Long non-coding RNA LINC00467 drives hepatocellular carcinoma progression via inhibiting NR4A3

RP11-495P10.1 promotes HCC cell proliferation by regulating reprogramming of glucose metabolism and acetylation of the NR4A3 promoter via the PDK1/PDH axis

The incidence and related death of hepatocellular carcinoma (HCC) have increased over the past decades. However, the molecular mechanisms underlying HCC pathogenesis are not fully understood. Long noncoding RNA (lncRNA) RP11-495P10.1 has been proven to be closely associated with the progression of prostate cancer, but its role and specific mechanism in HCC are still unknown. Here, we identify that RP11-495P10.1 is highly expressed in HCC tissues and cells and contributes to the proliferation of HCC cells. Moreover, this study demonstrates that RP11-495P10.1 affects the proliferation of HCC by negatively regulating the expression of nuclear receptor subfamily 4 group a member 3 (NR4A3). Glycometabolism reprogramming is one of the main characteristics of tumor cells. In this study, we discover that RP11-495P10.1 regulates glycometabolism reprogramming by changing the expression of pyruvate dehydrogenase kinase 1 (PDK1) and pyruvate dehydrogenase (PDH), thus contributing to the proliferation of HCC cells. Furthermore, knockdown of RP11-495P10.1 increases enrichment of H3K27Ac in the promoter of NR4A3 by promoting the activity of PDH and the production of acetyl-CoA, which leads to the increased transcription of NR4A3. Altogether, RP11-495P10.1 promotes HCC cell proliferation by regulating the reprogramming of glucose metabolism and acetylation of the NR4A3 promoter via the PDK1/PDH axis, which provides an lncRNA-oriented therapeutic strategy for the diagnosis and treatment of HCC.

A review on the role of LINC00467 in the carcinogenesis

LINC00467 is an example of long intergenic non-coding RNAs whose roles in human disorders are being identified. This gene coding LINC00467 is located on chromosome 1: 211,382,736 - 211,435,570 forward strand. This lncRNA has been firstly recognized through a microarray-based lncRNA profiling as an N-Myc target in neuroblastoma cells. Further studies have shown up-regulation of LINC00467 in different cancer including those originated from brain, gastrointestinal tract, lung and breast. It acts as a molecular sponge for miR-339, miR-138-5p, miR-107, miR-133b, miR-451a, miR-485-5p, miR-7-5p, miR-485-5p, miR-339-3p, miR-200a, miR-1285-3p, miR-299-5p, miR-509-3p, miR-18a-5p, miR-9-5p and miR-20b-5p. LINC00467 can regulate activity of NF-κB, STAT1, Wnt/b-catenin, Akt and ERK1/2 signaling pathways. Accumulating evidence indicates oncogenic role of LINC00467. The current review article aims at providing an overview of LINC00467 in the carcinogenesis.

LINC00467: an oncogenic long noncoding RNA

Long non-coding RNAs (lncRNAs) have been found to play essential roles in the cell proliferation, fission and differentiation, involving various processes in humans. Recently, there is more and more interest in exploring the relationship between lncRNAs and tumors. Many latest evidences revealed that LINC00467, an oncogenic lncRNA, is highly expressed in lung cancer, gastric cancer, colorectal cancer, hepatocellular carcinoma, breast cancer, glioblastoma, head and neck squamous cell carcinoma, osteosarcoma, and other malignant tumors. Besides, LINC00467 expression was linked with proliferation, migration, invasion and apoptosis via the regulation of target genes and multiple potential pathways. We reviewed the existing data on the expression, downstream targets, molecular mechanisms, functions, relevant signaling pathways, and clinical implications of LINC00467 in various cancers. LINC00467 may serve as a novel biomarker or therapeutic target for the diagnosis and prognosis of various human tumors.

LINC00467: A key oncogenic long non-coding RNA

The significance of long non-coding RNAs (lncRNAs) in the development and progression of human cancers has attracted increasing attention in recent years of investigations. Having versatile interactions and diverse functions, lncRNAs can act as oncogenes or tumor-suppressors to actively regulate cell proliferation, survival, stemness, drug resistance, invasion and metastasis. LINC00467, an oncogenic member of long intergenic non-coding RNAs, is upregulated in numerous malignancies and its high expression is often related to poor clinicopathological features. LINC00467 facilitates the progression of cancer via sponging tumor-suppressive microRNAs, inhibiting cell death cascade, modulating cell cycle controllers, and regulating signalling pathways including AKT, STAT3, NF-κB and Wnt/β-catenin. A growing number of studies have revealed that LINC00467 may serve as a novel prognostic biomarker and its inhibitory targeting has a valuable therapeutic potential to suppress the malignant phenotypes of cancer cells. In the present review, we discuss the importance of LINC00467 and provide a comprehensive collection of its functions and molecular mechanisms in a variety of cancer types.

Comprehensive insights into the function and molecular and pharmacological regulation of neuron-derived orphan receptor 1, an orphan receptor

Neuron-derived orphan receptor 1 (NOR1), also called nuclear receptor subfamily 4 group A member 3 (NR4A3), is a nuclear receptor belonging to the NR4A family. Since no endogenous ligand has been identified to date, NOR1 is also referred to as an orphan receptor. NOR1 is expressed in a variety of cells and tissues, including neurons, vascular smooth muscle cells, T lymphocytes, dendritic cells, tumor cells, heart, liver, and pancreas. Because NOR1 was first identified in apoptotic neurons, it is functionally associated with the regulation of cell migration and the growth of neuronal synapses. In-depth studies have shown that NOR1 can be edited by the immediate early gene and functions as a transcription factor. NOR1 has been shown to be rapidly induced by a number of stimulants including growth factors, fatty acids, and neurotransmitters. Elevated NOR1 levels may be involved in a number of pathophysiological processes. These include regulation of cellular apoptosis and regeneration, neuron formation, contextual fearing memory, inflammation, vascular smooth muscle proliferation, insulin secretion, and tumor development, whereby NOR1 mediates the pathogenesis of numerous diseases such as cerebral ischemia, depression, post-traumatic stress disorder, atherosclerosis, abdominal aortic aneurysm, cardiac hypertrophy, diabetes, osteoarthritis, rheumatoid arthritis, and cancer. However, to date, comprehensive insights into the function of NOR1 are not available in sources published online. In this review, we provide a brief overview of the function and molecular and pharmacological regulation of NOR1 in various pathological or physiological conditions to advance the development of NOR1 as a novel target for disease treatment.

Long Noncoding RNA LINC00467: Role in Various Human Cancers

Intricate genetic mutations promote the progression of different cancer types. Long noncoding RNAs (lncRNAs) have been widely demonstrated to participate in the genomic activities of various human cancers. Long intergenic non-coding RNA 467 (LINC00467) is an upregulated lncRNA in diverse diseases, especially in several types of cancers. Functional experiments of LINC00467 revealed that LINC00467 overexpression enhanced cell chemoresistance, proliferation, migration, and invasion in several types of cancers. Moreover, overexpressed LINC00467 was associated with a poor clinical prognosis. The present evidence suggests that LINC00467 may serve as a promising prognostic indicator and become a novel cancer therapeutic target. In this review, we introduce the biologic functions of lncRNAs and describe the molecular mechanism and clinical significance of LINC00467 in detail.

The LINC00261/MiR105-5p/SELL axis is involved in dysfunction of B cell and is associated with overall survival in hepatocellular carcinoma

Background

Previous studies have been reported the immune dysfunction of various live tissues. However, the potential molecular mechanism of post-transcriptional regulation of immune related genes in hepatocellular carcinoma (HCC) is still not clear. We tried to identify crucial immune related biomarkers associated with HCC patients' outcomes and to reveal the transcriptional regulation.

Method

The fractions of 22 immune cells in tumor and adjacent tissues were estimated by CIBERSORT. Kruskal-Wallis test and differentially expressed analyzes were used for comparative studies. Cox proportional hazard regression model, Kaplan-Meier estimates and Log-rank test were used for survival analyses.

Results

From The Cancer Genome Atlas (TCGA), the gene, lncRNA and miRNA expression profiles of 379 HCC samples with clinical information were used for comparative studies. Eleven adaptive and innate immune cell types were significantly altered in HCC samples, including B cell memory, regulatory T cells and follicular helper T cells. Differentially expressed competing endogenous RNA (ceRNA) network associated with patients' overall survival was identified. Then, the novel pathway, including LINC00261, MiR105-5p and selectin L(SELL) was found and may be potential novel biomarkers for patients' outcomes and immunotherapy. Furthermore, SELL was significantly positively correlated (correlation coefficients: 0.47-0.69) with 12 known gene signatures of immunotherapy except for programmed cell death 1 (PDCD1).

Conclusions

Our findings could provide insights into the selection of novel LINC00261/MiR105-5p/SELL pathway which is associated with overall survival and may impact on efficacy of immunotherapy in HCC.

Molecular Characteristics of T Cell-Mediated Tumor Killing in Hepatocellular Carcinoma

BACKGROUND

Although checkpoint blockade is a promising approach for the treatment of hepatocellular carcinoma (HCC), subsets of patients expected to show a response have not been established. As T cell-mediated tumor killing (TTK) is the fundamental principle of immune checkpoint inhibitor therapy, we established subtypes based on genes related to the sensitivity to TKK and evaluated their prognostic value for HCC immunotherapies.

METHODS

Genes regulating the sensitivity of tumor cells to T cell-mediated killing (referred to as GSTTKs) showing differential expression in HCC and correlations with prognosis were identified by high-throughput screening assays. Unsupervised clustering was applied to classify patients with HCC into subtypes based on the GSTTKs. The tumor microenvironment, metabolic properties, and genetic variation were compared among the subgroups. A scoring algorithm based on the prognostic GSTTKs, referred to as the TCscore, was developed, and its clinical and predictive value for the response to immunotherapy were evaluated.

RESULTS

In total, 18 out of 641 GSTTKs simultaneously showed differential expression in HCC and were correlated with prognosis. Based on the 18 GSTTKs, patients were clustered into two subgroups, which reflected distinct TTK patterns in HCC. Tumor-infiltrating immune cells, immune-related gene expression, glycolipid metabolism, somatic mutations, and signaling pathways differed between the two subgroups. The TCscore effectively distinguished between populations with different responses to chemotherapeutics or immunotherapy and overall survival.

CONCLUSIONS

TTK patterns played a nonnegligible role in formation of TME diversity and metabolic complexity. Evaluating the TTK patterns of individual tumor will contribute to enhancing our cognition of TME characterization, reflects differences in the functionality of T cells in HCC and guiding more effective therapy strategies.

Linc00467 promotion of gastric cancer development by directly regulating miR-7-5p expression and downstream epidermal growth factor receptor

Linc00467 is a vital regulator in tumor progression. This study explores the molecular mechanisms of linc00467 in gastric cancer (GC). Linc00467 expression was obtained and analyzed in GC tissue through exploration in the cancer genome atlas database. Then, real-time quantitative polymerase chain reaction was used to detect linc000467 expression in GC cells. Cell functions were observed using cell counting Kit-8, Transwell assay, Western blotting to testify the proliferation, migration, invasion, and the relative expression of epidermal growth factor receptor (EGFR) in GC cells. Moreover, a dual-luciferase reporter gene assay was used to verify the relationship between linc00467 and miR-7-5p. Results showed that the expression of linc00467 was overexpressed in GC. Linc00467 silencing decreased the GC cell proliferation, migration, and invasion. With mRNA verification and combined previous research, linc00467 directly regulated the miR-7-5p expression and downstream EGFR expression. Inhibited miR-7-5p could restore cell function, EGFR expression of GC cells when linc00467 knockdown occurs. Altogether, linc00467 directly regulates the miR-7-5p and EGFR signaling pathway to promote GC proliferation, migration, and invasion.

Overexpressed LINC00467 promotes the viability and proliferation yet inhibits apoptosis of gastric cancer cells via raising ITGB3 level

Long non-coding RNA (lncRNA) LINC00467 plays a proto-oncogenic role in non-small cell lung cancer. However, its effect and modulatory mechanism in gastric cancer (GC) are unknown. Thereby, we elucidated the mechanism of LINC00467 in GC. LINC00467 level in GC tissues was assessed by bioinformatic analysis, and clinicopathological parameters from GC patients were collected. The levels of LINC00467, integrin subunit beta 3 (ITGB3), proliferating cell nuclear antigen (PCNA), cleaved caspase-3 and cleaved poly (ADP-ribose) polymerase 1 (PARP1) in tissue samples or treated GC cells were assessed by quantitative real-time polymerase chain reaction (qRT-PCR), fluorescence in situ hybridization (FISH), or Western blot. The viability, proliferation and apoptosis of GC cells were detected by methyl thiazolyl tetrazolium assay, colony formation assay, and flow cytometry. Levels of LINC00467 and ITGB3 were up-regulated in GC, and highly expressed LINC00467 was positively associated with tumor size, differentiation, N stage, and T stage in GC patients. LINC00467 was enriched in cytoplasm of GC cells, and overexpressed LINC00467 promoted the viability and proliferation as well as levels of ITGB3 and PCNA, while suppressing the apoptosis and levels of cleaved caspase-3 and cleaved PARP1 in GC cells. Besides, the effects of shLINC00467 on inhibiting cell viability, proliferation of GC cells and PCNA level and promoting apoptosis as well as levels of cleaved caspase-3 and cleaved PARP1 were all partially reversed by overexpressed ITGB3. Overexpressed LINC00467 enhanced the viability and proliferation but inhibited apoptosis of GC cells via increasing ITGB3 level.

Circ_0030586 inhibits cell proliferation and stemness in bladder cancer by inactivating the ERK signaling via miR-665/NR4A3 axis

Increasing evidence reveals that circular RNAs (circRNAs) serve as oncogenes or tumor suppressors in the development of various tumors including bladder cancer (BCa). In this study, we explored the function and mechanism of circ_0030586 (also named circABCC4, ATP binding cassette subfamily C member 4) in BCa. The expression of circ_0030586 was significantly decreased in BCa tissues and cells, as suggested by RT-qPCR. The circular characteristics of circ_0030586 were verified by agarose gel electrophoresis and RNase R treatment. Colony formation, 5-Ethynyl-2'-deoxyuridine and sphere formation assays revealed that overexpression of circ_0030586 suppressed BCa cell proliferation and stemness in vitro. According to xenograft experiment, circ_0030586 overexpression suppressed tumor growth in vivo. Mechanistically, RNA pulldown and luciferase reporter assays were carried out to explore the interaction between genes. Circ_0030586 served as a competing endogenous RNA (ceRNA) for hsa-miR-665 to upregulate the expression of nuclear receptor subfamily 4 group A member 3 (NR4A3) which is a downstream target gene of miR-665 in BCa. MiR-665 exhibited high expression in BCa tissues and cells while NR4A3 expression was downregulated in BCa. MiR-665 overexpression or NR4A3 silencing reversed the suppressive effect of circ_0030586 overexpression on BCa cell proliferation and stemness. Moreover, western blot analysis revealed that circ_0030586 inactivated the extracellular signal-regulated kinase (ERK) pathway by upregulating NR4A3 expression. In conclusion, circ_0030586 inhibits BCa cell proliferation and stemness by serving as a ceRNA for miR-665 to upregulate NR4A3 expression and thus inactivate the ERK signaling.

Bioinformatic analysis and validation of microRNA-508-3p as a protective predictor by targeting NR4A3/MEK axis in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) featured a debilitating progressive disorder. Here, we intend to determine diagnosis‐valuable biomarkers for PAH and decode the fundamental mechanisms of the biological function of these markers. Two mRNA microarray profiles (GSE70456 and GSE117261) and two microRNA microarray profiles (GSE55427 and GSE67597) were mined from the Gene Expression Omnibus platform. Then, we identified the differentially expressed genes (DEGs) and differentially expressed miRNAs (DEMs), respectively. Besides, we investigated online miRNA prediction tools to screen the target gene of DEMs. In this study, 185 DEGs and three common DEMs were screened as well as 1266 target genes of the three DEMs were identified. Next, 16 overlapping dysregulated genes from 185 DEGs and 1266 target gene were obtained. Meanwhile, we constructed the miRNA gene regulatory network and determined miRNA‐508‐3p‐NR4A3 pair for deeper exploring. Experiment methods verified the functional expression of miR‐508‐3p in PAH and its signalling cascade. We observed that ectopic miR‐508‐3p expression promotes proliferation and migration of pulmonary artery smooth muscle cell (PASMC). Bioinformatic, dual‐luciferase assay showed NR4A3 represents directly targeted gene of miR‐508‐3p. Mechanistically, we demonstrated that down‐regulation of miR‐508‐3p advances PASMC proliferation and migration via inducing NR4A3 to activate MAPK/ERK kinase signalling pathway. Altogether, our research provides a promising diagnosis of predictor and therapeutic avenues for patients in PAH.

LncRNA LINC00467 acted as an oncogene in esophageal squamous cell carcinoma by accelerating cell proliferation and preventing cell apoptosis via the miR-485-5p/DPAGT1 axis

BACKGROUND AND AIM

Esophageal carcinoma has been regarded as one of the top 10 common malignancies globally. Esophageal squamous cell carcinoma (ESCC) is an important subtype of esophageal carcinoma with approximately 20% survival rate. Long noncoding RNAs were documented to regulate the occurrence or progression of several tumors. However, neither the biological role nor the molecular mechanism of LINC00467 has been explored. This research is aimed to investigating the regulatory mechanism of LINC00467 in ESCC.

METHODS

In this study, a series of experiments including reverse transcription-quantitative polymerase chain reaction, Cell Counting Kit-8, luciferase reporter, western blot, and RNA immunoprecipitation were designed and conducted to explore the potential function and mechanism of LINC00467 in ESCC.

RESULTS

According to experimental results, we found out upregulated LINC00467 improved cell proliferation, but hindered cell apoptosis. In mechanism, miR-485-5p was predicted, screened out, and validated to combine with LINC00467, which displayed lower expression in ESCC. Additionally, miR-485-5p negatively regulated and directly targeted DPAGT1. Rescue assays suggested that DPAGT1 amplification was able to recover the influence of LINC00467 deficiency on cell proliferation and apoptosis. Furthermore, knockdown of LINC00467 suppressed tumor growth in vivo.

CONCLUSION

We proved that LINC00467 acted as an oncogene in ESCC by accelerating cell proliferation and preventing cell apoptosis via miR-485-5p/DPAGT1 axis. This may provide a potential diagnostic marker for ESCC treatment.

Hepigenetics: A Review of Epigenetic Modulators and Potential Therapies in Hepatocellular Carcinoma

Hepatocellular carcinoma is the fifth most common cancer worldwide and the second most lethal, following lung cancer. Currently applied therapeutic practices rely on surgical resection, chemotherapy and radiotherapy, or a combination thereof. These treatment options are associated with extreme adversities, and risk/benefit ratios do not always work in patients' favor. Anomalies of the epigenome lie at the epicenter of aberrant molecular mechanisms by which the disease develops and progresses. Modulation of these anomalous events poses a promising prospect for alternative treatment options, with an abundance of felicitous results reported in recent years. Herein, the most recent epigenetic modulators in hepatocellular carcinoma are recapitulated on.

Long non-coding RNA LINC00467 drives hepatocellular carcinoma progression via inhibiting NR4A3

Hepatocellular carcinoma (HCC) is a main cause of cancer-related deaths globally. Long non-coding RNAs (lncRNAs) play important roles in diverse cancers. Our previous microarray-based lncRNA profiling showed that LINC00467 was highly expressed in HCC. Here, we further explored the expression, role and functional mechanism of lncRNA LINC00467 in HCC. Our findings revealed that LINC00467 was up-regulated in HCC tissues and HCC cell lines. Increased expression of LINC00467 was positively associated with tumour size and vascular invasion. In vitro functional experiments revealed that LINC00467 accelerated HCC cell proliferation, cell cycle progression and migration and reduced HCC cell apoptosis. In vivo functional assays revealed that LINC00467 drove HCC xenograft growth and HCC cell proliferation and repressed HCC cell apoptosis in vivo. Moreover, LINC00467 inhibited NR4A3 post-transcriptionally via interacting with NR4A3 mRNA to form double-stranded RNA, which was further degraded by Dicer. The expression of NR4A3 was inversely associated with LINC00467 in HCC tissues. Functional rescue assays found that restore of NR4A3 expression blocked the oncogenic roles of LINC00467 in HCC. Taken together, our results demonstrated that lncRNA LINC00467 was a novel highly expressed and oncogenic lncRNA in HCC via inhibiting NR4A3. Targeting LINC00467 or enhancing NR4A3 may be potential therapeutic strategies against HCC.