lncRNA HIF1A-AS2: A potential oncogene in human cancers (Review)

HIF1A-AS2 promotes the metabolic reprogramming and progression of colorectal cancer via miR-141-3p/FOXC1 axis

lncRNA can regulate tumorigenesis development and distant metastasis of colorectal cancer (CRC). However, the detailed molecular mechanisms are still largely unknown. Using RNA-sequencing data, RT-qPCR, and FISH assay, we found that HIF1A-AS2 was upregulated in CRC tissues and associated with poor prognosis. Functional experiments were performed to determine the roles of HIF1A-AS2 in tumor progression and we found that HIF1A-AS2 can promote the proliferation, metastasis, and aerobic glycolysis of CRC cells. Mechanistically, HIF1A-AS2 can promote FOXC1 expression by sponging miR-141-3p. SP1 can transcriptionally activate HIF1A-AS2. Further, HIF1A-AS2 can be packaged into exosomes and promote the malignant phenotype of recipient tumor cells. Taken together, we discovered that SP1-induced HIF1A-AS2 can promote the metabolic reprogramming and progression of CRC via miR-141-3p/FOXC1 axis. HIF1A-AS2 is a promising diagnostic marker and treatment target in CRC.

Insights into gemcitabine resistance in pancreatic cancer: association with metabolic reprogramming and TP53 pathogenicity in patient derived xenografts

BACKGROUND

With poor prognosis and high mortality, pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies. Standard of care therapies for PDAC have included gemcitabine for the past three decades, although resistance often develops within weeks of chemotherapy initiation through an array of possible mechanisms.

METHODS

We reanalyzed publicly available RNA-seq gene expression profiles of 28 PDAC patient-derived xenograft (PDX) models before and after a 21-day gemcitabine treatment using our validated analysis pipeline to identify molecular markers of intrinsic and acquired resistance.

RESULTS

Using normalized RNA-seq quantification measurements, we first identified oxidative phosphorylation and interferon alpha pathways as the two most enriched cancer hallmark gene sets in the baseline gene expression profile associated with intrinsic gemcitabine resistance and sensitivity, respectively. Furthermore, we discovered strong correlations between drug-induced expression changes in glycolysis and oxidative phosphorylation genes and response to gemcitabine, which suggests that these pathways may be associated with acquired gemcitabine resistance mechanisms. Thus, we developed prediction models using baseline gene expression profiles in those pathways and validated them in another dataset of 12 PDAC models from Novartis. We also developed prediction models based on drug-induced expression changes in genes from the Molecular Signatures Database (MSigDB)'s curated 50 cancer hallmark gene sets. Finally, pathogenic TP53 mutations correlated with treatment resistance.

CONCLUSION

Our results demonstrate that concurrent upregulation of both glycolysis and oxidative phosphorylation pathways occurs in vivo in PDAC PDXs following gemcitabine treatment and that pathogenic TP53 status had association with gemcitabine resistance in these models. Our findings may elucidate the molecular basis for gemcitabine resistance and provide insights for effective drug combination in PDAC chemotherapy.

Long non-coding RNAs as pathophysiological regulators, therapeutic targets and novel extracellular vesicle biomarkers for the diagnosis of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic relapsing disease of the gastrointestinal (GI) system that includes two groups, Crohn's disease (CD) and ulcerative colitis (UC). To cope with these two classes of IBD, the investigation of pathogenic mechanisms and the discovery of new diagnostic and therapeutic approaches are crucial. Long non-coding RNAs (lncRNAs) which are non-coding RNAs with a length of longer than 200 nucleotides have indicated significant association with the pathology of IBD and strong potential to be used as accurate biomarkers in diagnosing and predicting responses to the IBD treatment. In the current review, we aim to investigate the role of lncRNAs in the pathology and development of IBD. We first describe recent advances in research on dysregulated lncRNAs in the pathogenesis of IBD from the perspective of epithelial barrier function, intestinal immunity, mitochondrial function, and intestinal autophagy. Then, we highlight the possible translational role of lncRNAs as therapeutic targets, diagnostic biomarkers, and predictors of therapeutic response in colon tissues and plasma samples. Finally, we discuss the potential of extracellular vesicles and their lncRNA cargo in the pathophysiology, diagnosis, and treatment of IBD.

LncRNA microarray profiling identifies novel circulating lncRNAs in hidradenitis suppurativa

Long noncoding RNAs (lncRNAs) have been demonstrated to be involved in biological processes, both physiological and pathological, including cancer, cardiovascular diseases, multiple sclerosis, autoimmune hepatitis and types I and II diabetes. LncRNAs are also known to have a critical role in the physiology of skin, and in the pathology of cutaneous diseases. LncRNAs are involved in a wide range of biological activities, including transcriptional post‑transcriptional processes, epigenetics, RNA splicing, gene activation and or silencing, modifications and/or editing; therefore, lncRNAs may be useful as potential targets for disease treatment. Hidradenitis suppurativa (HS), also termed acne inversa, is a major skin disease, being an inflammatory disorder that affects ~1% of global population in a chronic manner. Its pathogenesis, however, is only partly understood, although immune dysregulation is known to have an important role. To investigate the biological relevance of lncRNAs with HS, the most differentially expressed lncRNAs and mRNAs were first compared. Furthermore, the lncRNA‑microRNA regulatory network was also defined via reverse transcription‑quantitative PCR analysis, whereby a trio of lncRNA expression signatures, lncRNA‑TINCR, lncRNA‑RBM5‑ASI1 and lncRNA‑MRPL23‑AS1, were found to be significantly overexpressed in patients with HS compared with healthy controls. In conclusion, the three lncRNAs isolated in the present study may be useful for improving the prognostic prediction of HS, as well as contributing towards an improved understanding of the underlying pathogenic mechanisms, thereby potentially providing new therapeutic targets.

Role of LncRNA H19 in tumor progression and treatment

As one of the earliest discovered lncRNA molecules, lncRNA H19 is usually expressed in large quantities during embryonic development and is involved in cell differentiation and tissue formation. In recent years, the role of lncRNA H19 in tumors has been gradually recognized. Increasing evidence suggests that its aberrant expression is closely related to cancer development. LncRNA H19 as an oncogene not only promotes the growth, proliferation, invasion and metastasis of many tumors, but also develops resistance to treatment, affecting patients' prognosis and survival. Therefore, in this review, we summarise the extensive research on the involvement of lncRNA H19 in tumor progression and discuss how lncRNA H19, as a key target gene, affects tumor sensitivity to radiotherapy, chemotherapy and immunotherapy by participating in multiple cellular processes and regulating multiple signaling pathways, which provides a promising prospect for further research into the treatment of cancer.

From molecular pathogenesis to therapy: Unraveling non-coding RNAs/DNMT3A axis in human cancers

Cancer is a comprehensive classification encompassing more than 100 forms of malignancies that manifest in diverse tissues within the human body. Recent studies have provided evidence that aberrant epigenetic modifications are pivotal indicators of cancer. Epigenetics encapsulates DNA methyltransferases as a crucial class of modifiers. DNMTs, including DNMT3A, assume central roles in DNA methylation processes that orchestrate normal biological functions, such as gene transcription, predominantly in mammals. Typically, deviations in DNMT3A function engender distortions in factors that drive tumor growth and progression, thereby exacerbating the malignant phenotype of tumors. Consequently, such abnormalities pose significant challenges in cancer therapy because they impede treatment efficacy. Non-coding RNAs (ncRNAs) represent a group of RNA molecules that cannot encode functional proteins. Recent investigation attests to the crucial significance of regulatory ncRNAs in epigenetic regulation. Notably, recent reports have illuminated the complex interplay between ncRNA expression and epigenetic regulatory machinery, including DNMT3A, particularly in cancer. Recent findings have demonstrated that miRNAs, namely miR-770-5p, miR-101, and miR-145 exhibit the capability to target DNMT3A directly, and their aberration is implicated in diverse cellular abnormalities that predispose to cancer development. This review aims to articulate the interplay between DNMT3A and the ncRNAs, focusing on its impact on the development and progression of cancer, cancer therapy resistance, cancer stem cells, and prognosis. Importantly, the emergence of such reports that suggest a connection between DNMT3A and ncRNAs in several cancers indicates that this connecting axis offers a valuable target with significant therapeutic potential that might be exploited for cancer management.

Long non-coding RNA HIF1A-AS2 promotes carcinogenesis by enhancing Gli1-mediated HIF1α expression in clear cell renal cell carcinoma

BACKGROUND

The most common urologic tumor in humans with the highest incidence rate is clear cell renal cell carcinoma (ccRCC). Long non-coding RNAs (lncRNAs) act as regulatory factors in several tumors. Here, we studied ccRCC regulated by hypoxia-inducible factor 1α (HIF1α)-antisense RNA 2 (AS2) or HIF1A-AS2.

METHODS

We performed wound-healing, transwell, and CCK-8 assays by decreasing or increasing the HIF1A-AS2 expression in RCC cell lines. Western blotting and qRT-PCR were used to identify the expression of downstream genes of the HIF1A-AS2 pathway. Gli1 and HIF1A-AS2 relationship was assessed using RIP and RNA pull-down assays. Lastly, transcriptome sequencing was performed on kidney cancer cells that had been knocked down to find possible regulatory mechanisms.

RESULTS

Our results suggest that high expression of HIF1A-AS2 may promote RCC cell proliferation and Gli1 expression as a downstream factor. Furthermore, they have physical binding sites and together regulate HIF1α to encourage the development of ccRCC. HIF1A-AS2 lncRNA may offer a new molecular target for ccRCC treatment.

CONCLUSION

lncRNA HIF1A-AS2 affects ccRCC development by regulating HIF1a expression through Gli1.

Long non-coding RNAs in non-small cell lung cancer: implications for preventing therapeutic resistance

Lung cancer has the highest mortality and morbidity rates among all cancers worldwide. Despite many complex treatment options, including radiotherapy, chemotherapy, targeted drugs, immunotherapy, and combinations of these treatments, efficacy is low in cases of resistance to therapy, metastasis, and advanced disease, contributing to low overall survival. There is a pressing need for the discovery of novel biomarkers and therapeutic targets for the early diagnosis of lung cancer and to determine the efficacy and outcomes of drug treatments. There is now substantial evidence for the diagnostic and prognostic value of long noncoding RNAs (lncRNAs). This review briefly discusses recent findings on the roles and mechanisms of action of lncRNAs in the responses to therapy in non-small cell lung cancer.

Hypoxic regulation of extracellular vesicles: Implications for cancer therapy

Extracellular vesicles (EVs) play a pivotal role in intercellular communication and have been implicated in cancer progression. Hypoxia, a pervasive hallmark of cancer, is known to regulate EV biogenesis and function. Hypoxic EVs contain a specific set of proteins, nucleic acids, lipids, and metabolites, capable of reprogramming the biology and fate of recipient cells. Enhancing the intrinsic therapeutic efficacy of EVs can be achieved by strategically modifying their structure and contents. Moreover, the use of EVs as drug delivery vehicles holds great promise for cancer treatment. However, various hurdles must be overcome to enable their clinical application as cancer therapeutics. In this review, we aim to discuss the current knowledge on the hypoxic regulation of EVs. Additionally, we will describe the underlying mechanisms by which EVs contribute to cancer progression in hypoxia and outline the progress and limitations of hypoxia-related EV therapeutics for cancer.

LncRNA FOXD2-AS1 Increased Proliferation and Invasion of Lung Adenocarcinoma via Cell-Cycle Regulation

Background

Long non-coding RNA FOXD2 antisense RNA 1 (FOXD2-AS1) has been reported in many malignancies. However, the molecular mechanism of many actions is not clarified. This study was conducted to investigate the function of FOXD2-AS1 in lung adenocarcinoma and its molecular mechanism.

Methods

Bioinformatics and in vitro analysis including RT-qPCR, CFU, CCK8, Transwell, Cell Apoptosis and Cell Cycle Assay were used for the analysis of gene expression and related effects.

Results

It revealed increased expression of lncRNA FOXD2-AS1 in lung adenocarcinoma cell lines (A549 cells), and abundant expression of lncRNA FOXD2-AS1 was also observed in the acquired lung adenocarcinoma tissues. In vitro results showed that knockdown of lncRNA FOXD2-AS1 in A549 cells weakened cell proliferation, invasion and increased apoptosis. At the same time, we found that reducing the expression of lncRNA FOXD2-AS1 caused cell cycle arrest in the G1/S phase. Differential gene analysis of lung adenocarcinoma and adjacent normal tissues showed that the cell cycle and its related process regulation were significantly enriched. Gene Set Enrichment Analysis (GSEA) analysis showed that miR-206, miR-143, lL6-JAK-STAT3 signalling pathway, STAT3, E2F targets, EZH2, P53 signalling pathway and E2F3 targets interacting with lncRNA FOXD2-AS1 were also enriched.

Conclusion

This study demonstrates the role and mechanism of the lncRNA FOXD2-AS1 in lung adenocarcinoma and provides a better understanding for the treatment of lung adenocarcinoma, which indicates that interfering with lncRNA FOXD2-AS1 expression may be a novel strategy.

Functional analysis of differentially expressed long non-coding RNAs in DENV-3 infection and antibody-dependent enhancement of viral infection

Dengue fever, as a mosquito-borne viral disease widely spread in tropical and subtropical regions, remarkably threatens public health, while the mechanism involved in host-DENV interaction has not been fully elucidated. Firstly, we analyzed the expression levels of long non-coding RNAs (lncRNAs) in THP-1 cells after DENV-3 infection and Antibody- Dependent Enhancement of viral infection (ADE-VI) by RNA-Seq. Secondly, through the RT-qPCR to confirm those differentially expressed (DE) lncRNAs. Then, we also analyzed the competitive endogenous RNA (CeRNA) regulatory network of DE lncRNAs. Finally, we predicted the encode ability of DE lncRNAs. It was found that on the X and Y chromosomes, the expression levels of lncRNAs in THP-1 cells after ADE-VI were significantly different from those in the negative control and the DENV-3 infection groups. There were 71 DE lncRNAs after DENV-3 infection, including 42 up-regulated and 29 down-regulated lncRNAs. A total of 70 DE lncRNAs after ADE-VI were detected, including 38 up-regulated and 32 down- regulated lncRNAs. After ADE-VI and DENV-3 infection, there were 35 DE lncRNAs, including 11 up-regulated and 24 down-regulated lncRNAs. The analysis of the CeRNA regulatory network of DE lncRNAs revealed that, TRIM29, STC2, and IGFBP5 were correlated with the ADE-VI. Additionally, it was found that lncRNAs not only participated in the CeRNA regulatory network, but also maybe encoded small peptides. Our findings provided clues for further investigation into the lncRNAs associated antiviral mechanism of ADE-VI and DENV-3 infection.

Long non-coding RNA (lncRNA) H19 in human cancer: From proliferation and metastasis to therapy

Initiation and development of cancer depend on multiple factors that mutations in genes and epigenetic level can be considered as important drivers. Epigenetic factors include a large family of members and understanding their function in cancer has been a hot topic. LncRNAs are RNA molecules with no capacity in synthesis of proteins, and they have regulatory functions in cells. LncRNAs are localized in nucleus and cytoplasm, and their abnormal expression is related to development of tumor. This manuscript emphasizes on the role of lncRNA H19 in various cancers and its association with tumor hallmarks. The function of lncRNA H19 in most tumors is oncogenic and therefore, tumor cells increase its expression for promoting their progression. LncRNA H19 contributes to enhancing growth and cell cycle of cancers and by EMT induction, it is able to elevate metastasis rate. Silencing H19 induces apoptotic cell death and disrupts progression of tumors. LncRNA H19 triggers chemo- and radio-resistance in cancer cells. miRNAs are dually upregulated/down-regulated by lncRNA H19 in increasing tumor progression. Anti-cancer agents reduce lncRNA H19 in impairing tumor progression and increasing therapy sensitivity. A number of downstream targets and molecular pathways for lncRNA H19 have been detected in cancers including miRNAs, RUNX1, STAT3, β-catenin, Akt2 and FOXM1. Clinical studies have revealed potential of lncRNA H19 as biomarker and its association with poor prognosis. LncRNA H19 can be transferred to cancer cells via exosomes in enhancing their progression.

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.

Long Non-Coding RNAs Might Regulate Phenotypic Switch of Vascular Smooth Muscle Cells Acting as ceRNA: Implications for In-Stent Restenosis

Coronary in-stent restenosis is a late complication of angioplasty. It is a multifactorial process that involves vascular smooth muscle cells (VSMCs), endothelial cells, and inflammatory and genetic factors. In this study, the transcriptomic landscape of VSMCs’ phenotypic switch process was assessed under stimuli resembling stent injury. Co-cultured contractile VSMCs and endothelial cells were exposed to a bare metal stent and platelet-derived growth factor (PDGF-BB) 20 ng/mL. Migratory capacity (wound healing assay), proliferative capacity, and cell cycle analysis of the VSMCs were performed. RNAseq analysis of contractile vs. proliferative VSMCs was performed. Gene differential expression (DE), identification of new long non-coding RNA candidates (lncRNAs), gene ontology (GO), and pathway enrichment (KEGG) were analyzed. A competing endogenous RNA network was constructed, and significant lncRNA–miRNA–mRNA axes were selected. VSMCs exposed to “stent injury” conditions showed morphologic changes, with proliferative and migratory capacities progressing from G0-G1 cell cycle phase to S and G2-M. RNAseq analysis showed DE of 1099, 509 and 64 differentially expressed mRNAs, lncRNAs, and miRNAs, respectively. GO analysis of DE genes showed significant enrichment in collagen and extracellular matrix organization, regulation of smooth muscle cell proliferation, and collagen biosynthetic process. The main upregulated nodes in the lncRNA-mediated ceRNA network were PVT1 and HIF1-AS2, with downregulation of ACTA2-AS1 and MIR663AHG. The PVT1 ceRNA axis appears to be an attractive target for in-stent restenosis diagnosis and treatment.