Long noncoding RNA MLK7-AS1 promotes ovarian cancer cells progression by modulating miR-375/YAP1 axis

METTL3 promotes non-small-cell lung cancer growth and metastasis by inhibiting FDX1 through copper death-associated pri-miR-21-5p maturation

Objective: We probed into the significance of METTL3 in the maturation process of pri-miR-21-5p. We specifically investigated its impact on the regulation of FDX1 and its involvement in the progression of non-small-cell lung cancer (NSCLC). Methods: The Cancer Genome Atlas (TCGA) identified NSCLC factors. Methylation-specific PCR (MSP), clonogenic tests and flow cytometry analyzed cells. Methylated RNA immunoprecipitation (Me-RIP) and dual-luciferase studied miR-21-5p/FDX1. Mice xenografts showed METTL3's tumorigenic effect. Results: METTL3, with high expression but low methylation in NSCLC, influenced cell behaviors. Its suppression reduced oncogenic properties. METTL3 enhanced miR-21-5p maturation, targeting FDX1 and boosting NSCLC tumorigenicity in mice. Conclusion: METTL3 may promote NSCLC development by facilitating pri-miR-21-5p maturation, upregulating miR-21-5p and targeting inhibition of FDX1.

Two antisense RNAs-AFAP1-AS1 and MLK7-AS1-promote colorectal cancer progression by sponging miR-149-5p and miR-485-5p

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths. Antisense RNAs (asRNAs) are closely associated with cancer malignancy. This study aimed to identify the action mechanism of asRNAs in controlling CRC malignancy. Analysis of the RNA sequencing data revealed that AFAP1-AS1 and MLK7-AS1 were upregulated in CRC patients and cell lines. High levels of both asRNAs were associated with poor prognosis in patients with CRC. Both in vitro and in vivo experiments revealed that the knockdown of the two asRNAs decreased the proliferative and metastatic abilities of CRC cells. Mechanistically, AFAP1-AS1 and MLK7-AS1 decreased the levels of miR-149-5p and miR-485-5p by functioning as ceRNAs. Overexpression of miRNAs by introducing miRNA mimics suppressed the expression of SHMT2 and IGFBP5 by directly binding to the 3' UTR of their mRNA. Knockdown of both asRNAs decreased the expression of SHMT2 and IGFBP5, which was reversed by inhibition of both miRNAs by miRNA inhibitors. In vivo pharmacological targeting of both asRNAs by small interfering RNA-loaded nanoparticles showed that knockdown of asRNAs significantly reduced tumor growth and metastasis. Our findings demonstrate that AFAP1-AS1 and MLK7-AS1 promote CRC progression by sponging the tumor-suppressing miRNAs miR-149-5p and miR-485-5p, thus upregulating SHMT2 and IGFBP5.

Extracellular Vesicles Derived circSH3PXD2A Inhibits Chemoresistance of Small Cell Lung Cancer by miR-375-3p/YAP1

Introduction

Small cell lung cancer (SCLC) is a subtype of lung cancer with high malignancy and poor prognosis. Rapid acquisition of chemoresistance is one of the main reasons leading to clinical treatment failure of SCLC. Studies have indicated that circRNAs participate in multiple processes of tumor progression, including chemoresistance. However, the molecular mechanisms of circRNAs driving the chemoresistance of SCLC are not well specified.

Methods

The differentially expressed circRNAs were screened by transcriptome sequencing of chemoresistant and chemosensitive SCLC cells. The EVs of SCLC cells were isolated and identified by ultracentrifugation, Western blotting, transmission electron microscopy, nanoparticle tracking analysis and EVs uptake assays. The expression levels of circSH3PXD2A in serum and EVs of SCLC patients and healthy individuals were detected by qRT‒PCR. The characteristics of circSH3PXD2A were detected by Sanger sequencing, RNase R assay, nuclear-cytoplasmic fraction assay, and fluorescence in situ hybridization assay. The mechanisms of circSH3PXD2A inhibiting SCLC progression were studied by bioinformatics analysis, chemoresistance assay, proliferation assay, apoptosis assay, transwell assay, pull-down assay, luciferase reporting assay, and mouse xenograft assay.

Results

It was identified that the circSH3PXD2A was a prominently downregulated circRNA in chemoresistant SCLC cells. The expression level of circSH3PXD2A in EVs of SCLC patients was negatively associated with chemoresistance, and the combination of EVs-derived circSH3PXD2A and serum ProGRP (Progastrin-releasing peptide) levels had better indications for DDP-resistant SCLC patients. CircSH3PXD2A inhibited the chemoresistance, proliferation, migration, and invasion of SCLC cells through miR-375-3p/YAP1 axis in vivo and in vitro. SCLC cells cocultured with EVs secreted by circSH3PXD2A-overexpressing cells exhibited decreased chemoresistance and cell proliferation.

Conclusion

Our results manifest that EVs-derived circSH3PXD2A inhibits the chemoresistance of SCLC through miR-375-3p/YAP1 axis. Moreover, EVs-derived circSH3PXD2A may serve as a predictive biomarker for DDP-resistant SCLC patients.

Long noncoding RNA SNHG6 promotes the malignant phenotypes of ovarian cancer cells via miR-543/YAP1 pathway

The long non-coding RNA small nucleolar RNA host gene 6 (SNHG6) acts as an oncogene in several cancers, and is highly expressed in ovarian cancer. MiR-543, a tumor suppressor, was expressed lowly in ovarian cancer. However, whether SNHG6 performed its oncogenic role via miR-543 in ovarian cancer, as well as the underlying mechanism is still not clear. In this study, we showed that the levels of SNHG6 and Yes-associated protein 1 (YAP1) were significantly elevated, while the level of miR-543 was significantly decreased, in ovarian cancer tissues compared with adjacent normal samples. We demonstrated that overexpression of SNHG6 significantly promoted the proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) of ovarian cancer cells SKOV3 and A2780. Knockdown of SNHG6 showed the opposite effects. MiR-543 level was negatively correlated with the SNHG6 level in ovarian cancer tissues. SHNG6 overexpression significantly inhibited the expression of miR-543, and SHNG6 knockdown significantly elevated the expression of miR-543 in ovarian cancer cells. The effects of SNHG6 on ovarian cancer cells were abrogated by miR-543 mimic, and strengthened by anti-miR-543. YAP1 was identified as a target of miR-543. Forced expression of miR-543 significantly inhibited the expression of YAP1. Moreover, YAP1 overexpression could reverse the effects of SNHG6 downregulation on the malignant phenotypes of ovarian cancer cells. In summary, our study showed that SNHG6 promoted the malignant phenotypes of ovarian cancer cells via miR-543/YAP1 pathway.

Long Noncoding RNA MAGI2-AS3 Represses Cell Progression in Clear Cell Renal Cell Carcinoma by Modulating the miR-629-5p/PRDM16 Axis

The objective of this study was to determine the regulatory mechanism of MAGI2-AS3 in clear cell renal cell carcinoma (ccRCC), thereby supplying a new insight for ccRCC treatment. Expression data in TCGA-KIRC were obtained. Target gene lncRNA for research was determined using expression analysis and clinical analysis. lncRNA's downstream regulatory miRNA and mRNA were predicted by bioinformatics databases. ccRCC cell malignant phenotypes were detected via CCK-8, colony formation, Transwell migration, and invasion assays. The targeting relationship between genes was assessed through dual-luciferase reporter gene analysis. Kaplan-Meier (K-M) analysis was carried out to verify the effect of MAGI2-AS3, miR-629-5p, and PRDM16 on the survival rate of ccRCC patients. MAGI2-AS3 expression in ccRCC tissue and cells was shown to be markedly decreased and its expression to continuously decline with tumor progression. MAGI2-AS3 suppresses ccRCC proliferation and migration. Dual-luciferase assay showed that MAGI2-AS3 binds miR-629-5p and that miR-629-5p binds PRDM16. In addition, functional experiments showed that MAGI2-AS3 facilitates PRDM16 expression by repressing miR-629-5p expression, thereby suppressing ccRCC cell aggression. K-M analysis showed that upregulation of either MAGI2-AS3 or PRDM16 significantly improves ccRCC patient survival, while upregulation of miR-629-5p has no significant impact. MAGI2-AS3 sponges miR-629-5p to modulate PRDM16 to mediate ccRCC development. Meanwhile, the MAGI2-AS3/miR-629-5p/PRDM16 axis, as a regulatory pathway of ccRCC progression, may be a possible therapeutic target and prognostic indicator of ccRCC.

LncGSAR Controls Ovarian Granulosa Cell Steroidogenesis via Sponging MiR-125b to Activate SCAP/SREBP Pathway

Long non-coding RNAs (lncRNAs) have been shown to play important roles in livestock fecundity, and many lncRNAs that affect follicular development and reproductive diseases have been identified in the ovary. However, only a few of them have been functionally annotated and mechanistically validated. In this study, we identified a new lncRNA (lncGSAR) and investigated its effects on the proliferation and steroidogenesis of ovine granulosa cells (GCs). High concentrations of glucose (add 33.6 mM glucose) caused high expression of lncGSAR in GCs by regulating its stability, and lncGSAR overexpression promoted GCs proliferation, estrogen secretion, and inhibited progesterone secretion, whereas interference with lncGASR had the opposite effect. Next, we found that the RNA molecules of lncGSAR act on MiR-125b as competitive endogenous RNA (ceRNA), and SREBP-cleavage-activating protein (SCAP) was verified as a target of MiR-125b. LncGASR overexpression increased the expression of SCAP, SREBP, and steroid hormone-related proteins, which can be attenuated by MiR-125b. Our results demonstrated that lncGSAR can act as a ceRNA to activate SCAP/SREBP signaling by sponging MiR-125b to regulate steroid hormone secretion in GCs. These findings provide new insights into the mechanisms of nutrient-regulated follicle development in ewes.

Biomarkers in Gynecologic Tumors

Gynecologic malignancies are one of the most frequent cancers amongst women. Biomarkers are crucial for the differential diagnosis of adnexal masses; however, their potential for diagnosis is limited. In the era of difficulty in ovarian cancer screening, novel biomarkers are defined, but CA125 still remains the most valuable one. Circulating tumor DNAs, DNA hypermethylation, metabolites, microRNAs, and kallikreins have recently turned out as ovarian cancer biomarkers and are being applied to clinical practice. For uterine cancer, genomic classification has now been described, it will be used as a prognostic tool. In this chapter, we describe ovarian, endometrial, and cervical cancer biomarkers in detail.

The interplay between noncoding RNA and YAP/TAZ signaling in cancers: molecular functions and mechanisms

The Hippo signaling pathway was found coordinately modulates cell regeneration and organ size. Its dysregulation contributes to uncontrolled cell proliferation and malignant transformation. YAP/TAZ are two critical effectors of the Hippo pathway and have been demonstrated essential for the initiation or growth of most tumors. Noncoding RNAs (ncRNAs), including miRNAs, lncRNAs, and circRNAs, have been shown to play critical roles in the development of many cancers. In the past few decades, a growing number of studies have revealed that ncRNAs can directly or indirectly regulate YAP/TAZ signaling. YAP/TAZ also regulate ncRNAs expression in return. This review summarizes the interactions between YAP/TAZ signaling and noncoding RNAs together with their biological functions on cancer progression. We also try to describe the complex feedback loop existing between these components.

Transcriptome sequencing and lncRNA-miRNA-mRNA network construction in cardiac fibrosis and heart failure

Cardiac fibrosis (CF) and heart failure (HF) are common heart diseases, and severe CF can lead to HF. In this study, we tried to find their common potential molecular markers, which may help the diagnosis and treatment of CF and HF. RNA library construction and high-throughput sequencing were performed. The DESeq2 package in R was used to screen differentially expressed mRNAs (DEmRNAs), differentially expressed lncRNA (DElncRNAs) and differentially expressed miRNA (DEmiRNAs) between different samples. The common DEmRNAs, DElncRNAs and DEmiRNAs for the two diseases were obtained. The ConsensusPathDB (CPDB) was used to perform biological function enrichment for common DEmRNAs. Gene interaction network was constructed to screen out key genes. Subsequently, real-time polymerase chain reaction (RT-PCR) verification was performed. Lastly, GSE104150 and GSE21125 data sets were utilized for expression validation and diagnostic analysis. There were 1477 DEmRNAs, 502 DElncRNAs and 36 DEmiRNAs between CF and healthy control group. There were 607 DEmRNAs, 379DElncRNAs,s and 42 DEmiRNAs between HF and healthy control group. CH and FH shared 146 DEmRNAs, 80 DElncRNAs, and 6 DEmiRNAs. Hsa-miR-144-3p, CCNE2, C9orf72, MAP3K20-AS1, LEF1-AS1, AC243772.2, FLJ46284, and AC239798.2 were key molecules in lncRNA-miRNA-mRNA network. In addition, hsa-miR-144-3p and CCNE2 may be considered as potential diagnostic gene biomarkers in HF. In this study, the identification of common biomarkers of CF and HF may help prevent CF to HF transition as early as possible.

LncRNA MAFG-AS1 promotes the malignant phenotype of ovarian cancer by upregulating NFKB1-dependent IGF1

Long non-coding RNAs (lncRNAs) were recently recognized to vitally function in a variety of cancer cellular events, including epithelial-mesenchymal transition (EMT), invasion, and migration, particularly in ovarian cancer (OC). Herein, we sought to investigate the potential role of MAFG-AS1 in the malignant behaviors of OC cells. The binding affinity between MAFG-AS1, miR-339-5p, NFKB1 or IGF1 was characterized so as to identify the underlying mechanism of corresponding their interactions. We conducted MAFG-AS1 overexpression or knockdown along with NFKB1 and IGF1 silencing to examine their effects on the EMT, migration, and invasion of OC cells. Tumors were xenografted in nude mice to validate the in vitro findings. Our data showed significantly high expression pattern of MAFG-AS1 in the OC tissues and cells. Further mechanistic investigations revealed that MAFG-AS1 upregulated the IGF1 expression pattern through recruitment of NFKB1, whereas MAFG-AS1 upregulated the NFKB1 expression pattern through binding to miR-339-5p. Thus, MAFG-AS1 overexpression accelerated the EMT, invasion, and migration of OC cells, which could be annulled by silencing of IGF1 or NFKB1. Besides, our in vitro findings were successfully recapitulated in the xenograft mice. These results determined that MAFG-AS1 stimulated the OC malignant progression by upregulating the NFKB1-mediated IGF1 via miR-339-5p, thus highlighting a novel potential therapeutic target against OC.

Long non-coding RNA CTSLP8 mediates ovarian cancer progression and chemotherapy resistance by modulating cellular glycolysis and regulating c-Myc expression through PKM2

PURPOSE

Long non-coding RNAs (lncRNAs) play vital roles in tumor progression and resistance. Ovarian cancer (OC), a common gynecological cancer, is associated with poor prognosis as it can progress to peritoneal metastasis and develop resistance to chemotherapy. This study aimed to examine the role of lncRNAs in the development of chemotherapy resistance in OC.

METHODS

The clinical samples were divided into chemotherapy-sensitive and chemotherapy-resistant groups based on the chemotherapy response at follow-up. The glycolysis levels in the two groups were analyzed using positron emission tomography/computed tomography (PET/CT) scanning and immunohistochemistry. GEO dataset analysis revealed the expression of CTSLP8 in chemotherapy-resistant patients with OC. Two pairs of normal and diamminodichloroplatinum (DDP)-resistant cells were transfected with CTSLP8 overexpression and knockdown constructs to examine the functions of CTSLP8 in the OC cells and elucidate the underlying mechanisms. The in vivo effect of CTSLP8 overexpression and knockdown on the chemotherapy response of tumors was examined using a mouse subcutaneous tumor model. The tissue chips were subjected to fluorescence in situ hybridization and immunohistochemical (IHC) staining to examine the correlation among CTSLP8 expression, DDP resistance, and prognosis in OC.

RESULTS

The dataset analysis demonstrated that CTSLP8 was upregulated in chemotherapy-resistant tumor tissues. CTSLP8 promoted the proliferation and development of DDP resistance in the OC cells. Moreover, CTSLP8 promoted c-Myc expression by facilitating the binding of PKM2 to the promoter region of c-Myc, thereby upregulating glycolysis. The analysis of tissue chips revealed that the upregulation of CTSLP8 was associated with the development of DDP resistance and poor prognosis in patients with OC.

CONCLUSIONS

These findings indicate that CTSLP8 forms a complex with PKM2 to regulate c-Myc, and this action results in the upregulation of cellular glycolysis, consequently promoting OC progression and development of chemotherapy resistance.

HEADLIGHTS

1. CTSLP8 was upregulated in the chemotherapy-resistant tumor tissues. 2. CTSLP8 promoted the proliferation and cisplatin resistance in the OC cells. 3. CTSLP8 promoted glycolysis by facilitating the binding of PKM2 to the promoter region of c-Myc. 4. Inhibition of CTSLP8 or the combination of c-Myc inhibitors with cisplatin were potential therapeutic strategies for chemotherapy-resistant of OC.

LncRNA SNHG20 promotes migration and invasion of ovarian cancer via modulating the microRNA-148a/ROCK1 axis

BACKGROUND

Ovarian cancer (OC) is characterized by early metastasis and poor prognosis, which threatens the health of women worldwide. Small nucleolar RNA host gene 20 (SNHG20), a long noncoding RNA (lncRNA), has been verified to be significantly up-regulated in several tumors, including OC. MicroRNA-148a (miR-148a)/rho-kinase1 (ROCK1) axis plays an important role in the modulation of tumor development. However, whether SNHG20 can regulate OC progression through miR-148a/ROCK1 axis remains unclear. Normal human ovarian epithelial cell line and four OC cell lines were adopted for in vitro experiments. Real-time PCR was performed to assess the levels of SNHG20 and miR-148a. OC cell proliferation, apoptosis, invasion and migration were detected using clone formation, flow cytometry, transwell, and wound healing assays, respectively. Tumor xenograft assay was applied to evaluate the effect of SNHG20 on tumor growth in vivo.

RESULTS

Significant higher expression of SNHG20 was observed in OC cell lines. SNHG20 markedly promoted the invasion, migration, proliferation and inhibited the apoptosis of OC cells. SNHG20 enhanced ROCK1 expression by sponging miR-148a, and the direct binding between SNHG20/ROCK1 and miR-148a was identified.

CONCLUSION

SNHG20 promoted invasion and migration of OC via targeting miR-148a/ROCK1 axis. The present research may provide a novel insight for the therapeutic strategies of OC.

MiRNA-375 inhibits retinoblastoma progression through targeting ERBB2 and inhibiting MAPK1/MAPK3 signalling pathway

BACKGROUND

Increasing evidence has shown that the dysregulation of miRNAs is involved in the pathogenesis of retinoblastoma (RB). This present study was aimed to investigate the significance of miR-375 in RB progression, and the underlying mechanism.

MATERIALS AND METHODS

The miR-375 expression was detected by RT-PCR. CCK-8 assay and transwell assays were used to measure RB cell viability, migration, and invasion. The downstream gene of miR-375 was verified by luciferase reporter assay. Western blot was applied to detect the related proteins of MAPK1/MAPK3 signalling pathway.

RESULTS

MiR-375 was decreased significantly in RB tissues, and its down-regulation was associated with the poor prognosis of RB patients. Over-expression of miR-375 inhibited RB cell proliferation, migration, and invasion. More importantly, miR-375 modulated ERBB2 expression negatively, and ERBB2 was confirmed as the target of miR-375. Moreover, ERBB2 overturned the inhibitory effect of miR-375 mimic on the progression of RB. MiR-375 mimic suppressed RB progression via inhibiting the activation of MAPK1/MAPK3 signalling pathway.

CONCLUSIONS

MiR-375 inhibited RB progression through targeting ERBB2 and suppressing MAPK1/MAPK3 signalling pathway, which might be a new target for the clinical treatment strategy.

NORHA, a novel follicular atresia-related lncRNA, promotes porcine granulosa cell apoptosis via the miR-183-96-182 cluster and FoxO1 axis

BACKGROUND

Follicular atresia has been shown to be strongly associated with a low follicle utilization rate and female infertility, which are regulated by many factors such as microRNAs (miRNAs), which constitute a class of noncoding RNAs (ncRNAs). However, little is known about long noncoding RNAs (lncRNAs), which constitute another ncRNA family that regulate follicular atresia.

RESULTS

A total of 77 differentially expressed lncRNAs, including 67 upregulated and 10 downregulated lncRNAs, were identified in early atretic follicles compared to healthy follicles by RNA-Sequencing. We characterized a noncoding RNA that was highly expressed in atretic follicles (NORHA). As an intergenic lncRNA, NORHA was one of the upregulated lncRNAs identified in the atretic follicles. To determine NORHA function, RT-PCR, flow cytometry and western blotting were performed, and the results showed that NORHA was involved in follicular atresia by influencing GC apoptosis with or without oxidative stress. To determine the mechanism of action, bioinformatics analysis, luciferase reporter assay and RNA immunoprecipitation assay were performed, and the results showed that NORHA acted as a 'sponge', that directly bound to the miR-183-96-182 cluster, and thus prevented its targeted inhibition of FoxO1, a major sensor and effector of oxidative stress.

CONCLUSIONS

We provide a comprehensive perspective of lncRNA regulation of follicular atresia, and demonstrate that NORHA, a novel lncRNA related to follicular atresia, induces GC apoptosis by influencing the activities of the miR-183-96-182 cluster and FoxO1 axis.

Cancer driver gene and non-coding RNA alterations as biomarkers of brain metastasis in lung cancer: A review of the literature

Brain metastasis (BM) is the most common event in patients with lung cancer. Despite multimodal treatments and advances in systemic therapies, development of BM remains one of the main factors associated with poor prognosis and mortality in patients with lung cancer. Therefore, better understanding of mechanisms involved in lung cancer brain metastasis (LCBM) is of great importance to suppress cancer cells and to improve the overall survival of patients. Several cancer-related genes such as EGFR and KRAS have been proposed as potential predictors of LCBM. In addition, there is ample evidence supporting crucial roles of non-coding RNAs (ncRNAs) in mediating LCBM. In this review, we provide comprehensive information on risk assessment, predictive, and prognostic panels for early detection of BM in patients with lung cancer. Moreover, we present an overview of LCBM molecular mechanisms, cancer driver genes, and ncRNAs which may predict the risk of BM in lung cancer patients. Recent clinical studies have focused on determining mechanisms involved in LCBM and their association with diagnosis, prognosis, and treatment outcomes. These studies have shown that alterations in EGFR, KRAS, BRAF, and ALK, as the most frequent coding gene alterations, and dysregulation of ncRNAs such as miR-423, miR-330-3p, miR-145, piR-651, and MALAT1 can be considered as potential biomarkers of LCBM.

METTL3 promotes the initiation and metastasis of ovarian cancer by inhibiting CCNG2 expression via promoting the maturation of pri-microRNA-1246

Ovarian cancer is a common gynecological malignant tumor with a high mortality rate and poor prognosis. There is inadequate knowledge of the molecular mechanisms underlying ovarian cancer. We examined the expression of methyltransferase-like 3 (METTL3) in tumor specimens using RT-qPCR, immunohistochemistry, and Western blot analysis, and tested the methylation of METTL3 by MSP. Levels of METTL3, miR-1246, pri-miR-1246 and CCNG2 were then analyzed and their effects on cell biological processes were also investigated, using in vivo assay to validate the in vitro findings. METTL3 showed hypomethylation and high expression in ovarian cancer tissues and cells. Hypomethylation of METTL3 was pronounced in ovarian cancer samples, which was negatively associated with patient survival. Decreased METTL3 inhibited the proliferation and migration of ovarian cancer cells and promoted apoptosis, while METTL3 overexpression exerted opposite effects. Mechanistically, METTL3 aggravated ovarian cancer by targeting miR-1246, while miR-1246 targeted and inhibited CCNG2 expression. High expression of METTL3 downregulated CCNG2, promoted the metabolism and growth of transplanted tumors in nude mice, and inhibited apoptosis. The current study highlights the promoting role of METTL3 in the development of ovarian cancer, and presents new targets for its treatment.

LINC00852 promotes the proliferation and invasion of ovarian cancer cells by competitively binding with miR-140-3p to regulate AGTR1 expression

Background

Dysregulation of long non-coding RNAs (lncRNAs) has been identified in ovarian cancer. However, the expression and biological functions of LINC00852 in ovarian cancer are not understood.

Methods

The expressions of LINC00852, miR-140-3p and AGTR1 mRNA in ovarian cancer tissues and cells were detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay. Gain- and loss-of-function assays were performed to explore the biological functions of LINC00852 and miR-140-3p in the progression of ovarian cancer in vitro. The bindings between LINC00852 and miR-140-3p were confirmed by luciferase reporter gene assay, RNA immunoprecipitation (RIP) assay and RNA pull-down assay.

Results

We found that LINC00852 expression was significantly up-regulated in ovarian cancer tissues and cells, whereas miR-140-3p expression was significantly down-regulated in ovarian cancer tissues. Functionally, LINC00852 knockdown inhibited the viability, proliferation and invasion of ovarian cancer cells, and promoted the apoptosis of ovarian cancer cells. Further investigation showed that LINC00852 interacted with miR-140-3p, and miR-140-3p overexpression suppressed the viability, proliferation and invasion of ovarian cancer cells. In addition, miR-140-3p interacted with AGTR1 and negatively regulated its level in ovarian cancer cells. Mechanistically, we found that LINC00852 acted as a ceRNA of miR-140-3p to promote AGTR1 expression and activate MEK/ERK/STAT3 pathway. Finally, LINC00852 knockdown inhibited the growth and invasion ovarian cancer in vivo.

Conclusion

LINC00852/miR-140-3p/AGTR1 is an important pathway to promote the proliferation and invasion of ovarian cancer.

Yes-associated protein expression is associated with poor prognosis in patients with colorectal cancer

Colorectal cancer (CRC) is the third leading cause of cancer-related death worldwide. The aim of the present study was to investigate the expression of yes-associated protein (YAP) in CRC tissues, and to determine the relationship between the expression levels of YAP and the clinicopathological characteristics and prognosis of patients with CRC. Bioinformatics analysis was conducted to examine the expression of YAP and its correlation with clinicopathological characteristics and key genes, using functional enrichment analysis. Immunohistochemistry was used to detect YAP expression in 181 CRC tissue samples and 30 normal colorectal mucosa samples. Western blotting and reverse transcription-quantitative PCR were performed to detect the expression of YAP and β-catenin in CRC cells, and cellular proliferation was assessed using a Cell Counting Kit-8 assay. Finally, apoptosis was analyzed using flow cytometry. Immunohistochemical staining indicated that the positive expression rate of YAP in CRC tissues was 73.5%, which was significantly higher than that in normal colorectal mucosa samples. The expression of YAP in CRC was associated with histological differentiation, lymph node metastasis and Duke's stage. However, no significant associations were observed between YAP expression and age, sex and T stage. Downregulation of YAP promoted the proliferation and the inhibited apoptosis of CRC cells, and YAP expression was positively correlated with that of β-catenin in both CRC tissues and cells. Furthermore, YAP expression was upregulated in CRC tissues, which was correlated with tumor progression and prognosis. Therefore, YAP expression may be used as an independent predictor of poor prognosis in patients with CRC, and the underling molecular mechanism may be associated with the combined effect of Hippo and Wnt/β-catenin signaling.

Ovarian Cancer: Biomarkers and Targeted Therapy

Ovarian cancer is one of the most common causes of death in women as survival is highly dependent on the stage of the disease. Ovarian cancer is typically diagnosed in the late stage due to the fact that in the early phases is mostly asymptomatic. Genomic instability is one of the hallmarks of ovarian cancer. While ovarian cancer is stratified into different clinical subtypes, there still exists extensive genetic and progressive diversity within each subtype. Early detection of the disorder is one of the most important steps that facilitate a favorable prognosis and a good response to medical therapy for the patients. In targeted therapies, individual patients are treated by agents targeting the changes in tumor cells that help them grow, divide and spread. Currently, in gynecological malignancies, potential therapeutic targets include tumor-intrinsic signaling pathways, angiogenesis, homologous-recombination deficiency, hormone receptors, and immunologic factors. Ovarian cancer is usually diagnosed in the final stages, partially due to the absence of an effective screening strategy, although, over the times, numerous biomarkers have been studied and used to assess the status, progression, and efficacy of the drug therapy in this type of disorder.

m6 A modification of lncRNA PCAT6 promotes bone metastasis in prostate cancer through IGF2BP2-mediated IGF1R mRNA stabilization

BACKGROUND

Bone metastasis is the leading cause of tumor-related death in prostate cancer (PCa) patients. Long noncoding RNAs (lncRNAs) have been well documented to be involved in the progression of multiple cancers. Nevertheless, the role of lncRNAs in PCa bone metastasis remains largely unclear.

METHODS

The expression of prostate cancer-associated transcripts was analyzed in published datasets and further verified in clinical samples and cell lines by RT-qPCR and in situ hybridization assays. Colony formation assay, MTT assay, cell cycle analysis, EdU assay, Transwell migration and invasion assays, wound healing assay, and in vivo experiments were carried out to investigate the function of prostate cancer-associated transcript 6 (PCAT6) in bone metastasis and tumor growth of PCa. Bioinformatic analysis, RNA pull-down, and RIP assays were conducted to identify the proteins binding to PCAT6 and the potential targets of PCAT6. The therapeutic potential of targeting PCAT6 by antisense oligonucleotides (ASO) was further explored in vivo.

RESULTS

PCAT6 was upregulated in PCa tissues with bone metastasis and increased PCAT6 expression predicted poor prognosis in PCa patients. Functional experiments found that PCAT6 knockdown significantly inhibited PCa cell invasion, migration, and proliferation in vitro, as well as bone metastasis and tumor growth in vivo. Mechanistically, METTL3-mediated m6 A modification contributed to PCAT6 upregulation in an IGF2BP2-dependent manner. Furthermore, PCAT6 upregulated IGF1R expression by enhancing IGF1R mRNA stability through the PCAT6/IGF2BP2/IGF1R RNA-protein three-dimensional complex. Importantly, PCAT6 inhibition by ASO in vivo showed therapeutic potential against bone metastasis in PCa. Finally, the clinical correlation of METTL3, IGF2BP2, IGF1R, and PCAT6 was further demonstrated in PCa tissues and cells.

CONCLUSIONS

Our study uncovers a novel molecular mechanism by which the m6 A-induced PCAT6/IGF2BP2/IGF1R axis promotes PCa bone metastasis and tumor growth, suggesting that PCAT6 may serve as a promising prognostic marker and therapeutic target against bone-metastatic PCa.

ELFN1-AS1 accelerates cell proliferation, invasion and migration via regulating miR-497-3p/CLDN4 axis in ovarian cancer

Previous studies indicated that long non-coding RNAs (LncRNAs) were involved in the progression of multiple cancers including ovarian cancer (OV). LncRNA ELFN1-AS1 functioned as an oncogene in many cancers, but its potential roles in OV were largely unclear. In the current study, we were aimed at clarifying the biological roles and molecular mechanisms of ELFN1-AS1 in OV. We found that ELFN1-AS1 was significantly upregulated in OV tissues and cell lines. High expression of ELFN1-AS1 was associated with poor prognosis in OV patients. Knockdown of ELFN1-AS1 inhibited the proliferation, migration and invasion of SKOV3 cell lines and repressed tumor growth in xenografted ovarian models. Mechanistically, ELFN1-AS1 promoted the proliferation, migration and invasion of SKOV3 cells by sponging miR-497-3p. Additionally, CLDN4 was verified to be the target of miR-497-3p. Rescue experiments revealed that miR-497-3p inhibition could partly reverse the inhibitory effect of ELFN1-AS1 silencing on proliferation, migration and invasion of SKOV3 cell lines. Taken together, our findings indicated that ELFN1-AS1 acted as an oncogene in ovarian cancer through regulating the expression of CLDN4 by directly interacting with miR-497-3p. The results suggested that ELFN1-AS1 might act as a promising therapeutic target for OV.

Long non-coding RNA LUCAT1 promotes the progression of clear cell renal cell carcinoma via the microRNA-375/YAP1 axis

Clear cell renal cell carcinoma (ccRCC) is a common renal cell carcinoma with a high mortality rate. Lung cancer-associated transcript 1 (LUCAT1) has been reported to be a potential biomarker of prognosis in human ccRCC. However, the underlying mechanism of the function of LUCAT1 in ccRCC remains poorly understood. The present study aimed to investigate the role and underlying mechanism of LUCAT1 in ccRCC. The expression level of LUCAT1, microRNA-375 (miR-375) and yes-associated protein 1 (YAP1) in ccRCC tissues and cells was detected by reverse transcription-quantitative PCR, and the protein level of YAP1 was detected by western blotting. The effects of LUCAT1 on cell proliferation, migration and invasion were analyzed using Cell Counting Kit-8 and Transwell assays. The association between miR-375 and LUCAT1 or miR-375 and YAP1 was predicted by lncBase Predicted v.2 or TargetScan and verified using dual-luciferase reporter assay. The effect of LUCAT1 on ccRCC progression in vivo was evaluated using a xenograft tumor model. The results revealed that LUCAT1 and YAP1 were upregulated and miR-375 was downregulated in ccRCC tissues and cells. LUCAT1 knockdown suppressed cell proliferation, migration and invasion, which were reversed by the inhibition of miR-375. In addition, YAP1 overexpression attenuated the inhibitory effects of miR-375 overexpression on cell proliferation, migration and invasion. Subsequent experiments suggested that LUCAT1 regulated YAP1 expression by sponging miR-375. Therefore, LUCAT1 exerted its role by regulating the miR-375/YAP1 axis in vitro. Moreover, LUCAT1 knockdown suppressed the growth of ccRCC xenograft tumors in vivo. These results collectively revealed that LUCAT1 promoted the proliferation, migration and invasion of ccRCC by the upregulation of YAP1 via sponging miR-375, which may be used as a potential therapeutic target for ccRCC.

Long Noncoding RNA MLK7-AS1 Promotes Non-Small-Cell Lung Cancer Migration and Invasion via the miR-375-3p/YWHAZ Axis

Long noncoding RNAs act essential regulators in lung cancer tumorigenesis. Our research aimed to investigate the potential function and molecular mechanisms of MLK7-AS1 in NSCLC (non-small-cell lung cancer). QRT-PCR results indicated that the MLK7-AS1 expression level was upregulated in NSCLC cells and tissues. MLK7-AS1 strengthened cell migration and invasion in H1299 and A549 cells. Luciferase reporter assay found that MLK7-AS1 functioned as an endogenous sponge for miR-375-3p. Transwell assay results showed that miR-375-3p suppressed cell migration and invasion in H1299 and A549 cells. YWHAZ was confirmed as a target gene of miR-375-3p by Targetscan. YWHAZ overexpression promoted the invasion of H1299 and A549 cells. MLK7-AS1 upregulated YWHAZ expression and enhanced H1299 and A549 cell invasion by sponging miR-375-3p. MLK7-AS1 improved the metastasis ability of A549 in vivo. In conclusion, MLK7-AS1 was identified as a novel oncogenic RNA in NSCLC and can function as a potential therapeutic target for NSCLC treatment.

Increased YAP1 expression is significantly associated with breast cancer progression, metastasis and poor survival

YAP1 plays a key role as a transcriptional coactivator in the Hippo pathway. Based on conflicting reports regarding YAP1 function in cancer, this study discerned its role in breast carcinogenesis. First, a systematic review of salient breast cancer studies targeting YAP1 dysregulation was performed. Additionally, freshly excised tumor specimens of approximately 200 breast cancer patients were processed for quantification of YAP1 expression at mRNA and protein levels using quantitative PCR and immunohistochemistry, respectively. YAP1 expression was nine folds higher in tumors versus controls and significantly associated with metastasis (p < 0.05) and poor survival in Pakistani breast cancer patients. These findings establish the role of YAP1 overexpression in tumorigenesis and metastasis. Hence, YAP1 inhibition may be considered a possible therapeutic strategy.

A ceRNA-associated risk model predicts the poor prognosis for head and neck squamous cell carcinoma patients

Head and neck squamous cell carcinoma (HNSCC) is one of the most malignant cancers with poor prognosis worldwide. Emerging evidence indicates that competing endogenous RNAs (ceRNAs) are involved in various diseases, however, the regulatory mechanisms of ceRNAs underlying HNSCC remain unclear. In this study, we retrieved differentially expressed long non-coding RNAs (DElncRNAs), messenger RNAs (DEmRNAs) and microRANs (DEmiRNAs) from The Cancer Genome Atlas database and constructed a ceRNA-based risk model in HNSCC by integrated bioinformatics approaches. Functional enrichment analyses showed that DEmRNAs might be involved in extracellular matrix related biological processes, and protein–protein interaction network further selected out prognostic genes, including MYL1 and ACTN2. Importantly, co-expressed RNAs identified by weighted co-expression gene network analysis constructed the ceRNA networks. Moreover, AC114730.3, AC136375.3, LAT and RYR3 were highly correlated to overall survival of HNSCC by Kaplan–Meier method and univariate Cox regression analysis, which were subsequently implemented multivariate Cox regression analysis to build the risk model. Our study provides a deeper understanding of ceRNAs on the regulatory mechanisms, which will facilitate the expansion of the roles on the ceRNAs in the tumorigenesis, development and treatment of HNSCC.

The role of altered long noncoding RNAs in overall survival of ovarian cancer: A systematic review and meta-analysis

In recent years, tremendous research efforts have been focused on investigating the effect of dysregulation of lncRNAs on cancer progression, most of which confirm a positive link. This inspired us to conduct the present meta-analysis to explore whether aberrant expression of multiple lncRNAs has a role in patients' outcome in ovarian cancer. This comprehensive meta-analysis pertains to the evaluation of association between dysregulated lncRNAs expression level with eventual outcome and clinicopathological characteristics of ovarian cancer patients. We systematically searched PubMed, Web of Science, and Scopus to find all eligible articles. Pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) for overall survival, disease-free survival and progression-free survival were measured with a fixed or random effects model. A total of 34 studies were included in the meta-analysis. Dysregulation of lncRNAs were contributed to shorter overall survival (34 studies, 1180 patients HR = 2.12, 95% CI: 1.73 ± 2.60, random-effects) in ovarian cancer. Furthermore, altered lncRNAs were also related to decreased progression-free survival (8 studies, 1180 patients HR: 1.88, 95% CI: (1.35-2.62) and disease-free survival (2 studies, 285 patients, HR: 6.07, 95% CI: 1.28-28.78) in this disease. Our analyses supported the robust prognostic significance of altered lncRNAs in ovarian cancer. However, more extended studies are encouraged to evaluate the clinical application potential of these lncRNAs in the prognosis evaluation of ovarian cancer.

Long non‑coding RNA ASAP1‑IT1 suppresses ovarian cancer progression by regulating Hippo/YAP signaling

Long non‑coding RNAs (lncRNAs) are a class of non‑protein coding transcripts that are involved in the regulation of gene expression in mammalian cells. Transcriptional co‑activator Yes associated protein 1 (YAP1) plays a key role in the progression of ovarian cancer. However, the regulation of Hippo/YAP signaling in ovarian cancer remains elusive. In the present study, the expression levels of lncRNA ASAP1‑IT1 were investigated. The analysis indicated that lncRNA ASAP1‑IT1 expression was downregulated in ovarian tumor samples and ovarian cancer cells. The overexpression of ASAP1‑IT1 inhibited ovarian cancer cell proliferation and induced cell apoptosis. Bioinformatics analysis predicted that miR‑2278, a previously reported upregulated miRNA in ovarian tumors, may bind to ASAP1‑IT1. Dual luciferase assay confirmed the direct regulatory association between ASAP1‑IT1 and miR‑2278. In addition, the data demonstrated that large tumor suppressor 2 (LATS2) was a target gene of miR‑2278, whose expression was upregulated by ASAP1‑IT1 in ovarian cancer cells. By regulating the expression of LATS2, ASAP1‑IT1 induced the downregulation of YAP1 expression in ovarian cancer cells. Moreover, the silencing of LATS2 attenuated the inhibition of cell proliferation and the apoptosis induced by ASAP1‑IT1 overexpression in ovarian cancer cells. The association among the expression levels of ASAP1‑IT1, miR‑2278 and LATS2 was observed in specimens obtained from patients with ovarian cancer. Taken together, the data presented herein demonstrate that ASAP1‑IT1 functions as a potential tumor suppressor lncRNA by upregulating LATS2 expression in ovarian cancer.

Long non-coding RNA FOXD2-AS1 promotes proliferation, migration and invasion of ovarian cancer cells via regulating the expression of miR-4492

The aim of the present study was to determine the role of long non-coding RNA (lncRNA) forkhead box D2 antisense 1 (FOXD2-AS1) in the development of ovarian cancer, investigate the underlying mechanisms and provide a potential diagnostic biomarker for ovarian cancer. A total of 39 ovarian cancer patients were included, and the ovarian cancer tissues and paracancer tissues were obtained. The ovarian cancer cell lines SKOV3 and OVCAR3 and the human ovarian normal epithelial cell line IOSE80 were cultured. The expression of lncRNA FOXD2-AS1 and miR-4492 was detected by reverse transcription-quantitative PCR. Small interfering RNA targeting FOXD2-AS1 (si-FOXD2-AS1), microRNA (miR)-4492 mimics, miR-4492 inhibitor and their corresponding controls were transfected into cells. The proliferation was detected with a Cell-Couting-Kit-8 assay, and migration and invasion were determined using Transwell assays. The mutual binding site of lncRNA FOXD2-AS1 and miR-4492 was predicted with the miRDB database and verified by a luciferase reporter assay. Finally, a rescue assay was performed. The results suggested that lncRNA FOXD2-AS1 was upregulated in ovarian cancer tissues and cell lines. si-FOXD2-AS1 was able to inhibit the proliferation, migration and invasion of ovarian cancer cells. lncRNA FOXD2-AS1 was confirmed to directly target miR-4492. The expression of lncRNA FOXD2-AS1 and miR-4492 exhibited a negative correlation. In a rescue experiment, miR-4492 inhibitor abrogated the effect of siFOXD2-AS1 in SKOV3 and OVCAR3 cell lines. In conclusion, lncRNA FOXD2-AS1 promotes the proliferation and invasion of ovarian cancer cells via regulating the expression of miR-4492. It may be a novel potential diagnostic biomarker and therapeutic target for ovarian cancer.

ELK1 activated-long noncoding RNA LBX2-AS1 aggravates the progression of ovarian cancer through targeting miR-4784/KDM5C axis

As one of the most common cancers in female, ovarian cancer (OC) has become a serious public burden now. Mounting researches have indicated long noncoding RNAs (lncRNAs) can affect many biological processes including cancer development. LncRNA LBX2-AS1 was identified to be an oncogene in some cancers, but the role of LBX2-AS1 in OC remains to be elucidated. Bioinformatics analysis and experiments including ChIP, RT-qPCR, RIP, luciferase reporter, western blot and CCK-8 were performed to explore the role of LBX2-AS1 in OC. LBX2-AS1 expression was markedly increased in OC tissues and cell lines. Functionally, LBX2-AS1 silencing inhibited cell proliferation, migration and stemness but facilitated cell apoptosis in OC. Moreover, depletion of LBX2-AS1 suppressed tumor growth of OC in vivo. Mechanically, LBX2-AS1 was activated by transcriptional factor ELK1. ELK1 enhanced the expression of LBX2-AS1 in OC cells. In addition, miR-4784 was confirmed to be sponged by LBX2-AS1. There was a negative expression correlation between LBX2-AS1 and miR-4784 in OC tissues. Subsequently, KDM5C was identified to be a direct target of miR-4784 in OC cells. KDM5C was negatively regulated by miR-4784 and positively regulated by LBX2-AS1 in terms of expression level. Upregulation of KDM5C reversed the inhibitory effect of LBX2-AS1 depletion on the progression of OC. This study proved that ELK1 activated-LBX2-AS1 aggravated the progression of OC by targeting the miR-4784/KDM5C axis, suggesting that LBX2-AS2 may be a promising diagnostic biomarker of OC.

LINC00665 promotes Ovarian Cancer progression through regulating the miRNA-34a-5p/E2F3 axis

Objective: To clarify the role of LINC00665 in ovarian cancer (OC) progression and the possible mechanism. Methods: LINC00665 levels in OC tissues and cell lines were detected by qRT-PCR. The correlation between LINC00665 and clinicopathologic characteristics of OC patients was assessed. Biological functions of OC cell phenotypes influenced by LINC00665 were examined by CCK-8, colony formation and Transwell assay. Dual-luciferase reporter assay and RIP assay were conducted to verify the interaction between LINC00665 and its downstream target. Results: LINC00665 was upregulated in OC and linked to poor prognosis. Knockdown of LINC00665 blocked malignant proliferative, migratory and invasive functions of OC cells. By competitively binding miRNA-34a-5p, LINC00665 abolished the inhibitory effect of miR-34a-3p on its downstream gene E2F3, thus promoting OC progression. Conclusion: LINC00665/miRNA-34a-5p/E2F3 axis is involved in OC progression, providing novel insights into the clinical treatment of OC.

The Essential Factors of Establishing Patient-derived Tumor Model

Establishing an applicable preclinical model is vital for translational cancer research. Patient-derived xenograft has been important preclinical model systems and widely used for cancer research. Patient-derived xenograft models that represent the tumors of the patients are necessary to better translate research discoveries and to test potential therapeutic approaches. However, research in this field is hampered by the limited engraftment rate. In this review, we go over a large number of researches on patient-derived xenograft transplantation and firstly systematically summarize the main factors in methodology to successfully establish models. These results will be applied to the development of patient-derived xenograft leading to better preclinical research.

LBX2-AS1 promotes ovarian cancer progression by facilitating E2F2 gene expression via miR-455-5p and miR-491-5p sponging

LBX2‐AS1 is a long non‐coding RNA that facilitates the development of gastrointestinal cancers and lung cancer, but its participation in ovarian cancer development remained uninvestigated. Clinical data retrieved from TCGA ovarian cancer database and the clinography of 60 ovarian cancer patients who received anti‐cancer treatment in our facility were analysed. The overall cell growth, colony formation, migration, invasion, apoptosis and tumour formation on nude mice of ovarian cancer cells were evaluated before and after lentiviral‐based LBX2‐AS1 knockdown. ENCORI platform was used to explore LBX2‐AS1‐interacting microRNAs and target genes of the candidate microRNAs. Luciferase reporter gene assay and RNA pulldown assay were used to verify the putative miRNA‐RNA interactions. Ovarian cancer tissue specimens showed significant higher LBX2‐AS1 expression levels that non‐cancerous counterparts. High expression level of LBX2‐AS1 was significantly associated with reduced overall survival of patients. LBX2‐AS1 knockdown significantly down‐regulated the cell growth, colony formation, migration, invasion and tumour formation capacity of ovarian cancer cells and increased their apoptosis in vitro. LBX2‐AS1 interacts with and thus inhibits the function of miR‐455‐5p and miR‐491‐5p, both of which restrained the expression of E2F2 gene in ovarian cancer cells via mRNA targeting. Transfection of miRNA inhibitors of these two miRNAs or forced expression of E2F2 counteracted the effect of LBX2‐AS1 knockdown on ovarian cancer cells. LBX2‐AS1 was a novel cancer‐promoting lncRNA in ovarian cancer. This lncRNA increased the cell growth, survival, migration, invasion and tumour formation of ovarian cancer cells by inhibiting miR‐455‐5p and miR‐491‐5p, thus liberating the expression of E2F2 cancer‐promoting gene.

LncRNAs in Ovarian Cancer Progression, Metastasis, and Main Pathways: ceRNA and Alternative Mechanisms

Ovarian cancer (OvCa) develops asymptomatically until it reaches the advanced stages with metastasis, chemoresistance, and poor prognosis. Our review focuses on the analysis of regulatory long non-coding RNAs (lncRNAs) competing with protein-coding mRNAs for binding to miRNAs according to the model of competitive endogenous RNA (ceRNA) in OvCa. Analysis of publications showed that most lncRNAs acting as ceRNAs participate in OvCa progression: migration, invasion, epithelial-mesenchymal transition (EMT), and metastasis. More than 30 lncRNAs turned out to be predictors of survival and/or response to therapy in patients with OvCa. For a number of oncogenic (CCAT1, HOTAIR, NEAT1, and TUG1 among others) and some suppressive lncRNAs, several lncRNA/miRNA/mRNA axes were identified, which revealed various functions for each of them. Our review also considers examples of alternative mechanisms of actions for lncRNAs besides being ceRNAs, including binding directly to mRNA or protein, and some of them (DANCR, GAS5, MALAT1, and UCA1 among others) act by both mechanisms depending on the target protein. A systematic analysis based on the data from literature and Panther or KEGG (Kyoto Encyclopedia of Genes and Genomes) databases showed that a significant part of lncRNAs affects the key pathways involved in OvCa metastasis, EMT, and chemoresistance.

LncRNA GAS8-AS1 Inhibits Ovarian Cancer Progression Through Activating Beclin1-Mediated Autophagy

Background

Early detection and diagnosis of ovarian cancer (OC) is complicated due to the concealment of the ovarian anatomical position and the lack of clinical manifestations and specific indicators of early OC. Therefore, it is urgent to study the pathogenesis of OC, especially the molecular mechanism.

Results

LncRNA GAS8-AS1 was decreased in OC tissues and cell lines, and high expression of GAS8-AS1 indicated a higher 5-year survival rate of OC patients. Overexpression of GAS8-AS1 suppressed growth of OC cells, while deletion of GAS8-AS1 promoted the progression of OC cells. Further data indicated GAS8-AS1 activated autophagy in OC cells. Functional experiments showed that 3-MA removed the inhibitory effect of GAS8-AS1 in OC cells. On the contrary, Rapamycin reversed the promoting effect of GAS8-AS1 in OC cells. Furthermore, GAS8-AS1 bound with Beclin1 and promoted its expression, and silencing of Beclin1 reversed the inhibitory role of GAS8-AS1 in OC progression. In vivo tumorigenesis assay showed GAS8-AS1 suppressed OC progression and activated Beclin1 mediated autophagy.

Conclusion

Our study suggested GAS8-AS1 inhibited OC progression by activating autophagy via binding with Beclin1, and GAS8-AS1 might be a potential therapeutic target for OC clinical treatment.

ACTA2-AS1 suppresses lung adenocarcinoma progression via sequestering miR-378a-3p and miR-4428 to elevate SOX7 expression

Lung adenocarcinoma (LUAD) is the most common histological subtype of lung cancer. The abnormal expression of long noncoding RNAs (lncRNAs) can facilitate or suppress the development of malignant tumors. lncRNA actin alpha 2, smooth muscle antisense RNA 1 (ACTA2-AS1) has been reported to function as a tumor suppressor in liver cancer, nevertheless, its influences on LUAD remain to be investigated. In this paper, ACTA2-AS1 was identified as a downregulated lncRNA in LUAD samples and cells. Functionally, ACTA2-AS1 overexpression restrained cell proliferation but accelerated cell apoptosis in LUAD. In addition, we determined the suppressive effect of ACTA2-AS1 on LUAD cell invasion, migration, and epithelial-mesenchymal transition progress. Mechanistically, ACTA2-AS1 exert functions as a competing endogenous RNA through serving as a sponge for microRNA-378a-3p (miR-378a-3p) and microRNA-4428 (miR-4428) to elevate SRY-related high-mobility group box 7 (SOX7) expression. Importantly, SOX7 silencing could recover the ACTA2-AS1-mediated cell functions. To summarize, ACTA2-AS1 suppresses the malignant processes of LUAD cells through sequestering miR-378a-3p and miR-4428 to augment SOX7 expression.

The Role of microRNAs in Epithelial Ovarian Cancer Metastasis

Epithelial ovarian cancer (EOC) is the deadliest gynecological cancer, and the major cause of death is mainly attributed to metastasis. MicroRNAs (miRNAs) are a group of small non-coding RNAs that exert important regulatory functions in many biological processes through their effects on regulating gene expression. In most cases, miRNAs interact with the 3′ UTRs of target mRNAs to induce their degradation and suppress their translation. Aberrant expression of miRNAs has been detected in EOC tumors and/or the biological fluids of EOC patients. Such dysregulation occurs as the result of alterations in DNA copy numbers, epigenetic regulation, and miRNA biogenesis. Many studies have demonstrated that miRNAs can promote or suppress events related to EOC metastasis, such as cell migration, invasion, epithelial-to-mesenchymal transition, and interaction with the tumor microenvironment. In this review, we provide a brief overview of miRNA biogenesis and highlight some key events and regulations related to EOC metastasis. We summarize current knowledge on how miRNAs are dysregulated, focusing on those that have been reported to regulate metastasis. Furthermore, we discuss the role of miRNAs in promoting and inhibiting EOC metastasis. Finally, we point out some limitations of current findings and suggest future research directions in the field.

LncRNA LINC00857 regulates the progression and glycolysis in ovarian cancer by modulating the Hippo signaling pathway

Ovarian cancer is one of the most common gynecological cancers with high morbidity and mortality, which seriously endangers women's health and quality of life. Long noncoding RNAs (lncRNAs) can regulate the progression of cancers, including ovarian cancer. LINC00857 (long intergenic non‐protein coding RNA 857) has been discovered to be a crucial factor in the regulation of cancer development. Nevertheless, the specific functions and mechanisms of LINC00857 in ovarian cancer remain unclear. The Hippo signaling pathway can involve in cancer progression. In our research, we aimed to investigate the correlation of LINC00857 and Hippo pathway. Quantitative real‐time polymerase chain reaction assay was utilized to test the expression of LINC00857 in ovarian cancer tissues and cells. Functional experiments revealed that LINC00857 silencing led to the inhibition on cell proliferation, migration, invasion, and glycolysis but accelerated cell apoptosis in ovarian cancer. Mechanism experiments, including RNA immunoprecipitation, RNA pull‐down, and luciferase reporter experiments demonstrated that LINC00857 could regulate YAP1 (Yes1 associated transcriptional regulator) by competitively binding to miR‐486‐5p in ovarian cancer. In a word, this study unveiled that LINC00857 regulates YAP1 by competitively binding to miR‐486‐5p and accelerates ovarian cancer progression.

Long noncoding RNA HOTTIP promotes the metastatic potential of ovarian cancer through the regulation of the miR-615-3p/SMARCE1 pathway

Upregulation of lncRNA HOXA transcript at the distal tip (HOTTIP) plays important roles in cancer progression. Nevertheless, its functions in the growth and metastasis of ovarian carcinoma are unknown. In this study, we demonstrated overexpression of HOTTIP in ovarian cancer cell lines and clinical tissues. Further, we showed that higher level of HOTTIP was associated with poor survival of ovarian cancer patients. Notably, HOTTIP silencing restrained proliferation, migration, and invasiveness of ovarian carcinoma cells. On the other hand, upregulation of HOTTIP remarkably exacerbated the aggressive traits of ovarian carcinoma cells. In addition, HOTTIP served as a sponge of miR-615-3p to upregulate SMARCE1 level. Further, upregulation of miR-615-3p or downregulation of SMARCE1 reversed the carcinogenic impacts of HOTTIP in ovarian cancer. HOTTIP and miR-615-3p expression levels in ovarian cancer cells were negatively correlated, whereas HOTTIP and SMARCE1 expression levels were positively correlated. In nude mice, downregulation of HOTTIP reduced cell growth in vivo. In summary, lncRNA HOTTIP promotes the growth and metastatic phenotypes of ovarian cancer via regulating miR-615-3p/SMARCE1 pathway.

Long noncoding RNA DUXAP8 regulates proliferation and apoptosis of ovarian cancer cells via targeting miR-590-5p

The aim of this study is to investigate the effect of lncRNA DUXAP8 on proliferation and apoptosis of ovarian cancer cells, and to explore its potential mechanism. DUXAP8 interfering and overexpressing cell lines were constructed and the cell proliferation and apoptosis were tested. Hematoxylin-eosin, TdT-mediated dUTP nick end labeling, and immunohistochemistry were used to detect the effect of DUXAP8 on the ability of tumor formation. Quantitative real-time polymerase chain reaction and western blot were used to detect the mRNA and protein expression of miR-590-5p and YAP1, respectively. Dual luciferase assay was used to determine the target relationship between DUXAP8, miR-590-5p, and YAP1. DUXAP8 interference and miR-590-5p down-regulated cell lines were further constructed. Compared with normal ovarian cells, the expression of DUXAP8 in ovarian cancer cells was significantly increased, while the expression of miR-590-5p was decreased (p < 0.05). After DUXAP8 interference, cell proliferation and colony formation were decreased, and apoptosis was increased. The results of in vivo experiment are consistent with the in vitro experiments. The expression of miR-590-5p was up-regulated and the expression of YAP1 was decreased after DUXAP8 interference. Moreover, miR590-5p inhibitor can attenuate the effect of DUXAP8 interference on ovarian cancer cells. Taken together, lncRNA DUXAP8 can regulate the proliferation and apoptosis of ovarian cancer cells, and its mechanism may be related to the regulation of YAP1 gene by targeting miR-590-5p.

Identification of long noncoding RNA RP11-89K21.1 and RP11-357H14.17 as prognostic signature of endometrial carcinoma via integrated bioinformatics analysis

Background

Endometrial carcinoma (EC) is one of the most common malignant tumors in gynecology. The potential functions and mechanisms of long noncoding RNAs (lncRNAs) in the occurrence and progression of EC remains unclear. It’s meaningful to explore lncRNAs signature for providing prognostic value of EC.

Methods

The differentially expressed lncRNAs and their prognostic values in EC were investigated based on The Cancer Genome Atlas (TCGA) database; the transcriptional factors (TFs), the competing endogenous RNA (ceRNA) mechanism, functional regulatory network and immune infiltration of RP11-89K21.1 and RP11-357H14.17 were further explored by various bioinformatics tools and databases.

Results

We firstly identified high expression of RP11-89K21.1 and RP11-357H14.17 were closely associated with shorten overall survival (OS) and poor prognosis in patients with EC. We also elucidated the networks of transcription factor and co-expression genes associated with RP11-89K21.1 and RP11-357H14.17. Furthermore, the ceRNA network mechanism was successfully constructed through 2 lncRNAs (RP11-89K21.1 and RP11-357H14.17), 11 miRNAs and 183 mRNAs. Functional enrichment analysis revealed that the targeting genes of RP11-89K21.1 and RP11-357H14.17 were strongly associated with microRNAs in cancer, vessel development, growth regulation, growth factor and cell differentiation, and involved in pathways including pathways in cancer, microRNAs in cancer and apoptotic signaling pathway.

Conclusions

We demonstrated for the first time that RP11-89K21.1 and RP11-357H14.17 may play crucial roles in the occurrence, development and malignant biological behavior of EC, and can be regarded as potential prognostic biomarkers for EC.

Role of lncRNAHCP5/microRNA-525-5p/PRC1 crosstalk in the malignant behaviors of ovarian cancer cells

PURPOSE

Owing to the late diagnosis and frequent metastasis, ovarian cancer (OC) exhibits a high mortality rate. The study was intended to figure out the function of long non-coding RNA (lncRNA) HCP5 in OC metastasis.

METHODS

Microarray analysis was conducted to probe aberrantly expressed lncRNAs in OC tissues. Artificial silencing of lncRNA HCP5 was introduced in OC cells to identify its role in cell viability, invasion, migration, and epithelial-mesenchymal transition (EMT). The potential downstream targets of lncRNA HCP5 were predicted by bio-information system and validated through dual luciferase reporter gene assays. Silencing of microRNA-525-5p (miR-525-5p) was introduced in cells to probe its role in cell behaviors. Xenograft tumors were induced in nude mice for in vivo experiments.

RESULTS

High expression of lncRNA HCP5 was found in OC tissues and cells. Silencing of lncRNA HCP5 led to a decrease in cell proliferation, invasion, migration and EMT process. LncRNA HCP5 is mainly sub-localized in cytoplasm. LncRNA HCP5 could act as a sponge for miR-525-5p, which could further bind to polycomb repressive complex 1 (PRC1). Knockdown of miR-525-5p partly recovered the biological behaviors of OC cells inhibited by HCP5 silencing. In addition, HCP5 promoted Wnt/β-catenin signaling pathway activity. Silencing of lncRNA HCP5 also impeded growth and metastasis of tumor in mice.

CONCLUSION

The study suggested that lncRNA HCP5 might promote malignant behaviors of OC cells through the miR-525-5p/PRC1 crosstalk and the Wnt/β-catenin pathway. Silencing of HCP5 might serve as a novel option for OC treatment.

LncRNA DDX11-AS1 Promotes Bladder Cancer Occurrence Via Protecting LAMB3 from Downregulation by Sponging miR-2355-5p

Background: As a subtype of human genitourinary system cancer, the morbidity of bladder cancer (BC) continues to rise. Because of the high potentiality of cell metastasis, the 5-year survival rate of BC is relatively low. Long noncoding RNAs (lncRNAs) have been verified by a large body of literature to engage in the tumorigenesis of a few cancers. DDX11-AS1 has been elucidated as a malignancy promoter in several cancers; therefore, its mysterious role in BC attracted our interest as being well worth investigating. Aim of the Study: The primary consideration of this article was to clarify the part that DDX11-AS1 plays in the progression of BC. Methods: The expression of DDX11-AS1 in BC was revealed by quantitative real-time polymerase chain reaction. The biological functions of DDX11-AS1 in BC were evaluated through CCK-8 (Cell Counting Kit-8), EDU, TUNEL (TdT-mediated dUTP nick-end labeling), flow cytometry analysis, and Western Blot assays. Luciferase or RNA immunoprecipitation assay was used to investigate the interaction between miR-2355-5p and DDX11-AS1 (or LAMB3). Results: DDX11-AS1 manifested remarkably high level in BC and promoted the malignancy of BC. Moreover, miR-2355-5p was validated to be able to bind with DDX11-AS1 and inhibit cell proliferation in BC. Furthermore, our data suggested that LAMB3 expression was evidently upregulated in BC cells and inversely modulated by miR-2355-5p. Besides, LAMB3 may bind with miR-2355-5p. Ultimately, rescue assays indicated that the restrained development of BC in sh-DDX11-AS1#1-transfected cells could be restored by enforced expression of LAMB3. Conclusion: DDX11-AS1 facilitates the tumorigenesis of BC by the miR-2355-5p/LAMB3 axis.

microRNAs as biomarkers of ovarian cancer

Introduction: Ovarian carcinoma (OC) is the leading cause of death in women with gynecologic cancers. Most patients are diagnosed at an advanced stage with a low five-year survival rate of 20-30%. Discovering novel biomarkers for early detection and outcome prediction of OC is an urgent medical need. miRNAs, a group of small non-coding RNAs, play critical roles in multiple biologic processes and cancer pathogenesis.Areas covered: We provide an in-depth look at the functions of miRNAs in OC, particularly focusing on their roles in chemoresistance and metastasis in OC. We also discuss the biological and clinical significance of miRNAs in exosomes and expand on long non-coding RNA which acts as ceRNA of miRNAs.Expert opinion: miRNAs participate in many biological processes including proliferation, apoptosis, chemoresistance, metastasis, epithelial-mesenchymal transition, and cancer stem cell. They will substantially contribute to our understanding of OC pathogenesis. Given their resistance to the degradation of ribonucleases and availability in plasma exosomes, miRNAs may serve as emerging biomarkers for cancer detection, therapeutic assessment, and prognostic prediction. Being a messenger, exosomal miRNAs are crucial for the crosstalk between cancer cells and stromal cells in tumor microenvironment.

The Challenges and Opportunities of LncRNAs in Ovarian Cancer Research and Clinical Use

Ovarian cancer is one of the most lethal gynecological malignancies worldwide because it tends to be detected late, when the disease has already spread, and prognosis is poor. In this review we aim to highlight the importance of long non-coding RNAs (lncRNAs) in diagnosis, prognosis and treatment choice, to make progress towards increasingly personalized medicine in this malignancy. We review the effects of lncRNAs associated with ovarian cancer in the context of cancer hallmarks. We also discuss the molecular mechanisms by which lncRNAs become involved in cellular physiology; the onset, development and progression of ovarian cancer; and lncRNAs' regulatory mechanisms at the transcriptional, post-transcriptional and post-translational stages of gene expression. Finally, we compile a series of online resources useful for the study of lncRNAs, especially in the context of ovarian cancer. Future work required in the field is also discussed along with some concluding remarks.

Recent advances in unraveling the molecular mechanisms and functions of HOXA11‑AS in human cancers and other diseases (Review)

A large number of previously published research articles have demonstrated that the expression levels of long noncoding RNAs (lncRNAs) are generally dysregulated, either through overexpression or underexpression, in cancer and other types of disease. As a recently discovered lncRNA, HOXA11 antisense RNA (HOXA11-AS) is able to serve as an oncogenic or tumor-suppressor gene and serves a vital role in the processes of proliferation, invasion, and migration of cancer cells. HOXA11-AS appears to be a major factor contributing to epigenetic modification, and exerts transcriptional, post-transcriptional, translational and post-translational regulatory effects on genes through a variety of mechanisms; for example, by competing endogenous RNA (ceRNA) and a molecular scaffold mechanism. A number of reports have demonstrated that HOXA11-AS functions as a protein scaffold for polycomb repressive complex 2 (PRC2), lysine-specific histone demethylase 1 (LSD1) and DNA methyltransferase 1 (DNMT1) to perform epigenetic modifications on chromosomes in the nucleus. Furthermore, HOXA11-AS is also located in the cytoplasm and can act as a ceRNA, which sponges miRNAs. In addition, HOXA11-AS may be useful as a biomarker for the diagnosis and prognosis of cancer. In the present review article, the clinical value, phenotype and mechanism of HOXA11-AS in a variety of tumors types are briefly summarized, as well as its clinical value in certain additional diseases. The perspective of the authors is that HOXA11-AS may represent an effective tumor marker and therapeutic target for cancer diagnosis and therapy.

A comprehensive review of the role of long non-coding RNAs in organs with an endocrine function

Long non-coding RNAs (lncRNAs) are transcripts with sizes larger than 200 nucleotides and no/ small open reading frame that cannot produce functional proteins. The number of these transcripts surpasses the number of coding genes. LncRNAs regulate many aspects of cell functions such as proliferation, cell cycle transition and differentiation; so their dysregulation has pervasive effects on cell phenotype. Increasing numbers of these transcripts have been shown to participate in the pathogenesis of cancer. In the current review, we summarize recent findings regarding the role of lncRNAs in tumors originated from organs which have an endocrine function. We mostly focused on adrenal, pancreas and pituitary gland as prototypes of these organs. Moreover, we presented the obtained data of the role of lncRNAs in prostate, ovarian and testicular cancers. Recent data highly supports the role of lncRNAs in the pathogenesis of cancers originated from these organs. Moreover, certain genomic loci within lncRNAs have been shown to be associated with risk of these cancers. Diagnostic and prognostic role of some lncRNAs in these cancers have been evaluated recently. Taken together, lncRNAs are putative biomarkers for cancers originated from organs which have an endocrine function.

miR-6089/MYH9/β-catenin/c-Jun negative feedback loop inhibits ovarian cancer carcinogenesis and progression

The pathogenesis of ovarian cancer remains to be elucidated. Our previous study demonstrated that myosin heavy chain 9 (MYH9) overexpression was associated with poor prognosis of epithelial ovarian cancer. However, the mechanism of MYH9 and its regulation by microRNA (miR) is not clear. The results of the present study demonstrated that miR-6089 was one of the microRNAs targeting MYH9, and miR-6089 overexpression suppressed ovarian cancer cell proliferation, migration, invasion and metastasis in vivo and in vitro. Mechanistic studies confirmed that miR-6089 directly targeted MYH9 to inactivate the Wnt/β-catenin signalling pathway and its downstream epithelial-to-mesenchymal transition (EMT), cell-cycle factors and c-Jun, whereas overexpression of MYH9 reversed the inhibitory effects of miR-6089 overexpression in ovarian cancer cells by upregulating the Wnt/β-catenin and its downstream EMT, cell-cycle factors and c-Jun. Interestingly, miR-6089 was transcriptionally inhibited by c-Jun, a transcription factor which could be induced by MYH9 via the Wnt/β-catenin pathway. Thus miR-6089/MYH9/β-catenin/c-Jun formed a negative feedback loop in ovarian cancer. In clinical samples, miR-6089 negatively correlated with MYH9 expression. Our study is the first to demonstrate that miR-6089 serves as a tumor-suppressive miRNA, and miR-6089/MYH9/β-catenin/c-Jun negative feedback loop inhibits ovarian cancer carcinogenesis and progression.

LncRNA LINC00173 enhances triple-negative breast cancer progression by suppressing miR-490-3p expression

Long non-coding RNA (lncRNA) LINC00173 has been previously shown to promote chemoresistance and progression of small-cell lung cancer. Herein, we examine the clinical significance and biological function of LINC00173 in triple-negative breast cancer (TNBC). Quantitative PCR analysis was performed to determine the expression of LINC00173 in TNBC and adjacent breast tissues (n = 84). The associations of LINC00173 expression with cancer features and survival of TNBC patients were analyzed. The function of LINC00173 in TNBC cell proliferation, colony formation, and invasion was explored. TNBCs expressed increased levels of LINC00173 relative to normal breast tissues. TNBC patients with high tumoral LINC00173 levels had a lower recurrence-free survival and overall survival rate than those with low LINC00173 expression. Silencing of LINC00173 inhibited the proliferation, colony formation, and invasion of TNBC cells, whereas overexpression of LINC00173 exerted opposite effects. In vivo studies confirmed the reduction of tumor growth by LINC00173 depletion. Mechanistic investigation revealed that LINC00173 suppressed miR-490-3p to promote aggressive phenotype in TNBC cells. There was an inverse correlation between miR-490-3p and LINC00173 in TNBC (r = -0.2647, P =  0.0149). Altogether, LINC00173 functions as an oncogene in TNBC through antagonization of miR-490-3p. Upregulation of LINC00173 is associated with poor prognosis in TNBC. Targeting LINC00173 provides a potential therapeutic strategy for TNBC.

Non-coding RNA LOXL1-AS1 exhibits oncogenic activity in ovarian cancer via regulation of miR-18b-5p/VMA21 axis

Long non-coding RNAs (lncRNAs) exert critical effects in the process of malignant cancers and lncRNA LOXL1 Antisense RNA 1 (LOXL1-AS1) has been demonstrated to be a pro-oncogene in multiple tumor types. In the current study, we illuminated the precise roles of LOXL1-AS1 in the development of ovarian cancer. LOXL1-AS1 is significantly overexpressed in ovarian carcinoma tissue compared with adjacent non-cancerous sample. The luciferase reporter gene assay reveals the relationship between LOXL1-AS1 and miR-18b-5p, miR-18b-5p and its target gene, Vacuolar ATPase Assembly Factor VMA21 (VMA21). Transfection of LOXL1-AS1 siRNA or miR-18b-5p mimics inhibits the growth and aggressive phenotypes of SKOV3 and OVCAR3 cell. Furthermore, miR-18b-5p suppresses ovarian carcinoma cell proliferation and metastasis by targeting VMA21 and LOXL1-AS1 regulates ovarian carcinoma cell growth and metastasis through sponging miR-18b-5p. These findings suggest that lncRNA LOXL1-AS1 promotes ovarian cancer cell growth, migratory and invasiveness via modulating miR-18b-5p/VMA21 axis.