Long Noncoding RNA LINC00467 Promotes Glioma Progression through Inhibiting P53 Expression via Binding to DNMT1

Multi-omics integration analysis reveals the role of N6-methyladenosine in lncRNA translation during glioma stem cell differentiation

Glioblastoma is one of the most lethal brain diseases in humans. Although recent studies have shown reciprocal interactions between N6-methyladenosine (m6A) modifications and long noncoding RNAs (lncRNAs) in gliomagenesis and malignant progression, the mechanism of m6A-mediated lncRNA translational regulation in glioblastoma remains unclear. Herein, we profiled the transcriptomes, translatomes, and epitranscriptomics of glioma stem cells and differentiated glioma cells to investigate the role of m6A in lncRNA translation comprehensively. We found that lncRNAs with numerous m6A peaks exhibit reduced translation efficiency. Transcript-level expression analysis demonstrates an enrichment of m6A around short open reading frames (sORFs) of translatable lncRNA transcripts. Further comparison analysis of m6A modifications in different RNA regions indicates that m6A peaks downstream of sORFs inhibit lncRNA translation more than those upstream. Observations in glioma-associated lncRNAs H19, LINC00467, and GAS5 further confirm the negative effect of m6A methylation on lncRNA translation. Overall, these findings elucidate the dynamic profiles of the m6A methylome and enhance the understanding of the complexity of lncRNA translational regulation.

Unraveling the role of LncRNAs in glioblastoma progression: insights into signaling pathways and therapeutic potential

Glioblastoma (GBM) is one of the most aggressive types of brain cancer, characterized by its poor prognosis and low survival rate despite current treatment modalities. Because GBM is lethal, clarifying the pathogenesis's underlying mechanisms is important, which are still poorly understood. Recent discoveries in the fields of molecular genetics and cancer biology have demonstrated the critical role that non-coding RNAs (ncRNAs), especially long non-coding RNAs (lncRNAs), play in the molecular pathophysiology of GBM growth. LncRNAs are transcripts longer than 200 nucleotides that do not encode proteins. They are significant epigenetic modulators that control gene e expression at several levels. Their dysregulation and interactions with important signaling pathways play a major role in the malignancy and development of GBM. The increasing role of lncRNAs in GBM pathogenesis is thoroughly examined in this review, with particular attention given to their regulation mechanisms in key signaling pathways such as PI3K/AKT, Wnt/β-catenin, and p53. It also looks into lncRNAs' potential as new biomarkers and treatment targets for GBM. In addition, the study discusses the difficulties in delivering lncRNA-based medicines across the blood-brain barrier and identifies areas that need more research to advance lncRNA-oriented treatments for this deadly cancer.

A novel prognostic risk-scoring system based on m5C methylation regulator-mediated patterns for glioma patients

N5-methylcytosine (m5C) methylation modification plays a crucial role in the epigenetic mechanisms underlying tumorigenesis, aggressiveness, and malignancy in diffuse glioma. Our study aimed to develop a novel prognostic risk-scoring system to assess the impact of m5C modification in glioma patients. Initially, we identified two distinct m5C clusters based on the expression level of m5C regulators in The Cancer Genome Atlas glioblastoma (TCGA-GBM) dataset. Differentially expressed genes (DEGs) between the two m5C cluster groups were determined. Utilizing these m5C regulation-related DEGs, we classified glioma patients into three gene cluster groups: A, B, and C. Subsequently, an m5C scoring system was developed through a univariate Cox regression model, quantifying the m5C modification patterns utilizing six DEGs associated with disease prognosis. The resulting scoring system allowed us to categorize patients into high- or low-risk groups based on their m5C scores. In test (TCGA-GBM) and validation (Chinese Glioma Genome Atlas [CGGA]-1018 and CGGA-301) datasets, glioma patients with a higher m5C score consistently exhibited shorter survival durations, fewer isocitrate dehydrogenase (IDH) mutations, less 1p/19q codeletion and higher World Health Organization (WHO) grades. Additionally, distinct immune cell infiltration characteristics were observed among different m5C cluster groups and risk groups. Our study developed a novel prognostic scoring system based on m5C modification patterns for glioma patients, complementing existing molecular classifications and providing valuable insights into prognosis for glioma patients.

lncRNA Biomarkers of Glioblastoma Multiforme

Long noncoding RNAs (lncRNAs) are RNA molecules of 200 nucleotides or more in length that are not translated into proteins. Their expression is tissue-specific, with the vast majority involved in the regulation of cellular processes and functions. Many human diseases, including cancer, have been shown to be associated with deregulated lncRNAs, rendering them potential therapeutic targets and biomarkers for differential diagnosis. The expression of lncRNAs in the nervous system varies in different cell types, implicated in mechanisms of neurons and glia, with effects on the development and functioning of the brain. Reports have also shown a link between changes in lncRNA molecules and the etiopathogenesis of brain neoplasia, including glioblastoma multiforme (GBM). GBM is an aggressive variant of brain cancer with an unfavourable prognosis and a median survival of 14-16 months. It is considered a brain-specific disease with the highly invasive malignant cells spreading throughout the neural tissue, impeding the complete resection, and leading to post-surgery recurrences, which are the prime cause of mortality. The early diagnosis of GBM could improve the treatment and extend survival, with the lncRNA profiling of biological fluids promising the detection of neoplastic changes at their initial stages and more effective therapeutic interventions. This review presents a systematic overview of GBM-associated deregulation of lncRNAs with a focus on lncRNA fingerprints in patients' blood.

The interactions between DNA methylation machinery and long non-coding RNAs in tumor progression and drug resistance

DNA methylation is one of the main epigenetic mechanisms in cancer development and progression. Aberrant DNA methylation of CpG islands within promoter regions contributes to the dysregulation of various tumor suppressors and oncogenes; this leads to the appearance of malignant features, including rapid proliferation, metastasis, stemness, and drug resistance. The discovery of two important protein families, DNA methyltransferases (DNMTs) and Ten-eleven translocation (TET) dioxygenases, respectively, which are responsible for deregulated transcription of genes that play pivotal roles in tumorigenesis, led to further understanding of DNA methylation-related pathways. But how these enzymes can target specific genes in different malignancies; recent studies have highlighted the considerable role of Long Non-coding RNAs (LncRNAs). LncRNAs recruit these enzymes to promoter regions of genes and mediate their functions, showing great potential as therapeutic agents targeting the epigenetic regulation of various genes. Considering the importance of combining the current treatment methods, especially chemotherapies, with DNA methylation inhibitors in improving patients' outcomes, this review aimed to summarize the recent findings about the interaction between DNA methylation machinery and LncRNAs in regulating genes involved in tumorigenesis and drug resistance. So, these studies could provide insights toward developing novel strategies for cancer-targeted therapy.

Natural flavonoids alleviate glioblastoma multiforme by regulating long non-coding RNA

Glioblastoma multiforme (GBM) is one of the most common primary malignant brain tumors in adults. Due to the poor prognosis of patients, the median survival time of GBM is often less than 1 year. Therefore, it is very necessary to find novel treatment options with a good prognosis for the treatment or prevention of GBM. In recent years, flavonoids are frequently used to treat cancer. It is a new attractive molecule that may achieve this promising treatment option. Flavonoids have been proved to have many biological functions, such as antioxidation, prevention of angiogenesis, anti-inflammation, inhibition of cancer cell proliferation, and protection of nerve cells. It has also shown the ability to regulate long non-coding RNA (LncRNA). Studies have confirmed that flavonoids can regulate epigenetic modification, transcription, and change microRNA (miRNA) expression of GBM through lncRNA at the gene level. It also found that flavonoids can induce apoptosis and autophagy of GBM cells by regulating lncRNA. Moreover, it can improve the metabolic abnormalities of GBM, interfere with the tumor microenvironment and related signaling pathways, and inhibit the angiogenesis of GBM cells. Eventually, flavonoids can block the tumor initiation, growth, proliferation, differentiation, invasion, and metastasis. In this review, we highlight the role of lncRNA in GBM cancer progression and the influence of flavonoids on lncRNA regulation. And emphasize their expected role in the prevention and treatment of GBM.

Targeting long non-coding RNA PVT1/TGF-β/Smad by p53 prevents glioma progression

Glioma is a primary intracranial malignant tumor with poor prognosis, and its pathogenesis is unclear. This study discussed the impact of p53/lncRNA plasmacytoma variant translocation 1 (lncRNA PVT1)/transforming growth factor beta (TGF-β)/Smad axis on the biological characteristics of glioma. Glioma and normal tissues were collected, in which relative lncRNA PVT1 and p53 expression was assessed. Pearson’s analysis was adopted for the correlation analysis between lncRNA PVT1 and p53. Short interfering RNA (siRNA) against lncRNA PVT1 (siRNA-PVT1), siRNA-p53 or both was transfected into the glioma cells to evaluate effects of lncRNA PVT1 and p53 on cell proliferation, migration, invasion, and apoptosis. Mouse xenograft model of glioma was established to verify function of lncRNA PVT1 and p53 in vivo. Relationship among p53, lncRNA PVT1 and TGF-β/Smad was predicted and confirmed. Glioma tissues and cells showed downregulated p53 expression and increased lncRNA PVT1 expression. An adverse relationship was noted between p53 expression and lncRNA PVT1 expression. p53 was shown to be enriched in the lncRNA PVT1 promoter region and resulted in its suppression. p53 inhibited glioma cell proliferation, migration, and invasion, and induced apoptosis as well as arrested tumor growth by downregulating lncRNA PVT1. LncRNA PVT1was found to bind to TGF-β and activate TGF-β/Smad pathway, promoting progression of glioma. Consequently, p53 exerts anti-oncogenic function on glioma development by suppressing lncRNA PVT1 and subsequently inactivating TGF-β/Smad pathway.

Particulate Matters Affecting lncRNA Dysregulation and Glioblastoma Invasiveness: In Silico Applications and Current Insights

With a reported rise in global air pollution, more than 50% of the population remains exposed to toxic air pollutants in the form of particulate matters (PMs). PMs, from various sources and of varying sizes, have a significant impact on health as long-time exposure to them has seen a correlation with various health hazards and have also been determined to be carcinogenic. In addition to disrupting known cellular pathways, PMs have also been associated with lncRNA dysregulation-a factor that increases predisposition towards the onset or progression of cancer. lncRNA dysregulation is further seen to mediate glioblastoma multiforme (GBM) progression. The vast array of information regarding cancer types including GBM and its various precursors can easily be obtained via innovative in silico approaches in the form of databases such as GEO and TCGA; however, a need to obtain selective and specific information correlating anthropogenic factors and disease progression-in the case of GBM-can serve as a critical tool to filter down and target specific PMs and lncRNAs responsible for regulating key cancer hallmarks in glioblastoma. The current review article proposes an in silico approach in the form of a database that reviews current updates on correlation of PMs with lncRNA dysregulation leading to GBM progression.

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.

Genomic and Epigenomic Features of Glioblastoma Multiforme and its Biomarkers

Glioblastoma multiforme is a serious and life-threatening tumor of central nervous system, characterized by aggressive behavior, poor prognosis, and low survival rate. Despite of the availability of aggressive antitumor therapeutic regimen for glioblastoma (radiotherapy followed by chemotherapeutic dose), recovery rate, and patients' survival ratio is attributed to the lack of selectivity of therapeutic drugs and less advancement in cancer therapeutics over last decade. Moreover, tools employed in conventional diagnosis of glioblastoma are more invasive and painful, making the process excruciating for the patients. These challenges urge for the need of novel biomarkers for diagnosis, prognosis, and prediction purpose with less invasiveness and more patient compliance. This article will explore the genetic biomarkers isocitrate dehydrogenase mutation, MGMT mutations, and EGFR that can be deployed as an analytical tool in diagnosis of disease and prognosis of a therapeutic course. The review also highlights the importance of employing novel microRNAs as prognostic biomarkers. Recent clinical advancements to treat GBM and to prevent relapse of the disease are also discussed in this article in the hope of finding a robust and effective method to treat GBM.

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.

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.

Downregulated Reprimo by LINC00467 participates in the growth and metastasis of gastric cancer

Gastric cancer (GC) as an aggressive malignancy still causes a global health problem. It has been documented that long noncoding RNAs are involved in GC development. Therefore, this research was designed to explore the role of LINC00467 in the growth and metastasis of GC. The expression of LINC00467 and Reprimo in GC tissues and cells was detected. The binding relationship among LINC00467, DNA methyltransferase 1 (DNMT1) and Reprimo was assessed following. Reprimo promoter methylation was detected by methylation sequencing. GC cell lines overexpressing or knock downing LINC00467 were constructed for pinpointing the effect of LINC00467 on cell functions as well as growth and metastasis of GC cells in vivo. LINC00467 was highly expressed, whereas Reprimo was poorly expressed in GC tissues and cells. Mechanically, LINC00467 promoted the methylation and decreased the expression of Reprimo promoter by recruiting DNMT1 in GC cells. Knockdown of LINC00467 diminished the malignant properties of GC cells. Knockdown of LINC00467 reduced tumorigenesis and metastasis of GC cells in vivo. LINC00467 might exert oncogenic effects in GC via Reprimo downregulation by recruiting DNMT1.

LINC00662 Promotes Proliferation and Invasion and Inhibits Apoptosis of Glioma Cells Through miR-483-3p/SOX3 Axis

LINC00662 plays a prominent role in the carcinogenesis and progression of diverse cancers. However, its biological functions in glioma are still unclear. LINC00662 expression in glioma tissue samples and cell lines was examined by quantitative real-time polymerase chain reaction. The correlation between LINC00662 expression and the clinical characteristics of 50 patients with glioma was analyzed. LINC00662 knockdown and overexpression cell lines were constructed, and the effects of LINC00662 on the proliferation, invasion, and apoptosis of glioma cells were evaluated by cell counting kit-8, 5-ethynyl-2'-deoxyuridine, Transwell, and flow cytometry assays, respectively. Besides, the relationships among LINC00662, miR-483-3p, and sex-determining region Y-box 3 (SOX3) were assessed by dual-luciferase reporter assay and RNA immunoprecipitation assay. Western blot was used to detect the regulatory effects of LINC00662 and miR-483-3p on SOX3 expression in glioma cells. LINC00662 expression level was elevated in glioma tissues and cell lines compared to that in normal tissues and cell lines. LINC00662 high expression was associated with the adverse prognosis of patients with glioma. Knockdown of LINC00662 repressed the proliferation and invasion of glioma cells, and promoted apoptosis. Additionally, it was revealed that LINC00662 acted as the molecular sponge of miR-483-3p, and SOX3 was verified as a direct target of miR-483-3p. The inhibition of miR-483-3p expression and SOX3 overexpression reversed the biological effects of LINC00662 knockdown on glioma cells. This study reports the key regulatory role of LINC00662/miR-483-3p/SOX3 axis in the tumorigenesis and progression of glioma, bringing novel insights into the underlying mechanisms of glioma.

LINC00467 facilitates the proliferation, migration and invasion of glioma via promoting the expression of inositol hexakisphosphate kinase 2 by binding to miR-339-3p

Our previous studies indicate that long noncoding RNA (lncRNA) LINC00467 can act as an oncogene to participate in the malignant progression of glioma, but the underlying molecular mechanism remains to be studied further. This study aimed to explore the biological role of the LINC00467/miR-339-3p/ inositol hexakisphosphate kinase 2 (IP6K2) regulatory axis in glioma. The Cancer Genome Atlas (TCGA), Oncomine databases and reverse transcription‑quantitative PCR (RT‑qPCR) were used to analyze IP6K2 expression in glioma. RT-PCR, EdU and transwell assays were conducted to observe the effect of IP6K2 on glioma cell proliferation, migration and invasion. Using bioinformatics analysis, RT-PCR, and dual luciferase reporter gene assay, the potential role of the LINC00467/miR-339-3p/IP6K2 regulatory axis in glioma was verified. The results showed that IP6K2 was up-regulated in glioma tissues and cell lines. Moreover, the expression level of IP6K2 was correlated with the clinical features of glioma patients. In vitro and in vivo experiments indicated that IP6K2 overexpression could promote the proliferation, migration, and invasion of glioma cells. Further bioinformatics analysis and in vitro assays revealed that LINC00467 could promote IP6K2 expression by binding to miR-339-3p and promote the malignant progression of glioma. Overall, LINC00467 could upregulate IP6K2 by binding to miR-339-3p and promote the proliferation, migration, and invasion of glioma cells. The LINC00467/miR-339-3p/IP6K2 regulatory axis might be a potential therapeutic target for glioma.

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.

Linc00467 promotes invasion and inhibits apoptosis of head and neck squamous cell carcinoma by regulating miR-1285-3p/TFAP2A

OBJECTIVE

To explore the invasion and apoptosis of head and neck squamous cell carcinoma (HNSCC) regulated by Linc00467 through the miR-1285-3p/TFAP2A axis.

METHODS

qRT-PCR was used to detect the expressions of Linc00467, miR-1285-3p, and TFAP2A in tissues and cells of HNSCC patients. The targeting relationships between Linc00467 and miR-1285-3p, miR-1285-3p, and TFAP2A were verified by dual-luciferase reporter assay. Transfection and grouping were carried out, after HNSCC cell lines were screened. Transwell assay and flow cytometry were used to test cell invasion and apoptosis, respectively.

RESULTS

Compared with normal tissues adjacent to the tumor, the expressions of Linc00467 and TFAP2A increased significantly in cancer tissues, while the expression of miR-1285-3p decreased (all P<0.05). Compared with the si-NC group, the invasion of the si-Linc00467 group decreased and the apoptosis rate increased (both P<0.05). In HNSCC cells, over-expression of Linc00467 promoted increased cell invasion and decreased apoptosis rate, which could be partially rescued by over-expression of miR-1285-3p (all P<0.05). Over-expression of miR-1285-3p caused decreased cell invasion and increased apoptosis rate, which was partially reversed by over-expression of TFAP2A (all P<0.05).

CONCLUSION

Linc00467 can be used as ceRNA to adsorb miR-1285-3p to regulate the expression of TFAP2A, promote invasion and inhibit apoptosis of HNSCC cells. Linc00467 inhibitors may become one of the targeted therapeutic drugs for HNSCC.

LncRNA SAMD12-AS1 promotes the progression of gastric cancer via DNMT1/p53 axis

BACKGROUND

Long noncoding RNAs (lncRNAs) are essential modulators of cancers initiation and progression via regulating gene expression and biological behaviors. LncRNA SAMD12-AS1 has been validated to promote the progression of several cancers, while its role in gastric cancer (GC) remains unclear. This study aims to explore the role of LncRNA SAMD12-AS1 in GC.

METHODS

qRT-PCR was performed to analyze the expression of lncRNA SAMD12-AS1 in GC tissues and cell lines, with Kaplan-Meier curve analyzing the correlation between LncRNA SAMD12-AS1 and prognosis. CCK-8 assay, and flow cytometry were applied to detect GC cells proliferation, cell cycle. Binding of RNA and proteins were detected via RNA binding protein immunoprecipitation (RIP) assay. Protein levels of oncogenesis-related genes were determined via western blotting.

RESULTS

SAMD12-AS1 was highly up-regulated in human gastric cancer tissues and cell lines compared to their normal counterparts. High SAMD12-AS1 expression was closely related to TNM stage, and shorter survival span of patients with GC. Moreover, SAMD12-AS1 was also found to promote the oncogenic role of GC cells via inhibiting the P53 signaling pathway. Mechanistically, SAMD12-AS1 might performed its biological roles in GC via directly interacting with DNMT1 and facilitating DNMT1 repress the P53 signaling pathway.

CONCLUSION

Our study demonstrated that SAMD12-AS1 promoted GC progression via DNMT1/P53 axis, indicating SAMD12-AS1 may be envisioned as a novel biomarker of, and therapeutic target for GC.

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.

Expression and prognostic characteristics of m5 C regulators in low-grade glioma

Glioma is the most common intracranial malignant tumour. A clear diagnosis and molecular targeted therapy are of great significance for improving the survival time and quality of life of patients with low‐grade glioma. 5‐methylcytosine methylation is one of the ways of RNA modification, but there are limited studies on the role of m⁵C methylation of low‐grade glioma. Single‐nucleotide variant, RNA expression matrix and corresponding clinical data of low‐grade glioma came from public database. The single‐nucleotide variant and expression of m⁵C regulators were estimated. A prognostic model based on m⁵C regulators was constructed by Cox regression. Potential functions of these molecules were assessed by gene set enrichment analysis. DNMT3A mutation was the most frequent among the m⁵C regulators in low‐grade glioma. NSUN3, TET2, TRDMT1, ALYREF, DNMT3B, DNMT1, NOP2 and NSUN2 were up‐regulated. One prognostic model was constructed which had a strong predictive power for the overall survival of low‐grade glioma. We studied the expression and prognostic characteristics of m⁵C regulators in low‐grade glioma, supplied biomarkers for the diagnosis and prognosis and provided the foundation for the study of the pathogenesis of low‐grade glioma.

LINC00467 Is Upregulated by DNA Copy Number Amplification and Hypomethylation and Shows ceRNA Potential in Lung Adenocarcinoma

Lung adenocarcinoma (LUAD) is the most common histological lung cancer, and it is the leading cause of cancer-related deaths worldwide. Long noncoding RNAs (lncRNAs) have been implicated in tumorigenesis. LINC00467 is a novel lncRNA that is abnormally expressed in several cancer types including LUAD. However, its function and regulatory mechanism in LUAD progression remain unclear. In this study, based on The Cancer Genome Atlas data mining, we demonstrated that DNA copy number amplification and hypomethylation was positively correlated with LINC00467 expression in LUAD. In addition, DNA copy number amplification was significantly associated with distant metastasis, immune infiltration and poor survival. Microarray analysis demonstrated that LINC00467 knockdown in the LUAD A549 cell line led to a distinct microRNA expression profile that impacted various target genes involved in multiple biological processes. This finding suggests that LINC00467 may regulate LUAD progression by functioning as a competing endogenous RNA (ceRNA). Finally, we constructed a ceRNA network that included two microRNAs (hsa-miR-1225-5p, hsa-miR-575) and five mRNAs (BARX2, BCL9, KCNK1, KIAA1324, TMEM182) specific to LINC00467 in LUAD. Subsequent Kaplan-Meier survival analysis in both The Cancer Genome Atlas and Gene Expression Omnibus databases revealed that two genes, BARX2 and BCL9, were potential prognostic biomarkers for LUAD patients. In conclusion, our data provide possible mechanisms underlying the abnormal upregulation of LINC00467 as well as a comprehensive view of the LINC00467-mediated ceRNA network in LUAD, thereby highlighting its potential role in diagnosis and therapy.

Exploring the Roles of lncRNAs in GBM Pathophysiology and Their Therapeutic Potential

Glioblastoma (GBM) remains the most devastating primary central nervous system malignancy with a median survival of around 15 months. The past decades of research have not yielded significant advancements in the treatment of GBM. In that same time, a novel class of molecules, long non-coding RNAs (lncRNAs), has been found to play a multitude of roles in cancer and normal biology. The increased accessibility of next generation sequencing technologies and the advent of lncRNA-specific microarrays have facilitated the study of lncRNA etiology. Molecular and computational methods can be applied to predict lncRNA function. LncRNAs can serve as molecular decoys, scaffolds, super-enhancers, or repressors. These molecules can serve as phenotypic switches for GBM cells at the expression and/or epigenetic levels. LncRNAs can affect stemness/differentiation, proliferation, invasion, survival, DNA damage response, and chromatin dynamics. Aberrant expression of these transcripts may facilitate therapy resistance, leading to tumor recurrence. LncRNAs could serve as novel theragnostic or prognostic biomarkers in GBM and other cancers. RNA-based therapeutics may also be employed to target lncRNAs as a novel route of treatment for primary or recurrent GBM. In this review, we explore the roles of lncRNAs in GBM pathophysiology and posit their novel therapeutic potential for GBM.

Epigenetic Mechanisms of LncRNAs Binding to Protein in Carcinogenesis

Epigenetic dysregulation is an important feature for cancer initiation and progression. Long non-coding RNAs (lncRNAs) are transcripts that stably present as RNA forms with no translated protein and have lengths larger than 200 nucleotides. LncRNA can epigenetically regulate either oncogenes or tumor suppressor genes. Nowadays, the combined research of lncRNA plus protein analysis is gaining more attention. LncRNA controls gene expression directly by binding to transcription factors of target genes and indirectly by complexing with other proteins to bind to target proteins and cause protein degradation, reduced protein stability, or interference with the binding of other proteins. Various studies have indicated that lncRNA contributes to cancer development by modulating genes epigenetically and studies have been done to determine which proteins are combined with lncRNA and contribute to cancer development. In this review, we look in depth at the epigenetic regulatory function of lncRNAs that are capable of complexing with other proteins in cancer development.

Genome-Wide DNA Methylation and LncRNA-Associated DNA Methylation in Metformin-Treated and -Untreated Diabetes

Metformin, which is used as a first line treatment for type 2 diabetes mellitus (T2DM), has been shown to affect epigenetic patterns. In this study, we investigated the DNA methylation and potential lncRNA modifications in metformin-treated and newly diagnosed adults with T2DM. Genome-wide DNA methylation and lncRNA analysis were performed from the peripheral blood of 12 screen-detected and 12 metformin-treated T2DM individuals followed by gene ontology (GO) and KEGG pathway analysis. Differentially methylated regions (DMRs) observed showed 22 hypermethylated and 11 hypomethylated DMRs between individuals on metformin compared to screen-detected subjects. Amongst the hypomethylated DMR regions were the SLC gene family, specifically, SLC25A35 and SLC28A1. Fifty-seven lncRNA-associated DNA methylation regions included the mitochondrial ATP synthase-coupling factor 6 (ATP5J). Functional gene mapping and pathway analysis identified regions in the axon initial segment (AIS), node of Ranvier, cell periphery, cleavage furrow, cell surface furrow, and stress fiber. In conclusion, our study has identified a number of DMRs and lncRNA-associated DNA methylation regions in metformin-treated T2DM that are potential targets for therapeutic monitoring in patients with diabetes.

Long Noncoding RNA LINC00173 Promotes NUTF2 Expression Through Sponging miR-765 and Facilitates Tumorigenesis in Glioma

Background

Glioma is one of the leading causes of cancer-related deaths. This study aimed to investigate the function and mechanism of long noncoding RNA (lncRNA) LINC00173 in the regulation of glioma progression.

Methods

LINC00173 expression was measured using qRT-PCR. Survival rate was analyzed through Kaplan–Meier method. CCK8, colony formation and EdU assays were performed to measure cell proliferation while transwell was used to determine cell migration and invasion. Luciferase reporter assay was conducted to test RNA interaction.

Results

LINC00173 expression was elevated in glioma tissues and cells. LINC00173 high expression predicted poor prognosis. Loss of LINC00173 inhibited proliferation, migration and invasion. LINC00173 interacted with miR-765 to enhance NUTF2 expression. MiR-765 expression was negatively correlated with LINC00173 and NUTF2 in glioma tissues. NUTF2 level was increased in glioma tissues. NUTF2 overexpression rescued the potential of proliferation, migration and invasion in LINC00173-silenced cells.

Conclusion

Our research demonstrated that LINC00173 promotes glioma progression through targeting miR-765/NUTF2 axis.