Long noncoding RNA NR2F1-AS1 enhances the malignant properties of osteosarcoma by increasing forkhead box A1 expression via sponging of microRNA-483-3p

LncRNA NR2F1-AS1 as a potential biomarker for prognosis in cancer patients: meta and bioinformatics analysis

BACKGROUND

Previous studies have shown that the differential expression of lncRNA NR2F1-AS1 is closely related to the prognosis of cancer, but the conclusion is still controversial. Therefore, we conducted a meta-analysis and bioinformatics analysis to explore the correlation between LncRNA NR2F1-AS1 and cancer prognosis.

METHODS

From the beginning to January 25, 2023, we searched for correlational studies on PubMed, Embase, the Cochrane Library, and Web of Science. We used pooled hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs) to determine the importance of LncRNA NR2F1-AS1 for survival and clinicopathological features of human cancers.

RESULTS

The meta-analysis of 637 patients in the 11 included articles showed that upregulation of LncRNA NR2F1-AS1 was associated with shorter overall survival (HR = 1.46,95%Cl 1.06-2.01, p = 0.02) in cancer patients. In addition, overexpression of LncRNA NR2F1-AS1 predicted TNM tumor stage (OR = 3.37, 95%Cl 2.07-5.48, p < 0.00001), and Distant metastasis (OR = 0.18, 95%Cl 0.06-0.48, p = 0.0007). However, the difference in age (OR = 1.10,95%Cl 0.71-1.71, p = 0.67), gender (OR = 1.26,95%Cl 0.79-2.00, p = 0.34), Lymph node metastasis (OR = 1.44,95%Cl 0.27-7.80, p = 0.67) or larger tumor size (OR = 1.56,95%Cl 0.48-5.08, p = 0.46) was not statistically significant.

CONCLUSION

Upregulation of LncRNA NR2F1-AS1 was associated with poor prognosis and advanced clinicopathologic features of tumor patients.

LncRNA NR2F1-AS1 was involved in azacitidine resistance of THP-1 cells by targeting IGF1 with miR-483-3p

BACKGROUND

The long noncoding RNAs' (lncRNAs) effect on cancer therapy resistance by targeting microRNA (miRNA) in the regulation of drug resistance genes has attracted more and more attention. This study attempted to explore the mechanism of "lncRNA NR2F1-AS1/miR-483-3p/IGF1″ axis in azacitidine resistance of THP-1 cells.

METHODS

THP-1 cells were treated with azacitidine to construct THP1-Aza cells. Cell number and morphological changes were observed by a microscope. CCK8, flow cytometry and transwell were used to detect cell proliferation, apoptosis, cycle, invasion and migration. The targeting relationships between NR2F1-AS1 and miR-483-3p, IGF1 and miR-483-3p were analyzed by dual-luciferase, respectively. RIP assay was applied to verify the interaction between NR2F1-AS1 and miR-483-3p. The relative mRNA expression levels of miR-483-3p, AKT1, PI3K, NR2F1-AS1 and IGF1 were detected by qRT-PCR. PI3K, p-PI3K, AKT, p-AKT and IGF1 protein expression were detected by western blot.

RESULTS

Compared with THP-1 cells, NR2F1-AS1 and IGF1 were highly expressed in THP1-Aza cells, and the miR-483-3p expression was significantly decreased in THP1-Aza cells. Knockdown of NR2F1-AS1 increased apoptosis and G1 phase, and reduced cells growth, invasion and migration ability of THP1-Aza cells. Dual-luciferase demonstrated that NR2F1-AS1 could bind to miR-483-3p, and miR-483-3p could bind to IGF1. RIP assay verified the interaction between NR2F1-AS1 and miR-483-3p. Compared with the si-NR2F1-AS1 group, miR-483-3p inhibitor or oe-IGF1 treatment reduced the apoptosis and cell cycle, and increased the cell growth, invasion and migration ability of THP-1-Aza cells.

CONCLUSION

LncRNA NR2F1-AS1 affects the sensitivity of THP-1 cells to azacitidine resistance by regulating the miR-483-3p/IGF1 axis, which may be a potential target for the treatment of acute monocytic leukemia.

A review on the role of NR2F1-AS1 in the development of cancer

NR2F1-AS1 is a natural antisense transcript with prominent roles in the carcinogenesis. It acts as an oncogene in almost all types of cancers except for cervical and colorectal cancers. It can act as a molecular sponge for miR-17, miR-371a-3p, miR-363, miR-29a-3p, miR-493-5p, miR-190a, miR-140, miR-642a, miR-363, miR-493-5p, miR-483-3p, miR-485-5p, miR-146a-5p, miR-877-5p, miR-338-3 P and miR-423-5p to influence expression of several cancer-related genes. Thus, the sponging role of NR2F1-AS1 is the most appreciated route of its contribution in the carcinogenesis. In addition, NR2F1-AS1 affects activity of IGF-1/IGF-1R/ERK, PI3K/AKT/GSK-3β and Hedgehog pathways. The current narrative review aims at summarization of the results of studies that highlighted the role of NR2F1-AS1 in the carcinogenesis.

Expression and Role of TRIM2 in Human Diseases

Tripartite motif (TRIM) protein family proteins contain more than 80 members in humans, and most of these proteins exhibit E3 ubiquitin ligase activity mediated through a RING finger domain. Their biological functions are very complex, and they perform diverse functions in cell evolution processes, such as intracellular signaling, development, apoptosis, protein quality control, innate immunity, autophagy, and carcinogenesis. Tripartite motif-containing protein 2 (TRIM2), a member of the TRIM superfamily, is an 81 kDa multidomain protein, also known as CMT2R or RNF86, located at 4q31.3. TRIM2 functions as an E3 ubiquitin ligase. Current studies have shown that TRIM2 can play roles in neuroprotection, neuronal rapid ischemic tolerance, antiviral responses, neurological diseases, etc. Moreover, based on some studies in tumors, TRIM2 regulates tumor proliferation, migration, invasion, apoptosis, and drug resistance through different mechanisms and plays a critical role in tumor occurrence and development. This review is aimed at providing a systematic and comprehensive summary of research on TRIM2 and at exploring the potential role of TRIM2 as a biomarker and therapeutic target in many kinds of human diseases.

Long Non-Coding RNAs in the Cell Fate Determination of Neoplastic Thymic Epithelial Cells

Thymic Epithelial Tumors (TETs) arise from epithelial cells of the thymus and are very rare neoplasms comprising Thymoma, Thymic carcinoma, and Thymic Neuroendocrine tumors that still require in-depth molecular characterization. Long non-coding RNAs (lncRNAs) are emerging as relevant gene expression modulators involved in the deregulation of several networks in almost all types of human cancer, including TETs. LncRNAs act at different control levels in the regulation of gene expression, from transcription to translation, and modulate several pathways relevant to cell fate determination under normal and pathological conditions. The activity of lncRNAs is strongly dependent on their expression, localization, and post-transcriptional modifications. Starting from our recently published studies, this review focuses on the involvement of lncRNAs in the acquisition of malignant traits by neoplastic thymic epithelial cells, and describes the possible use of these molecules as targets for the design of novel therapeutic approaches specific for TET. Furthermore, the involvement of lncRNAs in myasthenia gravis (MG)-related thymoma, which is still under investigation, is discussed.

lncRNA DARS-AS1 Promoted Osteosarcoma Progression through Regulating miR-532-3p/CCR7

Background

lncRNAs have been indicated to involve in cell invasion, proliferation, and metastasis. However, function of DARS-AS1 in osteosarcoma remains poorly explored.

Methods

DARS-AS1 and miR-532-3p level were measured using qRT-PCR. CCK-8 assay and cell invasion assay were done to study cell functions. Luciferase reporter assay was performed to study the mechanism about DARS-AS1 and miR-532-3p.

Results

We firstly showed that DARS-AS1 expression is upregulated in 73.5% (25/34) of cases with osteosarcoma. Moreover, DARS-AS1 expression is overexpressed in osteosarcoma specimens than in nontumor samples. The DARS-AS1 is overexpressed in the osteosarcoma cell lines (Saos-2, SOSP-9607, U2OS, and MG-63) compared to hFOB. Overexpression of DARS-AS1 promotes cell growth and invasion in MG-63 osteosarcoma cell. DARS-AS1 plays as one sponge for miR-532-3p in osteosarcoma cell, and miR-532-3p overexpression inhibits luciferase activity of DARS-AS1-WT, not DARS-AS1-MUT in MG-63 cell. Ectopic expression of DARS-AS1 inhibits miR-532-3p expression in MG-63 cell. Furthermore, miR-532-3p expression is downregulated in osteosarcoma specimens compared to in paired nontumor samples. MiR-532-3p expression is downregulated in osteosarcoma cell lines compared to hFOB. MiR-532-3p expression is negatively associated with DARS-AS1 expression in osteosarcoma specimens. miR-532-3p directly regulates CCR7 expression in osteosarcoma cell. Elevated DARS-AS1 expression enhances cell growth and invasion via regulating CCR7.

Conclusions

These data firstly suggested that DARS-AS1 exerted as one oncogene in osteosarcoma partly via regulating miR-532-3p/CCR7.

Hypoxia-induced long noncoding RNA NR2F1-AS1 maintains pancreatic cancer proliferation, migration, and invasion by activating the NR2F1/AKT/mTOR axis

Accumulating evidence has demonstrated the essential role of long noncoding RNAs (lncRNAs) in various types of human cancer, including pancreatic cancer (PC). However, the functions and regulatory mechanisms of nuclear receptor subfamily 2 group F member 1 antisense RNA 1 (NR2F1-AS1) that are responsible for its role in the malignant progression of PC cells remains to be investigated. In this study, the biological effects of NR2F1-AS1 and NR2F1 in PC were investigated by in vitro and in vivo experiments. The mechanisms of NR2F1-AS1 were monitored by bioinformatic predictive analysis and confirmatory experiments. Our results indicated that NR2F1-AS1 was overexpressed and positively correlated with poor survival in PC. Depletion of NR2F1-AS1 restrained PC cell proliferation, migration, invasion, and suppressed xenograft tumor growth and metastasis in vitro and in vivo. Mechanistic experiments suggested that NR2F1-AS1 positively regulated the neighboring NR2F1 gene, which subsequently activated AKT/mTOR signaling, resulting in the upregulation of hypoxia-inducible factor-1α (HIF-1α). Further investigations elucidated that NR2F1-AS1 expression was transcriptionally regulated by HIF-1α under hypoxia. These findings demonstrated that hypoxia-induced NR2F1-AS1 expression directly increased NR2F1 levels to promote PC cell proliferation, migration, and invasion by activating AKT/mTOR signaling. Together, these findings suggest that NR2F1-AS1 could be a prospective therapeutic target for PC.

LINC00662 Promotes Proliferation and Invasion and Inhibits Apoptosis of Glioma Cells Through miR-483-3p/SOX3 Axis

LINC00662 plays a prominent role in the carcinogenesis and progression of diverse cancers. However, its biological functions in glioma are still unclear. LINC00662 expression in glioma tissue samples and cell lines was examined by quantitative real-time polymerase chain reaction. The correlation between LINC00662 expression and the clinical characteristics of 50 patients with glioma was analyzed. LINC00662 knockdown and overexpression cell lines were constructed, and the effects of LINC00662 on the proliferation, invasion, and apoptosis of glioma cells were evaluated by cell counting kit-8, 5-ethynyl-2'-deoxyuridine, Transwell, and flow cytometry assays, respectively. Besides, the relationships among LINC00662, miR-483-3p, and sex-determining region Y-box 3 (SOX3) were assessed by dual-luciferase reporter assay and RNA immunoprecipitation assay. Western blot was used to detect the regulatory effects of LINC00662 and miR-483-3p on SOX3 expression in glioma cells. LINC00662 expression level was elevated in glioma tissues and cell lines compared to that in normal tissues and cell lines. LINC00662 high expression was associated with the adverse prognosis of patients with glioma. Knockdown of LINC00662 repressed the proliferation and invasion of glioma cells, and promoted apoptosis. Additionally, it was revealed that LINC00662 acted as the molecular sponge of miR-483-3p, and SOX3 was verified as a direct target of miR-483-3p. The inhibition of miR-483-3p expression and SOX3 overexpression reversed the biological effects of LINC00662 knockdown on glioma cells. This study reports the key regulatory role of LINC00662/miR-483-3p/SOX3 axis in the tumorigenesis and progression of glioma, bringing novel insights into the underlying mechanisms of glioma.

LncRNA-miRNA-mRNA regulatory axes in endometrial cancer: a comprehensive overview

INTRODUCTION

Recent research on tumorigenesis and progression has opened up an array of novel molecular mechanisms in the form of interactions between cellular non-coding RNAs (long non-coding RNA[lncRNA]/microRNA [miRNA]) and coding transcripts that regulate health and disease. Endometrial cancer (EC) is a prominent gynecological malignancy with a high incidence rate and poorly known etiology and prognostic factors that hinder the success of disease management. The emerging role of lncRNA-miRNA-mRNA interactions and their dysregulation in the pathophysiology of EC has been elucidated in many recent studies.

METHODS

A thorough literature review was conducted to explore information about lncRNA-miRNA-mRNA axes in EC.

RESULTS

Several lncRNAs act as molecular sponges that sequester various tumor suppressor miRNAs to inhibit their function, leading to the dysregulation of their target mRNA transcripts that contribute to the EC regulation.

CONCLUSIONS

This review summarizes these networks of molecular mechanisms and their contribution to different aspects of endometrial carcinogenesis, leading to a better conceptualization of the molecular pathways that underlie the disease and helping establish novel diagnostic biomarkers and therapeutic intervention points to aid the curative intent of EC.

ZEB1-regulated lnc-Nr2f1 promotes the migration and invasion of lung adenocarcinoma cells

Numerous long non-coding RNAs (lncRNAs) are differentially expressed in cancer cells compared with normal cells and are involved in tumor progression and metastasis. Metastasis is initiated by the epithelial-to-mesenchymal transition (EMT) process, which can also be regulated by lncRNAs. Given that ZEB1 is an important transcription factor inducing EMT, we screened lncRNAs controlled by ZEB1 using RNA sequencing in murine lung adenocarcinoma cells. Among several lncRNAs regulated by ZEB1, we selected lnc-Nr2f1. Lnc-Nr2f1 is upregulated by ZEB1 and TGF-β, a potent EMT signal. Growth, migration, and invasion of lung adenocarcinoma cells were decreased after lnc-Nr2f1 knockdown and increased after lnc-Nr2f1 overexpression. Interestingly, lnc-Nr2f1 was transcriptionally controlled by NR2F1, a transcription factor that is transcribed in the antisense direction. NR2F1 was also upregulated and positively correlated with ZEB1, forming a ZEB1/NR2F1/lnc-Nr2f1 axis. Lnc-Nr2f1, in turn, promoted Twist2 transcription through direct binding to its genomic DNA region. Collectively, lnc-Nr2f1 was upregulated by ZEB1 and NR2F1, and promoted migration and invasion of lung adenocarcinoma cells via TWIST2 regulation.

LncRNA nuclear receptor subfamily 2 group F member 1 antisense RNA 1 (NR2F1-AS1) aggravates nucleus pulposus cell apoptosis and extracellular matrix degradation

Emerging reports uncover that long noncoding RNAs (lncRNAs) help regulate intervertebral disc degeneration (IVDD). Here, we probe the function of lncRNA nuclear receptor subfamily 2 group F member 1 antisense RNA 1 (NR2F1-AS1) in IVDD. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was applied to verify the expression of NR2F1-AS1 and miR-145-5p in nucleus pulposus (NP) tissues from IVDD patients or NP cells dealt with IL-1β or TNF-α. Flow cytometry or the TdT-mediated dUTP nick end labeling (TUNEL) assay was performed to validate the apoptosis of NP cells with selective regulation of NR2F1-AS1 and miR-145-5p. ECM-related genes, FOXO1, Bax, and Bcl2 were evaluated by qRT-PCR or Western blot (WB). The targeted relationships between NR2F1-AS1 and miR-145-5p, miR-145-5p and FOXO1 were testified by the dual-luciferase reporter assay and the RNA immunoprecipitation (RIP) assay. Our outcomes substantiated that NR2F1-AS1 was up-regulated, while miR-145-5p was down-regulated in intervertebral disc tissues of IVDD patients or NP cells treated with IL-1β or TNF-α. Besides, overexpressing NR2F1-AS1 intensified ECM degradation and NP cell apoptosis induced by IL-1β, while knocking down NR2F1-AS1 or up-regulating miR-145-5p reversed IL-1β-mediated effects in NP cells. Meanwhile, NR2F1-AS1 choked miR-145-5p and abated its effects in NP cells. This study confirms that NR2F1-AS1 modulates IVDD progression by up-regulating the FOXO1 pathway through the sponge of miR-145-5p as a competitive endogenous RNA (ceRNA).

NR2F1-AS1 Acts as an Oncogene in Breast Cancer by Competitively Binding with miR-641

BACKGROUND

Long noncoding RNA (lncRNA) NR2F1-AS1 has been previously reported to be dysregulated in human cancers and implicated in the tumorigenesis and development of tumors. In this research, we detected the expression level and biological function of NR2F1-AS1 in breast cancer (BC).

METHODS

The expression of NR2F1-AS1 in BC tissues and cell lines was determined by qRT-PCR analysis. The associations of NR2F1-AS1 expression with clinical characteristics and survival rate of BC patients were also analyzed. Cell proliferation, migration, and invasion were measured by the CCK-8 and Transwell assay.

RESULTS

The results revealed that the total survival time of BC patients with high NR2F1-AS1 expression was lower than that of BC patients with low NR2F1-AS1 expression. Moreover, functional experiments demonstrated that knockdown of NR2F1-AS1 inhibited BC cell viability, migration, and invasion abilities, whereas overexpression of NR2F1-AS1 had the opposite effect. Mechanistic investigation revealed that NR2F1-AS1 can competitively bind with microRNA-641 (miR-641) in BC. These results revealed that NR2F1-AS1 functioned as an oncogene by sponging miR-641 expression in BC cell progression. Moreover, miR-641 was negatively correlated with NR2F1-AS1 in BC tissues.

CONCLUSION

Hence, NR2F1-AS1 was found to act as an oncogene in breast cancer by suppressing miR-641. We suggested that NR2F1-AS1 could be a potential biomarker for BC diagnosis and therapy.

NR2F1-AS1/miR-190a/PHLDB2 Induces the Epithelial-Mesenchymal Transformation Process in Gastric Cancer by Promoting Phosphorylation of AKT3

The median survival time of patients with advanced gastric cancer (GC) who received radiotherapy and chemotherapy was <1 year. Epithelial–mesenchymal transformation (EMT) gives GC cells the ability to invade, which is an essential biological mechanism in the progression of GC. The long non-coding RNA (lncRNA)-based competitive endogenous RNA (ceRNA) system has been shown to play a key role in the GC-related EMT process. Although the AKT pathway is essential for EMT in GC, the relationship between AKT3 subtypes and EMT in GC is unclear. Here, we evaluated the underlying mechanism of ceRNA involving NR2F1-AS1/miR-190a/PHLDB2 in inducing EMT by promoting the expression and phosphorylation of AKT3. The results of bioinformatics analysis showed that the expression of NR2F1-AS1/miR-190a/PHLDB2 in GC was positively associated with the pathological features, staging, poor prognosis, and EMT process. We performed cell transfection, qRT-PCR, western blot, cell viability assay, TUNEL assay, Transwell assay, cell morphology observation, and double luciferase assay to confirm the regulation of NR2F1-AS1/miR-190a/PHLDB2 and its effect on EMT transformation. Finally, GSEA and GO/KEGG enrichment analysis identified that PI3K/AKT pathway was positively correlated to NR2F1-AS1/miR-190a/PHLDB2 expression. AKT3 knockout cells were co-transfected with PHLDB2-OE, and the findings revealed that AKT3 expression and phosphorylation were essential for the PHLDB2-mediated EMT process. Thus, our results showed that NR2F1-AS1/miR-190a/PHLDB2 promoted the phosphorylation of AKT3 to induce EMT in GC cells. This study provides a comprehensive understanding of the underlying mechanism involved in the EMT process as well as the identification of new EMT markers.

Long noncoding RNA NR2F1-AS1 plays a carcinogenic role in gastric cancer by recruiting transcriptional factor SPI1 to upregulate ST8SIA1 expression

Gastric cancer (GC) is a highly malignant solid tumor of the digestive tract, which is associated with a high mortality rate. Long non-coding RNA (lncRNA) nuclear receptor subfamily 2 group F member 1 antisense RNA 1 (NR2F1-AS1) has been reported to exert a tumor-promoting effect in some types of cancer. The present study aimed to investigate the role of NR2F1-AS1 in GC. The expression levels of NR2F1-AS1 and its potential target gene were measured in GC cell lines. Bioinformatics analysis, an RNA immunoprecipitation assay and a chromatin immunoprecipitation assay were used to determine the binding relationship between NR2F1-AS1 and downstream genes. The effect of NR2F1-AS1 regulatory axis on AGC cell viability, proliferation, migration, invasion and epithelial-mesenchymal transition was evaluated. The results of the present study revealed that the knockdown of NR2F1-AS1 inhibited the proliferation, invasion and migration of GC cells. NR2F1-AS1 also upregulated the expression levels of ST8SIA1 by recruiting transcriptional factor SPI1. Thus, the effects of the knockdown of NR2F1-AS1 on GC cell functions were suggested to occur via regulation of ST8SIA1. In conclusion, the findings of the current study indicated that NR2F1-AS1 may promote the proliferation, invasion and migration of GC cells by recruiting SPI1, to upregulate ST8SIA1 expression. Thus, the regulation of their expression levels may provide a novel direction for the treatment of GC.

NR2F1-AS1 Promotes Pancreatic Ductal Adenocarcinoma Progression Through Competing Endogenous RNA Regulatory Network Constructed by Sponging miRNA-146a-5p/miRNA-877-5p

The role of NR2F1-AS1 in pancreatic ductal adenocarcinoma (PDAC) remains unknown. Therefore, we aimed to investigate the biological mechanism of NR2F1-AS1 in PDAC. The expression of NR2F1-AS1 was measured by using microarray data and real-time PCR. The effects of NR2F1-AS1 knockdown on proliferation, cell cycle progression, invasion in vitro and tumorigenesis in vivo were investigated. The mechanism of competitive endogenous RNAs was determined from bioinformatics analyses and validated by a dual-luciferase reporter gene assay. Potential target mRNAs from TargetScan 7.2 were selected for subsequent bioinformatics analysis. Key target mRNAs were further identified by screening hub genes and coexpressed protein-coding genes (CEGs) of NR2F1-AS1. NR2F1-AS1 was highly expressed in PDAC, and the overexpression of NR2F1-AS1 was associated with overall survival and disease-free survival. The knockdown of NR2F1-AS1 impaired PDAC cell proliferation, migration, invasion and tumorigenesis. NR2F1-AS1 competitively sponged miR-146a-5p and miR-877-5p, and low expression of the two miRNAs was associated with a poor prognosis. An integrative expression and survival analysis of the hub genes and CEGs demonstrated that the NR2F1-AS1–miR-146a-5p/miR-877-5p–GALNT10/ZNF532/SLC39A1/PGK1/LCO3A1/NRP2/LPCAT2/PSMA4 and CLTC ceRNA networks were linked to the prognosis of PDAC. In conclusion, NR2F1-AS1 overexpression was significantly associated with poor prognosis. NR2F1-AS1 functions as an endogenous RNA to construct a novel ceRNA network by competitively binding to miR-146a-5p/miR-877-5p, which may contribute to PDAC pathogenesis and could represent a promising diagnostic biomarker or potential novel therapeutic target in PDAC.

LncRNA LINC00662 Exerts an Oncogenic Effect on Osteosarcoma by the miR-16-5p/ITPR1 Axis

Background

Osteosarcoma (OS) is one of the most malignant bone tumors and has a high metastatic rate. Increasing research has demonstrated the vital roles of long noncoding RNAs (lncRNAs) in human cancers, including OS. LncRNA LINC00662 has been revealed to act as an oncogene involved in multiple tumor progression. This study aimed to investigate the expression pattern, function, and regulatory mechanism of LINC00662 in OS.

Methods

Patients who underwent OS surgery were involved in this study. Experiments including RT-qPCR, MTT, western blot, FISH, RNA pull-down, luciferase reporter, colony formation, transwell invasion and migration, and sphere formation assay were performed to investigate the regulatory role of LINC00662 in OS.

Results

In the present study, our findings demonstrated the upregulation of LINC00662 expression in OS tissues and cells, and high expression of LINC00662 predicted a poor clinical prognosis of patients' iNOS. Through a series of in vivo assays, LINC00662 knockdown suppressed OS cell proliferation, invasion, migration, and stemness property maintenance. Further mechanistical investigations indicated that LINC00662 functioned as a competing endogenous RNA (ceRNA) for sponging microRNA-16-5p (miR-16-5p) to upregulate the expression of IP receptor type 1 (ITPR1) in OS cells. Restoration assays validated the involvement of ITPR1 in LINC00662-mediated regulation of cell functions in OS.

Conclusion

LINC00662 exerts oncogenic functions in OS by targeting the miR-16-5p/ITPR1 axis.

Long Noncoding RNA NR2F1-AS1 Enhances the Migration and Invasion of Hepatocellular Carcinoma via Modulating miR-642a/DEK Pathway

Purpose

Hepatocellular carcinoma (HCC), a malignant tumor that exists worldwide, has a high morbidity and mortality rate. Previous studies have reported that lncRNA NR2F1-AS1 plays a critical role in several cancers. Here, we aimed to investigate the biological function of NR2F1-AS1 and its molecular mechanism in the migration and invasion of HCC.

Methods

Quantitative real-time PCR (qRT-PCR) was performed to analyze NR2F1-AS1 expression in HCC. The biological function was investigated by transwell invasion and migration assays. The protein level was identified by Western blot. In addition, the downstream targets of NR2F1-AS1 and miR-642a were confirmed by luciferase reporter assays.

Results

NR2F1-AS1 was significantly upregulated in HCC and associated with the poor prognosis of HCC patients. Biological function experiments revealed that the silence of NR2F1-AS1 suppressed cell invasion and migration in HCC. More importantly, NR2F1-AS1 directly interacted with miR-642a and negatively regulated miR-642a. DEK was the target of miR-642a, and NR2F1-AS1 positively regulated DEK expression by suppressing miR-642a.

Conclusion

Taken together, it is the first time we discovered the interaction of NR2F1-AS1 with miR-642a in modulating HCC cell invasion and migration.

Long non-coding RNA NR2F1-AS1 induces breast cancer lung metastatic dormancy by regulating NR2F1 and ΔNp63

Disseminated tumor cells often fall into a long term of dormant stage, characterized by decreased proliferation but sustained survival, in distant organs before awakening for metastatic growth. However, the regulatory mechanism of metastatic dormancy and awakening is largely unknown. Here, we show that the epithelial-like and mesenchymal-like subpopulations of breast cancer stem-like cells (BCSCs) demonstrate different levels of dormancy and tumorigenicity in lungs. The long non-coding RNA (lncRNA) NR2F1-AS1 (NAS1) is up-regulated in the dormant mesenchymal-like BCSCs, and functionally promotes tumor dissemination but reduces proliferation in lungs. Mechanistically, NAS1 binds to NR2F1 mRNA and recruits the RNA-binding protein PTBP1 to promote internal ribosome entry site (IRES)-mediated NR2F1 translation, thus leading to suppression of ΔNp63 transcription by NR2F1. Furthermore, ΔNp63 downregulatio results in epithelial-mesenchymal transition, reduced tumorigenicity and enhanced dormancy of cancer cells in lungs. Overall, the study links BCSC plasticity with metastatic dormancy, and reveals the lncRNA as an important regulator of both processes.

Disseminated tumor cells often become dormant before awakening for metastatic growth. Here, the authors report that the lncRNA, NR2F1-AS1, is upregulated in dormant mesenchymal-like breast cancer stem-like cells and promotes dissemination but inhibits proliferation, leading to metastatic dormancy.

Integrative analysis of prognostic long non-coding RNAs with copy number variation in bladder cancer

Copy number variations (CNVs), which can affect the role of long non-coding RNAs (lncRNAs), are important genetic changes seen in some malignant tumors. We analyzed lncRNAs with CNV to explore the relationship between lncRNAs and prognosis in bladder cancer (BLCA). Messenger RNA (mRNA) expression levels, DNA methylation, and DNA copy number data of 408 BLCA patients were subjected to integrative bioinformatics analysis. Cluster analysis was performed to obtain different subtypes and differently expressed lncRNAs and coding genes. Weighted gene co-expression network analysis (WGCNA) was performed to identify the co-expression gene and lncRNA modules. CNV-associated lncRNA data and their influence on cancer prognosis were assessed with Kaplan-Meier survival curve. Multi-omics integration analysis revealed five prognostic lncRNAs with CNV, namely NR2F1-AS1, LINC01138, THUMPD3-AS1, LOC101928489,and TMEM147-AS1,and a risk-score signature related to overall survival in BLCA was identified. Moreover, validated results in another independent Gene Expression Omnibus (GEO) dataset, GSE31684, were consistent with these results. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that the mitogen-activated protein kinase (MAPK) signaling pathway, focal adhesion pathway, and Janus kinase-signal transducers and activators of transcription (JAK-STAT) signaling pathway were enriched in a high-risk score pattern, suggesting that imbalance in these pathways is closely related to tumor development. We revealed the prognosis-related lncRNAs by analyzing the expression profiles of lncRNAs and CNVs, which can be used as prognostic biomarkers for BLCA.

The Effect and Mechanism of lncRNA NR2F1-As1/miR-493-5p/MAP3K2 Axis in the Progression of Gastric Cancer

Background

LncRNA NR2F1-AS1 has been identified as an oncogene in some human tumors, such as breast cancer, nonsmall cell lung cancer, and esophageal squamous cell carcinoma. Nonetheless, whether NR2F1-AS1 is involved in the progression of gastric cancer (GC) remains unknown.

Methods

The expression patterns of NR2F1-AS1, MAP3K2, and miR-493-5p in GC tissues and cells were detected by RT-qPCR. The protein expression of MAP3K2 was assessed by the Western blotting assay. The MTT assay and flow cytometry were performed to measure cell proliferation and cell apoptosis in GC cells. The transwell assay was adopted to assess cell migration in GC cells. The relationship between NR2F1-AS1, MAP3K2, and miR-493-5p was verified by a dual-luciferase reporter assay.

Results

The increased NR2F1-AS1 and MAP3K2 expressions were discovered in GC tissues and cells compared with control groups. Knockdown of NR2F1-AS1 and MAP3K2 dramatically suppressed cell proliferation and migration, while it enhanced cell apoptosis in GC cells. In addition, NR2F1-AS1 was found to be a sponge of miR-493-5p, and MAP3K2 was a downstream gene of miR-493-5p. Moreover, the expression of MAP3K2 was notably reduced by miR-493-5p, and NR2F1-AS1 counteracted the inhibition of miR-493-5p.

Conclusion

Thus, NR2F1-AS1 was verified to regulate GC cell progression by sponging miR-493-5p to upregulate MAP3K2 expression.

Bioinformatics analysis of the key potential ceRNA biomarkers in human thymic epithelial tumors

BACKGROUND

Thymic epithelial tumors (TETs), originating from the thymic epithelial cells, are the most common primary neoplasms of the anterior mediastinum. Emerging evidence demonstrated that the competing endogenous RNAs (ceRNAs) exerted a crucial effect on tumor development. Hence, it is urgent to understand the regulatory mechanism of ceRNAs in TETs and its impact on tumor prognosis.

METHODS

TETs datasets were harvested from the UCSC Xena as the training cohort, followed by differentially expressed mRNAs (DEmRNAs), lncRNAs (DElncRNAs), and miRNAs (DEmiRNAs) at different pathologic type (A, AB, B, and TC) identified via DESeq2 package. clusterProfiler package was utilized to carry out gene ontology and Kyoto encyclopedia of genes and genomes functional analysis on the DEmRNAs. Subsequently, the lncRNA-miRNA-mRNA regulatory network was constructed to screen the key DEmRNAs. After the key DEmRNAs were verified in the external cohort from Gene Expression Omnibus database, their associated-ceRNAs modules were used to perform the K-M and Cox regression analysis to build a prognostic significance for TETs. Lastly, the feasibility of the prognostic significance was validated by receiver operating characteristic (ROC) curves and the area under the curve.

RESULTS

Finally, a total of 463 DEmRNAs, 87 DElncRNAs, and 20 DEmiRNAs were obtained from the intersection of differentially expressed genes in different pathological types of TETs. Functional enrichment analysis showed that the DEmRNAs were closely related to cell proliferation and tumor development. After lncRNA-miRNA-mRNA network construction and external cohort validation, a total of 4 DEmRNAs DOCK11, MCAM, MYO10, and WASF3 were identified and their associated-ceRNA modules were significantly associated with prognosis, which contained 3 lncRNAs (lncRNA LINC00665, lncRNA NR2F1-AS1, and lncRNA RP11-285A1.1), 4 mRNAs (DOCK11, MCAM, MYO10, and WASF3), and 4 miRNAs (hsa-mir-143, hsa-mir-141, hsa-mir-140, and hsa-mir-3199). Meanwhile, ROC curves verified the accuracy of prediction ability of the screened ceRNA modules for prognosis of TETs.

CONCLUSION

Our study revealed that ceRNAs modules might exert a crucial role in the progression of TETs. The mRNA associated-ceRNA modules could effectively predict the prognosis of TETs, which might be the potential prognostic and therapeutic markers for TETs patients.

STAT3 activates the transcription of lncRNA NR2F1-AS1 to promote the progression of melanoma via regulating the miR-493-5p/GOLM1 axis

BACKGROUND

Long non-coding RNAs (lncRNAs) are vital regulators during the biological processes of melanoma. The present study aimed to uncover biological functions of lncRNA termed NR2F1 antisense RNA 1 (NR2F1-AS1) in melanoma and the potential mechanisms.

METHODS

Relative levels of NR2F1-AS1 and miR-493-5p in a total of 137 paired primary melanoma tissues and corresponding non-tumor tissues, as well as three melanoma cell lines, were examined by a real-time polymerase chain reaction. The clinical significance of NR2F1-AS1 expression was analyzed statistically. The STAT3 binding motif in the promoter region of NR2F1-AS1 was identified by JASPAR (http://jaspar.genereg.net). The association between STAT3 and NR2F1-AS1 was determined by dual-luciferase reporter and chromatin immunoprecipitation assays. The effects of NR2F1-AS1 on cell proliferation, migration and were measured by cell counting kit-8 (CCK-8), Edu, transwell and wound healing assays. Dual-luciferase reporter and RNA pull-down assays were applied to validate the interaction among NR2F1-AS1, miR-493-5p and GOLM1. Furthermore, in vivo experiments were conducted to demonstrate the oncogenic role of NR2F1-AS1 in melanoma.

RESULTS

Up-regulated NR2F1-AS1 and down-regulated miR-493-5p were detected in melanoma tumors and cells. The overexpression of NR2F1-AS1 was induced by STAT3. High NR2F1-AS1 expression was correlated to advanced tumor stage and poor prognosis of melanoma. Functional studies using CCK-8, Edu, transwell and wound healing assays revealed that the proliferative, migratory and invasive capacities of melanoma cells were attenuated by the by inhibition of NR2F1-AS1. Moreover, NR2F1-AS1 was able to up-regulate GOLM1 through recognizing and binding miR-493-5p. Furthermore, knockdown of miR-493-5p distinctly reversed these inhibitory effects of NR2F1-AS1 down-regulation on the tumorigenesis and progression of melanoma.

CONCLUSIONS

Our findings demonstrate a key role for NR2F1-AS1 in melanoma progression via targeting miR-493-5p/GOLM1 axis.

MAFG-driven osteosarcoma cell progression is inhibited by a novel miRNA miR-4660

Osteosarcoma (OS) is the most common primary bone malignancy in the adolescent population. MAFG (v-maf avian musculoaponeurotic fibrosarcoma oncogene homolog G) forms a heterodimer with Nrf2 (NF-E2-related factor 2), binding to antioxidant response element (ARE), which is required for Nrf2 signaling activation. We found that MAFG mRNA and protein expression is significantly elevated in human OS tissues as well as in established and primary human OS cells. In human OS cells, MAGF silencing or knockout (KO) largely inhibited OS cell growth, proliferation, and migration, simultaneously inducing oxidative injury and apoptosis activation. Conversely, ectopic overexpression of MAFG augmented OS cell progression in vitro. MicroRNA-4660 (miR-4660) directly binds the 3′ untranslated region (UTR) of MAFG mRNA in the cytoplasm of OS cells. MAFG 3′ UTR luciferase activity and expression as well as OS cell growth were largely inhibited with forced miR-4660 overexpression but augmented with miR-4660 inhibition. In vivo, MAGF short hairpin RNA (shRNA) or forced overexpression of miR-4660 inhibited subcutaneous OS xenograft growth in severe combined immunodeficient mice. Furthermore, MAFG silencing or miR-4660 overexpression inhibited OS xenograft in situ growth in proximal tibia of the nude mice. In summary, MAFG overexpression-driven OS cell progression is inhibited by miR-4660. The miR-4660-MAFG axis could be novel therapeutic target for human OS.

Role of lncRNA NR2F1-AS1 and lncRNA H19 Genes in Hepatocellular Carcinoma and Their Effects on Biological Function of Huh-7

Objective

This research was designed to probe into the expression and related mechanism of lncRNA NR2F1-AS1 and H19 in hepatocellular carcinoma (HCC).

Methods

Forty-two HCC patients who came to our hospital from February 2018 to August 2019 were included into a research group (RG). Meanwhile, 46 healthy controls were regarded as a control group (CG). BEL-7402, Huh-7 human hepatoma cells and HL-7702 human normal liver cells were purchased, and the NR2F1-AS1 and H19 levels in serum and tissues of HCC patients were detected. PcDNA3.1-NR2F1-AS1, si-NR2F1-AS1, NC, pcDNA3.1-H19 and si-H19 were transfected into BEL-7402 and Huh-7 cells. The NR2F1-AS1 and H19 levels in samples were detected via qRT-PCR, and the expression of apoptosis-related proteins in cells was tested through WB. Cell proliferation, invasion, or apoptosis was detected by CCK8, Transwell or flow cytometry, respectively.

Results

The NR2F1-AS1 and H19 levels were high in human hepatoma cells, and AUCs of lncRNA NR2F1-AS1 and lncRNA H19 were both >0.8. The lncRNA NR2F1-AS1 and lncRNA H19 were associated with HCC staging. After transfection of pcDNA3.1-NR2F1-AS1, si-NR2F1-AS1, NC, pcDNA3.1-H19, si-H19 BEL-7402 and Huh-7 cells, silencing NR2F1-AS1 and H19 expression can promote apoptosis and inhibit cell growth, while silencing their over-expression can inhibit the EMT process of Huh-7 cells.

Conclusion

lncRNA NR2F1-AS1 and lncRNA H19 genes are abnormally expressed in HCC. Furthermore, the two can suppress the EMT process of Huh-7 cells and promote apoptosis effectively.

NR2F1-AS1/miR-140/HK2 Axis Regulates Hypoxia-Induced Glycolysis and Migration in Hepatocellular Carcinoma

Background

Hypoxia is an important feature for the progression of hepatocellular carcinoma (HCC). Long noncoding RNA nuclear receptor subfamily 2 group F member 1 antisense RNA 1 (NR2F1-AS1) is dysregulated in HCC. However, the role and mechanism of N2RF1-AS1 in hypoxia-induced glycolysis and migration remain unclear.

Materials and Methods

Tumor tissues and adjacent samples were harvested from 40 HCC patients. HCC cells were treated by hypoxia. The levels of NR2F1-AS1, microRNA (miR)-140, and hexokinase 2 (HK2) were examined via quantitative reverse transcription polymerase chain reaction or Western blot. Glycolysis was analyzed via glucose uptake, lactate production, and adenosine triphosphate (ATP) levels. Cell migration was analyzed via transwell assay. The target association was analyzed via dual-luciferase reporter assay and RNA immunoprecipitation.

Results

NR2F1-AS1 level was enhanced in HCC tissues and cells. High expression of NR2F1-AS1 indicated poor overall survival. Silence of NR2F1-AS1 repressed hypoxia-induced glycolysis and migration in HCC cells. NR2F1-AS1 could regulate HK2 expression by modulating miR-140. miR-140 down-regulation or HK2 up-regulation mitigated the influence of NR2F1-AS1 silence on hypoxia-induced glycolysis and migration in HCC cells.

Conclusion

NR2F1-AS1 knockdown restrained hypoxia-induced glycolysis and migration in HCC cells via increasing miR-140 and decreasing HK2.

LINC01410 accelerated the invasion and proliferation of osteosarcoma by sponging miR-3128

Increasing evidence has shown that lncRNAs are closely correlated with cell apoptosis, autophagy and progression. However, the role of LINC01410 in osteosarcoma has not been verified. We determined that LINC01410 was overexpressed in osteosarcoma specimens and cell lines. The expression of LINC01410 was upregulated in 22 osteosarcoma patients (22/30, 73%) compared to control normal samples. Ectopic expression of LINC01410 promoted the osteosarcoma cell cycle, proliferation and invasion. Overexpression of LINC01410 induced N-cadherin and Vimentin expression and inhibited E-cadherin expression in osteosarcoma cells. LINC01410 acted as a sponge for miR-3128. The results showed that miR-3128 overexpression decreased the luciferase activity of WT-LINC01410 but not mut-LINC01410 in MG-63 cells. Upregulation of LINC01410 expression suppressed miR-3128 expression in MG-63 cells. Moreover, LINC01410 overexpression increased osteosarcoma cell invasion and growth by modulating miR-3128. These data indicated that LINC01410 acted as an oncogene in osteosarcomagenesis and might be a potential new strategy for osteosarcoma treatment.

Long noncoding RNA NR2F1-AS1 promotes the malignancy of non-small cell lung cancer via sponging microRNA-493-5p and thereby increasing ITGB1 expression

Several studies have reported that the long noncoding ribonucleic acid (lncRNA) NR2F1 antisense RNA 1 (NR2F1-AS1) affects multiple cellular pathways that are involved in tumorigenesis and tumor progression. The present study aimed to detect NR2F1-AS1 expression in non-small cell lung cancer (NSCLC), investigate the role of NR2F1-AS1 in promoting the tumorigenic behavior of NSCLC cells, and elucidate the mechanism underlying the effect of NR2F1-AS1 on NSCLC progression. Our results showed that NR2F1-AS1 expression was upregulated in NSCLC cells, and notably, its upregulation was correlated with adverse clinical characteristics and shorter overall survival in patients with NSCLC. The absence of NR2F1-AS1 functionally decreased NSCLC cell proliferation, migration, and invasion and promoted tumor cell apoptosis. In addition, the tumor growth of NSCLC cells in vivo was inhibited after NR2F1-AS1 silencing. Mechanistically, NR2F1-AS1 functioned as a competing endogenous RNA for miR-493-5p and consequently increased ITGB1 expression. Rescue assays further validated that an increased output of the miR-493-5p/ITGB1 axis could neutralize the regulatory impact of NR2F1-AS1 knockdown on the malignant phenotype of NSCLC cells. In summary, the NR2F1-AS1/miR-493-5p/ITGB1 pathway initiates pro-oncogenic behavior in NSCLC tumor progression, and the NR2F1-AS1/miR-493-5p/ITGB1 axis may provide new molecular targets for anticancer therapy against NSCLC.

Long non‑coding RNA NR2F1‑AS1 facilitates the osteosarcoma cell malignant phenotype via the miR‑485‑5p/miR‑218‑5p/BIRC5 axis

Long non-coding RNA (lncRNA) NR2F1 antisense RNA 1 (NR2F1-AS1) has been reported to be an oncogene in several cancer types, including osteosarcoma (OS). However, the underlying fundamental molecular mechanism of NR2F1-AS1 in OS remains largely unknown, which the present study aimed to elucidate. The present study demonstrated that NR2F1-AS1 expression is markedly increased in OS, and NR2F1-AS1 was shown to exert oncogenic functions in OS. Further molecular mechanistic studies revealed that microRNA (miR)-485-5p and miR-218-5p were direct targets of NR2F1-AS1. More importantly, miR-485-5p and miR-218-5p exhibited low expression levels and were negatively correlated with NR2F1-AS1 expression in OS tissues. It was then identified that baculoviral inhibitor of apoptosis repeat-containing 5 (BIRC5) was a direct target of miR-485-5p and miR-218-5p in OS cells. Furthermore, a series of experiments suggested that NR2F1-AS1 affects the proliferation, migration, invasion and apoptosis of OS cells by regulating BIRC5. Finally, it was revealed that silencing of NR2F1-AS1 repressed the OS cell malignant phenotype by binding with miR-485-5p and miR-218-5p, and then downregulating BIRC5 expression, which suggests that the NR2F1-AS1/miR-485-5p/miR-218-5p/BIRC5 axis could be a potential target for treating OS.

LINC01535 Promotes the Development of Osteosarcoma Through Modulating miR-214-3p/KCNC4 Axis

Background

Osteosarcoma (OS) is the most common primary bone tumor in group of children and adolescents. Increasing studies showed that long non-coding RNAs (lncRNAs) exerted important functions in the development of tumors, including OS. LINC01535 is an lncRNA which has been studied in cervical cancer but not in OS.

Aim of the Study

This study was aimed to explore the biological function and mechanism of LINC01535 in OS.

Methods

LINC01535 expression was detected by qRT-PCR. Colony formation assay, EdU assay and CCK-8 assay were applied to check cell proliferation ability in OS. Flow cytometry analysis was conducted to measure cell apoptosis capacity. Wound healing assay and transwell assay were performed to assess cell migration and invasion. Luciferase reporter assay and RNA pull-down assay were carried out to verify the molecular mechanism.

Results

The high expression of LINC01535 was presented in OS tissues and cell lines compared with adjacent normal tissues and human osteoblasts. Moreover, OS patients with high LINC01535 expression exhibited poor prognosis. Loss-of-function assay revealed that silenced LINC01535 significantly attenuated cell proliferation, migration and invasion, and enhanced cell apoptosis in OS. Through mechanistic exploration, we found that LINC01535 interacted with miR-214-3p, and KCNC4 was validated to be a target gene of miR-214-3p. The levels of KCNC4 mRNA and protein were positively modulated by LINC01535 and reversely mediated by miR-214-3p. Based on rescue experiments, KCNC4 overexpression reserved the suppressive function of silenced LINC01535 on OS cell growth, migration and invasion.

Conclusion

LINC01535, miR-214-3p and KCNC4 constituted an effective axis that exerted a pregnant regulation in OS development, which is a quite meaningful discovery for exploring potential therapeutic methods for OS patients.

MicroRNAs in cancer therapy: Their involvement in oxaliplatin sensitivity/resistance of cancer cells with a focus on colorectal cancer

The resistance of cancer cells into chemotherapy has restricted the efficiency of anti-tumor drugs. Oxaliplatin (OX) being an anti-tumor agent/drug is extensively used in the treatment of various cancer diseases. However, its frequent application has led to chemoresistance. As a consequence, studies have focused in finding underlying molecular pathways involved in OX resistance. MicroRNAs (miRs) are short endogenous non-coding RNAs that are able to regulate vital biological mechanisms such as cell proliferation and cell growth. The abnormal expression of miRs occurs in pathological events, particularly cancer. In the present review, we describe the involvement of miRs in OX resistance and sensitivity. The miRs are able to induce the oncogene factors and mechanisms, resulting in stimulation OX chemoresistance. Also, onco-suppressor miRs can enhance the sensitivity of cancer cells into OX chemotherapy and trigger apoptosis and cell cycle arrest, leading to reduced viability and progression of cancer cells. MiRs can also enhance the efficacy of OX chemotherapy. It is worth mentioning that miRs affect various down-stream targets in OX resistance/sensitivity such as STAT3, TGF-β, ATG4B, FOXO1, LATS2, NF-κB and so on. By identification of these miRs and their upstream and down-stream mediators, further studies can focus on targeting them to sensitize cancer cells into OX chemotherapy and induce apoptotic cell death.

Long noncoding RNA RHPN1-AS1 exerts pro-oncogenic actions in osteosarcoma by functioning as a molecular sponge of miR-506 to positively regulate SNAI2 expression

The long noncoding RNA, RHPN1 antisense RNA 1 (RHPN1-AS1), performs important regulatory actions in the progression of many human cancers. In this study, we aimed to analyze RHPN1-AS1 expression in osteosarcoma (OS) and to assess the influence of RHPN1-AS1 knockdown on the malignant behavior of OS cells. The molecular mechanisms by which RHPN1-AS1 affects the oncogenicity of OS were explored too. The expression of RHPN1-AS1 in OS was measured by RT-qPCR. The effects of the RHPN1-AS1 silencing in OS cells were studied both in vitro (in a Cell Counting Kit-8 assay, apoptosis analysis, and Transwell migration and invasion assays) and in vivo (by means of tumor xenografts in nude mice). Herein, RHPN1-AS1 expression was found to be significantly upregulated in OS tissues and cell lines. The elevated expression of RHPN1-AS1 closely correlated with the tumor size, TNM stage, distal metastasis and shorter overall survival in patients with OS. The depletion of RHPN1-AS1 restrained OS cell proliferation, migration, and invasion, and exerted proapoptotic effects in vitro. Furthermore, the knockdown of RHPN1-AS1 effectively reduced the tumor growth of OS cells in vivo. As for the mechanism, RHPN1-AS1 increased snail family zinc finger 2 (SNAI2 also known as SNAIL2) expression by acting as a competing endogenous RNA of miR-506. Notably, increasing the amount of miR-506 partially reversed the effects of the RHPN1-AS1 downregulation on OS cells. In conclusion, RHPN1-AS1 contributes to the malignancy of OS cells in vitro and in vivo, largely via upregulation of the miR-506-SNAI2 axis output.

The therapeutic value of the SphK1-targeting microRNA-3677 in human osteosarcoma cells

Sphingosine kinase 1 (SphK1) is a potential therapeutic target for human osteosarcoma (OS). SphK1-targeting microRNAs (miRNAs) could have important therapeutic value for OS. We discovered that micorRNA-3677 (miR-3677) is a SphK1-targeting miRNA, inhibiting OS cell progression. The results of RNA-Pull down assay confirmed direct binding between biotinylated-miR-3677 and SphK1 mRNA in primary human OS cells. In established and primary human OS cells forced overexpression of miR-3677, by a lentiviral construct, decreased SphK1 3’-UTR (untranslated region) activity and downregulated SphK1 expression. Both were however enhanced with miR-3677 inhibition in OS cells. Function studies demonstrated that OS cell growth, proliferation and migration were inhibited with miR-3677 overexpression, but augmented with miR-3677 inhibition. MiR-3677 overexpression-induced anti-OS cell activity was reversed with re-expression of the 3’-UTR-depleted SphK1. Additionally, in SphK1 knockout OS cells (by CRISPR/Cas9 strategy), altering miR-3677 expression failed to further alter cell functions. Finally, we show that miR-3677 expression was significantly downregulated in primary human OS tissues, correlating with SphK1 mRNA upregulation. We conclude that targeting SphK1 by miR-3677 inhibits human OS cell progression.

Roles and correlation of FOXA1 and ZIC1 in breast cancer

The aim of this study was to evaluate the prognostic role of Forkhead box A1 (FOXA1) in breast cancer and determine the relationship between FOXA1 and zinc finger of the cerebellum 1 (ZIC1). BCIP, GEPIA, and Oncomine databases were used to detect expression of FOXA1 and assess prognostic roles of FOXA1 and ZIC1 in invasive breast tumors. A total of 113 female invasive breast cancer cases were collected to investigate FOXA1 and ZIC1 expression via immunohistochemistry. Twenty pairs of frozen-thawed tumors were used to select reliable indicators via western blotting and real-time quantitative polymerase chain reaction. In addition, Kaplan-Meier curves and Cox regression analysis were performed to analyze the overall survival (OS) and relapse-free survival. Multiple databases showed that FOXA1 expression was elevated in invasive breast cancer and negatively related to ZIC1. BCIP database also displayed a poor prognosis of high FOXA1 and low ZIC1. FOXA1 was positively associated with tumor size, grading, lymph node metastasis, and Tumor Node Metastasis (TNM) staging, while ZIC1 expression was negatively related to grading, lymph node metastasis, and TNM staging. In Kaplan-Meier and Cox regression analysis, FOXA1 negative group and ZIC1 positive group had better OS rate and recurrence-free survival rate. In addition, a joint evaluation showed that "FOXA1- ZIC1+" had the highest OS and relapse-free survival, but "FOXA1+ ZIC1-" had the lowest ones. FOXA1 was negatively related to ZIC1 in breast cancer and they had different roles in clinicopathology and prognosis. Combined examination of FOXA1 and ZIC1 could bring more benefit to breast cancer patients.

Long Noncoding RNA ZFPM2-AS1 Enhances the Malignancy of Cervical Cancer by Functioning as a Molecular Sponge of microRNA-511-3p and Consequently Increasing FGFR2 Expression

Purpose

A long noncoding RNA called ZFPM2 antisense RNA 1 (ZFPM2-AS1) has been verified as a key modulator in multiple human cancer types. Nonetheless, the expression and functions of ZFPM2-AS1 in cervical cancer remain poorly understood. Therefore, our purpose was to characterize the expression pattern, clinical value, and detailed roles of ZFPM2-AS1 in cervical cancer.

Methods

Reverse-transcription quantitative PCR was carried out to measure ZFPM2-AS1 expression in cervical cancer. A Cell Counting Kit-8 assay, flow cytometry, Transwell migration and invasion assays, and a tumor xenograft experiment were conducted to determine the influence of ZFPM2-AS1 on cervical cancer cell proliferation, apoptosis, migration, and invasion in vitro and on tumor growth in vivo, respectively.

Results

ZFPM2-AS1 was found to be aberrantly upregulated in cervical cancer, and its upregulation was associated with unfavorable values of clinical parameters. A ZFPM2-AS1 knockdown significantly reduced cervical cancer cell proliferation, migration, and invasion and increased apoptosis in vitro. The ZFPM2-AS1 knockdown decelerated tumor growth of cervical cancer cells in vivo. Molecular investigation indicated that ZFPM2-AS1 acts as a molecular sponge of microRNA-511-3p (miR-511-3p) in cervical cancer cells. Fibroblast growth factor receptor 2 (FGFR2) mRNA was validated as a direct target of miR-511-3p in cervical cancer, and its expression was positively modulated by ZFPM2-AS1. The effects of the ZFPM2-AS1 knockdown on malignant characteristics of cervical cancer cells were greatly attenuated by miR-511-3p inhibition.

Conclusion

ZFPM2-AS1 promotes cervical cancer progression through upregulation of miR-511-3p–FGFR2 axis output, thereby pointing to possible diagnostics and therapeutics based on the ZFPM2-AS1–miR-511-3p–FGFR2 pathway.