Long non-coding RNA TP73-AS1 sponges miR-194 to promote colorectal cancer cell proliferation, migration and invasion via up-regulating TGFα

Competitive endogenous RNA networks: Decoding the role of long non-coding RNAs and circular RNAs in colorectal cancer chemoresistance

Colorectal cancer (CRC) is recognized as one of the most common gastrointestinal malignancies across the globe. Despite significant progress in designing novel treatments for CRC, there is a pressing need for more effective therapeutic approaches. Unfortunately, many patients undergoing chemotherapy develop drug resistance, posing a significant challenge for cancer treatment. Non-coding RNAs (ncRNAs) have been found to play crucial roles in CRC development and its response to chemotherapy. However, there are still gaps in our understanding of interactions among various ncRNAs, such as long non-coding RNAs (lncRNAs), circular RNAs (circRNAs) and microRNAs (miRNAs). These ncRNAs can act as either oncogenes or tumour suppressors, affecting numerous biological functions in different cancers including CRC. A class of ncRNA molecules known as competitive endogenous RNAs (ceRNAs) has emerged as a key player in various cellular processes. These molecules form networks through lncRNA/miRNA/mRNA and circRNA/miRNA/mRNA interactions. In CRC, dysregulation of ceRNA networks has been observed across various cellular processes, including proliferation, apoptosis and angiogenesis. These dysregulations are believed to play a significant role in the progression of CRC and, in certain instances, may contribute to the development of chemoresistance. Enriching our knowledge of these dysregulations holds promise for advancing the field of diagnostic and therapeutic modalities for CRC. In this review, we discuss lncRNA- and circRNA-associated ceRNA networks implicated in the emergence and advancement of drug resistance in colorectal carcinogenesis.

TP73-AS1 rs3737589 Polymorphism is Associated With the Clinical Stage of Colorectal Cancer

OBJECTIVE

TP73-AS1 can promote the occurrence and development of a variety of tumors, including colorectal cancer (CRC). The current study aimed to investigate the association between a potentially functional genetic polymorphism (rs3737589 T > C) on the TP73-AS1 gene and the susceptibility and clinical stage of CRC in a Chinese Han population.

METHODS

The polymorphic genotyping was performed by the SNaPshot method. The real-time quantitative PCR method and the luciferase assay were used separately to explore genotype-tissue expression and the function of the genetic polymorphism.

RESULTS

A total of 576 CRC patients and 896 healthy controls were included in the current study. The rs3737589 polymorphism was not associated with CRC susceptibility but was associated with the CRC stage (CC vs. TT: OR = 0.25, 95% CI = 0.12 - 0.54, P=0.0003; C vs. T: OR = 0.69, 95% CI = 0.53-0.89, P=0.006; and CC vs. (TC + TT): OR = 0.26, 95% CI = 0.12-0.56, P=0.0004). CRC patients carrying the rs3737589 CC genotype or C allele were less likely to have stage III/IV tumors than those carrying the rs3737589 TT genotype or T allele. The expression of TP73-AS1 was lower in CRC tissues with the rs3737589 CC genotype compared to those with the TT genotype. Bioinformatics analysis and the luciferase assay revealed that the C allele could promote the binding of miR-3166 and miR-4771 to TP73-AS1.

CONCLUSION

The TP73-AS1 gene rs3737589 polymorphism affecting miRNAs binding is associated with the CRC stage and may serve as a biomarker for predicting CRC progression.

A Prognostic Ferroptosis-Related lncRNA Model Associated With Immune Infiltration in Colon Cancer

Colon cancer (CC) is a common malignant tumor worldwide, and ferroptosis plays a vital role in the pathology and progression of CC. Effective prognostic tools are required to guide clinical decision-making in CC. In our study, gene expression and clinical data of CC were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. We identified the differentially expressed ferroptosis-related lncRNAs using the differential expression and gene co-expression analysis. Then, univariate and multivariate Cox regression analyses were used to identify the effective ferroptosis-related lncRNAs for constructing the prognostic model for CC. Gene set enrichment analysis (GSEA) was conducted to explore the functional enrichment analysis. CIBERSORT and single-sample GSEA were performed to investigate the association between our model and the immune microenvironment. Finally, three ferroptosis-related lncRNAs (XXbac-B476C20.9, TP73-AS1, and SNHG15) were identified to construct the prognostic model. The results of the validation showed that our model was effective in predicting the prognosis of CC patients, which also was an independent prognostic factor for CC. The GSEA analysis showed that several ferroptosis-related pathways were significantly enriched in the low-risk group. Immune infiltration analysis suggested that the level of immune cell infiltration was significantly higher in the high-risk group than that in the low-risk group. In summary, we established a prognostic model based on the ferroptosis-related lncRNAs, which could provide clinical guidance for future laboratory and clinical research on CC.

Regulatory Roles of Noncoding RNAs in the Progression of Gastrointestinal Cancers and Health Disparities

Annually, more than a million individuals are diagnosed with gastrointestinal (GI) cancers worldwide. With the advancements in radio- and chemotherapy and surgery, the survival rates for GI cancer patients have improved in recent years. However, the prognosis for advanced-stage GI cancers remains poor. Site-specific GI cancers share a few common risk factors; however, they are largely distinct in their etiologies and descriptive epidemiologic profiles. A large number of mutations or copy number changes associated with carcinogenesis are commonly found in noncoding DNA regions, which transcribe several noncoding RNAs (ncRNAs) that are implicated to regulate cancer initiation, metastasis, and drug resistance. In this review, we summarize the regulatory functions of ncRNAs in GI cancer development, progression, chemoresistance, and health disparities. We also highlight the potential roles of ncRNAs as therapeutic targets and biomarkers, mainly focusing on their ethnicity-/race-specific prognostic value, and discuss the prospects of genome-wide association studies (GWAS) to investigate the contribution of ncRNAs in GI tumorigenesis.

Competing Endogenous RNAs (ceRNAs) in Colorectal Cancer: A Review

Colorectal cancer (CRC) is a common type of cancer and the second leading cause of cancer-related deaths worldwide. Competing endogenous RNAs (ceRNAs) that contain microRNA response elements (MREs) are involved in CRC progression. They can compete with microRNAs (miRNAs) via their MREs, which can combine non-coding and coding RNAs via complex ceRNA networks. This molecular interaction has the potential to affect a wide variety of biological processes, and many cancers can occur as a result of an imbalanced ceRNA network. Recent research indicates that numerous dysregulated RNAs in CRC may function as ceRNAs, regulating multiple biological functions of the tumour, including proliferation, apoptosis, metastasis, invasion and migration. In this review, we discuss the role of protein-coding and non-coding RNAs, such as long non-coding RNAs, circular RNAs and pseudogenes, in the occurrence of ceRNA networks in CRC, and their function in cancer-related pathways, such as Wnt/β-catenin, mitogen-activated protein kinase and transforming growth factor-β signalling pathways. Additionally, we discuss validated ceRNAs associated with CRC biological functions and their potential role as novel prognostic and diagnostic biomarkers. Examining the role of ceRNAs in CRC sheds new light on cancer treatment and pathogenesis.

The role of lncRNA-mediated ceRNA regulatory networks in pancreatic cancer

Non-coding RNAs (ncRNAs), which occupy the vast majority of human transcripts are known for their inability to encode proteins. NcRNAs consist of a diverse range of RNA species, including long non-coding RNAs (lncRNAs), which have significant meaning for epigenetic modification, post-transcriptional regulation of target genes, molecular interference, etc. The dysregulation of ncRNAs will mediate the pathogenesis of diverse human diseases, like cancer. Pancreatic cancer, as one of the most lethal malignancies in the digestive system that is hard to make a definite diagnosis at an early clinicopathological stage with a miserable prognosis. Therefore, the identification of potential and clinically applicable biomarker is momentous to improve the overall survival rate and positively ameliorate the prognosis of patients with pancreatic carcinoma. LncRNAs as one kind of ncRNAs exert multitudinous biological functions, and act as molecular sponges, relying on microRNA response elements (MREs) to competitively target microRNAs (miRNAs), thereby attenuating the degradation or inhibition of miRNAs to their own downstream protein-coding target genes, also thus regulating the initiation and progression of neoplasms. LncRNAs, which emerge aforementioned function are called competing endogenous RNAs (ceRNAs). Consequently, abundant research of lncRNAs as potential biomarkers is of critical significance for the molecular diagnosis, targeted therapy, as well as prognosis monitoring of pancreatic cancer.

miR-320a promotes p53-dependent apoptosis of prostate cancer cells by negatively regulating TP73-AS1 invitro

TP73 antisense RNA 1 (TP73-AS1) is an oncogenic long non-coding RNA that is activated in several types of cancers. It has been shown that the activity of TP73-AS1 is controlled by several miRNAs, but post-transcriptional mechanisms that regulate TP73-AS1 activity in prostate cancer remain highly elusive. Accordingly, in the present study, we aimed to determine the miRNAs that are involved in the regulation of TP73-AS1 in prostate cancer and to show the effects of these molecules on the malignant proliferation of prostate cancer cells. Remarkably, colony formation and cell migration were suppressed while cell cycle arrest and apoptosis were induced in prostate cancer cells overexpressing miR-200a and miR-320a. miR-200a and miR-320a were found to be upregulated in TP73-AS1 suppressed prostate cancer cells. Also, TP73-AS1 was shown to be downregulated following miR-200a and miR-320a overexpression. However, overexpression of miR-320a had no significant effect on the expression of TP73. Further analysis revealed that miR-320a induces p53-dependent apoptosis. Consequently, our findings indicate that miR-320a induces p53-dependent apoptosis by negatively regulating TP73-AS1 long non-coding RNA.

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.

Colorectal liver metastasis: molecular mechanism and interventional therapy

Colorectal cancer (CRC) is one of the most frequently occurring malignancy tumors with a high morbidity additionally, CRC patients may develop liver metastasis, which is the major cause of death. Despite significant advances in diagnostic and therapeutic techniques, the survival rate of colorectal liver metastasis (CRLM) patients remains very low. CRLM, as a complex cascade reaction process involving multiple factors and procedures, has complex and diverse molecular mechanisms. In this review, we summarize the mechanisms/pathophysiology, diagnosis, treatment of CRLM. We also focus on an overview of the recent advances in understanding the molecular basis of CRLM with a special emphasis on tumor microenvironment and promise of newer targeted therapies for CRLM, further improving the prognosis of CRLM patients.

RHO GTPase-Related Long Noncoding RNAs in Human Cancers

RHO GTPases are critical signal transducers that regulate cell adhesion, polarity, and migration through multiple signaling pathways. While all these cellular processes are crucial for the maintenance of normal cell homeostasis, disturbances in RHO GTPase-associated signaling pathways contribute to different human diseases, including many malignancies. Several members of the RHO GTPase family are frequently upregulated in human tumors. Abnormal gene regulation confirms the pivotal role of lncRNAs as critical gene regulators, and thus, they could potentially act as oncogenes or tumor suppressors. lncRNAs most likely act as sponges for miRNAs, which are known to be dysregulated in various cancers. In this regard, the significant role of miRNAs targeting RHO GTPases supports the view that the aberrant expression of lncRNAs may reciprocally change the intensity of RHO GTPase-associated signaling pathways. In this review article, we summarize recent advances in lncRNA research, with a specific focus on their sponge effects on RHO GTPase-targeting miRNAs to crucially mediate gene expression in different cancer cell types and tissues. We will focus in particular on five members of the RHO GTPase family, including RHOA, RHOB, RHOC, RAC1, and CDC42, to illustrate the role of lncRNAs in cancer progression. A deeper understanding of the widespread dysregulation of lncRNAs is of fundamental importance for confirmation of their contribution to RHO GTPase-dependent carcinogenesis.

iLncRNAdis-FB: Identify lncRNA-Disease Associations by Fusing Biological Feature Blocks Through Deep Neural Network

Identification of lncRNA-disease associations is not only important for exploring the disease mechanism, but will also facilitate the molecular targeting drug discovery. Fusing multiple biological information is able to generate a more comprehensive view of lncRNA-disease association feature. However, the existing fusion strategies in this field fail to remove the noisy and irrelevant information from each data source. As a result, their predictive performance is still too low to be applied to real world applications. In this regard, a novel computational predictor called iLncRNAdis-FB is proposed based on the Convolution Neural Network (CNN) to integrate different data sources by using the feature blocks in a supervised manner. The lncRNA similarity matrix and disease similarity matrix are constructed, based on which the three-dimensional feature blocks are generated. These feature blocks are then fed into CNN to train the model so as to predict unknown lncRNA-disease associations. Experimental results show that iLncRNAdis-FB achieves better performance compared with other state-of-the-art predictors. Furthermore, a web server of iLncRNAdis-FB has been established at http://bliulab.net/iLncRNAdis-FB/, by which users can submit lncRNA sequences to detect their potential associated diseases.

LncRNA TP73-AS1 promotes the development of Epstein-Barr virus associated gastric cancer by recruiting PRC2 complex to regulate WIF1 methylation

BACKGROUND

Epstein-Barr virus associated gastric cancer (EBVaGC) become a growing health problem. TP73-AS1 showed high expression in EBVaGC cells. However, the function role and underlying mechanism of TP73-AS1 need further exploration.

METHODS

The expressions of TP73-AS1, WIF1, EZH2, β-catenin and epithelial-mesenchymal transition (EMT)-related proteins were detected using qRT-PCR and Western blotting. Cell proliferation, apoptosis, migration and invasion were measured by CCK-8, colony formation, flow cytometry, wound healing and transwell assays, respectively. WIF1 promoter methylation was analyzed by MS-PCR (MSP). RNA immunoprecipitation assay (RIP) and Chromatin immunoprecipitation assay (ChIP) measured the interactions of TP73-AS1/EZH2 and EZH2/WIF1. Subcutaneous tumor growth was monitored in nude mice and immunohistochemistry (IHC) detected proliferation marker Ki-67 expression.

RESULTS

TP73-AS1 was increased while WIF1 was decreased in EBVaGC cells. Silencing of TP73-AS1 or overexpression of WIF1 repressed the growth and migration while promoted apoptosis of EBVaGC cells. Knockdown of WIF1 reversed the anticancer effect of TP73-AS1 silencing. TP73-AS1 promoted the binding of EZH2 to the WIF1 promoter by directly binding to EZH2, and thus inhibiting the expression of WIF1 by enhancing H3K27me3 level of WIF1 promoter. Moreover, TP73-AS1 activated Wnt/β-catenin signaling pathway and promoted EMT by down-regulating WIF1. TP73-AS1 silencing inhibited the progression of EBVaGC in nude mice by epigenetically regulating WIF1.

CONCLUSION

TP73-AS1 regulated the promoter methylation of WIF1 by recruiting PRC2 complex to WIF1 promoter region, thereby promoting the progression of EBVaGC. These observations provided a novel theoretical basis to investigate more effective therapies of EBVaGC.

A novel lncRNA SOX2OT promotes the malignancy of human colorectal cancer by interacting with miR-194-5p/SOX5 axis

Long noncoding RNAs (lncRNAs) show emerging roles in colorectal cancer (CRC) development and are considered to be involved in the potential mechanism of tumor malignancy. While Sox2 overlapping transcript (SOX2OT) has been implicated in the progression of multiple cancers, its role in CRC remains to be explored. In this study, in situ hybridization (ISH) and qRT-PCR were performed to establish the functional relationships between SOX2OT and CRC deranged in CRC tissue and cells. Subsequently, SOX2OT shRNAs vectors were transfected into CRC cells to performed loss-of-function assays to detect the potential role of SOX2OT on proliferation and metastasis in vitro and vivo. The results showed SOX2OT was an oncogene that was up-regulated in human CRC tissues and cell lines. SOX2OT silencing suppressed cell proliferation, migration, and invasion in CRC cells in vitro, and inhibited tumorigenesis in the mouse xenografts. Bioinformatic predictive analysis coupled with the dual-luciferase reporter, RNA immunoprecipitation (RIP), and functional rescue assay elucidated the mechanistic network of the SOX2OT-miR-194-5p-SOX5 axis in CRC. Mechanistically, SOX2OT acted as a competing endogenous RNA (ceRNA) to upregulate SOX5 by sponging miR-194-5p. Downregulated SOX2OT boosted miR-194-5p expression, thus decreased the protein level of SOX5, which suppresses tumorgenesis of CRC.

Long non-coding RNA TP73-AS1 promotes pancreatic cancer growth and metastasis through miRNA-128-3p/GOLM1 axis

BACKGROUND

Previous studies have suggested that long non-coding RNAs (lncRNA) TP73-AS1 is significantly upregulated in several cancers. However, the biological role and clinical significance of TP73-AS1 in pancreatic cancer (PC) remain unclear.

AIM

To investigate the role of TP73-AS1 in the growth and metastasis of PC.

METHODS

The expression of lncRNA TP73-AS1, miR-128-3p, and GOLM1 in PC tissues and cells was detected by quantitative real-time polymerase chain reaction. The bioinformatics prediction software ENCORI was used to predict the putative binding sites of miR-128-3p. The regulatory roles of TP73-AS1 and miR-128-3p in cell proliferation, migration, and invasion abilities were verified by Cell Counting Kit-8, wound-healing, and transwell assays, as well as flow cytometry and Western blot analysis. The interactions among TP73-AS1, miR-128-3p, and GOLM1 were explored by bioinformatics prediction, luciferase assay, and Western blot.

RESULTS

The expression of TP73-AS1 and miRNA-128-3p was dysregulated in PC tissues and cells. High TP73-AS1 expression was correlated with a poor prognosis. TP73-AS1 silencing inhibited PC cell proliferation, migration, and invasion in vitro as well as suppressed tumor growth in vivo. Mechanistically, TP73-AS1 was validated to promote PC progression through GOLM1 upregulation by competitively binding to miR-128-3p.

CONCLUSION

Our results demonstrated that TP73-AS1 promotes PC progression by regulating the miR-128-3p/GOLM1 axis, which might provide a potential treatment strategy for patients with PC.

LncRNA TP73-AS1 enhances the malignant properties of pancreatic ductal adenocarcinoma by increasing MMP14 expression through miRNA -200a sponging

Pancreatic ductal adenocarcinoma (PDAC) is an invasive and aggressive cancer that remains a major threat to human health across the globe. Despite advances in cancer treatments and diagnosis, the prognosis of PDAC patients remains poor. New and more effective PDAC therapies are therefore urgently required. In this study, we identified a novel host factor, namely the LncRNA TP73-AS1, as overexpressed in PDAC tissues compared to adjacent healthy tissue samples. The overexpression of TP-73-AS1 was found to correlate with both PDAC stage and lymph node metastasis. To reveal its role in PDCA, we targeted TP73-AS1 using LnRNA inhibitors in a range of pancreatic cancer (PC) cell lines. We found that the inhibition of TP73-AS1 led to a loss of MMP14 expression in PC cells and significantly inhibited their migratory and invasive capacity. No effects of TP73-AS1 on cell survival or proliferation were observed. Mechanistically, we found that TP73-AS1 suppressed the expression of the known oncogenic miR-200a. Taken together, these data highlight the prognostic potential of TP73-AS1 for PC patients and highlight it as a potential anti-PDAC therapeutic target.

Silencing of Long Non-coding RNA ENST00000606790.1 Inhibits the Malignant Behaviors of Papillary Thyroid Carcinoma through the PI3K/AKT Pathway

PURPOSE

This study aimed to investigate the role and mechanism of lncRNA ENST00000606790.1 (ENST) in promoting the progression of papillary thyroid carcinoma (PTC).

METHODS

The expression of ENST in human PTC and normal para-cancerous thyroid (NPTC) tissues or cell lines was determined by RT-qPCR. Cell growth was determined by CCK8 assay. Cell colony formation was determined by cell colony formation assay. Cell cycle analysis was performed by staining cells with PI (Propidium Iodide). Cell invasion was assessed by transwell assay. Protein expression was examined by western-blot. siRNA was constructed to inhibit the expression of ENST. 740-Y-P was used to activate PI3K. The correlation between ENST expression and clinical outcomes was analyzed.

RESULTS

ENST was significantly up-regulated in PTC tissues or PTC cell lines (PTC and IHH4 cell lines), compared to NPTC tissues or normal cell lines, respectively. High expression of ENST was strongly correlated to lymph node metastasis and tumor size at diagnosis. Silencing of ENST significantly inhibited cell growth and colony formation, arrested the cell cycle at G2/M phase, upregulated the expression of CHK1, downregulated the expression of CDC25C, and inhibited cell invasion. Silencing of ENST significantly down-regulated the expression of PI3K, p-PI3K, AKT, and p-AKT in IHH4 cells. Furthermore, treatment with the PI3K activator  740-Y-P partially abolished the effect of silencing of ENST on PTC cells.

CONCLUSIONS

Overall, our results demonstrated that ENST can promote PTC progression by activating the PI3K/AKT signaling pathway, suggesting that ENST can serve as a potential biomarker and new therapeutic target for patients with PTC.

Long Noncoding RNAs in Gastrointestinal Cancer: Tumor Suppression Versus Tumor Promotion

Approximately 80% of the human genome harbors biochemical marks of active transcription that its majority transcribes to noncoding RNAs, namely long noncoding RNAs (lncRNAs). LncRNAs are heterogeneous RNA transcripts that regulate critical biological processes such as cell survival and death. They involve in the progression of different cancers by affecting transcriptional and post-transcriptional modifications as well as epigenetic control of numerous tumor suppressors and oncogenes. Recent findings show that aberrant expression of lncRNAs is associated with tumor initiation, progression, invasion, and overall survival of patients with gastrointestinal (GI) cancers. Some lncRNAs play as tumor suppressors in all GI cancers, but others play as tumor promoters. However, some other lncRNAs might function as a tumor suppressor in one GI cancer, but as a tumor promoter in another GI cancer type. This fact highlights possible context dependency of the expression patterns and roles of at least some lncRNAs in GI cancer development and progression. Here, we review the functional relation of lncRNAs involved in the development and progression of GI cancer by focusing on their roles as tumor suppressor and tumor promoter genes.

Long non-coding RNA MCF2L-AS1 promotes the aggressiveness of colorectal cancer by sponging miR-874-3p and thereby up-regulating CCNE1

BACKGROUND

Long non-coding RNAs (lncRNAs) have drawn growing attention because of the role which they play in various diseases, including colorectal cancer (CRC). However, the potential functions of lncRNA MCF2L antisense RNA 1 (MCF2L-AS1) in tumors remained largely unclear. The present study aimed to explore the clinical significance and the biological effects of lncRNA MCF2L antisense RNA 1 (MCF2L-AS1) in CRC.

METHODS

Reverse transcriptase-polymerase chain reaction was performed to determine the expression of MCF2L-AS1 in CRC. The clinical significance of MCF2L-AS1 in CRC patients was analyzed statistically. In vitro experiments were performed to determine the effects of MCF2L-AS1 on the cellular progression of CRC cells. Bioinformatic assays, luciferase reporter assays and RNA-pulldown assays were performed to predict for potential microRNAs that can interact with MCF2L-AS1 and mRNAs that can interact with miR-874-3p.

RESULTS

We identified a novel CRC-related lncRNA, MCF2L-AS1, which is distinctly highly expressed in CRC. Its diagnostic value for CRC patients was also demonstrated. Clinical assays revealed that high MCF2L-AS1 expression is associated with advanced stages, positive metastasis and the poor prognosis of CRC patients. Multivariate assays confirmed that MCF2L-AS1 expression is an independent poor prognostic factor for both 5-year overall survival and 5-year disease-free survival of CRC patients. Functionally, we confirmed that knockdown of MCF2L-AS1 distinctly suppresses the proliferation, migration and invasion of CRC cells and also promotes apoptosis. Mechanistic investigation showed that MCF2L-AS1 functions as an endogenous sponge for miR-874-3p to increase the expression of CCNE1.

CONCLUSIONS

Our findings identified a novel CRC-related lncRNA, MCF2L-AS1, which may be used as a potential diagnostic and prognostic biomarker for CRC patients. In addition, the newly identified MCF2L-AS1/miR-874-3p/CCNE1 axis can modulate the initiation and progression of CRC.

Role of long non-coding RNA TP73-AS1 in cancer

Cancer incidence rate has increased so much that it is the second leading cause of deaths worldwide after cardiovascular diseases. Sensitive and specific biomarkers are needed for an early diagnosis of cancer and in-time treatment. Recent studies have found that long non-coding RNAs (lncRNAs) participate in cancer tumorigenesis. LncRNA P73 antisense RNA 1T (TP73-AS1), also known as KIAA0495 and p53-dependent apoptosis modulator (PDAM), is located in human chromosomal band 1p36.32 and plays a crucial role in many different carcinomas. This review summarizes current findings on the role of TP73-AS1 and its signaling pathways in various cancers, including glioma, esophageal squamous cell carcinoma (ESCC), hepatocellular carcinoma (HCC), colorectal cancer (CRC), osteosarcoma, gastric cancer (GC), clear cell renal cell carcinoma (ccRCC), breast cancer (BC), bladder cancer, ovarian cancer, cholangiocarcinoma (CCA), lung cancer, and pancreatic cancer. Its aberrant expression generally correlates with clinicopathological characterization of patients. Moreover, TP73-AS1 regulates proliferation, migration, invasion, apoptosis, and chemoresistance cancer mechanisms, both in vivo and in vitro, through different signaling pathways. Therefore, TP73-AS1 may be considered as a marker for diagnosis and prognosis, also as a target for cancer treatment.

Knockdown of lncRNA ZNRD1-AS1 inhibits progression of bladder cancer by regulating miR-194 and ZEB1

BACKGROUND

Bladder cancer (BC) is a common urinary neoplasm with high incidence worldwide. Long noncoding RNA zinc ribbon domain containing 1 antisense RNA 1 (ZNRD1-AS1) has been reported to be upregulated in BC. However, the exact role of ZNRD1-AS1 as well as its mechanism remains poorly understood.

METHODS

Zinc ribbon domain containing 1 antisense RNA 1, and its potential downstream genes microRNA-194 (miR-194) and zinc finger E-box binding homeobox 1 (ZEB1) levels were detected via quantitative real-time polymerase chain reaction or western blot. Cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) were detected to assess the influences of ZNRD1-AS1, miR-194 and ZEB1 on BC cells by colony formation, cell counting kit-8 (CCK-8), transwell analysis or western blot. The relationship between miR-194 and ZNRD1-AS1 or ZEB1 was analyzed by luciferase activity analysis. The xenograft experiment was performed to assess the function of ZNRD1-AS1 in vivo.

RESULTS

Zinc ribbon domain containing 1 antisense RNA 1level was upregulated in BC. ZNRD1-AS1 silence repressed proliferation, migration, invasion and EMT in BC cells. MiR-194 was identified as a target of ZNRD1-AS1, and miR-194 upregulation repressed proliferation, migration, invasion, and EMT by ZNRD1-AS1 sponging. ZEB1 was targeted via miR-194 and its interference impeded proliferation, migration, invasion, and EMT. Moreover, ZNRD1-AS1 regulated ZEB1 expression via miR-194. Besides, inhibition of ZNRD1-AS1 attenuated tumor growth by miR-194/ZEB1 axis in vivo.

CONCLUSION

Knockdown of ZNRD1-AS1 suppressed BC cell development in vitro and in vivo via targeting miR-194 to regulate ZEB1, indicating a novel avenue for treatment of BC.

Long non-coding RNA TP73-AS1 contributes to glioma tumorigenesis by sponging the miR-103a/GALNT7 pathway

Glioma is the most aggressive, commonly occurring brain tumor in adults. Long non-coding RNAs (lncRNAs) are among the gene expression regulators in cancer development. Previous research posited that the up-regulation of LncRNA TP73-AS1 (TP73-AS1) in glioma is linked to low survival rates. However, the precise LncRNA TP73-AS1 mechanism in glioma remains unknown. Herein, we found that TP73-AS1 was up-regulated in glioma and was associated with a dismal prognosis. The silencing of TP73-AS1 repressed the multiplication of glioma cells and caused cell death. Mechanistically, we identified that TP73-AS1 in glioma acts as a ceRNA by sequestering miR-103a from GALNT7. Further, the results of this study revealed a reciprocal expression between TP73-AS1 and miR-103a, and a positive regulation between TP73-AS1 and GALNT7, validating the identified mechanism. Besides, luciferase reporter assay identified miR-103a as the direct binding site of both TP73-AS1 and GALNT7. Moreover, the findings of CCK-8 and colony-formation assays indicated that exogenous expression of GALNT7 reversed TP73-AS1-induced division inhibition of glioma cells. Altogether, our results established that TP73-AS1 facilitates the progression of glioma through competing for endogenous RNA (ceRNA) in a TP73-AS1/miR-103a/GALNT7 loop.

Non-coding RNAS and colorectal cancer liver metastasis

More than 50% of colorectal cancer (CRC) deaths are attributed to metastasis, and the liver is the most common distant metastatic site of CRC. The molecular mechanisms underlying CRC liver metastasis are very complicated and remain largely unknown. Accumulated evidence has shown that non-coding RNAs (NcRNAs) play critical roles in tumor development and progression. Here we reviewed the roles and underlying mechanisms of NcRNAs in CRC liver metastasis.

miRNA Clusters with Down-Regulated Expression in Human Colorectal Cancer and Their Regulation

Regulation of microRNA (miRNA) expression has been extensively studied with respect to colorectal cancer (CRC), since CRC is one of the leading causes of cancer mortality worldwide. Transcriptional control of miRNAs creating clusters can be, to some extent, estimated from cluster position on a chromosome. Levels of miRNAs are also controlled by miRNAs "sponging" by long non-coding RNAs (ncRNAs). Both types of miRNA regulation strongly influence their function. We focused on clusters of miRNAs found to be down-regulated in CRC, containing miR-1, let-7, miR-15, miR-16, miR-99, miR-100, miR-125, miR-133, miR-143, miR-145, miR-192, miR-194, miR-195, miR-206, miR-215, miR-302, miR-367 and miR-497 and analysed their genome position, regulation and functions. Only evidence provided with the use of CRC in vivo and/or in vitro models was taken into consideration. Comprehensive research revealed that down-regulated miRNA clusters in CRC are mostly located in a gene intron and, in a majority of cases, miRNA clusters possess cluster-specific transcriptional regulation. For all selected clusters, regulation mediated by long ncRNA was experimentally demonstrated in CRC, at least in one cluster member. Oncostatic functions were predominantly linked with the reviewed miRNAs, and their high expression was usually associated with better survival. These findings implicate the potential of down-regulated clusters in CRC to become promising multi-targets for therapeutic manipulation.

Prognostic value and therapeutic potential of the long noncoding RNA TP73-AS1 in cancers: A systematic review and meta-analysis

Studies published in recent years have demonstrated that abnormal long noncoding RNA (lncRNA) antisense RNA to TP73 gene (TP73-AS1) expression is markedly associated with tumorigenesis, cancer progression and the prognosis of cancer patients. We aimed to explore the prognostic value of TP73-AS1 in multiple cancers. We comprehensively searched PubMed, Embase, Web of Science and the Cochrane Library (up to February 21, 2019). Hazard ratios (HRs), odds ratios (ORs) and the corresponding 95% confidence intervals (95% CIs) were calculated to estimate the association of TP73-AS1 with survival and clinicopathological features. The potential targets and pathways of TP73-AS1 in multiple cancers were summarized. Nineteen studies that involved thirteen types of cancers and 1329 cancer patients were identified as eligible for this meta-analysis. The results showed that high TP73-AS1 expression was significantly correlated with shorter overall survival (OS) (HR = 1.962, 95% CI 1.630-2.362) and disease-free survival (DFS) (HR = 2.050, 95% CI 1.293-3.249). The summary HRs of OS were 2.101 (95% CI 1.516-2.911) for gastric cancer (GC) and 1.920 (95% CI 1.253-2.942) for osteosarcoma. Subgroup analysis of OS demonstrated that the differential expression of TP73-AS1 in cancer tissues was a potential source of heterogeneity. Furthermore, increased TP73-AS1 expression was markedly associated with larger tumor size (OR = 2.759, 95% CI 1.759-4.330), advanced histological grade (OR = 2.394, 95% CI 1.231-4.656), lymph node metastasis (OR = 2.687, 95% CI 1.211-5.962), distant metastasis (OR = 4.145, 95% CI 2.252-7.629) and advanced TNM stage (OR = 2.633, 95% CI 1.507-4.601). The results of Egger's test and sensitivity analysis verified the robustness of the original results. High TP73-AS1 expression can predict poor survival and poor clinicopathological features in cancer patients and TP73-AS1 might be a potential biomarker and therapeutic target.

An Antisense Oligonucleotide Drug Targeting miR-21 Induces H1650 Apoptosis and Caspase Activation

Non-small cell lung cancer is the most common malignant tumor in the world. Currently, chemotherapy is still the major method for non-small cell lung cancer treatment, but the problem of cancer drug resistance still exists, so we designed 5 different phosphorothioate oligonucleotides to silence key genes in tumor cell development, which could help avoid inducing cancer cell drug resistance. MicroRNAs have been shown to play a crucial role in the pathogenesis and progression of many malignancies, such as breast, colon, lung, and pancreatic cancer. According to the data from the Gene Expression Omnibus database, miR-21 has been reported to be one of the top 20 differentially expressed microRNAs screened using the Morpheus online tool, and miR-21 has been revealed to regulate a series of biological behaviors in cancer cells, including cell proliferation, migration, invasion, metastasis, and apoptosis. In recent years, gene therapy has emerged as a new therapeutic strategy for cancer treatment. Antisense oligonucleotides have recently been suggested as a novel approach for targeting microRNAs by antisense-based gene silencing. Five phosphorothioate oligonucleotides were designed, synthesized, and screened for anticancer activity. Reverse transcription-polymerase chain reaction was used to detect the relative expression of miR21. Among these 5 sequences, only phosphorothioate oligonucleotide 4 inhibited the proliferation of H1650 cells, and this effect was due to the induction of cancer cell apoptosis by activating the caspase-8 apoptotic pathway. In conclusion, this research confirmed the anticancer activity of phosphorothioate oligonucleotide 4 and revealed the underlying mechanism, which has the potential to be a novel anticancer strategy.

MALAT1 knockdown inhibits hypopharyngeal squamous cell carcinoma malignancy by targeting microRNA-194

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is involved in the oncogenesis and progression of various types of cancer. However, the function of MALAT1 in hypopharyngeal squamous cell carcinoma (HSCC) is not completely understood. In the present study, MALAT1 expression levels were determined using reverse transcription-quantitative PCR, and Cell Counting Kit-8, Transwell and flow cytometry assays were performed to investigate the biological functions of HSCC cells. The results indicated that MALAT1 was upregulated in HSCC. MALAT1 knockdown suppressed HSCC cell proliferation, migration and invasion, and promoted apoptosis compared with the control group. Additionally, microRNA (miR)-194 was identified as a target of MALAT1 and was expressed at low levels in HSCC tissues compared with adjacent non-tumor tissues. A miR-194 agomir inhibited malignant cell behaviors, including cell proliferation, migration and invasion, whereas miR-194 antagomir promoted malignant behaviors compared with the corresponding control groups. In addition, the results suggested that MALAT1 knockdown inhibited the malignant behaviors of HSCC cells by binding miR-194. miR-194 inhibition partially reversed the MALAT1 knockdown-induced inhibitory effects on HSCC cells. Furthermore, MALAT1 knockdown combined with miR194 mimics resulted in the lowest tumor volume among all tested groups in vivo. In conclusion, the results of the present study suggested that MALAT1 knockdown suppressed the malignant behavior of HSCC by targeting miR-194; therefore, MALAT1 may serve as a novel therapeutic target for HSCC.

Association of TP73-AS1 gene polymorphisms with the risk and survival of gastric cancer in a Chinese Han Population

It was investigated that TP73-AS1(TP73 antisense RNA 1) could function as an oncogene in gastric cancer (GC). The expression and function of long noncoding RNAs (lncRNAs) could be impacted by single nucleotide polymorphisms (SNPs), which are related to cancer susceptibility and prognosis. This study was to reveal the association between lncRNAs TP73-AS1 polymorphisms (rs1181865 A > G, rs9800 G > C, rs3737589 A > G, rs2298222 G > A, rs7515164 C > A) and GC in 1000 GC cases and 1000 controls in a Chinese Han population. Rs3737589 G allele had significant associations with the increasing risk of GC (G vs. A: p = .005). Rs3737589 variant genotypes (AG + GG) were related to an increased risk of GC in the elder population (age ≥60), females, nonsmokers, nondrinkers, individuals living in urban, and individuals without family history of GC in stratified analyses. Rs3737589 variant genotypes (AG + GG) were related to the advanced depth of tumor invasion (T3 + T4). Besides, we found that GC patients with AG or GG genotype of rs3737589 had poorer overall survival (OS) than those with AA genotype (p < .05). Our findings showed that the lncRNA TP73-AS1 rs3737589 polymorphism might increase the risk of GC, and rs3737589 polymorphism could be a potential biomarker to predict the prognosis of GC patients.

Biological and clinical relevance of metastasis-associated long noncoding RNAs in esophageal squamous cell carcinoma: A systematic review

Esophageal squamous cell carcinoma (ESCC) is a foremost cancer-related death worldwide owing to rapid metastasis and poor prognosis. Metastasis, as the most important reason for death, is biologically a multifaceted process involving a range of cell signaling pathways. Long noncoding RNAs (lncRNAs), as transcriptional regulators, can regulate numerous genomic processes and cellular processes such as cell proliferation, migration, and invasion. LncRNAs have also been shown to involve in/regulate the cancer metastasis-related signaling pathways. Hence, they have increasingly been brought to international attention in molecular oncology research. A number of researchers have attempted to reveal the biological and clinical relevance of lncRNAs in ESCC tumourigenesis and metastasis. The aberrant expression of these molecules in ESCC has regularly been reported to involve in various cellular processes and clinical features, including diagnosis, prognosis, and therapeutic responses. Here, we especially consider the pathways in which lncRNAs act as metastasis-mediated effectors, mainly by interacting with epithelial-mesenchymal transition-associated factors. We review the biological roles of lncRNAs through involving in ESCC metastasis as well as the clinical significance of the metastasis-related lncRNAs in cancer diagnosis and prognosis.

LncRNA TP73-AS1 Activates TGF-β1 to Promote the Migration and Invasion of Colorectal Cancer Cell

Purpose

LncRNA TP73-AS1 has been demonstrated to promote the developments of several types of human cancer. However, its role in colorectal cancer (CRC) is unknown.

Methods

All CRC patients (n=70, 40 males and 30 females, 38 to 66 years’ old, 52.1 ± 5.3 years’ old) in this study were enrolled in the Affiliated Hospital of Southwest Medical University from July 2012 to January 2014. Cells, vectors, and transient transfections, RT-qPCR, western-blotting, as well as measurements of cell migration and invasion abilities were carried out during the research.

Results

In the present study, we found that TP73-AS1 was upregulated in CRC tissues compared with adjacent non-CRC tissues in CRC patients. Upregulation of TP73-AS1 was closely correlated with poor prognosis. TGF-β1 was also upregulated in CRC tissues and positive correlated with TP73-AS1. TP73-AS1 overexpression caused upregulated TGF-β1 in CRC cells, while TGF-β1 overexpression showed no significant effect on TP73-AS1. TP73-AS1 and TGF-β1 overexpressions caused enhanced migration and invasion of CRC cells. TGF-β inhibitor treatment caused suppressed migration and invasion of CRC cells and attenuated effects of TP73-AS1 and TGF-β1 overexpression.

Conclusion

Therefore, TP73-AS1 may inactivate TGF-β1 to inhibit the migration and invasion of CRC cells.

Long Noncoding RNA (lncRNA)-Mediated Competing Endogenous RNA Networks Provide Novel Potential Biomarkers and Therapeutic Targets for Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer and has a high metastasis and reoccurrence rate. Long noncoding RNAs (lncRNAs) play an important role in CRC growth and metastasis. Recent studies revealed that lncRNAs participate in CRC progression by coordinating with microRNAs (miRNAs) and protein-coding mRNAs. LncRNAs function as competitive endogenous RNAs (ceRNAs) by competitively occupying the shared binding sequences of miRNAs, thus sequestering the miRNAs and changing the expression of their downstream target genes. Such ceRNA networks formed by lncRNA/miRNA/mRNA interactions have been found in a broad spectrum of biological processes in CRC, including liver metastasis, epithelial to mesenchymal transition (EMT), inflammation formation, and chemo-/radioresistance. In this review, we summarize typical paradigms of lncRNA-associated ceRNA networks, which are involved in the underlying molecular mechanisms of CRC initiation and progression. We comprehensively discuss the competitive crosstalk among RNA transcripts and the novel targets for CRC prognosis and therapy.

Two Novel Long Noncoding RNAs - RP11-296E3.2 and LEF1-AS1can - Separately Serve as Diagnostic and Prognostic Bio-Markers of Metastasis in Colorectal Cancer

BACKGROUND Late diagnosis and metastasis are leading causes of the high mortality of colorectal cancer (CRC). Long noncoding RNAs (lncRNAs) have been reported to play a critical role in the development and progression of CRC. This study aimed to explore the clinical significance of 2 novel lncRNAs - RP11-296E3.2 and LEF1-AS1 - including their expression pattern, as well as diagnostic and prognostic values, for metastatic CRC patients. MATERIAL AND METHODS lncRNAs expression was examined in tissues (91 cases) and plasma (60 cases) from CRC patients by real-time quantitative PCR (qRT-PCR), and the correlations between its expression and clinicopathological features and diagnosis values in metastasis were analyzed. TCGA datasets were further used to analyze their utility in prediction of overall survival (OS) and disease-free survival (DFS). ATP-based tumor chemosensitivity assay (ATP-TCA) was used to evaluated tumor chemoresistance. RESULTS Compared with adjacent normal tissues, RP11-296E3.2 was significantly downregulated while LEF1-AS1 was significantly upregulated in cancer tissues (p=0.0143, p=0.0322, respectively). High levels of RP11-296E3.2 and LEF1-AS1 in tissues and plasma were correlated with tumor metastasis (p=0.0488, p=0.0252 in tissues, p=0.0331, p=0.1862 in plasma, respectively). Further analysis showed that RP11-296E3.2 sensitivity and specificity in diagnosis of CRC metastasis is better than CEA in plasma (0.690 and 0.621, and 0.621 and 0.500, respectively), and the OS of metastatic CRC patients with higher LEF1-AS1 expression levels in tissues was short (log-rank p<0.05). CONCLUSIONS Our findings suggest that RP11-296E3.2 and LEF1-AS1 could separately serve as potential novel diagnosis and prognostic markers for CRC metastasis.

Interactions among lncRNAs, miRNAs and mRNA in colorectal cancer

Long non-coding RNAs (lncRNAs) are longer than 200 nts non-coding transcripts and have recently emerged as one of the largest and significantly diverse RNA families whereas microRNAs (miRNAs) are highly conserved short single-stranded ncRNAs (∼18-22 nucleotides). As families of small and long evolutionarily conserved ncRNAs, lncRNAs activate and repress genes via a variety of mechanisms at both transcriptional and translational levels, while miRNAs regulate protein-coding gene expression mainly through mRNA degradation or silencing, These ncRNAs have been proved to be involved in multiple biological functions, such as proliferation, differentiation, migration, angiogenesis and apoptosis. Today, while majority of studies have focused on defining the regulatory functions of lncRNAs and miRNAs, limited information have now available for the mutual regulations of lncRNAs, miRNAs and mRNA. Thus, the underlying molecular mechanisms, in particularly the interactions among lncRNAs, miRNAs and mRNA in development, growth, metastasis and therapeutic potential of cancer still remain obscure. Colorectal cancer (CRC) is known as the third most common and fourth leading cancer death worldwide. Increasing evidence showed the close correlations among aberrant expressions of lncRNAs, miRNAs and the occurrence, development of CRC. This review summarize the potential links among these RNAs in following three areas: 1, The biogenesis and roles of miRNAs in CRC; 2, The biogenesis and functions of lncRNAs in CRC; 3, The interactions among lncRNAs, miRNAs and mRNA in tumorigensis, growth, progression, EMT formation, chemoradiotherapy resistance, and therapeutic potential in CRC. We believe that identifying diverging lncRNAs, miRNAs and relevant genes, their interactions and complex molecular regulatory networks will provide important clues for understanding the mechanism and developing novel diagnostic and therapeutic strategies for CRC. Further efforts are warranted to bring the promise of regulating their activities into clinical utilities.

LncRNA TP73-AS1 sponges miR-141-3p to promote the migration and invasion of pancreatic cancer cells through the up-regulation of BDH2

LncRNA TP73 antisense RNA 1T (TP73-AS1) plays an important role in human malignancies. However, the levels of TP73-AS1 and its functional mechanisms in pancreatic cancer metastasis remain unknown, and the clinical significance of TP73-AS1 in human pancreatic cancer is also unclear. In the present study, the levels of TP73-AS1 and its candidate target miR-141 in pancreatic cancer and adjacent normal tissue were detected using qRT-PCR. The association between TP73-AS1 levels and the clinicopathologic characteristics of pancreatic cancer patients were analyzed. The relationship between TP73-AS1 and miR-141, and miR-141 and its candidate target 3-hydroxybutyrate dehydrogenase type 2 (BDH2) was confirmed using dual-luciferase reporter assays. TP73-AS1 and/or miR-141 were knocked down using siRNA or an inhibitor in pancreatic cancer cells and cell migration and invasion then examined. The results showed that TP73-AS1 was up-regulated in pancreatic cancer tissue and cell lines. High levels of TP73-AS1 were correlated with poor clinicopathological characteristics and shorter overall survival. MiR-141 was a direct target for TP73-AS1, while BDH2 was a direct target for miR-141. The knockdown of TP73-AS1 significantly inhibited the migration and invasion of pancreatic cancer cells, while the miR-141 inhibitor significantly restored the migration and invasion. Therefore, TP73-AS1 positively regulated BDH2 expression by sponging miR-141. These findings suggest that TP73-AS1 serves as an oncogene and promotes the metastasis of pancreatic cancer. Moreover, TP73-AS1 could serve as a predictor and a potential drug biotarget for pancreatic cancer.