LncRNAs in ovarian cancer

ILF3-AS1 promotes cell proliferation and inhibits cell apoptosis of breast cancer by binding with miR-4429 to upregulate RAB14

As one of the leading causes of cancer-related deaths among women, breast cancer accounts for a 30% increase of incidence worldwide since 1970s. Recently, increasing studies have revealed that the long non-coding RNA ILF3-AS1 is involved in the progression of various cancers. Nevertheless, the role of ILF3-AS1 in breast cancer remains largely unknown. In the present study, we found that ILF3-AS1 was highly expressed in breast cancer tissues and cells. ILF3-AS1 silencing inhibited breast cancer cell proliferation, migration and invasion, and promoted cell apoptosis. ILF3-AS1 bound with miR-4429 in breast cancer cells. Moreover, RAB14 was a downstream target of miR-4429, and miR-4429 expression was negatively correlated with RAB14 or ILF3-AS1 expression in breast cancer tissues. The result of rescue experiments demonstrated that overexpression of RAB14 can reverse the inhibitory effect of ILF3-AS1 knockdown on breast cancer cell proliferation, migration and invasion. Overall, ILF3-AS1 promotes the malignant phenotypes of breast cancer cells by interacting with miR-4429 to regulate RAB14, which might offer a new insight into the underlying mechanism of breast cancer.

Screening and prognostic value of potential biomarkers for ovarian cancer

Background

Ovarian cancer is a common gynecological malignant tumor that greatly threatens women's health, so we screened potential biomarkers of ovarian cancer and analyzed their prognostic value.

Methods

The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets were used to analyze the ovarian cancer-related genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to analyze the function of ovarian cancer-related genes. The survival-related genes were screened out through the least absolute shrinkage and selection operator (LASSO) method. Multivariate Cox regression model and stepwise regression analysis were performed to construct the risk model. The receiver operating characteristic (ROC) and the area under the ROC curve (AUC) were used to evaluate the prediction accuracy of risk score model. Finally, gene set enrichment analysis (GSEA) and immune cell infiltration analysis were performed to investigate the biological function and immune cell infiltration.

Results

A total of 111 genes were found to have common effects on survival. These genes were mainly involved in metabolism, protein phosphorylation and immune-related signaling pathways. Seven risk genes (AP3D1, DCAF10, FBXO16, LRFN4, PTPN2, SAYSD1, ZNF426) were screened out. Among these genes, AP3D1 and LRFN4 are risk genes and DCAF10, FBXO16, PTPN2, SAYSD1, and ZNF426 are protective genes. These findings suggest that risk status may be an independent prognostic factor. The risk score had a high predictive value for the prognosis of ovarian cancer. In addition, GSEA revealed that the biological function of genes expressed in patients at a high risk was mostly related to immune-related function. The contents of CD4⁺ T cells, macrophages, myeloid dendritic cells (mDC) and neutrophils were high in samples at a high risk for ovarian cancer.

Conclusions

The abnormal expression of AP3D1, DCAF10, FBXO16, LRFN4, PTPN2, SAYSD1 and ZNF426 is highly related to the progression of ovarian cancer. These seven genes can be used as independent prognostic markers of ovarian cancer. This study not only adds evidence to the pathogenesis of ovarian cancer but also provides scientific basis for judging the prognosis of ovarian cancer.

A novel ferroptosis related gene signature is associated with prognosis in patients with ovarian serous cystadenocarcinoma

Ovarian cancer (OV) is a common type of carcinoma in females. Many studies have reported that ferroptosis is associated with the prognosis of OV patients. However, the mechanism by which this occurs is not well understood. We utilized Genotype-Tissue Expression (GTEx) and The Cancer Genome Atlas (TCGA) to identify ferroptosis-related genes in OV. In the present study, we applied Cox regression analysis to select hub genes and used the least absolute shrinkage and selection operator to construct a prognosis prediction model with mRNA expression profiles and clinical data from TCGA. A series of analyses for this signature was performed in TCGA. We then verified the identified signature using International Cancer Genome Consortium (ICGC) data. After a series of analyses, we identified six hub genes (DNAJB6, RB1, VIMP/ SELENOS, STEAP3, BACH1, and ALOX12) that were then used to construct a model using a training data set. The model was then tested using a validation data set and was found to have high sensitivity and specificity. The identified ferroptosis-related hub genes might play a critical role in the mechanism of OV development. The gene signature we identified may be useful for future clinical applications.

Mechanism of Circular RNA RAD23B for Regulating Glycolysis and Proliferation of Ovarian Cancer Cells by Targeting MicroRNA-519b-3p

We investigated whether circRAD23B regulates glycolysis and proliferation of ovarian cancer cells by targeting miRNA-519b-3p. circRAD23B expression in ovarian cancer tissues was significantly higher than that in paracancerous tissues, and miRNA-519b-3p expression in ovarian cance tissues was significantly lower than that in paracancerous tissues (P < 0.05). Transfection sicircRAD23B or miRNA-519b-3p mimics can greatly attenuate cell viability, glucose consumption, lactic acid level, and CyclinD1 protein level (P < 0.05), and increase p21 protein level (P < 0.05). Double luciferase reporter experiment confirmed that circRAD23B could function as a miRNA-519b-3p sponge molecule. Co-transfection of si-circRAD23B and anti-miRNA-519b-3p could greatly decrease cell viability, glucose consumption, lactic acid level, and CyclinD1 protein level (P < 0.05), and increase p21 protein level by comparison with si-circRAD23B+anti-miRNA-NC group (P < 0.05). Inhibiting circRAD23B expression can, in turn, inhibit glycolysis and the proliferation of ovarian cancer cells by up-regulating miRNA-519b-3p expression.

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.

LncRNA WDFY3-AS2 promotes cisplatin resistance and the cancer stem cell in ovarian cancer by regulating hsa-miR-139-5p/SDC4 axis

BACKGROUND

Ovarian cancer (OC) is a high-mortality gynecological cancer that is typically treated with cisplatin, although such treatment often results in chemoresistance. Ovarian cancer resistance is usually related to cell stemness. Herein, we explored the function of lncRNA WDFY3-AS2 in OC cell resistance to cisplatin (DDP).

METHODS

Cisplatin resistant OC A2780 cell lines (A2780-DDP) were established by long-term exposure to cisplatin. CCK-8 assay were performed to evaluate the viability of A2780, and A2780-DDP cells. Quantitative RT-PCR was used to examine the expression of lncRNA WDFY3-AS2, miR-139-5p, and SDC4 in A2780-DDP cell lines. After treatment with cisplatin, cell apoptosis and CD44+CD166+-positive cells were measured by flow cytometry. The transwell assays were employed to measure the effect of WDFY3-AS2 on cell migration, and invasion. In addition, tumorsphere formation assay was used to enrich OC cancer stem cells (CSCs) from A2780-DDP cells. The expression of CSC markers (SOX2, OCT4, and Nanog) was detected by western blotting. The regulatory mechanism was confirmed by RNA pull down, and luciferase reporter assays. Furthermore, xenograft tumor in nude mice was used to assess the impact of WDFY3-AS2 on cisplatin resistance in OC in vivo.

RESULTS

WDFY3-AS2 was highly expressed in OC A2780-DDP cells, and silencing WDFY3-AS2 significantly inhibited proliferation, migration and invasion but increased apoptosis in OC A2780-DDP cells. Additionally, WDFY3-AS2 significantly promoted the A2780-DDP cells tumorspheres. WDFY3-AS2 was predicted to impact OC by sponging miR-139-5p and regulating SDC4. The xenografts inoculated with A2780-DDP cells additionally confirmed that tumor growth in vivo was reduced by si-WDFY3-AS2 transfection. MiR-139-5p inhibitor or SDC4 overexpression could restore the suppressive influence of silenced WDFY3-AS2 on tumor growth.

CONCLUSIONS

Together, WDFY3-AS2 may lead to change of cisplatin resistance by the expression of miR-139-5p/SDC4 in the OC A2870-DDP cells both in vitro and in vivo. Our finding may provide a drug target for the drug resistance of OC.

LINC00184 Promotes Ovarian Cancer Cells Proliferation and Cisplatin Resistance by Elevating CNTN1 Expression via Sponging miR-1305

Objective

Cisplatin resistance is one of the main reasons for treatment failure in ovarian cancer (OC). Here, the effects of LINC00184 on cisplatin-resistant OC were studied.

Patients and Methods

LINC00184, miR-1305 and CNTN1 expression in tissues from 70 OC patients was determined by qRT-PCR, in situ hybridization and Western blot. OC cell lines and OC cisplatin-resistant cell lines were cultured. Cells were transfected using Lipofectamine 2000 and treated with 100 nM cisplatin. Cell proliferation and apoptosis were researched by the CCK-8 assay and flow cytometry. A dual-luciferase reporter gene assay and RNA pull-down were performed to explore the relationship between two genes. LINC00184, miR-1305 and CNTN1 expression in cells was detected by qRT-PCR and Western blot. An in vivo experiment was conducted using nude mice. Ki67 and CNTN1 expression and apoptosis of xenograft tumors were investigated using immunohistochemistry and a TUNEL assay.

Results

LINC00184 was up-regulated in OC clinical tissues and OC cells, especially in cisplatin-resistant OC patients and cells (p<0.01 or p<0.0001). LINC00184 overexpression significantly enhanced OC cell proliferation and cisplatin resistance, and inhibited OC cell apoptosis (p<0.05 or p<0.01). LINC00184 elevated CNTN1 expression via sponging miR-1305. LINC00184 overexpression markedly exacerbated the malignant phenotype of OC cells and cisplatin-resistant OC cells via the miR-1305/CNTN1 axis (p<0.01). Silencing of LINC00184 significantly suppressed OC cell growth and cisplatin resistance in vivo (p<0.01). LINC00184 silencing inhibited Ki67 and CNTN1 expression and promoted apoptosis of xenograft tumors. CNTN1 overexpression promoted proliferation and cisplatin resistance, and reduced apoptosis of OC cells (p<0.05 or p<0.01).

Conclusion

LINC00184 promoted OC cell proliferation and cisplatin resistance by elevating CNTN1 expression via sponging miR-1305.

Ketamine Inhibits Ovarian Cancer Cell Growth by Regulating the lncRNA-PVT1/EZH2/p57 Axis

Ketamine is widely used for cancer pain treatment in clinic, and has been shown to inhibit various tumor cells growth. However, the effect of ketamine on ovarian cancer cells growth and the downstream molecules has not been defined. In the present study, we found that ketamine significantly inhibited the proliferation and survival of six ovarian cancer cell lines. Moreover, ketamine induced ovarian cancer cell cycle arrest, apoptosis, and inhibited colony formation capacity. Since lncRNAs have been identified as key regulators of cancer development, we performed bioinformatics analysis of a GEO dataset and found fourteen significantly altered lncRNAs in ovarian cancer patients. We then investigated the effect of ketamine on these lncRNAs, and found that ketamine regulated the expression of lncRNA PVT1. Mechanistically, ketamine regulated P300-mediated H3K27 acetylation activation in the promoter of PVT1. Our RNA immunoprecipitation experiment indicated that PVT1 bound histone methyltransferase enhancer of zeste homolog 2 (EZH2), and regulated the expression of target gene, including p57, and consequently altered ovarian cancer cell biology. Our study revealed that ketamine could be a potential therapeutic strategy for ovarian cancer patients.

Prediction of Lymph-Node Metastasis in Cancers Using Differentially Expressed mRNA and Non-coding RNA Signatures

Accurate prediction of lymph-node metastasis in cancers is pivotal for the next targeted clinical interventions that allow favorable prognosis for patients. Different molecular profiles (mRNA and non-coding RNAs) have been widely used to establish classifiers for cancer prediction (e.g., tumor origin, cancerous or non-cancerous state, cancer subtype). However, few studies focus on lymphatic metastasis evaluation using these profiles, and the performance of classifiers based on different profiles has also not been compared. Here, differentially expressed mRNAs, miRNAs, and lncRNAs between lymph-node metastatic and non-metastatic groups were identified as molecular signatures to construct classifiers for lymphatic metastasis prediction in different cancers. With this similar feature selection strategy, support vector machine (SVM) classifiers based on different profiles were systematically compared in their prediction performance. For representative cancers (a total of nine types), these classifiers achieved comparative overall accuracies of 81.00% (67.96-92.19%), 81.97% (70.83-95.24%), and 80.78% (69.61-90.00%) on independent mRNA, miRNA, and lncRNA datasets, with a small set of biomarkers (6, 12, and 4 on average). Therefore, our proposed feature selection strategies are economical and efficient to identify biomarkers that aid in developing competitive classifiers for predicting lymph-node metastasis in cancers. A user-friendly webserver was also deployed to help researchers in metastasis risk determination by submitting their expression profiles of different origins.

The role of IGF2BP2, an m6A reader gene, in human metabolic diseases and cancers

The human insulin-like growth factor 2 (IGF2) mRNA binding proteins 2 (IGF2BP2/IMP2) is an RNA-binding protein that regulates multiple biological processes. Previously, IGF2BP2 was thought to be a type 2 diabetes (T2D)-associated gene. Indeed IGF2BP2 modulates cellular metabolism in human metabolic diseases such as diabetes, obesity and fatty liver through post-transcriptional regulation of numerous genes in multiple cell types. Emerging evidence shows that IGF2BP2 is an N6-methyladenosine (m6A) reader that participates in the development and progression of cancers by communicating with different RNAs such as microRNAs (miRNAs), messenger RNAs (mRNAs) and long non-coding RNAs (lncRNAs). Additionally, IGF2BP2 is an independent prognostic factor for multiple cancer types. In this review, we summarize the current knowledge on IGF2BP2 with regard to diverse human metabolic diseases and its potential for cancer prognosis.

Long non-coding RNA GClnc1 knockdown suppresses progression of epithelial ovarian cancer by recruiting FOXC2 to disrupt the NOTCH1/NF-κB/Snail pathway

PURPOSE

Epithelial ovarian cancer (EOC) is a highly fatal gynecological cancer. A long noncoding RNA (lncRNA) gastric cancer-associated lncRNA1 (GClnc1) has been revealed to play critical roles in metastasis. Therefore, the present study aims to explore the correlation between GClnc1 and the metastasis and progression of EOC.

METHODS

First, 57 paired EOC and paracancerous tissues were collected to detect GClnc1 expression by RT-qPCR. Subsequently, OVC1 and SKOV3 cells with GClnc1 silencing/overexpression were developed to detect changes in cell activity, apoptosis, migration and invasion abilities. Then, the subcellular localization of GClnc1 was detected by nuclear/cytoplasmic fractionation, ISH and FISH assays. The binding relationships between GClnc1 and forkhead box protein C2 (FOXC2), and between FOXC2 and NOTCH1 were predicted and verified.

RESULTS

GClnc1 was significantly overexpressed in EOC tissues, and knockdown of GClnc1 inhibited cell viability and promoted apoptosis. Moreover, GClnc1 in the nucleus bound to the transcription factor FOXC2, thereby activating the transcription of NOTCH1. NOTCH1 overexpression enhanced the proliferation and epithelial-mesenchymal transition of SKOV3 and OVC1 cells. Moreover, NOTCH1 activated the NF-κB/Snail signaling. Finally, in vivo experiments demonstrated that GClnc1 knockdown suppressed the growth and metastasis of SKOV3 and OVC1 cells in vivo.

CONCLUSIONS

GClnc1 promoted NOTCH1 transcription by recruiting FOXC2, thereby activating the NF-κB/Snail signaling and promoting EOC cell growth and metastasis.

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.

Long non‑coding RNA MCM3AP‑AS1 drives ovarian cancer progression via the microRNA‑143‑3p/TAK1 axis

The long non‑coding RNA (lncRNA) MCM3AP antisense 1 (MCM3AP‑AS1) has previously been shown to be a key regulator of multiple types of cancer; however whether it is important in the context of ovarian cancer (OC) is uncertain. The present study determined that MCM3AP‑AS1 expression in samples from patients with OC was significantly increased, and was associated with tumor stage, presence of lymph node metastases and poorer overall survival. The role of this lncRNA was investigated in vitro, and it was observed that knockdown of MCM3AP‑AS1 impaired OC cell proliferation, migration and colony formation. Similarly, it disrupted tumor growth in vivo. The present study further determined that MCM3AP‑AS1 was able to directly interact with microRNA (miRNA or miR)‑143‑3p as a competing endogenous (ce)RNA for this miRNA, thereby regulating the expression of transforming growth factor‑β‑activated kinase 1 (TAK1), a known target of miR‑143‑3p in OC. Consistent with this, inhibition of miR‑143‑3p was sufficient to partially reverse the effects of MCM3AP‑AS1‑knockdown, which inhibited the proliferation, migration and invasion of OC cells. Together, these results indicate that MCM3AP‑AS1 serves as an oncogenic lncRNA in OC by binding to miR‑143‑3p and thereby promoting TAK1 expression, and suggest that this lncRNA may be a possible target for therapy in OC.

The Interplay between Long Noncoding RNAs and Proteins of the Epigenetic Machinery in Ovarian Cancer

Comprehensive large-scale sequencing and bioinformatics analyses have uncovered a myriad of cancer-associated long noncoding RNAs (lncRNAs). Aberrant expression of lncRNAs is associated with epigenetic reprogramming during tumor development and progression, mainly due to their ability to interact with DNA, RNA, or proteins to regulate gene expression. LncRNAs participate in the control of gene expression patterns during development and cell differentiation and can be cell and cancer type specific. In this review, we described the potential of lncRNAs for clinical applications in ovarian cancer (OC). OC is a complex and heterogeneous disease characterized by relapse, chemoresistance, and high mortality rates. Despite advances in diagnosis and treatment, no significant improvements in long-term survival were observed in OC patients. A set of lncRNAs was associated with survival and response to therapy in this malignancy. We manually curated databases and used bioinformatics tools to identify lncRNAs implicated in the epigenetic regulation, along with examples of direct interactions between the lncRNAs and proteins of the epigenetic machinery in OC. The resources and mechanisms presented herein can improve the understanding of OC biology and provide the basis for further investigations regarding the selection of novel biomarkers and therapeutic targets.

NEAT1 Knockdown Suppresses the Cisplatin Resistance in Ovarian Cancer by Regulating miR-770-5p/PARP1 Axis

Background

Long noncoding RNAs play essential roles in regulating drug resistance in cancers. However, how and whether lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) could mediate cisplatin resistance in ovarian cancer remain poorly understood.

Patients and Methods

Eighteen cisplatin-sensitive and 19 cisplatin-resistant patients with ovarian cancer were recruited. Cisplatin-resistant ovarian cancer cells were used for this study. The expression levels of NEAT1, microRNA (miR)-770-5p and poly adenosine diphosphate-ribose polymerase 1 (PARP1) were detected by quantitative real-time polymerase chain reaction or Western blot. Cisplatin resistance was assessed by the half-maximal inhibitory concentration (IC50) of cisplatin, cell viability and apoptosis using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide, flow cytometry and Western blot, respectively. The target association between miR-770-5p and NEAT1 or PARP1 was investigated by dual-luciferase reporter assay. The xenograft model was used to investigate cisplatin resistance in vivo.

Results

NEAT1 expression is elevated in cisplatin-resistant ovarian cancer tissues and cells. Knockdown of NEAT1 repressed cisplatin resistance by decreasing the IC50 of cisplatin, cell viability and increasing apoptosis. MiR-770-5p was bound to NEAT1 and PARP1 was confirmed as a target of miR-770-5p. MiR-770-5p inhibition or PARP1 restoration could abate the effect of NEAT1 silencing on cisplatin resistance in cisplatin-resistant ovarian cancer cells. Moreover, NEAT1 knockdown reduced PARP1 expression by increasing miR-770-5p. Interference of NEAT1 decreased xenograft tumor growth by regulating miR-770-5p and PARP1.

Conclusion

Knockdown of NEAT1 inhibited cisplatin resistance in ovarian cancer cells by up-regulating miR-770-5p and down-regulating PARP1, providing a new target for improving the efficacy of cisplatin-based therapy in ovarian cancer.

The Biological and Clinical Role of the Long Non-Coding RNA LOC642852 in Ovarian Carcinoma

The objective of the present study was to analyze the biological and clinical role of the long non-coding RNA LOC642852 in ovarian carcinoma (OC). LOC642852 expression was analyzed in seven OC cell lines (OVCAR-3, OVCAR-8, OVCA 433, OVCA 429, OC 238, DOV13, ES-2) and 139 high-grade serous carcinoma (HGSC) specimens (85 effusions, 54 surgical specimens). Following LOC642852 knockout (KO) using the CRISPR/Cas9 system, OVCAR-8 HGSC cells were analyzed for spheroid formation, migration, invasion, proliferation, matrix metalloproteinase (MMP) activity, and expression of cell signaling proteins. OVCAR-8 cells with LOC642852 KO were significantly less motile and less invasive compared to controls, with no differences in spheroid formation, proliferation, or matrix metalloproteinase (MMP) activity. Total Akt and Erk levels were comparable in controls and KO cells, but their phosphorylation was significantly increased in the latter. In clinical specimens, LOC642852 was overexpressed in ovarian tumors and omental/peritoneal metastases compared to effusion specimens (p = 0.013). A non-significant trend for shorter overall (p = 0.109) and progression-free (p = 0.056) survival was observed in patients with HGSC effusions with high LOC642852 levels. Bioinformatics analysis showed potential roles for LOC642852 as part of the TLE3/miR-221-3p ceRNA network and in relation to the FGFR3 protein. In conclusion, LOC642852 inactivation via CRISPR/Cas9 affects cell signaling, motility, and invasion in HGSC cells. LOC642852 is differentially expressed in HGSC cells at different anatomical sites. Its potential role in regulating the TLE3/miR-221-3p ceRNA network and FGFR3 merits further research.

Identification of aberrantly expressed long non-coding RNAs in ovarian high-grade serous carcinoma cells

PURPOSE

To identify the aberrantly expressed long non-coding RNAs (lncRNAs) in ovarian high-grade serous carcinoma (HGSC).

METHODS

Total RNA was isolated in HGSC cell lines, ovarian surface epithelial cells, and normal ovaries. Aberrantly expressed lncRNAs in HGSC were identified by PCR array, which analyzes 84 kinds of lncRNAs. To infer their functions, HGSC cell lines with different levels of expression of the identified lncRNAs were established, and then, activities of proliferation, migration, and apoptosis were examined. Expression levels of the identified lncRNAs were also examined in multiple ovarian HGSC tissues.

RESULTS

Ten aberrantly expressed lncRNAs, six upregulated and four downregulated, were identified in the HGSC cell lines. The authors established four HGSC cell lines: in two of the cell lines, one of the upregulated lncRNAs was knocked down, and in two other cell lines, one of the downregulated lncRNAs (MEG3 and POU5F1P5) was overexpressed. Migration activities were inhibited in the HGSC cell lines overexpressing MEG3 or POU5F1P5 while there were no differences in proliferation and apoptosis between the established and control cell lines. The four lncRNAs downregulated in the HGSC cell lines were also observed to be downregulated in ovarian HGSC tissues.

CONCLUSION

The authors identified four downregulated lncRNAs in ovarian HGSC.

Circular RNA Circ_0025033 Promotes the Evolvement of Ovarian Cancer Through the Regulation of miR-330-5p/KLK4 Axis

Background

Circular RNAs (circRNAs) are significant molecular targets in various types of human cancers. The functional mechanism of circRNA_0025033 (circ_0025033) in ovarian cancer (OC) was discussed in the current report.

Methods

The quantitative real-time polymerase chain reaction (qRT-PCR) was used for determining the circ_0025033 and microRNA-330-5p (miR-330-5p) levels. Cell Counting Kit-8 (CCK-8) and transwell assays were separately exploited to analyze cell viability and migration/invasion. Cell apoptosis was assessed using flow cytometry. The protein levels of epithelial–mesenchymal transition (EMT)-related makers and kallikrein-related peptidase 4 (KLK4) were measured by Western blotting. The target combination was confirmed by dual-luciferase reporter assay, RNA immunoprecipitation (RIP) and RNA pull-down assays. And the effect of circ_0025033 on OC in vivo was explored via xenograft tumor assay.

Results

Circ_0025033 was overexpressed in OC tissues and cells. Circ_0025033 knockdown inhibited OC cell viability, migration, invasion and EMT while expedited apoptosis. MiR-330-5p was a target of circ_0025033 and circ_0025033 regulated OC cellular behaviors by sequestering miR-330-5p. Moreover, miR-330-5p targeted KLK4 and circ_0025033 affected the KLK4 expression by sponging miR-330-5p. And miR-330-5p functioned as a tumor inhibitor in OC via targeting KLK4. In vivo, circ_0025033 promoted OC growth by the miR-330-5p/KLK4 axis.

Conclusion

This study demonstrated that circ_0025033 contributed to the progression of OC via the miR-330-5p/KLK4 axis and might be a candidate target in the identification and treatment of OC.

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.

Downregulation of Lnc-OC1 attenuates the pathogenesis of polycystic ovary syndrome

Long non-coding RNAs (lncRNAs) play a vital role in the progression of many human diseases. The aim of this study is to explore the relationship between lncRNA-ovarian cancer associated 1 (Lnc-OC1) and PCOS. In this study, we found that Lnc-OC1 was significantly higher in PCOS granulosa cells (GCs) compared to non-PCOS GCs. Lnc-OC1 knockdown inhibited cell viability and promoted cell apoptosis, expression of aromatase mRNA and production of estradiol in KGN cells. In PCOS mice, Lnc-OC1 promoted the serum insulin release, production of angiogenesis-related factors and IκBα phosphorylation, which could be partially restored by Lnc-OC1 shRNA. These results suggest that Lnc-OC1 plays an important part in the pathogenesis of PCOS.

LncRNA LEF1-AS1 Promotes Ovarian Cancer Development Through Interacting with miR-1285-3p

Background

Growing evidence indicates that long noncoding RNA (lncRNA) is a group of important regulator in cancer development. However, the correlation between lncRNA and ovarian cancer remains elusive. Here, we aimed to investigate the roles of LEF1-AS1 in ovarian cancer progression.

Methods

LEF1-AS1 expression was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). Survival rate was analyzed by Kaplan-Meier method. Cell Counting Kit-8 (CCK8) and colony formation assays were used for proliferation analysis. Transwell assay was utilized for analyses of migration and invasion. Luciferase reporter assay was performed to test the interaction between LEF1-AS1 and miR-1285-3p.

Results

We showed that LEF1-AS1 expression was upregulated in ovarian cancer tissues compared with normal tissues. Besides, LEF1-AS1 level was positively correlated with lymph node metastasis and advanced stage. Enhanced expression of LEF1-AS1 may predict a poor prognosis. Moreover, LEF1-AS1 knockdown suppressed ovarian cancer cell proliferation, migration and invasion. Mechanistically, LEF1-AS1 exerted its oncogenic functions through interacting with miR-1285-3p to inhibit miRNA activity. Rescue assay validated that miR-1285-3p inhibitors abrogated LEF1-AS1-silencer-caused suppression of ovarian cancer progression.

Conclusion

Our study revealed that LEF1-AS1 acts as a vital regulation in ovarian cancer progression.

The Communication Between the PI3K/AKT/mTOR Pathway and Y-box Binding Protein-1 in Gynecological Cancer

Studies of the mechanistic (mammalian) target of rapamycin inhibitors (mTOR) represent a step towards the targeted treatment of gynecological cancers. It has been shown that women with increased levels of mTOR signaling pathway targets have worse prognosis compared to women with normal mTOR levels. Yet, targeting mTOR alone has led to unsatisfactory outcomes in gynecological cancer. The aim of our review was therefore to provide an overview of the most recent clinical results and basic findings on the interplay of mTOR signaling and cold shock proteins in gynecological malignancies. Due to their oncogenic activity, there are promising data showing that mTOR and Y-box-protein 1 (YB-1) dual targeting improves the inhibition of carcinogenic activity. Although several components differentially expressed in patients with ovarian, endometrial, and cervical cancer of the mTOR were identified, there are only a few investigated downstream actors in gynecological cancer connecting them with YB-1. Our analysis shows that YB-1 is an important player impacting AKT as well as the downstream actors interacting with mTOR such as epidermal growth factor receptor (EGFR), Snail or E-cadherin.

KCNQ1OT1 promotes ovarian cancer progression via modulating MIR-142-5p/CAPN10 axis

Background

Long non‐coding RNA (lncRNA) has been regarded as crucial regulator for cancer progression. Roles of KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1) in cancers including osteosarcoma and colon cancer have been previously reported. However, its role in ovarian cancer (OC) remains unclear.

Methods

Expression level of KCNQ1OT1 on OC cells and normal cell was analyzed with quantitative real‐time PCR. Gain and loss‐of‐function experiments were performed to analyze the biological roles of KCNQ1OT1 in OC. Moreover, whether KCNQ1OT1 functions its role via mediating MICRORNA‐142‐5p (MIR‐142‐5p)/calpain 10 (CAPN10) axis was analyzed. In addition, effects of KCNQ1OT1, MIR‐142‐5p, and CAPN10 on overall survival of OC patients were analyzed at Kaplan–Meier plotter website.

Results

We showed KCNQ1OT1 was elevated expression in OC cells and indicated poorer overall survival of OC patients. Besides, we found KCNQ1OT1 could promote OC cell proliferation and migration in vitro. Moreover, MIR‐142‐5p was found reduced expression, while CAPN10 was found elevated expression in OC cells compared with normal cell. Kaplan–Meier curve analysis showed low MIR‐142‐5p or high CAPN10 expression were indicators for poorer overall survival of OC patients. At length, we showed KCNQ1OT1 could regulate OC development via MIR‐142‐5p/CAPN10 axis.

Conclusions

Taken together, KCNQ1OT1 upregulates CAPN10 expression via sponging MIR‐142‐5p, thus promoting the proliferation and migration of OC.

LINC00511 promotes the malignant phenotype of clear cell renal cell carcinoma by sponging microRNA-625 and thereby increasing cyclin D1 expression

The expression pattern and detailed roles of long noncoding RNA LINC00511 in clear cell renal cell carcinoma (ccRCC) remain unknown. We measured LINC00511 expression in ccRCC. We clarified the clinical characteristics associated with LINC00511 in ccRCC. We examined the biological roles of LINC00511 in the progression of ccRCC, and we identified the potential mechanisms involved. LINC00511 was upregulated in ccRCC tissues and cell lines. High LINC00511 expression significantly correlated with TNM classification, lymph node metastasis, and short overall survival among patients with ccRCC. Additionally, LINC00511 knockdown restricted ccRCC cell proliferation, colony formation, and metastasis in vitro; accelerated cell cycle arrest at G0–G1 and apoptosis in vitro; and decreased tumor growth in vivo. Investigation of the mechanism revealed that LINC00511 directly interacted with microRNA-625 (miR-625), and the inhibitory effects of the LINC00511 knockdown on malignant characteristics were neutralized by miR-625 silencing. Furthermore, cyclin D1 (CCND1) was identified as a direct target of miR-625 in ccRCC cells. The tumor-suppressive activity of miR-625 upregulation on ccRCC cells was reversed by CCND1 reintroduction. In conclusion, LINC00511 serves as a competing endogenous RNA that regulates CCND1 expression by sponging miR-625 in ccRCC. Hence, the LINC00511/miR-625/CCND1 pathway might be a promising therapeutic target in ccRCC.

Long noncoding RNA WDFY3-AS2 suppresses tumor progression by acting as a competing endogenous RNA of microRNA-18a in ovarian cancer

Ovarian cancer (OC) is a fatal cancer in women, mainly due to its aggressive nature and poor survival rate. The lncRNA-miRNA-mRNA (long noncoding RNA-microRNA-messenger RNA) interaction is promising biomarkers for the improving prognosis of OC. Therefore, we explored the regulatory mechanism of WDFY3-AS2/miR-18a/RORA axis involved in the biological activities of OC cells. Microarray analysis predicted differentially expressed lncRNA, miRNA, and mRNA related to OC, followed by investigating the relationship among them. The expression patterns of the identified lncRNA WDFY3-AS2, miR-18a, and RORA were measured in OC tissue and cells. Gain- and loss-of-function experiments were performed to characterize the effect of lncRNA WDFY3-AS2 on OC cells, as well as the involvement of miR-18a and RAR related orphan receptor A (RORA). The in vitro assays were validated by in vivo experiments. According to bioinformatics analysis, WDFY3-AS2 was speculated to affect OC by sponging miR-18a and modulating RORA. WDFY3-AS2 and RORA were underexpressed in OC, while miR-18a was highly expressed. Notably, WDFY3-AS2 acts as a competing endogenous RNA to sponge miR-18a and upregulate RORA. Upon overexpressing WDFY3-AS2 or inhibiting miR-18a, RORA expression was increased, thereby the OC cell proliferation, migration, invasion, and epithelial-to-mesenchymal transition (EMT) were suppressed, accompanied by enhanced apoptosis. In vivo experiments confirmed that the tumor growth was reduced in response to overexpressed WDFY3-AS2 or inhibited miR-18a. Taken together, the lncRNA WDFY3-AS2/miR-18a axis regulates the tumor progression of OC by targeting RORA, providing new insights for prevention and control of OC.