HOTAIR Promotes Proliferation, Migration, and Invasion of Ovarian Cancer SKOV3 Cells Through Regulating PIK3R3

Role of exosomal non‑coding RNAs in ovarian cancer (Review)

Ovarian cancer (OC) is a common gynecological disease with a high mortality rate worldwide due to its insidious nature and undetectability at an early stage. The standard treatment, combining platinum‑based chemotherapy with cytoreductive surgery, has suboptimal results. Therefore, early diagnosis of OC is crucial. All cell types secrete extracellular vesicles, particularly exosomes. Exosomes, which contain lipids, proteins, DNA and non‑coding RNAs (ncRNAs), are novel methods of intercellular communication that participate in tumor development and progression. ncRNAs are categorized by size into long ncRNAs (lncRNAs) and small ncRNAs (sncRNAs). sncRNAs further include transfer RNAs, small nucleolar RNAs, PIWI‑interacting RNAs and microRNAs (miRNAs). miRNAs inhibit protein translation and promote messenger RNA (mRNA) cleavage to suppress gene expression. By sponging downstream miRNAs, lncRNAs and circular RNAs can regulate target gene expression, thereby weakening the interactions between miRNAs and mRNAs. Exosomes and exosomal ncRNAs, commonly present in human biological fluids, are promising biomarkers for OC. The present article aimed to review the potential role of exosomal ncRNAs in the diagnosis and prognosis of OC by summarizing the characteristics, processes, roles and isolation methods of exosomes and exosomal ncRNAs.

Long non-coding RNAs in cancer: multifaceted roles and potential targets for immunotherapy

Cancer remains a major global health concern with high mortality rates mainly due to late diagnosis and poor prognosis. Long non-coding RNAs (lncRNAs) are emerging as key regulators of gene expression in human cancer, functioning through various mechanisms including as competing endogenous RNAs (ceRNAs) and indirectly regulating miRNA expression. LncRNAs have been found to have both oncogenic and tumor-suppressive roles in cancer, with the former promoting cancer cell proliferation, migration, invasion, and poor prognosis. Recent research has shown that lncRNAs are expressed in various immune cells and are involved in cancer cell immune escape and the modulation of the tumor microenvironment, thus highlighting their potential as targets for cancer immunotherapy. Targeting lncRNAs in cancer or immune cells could enhance the anti-tumor immune response and improve cancer immunotherapy outcomes. However, further research is required to fully understand the functional roles of lncRNAs in cancer and the immune system and their potential as targets for cancer immunotherapy. This review offers a comprehensive examination of the multifaceted roles of lncRNAs in human cancers, with a focus on their potential as targets for cancer immunotherapy. By exploring the intricate mechanisms underlying lncRNA-mediated regulation of cancer cell proliferation, invasion, and immune evasion, we provide insights into the diverse therapeutic applications of these molecules.

PIK3R3, a regulatory subunit of PI3K, modulates ovarian cancer stem cells and ovarian cancer development and progression by integrative analysis

Background

Ovarian cancer is the most lethal gynecologic disease and is one of the most commonly diagnosed cancers among women worldwide. The phosphatidylinositol 3-kinase (PI3K) family plays an important regulatory role in various cancer signaling pathways, including those involved in ovarian cancer development; however, its exact function remains to be fully understood. We conducted this study to understand the role of P13K in the molecular mechanisms underlying ovarian cancer development.

Methods

To determine the differential gene expression of phosphoinositide-3-kinase regulatory subunit 3 (PIK3R3), a regulatory subunit of PI3K, in normal, tumor, and metastatic ovary tissues, TNM plotter analysis was performed. The microarray dataset GSE53759 was downloaded from Gene Expression Omnibus. ROC plotter analysis was conducted to understand the potential of PIK3R3 as a predictive marker for effectiveness of therapy in ovarian cancer. muTarget was used to identify mutations that alter PIK3R3 expression in ovarian cancer. To determine the interacting partners for PIK3R3 in ovarian tissues, the interactome-atlas tool was used. The Kyoto encyclopedia of genes and genomes (KEGG) analysis was conducted to identify the pathways in which these interacting partners were primarily enriched.

Results

PIK3R3 was overexpressed in ovarian and metastatic tumors. Elevated PIK3R3 levels were observed in ovarian cancer stem cells, wherein inhibiting PIK3R3 expression significantly reduced the size of ovarian cancer spheroids. Treatment of ovarian cancer stem cells with PF-04691502 (10 μM), an inhibitor of both PI3K and mTOR kinases, also reduced the size of spheroids and the level of OCT4. PIK3R3 was highly expressed in ovarian cancer with several somatic mutations and was predicted better outcomes in patients undergoing Avastin® chemotherapy using bioinformatic tool. Protein interaction analysis showed that PIK3R3 interacts with 157 genes, including GRB2, EGFR, ERBB3, PTK2, HCK, IGF1R, YES1, and PIK3CA, in the ovary. KEGG enrichment analysis revealed that the interacting partners of PIK3R3 are involved in the ErbB signaling pathway, proteoglycans in cancer, FoxO, prolactin, chemokine, and insulin signaling pathways.

Conclusions

PIK3R3 plays a pivotal role in ovarian cancer development and is therefore a potential candidate for developing novel therapeutic approaches.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09807-7.

Long Non-coding RNA HOTAIR in Central Nervous System Disorders: New Insights in Pathogenesis, Diagnosis, and Therapeutic Potential

Central nervous system (CNS) disorders, such as ischemic stroke, neurodegenerative diseases, multiple sclerosis, traumatic brain injury, and corresponding neuropathological changes, often lead to death or long-term disability. Long non-coding RNA (lncRNA) is a class of non-coding RNA with a transcription length over 200 nt and transcriptional regulation. lncRNA is extensively involved in physiological and pathological processes through epigenetic, transcription, and post-transcriptional regulation. Further, dysregulated lncRNA is closely related to the occurrence and development of human diseases, including CNS disorders. HOX Transcript antisense RNA (HOTAIR) is the first discovered lncRNA with trans-transcriptional regulation. Recent studies have shown that HOTAIR may participate in the regulation of the occurrence and development of CNS disorders. In addition, HOTAIR has the potential to become a new biomarker for the diagnosis and prognosis assessment of CNS disorders and even provide a new therapeutic target for CNS disorders. Here, we reviewed the research results of HOTAIR in CNS disorders to provide new insights into the pathogenesis, diagnostic value, and therapeutic target potential of HOTAIR in human CNS disorders.

Hotair promotes the migration and proliferation in ovarian cancer by miR-222-3p/CDK19 axis

Previous studies in our laboratory have reported that miR-222-3p was a tumor-suppressive miRNA in OC. This study aims to further understand the regulatory role of miR-222-3p in OC and provide a new mechanism for its prevention and treatment. We first found that miR-222-3p inhibited the migration and proliferation of OC cells. Then, we observed CDK19 was highly expressed in OC and inversely correlated with miR-222-3p. Besides, we observed that miR-222-3p directly binds to the 3′-UTR of CDK19 and inhibits CDK19 translation, thus inhibiting OC cell migration and proliferation in vitro and repressed tumor growth in vivo. We also observed the inhibitory effect of Hotair on miR-222-3p in OC. In addition, Hotair could promote the proliferation and migration of OC cells in vitro and facilitate the growth and metastasis of tumors in vivo. Moreover, Hotair was positively correlated with CDK19 expression. These results suggest Hotair indirectly up-regulates CDK19 through sponging miR-222-3p, which enhances the malignant behavior of OC. This provides a further understanding of the mechanism of the occurrence and development of OC.

Long non-coding RNAs: A view to kill ovarian cancer

An emerging role of long non-coding RNAs (lncRNAs) in tumor progression has been revealed in the last decade. Through interactions with nucleic acids and proteins, lncRNAs could act as enhancers, scaffolds or decoys for a number of oncoproteins and tumor suppressors. The aberrant lncRNA expression or mutations are often associated with changes in a variety of cellular processes, including proliferation, stress response and cell death. Here, we will focus on the tumor-associated lncRNAs in ovarian cancer according to their contribution to cancer hallmarks, such as intense proliferation, cell death resistance, altered energy metabolism, invasion and metastasis, and immune evasion. Moreover, the potential clinical implications of lncRNAs and their significance for the diagnosis, prognosis and therapy of ovarian cancer will be discussed.

Deciphering the Long Non-Coding RNAs and MicroRNAs Coregulation Networks in Ovarian Cancer Development: An Overview

Non-coding RNAs are emergent elements from the genome, which do not encode for proteins but have relevant cellular functions impacting almost all the physiological processes occurring in eukaryotic cells. In particular, microRNAs and long non-coding RNAs (lncRNAs) are a new class of small RNAs transcribed from the genome, which modulate the expression of specific genes at transcriptional and posttranscriptional levels, thus adding a new regulatory layer in the flux of genetic information. In cancer cells, the miRNAs and lncRNAs interactions with its target genes and functional pathways are deregulated as a consequence of epigenetic and genetic alterations occurring during tumorigenesis. In this review, we summarize the actual knowledge on the interplay of lncRNAs with its cognate miRNAs and mRNAs pairs, which interact in coregulatory networks with a particular emphasis on the mechanisms underlying its oncogenic behavior in ovarian cancer. Specifically, we reviewed here the evidences unraveling the relevant roles of lncRNAs/miRNAs pairs in altered regulation of cell migration, angiogenesis, therapy resistance, and Warburg effect. Finally, we also discussed its potential clinical implications in ovarian cancer and related endocrine disease therapies.

HOTAIR lncRNA promotes epithelial-mesenchymal transition by redistributing LSD1 at regulatory chromatin regions

Epithelial‐to‐mesenchymal transition (EMT) describes the loss of epithelial traits and gain of mesenchymal traits by normal cells during development and by neoplastic cells during cancer metastasis. The long noncoding RNA HOTAIR triggers EMT, in part by serving as a scaffold for PRC2 and thus promoting repressive histone H3K27 methylation. In addition to PRC2, HOTAIR interacts with the LSD1 lysine demethylase, an epigenetic regulator of cell fate during development and differentiation, but little is known about the role of LSD1 in HOTAIR function during EMT. Here, we show that HOTAIR requires its LSD1‐interacting domain, but not its PRC2‐interacting domain, to promote the migration of epithelial cells. This activity is suppressed by LSD1 overexpression. LSD1‐HOTAIR interactions induce partial reprogramming of the epithelial transcriptome altering LSD1 distribution at promoter and enhancer regions. Thus, we uncover an unexpected role of HOTAIR in EMT as an LSD1 decommissioning factor, counteracting its activity in the control of epithelial identity.

p55PIK deficiency and its NH2-terminal derivative inhibit inflammation and emphysema in COPD mouse model

Chronic obstructive pulmonary disease (COPD) is composed of chronic airway inflammation and emphysema. Recent studies show that Class IA phosphatidylinositol 3-kinases (PI3Ks) play an important role in the regulation of inflammation and emphysema. However, there are few studies on their regulatory subunits. p55PIK is a regulatory subunit of Class IA PI3Ks, and its unique NH₂-terminal gives it special functions. p55PIK expression in the lungs of nonsmokers, smokers, and patients with COPD was examined. We established a fusion protein TAT-N15 from the NH₂-terminal effector sequence of p55PIK and TAT (the transduction domain of HIV transactivator protein) and investigated the effects of silencing p55PIK or adding TAT-N15 on cigarette smoke exposure at the cellular and animal level. p55PIK expression was increased in patients with COPD. p55PIK deficiency and TAT-N15 significantly inhibited the cigarette smoke extract-induced IL-6, IL-8, and activation of the Akt and the NF-κB pathway in BEAS-2B. p55PIK deficiency and TAT-N15 intranasal administration prevented emphysema and the lung function decline in mice exposed to smoke for 6 mo. p55PIK deficiency and TAT-N15 significantly inhibited lung inflammatory infiltration, reduced levels of IL-6 and KC in mice lung homogenate, and inhibited activation of the Akt and the NF-κB signaling in COPD mice lungs. Our studies indicate that p55PIK is involved in the pathogenesis of COPD, and its NH₂-terminal derivative TAT-N15 could be an effective drug in the treatment of COPD by inhibiting the activation of the Akt and the NF-κB pathway.

Non-Coding RNAs as Biomarkers of Tumor Progression and Metastatic Spread in Epithelial Ovarian Cancer

Simple Summary

Despite advances in cancer research in recent years, efficient predictive biomarkers of tumor progression and metastatic spread for ovarian cancer are still missing. Therefore, we critically address recent findings in the field of non-coding RNAs (microRNAs and long non-coding RNAs) and DNA methylation in ovarian cancer patients as promising novel biomarkers of ovarian cancer progression.

Abstract

Ovarian cancer is one of the most common causes of death among gynecological malignancies. Molecular changes occurring in the primary tumor lead to metastatic spread into the peritoneum and the formation of distant metastases. Identification of these changes helps to reveal the nature of metastases development and decipher early biomarkers of prognosis and disease progression. Comparing differences in gene expression profiles between primary tumors and metastases, together with disclosing their epigenetic regulation, provides interesting associations with progression and metastasizing. Regulatory elements from the non-coding RNA families such as microRNAs and long non-coding RNAs seem to participate in these processes and represent potential molecular biomarkers of patient prognosis. Progress in therapy individualization and its proper targeting also rely upon a better understanding of interactions among the above-listed factors. This review aims to summarize currently available findings of microRNAs and long non-coding RNAs linked with tumor progression and metastatic process in ovarian cancer. These biomolecules provide promising tools for monitoring the patient’s response to treatment, and further they serve as potential therapeutic targets of this deadly disease.

Integrative microRNA and gene expression analysis identifies new epigenetically regulated microRNAs mediating taxane resistance in ovarian cancer

Taxane is a family of front-line chemotherapeutic agents against ovarian cancer (OC). The therapeutic efficacy is frequently counteracted by the development of chemoresistance, leading to high rates of relapse in OC patients. The role(s) of microRNAs (miRNAs) in cancer chemoresistance had been supported by many evidences Epigenetic regulation by miRNAs has been reported to influence cancer development and response to therapeutics, however, their role in OC resistance to paclitaxel (PTX) is unclear. Here, we conducted miRNA profiling in the responsive and PTX-resistant OC cell lines before and after treatment with epigenetic modulators. We reveal 157 miRNAs to be downregulated in the PTX-resistant cells compared to parental controls. The expression of five miRNAs (miRNA-7-5p, -204-3p, -501-5p, -3652 and -4286) was restored after epigenetic modulation, which was further confirmed by qPCR. In silico analysis of the signaling pathways targeted by the selected miRNAs identified the PI3K-AKT pathway as the primary target. Subsequent cDNA array analysis confirmed multiple PI3K-AKT pathway members such as AKT2, PIK3R3, CDKN1A, CCND2 and FGF2 to be upregulated in PTX-resistant cells. STRING analysis showed the deregulated genes in PTX-resistant cells to be primarily involved in cell cycle progression and survival. Thus, high throughput miRNA and cDNA profiling coupled with pathway analysis and data mining provide evidence for epigenetically regulated miRNAs-induced modulation of signaling pathways in PTX resistant OC cells. It paves the way to more in-depth mechanistic studies and new therapeutic strategies to combat chemoresistance.

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.

Key factors mediated by PI3K signaling pathway and related genes in endometrial carcinoma

By analyzing the gene expression of endometrial carcinoma (EC) patients, the key factors in PI3K signaling pathway and its related genes mediating EC were explored. The EC samples and normal endometrial samples were downloaded from TCGA database and GTEx database. The R language "limma" package was used for differential analysis, and the expression level of genes in each tissue was analyzed by "gganatogram" package. Functional enrichment analysis of differential genes was carried out by KOBAS, an online bioinformatics website. The correlation between key genes and differential genes was evaluated using TCGA data and GTEx combined gene expression data. The corresponding clinical data were downloaded from TCGA database and GTEx database, and the R language "survival" package was used to assess the potential of candidate differential genes as a key factor of EC. Based on the combined differential analysis of TCGA and GTEx databases, 299 genes with significant differential in expression were finally got. Functional enrichment analysis revealed that genes were predominantly enriched in the entry of "Pathways in cancer", including RAC2 and PIK3R3 genes which were related with the abnormal PI3K pathway in cancer. PIK3R3, a key gene in the PI3K signaling pathway, was highly-expressed in EC. SPDEF, GCNT2, KIAA1324, C9orf152, MARVELD3, and APEX2 genes were found to be positively correlated with PIK3R3 in EC, all of which were highly expressed in EC. KM survival analysis showed that SPDEF, GCNT2, KIAA1324 and C9orf152 were significantly correlated with patients' survival. ROC analysis showed that SPDEF, GCNT2, KIAA1324 and C9orf152 gene could be used as potential markers for prognosis and survival of EC patients. It was found that PIK3R3, a key gene in the PI3K signaling pathway, was highly expressed in EC. The SPDEF, GCNT2, KIAA1324 and C9orf152 genes were also highly expressed in EC, and were positively correlated with PIK3R3 in EC. Moreover, they are significantly correlated with the patients' survival, suggesting that they may be potential markers for the prognosis of patients with EC.

PCR-Free Detection of Long Non-Coding HOTAIR RNA in Ovarian Cancer Cell Lines and Plasma Samples

Long non-coding RNA HOX transcript antisense intergenic RNA (HOTAIR) is one of the promising biomarkers that has widely been used in determining the stages of many cancers, including ovarian cancer. In cancer diagnostics, the two key analytical challenges for detecting long non-coding RNA biomarkers are i) the low concentration levels (nM to fM range) in which they are found and ii) the analytical method where broad dynamic range is required (four to six orders of magnitude) due to the large variation in expression levels for different HOTAIR RNAs. To meet these challenges, we report on a biosensing platform for the visual (colorimetric) estimation and subsequent electrochemical quantification of ovarian-cancer-specific HOTAIR using a screen-printed gold electrode (SPE-Au). Our assay utilizes a two-step strategy that involves (i) magnetic isolation and purification of target HOTAIR sequences and (ii) subsequent detection of isolated sequences using a sandwich hybridization coupled with horseradish peroxidase (HRP)-catalyzed reaction of 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide. The assay achieved a detection limit of 1.0 fM HOTAIR in spiked buffer samples with excellent reproducibility (% RSD ≤ 5%, for n = 3). It was successfully applied to detect HOTAIR in cancer cell lines and a panel of plasma samples derived from patients with ovarian cancer. The analytical performance of the method was validated with standard RT-qPCR. We believe that the proof of concept assay reported here may find potential use in routine clinical settings for the screening of cancer-related lncRNAs.

MAGI2-AS3 suppresses MYC signaling to inhibit cell proliferation and migration in ovarian cancer through targeting miR-525-5p/MXD1 axis

Ovarian cancer (OV) is one of the most lethal gynecological malignance in females, and usually diagnosed at advanced stages. Long noncoding RNAs (lncRNAs) exhibit their crucial functions in modulatory mechanisms of cancers. Substantive studies have proven the anti-tumor role of MAGI2-AS3 in multiple cancers, but the physiological functions of MAGI2-AS3 in OV need more detailed explanations. The current study corroborated that overexpression of MAGI2-AS3 executed inhibitory activity in OV via hindering cell proliferation, cell cycle, migration as well as invasion while promoted apoptosis. Moreover MAGI2-AS3 bound with miR-525-5p and negatively regulated the expression of miR-525-5p. Further studies testified that MXD1 was a downstream target of miR-525-5p and the competing relationship between MAGI2-AS3 and MXD1 were confirmed by RNA pull down. Based on the combination between MAX and MYC, we analyzed the effects of MAGI2-AS3 on MXD1 and MYC, unveiling the competing relationship between MXD1 and MYC for binding to MAX. Finally, we constructed rescue assays to certify that MAGI2-AS3 suppressed the course of OV via enhancing MXD1 expression. In summary, MAGI2-AS3 repressed the progression of OV by targeting miR-525-5p/MXD1 axis, offering a novel insight into understanding OV at the molecular level.

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.

MiR-186 bidirectionally regulates cisplatin sensitivity of ovarian cancer cells via suppressing targets PIK3R3 and PTEN and upregulating APAF1 expression

Ovarian cancer is a highly lethal malignancy in the female reproductive system. Platinum drugs, represented by cisplatin, are the first-line chemotherapeutic agents for treatment of various malignancies including ovarian cancer, but drug resistance leads to chemotherapy failure. MicroRNAs emerged as promising molecules in reversal of cisplatin resistance. MiR-186 was reported to be downregulated in the cisplatin-resistant ovarian cell lines and miR-186 expression increased cisplatin sensitivity. However, we found the bidirectional regulatory effects of miR-186 on cisplatin sensitivity for the first time that overexpression of miR-186 at low concentration increased the cisplatin sensitivity of ovarian cancer cells A2780/DDP, while high concentration of miR-186 decreased the cisplatin sensitivity. The survival assay in other types of cancer cell lines verified the bidirectional regulatory function of miR-186 on cisplatin sensitivity in dose and cell type dependent manners. MiR-186 suppressed the protein levels of PTEN and PIK3R3 dose-dependently, which are opposite regulatory molecules of the oncogenic AKT pathway. MiR-186 also enhanced the protein levels of apoptotic gene APAF1 dose-dependently. We proposed the final effects of PTEN and APAF1 outweighed PIK3R3 when miR-186 at low concentration so as to increase the cisplatin sensitivity of ovarian cancer cells, while the final effects of PIK3R3 outweighed PTEN and APAF1 when miR-186 at high concentration so as to decrease the cisplatin sensitivity. We concluded the outcome of regulation of these opposite functional molecules contributed to the bidirectional regulatory effects of miR-186 in ovarian cancer cisplatin sensitivity. It deserves more attentions when developing therapeutic strategies based on the bidirectional functional miRNAs.

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.

Upregulated lncRNA UCA1 inhibits trophoblast cell invasion and proliferation by downregulating JAK2

Numerous studies have suggested that urothelial cancer-associated 1 (UCA1) acts as a suppressor gene affecting cell proliferation and migration. However, the biological role and the potential mechanism of UCA1 in the progression of pre-eclampsia (PE) remains unclear. The UCA1 level was markedly upregulated in PE pregnancies relative to non-PE ones in GSE75010 and tissues. A higher body mass index (BMI), maximum systolic blood pressure (BP), and maximum diastolic BP were observed in PE pregnancies, whereas the newborn weight z-score was lower compared with those of non-PE pregnancies. Knockdown of UCA1 accelerated the proliferative migratory abilities and cell cycle progression, but inhibited apoptosis of HTR-8/SVneo and JAR cells. Then, we found that Janus kinases 2 (JAK2) was negatively correlated with UCA1. In addition, JAK2 was downregulated in the placenta of PE pregnancies and was negatively regulated by UCA1. UCA1 was mainly enriched in the nucleus. Knockdown of UCA1 reduced the occupancies of the enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) and H3K27me3 on the Janus kinase 2 (JAK2) promoter regions. Finally, rescue experiments found that transfection of short-hairpin JAK2 attenuated proliferative and migratory abilities of trophoblasts, which were partially reversed after UCA1 knockdown. In short, UCA1 is upregulated in the trophocytes of PE pregnancies and accelerates trophoblast cell invasion and proliferation by downregulating JAK2.

The HOTAIR/miR-214/ST6GAL1 crosstalk modulates colorectal cancer procession through mediating sialylated c-Met via JAK2/STAT3 cascade

Background

The regulatory non-coding RNAs, including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), emerge as pivotal markers during tumor progression. Abnormal sialylated glycoprotein often leads to the malignancy of colorectal cancer (CRC).

Methods

Differential levels of HOTAIR and ST6GAL1 are analyzed by qRT-PCR. Functionally, CRC cell proliferation, aggressiveness and apoptosis are measured through relevant experiments, including CCK8 assay, colony formation assay, transwell assay, western blot and flow cytometry. Dual-luciferase reporter gene assay and RIP assay confirm the direct interaction between HOTAIR and miR-214. The lung metastasis, liver metatstasis and xenografts nude mice models are established to show the in vivo effect of HOATIR.

Results

Here, differential levels of HOTAIR and ST6GAL1 are primarily observed in CRC samples and cells. Upregulated HOTAIR and ST6GAL1 are crucial predictors for poor CRC prognosis. Altered level of ST6GAL1 modulates CRC malignancy. Furthermore, ST6GAL1 and HOTAIR are confirmed as the direct targets of miR-214, and ST6GAL1 is regulated by HOTAIR via sponging miR-214. ST6GAL1 induces the elevated metabolic sialylation of c-Met, which is co-mediated by HOTAIR and miR-214. Sialylated c-Met affects the activity of JAK2/STAT3 pathway. The regulatory role of HOTAIR/miR-214/ST6GAL1 axis also impacts CRC procession. In addition, HOTAIR mediates lung metastasis, liver metastasis and tumorigenesis in vivo. ShHOTAIR and AMG-208 are combined to inhibit tumorigenesis for successful drug development.

Conclusion

The HOTAIR/miR-214/ST6GAL1 axis commands the CRC malignancy by modifying c-Met with sialylation and activating JAK2/STAT3 pathway. Our study presents novel insights into CRC progression and provided prospective therapeutic target for CRC.

Long Noncoding RNA VIM Antisense RNA 1 (VIM-AS1) Plays an Important Role in Development of Preeclampsia by Regulation of Epithelial Mesenchymal Transition

Background

Long noncoding RNAs play important roles in the development of various diseases. This study aimed to evaluate the effects and mechanism of VIM antisense RNA 1 (VIM-AS1) in the development of preeclampsia.

Material/Methods

HTR-8/SVneo cells were divided into normal control (NC), Model, Blank, and VIM-AS1 groups. These groups were analyzed for their VIM-AS1 gene expressions by RT-PCR, HTR-8/SVneo cell invasion was assessed by transwell and migration by wound healing, cell morphology was assessed by microscopy examination, and E-cadherin, Snail, and Vimentin genes expressions were assessed by RT-PCR and WB assay.

Results

VIM-AS1 gene expression was significantly different among normal placenta tissue, mild preeclampsia tissues, and severe preeclampsia tissues (P<0.001 or P<0.01). VIM-AS1 gene expressions, cell invasions, and wound healing rates in the Model and Blank groups were significantly suppressed compared with that of NC group (P<0.001, all). With VIM-AS1 supplementation, VIM-AS1 gene expression, cell invasion, and wound healing rate in the VIM-AS1 group were significantly increased compared with that in the Model group (P<0.001). RT-PCR and WB assay showed that E-cadherin gene and protein expressions in Model and Blank groups were significantly upregulated compared with the NC group (P<0.001); Snail and Vimentin gene and protein expressions in the Model and Blank groups were significantly downregulated compared with the NC group (P<0.001). With VIM-AS1 supplementation, E-cadherin, Snail, and Vimentin gene and proteins expression levels in the VIM-AS1 group were significantly different compared with that in the Model group (P<0.001).

Conclusions

VIM-AS1 promotes preeclampsia via inducing epithelial-to-mesenchymal transition (EMT).

Long non-coding RNA HOTAIR functions as a competitive endogenous RNA to regulate PRAF2 expression by sponging miR-326 in cutaneous squamous cell carcinoma

Background

LncRNAs may exert a regulatory effect in tumorigenesis. Although the expression of lncRNA HOTAIR has been confirmed to be notably elevated in the tissues of CSCC, its biological mechanism in CSCC is still unknown.

Methods

HOTAIR expression level in CSCC cell lines was monitored via qRT-PCR. Then CCK-8 assay, Transwell assay and EdU assay were adopted to detect cell migration and proliferation. Meanwhile, through bioinformatics analysis and luciferase reporter gene detection, a new target of HOTAIR was identified. Additionally, Western blotting and RIP analysis were adopted to discuss the possible mechanism.

Results

HOTAIR expression in CSCC cell lines exhibited an obvious elevation. Cell function analysis revealed that HOTAIR overexpression remarkably facilitated CSCC cell migration, proliferation and EMT process, which were impeded by down-regulation of HOTAIR. Furthermore, HOTAIR competitively bound to miR-326, so as to positively modulate miR-326 expression.

Conclusions

These results present that HOTAIR, as a ceRNA, regulates PRAF2 expression by competitive binding to miR-326 during CSCC.

Role of a novel circulatory RNA-based biomarker panel expression in ovarian cancer

Ovarian cancer (OC) is considered the sixth commonest cancer affecting women globally. We choose novel integrated specific ovarian cancer RNA biomarker panel; pellino E3 ubiquitin protein ligase family member 3 (PELI3) gene expressions along with its selected epigenetic regulators (microRNA (miR-361-3p) and long noncoding RNA (lncRNA RP5-837J1.2) by bioinformatic methods. Then, differential expressions of the selected panel in the sera of 50 OC patients, 42 cases with benign ovarian lesions, and among 45 controls were determined using real-time polymerase chain reaction quantitative (qRT-PCR). Furthermore, their expression was measured also in malignant ovarian tissues and adjacent nontumor tissues in 23 of 50 OC patients by quantitative qRT-PCR. The current study reported, for the first time, upregulation of serum lncRNA RP5-837J1.2 with concomitant downregulation of miR-361-3p and PELI3 mRNA in malignant group compared with benign and controls groups. There were associations of serum lncRNA RP5-837J1.2 with the affected ovary and worse International Federation of Gynecology and Obstetrics staging; associations of miR-361-3p with tumor size, grade, stage, and presence of metastasis; as well as associations among PELI3 mRNA expression and tumor size, grade, stage, and presence of metastasis among the OC group. In tumor tissues, miR-361-3p and PELI3 mRNA levels were at a higher level than that of nontumor tissues; however, tumor tissue showed lower level of lncRNA RP5-837J1.2 compared to normal tissue. There were positive correlations between serum and tissue level of RNA RP5-837J1.2, miR-361-3p, and PELI3 mRNA, but they did not reach statistical significance. Receiver operating characteristics curve analyses showed that lncRNA RP5-837J1.2, miR-361-3p, and PELI3 mRNA expression levels can discriminate among OC patient, cases with benign mass, and controls with an accuracy of 96, 76, and 83%, respectively; which increased if they are combined. This novel diagnostic RNA-based panel biomarker could be helpful for OC diagnosis.

Identification of key genes and pathways between type I and type II endometrial cancer using bioinformatics analysis

Endometrial carcinoma (EC) is a common malignant neoplasm of the female reproductive tract. The malignant degree of type II EC is much greater than that of type I EC, usually presenting with a high recurrence rate and a poor prognosis. Therefore, the present study aimed to examine the principal genes associated with the degree of differentiation in type I and type II EC and reveal their potential mechanisms. Differentially expressed genes (DEGs) were selected from the gene expression profiles derived from The Cancer Genome Atlas. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted. In the present study, the KEGG pathway enrichment analysis revealed that 5,962 upregulated DEGs were significantly enriched in the ‘p53 signaling pathway’ and involved in ‘lysine degradation’. In addition, 3,709 downregulated DEGs were enriched in ‘pathways in cancer’, as well as ‘tight junction regulation’, the ‘cell cycle’ and the ‘Wnt signaling pathway’. The 13 top hub genes MAPK1, PHLPP1, ESR1, MDM2, CDKN2A, CDKN1A, AURKA, BCL2L1, POLQ, PIK3R3, RHOQ, EIF4E and LATS2 were identified via the protein-protein interaction network. Furthermore, the OncoPrint algorithm from cBioPortal declared that 25% of EC cases carried genetic alterations. The altered DEGs (MAPK1, MDM2, AURKA, EIF4E and LATS2) may be involved in tumor differentiation and may be valuable diagnostic biomarkers. In conclusion, a number of principal genes were identified in the present study that may be determinants of poorly differentiated type II EC carcinogenesis, which may contribute to future research into potential molecular mechanisms. In addition, these genes may help identify candidate biomarkers and novel therapeutic targets for type II EC.

The Association of HOTAIR with the Diagnosis and Prognosis of Gastric Cancer and Its Effect on the Proliferation of Gastric Cancer Cells

BACKGROUND

Long noncoding RNAs (lncRNAs) are a group of noncoding RNA with the length of more than 200nt. They have been identified as important diagnostic and prognostic molecules for many cancers and play an important role in the development of cancers. However, their clinical value and roles in gastric cancer (GC) remain unclear.

METHODS

The expression levels of HOTAIR in 54 GC tissues and their matched adjacent nontumor tissues from GC patients and 24 normal mucosa or those with minimal gastritis as healthy controls were determined by qRT-PCR. The expression levels of HOTAIR in human GC cell lines and a normal gastric epithelium cell line were also assessed by qRT-PCR. The potential relationships between its level in GC tissues and the clinicopathological features were analyzed. Furthermore, a receiver operating characteristic (ROC) curve was constructed. Additionally, the correlation between this lncRNA and overall survival (OS) was analyzed. SiRNA transfection was used to silence the expression of HOTAIR in GC cells. And cell proliferation and cell cycle assays were employed to determine the effect of HOTAIR on GC cell growth. Western blot was performed for the detection of the P53, P21, and Bcl2 proteins.

RESULTS

The expression levels of HOTAIR were significantly upregulated in GC tissues and cell lines. Increased HOTAIR was associated with tumor differentiation, lymph node and distant metastasis, and clinical stage. Furthermore, the area under the ROC curve (AUC) was up to 0.8416 (95 % CI=0.7661 to 0.9170, P<0.0001). The sensitivity and specificity were 66.67 and 87.04%, respectively. The correlation between HOTAIR expression and overall survival (OS) was statistically significant. The hazard ratio was 2.681, and 95% CI of ratio was 1.370 to 5.248. In addition, knockdown of HOTAIR can inhibit GC cell growth and affect cell cycle distribution. And knockdown of HOTAIR could enhance the protein levels of P21 and P53.

CONCLUSION

The present study demonstrated that HOTAIR was highly expressed in GC tissues and may serve as a potential diagnostic and prognostic biomarker for GC. And HOTAIR promoted GC cell proliferation.

Characteristics of the competition among RNAs for the binding of shared miRNAs

Competing endogenous RNAs (ceRNAs) are RNAs that share common miRNA binding sites and compete with each other for the miRNA association at these sites. The observation of this phenomenon in the cells altered the view of the miRNA target RNAs from molecules that are passively controlled by miRNAs to molecules that also modulate the miRNAs activity. In this review, we build a general profile of ceRNAS characteristics in order to facilitate ceRNAs identification by researchers. The information summarized here contains an actualized list of previously reported ceRNAs and classes of RNAs that can participate in this type of interaction, the expression behavior and characteristics of ceRNAs and miRNAs in the context of competition, the influence of the shared MREs/miRNAs numbers and the miRNA binding strength on the competition, reports on competition between RNAs in different subcellular localizations and the concept that ceRNAs may form a huge regulatory network in the cell.

Regulatory roles of long noncoding RNAs implicated in cancer hallmarks

Cancer cells acquire numerous biological properties (designated "cancer hallmarks"), such as cell survival and energy metabolism, that facilitate tumor growth and metastatic dissemination during development. To date, eight hallmarks of cancer have been identified that provide a logical framework for understanding the remarkable diversity of neoplastic diseases, as proposed by Douglas Hanahan and Robert A. Weinberg. Long noncoding RNAs (lncRNAs), a category of transcripts widely demonstrated to exert significant regulatory effects on biological processes, have attracted considerable research attention due to their association with the occurrence and development of cancer. The mechanisms by which lncRNAs exert their functions require elucidation to optimize their potential utility as alternative biomarkers and therapeutic targets during tumor occurrence and progression. In this review, we have discussed recent research progress on lncRNAs involved in various cancer hallmarks and their related mechanisms of action, with a view to providing an updated picture of their immense therapeutic potential in the fight against cancer.

Integrating Multiple Heterogeneous Networks for Novel LncRNA-Disease Association Inference

Accumulating experimental evidence has indicated that long non-coding RNAs (lncRNAs) are critical for the regulation of cellular biological processes implicated in many human diseases. However, only relatively few experimentally supported lncRNA-disease associations have been reported. Developing effective computational methods to infer lncRNA-disease associations is becoming increasingly important. Current network-based algorithms typically use a network representation to identify novel associations between lncRNAs and diseases. But these methods are concentrated on specific entities of interest (lncRNAs and diseases) and they do not allow to consider networks with more than two types of entities. Considering the limitations in previous computational methods, we develop a new global network-based framework, LncRDNetFlow, to prioritize disease-related lncRNAs. LncRDNetFlow utilizes a flow propagation algorithm to integrate multiple networks based on a variety of biological information including lncRNA similarity, protein-protein interactions, disease similarity, and the associations between them to infer lncRNA-disease associations. We show that LncRDNetFlow performs significantly better than the existing state-of-the-art approaches in cross-validation. To further validate the reproducibility of the performance, we use the proposed method to identify the related lncRNAs for ovarian cancer, glioma, and cervical cancer. The results are encouraging. Many predicted lncRNAs in the top list have been verified by the biological studies.

miR-224-5p inhibits proliferation, migration, and invasion by targeting PIK3R3/AKT3 in uveal melanoma

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. Accumulating investigations have identified the aberrant expression of miRNAs (microRNAs) in UM, such as miR-181, miR-20a, miR-144, miR-146a. The purpose of this study is to investigate the biological function of miR-224-5p in UM. The expression of miR-224-5p, PIK3R3, and AKT3 in 30 tumor tissues and paired adjacent noncancerous tissues were analyzed using Western blot analysis and quantitative real-time polymerase chain reaction (qRT-PCR) assays. Cell proliferation assay, transwell assay, and wound healing assay were used to measure the effects of miR-224-5p on the motility of UM in vitro. Western blot analysis and luciferase assays were used to detect the expression of PIK3R3 and AKT3 as miR-224-5p downstream targets. The results of Western blot analysis and qRT-PCR assays indicated that the expression of miR-224-5p was lower in UM tissues compared to normal tissue, while the expression of PIK3R3 and AKT3 were simultaneously increased. Upregulation of miR-224-5p significantly inhibited capacities of proliferation, invasion, and migration of OCM-1A cells and decreased expression of PIK3R3 and AKT3. Luciferase assay demonstrated PIK3R3 and AKT3 as downstream targets of miR-224-5p. Moreover, upregulating PIK3R3 and AKT3 restrained miR-224-5p-induced inhibition of the motility of OCM-1A cells. Thus, our study proved that miR-224-5p was involved in proliferation, invasion, and migration of UM cells via regulation the expression of PIK3R3 and AKT3. And the results also established a miR-224-5p/PIK3R3/PI3K/AKT axis in the regulation of UM progression, providing an experimental basis for further exploring the miR-224-5p as a therapeutic and diagnosis target for patients with UM.

MicroRNA‑601 serves as a potential tumor suppressor in hepatocellular carcinoma by directly targeting PIK3R3

Recently, microRNAs (miRNAs) have been acknowledged as important regulators of hepatocarcinogenesis and tumor progression. Therefore, identifying the underlying molecular mechanisms of miRNAs in the occurrence and development of hepatocellular carcinoma (HCC) may be important for understanding the pathogenesis of HCC and aid the identification of potential therapeutic strategies. In the present study, miRNA (miR)‑601 was significantly downregulated in HCC tissues and cell lines; low miR‑601 expression was strongly associated with tumor, node and metastasis staging and lymph node metastasis of patients with HCC. In addition, the overexpression of miR‑601 expression significantly inhibited the proliferation and invasion of HCC cells. Regarding the underlying mechanism, phosphoinositide‑3‑kinase regulatory subunit 3 (PIK3R3) was predicted to be a direct target of miR‑601 in HCC cells. Furthermore, restoration of PIK3R3 expression in these cells counteracted the inhibitory effects of miR‑601 on cell proliferation and invasion in HCC. Notably, miR‑601 overexpression inhibited the protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway in HCC via the regulation of PIK3R3. Collectively, these results demonstrated that miR‑601 may inhibit the progression of HCC by directly targeting PIK3R3 and regulating the AKT/mTOR signaling pathway. Therefore, miR‑601 may be an effective therapeutic target for the treatment of patients with HCC.

HOTAIR promotes osteosarcoma development by sponging miR-217 and targeting ZEB1

Long noncoding RNAs (lncRNAs) have drawn increasing attention because of the role which they play in various diseases, including osteosarcoma. So far, the function and mechanism of HOTAIR in osteosarcoma are unclear. In our study, we observed that HOTAIR was elevated accompanied with a decrease of miR-217 and an increase of ZEB1 in human osteosarcoma cells including U2OS, MG63, Saos-2, and SW1353 compared with human osteoblast cell line hFOB. In addition, the subsequent functional assay exhibited that silencing HOTAIR could significantly repress osteosarcoma cell growth, migration, invasion, and induce cell apoptosis capacity, which indicated that HOTAIR exerted an oncogenic role in osteosarcoma. Moreover, it was revealed by using bioinformatics analysis that HOTAIR can be targeted by microRNA-217 (miR-217). miR-217 has been recognized as a crucial tumor suppressive gene in cancers. We verified that mimics of miR-217 were able to suppress the osteosarcoma development. Furthermore, real-time quantitative PCR showed that HOTAIR siRNA increased miR-217 expression. Besides these, ZEB1 was identified as a downstream gene of miR-217 and we found that HOTAIR can mediate osteosarcoma progress by upregulating ZEB1 expression via acting as a competitive endogenous RNA (ceRNA) via miR-217. Taken these together, our findings in this study indicated that HOTAIR/miR-217/ZEB1 axis, as a novel research point can provide new insights into molecular mechanism of osteosarcoma development.

LncRNA HOTAIR/miR-613/c-met axis modulated epithelial-mesenchymal transition of retinoblastoma cells

Since lncRNAs could modulate neoplastic development by modulating downstream miRNAs and genes, this study was carried out to figure out the synthetic contribution of HOTAIR, miR-613 and c-met to viability, apoptosis and proliferation of retinoblastoma cells. Totally 276 retinoblastoma tissues and tumour-adjacent tissues were collected, and human retinoblastoma cell lines (ie, Y79, HXO-Rb44, SO-Rb50 and WERI-RB1) were also gathered. Moreover, transfections of pcDNA3.1-HOTAIR, si-HOTAIR, miR-613 mimic, miR-613 inhibitor, pcDNA3.1/c-met were performed to evaluate the influence of HOTAIR, miR-613 and c-met on viability, apoptosis and epithelial-mesenchymal transition (EMT) of retinoblastoma cells. Dual-luciferase reporter gene assay was also arranged to confirm the targeted relationship between HOTAIR and miR-613, as well as between miR-613 and c-met. Consequently, up-regulated HOTAIR and down-regulated miR-613 expressions displayed associations with poor survival status of retinoblastoma patients (P < 0.05). Besides, inhibited HOTAIR and promoted miR-613 elevated E-cadherin expression, yet decreased Snail and Vimentin expressions (P < 0.05). Simultaneously, cell proliferation and cell viability were also less-motivated (P < 0.05). Nonetheless, c-met prohibited the functioning of miR-613, resulting in promoted cell proliferation and viability, along with inhibited cell apoptosis (P < 0.05). Finally, HOTAIR was verified to directly target miR-613, and c-met was the direct target gene of miR-613 (P < 0.05). In conclusion, the role of lncRNA HOTAIR/miR-613/c-met signalling axis in modulating retinoblastoma cells' viability, apoptosis and expressions of EMT-specific proteins might provide evidences for developing appropriate diagnostic and treatment strategies for retinoblastoma.

Upregulation of KIF26B, Cell Migration and Proliferation of Human Ovarian Cancer Cell Lines In Vitro, and Patient Outcomes from Human Bioinformatic Analysis

Background

The aim of this study was to assess the expression profile of the KIF26B gene, its effects on ovarian cancer cell behavior in vitro, the clinical prognostic value of expression of the KIF26B gene and associated signaling pathways, from bioinformatics data analysis.

Material/Methods

The Cancer Genome Atlas-Ovarian Cancer (TCGA-OV) database and the online Kaplan-Meier plotter for ovarian cancer were analyzed. Human ovarian cancer cell lines A2780 and SKOV3 were used to study the in vitro effects of KIF26B gene expression on cell proliferation and cell invasion. Genes that interacted with, co-localized to, and were co-expressed with the KIF26B gene (Pearson’s r ≥0.6) were identified and underwent Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis.

Results

Increased expression of the KIF26B gene increased the proliferation and migration of A2780 and SKOV3 cells in vitro. KIF26B protein expression was upregulated in ovarian cancer tissue and was associated with lymphatic and venous invasion. TCGA-OV data analysis showed that increased expression of the KIF26B gene was significantly associated with reduced 3-year, 5-year, and 10-year overall survival (OS), progression-free survival (PFS), and post-progression survival (PPS). The genes that interacted with, co-localized to, and were co-expressed with KIF26B were enriched in several KEGG pathways; upregulation of the KIF26B gene was associated with TGF-β signaling pathway.

Conclusions

Upregulation of KIF26B enhanced proliferation and migration of ovarian cancer cells in vitro. Bioinformatics analysis supported the association between increased expression of the KIF26B gene and reduced clinical outcome in patients with ovarian carcinoma.

STAT3/HOTAIR Signaling Axis Regulates HNSCC Growth in an EZH2-dependent Manner

Purpose: PI3K and STAT3 are frequently activated in cancer progression. However, little is known about the underlying mechanisms by which PI3K and STAT3 regulate head and neck squamous cell cancer (HNSCC) growth. The lncRNA HOX transcript antisense RNA (HOTAIR) was found to modulate the progression of HNSCC. In this study, we attempted to establish the correlation of PI3K/STAT3/HOTAIR signaling with the progression of HNSCC and its sensitivity toward platinum-based and targeted anti-EGFR combination therapy.Experimental Design: We first analyzed the STAT3/HOTAIR and PI3K/AKT level in human HNSCC samples. We then activated or suppressed STAT3/HOTAIR and determined the effects on HNSCC cell proliferation in vitro and the growth of UM1 xenograft tumor, an orthotopic model of HNSCC. The sensitivity of HNSCC cells toward cisplatin and cetuximab was determined by in vitro assays.Results: HNSCC samples showed significantly robust expression/activation of STAT3, HOTAIR, PI3K, and AKT, compared with normal squamous epithelium. STAT3 inhibition with WP1066 decreased HOTAIR level and sensitized HNSCC to cisplatin or cetuximab. STAT3 promoted HOTAIR transcription and its interaction with pEZH2-S21, resulting in enhanced growth of HNSCC cells. In addition, overexpression of HOTAIR promoted the growth of UM1 xenograft tumors in vivoConclusions: Our results suggest that STAT3 signaling promotes HNSCC progression via regulating HOTAIR and pEZH2-S21 in HNSCC with PI3K overexpression/activation. These findings provide a rationale to target the STAT3/HOTAIR/pEZH2-S21 regulatory axis for treating patients with HNSCC. Clin Cancer Res; 24(11); 2665-77. ©2018 AACR.

Inflammatory related gene IKKα, IKKβ, IKKγ cooperates to determine liver cancer stem cells progression by altering telomere via heterochromatin protein 1-HOTAIR axis

Cancer stem cells are associated with tumor recurrence. IKK is a protein kinase that is composed of IKKα, IKKβ, IKKγ. Herein, we demonstrate that IKKα plus IKKβ promoted and IKKγ inhibited liver cancer stem cell growth in vitro and in vivo. Mechanistically, IKKα plus IKKβ enhanced and IKKγ inhibited the interplay among HP1α, HP1β and HP1γ that competes for the interaction among HP1α, SUZ12, HEZ2. Therefore, IKKα plus IKKβ inhibited and IKKγ enhanced the activity of H3K27 methyltransferase SUZ12 and EZH2, which methylates H3K27 immediately sites on HOTAIR promoter region. Therefore, IKKα plus IKKβ increased and IKKγ decreased the HOTAIR expression. Strikingly, IKKα plus IKKβ decreases and IKKγ increases the HP1α interplays with DNA methyltransferase DNMT3b, which increases or decreases TERRA promoter DNA methylation. Thus IKKα plus IKKβ reduces and IKKγ increases to recruit TRF1 and RNA polymerase II deposition and elongation on the TERRA promoter locus, which increases or decreases TERRA expression. Furthermore, IKKα plus IKKβ decreases/increases and IKKγ increases/decreases the interplay between TERT and TRRRA/between TERT and TREC. Ultimately, IKKα plus IKKβ increases and IKKγ decreases the telomerase activity. On the other hand, at the telomere locus, IKKα plus IKKβ increases/drcreases and IKKγ decreases/increases TRF2, POT1, pPOT1, Exo1, pExo1, SNM1B, pSNM1B/CST-AAF binding, which keep active telomere regulatory genes and poised for telomere length. Strikingly, HOTAIR is required for IKKα plus IKKβ and IKKγ to control telomerase activity and telomere length. These observations suggest that HOTAIR operates the action of IKKα, IKKβ, IKKγ in liver cancer stem cells. This study provides a novel basis to elucidate the oncogenic action of IKKα, IKKβ, IKKγ and prompts that IKKα, IKKβ, IKKγ cooperate to HOTAR to be used as a novel therapeutic targets for liver cancer.

The effect of lncRNA HOTAIR on chemoresistance of ovarian cancer through regulation of HOXA7

This study aimed at investigating the biological functions of long non-coding RNAs (lncRNAs) hox transcript antisense intergenic RNA (HOTAIR) in resistant ovarian cancer cells, exploring the regulation effect of HOTAIR on HOXA7, and investigating their influence on the chemosensitivity of ovarian cancer cells. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied for the verification of HOTAIR expression in resistant and sensitive groups. How HOTAIR downregulation affected cell proliferation, migration and invasion, and apoptosis were determined using the MTT assay and the colony formation assay, the Transwell assay and flow cytometry analysis, respectively. Immunohistochemistry was used to inspect the protein expression of HOXA7 in resistant and sensitive ovarian cancer tissues. The regulation relationship between HOTAIR and HOXA7 was investigated by qRT-PCR and Western blot. The effect of HOTAIR and HOXA7 on tumor growth was confirmed by the tumor xenograft model of nude mice. By knocking down HOXA7, HOTAIR downregulation restrained the ovarian cancer deterioration in functional experiments. Silencing of HOTAIR and HOXA7 could effectively inhibit tumor growth and increase chemosensitivity of ovarian tumors in nude mice. Downregulation of HOTAIR negatively affected the survival and activity of resistant ovarian cancer cells, and suppressed the expression of HOXA7. Silencing of HOTAIR and HOXA7 could increase the chemosensitivity of ovarian cancer cells, thus suppressing tumor development.

Expression and clinical role of long non-coding RNA in high-grade serous carcinoma

OBJECTIVE

To profile long non-coding RNA (lncRNA) expression at the various anatomic sites of high-grades serous carcinoma (HGSC) and in effusion-derived exosomes.

METHODS

LncRNA profiling was performed on 60 HGSC specimens, including 10 ovarian tumors, 10 solid metastases and 10 malignant effusions, as well as exosomes from 30 effusion supernatants. Anatomic site-related expression of ESRG, Link-A, GAS5, MEG3, GATS, PVT1 H19, Linc-RoR, HOTAIR and MALAT1 was validated by quantitative PCR and assessed for clinical relevance in a series of 77 HGSC effusions, 40 ovarian carcinomas, 21 solid metastases and 42 supernatant exosomes.

RESULTS

Significantly different (p<0.05) expression of 241, 406 and 3634 lncRNAs was found in comparative analysis of the ovarian tumors to solid metastases, effusions and exosomes, respectively. Cut-off at two-fold change in lncRNA expression identified 54 lncRNAs present at the 3 anatomic sites and in exosomes. Validation analysis showed significantly different expression of 5 of 10 lncRNAs in the 4 specimen groups (ESRG, Link-A, MEG3, GATS and PVT1, all p<0.001). Higher ESRG levels in HGSC effusions were associated with longer overall survival in the entire effusion cohort (p=0.023) and in patients with pre-chemotherapy effusions tapped at diagnosis (p=0.048). Higher Link-A levels were associated with better overall (p=0.015) and progression-free (p=0.023) survival for patients with post-chemotherapy effusions. Link-A was an independent prognostic marker in Cox multivariate analysis in the latter group (p=0.045).

CONCLUSIONS

We present the first evidence of differential LncRNA expression as function of anatomic site in HGSC. LncRNA levels in HGSC effusions are candidate prognostic markers.

Integrated Proteomic and Transcriptomic Analysis Reveals Long Noncoding RNA HOX Transcript Antisense Intergenic RNA (HOTAIR) Promotes Hepatocellular Carcinoma Cell Proliferation by Regulating Opioid Growth Factor Receptor (OGFr)

Long noncoding RNA HOX transcript antisense RNA (HOTAIR) is involved in human tumorigenesis and is dysregulated in hepatocellular carcinoma (HCC). However, the molecular mechanisms underlying HOTAIR functions in HCC are largely unknown. Here, we employed an integrated transcriptomic and quantitative proteomic analysis to systematically explore the regulatory role of HOTAIR in HCC. A total of 673 transcripts and 293 proteins were found to be dysregulated after HOTAIR inhibition. Bioinformatics studies indicated that differentially expressed genes (DEGs) and differentially expressed proteins (DEPs) are involved in many biological processes, especially cancer-related signaling pathways. A set of DEGs and DEPs were validated by quantitative RT-PCR, Western blot and parallel reaction monitoring (PRM) analysis, respectively. Further functional studies of the opioid growth factor receptor (OGFr), a negative biological regulator of cell proliferation in HCC, revealed that HOTAIR exerts its effects on cell proliferation, at least in part, through the regulation of OGFr expression. By correlating the omics data with functional studies, the current results provide novel insights into the functional mechanisms of HOTAIR in HCC cells.

Naked-eye and electrochemical detection of isothermally amplified HOTAIR long non-coding RNA

A naked-eye, colorimetric and electrochemical detection of HOTAIR long non-coding RNA has been demonstrated.

Long noncoding RNA lncBRM facilitates the proliferation, migration and invasion of ovarian cancer cells via upregulation of Sox4

Ovarian cancer (OC) is one of the most fatal gynecological cancer in women worldwide. Long noncoding RNA (lncRNA) lncBRM was found to be associated with the progression and prognosis of hepatocellular carcinoma (HCC). However, the expression level, clinical significance and functions in OC tumorigenesis and progression remain unclear. Our present research demonstrated that lncBRM expression was significantly increased in OC tissues. Upregulation of lncBRM expression was correlated with histological grade, FIGO stages, lymph node metastasis and poor prognosis of patients with OC. Functional assays showed that lncBRM positively regulated cell proliferation, migration and invasion in OC. Moreover, lncBRM upregulated Sox4 by competitively binding miR-204. Together, lncBRM functions as an oncogene in OC and can be a promising therapeutic target for OC treatment.

Linc-ROR induces epithelial-to-mesenchymal transition in ovarian cancer by increasing Wnt/β-catenin signaling

Long intergenic non-protein coding RNA, regulator of reprogramming (linc-ROR) is an intergenic long non-coding RNA (lncRNA) previously shown to contribute to tumorigenesis in several malignancies. However, little is known about whether linc-ROR has a role in ovarian cancer progression. In this study, we found that linc-ROR expression was increased in high-grade ovarian serous cancer tissues compared with normal ovarian tissues or normal fallopian tube tissues. Furthermore, the level of linc-ROR expression was associated with ovarian cancer International Federation of Gynecology and Obstetrics stage and lymph node metastasis. Linc-ROR promoted ovarian cancer cell proliferation both in vitro and in vivo, and contributed to cell migration and invasion. Linc-ROR knockdown in ovarian cancer cell lines inhibited the epithelial-to-mesenchymal transition (EMT) program, which led to ovarian cancer cell metastasis through the repression of canonical Wnt/β-catenin signaling. Together, our results indicated that linc-ROR induces EMT in ovarian cancer cells and may be an important molecule in the invasion and metastasis of ovarian cancer.

HOTAIR: a key regulator in gynecologic cancers

Long non-coding RNAs (lncRNAs) play critical roles in the initiation and progression of human cancers. HOX transcript antisense RNA (HOTAIR) is an lncRNA localized to the mammalian HOXC gene cluster; it can interact with polycomb repressive complex 2 and the lysine-specific histone demethylase/CoREST/REST complex, and it manipulates the expression of various genes. HOTAIR promotes tumor invasion and metastasis by silencing tumor suppressors, and activating oncogenes and signaling pathways. HOTAIR is deregulated in many human cancers; despite its critical roles in health and disease, the underlying mechanisms governing HOTAIR function are unknown. In this review, we summarize the recent findings on the roles of HOTAIR in gynecologic cancers.

Prognostic and diagnostic significance of lncRNAs expression in cervical cancer: a systematic review and meta-analysis

Long noncoding RNAs (lncRNAs) have been reported to be abnormally expressed in cervical cancer (CC) and presumably serve as diagnostic or prognostic markers. We thus performed a systematic review and meta-analysis to evaluate the clinical values of dysregulated lncRNAs in CC. A literature search was performed using the electronic databases PubMed, Embase, and Web of Science. A total of 22 relevant studies were eligible, including 21 on clinicopathological features, 18 on prognosis, and 4 on diagnosis. For clinicopathological features, HOTAIR expression was positively associated with tumor size (odds ratio [OR]=2.19, 95% confidence interval [CI] 1.42-3.38, P=0.000) and lymph node metastasis (OR=6.04, 95% CI 3.51-10.42, P=0.000). For the prognostic values, up-regulated HOTAIR had an unfavorable impact on overall survival ([OS]; hazard ratio [HR]=1.94, 95%CI 1.17-3.22, P=0.011) and disease-free survival (HR=2.61, 95%CI 1.35-5.05, P=0.004), and high PVT1 expression was correlated with shorter OS (HR=1.66, 95%CI 1.21-2.29, P=0.002). For the diagnostic values, the pooled result showed an area under the curve (AUC) of 0.85, with 85% sensitivity and 81% specificity in discriminating patients with CC from healthy controls. Overall, we conclude that lncRNAs might serve as promising indicators for prognostic and diagnostic evaluation of patients with CC.

LncRNA HOTAIR regulates HIF-1α/AXL signaling through inhibition of miR-217 in renal cell carcinoma

Long non-coding RNA HOTAIR was regarded as an oncogene in multiple cancers. Previous studies have shown that HOTAIR is involved in the proliferation and tumorigenesis of renal carcinoma cells, while microRNA (miR)-217 functions as a tumor suppressor in renal cell carcinoma (Rcc). However, the underlying molecular mechanism of HOTAIR in Rcc, especially in association with miR-217, has not been studied. In this study, we first demonstrated that HOTAIR expression was upregulated, which was correlated with tumor progression, and miR-217 downregulated in Rcc tissues and cells. Importantly, HOTAIR expression was negatively correlated with miR-217 expression in Rcc tissues. Gain- and loss-of-function of HOTAIR revealed that HOTAIR functioned as a ceRNA for miR-217 to facilitate HIF-1α expression and then upregulated AXL level promoting Rcc proliferation, migration, and EMT process, and inhibiting apoptosis. Furthermore, HOTAIR knockdown suppressed tumor growth and reduced the expression of proliferation antigen ki-67, HIF-1α, and AXL, but upregulated the expression of miR-217 in vivo. Finally, with AXL inhibitor BGB324, we confirmed that HOTAIR promoted Rcc activity through AXL signaling both in vitro and in vivo. In conclusion, these results suggest that HOTAIR promotes Rcc tumorigenesis via miR-217/HIF-1α/AXL signaling, which may provide a new target for the diagnosis and therapy of Rcc disease.

Alginate Particles with Ovalbumin (OVA) Peptide Can Serve as a Carrier and Adjuvant for Immune Therapy in B16-OVA Cancer Model

BACKGROUND Alginate is a natural polysaccharide obtained from brown algae and has been shown to have numerous applications in biomedical science, such as wound healing, delivery of bioactive agents, and cell transplantation. Ovalbumin (OVA) peptide 323-339 has been reported to be involved in immune response.  MATERIAL AND METHODS This work investigated the use of alginate particles as a carrier and adjuvant for the immune therapy of cancer. Alginate particles loaded with OVA peptide were produced via emulsion. A tumor model was established in C57BL/6J mice via subcutaneous injection of 3×105 B16-OVA tumor cells. The effect of alginate/OVA peptide on cell viability was analyzed by use of the CCK-8 assay kit. Activation of macrophages was examined by checking cell surface makers CD40 and CD86 by FACs. RESULTS Alginate/OVA peptide inhibited tumor progression more effectively than using the peptide alone. The viability and uptake study illustrated that this particle is safe and non-toxic. The activation study demonstrated that alginate particles can promote the activation of surface markers on macrophages. ELISA assay showed that the particles with peptide can promote the secretion of inflammatory and effector cytokines from macrophages.  CONCLUSIONS This study demonstrated that alginate has dual functions in immune therapy of cancer, serving both as a carrier and an adjuvant.