LncRNA TUG1 promotes the progression of colorectal cancer via the miR-138-5p/ZEB2 axis

The ceRNA network regulates epithelial-mesenchymal transition in colorectal cancer

Epithelial-mesenchymal transition (EMT) is a biological process that transforms epithelial cells into a mesenchymal phenotype, conferring cell migration and invasion capabilities. EMT is involved in the progression and metastasis of colorectal cancer (CRC). Recently, emerging evidence has shown dysregulation of non-coding RNA (ncRNA) was linked to EMT. ncRNAs, including long non-coding RNA (lncRNA), regulate the transcription of downstream target genes (mRNA) through interaction with microRNAs (miRNAs); these are termed competitive endogenous RNA (ceRNA) networks. CeRNA dysregulation-induced EMT, which is linked to the progression and prognosis of CRC, has attracted wide attention. However, understanding the role of the regulation of the ceRNA network in the EMT of CRC remains limited. We discuss the molecular functions of lncRNA, the ceRNA networks related to miRNAs and mRNAs in EMT, as well as EMT transcription factors, such as the zinc finger E-box binding homeobox 1/2 (ZEB1/2), SNAIL, SLUG, and TWIST1/2. In addition, miRNAs and lncRNAs that directly target genes, thereby initiating different signaling pathways to promote EMT in CRC, were summarized. Clarifying the role of these molecules in EMT is critical for understanding molecular mechanisms and exploring the potential therapeutic targets of CRC.

The pathogenic roles of lncRNA-Taurine upregulated 1 (TUG1) in colorectal cancer

Colorectal cancer (CRC) is a gastrointestinal tumor that develops from the colon, rectum, or appendix. The prognosis of CRC patients especially those with metastatic lesions remains unsatisfactory. Although various conventional methods have been used for the treatment of patients with CRC, the early detection and identification of molecular mechanisms associated with CRC is necessary. The scientific literature reports that altered expression of long non-coding RNAs (lncRNAs) contributed to the pathogenesis of CRC cells. LncRNA TUG1 was reported to target various miRNAs and signaling pathways to mediate CRC cell proliferation, migration, and metastasis. Therefore, TUG1 might be a potent predictive/prognostic biomarker for diagnosis of CRC.

lncRNA TUG1 promotes the development of oral squamous cell carcinoma by regulating the MAPK signaling pathway by sponging miR-593-3p

Dysregulation of non-coding RNAs (ncRNAs) has been proved to play important roles in oral squamous cell carcinoma (OSCC). This study aimed to determine the combined role of lncRNA TUG1, miR-593-3p, and MAPK signaling in oral squamous cell carcinoma (OSCC) development. Here, we found that TUG1 was up-regulated in OSCC tissues and cell lines. Silencing TUG1 suppressed proliferation migration, invasion and promoted apoptosis of OSCC cells. We also validated that knockdown of TUG1 suppressed MAPK signaling pathway and inhibited EMT process in OSCC cells. Then, a novel LncRNA TUG1/ miR-593-3p/MAPK axis was verified to rescue cell viability in OSCC cells. Mechanistically, miR-593-3p bound to lncRNA TUG1, and lncRNA TUG1 positively regulated MAPK related proteins through acting as RNA sponger for miR-593-3p. Further gain- and loss-of-function experiments evidenced that the protective effects of lncRNA TUG1 knock-down on OSCC cells were abrogated by silencing miRNA-593-3p. The OSCC nude mice model experiments demonstrated that depletion of TUG1 further inhibited tumor growth. In conclusion, appropriate diagnostic biomarkers and therapies for OSCC can be identified by targeting the TUG1/miR-593-3p/MAPK axis.

Potentials of long non-coding RNAs as biomarkers of colorectal cancer

Colorectal cancer (CRC) is the third most common malignant tumor worldwide and the fourth major cause of cancer-related death, with high morbidity and increased mortality year by year. Although significant progress has been made in the therapy strategies for CRC, the great difficulty in early diagnosis, feeble susceptibility to radiotherapy and chemotherapy, and high recurrence rates have reduced therapeutic efficacy resulting in poor prognosis. Therefore, it is urgent to understand the pathogenesis of CRC and unravel novel biomarkers to improve the early diagnosis, treatment and prediction of CRC recurrence. Long non-coding RNAs (lncRNAs) are non-coding RNAs with a length of more than 200 nucleotides, which are abnormally expressed in tumor tissues and cell lines, activating or inhibiting specific genes through multiple mechanisms including transcription and translation. A growing number of studies have shown that lncRNAs are important regulators of microRNAs (miRNAs, miRs) expression in CRC and may be promising biomarkers and potential therapeutic targets in the research field of CRC. This review mainly summarizes the potential application value of lncRNAs as novel biomarkers in CRC diagnosis, radiotherapy, chemotherapy and prognosis. Additionally, the significance of lncRNA SNHGs family and lncRNA-miRNA networks in regulating the occurrence and development of CRC is mentioned, aiming to provide some insights for understanding the pathogenesis of CRC and developing new diagnostic and therapeutic strategies.

Long Non-Coding RNAs as Potential Regulators of EMT-Related Transcription Factors in Colorectal Cancer—A Systematic Review and Bioinformatics Analysis

Simple Summary

Emerging evidence highlights long non-coding RNAs as important regulators of epithelial–mesenchymal transition. Numerous studies have attempted to define their possible diagnostic, prognostic and therapeutic values in various human cancers. The aim of this review is to summarize long non-coding RNAs involved in the regulation of epithelial–mesenchymal transition in colorectal carcinoma. Additional candidate long non-coding RNAs are identified through a bioinformatics analysis.

Abstract

Epithelial–mesenchymal transition (EMT) plays a pivotal role in carcinogenesis, influencing cancer progression, metastases, stemness, immune evasion, metabolic reprogramming and therapeutic resistance. EMT in most carcinomas, including colorectal carcinoma (CRC), is only partial, and can be evidenced by identification of the underlying molecular drivers and their regulatory molecules. During EMT, cellular reprogramming is orchestrated by core EMT transcription factors (EMT-TFs), namely ZEB1/2, TWIST1/2, SNAI1 (SNAIL) and SNAI2 (SLUG). While microRNAs have been clearly defined as regulators of EMT, the role of long non-coding RNAs (lncRNAs) in EMT is poorly defined and controversial. Determining the role of lncRNAs in EMT remains a challenge, because they are involved in a number of cellular pathways and are operating through various mechanisms. Adding to the complexity, some lncRNAs have controversial functions across different tumor types, acting as EMT promotors in some tumors and as EMT suppressors in others. The aim of this review is to summarize the role of lncRNAs involved in the regulation of EMT-TFs in human CRC. Additional candidate lncRNAs were identified through a bioinformatics analysis.

Evaluating adipose-derived stem cell exosomes as miRNA drug delivery systems for the treatment of bladder cancer

Objectives

Exosomes are essential mediators of intercellular communication as they transport proteins and RNAs between cells. Owing to their tumor‐targeting capacity, immune compatibility, low toxicity, and long half‐life, mesenchymal stem cell‐derived exosomes have great potential for the development of novel antitumor strategies. In this context, the role of exosomes produced by adipose‐derived mesenchymal stem cells (ADSCs) for the treatment of bladder cancer (BC) remains unclear. Here, we investigated the use of ADSCs as a source of therapeutic exosomes, as well as their efficacy in delivering the tumor suppressor miR‐138‐5p in BC.

Methods

ADSCs stably expressing miR‐138‐5p were established using Lentivirus infection, and ADSC‐derived miR‐138‐5p exosomes (Exo‐miR‐138‐5p) were isolated from the cell culture medium. The effect of Exo‐miR‐138‐5p on BC cell migration, invasion, and proliferation was evaluated in vitro using wound healing, transwell invasion, and proliferation assays. The in vivo effect of Exo‐miR‐138‐5p was investigated using a subcutaneous xenograft mouse model.

Results

Exo‐miR‐138‐5p prevented the migration, invasion, and proliferation of BC cells in vitro. Moreover, ADSC‐derived exosomes could penetrate tumor tissues and successfully deliver miR‐138‐5p to suppress the growth of xenograft tumors in vivo.

Conclusions

The present results reveal that ADSC‐derived exosomes are an effective delivery vehicle for small molecule drugs in vivo, and exosome‐delivered miR‐138‐5p is a promising therapeutic agent for BC treatment.

Long non-coding RNAs as the critical regulators of epithelial mesenchymal transition in colorectal tumor cells: an overview

Colorectal cancer (CRC) is the second most common cause of cancer mortality and a major health challenge worldwide. Despite advances in therapeutic and diagnostic methods, there is still a poor prognosis in CRC patients. Tumor recurrence and metastasis are the main causes of high mortality rate in these patients, which are due to late diagnosis in advanced tumor stages. Epithelial-mesenchymal transition (EMT) is known to be the most important cause of CRC metastasis, during which tumor cells obtain metastasis ability by losing epithelial features and gaining mesenchymal features. Long non-coding RNAs (lncRNAs) are pivotal regulators of EMT process. Regarding the higher stability of lncRNAs compared with coding RNAs in body fluids, they can be used as non-invasive diagnostic markers for EMT process. In the present review, we summarized all of the lncRNAs involved in regulation of EMT process during CRC progression and metastasis. It was observed that lncRNAs mainly induced the EMT process in CRC cells by regulation of EMT-related transcription factors, Poly comb repressive complex (PRC), and also signaling pathways such as WNT, NOTCH, MAPK, and Hippo.

Comprehensive bioinformatics analysis of functional molecules in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the 3rd most common cancer and the 2nd leading cause of cancer-related death. Numerous studies have found that aberrations in cellular molecules play an important role in the development of tumors. Studying and determining the interactions between these molecules can contribute to the diagnosis, treatment, and prognosis of tumors.

METHODS

The GSE151021, GSE156720, and GSE156719 data sets were analyzed to screen the differentially expressed messenger RNAs (DEmRNAs), long non-coding RNAs (DElncRNAs), and microRNAs (DEmiRNAs) in CRC. Database for Annotation, Visualization and Integrated Discovery (DAVID) and the Search Tool for the Retrieval of Interacting Genes/Proteins software were used to examine gene enrichment and the hub genes. Gene Expression Profiling Interactive Analysis 2 (GEPIA2) and UALCAN was used to verify the expression of the hub genes. To analyze the overall survival (OS) of the hub genes, Kaplan-Meier plotter (KM plotter) was performed. Finally, the miRCancer database, TargetScan, and GSE156719 were used to identify the targets of the identified miRNAs. To predict the lncRNA-miRNA interactions, we used DIANA-LncBase v2 and GSE156720. Finally, the visualization protein‑protein interaction (PPI), competitive endogenous RNA (ceRNA) network was constructed using Cytoscape v3.1.

RESULTS

By analyzing GSE151021 and GSE156720, 23 upregulated mRNAs and 10 downregulated mRNAs were identified as sharing the differentially expressed genes (DEGs) between CRC and adjacent tissues. Furthermore, nucleolar protein 14 (NOP14), the sonic hedgehog (SHH) signaling molecule, phorbol-12-myristate-13-acetate-induced protein 1 (PMAIP1), the BCL2 apoptosis regulator (BCL2), and zinc finger E-box binding homeobox 2 (ZEB2) were considered hub genes. The constructed lncRNA-miRNA-mRNA network revealed 7 intersecting miRNAs (4 upregulated and 3 downregulated), 79 lncRNAs (40 upregulated and 39 downregulated), and 5 mRNAs (3 upregulated and 2 downregulated). Finally, we determined that the dysregulation of lncRNAs, such as HCG16, CASC9, SNHG16, HAND2-AS1, and NR2F1-AS1, secluded altered the expression of several miRNAs, such as hsa-miR-193a-5p, hsa-miR-485-5p, hsa-miR-17-5p, and hsa-miR-92a-3p, and affected the occurrence and development of CRC.

CONCLUSIONS

We identified a series of DElncRNAs, DEmRNAs, and DEmiRNAs in CRC that might be considered potential biomarkers in understanding the complex molecular pathways leading to CRC development.

The Role of LncRNA TUG1 in Obesity-Related Diseases

With the continuous improvement of living standards, obesity has become an inevitable hotspot in our daily life. It remains a chronic and recurrent disease with serious adverse consequences. Over the past few years, several articles suggested that long non-coding RNA taurine increased gene 1（lncRNA TUG1）, a useful RNA, was suggested to show a relationship to obesity-related disease occurrence and development. Exosome is an emerging research field, which contains substances that are actively involved in regulating the molecular mechanisms of disease. This review summarizes the current relevant TUG1 in different molecular pathways of diseases related to obesity, relationship between exosomes and TUG1 or diseases related to obesity. The aim is to explore TUG1 as a novel target for obesity, which can deepen the knowledge regarding epigenetic regulation pathway. Besides, it is likely to be a potential future targeting diseases related to obesity site treatment and diagnosis.

Insulin-like growth factor 2 mRNA-binding protein 2-stabilized long non-coding RNA Taurine up-regulated gene 1 (TUG1) promotes cisplatin-resistance of colorectal cancer via modulating autophagy

Long non-coding RNAs (lncRNAs) have been demonstrated to influence the chemoresistance of colorectal cancer (CRC). Therefore, the study is designed to investigate the regulatory function and mechanism of Taurine up-regulated gene 1 (TUG1) in the cisplatin resistance of CRC. qRT-PCR checked the expressions of TUG1, Insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2), and miR-195-5p in CRC tissues and cells. The TUG1 or miR-195-5p overexpression model was engineered in CRC cells, followed by treatment with DDP or the autophagy inhibitor (Chloroquine, CQ). CCK8 (Cell Counting Kit-8) and the colony formation experiment monitored cell proliferation. Flow cytometry examined apoptosis, Transwell tracked migration and invasion, and Western blot ascertained the protein profiles of autophagy proteins (LC3I/LC3II and Beclin1) and the HDGF/DDX5/β-catenin pathway. Dual-luciferase gene reporter assay and RNA immunoprecipitation confirmed the binding correlation between TUG1 and miR-195-5p and between miR-195-5p and HDGF. Furthermore, in-vivo experiments in nude mice probed the function and mechanism of IGF2BP2 in CRC cell growth. The profiles of TUG1 and IGF2BP2 were elevated in CRC tissues, and IGF2BP2 enhanced TUG1’s expression in CRC cells. TUG1 activated autophagy to facilitate CRC cells’ resistance to DDP. TUG1 targets miR-195-5p, and miR-195-5p targets HDGF. Overexpression of miR-195-5p abated the cancer-promoting function of TUG1 and curbed the profile of the HDGF/DDX5/β-catenin axis. TUG1 stabilized by IGF2BP2 boosted CRC cell proliferation, migration, migration, and autophagy via the miR-195-5p/HDGF/DDX5/β-catenin axis, hence enhancing CRC cell’s resistance to DDP.

lncRNA TUG1 Facilitates Colorectal Cancer Stem Cell Characteristics and Chemoresistance by Enhancing GATA6 Protein Stability

Background

Chemoresistance and tumor recurrence lead to high deaths in colorectal cancer (CRC) patients. Cancer stem cells (CSCs) contribute to these pathologic properties, but the exact mechanisms are still poorly understood. This study identified that long noncoding RNA (lncRNA) TUG1 was highly expressed in CRC stem cells and investigated its mechanism.

Methods

After the CD133⁺/CD44⁺ cells with cancer stem cell (CSC) characteristics were isolated and identified by flow cytometry, lncRNA TUG1 expression was quantified by quantitative real-time PCR. The lncRNA TUG1 function was further investigated using gain- and loss-of-function assays, sphere formation, Western blot, Cell Counting Kit-8 assay, and cell apoptosis detection. Moreover, the mechanism was explored by RNA pull-down assay, RNA immunoprecipitation, and cycloheximide- (CHX-) chase assays.

Results

lncRNA TUG1 was elevated in CD133⁺/CD44⁺ cells with CSC characteristics. Functionally, lncRNA TUG1 increased the characteristics and oxaliplatin resistance of CRC stem cells. Mechanically, lncRNA TUG1 interacted with GATA6 and positively regulated its protein level and the rescue assays corroborated that lncRNA TUG1 knockdown repressed the characteristics and oxaliplatin resistance of CRC stem cells by decreasing GATA6 and functioned in CRC by targeting the GATA6-BMP signaling pathway. Furthermore, the in vivo assay verified the lncRNA TUG1 function in facilitating the characteristics and oxaliplatin resistance of CRC stem cells.

Conclusion

lncRNA TUG1 facilitated CRC stem cell characteristics and chemoresistance by enhancing GATA6 protein stability.

Circular RNA circVAPA contributes to non-small-cell lung cancer progression via miR-342-3p-dependent regulation of ZEB2

BACKGROUND

Accumulating evidence demonstrated that circular RNAs (circRNAs) play pivotal regulatory roles in the pathology of cancers. Disclosing the roles and molecular mechanisms of circRNAs in tumorigenesis and development is essential to identify novel diagnostic and therapeutic targets. In this study, we explored the role of circVAPA in non-small-cell lung cancer (NSCLC) progression and its associated mechanism.

METHODS

The expression level of RNA was analyzed by real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferation was assessed by MTT assay and colony-forming assay. Cell apoptosis was analyzed by flow cytometry. Cell migration and invasion were assessed by transwell assays. Dual-luciferase reporter, RNA pull-down, and RNA immunoprecipitation (RIP) assays were used to test the intermolecular interactions. The role of circVAPA was assessed in vivo. And xenograft tumor tissues were analyzed by immunohistochemistry (IHC) staining.

RESULTS

CircVAPA expression was upregulated in NSCLC tissues and cell lines, and a high level of circVAPA was associated with a poor prognosis of NSCLC patients. CircVAPA silencing suppressed the proliferation, migration, and invasion and induced the apoptosis of NSCLC cells. CircVAPA served as a molecular sponge for microRNA-342-3p (miR-342-3p). miR-342-3p interference largely reversed circVAPA knockdown-mediated anti-tumor effects in NSCLC cells. Zinc finger E-box-binding homeobox 2 (ZEB2) was a target of miR-342-3p, and miR-342-3p overexpression suppressed the malignant behaviors of NSCLC cells largely by downregulating ZEB2. CircVAPA silence repressed xenograft tumor growth in vivo, and IHC assay confirmed that circVAPA silence restrained the proliferation and metastasis but induced the apoptosis of NSCLC cells in vivo.

CONCLUSION

CircVAPA contributes to the progression of NSCLC by binding to miR-342-3p to upregulate ZEB2. CircVAPA/miR-342-3p/ZEB2 axis might be a novel potential target for NSCLC treatment.

The miRNA mir-582-3p suppresses ovarian cancer progression by targeting AKT/MTOR signaling via lncRNA TUG1

Ovarian cancer (OC) is one of the most common malignancies of the female reproductive system. The miRNA miR-582-3p is associated with a variety of tumors, and the aim of this study was to investigate the role and mechanisms of miR-582-3p specifically in ovarian carcinogenesis and progression. Low expression of miR-582-3p was noted in OC tissue and cell lines, and lower expression of miR-582-3p correlated with lower overall survival in OC patients. Knockdown of miR-582-3p promoted the proliferation and migration of OC cells, while overexpression inhibited them. TUG1, a long non-coding RNA, was found to bind to miR-582-3p, and inhibition of lncRNA TUG1 decreased viability and migration and weakened the effect of miR-582-3p knockdown in OC cells. Implantation of OC cells with reduced miR-582-3p caused increased tumor growth, while lncRNA TUG1 knockdown suppressed tumor growth and relieved the impact of reduced miR-582-3p in vivo. Phosphorylation of AKT and mTOR were significantly enhanced with decreased miR-582-3p expression, but lncRNA TUG1 knockdown attenuated this trend in vitro and in vivo. The novel miR-582-3p represses the malignant properties of OC via the AKT/mTOR signaling pathway by targeting lncRNA TUG1. This axis may represent valuable prognostic biomarkers and therapeutic targets for OC.

Knockdown of lncRNA TUG1 protects lens epithelial cells from oxidative stress-induced injury by regulating miR-196a-5p expression in age-related cataracts

Oxidative stress plays an important role in the pathogenesis of cataracts. Under oxidative stress, apoptosis of lens epithelial cells (LECs) is activated, which may cause lens opacity and accelerate the development of cataracts. Long non-coding RNA (lncRNA) and microRNA (miRNA/miR) are involved in cataracts. Previous studies have demonstrated that lncRNA taurine upregulated 1 (TUG1) promotes cell apoptosis induced by ultraviolet radiation by downregulating the expression of miR-421. However, the mechanism underlying TUG1 in age-related cataract remains to be elucidated. The present study aimed to investigate the effect of TUG1 in age-related cataracts and to determine the related underlying molecular mechanism. In the present study, the association between TUG1 and microRNA (miR)-196a-5p was predicted using StarBase and verified using a dual luciferase reporter assay in 293 cells. The LEC line SRA01/04 was exposed to 200 µM hydrogen peroxide (H₂O₂) for 24 h to establish an in vitro oxidative stress model. The mRNA expression levels of TUG1 and miR-196a-5p were analyzed using reverse transcription-quantitative PCR, whilst cell viability and apoptosis were determined using MTT and flow cytometry assays, respectively. The protein expression levels of cleaved caspase-3 and caspase-3 in SRA01/04 cells were determined using western blotting. The results of the present study revealed that TUG1 directly targeted miR-196a-5p expression. In addition, the expression levels of miR-196a-5p were downregulated in SRA01/04 cells following oxidative stress, whilst TUG1 expression was upregulated. Cell transfection with TUG1-small interfering RNA (siRNA) upregulated miR-196a-5p expression levels in SRA01/04 cells, which was reversed following co-transfection with the miR-196a-5p inhibitor. Transfection with TUG1-siRNA also reduced the levels of H₂O₂-induced oxidative damage in SRA01/04 cells, which was demonstrated by increased cell viability, reduced levels of apoptosis and downregulated cleaved caspase-3 levels. Conversely, transfection with the miR-196a-5p inhibitor reversed these effects aforementioned. Overexpression of miR-196a-5p reduced H₂O₂-induced oxidative damage in SRA01/04 cells. In conclusion, findings from the present study suggested that knocking down TUG1 expression may protect LECs from oxidative stress-induced apoptosis by upregulating the expression of miR-196a-5p.

Long non-coding RNA TUG1 accelerates abnormal growth of airway smooth muscle cells in asthma by targeting the miR-138-5p/E2F3 axis

Asthma is a chronic airway inflammatory disease. The present study aimed to explore the effect of the long non-coding RNA taurine-upregulated gene 1 (TUG1) on the viability and migration of airway smooth muscle cells (ASMCs) in asthma. Rat asthma models were constructed with ovalbumin sensitization and challenge and the level of serum immunoglobulin E (IgE) and the rates of inspiratory and expiratory resistance were measured. Reverse transcription-quantitative PCR was also performed to determine the expression levels of TUG1. Platelet-derived growth factor-BB (PDGF-BB)-treated ASMCs were then used as a cell model of asthma. The viability and migratory abilities of ASMCs were analysed with the MTT and Transwell assays. Additionally, a dual-luciferase reporter assay was used to confirm the relationship between TUG1 and microRNA (miR)-138-5p and between transcription factor E2F3 and miR-138-5p. The expression of TUG1, level of serum IgE, inspiratory resistance and expiratory resistance were clearly increased in the rat asthma model in comparison with controls. Knockdown of TUG1 the viability and migration of PDGF-BB-induced ASMCs and reduced the inspiratory and expiratory resistances. In addition, TUG1 functioned as a bait of miR-138-5p, and miR-138-5p modulated E2F3 expression. Knockdown of E2F3 hindered the abnormal growth of ASMCs. Moreover, miR-138-5p inhibition or E2F3 overexpression reversed the inhibitory effects of TUG1 knockdown on viability and migration of PDGF-BB-induced ASMCs. The TUG1/miR-138-5p/E2F3 regulatory axis appeared to play a critical role in accelerating the viability and migration of ASMCs and may therefore have a role in asthma.

ZEB2, the Mowat-Wilson Syndrome Transcription Factor: Confirmations, Novel Functions, and Continuing Surprises

After its publication in 1999 as a DNA-binding and SMAD-binding transcription factor (TF) that co-determines cell fate in amphibian embryos, ZEB2 was from 2003 studied by embryologists mainly by documenting the consequences of conditional, cell-type specific Zeb2 knockout (cKO) in mice. In between, it was further identified as causal gene causing Mowat-Wilson Syndrome (MOWS) and novel regulator of epithelial–mesenchymal transition (EMT). ZEB2’s functions and action mechanisms in mouse embryos were first addressed in its main sites of expression, with focus on those that helped to explain neurodevelopmental and neural crest defects seen in MOWS patients. By doing so, ZEB2 was identified in the forebrain as the first TF that determined timing of neuro-/gliogenesis, and thereby also the extent of different layers of the cortex, in a cell non-autonomous fashion, i.e., by its cell-intrinsic control within neurons of neuron-to-progenitor paracrine signaling. Transcriptomics-based phenotyping of Zeb2 mutant mouse cells have identified large sets of intact-ZEB2 dependent genes, and the cKO approaches also moved to post-natal brain development and diverse other systems in adult mice, including hematopoiesis and various cell types of the immune system. These new studies start to highlight the important adult roles of ZEB2 in cell–cell communication, including after challenge, e.g., in the infarcted heart and fibrotic liver. Such studies may further evolve towards those documenting the roles of ZEB2 in cell-based repair of injured tissue and organs, downstream of actions of diverse growth factors, which recapitulate developmental signaling principles in the injured sites. Evident questions are about ZEB2’s direct target genes, its various partners, and ZEB2 as a candidate modifier gene, e.g., in other (neuro)developmental disorders, but also the accurate transcriptional and epigenetic regulation of its mRNA expression sites and levels. Other questions start to address ZEB2’s function as a niche-controlling regulatory TF of also other cell types, in part by its modulation of growth factor responses (e.g., TGFβ/BMP, Wnt, Notch). Furthermore, growing numbers of mapped missense as well as protein non-coding mutations in MOWS patients are becoming available and inspire the design of new animal model and pluripotent stem cell-based systems. This review attempts to summarize in detail, albeit without discussing ZEB2’s role in cancer, hematopoiesis, and its emerging roles in the immune system, how intense ZEB2 research has arrived at this exciting intersection.

Long noncoding RNA TUG1 regulates the progression of colorectal cancer through miR-542-3p/TRIB2 axis and Wnt/β-catenin pathway

BACKGROUND

Colorectal cancer (CRC) is one of the third normal malignancy worldwide. Taurine-upregulated gene 1 (TUG1), a member of long noncoding RNAs (lncRNAs), has been reported to be involved in various cancers. However, the mechanism underlying TUG1 in the progression of CRC remains unclear.

METHODS

The expression of TUG1, microRNA-542-3p (miR-542-3p), and tribbles homolog 2 (TRIB2) in CRC tissues and cells (LoVo and HCT116) were detected by quantitative real-time PCR (qRT-PCR). Methyl thiazolyl tetrazolium (MTT), transwell and flow cytometry assays were employed to evaluate the effects of TUG1 in CRC cells. The interaction between miR-542-3p and TUG1 or TRIB2 were verified by dual-luciferase reporter assay. A xenograft tumor model in nude mice was established to investigate the biological role of TUG1 in CRC in vivo.

RESULTS

TUG1 was increased in CRC tissues and cells (LoVo and HCT116) in contrast with adjacent normal tissues and normal intestinal mucous cells (CCC-HIE-2). Downregulation of TUG1 or TRIB2 suppressed the proliferation, migration, invasion, and induced apoptosis in CRC cells. And knockdown of TUG1 repressed tumor growth in vivo. Besides, overexpression of TRIB2 reversed the effects of TUG1 depletion on the progression of CRC. Meanwhile, TUG1 interacted with miR-542-3p and TRIB2 was a target of miR-542-3p. Furthermore, miR-542-3p knockdown or TRIB2 overexpression partly reversed the suppression effect of TUG1 depletion on the Wnt/β-catenin pathway.

CONCLUSIONS

TUG1 served as a tumor promoter, impeded the progression of CRC by miR-542-3p/TRIB2 axis to inactivate of Wnt/β-catenin pathway, which providing a novel target for CRC treatment.

LncRNA signature in colorectal cancer

Colorectal cancer (CRC) is among the most frequent cancers and is associated with high mortality particularly when being diagnosed in advanced stages. Although several environmental and intrinsic risk factors have been identified, the underlying cause of CRC is not clear in the majority of cases. Several studies especially in the recent decade have pointed to the role of epigenetic factors in this kind of cancer. Long non-coding RNAs (lncRNAs) as important contributors in the epigenetic mechanisms are involved in the initiation, progression and metastasis of CRC. Tens of oncogenic lncRNAs and a lower number of tumor suppressor lncRNAs have been recently identified to be dysregulated in CRC cells and tissues. Notably, expressions of a number of these transcripts have been dysregulated in serum samples of CRC patients, providing a non-invasive route for detection of this kind of cancer. The involvement of lncRNAs in the regulation of autophagy has provided them the ability to modulate response of CRC cells to chemotherapeutic modalities. In the current manuscript, we review the studies which evaluated the role of lncRNAs in the pathogenesis and progression of CRC to appraise their application as diagnostic/ prognostic markers.

Circ_0006174 Accelerates Colorectal Cancer Progression Through Regulating miR-138-5p/MACC1 Axis

Background

Circular RNAs (circRNAs) were reported to be involved in the progression of a variety of cancers, including colorectal cancer (CRC). However, the precise functions and mechanism of circRNAs in CRC have not been elucidated. This study aimed to investigate the effect and mechanism underlying circ_0006174 in CRC.

Methods

The expression of circ_0006174, microRNA (miR-138-5p) and metastasis associated in colon cancer 1 (MACC1) mRNA was detected by quantitative real-time polymerase chain reaction (RT-qPCR) assay. Western blot was employed to measure MACC1 protein expression. The effects of circ_0006174 knockdown, MACC1 overexpression or miR-138-5p inhibition on cell proliferation, migration, invasion, and apoptosis were assessed by cell counting kit 8 (CCK-8) assay, clone formation assay, transwell assay and flow cytometry assay, respectively. The interaction between miR-138-5p and circ_0006174 or MACC1 was confirmed by RNA pull down assay or dual-luciferase reporter assay. Xenograft tumor model in nude mice was used to verify the function of circ_0006174 in vivo.

Results

Circ_0006174 and MACC1 expression was highly expressed, while miR-138-5p expression was downregulated in CRC cells and tissues. Meanwhile, circ_0006174 functioned as a sponge of miR-138-5p to upregulate MACC1 expression. Furthermore, circ_0006174 knock down-mediated suppression on cell proliferation, migration and invasion, and promotion on cell apoptosis could be alleviated by MACC1 overexpression or miR-138-5p inhibition in CRC cells. Besides, circ_0006174 knockdown also inhibited CRC procession in vivo.

Conclusion

Circ_0006174 advanced CRC progression via sponging miR-138-5p to upregulate MACC1 expression, which may provide a promising molecular target for CRC treatment.

LncRNA EWSAT1 Promotes Colorectal Cancer Progression Through Sponging miR-326 to Modulate FBXL20 Expression

BACKGROUND

Ewing sarcoma-associated transcript 1 (EWSAT1) has been reported to be a pivotal modulator in a series of cancers. However, the function of EWSAT1 in colorectal cancer (CRC) has not been elaborated. This study aimed to explore the role of EWSAT1 in CRC progression and the underlying mechanisms.

METHODS

The expression patterns of EWSAT1, miR-326 and FBXL20 were examined by qCRCR. Si-EWSAT1 was transfected to study the effects of EWSAT1 on cell proliferation and metastasis. Rescue experiments were performed to investigate the underlying mechanisms in vitro. Xenograft models were used to evaluate the role of EWSAT1 in vivo.

RESULTS

We found that EWSAT1 was highly expressed in CRC tissues and cell lines and associated with poor overall survival. In vitro, knockdown of EWSAT1 suppressed the cell proliferation, migration and invasion. Moreover, miR-326 was found to be a target of EWSAT1, and miR-326 inhibitor could partially reverse the effects on CRC cell progression induced by si-EWSAT1. Subsequently, we validated FBXL20 as a vital downstream target for miR-326, and EWSAT1 positively regulated FBXL20 via miR-326 in vitro. In addition, these findings were confirmed by in vivo experiments.

CONCLUSION

Taken together, the data showed that EWSAT1 promoted CRC progression via targeting miR-326/FBXL20 pathway, which might provide a novel therapeutic target for CRC treatment.

Tumour Microenvironment: Roles of the Aryl Hydrocarbon Receptor, O-GlcNAcylation, Acetyl-CoA and Melatonergic Pathway in Regulating Dynamic Metabolic Interactions across Cell Types-Tumour Microenvironment and Metabolism

This article reviews the dynamic interactions of the tumour microenvironment, highlighting the roles of acetyl-CoA and melatonergic pathway regulation in determining the interactions between oxidative phosphorylation (OXPHOS) and glycolysis across the array of cells forming the tumour microenvironment. Many of the factors associated with tumour progression and immune resistance, such as yin yang (YY)1 and glycogen synthase kinase (GSK)3β, regulate acetyl-CoA and the melatonergic pathway, thereby having significant impacts on the dynamic interactions of the different types of cells present in the tumour microenvironment. The association of the aryl hydrocarbon receptor (AhR) with immune suppression in the tumour microenvironment may be mediated by the AhR-induced cytochrome P450 (CYP)1b1-driven 'backward' conversion of melatonin to its immediate precursor N-acetylserotonin (NAS). NAS within tumours and released from tumour microenvironment cells activates the brain-derived neurotrophic factor (BDNF) receptor, TrkB, thereby increasing the survival and proliferation of cancer stem-like cells. Acetyl-CoA is a crucial co-substrate for initiation of the melatonergic pathway, as well as co-ordinating the interactions of OXPHOS and glycolysis in all cells of the tumour microenvironment. This provides a model of the tumour microenvironment that emphasises the roles of acetyl-CoA and the melatonergic pathway in shaping the dynamic intercellular metabolic interactions of the various cells within the tumour microenvironment. The potentiation of YY1 and GSK3β by O-GlcNAcylation will drive changes in metabolism in tumours and tumour microenvironment cells in association with their regulation of the melatonergic pathway. The emphasis on metabolic interactions across cell types in the tumour microenvironment provides novel future research and treatment directions.