LncRNA MCM3AP-AS1 Regulates Epidermal Growth Factor Receptor and Autophagy to Promote Hepatocellular Carcinoma Metastasis by Interacting with miR-455

ncRNA-mediated SOX4 overexpression correlates with unfavorable outcomes and immune infiltration in hepatocellular carcinoma

BACKGROUND

The activity and number of immune cells in the tumor microenvironment are closely related to the overall survival of patients with hepatocellular carcinoma (HCC). The sex-determining region Y-box 4 (SOX4) gene is abnormally expressed in various tumor tissues and is critical for tumor development. However, the correlation between SOX4 expression in HCC and tumor immunity is unclear.

METHODS

SOX4 expression was explored using data from The Cancer Genome Atlas, and UALCAN databases. Real-time reverse transcription quantitative and western blotting were used to analyze SOX4 expression in several liver cancer cell lines. Additionally, correlations among SOX4 expression, cancer immune characteristics, and infiltrated immune cell gene marker sets in patients with HCC were analyzed using data from the Tumor Immune Estimation Resource, Gene Expression Profiling Interactive Analysis, and Tumor-Immune System Interactions databases. Moreover, we evaluated SOX4 expression in HCC tissues and the correlation of SOX4 expression with survival rate. Subsequently, noncoding RNAs (ncRNAs) responsible for SOX4 overexpression were identified using expression, correlation, and survival analyses.

RESULTS

SOX4 expression was significantly upregulated in HCC and correlated with a poor prognosis. Additionally, SOX4 upregulation in HCC positively correlated with immune cell infiltration, several biomarkers of immune cells, and immune checkpoint expression. Finally, the MCM3AP-AS1/hsa-miR-204-5p axis was identified as the most likely upstream ncRNA-related pathway for SOX4 in HCC. These results indicated that ncRNA-mediated upregulation of SOX4 correlated with the immune infiltration level and poor prognosis in HCC. Our findings provide new directions for the development of novel immunotherapeutic targets for HCC.

New HCC Subtypes Based on CD8 Tex-Related lncRNA Signature Could Predict Prognosis, Immunological and Drug Sensitivity Characteristics of Hepatocellular Carcinoma

Purpose

Hepatocellular carcinoma has become one of the severe diseases threatening human health. T cell exhaustion is deemed as a reason for immunotherapy resistance. However, little is known about the roles of CD8 Tex-related lncRNAs in HCC.

Materials and Methods

We processed single-cell RNA sequencing to identify CD8 Tex-related genes. CD8 Tex-related lncRNAs were identified based on their correlations with mRNAs. Unsupervised clustering approach was used to identify molecular clusters of CD8 Tex-related lncRNAs. Differences in prognosis and immune infiltration between the clusters were explored. Machine learning algorithms were used to construct a prognostic signature. Samples were classified as low- and high-risk groups based on their risk scores. We identified prognosis-related lncRNAs and constructed a ceRNA network. In vitro experiments were conducted to investigate the impacts of CD8 Tex-related lncRNAs on proliferation and apoptosis of HCC cells.

Results

We clarified cell types within two HCC single-cell datasets. We identified specific markers of CD8 Tex cells and analyzed their potential functions. Twenty-eight lncRNAs were identified as CD8 Tex-related. Based on CD8 Tex-related lncRNAs, samples were categorized into two distinct clusters, which exhibited significant differences in survival rates and immune infiltration. Ninety-six algorithm combinations were employed to establish a prognostic signature. RSF emerged as the one with the highest C-index. Patients in high- and low-risk groups exhibited marked differences in prognosis, enriched pathways, mutations and drug sensitivities. MCM3AP-AS1, MAPKAPK5-AS1 and PART1 were regarded as prognosis-related lncRNAs. A ceRNA network was constructed based on CD8 Tex-related lncRNAs and mRNAs. Experiments on cell lines and organoids indicated that downregulation of MCM3AP-AS1, MAPKAPK5-AS1 and PART1 suppressed cell proliferation and induced apoptosis.

Conclusion

CD8 Tex-related lncRNAs played crucial roles in HCC progression. Our findings provided new insights into the regulatory mechanisms of CD8 Tex-related lncRNAs in HCC.

Novel Long Noncoding RNAs, LINC01093 and MYLK-AS1, Serve as Potential Diagnostic and Prognostic Biomarkers or Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most fatal human malignancies worldwide. In this research, we aimed to identify long noncoding RNAs (lncRNAs) as biomarkers for HCC diagnosis and prognosis. lncRNA expression profiles were obtained from Gene Expression Omnibus and The Cancer Genome Atlas databases. The differentially expressed lncRNAs between HCC and adjacent tissues were analyzed with bioinformatic tools. Four lncRNAs with area under the curve of the receiver operating characteristic curve >0.9 were selected from both datasets. Univariate and Kaplan-Meier analyses were performed to obtain LINC01093, MYLK-AS1, and MCM3AP-AS1 as the optimal diagnostic and prognostic biomarkers. Finally, qPCR confirmed that LINC01093 and MYLK-AS1 were significantly differentially expressed in HCC and adjacent normal tissues. In general, we demonstrated that novel lncRNAs, LINC01093 and MYLK-AS1, could be used as potential diagnostic and prognostic biomarkers for HCC.

Targeting Autophagy Using Long Non-Coding RNAs (LncRNAs): New Landscapes in the Arena of Cancer Therapeutics

Cancer has become a global health hazard accounting for 10 million deaths in the year 2020. Although different treatment approaches have increased patient overall survival, treatment for advanced stages still suffers from poor clinical outcomes. The ever-increasing prevalence of cancer has led to a reanalysis of cellular and molecular events in the hope to identify and develop a cure for this multigenic disease. Autophagy, an evolutionary conserved catabolic process, eliminates protein aggregates and damaged organelles to maintain cellular homeostasis. Accumulating evidence has implicated the deregulation of autophagic pathways to be associated with various hallmarks of cancer. Autophagy exhibits both tumor-promoting and suppressive effects based on the tumor stage and grades. Majorly, it maintains the cancer microenvironment homeostasis by promoting viability and nutrient recycling under hypoxic and nutrient-deprived conditions. Recent investigations have discovered long non-coding RNAs (lncRNAs) as master regulators of autophagic gene expression. lncRNAs, by sequestering autophagy-related microRNAs, have been known to modulate various hallmarks of cancer, such as survival, proliferation, EMT, migration, invasion, angiogenesis, and metastasis. This review delineates the mechanistic role of various lncRNAs involved in modulating autophagy and their related proteins in different cancers.

The role of LncRNA MCM3AP-AS1 in human cancer

Long noncoding RNAs (lncRNA) play pivotal roles in every level of gene and genome regulation. MCM3AP-AS1 is a lncRNA that has an oncogenic role in several kinds of cancers. Aberrant expression of MCM3AP-AS1 has been reported to be involved in the progression of diverse malignancies, including colorectal, cervical, prostate, lymphoma, lung, ovary, liver, bone, and breast cancers. It is generally believed that MCM3AP-AS1 expression is associated with cancer cell growth, proliferation, angiogenesis, and metastasis. MCM3AP-AS1 by targeting various signaling pathways and microRNAs (miRNAs) presents an important role in cancer pathogenesis. MCM3AP-AS1 as a competitive endogenous RNA has the ability to sponge miRNA, inhibit their expressions, and bind to different target mRNAs related to cancer development. Therefore, MCM3AP-AS1 by targeting several signaling pathways, including the FOX family, Wnt, EGF, and VEGF can be a potent target for cancer prediction and diagnosis. In this review, we will summarize the role of MCM3AP-AS1 in various human cancers.

The Prognostic Value of lncRNA MCM3AP-AS1 on Clinical Outcomes in Various Cancers: A Meta- and Bioinformatics Analysis

Background. MCM3AP antisense RNA 1 (MCM3AP-AS1) is a newly identified potential tumor biomarker. Nevertheless, the prognostic value of MCM3AP-AS1 in cancer has been inconsistent in the available studies. We performed this meta-analysis to identify the prognostic role of MCM3AP-AS1 in various cancers. Methods. We searched PubMed, Web of Science, EMBASE, and the Cochrane Library databases to screen relevant studies. Hazard ratios (HR) or odds ratios (OR) and corresponding 95% confidence intervals (CI) were used to evaluate the relationship between aberrant MCM3AP-AS1 expression and survival and clinicopathological features (CFS) of cancer patients. A meta-analysis was performed using STATA 12.0 software. Additionally, results were validated by an online database based on The Cancer Genome Atlas (TCGA). Subsequently, we analyzed the MCM3AP-AS1-related genes and molecular mechanisms based on the MEM database. Results. Our results showed that overexpression of MCM3AP-AS1 was related to poor overall survival (OS) ( $\text{HR}=2.00$ , 95% CI, 1.52–2.64, $P<0.001$ ) and relapse-free survival (RFS) ( $\text{HR}=3.28$ , 95% CI 1.56–6.88, $P=0.002$ ). In addition, MCM3AP-AS1 overexpression was associated with TNM stage, differentiation grade, and lymph node metastasis, but not significantly with age, gender, and tumor size. In addition, MCM3AP-AS1 overexpression was verified by the GEPIA online database to be associated with poorer survival. The further functional investigation suggested that MCM3AP-AS1 may be involved in several cancer-related pathways. Conclusions. The overexpression of MCM3AP-AS1 was related to poor survival and CFS. MCM3AP-AS1 may be considered a novel prognostic marker and therapeutic target in various cancers.

Long Non-Coding RNA MCM3AP-AS1: A Crucial Role in Human Malignancies

The incidence of cancer continues to grow and is one of the leading causes of death in the world. Long noncoding RNAs (LncRNAs) is a group of RNA transcripts greater than 200 nucleotides in length, and although it cannot encode proteins, it can regulate different biological functions by controlling gene expression, transcription factors, etc. LncRNA micro-chromosome maintenance protein 3-associated protein antisense RNA 1 (MCM3AP-AS1) is involved in RNA processing and cell cycle-related functions, and MCM3AP-AS1 is dysregulated in expression in various types of cancers. This biomarker is involved in many processes related to carcinogens, such as cell proliferation, apoptosis, cell cycle, and migration. In this review, we summarize the roles of MCM3AP-AS1 in different human cancers and its biological functions with a view to providing ideas for future research.

MCM3AP-AS1: A LncRNA Participating in the Tumorigenesis of Cancer Through Multiple Pathways

Background:

More and more shreds of evidence show that the occurrence and development of tumors are closely related to the abnormal expression of LncRNA. A large number of experiments have found that overexpression or under-expression of MCM3AP-AS1 can affect the occurrence and development of cancer cells in varying degrees, such as proliferation, invasion, and translocation. Besides, MCM3AP-AS1 may become a promising target for many tumor biotherapies. This article reviews the pathophysiological functions and molecular mechanisms of MCM3AP-AS1 in various tumors.

Methods:

This paper systematically summarizes the published literatures in PubMed. The molecular mechanism of MCM3AP-AS1 in a variety of tumors is reviewed.

Results:

The abnormal expression of MCM3AP-AS1 in different tumors is closely related to tumor proliferation, invasion, and migration. MCM3AP-AS1 mediates or participates in related signaling pathways to regulate the expression of targeted miRNAs and proteins. MCM3AP-AS1 plays a vital role in tumor diagnosis and treatment.

Conclusion:

LncRNA MCM3AP-AS1 is a feasible tumor marker and a potential therapeutic target for many kinds of tumors.

Non-coding RNAs as new autophagy regulators in cancer progression

Recent advances highlight that non-coding RNAs (ncRNAs) are emerging as fundamental regulators in various physiological as well as pathological processes by regulating macro-autophagy. Studies have disclosed that macro-autophagy, which is a highly conserved process involving cellular nutrients, components, and recycling of organelles, can be either selective or non-selective and ncRNAs show their regulation on selective autophagy as well as non-selective autophagy. The abnormal expression of ncRNAs will result in the impairment of autophagy and contribute to carcinogenesis and cancer progression by regulating both selective autophagy as well as non-selective autophagy. This review focuses on the regulatory roles of ncRNAs in autophagy and their involvement in cancer which may provide valuable therapeutic targets for cancer management.

Autophagy and gastrointestinal cancers: the behind the scenes role of long non-coding RNAs in initiation, progression, and treatment resistance

Gastrointestinal (GI) cancers comprise a heterogeneous group of complex disorders that affect different organs, including esophagus, stomach, gallbladder, liver, biliary tract, pancreas, small intestine, colon, rectum, and anus. Recently, an explosion in nucleic acid-based technologies has led to the discovery of long non-coding RNAs (lncRNAs) that have been found to possess unique regulatory functions. This class of RNAs is >200 nucleotides in length, and is characterized by their lack of protein coding. LncRNAs exert regulatory effects in GI cancer development by affecting different functions such as the proliferation and metastasis of cancer cells, apoptosis, glycolysis and angiogenesis. Over the past few decades, considerable evidence has revealed the important role of autophagy in both GI cancer progression and suppression. In addition, recent studies have confirmed a significant correlation between lncRNAs and the regulation of autophagy. In this review, we summarize how lncRNAs play a behind the scenes role in the pathogenesis of GI cancers through regulation of autophagy.

Overexpression of long noncoding RNA MCM3AP-AS1 promotes osteogenic differentiation of dental pulp stem cells via miR-143-3p/IGFBP5 axis

MCM3AP-AS1 regulates the cartilage repair in osteoarthritis, but how it regulates osteogenic differentiation of dental pulp stem cells (DPSCs) remains to be determined. DPSCs were isolated and induced for osteogenic differentiation. MCM3AP-AS1 expression was increased along with the osteogenic differentiation of DPSCs, whose expression was positive correlated with those of OCN, alkaline phosphatase (ALP) and RUNX2. On contrary, miR-143-3p expression was decreased along with the osteogenic differentiation and was negatively correlated with those of OCN, ALP and RUNX2. Dual-luciferase reporter gene assay showed that miR-143-3p can be negatively regulated by MCM3AP-AS1 and can regulate IGFBP5. MCM3AP-AS1 overexpression increased the expression levels of osteogenesis-specific genes, ALP activity and mineralized nodules during DPSC osteogenic differentiation, while IGFBP5 knockdown or miR-143-3p overexpression counteracted the effect of MCM3AP-AS1 overexpression in DPSCs. Therefore, this study demonstrated the role of MCM3AP-AS1/miR-143-3p/IGFBP5 axis in regulating DPSC osteogenic differentiation.

MCM3AP-AS1: An Indispensable Cancer-Related LncRNA

Long non-coding RNAs (lncRNAs) are a class of RNA molecules with transcripts longer than 200 nucleotides that have no protein-coding ability. MCM3AP-AS1, a novel lncRNA, is aberrantly expressed in human cancers. It is significantly associated with many clinical characteristics, such as tumor size, tumor-node-metastasis (TNM) stage, and pathological grade. Additionally, it considerably promotes or suppresses tumor progression by controlling the biological functions of cells. MCM3AP-AS1 is a promising biomarker for cancer diagnosis, prognosis evaluation, and treatment. In this review, we briefly summarized the published studies on the expression, biological function, and regulatory mechanisms of MCM3AP-AS1. We also discussed the clinical applications of MCM3AP-AS1 as a biomarker.

LncRNA-MCM3AP-AS1 Promotes the Progression of Infantile Hemangiomas by Increasing miR-138-5p/HIF-1α Axis-Regulated Glycolysis

Infantile hemangioma (IH) is a common benign tumor of endothelial cells in infants. Most hemangiomas are self-limited, but a few may develop and lead to serious complications that affect the normal life of children. Therefore, finding an effective treatment strategy for IH is a pressing need. Recent studies have demonstrated that non-coding RNAs affect the progression of multiple tumors. This study aims to investigate the mechanism by which LncRNA-MCM3AP-AS1 promotes glycolysis in the pathogenesis of IH. We first documented that the expression of LncRNA MCM3AP-AS1 was significantly upregulated in IH. Furthermore, we demonstrated that MCM3AP-AS1 bound to miR-106b-3p which promotes glycolysis in IH. In addition, we found that inhibition of HIF-1α contributed to the transformation of glycolysis to normal aerobic oxidation, partially reversed the promoting effect on glycolysis by the up-regulation of LncRNA MCM3AP-AS1 in IH disease. More importantly, we demonstrated this phenomenon existed in IH patients. Taken together, we demonstrate that LncRNA-MCM3AP-AS1 promotes the progression of infantile hemangiomas by increasing the glycolysis via regulating miR-138-5p/HIF-1α axis.

Autophagy plays a double-edged sword role in liver diseases

As a highly evolutionarily conserved process, autophagy can be found in all types of eukaryotic cells. Such a constitutive process maintains cellular homeostasis in a wide variety of cell types through the encapsulation of damaged proteins or organelles into double-membrane vesicles. Autophagy not only simply eliminates materials but also serves as a dynamic recycling system that produces new building blocks and energy for cellular renovation and homeostasis. Previous studies have primarily recognized the role of autophagy in the degradation of dysfunctional proteins and unwanted organelles. However, there are findings of autophagy in physiological and pathological processes. In hepatocytes, autophagy is not only essential for homeostatic functions but also implicated in some diseases, such as viral hepatitis, alcoholic hepatitis, and hepatic failure. In the present review, we summarized the molecular mechanisms of autophagy and its role in several liver diseases and put forward several new strategies for the treatment of liver disease.

A Positive Feedback Loop of lncRNA MIR31HG-miR-361-3p -YY1 Accelerates Colorectal Cancer Progression Through Modulating Proliferation, Angiogenesis, and Glycolysis

Background

Colorectal cancer (CRC) is a common malignant tumor with high metastatic and recurrent rates. This study probes the effect and mechanism of long non-coding RNA MIR31HG on the progression of CRC cells.

Materials and Methods

Quantitative real-time PCR (qRT-PCR) was used to analyze the expression of MIR31HG and miR-361-3p in CRC tissues and normal tissues. Gain- or loss-of-function assays were conducted to examine the roles of MIR31HG, miR-361-3p and YY1 transcription factor (YY1) in the CRC progression. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and colony formation experiment were conducted to test CRC cell proliferation. CRC cell invasion was determined by Transwell assay. The glucose detection kit and lactic acid detection kit were utilized to monitor the levels of glucose and lactate in CRC cells. The glycolysis level in CRC cells was examined by the glycolytic stress experiment. Western blot was performed to compare the expression of glycolysis-related proteins (PKM2, GLUT1 and HK2) and angiogenesis-related proteins (including VEGFA, ANGPT1, HIF1A and TIMP1) in HUVECs. The binding relationships between MIR31HG and miR-361-3p, miR-361-3p and YY1 were evaluated by the dual-luciferase reporter assay and RNA immunoprecipitation (RIP).

Results

MIR31HG was up-regulated in CRC tissues and was associated with poorer prognosis of CRC patients. The in-vitro and in-vivo experiments confirmed that overexpressing MIR31HG heightened the proliferation, growth, invasion, glycolysis and lung metastasis of CRC cells as well as the angiogenesis of HUVECs. In addition, MIR3HG overexpression promoted YY1 mRNA and protein level, and forced overexpression of YY1 enhanced MIR31HG level. Overexpressing YY1 reversed the tumor-suppressive effect mediated by MIR31HG knockdown. miR-361-3p, which was inhibited by MIR31HG overexpression, repressed the malignant behaviors of CRC cells. miR-361-3p-mediated anti-tumor effects were mostly reversed by upregulating MIR31HG. Further mechanism studies illustrated that miR-361-3p targeted and negatively regulated the expression of YY1.

Conclusion

This study reveals that MIR31HG functions as an oncogenic gene in CRC via forming a positive feedback loop of MIR31HG-miR-361-3p-YY1.

Long non-coding RNA MCM3AP antisense RNA 1 promotes non-small cell lung cancer progression through targeting microRNA-195-5p

Lung cancer (LC) ranks first among all causes of cancer-related death, with non-small cell lung cancer (NSCLC) taking up 85% of lung cancer cases. Although lncRNA MCM3AP antisense RNA 1 (MCM3AP-AS1) has been reported to be an oncogenic factor in NSCLC, its detailed mechanism in NSCLC is unknown. In this study, quantitative real-time polymerase chain reaction (qRT-PCR) was performed to determine MCM3AP-AS1, microRNA (miR)-195-5p and E2F transcription factor 3 (E2F3) mRNA expressions in NSCLC tissues and cells. Western blot was utilized to determine the expression levels of E2F3, BCL2-associated X protein (Bax), B-cell lymphoma-2 (Bcl-2), E-cadherin and N-cadherin. CCK-8 and Transwell assays were conducted to examine cell proliferation, migration and invasion, respectively. Dual-luciferase reporter assay and RNA immunoprecipitation experiments were used to determine the regulatory relationships between MCM3AP-AS1 and miR-195-5p, and miR-195-5p and E2F3. We demonstrated that MCM3AP-AS1 was overexpressed in NSCLC tissues and cells, and MCM3AP-AS1 overexpression accelerated the proliferation, migration and invasion of NSCLC cells. In addition, MCM3AP-AS1 overexpression markedly up-modulated Bcl-2 expression and repressed Bax expression; MCM3AP-AS1 overexpression also significantly up-regulated N-cadherin expression and suppressed E-cadherin expression in NSCLC cells. What is more, in NSCLC cells, miR-195-5p was a target of MCM3AP-AS1, and the latter worked as a molecular sponge for miR-195-5p to regulate E2F3 expression. Collectively, MCM3AP-AS1, serving as a competitive endogenous RNA (ceRNA) to regulate miR-195-5p/E2F3 axis, promotes NSCLC progression, which is a promising therapeutic target for NSCLC.

The Impact of Long Non-Coding RNAs in the Pathogenesis of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is among the utmost deadly human malignancies. This type of cancer has been associated with several environmental, viral, and lifestyle risk factors. Among the epigenetic factors which contribute in the pathogenesis of HCC is dysregulation of long non-coding RNAs (lncRNAs). These transcripts modulate expression of several tumor suppressor genes and oncogenes and alter the activity of cancer-related signaling axes. Several lncRNAs such as NEAT1, MALAT1, ANRIL, and SNHG1 have been up-regulated in HCC samples. On the other hand, a number of so-called tumor suppressor lncRNAs namely CASS2 and MEG3 are down-regulated in HCC. The interaction between lncRNAs and miRNAs regulate expression of a number of mRNA coding genes which are involved in the pathogenesis of HCC. H19/miR-15b/CDC42, H19/miR-326/TWIST1, NEAT1/miR-485/STAT3, MALAT1/miR-124-3p/Slug, MALAT1/miR-195/EGFR, MALAT1/miR-22/SNAI1, and ANRIL/miR-144/PBX3 axes are among functional axes in the pathobiology of HCC. Some genetic polymorphisms within non-coding regions of the genome have been associated with risk of HCC in certain populations. In the current paper, we describe the recent finding about the impact of lncRNAs in HCC.

Identification of HCG18 and MCM3AP-AS1 That Associate With Bone Metastasis, Poor Prognosis and Increased Abundance of M2 Macrophage Infiltration in Prostate Cancer

Background:

Bone metastasis is a leading cause of the high mortality rate of prostate cancer (PCa), but curative strategies remain lacking. Recent studies suggest long non-coding RNAs (lncRNAs) may be potential targets to develop drugs. However, PCa bone metastasis-specifically-related lncRNAs were rarely reported. This study aimed to identify crucial lncRNAs and reveal their function mechanisms.

Methods:

GSE32269 and GSE26964 microarray datasets, downloaded from the Gene Expression Omnibus database, were used to analyze differentially expressed genes (DEGs)/lncRNAs (DELs) and miRNAs (DEMs), respectively. Weighted gene co-expression network analysis was performed to screen PCa bone metastasis-associated modules. The co-expression and competing endogenous RNAs (ceRNAs) networks were constructed to identify hub lncRNAs. Univariate Cox regression analysis was conducted to determine their prognostic values. The correlation of lncRNAs with immune infiltrating cells was analyzed by using Tumor IMmune Estimation Resource. Therapeutic drugs were predicted by querying the Connectivity Map (CMap) and the Comparative Toxicogenomics Database (CTD).

Results:

A total of 18 DELs, 2,614 DEGs and 86 DEMs were screened between bone metastatic and primary PCa samples. Four modules enriched by DEGs were shown to be bone metastasis-associated. LncRNA HCG18 and MCM3AP-AS1 were identified to be important because they existed in both of the co-expression and ceRNA networks (forming the relationship pairs: HCG18/MCM3AP-AS1-KNTC1, MCM3AP-AS1-hsa-miR-508-3p-DTL and HCG18/MCM3AP-AS1-hsa-miR-127-3p-CDKN3). All the genes in these interaction pairs were significantly associated with overall survival of PCa patients. Also, HCG18, MCM3AP-AS1 and their target mRNAs were positively correlated with various tumor-infiltrated immune cells, especially increased M2 macrophages. Valproic acid and trichostatin A may be effective to treat PCa bone metastasis by targeting HCG18 and MCM3AP-AS1.

Conclusion:

HCG18 and MCM3AP-AS1 that regulate M2 macrophage infiltration may be important targets to treat PCa bone metastasis and improve prognosis.

MCM3AP-AS1 promotes cisplatin resistance in gastric cancer cells via the miR-138/FOXC1 axis

The dysregulation of long non-coding RNAs (lncRNAs) serves a pivotal role in the pathogenesis and development of multiple types of human cancer, including gastric cancer (GC). MCM3AP-antisense 1 (MCM3AP-AS1) has been reported to function as a tumor promoter in various types of cancer. However, the biological function of MCM3AP-AS1 in the resistance of GC cells to cisplatin (CDDP) remains to be elucidated. The present study aimed to elucidate the mechanisms of MCM3AP-AS1 in the resistance of GC cells to CDDP. The expression levels of MCM3AP-AS1, miR-138 and FOXC1 were measured via reverse transcription-quantitative PCR. In addition, cell viability, migration and invasion were assessed via the Cell Counting Kit-8, wound healing and transwell assays, respectively. The interaction between genes was confirmed via the dual-luciferase reporter and pull-down assays. Western blot analysis was performed to detect FOXC1 protein expression. In the present study, it was demonstrated that MCM3AP-AS1 expression was upregulated in CDDP-resistant GC cells and that MCM3AP-AS1-knockdown suppressed CDDP resistance in GC cells. Moreover, the examination of the molecular mechanism indicated that MCM3AP-AS1 upregulated FOXC1 expression by sponging microRNA (miR)-138. Additionally, it was identified that the overexpression of FOXC1 abolished MCM3AP-AS1-knockdown- or miR-138 mimic-mediated inhibitory effects on CDDP resistance in GC cells. In conclusion, the present findings suggested that MCM3AP-AS1 enhanced CDDP resistance by sponging miR-138 to upregulate FOXC1 expression, indicating that MCM3AP-AS1 may be a novel promising biomarker for the diagnosis and treatment of patients with GC.

MiR-455-5p monitors myotube morphogenesis by targeting mylip

As a posttranscriptional regulatory factor, microRNA (miRNA) plays an important role in the formation of myotubes. However, little is known about the mechanism of miRNA regulating myotube morphogenesis. Here, we aimed to characterize the function of miR-455-5p in myotube morphogenesis by inducing differentiation in C2C12 myoblasts containing murine Mylip fragments with the miR-455-5p target sequence. We found that miR-455-5p overexpression promoted the differentiation and hypertrophy of myotubes, while miR-455-5p inhibition led to the failure of myotube differentiation and formation of short myotubes. Furthermore, we demonstrated that miR-455-5p directly targeted the Mylip 3'-untranslated region, which plays a key role in monitoring myotube morphogenesis. Interestingly, the expression and function of Mylip were opposite to those of miR-455-5p during myogenesis. Our data uncovered novel miR-455-5p targets and established a functional link between Mylip and myotube morphogenesis. Understanding the involvement of Mylip in myotube morphogenesis provides insight into the function of the gene regulatory network.

Linc00426 accelerates lung adenocarcinoma progression by regulating miR-455-5p as a molecular sponge

Increasing lines of evidence indicate the role of long non-coding RNAs (LncRNAs) in gene regulation and tumor development. Hence, it is important to elucidate the mechanisms of LncRNAs underlying the proliferation, metastasis, and invasion of lung adenocarcinoma (LUAD). We employed microarrays to screen LncRNAs in LUAD tissues with and without lymph node metastasis and revealed their effects on LUAD. Among them, Linc00426 was selected for further exploration in its expression, the biological significance, and the underlying molecular mechanisms. Linc00426 exhibits ectopic expression in LUAD tissues and cells. The ectopic expression has been clinically linked to tumor size, lymphatic metastasis, and tumor differentiation of patients with LUAD. The deregulation of Linc00426 contributes to a notable impairment in proliferation, invasion, metastasis, and epithelial-mesenchymal transition (EMT) in vitro and in vivo. Mechanistically, the deregulation of Linc00426 could reduce cytoskeleton rearrangement and matrix metalloproteinase expression. Meanwhile, decreasing the level of Linc00426 or increasing miR-455-5p could down-regulate the level of UBE2V1. Thus, Linc00426 may act as a competing endogenous RNA (ceRNA) to abate miR-455-5p-dependent UBE2V1 reduction. We conclude that Linc00426 accelerates LUAD progression by acting as a molecular sponge to regulate miR-455-5p, and may be a potential novel tumor marker for LUAD.

The Roles of ceRNAs-Mediated Autophagy in Cancer Chemoresistance and Metastasis

Simple Summary

Chemoresistance and metastasis are the main causes of treatment failure in cancers. Autophagy contribute to the survival and metastasis of cancer cells. Competing endogenous RNA (ceRNA), particularly long non-coding RNAs and circular RNA (circRNA), can bridge the interplay between autophagy and chemoresistance or metastasis in cancers via sponging miRNAs. This review aims to discuss on the function of ceRNA-mediated autophagy in the process of metastasis and chemoresistance in cancers. ceRNA network can sequester the targeted miRNA expression to indirectly upregulate the expression of autophagy-related genes, and thereof participate in autophagy-mediated chemoresistance and metastasis. Our clarification of the mechanism of autophagy regulation in metastasis and chemoresistance may greatly improve the efficacy of chemotherapy and survival in cancer patients. The combination of the tissue-specific miRNA delivery and selective autophagy inhibitors, such as hydroxychloroquine, is attractive to treat cancer patients in the future.

Abstract

Chemoresistance and metastasis are the main causes of treatment failure and unfavorable outcome in cancers. There is a pressing need to reveal their mechanisms and to discover novel therapy targets. Autophagy is composed of a cascade of steps controlled by different autophagy-related genes (ATGs). Accumulating evidence suggests that dysregulated autophagy contributes to chemoresistance and metastasis via competing endogenous RNA (ceRNA) networks including lncRNAs and circRNAs. ceRNAs sequester the targeted miRNA expression to indirectly upregulate ATGs expression, and thereof participate in autophagy-mediated chemoresistance and metastasis. Here, we attempt to summarize the roles of ceRNAs in cancer chemoresistance and metastasis through autophagy regulation.

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

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

Pro-Angiogenic and Pro-Inflammatory Regulation by lncRNA MCM3AP-AS1-Mediated Upregulation of DPP4 in Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (ccRCC) represents the most common type of renal cell carcinoma (RCC) in adults, in addition to the worst prognosis among the common epithelial kidney tumors. Inflammation and angiogenesis seem to potentiate tumor growth and metastasis of the malignancy. The current study explored the contributions of the lncRNA MCM3AP-AS1 in tumor-associated inflammation and angiogenesis in ccRCC with a specific focus on its transcriptional regulation and its interactions with transcription factor E2F1 and DPP4. Tumor tissues and matched adjacent non-tumor tissues were collected from 78 ccRCC patients. Methylation-specific PCR and ChIP assays were applied to detect the methylation at the promoter region of MCM3AP-AS1. Dual-luciferase reporter assay, RIP, RNA pull-down, and ChIP assays were employed to confirm the interactions between MCM3AP-AS1, E2F1, and DPP4. Nude mice were subcutaneously xenografted with human ccRCC cells. Cell proliferation was evaluated by CCK-8 assays and EDU staining in ccRCC cells in vitro and by immunohistochemical staining of Ki67 in vivo. Inflammation was examined by detecting the secretion of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6). Pro-angiogenic ability of ccRCC cells was assessed by the co-culture with human umbilical vein endothelial cells (HUVEC) in vitro and by microvessel density (MVD) measurements and angiogenesis in the chicken chorioallantoic membrane. MCM3AP-AS1 was highly-expressed in ccRCC and associated with poor patient survival. Demethylation of MCM3AP-AS1 was noted in ccRCC tissues and cells. Over-expression of MCM3AP-AS1 enhanced cell proliferation, the release of pro-inflammatory cytokines, and the tube formation of HUVECs in cultured human Caki-1 and 786-O cells. MCM3AP-AS1 was shown to enhance the E2F1 enrichment at the DPP4 promoter, to further increase the expression of DPP4. Knockdown of DPP4 could abate pro-angiogenic and pro-inflammatory abilities of MCM3AP-AS1 in ccRCC cells. Pro-angiogenic and pro-inflammatory abilities of MCM3AP-AS1 in vivo were confirmed in mice subcutaneously xenografted with human ccRCC cells. Our findings demonstrate a novel mechanism by which lncRNA MCM3AP-AS1 exerts pro-angiogenic and pro-inflammatory effects, highlighting the potential of MCM3AP-AS1 as a promising target for treating ccRCC.

MiR-34a Inhibits Cell Proliferation and Induces Apoptosis in Human Nasopharyngeal Carcinoma by Targeting lncRNA MCM3AP-AS1

Introduction

MCM3AP-AS1 has been characterized as an oncogenic lncRNA in several types of cancer, while its role in nasopharyngeal carcinoma (NPC) is unknown. This study aimed to investigate the role of MCM3AP-AS1 in NPC.

Patients and Methods

Paired NPC tissues and non-tumor tissues were collected from 55 NPC patients. Expression of MCM3AP-AS1 and miR-34a in paired tissues was analyzed by RT-qPCR. Interactions between MCM3AP-AS1 and miR-34a were analyzed by overexpression experiments. The roles of MCM3AP-AS1 and miR-34a in regulating NPC cell proliferation and apoptosis were explored by cell proliferation assay and cell apoptosis assay, respectively.

Results

Our bioinformatics analysis showed that MCM3AP-AS1 may be targeted by miR-34a, which is a well-studied tumor suppressor miRNA. In this study, we showed that miR-34a was downregulated and MCM3AP-AS1 was upregulated in NPC. An inverse correlation between the expression of MCM3AP-AS1 and miR-34a was found across NPC tissue samples. High expression level of MCM3AP-AS1 and low levels of miR-34a in NPC tissues predicted the poor survival. In NPC cells, overexpression of MCM3AP-AS1 did not affect the expression of miR34a, while overexpression of miR-34a led to downregulated MCM3AP-AS1. Cell proliferation and apoptosis assay showed that overexpression of miR-34a reduced the enhancing effects of overexpressing MCM3AP-AS1 on cell proliferation and the inhibitory effects on cell apoptosis.

Conclusion

MiR-34a inhibits cell proliferation and induces apoptosis in human NPC by targeting MCM3AP-AS1.

Bioinformatics profiling integrating a three immune-related long non-coding RNA signature as a prognostic model for clear cell renal cell carcinoma

Background

Renal cell carcinoma (RCC) is one of the most common aggressive malignant tumors in urogenital system, and the clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal carcinoma. Immune related long non-coding RNAs (IRlncRs) plentiful in immune cells and immune microenvironment (IME) are potential in evaluating prognosis and assessing the effects of immunotherapy. A completed and meaningful IRlncRs analysis based on abundant ccRCC gene samples from The Cancer Genome Atlas (TCGA) will provide insight in this field.

Methods

Based on the TCGA dataset, we integrated the expression profiles of IRlncRs and overall survival (OS) in the 611 ccRCC patients. The immune score of each sample was calculated based on the expression level of immune-related genes and used to identify the most meaningful IRlncRs. Survival-related IRlncRs (sIRlncRs) was estimated by calculating the algorithm of difference and COX regression analysis in ccRCC patients. Based on the median immune-related risk score (IRRS) developed from the screened sIRlncRs, the high-risk and low-risk components were distinguished. Functional annotation was detected by gene set enrichment analysis (GSEA) and principal component analysis (PCA), and the immune composition and purity of the tumor was evaluated by microenvironment cell population records. The expression levels of three sIRlncRs were verified in various tissues and cell lines.

Results

A total of 39 IRlncRs were collected by Pearson correlation analyses among immune score and the lncRNA expression. A total of 7 sIRlncRs were significantly associated with the clinical outcomes of ccRCC patients. Three sIRlncRs (ATP1A1-AS1, IL10RB-DT and MELTF-AS1) with the most significant prognostic values were enrolled to build the IRRS model in which the OS of in the high-risk group was shorter than that in the low-risk group. The IRRS was identified as an independent prognosis factor and correlated with the OS. The high-risk group and low-risk group illustrated different distributions in PCA and different immune status in GSEA. Besides, we found the more significant expression in certain ccRCC cell lines and tumor tissues of ccRCC patients compared with the HK-2 and adjacent tissues respectively. Additionally, the expression levels of lncR-MELTF-AS1 and IL10RB-DT were remarkably enhanced along the more advanced T-stages, but the lncR-ATP1A1-AS1 showed the inverse gradient.

Conclusion

Our results demonstrate some sIRlncRs with remark clinical relevance show the latent monitoring and prognosis values for ccRCC patients and may provide new insight in immunological researches and treatment strategies of ccRCC patients.

Integrative analysis of dysregulated lncRNA-associated ceRNA network reveals potential lncRNA biomarkers for human hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is an aggressive cancer with a poor prognosis and a high incidence. The molecular changes and novel biomarkers of HCC need to be identified to improve the diagnosis and prognosis of this disease. We investigated the current research concentrations of HCC and identified the transcriptomics-related biomarkers of HCC from The Cancer Genome Atlas (TGCA) database.

Methods

We investigated the current research concentrations of HCC using literature metrology analysis for studies conducted from 2008 to 2018. We identified long noncoding RNAs (lncRNAs) that correlated with the clinical features and survival prognoses of HCC from The Cancer Genome Atlas (TGCA) database. Differentially expressed genes (lncRNAs, miRNAs, and mRNAs) were also identified by TCGA datasets in HCC tumor tissues. A lncRNA competitive endogenous RNA (ceRNA) network was constructed from lncRNAs based on intersected lncRNAs. Survival times and the association between the expression levels of the key lncRNAs of the ceRNA network and the clinicopathological characteristics of HCC patients were analyzed using TCGA. Real-time polymerase chain reaction (qRT-PCR) was used to validate the reliability of the results in tissue samples from 20 newly-diagnosed HCC patients.

Results

Analysis of the literature pertaining to HCC research revealed that current research is focused on lncRNA functions in tumorigenesis and tumor development. A total of 128 HCC dysregulated lncRNAs were identified; 66 were included in the co-expressed ceRNA network. We analyzed survival times and the associations between the expression of 66 key lncRNAs and the clinicopathological features of the HCC patients identified from TCGA. Twenty-six lncRNAs were associated with clinical features of HCC (P < 0.05) and six key lncRNAs were associated with survival time (log-rank test P < 0.05). Six key lncRNAs were selected for the validation of their expression levels in 20 patients with newly diagnosed HCC using qRT-PCR. Consistent fold changes in the trends of up and down regulation between qRT-PCR validation and TCGA proved the reliability of our bioinformatics analysis.

Conclusions

We used integrative bioinformatics analysis of the TCGA datasets to improve our understanding of the regulatory mechanisms involved with the functional features of lncRNAs in HCC. The results revealed that lncRNAs are potential diagnostic and prognostic biomarkers of HCC.

Long non-coding RNA MCM3AP-AS1 promotes growth and migration through modulating FOXK1 by sponging miR-138-5p in pancreatic cancer

Background

Pancreatic cancer (PC) is a type of malignant gastrointestinal tumor. Long non-coding RNA MCM3AP antisense RNA 1 (MCM3AP-AS1) has been reported to stimulate proliferation, migration and invasion in several types of tumors. However, the role of MCM3AP-AS1 in PC remains unclear.

Methods

MCM3AP-AS1, microRNA miR-138-5p (miR-138-5p) and FOXK1 levels were detected using quantitative real time PCR. Cell proliferation, migration and invasion were analyzed. Dual luciferase reporter assay was used to confirm the relationship between MCM3AP-AS1 and miR-138-5p, between miR-138-5p and FOXK1. Protein levels were identified using western blot analysis.

Results

MCM3AP-AS1 overexpression promoted proliferation, migration and invasion in PC cells. MCM3AP-AS1 silencing showed a suppressive effect on cell growth in PC cells. Moreover, MCM3AP-AS1 knockdown suppressed tumor growth in mice. Dual luciferase reporter assay demonstrated MCM3AP-AS1 could sponge microRNA-138-5p (miR-138-5p), and FOXK1 could bind with miR-138-5p. Positive correlation between MCM3AP-AS1 and FOXK1 was testified, as well as negative correlation between miR-138-5p and FOXK1. MCM3AP-AS1 promoted FOXK1 expression by targeting miR-138-5p, and MCM3AP-AS1 facilitated growth and invasion in PC cells by FOXK1.

Conclusion

MCM3AP-AS1 promoted growth and migration through modulating miR-138-5p/FOXK1 axis in PC, providing insights into MCM3AP-AS1/miR-138-5p/FOXK1 axis as novel candidates for PC therapy from bench to clinic.