.2 and NONRATT029969.2) and their location-associated mRNAs (STAT3 and Il1r1) in the rats from the I/R injury group were all significantly up-regulated versus the sham group.

Conclusions

The DE lncRNAs (NONRATT006032.2, NONRATT006033.2, NONRATT006034.2 and NONRATT006035.2) could be compatible with their role in myocardial protection by stimulating their co-located gene (STAT3) after hemorrhagic shock and resuscitation. The final prognosis of I/R injury might be regulated by different genes, which is regarded as a complex network.

Electronic supplementary material

The online version of this article (10.1186/s12867-018-0113-8) contains supplementary material, which is available to authorized users.

The emergence of long non-coding RNAs in hepatocellular carcinoma: an update

Hepatocellular carcinoma (HCC) accounting for roughly 90% of all primary liver neoplasms is the sixth most frequent neoplasm and the second prominent reason of tumor fatality worldwide. As regulators of diverse biological processes, long non-coding RNAs (lncRNAs) are involved in onset and development of neoplasms. With the continuous booming of well-featured lncRNAs in HCC from 2016 to now, we reviewed the newly-presented comprehension about the relationship between lncRNAs and HCC in this study. To be specific, we summarized the overview function and study tools of lncRNAs, elaborated the roles of lncRNAs in HCC, and sketched the molecule mechanisms of lncRNAs in HCC. In addition, the application of lncRNAs serving as biomarkers in early diagnosis and outcome prediction of HCC patients was highlighted.

Overexpression of the long noncoding RNA CCAT1 promotes metastasis via epithelial-to-mesenchymal transition in lung adenocarcinoma

The long noncoding RNA (lncRNA) colon cancer-associated transcript 1 (CCAT1) has been identified as an oncogene in multiple types of human malignancy, and the aberrant expression of CCAT1 has been associated with the tumorigenesis and progression of cancer. However, the underlying mechanism of how CCAT1 affects malignant behaviors in lung adenocarcinoma cells remains unknown. In the current study, the expression of CCAT1 was identified to be increased in lung adenocarcinoma tissues (n=96) by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and its expression level was associated with epidermal growth factor receptor (EGFR) expression (P=0.011), lymphatic metastasis (P=0.003) and tumor node metastasis (TNM) stage (P=0.003). In vitro, by using Transwell assays, the overexpression of CCAT1 was demonstrated to promote the migration and invasion of H358 lung adenocarcinoma cells; while downregulation of CCAT1 expression inhibited H1650 cell migration and invasion. Furthermore, western blot analysis indicated that aberrant CCAT1 expression may induce epithelial-to-mesenchymal transition (EMT) by regulating the expression levels of EMT markers (E-cadherin, N-cadherin and vimentin). In conclusion, these results indicate that CCAT1 is able to promote the metastasis of lung adenocarcinoma cells by inducing EMT.

Upregulation of lncRNA Sox2ot indicates a poor prognosis for patients with hepatocellular carcinoma and promotes cell invasion

Long non-coding RNA Sox2 overlapping transcript (lncRNA Sox2ot) expression has been demonstrated to be upregulated in a number of types of tumor, and may act as an oncogene. The present study aimed to evaluate the clinical role of lncRNA Sox2ot and its association with the epithelial-mesenchymal transition in hepatocellular carcinoma (HCC). Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to determine the expression of lncRNA Sox2ot in 86 cases of HCC tissues and adjacent non-tumor tissues. Kaplan-Meier and log-rank test was used to analyze the association between lncRNA Sox2ot expression and disease-free (DFS) or overall (OS) survival time. In addition, the capacity of HCC cells with lncRNA Sox2ot knockdown for invasion was evaluated via transwell cell invasion assays. RT-qPCR and western blot analyses were also performed to determine the mRNA and protein expression of Twist1, E-cadherin and N-cadherin in the HCC cells. It was indicated that lncRNA Sox2ot expression levels were significantly higher in HCC tissues compared with adjacent non-tumor tissues. Increased expression levels of lncRNA Sox2ot were associated with the tumor size, the tumor number and vein invasion in patients with HCC. An association was observed between lncRNA Sox2ot and the DFS and OS of patients with HCC. Furthermore, it was determined that cell invasion was inhibited following the siRNA knockdown of lncRNA Sox2ot in MHCC97H and SMCC-7721 cells via transwell cell invasion assays. Furthermore, it was demonstrated that knockdown of lncRNA Sox2ot downregulated the mRNA and protein expression of Twist1 and N-cadherin, but upregulated the E-cadherin expression levels in MHCC97H and SMCC-7721 cells. Thus, it was indicated that lncRNA Sox2ot may be a novel predictive biomarker and a potential therapeutic target for HCC.

Long non-coding RNA NRON is downregulated in HCC and suppresses tumour cell proliferation and metastasis

Dysregulation of long non-coding RNAs is a newly identified mechanism for tumour progression. Previous studies have suggested that the nuclear factor of activated T cells (NFAT) gene plays a very important role in cancer growth and metastasis. However, lncNRON is a newly identified repressor of NFAT, and its function is largely unknown, especially in hepatocellular carcinoma (HCC). Therefore, the expression levels of lncNRON in 215 pairs of HCC tissue were evaluated by qRT-PCR, and its relationship to clinicopathological parameters, recurrence, and survival was analysed. Furthermore, stably overexpressing lncNRON cell lines were constructed and evaluated for cell phenotype. Finally, we detected epithelial-to-mesenchymal transition (EMT) proteins to determine the underlying mechanism involved in lncNRON function. We observed that lncNRON was downregulated in HCC tumour tissues; low lncNRON expression was associated with poor tumour differentiation and the presence of vascular tumour thrombus, which tended to result in poor clinical outcomes, as demonstrated by the recurrence rate and survival curves. Functional analysis showed that lncNRON overexpression impaired colony formation and cell viability and inhibited cell migration and invasion. A study using tumour-bearing mice showed that lncNRON markedly limited tumour growth and lung metastasis in vivo. Importantly, western blot analysis revealed that the expression of the EMT-related epithelial marker, E-cadherin, increased, whereas the expression of mesenchymal markers N-cadherin, snail, and vimentin was attenuated by lncNRON overexpression in HCC cells. Therefore, lower lncNRON expression indicates a poorer clinical outcome in HCC. LncNRON overexpression can suppress HCC growth and metastasis via inhibiting the EMT, and lncNRON may function as a new HCC prognostic marker.

Long noncoding RNAs: Undeciphered cellular codes encrypting keys of colorectal cancer pathogenesis

Long noncoding RNAs are non-protein coding transcripts longer than 200 nucleotides in length. By the advance in genetic and bioinformatic technologies, the new genomic landscape including noncoding transcripts has been revealed. Despite their non-capacity to be translated into proteins, lncRNAs have a versatile functions through various mechanisms interacting with other cellular molecules including DNA, protein, and RNA. Recent research interest and endeavor have identified the functional role of lncRNAs in various diseases including cancer. Colorectal cancer (CRC) is not only one of the most frequent cancer but also one of the cancer types with remarkable achievements in lncRNA research. Of the numerous notable lncRNAs identified and characterized in CRC, we will focus on key lncRNAs with the high potential as CRC-specific biomarkers in this review.

The association of CCAT2 rs6983267 SNP with MYC expression and progression of uterine cervical cancer in the Polish population

PURPOSE

Previous studies have reported a significant contribution of NC_000008.10:g.128413305 G>T (rs6983267) single-nucleotide polymorphism (SNP) in the MYC enhancer region to the susceptibility of various cancers. However, the role of rs6983267 SNP in cervical cancer (CC) development and progression has not been demonstrated to date. Therefore, we evaluated the role of rs6983267 SNP in MYC expression in cervical cancers and non-cancerous cervical tissues. In addition, we assessed the role of this SNP in the development and progression of CC.

METHODS

Using high-resolution melting analysis, we evaluated rs6983267 SNP frequency in women diagnosed with cervical squamous cell carcinoma (SCC) (n = 481) and controls (n = 502) in a Polish Caucasian population. Logistic regression analysis was employed to adjust for the effects of age, parity, oral contraceptive use, tobacco smoking, and menopausal status.

RESULTS

Dividing patients based on clinical characteristics demonstrated an association of the rs6983267 genotype with tumor stage III and grade of differentiation G2 and G3. The p trend value calculated for the rs6983267 SNP in patients with stage III was 0.0006. We also observed a significant contribution of rs6983267 SNP to tumor grade of differentiation G2 and G3. Additional contributors were oral contraceptive use, smoking, and postmenopausal age. We found statistically significant increase of MYC transcript levels in cervical SCC tissues from carriers of the GG vs. T/T (p < 0.00001), G/T vs. T/T (p = 0.0002), and in the non-cancerous cervical tissues from carriers of the GG vs. T/T (p = 0.00046).

CONCLUSION

The rs6983267 SNP may contribute to the increased MYC expression as well as the spread and rapid growth of cervical SCC as compared to lower grade carcinomas.

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 mRNAs 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.

Non coding RNA analysis in fibrolamellar hepatocellular carcinoma

Fibrolamellar hepatocellular carcinoma (FLC) is a rare primary liver cancer found in adolescents and young adults without underlying liver disease. A deletion of ~400 kD has been found in one copy of chromosome 19 in the tumor tissue of all patients tested. This produces a fusion of the genes DNAJB1 and PRKACA which, in turn, produces a chimeric transcript and protein. Transcriptomic analysis of the tumor has shown upregulation of various oncologically relevant pathways, including EGF/ErbB, Aurora Kinase A, pak21 and wnt. To explore other factors that may contribute to oncogenesis, we examined the microRNA (miRNA) and long non-coding RNA (lncRNA) expression in FLC. The non-coding RNA expression profile in tumor tissue samples is distinctly different from the adjacent normal liver and from other liver tumors. Furthermore, miRZip knock down or over expression of certain miRNAs led to changes in the levels of coding genes that recapitulated changes observed in FLC, suggesting mechanistically that the changes in the cellular levels of miRNA are not merely correlative. Thus, in addition to serving as diagnostic tools for FLC, non-coding RNAs may serve as therapeutic targets.

Long noncoding RNAs in the initiation, progression, and metastasis of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. Despite awareness of risk factors for the development of HCC and advances in the diagnosis and clinical management of the disease, the molecular mechanisms underlying hepatocarcinogenesis remain poorly understood. Recent experimental studies provide strong evidence that long noncoding RNAs (lncRNAs), non-protein-coding transcripts with lengths >200 basepairs, contribute to the pathogenesis of numerous human diseases. Over the past decade, a role for lncRNAs in the initiation, progression, and metastasis of HCC has likewise emerged and developed into a highly active area of research. Although many lncRNAs appear to be dysregulated in HCC, extensive functional characterization has been performed on only a small proportion of these candidates to date. This review summarizes select lncRNAs that have been shown to wield functional relevance in the initiation, progression, or metastasis of HCC, focusing on the specific mechanisms by which lncRNA effects might be linked to clinical manifestations of the disease. In addition, an overview of circulating lncRNAs that have been identified as potential biomarkers for the diagnosis and prognosis of HCC is provided.

Long non-coding RNAs as biomarkers and therapeutic targets: Recent insights into hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most prevalent primary liver cancer worldwide, and the survival rates of patients with HCC remains quite low after 5years. Long non-coding RNAs (LncRNAs) are a novel class of non-coding RNAs that are capable of regulating gene expression at various levels. Recent works have demonstrated that lncRNAs are often dysregulated in HCC, and the dysregulation of some of these lncRNAs are associated with the clinicopathological features of HCC. They regulate cell proliferation, apoptosis, autophagy, Epithelial-Mesenchymal Transition (EMT), invasion and metastasis of HCC by modulating gene expression and cancer-related signaling pathways, and thus contribute to the onset and progression of HCC. In this review, we provide a comprehensive survey of dysregulated lncRNAs in HCC, with particular focus on the functions and regulatory mechanisms of several essential and important lncRNAs, and discuss their potential clinical application as early diagnostic and/or prognostic biomarkers or therapeutic targets for HCC.

Long non-coding RNA CARLo-5 promotes tumor progression in hepatocellular carcinoma via suppressing miR-200b expression

Long non-coding RNAs (lncRNAs) play key roles in cancer initiation and progression. The aim was to investigate the biological functions and clinical significance of long non-coding RNA CARLo-5 in hepatocellular carcinoma (HCC). QRT-PCR was performed to investigate CARLo-5 expression in HCC tissues and cells. Kaplan-Meier curve and multivariate analysis validated the association between CARLo-5 expression and overall survival (OS) in HCC patients. Cell proliferation and invasion was performed by CCK8 cell proliferation, cell colony formation and transwell invasion assays. Western-blot assay was performed to evaluate the protein expression of Twist1, ZEB1, E-cadherin and Vimentin. Tumor xenografts were performed to evaluate the effect of CARLo-5 on tumor growth in vivo. RNA Immunoprecipitation (RIP) and Chromatin Immunoprecipitation (ChIP) were also performed. Our results showed that CARLo-5 expression was significantly higher in HCC tissues and upregulated CARLo-5 expression was closely correlated with tumor size and advanced tumor stage. Kaplan-Meier curve and multivariate analysis validated that higher CARLo-5 expression predicted a poor prognosis for HCC patients and was an independent risk factor for OS in HCC patients. In vitro, knockdown of CARLo-5 inhibited cell proliferation, colony formation, cell invasion and inhibited the cell epithelial-mesenchymal transition (EMT) by up-regulating the E-cadherin expression and down-regulating Twist1, ZEB1 and vimentin expression in HCC cells. Furthermore, we demonstrated that CARLo-5 inhibited the miR-200b expression via EZH2. In vivo, knockdown of CARLo-5 significantly inhibited the tumor growth. Thus, our results indicated that CARLo-5 represented a novel tumor biomarker and therapeutic target for HCC.

MicroRNA-363-3p is downregulated in hepatocellular carcinoma and inhibits tumorigenesis by directly targeting specificity protein 1

microRNAs exhibit important regulatory roles in tumorigenesis and tumor development, such as in hepatocellular carcinoma (HCC). The present study aimed to investigate the expression and functional roles of microRNA (miR)‑363‑3p in HCC. miR-363-3p expression levels in a number of HCC tissues and cell lines were measured by reverse transcription-quantitative PCR (RT‑qPCR). The effects of miR‑363‑3p expression on HCC cell proliferation, migration and invasion were exa-mined by MTT assay, Transwell migration and invasion assay, respectively. The effects of miR‑363‑3p on its downstream target gene, specificity protein 1 (SP1), were examined by bioinformatics analysis, luciferase reporter assay, RT‑qPCR and western blotting. An SP1 overexpression vector was subsequently transfected into HCC cells to assess any selective effects on miR‑363‑3p in modulating HCC. The results revealed that miR‑363‑3p expression levels were downregulated in both HCC tissues and cell lines, and this low expression level was correlated with tumor size, tumor‑node‑metastasis stage and venous infiltration in patients with HCC. Upregulation of miR‑363‑3p inhibited cell proliferation, migration and invasion in HCC cell cultures. In HCC cells transfected with an SP1 expression vector the miR‑363‑3p‑induced tumor suppressive roles on cell proliferation, migration and invasion were reversed. In conclusion, results from the present study indicated that miR‑363‑3p is a tumor suppressor in HCC and functions through a mechanism involving SP1, suggesting that miR‑363‑3p may be a potential new therapeutic target for the treatment of HCC.

lncRNAs as prognostic molecular biomarkers in hepatocellular carcinoma: a systematic review and meta-analysis

The latest studies have shown that long non-coding RNAs (lncRNAs) may be considered markers as their expression levels were abnormal in cancer and can be used as a molecular biomarker for the potential assessment of cancer prognosis. In this study, we aimed to assess the prognostic value of lncRNA as marker of patients with hepatocellular carcinoma. We performed a detailed search of the PubMed and Embase databases for articles on the prognostic value of various lncRNAs in HCC. We then carefully extracted the relevant data from the articles, and we used the meta-analysis method to analyze these results; heterogeneity and publication bias were also evaluated. With 40 associative studies included, we found that high expression of 27 types of lncRNA was associated with a poor prognosis in HCC patients, and low expression of 18 types of lncRNAs was associated with a worse prognosis. Patients with higher lncRNA expression had significantly poor overall survival (OS; pooled HR, 1.25; 95% confidence interval [CI], 1.03–1.52) as well as significantly poor recurrence-free survival (RFS; pooled HR, 1.66; 95% CI, 1.26–2.17). Overexpression of lncRNAs may not meaningfully predict disease-free survival (DFS; pooled HR, 1.04; 95% CI, 0.52–2.07; p = 0.91). Our meta-analysis demonstrated that lncRNAs may serve as predictive biomarkers for cancer prognosis.

Prognostic value of long non-coding RNA CCAT1 expression in patients with cancer: A meta-analysis

Background

LncRNA CCAT1 is significantly overexpressed in various types of cancers, suggesting that it might be associated with prognosis and clinicopathological features in patients with cancer.

Methods

A comprehensive search was performed in Pubmed, Web of Science, OVID and CNKI databases. We also retrieved articles from other sources, such as retrieving from the reference lists of relevant articles. Eligible studies were included based on defined exclusion and inclusion criteria to perform a meta-analysis. STATA 14.0 was used to estimate pooled hazard ratios (HRs) with 95% confidence interval (95% CI), the heterogeneity among studies and publication bias to judge the prognostic value.

Results

A total of 1587 patients from 11 eligible studies were included in the meta-analysis. The results showed that high expression level of CCAT1 was significantly associated with shorter overall survival in cancer patients (HR 2.335, 95% CI:1.551–3.517); in the subgroup analysis, region (China or UK), sample size (more or less than 100), type of cancer (digestive or non-digestive disease) and paper quality (score more or less than 7) did not alter the association between CCAT1 expression and cancer prognosis but preoperative treatment did. And CCAT1 expression was an independent prognostic marker for overall survival in patients with cancer (pooled HR 2.195, 95%CI:1.316–3.664) using Cox multivariate analyses. The clinicopathological parameters analysis further showed that increased expression level of CCAT1 was correlated with tumor size, lymph node metastasis, TNM stage, distant metastasis, microvascular invasion and capsular formation in relevant cancers.

Conclusions

The meta-analysis results from present study suggested that increased expression level of CCAT1 was associated with poor prognosis and can serve as an independent biomarker. And the expression level of CCAT1 was associated with clinicopathological features in relevant cancers.

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

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

Expression of cyclooxygenase-2 is correlated with lncRNA-COX-2 in cirrhotic mice induced by carbon tetrachloride

Multiple long non-coding RNAs (lncRNAs) have been demonstrated to be involved in liver disease. Increased cyclooxygenase-2 (COX‑2) levels have also been reported to be involved in the progression of liver cirrhosis. In the present study, the correlations between lncRNA‑COX‑2 RNA expression levels, COX‑2 mRNA expression levels and liver fibrosis were examined. Liver fibrosis was induced by intraperitoneal injection of carbon tetrachloride (CCl4) in mice for 2 months (CCl4‑2M) or 3 months (CCl4‑3M). Liver histopathological evaluation was conducted using hematoxylin and eosin and Masson trichrome staining. Hepatic expression of COX‑2 and lncRNA‑COX‑2 was evaluated by reverse transcription‑quantitative polymerase chain reaction and immunohistochemical staining. Compared with the control group, fibrotic areas were increased four and nine times in the CCl4‑2M group and the CCl4‑3M group, respectively. LncRNA-COX-2 and COX‑2 upregulation were observed in the cirrhotic liver. COX‑2 mRNA expression levels and lncRNA-COX-2 RNA expression levels were significantly positively correlated with the fibrotic area. In addition, COX‑2 mRNA expression was significantly positively correlated with lncRNA‑COX‑2 expression. These results suggest that expression of COX‑2 and lncRNA‑COX‑2 increased with the progression of liver fibrosis. LncRNA-COX-2 may potentially be considered as a novel therapeutic target for liver fibrosis.

CCAT1: an oncogenic long noncoding RNA in human cancers

PURPOSE

Long noncoding RNAs (lncRNAs) are a new class of noncoding RNAs that participate in a variety of biological processes such as cell proliferation, cell cycle, differentiation and apoptosis, mainly by regulation of gene expression at various levels, including chromatin, splicing, transcriptional and post-transcriptional levels. CCAT1 is a recently identified oncogenic lncRNA, which has been reported to be consistently upregulated in multiple cancer tissues and closely correlated with initiation and progression of cancers. The aim of this paper is to provide an overview of various roles of CCAT1 in human cancers.

METHODS AND RESULTS

We searched studies in electronic databases. Studies have shown the high expression pattern and oncogenic role of CCAT1 in different types of cancer, and aberrant expression of CCAT1 is involved in several processes correlated with carcinogenesis such as cell proliferation, apoptosis, migration and invasion by regulating different target genes and pathways.

CONCLUSION

LncRNA CCAT1 promises to be a novel diagnostic biomarker, therapeutic target, as well as prognostic biomarker in human cancers.

Meta-analysis of the prognostic value of abnormally expressed lncRNAs in hepatocellular carcinoma

Many long noncoding RNAs (lncRNAs) have been reported to be abnormally expressed in hepatocellular carcinoma (HCC), and may have the potential to serve as prognostic markers. In this study, a meta-analysis was conducted to systematically evaluate the prognostic value of various lncRNAs in HCC. Eligible literatures were systematically collected from PubMed, Embase, Web of Science, and Cochrane Library (up to December 30, 2015). The main outcomes including overall survival, relapse-free survival, and disease-free survival were analyzed. Pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated using random- or fixed-effects models. A total of 2,991 patients with HCC in People’s Republic of China from 27 studies were included in the analysis. The level of lncRNAs showed a significant association with clinical outcomes. Abnormally elevated lncRNA transcription level predicted poor overall survival (HR: 1.68, 95% CI: 1.20–2.34, P=0.002; I²=75.5%, P=0.000) and relapse-free survival (HR: 2.08, 95% CI: 1.65–2.61, P<0.001; I²=24.0%, P=0.215), while no association was observed with disease-free survival of HCC patients (HR: 1.39, 95% CI: 0.51–3.78, P=0.524; I²=81.3%, P=0.005). Subgroup analysis further showed that lncRNA transcription level was significantly associated with tumor size (relative risk [RR]: 1.19, 95% CI: 1.01–1.39, P=0.035), microvascular invasion (RR: 1.44, 95% CI: 1.10–1.89, P=0.009), and portal vein tumor thrombus (RR: 1.50, 95% CI: 1.03–2.20, P=0.036). Publication bias and sensitivity analysis further confirmed the stability of our results. Our present meta-analysis indicates that abnormal lncRNA transcription level may serve as a promising indicator for prognostic evaluation of patients with HCC in People’s Republic of China.

Meta-analysis of the prognostic value of abnormally expressed lncRNAs in hepatocellular carcinoma

Many long noncoding RNAs (lncRNAs) have been reported to be abnormally expressed in hepatocellular carcinoma (HCC), and may have the potential to serve as prognostic markers. In this study, a meta-analysis was conducted to systematically evaluate the prognostic value of various lncRNAs in HCC. Eligible literatures were systematically collected from PubMed, Embase, Web of Science, and Cochrane Library (up to December 30, 2015). The main outcomes including overall survival, relapse-free survival, and disease-free survival were analyzed. Pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated using random- or fixed-effects models. A total of 2,991 patients with HCC in People's Republic of China from 27 studies were included in the analysis. The level of lncRNAs showed a significant association with clinical outcomes. Abnormally elevated lncRNA transcription level predicted poor overall survival (HR: 1.68, 95% CI: 1.20-2.34, P=0.002; I (2)=75.5%, P=0.000) and relapse-free survival (HR: 2.08, 95% CI: 1.65-2.61, P<0.001; I (2)=24.0%, P=0.215), while no association was observed with disease-free survival of HCC patients (HR: 1.39, 95% CI: 0.51-3.78, P=0.524; I (2)=81.3%, P=0.005). Subgroup analysis further showed that lncRNA transcription level was significantly associated with tumor size (relative risk [RR]: 1.19, 95% CI: 1.01-1.39, P=0.035), microvascular invasion (RR: 1.44, 95% CI: 1.10-1.89, P=0.009), and portal vein tumor thrombus (RR: 1.50, 95% CI: 1.03-2.20, P=0.036). Publication bias and sensitivity analysis further confirmed the stability of our results. Our present meta-analysis indicates that abnormal lncRNA transcription level may serve as a promising indicator for prognostic evaluation of patients with HCC in People's Republic of China.