Long Noncoding RNA Highly Upregulated in Liver Cancer Activates p53-p21 Pathway and Promotes Nasopharyngeal Carcinoma Cell Growth

lncRNAs are potential prognostic markers in patients with nasopharyngeal carcinoma in China: A systematic review and meta‑analysis

The present study aimed to investigate the association between the expression profiles of long non-coding RNAs (lncRNAs) and the clinical characteristics or prognosis of patients with nasopharyngeal carcinoma (NPC). The findings presented in the present review may provide novel strategies for the prevention and treatment of NPC. For the analyses, medical databases, including PubMed, Web of Science and Cochrane library were searched using specific search terms, search strategies and screening strategies. Endnote X9 document management software was then employed to extract documents from January, 2010 to May, 2023. Data were extracted following the prescribed standards. Review Manager 5.4 and STATA 12.0 data analysis software were used for data analysis. A total of 490 publications were analyzed for inclusion. In total, 29 publications, composed of 24 studies with upregulated lncRNAs and 5 studies with downregulated lncRNAs, were included in the final analysis. The analysis revealed that the upregulation of lncRNAs was significantly associated with T stage, N stage and clinical stage, as well as with the overall survival (OS) and disease-free survival (DFS) of patients with NPC (P<0.05). However, there was no significant association between the upregulated lncRNAs and sex, M stage or relapse-free survival (RFS) (P>0.05). On the other hand, the suppression of lncRNA expression was significantly associated with N stage, M stage, clinical stage and the OS of patients with NPC (P<0.05), but not with T stage and RFS (P>0.05). Taken together, the present review demonstrates that the up- and downregulation of different lncRNAs was associated with an advanced clinical stage and a shorter OS of patients with NPC. Therefore, lncRNAs may serve as potential prognostic factors in NPC.

Tumor- and metastasis-promoting roles of miR-488 inhibition via HULC enhancement and EZH2-mediated p53 repression in gastric cancer

Dysregulation of microRNAs (miRNAs or miRs) is implicated in the development of gastric cancer (GC), which is possibly related to their roles in targeting tumor-suppressive or tumor-promoting genes. Herein, the current study was intended to ascertain the function of miR-488 and its modulatory mechanism in GC. Initially, human GC cells were assayed for their in vitro malignancy after miRNA gain- or loss-of-function and RNA interference or overexpression. Also, tumorigenesis and liver metastasis were evaluated in nude mouse models. Results demonstrated that miR-488 elevation suppressed GC (MKN-45 and OCUM-1) cell proliferation, migration, and invasiveness in vitro and reduced their tumorigenesis and liver metastasis in vivo. The luciferase assay identified that miR-488 bound to HULC and inhibited its expression. Furthermore, HULC could enhance EZH2-H3K27me3 enrichment at the p53 promoter region and epigenetically repress the p53 expression based on the data from RIP- and ChIP-qPCR assay. Additionally, HULC was validated to enhance GC growth and metastasis in vitro and in vivo. Overall, HULC re-expression elicited by miR-488 inhibition can enhance EZH2-H3K27me3 enrichment in the p53 promoter and repress the p53 expression, thus promoting the growth and metastasis of GC.

Long noncoding RNA HULC regulates the NF-κB pathway and represents a promising prognostic biomarker in liver cancer

BACKGROUND

Long noncoding RNAs (lncRNAs) are involved in a diverse array of biological processes. While lncRNAs are commonly upregulated in hepatocellular carcinoma (HCC), the specific regulatory roles they play in this oncogenic context require further study and clarification. Although HULC (lncRNA highly upregulated in liver cancer) is involved in disease pathogenesis, its precise role in this context remains unclear.

METHODS

Here, we have explored the mechanistic relevance of HULC expression by assessing its expression in patient samples. The importance of this lncRNA in the onset and progression of HCC was investigated through in vitro approaches including Western blotting, quantitative PCR, Transwell assays, electron microscopy, wound healing assays, and real-time cell analysis (RTCA). Additionally, the in vivo functions of this lncRNA were assessed using an orthotopic HCC xenograft in nude mouse model system.

RESULTS

HULC was identified as a lncRNA that is highly upregulated in human liver tumors. In vitro, HULC was able to promote HCC malignancy, although its excess overexpression also led robust autophagic induction, promoting the increased expression of autophagy-associated genes including LC3 and Beclin-1. At a mechanistic level, HULC was able to promote the phosphorylation of p65 and IkBkB thus enhancing autophagy by increasing LC3II levels in a manner dependent upon the NF-κB pathway. HULC downregulation was also linked to impaired orthotopic HCC tumor growth in vivo. The link between HULC and autophagy may play a role in disease progression.

CONCLUSIONS

These results suggest that HULC is an oncogenic lncRNA, and may thus offer value as a prognostic biomarker and promoter of HCC development, in addition to being a potential therapeutic target in this cancer type.

Hedyotis diffusae Herba-Andrographis Herba inhibits the cellular proliferation of nasopharyngeal carcinoma and triggers DNA damage through activation of p53 and p21

Dysregulation of the cell cycle and the resulting aberrant cellular proliferation has been highlighted as a hallmark of cancer. Certain traditional Chinese medicines can inhibit cancer growth by inducing cell cycle arrest. In this study we explore the effect of Hedyotis diffusae Herba-Andrographis Herba on the cell cycle of nasopharyngeal carcinoma (NPC). Hedyotis diffusae Herba-Andrographis Herba-containing serum was prepared and then added to the cell culture medium. BrdU, comet, and FUCCI assays, western blot analysis and flow cytometry analysis revealed that Hedyotis diffusae Herba-Andrographis Herba treatment significantly alters cell proliferation, DNA damage, and cell cycle distribution. Xenograft mouse model experiments were performed, confirming these in vitro findings in vivo. Treatment with Hedyotis diffusae Herba-Andrographis Herba inhibited cell proliferation, promoted DNA damage, and arrested NPC cells progression from G1 to S phase. Further examination of the underlying molecular mechanisms revealed that treatment with Hedyotis diffusae Herba-Andrographis Herba increased the expression of p53 and p21, while reducing that of CCND1, Phospho-Rb, E2F1, γH2AX, and Ki-67 both in vivo and in vitro. Conversely, the inhibition of p53 and p21 could abolish the promoting effect of Hedyotis diffusae Herba-Andrographis Herba on the NPC cell cycle arrest at the G1 phase, contributing to the proliferation of NPC cells. Hedyotis diffusae Herba-Andrographis Herba suppressed the tumor growth in vivo. Overall, these findings suggest that Hedyotis Diffusae Herba-Andrographis prevent the progression of NPC by inducing NPC cell cycle arrest at the G1 phase through a p53/p21-dependent mechanism, providing a novel potential therapeutic treatment against NPC.

Long noncoding RNAs in the regulation of p53-mediated apoptosis in human cancers

Long noncoding RNAs (lncRNAs) are widely known for their regulatory function in transcriptional and posttranscriptional processes. The involvement of such non-protein-coding RNAs in nuclear organization and chromatin remodeling is often associated with an increased risk of human malignancies. In cancer, lncRNAs either promote cell survival or may act as a growth suppressor, thus conferring a key regulatory function other than their established role in fundamental cellular processes. Interestingly, lncRNAs interfere with the stages of apoptosis and related pathways involving p53. Many of these molecules either regulate or are regulated by p53 while mounting oncogenic events. Consequently, they may confer both prosurvival or proapoptotic functions depending upon the tissue type. Since the mechanism of cell death is bypassed in many human cancers, it has emerged that the lncRNAs are either overexpressed or knocked down to sensitize cells to apoptotic stimuli. Nonetheless, the abundant expression of lncRNAs in tumor cells renders them suitable targets for anticancer therapies. Although the role of lncRNAs in the p53 network and apoptosis has been independently defined, their interplay in activating p53-target genes during cell cycle arrest remains unexplored. Thus, we have specifically reviewed the possible involvement of lncRNAs in the p53-mediated apoptosis of human cancer cells. In particular, we summarize the growing evidence from individual studies and analyze whether lncRNAs are essential to facilitate apoptosis in a p53-dependent manner. This may lead to the identification of p53-associated lncRNAs that are suitable therapeutic targets or diagnostic/prognostic markers.

Long non-coding RNAs regulating multiple proliferative pathways in cancer cell

Long non-coding RNAs (lncRNAs) belong to an extremely heterogeneous class of non-coding RNAs with a length ranging from 200 to 100,000 bp. They modulate a series of cellular pathways in both physiological and pathological context. It is no coincidence that they are expressed in an aberrant way in pathologies such as cancer, so as to deserve to be subclassified as oncogenes or tumor suppressors. These molecules are also involved in the regulation of cancer cell proliferation. Several lncRNAs are able to modulate cell growth both positively and negatively, and in this review we have focused on a small group of them, characterized by the simultaneous action on different pathways regulating cell proliferation. They have been considered in the light of their behavior in three different subtypes of proliferative pathways that we can define as (I) tumor suppressor, (II) oncogenic and (III) transcriptionally-driven. More specifically, we have characterized some lncRNAs considered oncogenes (such as H19, linc-ROR, MALAT1, HULC, HOTAIR and ANRIL), tumor suppressors (such as MEG3 and lincRNA-p21), and both oncogenes/tumor suppressors (UCA1 and TUG1) in a little more detail. As can be understood from the review, the interactions between lncRNAs and their molecular targets, only in the context of controlling cell proliferation, give rise to an intricate molecular network, the understanding of which, in the future, will certainly be of help for the treatment of molecular diseases such as cancer.

Determination of antiviral action of long non-coding RNA loc107051710 during infectious bursal disease virus infection due to enhancement of interferon production

The functions and profiles of lncRNAs during infectious bursal disease virus (IBDV) infection have not been determined, yet. The objectives of this study were to determine the antiviral action of loc107051710 lncRNA during IBDV infection by investigating the relationship between loc107051710 and IRF8, Type I IFN, STATs, and ISGs. DF-1 cells were either left untreated as non-infected controls (n = 1) or infected with IBDV (n = 3). RNA sequencing was applied for analysis of mRNAs and lncRNAs expression. Differentially expressed genes were verified by RT-qPCR. Then identification, of 230 significantly different expressed genes (182 mRNAs and 48 lncRNA) by pairwise comparison of the infected and control groups, was carried out. The functions of differentially expressed lncRNAs were investigated by selection of lncRNAs and mRNAs significantly enriched in the aforementioned biological processes and signaling pathways for construction of lncRNA-mRNA co-expression networks. The techniques of gene ontology and Kyoto Encyclopedia of Genes and Genomes pathways were applied. It was suggested that these differentially expressed genes were involved in the interaction between the host and IBDV. Loc107051710 was found to have potential antiviral effects. RT-qPCR and western blot were applied and revealed that loc107051710 was required for induction of IRF8, type I IFN, STAT, and ISG expression, and its knockdown promoted IBDV replication. By fluorescence in situ hybridization, it was found that loc107051710 was translocated from the nucleus to the cytoplasm after infection with IBDV. Overall, loc107051710 promoted the production of IFN-α and IFN-β by regulating IRF8, thereby promoting the antiviral activity of ISGs.

LncRNA JPX overexpressed in oral squamous cell carcinoma drives malignancy via miR-944/CDH2 axis

OBJECTIVES

Oral squamous cell carcinoma (OSCC) is a common head and neck cancer with high incidence. Numerous reports have elucidated that long non-coding RNAs (lncRNAs) serve as crucial regulatory factors in various diseases including cancer. Nonetheless, the role of lncRNA JPX in OSCC is still not elaborated.

SUBJECTS AND METHODS

In our research, we detected the expression of lncRNA JPX through qRT-PCR. Colony formation, EdU staining, Transwell, TUNEL, and caspase-3 activity assays were applied for estimating the function of lncRNA JPX in OSCC. RIP, pull-down, and luciferase reporter experiments were adopted to examine the interrelations between lncRNA JPX, miR-944, and CDH2.

RESULTS

LncRNA JPX was discovered as highly expressed in OSCC cells. Silencing lncRNA JPX restrained OSCC cell proliferation, migration, and invasion. Interestingly, lncRNA JPX bound with miR-944 and then augmented CDH2 via a competing endogenous RNA (ceRNA) mechanism. Importantly, overexpressed CDH2 recovered the suppression of silenced lncRNA JPX on the oncogenic behaviors of OSCC cells.

CONCLUSIONS

In short, lncRNA JPX contributes to OSCC cell proliferation, migration, and invasion via miR-944/CDH2 axis, which offers a new direction for potential targeted treatment of OSCC.

LINC00174 is an oncogenic lncRNA of hepatocellular carcinoma and regulates miR-320/S100A10 axis

Hepatocellular carcinoma (HCC) is one of the deadliest cancers. Multiple long non-coding RNAs (lncRNAs) are recently identified as crucial oncogenic factors or tumour suppressors. In this study, we explored the effects of LINC00174 on the progression of HCC. Expression levels of LINC00174 and microRNA-320 (miR-320) in HCC tissue samples were measured using quantitative real-time polymerase chain reaction (qRT-PCR). The association between pathological indices and LINC00174 was also analysed. Human HCC cell lines Hep3B and Huh7 were used as cell models. CCK-8 and bromodeoxyuridine (BrdU) assays were used to assess the effect of LINC00174 on HCC cell line proliferation. Flow cytometry was used to study the effect of LINC00174 on HCC apoptosis. Transwell assay was conducted to detect the effect of LINC00174 on migration and invasion. Furthermore, luciferase reporter assay and RNA immunoprecipitation (RIP) assay were used to confirm the binding relationship between miR-320 and LINC00174. Additionally, western blot was used to detect the regulatory function of LINC00174 on oncogene S100 calcium binding protein A10 (S100A10). We demonstrated that LINC00174 expression in HCC clinical samples was significantly increased and this was correlated with higher T stage. Its overexpression remarkably accelerated proliferation and metastasis of HCC cells while reduced apoptosis. Accordingly, knockdown of it suppressed the malignant phenotypes of HCC cells. Overexpression of LINC00174 significantly reduced the expression of miR-320 by sponging it, in turn enhanced the expression of S100A10. In conclusion, LINC00174 is a sponge of tumour suppressor miR-320, enhances the expression of S100A10 indirectly and functions as an oncogenic lncRNA in HCC. SIGNIFICANCE OF THE STUDY: LINC00174 is a novel lncRNA, whose function is rarely investigated. It is reported that it is oncogenic in colorectal cancer, while its role in HCC remains unclear. Herein, we report that LINC00174 is significantly up-regulated in HCC tissues and promotes the malignant phenotypes. We demonstrate that LINC00174 functions as a sponge for miR-320, increases the expression level of oncogene S100A10 in HCC. This study helps clarify the mechanism of HCC tumorigenesis and progression, and uncover the role of LINC00174 in human disease.

Silencing of Long Non-coding RNA SMAD5-AS1 Reverses Epithelial Mesenchymal Transition in Nasopharyngeal Carcinoma via microRNA-195-Dependent Inhibition of SMAD5

Long non-coding RNAs (lncRNAs) have gained widespread attention in recent years as a key regulator of diverse biological processes, but the knowledge of the mechanisms by which they act is still very limited. Differentially expressed lncRNA SMAD5 antisense RNA 1 (SMAD5-AS1) in nasopharyngeal carcinoma (NPC) and normal samples shown by in silico analyses were selected as the main subject, and then microRNA-195 (miR-195) was suggested to bind to SMAD5-AS1 and SMAD5. Therefore, the purpose of the present study was to investigate the effects of SMAD5-AS1/miR-195/SMAD5 on epithelial-mesenchymal transition (EMT) in NPC cells. High expression of SMAD5-AS1 and SMAD5 but low miR-195 expression was determined in NPC tissues and NPC cell lines by RT-qPCR and western blot analysis. SMAD5-AS1 could upregulate SMAD5 expression by competitively binding to miR-195 in NPC cells. Loss- and gain-of-function investigations were subsequently conducted in NPC cells (CNE-2 and CNE-1) to explore the role of SMAD5-AS, miR-195 and SMAD5 in NPC progression by assessing cellular biological functions and tumorigenic ability in vivo as well as determining the expression of EMT markers. Downregulation of SMAD5-AS1 or SMAD5 or overexpression of miR-195 led to inhibited NPC cell proliferation, invasion and migration and reversed EMT, enhanced apoptosis in vitro as well as restrained tumor growth in vivo. In conclusion, our findings indicate that silencing of lncRNA SMAD5-AS1 induces the downregulation of SMAD5 by miR-195, eventually repressing EMT in NPC. Hence, SMAD5-AS1 may represent a potential therapeutic target for NPC intervention.

Long noncoding RNA HULC promotes hepatocellular carcinoma progression

Long noncoding RNAs (lncRNAs) are overexpressed in many types of cancers, suggesting they may promote tumorigenesis. The lncRNA “highly upregulated in liver cancer” (HULC) promotes hepatocellular carcinoma (HCC) by mechanisms that are not fully understood. In the present study, we showed that HULC is overexpressed in HCC tissues, which correlates with an unfavorable prognosis in HCC patients. We also found that HULC promotes the proliferation, migration, and invasion of HCC cells in vitro, and xenograft tumor growth in vivo. Our mechanistic studies showed that HULC works as a competing endogenous RNA for miR-2052, and that the MET receptor tyrosine kinase is a downstream target of miR-2052 in HCC. Furthermore, HULC inhibits miR-2052, thereby stimulating MET expression in HCC. Finally, MET overexpression reverses the effects of HULC depletion. In sum, our findings reveal a novel regulatory signaling cascade, the HULC/miR-2052/MET axis, which could potentially be exploited for therapeutic benefits in the treatment of HCC.

Comprehensive bioinformatics analysis reveals potential lncRNA biomarkers for overall survival in patients with hepatocellular carcinoma: an on-line individual risk calculator based on TCGA cohort

Background

Accumulated evidences have demonstrated that long non-coding RNAs (lncRNAs) are correlated with prognosis of patients with hepatocellular carcinoma. The current study aimed to develop and validate a prognostic lncRNA signature to improve the prediction of overall survival in hepatocellular carcinoma patients.

Methods

The study cohort involved 348 hepatocellular carcinoma patients with lncRNA expression information and overall survival information. Through gene mining approach, the current study established a prognostic lncRNA signature (named LncRNA risk prediction score) for predicting the overall survival of hepatocellular carcinoma patients.

Results

The current study built a predictive nomogram based on ten prognostic lncRNA predictors through Cox regression analysis. In model group, the Harrell’s concordance indexes of LncRNA risk prediction score were 0.811 (95% CI 0.769–0.853) for 1-year overall survival, 0.814 (95% CI 0.772–0.856) for 3-year overall survival and 0.796 (95% CI 0.754–0.838) for 5-year overall survival respectively. In validation cohort, the Harrell’s concordance indexes of LncRNA risk prediction score were 0.779 (95% CI 0.737–0.821), 0.828 (95% CI 0.786–0.870) and 0.796 (95%CI 0.754–0.838) for 1-year survival, 3-year survival and 5-year survival respectively. LncRNA risk prediction score could stratify hepatocellular carcinoma patients into low risk group and high risk group. Further survival curve analysis demonstrated that the overall survival rate of high risk patients was significantly poorer than that of low risk patients (P < 0.001).

Conclusions

In conclusion, the current study developed and validated a prognostic signature to predict the individual mortality risk for hepatocellular carcinoma patients. LncRNA risk prediction score is helpful to identify the patients with high mortality risk and optimize the individualized treatment decision. The web calculator can be used by click the following URL: https://zhangzhiqiao2.shinyapps.io/Smart_cancer_predictive_system_HCC_3/.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0890-2) contains supplementary material, which is available to authorized users.

Inhibition of lncRNA HULC improves hepatic fibrosis and hepatocyte apoptosis by inhibiting the MAPK signaling pathway in rats with nonalcoholic fatty liver disease

This study is conducted to investigate the role of long noncoding RNA highly upregulated in liver cancer (lncRNA HULC) on hepatic fibrosis and hepatocyte apoptosis by inhibiting the mitogen-activated protein kinase (MAPK) signaling pathway in rats with nonalcoholic fatty liver disease (NAFLD). The successfully modeled rats were injected with HULC siRNA or small interfering RNA (siRNA) negative control into the tail vein. The expression of HULC in liver tissues was detected by reverse transcription quantitative polymerase reaction chain. The role of HULC in pathological state and liver function-related indexes of liver lipid deposition, the degree of hepatic fibrosis and hepatocyte apoptosis in rats with NAFLD were also investigated through a series of experiments. Increased expression of HULC was found in liver tissue of NAFLD rats. Inhibition of HULC improved the pathological state and liver function-related indexes of liver lipid deposition, improved the degree of hepatic fibrosis, reduced hepatocyte apoptosis, and inhibited the MAPK signaling pathway in the liver tissue of NAFLD rats. The inhibition of p38 and JNK improved the pathological state of liver lipid deposition and liver function to some extent, improved the degree of hepatic fibrosis, and reduced the apoptosis of hepatocytes in NAFLD rats. Collectively, this present study provides evidence that inhibition of lncRNA HULC improves hepatic fibrosis and decrease hepatocyte apoptosis in rats with NAFLD by inhibiting the MAPK signaling pathway.

Involvement of long non-coding RNA HULC (highly up-regulated in liver cancer) in pathogenesis and implications for therapeutic intervention

INTRODUCTION

HULC (highly upregulated in liver cancer) is a long non-coding RNA (lncRNA) which is, as its name suggests, highly upregulated in hepatocellular carcinoma and in several other cancers. Increased HULC expression levels are strongly associated with clinicopathologic features such as tumor stages and overall survival and is a driver of tumor proliferation, migration, and invasion. Areas covered: This review addresses the discovery of HULC and discusses the consequences of HULC deregulation in cancer, the underlying molecular mechanisms and the potential of HULC as a biomarker and therapeutic target. Expert opinion: HULC is a promising candidate as a therapeutic target in cancer; however, more studies are necessary to further elucidate the underlying molecular mechanism(s), especially in cancer types other than hepatocellular carcinomas. Future studies that focus on an optimized HULC-targeting approach are necessary to clarify the best strategy to target this lncRNA in vivo and in patients.

MicroRNA-372 enhances radiosensitivity while inhibiting cell invasion and metastasis in nasopharyngeal carcinoma through activating the PBK-dependent p53 signaling pathway

Nasopharyngeal carcinoma (NPC) is a common cancer found in the nasopharynx, which plagues countless NPC patients. MicroRNA‐372 (miR‐372) has been reported to be involved in various tumors. Here, we explored the important role of miR‐372 in radiosensitivity, invasion, and metastasis of NPC. Microarray analysis was conducted to search the NPC‐related differentially expressed genes (DEGs) and predict the miRs regulating PBK, which suggested that miR‐372 could influence the development of NPC via PBK and the p53 signaling pathway. Importantly, miR‐372 was observed to target PBK, thus down‐regulating its expression. Then, NPC 5‐8F and C666‐1 cells were selected, and treated with ionization radiation and alteration of miR‐372 and PBK expression to explore the functional role of miR‐372 in NPC. The expression of miR‐372, PBK, Bcl‐2, p53, and Bax as well as the extent of Akt phosphorylation were measured. In addition, cell colony formation, cell cycle, proliferation, apoptosis, migration, and invasion were detected. At last, tumor growth and the effect of miR‐372 on radiosensitivity of NPC were evaluated. Besides, over‐expressed miR‐372 down‐regulated Bcl‐2 and PBK expression and the extent of Akt phosphorylation while up‐regulated the expression of p53 and Bax. Additionally, miR‐372 over‐expression and radiotherapy inhibited cell clone formation, proliferation, tumor growth, migration, invasion, and cell cycle entry, but promoted cell apoptosis. However, the restoration of PBK in NPC cells expressing miR‐372 reversed the anti‐tumor effect of miR‐372 and activation of the p53 signaling pathway. In conclusion, the study shows that up‐regulated miR‐372 promotes radiosensitivity by activating the p53 signaling pathway via inhibition of PBK.

Emerging roles of long non-coding RNAs in tumor metabolism

Compared with normal cells, tumor cells display distinct metabolic characteristics. Long non-coding RNAs (lncRNAs), a large class of regulatory RNA molecules with limited or no protein-coding capacity, play key roles in tumorigenesis and progression. Recent advances have revealed that lncRNAs play a vital role in cell metabolism by regulating the reprogramming of the metabolic pathways in cancer cells. LncRNAs could regulate various metabolic enzymes that integrate cell malignant transformation and metabolic reprogramming. In addition to the known functions of lncRNAs in regulating glycolysis and glucose homeostasis, recent studies also implicate lncRNAs in amino acid and lipid metabolism. These observations reveal the high complexity of the malignant metabolism. Elucidating the metabolic-related functions of lncRNAs will provide a better understanding of the regulatory mechanisms of metabolism and thus may provide insights for the clinical development of cancer diagnostics, prognostics and therapeutics.

Prognostic significance of the long noncoding RNAs in nasopharyngeal carcinoma: a systematic review and meta-analysis

Background and objective

Nasopharyngeal carcinoma (NPC) is a common head and neck malignancy. Despite recent advances in treatment, the prognosis, particularly for those at the advanced stages, remains poor. Moreover, the underlying genetic and molecular events have remained obscure so far. Recently, increasing evidence has demonstrated that long noncoding RNAs (lncRNAs) could act as either oncogenes or tumor suppressor genes in various cancers depending on their targets. And some lncRNAs have been shown to be aberrantly expressed in NPC. In this meta-analysis, we try to elucidate the possible role of lncRNAs and their expression on prognosis in NPC.

Methods

We searched the databases of PubMed, Embase, and Web of Science for relevant articles ranging from January 2000 to December 2017. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were used to evaluate the prognostic value of lncRNAs in NPC. Odds ratios (ORs) were used to assess the association between lncRNAs and clinicopathological characteristics.

Results

A total of 14 eligible publications including 14 on prognosis and eight on clinicopathological characteristics were identified. Our results demonstrated that the high expression of lncRNAs was related to poor overall survival (OS; HR =1.55; 95% CI =1.01, 2.40; P=0.05) and disease-free survival (DFS; HR =1.83; 95% CI =1.07, 3.13; P=0.03) of NPC. Moreover, the expression of lncRNAs was correlated with male gender (OR =1.42; 95% CI =1.05, 1.91; P=0.02), lymph node status (OR =2.20; 95% CI =1.29, 3.73; P=0.004), and tumor node metastasis (TNM) clinical stage (OR =2.55; 95% CI =1.12, 5.78; P=0.03).

Conclusion

This meta-analysis shows that the level of expression of lncRNAs may be a potential prognostic indicator in NPC.

The association of lncRNA-HULC polymorphisms with hepatocellular cancer risk and prognosis

BACKGROUND

Genetic polymorphisms in lncRNA HULC may affect the susceptibility and clinical outcome of cancer. We aimed to investigate the association of HULC tagSNPs with the risk and prognosis of hepatocellular cancer, as well as the influence of the SNPs on lncRNA expression level.

METHODS

A total of 1338 samples were recruited in the risk study. Among them, 351 HCC patients were involved in the prognosis study. SNP genotyping was performed using KASP method and lncRNA expression was detected by Real-time PCR.

RESULTS

We found a promoter SNP, rs1041279, was associated with a 1.41-fold increased HCC risk (P = 0.032). In the stratified analysis, rs1041279 had greater ORs for the increased HCC risk in the male subgroup (P = 0.014, OR = 1.54). Furthermore, multi-logistic regression analysis revealed a two-way interaction effect of smoking-rs2038540 SNP on HCC risk (OR = 4.20). And MDR analysis consistently demonstrated a SNP-environmental interaction among smoking-drinking-rs2038540 SNP as the best model for predicting HCC risk (P = 0.0107). In our study, no significant association was found between HULC SNPs and the overall survival (P > 0.05), and no significant effect was observed of rs1041279 SNP on lncRNA-HULC expression (P > 0.05).

CONCLUSION

lncRNA-HULC rs1041279 SNP and the interaction of rs2038540 SNP with environmental factors could enhance HCC risk.

Systematic analyses of a novel lncRNA-associated signature as the prognostic biomarker for Hepatocellular Carcinoma

Accumulating evidence implies that long noncoding RNAs (lncRNAs) play a crucial role in predicting survival for Hepatocellular carcinoma (HCC) patients. This study aims to capture the current research hotspots of HCC, based on the analysis of publications related to HCC research from 2013 to 2017, and to identify a novel lncRNA signature for HCC prognosis through the data mining in The Cancer Genome Atlas (TCGA). “Prognosis” and “biomarker” were located in the core of the HCC research hotspot. Moreover, long noncoding RNA was the top one research frontier in HCC research. The associations between survival outcome and the expression of lncRNAs were evaluated by the univariate and multivariate Cox proportional hazards regression analyses. Four lncRNAs (LINC00261, TRELM3P, GBP1P1, and CDKN2B‐AS1) were identified as significantly correlated with overall survival (OS). These four lncRNAs were gathered as a single prognostic signature. There was a significant positive correlation between HCC patients with low‐risk scores and overall survival (HR = 1.802, 95%CI [1.224‐2.652], P = .003). Further analysis suggested that the prognostic value of this four‐lncRNA signature was independent in clinical features. The enrichment analysis of prognostic lncRNA‐related gene was performed to find out the related pathways. Our study indicates that this novel lncRNA expression signature may be a useful biomarker of the prognosis for HCC patients, based on bioinformatics analysis.

Long non-coding RNA GPR65-1 is up-regulated in gastric cancer and promotes tumor growth through the PTEN-AKT-slug signaling pathway

Increasing evidence has shown that abnormal expression of lncRNAs is involved in various biological behaviors and major cellular pathways of human cancers. However, the role of lncRNAs in the progression of gastric cancer has not been adequately investigated. Therefore, in this study, we investigated the expression levels of linc-GPR65-1 using Quantitative real-time PCR (qRT-PCR) and found that linc-GPR65-1 was significantly up-regulated in 50 gastric cancer tissues compared to the corresponding normal tissues. In addition, increased linc-GPR65-1 expression was associated with TNM stage (P = 0.037), tumor size (P = 0.024), distal metastasis (P = 0.023), and poor prognosis of gastric cancer patients. Moreover, functional assays indicated that decreased linc-GPR65-1 expression inhibited the aggressive phenotypes of gastric cancer cells, and enhanced linc-GPR65-1 expression resulted in the opposite phenomenon. Then, a cancer signaling phosphoantibody microarray was conducted to explore the potential mechanisms of linc-GPR65-1 in regulating gastric cancer progression and observed that linc-GPR65-1 could regulate the PTEN-AKT-slug signaling pathway. These data showed that linc-GPR65-1, regulating the PTEN-AKT-slug signaling pathway, might act as a tumor promoter and serve as a novel target for gastric cancer prevention and therapy.

lncRNA HULC promotes the growth of hepatocellular carcinoma cells via stabilizing COX-2 protein

Highly upregulated in liver cancer (HULC), a lncRNA overexpressed in hepatocellular carcinoma (HCC), has been demonstrated to be involved in the carcinogenesis and progression of HCC. However, the mechanisms of HULC promoting the abnormal growth of HCC cells are still not well elucidated. In the present study, we for the first time demonstrated that HULC promoted the growth of HCC cells through elevating COX-2 protein. Moreover, the study of the corresponding mechanism by which HULC upregulated COX-2 showed that HULC enhanced the level of ubiquitin-specific peptidase 22 (USP22), which decreased ubiquitin-mediated degradation of COX-2 protein by removing the conjugated polyubiquitin chains from COX-2 and finally stabilized COX2 protein. In addition, knockdown of USP22 or COX-2 attenuated HULC-mediated abnormal growth of HCC cells. In conclusion, our results demonstrated that "USP22/COX-2" axis played an important role in HULC promoting growth of HCC cells. The identification of this novel pathway may pave a road for developing new potential anti-HCC strategies.