A novel lncRNA, LUADT1, promotes lung adenocarcinoma proliferation via the epigenetic suppression of p27

Prostate cancer biomarkers: from early diagnosis to precision treatment

Prostate cancer (PCa) is the second most prevalent cancer in men. In 2020, approximately 1,414,259 new cases were reported that accounted for 3,75,324 deaths (Sung et al. in CA 71:209-249, 2021). PCa is often asymptomatic at early stages; hence, routine screening and monitoring based on reliable biomarkers is crucial for early detection and assessment of cancer progression. Early diagnosis of disease is key step in reducing PCa-induced mortality. Biomarkers such as PSA have played vital role in reducing recent PCa deaths. Recent research has identified many other biomarkers and also refined PSA-based tests for non-invasive diagnosis of PCa in patients. Despite progress in screening methods, an important issue that influences treatment is heterogeneity of the cancer in different individuals, necessitating personalized treatment. Currently, focus is to identify biomarkers that can accurately diagnose PCa at early stage, indicate the stage of the disease, metastatic nature and chances of survival based on individual patient profile (Fig. 1). Fig. 1 Graphical abstract.

Modulation of long noncoding RNAs by polyphenols as a novel potential therapeutic approach in lung cancer: A comprehensive review

Lung cancer stands as a formidable global health challenge, necessitating innovative therapeutic strategies. Polyphenols, bioactive compounds synthesized by plants, have garnered attention for their diverse health benefits, particularly in combating various cancers, including lung cancer. The advent of whole-genome and transcriptome sequencing technologies has illuminated the pivotal roles of long noncoding RNAs (lncRNAs), operating at epigenetic, transcriptional, and posttranscriptional levels, in cancer progression. This review comprehensively explores the impact of polyphenols on both oncogenic and tumor-suppressive lncRNAs in lung cancer, elucidating on their intricate regulatory mechanisms. The comprehensive examination extends to the potential synergies when combining polyphenols with conventional treatments like chemotherapy, radiation, and immunotherapy. Recognizing the heterogeneity of lung cancer subtypes, the review emphasizes the need for the integration of nanotechnology for optimized polyphenol delivery and personalized therapeutic approaches. In conclusion, we collect the latest research, offering a holistic overview of the evolving landscape of polyphenol-mediated modulation of lncRNAs in lung cancer therapy. The integration of polyphenols and lncRNAs into multidimensional treatment strategies holds promise for enhancing therapeutic efficacy and navigating the challenges associated with lung cancer treatment.

LINC00355 promotes gastric carcinogenesis by scaffolding p300 to activate CDC42 transcription and enhancing HNRNPA2B1 to stabilize CDC42 mRNA dependent on m6A

LINC00355 is involved in the tumorigenesis of several types of cancer. We verified that LINC00355 is upregulated in gastric cancer (GC) and contributes to GC cells' proliferation and metastasis. RNA sequencing (RNA-seq) and rescue assays suggested that LINC00355 controls gastric carcinogenesis by regulating the expression of cell division cycle 42 (CDC42) guanosine triphosphatase (GTPases), thereby activating their downstream pathways. Most previous studies have shown that LINC00355 acts as a ceRNA by sponging miRNAs to modulate downstream gene expression. Our group focus on epigenetic regulatory potential of LINC00355 in gene expression. Mechanistically, LINC00355 binds to p300 histone acetyltransferase, specifying the histone modification pattern on the CDC42 promoter to activate CDC42 transcription, thereby altering GC cell biology. In addition, HNRNPA2B1, which is upregulated by LINC00355, recognizes the N6-methyladenosine (m6A) sites of CDC42 and enhances the stability of CDC42 mRNA transcripts. Therefore, LINC00355 is mechanistically, functionally, and clinically oncogenic in GC cells.

Long non-coding RNAs in lung cancer: Unraveling the molecular modulators of MAPK signaling

Lung cancer (LC) continues to pose a significant global medical burden, necessitating a comprehensive understanding of its molecular foundations to establish effective treatment strategies. The mitogen-activated protein kinase (MAPK) signaling system has been scientifically associated with LC growth; however, the intricate regulatory mechanisms governing this system remain unknown. Long non-coding RNAs (lncRNAs) are emerging as crucial regulators of diverse cellular activities, including cancer growth. LncRNAs have been implicated in LC, which can function as oncogenes or tumor suppressors, and their dysregulation has been linked to cancer cell death, metastasis, spread, and proliferation. Due to their involvement in critical pathophysiological processes, lncRNAs are gaining attention as potential candidates for anti-cancer treatments. This article aims to elucidate the regulatory role of lncRNAs in MAPK signaling in LC. We provide a comprehensive review of the key components of the MAPK pathway and their relevance in LC, focusing on aberrant signaling processes associated with disease progression. By examining recent research and experimental findings, this article examines the molecular mechanisms through which lncRNAs influence MAPK signaling in lung cancer, ultimately contributing to tumor development.

Emerging role of exosome-derived non-coding RNAs in tumor-associated angiogenesis of tumor microenvironment

The tumor microenvironment (TME) is an intricate ecosystem that is actively involved in various stages of cancer occurrence and development. Some characteristics of tumor biological behavior, such as proliferation, migration, invasion, inhibition of apoptosis, immune escape, angiogenesis, and metabolic reprogramming, are affected by TME. Studies have shown that non-coding RNAs, especially long-chain non-coding RNAs and microRNAs in cancer-derived exosomes, facilitate intercellular communication as a mechanism for regulating angiogenesis. They stimulate tumor growth, as well as angiogenesis, metastasis, and reprogramming of the TME. Exploring the relationship between exogenous non-coding RNAs and tumor-associated endothelial cells, as well as their role in angiogenesis, clinicians will gain new insights into treatment as a result.

Diagnostic utility of pleural cell-free nucleic acids in undiagnosed pleural effusions

Pleural effusion (PE) is a common sign caused by various disorders. Microbiology, histology and cytology are reference standards for these disorders. However, these diagnostic tools have limitations, including invasiveness, high cost, long turnaround time, and observer-dependent. Soluble biomarkers in pleural fluid (PF) are promising diagnostic tools because they are mininvasive, economical, and objective. Recent studies have revealed that some cell-free nucleic acids (e.g., DNA, mRNA, microRNA, and lncRNA) in PF are potential diagnostic markers for many disorders. Here, we review the performance of PF cell-free nucleic acids for differentiating and stratification of PE.

LncRNA LUADT1 inhibits cell apoptosis in diabetic retinopathy by regulating miR-383/peroxiredoxin 3 axis

This study aimed to investigate the involvement of long non-coding RNA (lncRNA) lung adenocarcinoma transcript 1 (LUADT1) LUADT1 in diabetic retinopathy (DR). We found LUADT1 may interact with miR-383 by RNA interaction prediction. QPCR analysis showed that lncRNA LUADT1 was downregulated, and miR-383 was upregulated in DR. However, correlation analysis revealed no significant correlation between them. In retinal pigment epithelial cells (RPEpiC, h1RPE7 from Sigma-Aldrich), overexpression of LUADT1 and miR-383 failed to affect the expression of each other. However, LUADT1 overexpression led to increased and miR-383 overexpression led to decreased expression level of peroxiredoxin 3 (PRX3). Cell apoptosis analysis showed that LUADT1 and PRX3 overexpression resulted in the decreased cell apoptosis. MiR-383 played an opposite role and reduced the effects of LUADT1 and PRX3 overexpression. Therefore, LUADT1 regulates PRX3 by serving as the endogenous sponge of miR-383 in DR to regulate cell apoptosis.

An Unanticipated Modulation of Cyclin-Dependent Kinase Inhibitors: The Role of Long Non-Coding RNAs

It is now definitively established that a large part of the human genome is transcribed. However, only a scarce percentage of the transcriptome (about 1.2%) consists of RNAs that are translated into proteins, while the large majority of transcripts include a variety of RNA families with different dimensions and functions. Within this heterogeneous RNA world, a significant fraction consists of sequences with a length of more than 200 bases that form the so-called long non-coding RNA family. The functions of long non-coding RNAs range from the regulation of gene transcription to the changes in DNA topology and nucleosome modification and structural organization, to paraspeckle formation and cellular organelles maturation. This review is focused on the role of long non-coding RNAs as regulators of cyclin-dependent kinase inhibitors’ (CDKIs) levels and activities. Cyclin-dependent kinases are enzymes necessary for the tuned progression of the cell division cycle. The control of their activity takes place at various levels. Among these, interaction with CDKIs is a vital mechanism. Through CDKI modulation, long non-coding RNAs implement control over cellular physiology and are associated with numerous pathologies. However, although there are robust data in the literature, the role of long non-coding RNAs in the modulation of CDKIs appears to still be underestimated, as well as their importance in cell proliferation control.

Evaluating the expression of tumorigenic long noncoding RNAs in circulating exosomes isolated from non-small-cell lung cancer patients

Aim: To evaluate the correlation of long noncoding RNAs (lncRNAs) expression in circulating exosomes and the cancerous and noncancerous tissues in patients with non-small-cell lung carcinoma. Methods: The relative expression of the four lncRNAs including LUADT1, MALAT1, NEAT1 and MIAT between tumor tissue, adjacent noncancerous tissues and circulating exosomes were evaluated by quantitative reverse transcription PCR. Results & conclusion: The relative expression of the lncRNAs, including LUADT1, MALAT1 and NEAT1, was upregulated and MIAT was downregulated in tumor tissue compared with noncancerous tissue samples. The expression of lncRNAs in circulating exosomes was not significantly different from cancerous tissue. Our results indicate that the studied exosomal lncRNAs have a good potential to be further evaluated as prognostic/diagnostic biomarkers in patients with non-small-cell lung cancer.

Down-regulation of lncRNA LUADT1 suppresses cervical cancer cell growth by sequestering microRNA-1207-5p

Emerging evidence has proved the essential roles of long non-coding RNAs (lncRNAs) in cervical carcinoma (CC). LncRNA lung adenocarcinoma-associated transcript 1 (LUADT1) is overexpressed and plays an oncogenic role in various cancers; however, the function and clinical values of LUADT1 in CC remain unclear. In this study we found that LUADT1 is highly expressed in CC tissues and cells. Up-regulated LUADT1 is significantly correlated with the more aggressive status and poorer survival of CC patients. studies show that LUADT1 depletion suppresses CC proliferation, and leads to cell apoptosis and cell cycle arrest. Furthermore, the xenograft mouse assay demonstrates that LUADT1 knockdown remarkably suppresses tumor growth. Mechanistically, LUADT1 binds to miR-1207-5p and inhibits miR-1207-5p expression in CC cells. Septin 9 (SEPT9) is identified as a miR-1207-5p target which is negatively regulated by LUADT1. Overexpression of SEPT9 abrogates the suppressed proliferation of CC cells induced by LUADT1 knockdown. These results demonstrate that LUADT1 sponges miR-1207-5p and consequently modulates SEPT9 expression in CC. Our study suggests the possible application of LUADT1 as a prognostic and therapeutic target to inhibit CC.

Understanding the Critical Role of Glycolysis-Related lncRNAs in Lung Adenocarcinoma Based on Three Molecular Subtypes

Background

Glycolysis is closely associated with tumor progression, but the roles of lncRNAs in glycolysis have not been comprehensively investigated in lung adenocarcinoma (LUAD). This study is aimed at studying the possible mechanisms of glycolysis-related lncRNAs in tumor development and providing a guidance for targeted therapy.

Methods

Unsupervised consensus clustering was used to identify molecular subtypes. Gene enrichment analysis was applied to screen important pathways involved in tumor progression. A series of immune analysis was performed to assess immune infiltration. Critical transcription factors (TFs) interacting with lncRNAs were selected by Pearson correlation analysis. A first-order partial correlation analysis was implemented to identify critical lncRNAs with prognostic significance.

Results

Three molecular subtypes (C1, C2, and C3) were identified with distinct overall survival. Three subtypes showed differential immune infiltration, and C3 subtype was the optimal for immunotherapy treatment. Ten lncRNA-TF pairs among four glycolysis-related lncRNAs (FTX, LINC00472, PSMA3-AS1, and SNHG14) and six TFs (FOXP1, SP1, MYC, FOXM1, HIF1A, and FOS) were involved in tumor progression. We identified four critical glycolysis-related lncRNAs significantly associated with prognosis.

Conclusions

This study identified three molecular subtypes that could guide personalized therapy. The four-lncRNA prognostic model can serve as an indicator for predicting prognosis or early screening of lung adenocarcinoma patients. The current results improve the understanding of the relation between lncRNAs and glycolysis.

Loss of RPS27a expression regulates the cell cycle, apoptosis, and proliferation via the RPL11-MDM2-p53 pathway in lung adenocarcinoma cells

Background

Depletion of certain ribosomal proteins induces p53 activation, which is mediated mainly by ribosomal protein L5 (RPL5) and/or ribosomal protein L11 (RPL11). Therefore, RPL5 and RPL11 may link RPs and p53 activation. Thus, this study aimed to explore whether RPs interact with RPL11 and regulate p53 activation in lung adenocarcinoma (LUAD) cells.

Methods

The endogenous RPL11-binding proteins in A549 cells were pulled down through immunoprecipitation and identified with a proteomics approach. Docking analysis and GST-fusion protein assays were used to analyze the interaction of ribosomal protein S27a (RPS27a) and RPL11. Co-immunoprecipitation and in vitro ubiquitination assays were used to detect the effects of knockdown of RPS27a on the interaction between RPS27a and RPL11, and on p53 accumulation. Cell cycle, apoptosis, cell invasion and migration, cell viability and colony-formation assays were performed in the presence of knockdown of RPS27a. The RPS27a mRNA expression in LUAD was analyzed on the basis of the TCGA dataset, and RPS27a expression was detected through immunohistochemistry in LUAD samples. Finally, RPS27a and p53 expression was analyzed through immunohistochemistry in A549 cell xenografts with knockdown of RPS27a.

Results

RPS27a was identified as a novel RPL11 binding protein. GST pull-down assays revealed that RPS27a directly bound RPL11. Knockdown of RPS27a weakened the interaction between RPS27a and RPL11, but enhanced the binding of RPL11 and murine double minute 2 (MDM2), thereby inhibiting the ubiquitination and degradation of p53 by MDM2. Knockdown of RPS27a stabilized p53 in an RPL11-dependent manner and induced cell viability inhibition, cell cycle arrest and apoptosis in a p53-dependent manner in A549 cells. The expression of RPS27a was upregulated in LUAD and correlated with LUAD progression and poorer prognosis. Overexpression of RPS27a correlated with upregulation of p53, MDM2 and RPL11 in LUAD clinical specimens. Knockdown of RPS27a increased p53 activation, thus, suppressing the formation of A549 cell xenografts in nude mice.

Conclusions

RPS27a interacts with RPL11, and RPS27a knockdown enhanced the binding of RPL11 and MDM2, thereby inhibiting MDM2-mediated p53 ubiquitination and degradation; in addition, RPS27a as important roles in LUAD progression and prognosis, and may be a therapeutic target for patients with LUAD.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-02230-z.

Long non-coding RNA LUADT1 promotes nasopharyngeal carcinoma cell proliferation and invasion by downregulating miR-1207-5p

Nasopharyngeal carcinoma (NPC) is a typical type of malignant tumor. This research paper aims to study the function and mechanism of long non-coding RNA lung adenocarcinoma-related transcript 1 (lncRNA-LUADT1) in the progression of NPC. In this study, the expressions of lncRNA-LUADT1, miR-1207-5p, and TEAD1 in NPC tissues and cell lines were detected by RT-qPCR. Initially, the expression of lncRNA-LUADT1 and TEAD1 were significantly up-regulated in NPC tissues and cells, while miR-1207-5p was significantly down-regulated. Next, miR-1207-5p was confirmed to bind to lncRNA-LUADT1 or TEAD1 by bioinformatics and luciferase reporter assay. In addition, after interfering with lncRNA-LUADT1 expression, experiments of CCK8, EDU staining, and Transwell invasion were used to detect proliferation, invasion, and migration of NPC cells. The results showed that interfering with lncRNA-LUADT1 expression could inhibit the proliferation, invasion, and migration of NPC cells. Western blot showed that lncRNA-LUADT1 knockdown significantly decreased the expression of Hippo/YAP pathway protein (YAP1 and TAZ). However, interfering with the expression of miR-1207-5p reversed these results. In addition, the nude mouse tumor formation experiment suggested that low-expressed lncRNA-LUADT1 reduced the volume and weight of tumor tissues. In summary, lncRNA-LUADT1 down-regulation could inhibit NPC cell proliferation and invasion, which may be achieved through regulating miR-1207-5p expression and affecting TEAD1 expression, thus inhibiting the activation of Hippo/YAP signaling pathway.

The Emerging Roles of Long Noncoding RNAs as Hallmarks of Lung Cancer

Noncoding ribonucleic acids (ncRNAs) are closely associated with tumor initiation, growth, and progress in lung cancer. Long ncRNAs (lncRNAs), as one of the three subclasses of ncRNAs, play important roles in chromatin modification, transcription, and post-transcriptional processing. Various lncRNAs have recently been reported to be dysfunctional or dysregulated in cancers and have pro- or anti-tumor potential. Importantly, as a new class of cancer biomarkers, studies have demonstrated the plausibility of using certain subsets of lncRNAs as promising diagnostic, therapeutic, or prognostic strategies to manage cancers. This review focuses on lncRNAs associated with hallmarks of lung cancer, especially those discovered in the last five years. The expression levels of these lncRNAs in tumor samples are discussed, alongside their mechanisms of action, drug resistance, and potential as diagnostic and prognostic markers for lung cancer.

Long non-coding RNA GLIDR accelerates the tumorigenesis of lung adenocarcinoma by miR-1270/TCF12 axis

Lung adenocarcinoma (LUAD) is a deadly cancer with a high incidence worldwide. Long noncoding RNAs (lncRNAs) have been confirmed to have the regulatory effects on the occurrence and development of LUAD. But the specific functions of lncRNA GLIDR in LUAD are still not explicit and need to be investigated. On the basis of the outcomes of RT-qPCR experiments, the relative expression of GLIDR was evidently up-regulated in LUAD cells, while that of miR-1270 was down-regulated. The down-regulation of GLIDR inhibits cell proliferation in accordance with the results of CCK-8, EdU and colony formation assays, and accelerates cell apoptosis according to the results of flow cytometry and JC-1 analyses. Luciferase reporter, RNA pull down and RIP assays indicated that GLIDR could sponge miR-1270 in LUAD. Additionally, TCF12 was proved as the target gene of miR-1270. Furthermore, rescue experiments indicated that overexpression of TCF12 could offset the inhibitory functions of silencing GLIDR on cell behaviors. In brief, this study has demonstrated that GLIDR/miR-1270/TCF12 axis plays the crucial role in LUAD, which offers a new insight into researches on molecular mechanism concerning LUAD and provides with a new perspective for LUAD treatment.

Research progress of lncRNAs in diabetic retinopathy

Diabetic retinopathy (DR), which is known as a severe complication of type 2 diabetes mellitus, can cause varying degrees of damage to visual acuity. The pathogenesis of DR is multifactorial and not fully understood. Many previous research studies have revealed that an aberrant level of some long non-coding RNAs (lncRNAs) may accelerate the development of DR. These lncRNAs are regulatory factors and research related to them is always underway. In this review, we will update several types of lncRNAs based on the previous studies which are related to the development of DR and discuss its potential mechanisms of action and connections. Generally, the review will help us know more about lncRNAs and provide directions for future research related to DR.

Long Non-coding RNAs in Traumatic Brain Injury Accelerated Fracture Healing

It is commonly observed that patients with bone fracture concomitant with traumatic brain injury (TBI) had significantly increased fracture healing, but the underlying mechanisms were not fully revealed. Long non-coding RNAs (lncRNAs) are known to play complicated roles in bone homeostasis, but their role in TBI accelerated fracture was rarely reported. The present study was designed to determine the role of lncRNAs in TBI accelerated fracture via transcriptome sequencing and further bioinformatics analyses. Blood samples from three fracture-only patients, three fracture concomitant with TBI patients, and three healthy controls were harvested and were subsequently subjected to transcriptome lncRNA sequencing. Differentially expressed genes were identified, and pathway enrichment was performed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. High-dimensional data visualization by self-organizing map (SOM) machine learning was applied to further interpret the data. An xCell method was then used to predict cellular behavior in all samples based on gene expression profiles, and an lncRNA-cell interaction network was generated. A total of 874 differentially expressed genes were identified, of which about 26% were lncRNAs. Those identified lncRNAs were mainly enriched on TBI-related and damage repair-related pathways. SOM analyses revealed that those differentially expressed lncRNAs could be divided into three major module implications and were mainly enriched on transcriptional regulation and immune-related signal pathways, which promote us to further explore cellular behaviors based on differentially expressed lncRNAs. We have predicted that basophils, CD8+ T effector memory cells, B cells, and naïve B cells were significantly downregulated, while microvascular endothelial cells were predicted to be significantly upregulated in the Fr/TBI group, was the lowest and highest, respectively. ENSG00000278905, ENSG00000240980, ENSG00000255670, and ENSG00000196634 were the most differentially expressed lncRNAs related to all changes of cellular behavior. The present study has revealed for the first time that several critical lncRNAs may participate in TBI accelerated fracture potentially via regulating cellular behaviors of basophils, cytotoxic T cells, B cells, and endothelial cells.

Study of long non-coding RNA highly upregulated in liver cancer (HULC) in breast cancer: A clinical & in vitro investigation

Background & objectives:

Breast cancer remains the most common malignancy among women worldwide. Long non-coding RNAs (lncRNAs) have been shown to play critical roles in tumour initiation and progression. This study was aimed to evaluate the potential role of lncRNA highly upregulated in liver cancer (HULC) in breast cancer.

Methods:

The expression of HULC was evaluated in breast cancer patients and cell lines using real-time quantitative reverse transcription polymerase chain reaction. Small interfering RNA-based knockdown was also employed to study the potential role of HULC in breast cancer cell lines including ZR-75-1, MCF7 and MDA-MB-231.

Results:

HULC was significantly upregulated in tumour tissues compared to non-tumoural margins (P<0.001). The receiver operating characteristic (ROC) curve analysis demonstrated the biomarker potential of HULC (ROC^AUC=0.78, P<0.001). The HULC knockdown induced apoptosis and suppressed cellular migration in breast cancer cell lines.

Interpretation & conclusions:

Our results indicated that HULC was upregulated in breast cancer and might play a role in tumourigenesis. The HULC may have a potential to be exploited as a new biomarker and therapeutic target in breast cancer.

Classifying gastric cancer using FLORA reveals clinically relevant molecular subtypes and highlights LINC01614 as a biomarker for patient prognosis

Molecular-based classifications of gastric cancer (GC) were recently proposed, but few of them robustly predict clinical outcomes. While mutation and expression signature of protein-coding genes were used in previous molecular subtyping methods, the noncoding genome in GC remains largely unexplored. Here, we developed the fast long-noncoding RNA analysis (FLORA) method to study RNA sequencing data of GC cases, and prioritized tumor-specific long-noncoding RNAs (lncRNAs) by integrating clinical and multi-omic data. We uncovered 1235 tumor-specific lncRNAs, based on which three subtypes were identified. The lncRNA-based subtype 3 (L3) represented a subgroup of intestinal GC with worse survival, characterized by prevalent TP53 mutations, chromatin instability, hypomethylation, and over-expression of oncogenic lncRNAs. In contrast, the lncRNA-based subtype 1 (L1) has the best survival outcome, while LINC01614 expression further segregated a subgroup of L1 cases with worse survival and increased chance of developing distal metastasis. We demonstrated that LINC01614 over-expression is an independent prognostic factor in L1 and network-based functional prediction implicated its relevance to cell migration. Over-expression and CRISPR-Cas9-guided knockout experiments further validated the functions of LINC01614 in promoting GC cell growth and migration. Altogether, we proposed a lncRNA-based molecular subtype of GC that robustly predicts patient survival and validated LINC01614 as an oncogenic lncRNA that promotes GC proliferation and migration.

Non-Coding RNAs in Cancer Diagnosis and Therapy: Focus on Lung Cancer

Over the last several decades, clinical evaluation and treatment of lung cancers have largely improved with the classification of genetic drivers of the disease, such as EGFR, ALK, and ROS1. There are numerous regulatory factors that exert cellular control over key oncogenic pathways involved in lung cancers. In particular, non-coding RNAs (ncRNAs) have a diversity of regulatory roles in lung cancers such that they have been shown to be involved in inducing proliferation, suppressing apoptotic pathways, increasing metastatic potential of cancer cells, and acquiring drug resistance. The dysregulation of various ncRNAs in human cancers has prompted preclinical studies examining the therapeutic potential of restoring and/or inhibiting these ncRNAs. Furthermore, ncRNAs demonstrate tissue-specific expression in addition to high stability within biological fluids. This makes them excellent candidates as cancer biomarkers. This review aims to discuss the relevance of ncRNAs in cancer pathology, diagnosis, and therapy, with a focus on lung cancer.

Long Noncoding RNA FGD5-AS1 Knockdown Decrease Viability, Migration, and Invasion of Non-Small Cell Lung Cancer (NSCLC) Cells by Regulating the MicroRNA-944/MACC1 Axis

Objective:

Long noncoding RNA FGD5 antisense RNA 1 (FGD5-AS1) participates in the regulation of non-small cell lung cancer (NSCLC) progression, but the underlying mechanisms are not fully revealed. This study aimed to determine the regulatory mechanism of FGD5-AS1 on the viability, migration, and invasion of NSCLC cells.

Methods:

QRT-PCR was performed to measure the expression of FGD5-AS1, microRNA-944 (miR-944), and MACC1 in NSCLC. The correlation between FGD5-AS1 and clinicopathological features of NSCLC patients was analyzed. The viability of NSCLC cells were detected using MTT assay, and the migration and invasion were measured by transwell assay. Additionally, dual-luciferase reporter assay was used to demonstrate the interactions among FGD5-AS1, miR-944, and MACC1. Furthermore, exosomes were isolated from NSCLC cells and identified by transmission electron microscopy (TEM) and western blot. Then, the macrophages treated with exosomes were co-cultured with NSCLC cells to assess the effect of exosomes containing lower FGD5-AS1 level on NSCLC.

Results:

The expression of FGD5-AS1 and MACC1 was increased in NSCLC, but miR-944 expression was decreased. FGD5-AS1 expression had significantly correlation with TNM stage and metastasis in NSCLC patients. FGD5-AS1 knockdown decreased the viability, migration, and invasion of NSCLC cells. Additionally, FGD5-AS1 and MACC1 were both targeted by miR-944 with the complementary binding sites at 3’ UTR. In the feedback experiments, miR-944 inhibition or MACC1 overexpression reversed the reduction effect of FGD5-AS1 knockdown on the tumorigenesis of NSCLC. Moreover, silencing of FGD5-AS1 suppressed macrophages M2 polarization, and eliminated the promoting effects of exosomes mediated macrophages on NSCLC cell migration and invasion.

Conclusions:

FGD5-AS1 knockdown attenuated viability, migration, and invasion of NSCLC cells by regulating the miR-944/MACC1 axis, providing a new therapeutic target for NSCLC.

Long non-coding RNAs as potential biomarkers in the prognosis and diagnosis of lung cancer: A review and target analysis

Long non-coding RNAs (lncRNA) have been emerged as a novel class of molecular regulators in cancer. They are dysregulated in many types of cancer; however, there is not enough knowledge available on their expression and functional profiles. Lung cancer is the leading cause of the cancer deaths worldwide. Generally, lncRNAs may be associated with lung tumor pathogenesis and they may act as biomarkers for the cancer prognosis and diagnosis. Compared to other invasive prognostic and diagnostic methods, detection of lncRNAs might be a user-friendly and noninvasive method. In this review article, we selected 27 tumor-associated lncRNAs by literature reviewing to further discussing in detail for using as diagnostic and prognostic biomarkers in lung cancer. Also, in an in silico target analysis, the "Experimentally supported functional regulation" approach of the LncTarD web tool was used to identifying the target genes and regulatory mechanisms of the selected lncRNAs. The reports on diagnostic and prognostic potential of all selected lncRNAs were discussed. However, the target genes and regulatory mechanisms of the 22 lncRNAs were identified by in silico analysis and we found the pathways that are controlled by each target group of lncRNAs. They use epigenetic mechanisms, ceRNA mechanisms, protein interaction and sponge mechanism. Also, 10, 23, 5, and 28 target genes for each of these mechanisms were identified, respectively. Finally, each group of target genes controls 50, 12, 7, and 2 molecular pathways, respectively. In conclusion, LncRNAs could be used as biomarkers in lung cancer due to their roles in control of several signaling pathways related to lung tumors. Also, it seems that lncRNAs, which use epigenetic mechanisms for modulating a large number of pathways, could be considered as important subjects for lung cancer-related diagnostic and prognostic biomarkers.

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.

Upregulated Collagen COL10A1 Remodels the Extracellular Matrix and Promotes Malignant Progression in Lung Adenocarcinoma

Collagens are major components of the ECM in various organs, including the lungs. Ectopic expression of collagens can regulate the tumor progression and disease outcome through remodeling of the extracellular matrix (ECM). However, it remains largely unexplored whether collagens are involved in the tumor progression of lung adenocarcinoma (LUAD). Analysis of three LUAD transcriptional expression profiles showed that COL10A1 mRNA expression was up-regulated and associated with poor prognosis. Gain- and loss-of-function studies were performed to observe that up-regulated COL10A1 promotes LUAD cell proliferation and invasion in vitro and in vivo. In molecular mechanism study, we found that COL10A1 interacts with DDR2 and affects the downstream FAK signaling pathway to regulate LUAD cell progression. The expression of COL10A1 on tissue microarray (TMA) was also measured to explore the association between COL10A1 expression and patient outcome. The results addressed that COL10A1 is up-regulated and positively correlated with lymph node metastasis in lung adenocarcinoma, and the COL10A1 expression is also an independent prognostic factor. In summary, the up-regulated COL10A1 remodels the ECM and the COL10A1/DDR2/FAK axis regulates the proliferation and metastasis of LUAD cells, implying that COL10A1 is a promising therapeutic target and prognostic marker for LUAD patients.

LncRNA LUADT1 sponges miR-195 to prevent cardiac endothelial cell apoptosis in sepsis

Background

The oncogenic role of the newly identified lncRNA LUADT1 has been revealed in lung adenocarcinoma. It was reported that LUADT1 plays a critical role in multiple human diseases. This study was carried out to investigate the role of LUADT1 in sepsis.

Methods

Sixty patients with sepsis and sixty healthy volunteers were recruited for this study. Plasma samples were collected from all participants. Human primary coronary artery endothelial cells were also used in this study. The expression of Pim-1, miR-195 and LUADT1 were detected by RT-qPCR. The interaction between miR-195 and LUADT1 was determined by overexpression experiments and luciferase activity assay. Cell apoptosis was detected by flow cytometry. The expression of apoptosis-related protein was detected by Western blotting.

Results

Bioinformatics analysis revealed the potential interaction between LUADT1 and miR-195, which was confirmed by dual luciferase reporter assay. LUADT1 was downregulated in patients with sepsis. Moreover, LPS treatment downregulated the expression of LUADT1 in primary cardiac endothelial cells. Overexpression of LUADT1 and miR-195 did not affect the expression of each other in primary cardiac endothelial cells. Interestingly, overexpression of LUADT1 was found to upregulate the expression of Pim-1, a target of miR-195. In addition, it was found that overexpression of LUADT1 and Pim-1 reduced the enhancement effects of miR-195 on LPS-induced cardiac endothelial cell apoptosis.

Conclusion

In summary, LUADT1 may protect cardiac endothelial cells against apoptosis in sepsis by regulating the miR-195/Pim-1 axis.

Identification of key genes in lung adenocarcinoma based on a competing endogenous RNA network

Lung adenocarcinoma (LUAD) is the most commonly diagnosed type of lung cancer and exhibits a high morbidity. The present study aimed to investigate the long non-coding RNA (lncRNA)-associated competing endogenous RNA (ceRNA) mechanisms in LUAD. The receptor activity modifying protein 2-antisense RNA 1 (RAMP2-AS1) was identified using GSE113852 and GSE130779 datasets downloaded from the Gene Expression Omnibus database, and the downregulation of RAMP2-AS1 was the most significant in LUAD. In addition, microRNA (miR)-296-5p was identified to bind to RAMP2-AS1 via bioinformatics analysis. Subsequently, CD44, cyclin D3 (CCND3), neurocalcin δ (NCALD), microtubule actin crosslinking factor 1 (MACF1) and potassium channel tetramerization domain containing 15 were obtained by intersecting the predicted target genes of miR-296-5p and 368 differentially expressed mRNAs in LUAD. According to the Gene Expression Profiling Interactive Analysis and UALCAN databases, these five mRNAs were downregulated in LUAD, and their expression levels were positively correlated with those of RAMP2-AS1. CD44, CCND3, NCALD and MACF1 were selected as key mRNAs in LUAD based on prognostic analyses. Furthermore, functional enrichment analyses were performed and an interaction network was constructed to reveal the functions of the RAMP2-AS1-associated ceRNA in LUAD. The results indicated that the functions were mainly enriched in generic transcription pathways, cyclin D-associated events in G₁ and epithelial stromal transformation. Reverse transcription-quantitative PCR assays revealed that RAMP2-AS1, CD44, CCND3, NCALD and MACF1 expression was lower in tumor tissues than in normal tissues, while miR-296-5p expression was higher in tumor tissues compared with in normal tissues. The association between RAMP2-AS1 and MACF1 was further confirmed using in vitro experiments. Overall, the present results indicated that RAMP2-AS1, miR-296-5p, CD44, CCND3, NCALD and MACF1 may be involved in LUAD progression and may therefore serve as potential biomarkers and provide a theoretical basis for the study of the pathogenesis of LUAD.

ZEB1-activated LINC01123 accelerates the malignancy in lung adenocarcinoma through NOTCH signaling pathway

Growing incidence of lung adenocarcinoma (LUAD) has been detected recently. Multiple long non-coding RNAs (lncRNAs) have been proven as tumor facilitators or inhibitors by extensive works. Present study concentrated on characterizing the potential role of LINC01123 in LUAD. We explored the differential expression of LINC01123 through qRT-PCR and found the amplification of LINC01123 in LUAD cell lines. It was ascertained that LINC01123 was definitely responsible for the malignant processes of LUAD cells. Further, we validated the ceRNA network of LINC01123/miR-449b-5p/NOTCH1 in LUAD via mechanical experiments. As a transcriptional factor related to epithelial mesenchymal transition (EMT), ZEB1 was responsible for the transcriptional activation of both LINC01123 and NOTCH1. The involvement of NOTCH signaling in LUAD was interrogated through evaluating functional changes after treating with FLI-06 (NOTCH pathway suppressor). It showed that FLI-06-caused NOTCH signaling inactivation suppressed malignant functions in LUAD cells. Additionally, LINC01123 facilitated NOTCH1-dependent NOTCH signaling activation. Rescue experiments probed the modulatory function of LINC01123/miR-449b-5p/NOTCH1 in LUAD cellular processes. Altogether, ZEB1-activated LINC01123 accelerates the malignancy in LUAD through miR-449b-5p/NOTCH1 axis-mediated NOTCH signaling pathway, while NOTCH1 boosts ZEB1 in return. These observations suggest the huge potential of LINC01123 as a new target for LUAD therapy.

linc00968 inhibits the tumorigenesis and metastasis of lung adenocarcinoma via serving as a ceRNA against miR-9-5p and increasing CPEB3

Increasing evidence confirms that long noncoding RNAs (lncRNAs) exert vital functions in multiple biological process among malignant cancers. In the current study, we uncovered that linc00968 was downregulated in lung adenocarcinoma (LUAD). Furthermore, the low level of linc00968 was correlated with worse prognosis in patients with LUAD. Upregulation of linc00968 restrained the growth and metastatic phenotypes of LUAD cell in vitro and in vivo. Using bioinformation methods and luciferase reporter assay, we identified that linc00968 acted as a competing endogenous RNA (ceRNA) via sponging miR-9-5p to modulate the level of Cytoplasmic Polyadenylation Element Binding Protein 3 (CPEB3) in LUAD. In addition, LUAD cell migration, colony formation and epithelial-mesenchymal transition (EMT) process were suppressed by linc00968 while these aggressive traits were reversed by miR-142-5p or CPEB3 silencing. Altogether, our work disclosed that linc00968 played a critical role in LUAD and linc00968/miR-9-5p/CPEB3 regulatory axis might be a potential treatment target in LUAD.

LncRNA MEG3 inhibits the progression of prostate cancer by facilitating H3K27 trimethylation of EN2 through binding to EZH2

This study aims to study the effects of intra-nuclear lncRNA MEG3 on the progression of prostate cancer and the underlying mechanisms. Expressions of relative molecules were detected by Quantitative real time PCR (qRT-PCR) and western blot. Chromatin immunoprecipitation and RNA immunoprecipitation (RIP) assays were used to evaluate the interaction between intra-nuclear MEG3, histone methyltransferase EZH2 and Engrailed-2 (EN2). The impacts of MEG3 on the viability, proliferation and invasion of prostate cancer cells (PC3) were evaluated by methyl thiazolyl tetrazolium, colony formation and transwell assays, respectively. PC3 cells were transfected with MEG3 and transplanted into nude mice to analyse the effect of MEG3 on tumourigenesis of PC3 cells in vivo. EN2 expression was inversely proportional to MEG3 in the prostate cancer tissues and PC3 cells. RIP results showed that intra-nuclear MEG3 could bind to EZH2. Knockdown of MEG3 and/or EZH2 up-regulated EN2 expression and reduced the recruitment of EZH2 and H3K27me3 to EN2, while over-expressed MEG3 caused opposite effects. MEG3 over-expression suppressed cell viability, colony formation, cell invasion and migration of PC3 cells in vitro and inhibited tumourigenesis of PC3 cells in vivo, while EN2 over-expression diminished the effects. These findings indicated that MEG3 facilitated H3K27 trimethylation of EN2 via binding to EZH2, thus suppressed the development of prostate cancer.

LINC00667/miR-449b-5p/YY1 axis promotes cell proliferation and migration in colorectal cancer

Background

Long non-coding RNAs (lncRNAs) have been defined as vital regulators in the progression of human cancers, including colorectal cancer (CRC). Long intergenic non-protein coding RNA 667 (LINC00667) is a tumor promoter in several cancer types, while its role in CRC remains to be unmasked. This study focused on exploring the potential function and regulatory mechanism of LINC00667 in CRC.

Methods

qRT-PCR analysis was applied to detect the expression of LINC00667 in CRC cells. Loss-of function assays revealed the role of LINC00667 silencing in regulating CRC cell proliferation, apoptosis and migration. In vivo study demonstrated the effect of LINC00667 silencing on CRC cell growth. Mechanism experiments were conducted to determine the upstream or the downstream molecular mechanism of LINC00667 in CRC cells.

Results

LINC00667 was expressed at high level in CRC cells. LINC00667 knockdown significantly inhibited CRC cell growth and migration. YY1 transcription factor induced the upregulation of LINC00667 in CRC cells by transcriptionally activating LINC00667. In addition, miR-449b-5p could interact with LINC00667 in CRC cells. Intriguingly, miR-449b-5p directly targeted to YY1, thus inhibiting YY1 expression. YY1 recovered the CRC cell functions impaired by LINC00667 silencing.

Conclusions

LINC00667 is transcriptionally activated by YY1 and promotes cell proliferation and migration in CRC by sponging miR-449b-5p to upregulate YY1.

LncRNA LUADT1 Promotes Oral Squamous Cell Carcinoma Cell Proliferation by Regulating miR-34a/GAS1 Axis

Introduction

The oncogenic role of lncRNA LUADT1 has been investigated only in lung cancer. This study aimed to investigate the role of LUADT1 in oral squamous cell carcinoma (OSCC).

Patients and Methods

The expression levels of LUADT1 in paired OSCC and non-tumor tissues from OSCC patients were determined by RT-qPCR. A 5-year follow-up study was performed to analyze the prognostic value of LUADT1 for OSCC. Dual-luciferase assay and overexpression experiments were performed to assess the interactions among LUADT1, miR-34a and GASL1. Cell proliferation was analyzed by cell proliferation assay.

Results

In this study, we found that LUADT1 was upregulated in OSCC and predicted poor survival. LUADT1 was predicted to interact with miR-34a, which was confirmed by dual-luciferase activity assay. However, overexpression experiments showed that they did not affect the expression of each other. Interestingly, overexpression of LUADT1 resulted in upregulation of GAS1, a target of miR-34a. Cell proliferation assay revealed that overexpression of LUADT1 and GAS1 resulted in promoted cell proliferation. MiR-34a played an opposite role and reversed the effects of LUADT1 overexpression.

Conclusion

LUADT1 may promote OSCC proliferation by regulating miR-34a/GAS1 axis.

Sputum long non-coding RNA biomarkers for diagnosis of lung cancer

BACKGROUND

Analysis of molecular changes in sputum may help diagnose lung cancer. Long non-coding RNAs (lncRNAs) play vital roles in various biological processes, and their dysregulations contribute to the development and progression of lung tumorigenesis. Herein, we determine whether aberrant lncRNAs could be used as potential sputum biomarkers for lung cancer.

METHODS

Using reverse transcription PCR, we measure expressions of lung cancer-associated lncRNAs in sputum of a discovery cohort of 67 lung cancer patients and 65 cancer-free smokers with benign diseases and a validation cohort of 59 lung cancer patients and 60 cancer-free smokers with benign diseases.

RESULTS

In the discovery cohort, four of the lncRNAs displayed a significantly different level in sputum of lung cancer patients vs.cancer-free smokers with benign diseases (all P< 0.001). From the four lncRNAs, three lncRNAs (SNHG1, H19, and HOTAIR) are identified as a biomarker panel, producing 82.09% sensitivity and 89.23% specificity for diagnosis of lung cancer. Furthermore, the biomarker panel has a higher sensitivity (82.09% vs. 52.24%, P= 0.02) and a similar specificity compared with sputum cytology (89.23% vs. 90.77%, P= 0.45). In addition, the lncRNA biomarker panel had a higher sensitivity (87.50% vs. 70.07%, p= 0.03) for diagnosis of squamous cell carcinoma compared with adenocarcinoma of the lung, while maintaining the same specificity (89.23%). The potential of the sputum lncRNA biomarkers for lung cancer detection is confirmed in the validation cohort.

CONCLUSION

We have for the first time shown that the analysis of lncRNAs in sputum might be a noninvasive approach for diagnosis of lung cancer.

Long Noncoding RNA LUADT1 Is Upregulated in Melanoma and May Sponge miR-28-5p to Upregulate RAP1B

Background: Long noncoding RNA (lncRNA) LUADT1 is a known oncogenic lncRNA in lung cancer. This study aimed to explore the roles of LUADT1 in melanoma. Materials and Methods: Sixty pairs of melanoma and nontumor tissues were obtained from 60 melanoma patients (37 men and 23 women, 38-68 years, 52.1 ± 4.9 years) at the First Affiliated Hospital of Zhejiang University School of Medicine. Gene expression was analyzed by quantitative polymerase chain reaction and western blot. Cell transfections were performed to analyze gene expression. Results: We found that LUADT1 was upregulated in melanoma and high levels of LUADT1 predicted poor survival. RNA interaction prediction showed that LUADT1 can form base pairing with miR-28-5p. In melanoma cells, LUADT1 overexpression mediated the upregulated Ras-related protein Rap-1b (RAP1B). Cell proliferation assay showed that LUADT1 and RAP1B overexpression mediated the increased proliferation rate of melanoma cells. In addition, miR-28-5p overexpression played opposite roles attenuating the effects of LUADT1 overexpression on both RAP1B expression and cancer cell proliferation. Conclusions: LUADT1 in melanoma and may sponge miR-28-5p to upregulate RAP1B, thereby promoting cancer cell proliferation.

The long non-coding RNA PIK3CD-AS2 promotes lung adenocarcinoma progression via YBX1-mediated suppression of p53 pathway

The underlying mechanisms of long non-coding RNAs (lncRNA) participating in the progression of lung cancers are largely unknown. We found a novel lncRNA, PIK3CD antisense RNA 2 (PIK3CD-AS2), that contributes to lung adenocarcinoma (LUAD) progression. The expression characteristics of PIK3CD-AS2 in LUAD were analyzed using microarray expression profile, The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets, and validated in 92 paired LUAD tissues by chromogenic in situ hybridization. Our data confirmed that PIK3CD-AS2 expression is a crucial regulator of LUAD progression and associated with shorter patient survival. In vitro studies showed that PIK3CD-AS2 increased cell growth and slowed apoptosis in p53^wt cells but not in p53^null cells. Mechanically, it is demonstrated that PIK3CD-AS2 bound to and maintained the stability of Y-box binding protein 1 (YBX1), a potent destabilizer of p53, by impeding its ubiquitination and degradation. Downexpression of YBX1 reversed PIK3CD-AS2-mediated inhibition of p53 signaling. Additionally, the therapeutic effect evaluation of a locked nuclear acid (LNA) specifically targeting PIK3CD-AS2 showed an anti-tumor activity in mice with A549 cells xenograft and p53 wild-type LUAD patient-derived tumor xenograft (PDTX) model. Clinically, the high expression of PIK3CD-AS2 showed a poor disease-free survival in p53 wild-type patients in TCGA database. Our findings suggest that PIK3CD-AS2 regulates LUAD progression and elucidate a new PIK3CD-AS2/YBX1/p53 signaling axis, providing a potential lncRNA-directed therapeutic strategy especially in p53 wild-type LUAD patients.

Cell proliferation is induced in renal cell carcinoma through miR-92a-3p upregulation by targeting FBXW7

Renal cell carcinoma (RCC) is the most common type of kidney cancer whose incidence has gradually increased worldwide. MicroRNAs (miRNAs) represent a type of short endogenous non-coding RNA containing approximately 22 nucleotides, which are capable of regulating mRNAs at the post-transcriptional level in human cells. miRNAs have been demonstrated to mediate gene expression by influencing important regulatory genes. Accumulating evidence indicates that certain miRNAs are involved in RCC development. The present study investigated the underlying mechanism and functional role of miR-92a-3p in RCC cells using reverse transcription-quantitative polymerase chain reaction, western blotting, 3′ UTR luciferase assay, cell proliferation assay and soft agar assay. The results demonstrated that miR-92a-3p expression level is significantly upregulated in RCC tissues and cell lines; however, F-box and WD repeat domain containing 7 (FBXW7) expression level was significantly downregulated in RCC tissues and cell lines. Subsequently, whether FBXW7 could be considered as a direct target of miR-92a-3p in RCC cells was investigated. The results demonstrated that miR-92a-3p overexpression significantly promoted RCC cell proliferation and colony formation. Conversely, miR-92a-3p downregulation significantly inhibited RCC cell proliferation and colony formation. In addition, FBXW7 knockdown significantly enhanced RCC cell proliferation and colony formation. Conversely, FBXW7 overexpression significantly inhibited RCC cell proliferation and colony formation. Collectively, these results demonstrated that miR-92a-3p/FBXW7 pathway may represent a novel strategy and therapeutic target for RCC.

LncRNA ZFPM2-AS1 promotes lung adenocarcinoma progression by interacting with UPF1 to destabilize ZFPM2

Lung adenocarcinoma (LUAD), a histological subclass of non-small-cell lung cancer, is globally the leading cause of cancer-related deaths. Long noncoding RNAs (lncRNAs) are emerging as cancer regulators. Zinc finger protein multitype 2 antisense RNA 1 (ZFPM2-AS1) is an oncogene in gastric cancer, but its functions have not been investigated in LUAD. We showed that ZFPM2-AS1 expression is high in LUAD samples based on GEPIA database (http://gepia.cancer-pku.cn/) and validated ZFPM2-AS1 upregulation in LUAD cell lines. Functionally, ZFPM2-AS1 facilitated proliferation, invasion, and epithelial-to-mesenchymal transition of LUAD cells. Thereafter, we found that ZFPM2 was negatively regulated by ZFPM2-AS1, and identified the suppressive effect of ZFPM2 regulation by ZFPM2-AS1 on LUAD progression. Mechanistically, we showed that ZFPM2-AS1 interacted with up-frameshift 1 (UPF1) to regulate mRNA decay of ZFPM2. Rescue assays in vitro and in vivo confirmed that ZFPM2-AS1 regulated LUAD progression and tumor growth through ZFPM2. Taken together, our findings demonstrate a role for the ZFPM2-AS1-UPF1-ZFPM2 axis in LUAD progression, suggesting ZFPM2-AS1 as a new potential target for LUAD treatment.

LncRNA LUADT1 regulates miR-34a/SIRT1 to participate in chondrocyte apoptosis

It is known that miR-34a can promote the apoptosis of chondrocytes, which directly contribute to osteoarthritis (OA). Through bioinformatics analysis, we found that long noncoding RNA LUADT1 may interact with miR-34a. We, therefore, further investigate the interactions between them in osteoarthritis. We found that LUADT1 was downregulated, while miR-34a was upregulated in OA synovial fluid. Correlation analysis revealed no significant correlation between them. Overexpression experiment also revealed no significant effects of LUADT1 and miR-34a on the expression of each other. However, the dual-luciferase assay showed that LUADT1 and miR-34a can directly interact with each other. Moreover, LUADT1 overexpression led to the upregulation of SIRT1, which is a downstream target of miR-34a. Cell apoptosis showed that LUADT1 and SIRT1 overexpression led to decreased, while miR-34a led to increased apoptotic rates of chondrocytes. Therefore, LUADT1 regulates miR-34a/SIRT1 to participate in chondrocyte apoptosis.

Circular RNA circRHOBTB3 acts as a sponge for miR-654-3p inhibiting gastric cancer growth

Background

Circular RNAs (circRNAs) have recently emerged as a new family of noncoding RNAs that are involved in the causation and progression of various cancers. However, the roles of circRNAs in the tumorigenesis of gastric cancer (GC) are still largely unknown.

Methods

The expression profiles of circRNAs in GC were identified in open GEO database and were evaluated at the mRNA level in clinical GC samples compared with paired non-tumorous tissues. Kaplan-Meier survival curve was used to analyze the correlation of circRNA and patients’ prognosis. Subsequently, the circular structures of candidate circRNAs were validated by Sanger sequencing, divergent primer PCR, and RNase R treatments. Gain- and loss-of-function analyses were performed to evaluate the functional significance of it in GC initiation and progression. Dual-luciferase reporter and RNA pull-down assays were used to identify the microRNA (miRNA) sponge mechanism of circRNAs.

Results

The expression of circRHOBTB3 was lower in GC tissues and cell lines. Downregulation of circRHOBTB3 was significantly correlated with poor differentiation and unfavorable prognosis in patients with GC. Overexpression of circRHOBTB3 in GC cells led to decreased proliferation and induced G₁/S arrest in vitro, accompanied with inhibited xenograft tumor growth in vivo, while the opposite effects were achieved in circRHOBTB3-silenced cells. Furthermore, we demonstrated that circRHOBTB3 acts as a sponge for miR-654-3p and verified that p21 is a novel target of miR-654-3p.

Conclusion

Taken together, this study revealed that circRHOBTB3 might function as competing endogenous RNA (ceRNA) for miR-654-3p, which could contribute to growth inhibition of GC through activating p21 signaling pathway. Our data suggested that circRHOBTB3 would serve as a novel promising diagnosis marker and therapeutic target for GC.

LncRNA LUADT1 sponges miR-15a-3p to upregulate Twist1 in small cell lung cancer

Lung adenocarcinoma associated transcript 1 (LUADT1) has been reported as an oncogenic long non-coding RNA (lncRNA) in lung adenocarcinoma, while its roles in small cell lung cancer (SCLC) are unknown. Our RNA interaction bioinformatics prediction showed that LUADT1 could form strong base pairing with miR-15a-3p, which is a tumor-suppressive miRNA that can target Twist1. We found that LUADT1 and Twist1 were upregulated in SCLC, while miR-15a-3p was downregulated in SCLC. However, LUADT1 was posively correlated with Twist1 but was not significnatly correlated with miR-15a-3p. Overexpression experiments showed that and LUADT1 and miR-15a-3p did not significantly affect the expression of each other. Moreover, LUADT1 overexpression mediated the upregualtion of Twist1, and miR-15a-3p overexpression played an oppsoite role. Transwell assays showed that LUADT1 and Twist1 overexpression mediated the increased rate of cell invasion and migration, while miR-15a-3p overexpression mediated the decreased rate of cell invasion and migration. In addition, miR-15a-3p overexpression played an oppsoite role and attenuated the effects of LUADT1 overexpression. Therefore, LUADT1 may sponge miR-15a-3p to upregulate Twist1 in SCLC, thereby promoting cancer cell invasion and migration. TRIAL REGISTRATION: 2017GZH-1-201,746,382, registered at Jan 02,2017.

Long non-coding RNA in lung cancer

Lung cancer is the leading cause of cancer-related death worldwide. Owing to the difficulty in early diagnosis and the lack of effective treatment strategies, the 5-year survival rates for lung cancer remain very low. With the development of whole genome and transcriptome sequencing technology, long non-coding RNA (lncRNA) has attracted increasing attention. LncRNAs regulate gene expression at the epigenetic, transcriptional and post-transcriptional levels and are widely involved in a variety of diseases, including tumorigenesis. In lung cancer studies, multiple differentially expressed lncRNAs have been identified; several lncRNAs were identified as oncogenic lncRNAs with tumor-driving effects, while other lncRNAs play a role in tumor inhibition and are called tumor-suppressive lncRNAs. These tumor-suppressive lncRNAs are involved in multiple physiological processes such as cell proliferation, apoptosis, and metastasis and thus participate in tumor progression. In this review, we discussed the oncogenic and tumor-suppressive lncRNAs in lung cancer, as well as their biological functions and regulatory mechanisms. Furthermore, we found the potential significance of lncRNAs in clinical diagnosis and treatment.

A novel long non-coding RNA LINC00355 promotes proliferation of lung adenocarcinoma cells by down-regulating miR-195 and up-regulating the expression of CCNE1

Lung adenocarcinoma is the most common subtype of non-small-cell lung cancer affecting people all over the globe. Recent studies have indicated that long non-coding RNAs (lncRNAs) possess the ability to regulate gene expression. Initially, we uncovered increased LINC00355 expressions in lung adenocarcinoma tissues and cells. Functionally, our findings demonstrated that LINC00355 silencing suppressed the proliferation in vitro and in vivo. In addition, we found that LINC00355 negatively regulated miR-195 in lung adenocarcinoma cells. Simultaneously, silencing LINC00355 by shRNA resulted in suppressed proliferation, colony formation and promoted cell cycle arrest and apoptosis via miR-195. Moreover, silencing LINC00355 by shRNA inhibited the cyclin E1 (CCNE1) gene expression via miR-195 in lung adenocarcinoma cells. Collectively, this study demonstrates the novel lncRNA LINC00355 in regulatory network of CCNE1 via miR-195 in lung adenocarcinoma, highlighting LINC00355 as a new target for the treatment of lung adenocarcinoma.

Long non-coding RNAs in non-small cell lung cancer: functions and distinctions from other malignancies

Lung cancer leads to the most cancer-related death in the world. It was shown from the increasing evidences that long non-coding RNAs (lncRNAs) are emerging as molecules for diagnosis, prognosis and even therapy of lung cancer and other malignancies. The biological functions or involved signaling pathways of lncRNAs are always found to be inconsistent among different types of malignancies. However, no available literature has systemically summarized differences in the functions and underlying molecular mechanisms of lncRNAs between lung cancer and other cancers. In this review, the biological functions and molecular mechanisms of lncRNAs in lung cancer were introduced. Furthermore, their functional differences between lung cancer and other malignancies were discussed. Finally, their potential clinical applications in future lung cancer therapy were focused on.

Integrative analysis of mRNAs, miRNAs and lncRNAs in urban particulate matter SRM 1648a-treated EA.hy926 human endothelial cells

Considering the unique physiochemical properties of concentrated ambient particles (CAPs), it is extremely important to be aware of their toxic effect. A number of studies have investigated the vascular toxicity of CAPs, while potential mechanisms are still not clearly defined. Differentially expressed mRNAs, miRNAs and lncRNAs were analyzed in EA.hy926 endothelial cells after incubation with 2.5 and 10 μg/cm² urban particulate matter SRM 1648a for 24 h. As a result, the microarray profile showed that 97 mRNA, 18 miRNA, and 356 lncRNA transcripts are dysregulated in 2.5 μg/cm² group. And the expression of 440 mRNAs, 40 miRNAs, and 1283 lncRNAs significantly changes in 10 μg/cm² group. Through the miRNA-mRNA-transcription factor (TF) network, hsa-miR-128-3p, miR-18-5p and miR-376a-3p, miR-4306 as well, are key miRNAs in SRM 1648a-induced endothelial damage. Withal, lncRNA-mRNA-TF analysis hinted the importance of lncRNA T018951 and T200627. Subsequently, competing endogenous RNA (CeRNA) network was constructed for the comprehensive analysis of the regulation dogma between mRNAs and non-coding RNAs. It suggested that 35 GO terms and 1 KEGG pathway are significantly enriched in 2.5 μg/cm² group. Meanwhile, 185 terms and 18 pathways are important in 10 μg/cm² group. Pathway analysis revealed that Gap junction, Ras and MAPK signaling pathways are most significant in endothelial cell lesion. In conclusion, integrative analysis of mRNA and non-coding RNA in human endothelial cells suggests that a vast majority of non-coding RNAs regulate vascular toxicity in response to SRM 1648a. Moreover, it highlights the need for comprehensive analysis of latent mechanisms through a combination of signaling pathways with epigenetics studies.

Long Non-coding RNAs as Communicators and Mediators Between the Tumor Microenvironment and Cancer Cells

Long non-coding RNAs (lncRNAs) are a class of more than 200 nucleotides RNA transcripts which have limited protein coding capacity. They regulate numerous biological processes in cancers through diverse molecular mechanisms. Aberrant expression of lncRNAs has been frequently associated with human cancer. Furthermore, the tumor microenvironment (TME) is composed of different cells such as cancer-associated fibroblasts (CAFs), endothelial cells and infiltrated immune cells, and all of which participate in communication with tumor cells affecting the progression of tumor. LncRNAs are directly and indirectly involved in the crosstalk between stromal cells and tumor cells and dysregulated lncRNAs expression in these cells could drive tumorigenesis. In this review, we explore the influence of aberrantly expressed lncRNAs in tumor progression, clarify the critical roles of lncRNAs in the TME, summarize findings on crosstalk between infiltrated immune cells, CAFs, endothelial cells, and tumor cells via lncRNAs, and discuss the promise of lncRNAs as tumor diagnostic markers and therapeutic targets.

lncRNA SLC16A1-AS1 as a novel prognostic biomarker in non-small cell lung cancer

Long non-coding RNAs (lncRNAs) have proved to act as crucial biomarkers in tumors. Novel biomarkers in non-small cell lung cancer (NSCLC) need to be investigated badly. To identify the differentially expressed lncRNAs between NSCLC tissue and adjacent tissue, microarray analysis was performed. lncRNA SLC16A1-AS1 was significantly less expressed in NSCLC tissue than that in adjacent tissue. Gain-of-function experiments was performed to determine the biological functions of SLC16A1-AS. In situhybridization and survival analysis were applied in lung cancer tissue samples to determine the prognostic role of SLC16A1-AS1. It was showed that SLC16A1-AS1 was remarkably downregulated in NSCLC tissues and cell lines. Functionally, SLC16A1-AS1 overexpression could inhibit the viability and proliferation of lung cancer cell, block the cell cycle and promote cell apoptosis in vitro which may result from reduced phosphorylation of rat sarcoma (RAS)/ proto-oncogene serine/threonine-protein kinase (RAF)/ mitogen-activated protein kinase kinase (MEK)/ extracellular regulated protein kinases (ERK) pathway caused by elevated expression of SLC16A1-AS1. Clinical sample analysis showed that SLC16A1-AS1 had a favorable impact on the overall survival and progression-free survival of patients with NSCLC. Our results suggested that SLC16A1-AS1 may act as a potential biomarker for patients with NSCLC.

Identification of lung-adenocarcinoma-related long non-coding RNAs by random walking on a competing endogenous RNA network

Background

Identification of novel risk long non-coding RNAs (lncRNAs) in lung adenocarcinoma (LUAD) is still a significant challenge in cancer research.

Methods

In this study, we first constructed a LUAD-specific competing endogenous RNA (ceRNA) network using both experimental- and computational-supported datasets. Then, a random walking with restart method was performed to predict LUAD-associated risk lncRNAs based on the ceRNA network. The role of lncRNA MAPKAPK5-AS1 was assessed by siRNA transfection, followed by a colony formation assay, the CCK-8 assay, and immunofluorescence on A549 cells.

Results

Our method achieved an area under the curve (AUC) value of over 0.83. Of the several potential novel LUAD-related lncRNAs identified, the highest ranked lncRNA was SNHG12, which, interestingly, was also shown to promote tumorigenesis and metastasis in LUAD in a recent study. Furthermore, we found that the expression of MAPKAPK5-AS1, which was ranked second, was higher in both LUAD tissues and three LUAD cell lines. After the silencing of MAPKAPK5-AS1 by siRNA transfection, a colony formation assay revealed fewer colonies, and a CCK-8 assay revealed significantly suppressed growth of A549 cells. Moreover, immunofluorescence staining of Ki-67, a proliferation marker, revealed that the proliferation capability of A549 was dramatically reduced following MAPKAPK5-AS1 downregulation. AO/EB staining showed an increased proportion of apoptotic cells among A549 cells depleted of MAPKAPK5-AS1.

Conclusions

In brief, the lncRNAs were predicted to serve as potential biomarkers for the diagnosis, treatment, and prognosis of LUAD.

Long non-coding RNA (lncRNA) transcriptional landscape in breast cancer identifies LINC01614 as non-favorable prognostic biomarker regulated by TGFβ and focal adhesion kinase (FAK) signaling

Long non-coding RNAs (lncRNAs) represent a class of epigenetic regulators implicated in a number of physiological and pathological conditions. Herein, we characterized the lncRNA expression portrait from 837 patients with invasive breast cancer and 105 normals from the cancer genome atlas (TCGA), which revealed eighteen upregulated and forty-six downregulated lncRNAs. Clustering analysis revealed distinct lncRNA profile for the triple negative breast cancer (TNBC) and normal breast tissue, while less separation was observed among the HER2⁺HR⁺, HER2⁺HR⁻, HER2⁻HR⁺ molecular subtypes. LINC01614, and LINC01235 correlated with worse disease-free survival (DFS), while the expression of lnc-LRR1–1, lnc-ODF3B-2, AC015712.5, lnc-LAMB3–1, lnc-SPP2–3, and lnc-MAP9–2 correlated with better DFS. The expression of LINC01235 correlated with worse overall survival (OS), while the expression of MIR205HG, lnc-MAP2K6–5, FGF14-AS2, lnc-SPP2–3 correlated with better OS. Highest expression of LINC01614 was observed in progesterone receptor (PR)⁺, Estrogen receptor (PR)⁺, and HER2⁺ tumors, while lowest expression was in TNBC. Concordantly, LINC01614 was highly expressed in the luminalB/HER2⁺ subtype from the SRP062132 dataset. Elevated expression of LINC01614 was subsequently validated in primary breast cancer tissue and breast cancer cell lines. Bioinformatics and pathway analyses on LINC01614^high vs. LINC01614^low BC tissue revealed TGFβ1 and ECM as the most activated networks in LINC01614^high tumors. Concordantly, strong correlation between the expression of LINC01614 and COL10A1 (R² = 0.6929), SPOCK1 (R² = 0.5156), ZEB1 (R² = 0.3372), TGFBI (R² = 0.2978), TGFB1 (R² = 0.1985), ACTA2 (R² = 0.1833), and TAGLN (R² = 0.1909) was observed. Mechanistically, exogenous TGFB1 induced LINC01614 expression in the BT474 triple positive BC model, while small-molecule inhibition of transforming growth factor β (TGFβ, SB-431542) or focal adhesion kinase (FAK, PF-573228) abrogated LINC01614 expression. Our data revealed the lncRNA transcription landscape in breast cancer and its molecular subtypes. Our data provide novel insight implicating LINC01614 as unfavorable prognostic marker in BC, its association with the HR⁺/HER2⁺ BC molecular subtype and its regulation by TGFβ and FAK signaling.

Upregulation of long noncoding RNA LINC00152 promotes proliferation and metastasis of esophageal squamous cell carcinoma

Purpose: Esophageal cancer is a major cause of cancer-related mortality worldwide. The long noncoding RNA LINC00152 has been confirmed to play an oncogenic role in many cancers. However, the expression pattern and function of LINC00152 in human esophageal squamous cell carcinoma (ESCC) remain unclear.

Materials and methods: We evaluated LINC00152 expression in ESCC by qPCR and in situ hybridization. Proliferation, apoptosis, cell cycle, migration and invasion were examined in ESCC cells knocked down for LINC00152 knockdown by siRNA. Furthermore, an mRNA microarray was performed in ESCC cells with LINC00152 knockdown.

Results: LINC00152 was significantly upregulated in human ESCC clinical samples (P<0.001) and cell lines (P=0.008), and LINC00152 overexpression was related to lymphatic metastasis (P=0.03) and advanced pTNM classification (P=0.005). Furthermore, ESCC patients with LINC00152 overexpression had significantly shorter overall survival (P=0.007), and LINC00152 overexpression was an independent risk factor for overall survival of ESCC patients. LINC00152 knockdown inhibited the proliferation, migration and invasion of ESCC cells in vitro. In addition, mechanistic investigations through mRNA array and immunoblot analyses demonstrated that LINC00152 regulated the expression of several cell cycle-related proteins and SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) interactions in vesicular transport pathway proteins.

Conclusion: Our research indicated that LINC00152 exhibits oncogenic functions in ESCC and may represent a potential new target for ESCC therapy.

Long Noncoding RNA SBF2-AS1 Is Critical for Tumorigenesis of Early-Stage Lung Adenocarcinoma

Emerging evidence demonstrates that long non-coding RNAs (lncRNAs) are deeply involved in the development of various cancers. This study identified that SBF2-AS1, an early-stage-specific lncRNA, is critical for the tumorigenesis of lung adenocarcinoma (LUAD). We first analyzed LUAD transcriptome data from The Cancer Genome Atlas and the GEO database by weighted gene co-expression network analysis (WGCNA). Five early LUAD-specific lncRNAs were filtered out, and only SBF2-AS1 was upregulated in LUAD. High expression of SBF2-AS1 indicates poor survival of LUAD, especially the early-stage LUAD, but not lung squamous cell carcinoma. SBF2-AS1 promotes LUAD cells proliferation in vitro, and RNA-sequencing data shows that many cell-cycle-related genes were downregulated after SBF2-AS1 knockdown. Mechanically, SBF2-AS1 could competitively bind with miR-338-3p and miR-362-3p to increase E2F1 expression. Finally, we show that the SBF2-AS1-miR-338-3p/362-3p-E2F1 axis could promote LUAD tumorigenesis in vitro and in vivo. Our study demonstrates that SBF2-AS1, an early-stage-specific lncRNA, promotes LUAD tumorigenesis by sponging miR-338-3p and miR-362-3p and increasing E2F1 expression. The SBF2-AS1-miR-338-3p/362-3p-E2F1 regulatory axis may serve as a prognostic marker and potential therapeutic target for LUAD.