Kockdown of OIP5-AS1 expression inhibits proliferation, metastasis and EMT progress in hepatoblastoma cells through up-regulating miR-186a-5p and down-regulating ZEB1

Metabolic and Epigenetic Mechanisms in Hepatoblastoma: Insights into Tumor Biology and Therapeutic Targets

BACKGROUND

Hepatoblastoma, the most common pediatric liver malignancy, is characterized by significant molecular heterogeneity and poor prognosis in advanced stages. Recent studies highlight the importance of metabolic reprogramming and epigenetic dysregulation in hepatoblastoma pathogenesis. This review aims to explore the metabolic alterations and epigenetic mechanisms involved in hepatoblastoma and how these processes contribute to tumor progression and survival.

METHODS

Relevant literature on metabolic reprogramming, including enhanced glycolysis, mitochondrial dysfunction, and shifts in lipid and amino acid metabolism, as well as epigenetic mechanisms like DNA methylation, histone modifications, and non-coding RNAs, was reviewed. The interplay between these pathways and their potential as therapeutic targets were examined.

RESULTS

Hepatoblastoma exhibits metabolic shifts that support tumor growth and survival, alongside epigenetic changes that regulate gene expression and promote tumor progression. These pathways are interconnected, with metabolic changes influencing the epigenetic landscape and vice versa.

CONCLUSIONS

The dynamic interplay between metabolism and epigenetics in hepatoblastoma offers promising avenues for therapeutic intervention. Future research should focus on integrating metabolic and epigenetic therapies to improve patient outcomes, addressing current gaps in knowledge to develop more effective treatments.

Summary of biological research on hepatoblastoma: a scoping review

Background

Hepatoblastoma is the most prevalent primary hepatic malignancy in children, comprising 80% of pediatric hepatic malignancies and 1% of all pediatric malignancies. However, traditional treatments have proven inadequate in effectively curing hepatoblastoma, leading to a poor prognosis.

Methods

A literature search was conducted on multiple electronic databases (PubMed and Google Scholar). A total of 86 articles were eligible for inclusion in this review.

Result

This review aims to consolidate recent developments in hepatoblastoma research, focusing on the latest advances in cancer-associated genomics, epigenetic studies, transcriptional programs and molecular subtypes. We also discuss the current treatment approaches and forthcoming strategies to address cancer-associated biological challenges.

Conclusion

To provide a comprehensive summary of the molecular mechanisms associated with hepatoblastoma occurrence, this review highlights three key aspects: genomics, epigenetics, and transcriptomics. Our review aims to facilitate the exploration of novel molecular mechanisms and the development of innovative clinical treatment strategies for hepatoblastoma.

Non-coding RNAs and epithelial mesenchymal transition in cancer: molecular mechanisms and clinical implications

Epithelial-mesenchymal transition (EMT) is a fundamental process for embryonic development during which epithelial cells acquire mesenchymal characteristics, and the underlying mechanisms confer malignant features to carcinoma cells such as dissemination throughout the organism and resistance to anticancer treatments. During the past decades, an entire class of molecules, called non-coding RNA (ncRNA), has been characterized as a key regulator of almost every cellular process, including EMT. Like protein-coding genes, ncRNAs can be deregulated in cancer, acting as oncogenes or tumor suppressors. The various forms of ncRNAs, including microRNAs, PIWI-interacting RNAs, small nucleolar RNAs, transfer RNA-derived RNA fragments, long non-coding RNAs, and circular RNAs can orchestrate the complex regulatory networks of EMT at multiple levels. Understanding the molecular mechanism underlying ncRNAs in EMT can provide fundamental insights into cancer metastasis and may lead to novel therapeutic approaches. In this review, we describe recent advances in the understanding of ncRNAs in EMT and provide an overview of recent ncRNA applications in the clinic.

LncRNA OIP5-AS1 Knockdown Targets miR-183-5p/GLUL Axis and Inhibits Cell Proliferation, Migration and Metastasis in Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is often associated with the infection of Epstein-Barr virus in nasopharynx and is mainly happened in South China and Southeast Asia. Recently, noncoding RNAs have been reported to regulate NPC carcinogenesis. LncRNA OIP5-AS1 participates in tumorigenesis and progression; however, the inherent mechanism of OIP5-AS1-mediated progression of NPC is unclear. In the current study, we aimed to explore the role of OIP5-AS1 in NPC progression. We measured the cell viability, apoptosis, migration, and invasion in NPC cells after OIP5-AS1 modulation. Moreover, we determined whether OIP5-AS1 exerts its oncogenic functions via sponging miR-183-5p in NPC. Furthermore, we determined whether glutamate ammonia ligase (GLUL) was a downstream target of miR-183-5p. We found that OIP5-AS1 downregulation inhibited the viability, migration and invasion of NPC via targeting miR-183-5p. We also identified that GLUL might be a potential downstream target of miR-183-5p in NPC cells. Mechanistically, OIP5-AS1 promotes cell motility via regulating miR-183-5p and GLUL in NPC cells. We concluded that OIP5-AS1 performed its biological functions via targeting miR-183-5p and GLUL in NPC cells.

Long Non-Coding RNAs in Pancreatic Cancer: Biologic Functions, Mechanisms, and Clinical Significance

Despite tremendous efforts devoted to research in pancreatic cancer (PC), the mechanism underlying the tumorigenesis and progression of PC is still not completely clear. Additionally, ideal biomarkers and satisfactory therapeutic strategies for clinical application in PC are still lacking. Accumulating evidence suggests that long non-coding RNAs (lncRNAs) might participate in the pathogenesis of diverse cancers, including PC. The abnormal expression of lncRNAs in PC is considered a vital factor during tumorigenesis that affects tumor cell proliferation, migration, invasion, apoptosis, angiogenesis, and drug resistance. With this review of relevant articles published in recent years, we aimed to summarize the biogenesis mechanism, classifications, and modes of action of lncRNAs and to review the functions and mechanisms of lncRNAs in PC. Additionally, the clinical significance of lncRNAs in PC was discussed. Finally, we pointed out the questions remaining from recent studies and anticipated that further investigations would address these gaps in knowledge in this field.

The role of lncRNA OIP5-AS1 in cancer development and progression

OIP5-AS1, a conserved lncRNA, has been reported to be involved in several biological and pathological processes, including oncogenesis. OIP5-AS1 exerts its oncogenic or antitumor functions via regulation of different miRNAs in various cancer types. In this review, we describe the dysregulation of OIP5-AS1 expression in a variety of human cancers. Moreover, we discuss the multiple functions of OIP5-AS1 in cancer, including in proliferation, apoptosis, autophagy, ferroptosis, cell cycle, migration, metastasis, invasion, epithelial to mesenchymal transition, angiogenesis, cancer stem cells and drug resistance. Furthermore, we provide a future perspective for OIP5-AS1 research. We conclude that targeting OIP5-AS1 might be a promising cancer therapy approach.

Long non-coding RNA OIP5-AS1 suppresses microRNA-92a to augment proliferation and metastasis of ovarian cancer cells through upregulating ITGA6

OBJECTIVE

Recently, long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been identified as essential biomarkers during development of malignancies. This study was performed to study the roles of lncRNA opa-interacting protein 5 antisense transcript 1 (OIP5-AS1) and miR-92a in ovarian cancer (OC).

METHODS

OIP5-AS1, miR-92a and integrin alpha 6 (ITGA6) expression in OC tissues and cells was assessed. The screened OC cells were respectively with OIP5-AS1-, miR-92a- and ITGA6-related vectors or oligonucleotides . The viability, migration, invasion and apoptosis of the cells were determined and the levels of epithelial-mesenchymal transition (EMT)-related proteins were also measured. The interactions between OIP5-AS1 and miR-92a, and between miR-92a and ITGA6 were confirmed.

RESULTS

OIP5-AS1 and ITGA6 were upregulated while miR-92a was downregulated in OC. Inhibited OIP5-AS1 or downregulated ITGA6 or elevated miR-92a repressed EMT, viability, migration and invasion, and promoted apoptosis of OC cells. OIP5-AS1 as a competing endogenous RNA interacted with miR-92a to regulate ITGA6. These effects that induced by silenced OIP5-AS1 could be reversed by miR-92a inhibition while those that induced by up-regulated miR-92a were reduced by restored ITGA6.

CONCLUSION

OIP5-AS1 silencing promoted miR-92a to repress proliferation and metastasis of OC cells through inhibiting ITGA6.

LncRNA MIR205HG accelerates cell proliferation, migration and invasion in hepatoblastoma through the activation of MAPK signaling pathway and PI3K/AKT signaling pathway

Background

Hepatoblastoma (HB) is identified to be the most common liver malignancy which occurs in children. Long non-coding RNAs (lncRNAs) have been implicated in numerous biological processes and diseases, including HB. LncRNA MIR205 host gene (MIR205HG) has been investigated in multiple cancers, however, its role in HB remains to be elucidated.

Methods

MIR205HG expression was analyzed by RT-qPCR. EdU, colony formation and transwell assays were implemented to measure the biological function of MIR205HG on the progression of HB. Mechanism assays were carried out to probe into the underlying mechanism of MIR205HG in HB cells.

Results

MIR205HG was significantly overexpressed in HB. Moreover, MIR205HG inhibition suppressed the proliferative, migratory and invasive capacities of HB cells. Furthermore, MIR205HG competitively bound to microRNA-514a-5p (miR-514a-5p) and targeted mitogen-activated protein kinase 9 (MAPK9) to stimulate mitogen activated protein kinase (MAPK) signaling pathway. Besides, MIR205HG also served as a sponge for microRNA-205-5p (miR-205-5p) to activate the PI3K/AKT signaling pathway.

Conclusion

MIR205HG drives the progression of HB which might provide an efficient marker and new therapeutic target for HB.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13062-021-00309-3.

Long non-coding RNA OIP5-AS1 (Cyrano): A context-specific regulator of normal and disease processes

Long non-coding (lnc) RNAs have been implicated in a plethora of normal biological functions, and have also emerged as key molecules in various disease processes. OIP5-AS1, also commonly known by the alias Cyrano, is a lncRNA that displays broad expression across multiple tissues, with significant enrichment in particular contexts including within the nervous system and skeletal muscle. Thus far, this multifaceted lncRNA has been found to have regulatory functions in normal cellular processes including cell proliferation and survival, as well as in the development and progression of a myriad disease states. These widespread effects on normal and disease states have been found to be mediated through context-specific intermolecular interactions with dozens of miRNAs and proteins identified to date. This review explores recent studies to highlight OIP5-AS1's contextual yet pleiotropic roles in normal homeostatic functions as well as disease oetiology and progression, which may influence its utility in the generation of future theranostics.

The Integrative Analysis of Competitive Endogenous RNA Regulatory Networks in Coronary Artery Disease

Background: Coronary artery disease (CAD) is the leading cause of cardiovascular death. The competitive endogenous RNAs (ceRNAs) hypothesis is a new theory that explains the relationship between lncRNAs and miRNAs. The mechanism of ceRNAs in the pathological process of CAD has not been fully elucidated. The objective of this study was to explore the ceRNA mechanism in CAD using the integrative bioinformatics analysis and provide new research ideas for the occurrence and development of CAD.

Methods: The GSE113079 dataset was downloaded, and differentially expressed lncRNAs (DElncRNAs) and genes (DEGs) were identified using the limma package in the R language. Weighted gene correlation network analysis (WGCNA) was performed on DElncRNAs and DEGs to explore lncRNAs and genes associated with CAD. Functional enrichment analysis was performed on hub genes in the significant module identified via WGCNA. Four online databases, including TargetScan, miRDB, miRTarBase, and Starbase, combined with an online tool, miRWalk, were used to construct ceRNA regulatory networks.

Results: DEGs were clustered into ten co-expression modules with different colors using WGCNA. The brown module was identified as the key module with the highest correlation coefficient. 188 hub genes were identified in the brown module for functional enrichment analysis. DElncRNAs were clustered into sixteen modules, including seven modules related to CAD with the correlation coefficient more than 0.5. Three ceRNA networks were identified, including OIP5-AS1-miR-204-5p/miR-211-5p-SMOC1, OIP5-AS1-miR-92b-3p-DKK3, and OIP5-AS1-miR-25-3p-TMEM184B.

Conclusion: Three ceRNA regulatory networks identified in this study may play crucial roles in the occurrence and development of CAD, which provide novel insights into the ceRNA mechanism in CAD.

Prognostic and Therapeutic Potential of the OIP5 Network in Papillary Renal Cell Carcinoma

Papillary renal cell carcinoma (pRCC) is an aggressive but minor type of RCC. The current understanding and management of pRCC remain poor. We report here OIP5 being a novel oncogenic factor and possessing robust prognostic values and therapeutic potential. OIP5 upregulation is observed in pRCC. The upregulation is associated with pRCC adverse features (T1P < T2P < CIMP, Stage1 + 2 < Stage 3 < Stage 4, and N0 < N1) and effectively stratifies the fatality risk. OIP5 promotes ACHN pRCC cell proliferation and xenograft formation; the latter is correlated with network alterations related to immune regulation, metabolism, and hypoxia. A set of differentially expressed genes (DEFs) was derived from ACHN OIP5 xenografts and primary pRCCs (n = 282) contingent to OIP5 upregulation; both DEG sets share 66 overlap genes. Overlap66 effectively predicts overall survival (p < 2 × 10^-16) and relapse (p < 2 × 10^-16) possibilities. High-risk tumors stratified by Overlap66 risk score possess an immune suppressive environment, evident by elevations in Treg cells and PD1 in CD8 T cells. Upregulation of PLK1 occurs in both xenografts and primary pRCC tumors with OIP5 elevations. PLK1 displays a synthetic lethality relationship with OIP5. PLK1 inhibitor BI2356 inhibits the growth of xenografts formed by ACHN OIP5 cells. Collectively, the OIP5 network can be explored for personalized therapies in management of pRCC patients.

Long Noncoding RNA OIP5-AS1 Contributes to the Progression of Atherosclerosis by Targeting miR-26a-5p Through the AKT/NF-κB Pathway

Atherosclerosis (AS) is a cardiovascular disease caused by multiple factors, leading to high mortality and morbidity in aged people. Some long noncoding RNAs have been reported to be associated with AS progression. However, the roles of OIP5-AS1 in AS development are still little known. In this study, the levels of OIP5-AS1 and miR-26a-5p in oxidized low-density lipoprotein (ox-LDL)-treated human umbilical vein endothelial cells (HUVECs) were determined by quantitative real-time polymerase chain reaction. Cell proliferation and apoptosis were evaluated by Cell Counting Kit-8 assay and flow cytometric analysis, respectively. The protein levels of proliferating cell nuclear antigen, B-cell lymphoma-2, cleaved caspase 3, inflammatory cytokines (IL-6 and IL-1β), protein kinase B (AKT), p-AKT, p65, p-p65, IκBα, and p-IκBα were detected by Western blot analysis. The targeting relationship between OIP5-AS1 and miR-26a-5p was verified by dual-luciferase reporter assay, RNA immunoprecipitation assay, and RNA pull-down assay. As a result, the expression of OIP5-AS1 was upregulated and miR-26a-5p was downregulated in ox-LDL-treated HUVECs. MiR-26a-5p was identified as a direct target of OIP5-AS1. OIP5-AS1 knockdown reversed the inhibitory effect on cell proliferation and the promotional effects on apoptosis and inflammation induced by ox-LDL treatment in HUVECs. Interestingly, the effects caused by OIP5-AS1 knockdown were further attenuated by miR-26a-5p inhibition. Furthermore, OIP5-AS1 knockdown blocked the AKT/NF-κB pathway by regulating miR-26a-5p expression. In conclusion, OIP5-AS1 knockdown promoted cell proliferation and suppressed apoptosis and inflammatory response in ox-LDL-treated HUVECs by targeting miR-26a-5p through blocking the AKT/NF-κB pathway, indicating a promising strategy for AS treatment.

METTL14 promotes tumorigenesis by regulating lncRNA OIP5-AS1/miR-98/ADAMTS8 signaling in papillary thyroid cancer

Background

Papillary thyroid cancer (PTC) is the most common type of cancer of the endocrine system. Long noncoding RNAs (lncRNAs) are emerging as a novel class of gene expression regulators associated with tumorigenesis. Through preexisting databases available for differentially expressed lncRNAs in PTC, we uncovered that lncRNA OIP5-AS1 was significantly upregulated in PTC tissues. However, the function and the underlying mechanism of OIP5-AS1 in PTC are poorly understood.

Methods

Expression of lncRNA OIP5-AS1 and miR-98 in PTC tissue and cells were measured by quantitative real-time PCR (qRT-PCR). And expression of METTL14 and ADAMTS8 in PTC tissue and cells were measured by qRT-PCR and western blot. The biological functions of METTL14, OIP5-AS1, and ADAMTS8 were examined using MTT, colony formation, transwell, and wound healing assays in PTC cells. The relationship between METTL14 and OIP5-AS1 were evaluated using RNA immunoprecipitation (RIP) and RNA pull down assay. And the relationship between miR-98 and ADAMTS8 were examined by luciferase reporter assay. For in vivo experiments, a xenograft model was used to investigate the effects of OIP5-AS1 and ADAMTS8 in PTC.

Results

Functional validation revealed that OIP5-AS1 overexpression promotes PTC cell proliferation, migration/invasion in vitro and in vivo, while OIP5-AS1 knockdown shows an opposite effect. Mechanistically, OIP5-AS1 acts as a target of miR-98, which activates ADAMTS8. OIP5-AS1 promotes PTC cell progression through miR-98/ADAMTS8 and EGFR, MEK/ERK pathways. Furthermore, RIP and RNA pull down assays identified OIP5-AS1 as the downstream target of METTL14. Overexpression of METTL14 suppresses PTC cell proliferation and migration/invasion through inhibiting OIP5-AS1 expression and regulating EGFR, MEK/ERK pathways.

Conclusions

Collectively, our findings demonstrate that OIP5-AS1 is a METTL14-regulated lncRNA that plays an important role in PTC progression and offers new insights into the regulatory mechanisms underlying PTC development.

Downregulation of OIP5-AS1 affects proNGF-induced pancreatic cancer metastasis by inhibiting p75NTR levels

We aimed to explore the mechanism by which long non-coding RNA (lncRNA) OIP5-AS1 affects proNGF (precursor nerve growth factor)-induced pancreatic cancer metastasis by targeting the miR-186-5p/NGFR axis. Bioinformatics was used to analyse whether OIP5-AS1 targets miR-186-5p/NGFR and their expression characteristics in pancreatic cancer. OIP5-AS1 and NGFR were overexpressed in pancreatic cancer, and their levels showed a significant positive correlation. Clinical trials also demonstrated that high expression of OIP5-AS1 and NGFR and low expression of miR-186-5p played a pro-cancer role in pancreatic cancer. MiR-186-5p inhibited the migration and invasion of colon cancer cells by targeting NGFR-regulated p75NTR. OIP5-AS1 regulated the action of miR-186-5p on NGFR mRNA and p75NTR by targeting miR-186-5p. Downregulation of NGFR inhibited the expression of p75NTR protein and blocked the role of proNGF in promoting the migration and invasion of pancreatic cancer cells. Animal experiments also showed that the knockdown of miR-186-5p promoted cancer via the expression of NGFR mRNA and p75NTR protein, while the downregulation of proNGF blocked the effects. OIP5-AS1, as a ceRNA, promotes the progression of pancreatic cancer by targeting miR-186-5p/NGFR and affecting the prognosis of patients, which may be related to the action of proNGF.

A review on the role of oncogenic lncRNA OIP5-AS1 in human malignancies

OIP5-AS1 is a long non-coding transcript with high expression in nervous system, but crucial functions in the neoplastic transformation. This lncRNA partake in the regulation of cell cycle transition at different points. Moreover, it acts a competing endogenous RNA for tens of microRNAs among them are miR-338-3p, miR-204-5p, miR-641, miR-422a, miR-367-3p, miR-153-3p, miR-186, miR-369-3p, miR-137, miR-342-3p, miR‑429, miR-3163, miR-363-3p, miR-186a-5p, hsa-miR-26a-3p, miR‑300, miR-217, miR-378a-3p and miR-448. OIP5-AS1 influence the carcinogenesis via different routes among them is modulation of epithelial-mesenchymal transition. Expression of OIP5-AS1 has been elevated in nearly all kinds of neoplastic tissues except for multiple myeloma. Moreover, in bladder, gastric cancer and lung cancers, assessment of its expression in clinical samples has led to conflicting results. In the current paper, we have provided a comprehensive collection of research papers that evaluated function of OIP5-AS1 in diverse cancer types.

Identification of hub lncRNA ceRNAs in multiple sclerosis based on ceRNA mechanisms

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system, and the pathogenesis is influenced by genetic susceptibility. Accumulating evidence has demonstrated that long non-coding RNAs (lncRNAs) play essential roles in complex diseases, including acting as competing endogenous RNAs (ceRNAs). However, the functional roles and regulatory mechanisms of lncRNAs acting as ceRNAs in MS are still unclear. In this study, we identified hub lncRNA ceRNAs in MS based on ceRNA mechanisms and annotated their functions. The lncRNA-associated ceRNA network (LACN) was constructed by integrating the expression profiles of lncRNA/mRNA and miRNA in MS and normal samples, and the experimentally validated interactions of lncRNA-miRNA and mRNA-miRNA. We found three hub lncRNA ceRNAs (XIST, OIP5-AS1, and CTB-89H12.4) using the network analysis and obtained 96 lncRNA-mediated competing triplets (LCTs, lncRNA-miRNA-mRNA) with the hub lncRNA ceRNAs, which constituted 3 hub ceRNA modules. The functional analysis identified 12 pathways enriched by the 3 hub lncRNA ceRNAs, of which 6 were confirmed to be related to MS. For example, XIST was enriched in the 'spliceosome' and 'RNA transport' related to the typing of MS, and CTB-89H12.4 was enriched in the 'mTOR signaling pathway,' a potential therapeutic target for MS. We dissected the expression patterns of the 96 LCTs in MS individually. LCT XIST-miR-326-HNRNPA1, for which the expression pattern in MS revealed that XIST and HNRNPA1 were up-regulated and miR-326 was down-regulated, consisted of risk RNAs for MS that were validated by other research. Therefore, XIST-miR-326-HNRNPA1 might play a central role in the pathogenesis of MS. These results will contribute to the discovery of novel biomarkers and the development of new therapeutic methods for MS.

A chromatin-associated splicing isoform of OIP5-AS1 acts in cis to regulate the OIP5 oncogene

A large portion of the human genome is transcribed into long noncoding RNAs that can range from 200 nucleotides to several kilobases in length. The number of identified lncRNAs is still growing, but only a handful of them have been functionally characterized. However, it is known that the functions of lncRNAs are closely related to their subcellular localization. Cytoplasmic lncRNAs can regulate mRNA stability, affect translation and act as miRNA sponges, while nuclear-retained long noncoding RNAs have been reported to be involved in transcriptional control, chromosome scaffolding, modulation of alternative splicing and chromatin remodelling. Through these processes, lncRNAs have diverse regulatory roles in cell biology and diseases. OIP5-AS1 (also known as Cyrano), a poorly characterized lncRNA expressed antisense to the OIP5 oncogene, is deregulated in multiple cancers. We showed that one of the OIP5-AS1 splicing forms (ENST00000501665.2) is retained in the cell nucleus where it associates with chromatin, thus narrowing down the spectrum of its possible mechanisms of action. Its knockdown with antisense LNA gapmeRs led to inhibited expression of a sense partner, OIP5, strongly suggesting a functional coupling between OIP5 and ENST00000501665.2. A subsequent bioinformatics analysis followed by RAP-MS and RNA Immunoprecipitation experiments suggested its possible mode of action; in particular, we found that ENST00000501665.2 directly binds to a number of nuclear proteins, including SMARCA4, a component of the SWI/SNF chromatin remodelling complex, whose binding motif is located in the promoter of the OIP5 oncogene.

LncRNA OIP5-AS1 Promotes Breast Cancer Progression by Regulating miR-216a-5p/GLO1

BACKGROUND

Breast cancer is a familiar malignant tumor, which is a great threat to women's life. Long noncoding RNA Opa interacting protein 5-antisense RNA 1 (OIP5-AS1) has been reported to be associated with numerous cancers. This study aimed to explore the role of OIP5-AS1 and the mechanism of its action in the progression of breast cancer.

METHODS

The expression of OIP5-AS1 and miR-216a-5p was detected by quantitative real-time polymerase chain reaction. Cell proliferation, apoptosis, migration, or invasion was assessed by 4-5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, flow cytometry, or transwell assay, respectively. The binding sites were predicted by bioinformatics tool starBase2.0 (http://starbase.sysu.edu.cn/starbase2/index.php). The interaction between miR-216a-5p and OIP5-AS1 or glyoxalase 1 (GLO1) was confirmed by dual-luciferase reporter assay. The expression of GLO1 was quantified by Western blot. Nude mouse tumorigenicity assays were conducted to verify the role of OIP5-AS1 in vivo.

RESULTS

OIP5-AS1 and GLO1 were highly expressed in both clinical tumor tissues and cell lines, whereas miR-216a-5p was downregulated. Knockdown of OIP5-AS1 suppressed proliferation, migration, and invasion but promoted apoptosis of breast cancer cells. MiR-216a-5p was a target of OIP5-AS1 and interacted with GLO1. MiR-216a-5p inhibition or GLO1 overexpression reversed the effects of OIP5-AS1 knockdown on the development of breast cancer cells. OIP5-AS1 knockdown depleted tumor growth in vivo.

CONCLUSIONS

OIP5-AS1 knockdown suppressed the progression of breast cancer by inducing GLO1 expression via competitively binding to miR-216a-5p, suggesting that OIP5-AS1 was a hopeful biomarker for the therapy of breast cancer.

Long Non-Coding RNA OIP5-AS1 Contributes to Gallbladder Cancer Cell Invasion and Migration by miR-143-3p Suppression

Objective

This study was designed to investigate the effect of long non-coding RNA (lncRNA) OIP5-AS1 on cell migration and invasion of gallbladder cancer (GBC) and its specific mechanism.

Methods

The expressions of lncRNA OIP5-AS1 and miR-143-3p in GBC cell lines (GBC-SD, SGC996 and NOZ) and gallbladder epithelial cells (HGBE cells) were measured by qRT-PCR. After loss- and gain-of-function experiments for OIP5-AS1 and miR-143-3p in GBC-SD cells, CCK-8 was applied to examine cell viability, cell scratch assay to measure cell migration, and transwell chamber to inspect cell invasion capacity. The interaction between OIP5-AS1 and miR-143-3p was predicted by StarBase. Then, luciferase reporter gene assay and RNA pull-down were used to verify the targeting relationship between miR-143-3p and OIP5-AS1.

Results

OIP5-AS1 was highly expressed and miR-143-3p was downregulated in GBC cell lines, when compared with HGBE cells. Overexpression of OIP5-AS1 or downregulation of miR-143-3p facilitated GBC-SD cell invasion, proliferation and migration, while different expression patterns were found in GBC-SD cells in response to OIP5-AS1 suppression or miR-143-3p overexpression. OIP5-AS1 negatively mediated miR-143-3p. MiR-143-3p upregulation partially reversed the inhibitory effect of OIP5-AS1 knockdown on GBC-SD cell activities.

Conclusion

LncRNA OIP5-AS1 accelerates the progression of GBC by suppressing miR-143-3p.

LncRNA OIP5-AS1 upregulates snail expression by sponging miR-34a to promote ovarian carcinoma cell invasion and migration

Background

Although OIP5-AS1 has been characterized as an oncogenic lncRNA in many types of cancer, its role and underlying mechanism in ovarian carcinoma (OC) remains unknown. This study aimed to investigate the role of OIP5-AS1 in OC.

Methods

OC tissues and non-tumor tissues (ovary tissues within 3 cm around tumors) were collected from 58 OC patients (age range 36 to 67 years old, mean age 51.4 ± 5.9 years old). The expression of OIP5-AS1 and snail in paired tissues were determined by RT-qPCR. The interaction between OIP5-AS1 and miR-34a was predicted by IntaRNA2.0 and confirmed by dual luciferase reporter assay. The effects of overexpression of OIP5-AS1 and miR-34a on the expression of snail were analyzed by RT-qPCR and Western blotting. Cell invasion and migration were analyzed by Transwell assay.

Results

We observed that the expression of OIP5-AS1 and snail was upregulated and positively correlated with each other in OC. RNA–RNA interaction analysis showed that OIP5-AS1 might sponge miR-34a. In OC cells, overexpression of OIP5-AS1 resulted in the upregulated expression of snail, while overexpression of miR-34a downregulated the expression of snail. In addition, overexpression of miR-34a reduced the effects of overexpression of OIP5-AS1 on the expression of snail. In cell invasion and migration assay, overexpression of OIP5-AS1 and snail resulted in increased OC cell invasion and migration, while overexpression of miR-34a decreased OC cell invasion and migration. Moreover, overexpression of miR-34a attenuated the effects of OIP5-AS1 overexpression on OC cell invasion and migration.

Conclusions

Therefore, OIP5-AS1 may upregulate snail expression in OC by sponging miR-34a to promote OC cell invasion and migration.

Prognostic and clinicopathologic significance of long non-coding RNA opa-interacting protein 5-antisense RNA 1 in multiple human cancers

Background: OIP5-AS1 has been reported to be aberrantly expressed in multiple cancers and associated with clinical outcomes. We conducted this study to assess the generalized prognostic value of OIP5-AS1 in cancers.Methods: PubMed, Web of science, and Cochrane Library were searched for eligible studies. Hazards ratios (HRs) or odd ratios (ORs) with 95% confidence intervals (CIs) were pooled to estimate the prognostic value of OIP5-AS1 in cancers, including overall survival (OS), age, gender, tumor size, clinical stage, and lymph node metastasis (LNM). Publication bias was measured by Begg's test and funnel plot. Sensitivity analysis were used to detect the stability of pooled results.Results: Overall, eleven studies containing 713 patients were eventually enrolled. The pooled results showed that high OIP5-AS1 expression was correlated with shorter OS (HR = 0.48, 95%CI: 0.35-0.64), regardless of the sample size, tumor type and follow-up time. Furthermore, elevated expression of OIP5-AS1 indicated advanced clinical stage (OR = 2.12, 95% CI: 1.06-4.23), but not associated with age, gender, tumor size and LNM. No publication bias was detected.Conclusion: High expression of lncRNA OIP5-AS1 may predict a poor OS and advanced clinical stage, implicating that OIP5-AS1 may be a possible prognostic factor in cancers.

Long non coding RNA OIP5‑AS1 promotes metastasis of breast cancer via miR‑340‑5p/ZEB2 axis

Breast cancer is the most common invasive cancer in women with the highest number of related deaths which is caused by distal metastasis. Recently, integrated analysis of gene expression profile suggested widespread gene dysregulation in various types of cancer. Research in the past decade has focused on long non-coding RNAs (lncRNAs), particularly in cell proliferation, tumor progression and metastasis. OPA-interacting protein 5 antisense transcript 1 (OIP5-AS1) is an evolutionarily conserved long non-coding RNA that has been linked to oncogenesis in multiple cancers. In breast cancer, dysregulation of OIP5-AS1 was reported but the precise role in cancer development and progression remains unclear. In the present study, using small interfering RNA (siRNA) targeting OIP5-AS1, it was shown that knockdown of OIP5-AS1 was associated with alteration of EMT markers and suppressed migration and invasion of breast cancer cells. Among the EMT-related transcription factors, ZEB1 and ZEB2 were significantly downregulated with OIP5-AS1 knockdown. Computational analysis and a dual-luciferase reporter system identified miR-340-5p was the target gene for OIP5-AS1. Further experiments verified the function of OIP5-AS1 in cell invasion was dependent on miR-340a-5p through regulating target gene ZEB2. In vivo study demonstrated that overexpressing OIP5-AS1 in breast cancer cells promoted lung metastasis in nude mice. The findings of the present study revealed the mechanism of OIP5-AS1 in breast cancer metastasis. Overall, our study may provide a potential therapeutic target for breast cancer metastasis.

Identification of New Potential LncRNA Biomarkers in Hirschsprung Disease

Hirschsprung disease (HSCR) is a neurocristopathy defined by intestinal aganglionosis due to alterations during the development of the Enteric Nervous System (ENS). A wide spectrum of molecules involved in different signaling pathways and mechanisms have been described in HSCR onset. Among them, epigenetic mechanisms are gaining increasing relevance. In an effort to better understand the epigenetic basis of HSCR, we have performed an analysis for the identification of long non-coding RNAs (lncRNAs) by qRT-PCR in enteric precursor cells (EPCs) from controls and HSCR patients. We aimed to test the presence of a set lncRNAs among 84 lncRNAs in human EPCs, which were previously related with crucial cellular processes for ENS development, as well as to identify the possible differences between HSCR patients and controls. As a result, we have determined a set of lncRNAs with positive expression in human EPCs that were screened for mutations using the exome data from our cohort of HSCR patients to identify possible variants related to this pathology. Interestingly, we identified three lncRNAs with different levels of their transcripts (SOCS2-AS, MEG3 and NEAT1) between HSCR patients and controls. We propose such lncRNAs as possible regulatory elements implicated in the onset of HSCR as well as potential biomarkers of this pathology.

Integrative analysis of competitive endogenous RNA network reveals the regulatory role of non-coding RNAs in high-glucose-induced human retinal endothelial cells

Background

Increasing evidence has suggested that non-coding RNAs (ncRNAs) play critical roles in the pathogenesis of diabetic retinopathy (DR), but their underlying mechanisms remain unclear. The purpose of this study was to determine latent key genes and to structure a competing endogenous RNA (ceRNA) regulatory network to discover the potential molecular mechanisms governing the effects of high glucose on human retinal endothelial cells (HRECs).

Methods

We obtained microarray data for long non-coding RNA (lncRNA) and mRNA of high-glucose-induced HREC samples from NCBI GEO datasets. The ceRNA network was screened using intersecting prediction results from miRcode, TargetScan, miRTarBase and miRDB. The protein–protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes and hub genes were obtained using the cytoHubba app. The ClusterProfiler package was applied for performing Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The expression of key RNAs was verified using the qRT-PCR method. A key ceRNA subnetwork was constructed based on the criticality of the genes and its binding sites were verified by luciferase reporter assay. The viability and apoptosis of HRECs were tested using the transfection of the miR-449c inhibitor.

Results

A total of 3,328 lncRNAs and 2,017 mRNAs were screened for differentially expressed (DE) profiles. The newly constructed ceRNA network was composed of 410 lncRNAs, 35 miRNAs and 122 mRNAs. The 10 hub genes were identified through the PPI network. GO and KEGG analysis revealed that DE mRNAs were mainly related to the positive regulation of the mRNA catabolic process, cell polarity, and the G1/S transition of mitotic and cell cycle signaling pathways. QRT-PCR was used to verify RNAs and the most important genes were screened out. A key ceRNA subnetwork OIP5-AS1/miR-449c/MYC was established. The binding site was verified by luciferase reporter assay. The expression levels of OIP5-AS1 and MYC increased after miR-449c inhibitor transfection, miR-449c decreased, HRECs activity increased, and apoptosis decreased, compared with the control group.

Conclusion

We successfully built the key ceRNA subnetwork, OIP5-AS1/miR-449c/MYC, by applying the GEO database for data analysis and mining. The results from the ceRNA network allow us to better understand the effect of ncRNAs on HRECs under hyperglycemic conditions and the pathogenesis of DR.

LncRNA OIP5-AS1 promotes the malignancy of pancreatic ductal adenocarcinoma via regulating miR-429/FOXD1/ERK pathway

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC), a subtype of pancreatic cancer, is a malignant tumor with unfavorable prognosis. Despite accumulating researches have made efforts on finding novel therapeutic methods for this disease, the underlying mechanism of long non-coding RNAs (lncRNAs) remains elusive. OIP5 antisense RNA 1 (OIP5-AS1) has been reported to play important role in the occurrence and development of multiple human cancers. This study was aimed at unveiling the regulatory role of OIP5-AS1 in PDAC.

METHODS

RT-qPCR analysis revealed the OIP5-AS1 expression in PDAC tissues and adjacent normal ones. Kaplan-Meier method was applied to analyze the overall survival of patients with high or low level of OIP5-AS1. Gain- or loss-of function assays were performed to assess the effects of OIP5-AS1 knockdown on cell functions, including proliferation, migration and EMT process. Mechanism experiments, such as luciferase reporter and RNA pull-down assays proved the interaction between OIP5-AS1 and miR-429 as well as that between miR-429 and FOXD1.

RESULTS

OIP5-AS1 was up-regulated in PDAC tissues and cell lines, and high level of OIP5-AS1 indicated poor prognosis in PDAC patients. OIP5-AS1 knockdown hindered cell proliferation, migration and epithelial-mesenchymal transition (EMT) process, while overexpression of OIP5-AS1 caused the opposite results. OIP5-AS1 activated ERK pathway through up-regulating forkhead box D1 (FOXD1) expression by sponging miR-429. Furthermore, OIP5-AS1 facilitated cell growth in vivo.

CONCLUSION

OIP5-AS1 exerted oncogenic function in PDAC cells through targeting miR-429/FOXD1/ERK pathway.

Long non-coding RNA OIP5-AS1 promotes the growth of gastric cancer through the miR-367-3p/HMGA2 axis

Increasing evidence shows that aberrant lncRNAs expression contributes to the progression of gastric cancer (GC). The role of the novel lncRNA OIP5-AS1 and its underlying mechanisms in the growth of GC is largely unknown. Here we demonstrate for the first time that OIP5-AS1 expression was up-regulated in GC tissues and cell lines, which significantly correlated with unfavorable clinical characteristics and shorter survival. The results of in vitro and in vivo gain- and loss-of-function experiments indicate that OIP5-AS1 promoted cell proliferation and colony formation while inhibiting apoptosis of GC cells. OIP5-AS1 functioned as an endogenous sponge for miR-367-3p in GC cells. Restoration of miR-367-3p expression abolished the biological effects of OIP5-AS1 on GC cells. Moreover, we show that HMGA2 was a downstream target of miR-367-3p and mediated the effects of OIP5-AS1 on GC cells. OIP5-AS1 regulated the activities of the PI3K/AKT and Wnt/β-catenin pathways through HMGA2. In conclusion, OIP5-AS1 functions as an oncogenic lncRNA that promotes the progression of GC and may serve as a therapeutic target for managing GC.

LncRNA OIP5-AS1 promotes cell proliferation and migration and induces angiogenesis via regulating miR-3163/VEGFA in hepatocellular carcinoma

Long noncoding RNAs (lncRNAs) have been reported to play a significant role in the occurrence and progression of tumors. In different tumors, they can either act as an oncogene or tumor suppressor via modulating various target mRNAs. OIP5-AS1 belongs to lncRNA family. It has been reported to be involved in the tumorigenesis of some cancers, such as bladder cancer, gastric cancer, and multiple myeloma. However, the role it plays in hepatocellular carcinoma (HCC) remains unclear. This study aims to explore the inherent mechanism of lncRNA OIP5-AS1 in HCC. In the first place, qRT-PCR found that OIP5-AS1 and VEGFA expressions were significantly increased while miR-3163 was obviously reduced in HCC cells and tissues. Next, a series of functional experiments found that knockdown of OIP5-AS1 suppressed HCC cell proliferation, migration and angiogenesis abilities while promoting cell apoptosis simultaneously. Last but not least, miR-3163 inhibition or VEGFA overexpression can reverse the anti-tumor effect of OIP5-AS1. In summary, OIP5-AS1 affects HCC proliferation, metastasis, and angiogenesis in HCC by regulating VEGFA expression through sponging miR-3163.

LncRNA OIP5-AS1 facilitates gastric cancer cell growth by targeting the miR-422a/ANO1 axis

OPA-interacting protein 5 antisense transcript 1 (OIP5-AS1) plays an important regulatory role in various types of cancers. However, the functional role and regulatory mechanisms of OIP5-AS1 in gastric cancer (GC) remain largely unknown. In this study, we found that the expression of OIP5-AS1 was increased in GC tissues compared with that in adjacent non-cancerous tissues, which was significantly associated with shorter overall survival time of patients. In addition, OIP5-AS1 expression was also increased in GC cell lines including NCI-N87, MKN-45, BGC-823 and SGC-7901, when compared with that in normal gastric epithelial cell line GES-1. Knockdown of OIP5-AS1 markedly suppressed the proliferation and colony formation activities of GC cells, induced G0/G1 arrest and apoptosis of GC cells in vitro, and restrained tumor growth in vivo. Mechanistically, OIP5-AS1 functions as an oncogenic competing endogenous RNA by binding to and sequestering miR-422a to elevate the expression of anoctamin-1. Our study first demonstrated that OIP5-AS1 is a critical and powerful regulator of GC pathogenesis and may represent a novel candidate target for GC therapy.

Potential therapies for residual hepatoblastoma following incomplete ablation treatment in a nude mouse subcutaneous xenograft model based on lncRNA and mRNA expression profiles

Tumor recurrence following radiofrequency ablation (RFA) treatment in liver cancer is an important factor affecting patient prognosis. Furthermore, the biological role of long non‑coding RNAs (lncRNAs) in residual hepatoblastoma (HB) tissues after RFA remains largely unknown. By using microarray technology, this study investigated the expression of lncRNAs and mRNAs among four pairs of HB tissues (incomplete ablation treatment and no treatment) in a nude mouse subcutaneous xenograft model. Subsequently, bioinformatics analysis was used to understand the functions and pathways of the identified mRNAs. Finally, a connectivity map (CMap) analysis was conducted to identify potential therapeutic strategies for residual HB tissues. Compared with the untreated nude mouse subcutaneous xenograft model, in the experimental group, a significant difference in the expression of 740 lncRNAs and 663 mRNAs was detected. Subsequently, bioinformatics analysis revealed that the differentially expressed mRNAs were significantly enriched in pathways associated with antigen processing, the presentation of endogenous antigens, the regulation of cellular metabolic processes, MAPK signaling and cell cycle regulation. Additionally, six compounds (valproic acid, metformin, tanespimycin, wortmannin, fulvestrant and MK‑886) were identified by CMap analysis as potential therapeutic agents for the treatment of residual HB tissues. These findings provide a novel insight into the pathogenesis of residual HB and potential therapeutic strategies for aggressive tumor recurrence following RFA treatment in patients with HB.

MicroRNA hsa-mir-3923 serves as a diagnostic and prognostic biomarker for gastric carcinoma

Gastric carcinoma (GC) refers to a common digestive system disease that exhibits a very high incidence. MicroRNA hsa-mir-3923 belongs to a type of miRNA, of which the function has been merely investigated in breast, pancreatic cancers and pre-neoplasic stages of gastric cancer. It has not been studied or reported in gastric carcinoma, so the relationship between gastric hsa-mir-3923 expression and the clinics feature and pathology of GC cases was examined. This study employed data mining for analyzing gastric carcinoma data in The Cancer Genome Atlas database. A Chi squared test was performed for assessing the relations of hsa-mir-3923 expression with clinics-related and pathology-regulated variables. This study conducted the assessment of the role of hsa-mir-3923 in prognostic process using Kaplan-Meier curves, Receiver operating characteristic (ROC) analysis and proportional hazards model (Cox) study. With the use of Gene Expression Omnibus, this study carried out gene set enrichment analysis (GSEA). In the meantime, the common miRNA database was compared to predict potential target genes; as revealed by co-expression analysis, a regulatory network probably existed, containing hsa-mir-3923. For the analysis of the most tightly associated cytological behavior and pathway in GC, this study adopted the databases for Annotation, Visualization and Integrated Discovery (David) and KO-Based Annotation System (KOBAS). Cytoscape, R and STRING were employed for mapping probable regulatory networks displaying relations to hsa-mir-3923. Lastly, we obtained 69 genes most tightly associated with hsa-mir-3923 and described their relationship with Circos plot. As revealed from the results, hsa-mir-3923 displayed up-regulation in gastric carcinoma, and it displayed associations with vital status, N stage and histologic grade when being expressed. The predicted results of miRNA target genes suggested that there may be a close relationship between 66 genes and hsa-mir-3923 in gastric cancer. As indicated from co-expression data, a small regulating network of 4 genes probably existed. Our results elucidated that hsa-mir-3923 high-expression reveals poor prognosis of GC patients.

Long non-coding RNA OIP5-AS1 serves as an oncogene in laryngeal squamous cell carcinoma by regulating miR-204-5p/ZEB1 axis

Laryngeal squamous cell carcinoma (LSCC) is the most common type of laryngeal cancer with poor prognosis. In the present study, we aimed to investigate the biological role of long non-coding RNA OIP5-AS1 in LSCC. The results demonstrated that the expression levels of OIP5-AS1 were significantly increased in LSCC tissues and cell lines. High expression of OIP5-AS1 was closely correlated with lymph node metastasis and advanced clinical stage of LSCC patients. Moreover, in vitro assays showed that OIP5-AS1 overexpression promoted the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of LSCC cells, whereas OIP5-AS1 knockdown exerted suppressive effects on LSCC cells. Furthermore, OIP5-AS1 was confirmed to serve as a competing endogenous RNA of miR-204-5p in LSCC cells, and restoration of miR-204-5p counteracted the OIP5-AS1-mediated oncogenic effects. In conclusion, our study provides promising evidence that lncRNA OIP5-AS1 functions as a tumor promoter in LSCC and may be used as a potential target for LSCC therapy.

The Long Non-coding RNA ZFAS1 Sponges miR-193a-3p to Modulate Hepatoblastoma Growth by Targeting RALY via HGF/c-Met Pathway

Hepatoblastoma (HB) is the most common and aggressive malignant hepatic neoplasm in childhood and the therapeutic outcomes remain undesirable due to its recurrence and metastasis. Recently, long non-coding RNA (lncRNA) zinc finger antisense 1 (ZFAS1) has been reported to be an oncogenic gene in multiple cancers. However, the expression status and specific role of ZFAS1 involved in cancer progression of human HB remain unknown. This study aimed to identify the role of ZFAS1/miR-193a-3p/RALY axis in the development of HB. Here we showed that the expression of ZFAS1 was significantly upregulated in both HB tissues and cell lines. High ZFAS1 expression was significantly associated with aggressive tumor phenotypes and poorer overall survival in HB. In vitro and in vivo function assays indicated that silencing of ZFAS1 significantly suppressed HB cell proliferation and invasion. Furthermore, miR-193a-3p was identified to be the target of ZFAS1. Subsequently, RALY was confirmed to be regulated by miR-193a-3p/ZFAS1 axis. Mechanistically, our results indicated that the ZFAS1 participated to the progression of HB via regulating the HGF/c-Met signaling. Collectively, these data demonstrated that ZFAS1 acted as an oncogene to promote initiation and progression of HB by regulating miR-193a-3p/RALY (RALY Heterogeneous Nuclear Ribonucleoprotein) axis via HGF/c-Met Pathway, which provides an efficient marker and new therapeutic target for HB.

LncRNA ROR1‑AS1 high expression and its prognostic significance in liver cancer

Hepatocellular carcinoma (HCC) is a common disease of the digestive system with no curative treatments. Long noncoding RNA tyrosine protein kinase transmembrane receptor 1 antisense RNA 1 (lncRNA ROR1-AS1) is an lncRNA whose functions have been predicted in human diseases; however, its important role in cancer has been probed only in mantle cell lymphoma, not in HCC. Therefore, the present study aimed to elucidate the prognostic significance of lncRNA ROR1-AS1 in HCC. The Cancer Genome Atlas Liver Hepatocellular Carcinoma was used to analyze the expression of ROR1-AS1 in liver cancer. χ² tests were performed to evaluate associations between clinical characteristics and ROR1-AS1 expression. The role of ROR1-AS1 in HCC prognosis was assessed using Kaplan-Meier curves and proportional hazards model (Cox) analysis. Gene set enrichment analysis was performed by using a Gene Expression Omnibus dataset. At the same time, Multi Experiment Matrix was used to predict genes that may be co-expressed with ROR1-AS1. The Database for Annotation, Visualization and Integrated Discovery and KO-Based Annotation System were used to analyze the most closely associated cytological behaviors and pathways in HCC. Then, the genes in the three databases were integrated to screen mRNAs, microRNAs and lncRNAs that had co-expression relationships with ROR1-AS1. Cytoscape, Search Tool for the Retrieval of Interacting Genes/Proteins and Molecular Evolutionary Genetics Analysis were used to map potential regulatory networks and developmental relationships associated with ROR1-AS1. Finally, 12 genes most closely associated with ROR1-AS1 were identified, and their relationship was described using a Circos plot. The results showed that ROR1-AS1 was upregulated in HCC, and its expression was related to clinical stage, T stage and N stage. Furthermore, Kaplan-Meier curves and Cox analysis indicated that high expression of ROR1-AS1 was associated with poor prognosis, and that ROR1-AS1 was an independent risk factor for HCC. Co-expression data suggested that there may be a large regulatory network of 45 genes with indirect associations with ROR1-AS1, a small regulatory network of 15 genes with direct or indirect regulatory relationships, and a special regulatory network containing 12 genes directly associated with ROR1-AS1. The present findings indicated that high expression of ROR1-AS1 suggests poor prognosis in patients with HCC.

Retracted Article: Knockdown of long non-coding RNA OIP5-AS1 suppresses cell proliferation and migration in ox-LDL-induced human vascular smooth muscle cells (hVMSCs) through targeting miR-152-3p/PAPPA axis

Emerging evidence has demonstrated that long non-coding RNA Opa-interacting protein 5 antisense RNA 1 (OIP5-AS1) is associated with cellular behaviors among malignant tumors. However, the role of OIP5-AS1 in atherosclerosis remains largely undefined. The aim of this study was to explore the expression and role of OIP5-AS1 in a cell model of atherosclerosis, as well as the underlying mechanism. We found that expression of OIP5-AS1 was upregulated in human vascular smooth muscle cells (hVMSCs) under oxidized low density lipoprotein (ox-LDL) administration, and knockdown of OIP5-AS1 suppressed cell viability (CCK-8) and proliferating cell nuclear antigen (PCNA) protein level in ox-LDL-treated hVMSCs, as well as inhibited cell migration rate (wound healing assay) and protein expression of matrix metalloproteinase (MMP)-2 and MMP-9. Mechanically, OIP5-AS1 functioned as competing endogenous RNA (ceRNA) to positively regulate PAPPA expression through sponging miRNA-152-3p (miR-152), and pregnancy-associated plasma protein A (PAPPA) was identified as a downstream target gene for miR-152. Moreover, expression of miR-152 was downregulated and PAPPA was upregulated in ox-LDL-treated hVMSCs. Similarly to OIP5-AS1 knockdown, miR-215 overexpression could inhibit cell proliferation and migration of hVMSCs administrated by ox-LDL, which was abated by PAPPA upregulation. Moreover, miR-215 downregulation partially reversed the suppressive role of OIP5-AS1 knockdown as well. In conclusion, knockdown of OIP5-AS1 suppressed ox-LDL-treated hVMSC proliferation and migration presumably through targeting miR-152/PAPPA axis, suggesting a novel OIP5-AS1/miR-152/PAPPA pathway in atherogenesis.

Insights into Biological Role of LncRNAs in Epithelial-Mesenchymal Transition

Long non-coding RNAs (lncRNAs) are versatile regulators of gene expression and play crucial roles in diverse biological processes. Epithelial-mesenchymal transition (EMT) is a cellular program that drives plasticity during embryogenesis, wound healing, and malignant progression. Increasing evidence shows that lncRNAs orchestrate multiple cellular processes by modulating EMT in diverse cell types. Dysregulated lncRNAs that can impact epithelial plasticity by affecting different EMT markers and target genes have been identified. However, our understanding of the landscape of lncRNAs important in EMT is far from complete. Here, we summarize recent findings on the mechanisms and roles of lncRNAs in EMT and elaborate on how lncRNAs can modulate EMT by interacting with RNA, DNA, or proteins in epigenetic, transcriptional, and post-transcriptional regulation. This review also highlights significant EMT pathways that may be altered by diverse lncRNAs, thereby suggesting their therapeutic potential.

Long noncoding RNA PVT1 promotes hepatoblastoma cell proliferation through activating STAT3

Background

Hepatoblastoma is the most common liver malignancy in children. The long noncoding RNA (IncRNA) PVT1 plays oncogenic roles in human cancers; however, its regulation and function in hepatoblastoma remain poorly understood.

Purpose

This study was designed to investigate the regulation and function of PVT1 in hepatoblastoma.

Methods

PVT1 expression was compared between human hepatoblastoma tissues and adjacent non-tumor tissues, and then analyzed using Kaplan-Meier method. The proliferation of hepatoblastoma cells was determined by BrdU incorporation assay. The tumor xenograft model was used to assess tumor proliferation in vivo. The gene expression level was measured by qRT-pCR, Western blot and immunohistochemistry analyses.

Results

Compared with normal counterparts, PVT1 is upregulated in human hepatoblastoma tissues as well as in hepatoblastoma cell lines. Additionally, PVT1 promotes the proliferation of hepatoblastoma cells in vitro and accelerates tumor growth in xenograft model in vivo. Mechanistically, PVT1 promotes the activation of the signal transducer and activator of transcription 3 (STAT3), which leads to the transcriptional activation of downstream targets involved in cell cycle progression, and moreover,STAT3 inhibition with the selective inhibitor stattic abolishes PVT1 pro-proliferative role in hepatoblastoma cells.

Conclusion

PVT1 promotes hepatoblastoma cell proliferation through activating STAT3-induced cell cycle progression, which may implicate PVT1 as a potential therapeutic target for hepatoblastoma treatment.

The Emerging Roles of Cancer Stem Cells and Wnt/Beta-Catenin Signaling in Hepatoblastoma

Hepatoblastoma (HB) is the most common form of primary liver malignancy found in pediatric populations. HB is considered to be clonal and arises from hepatoblasts, or embryonic liver progenitor cells. These less differentiated tumor-initiating progenitor cells, or cancer stem cells (CSCs), may contribute to tumor recurrence and resistance to therapies, and have high metastatic abilities. Phenotypic heterogeneity, undesired genetic and epigenetic alterations, and dysregulated signaling pathways provide CSCs with a survival advantage over current therapies. The molecular and cellular basis of HB and the mechanism of CSC induction are not fully understood. The Wnt/beta-catenin pathway is one of the major developmental pathways and is believed to play an important role in the pathogenesis of HB and CSC formation. This review summarizes the cellular and molecular characteristics of HB with a specific emphasis on CSCs and Wnt/beta-catenin signaling.

Long noncoding RNA OIP5-AS1 acts as a competing endogenous RNA to promote glutamine catabolism and malignant melanoma growth by sponging miR-217

The long noncoding RNA (lncRNA) OIP5-AS1 has been considered to promote the growth and metastasis of many human tumors. However, the role of OIP5-AS1 in melanoma has not been reported. In this study, we found that OIP5-AS1 levels were significantly elevated in melanoma tissue and that high OIP5-AS1 expression was an independent risk factor for the poor survival of patients with melanoma. miR-217 suppressed glutamine catabolism in melanoma cells by targeting glutaminase (GLS), the rate-limiting enzyme of glutamine catabolism. We also demonstrated that OIP5-AS1 acted as a sponge of miR-217 to upregulate GLS expression, thus promoting glutamine catabolism and melanoma growth. Overall, this result elucidates a new mechanism for OIP5-AS1 in metabolism in melanoma and provides a potential therapeutic target for patients with melanoma.

Long noncoding RNA OIP5-AS1 in cancer

Long noncoding RNAs (lncRNAs) can be over two hundred nucleotides in length and lack an obvious open reading frame (ORF). Interestingly, these RNAs form a group of nucleic acids involved in a variety of diverse cellular mechanisms involving proliferation, differentiation, apoptosis,and senescence. Given these characteristics, it is not unexpected that the aberrant expression of certain lncRNAs is strongly linked to oncogenesis and tumor advancement. OIP5-AS1, a prominent tumor-associated lncRNA, contributes to intricate cellular mechanisms during the evolution of malignant tumors. For example, it not only represses cyclin G-associated kinase (GAK) expression thus impacting mitosis, but also regulates cell proliferation and apoptosis in many cancers, including lung adenocarcinoma, breast, glioma and hepatoblastoma. In this paper, we review our current understanding of OIP5-AS1 in carcinogenesis and its potential application as a clinical biomarker or therapeutic target in malignancy.

Low lncRNA ZNF385D‑AS2 expression and its prognostic significance in liver cancer

Hepatocellular carcinoma (HCC) is a common digestive system disease with no curative treatment. Zinc finger protein 385D antisense RNA 2 (ZNF385D-AS2) is a long non-coding RNA (lncRNA) that has been predicted to function in human diseases, including several types of cancer. Yet, it has not been investigated in relation to liver cancer. Thus, the present study was designed with an aim to elucidate the prognostic significance of lncRNA ZNF385D-AS2 in HCC. The Cancer Genome Atlas-Liver Hepatocellular Carcinoma (TCGA-LIHC) collection of data was utilized to analyze the expression of lncRNA ZNF385D-AS2 in liver cancer. Then Chi-square tests were used to evaluate the correlation between clinical characteristics and lncRNA ZNF385D-AS2 expression. The significance of lncRNA ZNF385D-AS2 in patient prognosis was evaluated using Kaplan-Meier curves and Cox analysis. Concomitantly, Gene Set Enrichment Analysis (GSEA) was performed to analyze the most closely related cytological behavior. Finally, we used the Database for Annotation, Visualization and Integrated Discovery (DAVID) and KOBAS software and data from the Gene Expression Omnibus (GEO) database to analyze the possible competing endogenous RNA (ceRNA) network pattern as well as the co-expression network in liver cancer. Based on the results, analysis of RNA-Seq gene expression data for 303 patients with primary tumors revealed low expression of ZNF385D-AS2 in liver cancer. Low expression of ZNF385D-AS2 was found to be significantly associated with sex (P=0.050), T stage (P=0.049), M stage (P=0.040), N stage (P<0.001) and clinical stage (P=0.037). Patients with ZNF385D-AS2 low-expression liver cancers had a shorter median overall survival compared with the patients with ZNF385D-AS2 high-expression liver cancers (P=0.0079). Cox analysis identified ZNF385D-AS2 low-expression as an independent prognostic variable (AUC=0.594) for overall survival in liver cancer patients. Co-expression and ceRNA predictive analysis data suggested that there may be a regulatory signaling axis between ZNF385D-AS2 and miR-96 and miR-182. In conclusion, our results suggests that low expression of ZNF385D-AS2 is predictive of a poor prognosis of liver cancer patients.

LncRNA OIP5-AS1 predicts poor prognosis and regulates cell proliferation and apoptosis in bladder cancer

Opa-interacting protein 5 antisense RNA 1 (OIP5-AS1) is a long intergenic noncoding RNA, which has been suggested to be dysregulated in human cancers and served as tumor suppressor or promoter depending on tumor types. However, the role of OIP5-AS1 in bladder cancer was still unknown. In our study, OIP5-AS1 was overexpressed in bladder cancer, and associated with clinical progression and short overall survival. The loss-of-function studies suggested downregulation of OIP5-AS1 expression decreased cell viability, induced cell-cycle arrest and promoted cell apoptosis in bladder cancer. There was a positive association between OIP5-AS1 expression and OIP5 expression in bladder cancer tissues. Moreover, downregulation of OIP5-AS1 expression reduced messenger RNA and protein levels of OIP5 in bladder cancer cell lines. In conclusion, OIP5-AS1 is a useful biomarker for predicting clinical progression and poor prognosis and promotes cell proliferation through modulating OIP5 expression.

LncRNA OIP5-AS1 Promotes the Proliferation of Hemangioma Vascular Endothelial Cells via Regulating miR-195-5p/NOB1 Axis

Background: Hemangioma, which is a benign vascular neoplasm, has been demonstrated to be the most common tumor of infancy, resulting from aberrant proliferation of endothelial cells and pericytes.

Objective: The aim of this study was to determine the role of lncRNA OIP5-AS1 on the proliferation and metastasis of human hemangioma endothelial cells (HemECs).

Methods: In this study, we examined the expression of OIP5-AS1 and miR-195-5p in hemangiomas patients. The effects of knockdown or ectopic expression of OIP5-AS1 on the viability, proliferation and apoptosis of HemECs were explored. Rescue assays were performed to explore the effects of OIP5-AS1/miR-195-5p/NOB1 axis on biological behaviors in the HemECs.

Results: It was found that OIP5-AS1 was overexpressed in both hemangioma tissues and HemECs cells. OIP5-AS1 knockdown suppressed the proliferation, migration, and invasion of HemECs cell, while overexpression of OIP5-AS1 had opposite effects LncRNA OIP5-AS1 acted as a ceRNA through binding with miR-195-5p to upregulate NOB1 in HemECs.

Conclusion: Taken together, lncRNA OIP5-AS1 acted as a ceRNA to drive proliferation, migration and invasion of HemECs through regulating miR-195-5p/NOB1 axis.

Long Noncoding RNA and Epithelial Mesenchymal Transition in Cancer

Epithelial-mesenchymal transition (EMT) is a multistep process that allows epithelial cells to acquire mesenchymal properties. Fundamental in the early stages of embryonic development, this process is aberrantly activated in aggressive cancerous cells to gain motility and invasion capacity, thus promoting metastatic phenotypes. For this reason, EMT is a central topic in cancer research and its regulation by a plethora of mechanisms has been reported. Recently, genomic sequencing and functional genomic studies deepened our knowledge on the fundamental regulatory role of noncoding DNA. A large part of the genome is transcribed in an impressive number of noncoding RNAs. Among these, long noncoding RNAs (lncRNAs) have been reported to control several biological processes affecting gene expression at multiple levels from transcription to protein localization and stability. Up to now, more than 8000 lncRNAs were discovered as selectively expressed in cancer cells. Their elevated number and high expression specificity candidate these molecules as a valuable source of biomarkers and potential therapeutic targets. Rising evidence currently highlights a relevant function of lncRNAs on EMT regulation defining a new layer of involvement of these molecules in cancer biology. In this review we aim to summarize the findings on the role of lncRNAs on EMT regulation and to discuss their prospective potential value as biomarkers and therapeutic targets in cancer.

The Role of MicroRNAs in Hepatoblastoma Tumors

Hepatoblastoma is the most common hepatic malignancy during childhood. However, little is still known about the molecular mechanisms that govern the development of this disease. This review is focused on the recent advances regarding the study of microRNAs in hepatoblastoma and their substantial contribution to improv our knowledge of the pathogenesis of this disease. We show here that miRNAs represent valuable tools to identify signaling pathways involved in hepatoblastoma progression as well as useful biomarkers and novel molecular targets to develop alternative therapeutic strategies in this disease.

LncRNA OIP5-AS1 inhibits osteoblast differentiation of valve interstitial cells via miR-137/TWIST11 axis

OIP5-AS1, a highly abundant imprinted long non-coding RNA (lncRNA), has been implicated in calcific aortic valve disease (CAVD). However, the function and underlying mechanism of OIP5-AS1 in CAVD progression remains unknown. In this study, osteoblastic differentiation of valve interstitial cells (VICs) isolated from human calcific aortic valves was induced by osteogenic medium. The protein levels of osteogenic markers were determined by immunofluorescence and western blotting. OIP5-AS1, miR-137 and TWIST-related protein 1 (TWIST1) expressions were detected by quantitative real-time PCR (qRT-PCR). ALP activity was evaluated by spectrophotometry. Mineralized bone matrix formation was assessed by Alizarin Red S staining. The interaction between OIP5-AS1 and miR-137 was studied using luciferase reporter assay, RNA pull-down assay and RNA-binding protein immunoprecipitation (RIP) assay. Luciferase reporter assay was also used to identify the possible interaction between miR-137 and TWIST11. The results showed that downregulated expression of OIP5-AS1 was observed in human aortic VICs after osteogenic induction. In vitro experiments revealed that OIP5-AS1 acted as a negative regulator of osteogenic differentiation. Mechanistically, we further showed that OIP5-AS1 could relieve osteogenic differentiation of VICs via upregulating miR-137 target gene TWIST1. Our study provides novel mechanistic insights into the cross-talk between OIP5-AS1, miR-137, and TWIST11, shedding light on the therapy for CAVD.

Downregulation of long non-coding RNA Opa interacting protein 5-antisense RNA 1 inhibits breast cancer progression by targeting sex-determining region Y-box 2 by microRNA-129-5p upregulation

Several studies have shown an important role for long non‐coding RNA (lncRNA) in breast cancer progression. The present study investigated the role of lncRNA Opa interacting protein 5‐antisense RNA 1 (OIP5‐AS1) in the progression of breast cancer. OIP5‐AS1 was significantly upregulated in breast cancer tissues and in breast cancer cell lines, and OIP5‐AS1 downregulation inhibited the malignant behavior of breast cancer in vitro and in vivo. For in‐depth exploration of the mechanism of OIP5‐AS1 in breast cancer, we found that expression of microRNA‐129‐5p(miR‐129‐5p), which was found to bind sites in the sequence of OIP5‐AS1, in breast cancer tissues was negatively correlated with OIP5‐AS1. Also, luciferase assays indicated that OIP5‐AS1 acted as a miR‐129‐5p sponge, resulting in upregulated expression of the sex‐determining region Y‐box 2 (SOX2) transcription factor. Our study showed that OIP5‐AS1 plays a critical role in promoting breast cancer progression and that OIP5‐AS1 downregulation targets SOX2 by miR‐129‐5p upregulation.