Construction of differential mRNA-lncRNA crosstalk networks based on ceRNA hypothesis uncover key roles of lncRNAs implicated in esophageal squamous cell carcinoma

Functional role of lncRNAs in gastrointestinal malignancies: the peculiar case of small nucleolar RNA host gene family

Long noncoding RNAs (lncRNAs) play crucial roles in normal physiology and are often de-regulated in disease states such as cancer. Recently, a class of lncRNAs referred to as the small nucleolar RNA host gene (SNHG) family have emerged as important players in tumourigenesis. Here, we discuss new findings describing the role of SNHGs in gastrointestinal tumours and summarize the three main functions by which these lncRNAs promote carcinogenesis, namely: competing with endogenous RNAs, modulating protein function, and regulating epigenetic marking. Furthermore, we discuss how SNHGs participate in different hallmarks of cancer, and how this class of lncRNAs may serve as potential biomarkers in cancer diagnosis and therapy.

H19: An Oncogenic Long Non-coding RNA in Colorectal Cancer

Colorectal cancer (CRC) has been recorded amongst the most common cancers in the world, with high morbidity and mortality rates, and relatively low survival rates. With risk factors such as chronic illness, age, and lifestyle associated with the development of CRC, the incidence of CRC is increasing each year. Thus, the discovery of novel biomarkers to improve the diagnosis and prognosis of CRC has become beneficial. Long non-coding RNAs (lncRNAs) have been emerging as potential players in several tumor types, one among them is the lncRNA H19. The paternally imprinted oncofetal gene is expressed in the embryo, downregulated at birth, and reappears in tumors. H19 aids in CRC cell growth, proliferation, invasion, and metastasis via various mechanisms of action, significantly through the lncRNA-microRNA (miRNA)-messenger RNA (mRNA)-competitive endogenous RNA (ceRNA) network, where H19 behaves as a miRNA sponge. The RNA transcript of H19 obtained from the first exon of the H19 gene, miRNA-675 also promotes CRC carcinogenesis. Overexpression of H19 in malignant tissues compared to adjacent non-malignant tissues marks H19 as an independent prognostic marker in CRC. Besides its prognostic value, H19 serves as a promising target for therapy in CRC treatment.

Machine learning multi-omics analysis reveals cancer driver dysregulation in pan-cancer cell lines compared to primary tumors

Cancer cell lines have been widely used for decades to study biological processes driving cancer development, and to identify biomarkers of response to therapeutic agents. Advances in genomic sequencing have made possible large-scale genomic characterizations of collections of cancer cell lines and primary tumors, such as the Cancer Cell Line Encyclopedia (CCLE) and The Cancer Genome Atlas (TCGA). These studies allow for the first time a comprehensive evaluation of the comparability of cancer cell lines and primary tumors on the genomic and proteomic level. Here we employ bulk mRNA and micro-RNA sequencing data from thousands of samples in CCLE and TCGA, and proteomic data from partner studies in the MD Anderson Cell Line Project (MCLP) and The Cancer Proteome Atlas (TCPA), to characterize the extent to which cancer cell lines recapitulate tumors. We identify dysregulation of a long non-coding RNA and microRNA regulatory network in cancer cell lines, associated with differential expression between cell lines and primary tumors in four key cancer driver pathways: KRAS signaling, NFKB signaling, IL2/STAT5 signaling and TP53 signaling. Our results emphasize the necessity for careful interpretation of cancer cell line experiments, particularly with respect to therapeutic treatments targeting these important cancer pathways.

LINC00240/miR-155 axis regulates function of trophoblasts and M2 macrophage polarization via modulating oxidative stress-induced pyroptosis in preeclampsia

Background

This study aimed to investigate the effects of LINC00240/miR-155/Nrf2 axis on trophoblast function and macrophage polarization in the pathogenesis of preeclampsia.

Methods

Bindings between LINC00240, miR-155 and Nrf2 were validated by dual luciferase reporter assay or RNA-immunoprecipitation. Cell proliferation, migration, invasion, and pyroptosis were detected by CCK-8, clone formation, wound healing, Transwell system, and flow cytometry, respectively. Macrophage polarization was tested by flow cytometry. The expression levels of LINC00240, miR-155, Nrf2, and oxidative stress and pyroptosis-related markers in in vitro and in vivo preeclampsia models were analyzed by qPCR, western blot, or ELISA assays. Blood pressure, urine protein levels, liver and kidney damages, and trophoblast markers in placenta tissues were further studied in vivo.

Results

Placenta tissues from preeclampsia patients and animals showed decreased LINC00240 and Nrf2 and increased miR-155 expression levels, and the decreased M2 macrophage polarization. LINC00240 directly bound and inhibited expression of miR-155, which then inhibited oxidative stress-induced pyroptosis, promoting proliferation, migration and invasion abilities of trophoblasts, and M2 macrophage polarization. Inhibition of miR-155 led to increased Nrf2 expression and similar changes as LINC00240 overexpression in trophoblast function and macrophage polarization. Overexpression of LINC00240 in in vivo preeclampsia model decreased blood pressure, urine protein, liver and kidney damages, increased fetal weight and length, and induced trophoblast function and M2 macrophage polarization.

Conclusion

LINC00240 inhibited symptoms of preeclampsia through regulation on miR-155/Nrf2 axis, which suppressed oxidative stress-induced pyroptosis to improve trophoblast function and M2 macrophage polarization. LINC00240 could be a potential therapeutic target for preeclampsia.

lncRNA PVT1: a novel oncogene in multiple cancers

Long noncoding RNAs are involved in epigenetic gene modification, including binding to the chromatin rearrangement complex in pre-transcriptional regulation and to gene promoters in gene expression regulation, as well as acting as microRNA sponges to control messenger RNA levels in post-transcriptional regulation. An increasing number of studies have found that long noncoding RNA plasmacytoma variant translocation 1 (PVT1) plays an important role in cancer development. In this review of a large number of studies on PVT1, we found that PVT1 is closely related to tumor onset, proliferation, invasion, epithelial–mesenchymal transformation, and apoptosis, as well as poor prognosis and radiotherapy and chemotherapy resistance in some cancers. This review comprehensively describes PVT1 expression in various cancers and presents novel approaches to the diagnosis and treatment of cancer.

The Role of NcRNAs to Regulate Immune Checkpoints in Cancer

At present, the incidence of cancer is becoming more and more common, but its treatment has always been a problem. Although a small number of cancers can be treated, the recurrence rates are generally high and cannot be completely cured. At present, conventional cancer therapies mainly include chemotherapy and radiotherapy, which are the first-line therapies for most cancer patients, but there are palliatives. Approaches to cancer treatment are not as fast as cancer development. The current cancer treatments have not been effective in stopping the development of cancer, and cancer treatment needs to be imported into new strategies. Non-coding RNAs (ncRNAs) is a hot research topic at present. NcRNAs, which include microRNAs (miRNAs), circular RNAs (circRNAs), and long non-coding RNAs (lncRNAs), participate in all aspects of cancer biology. They are involved in the progression of tumors into a new form, including B-cell lymphoma, glioma, or the parenchymal tumors such as gastric cancer and colon cancer, among others. NcRNAs target various immune checkpoints to affect tumor proliferation, differentiation, and development. This might represent a new strategy for cancer treatment.

LINC00240 knockdown inhibits nasopharyngeal carcinoma progress by targeting miR-26a-5p

Objective

This study intended to explore the regulatory functions of LINC00240 on nasopharyngeal carcinoma (NPC).

Methods

MiR‐26a‐5p inhibitor, mimic, and siLINC00240 were transfected into NPC cells. QRT‐PCR was employed to assess miR‐26a‐5p and LINC00240 expressions. The targeting relationship of LINC00240 and miR‐26a‐5p was analyzed through dual luciferase reporter and RNA immunoprecipitation assay. Cell counting kit‐8 assay, colony formation assay, flow cytometry assay, wound healing assay, Transwell assay and in vitro angiogenesis assay were adopted for the evaluation of the effects of LINC00240 or miR‐26a‐5p and LINC00240 on NPC cells regarding cell proliferation, apoptosis and cycle, migration, invasion, and angiogenesis. EZH2, cell cycle, and epithelial‐mesenchymal transition (EMT)‐related protein expression was tested through Western blot.

Results

LINC00240 had a high expression in NPC tissues and cell lines. Silenced LINC00240 significantly suppressed the 5‐8F and HK1 cell proliferation, invasion, migration, and angiogenesis, but raised cell apoptosis, and cells were blocked in G0/G1 phase. MiR‐26a‐5p was a target of LINC00240. MiR‐26a‐5p upregulation suppressed the NPC cell proliferation, migration, invasion, angiogenesis, N‐cadherin and EZH2 expression, while it elevated apoptosis and p21, p27 and E‐cadherin expressions, whereas miR‐26a‐5p downregulation performed conversely. LINC00240 knockdown partially offset the effects of miR‐26a‐5p downregulation on cell proliferation, migration, invasion, angiogenesis, apoptosis, and EZH2.

Conclusion

LINC00240 knockdown restrained cell proliferation, invasion, migration, and angiogenesis, while it advanced apoptosis via miR‐26a‐5p in NPC by EZH2 inhibition.

Role and Mechanism of lncRNA-pvt1 in the Pathogenesis of Acute Lymphoblastic Leukemia in Children

Objective

To investigate the role and mechanism of lncRNA-pvt1 in the pathogenesis of childhood acute lymphoblastic leukemia (ALL).

Methods

The expression of lncRNA-pvt1 in bone marrow tissues of ALL patients after initial diagnosis and complete remission was detected by RT-PCR to explore its possible involvement in the pathogenesis of ALL. The proliferation and apoptosis of Jurkat cells transfected with lncRNA-pvt1 were observed by MTT and flow cytometry.

Results

lncRNA-pvt1 expression was upregulated in bone marrow of ALL patients. Knockdown of lncRNA-pvt1 inhibited Jurkat cell proliferation and increased its apoptosis rate.

Conclusion

Silencing lncRNA-pvt1 expression can inhibit the development of ALL.

Variation in the co-expression profile highlights a loss of miRNA-mRNA regulation in multiple cancer types

Recent research provides insight into the ability of miRNA to regulate various pathways in several cancer types. Despite their involvement in the regulation of the mRNA via targeting the 3′UTR, there are relatively few studies examining the changes in these regulatory mechanisms specific to single cancer types or shared between different cancer types.

We analyzed samples where both miRNA and mRNA expression had been measured and performed a thorough correlation analysis on 7494 experimentally validated human miRNA-mRNA target-gene pairs in both healthy and tumoral samples.

We show how more than 90% of these miRNA-mRNA interactions show a loss of regulation in the tumoral samples compared with their healthy counterparts.

As expected, we found shared miRNA-mRNA dysregulated pairs among different tumors of the same tissue. However, anatomically different cancers also share multiple dysregulated interactions, suggesting that some cancer-related mechanisms are not tumor-specific. 2865 unique miRNA-mRNA pairs were identified across 13 cancer types, ≈ 40% of these pairs showed a loss of correlation in the tumoral samples in at least 2 out of the 13 analyzed cancers. Specifically, miR-200 family, miR-155 and miR-1 were identified, based on the computational analysis described below, as the miRNAs that potentially lose the highest number of interactions across different samples (only literature-based interactions were used for this analysis).

Moreover, the miR-34a/ALDH2 and miR-9/MTHFD2 pairs show a switch in their correlation between healthy and tumor kidney samples suggesting a possible change in the regulation exerted by the miRNAs. Interestingly, the expression of these mRNAs is also associated with the overall survival. The disruption of miRNA regulation on its target, therefore, suggests the possible involvement of these pairs in cell malignant functions.

The analysis reported here shows how the regulation of miRNA-mRNA interactions strongly differs between healthy and tumoral cells, based on the strong correlation variation between miRNA and its target that we obtained by analyzing the expression data of healthy and tumor tissue in highly reliable miRNA-target pairs. Finally, a go term enrichment analysis shows that the critical pairs identified are involved in cellular adhesion, proliferation, and migration.

Long non-coding RNA DLX6-AS1 knockdown suppresses the tumorigenesis and progression of non-small cell lung cancer through microRNA-16-5p/BMI1 axis

BACKGROUND

Non-small cell lung cancer (NSCLC) is a huge threat to sufferers' life and overall health. Long non-coding RNA (lncRNA) distal-less homeobox 6 antisense RNA 1 (DLX6-AS1) has been revealed to function as a carcinogenesis factor in some cancers. This research aimed to scrutinize the role and mechanism underlying DLX6-AS1 in NSCLC tumorigenesis and progression.

METHODS

The levels of DLX6-AS1, microRNA-16-5p (miR-16-5p), and BMI1 mRNA were estimated via reverse transcription-quantitative PCR (RT-qPCR) assay. The protein levels were disclosed by western blot assay. Cell proliferative potential was estimated by colony formation and Cell Counting Kit-8 (CCK-8) assays. Cell migration was estimated by Transwell and wound healing assay. A Transwell assay was executed to estimate cell invasion. The relationships of DLX6-AS1, miR-16-5p, and BMI1 were forecasted by bioinformatics analysis, and confirmed by luciferase reporter assay and RNA immunoprecipitation (RIP) assay. A xenograft mice model was employed to to inspect the function of DLX6-AS1 knockdown on NSCLC tumorigenesis in vivo.

RESULTS

DLX6-AS1 was overexpressed in NSCLC tissues and cells, and was inextricably linked with the poor prognosis of NSCLC patients. Depletion of DLX6-AS1 oppressed cell proliferation, migration, invasion, epithelial-mesenchymal transition (EMT) but promoted apoptosis in NSCLC. MiR-16-5p is a target of DLX6-AS1 and directly targets BMI1. Moreover, the anti-tumor impacts of miR-16-5p were overturned by overexpression of DLX6-AS1 or BMI1 in NSCLC cells. Additionally, DLX6-AS1 silencing inhibited tumor growth of NSCLC in vivo.

CONCLUSIONS

In conclusion, lncRNA DLX6-AS1 downregulation suppressed the tumorigenesis and progression of NSCLC via miR-16-5p/BMI1 axis in vitro and in vivo, elucidating the vital roles and downstream targets of DLX6-AS1 in NSCLC.

LINC00467 Promotes Prostate Cancer Progression via M2 Macrophage Polarization and the miR-494-3p/STAT3 Axis

Background

The long non-coding RNA LINC00467 plays a vital role in many malignancies. Nevertheless, the role of LINC00467 in prostate carcinoma (PC) is unknown. Herein, we aimed to explore the mechanism by which LINC00467 regulates PC progression.

Methods

We used bioinformatics analyses and RT-qPCR to investigate the expression of LINC00467 in PC tissues and cells. The function of LINC00467 in the progression of PC was confirmed by loss-of-function experiments. PC cell proliferation was assessed by CCK-8 and EdU assays. The cell cycle progression of PC cells was examined by flow cytometry. Moreover, Transwell assays were used to investigate the migration and invasion of PC cells. Western blot assays were used to detect the expression of factors associated with epithelial–mesenchymal transition. The interactions of LINC00467 with prostate cancer progression and M2 macrophage polarization were confirmed by RT-qPCR. The subcellular localization of LINC00467 was investigated via the fractionation of nuclear and cytoplasmic RNA. Bioinformatics data analysis was used to predict the correlation of LINC00467 expression with miR-494-3p expression. LINC00467/miR-494-3p/STAT3 interactions were identified by using a dual-luciferase reporter system. Finally, the influence of LINC00467 expression on PC progression was investigated with an in vivo nude mouse model of tumorigenesis.

Results

We established that LINC00467 expression was upregulated in PC tissues and cells. Downregulated LINC00467 expression inhibited PC cell growth, cell cycle progression, migration, and invasion. Downregulated LINC00467 expression similarly inhibited PC cell migration via M2 macrophage polarization. Western blot analysis showed that LINC00467 could regulate the STAT3 pathway. We established that LINC00467 is mainly localized to the cytoplasm. Bioinformatics analysis and rescue experiments indicated that LINC00467 promotes PC progression via the miR-494-3p/STAT3 axis. Downregulated LINC00467 expression was also able to suppress PC tumor growth in vivo.

Conclusions

Our study reveals that LINC00467 promotes prostate cancer progression via M2 macrophage polarization and the miR-494-3p/STAT3 axis.

The role and underlying mechanism of miR-1299 in cancer

A type of evolutionarily conserved, noncoding, small, endogenous, single-stranded RNA, miRNAs are widely distributed in eukaryotes, where they participate in various biological processes as critical regulatory molecules. miR-1299 has mainly been investigated in cancers. miR-1299 is a tumor suppressor that regulates the expression of its target genes, activating or inhibiting the transcription of genes regulating biological activities including cell proliferation, migration, survival and programmed cell death. miR-1299 has become a hotspot in research of disease mechanisms and biomarkers; elucidation of the regulatory roles of miR-1299 in tumorigenesis, proliferation, apoptosis, invasion, migration and angiogenesis may provide a new perspective for understanding its biological functions as a tumor suppressor.

As key regulatory molecules, microRNAs participate in various biological processes and have become a widespread research focus. This article discusses how the microRNA miR-1299 plays a role as a tumor suppressor and participates in the regulation of tumor pathogenesis. We provide an overview of the role of miR-1299 in tumor diseases and discuss the pathogenesis and regulation mechanisms of miR-1299 in different specific cancers.

Functional Prediction of Long Noncoding RNAs in Cutaneous Melanoma Using a Systems Biology Approach

Cutaneous melanoma is the most aggressive type of skin cancer which its incidence has significantly increased in recent years worldwide. Thus, more investigations are required to identify the underlying mechanisms of melanoma malignant transformation and metastasis. In this context, long noncoding RNAs (lncRNAs) are a new type of noncoding transcripts that their dysregulations are associated with almost all cancers including melanoma. However, the precise functional roles of most of the significantly altered lncRNAs in melanoma have not yet been fully inspected. In this study, a comprehensive list of lncRNAs was interrogated across cutaneous melanoma samples to identify the significantly altered/dysregulated lncRNAs. To this end, lncRNAs were filtered in several steps and the selected lncRNAs projected to a bioinformatic and systems biology analysis using several publicly available databases and tools such as GEPIA and cBioPortal. According to our results, 30 lncRNAs were notably altered/dysregulated in cutaneous melanoma most of which were co-expressed with each other. Also, co-expression/alteration and differential expression analyses led to the selection of 12 out of these 30 lncRNAs as cutaneous melanoma key lncRNAs. Furthermore, functional demonstrated that these 12 lncRNAs might be involved in melanoma-relevant biological processes and pathways. In addition, the end result of our analyses demonstrated that these lncRNAs are associated with the clinicopathological features of melanoma patients. These 12 lncRNAs need to be further investigated in future studies to characterize their exact roles in melanoma development and to identify their potential for being used as drug targets and/or biomarkers for cutaneous melanoma.

Long non-coding RNAs and cancer metastasis: Molecular basis and therapeutic implications

Cancer metastasis, defined by the epithelial to mesenchymal transition (EMT) of tumor cells, disseminates from the primary site to progressively colonize in distant tissues, and accounts for most cancer-associated deaths. However, studies on the molecular basis of cancer metastasis are still in their infancy. Besides genetic mutations, accumulating evidence indicates that epigenetic alterations also contribute in a major way to the refractory nature of cancer metastasis. Considered as one of the essential epigenetic regulators, long non-coding RNAs (lncRNAs) can act as signaling regulators, decoys, guides and scaffolds, modulating key molecules in every step of cancer metastasis including dissemination of carcinoma cells, intravascular transit, and metastatic colonization. Although still having limited clinical application, it is encouraging to witness that several lncRNAs, including CCAT1 and HOTAIR, are under clinical evaluation as potential biomarkers for cancer staging and assessment of metastatic potential. In this review, we focus on the molecular mechanisms underlying lncRNAs in the regulation of cancer metastasis and discuss their clinical potential as novel therapeutic targets as well as their diagnostic and prognostic significance for cancer treatment. Gaining clear insights into the detailed molecular basis underlying lncRNA-modulated cancer metastasis may provide previously unrecognized diagnostic and therapeutic strategies for metastatic patients.

LncRNA CASC9 attenuates lactate dehydrogenase-mediated oxidative stress and inflammation in spinal cord injury via sponging miR-383-5p

Long non-coding RNAs (lncRNAs) play important roles in various diseases, but the effect of lncRNA CASC9 on spinal cord injury (SCI) remains unclear. Therefore, the present study was conducted to explore the role of this lncRNA in SCI. SCI model was established by laminectomy in rats in vivo or induced by LPS in PC12 cells in vitro. Methylprednisolone (MP) was used for treatment in vivo. Spinal cord tissues were stained with H&E, and the oxidative stress- and inflammation-related factors were detected using their commercial kits. Cell apoptosis was determined using flow cytometry assay. Relative expression of corresponding genes was measured using qRT-PCR and western blotting. Luciferase reporter assay was used to verify binding site between CASC9 and miR-383-5p, as well as miR-383-5p and LDHA. The results showed that lncRNA CASC9 was downregulated and miR-383-5p was upregulated in SCI rats and LPS-induced PC12 cells. Severe histological injury and increased water content were also found in SCI rats. Increased levels of LDH, MDA, lactic acid, TNF-α, and IL-1β were found in SCI rats and LPS-induced PC12 cells. These changes could be reversed by MP treatment in vivo or overexpression of CASC9 in vitro. Besides, overexpression of CASC9 decreased cell apoptosis and protein expression of LDHA and increased protein expression of Nrf2 and HO-1 in LPS-induced PC12 cells. Furthermore, miR-383-5p was a direct target of CASC9 and was negatively regulated by CASC9. LDHA was a direct target of miR-383-5p and was negatively regulated by CASC9. In conclusion, lncRNA CASC9 exerted a protective role against oxidative stress, inflammation, and cell apoptosis in SCI, providing a novel therapeutic target or prognostic factor for SCI.

LncRNA LINC00240 suppresses invasion and migration in non-small cell lung cancer by sponging miR-7-5p

Background

lncRNAs have important roles in regulating cancer biology. Accumulating evidence has established a link between the dysregulation of lncRNAs and microRNA in cancer progression. In previous studies, miR-7-5p has been found to be significantly down-regulated in mesenchymal-like lung cancer cell lines and directly regulated EGFR. In this work, we investigated the lncRNA partner of miR-7-5p in the progression of lung cancer.

Methods

We investigated the expression of miR-7-5p and the lncRNA after transfection with an miR-7-5p mimics using a microarray. The microarray results were validated using quantitative real time-polymerase Chain Reaction (qRT-PCR). The regulatory effects of lncRNA on miR-7-5p and its target were evaluated by changes in the expression of miR-7-5p after transfection with siRNAs for lncRNA and the synthesis of full-length lncRNA. The effect of miR-7-5p on lncRNA and the miRNA target was evaluated after transfection with miRNA mimic and inhibitor. The role of lncRNA in cancer progression was determined using invasion and migration assays. The level of lncRNA and EGFR in lung cancer and normal lung tissue was analyzed using TCGA data.

Results

We found that LINC00240 was downregulated in lung cancer cell line after miR-7-5p transfection with an miR-7-5p mimic. Further investigations revealed that the knockdown of LINC00240 induced the overexpression of miR-7-5p. The overexpression of miR-7-5p diminished cancer invasion and migration. The EGFR expression was down regulated after siRNA treatment for LINC00240. Silencing LINC00240 suppressed the invasion and migration of lung cancer cells, whereas LINC00240 overexpression exerted the opposite effect. The lower expression of LINC00240 in squamous lung cancer was analyzed using TCGA data.

Conclusions

Taken together, LINC00240 acted as a sponge for miR-7-5p and induced the overexpression of EGFR. LINC00240 may represent a potential target for the treatment of lung cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-020-07755-8.

Differential Co-Expression Analyses Allow the Identification of Critical Signalling Pathways Altered during Tumour Transformation and Progression

Biological systems respond to perturbations through the rewiring of molecular interactions, organised in gene regulatory networks (GRNs). Among these, the increasingly high availability of transcriptomic data makes gene co-expression networks the most exploited ones. Differential co-expression networks are useful tools to identify changes in response to an external perturbation, such as mutations predisposing to cancer development, and leading to changes in the activity of gene expression regulators or signalling. They can help explain the robustness of cancer cells to perturbations and identify promising candidates for targeted therapy, moreover providing higher specificity with respect to standard co-expression methods. Here, we comprehensively review the literature about the methods developed to assess differential co-expression and their applications to cancer biology. Via the comparison of normal and diseased conditions and of different tumour stages, studies based on these methods led to the definition of pathways involved in gene network reorganisation upon oncogenes' mutations and tumour progression, often converging on immune system signalling. A relevant implementation still lagging behind is the integration of different data types, which would greatly improve network interpretability. Most importantly, performance and predictivity evaluation of the large variety of mathematical models proposed would urgently require experimental validations and systematic comparisons. We believe that future work on differential gene co-expression networks, complemented with additional omics data and experimentally tested, will considerably improve our insights into the biology of tumours.

Upregulation of HOTAIRM1 increases migration and invasion by glioblastoma cells

Long noncoding RNAs (lncRNAs) promote invasion and migration by glioblastoma (GBM) cells. In this study, quantitative real-time polymerase chain reaction was used to detect expression levels of the lncRNA HOTAIRM1 in GBM tissue samples and cells. The function of HOTAIRM1 was examined using wound healing assays, transwell assays, and in vivo experiments after GBM cells were transfected with either sh-ctrl or sh-HOTAIRM1. Luciferase reporter assays and RIP assays were performed to determine the interactions between HOTAIRM1 and miR-153-5p and between miR-153-5p and SNAI2. We also used luciferase reporter assays and ChIP assays to assess the transcriptional regulation of HOTAIRM1 by SNAI2 and CDH1. HOTAIRM1 was significantly overexpressed in GBM tissues and cells. HOTAIRM1 knockdown significantly weakened the migration and invasion by GBM cells. HOTAIRM1 was found to sponge miR-153-5p, and SNAI2 is a direct target of miR-153-5p. In addition, SNAI2 was shown to force HOTAIRM1 expression through directly promoting transcription and suppressing the negative regulation of CDH1 on transcription. Our results indicate a positive feedback loop between HOTAIRM1 and SNAI2, and suggest that the lncRNA HOTAIRM1 is a potential biomarker and therapeutic target in GBM.

Role and the molecular mechanism of lncRNA PTENP1 in regulating the proliferation and invasion of cervical cancer cells

Cervical cancer ranks second in the major causes of cancer-relevant death in female population worldwide. It is extensively reported that lncRNAs are implicated in biological activities of diverse cancers. LncRNA PTENP1 has been recently reported as a tumor suppressor in several malignancies. However, the pathophysiological function and the potential regulatory mechanism of PTENP1 in cervical cancer have never been studied. In this research, PTENP1 was pronouncedly downregulated in cervical cancer tissues, and low PTENP1 level was tightly linked to advanced stage and poor prognosis in cervical cancer. Overexpressing PTENP1 inhibited cervical cancer progression by suppressing cell growth, motility and epithelial-to-mesenchymal transition (EMT). PTENP1 was confirmed to decoy miR-27a-3p to upregulate EGR1 expression in cervical cancer cells. Additionally, EGR1 knockdown reversed the repressive effect of PTENP1 overexpression on cervical cancer progression. In a word, current study was the first to uncover the biological functions of PTENP1 as well as its modulatory mechanism in cervical cancer, which may offer a new potent target for treating patients with cervical cancer.

Screening and evaluation of key genes in contributing to pathogenesis of hepatic fibrosis based on microarray data

BACKGROUND

Hepatic fibrosis (HF), which is characterized by the excessive accumulation of extracellular matrix (ECM) in the liver, usually progresses to liver cirrhosis and then death. To screen differentially expressed (DE) long non-coding RNAs (lncRNAs) and mRNAs, explore their potential functions to elucidate the underlying mechanisms of HF.

METHODS

The microarray of GSE80601 was downloaded from the Gene Expression Omnibus database, which is based on the GPL1355 platform. Screening for the differentially expressed LncRNAs and mRNAs was conducted between the control and model groups. Then, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to analyze the biological functions and pathways of the DE mRNAs. Additionally, the protein-protein interaction (PPI) network was delineated. In addition, utilizing the Weighted Gene Co-expression Network Analysis (WGCNA) package and Cytoscape software, we constructed lncRNA-mRNA weighted co-expression networks.

RESULTS

A total of 254 significantly differentially expressed lncRNAs and 472 mRNAs were identified. GO and KEGG analyses revealed that DE mRNAs regulated HF by participating in the GO terms of metabolic process, inflammatory response, response to wounding and oxidation-reduction. DE mRNAs were also significantly enriched in the pathways of ECM-receptor interaction, PI3K-Akt signaling pathway, focal adhesion (FA), retinol metabolism and metabolic pathways. Moreover, 24 lncRNAs associated with 40 differentially expressed genes were observed in the modules of lncRNA-mRNA weighted co-expression network.

CONCLUSIONS

This study revealed crucial information on the molecular mechanisms of HF and laid a foundation for subsequent genes validation and functional studies, which could contribute to the development of novel diagnostic markers and provide new therapeutic targets for the clinical treatment of HF.

Construction of a 14-lncRNA risk score system predicting survival of children with acute myelocytic leukemia

Acute myelocytic leukemia (AML) is a frequent type of acute leukemia. The present study was performed to build a risk score system for the prognostic prediction of AML. AML RNA-sequencing data from samples from 111 children were downloaded from The Cancer Genome Atlas database. Using the DEseq and edgeR packages, the differentially expressed long non-coding RNAs (DE-lncRNAs) between bad and good prognosis groups were identified. A survival package was used to screen prognosis-associated lncRNAs and clinical factors. The optimal lncRNA combination was selected using the penalized package, and the risk-score system was built and evaluated. After the lncRNA-mRNA expression correlation network was constructed, the potential pathways involving the key lncRNAs were enriched using Gene Set Enrichment Analysis. Among the 61 DE-lncRNAs, 48 lncRNAs were significantly associated with prognosis. Relapse was an independent prognostic factor. The optimal 14-lncRNA risk score system was constructed. After 730 differentially expressed mRNAs were identified between the good and bad prognosis groups divided using a prognostic index, the lncRNA-mRNA expression correlation network was constructed. Enrichment analysis showed that semaphorin-3C [SEMA3C; regulated by probable leucine-tRNA ligase, mitochondrial (LARS2-AS1)] and secreted frizzled-related protein 5 [SFRP5; mediated by WASH complex subunit 5 (WASHC5)-antisense RNA 1 (AS1)] were involved in axon guidance and the Wnt signaling pathway, respectively. A 14-lncRNA (including paired box protein Pax8-AS1 and MYB AS1) risk-score system might be effective in predicting the prognosis of AML. Axon guidance (involving SEMA3C and LARS2-AS1) and the Wnt signaling pathway (involving SFRP5 and WASHC5-AS1) might be two important pathways affecting the prognosis of AML.

Polymorphisms in Neuronal Growth Regulator 1 and Otoancorin Alternate the Susceptibility to Lung Cancer in Chinese Nonsmoking Females

Cell adhesion molecules (CAMs) play crucial roles in the genesis and progress of tumor. We investigated the effects of single nucleotide polymorphisms (SNPs) of CAMs, neuronal growth regulator 1 (NEGR1), and Otoancorin (OTOA) on lung cancer susceptibility in Chinese nonsmoking females. Logistic regression and Cox regression analyses were conducted to investigate the effects of SNPs and environmental factors. For rs3102911, genotype TT carriers decreased the risk of lung cancer with an odds ratio (OR) of 0.635. AA genotypes of rs741718 increased the risk of lung cancer with an OR of 3.527. In stratified analysis, genotype AA carriers of rs741718 had a high susceptibility to lung adenocarcinoma compared with GG and AG genotypes. Analyses of association between SNPs and clinical characteristics revealed that rs3102911 as a protective factor and rs741718 as a risk factor influenced the lung cancer occurrence and progression in nonsmoking females.

Long non-coding RNA KRT16P2/miR-1294/EGFR axis regulates laryngeal squamous cell carcinoma cell aggressiveness

Laryngeal squamous cell carcinoma (LSCC) is one of the most commonly seen head and neck malignancies. Identifying potent markers and/or targets for early diagnosis and individualized therapies for LSCC remains a considerable challenge. The present study analyzed online data and identified lncRNA KRT16P2 as a significantly upregulated long non-coding RNA (lncRNA) in LSCC. KRT16P2 knockdown in LSCC cells inhibited cancer cell proliferation, invasion, and migration. Similar to KRT16P2, EGFR expression was also significantly upregulated in LSCC. KRT16P2 and EGFR were positively correlated in LSCC tissue samples. EGFR knockdown also dramatically inhibited LSCC cell proliferation and aggressiveness (invasion and migration). Through online data and online tools, miR-1294 was predicted to target KRT16P2 and EGFR 3'UTR simultaneously. KRT16P2 inhibited miR-1294 expression, and miR-1294 inhibited EGFR expression through direct binding. miR-1294 overexpression repressed LSCC cell proliferation and aggressiveness. The effects of KRT16P2 silence on the expression of EGFR, LSCC cell proliferation, invasion, and migration, the protein levels of ki-67, PCNA, and cleaved-Caspase 3, as well as the phosphorylation of AKT, were all significantly reversed by miR-1294 inhibition. In conclusion, we demonstrated a lncRNA KRT16P2/miR-1294/EGFR axis that regulates LSCC cell proliferation, invasion, and migration. The clinical application of this axis needs further in vivo and clinical investigation.

Comprehensive Analysis of Competing Endogenous RNA (ceRNA) Network Based on RNAs Differentially Expressed in Lung Adenocarcinoma Using The Cancer Genome Atlas (TCGA) Database

Background

The aim of this study was to explore a comprehensive analysis of the competing endogenous (ceRNA) network of lung adenocarcinoma and predict its regulatory mechanism and prognosis correlation based on The Cancer Genome Atlas (TCGA) database.

Material/Methods

The genes expression data from 535 lung adenocarcinoma cases and 59 normal tissue cases were acquired and downloaded from TCGA database, and differentially expressed messenger RNA (mRNA), long noncoding RNA (lncRNA) and microRNA (miRNA) were selected primarily by “edgeR” package in R software, which further constructs lncRNA-miRNA-mRNA ceRNA network. We then proceed to carry out Gene Ontology enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and Kaplan-Meier survival analysis of the mRNAs involved in the ceRNA network.

Results

There are 3 mRNAs (ANLN, IGFBP1, and TFAP2A) in differentially expressed genes, 4 lncRNAs (AC015923.1, FGF12-AS2, LINC00211, and MED4-AS1), and 2 miRNAs (miR-31 and miR-490) associated with the prognostic of lung adenocarcinoma. Besides, LINC00461 and has-mir-139 as key nodes were found in the ceRNA network. Significantly, miR-31 shows the greatest prognostic value related to the adverse effect of the prognostic of lung adenocarcinoma (P<0.001).

Conclusions

By analyzing the expression data of lung adenocarcinoma in TCGA database, we found that 3 mRNAs, 4 lncRNAs, and 2 miRNAs were screened as potential prognostic factors for lung adenocarcinoma. In addition, LINC00461 and has-mir-139 are 2 important regulatory network nodes in lung adenocarcinoma ceRNA.

Long non-coding RNA TUG1 knockdown hinders the tumorigenesis of multiple myeloma by regulating the microRNA-34a-5p/NOTCH1 signaling pathway

Multiple myeloma (MM) is a serious health issue in hematological malignancies. Long non-coding RNA taurine-upregulated gene 1 (TUG1) has been reported to be highly expressed in the plasma of MM patients. However, the functions of TUG1 in MM tumorigenesis along with related molecular basis are still undefined. In this study, increased TUG1 and decreased microRNA-34a-5p (miR-34a-5p) levels in MM tissues and cells were measured by the real-time quantitative polymerase reaction assay. The expression of relative proteins was determined by the Western blot assay. TUG1 knockdown suppressed cell viability, induced cell cycle arrest and cell apoptosis in MM cells, as shown by Cell Counting Kit-8 and flow cytometry assays. Bioinformatics analysis, luciferase reporter assay, and RNA pull-down assay indicated that miR-34a-5p was a target of TUG1 and directly bound to notch receptor 1 (NOTCH1), and TUG1 regulated the NOTCH1 expression by targeting miR-34a-5p. The functions of miR-34a-5p were abrogated by TUG1 upregulation. Moreover, TUG1 loss impeded MM xenograft tumor growth in vivo by upregulating miR-34a-5p and downregulating NOTCH1. Furthermore, TUG1 depletion inhibited the expression of Hes-1, Survivin, and Bcl-2 protein in MM cells and xenograft tumors. TUG1 knockdown inhibited MM tumorigenesis by regulating the miR-34a-5p/NOTCH1 signaling pathway in vitro and in vivo, deepening our understanding of the TUG1 function in MM.

LINC01410/miR-23c/CHD7 functions as a ceRNA network to affect the prognosis of patients with endometrial cancer and strengthen the malignant properties of endometrial cancer cells

In previous studies, long non-coding RNA LINC01410 (LINC01410) has been found to promote cells proliferation and invasion in colon and gastric cancers. However, the function of LINC01410 in endometrial cancer (EC) is still elusive. The expression patterns of LINC01410/miR-23c/Chromodomain Helicase DNA-Binding Protein 7 (CHD7) in EC tissues and the prognosis of patients with different expression of LINC01410/miR-23c/CHD7 were determined by consulting TCGA database. EC patients with complete clinical data were applied for clinicopathological correlation analysis. The biological characteristics of EC cells were analyzed with the support of CCK-8 and transwell assays. CHD7 expression was assessed by qRT-PCR and western blot assays. Targeted associations between LINC01410 and miR-23c, as well as miR-23c and CHD7 were speculated by prediction website and verified by dual-luciferase assay. Rescue assays were performed to explore the interrelation among LINC01410, miR-23c and CHD7. Our data illustrated that LINC01410 high expression was presented in EC tissues and was positively related to the poor prognosis of patients in EC, as well as the malignant behaviors of EC cells. Through bioinformatics analysis, we surmised that LINC01410/miR-23c/CHD7 may play a role through the formation of competing endogenous RNA (ceRNA) mechanism. CHD7 expression was positively regulated by LINC01410, and inversely controlled by miR-23c. Furthermore, the promoting effects of miR-23c inhibitor or CHD7 upregulation on EC cell growth and aggressiveness were attenuated by LINC01410 silencing. Our results indicated that high expression of LINC01410 promoted EC cell progression through modulating miR-23c/CHD7 axis, providing a new direction for revealing the molecular mechanism of EC.

Using RNA sequencing to identify a putative lncRNA-associated ceRNA network in laryngeal squamous cell carcinoma

Accumulating evidence indicates that lncRNAs can interact with miRNAs to regulate target mRNAs through competitive interactions. However, this mechanism remains largely unexplored in laryngeal squamous cell carcinoma (LSCC). In this study, transcriptome-wide RNA sequencing was performed on 3 pairs of LSCC tissues and adjacent normal tissues to investigate the expression profiles of lncRNAs, miRNAs and mRNAs, with differential expression of 171 lncRNAs, 36 miRNAs and 1709 mRNAs detected. Seven lncRNAs, eight mRNAs and three miRNAs were identified to be dysregulated in patients' tissues by using qRT-PCR. GO and KEGG pathway enrichment analyses were performed to elucidate the potential functions of these differentially expressed genes in LSCC. Subsequently, a ceRNA (lncRNA-miRNA-mRNA) network including 4631 ceRNA pairs was constructed based on predicted miRNAs shared by lncRNAs and mRNAs. Cis- and transregulatory lncRNAs were analysed by bioinformatics-based methods. Importantly, mRNA-related ceRNA networks (mRCNs) were further obtained based on potential cancer-related coding genes. Coexpression between lncRNAs and downstream mRNAs was used as a criterion for the validation of mRCNs, with the ZNF561-AS1-miR217-WNT5A and SATB1-AS1-miR1299-SAV1/CCNG2/SH3 KBP1/JADE1/HIPK2 ceRNA regulatory interactions determined, followed by experimental validation after siRNA transfection. Moreover, ceRNA activity analysis revealed that different activities of ceRNA modules existing in specific pathological environments may contribute to the tumorigenesis of LSCC. Consistently, both downregulated SATB1-AS1 and ZNF561-AS1 significantly promoted laryngeal cancer cell migration and invasion, indicating their important roles in LSCC via a ceRNA regulatory mechanism. Taken together, the results of this investigation uncovered and systemically characterized a lncRNA-related ceRNA regulatory network that may be valuable for the diagnosis and treatment of LSCC.

The cox-filter method identifies respective subtype-specific lncRNA prognostic signatures for two human cancers

BACKGROUND

The most common histological subtypes of esophageal cancer are squamous cell carcinoma (ESCC) and adenocarcinoma (EAC). It has been demonstrated that non-marginal differences in gene expression and somatic alternation exist between these two subtypes; consequently, biomarkers that have prognostic values for them are expected to be distinct. In contrast, laryngeal squamous cell cancer (LSCC) has a better prognosis than hypopharyngeal squamous cell carcinoma (HSCC). Likewise, subtype-specific prognostic signatures may exist for LSCC and HSCC. Long non-coding RNAs (lncRNAs) hold promise for identifying prognostic signatures for a variety of cancers including esophageal cancer and head and neck squamous cell carcinoma (HNSCC).

METHODS

In this study, we applied a novel feature selection method capable of identifying specific prognostic signatures uniquely for each subtype - the Cox-filter method - to The Cancer Genome Atlas esophageal cancer and HSNCC RNA-Seq data, with the objectives of constructing subtype-specific prognostic lncRNA expression signatures for esophageal cancer and HNSCC.

RESULTS

By incorporating biological relevancy information, the lncRNA lists identified by the Cox-filter method were further refined. The resulting signatures include genes that are highly related to cancer, such as H19 and NEAT1, which possess perfect prognostic values for esophageal cancer and HNSCC, respectively.

CONCLUSIONS

The Cox-filter method is indeed a handy tool to identify subtype-specific prognostic lncRNA signatures. We anticipate the method will gain wider applications.

Natural killer T cell cytotoxic activity in cervical cancer is facilitated by the LINC00240/microRNA-124-3p/STAT3/MICA axis

Long noncoding RNAs play significant roles in diverse cancers. In this study, we found that LINC00240 expression was markedly increased in cervical cancer. Functional in vitro assays in cervical cancer cells showed that LINC00240 enhanced the growth, migration, and invasion of cervical cancer cells. The target of LINC00240 was confirmed as microRNA(miR)-124-3p. Inhibition of miR-124-3p significantly enhanced cervical cancer progression via targeting of STAT3, which is greatly activated in tumor-infiltrating immune cells. LINC00240 expression was able to induce STAT3 expression via sponging of miR-124-3p, and showed a positive association with STAT3 expression in cervical cancer tissues. MHC class I-related chain (MIC)-A plays a key role in activating natural killer T (NKT) cells and serves as a downstream target of STAT3. Here, MICA was inhibited by up-regulation of LINC00240, and could be rescued by STAT3 knockdown. In addition, LINC00240 overexpression suppressed the cytotoxic activity of NKT cells by affecting the STAT3/MICA axis. Subsequently, we found that LINC00240 expression promoted cervical cancer progression via induction of miR-124-3p/STAT3/MICA-mediated NKT cell tolerance. Considering these findings, we conclude that LINC00240 might be a novel target for cervical cancer.

Reduced miR-203 predicts metastasis and poor survival in esophageal carcinoma

We analyzed data from two non-coding RNA profiling arrays made available by the Gene Expression Omnibus (GEO) and found 17 miRNAs with remarkable differential expression between malignant and normal esophageal tissue. Correlation analysis between expression of these 17 miRNAs and patients’ clinicopathological characteristics showed that miR-203 was down-regulated in esophageal carcinoma (EC) tissues and was significantly associated with lymph node metastasis and poor overall survival. Overexpression of miR-203 significantly attenuated cellular proliferation, migration and invasion by EC cells in culture. Additionally, gene expression profiles and bioinformatics analysis revealed KIF5C to be a direct target of miR-203, and KIF5C overexpression partially counteracted the tumor inhibitory effects of miR-203 on EC cells. We also observed that miR-203, reduced KIFC5 protein levels, promoted cytoplasmic accumulation of Axin2, and reversed the invasive phenotype of EC cells. Taken together, these data demonstrate that miR-203 is a tumor suppressor in EC cells and its expression level could potentially be used as a prognostic indicator for EC patient outcomes.

LINC01234/MicroRNA-31-5p/MAGEA3 Axis Mediates the Proliferation and Chemoresistance of Hepatocellular Carcinoma Cells

Hepatocellular carcinoma (HCC) is a prevalent malignancy characterized by aggressiveness and poor prognosis; however, the molecular mechanism remains to be fully identified. Based on the analysis of The Cancer Genome Atlas (TCGA) database, melanoma-associated antigen A3 (MAGEA3) and long non-coding RNA (lncRNA) LINC01234 were upregulated in HCC and associated with poor prognosis of HCC. We investigated the mechanism of how MAGEA3 and LINC01234 influenced HCC cellular functions and cisplatin resistance. MAGEA3 depletion inhibited proliferation, invasion, and cisplatin resistance of HepG2 cells and Huh7 cells in vitro, reduced resistance-associated protein 2 (MRP2), MRP3, and multidrug resistance protein 1 (MDR-1) expression, and elevated ALB expression. RNA pull-down and RIP assays identified the binding of LINC01234 and MAGEA3 to microRNA-31-5p (miR-31-5p). LINC01234 could restore MAGEA3 expression by binding to miR-31-5p. Furthermore, we delivered plasmids into HepG2 cells and Huh7 cells to alter the expression of LINC01234 and miR-31-5p. When miR-31-5p was downregulated, the proliferation and invasion of HepG2 cells and Huh7 cells were enhanced and the cisplatin-induced apoptosis was inhibited, while LINC01234 knockdown could diminish the effects caused by miR-31-5p depletion. In summary, these data highlight the vital role of MAGEA3/LINC01234/miR-31-5p axis in the HCC progression and chemoresistance of HCC cells.

Integrated analysis highlights multiple long non‑coding RNAs and their potential roles in the progression of human esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a prevalent aggressive malignant tumor with poor prognosis. Investigations into the molecular changes that occur as a result of the disease, as well as identification of novel biomarkers for its diagnosis and prognosis, are urgently required. Long non‑coding RNAs (lncRNAs) have been reported to play a critical role in tumor progression. The present study performed data mining analyses for ESCC via an integrated study of accumulated datasets and identification of the differentially expressed lncRNAs from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. The identified intersection of differentially expressed genes (lncRNAs, miRNAs and mRNAs) in ESCC tissues between the GEO and TCGA datasets was investigated. Based on these intersected lncRNAs, the present study constructed a competitive endogenous RNA (ceRNA) network of lncRNAs in ESCC. A total of 81 intersection lncRNAs were identified; 67 of these were included in the ceRNA network. Functional analyses revealed that these 67 key lncRNAs primarily dominated cellular biological processes. The present study then analyzed the associations between the expression levels of these 67 key lncRNAs and the clinicopathological characteristics of the ESCC patients, as well as their survival time using TCGA. The results revealed that 31 of these lncRNAs were associated with tumor grade, tumor‑node‑metastasis (TNM) stage and lymphatic metastasis status (P<0.05). In addition, 15 key lncRNAs were demonstrated to be associated with survival time (P<0.05). Finally, 5 key lncRNAs were selected for validation of their expression levels in 30 patients newly diagnosed with ESCC via reverse transcription‑quantitative PCR (RT‑qPCR). The results suggested that the fold changes in the trends of up‑ and downregulation between GEO, TCGA and RT‑qPCR were consistent. In addition, it was also demonstrated that a select few of these 5 key lncRNAs were significantly associated with TNM stage and lymph node metastasis (P<0.05). The results of the clinically relevant analysis and the aforementioned bioinformatics were similar, hence proving that the bioinformatics analysis used in the present study is credible. Overall, the results from the present study may provide further insight into the functional characteristics of lncRNAs in ESCC through bioinformatics integrative analysis of the GEO and TCGA datasets, and reveal potential diagnostic and prognostic biomarkers for ESCC.

Comprehensive analysis of competing endogenous RNA networks associated with cholangiocarcinoma

Cholangiocarcinoma (CCA) is the second most common type of primary malignancy of the liver. Certain long non-coding RNAs (lncRNAs) have been demonstrated to have key roles in tumor pathogenesis by binding to microRNAs (miRNAs). However, the competing endogenous RNA (ceRNA) network of CCA remains to be fully determined. In the present study, the RNA expression profiles for CCA were downloaded from The Cancer Genome Atlas and further analyzed. A total of 318 differentially expressed (DE) lncRNAs, 87 DE miRNAs and 3,851 DE mRNAs were identified from 36 CCA samples and 9 adjacent non-tumor samples (for lncRNAs and miRNAs, fold change ≥2.5 and P<0.01; for mRNAs, fold change ≥2 and P<0.01). Further bioinformatics analyses were performed and the ceRNA network for CCA was constructed, which included 16 lncRNAs, 55 miRNAs and 373 mRNAs. Survival analysis of all genes in the network revealed that high expression of the mRNAs fucosyltransferase 4 (P<0.005) and huntingtin-interacting protein 1 related (P<0.001) has a positive impact on the overall survival of patients with CAA. Furthermore, the lncRNAs H19 and PVT1, and the miRNAs Homo sapiens (hsa)-miR-16-5p and hsa-miR-424-5p, together with peroxisome proliferator-activated receptors, may also have important roles in the pathogenesis of CCA. The present study provided data to further the understanding of and research into the molecular mechanisms implicated in CCA.

Cancer-related long noncoding RNAs show aberrant expression profiles and competing endogenous RNA potential in esophageal adenocarcinoma

Long non-coding RNAs (lncRNAs) govern gene expression by competitively binding to microRNA response elements (MREs). Although they were initially considered as transcriptional noise, lncRNAs have attracted increased attention in oncology. Dysregulation of lncRNAs occurs in various types of human tumor, including esophageal adenocarcinoma (EAC). However, the functions of these cancer-associated lncRNAs and of their related competitive endogenous RNA (ceRNA) network in EAC remains unknown. To determine the relevant potential mechanisms, the present study analyzed the transcriptome sequencing data and clinical information of 79 patients with EAC, including 79 tumor samples and 11 normal samples, which were obtained from The Cancer Genome Atlas esophageal cancer project. The edgeR v3.25.0 software was used for differential gene expression analysis. The results exhibited 561 cancer-associated lncRNAs with a >2.0-fold change and a false discovery rate-adjusted P<0.01. Among these lncRNAs, 26 were significantly associated with patient overall survival. According to data from bioinformatics databases and differentially expressed RNAs, an lncRNA-regulated ceRNA network for EAC was constructed. The results demonstrated that the aberrantly expressed lncRNA-associated ceRNA network included 37 EAC cancer-associated lncRNAs, five miRNAs and 13 mRNAs. In conclusion, the present study identified novel lncRNAs as candidate prognostic biomarkers and revealed a potential regulatory network of gene expression in EAC.

Construction and Investigation of a lncRNA-Associated ceRNA Regulatory Network in Cholangiocarcinoma

Background/Aims: As a type of malignant tumor commonly found in the bile duct, cholangiocarcinoma (CCA) has a poor prognosis. Long non-coding RNA (lncRNA) has recently drawn increasing attention because it functions as a competing endogenous RNA (ceRNA) to hinder miRNA functions that participate in posttranscriptional regulatory networks in tumors. Therefore, to investigate the mechanisms of CCA carcinogenesis and to enhance treatment efficiency, the expression profiles, including lncRNA, miRNA, and mRNA data, were comprehensively integrated and analyzed in this study.

Methods: A comprehensive comparison was performed on the RNA-sequencing and miRNA profiles data of 36 CCA samples and 9 normal samples from The Cancer Genome Atlas (TCGA) database. Then, a dysregulated lncRNA-related ceRNA network was established by using four public databases.

Results: In summary, 1,410 lncRNAs, 64 miRNAs, and 3,494 mRNAs appeared as genes that were aberrantly expressed in CCA. Then, a dysregulated ceRNA network related to the lncRNAs was constructed. The network included 116 lncRNAs, 13 miRNAs and 60 mRNAs specific to CCA. The survival analysis showed that, among them, 26 lncRNAs, 3 miRNAs, and 13 mRNAs were prognostic biomarkers for patients with CCA. Finally, three mRNAs were selected for validation of their expression levels in the Gene Expression Omnibus (GEO) database. The results indicated that the expression of those genes was highly consistent between the TCGA and GEO databases.

Conclusions: The findings in this study provide a better understanding of the ceRNA network involved in CCA biology and lay a solid foundation for improving CCA diagnosis and prognosis.

Effect of astragalosides on long non-coding RNA expression profiles in rats with adjuvant-induced arthritis

Rheumatoid arthritis (RA) is an autoimmune disease of unknown etiology, which occurs in ~1.0% of the general population. Increasing studies have suggested that long non-coding RNAs (lncRNAs) may serve important roles in various biological processes and may be associated with the pathogenesis of different types of disease, including RA. Astragalosides (AST) has been used as a traditional Chinese medicine for the treatment of RA. However, the mechanism underlying its therapeutic effect has remained unclear to date. Thus, there is an urgent need to elucidate the possible mechanism of AST in the treatment of RA from the perspective of lncRNAs. In the present study, the lncRNAs and mRNAs of a vehicle group, animal model group and AST treatment (control) group were determined by Arraystar Rat lncRNA/mRNA microarray. The differentially expressed genes with a fold change >1.5 and P<0.05 were selected and analyzed. Gene Ontology (GO) and pathway analysis was performed using the Database for Annotation, Visualization and Integration Discovery, and the coding-non-coding gene co-expression network was drawn based on the correlation analysis between the differentially expressed lncRNAs and mRNAs. Based on node degree and the correlation between bioinformatics analysis and RA, the critical differentially expressed lncRNAs were selected, analyzed and verified by reverse transcription-quantitative PCR (RT-qPCR) analysis. The results showed that, following AST treatment, up to 75 lncRNAs and 247 mRNAs were found to be differentially expressed among the three groups. GO and pathway analysis manifested that 135 GO terms and 17 pathways were enriched by differentially expressed genes. Four lncRNAs (MRAK012530, MRAK132628, MRAK003448 and XR_006457) were selected as the critical lncRNAs and their trend in expression showed consistency between the RT-qPCR and microarray data. In conclusion, AST had a regulatory effect on differentially expressed lncRNAs during the development of RA, and four lncRNAs could be selected as critical therapeutic targets of AST.

Adaptive Elman Model of Gene Regulation Network Based on Time Series Data

Background:

Time series expression data of genes contain relations among different genes, which are difficult to model precisely. Slime-forming bacteria is one of the three major harmful bacteria types in industrial circulating cooling water systems.

Objective:

This study aimed at constructing gene regulation network(GRN) for slime-forming bacteria to understand the microbial fouling mechanism.

Methods:

For this purpose, an Adaptive Elman Neural Network (AENN) to reveal the relationships among genes using gene expression time series is proposed. The parameters of Elman neural network were optimized adaptively by a Genetic Algorithm (GA). And a Pearson correlation analysis is applied to discover the relationships among genes. In addition, the gene expression data of slime-forming bacteria by transcriptome gene sequencing was presented.

Results:

To evaluate our proposed method, we compared several alternative data-driven approaches, including a Neural Fuzzy Recurrent Network (NFRN), a basic Elman Neural Network (ENN), and an ensemble network. The experimental results of simulated and real datasets demonstrate that the proposed approach has a promising performance for modeling Gene Regulation Networks (GRNs). We also applied the proposed method for the GRN construction of slime-forming bacteria and at last a GRN for 6 genes was constructed.

Conclusion:

The proposed GRN construction method can effectively extract the regulations among genes. This is also the first report to construct the GRN for slime-forming bacteria.

Improved characterization of the relationship between long intergenic non-coding RNA Linc00152 and the occurrence and development of malignancies

Linc00152, located on chromosome 2p11.2, is a long intergenic non-coding RNA molecule with 828 nucleotides that is highly expressed in many types of human tumor tissues, especially in malignant tumors of the digestive system. Linc00152 promotes the occurrence and development of tumors by increasing tumor cell proliferation, invasion, metastasis, and apoptosis. Additionally, linc00152 contributes to the carcinogenesis of several cancers, including gastric cancer, liver cancer, hepatocellular carcinoma, gallbladder cancer, clear cell renal cell carcinoma, and colorectal cancer, by disturbing various signaling pathways (eg PI3K/AKT, mTOR, IL-1, and NOTCH 1 signaling pathways). High linc00152 expression levels are associated with chemoresistance as well as poor prognosis and shorter survival. Continual advances made in the relevant research have indicated that linc00152 may be useful as a new tumor molecular biomarker, applicable for tumor diagnosis, targeted therapy, and prognosis assessment. This review summarizes the progress in the research into the relationship between linc00152 and the occurrence and development of malignancies based on molecular functions, regulatory mechanisms, and clinical applications.

PVT1 Signaling Is a Mediator of Cancer Progression

There is increasing evidence that PVT1 has oncogenic properties and regulates proliferation and growth of many cancers. Themolecular mechanisms of action of PVT1 are mediated, in part, by microRNAs (miRNAs). However, some well-established transcription factors involved in cancer cell proliferation share a common thread of microRNA associations with PVT1. Furthermore, these microRNAs are also involved in mechanisms that lead to the development of drug resistance in cancer cells. While several microRNAs have been implicated directly in PVT1-mediated tumorigenesis, significant steps need to be taken to elucidate these important relationships. We synthesize the current knowledge of the miRNAs and associated genes by which PVT1 contributes to tumorigenesis. Overall, the trend suggests a negative correlation of microRNA expression with PVT1. It is clear that future studies involving PVT1 should be carried out in conjunction with microRNA analysis and should include large scale lncRNA-miRNA-mRNA network analysis. Likewise, the relationship between established transcription factors such as p53 and MYC, and processes like epithelial-mesenchymal transition may offer valuable insight into the yet unknown mechanisms of PVTI-mediated cancer progression via microRNA-dependent signaling networks.

Global miRNA, lncRNA, and mRNA Transcriptome Profiling of Endometrial Epithelial Cells Reveals Genes Related to Porcine Reproductive Failure Caused by Porcine Reproductive and Respiratory Syndrome Virus

Porcine reproductive and respiratory syndrome virus (PRRSV) can cause respiratory disease and reproductive failure in pregnant pigs. Previous transcriptome analyses in susceptive cells have mainly concentrated on pulmonary alveolar macrophages (PAM) and Marc-145 cells, and on the respiratory system. Some studies reported that apoptosis of placental cells and pig endometrial epithelial cells (PECs) is an obvious sign linked to reproductive failure in pregnant sows, but the mechanism is still unknown. In this study, Sn-positive PECs were isolated and apoptosis rates were assessed by flow cytometry. PRRSV-infected PECs exhibited apoptosis, indicative of their susceptibility to PRRSV. Subsequently, the whole transcriptome was compared between mock- and PRRSV-infected PECs and 54 differentially expressed microRNAs (DEmiRNAs), 104 differentially expressed genes (DEGs), 22 differentially expressed lncRNAs (DElncRNAs), and 109 isoforms were obtained, which were mainly enriched in apoptosis, necroptosis, and p53 signal pathways. Integration analysis of DEmiRNA and DEG profiles revealed two microRNAs (ssc-miR-339-5p and ssc-miR-181d-5p) and five genes (SLA-DQB1, THBS1, SLC3A1, ZFP37, and LOC100517161) participating in the apoptosis signal, of which THBS1 and SLC3A1 were mainly linked to the p53 pathway. Integration analysis of DEGs with DElncRNA profiles identified genes involved in apoptosis signal pathway are regulated by LTCONS_00010766 and LTCONS_00045988. Pathway enrichment revealed that the phagosome and p53 pathways are the two main signals causing apoptosis of PECs, and functional analysis revealed a role of miR-339-5p in regulating apoptosis of PECs after PRRSV inoculation.

Exosomal transfer of long non-coding RNA SBF2-AS1 enhances chemoresistance to temozolomide in glioblastoma

Background

Acquired drug resistance is a constraining factor in clinical treatment of glioblastoma (GBM). However, the mechanisms of chemoresponsive tumors acquire therapeutic resistance remain poorly understood. Here, we aim to investigate whether temozolomide (TMZ) resistance of chemoresponsive GBM was enhanced by long non-coding RNA SBF2 antisense RNA 1 (lncRNA SBF2-AS1) enriched exosomes.

Method

LncSBF2-AS1 level in TMZ-resistance or TMZ-sensitive GBM tissues and cells were analyzed by qRT-PCR and FISH assays. A series of in vitro assay and xenograft tumor models were performed to observe the effect of lncSBF2-AS1 on TMZ-resistance in GBM. CHIP assay were used to investigate the correlation of SBF2-AS1 and transcription factor zinc finger E-box binding homeobox 1 (ZEB1). Dual-luciferase reporter, RNA immunoprecipitation (RIP), immunofluorescence and western blotting were performed to verify the relation between lncSBF2-AS1, miR-151a-3p and XRCC4. Comet assay and immunoblotting were performed to expound the effect of lncSBF2-AS1 on DNA double-stand break (DSB) repair. A series of in vitro assay and intracranial xenografts tumor model were used to determined the function of exosomal lncSBF2-AS1.

Result

It was found that SBF2-AS1 was upregulated in TMZ-resistant GBM cells and tissues, and overexpression of SBF2-AS1 led to the promotion of TMZ resistance, whereas its inhibition sensitized resistant GBM cells to TMZ. Transcription factor ZEB1 was found to directly bind to the SBF2-AS1 promoter region to regulate SBF2-AS1 level and affected TMZ resistance in GBM cells. SBF2-AS1 functions as a ceRNA for miR-151a-3p, leading to the disinhibition of its endogenous target, X-ray repair cross complementing 4 (XRCC4), which enhances DSB repair in GBM cells. Exosomes selected from temozolomide-resistant GBM cells had high levels of SBF2-AS1 and spread TMZ resistance to chemoresponsive GBM cells. Clinically, high levels of lncSBF2-AS1 in serum exosomes were associated with poor response to TMZ treatment in GBM patients.

Conclusion

We can conclude that GBM cells remodel the tumor microenvironment to promote tumor chemotherapy-resistance by secreting the oncogenic lncSBF2-AS1-enriched exosomes. Thus, exosomal lncSBF2-AS1 in human serum may serve as a possible diagnostic marker for therapy-refractory GBM.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1139-6) contains supplementary material, which is available to authorized users.

Transcriptional factor regulation network and competitive endogenous RNA (ceRNA) network determining response of esophageal squamous cell carcinomas to neoadjuvant chemoradiotherapy

Background

Neoadjuvant chemoradiotherapy (nCRT) followed by surgery benefits survival for patients with esophageal squamous cell carcinomas (ESCC) compared with surgery alone, but the clinical outcomes of nCRT are heterogeneous. This study aimed to elucidate transcriptional factor (TF) regulation network and competitive endogenous RNA (ceRNA) network determining response of ESCC to nCRT.

Materials and Methods

RNA microarray data of GSE59974 and GSE45670 were analyzed to investigate the significant changes of lincRNAs, miRNAs, mRNAs in responders and non-responders of nCRT in ESCC. Functional and enrichment analyses were conducted by clusterProfiler. The target lincRNAs and mRNAs of miRNAs were predicted by miRWalk. The ceRNA and TF regulatory networks were constructed using Cytoscape.

Results

Differentially expressed genes between responders and non-responders mainly enriched in biological process including Wnt signaling pathway and regulation of cell development and morphogenesis involved in differentiation. Besides, these genes showed enrichment in molecular function of glycosaminoglycan binding, metalloendopeptidase inhibitor and growth factor activity. KEGG analysis enriched these genes in pathways of neurotrophin signaling pathway, cell adhesion molecules and Wnt signaling pathway. We also constructed ceRNA network and TF network regulating response of ESCC to nCRT. Core regulatory miRNAs were miR-520a, miR-548am, miR-3184, miR-548d, miR-4725, miR-148a, miR-4659a and key regulatory TFs included MBNL1, SLC26A3, BMP4, ZIC1 and ANKRD7.

Conclusion

We identified significantly altered lincRNAs, miRNAs and mRNAs involved in the nCRT response of ESCC. In addition, the ceRNA regulatory network of lincRNA-miRNA-mRNA and TF regulatory network were constructed, which would elucidate novel molecular mechanisms determining nCRT response of ESCC, thus providing promising clues for clinical therapy.

Long Noncoding RNA Expression Signatures of Colon Cancer Based on the ceRNA Network and Their Prognostic Value

Background

The specific functional roles of long noncoding RNAs (lncRNAs) as ceRNAs in colon cancer and their potential implications for colon cancer prognosis remain unclear. In the present study, a genome-wide analysis was performed to investigate the potential lncRNA-mediated ceRNA interplay in colon cancer based on the “ceRNA hypothesis.” The prognostic value of the lncRNAs was evaluated.

Methods

A dysregulated lncRNA-associated ceRNA network was constructed based on the miRNA, lncRNA, and mRNA expression profiles in combination with the miRNA regulatory network by using an integrative computational method. Molecular biological techniques, including qPCR and gene knockdown techniques, were used to verify candidate targets in colon cancer. Survival analysis was performed to identify the candidate lncRNAs with prognostic value.

Results

Our network analysis uncovered several novel lncRNAs as functional ceRNAs through crosstalk with miRNAs. The QRT-PCR assays of patient tissues as well as gene knockdown colon cancer cells confirmed the expression of top lncRNAs and their correlation with target genes in the ceRNA network. Functional enrichment analysis predicted that differentially expressed lncRNAs might participate in broad biological functions associated with tumor progression. Moreover, these lncRNAs may be involved in a range of cellular pathways, including the apoptosis, PI3K-AKT, and EGFR signaling pathways. The survival analysis showed that the expression level of several lncRNAs in the network was correlated with the prognosis of patients with colon cancer.

Conclusions

This study uncovered a dysregulated lncRNA-associated ceRNA network in colon cancer. The function of the identified lncRNAs in colon cancer was preliminarily explored, and their potential prognostic value was evaluated. Our study demonstrated that lncRNAs could potentially serve as important regulators in the development and progression of colon cancer. Candidate prognostic lncRNA biomarkers in colon cancer were identified.

Identification and regulation pattern analysis of long noncoding RNAs in meibomian gland carcinoma

Aim: To identify long noncoding RNAs (lncRNAs) and to elucidate regulation patterns of lncRNAs in meibomian gland carcinoma (MGC). Materials & methods: We used RNA-Seq, gene ontology, ClueGO, Ingenuity Pathway Analysis and co-expression network analyses to profile the expression and regulation patterns of lncRNAs and mRNAs in MGC. Results: We identified 500 lncRNAs and 326 mRNAs as differentially expressed. Co-expression regulatory networks with lncRNAs and mRNAs were constructed. The differentially expressed mRNAs and lncRNAs were enriched by fundamental biological functions that are implicated in the inflammatory signaling pathway and tumor proliferation (IL6 and PTGS2). Conclusion: LncRNAs might play important roles via the competing endogenous RNA regulation pattern in MGC tumorigenesis and contribute to the molecular pathogenesis of MGC.

lncRNA CASC9 positively regulates CHK1 to promote breast cancer cell proliferation and survival through sponging the miR‑195/497 cluster

Accumulating evidence has demonstrated that long non-coding RNAs (lncRNAs) play important roles in the pathogenesis and development of diverse types of human disorders. Cancer susceptibility candidate 9 (CASC9), a gene encoding a lncRNA, has frequently been reported to be dysregulated and has been implicated in multiple types of human malignancies. However, the biological role of lncRNA CASC9 in breast cancer (BC) remains largely unknown. The present study aimed to investigate the role of lncRNA CASC9 in BC and to elucidate the potential molecular mechanisms involved. In the present study, lncRNA CASC9 was found to be significantly upregulated in both BC tissues and cell lines. Furthermore, functional analyses revealed that lncRNA CASC9 accelerated BC cell proliferation, promoted cell cycle progression and suppressed cell apoptosis. Moreover, mechanical experiments demonstrated that lncRNA CASC9 positively regulated checkpoint kinase 1 (CHK1) by competitively binding to the miR-195/497 cluster in BC cells. Additionally, the knockdown of lncRNA CASC9 was observed to suppress breast tumor growth in vivo. Taken together, the results of this study indicate that lncRNA CASC9 plays an oncogenic role in BC through sponging the miR-195/497 cluster, and that lncRNA CASC9 may be used as a novel therapeutic target and as a potential diagnostic marker for BC.

LINC00152 facilitates tumorigenesis in esophageal squamous cell carcinoma via miR-153-3p/FYN axis

Long non-coding RNAs (LncRNAs) have been found to be associated with the biological behaviors of human cancers. LINC00152 is reported as an oncogene in many kinds of malignancies. However, the functions and mechanisms of LINC00152 involved in esophageal squamous cell carcinoma (ESCC) remain elusive. Our results revealed that LINC00152 expression was up-regulated in ESCC, and correlated with advanced TNM stage, lymph node metastasis, and poor prognosis of ESCC patients. Functionally, LINC00152 knockdown suppressed proliferation, decreased colony forming ability, and induced apoptosis in ESCC cells. Mechanically, LINC00152 functioned as a competing endogenous RNA (ceRNA) to sponge miR-153-3p, thereby facilitating its downstream target FYN. Moreover, miR-153-3p-mediated tumor-suppressive effects were partly reversed following LINC00152 overexpression. Also, FYN knockdown displayed a similar anti-cancerous role in ESCC cells. Taken together, LINC00152 contributed to ESCC progression by down-regulating miR-153-3p and promoting FYN expression, uncovering a novel LINC00152/miR-153-3p/FYN regulatory pathway in ESCC.

Possible biomarkers for predicting lymph node metastasis of esophageal squamous cell carcinoma: a review

Esophageal cancer is the eighth most common form of cancer worldwide, and esophageal squamous cell carcinoma (ESCC) is a major type of esophageal cancer that arises from epithelial cells of the esophagus. Local lymph node metastasis (LNM) is a typical sign of failure for ESCC clinical treatments, and a link has been established between LNM and the aberrant expression of specific biomarkers. In this review, we summarize what is known about nine factors significantly associated with LNM in ESCC patients: phosphatase and tensin homolog (PTEN), mucin 1, vascular endothelial growth factor-C, tumor necrosis factor alpha-induced protein 8 (TNFAIP8), Raf-1 kinase inhibitory protein, stathmin (STMN1), metastasis-associated protein 1, caveolin-1, and interferon-induced transmembrane protein 3. The function of these nine proteins involves four major mechanisms: tumor cell proliferation, tumor cell migration and invasion, epithelium–mesenchymal transition, and chemosensitivity. The roles of PTEN, STMN1, and TNFAIP8 involve at least two of these mechanisms, and we suggest that they are possible biomarkers for predicting LNM in ESCC. However, further retrospective research into PTEN, STMN1, and TNFAIP8 is needed to test their possibilities as indicators.

Novel link prediction for large-scale miRNA-lncRNA interaction network in a bipartite graph

Background

Current knowledge and data on miRNA-lncRNA interactions is still limited and little effort has been made to predict target lncRNAs of miRNAs. Accumulating evidences suggest that the interaction patterns between lncRNAs and miRNAs are closely related to relative expression level, forming a titration mechanism. It could provide an effective approach for characteristic feature extraction. In addition, using the coding non-coding co-expression network and sequence data could also help to measure the similarities among miRNAs and lncRNAs. By mathematically analyzing these types of similarities, we come up with two findings that (i) lncRNAs/miRNAs tend to collaboratively interact with miRNAs/lncRNAs of similar expression profiles, and vice versa, and (ii) those miRNAs interacting with a cluster of common target genes tend to jointly target at the common lncRNAs.

Methods

In this work, we developed a novel group preference Bayesian collaborative filtering model called GBCF for picking up a top-k probability ranking list for an individual miRNA or lncRNA based on the known miRNA-lncRNA interaction network.

Results

To evaluate the effectiveness of GBCF, leave-one-out and k-fold cross validations as well as a series of comparison experiments were carried out. GBCF achieved the values of area under ROC curve of 0.9193, 0.8354+/− 0.0079, 0.8615+/− 0.0078, and 0.8928+/− 0.0082 based on leave-one-out, 2-fold, 5-fold, and 10-fold cross validations respectively, demonstrating its reliability and robustness.

Conclusions

GBCF could be used to select potential lncRNA targets of specific miRNAs and offer great insights for further researches on ceRNA regulation network.

Electronic supplementary material

The online version of this article (10.1186/s12920-018-0429-8) contains supplementary material, which is available to authorized users.

Prognostic Value of MicroRNAs in Esophageal Carcinoma: A Meta-Analysis

Background

Numerous articles have reported that abnormal expression levels of microRNAs (miRNAs) are related to the survival times of esophageal carcinoma (EC) patients, which contains esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC). Nevertheless, there has not been a comprehensive meta-analysis to assess the accurate prognostic value of miRNAs in EC.

Methods

Studies published in English up to April 12, 2018 that evaluated the correlation of the expression levels of miRNAs with overall survival (OS) in EC were identified by online searches in PubMed, EMBASE, Web of Science, and the Cochrane Database of Systematic Reviews performed by two independent authors. The pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were used to estimate the correlation between OS and miRNA expression. HR ≥ 2 was considered cutoff for considering the miRNA as prognostic candidate.

Results

Forty-four pertinent articles with 22 miRNAs and 4310 EC patients were ultimately included. EC patients with tissue expression levels of high miR-21 or low miR-133a (HR = 2.48, 95% CI = 1.50–4.12), miR-133b (HR = 2.15, 95% CI = 1.27–3.62), miR-138 (HR = 2.27, 95% CI = 1.68–3.08), miR-203 (HR = 2.83, 95% CI = 1.35–5.95), miR-375 and miR-655 (HR = 2.66, 95% CI = 1.16–6.12) had significantly poorer OS (P < 0.05). In addition, EC patients with blood expression levels of high miR-21 (HR = 2.19, 95% CI = 1.31–3.68) and miR-223 had significantly shorter OS (P < 0.05).

Conclusions

In conclusion, tissue expression levels of miR-21, miR-133a, miR-133b, miR-138, miR-203, miR-375, and miR-655 and blood expression levels of miR-21 and miR-223 demonstrate significant prognostic value. Among them, the expression levels of miR-133a, miR-133b, miR-138, miR-203, and miR-655 in tissue and the expression level of miR-21 in blood are potential prognostic candidates for predicting OS in EC.