Role of long noncoding RNA taurine-upregulated gene 1 in cancers

Critical roles of lncRNA-mediated autophagy in urologic malignancies

Urologic oncology is a significant public health concern on a global scale. Recent research indicates that long chain non-coding RNAs (lncRNAs) and autophagy play crucial roles in various cancers, including urologic malignancies. This article provides a summary of the latest research findings, suggesting that lncRNA-mediated autophagy could either suppress or promote tumors in prostate, kidney, and bladder cancers. The intricate network involving different lncRNAs, target genes, and mediated signaling pathways plays a crucial role in urological malignancies by modulating the autophagic process. Dysregulated expression of lncRNAs can disrupt autophagy, leading to tumorigenesis, progression, and enhanced resistance to therapy. Consequently, targeting particular lncRNAs that control autophagy could serve as a dependable diagnostic tool and a promising prognostic biomarker in urologic oncology, while also holding potential as an effective therapeutic approach.

Osteosarcoma in a ceRNET perspective

Osteosarcoma (OS) is the most prevalent and fatal type of bone tumor. It is characterized by great heterogeneity of genomic aberrations, mutated genes, and cell types contribution, making therapy and patients management particularly challenging. A unifying picture of molecular mechanisms underlying the disease could help to transform those challenges into opportunities.This review deeply explores the occurrence in OS of large-scale RNA regulatory networks, denominated "competing endogenous RNA network" (ceRNET), wherein different RNA biotypes, such as long non-coding RNAs, circular RNAs and mRNAs can functionally interact each other by competitively binding to shared microRNAs. Here, we discuss how the unbalancing of any network component can derail the entire circuit, driving OS onset and progression by impacting on cell proliferation, migration, invasion, tumor growth and metastasis, and even chemotherapeutic resistance, as distilled from many studies. Intriguingly, the aberrant expression of the networks components in OS cells can be triggered also by the surroundings, through cytokines and vesicles, with their bioactive cargo of proteins and non-coding RNAs, highlighting the relevance of tumor microenvironment. A comprehensive picture of RNA regulatory networks underlying OS could pave the way for the development of innovative RNA-targeted and RNA-based therapies and new diagnostic tools, also in the perspective of precision oncology.

Long noncoding RNA TUG1 promotes cisplatin resistance in ovarian cancer via upregulation of DNA polymerase eta

Chemoresistance is a major cause of high mortality and poor survival in patients with ovarian cancer (OVCA). Understanding the mechanisms of chemoresistance is urgently required to develop effective therapeutic approaches to OVCA. Here, we show that expression of the long noncoding RNA, taurine upregulated gene 1 (TUG1), is markedly upregulated in samples from OVCA patients who developed resistance to primary platinum-based therapy. Depletion of TUG1 increased sensitivity to cisplatin in the OVCA cell lines, SKOV3 and KURAMOCHI. Combination therapy of cisplatin with antisense oligonucleotides targeting TUG1 coupled with a drug delivery system effectively relieved the tumor burden in xenograft mouse models. Mechanistically, TUG1 acts as a competing endogenous RNA by downregulating miR-4687-3p and miR-6088, both of which target DNA polymerase eta (POLH), an enzyme required for translesion DNA synthesis. Overexpression of POLH reversed the effect of TUG1 depletion on cisplatin-induced cytotoxicity. Our data suggest that TUG1 upregulation allows OVCA to tolerate DNA damage via upregulation of POLH; this provides a strong rationale for targeting TUG1 to overcome cisplatin resistance in OVCA.

Long noncoding RNAs regulate intrauterine adhesion and cervical cancer development and progression

Intrauterine adhesion, one of reproductive system diseases in females, is developed due to endometrial injury, such as infection, trauma, uterine congenital abnormalities and uterine curettage. Intrauterine adhesion affects female infertility and causes several complications, including amenorrhoea, hypomenorrhoea, and recurrent abortion. Cervical cancer is one of the common gynecological tumors and the fourth leading cancer-related death in women worldwide. Although the treatments of cervical cancer have been improved, the advanced cervical cancer patients have a low survival rate due to tumor recurrence and metastasis. The molecular mechanisms of intrauterine adhesion and cervical tumorigenesis have not been fully elucidated. In recent years, long noncoding RNAs (lncRNAs) have been known to participate in intrauterine adhesion and cervical carcinogenesis. Therefore, in this review, we will summarize the role of lncRNAs in regulation of intrauterine adhesion development and progression. Moreover, we will discuss the several lncRNAs in control of cervical oncogenesis and progression. Furthermore, we highlight that targeting lncRNAs could be used for treatment of intrauterine adhesion and cervical cancer.

Non-Coding RNAs as Key Regulators in Lung Cancer

For several decades, most lung cancer investigations have focused on the search for mutations in candidate genes; however, in the last decade, due to the fact that most of the human genome is occupied by sequences that do not code for proteins, much attention has been paid to non-coding RNAs (ncRNAs) that perform regulatory functions. In this review, we principally focused on recent studies of the function, regulatory mechanisms, and therapeutic potential of ncRNAs including microRNA (miRNA), long ncRNA (lncRNA), and circular RNA (circRNA) in different types of lung cancer.

lncRNA TUG1 as potential novel biomarker for prognosis of cardiovascular diseases

Globally, cardiovascular diseases (CVDs) are among the leading causes of death. In light of the high prevalence and mortality of CVDs, it is imperative to understand the molecules involved in CVD pathogenesis and the signaling pathways that they initiate. This may facilitate the development of more precise and expedient diagnostic techniques, the identification of more effective prognostic molecules and the identification of potential therapeutic targets. Numerous studies have examined the role of lncRNAs, such as TUG1, in CVD pathogenesis in recent years. According to this review article, TUG1 can be considered a biomarker for predicting the prognosis of CVD.

In Silico Bioinformatics Analysis on the Role of Long Non-Coding RNAs as Drivers and Gatekeepers of Androgen-Independent Prostate Cancer Using LNCaP and PC-3 Cells

Prostate cancer (PCa) is the leading cancer in men globally. The association between PCa and long non-coding RNAs (lncRNAs) has been reported. Aberrantly expressed lncRNAs have been documented in each of the cancer "hallmarks". Androgen signaling plays an important role in PCa progression. This study aimed to profile the aberrantly expressed lncRNAs in androgen-dependent (LNCaP) PCa compared to androgen-independent (PC-3) PCa cells. This was achieved by using a 384-well plate of PCa lncRNA gene panel. Differential expression of ±2 up or downregulation was determined using the CFX Maestro software v2.1. LncSEA and DIANA-miRPath were used to identify the enriched pathways. Telomerase RNA component (TERC) lncRNA was illustrated to participate in various tumourigenic classes by in silico bioinformatics analysis and was thus selected for validation using RT-qPCR. Further bioinformatics analysis revealed the involvement of differentially expressed lncRNAs in oncogenic pathways. Some lncRNAs undergo hypermethylation, others are encapsulated by exosomes, while others interact with several microRNAs (miRNAs), favouring tumourigenic pathways. Notably, TERC lncRNA was shown to interact with tumour-suppressor miRNAs hsa-miR-4429 and hsa-miR-320b. This interaction in turn activates TGF-β-signaling and ECM-receptor interaction pathways, favouring the progression of PCa. Understanding lncRNAs as competitive endogenous RNA molecules and their interactions with miRNAs may aid in the identification of novel prognostic PCa biomarkers and therapeutic targets.

Metabolomics of head and neck cancer in biofluids: an integrative systematic review

INTRODUCTION

Head and neck cancer (HNC) is the fifth most common cancer globally. Diagnosis at early stages are critical to reduce mortality and improve functional and esthetic outcomes associated with HNC. Metabolomics is a promising approach for discovery of biomarkers and metabolic pathways for risk assessment and early detection of HNC.

OBJECTIVES

To summarize and consolidate the available evidence on metabolomics and HNC in plasma/serum, saliva, and urine.

METHODS

A systematic search of experimental research was executed using PubMed and Web of Science. Available data on areas under the curve was extracted. Metabolic pathway enrichment analysis were performed to identify metabolic pathways altered in HNC. Fifty-four studies were eligible for data extraction (33 performed in plasma/serum, 15 in saliva and 6 in urine).

RESULTS

Metabolites with high discriminatory performance for detection of HNC included single metabolites and combination panels of several lysoPCs, pyroglutamate, glutamic acid, glucose, tartronic acid, arachidonic acid, norvaline, linoleic acid, propionate, acetone, acetate, choline, glutamate and others. The glucose-alanine cycle and the urea cycle were the most altered pathways in HNC, among other pathways (i.e. gluconeogenesis, glycine and serine metabolism, alanine metabolism, etc.). Specific metabolites that can potentially serve as complementary less- or non-invasive biomarkers, as well as metabolic pathways integrating the data from the available studies, are presented.

CONCLUSION

The present work highlights utility of metabolite-based biomarkers for risk assessment, early detection, and prognostication of HNC, as well as facilitates incorporation of available metabolomics studies into multi-omics data integration and big data analytics for personalized health.

TUG1 aggravates intracerebral hemorrhage injury by inhibiting angiogenesis in an miR-26a-dependent manner

Long non-coding RNA taurine-upregulated gene 1 (TUG1) plays pivotal roles in angiogenesis, an important mechanism of neural repair after intracerebral hemorrhage (ICH). However, the role of TUG1 in angiogenesis following ICH is not clear. Therefore, in this study, we investigated the role and the underlying mechanism of TUG1 in neurologic impairment and cerebral angiogenesis following ICH. The ICH rat model was established and then rats were injected with TUG1-expressing plasmid (pcDNA-TUG1) or miR-26a mimic, a critical regulator of VEGF-mediated angiogenesis. We confirmed the overexpression of TUG1 and miR-26a by qRT-PCR. The neurological deficits of ICH rats were evaluated by modified neurological severity scores. The expression of angiogenesis markers VEGF and CD31 were examined by immunohistochemistry and western blot. The interaction between TUG1 and miR-26a was determined by luciferase reporter assay. Our results showed that ICH caused a marked upregulation of TUG1 and a significant downregulation of miR-26a. TUG1 overexpression led to the deterioration of neurologic function and inhibited cerebral angiogenesis in ICH rats. In contrast, overexpression of miR-26a alleviated the neurologic damage and promoted cerebral angiogenesis in ICH rats, but these could be attenuated by TUG1 overexpression. Furthermore, TUG1 directly bound to miR-26a and inhibited its expression. Importantly, TUG1 overexpression inhibited the expression of VEGF by targeting miR-26a. In conclusion, our results indicated that TUG1 aggravated ICH-mediated injury by suppressing angiogenesis by downregulating miR-26a. This suggests a rationale for targeting TUG1/miR-26a in the therapy of ICH.

LncRNA MALAT1-related signaling pathways in osteosarcoma

Osteosarcoma (OS) is a common and malignant form of bone cancer, which affects children and young adults. OS is identified by osteogenic differentiation and metastasis. However, the exact molecular mechanism of OS development and progression is still unclear. Recently, long non-coding RNAs (lncRNA) have been proven to regulate OS proliferation and drug resistance. LncRNAs are longer than 200 nucleotides that represent the extensive applications in the processing of pre-mRNA and the pathogenesis of human diseases. Metastasis-associated lung adenocarcinoma transcript-1 (MALAT1) is a well-known lncRNA known as a transcriptional and translational regulator. The aberrant expression of MALAT1 has been shown in several human cancers. The high level of MALAT1 is involved in OS cell growth and tumorigenicity by targeting several signaling pathways and miRNAs. Hence, MALAT1 might be a suitable approach for OS diagnosis and treatment. In this review, we will summarize the role of lncRNA MALAT1 in the pathophysiology of OS.

The emerging roles of long non-coding RNA in host immune response and intracellular bacterial infections

The long non-coding RNAs (lncRNAs) are evolutionarily conserved classes of non-coding regulatory transcripts of > 200 nucleotides in length. They modulate several transcriptional and post-transcriptional events in the organism. Depending on their cellular localization and interactions, they regulate chromatin function and assembly; and alter the stability and translation of cytoplasmic mRNAs. Although their proposed range of functionality remains controversial, there is increasing research evidence that lncRNAs play a regulatory role in the activation, differentiation and development of immune signaling cascades; microbiome development; and in diseases such as neuronal and cardiovascular disorders; cancer; and pathogenic infections. This review discusses the functional roles of different lncRNAs in regulation of host immune responses, signaling pathways during host-microbe interaction and infection caused by obligate intracellular bacterial pathogens. The study of lncRNAs is assuming significance as it could be exploited for development of alternative therapeutic strategies for the treatment of severe and chronic pathogenic infections caused by Mycobacterium, Chlamydia and Rickettsia infections, as well as commensal colonization. Finally, this review summarizes the translational potential of lncRNA research in development of diagnostic and prognostic tools for human diseases.

Functional roles of lncRNA-TUG1 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) or hepatoma is malignant cancer that starts from the main liver cells. Although various classical methods have been used for patients with HCC, various molecular mechanisms involved in HCC progression should be invested. Previous studies demonstrated that abnormal expression of long non-coding RNAs (lncRNAs) presented important roles in the pathogenesis of HCC cells. LncRNA TUG1 was found to mediate HCC cell growth, EMT, and metastasis. Therefore, targeting TUG1 and its downstream genes may be a suitable approach for patients with HCC. In this review, we summarized the potential roles of TUG1 in HCC.

The Emerging Role of Long Non-Coding RNAs in Esophageal Cancer: Functions in Tumorigenesis and Clinical Implications

Esophageal cancer (EC) is one of the most common malignancies of digestive tracts with poor five-year survival rate. Hence, it is very significant to further investigate the occurrence and development mechanism of esophageal cancer, find more effective biomarkers and promote early diagnosis and effective treatment. Long non-coding RNAs (lncRNAs) are generally defined as non-protein-coding RNAs with more than 200 nucleotides in length. Existing researches have shown that lncRNAs could act as sponges, guides, scaffolds, and signal molecules to influence the oncogene or tumor suppressor expressions at transcriptional, post-transcriptional, and protein levels in crucial cellular processes. Currently, the dysregulated lncRNAs are reported to involve in the pathogenesis and progression of EC. Importantly, targeting EC-related lncRNAs through genome editing, RNA interference and molecule drugs may be one of the most potential therapeutic methods for the future EC treatment. In this review, we summarized the biological functions and molecular mechanisms of lncRNAs, including oncogenic lncRNAs and tumor suppressor lncRNAs in EC. In addition, we generalized the excellent potential lncRNA candidates for diagnosis, prognosis and therapy in EC. Finally, we discussed the current challenges and opportunities of lncRNAs for EC.

LncRNA TUG1 Promotes Apoptosis, Invasion, and Angiogenesis of Retinal Endothelial Cells in Retinopathy of Prematurity via MiR-145-5p

Purpose

Retinopathy of prematurity (ROP) is a common retinal vascular disease in premature neonates. In recent years, there is increasing evidence that the long non-coding RNA taurine upregulated gene 1 (TUG1) plays a regulatory role in vascular diseases, suggesting a potential role for TUG1 in vascular endothelial cells. We hypothesized that TUG1 may be associated with ROP. Our aim, therefore, was to explore the biological functions of TUG1 in aberrant retinal development.

Methods

We used the mouse oxygen-induced retinopathy (OIR) model to simulate the pathological changes of retinal in ROP. Quantitative real-time polymerase chain reaction was used to detect the expression of TUG1, miR-145-5p and cellular communication network factor 1 (CCN1). Human retinal endothelial cells (HRECs) were treated with CoCl₂ to mimic hypoxia conditions. Cellular functional changes were observed after transfection with RNA interference (RNAi)-TUG1 and miR-145-5p mimics. The apoptosis of HRECs was detected by flow cytometry, the migration ability was detected by wound healing and transwell migration assays, and the ability of angiogenesis was detected by tube formation assay. The potential binding sites between TUG1, miR-145-5p, and CCN1 were verified by dual-luciferase reporter assays. The degree of retinopathy was evaluated by staining retinal sections with hematoxylin and eosin, and the expression of CCN1, HIF-1α, VEGF, caspase-3, Bcl-2, IL-1β, and TNF-α protein was analyzed by Western blotting and immunohistochemistry.

Results

In the retina tissue of OIR mice, TUG1, miR-145-5p, and CCN1 were differentially expressed. Knocking down TUG1 attenuated apoptosis, migration, and angiogenesis induced by hypoxia on HRECs, as did miR-145-5p overexpression. Results from reporter assays indicate direct interactions between TUG1, miR-145-5p, and CCN1. Intravitreal injection of miR-145-5p mimics reduced the degree of retinopathy.

Conclusion

TUG1 acts as a molecular sponge of miR-145-5p to regulate CCN1 expression and thus regulate the development of retinal neovascularization. This regulatory mechanism may provide a new theoretical basis for the prevention and treatment of ROP.

Positive Feedback Regulation of Circular RNA Hsa_circ_0000566 and HIF-1α promotes Osteosarcoma Progression and Glycolysis Metabolism

Hypoxia is an indispensable factor for cancer progression and is closely associated with the Warburg effect. Circular RNAs (CircRNA) have garnered considerable attention in molecular malignancy therapy as they are potentially important modulators. However, the roles of circRNAs and hypoxia in osteosarcoma (OS) progression have not yet been elucidated. This study reveals the hypoxia-sensitive circRNA, Hsa_circ_0000566, that plays a crucial role in OS progression and energy metabolism under hypoxic stress. Hsa_circ_0000566 is regulated by hypoxia-inducible factor-1α (HIF-1α) and directly binds to it as well as to the Von Hippel-Lindau (VHL) E3 ubiquitin ligase protein. Consequentially, binding between VHL and HIF-1α is impeded. Furthermore, Hsa_circ_0000566 contributes to OS progression by binding to HIF-1α (while competing with VHL) and by confers protection against HIF-1α against VHL-mediated ubiquitin degradation. These findings demonstrate the existence of a positive feedback loop formed by HIF-1α and Hsa_circ_0000566 and the key role they play in OS glycolysis. Taken together, these data indicate the significance of Hsa_circ_0000566 in the Warburg effect and suggest that Hsa_circ_0000566 could be a potential therapeutic target to combat OS progression.