LncRNA UCA1 sponges miR-204-5p to promote migration, invasion and epithelial-mesenchymal transition of glioma cells via upregulation of ZEB1

EZH2 as a potential therapeutic target for gastrointestinal cancers

Gastrointestinal (GI) cancers continue to be a major cause of mortality and morbidity globally. Understanding the molecular pathways associated with cancer progression and severity is essential for creating effective cancer treatments. In cancer research, there is a notable emphasis on Enhancer of zeste homolog 2 (EZH2), a key player in gene expression influenced by its irregular expression and capacity to attach to promoters and alter methylation status. This review explores the impact of EZH2 signaling on various GI cancers, such as colorectal, gastric, pancreatic, hepatocellular, esophageal, and cholangiocarcinoma. The primary function of EZH2 signaling is to facilitate the accelerated progression of cancer cells. Additionally, EZH2 has the capacity to modulate the reaction of GI cancers to chemotherapy and radiotherapy. Numerous pathways, including long non-coding RNAs and microRNAs, serve as upstream regulators of EZH2 in these types of cancer. EZH2's enzymatic activity enables it to attach to target gene promoters, resulting in methylation that modifies their expression. EZH2 could be considered as an independent prognostic factor, with increased expression correlating with a worse disease prognosis. Additionally, a range of gene therapies including small interfering RNA, and anti-tumor agents are being explored to target EZH2 for cancer treatment. This comprehensive review underscores the current insights into EZH2 signaling in gastrointestinal cancers and examines the prospect of therapies targeting EZH2 to enhance patient outcomes.

Linc-ROR Promotes EMT by Targeting miR-204-5p/SMAD4 in Endometriosis

Endometriosis (EMs) is a systemic and chronic disease with cancer-like feature, namely, distant implantation, which caused heavy healthy burden of nearly 200 million females. LncRNAs have been proved as new modulators in epithelial-mesenchymal transition (EMT) and EMs. Quantitative real-time PCR was conducted to measure the expression level of long intergenic non-protein coding RNA, regulator of reprogramming (Linc-ROR), and miR-204-5p in ectopic endometrium (n = 25), eutopic endometrium (n = 20), and natural control endometrium (n = 22). Overexpression of Linc-ROR, knockdown or overexpression of miR-204-5p in End1/E6E7 and Ishikawa cells, was conducted to detect the function of Linc-ROR and miR-204-5p in EMs. Furthermore, luciferase reports were used to confirm the combination of Linc-ROR and miR-204-5p and the combination between miR-204-5p and SMAD4. Cell-Counting Kit-8, EdU assay, transwell assays, and Western blotting were used to detect the function of Linc-ROR and miR-204-5p in EMs cancer-like behaviors and EMT process. Linc-ROR was up-regulated in ectopic endometrium. Overexpressed Linc-ROR promotes cell proliferation, invasion, and EMT process. Linc-ROR regulated the EMT process, cellular proliferation, and invasion of EMs via binding to miR-204-5p. In addition, overexpression of Linc-ROR up-regulated SMAD4, a target protein of miR-204-5p, with which regulated EMT process and cancer-like behaviors in EMs together. Linc-ROR/miR-204-5p/SMAD4 axis plays a vital role in regulation EMT process in EMs, which might become a novel therapeutic targets and powerful biomarkers in EMs therapy.

Regulation of EMT Markers, Extracellular Matrix, and Associated Signalling Pathways by Long Non-Coding RNAs in Glioblastoma Mesenchymal Transition: A Scoping Review

Glioblastoma (GBM) mesenchymal (MES) transition can be regulated by long non-coding RNAs (lncRNAs) via modulation of various factors (Epithelial-to-Mesenchymal (EMT) markers, biological signalling, and the extracellular matrix (ECM)). However, understanding of these mechanisms in terms of lncRNAs is largely sparse. This review systematically analysed the mechanisms by which lncRNAs influence MES transition in GBM from a systematic search of the literature (using PRISMA) performed in five databases (PubMed, MEDLINE, EMBASE, Scopus, and Web of Science). We identified a total of 62 lncRNAs affiliated with GBM MES transition, of which 52 were upregulated and 10 were downregulated in GBM cells, where 55 lncRNAs were identified to regulate classical EMT markers in GBM (E-cadherin, N-cadherin, and vimentin) and 25 lncRNAs were reported to regulate EMT transcription factors (ZEB1, Snai1, Slug, Twist, and Notch); a total of 16 lncRNAs were found to regulate the associated signalling pathways (Wnt/β-catenin, PI3k/Akt/mTOR, TGFβ, and NF-κB) and 14 lncRNAs were reported to regulate ECM components (MMP2/9, fibronectin, CD44, and integrin-β1). A total of 25 lncRNAs were found dysregulated in clinical samples (TCGA vs. GTEx), of which 17 were upregulated and 8 were downregulated. Gene set enrichment analysis predicted the functions of HOXAS3, H19, HOTTIP, MEG3, DGCR5, and XIST at the transcriptional and translational levels based on their interacting target proteins. Our analysis observed that the MES transition is regulated by complex interplays between the signalling pathways and EMT factors. Nevertheless, further empirical studies are required to elucidate the complexity in this process between these EMT factors and the signalling involved in the GBM MES transition.

Zinc Finger E-Box Binding Homeobox Family: Non-Coding RNA and Epigenetic Regulation in Gliomas

Gliomas are the most common malignant brain tumours. Among them, glioblastoma (GBM) is a grade four tumour with a median survival of approximately 15 months and still limited treatment options. Although a classical epithelial to mesenchymal transition (EMT) is not the case in glioma due to its non-epithelial origin, the EMT-like processes may contribute largely to the aggressive and highly infiltrative nature of these tumours, thus promoting invasive phenotype and intracranial metastasis. To date, many well-known EMT transcription factors (EMT-TFs) have been described with clear, biological functions in glioma progression. Among them, EMT-related families of molecules such as SNAI, TWIST and ZEB are widely cited, well-established oncogenes considering both epithelial and non-epithelial tumours. In this review, we aimed to summarise the current knowledge with a regard to functional experiments considering the impact of miRNA and lncRNA as well as other epigenetic modifications, with a main focus on ZEB1 and ZEB2 in gliomas. Although we explored various molecular interactions and pathophysiological processes, such as cancer stem cell phenotype, hypoxia-induced EMT, tumour microenvironment and TMZ-resistant tumour cells, there is still a pressing need to elucidate the molecular mechanisms by which EMT-TFs are regulated in gliomas, which will enable researchers to uncover novel therapeutic targets as well as improve patients' diagnosis and prognostication.

MicroRNA-204-5p: A pivotal tumor suppressor

MicroRNAs (miRNAs) are a class of non-coding single-stranded RNA molecules with a length of approximately 18-25 nt nucleotides that regulate gene expression post-transcriptionally. MiR-204-5p originates from the sixth intron of the transient receptor potential cation channel subfamily M member 3 (TRPM3) gene. MiR-204-5p is frequently downregulated in various cancer types and is related to the clinicopathological characteristics and prognosis of cancer patients. So far, many studies have determined that miR-204-5p functions as a tumor suppressor for its extensive and powerful capacity to inhibit tumor proliferation, metastasis, autophagy, and chemoresistance in multiple cancer types. MiR-204-5p appears to be a promising prognostic biomarker and a therapeutic target for human cancers. This review summarized the latest advances on the role of miR-204-5p in human cancers.

MIR99AHG/miR-204-5p/TXNIP/Nrf2/ARE Signaling Pathway Decreases Glioblastoma Temozolomide Sensitivity

Glioblastoma (GBM) is the most prevalent primary cerebral tumor in adults with high aggressiveness. Temozolomide (TMZ) is considered as the most widely used chemotherapy for GBM patients. Accumulating studies have proved that long non-coding RNAs (lncRNAs) participate in the pathogenesis of tumors. The aim of our study is to disclose the role of mir-99a-let-7c cluster host gene (MIR99AHG) in GBM. MIR99AHG expression was discovered to be elevated in GBM cells through quantitative real-time polymerase chain reaction (RT-qPCR) analysis. Loss-of-function experiments demonstrated that MIR99AHG silencing enhanced TMZ sensitivity of GBM both in vitro and in vivo. RNA pull down, RNA-binding protein immunoprecipitation (RIP), and luciferase reporter assays were implemented to unveil the underlying mechanism of MIR99AHG in GBM. The results of the mechanism assays implied that MIR99AHG interacted with microRNA-204-5p (miR-204-5p) and enhanced thioredoxin interacting protein (TXNIP) expression to inactivate the Nrf2/ARE signaling pathway. MIR99AHG/miR-204-5p/TXNIP regulatory axis was verified by rescue experiments in GBM. To summarize, MIR99AHG plays a promoting role in the TMZ resistance of GBM cells. The findings in this study might provide novel sight for the treatment for GBM.

Genetic variations in UCA1, a lncRNA functioning as a miRNA sponge, determine endometriosis development and the potential associated infertility via regulating lipogenesis

Endometriosis is a hormone-associated disease which has been considered as the precursor for certain types of ovarian cancer. In recent years, emerging evidence demonstrated potent roles of lncRNA in regulating cancer development. Since endometriosis shares several features with cancer, we investigated the possible involvement of cancer-related lncRNAs in endometriosis, including UCA1, GAS5 and PTENP1. By using massARRAY system, we investigated certain genetic variations in cancer-related lncRNAs that can change the thermo-stability, leading to up-regulation or down-regulation of those lncRNAs. Our data indicated three risk genetic haplotypes in UCA1 which can stabilize the RNA structure and increase the susceptibility of endometriosis. Of note, such alterations were found to be associated with long-term pain and infertility in patients. It has been known that UCA1 can function as a ceRNA to sponge and inhibit miRNAs, resulting in loss-of-control on downstream target genes. Gene network analyses revealed fatty acid metabolism and mitochondria beta-oxidation as the major pathways associated with altered UCA1 expression in endometriosis patients. Our study thus provides evidence to highlight functional/epigenetic roles of UCA1 in endometriosis development via regulating fatty acid metabolism in women.

Mechanisms of long non-coding RNAs in biological phenotypes and ferroptosis of glioma

Glioma, one of the most common malignant tumors in the nervous system, is characterized by limited treatment, high mortality and poor prognosis. Numerous studies have shown that lncRNAs play an important role in the onset and progression of glioma by acting on various classical signaling pathways of tumors through signaling, trapping, guiding, scaffolding and other functions. LncRNAs contribute to the malignant progression of glioma via proliferation, apoptosis, epithelial-mesenchymal transformation, chemotherapy resistance, ferroptosis and other biological traits. In this paper, relevant lncRNA signaling pathways involved in glioma progression were systematically evaluated, with emphasis placed on the specific molecular mechanism of lncRNAs in the process of ferroptosis, in order to provide a theoretical basis for the application of lncRNAs in the anticancer treatment of glioma.

Dysregulation of miR-204-5p/APLN axis affects malignant progression and cell stemness of esophageal cancer

OBJECTIVE

This study attempted to investigate the mechanism of miR-204-5p and its downstream gene in regulating bio-functions of esophageal cancer (EC).

METHODS

Bioinformatics analysis was performed to select the mature miRNAs, mRNAs, and clinical data of EC. The miRNA-mRNA regulatory axis was predicted through bioinformatics and used Dual-luciferase analysis to verify the interaction between miR-204-5p and APLN. qRT-PCR was applied to analyze expression of miR-204-5p and APLN mRNA. Western blot was utilized to detect APLN protein expression. Functional assays like CCK-8, wound healing, Transwell, and stem cell sphere formation assays were launched to confirm proliferative, migratory, invasive and stemness of cells in different treatment groups.

RESULTS

MiR-204-5p was lowly expressed while its target gene APLN was highly expressed in tumor tissues. Besides, miR-204-5p overexpression hindered proliferation, invasion, migration, and stemness of EC cells. Additionally, dual-luciferase assay verified the interaction of miR-204-5p and APLN. MiR-204-5p could downregulate APLN level and its overexpression reduced the effect of APLN on EC cell functions.

CONCLUSION

Dysregulation of miR-204-5p/APLN axis was linked with malignant progression of EC. MiR-204-5p/APLN may be an underlying candidate for the design of anticarcinogens.

Non-coding RNAs and glioblastoma: Insight into their roles in metastasis

Glioma, also known as glioblastoma multiforme (GBM), is the most prevalent and most lethal primary brain tumor in adults. Gliomas are highly invasive tumors with the highest death rate among all primary brain malignancies. Metastasis occurs as the tumor cells spread from the site of origin to another site in the brain. Metastasis is a multifactorial process, which depends on alterations in metabolism, genetic mutations, and the cancer microenvironment. During recent years, the scientific study of non-coding RNAs (ncRNAs) has led to new insight into the molecular mechanisms involved in glioma. Many studies have reported that ncRNAs play major roles in many biological procedures connected with the development and progression of glioma. Long ncRNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs) are all types of ncRNAs, which are commonly dysregulated in GBM. Dysregulation of ncRNAs can facilitate the invasion and metastasis of glioma. The present review highlights some ncRNAs that have been associated with metastasis in GBM. miRNAs, circRNAs, and lncRNAs are discussed in detail with respect to their relevant signaling pathways involved in metastasis.

Fibrogenic signals persist in DAA-treated HCV patients after sustained virological response

BACKGROUND & AIMS

Patients with HCV who achieve a sustained virological response (SVR) on direct-acting antiviral (DAA) therapy still need to be monitored for signs of liver disease progression. To this end, the identification of both disease biomarkers and therapeutic targets is necessary.

METHODS

Extracellular vesicles (EVs) purified from plasma of 15 healthy donors (HDs), and 16 HCV-infected patients before (T0) and after (T6) DAA treatment were utilized for functional and miRNA cargo analysis. EVs purified from plasma of 17 HDs and 23 HCV-infected patients (T0 and T6) were employed for proteomic and western blot analyses. Functional analysis in LX2 cells measured fibrotic markers (mRNAs and proteins) in response to EVs. Structural analysis was performed by qPCR, label-free liquid chromatography-mass spectrometry and western blot.

RESULTS

On the basis of observations indicating functional differences (i.e. modulation of FN-1, ACTA2, Smad2/3 phosphorylation, collagen deposition) of plasma-derived EVs from HDs, T0 and T6, we performed structural analysis of EVs. We found consistent differences in terms of both miRNA and protein cargos: (i) antifibrogenic miR204-5p, miR181a-5p, miR143-3p, miR93-5p and miR122-5p were statistically underrepresented in T0 EVs compared to HD EVs, while miR204-5p and miR143-3p were statistically underrepresented in T6 EVs compared to HD EVs (p <0.05); (ii) proteomic analysis highlighted, in both T0 and T6, the modulation of several proteins with respect to HDs; among them, the fibrogenic protein DIAPH1 was upregulated (Log₂ fold change of 4.4).

CONCLUSIONS

Taken together, these results highlight structural EV modifications that are conceivably causal for long-term liver disease progression in patients with HCV despite DAA-mediated SVR.

LAY SUMMARY

Direct-acting antivirals lead to virological cure in the majority of patients with chronic hepatitis C virus infection. However, the risk of liver disease progression or complications in patients with fibrosis and cirrhosis remains in some patients even after virological cure. Herein, we show that extracellular vesicle modifications could be linked to long-term liver disease progression in patients who have achieved virological cure; these modifications could potentially be used as biomarkers or treatment targets in such patients.

SNHG9 promotes Hepatoblastoma Tumorigenesis via miR-23a-5p/Wnt3a Axis

Background: Hepatoblastoma is a common hepatic tumor occurring in children between 0-5 years. Accumulating studies have shown lncRNA's potential role in distinct cancer progression and development, including hepatoblastoma. SnoRNA host gene 9 (SNHG9) is associated with the progression of distinct human cancers, but, its specific molecular mechanisms in hepatoblastoma is not unknown.

Methods: In this study, we estimated SNHG9 expression in hepatoblastoma tissue and cell lines by quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). Next, we downregulated and upregulated SNHG9 expression in hepatoblastoma cell lines and then determined cell proliferation (CCK-8), colony formation, and cellular apoptosis activity. The dual luciferase reporter activity, RNA immunoprecipitation (RIP), biotin RNA pull down and Spemann's Pearson correlation coefficient assay were performed to establish the interaction between SNHG9, WNt3a and miR- 23a-5p. A xenograft in-vivo tumorgenicity test was performed to elucidate the role of SNHG9 hepatoblastoma in tumorigenesis. SNHG9 role in Cisplatin drug resistance in hepatoblastoma was also determined.

Results: SNHG9 was significantly upregulated in hepatoblastoma tissue and cell lines. SNHG9 overexpression on HUH6 & HepG2 resulted in a significant increase in cell proliferation and clonogenic activity while SNHG9 knock down resulted in a sustained inhibition of cell proliferation and clonogenic activity. Dual luciferase activity, RNA immunoprecipitation and biotin pull down confirmed the direct interaction of miR-23a-5p with SNHG9. The xenograft tumorgenicity test showed SNHG9 downregulation significantly inhibited the tumor growth in BALB/c mice. ROC and Kaplan-Meier analysis showed potential prognostic and diagnostic importance of SNHG9 in hepatoblastoma.

Conclusion: We concluded that SNHG9/miR-23a-5p/Wnt3a axis promotes the progression hepatoblastoma tumor.

Metastasis associated long noncoding RNAs in glioblastoma: Biomarkers and therapeutic targets

Glioblastoma (GBM) is the most aggressive, malignant, and therapeutically challenging Grade IV tumor of the brain. Although the possibility of distant metastasis is extremely rare, GBM is known to cause intracranial metastasis forming aggressive secondary lesions resulting in a dismal prognosis. Metastasis also plays an important role in tumor dissemination and recurrence making GBM largely incurable. Recent studies have indicated the importance of long noncoding RNAs (lncRNAs) in GBM metastasis. lncRNAs are a class of regulatory noncoding RNAs (>200 nt) that interact with DNA, RNA, and proteins to regulate various biological processes. This is the first comprehensive review summarizing the lncRNAs associated with GBM metastasis and the underlying molecular mechanism involved in migration/invasion. We also highlight the complex network of lncRNA/miRNA/protein that collaborate/compete to regulate metastasis-associated genes. Many of these lncRNAs also show attractive potential as diagnostic/prognostic biomarkers. Finally, we discuss various therapeutic strategies and potential applications of lncRNAs as therapeutic targets for the treatment of GBM.

Long Non-Coding RNAs in Diagnosis, Treatment, Prognosis, and Progression of Glioma: A State-of-the-Art Review

Glioma is the most common malignant central nervous system tumor with significant mortality and morbidity. Despite considerable advances, the exact molecular pathways involved in tumor progression are not fully elucidated, and patients commonly face a poor prognosis. Long non-coding RNAs (lncRNAs) have recently drawn extra attention for their potential roles in different types of cancer as well as non-malignant diseases. More than 200 lncRNAs have been reported to be associated with glioma. We aimed to assess the roles of the most investigated lncRNAs in different stages of tumor progression and the mediating molecular pathways in addition to their clinical applications. lncRNAs are involved in different stages of tumor formation, invasion, and progression, including regulating the cell cycle, apoptosis, autophagy, epithelial-to-mesenchymal transition, tumor stemness, angiogenesis, the integrity of the blood-tumor-brain barrier, tumor metabolism, and immunological responses. The well-known oncogenic lncRNAs, which are upregulated in glioma, are H19, HOTAIR, PVT1, UCA1, XIST, CRNDE, FOXD2-AS1, ANRIL, HOXA11-AS, TP73-AS1, and DANCR. On the other hand, MEG3, GAS5, CCASC2, and TUSC7 are tumor suppressor lncRNAs, which are downregulated. While most studies reported oncogenic effects for MALAT1, TUG1, and NEAT1, there are some controversies regarding these lncRNAs. Expression levels of lncRNAs can be associated with tumor grade, survival, treatment response (chemotherapy drugs or radiotherapy), and overall prognosis. Moreover, circulatory levels of lncRNAs, such as MALAT1, H19, HOTAIR, NEAT1, TUG1, GAS5, LINK-A, and TUSC7, can provide non-invasive diagnostic and prognostic tools. Modulation of expression of lncRNAs using antisense oligonucleotides can lead to novel therapeutics. Notably, a profound understanding of the underlying molecular pathways involved in the function of lncRNAs is required to develop novel therapeutic targets. More investigations with large sample sizes and increased focus on in-vivo models are required to expand our understanding of the potential roles and application of lncRNAs in glioma.

Roles of long non-coding RNAs in the hallmarks of glioma

Glioma is one of the most common types of tumor of the central nervous system. Due to the aggressiveness and invasiveness of high-level gliomas, the survival time of patients with these tumors is short, at ~15 months, even after combined treatment with surgery, radiotherapy and/or chemotherapy. Recently, a number of studies have demonstrated that long non-coding RNA (lncRNAs) serve crucial roles in the multistep development of human gliomas. Gliomas acquire numerous biological abilities during multistep development that collectively constitute the hallmarks of glioma. Thus, in this review, the roles of lncRNAs associated with glioma hallmarks and the current and future prospects for their development are summarized.

MicroRNAs and Their Influence on the ZEB Family: Mechanistic Aspects and Therapeutic Applications in Cancer Therapy

Molecular signaling pathways involved in cancer have been intensively studied due to their crucial role in cancer cell growth and dissemination. Among them, zinc finger E-box binding homeobox-1 (ZEB1) and -2 (ZEB2) are molecules that play vital roles in signaling pathways to ensure the survival of tumor cells, particularly through enhancing cell proliferation, promoting cell migration and invasion, and triggering drug resistance. Importantly, ZEB proteins are regulated by microRNAs (miRs). In this review, we demonstrate the impact that miRs have on cancer therapy, through their targeting of ZEB proteins. MiRs are able to act as onco-suppressor factors and inhibit the malignancy of tumor cells through ZEB1/2 down-regulation. This can lead to an inhibition of epithelial-mesenchymal transition (EMT) mechanism, therefore reducing metastasis. Additionally, miRs are able to inhibit ZEB1/2-mediated drug resistance and immunosuppression. Additionally, we explore the upstream modulators of miRs such as long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), as these regulators can influence the inhibitory effect of miRs on ZEB proteins and cancer progression.

Exosome-mediated delivery of miR-204-5p inhibits tumor growth and chemoresistance

Background

Nano‐sized extracellular vesicles secreted by cells play key roles in intercellular crosstalk, and appear to be an excellent biocompatible material as therapeutic cargoes in vivo. Previously, we have demonstrated that miR‐204‐5p is a key tumor suppressor that could inhibit tumor growth, metastasis and chemoresistance.

Methods

A HEK293T cell line stably expressing miR‐204‐5p (293T‐miR‐204) was constructed by lentivirus transduction. Fluorescence real‐time quantitative PCR (qPCR) was applied to measure the expression of miR‐204‐5p. CCK‐8 and colony formation assays were used to evaluate the in vitro anticancer effects, and the flow cytometry was used to detect apoptosis. The in vivo therapeutic effects of exosomal miR‐204‐5p were evaluated using a xenograft mouse model. Western blots were used to detect the protein levels of CD63, Flotillin‐2, RAB22A and Bcl2. The protein levels of RAB22A and Bcl2 in tumor tissues were measured by immunohistochemistry staining.

Results

MiR‐204‐5p was clearly upregulated in CRC cells after coculturing with 293T‐miR‐204 cell‐derived conditioned medium (CM) or exosomes. CCK‐8 and colony formation assays showed that the cell proliferation ability of CRC cells was clearly inhibited by 293T‐miR‐204 cell‐derived CM or exosomes. The inhibitory effects of exosomal miR‐204‐5p on cell proliferation were further confirmed in other types of cancers. Exosomal miR‐204‐5p could induce apoptosis and increase the sensitivity of cancer cells to the chemotherapeutic drug—5‐fluorourcil. In addition, exosomal miR‐204‐5p inhibited the tumor growth in mice. Western blot assay and IHC staining showed that the protein levels of miR‐204‐5p targets were clearly decreased in cancer cells or xenograft tissues treated with exosomal miR‐204‐5p.

Conclusions

In this study, we confirmed that exosomal miR‐204‐5p could efficiently inhibit cancer cell proliferation, induce apoptosis and increase chemosensitivity by specifically suppressing the target genes of miR‐204‐5p in human cancer cells.

lncRNA NR2F1-AS1 promotes breast cancer angiogenesis through activating IGF-1/IGF-1R/ERK pathway

Long non‐coding RNAs (lncRNAs) take various effects in cancer mostly through sponging with microRNAs (miRNAs). lncRNA NR2F1‐AS1 is found to promote tumour progression in hepatocellular carcinoma, endometrial cancer and thyroid cancer. However, the role of lncRNA NR2F1‐AS1 in breast cancer angiogenesis remains unknown. In this study, we found lncRNA NR2F1‐AS1 was positively related with CD31 and CD34 in breast cancer through Pearson's correlation analysis, while lncRNA NR2F1‐AS1 transfection promoted human umbilical vascular endothelial cell (HUVEC) tube formation. In breast cancer cells, lncRNA NR2F1‐AS1 enhanced the HUVEC proliferation, tube formation and migration ability through tumour‐conditioned medium (TCM). In zebrafish model, lncRNA NR2F1‐AS1 increased the breast cancer cell‐related neo‐vasculature and subsequently promoted the breast cancer cell metastasis. In mouse model, lncRNA NR2F1‐AS1 promoted the tumour vessel formation, increased the micro vessel density (MVD) and then induced the growth of primary tumour. Mechanically, lncRNA NR2F1‐AS1 increased insulin‐like growth factor‐1 (IGF‐1) expression through sponging miRNA‐338‐3p in breast cancer cells and then activated the receptor of IGF‐1 (IGF‐1R) and extracellular signal‐regulated kinase (ERK) pathway in HUVECs. These results indicated that lncRNA NR2F1‐AS1 could promote breast cancer angiogenesis through IGF‐1/IGF‐1R/ERK pathway.

DLX6-AS1/miR-204-5p/OCT1 positive feedback loop promotes tumor progression and epithelial-mesenchymal transition in gastric cancer

BACKGROUND

Accumulating evidence indicates that long non-coding RNAs (lncRNAs) participate in progression of gastric cancer (GC). Nevertheless, the function and expression level of DLX6-AS1 in GC remain unknown.

METHODS

We explored the sequencing data of DLX6-AS1 downloaded from The Cancer Genome Atlas. The expression of DLX6-AS1, miR-204-5p and OCT1 in 56 GC patients and GC cell lines was quantified by qRT-PCR and western blotting. Furthermore, we performed in vitro functional assays to assess proliferation, invasion and migration of GC cells by knockdown of DLX6-AS1. The expression level of epithelial-mesenchymal transition (EMT)-related genes was also determined by qRT-PCR and western blotting. Actin remodeling was detected by F-actin phalloidin staining. The luciferase reporter assay and chromatin immunoprecipitation assay was utilized to confirm the bioinformatic prediction. The function of the DLX6-AS1/miR-204-5p/OCT1 axis in GC proliferation was clarified by rescue assays.

RESULTS

We first demonstrated that DLX6-AS1 was upregulated in GC tissues and cell lines and was associated with T3/T4 invasion, distant metastasis and poor clinical prognosis. Further functional analysis showed that downregulation of DLX6-AS1 inhibited GC cell proliferation, migration, invasion and EMT in vitro. Mechanistic investigation indicated that DLX6-AS1 acted as a cancer-promoting competing endogenous RNA (ceRNA) by binding miR-204-5p and upregulating OCT1. Moreover, the transcription factor OCT1 was confirmed to enhance DLX6-AS1 expression by targeting the promoter region.

CONCLUSIONS

This study revealed that OCT1-induced DLX6-AS1 promoted GC progression and the EMT via the miR-204-5p/OCT1 axis, suggesting that this lncRNA might be a promising prognostic biomarker and therapeutic target for GC.

11 Long noncoding RNA UCA1 functions as miR-135a sponge to promote the epithelial to mesenchymal transition in glioma

The dysregulation of long noncoding (lncRNA) UCA1 may play an important role in tumor progression. However, the function in gliomas is unclear. Therefore, this experiment was designed to explore the pathogenesis of glioma based on lncRNA UCA1. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of lncRNA UCA1, miR-135a, and HOXD9 in gliomas tissues. The effect of lncRNA UCA1 and miR-135a on tumor cell proliferation and migration invasiveness was examined by CCK-8 and transwell assays. Target gene prediction and screening, luciferase reporter assay were used to verify downstream target genes of lncRNA UCA1. Expression of E-cadherin, N-cadherin, vimentin, and HOXD9 was detected by RT-qPCR and Western blotting. The tumor changes in mice were detected by in vivo experiments in nude mice. lncRNA UCA1 was highly expressed in glioma tissues and cell lines. lncRNA UCA1 expression was associated with significantly poor overall survival in gliomas. Moreover, lncRNA UCA1 significantly enhanced cell proliferation and migration, and promoted the occurrence of EMT. In addition, lncRNA UCA1 promoted the development of EMT by positively regulating HOXD9 expression as a miR-135a sponge. In vivo experiments indicated that UCA1 exerted its biological functions by modulating miR-135a and HOXD9. In conclusion, lncRNA UCA1 can induce the activation of HOXD9 by inhibiting the expression of miR-135a and promote the occurrence of EMT in glioma.

Prognostic and clinicopathological significance of long non-coding RNA UCA1 in colorectal cancer: Results from a meta-analysis

OBJECTIVE

Urothelial cancer-associated 1 (UCA1), an oncogenic long non-coding RNA, was aberrantly upregulated in colorectal cancer (CRC). This study aimed to further explore the clinical value of UCA1 in CRC.

METHODS

Eligible studies were retrieved by searching Pubmed, Embase, Cochrane Library, Web of Science, Chinese National Knowledge Infrastructure, and Wanfang databases. Pooled hazard ratio (HR) and odds ratio (OR) with 95% confidence interval (CI) were applied to assess the prognostic role and clinical significance of UCA1.

RESULTS

A total of 7 eligible studies with 775 cancer patients were recruited in the meta-analysis. The results showed that UCA1 overexpression was significantly correlated with poor overall survival in patients with CRC (HR = 2.25, 95% CI: 1.77-2.87, P < .001). There was also a significantly negative association between high UCA1 levels and tumor differentiation (OR = 2.84, 95% CI: 1.87-4.31, P < .001), lymph node metastasis (OR = 3.48, 95% CI: 2.24-5.41, P < .001), distant metastasis (OR = 2.67, 95% CI: 1.32-5.38, P = .006), tumor node metastasis stage (OR = 3.01, 95% CI: 2.16-4.18, P < .001), tumor invasion depth (OR = 2.18, 95% CI: 1.03-4.61, P = .04), and tumor size (OR = 2.27, 95% CI: 1.56-3.32, P < .001).

CONCLUSIONS

Our study revealed that UCA1 overexpression was associated with poor prognosis and more advanced clinicopathological features, suggesting that UCA1 may serve as an indicator for unfavorable outcome of patients with CRC.

Long Noncoding RNA UCA1 Accelerates Nasopharyngeal Carcinoma Cell Progression By Modulating miR-124-3p/ITGB1 Axis

Background

Nasopharyngeal carcinoma (NPC) is a common malignant cancer that is distributed particularly in Southeastern Asia. Previous studies have manifested that long noncoding RNA urothelial carcinoma associated 1 (UCA1) was involved in NPC tumorigenesis and metastasis. However, the biological mechanism of UCA1 for NPC cell progression requires further investigation.

Methods

The expression levels of UCA1, miR-124-3p, integrin beta-1 (ITGB1) were detected by qRT-PCR. Protein expression of ITGB1 was determined by Western blot assay. Cell proliferation, migration and invasion were evaluated by CCK8 and transwell assay, respectively. The interaction between miR-124-3p and UCA1 or ITGB1 was determined by luciferase reporter system, RIP and RNA pull-down assay. Mice model was established by subcutaneously injecting SUNE1 cells stably transfected with sh-UCA1 and sh-NC.

Results

The expression of UCA1 was up-regulated in NPC tissues and cells. However, UCA1 knockdown hindered NPC cell growth, migration and invasion. In addition, the interaction between miR-124-3p and UCA1 or ITGB1 was confirmed by luciferase reporter system, RIP and RNA pull-down assay. Besides, miR-124-3p inhibitor abrogated UCA1 silencing-mediated suppression on cell progression in NPC. Moreover, UCA1 accelerated NPC cell progression through modulating ITGB1 via sponging miR-124-3p. In vivo experiments revealed the interference of UCA1-inhibited tumor growth by regulating miR-124-3p/ITGB1 axis.

Conclusion

UCA1 acts as an oncogene to promote NPC cell proliferation by up-regulating ITGB1 through suppressing miR-124-3p in vitro and in vivo, providing a potential target for NPC diagnosis and treatment.

UCA1 long non-coding RNA: An update on its roles in malignant behavior of cancers

The lncRNA urothelial carcinoma-associated 1 (UCA1) is a 1.4 kb long transcript which has been firstly recognized in human bladder cancer cell line. Subsequent studies revealed its over-expression in a wide array of human cancer cell lines and patients' samples. In addition to conferring malignant phenotype to cells, it enhances resistance to conventional anti-cancer drugs. Moreover, transcript levels of this lncRNA have been regarded as diagnostic markers in several cancer types including gastric, bladder and liver cancers. The underlying mechanism of its participation in carcinogenesis has been identified in some cancer types. Sponging tumor suppressor miRNAs, interacting with cancer-promoting signaling pathways and enhancing cell cycle progression are among these mechanisms. Although few studies have shown anti-carcinogenic properties for this lncRNA, the bulk of evidence supports its oncogenic roles. In the current study, we have reviewed the current literature on the role of UCA1 in the carcinogenic process based on the results of in vitro studies, investigations in animal models and assessment of UCA1 expression in clinical samples.

miR-204-5p regulates cell proliferation, invasion, and apoptosis by targeting IL-11 in esophageal squamous cell carcinoma

Esophageal cancer (EC) is the world's eighth most common malignant neoplasm and is ranked as the sixth leading cause of death related to cancer. Aberrant microRNA (miRNA) expression has been reported to be associated with esophageal squamous cell carcinoma. However, the molecular mechanism of miR-204-5p in esophageal squamous cell carcinoma (ESCC) is not clear. Therefore, the aim of this study was to investigate the potential role of miR-204-5p in ESCC. In the present study, we found that miR-204-5p could affect ESCC proliferation, invasion, apoptosis, and cell cycle in cell and mouse models. A dual-luciferase reporter assay showed that miR-204-5p expression was negatively correlated with interleukin-11 (IL-11) expression. IL-11 overexpression reversed the suppressive effects of miR-204-5p in the cell lines. These results indicated that miR-204-5p functions as a tumor suppressor by directly targeting IL-11 in ESCC.

Long non-coding RNA LINC00174 promotes glycolysis and tumor progression by regulating miR-152-3p/SLC2A1 axis in glioma

BACKGROUND

Long non-coding RNA plays a crucial role in the occurrence and progression of glioma. We aimed to explore the function of LINC00174 in cell proliferation, apoptosis, migration, invasion and glycolysis of glioma cells, and investigate the molecular mechanism involved.

METHODS

LINC00174 expression in glioma tissues and peritumoral brain edema (PTBE) tissues was examined by RT-qPCR and in situ hybridization. The CCK-8, TUNEL, wound healing, transwell, and ELISA assays were performed to identify the effects of LINC00174 knockdown on cell viability, apoptosis, migration, invasion, and glycolysis, respectively. RNA immunoprecipitation, dual-luciferase reporter, RNA pull down, and western blot assays were performed to explore the molecular mechanisms of LINC00174 in glioma cells. A nude mouse xenograft model was used to investigate the role of LINC00174 in xenograft glioma growth.

RESULTS

LINC00174 was overexpressed in glioma tissues and cell lines. LINC00174 knockdown inhibited cell proliferation, migration, invasion and glycolysis of glioma cells, and LINC00174 exerted a tumorigenesis role. LINC00174 could interact with miR-152-3p/SLC2A1 axes. The miR-152-3p inhibitor or the SLC2A1 overexpression could rescue the anti-tumor effect of LINC00174 knockdown on glioma cells. Moreover, downregulation of LINC00174 also inhibited tumor volume and delayed the tumor growth in vivo.

CONCLUSION

LINC00174 accelerated carcinogenesis of glioma via sponging miR-1523-3p and increasing the SLC2A1 expression, which could be considered as a molecular target for glioma diagnosis and therapy.

Downregulated lncRNA UCA1 acts as ceRNA to adsorb microRNA-498 to repress proliferation, invasion and epithelial mesenchymal transition of esophageal cancer cells by decreasing ZEB2 expression

Objective: Esophageal cancer (EC) is one of the most general malignant tumors in humans. There were few studies researching the connections between lncRNA UCA1 and EC. This study is to research the effect of lncRNA UCA1 adsorbing microRNA-498 (miR-498) as a ceRNA to regulate ZEB2 expression on epithelial mesenchymal transition (EMT), invasion and migration of EC cells. Methods: UCA1, miR-498 and ZEB2 expression in EC tissues and cells was detected by RT-qPCR or western blot analysis. EC cells were transfected with siRNA-UCA1, miR-498 mimics or their controls to determine cell colony, proliferation, cycle distribution, apoptosis, migration and invasion by colony formation assay, CCK-8 assay, flow cytometry, and Transwell assay, respectively. The protein expression of PCNA, c-Myc, E-cadherin, N-cadherin, MMP-2 and MMP-9 was detected by Western blot analysis. The growth rate and weight of transplanted tumor in nude mice were observed. Results: There were overly expressed UCA1 and ZEB2 and lowly expressed miR-498 in EC tissues and cells. LncRNA UCA1 acted as ceRNA to inhibit miR-498 expression and thereby increasing ZEB2 expression. With down-regulated UCA1 and up-regulated miR-498, ZEB2 expression, cell proliferation, colony formation, invasion, migration ability, EMT, tumor growth rate and weight in nude mice were apparently reduced. Conclusion: This study demonstrates that inhibited UCA1 up-regulated miR-498 and down-regulated ZEB2, thereby repressing proliferation activity, invasion, migration, and EMT of EC cells.

miR-1271 inhibits growth, invasion and epithelial-mesenchymal transition by targeting ZEB1 in ovarian cancer cells

Objective

MicroRNA-1271 (miR-1271) has a role in suppressing cell growth, cell cycle and promoting cell apoptosis in many cancers. This research was to explore the great role of miR-1271 in ovarian cancer (OC).

Patients and Methods

RT-qPCR was utilized to evaluate the mRNA levels of miR-1271 and its target gene. The proliferative and invasive abilities were measured using Cell Counting Kit-8 and transwell assays. The overall survival rate of OC patients was assessed by Kaplan–Meier method.

Results

miR-1271 was downregulated in OC tissues, and downregulation of miR-1271 predicted a poor outcome of the OC patients. Zinc finger E-box binding homeobox 1 (ZEB1) was a target gene of miR-1271 and its expression was regulated by miR-1271 in OC. The expression of miR-1271 had a negative connection with the expression of ZEB1 in OC tissues. miR-1271 inhibited cell viability and invasion-mediated epithelial–mesenchymal transition in SKOV3 cells. ZEB1 reversed partial roles of miR-1271 on viability and invasion in OC.

Conclusion

miR-1271 inhibited cell proliferation and invasion-mediated EMT in OC. The newly identified miR-1271/ZEB1 axis provides novel insight into the pathogenesis of OC.

Crosstalk between the lncRNA UCA1 and microRNAs in cancer

Long non-coding RNAs (lncRNAs) are a major subset of highly conserved non-coding RNAs (ncRNAs) that consist of at least 200 nucleotides and have limited protein-coding potential. Cumulative data have shown that lncRNAs are deregulated in many types of cancer and may control pathophysiological processes of cancer at various levels, including transcription, post-transcription and translation. Recently, lncRNAs have been demonstrated to interact with microRNAs (miRNAs), another major subset of ncRNAs, which regulate physiological and pathological processes by inhibiting target mRNA translation or promoting mRNA degradation. The lncRNA urothelial carcinoma-associated 1 (UCA1) has recently gained much attention as it is overexpressed in many types of cancer and is involved in carcinogenesis. Here, we review the crosstalk between UCA1 and miRNAs during the pathogenesis of cancer, with a focus on cancer-cell proliferation, invasion, drug resistance, and metabolism.

The Long Noncoding RNA UCA1 Negatively Regulates Melanogenesis in Melanocytes

The long noncoding RNA UCA1 was first discovered in bladder cancer and is known to regulate the proliferation and migration of melanoma. However, its role in melanogenesis is unclear. In this study, we aimed to explore the role and mechanism of UCA1 in melanogenesis. Our findings showed that the expression of UCA1 was negatively correlated with melanin content in melanocytes and pigmented nevus. Overexpression of UCA1 in melanocytes decreased melanin content and the expression of melanogenesis-related genes, whereas knockdown of UCA1 in melanocytes had the opposite effect. High-throughput sequencing revealed that microphthalmia-associated transcription factor (MITF), an important transcription factor affecting melanogenesis, was also negatively correlated with the expression of UCA1. Furthermore, the transcription factor CRE-binding protein (CREB), which promotes MITF expression, was negatively regulated by UCA1. The cAMP/protein kinase A (PKA), extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) signaling pathways, which are upstream of the CREB/MITF/melanogenesis axis, were activated or inhibited in response to silencing or enhancing UCA1 expression, respectively. In addition, enhanced UCA1 expression downregulates the expression of melanogenesis-related genes induced by UVB in melanocytes. In conclusion, UCA1 may negatively regulate the CREB/MITF/melanogenesis axis through inhibiting the cAMP/PKA, ERK, and JNK signaling pathways in melanocytes. UCA1 may be a potential therapeutic target for the treatment of pigmented skin diseases.

LncRNA MALAT1, an lncRNA acting via the miR-204/ZEB1 pathway, mediates the EMT induced by organic extract of PM2.5 in lung bronchial epithelial cells

Extensive cohort studies have explored the hazards of particulate matter with aerodynamic diameter 2.5 μm or smaller (PM2.5) to human respiratory health; however, the molecular mechanisms for PM2.5 carcinogenesis are poorly understood. Long non-coding RNAs (lncRNAs) are involved in various pathophysiological processes. In the present study, we investigated the effect of PM2.5 on the epithelial-mesenchymal transition (EMT) in lung bronchial epithelial cells and the underlying mechanisms mediated by an lncRNA. Organic extracts of PM2.5 from Shanghai were used to treat human bronchial epithelial cell lines (HBE and BEAS-2B). The PM2.5 organic extracts induced the EMT and cell transformation. High levels of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), mediated by NF-κB, were involved in the EMT process. For both cell lines, there was a similar response. In addition, MALAT1 interacted with miR-204 and reversed the inhibitory effect of its target gene, ZEB1, thereby contributing to the EMT and malignant transformation. In sum, these findings show that NF-κB transcriptionally regulates MALAT1, which, by binding with miR-204 and releasing ZEB1, promotes the EMT. These results offer an understanding of the regulatory network of the PM2.5-induced EMT that relates to the health risks associated with PM2.5.

LLCLPLDA: a novel model for predicting lncRNA-disease associations

Long noncoding RNAs play a significant role in the occurrence of diseases. Thus, studying the relationship prediction between lncRNAs and disease is becoming more popular. Researchers hope to determine effective treatments by revealing the occurrence and development of diseases at the molecular level. However, the traditional biological experimental way to verify the association between lncRNAs and disease is very time-consuming and expensive. Therefore, we developed a method called LLCLPLDA to predict potential lncRNA-disease associations. First, locality-constrained linear coding (LLC) is leveraged to project the features of lncRNAs and diseases to local-constraint features, and then, a label propagation (LP) strategy is used to mix up the initial association matrix and the obtained features of lncRNAs and diseases. To demonstrate the performance of our method, we compared LLCLPLDA with five methods in the leave-one-out cross-validation and fivefold cross-validation scheme, and the experimental results show that the proposed method outperforms the other five methods. Additionally, we conducted case studies on three diseases: cervical cancer, gliomas, and breast cancer. The top five predicted lncRNAs for cervical cancer and gliomas were verified, and four of the five lncRNAs for breast cancer were also confirmed.

AC016405.3, a novel long noncoding RNA, acts as a tumor suppressor through modulation of TET2 by microRNA-19a-5p sponging in glioblastoma

Long non-coding RNAs (lncRNAs) are crucial regulators in various malignancies including glioblastoma multiforme (GBM). In the present study, we screened out a new lncRNA, AC016405.3, through a previous genome-wide lncRNA microarray analysis in GBM. It showed that AC016405.3 was downregulated in GBM tissue specimens and cell lines, and it also illustrated that the downregulated AC016405.3 was closely correlated with several aggressive features of patients with GBM. Functionally, we found that overexpression of AC016405.3 suppressed GBM cells' proliferation and metastasis using a gain of function experiment. We further showed that microRNA (miR)-19a-5p, a carcinogenic miRNA, was a downstream miRNA of AC016405.3. AC016405.3 was revealed as a target of miR-19a-5p, and overexpression of miR-19a-5p reversed the inhibitive effect of AC016405.3 on GBM cell proliferation and metastasis. Furthermore, a novel downstream gene of miR-19a-5p, TET2, was identified through a constructed microarray analysis. We showed that TET2 was downregulated in GBM and was involved in miR-19a-5p-mediated proliferation and metastasis by directly being targeted. Finally, through a western blot assay and a series of functional CCK-8 and metastatic assays, we showed that AC016405.3 suppressed proliferation and metastasis through modulation of TET2 by sponging of miR-19a-5p in GBM cells. In summary, the findings of the current study identified a novel lncRNA and illustrated that AC016405.3, acting as an anti-oncogene, suppressed GBM cell proliferation and metastasis by regulating TET through miR-19a-5p sponging. Our present study might provide a new axis in the molecular treatment of GBM.

Architects meets Repairers: The interplay between homeobox genes and DNA repair

Homeobox genes are widely considered the major protagonists of embryonic development and tissue formation. For the past decades, it was established that the deregulation of these genes is intimately related to developmental abnormalities and a broad range of diseases in adults. Since the proper regulation and expression of homeobox genes are necessary for a successful developmental program and tissue function, their relation to DNA repair mechanisms become a necessary discussion. However, important as it is, studies focused on the interplay between homeobox genes and DNA repair are scarce, and there is no critical discussion on the subject. Hence, in this work, I aim to provide the first review of the current knowledge of the interplay between homeobox genes and DNA repair mechanisms, and offer future perspectives on this, yet, young ground for new researches. Critical discussion is conducted, together with a careful assessment of each reviewed topic.

LncRNA UCA1 is necessary for TGF-β-induced epithelial-mesenchymal transition and stemness via acting as a ceRNA for Slug in glioma cells

The 5‐year survival rate of patients with glioma is < 5%, and therefore there is an urgent need to find novel potential targets for facilitating its diagnosis and treatment. The long non‐coding RNA (lncRNA) UCA1 has been shown to promote the proliferation and invasion of cervical cancer cells through regulating miR‐206 expression, but the involvement of UCA1 in regulating the stemness and epithelial–mesenchymal transition (EMT) of glioma cells is unknown. Here, we report that the expression of UCA1 is significantly increased by transforming growth factor‐β (TGF‐β) treatment in glioma cells and is greater in glioma tissues than in normal adjacent tissues. Additionally, TGF‐β induced EMT and the stemness of glioma cells, whereas knockdown of lncRNA UCA1 attenuated these two processes and their enhancement by TGF‐β. Mechanistically, knockdown of UCA1 decreased Slug expression by acting as a competitive endogenous RNA (ceRNA) through competitive binding with miR‐1 and miR‐203a; this effect was further evidenced by the fact that transfection with miR‐1 or miR‐203a inhibitors abrogated the effects of UCA1 knockdown on Slug expression, and UCA1 colocalized with miR‐1 and miR‐203a in glioma tissues. Notably, ectopic expression of Slug rescued the attenuation of UCA1 knockdown on EMT and the stemness of glioma cells. These results indicate that UCA1 may act as a ceRNA to promote Slug expression, which underlies TGF‐β‐induced EMT and stemness of glioma cells.