Regulatory effects of lncRNA ATB targeting miR-200c on proliferation and apoptosis of colorectal cancer cells

Role of non-coding RNAs as new therapeutic targets in regulating the EMT and apoptosis in metastatic gastric and colorectal cancers

Colorectal cancer (CRC) and gastric cancer (GC), are the two most common cancers of the gastrointestinal tract, and are serious health concerns worldwide. The discovery of more effective biomarkers for early diagnosis, and improved patient prognosis is important. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), can regulate cellular processes such as apoptosis and the epithelial-mesenchymal transition (EMT) leading to progression and resistance of GC and CRC tumors. Moreover these pathways (apoptosis and EMT) may serve as therapeutic targets, to prevent metastasis, and to overcome drug resistance. A subgroup of ncRNAs is common to both GC and CRC tumors, suggesting that they might be used as biomarkers or therapeutic targets. In this review, we highlight some ncRNAs that can regulate EMT and apoptosis as two opposite mechanisms in cancer progression and metastasis in GC and CRC. A better understanding of the biological role of ncRNAs could open up new avenues for the development of personalized treatment plans for GC and CRC patients.

The function of LncRNA-ATB in cancer

Cancer as a progressive and complex disease is caused by early chromosomal changes and stimulated cellular transformation. Previous studies reported that long non-coding RNAs (lncRNAs) play pivotal roles in the initiation, maintenance, and progression of cancer cells. LncRNA activated by TGF-β (ATB) has been shown to be dysregulated in different types of cancer. Aberrant expression of lncRNA-ATB plays an important role in the progression of diverse malignancies. High expression of LncRNA-ATB is associated with cancer cell growth, proliferation, metastasis, and EMT. LncRNA-ATB by targeting various signaling pathways and microRNAs (miRNAs) can trigger cancer pathogenesis. Therefore, lncRNA-ATB can be a novel target for cancer prediction and diagnosis. In this review, we will focus on the function of lncRNA-ATB in various types of human cancers.

Comprehensive landscape and future perspectives of long noncoding RNAs (lncRNAs) in colorectal cancer (CRC): Based on a bibliometric analysis

This review aimed to use bibliometric analysis to sort out, analyze and summarize the knowledge foundation and hot topics in the field of long noncoding RNAs (lncRNAs) in colorectal cancer (CRC), and point out future trends to inspire related research and innovation. We used CiteSpace to analyze publication outputs, countries, institutions, authors, journals, references, and keywords. Knowledge foundations, hotspots, and future trends were then depicted. The overall research showed the trend of biomedical-oriented multidisciplinary. Much evidence indicates that lncRNA plays the role of oncogene or tumor suppressor in the occurrence and development of CRC. Besides, many lncRNAs have multiple mechanisms. lncRNAs and metastasis of CRC, lncRNAs and drug resistance of CRC, and the clinical application of lncRNAs in CRC are current research hotspots. Through insight into the development trend of lncRNAs in CRC, this study will help researchers extract hidden valuable information for further research.

Apoptosis evasion via long non-coding RNAs in colorectal cancer

Long non-coding RNA (LncRNA) is a novel and diverse class of regulatory transcripts that are frequently dysregulated in numerous tumor types. LncRNAs are involved in a complicated molecular network, regulating gene expression, and modulating diverse cellular activities in different cancers including colorectal cancer (CRC). Evidence indicates that lncRNAs can be used as a potential biomarker for the prognosis and diagnosis of CRC as they are aberrantly expressed in CRC cells. The high expression or silencing of lncRNAs is associated with cell proliferation, invasion, metastasis, chemoresistance and apoptosis in CRC. LncRNAs exert both pro-apoptotic and anti-apoptotic functions in CRC. The expression of some oncogene lncRNAs is upregulated which leads to the inhibition of apoptotic pathways, similarly, the tumor suppressor lncRNAs are downregulated in CRC. In this review, we describe the function and mechanisms of lncRNAs to regulate the expression of genes that are involved directly or indirectly in controlling cellular apoptosis in CRC. Furthermore, we also discussed the different apoptotic pathways in normal cells and the mechanisms by which CRC evade apoptosis.

The role of miR-200 family in the regulation of hallmarks of cancer

MiRNAs are short non-coding RNAs that regulate gene expression post-transcriptionally contributing to the development of different diseases including cancer. The miR-200 family consists of five members, miR-200a, miR-200b, miR-200c, miR-141, and miR-429. Their expression is dysregulated in cancer tissue and their level is altered in the body fluids of cancer patients. Moreover, the levels of miR-200 family members correlate with clinical parameters such as cancer patients' survival which makes them potentially useful as diagnostic and prognostic biomarkers. MiRNAs can act as either oncomiRs or tumor suppressor miRNAs depending on the target genes and their role in the regulation of key oncogenic signaling pathways. In most types of cancer, the miR-200 family acts as tumor suppressor miRNA and regulates all features of cancer. In this review, we summarized the expression pattern of the miR-200 family in different types of cancer and their potential utility as biomarkers. Moreover, we comprehensively described the role of miR-200 family members in the regulation of all hallmarks of cancer proposed by Hanahan and Weinberg with the focus on the epithelial-mesenchymal transition, invasiveness, and metastasis of tumor cells.

LncRNA-ENST00000543604 exerts a tumor-promoting effect via miRNA 564/AEG-1 or ZNF326/EMT and predicts the prognosis of and chemotherapeutic effect in colorectal cancer

Objectives

Colorectal cancer(CRC) is a common malignant tumor. Recent studies have found that lncRNAs play an important role in the occurrence and development of colorectal cancer.

Methods

Based on high-throughput sequencing results of fresh CRC tissues and adjacent tissues, we identified lncRNA-ENST00000543604 (lncRNA 604) as the research object by qRT-PCR in CRC tissues and cells. We explored the mechanism of lncRNA 604 action by using luciferin reporter, qRT-PCR and Western blot assays. Kaplan-Meier survival analysis and a Cox regression model were used to analyze the correlation of lncRNA 604 and its regulatory molecules with the prognosis of and chemotherapy efficacy in CRC patients.

Results

In this study, we found that the expression levels of lncRNA 604 were increased in CRC. LncRNA 604 could promote CRC cell proliferation and metastasis through the miRNA 564/AEG-1 or ZNF326/EMT signaling axis in vivo and in vitro. LncRNA 604 could predict the prognosis of CRC and was an independent negative factor. LncRNA 604 exerted a synergistic effect with miRNA 564 or ZNF326 on the prognosis of CRC. LncRNA 604 could improve chemoresistance by increasing the expression of AEG-1, NF-κB, and ERCC1.

Conclusions

Our study demonstrated that lncRNA 604 could promote the progression of CRC via the lncRNA 604/miRNA 564/AEG-1/EMT or lncRNA 604/ZNF326/EMT signaling axis. LncRNA 604 could improve chemoresistance by increasing drug resistance protein expression.

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.

MicroRNAs and 'Sponging' Competitive Endogenous RNAs Dysregulated in Colorectal Cancer: Potential as Noninvasive Biomarkers and Therapeutic Targets

The gastrointestinal (GI) tract in mammals is comprised of dozens of cell types with varied functions, structures, and histological locations that respond in a myriad of ways to epigenetic and genetic factors, environmental cues, diet, and microbiota. The homeostatic functioning of these cells contained within this complex organ system has been shown to be highly regulated by the effect of microRNAs (miRNA). Multiple efforts have uncovered that these miRNAs are often tightly influential in either the suppression or overexpression of inflammatory, apoptotic, and differentiation-related genes and proteins in a variety of cell types in colorectal cancer (CRC). The early detection of CRC and other GI cancers can be difficult, attributable to the invasive nature of prophylactic colonoscopies. Additionally, the levels of miRNAs associated with CRC in biofluids can be contradictory and, therefore, must be considered in the context of other inhibiting competitive endogenous RNAs (ceRNA) such as lncRNAs and circRNAs. There is now a high demand for disease treatments and noninvasive screenings such as testing for bloodborne or fecal miRNAs and their inhibitors/targets. The breadth of this review encompasses current literature on well-established CRC-related miRNAs and the possibilities for their use as biomarkers in the diagnoses of this potentially fatal GI cancer.

A diagnostic and prognostic value of blood-based circulating long non-coding RNAs in Thyroid, Pancreatic and Ovarian Cancer

Several studies have demonstrated the potential of circulating long non-coding RNAs (lncRNAs) as promising cancer biomarkers. Herein, we addressed the regulatory role of circulating lncRNAs and their potential value as diagnostic/prognostic markers for thyroid, pancreatic and ovarian cancers. Furthermore, we analyzed and measured the clinical implications and association of lncRNAs with sensitivity, specificity, and area under the ROC curve (AUC). Based on our meta-analysis, we found that GAS8-AS1 could discriminate thyroid cancer from non-cancer and other cancers with higher accuracy (AUC = 0.746; sensitivity = 61.70%, and specificity = 90.00%). Similarly, for ovarian cancer, lncRNA RP5-837J1.2 was found to have ideal diagnostic potential with critical clinical specifications of AUC = 0.996; sensitivity = 97.30% and specificity = 94.60%. Whereas we could not find any lncRNA having high diagnostic/prognostic efficiency in pancreatic cancer. We believe that lncRNAs mentioned above may explore clinical settings for the diagnosis and prognosis of cancer patients.

Differential Expression of Decorin in Metastasising Colorectal Carcinoma Is Regulated by miR-200c and Long Non-Coding RNAs

Decorin (DCN) is one of the matricellular proteins that participate in normal cells’ function as well as in cancerogenesis. While its expression in primary tumours is well known, there is limited data about its expression in metastases. Furthermore, the post-transcriptional regulation of DCN is still questionable, although it is well accepted that it is an important mechanism of developing metastatic cancer. The aim of our study was to analyse the expression of DCN and its potential regulatory ncRNAs in metastatic colorectal carcinoma (CRC). Nineteen patients with metastatic CRC were included. Using qPCR, we analysed the expression of DCN, miR-200c and five lncRNAs (LUCAT1, MALAT1, lncTCF7, XIST, and ZFAS1) in lymph node and liver metastases in comparison to the invasive front and central part of a primary tumour. Our results showed insignificant upregulation of DCN and significant upregulation for miR-200c, MALAT1, lncTCF7 and ZFAS1 in metastases compared to the primary tumour. miR-200c showed a positive correlation with DCN, and the aforementioned lncRNAs exhibited a significant positive correlation with miR-200c expression in metastatic CRC. Our results suggest that DCN as well as miR-200c, MALAT1, lncTCF7 and ZFAS1 contribute to the development of metastases in CRC and that regulation of DCN expression in CRC by ncRNAs is accomplished in an indirect manner.

MicroRNAs regulating SOX2 in cancer progression and therapy response

The proliferation, metastasis and therapy response of tumour cells are tightly regulated by interaction among various signalling networks. The microRNAs (miRNAs) can bind to 3'-UTR of mRNA and down-regulate expression of target gene. The miRNAs target various molecular pathways in regulating biological events such as apoptosis, differentiation, angiogenesis and migration. The aberrant expression of miRNAs occurs in cancers and they have both tumour-suppressor and tumour-promoting functions. On the contrary, SOX proteins are capable of binding to DNA and regulating gene expression. SOX2 is a well-known member of SOX family that its overexpression in different cancers to ensure progression and stemness. The present review focuses on modulatory impact of miRNAs on SOX2 in affecting growth, migration and therapy response of cancers. The lncRNAs and circRNAs can function as upstream mediators of miRNA/SOX2 axis in cancers. In addition, NF-κB, TNF-α and SOX17 are among other molecular pathways regulating miRNA/SOX2 axis in cancer. Noteworthy, anti-cancer compounds including bufalin and ovatodiolide are suggested to regulate miRNA/SOX2 axis in cancers. The translation of current findings to clinical course can pave the way to effective treatment of cancer patients and improve their prognosis.

A scoping review on the potentiality of PD-L1-inhibiting microRNAs in treating colorectal cancer: Toward single-cell sequencing-guided biocompatible-based delivery

Tumoral programmed cell death ligand 1 (PD-L1) has been implicated in the immune evasion and development of colorectal cancer. Although monoclonal immune checkpoint inhibitors can exclusively improve the prognosis of patients with microsatellite instability-high (MSI-H) and tumor mutational burden-high (TMB-H) colorectal cancer, specific tumor-suppressive microRNAs (miRs) can regulate multiple oncogenic pathways and inhibit the de novo expression of oncoproteins, like PD-L1, both in microsatellite stable (MSS) and MSI-H colorectal cancer cells. This scoping review aimed to discuss the currently available evidence regarding the therapeutic potentiality of PD-L1-inhibiting miRs for colorectal cancer. For this purpose, the Web of Science, Scopus, and PubMed databases were systematically searched to obtain peer-reviewed studies published before 17 March 2021. We have found that miR-191-5p, miR-382-3p, miR-148a-3p, miR-93-5p, miR-200a-3p, miR-200c-3p, miR-138-5p, miR-140-3p, and miR-15b-5p can inhibit tumoral PD-L1 in colorectal cancer cells. Besides inhibiting PD-L1, miR-140-3p, miR-382-3p, miR-148a-3p, miR-93-5p, miR-200a-3p, miR-200c-3p, miR-138-5p, and miR-15b-5p can substantially reduce tumor migration, inhibit tumor development, stimulate anti-tumoral immune responses, decrease tumor viability, and enhance the chemosensitivity of colorectal cancer cells regardless of the microsatellite state. Concerning the specific, effective, and safe delivery of these miRs, the single-cell sequencing-guided biocompatible-based delivery of these miRs can increase the specificity of miR delivery, decrease the toxicity of traditional nanoparticles, transform the immunosuppressive tumor microenvironment into the proinflammatory one, suppress tumor development, decrease tumor migration, and enhance the chemosensitivity of tumoral cells regardless of the microsatellite state.

lncRNA MALAT1/miR‑26a/26b/ST8SIA4 axis mediates cell invasion and migration in breast cancer cell lines

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a long non-coding RNA that is overexpressed in various human cancers, including breast cancer. Evidence has associated the function of the α-2,8-sialyltransferase (ST8SIA) family with breast cancer. The present study aimed to investigate the potential roles of MALAT1 in breast cancer development and progression using analyses of both breast cancer tissues and cell lines. The mRNA levels of MALAT1, microRNA (miR)-26a/26b and ST8SIA4 were detected by reverse transcription-quantitative PCR (RT-qPCR) and the protein level of ST8SIA4 was assessed by western blot analysis. Cell proliferation, invasion and migration were detected by CCK-8, wound healing and Transwell assays, respectively. Interactions between MALAT1 and miR-26a/26b were assessed using fluorescence in situ hybridization, RNA immunoprecipitation and luciferase reporter assays. Herein, different levels of MALAT1 were primarily observed in human breast cancer samples and cells. Upregulated MALAT1 was a crucial predictor of poor breast cancer prognosis. Altered MALAT1 modulated cell progression in breast cancer. Moreover, miR-26a/26b was confirmed as a direct regulator of MALAT1, and ST8SIA4 was predicted as a target of miR-26a/26b. Functional analysis in human breast cancer cell lines demonstrated that MALAT1 modulated breast cancer cell tumorigenicity by acting as a competing endogenous lncRNA (ceRNA) to regulate ST8SIA4 levels by sponging miR-26a/26b. The identification of the MALAT1/miR-26a/26b/ST8SIA4 axis which contributes to breast cancer progression may constitute a potential new therapeutic target.

miRNA Clusters with Up-Regulated Expression in Colorectal Cancer

Simple Summary

As miRNAs show the capacity to be used as CRC biomarkers, we analysed experimentally validated data about frequently up-regulated miRNA clusters in CRC tissue. We identified 15 clusters that showed increased expression in CRC: miR-106a/363, miR-106b/93/25, miR-17/92a-1, miR-181a-1/181b-1, miR-181a-2/181b-2, miR-181c/181d, miR-183/96/182, miR-191/425, miR-200c/141, miR-203a/203b, miR-222/221, mir-23a/27a/24-2, mir-29b-1/29a, mir-301b/130b and mir-452/224. Cluster positions in the genome are intronic or intergenic. Most clusters are regulated by several transcription factors, and by long non-coding RNAs. In some cases, co-expression of miRNA with other cluster members or host gene has been proven. miRNA expression patterns in cancer tissue, blood and faeces were compared. The members of the selected clusters target 181 genes. Their functions and corresponding pathways were revealed with the use of Panther analysis. Clusters miR-17/92a-1, miR-106a/363, miR-106b/93/25 and miR-183/96/182 showed the strongest association with metastasis occurrence and poor patient survival, implicating them as the most promising targets of translational research.

Abstract

Colorectal cancer (CRC) is one of the most common malignancies in Europe and North America. Early diagnosis is a key feature of efficient CRC treatment. As miRNAs can be used as CRC biomarkers, the aim of the present study was to analyse experimentally validated data on frequently up-regulated miRNA clusters in CRC tissue and investigate their members with respect to clinicopathological characteristics of patients. Based on available data, 15 up-regulated clusters, miR-106a/363, miR-106b/93/25, miR-17/92a-1, miR-181a-1/181b-1, miR-181a-2/181b-2, miR-181c/181d, miR-183/96/182, miR-191/425, miR-200c/141, miR-203a/203b, miR-222/221, mir-23a/27a/24-2, mir-29b-1/29a, mir-301b/130b and mir-452/224, were selected. The positions of such clusters in the genome can be intronic or intergenic. Most clusters are regulated by several transcription factors, and miRNAs are also sponged by specific long non-coding RNAs. In some cases, co-expression of miRNA with other cluster members or host gene has been proven. miRNA expression patterns in cancer tissue, blood and faeces were compared. Based on experimental evidence, 181 target genes of selected clusters were identified. Panther analysis was used to reveal the functions of the target genes and their corresponding pathways. Clusters miR-17/92a-1, miR-106a/363, miR-106b/93/25 and miR-183/96/182 showed the strongest association with metastasis occurrence and poor patient survival, implicating them as the most promising targets of translational research.

Mitomycin C Inhibits Esophageal Fibrosis by Regulating Cell Apoptosis and Autophagy via lncRNA-ATB and miR-200b

Benign esophageal strictures (BESs) frequently results from esophageal fibrosis. The transformation of fibroblasts into fibrocyte is an important cause of fibrosis. The treatment of fibrosis is challenging. Some previous studies have indicated the antifibrotic effect of mitomycin C (MMC). However, the mechanism of action of MMC and its optimal dose for treatment remains unclear. In the present study, the role of MMC in fighting fibrosis and its mechanism was investigated. Human esophageal fibroblast cells (HEFs)were treated without or with MMC, at 2, 5, 10 μg/ml, combining with mimic lncRNA-ATB, miR-200b inhibitor, rapamycin (RAPA), and 3-Methyladenine (3-MA). The cell viability, and cell apoptosis were evaluated. In addition, expression of apoptosis related proteins (caspase8 and caspase3), autophagy related proteins (LC3II and ATG5) and fibrosis related proteins (α-SMA collagen-1 and TGF-β) were also evaluated. Furthermore, autophagosome was observed by transmission electron microscope. Results showed that the expression of lncRNA-ATB was down-regulated and miR-200b was up-regulated after treated with MMC. And MMC induced cell apoptosis and inhibited cell autophagy. On the other hand, RAPA, mimic lncRNA-ATB and miR-200b inhibitor reduced fibrogenic effect of MMC on HEFs. Collectively, this study suggests that MMC inhibited esophageal fibrosis by regulating cell apoptosis and autophagy via downregulating lncRNA-ATB and upregulating miR-200b.

miRNA-200a Regulating Proliferation, Migration, and Infiltration of Tongue Squamous Cell Carcinoma Cells by Targeting DEK Proto-Oncogene

Tongue squamous cell carcinoma (TSCC) is the most frequently occurring oral cancer and is characterized by high proliferation and metastasis rates. Incomplete understanding of the pathogenesis of TSCC coupled with frequent tongue movement increases the difficulty of therapy. Additionally, TSCC is prone to recurrence and metastasis after treatment. Thus, exploring mechanisms of proliferation, migration, and infiltration of TSCC cancer cells is essential for reducing morbidity and mortality. Transfection of miRNA-200a mimics into SCC15 cells showed that miRNA-200a expression decreased significantly, and DEK expression significantly increased. Transfection of miRNA-200a mimics (miRNA-200a group), negative control mimics (miRNA-NC group), empty vector (miRNA-200a + pcDNA3.1 group), and miRNA-200a mimics and DEK overexpression vector (miRNA-200a + DEK group) into SCC15 cells respectively indicates that overexpression of miRNA-200a substantially inhibits SCC15 cell proliferation, infiltration and migration, decreases PCNA and Vimentin expression, and promotes E-cadherin expression. miRNA-200a + DEK transfection induced greater cell proliferation, infiltration and migration, much higher PCNA and Vimentin expression, and significantly lower E-cadherin expression. Luciferase reporter gene detection of overexpressed DEK or DEK expression after inhibiting miRNA-200a expression indicated a targeting association between miRNA-200a and DEK. miRNA-200a inhibits proliferation, infiltration and migration ability of TSCC by targeting DEK and may represent a novel means for clinical intervention in TSCC. miRNA-200a inhibits proliferation, invasion, and migration of TSCC by targeting DEK.

MiR-200c/FUT4 axis prevents the proliferation of colon cancer cells by downregulating the Wnt/β-catenin pathway

BACKGROUND

MicroRNA (miR)-200c has been widely reported to be involved in colon cancer progress. However, the mechanisms of miR-200c in regulating tumor metastasis and growth remain to be fully elucidated. This study aimed to investigate the mechanism of miR-200c targets fucosyltransferase 4 (FUT4) on the proliferation of colon cancer.

METHODS

The miR-200c and FUT4 mRNA levels in LoVo and SW480 cells were measured by real-time quantitative polymerase chain reaction. Further, miR-200c mimic, FUT4 siRNA and FUT4 mimic were transfected into cells, separately. Cell counting kit-8, plate colony formation and transwell assays were used to analyse the cells biological behaviour.. Immunofluorescence was used to analyse the Ki-67 expression Moreover, the Wnt/β-catenin pathway-related proteins were detected by western blots. A double luciferase experiment was performed to confirm the relationship between miR-200c and FUT4. In vivo, tumour growth and Wnt/β-catenin pathway-related proteins were also analysed.

RESULTS

In vitro, the expression of miR-200c and FUT4 were negatively correlated in LoVo and SW480 cells (correlation coefficients were - 0.9046 and - 0.9236, respectively). MiR-200c overexpression inhibited the proliferation, migration and invasion of LoVo and SW480 cells by downregulating FUT4. The Ki67-positive cells and Wnt/β-catenin signalling pathway-related proteins were reduced in the miR-200c overexpression and FUT4 silencing groups. A dual luciferase reporting system identified FUT4 as the target of miR-200c. The results in vivo were further confirmed the foundation of cells study.

CONCLUSIONS

In summary, miR-200c overexpression inhibits proliferation of colon cancer targeting FUT4 to downregulate the Wnt/β-catenin pathway, which promises molecular targets to inhibit metastasis for colon cancer therapy.

Long noncoding RNA ATB promotes ovarian cancer tumorigenesis by mediating histone H3 lysine 27 trimethylation through binding to EZH2

Ovarian cancer (OC) remains one of the most lethal gynecological malignancies. The unfavourable prognosis is mainly due to the lack of early‐stage diagnosis, drug resistance and recurrence. Therefore, it needs to investigate the mechanism of OC tumorigenesis and identify effective biomarkers for the clinical diagnosis. It is reported that long noncoding RNAs (lncRNAs) play important roles during the tumorigenesis of OC. Therefore, the present study aimed to study the role and clinical significance of LncRNAs ATB (lnc‐ATB) in the development and progression of OC. In our research, lnc‐ATB expression in OC tissues was elevated compared with adjacent normal tissues and high expression of lnc‐ATB was associated with poor outcomes of OC patients. The silencing of lnc‐ATB blocked cell proliferation, invasion and migration in SKOV3 and A2780 cells. RNA immunoprecipitation and RNA pull‐down results showed that lnc‐ATB positively regulated the expression of EZH2 via directly interacting with EZH2. Besides, the overexpression of EZH2 partly rescued lnc‐ATB silencing‐inducing inhibition of cell proliferation, invasion and migration. Chromatin immunoprecipitation assay results demonstrated that the silencing of lnc‐ATB reduced the occupancy of caudal‐related homeobox protein 1, Forkhead box C1, Large tumour suppressor kinase 2, cadherin‐1 and disabled homolog 2 interacting protein promoters on EZH2 and H3K27me3. These data revealed the oncogenic of lnc‐ATB and provided a novel biomarker for OC diagnosis. Furthermore, these findings indicated the mechanism of lnc‐ATB functioning in the progression of OC, which provided a new target for OC therapy.

Long non-coding RNA ATB is associated with metastases and promotes cell invasion in colorectal cancer via sponging miR-141-3p

Long non-coding RNAs (lncRNAs) serve crucial roles in cancer development and progression. lncRNA-activated by transforming growth factor-β (lncRNA-ATB) mediates cell proliferation. However, the association between lncRNA-ATB and human colorectal cancer (CRC) is not completely understood. Therefore, the present study aimed to investigate the role of lncRNA-ATB in CRC, as well as the underlying mechanism. 50 pairs of tumor tissues and adjacent normal tissues from patients with primary CRC were collected. The expression of lncRNA-ATB and microRNA (miR)-141-3p in CRC tissues, adjacent normal tissues and cell lines was detected using reverse transcription-quantitative PCR. CCK-8, colony formation, Transwell, western blot, dual luciferase reporter gene, RNA immunoprecipitation and immunohistochemistry staining assays were conducted to assess the biological function of lncRNA-ATB and miR-141-3p in CRC progression. lncRNA-ATB was upregulated in CRC tissues and cell lines compared with healthy tissues and cells, respectively. Moreover, high expression of lncRNA-ATB was significantly associated with advanced TNM stage and metastasis in CRC. In addition, the results indicated that lncRNA-ATB expression predicted the prognosis and overall survival of patients with CRC. Compared with small interfering RNA-negative control, lncRNA-ATB knockdown inhibited CRC cell proliferation, migration and invasion, whereas, compared with vector, lncRNA-ATB overexpression promoted CRC cell proliferation, migration and invasion. Furthermore, the in vivo experiment suggested that lncRNA-ATB knockdown inhibited tumor growth. The results also indicated that lncRNA-ATB may contribute to CRC progression via binding to tumor suppressor microRNA-141-3p. Collectively, the present study suggested a crucial role of lncRNA-ATB in CRC tumorigenesis, suggesting that lncRNA-ATB may serve as an important marker for the diagnosis and development of CRC.

Mechanisms of long non-coding RNA function in colorectal cancer tumorigenesis

Colorectal cancer (CRC) is one of the most common cancers globally. Although a variety of CRC screening methods have been developed, many patients are diagnosed at advanced stages of CRC with tumor invasion and distance metastasis. Several studies have suggested the long noncoding RNAs (lncRNAs) as one of the main contributors in CRC tumorigenesis, although the exact underlying mechanism of lncRNAs in CRC is still unknown. Numerous studies have indicated aberrant expression of lncRNAs in CRC through different modes of action such as cell proliferation, apoptosis, cell cycle, DNA repair response, drug-resistance, migration, and metastasis. Furthermore, lncRNA polymorphisms can influence the risk of CRC development. Accordingly, lncRNAs can be served as promising diagnostic or prognostic biomarkers and also desired therapeutic targets affecting the outcome of patients with CRC. In this review, we summarized the updated and novel evidence that identifies different roles of lncRNAs in the tumorigenesis of CRC.

Long noncoding RNA HCG18 up-regulates the expression of WIPF1 and YAP/TAZ by inhibiting miR-141-3p in gastric cancer

Background

Accumulating works show that lncRNAs play critical roles in the development of gastric cancer (GC). LncRNA HLA complex group 18 (HCG18) was implicated in the progression of bladder cancer and glioma, but its role in GC is unknown.

Methods

RT‐PCR was used to detect HCG18 and miR‐141‐3p expression in GC specimen. GC cell lines (AGS and MKN‐28) were exploited as cell model. The biological effect of HCG18 on cancer cells was probed by CCK‐8, colony formation, flow cytometry, Transwell and wound‐healing experiments in vitro, and subcutaneous xenotransplanted tumor model and tail vein injection model in vivo. Interaction between HCG18 and miR‐141‐3p was determined by bioinformatics analysis, RT‐PCR, and luciferase reporter experiments. Downstream gene expression of miR‐141‐3p, including Wiskott–Aldrich syndrome protein interacting protein family member 1 (WIPF1), Yes associated protein 1 (YAP), and tafazzin (TAZ) were detected using Western blot.

Results

HCG18 was markedly up‐regulated in GC specimens, while miR‐141‐3p was markedly down‐regulated. Down‐regulation of HCG18 inhibited viability, migration, and invasion of GC cells, while miR‐141‐3p transfection led to opposite effect. HCG18 could down‐regulate miR‐141‐3p through adsorbing it, and a negative association between HCG18 and miR‐141‐3p was found in GC specimens. HCG18 promoted WIPF1, YAP and TAZ expression, nonetheless, such influence was reversed by co‐transfecting with miR‐141‐3p.

Conclusion

HCG18 was aberrantly up‐regulated in GC tissues, and it indirectly regulated the activity of Hippo signaling through counteracting miR‐141‐3p expression.

LncRNA ENST00000563492 promoting the osteogenesis-angiogenesis coupling process in bone mesenchymal stem cells (BMSCs) by functions as a ceRNA for miR-205-5p

Pain, physical dysfunction, and mental disorders caused by bone nonunion bring great burden to patients. Bone mesenchymal stem cells (BMSCs) isolated from bone nonunion patients with poor proliferation and osteogenic ability are compared with that from normal bone-healing patients. Long noncoding RNAs (lncRNAs) are a class of RNAs that are more than 200 nucleotides in length, lack an open-reading frame encoding a protein, and have little or no protein-coding function, and could regulate gene expression, which is involved in the regulation of important life activities, such as growth, development, aging, and death at epigenetic, transcriptional, and post-transcriptional levels. In this study, we intended to investigate the difference of lncRNA expression between patients with nonunion and normal fracture healing. Our result found that lncRNA ENST00000563492 was downregulated in bone nonunion tissues. LncRNA ENST00000563492 promotes osteogenic differentiation of BMSCs through upregulating the expression of CDH11. On the other hand, LncRNA ENST0000563492 could improve the osteogenesis–angiogenesis coupling process through enhancing the expression of VEGF during osteogenic differentiation of BMSCs. LncRNA ENST00000563492 functions as a ceRNA for miR-205-5p that was targeting CDH11 and VEGF. LncRNA ENST00000563492 could promote the osteogenesis of BMSCs in vivo. Our result indicated that lncRNA ENST00000563492 may be a new target for bone nonunion.

Prognostic value of long non-coding RNA ATB in digestive system cancers: A meta-analysis

BACKGROUND

The present meta-analysis has evaluated the association between lncRNA ATB, prognosis and clinicopathological parameters in patients with digestive cancers.

METHODS

Eligible studies were gathered from Web of Science, PubMed, Embase, Cochrane Library, WanFang databases and China National Knowledge Infrastructure (up to October 15, 2019). Hazard ratios (HRs) and 95 % confidence intervals (CIs) were calculated to estimate the prognosis and clinicopathological parameters of lncRNA ATB in patients with digestive cancers.

RESULT

We divided this study into two groups, pancreatic cancer (PC, downregulation) and non-pancreatic cancer (non-PC, upregulation). In the non-PC group, high expression levels of lncRNA ATB were significantly related to poor OS (pooled HR = 2.19, 95 % CI 1.68-2.85, P＜0.00001). In contrast, increased levels of lncRNA ATB in pancreatic cancer tissue were favorable factors in OS (HR = 0.47, 95 % CI 0.32-0.69, P = 0.0001). The pooled data suggested that high expression levels of lncRNA ATB predicted a poor DFS in CRC and a poor RFS in HCC. Increased expression of lncRNA ATB was correlated with negative lymph node metastasis and TNM stage in the non-PC group. In contrast, lncRNA ATB were favorable factors for LNM and TNM stages in pancreatic cancer.

CONCLUSION

LncRNA ATBs, whether cancer promoters or suppressors, were potential biomarkers and therapeutic targets for digestive system cancers.

LncRNA-ATB in cancers: what do we know so far?

Cancer-related deaths did not apparently decrease in the past decades despite aggressive treatments. It's reported that cancer will become the leading cause of death worldwide in the twenty-first century. Increasing evidence has revealed that lncRNAs will emerge as promising cancer biomarkers or therapeutic targets in cancer treatment. LncRNA-ATB, a long noncoding RNA activated by TGF-β, was found to be abnormally expressed in certain cancers and participate in the development and progression of tumors. In addition, aberrant lncRNA-ATB expression was also associated with clinical characteristics of tumors. The purpose of this review is to summarize functions and underlying mechanisms of lncRNA-ATB in tumors, and discuss whether lncRNA-ATB can be a biomarker and therapeutic target in cancers.

lncRNA-ATB promotes stemness maintenance in colorectal cancer by regulating transcriptional activity of the β-catenin pathway

Long non-coding RNA activated by transforming growth factor-β (ATB) was recently reported to be involved in a wide range of physiological and pathological processes. However, the role of ATB in colorectal cancer (CRC) stemness remains unclear. In the present study, the functional role of ATB in maintaining stemness of CRC was determined using colony formation and sphere formation assays, and xenograft models. Reverse transcription-quantitative PCR, western blotting and immunohistochemistry were performed to investigate the mechanisms underlying the effects of ATB. Knockdown of ATB impaired colony formation and sphere formation in CRC cells, accompanied by an inhibition of colon tumor growth. Further results suggested that ATB regulated the transcriptional activity of the β-catenin pathway by inhibiting β-catenin expression. In addition, the results confirmed the role of β-catenin in ATB-mediated regulation of stemness in CRC. Collectively, the results indicated that ATB is a promising therapeutic target for CRC.

LncRNA-ATB Promotes the Tumorigenesis of Ovarian Cancer via Targeting miR-204-3p

Background

Ovarian cancer ranks fifth among the most prevalent cancer type in females all over the world. It is the second most frequent malignant tumor which accounts for 3% of cancer in females. Therefore, to explore the mechanism of carcinogenesis in ovarian cancer is important to develop new treatment methods. It has been previously found that lncRNA-ATB could promote the tumorigenesis of malignant tumors. However, the role of lncRNA-ATB during the progression of ovarian cancer remains unclear.

Methods

Gene expressions in tissues or cells were detected by using qRT-PCR. Western blot was performed to investigate the protein expressions in ovarian cancer cells. Cell apoptosis was tested by flow cytometry. Moreover, the correction between lncRNA-ATB and miR-204-3p was examined by Dual-luciferase reporter assay and RNA pulldown. Cell proliferation and invasion were detected by CCK-8, Ki-67 staining and transwell assay, respectively. Finally, xenograft mice model was established to confirm the result of in vitro experiments.

Results

LncRNA-ATB silencing significantly inhibited the proliferation and induced apoptosis of ovarian cancer cells. In addition, luciferase activity suggested that lncRNA-ATB negatively regulated miR-204-3p in ovarian cancer. Besides, Nidogen 1 (NID1) was the direct target of miR-204-3p. Overexpression of NID1 could notably reverse the inhibitory effect of lncRNA-ATB knockdown on the progression of ovarian cancer. Finally, lncRNA-ATB silencing notably attenuated the severity of ovarian cancer in vivo.

Conclusion

Downregulation of lncRNA-ATB significantly inhibited the tumorigenesis of ovarian cancer in vitro and in vivo, which may serve as a potential novel target for the treatment of ovarian cancer.

LOXL1-AS1 Drives The Progression Of Gastric Cancer Via Regulating miR-142-5p/PIK3CA Axis

Background

Gastric cancer (GC) is a deadly disease, and its incidence is especially high in East Asia including China. Recently, some long non-coding RNA (lncRNAs) have been identified as oncogenes or tumor suppressors. This study aimed to determine the function and mechanism of lncRNA LOXL1-AS1 on the progression of GC.

Methods

RT-PCR was done to measure the expression levels of LOXL1-AS1 and miR-142-5p in GC tissues. The association between pathological indexes and LOXL1-AS1 expression was also analyzed. Human GC cell lines AGS and BGC823 were used as cell models. CCK-8 and colony formation assays were conducted to assess the effect of LOXL1-AS1 on the proliferation of GC cell lines. Transwell assay was conducted to determine the influence of LOXL1-AS1 on cell migration and invasion. Furthermore, luciferase reporter assay was carried out to confirm the relationship of miR-142-5p with LOXL1-AS1. Additionally, Western blot was done to detect the regulatory function of LOXL1-AS1 on PIK3CA, a target of miR-142-5p. In vivo experiment was also performed to validate the roles and mechanism of LOXL1-AS1 on the growth and metastasis of GC cells.

Results

LOXL1-AS1 expression in GC samples was significantly increased, which was correlated with unfavorable pathological indexes. Highly expressed LOXL1-AS1 was closely linked to shorter overall survival time and post-progression survival time of the patients. LOXL1-AS1 markedly modulated the malignant phenotypes of GC cells. Additionally, overexpressed LOXL1-AS1 notably reduced the expression of miR-142-5p, but enhanced the expression level of PIK3CA. In vivo experiments further validated that knockdown of LOXL1-AS1 inhibited the growth and metastasis of GC cells via regulating miR-142-5p and PIK3CA.

Conclusion

LOXL1-AS1 was a sponge of tumor suppressor miR-142-5p in GC, enhanced the expression of PIK3CA indirectly and functioned as an oncogenic lncRNA.

Significance of expression of lncRNA-ATB in serum of patients with cholestatic liver disease

BACKGROUND

Cholestatic liver disease (CSLD) refers to a collection of liver diseases that can cause cholestasis. The etiology of CSLD is complex, the pathogenesis needs to be elucidated, and there is still a lack of effective treatment. Over the past decade, there has been a deep understanding of many aspects of CSLD, which provides more effective means for its accurate diagnosis and treatment. However, many problems are still pending, and further research is urgently needed.

AIM

To observe the difference of serum lncRNA-ATB levels between patients with intrahepatic cholestasis and normal people, and to explore the correlation between the changes of serum lncRNA-ATB and disease condition and prognosis in patients with intrahepatic cholestasis.

METHODS

Seventy-five patients with intrahepatic cholestasis of different etiologies and 30 healthy controls were included. The expression of lncRNA-ATB in serum samples of the above subjects was detected by qRT-PCR. The levels of lncRNA-ATB between normal controls and patients with cholestasis and between patients with different degrees of cholestasis were analyzed. Linear correlation analysis was used to analyze the correlation between the changes of lncRNA-ATB and clinical biochemical indicators, and receiver operating characteristic curve analysis was performed to analyze the clinical significance of the changes of lncRNA-ATB in judging the condition of intrahepatic cholestasis.

RESULTS

Compared with the healthy control group, lncRNA-ATB increased significantly in the serum of patients with intrahepatic cholestasis (P < 0.05). There was no significant difference in the expression of lncRNA-ATB between patients with cholestatic liver disease caused by different etiologies and and between patients with different courses of cholestasis (P > 0.05). Serum lncRNA-ATB decreased with the aggravation of cholestasis (P < 0.001). There was a negative correlation between lncRNA-ATB and total bile acid (r = -0.627, P < 0.001). The area under the curve of lncRNA-ATB in the diagnosis of cholestasis liver disease was 0.856 (95%CI: 0.809-0.904, P < 0.001), with a sensitivity of 81.42% and specificity of 73.45%.

CONCLUSION

The level of lncRNA-ATB in serum of patients with intrahepatic cholestasis liver disease is significantly increased, and it decreases with the aggravation of cholestasis. The expression level of LncRNA-ATB is expected to be a biomarker for judging the condition and prognosis of patients with intrahepatic cholestasis.