Long non-coding RNA BRE-AS1 represses non-small cell lung cancer cell growth and survival via up-regulating NR4A3

microRNA 21 and long non-coding RNAs interplays underlie cancer pathophysiology: A narrative review

Non-coding RNAs (ncRNAs) are a diverse group of functional RNA molecules that lack the ability to code for proteins. Despite missing this traditional role, ncRNAs have emerged as crucial regulators of various biological processes and have been implicated in the development and progression of many diseases, including cancer. MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are two prominent classes of ncRNAs that have emerged as key players in cancer pathophysiology. In particular, miR-21 has been reported to exhibit oncogenic roles in various forms of human cancer, including prostate, breast, lung, and colorectal cancer. In this context, miR-21 overexpression is closely associated with tumor proliferation, growth, invasion, angiogenesis, and chemoresistance, whereas miR-21 inactivation is linked to the regression of most tumor-related processes. Accordingly, miR-21 is a crucial modulator of various canonical oncogenic pathways such as PTEN/PI3K/Akt, Wnt/β-catenin, STAT, p53, MMP2, and MMP9. Moreover, interplays between lncRNA and miRNA further complicate the regulatory mechanisms underlying tumor development and progression. In this regard, several lncRNAs have been found to interact with miR-21 and, by functioning as competitive endogenous RNAs (ceRNAs) or miRNA sponges, can modulate cancer tumorigenesis. This work presents and discusses recent findings highlighting the roles and pathophysiological implications of the miR-21-lncRNA regulatory axis in cancer occurrence, development, and progression. The data collected indicate that specific lncRNAs, such as MEG3, CASC2, and GAS5, are strongly associated with miR-21 in various types of cancer, including gastric, cervical, lung, and glioma. Indeed, these lncRNAs are well-known tumor suppressors and are commonly downregulated in different types of tumors. Conversely, by modulating various mechanisms and oncogenic signaling pathways, their overexpression has been linked with preventing tumor formation and development. This review highlights the significance of these regulatory pathways in cancer and their potential for use in cancer therapy as diagnostic and prognostic markers.

Knockdown of HM13 Inhibits Metastasis, Proliferation, and M2 Macrophage Polarization of Non-small Cell Lung Cancer Cells by Suppressing the JAK2/STAT3 Signaling Pathway

An upregulated histocompatibility minor 13 (HM13) has been studied in various tumors, yet the exact mechanism of HM13 in non-small cell lung cancer (NSCLC) is unclear. In view of same, the present study investigates crucial role and action mechanism of HM13 in human NSCLC. HM13 expression was higher in NSCLC tissue and cells through the Western blotting technique along with qRT-PCR. As per data from The Cancer Genome Atlas (TCGA), NSCLC patients having high HM13 expression show lower overall survival. 5-ethynyl-2-deoxyuridine (EdU), Cell Counting Kit-8 (CCK-8), and transwell tests were assessed for NSCLC cell growth, and invasion, and we found that silencing of HM13 inhibited the NSCLC cell proliferation, invasion. Additionally, to investigate the effects of HM13 on THP-1 macrophage polarization, a co-culture model of NSCLC and THP-1 macrophages were used. The CD206 + macrophages were examined using flow cytometry. As the markers of M2 macrophage, the mRNA levels of IL-10 and TGF-β of THP-1 cells were also detected by qRT-PCR. Knockdown of HM13 could inhibit the M2 polarization. Further experiments demonstrated that downregulated HM13 could inhibit the JAK2/STAT3 signaling pathway. RO8191 (activator of JAK/STAT3 pathway) influenced the invasion, proliferation, and expression of JAK2/STAT3 signaling pathway and Epithelial-mesenchymal transition (EMT) markers induced by HM13 silencing. HM13 knockdown also inhibited the tumor growth in vivo by xenograft nude mouse model. By inhibiting JAK2/STAT3 signaling pathway, HM13 knockdown inhibited the NSCLC cell proliferation, metastasis tumor growth, and tumor-associated macrophage M2 polarization. In NSCLC, HM13 could be a therapeutic target to treat the NSCLC.

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.

From carcinogenesis to therapeutic avenues: lncRNAs and mTOR crosstalk in lung cancer

Long non-coding RNAs (lncRNAs) have been demonstrated to have a crucial function in the modulation of the activity of genes, impacting a variety of homeostatic processes involving growth, survival, movement, and genomic consistency. Certain lncRNAs' aberrant expression has been linked to carcinogenesis, tumor growth, and therapeutic resistance. They are beneficial for the management of malignancies since they can function as cancer-causing or cancer-suppressing genes and behave as screening or prognosis indicators. The modulation of the tumor microenvironment, metabolic modification, and spread have all been linked to lncRNAs in lung cancer. Recent research has indicated that lncRNAs may interact with various mTOR signalling systems to control expression in lung cancer. Furthermore, the route can affect how lncRNAs are expressed. Emphasizing the function of lncRNAs as crucial participants in the mTOR pathway, the current review intends to examine the interactions between the mTOR cascade and the advancement of lung cancer. The article will shed light on the roles and processes of a few lncRNAs associated with the development of lung cancer, as well as their therapeutic prospects.

Identification of prognosis-related lncRNAs and cell validation in lung squamous cell carcinoma based on TCGA data

Objective

To discern long non-coding RNAs (lncRNAs) with prognostic relevance in the context of lung squamous cell carcinoma (LUSC), we intend to predict target genes by leveraging The Cancer Genome Atlas (TCGA) repository. Subsequently, we aim to investigate the proliferative potential of critical lncRNAs within the LUSC milieu.

Methods

DESeq2 was employed to identify differentially expressed genes within the TCGA database. Following this, we utilized both univariate and multivariate Cox regression analyses to identify lncRNAs with prognostic relevance. Noteworthy lncRNAs were selected for validation in cell lines. The intracellular localization of these lncRNAs was ascertained through nucleocytoplasmic isolation experiments. Additionally, the impact of these lncRNAs on cellular proliferation, invasion, and migration capabilities was investigated using an Antisense oligonucleotides (ASO) knockdown system.

Results

Multivariate Cox regression identified a total of 12 candidate genes, consisting of seven downregulated lncRNAs (BRE-AS1, CCL15-CCL14, DNMBP-AS1, LINC00482, LOC100129034, MIR22HG, PRR26) and five upregulated lncRNAs (FAM83A-AS1, LINC00628, LINC00923, LINC01341, LOC100130691). The target genes associated with these lncRNAs exhibit significant enrichment within diverse biological pathways, including metabolic processes, cancer pathways, MAPK signaling, PI3K-Akt signaling, protein binding, cellular components, cellular transformation, and other functional categories. Furthermore, nucleocytoplasmic fractionation experiments demonstrated that LINC00923 and LINC01341 are predominantly localized within the cellular nucleus. Subsequent investigations utilizing CCK-8 assays and colony formation assays revealed that the knockdown of LINC00923 and LINC01341 effectively suppressed the proliferation of H226 and H1703 cells. Additionally, transwell assays showed that knockdown of LINC00923 and LINC01341 significantly attenuated the invasive and migratory capacities of H226 and H1703 cells.

Conclusion

This study has identified 12 candidate lncRNA associated with prognostic implications, among which LINC00923 and LINC01341 exhibit potential as markers for the prediction of LUSC outcomes.

Long non-coding RNAs: an overview on miRNA sponging and its co-regulation in lung cancer

Lung cancer is the most devastating cause of death among all cancers worldwide, and non-small cell lung cancer (NSCLC) accounts for 80% of all the lung cancer cases. Beyond common genetic research and epigenomic studies, the extraordinary investigations of non-coding RNAs have provided insights into the molecular basis of cancer. Existing evidence from various cancer models highlights that the regulation of non-coding RNAs is crucial and that their deregulation may be a common reason for the development and progression of cancer, and competition of cancer therapeutics. Non-coding RNAs, such as long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), are increasingly recognized as potential cancer biomarkers for early detection and application of therapeutic strategies. The miRNAs have gained importance as master regulators of target mRNAs by negatively regulating their expression. The lncRNAs function as both tumor suppressors and oncogenes, and also compete with miRNAs that influence the translational inhibition processes. This review addresses the role of lncRNAs in lung cancer development, highlights their mechanisms of action, and provides an overview of the impact of lncRNAs on lung cancer survival and progression via miRNA sponging. The improved understanding of lung cancer mechanisms has opened opportunities to analyze molecular markers and their potential therapeutics.

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 non-coding RNAs and exosomal lncRNAs: Potential functions in lung cancer progression, drug resistance and tumor microenvironment remodeling

Among the different kinds of tumors threatening human life, lung cancer is one that is commonly observed in both males and females. The aggressive behavior of lung cancer and interactions occurring in tumor microenvironment enhances the malignancy of this tumor. The lung tumor cells have demonstrated capacity in developing chemo- and radio-resistance. LncRNAs are a category of non-coding RNAs that do not encode proteins, but their aberrant expression is responsible for tumor development, especially lung cancer. In the present review, we focus on both lncRNAs and exosomal lncRNAs in lung cancer, and their ability in regulating proliferation and metastasis. Cell cycle progression and molecular mechanisms related to lung cancer metastasis such as EMT and MMPs are regulated by lncRNAs. LncRNAs interact with miRNAs, STAT, Wnt, EZH2, PTEN and PI3K/Akt signaling pathways to affect progression of lung cancer cells. LncRNAs demonstrate both tumor-suppressor and tumor-promoting functions in lung cancer. They can be considered as biomarkers in lung cancer and especially exosomal lncRNAs present in body fluids are potential tools for minimally invasive diagnosis. Furthermore, we discuss regulation of lncRNAs by anti-cancer drugs and genetic tools as well as the role of these factors in therapy response of lung cancer cells.

DNA-methylation-induced silencing of DIO3OS drives non-small cell lung cancer progression via activating hnRNPK-MYC-CDC25A axis

DNA methylation is a class of epigenetic modification manner, which is responsible for the inactivation of various tumor suppressors. Recently, long non-coding RNAs (lncRNAs) were revealed to be implicated in a variety of malignancies, including non-small cell lung cancer (NSCLC). However, the contributions of lncRNAs to DNA-methylation-induced oncogenic effects in NSCLC remain largely unknown. In this study, we identified a DNA-methylation-repressed lncRNA DIO3 opposite strand upstream RNA (DIO3OS) in NSCLC. DIO3OS is downregulated in NSCLC, and its low expression is related to poor prognosis. Ectopic expression of DIO3OS repressed NSCLC cell growth and motility and promoted NSCLC cell apoptosis in vitro. DIO3OS also repressed NSCLC tumorigenesis and metastasis in vivo. DIO3OS knockdown exhibited opposite biological effects. DIO3OS competitively bound heterogeneous nuclear ribonucleoprotein K (hnRNPK), repressed the binding of hnRNPK to MYC DNA and MYC mRNA, reduced the promoting roles of hnRNPK on MYC transcription and translation, led to the repression of MYC transcription and translation, and therefore remarkably decreased the expression of MYC and CDC25A, a downstream target of MYC. Additionally, depletion of hnRNPK blocked the tumor-suppressive roles of DIO3OS in NSCLC. In conclusion, these findings identified DIO3OS as an important protective factor against NSCLC via modulating hnRNPK-MYC-CDC25A axis.

Knockdown of long noncoding RNA AC245100.4 inhibits the tumorigenesis of prostate cancer cells via the STAT3/NR4A3 axis

Aim: To explore the role and mechanism of long noncoding RNA AC245100.4 and NR4A3 in prostate cancer (PCa). Methods: RNA-sequencing analysis was used to detect the downstream genes of AC245100.4. A series of gain- and loss-of-function approaches were used to investigate the roles of AC245100.4 and NR4A3. RNA immunoprecipitation was performed to examine the interaction between AC245100.4 and STAT3. Results: AC245100.4 was significantly upregulated in PCa cells and tissues. Knockdown of AC21500.4 significantly inhibited the tumorigenesis of PCa cells. Mechanistically, AC245100.4 deregulated the transcription of NR4A3 via increasing p-STAT3, which acted as a transcriptional repressor of NR4A3. Conclusion: Knockdown of long noncoding RNA AC245100.4 inhibits the tumorigenesis of PCa cells via the STAT3/NR4A3 axis.

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.

Long non-coding RNA BRE-AS1 inhibits the proliferation, migration, and invasion of cancer cells in triple-negative breast cancer and predicts patients' survival by downregulating miR-21

Background

BRE-AS1 is a recently identified tumor suppressor in non-small cell lung cancer. It role in other human diseases remains elusive.

Methods

Differential expression of BRE-AS1 in with triple-negative breast cancer (TNBC) patients (n = 74, patient group) and healthy volunteers (n = 58, control group) was studied with RT-qPCR. The direct interaction between BRE-AS1 and premature microRNA-21 (miR-21) was assessed by RNA pull-down assay. The interactions among BRE-AS1, miR-21 and PTEN were evaluated by overexpression assays. CCK-8 assay and Transwell assay were used to evaluate cell behaviors.

Results

BRE-AS1 was downregulated in TNBC, while miR-21 was highly expressed in TNBC. Low expression levels of lncRNA BRE-AS1 and high expression levels of miR-21 were significantly correlated with unfavorable survival outcomes. BRE-AS1 and miRNA-21 were inversely correlated across TNBC samples, not control samples. BRE-AS1 decreased miR-21 expression and increased PTEN expression while miR-21showed no role in BRE-AS1 expression. RNA pull-down assay illustrated that BRE-AS1 may sponge premature miR-21 to suppress it maturation. Overexpression of BRE-AS1 decreased cell behaviors, while overexpression of miR-21 promoted cell behaviors. MiR-21 suppressed the role of BRE-AS1 in cancer cell behaviors.

Conclusion

Therefore, BRE-AS1 may inhibit TNBC by downregulating miR-21.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08294-6.

LncRNAs in Non-Small-Cell Lung Cancer

Lung cancer is associated with a high mortality, with around 1.8 million deaths worldwide in 2018. Non-small-cell lung cancer (NSCLC) accounts for around 85% of cases and, despite improvement in the management of NSCLC, most patients are diagnosed at advanced stage and the five-year survival remains around 15%. This highlights a need to identify novel ways to treat the disease to reduce the burden of NSCLC. Long non-coding RNAs (lncRNAs) are non-coding RNA molecules longer than 200 nucleotides in length which play important roles in gene expression and signaling pathways. Recently, lncRNAs were implicated in cancer, where their expression is dysregulated resulting in aberrant functions. LncRNAs were shown to function as both tumor suppressors and oncogenes in a variety of cancer types. Although there are a few well characterized lncRNAs in NSCLC, many lncRNAs remain un-characterized and their mechanisms of action largely unknown. LncRNAs have success as therapies in neurodegenerative diseases, and having a detailed understanding of their function in NSCLC may guide novel therapeutic approaches and strategies. This review discusses the role of lncRNAs in NSCLC tumorigenesis, highlighting their mechanisms of action and their clinical potential.

Function of Nr4a Orphan Nuclear Receptors in Proliferation, Apoptosis and Fuel Utilization Across Tissues

The Nr4a family of nuclear hormone receptors is composed of three members-Nr4a1/Nur77, Nr4a2/Nurr1 and Nr4a3/Nor1. While currently defined as ligandless, these transcription factors have been shown to regulate varied processes across a host of tissues. Of particular interest, the Nr4a family impinge, in a tissue dependent fashion, on cellular proliferation, apoptosis and fuel utilization. The regulation of these processes occurs through both nuclear and non-genomic pathways. The purpose of this review is to provide a balanced perspective of the tissue specific and Nr4a family member specific, effects on cellular proliferation, apoptosis and fuel utilization.

Forced expression of NR4A3 induced the differentiation of human neuroblastoma-derived NB1 cells

Nuclear receptor subfamily 4, group A, member 3 (NR4A3) is a member of the NR4A subgroup of orphan nuclear receptors, implicated in the regulation of diverse biological functions, including metabolism, angiogenesis, inflammation, cell proliferation, and apoptosis. Although many reports have suggested the involvement of NR4A3 in the development and/or progression of tumors, its role varies among tumor types. Previously, we reported that DNA hypomethylation at NR4A3 exon 3 is associated with lower survival rate of neuroblastoma (NB) patients. As hypomethylation of this region results in reduced expression of NR4A3, our observations suggested that NR4A3 functions as a tumor suppressor in NB. However, the exact mechanisms underlying its functions have not been clarified. In the present study, we analyzed public databases and showed that reduced NR4A3 expression was associated with shorter survival period of NB in two out of three datasets. An in vitro study revealed that forced expression of NR4A3 in human NB-derived cell line NB1 resulted in elongation of neurites along with overexpression of GAP43, one of the differentiation markers of NB. On the other hand, siRNA-mediated knockdown of NR4A3 suppressed the expression level of GAP43. Interestingly, the forced expression of NR4A3 induced only the GAP43 but not the other molecules involved in NB cell differentiation, such as MYCN, TRKA, and PHOX2B. These results indicated that NR4A3 directly activates the expression of GAP43 and induces differentiated phenotypes of NB cells, without affecting the upstream signals regulating GAP43 expression and NB differentiation.

LncRNA BRE-AS1 interacts with miR-145-5p to regulate cancer cell proliferation and apoptosis in prostate carcinoma and has early diagnostic values

Long non-coding RNA (LncRNA) BRE-AS1 has recently proven to be a tumor suppressor in lung cancer. The present study aimed to investigate the involvement of lncRNA BRE-AS1 in prostate carcinoma (PC). In the present study we found that plasma BRE-AS1 and miR-145-5p were both down-regulated in PC patients than in healthy controls. Down-regulation of BRE-AS1 and miR-145-5p effectively distinguished early-stage PC patients from healthy controls. A significant and positive correlation between BRE-AS1 and miR-145-5p was only found in PC patients. BRE-AS1 overexpression mediated miR-145-5p up-regulation in PC cells, while miR-145-5p overexpression did not significantly affect BRE-AS1. Overexpression of BRE-AS1 and miR-145-5p led to inhibited proliferation and promoted apoptosis of PC cells. miR-145-5p inhibitor attenuated the effects of BRE-AS1 overexpression on cancer cell behaviors. Therefore, lncRNA BRE-AS1 may regulate cancer cell proliferation and apoptosis in PC by interacting with miR-145-5p.

Long noncoding antisense RNA FAM83A-AS1 promotes lung cancer cell progression by increasing FAM83A

The abnormal expression of long noncoding RNAs (lncRNAs) is closely associated with human cancers. As one special group of lncRNAs, natural antisense transcripts (NATs) can be transcribed from both DNA strands at the same locus but in the opposite direction from the gene transcript. Their expression levels are altered in many cancers, but their roles are poorly understood. We strove to find NATs involved in human non-small-cell lung cancer (NSCLC) and to reveal their mechanism of action in cancer. We analysed the NATs in NSCLC from the TCGA database by circlncRNAnet. One NAT, family with sequence similarity 83 member A antisense RNA 1 (FAM83A-AS1), was found to be markedly upregulated and positively correlated with its cognate sense counterpart, FAM83A, in NSCLC. Moreover, overexpression of FAM83A-AS1 increased FAM38A protein levels and induced ERK1/2 phosphorylation downstream of FAM83A in cells. Finally, overexpression of FAM83A-AS1 promoted LUAD cell proliferation and invasion. In summary, lncRNA FAM83A-AS1 promotes LUAD by increasing FAM83A expression.