Long Non-coding RNA LOXL1-AS1 Drives Breast Cancer Invasion and Metastasis by Antagonizing miR-708-5p Expression and Activity

Long non-coding RNAs and their role in breast cancer pathogenesis and drug resistance: Navigating the non-coding landscape review

Despite the progress made in the development of targeted therapies, breast cancer (BC) continues to pose a significant threat to the health of women. Transcriptomics has emerged due to the advancements in high-throughput sequencing technology. This provides crucial information about the role of non-coding RNAs (ncRNAs) in human cells, particularly long ncRNAs (lncRNAs), in disease development and function. When the control of these ncRNAs is disrupted, various illnesses emerge, including cancer. Numerous studies have produced empirical data on the function of lncRNAs in tumorigenesis and disease development. However, the roles and mechanisms of numerous lncRNAs remain unidentified at the molecular level because their regulatory role and the functional implications of abnormalities in cancer biology have yet to be thoroughly defined. The review gives an itemized summary of the most current developments in the role of lncRNA in BC, focusing on three main pathways, PI3K, MAPK, NF-kB, and hypoxia, and their resistance mechanisms.

Exosome-transported circ_0001955 as a potent driver of breast cancer by regulating the miR-708-5p/PGK1 axis

BACKGROUND

Increasing evidence shows that exosome-mediated delivery of circular RNA (circRNA) is implicated in breast cancer progression. This study aimed to elucidate the role of exosome-transported circ_0001955 in breast cancer.

METHODS

The expression of circ_0001955, miR-708-5p, and phosphoglycerate kinase 1 (PGK1) messenger RNA (mRNA) was detected by quantitative real-time polymerase chain reaction (qRT-PCR); the protein levels of PGK1 and hexokinase 2 (HK2) were detected by western blot (WB). 5'-Ethynyl-2'-deoxyuridine (EdU) and colony formation assay were used to determine cell proliferation. Glycolytic metabolism was analyzed by corresponding kits to detect the associated indicators. The role of circ_0001955 in vivo was studied by establishing animal models. The potential binding relationship between miR-708-5p and circ_0001955 or PGK1 was verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay.

RESULTS

Circ_0001955 was highly expressed in breast cancer tissues and cell lines, as well as in exosomes from breast cancer cell lines. The deficiency of circ_0001955 blocked proliferation, decreased the IC50 value of paclitaxel (PTX), and blocked glycolysis in MCF-7 and MDA-MB-231 cells. Circ_0001955 knockdown also inhibited tumor growth in vivo. Circ_0001955 directly combined with miR-708-5p, and the miR-708-5p inhibitor reversed the effects of sh-circ_0001955. PGK1 was a target of miR-708-5p, and circ_0001955 indirectly promoted PGK1 expression by binding to miR-708-5p. PGK1 overexpression abolished the function of miR-708-5p in breast cancer.

CONCLUSION

Exosomal circ_0001955 excreted from breast cancer cells facilitated proliferation and glycolysis and enhanced the IC50 value of PTX in breast cancer cells by sponging miR-708-5p to upregulate PGK1.

A comprehensive review on lncRNA LOXL1-AS1: molecular mechanistic pathways of lncRNA LOXL1-AS1 in tumorigenicity of cancer cells

Long non-coding RNAs (lncRNAs) are versatile RNAs that regulate various cellular processes, such as gene regulation, by acting as signals, decoys, guides, and scaffolds. A novel recognized lncRNA, LOXL1-antisense RNA 1 (LOXL1-AS1), is dysregulated in some diseases, including cancer, and acts as an oncogenic lncRNA in many types of cancer cells. Upregulation of LOXL1-AS1 has been involved in proliferation, migration, metastasis, and EMT, as well as inhibiting apoptosis in cancer cells. Most importantly, the malignant promoting activity of LOXL1-AS1 can be mostly mediated by sequestering specific miRNAs and inhibiting their binding to the 3´UTR of their target mRNAs, thereby indirectly regulating gene expression. Additionally, LOXL1-AS1 can decoy transcription factors and proteins and prevent their binding to their regulatory regions, inhibiting their mechanistic activity on the regulation of gene expression and signaling pathways. This review presents the mechanistic pathways of the oncogenic role of LOXL1-AS1 by modulating its target miRNAs and proteins in various cancer cells. Having information about the molecular mechanisms regulated by LOXL1-AS1 in cancer cells can open ways to find out particular prognostic biomarkers, as well as discover novel therapeutic approaches for different types of cancer.

Involvement of long non-coding RNA LOXL1-AS1 in the tumourigenesis and development of malignant tumours: a narrative review

Background and Objective

Long noncoding RNAs (lncRNAs) are involved in a wide variety of physiological and pathological processes in organisms. LncRNAs play a significant role as oncogenic or tumour-suppressing factors in various biological processes associated with malignant tumours and are closely linked to the occurrence and development of malignancies. Lysyl oxidase like 1 antisense RNA 1 (LOXL1-AS1) is a recently discovered lncRNA. It is upregulated in various malignant tumours and is associated with pathological characteristics such as tumour size, tumour node metastasis (TNM) staging, lymph node metastasis, and tumour prognosis. LOXL1-AS1 exerts its oncogenic role by competitively binding with multiple microRNAs (miRs), thereby regulating the expression of downstream target genes and controlling relevant signalling pathways. This article aims to explore the structure and the function of LOXL1-AS1, and the relationship between LOXL1-AS1 and the occurrence and development of human malignant tumours to provide a reference for further clinical research.

Methods

English literature on LOXL1-AS1 in the occurrence and development of various malignant tumours was searched in PubMed. The main search terms were "LOXL1-AS1", "tumour".

Key Content and Findings

This article mainly summarizes the biological processes in which LOXL1-AS1 is involved in various human malignant tumours and the ways in which this lncRNA affects malignant biological behaviours such as proliferation, metastasis, invasion, and apoptosis of tumour cells through different molecular regulatory mechanisms. This article also explores the potential clinical significance and application prospects of LOXL1-AS1, aiming to provide a theoretical basis and reference for the clinical diagnosis, treatment, and screening of prognostic markers for malignant tumours.

Conclusions

LOXL1-AS1 acts as a competing endogenous RNA (ceRNA), binding to miRs to regulate downstream target genes and exert its oncogenic effects. LOXL1-AS1 may become a novel molecular biomarker for cancer diagnosis and treatment in humans, and it may also serve as an independent prognostic indicator.

Long non-coding RNA LOXL1-AS1: a potential biomarker and therapeutic target in human malignant tumors

Long non-coding RNAs (lncRNAs) are transcripts that contain more than 200 nucleotides. Despite their inability to code proteins, multiple studies have identified their important role in human cancer through different mechanisms. LncRNA lysyl oxidase like 1 antisense RNA 1 (LOXL1-AS1), a newly discovered lncRNA located on human chromosome 15q24.1, has recently been shown to be involved in the occurrence and progression of various malignancies, such as colorectal cancer, gastric cancer, hepatocellular carcinoma, prostate cancer, non-small cell lung cancer, ovarian cancer, cervical cancer, breast cancer, glioma, thymic carcinoma, pancreatic carcinoma. LOXL1-AS1 acts as competitive endogenous RNA (ceRNA) and via sponging various miRNAs, including miR-374b-5p, miR-21, miR-423-5p, miR-589-5p, miR-28-5p, miR-324-3p, miR-708-5p, miR-143-3p, miR-18b-5p, miR-761, miR-525-5p, miR-541-3p, miR-let-7a-5p, miR-3128, miR-3614-5p, miR-377-3p and miR-1224-5p to promote tumor cell proliferation, invasion, migration, apoptosis, cell cycle, and epithelial-mesenchymal transformation (EMT). In addition, LOXL1-AS1 is involved in the regulation of P13K/AKT and MAPK signaling pathways. This article reviews the current understanding of the biological function and clinical significance of LOXL1-AS1 in human cancers. These findings suggest that LOXL1-AS1 may be both a reliable biomarker and a potential therapeutic target for cancers.

Potential role of lncRNA LOXL1-AS1 in human cancer development: a narrative review

Background and Objective

Long non-coding RNAs (lncRNAs) are a group of non-coding RNAs consisting of more than 200 nucleotides that are widely involved in various physiological and pathobiological processes in the body. LncRNA plays a crucial role in tumorigenesis and development with its unique functions, such as playing a role in a variety of biological processes of malignant tumors as a cancer-promoting factor or a cancer-suppressor factor. Lysyl oxidase-like protein 1-antisense RNA1 (LOXL1-AS1) is a novel functional lncRNA recently reported. This article reviews the current findings on the role of LOXL1-AS1 in cancer, and discusses the potential clinical significance and application prospects, in order to provide a theoretical basis and reference for the clinical diagnosis, treatment and screening of prognostic markers for malignant tumors.

Methods

The PubMed and Embase databases were searched using the keywords "cancer" or "tumor" or "neoplasm" and "LOXL1-AS1" for publications from 2018 to the present. The English literature was searched, with a focus on relevant articles. These articles validated the role and mechanism of LOXL1-AS1 in different cancers.

Key Content and Findings

LOXL1-AS1 is a recently reported novel lncRNA, which is abnormally expressed and upregulated in more than ten cancers, and is positively correlated with adverse clinical features and poor prognosis in cancer patients. LOXL1-AS1 competently binds to a variety of microRNAs to regulate the expression of downstream target genes and regulate related signaling pathways, including proliferation, migration, invasion and inhibition of malignant biological behaviors such as apoptosis.

Conclusions

LOXL1-AS1 is expected to become a novel biomarker for cancer diagnosis and treatment, with great potential as an independent prognostic indicator.

Discovery of novel microRNA mimic repressors of ribosome biogenesis

While microRNAs and other non-coding RNAs are the next frontier of novel regulators of mammalian ribosome biogenesis (RB), a systematic exploration of microRNA-mediated RB regulation has not yet been undertaken. We carried out a high-content screen in MCF10A cells for changes in nucleolar number using a library of 2603 mature human microRNA mimics. Following a secondary screen for nucleolar rRNA biogenesis inhibition, we identified 72 novel microRNA negative regulators of RB after stringent hit calling. Hits included 27 well-conserved microRNAs present in MirGeneDB, and were enriched for mRNA targets encoding proteins with nucleolar localization or functions in cell cycle regulation. Rigorous selection and validation of a subset of 15 microRNA hits unexpectedly revealed that most of them caused dysregulated pre-rRNA processing, elucidating a novel role for microRNAs in RB regulation. Almost all hits impaired global protein synthesis and upregulated CDKN1A (p21) levels, while causing diverse effects on RNA Polymerase 1 (RNAP1) transcription and TP53 protein levels. We provide evidence that the MIR-28 siblings, hsa-miR-28-5p and hsa-miR-708-5p, potently target the ribosomal protein mRNA RPS28 via tandem primate-specific 3' UTR binding sites, causing a severe pre-18S pre-rRNA processing defect. Our work illuminates novel microRNA attenuators of RB, forging a promising new path for microRNA mimic chemotherapeutics.

Discovery of novel microRNA mimic repressors of ribosome biogenesis

While microRNAs and other non-coding RNAs are the next frontier of novel regulators of mammalian ribosome biogenesis (RB), a systematic exploration of microRNA-mediated RB regulation has not yet been undertaken. We carried out a high-content screen in MCF10A cells for changes in nucleolar number using a library of 2,603 mature human microRNA mimics. Following a secondary screen for nucleolar rRNA biogenesis inhibition, we identified 72 novel microRNA negative regulators of RB after stringent hit calling. Hits included 27 well-conserved microRNAs present in MirGeneDB, and were enriched for mRNA targets encoding proteins with nucleolar localization or functions in cell cycle regulation. Rigorous selection and validation of a subset of 15 microRNA hits unexpectedly revealed that most of them caused dysregulated pre-rRNA processing, elucidating a novel role for microRNAs in RB regulation. Almost all hits impaired global protein synthesis and upregulated CDKN1A ( p21 ) levels, while causing diverse effects on RNA Polymerase 1 (RNAP1) transcription and TP53 protein levels. We discovered that the MIR-28 siblings, hsa-miR-28-5p and hsa-miR-708-5p, directly and potently target the ribosomal protein mRNA RPS28 via tandem primate-specific 3' UTR binding sites, causing a severe pre-18S pre-rRNA processing defect. Our work illuminates novel microRNA attenuators of RB, forging a promising new path for microRNA mimic chemotherapeutics.

The Emerging Role of Epigenetics in Metabolism and Endocrinology

Each cell in a multicellular organism has its own phenotype despite sharing the same genome. Epigenetics is a somatic, heritable pattern of gene expression or cellular phenotype mediated by structural changes in chromatin that occur without altering the DNA sequence. Epigenetic modification is an important factor in determining the level and timing of gene expression in response to endogenous and exogenous stimuli. There is also growing evidence concerning the interaction between epigenetics and metabolism. Accordingly, several enzymes that consume vital metabolites as substrates or cofactors are used during the catalysis of epigenetic modification. Therefore, altered metabolism might lead to diseases and pathogenesis, including endocrine disorders and cancer. In addition, it has been demonstrated that epigenetic modification influences the endocrine system and immune response-related pathways. In this regard, epigenetic modification may impact the levels of hormones that are important in regulating growth, development, reproduction, energy balance, and metabolism. Altering the function of the endocrine system has negative health consequences. Furthermore, endocrine disruptors (EDC) have a significant impact on the endocrine system, causing the abnormal functioning of hormones and their receptors, resulting in various diseases and disorders. Overall, this review focuses on the impact of epigenetics on the endocrine system and its interaction with metabolism.

Coding roles of long non-coding RNAs in breast cancer: Emerging molecular diagnostic biomarkers and potential therapeutic targets with special reference to chemotherapy resistance

Dysregulation of epigenetic mechanisms have been depicted in several pathological consequence such as cancer. Different modes of epigenetic regulation (DNA methylation (hypomethylation or hypermethylation of promotor), histone modifications, abnormal expression of microRNAs (miRNAs), long non-coding RNAs, and small nucleolar RNAs), are discovered. Particularly, lncRNAs are known to exert pivot roles in different types of cancer including breast cancer. LncRNAs with oncogenic and tumour suppressive potential are reported. Differentially expressed lncRNAs contribute a remarkable role in the development of primary and acquired resistance for radiotherapy, endocrine therapy, immunotherapy, and targeted therapy. A wide range of molecular subtype specific lncRNAs have been assessed in breast cancer research. A number of studies have also shown that lncRNAs may be clinically used as non-invasive diagnostic biomarkers for early detection of breast cancer. Such molecular biomarkers have also been found in cancer stem cells of breast tumours. The objectives of the present review are to summarize the important roles of oncogenic and tumour suppressive lncRNAs for the early diagnosis of breast cancer, metastatic potential, and chemotherapy resistance across the molecular subtypes.

Roles and Mechanisms of Long Non-Coding RNAs in Breast Cancer

Breast cancer is a major health threat and the second leading cause of cancer-related deaths in women worldwide. The detailed mechanisms involved in the initiation and progression of breast cancer remain unclear. In recent years, amounting evidence indicated that long non-coding RNAs (lncRNAs) played crucial roles in regulating various biological processes and malignancy tumors, including breast cancer. In this review, we briefly introduce the functions and underlying mechanisms by which lncRNAs are involved in breast cancer. We summarize the roles of the lncRNAs in regulating malignant behaviors of breast cancer, such as cell proliferation, migration and invasion, epithelial-mesenchymal transition (EMT), apoptosis, and drug resistance. Additionally, we also briefly summarize the roles of circular RNAs (circRNAs) in breast cancer carcinogenesis.

The Double Face of miR-708: A Pan-Cancer Player with Dissociative Identity Disorder

Over the last decades, accumulating evidence has shown tumor-dependent profiles of miR-708, being either up- or downregulated, and thus, acting as a "Janus" regulator of oncogenic pathways. Herein, its functional duality was assessed through a thorough review of the literature and further validation in silico using The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. In the literature, miR-708 was found with an oncogenic role in eight tumor types, while a suppressor tumor role was described in seven cancers. This double profile was also found in TCGA and GEO databases, with some tumor types having a high expression of miR-708 and others with low expression compared with non-tumor counterparts. The investigation of validated targets using miRBase, miRTarBase, and miRecords platforms, identified a total of 572 genes that appeared enriched for PI3K-Akt signaling, followed by cell cycle control, p53, Apellin and Hippo signaling, endocrine resistance, focal adhesion, and cell senescence regulations, which are all recognized contributors of tumoral phenotypes. Among these targets, a set of 15 genes shared by at least two platforms was identified, most of which have important roles in cancer cells that influence either tumor suppression or progression. In a clinical scenario, miR-708 has shown to be a good diagnostic and prognosis marker. However, its multitarget nature and opposing roles in diverse human tumors, aligned with insufficient experimental data and the lack of proper delivery strategies, hamper its potential as a sequence-directed therapeutic.

LINC00467: A key oncogenic long non-coding RNA

The significance of long non-coding RNAs (lncRNAs) in the development and progression of human cancers has attracted increasing attention in recent years of investigations. Having versatile interactions and diverse functions, lncRNAs can act as oncogenes or tumor-suppressors to actively regulate cell proliferation, survival, stemness, drug resistance, invasion and metastasis. LINC00467, an oncogenic member of long intergenic non-coding RNAs, is upregulated in numerous malignancies and its high expression is often related to poor clinicopathological features. LINC00467 facilitates the progression of cancer via sponging tumor-suppressive microRNAs, inhibiting cell death cascade, modulating cell cycle controllers, and regulating signalling pathways including AKT, STAT3, NF-κB and Wnt/β-catenin. A growing number of studies have revealed that LINC00467 may serve as a novel prognostic biomarker and its inhibitory targeting has a valuable therapeutic potential to suppress the malignant phenotypes of cancer cells. In the present review, we discuss the importance of LINC00467 and provide a comprehensive collection of its functions and molecular mechanisms in a variety of cancer types.

Histone modification and histone modification-targeted anti-cancer drugs in breast cancer: Fundamentals and beyond

Dysregulated epigenetic enzymes and resultant abnormal epigenetic modifications (EMs) have been suggested to be closely related to tumor occurrence and progression. Histone modifications (HMs) can assist in maintaining genome stability, DNA repair, transcription, and chromatin modulation within breast cancer (BC) cells. In addition, HMs are reversible, dynamic processes involving the associations of different enzymes with molecular compounds. Abnormal HMs (e.g. histone methylation and histone acetylation) have been identified to be tightly related to BC occurrence and development, even though their underlying mechanisms remain largely unclear. EMs are reversible, and as a result, epigenetic enzymes have aroused wide attention as anti-tumor therapeutic targets. At present, treatments to restore aberrant EMs within BC cells have entered preclinical or clinical trials. In addition, no existing studies have comprehensively analyzed aberrant HMs within BC cells; in addition, HM-targeting BC treatments remain to be further investigated. Histone and non-histone protein methylation is becoming an attractive anti-tumor epigenetic therapeutic target; such methylation-related enzyme inhibitors are under development at present. Consequently, the present work focuses on summarizing relevant studies on HMs related to BC and the possible mechanisms associated with abnormal HMs. Additionally, we also aim to analyze existing therapeutic agents together with those drugs approved and tested through pre-clinical and clinical trials, to assess their roles in HMs. Moreover, epi-drugs that target HMT inhibitors and HDAC inhibitors should be tested in preclinical and clinical studies for the treatment of BC. Epi-drugs that target histone methylation (HMT inhibitors) and histone acetylation (HDAC inhibitors) have now entered clinical trials or are approved by the US Food and Drug Administration (FDA). Therefore, the review covers the difficulties in applying HM-targeting treatments in clinics and proposes feasible approaches for overcoming such difficulties and promoting their use in treating BC cases.

MiR-708-5p/Pit-1 axis mediates high phosphate-induced calcification in vascular smooth muscle cells via Wnt8b/β-catenin pathway

Recently, the underlying mechanism of vascular calcification (VC) has been partially elucidated. However, it is still high incidence, and no effective treatment has been found. This study aims at figuring out the underlying mechanisms of microRNA-708-5p (miR-708-5p)/sodium-phosphate transporter 1 (Pit-1) axis in high phosphate (HP)-induced VC of T/G HA-VSMCs. Alizarin Red S staining was used to evaluate calcium salt deposition, and the activity of alkaline phosphatase (ALP) was determined by measuring the absorbance at 405 nm. RT-qPCR and Western blot were performed to assess the levels of miR-708-5p and Pit-1, the levels of ALP, Pit-1, β-catenin, glycogen synthesis kinase 3 β (GSK3β), and p-GSK3β proteins, respectively. The interaction between miR-708-5p and Pit-1 was validated by luciferase reporter assay. Our findings illustrated that miR-708-5p was downregulated and Pit-1was upregulated in HP-induced VC. MiR-708-5p mimics inhibited HP-induced VC. Further experiments demonstrated that miR-708-5p targets Pit-1. In addition, miR-708-5p inactivates the Wnt8b/β-catenin pathway via targeting Pit-1 to reduce HP-induced VC. MiR-708-5p has a crucial effect on VC via targeting Pit-1 and inhibiting Wnt8b/β-catenin pathway, it may serve as a new target for VC treatment.

MicroRNA Expression in Pseudoexfoliation Syndrome with the Use of Next-Generation Sequencing

Pseudoexfoliation syndrome (PEX) is a clinically important and biologically intriguing systemic disorder of the extracellular matrix. PEX etiopathogenesis was proved to be connected to multiple genes and other factors. However, the exact etiopathogenesis remains unknown. The aim of this study was to analyze miR expression in PEX using next-generation sequencing. An attempt was made to find the most commonly occurring miR in PEX, to evaluate miR that may have an essential role in the etiology of PEX syndrome. In addition, the correlation between the selected miRs’ expressions and age was investigated. Anterior lens capsules were obtained during cataract surgery. Next-generation sequencing was conducted on Illumina MiSeq. The average age was 68.2 years (with standard deviation +/− 6.92 years). Ten miRs with the highest level of expression represent approx. 95% of all readings. Four miRs with statistically significant differences in expression between groups have been distinguished: miR-671-3p, miR374a-5p, miR-1307-5p and miR-708-5p. The relationship between the most frequent miRs’ expressions and age has been evaluated and no correlation has been detected. In view of the above, it seems reasonable to examine the influence of miR on the biogenesis of PEX. Further studies on miR-671-3p, miR-374a-5p, miR-1307-5p and miR-708-5p expression in PEX are needed.

A Portable Controllable Compressive Stress Device to Monitor Human Breast Cancer Cell Protrusions at Single-Cell Resolution

In vitro devices offer more numerous methods than in vivo models to investigate how cells respond to pressure stress and quantify those responses. Several in vitro devices have been developed to study the cell response to compression force. However, they are unable to observe morphological changes of cells in real-time. There is also a concern about cell damage during the process of harvesting cells from 3D gels. Here we report a device employing transparent, thin gel layers to clamp cells between the interfaces and applied a controllable compression force by stacking multiple layers on the top. In this approach, cells can be monitored for alteration of cellular protrusions, whose diversity has been proven to promote cancer cell dissemination, with single-cell resolution under compression force. Furthermore, p-Rac-1 and rhodamine staining on the device directly to confirm the actin filaments of lamellipodia. The method was able to fulfill real-time live-cell observation at single-cell resolution and can be readily used for versatile cell analysis. MDA-MB-231 and MCF7 breast cancer cells were utilized to demonstrate the utility of the device, and the results showed that the stimuli of compression force induce MDA-MB-231 and MCF7 to form lamellipodia and bleb protrusions, respectively. We envision the device may be used as a tool to explore mechanisms of membrane protrusion transitions and to screen drug candidates for inhibiting cancer cell protrusion plasticity for cancer therapy.

The LOXL1 antisense RNA 1 (LOXL1-AS1)/microRNA-423-5p (miR-423-5p)/ectodermal-neural cortex 1 (ENC1) axis promotes cervical cancer through the mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway

As the fourth commonest malignancy among females worldwide, cervical cancer (CC) poses a huge challenge to human health. The pivotal regulatory roles of lncRNAs in cancers have been highlighted. LOXL1 antisense RNA 1 (LOXL1-AS1) has been reported to play a key role in cervical squamous cell carcinoma and other various cancers. Thus, we investigated the roles and mechanisms of lncRNA LOXL1-AS1 in CC. The in vivo experiments demonstrated that LOXL1-AS1 downregulation inhibited tumor growth and metastasis and proliferation of CC cells. The results of RT-qPCR demonstrated that LOXL1-AS1 and ectodermal-neural cortex 1 (ENC1) expression levels were upregulated in CC cells and tissues, while microRNA-423-5p (miR-423-5p) level was downregulated. As subcellular fractionation assays, RNA pull down assays and luciferase reporter assays revealed, LOXL1-AS1 bound to miR-423-5p and miR-423-5p targeted ENC1. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays, wound healing and colony formation assays demonstrated that miR-423-5p upregulation and LOXL1-AS1 downregulation inhibited CC cell proliferation and migration, while ENC1 upregulation attenuated the inhibitory effects of miR-423-5p upregulation on the malignant phenotypes of CC cells. Western blotting was conducted to measure protein levels and the results showed that ENC1 knockdown inhibited the activation of ERK/MEK pathway. In summary, the LOXL1-AS1/miR-423-5p/ENC1 axis accelerates CC development through the MEK/ERK pathway.

A diagnostic and prognostic value of blood-based circulating long non-coding RNAs in Thyroid, Pancreatic and Ovarian Cancer

Several studies have demonstrated the potential of circulating long non-coding RNAs (lncRNAs) as promising cancer biomarkers. Herein, we addressed the regulatory role of circulating lncRNAs and their potential value as diagnostic/prognostic markers for thyroid, pancreatic and ovarian cancers. Furthermore, we analyzed and measured the clinical implications and association of lncRNAs with sensitivity, specificity, and area under the ROC curve (AUC). Based on our meta-analysis, we found that GAS8-AS1 could discriminate thyroid cancer from non-cancer and other cancers with higher accuracy (AUC = 0.746; sensitivity = 61.70%, and specificity = 90.00%). Similarly, for ovarian cancer, lncRNA RP5-837J1.2 was found to have ideal diagnostic potential with critical clinical specifications of AUC = 0.996; sensitivity = 97.30% and specificity = 94.60%. Whereas we could not find any lncRNA having high diagnostic/prognostic efficiency in pancreatic cancer. We believe that lncRNAs mentioned above may explore clinical settings for the diagnosis and prognosis of cancer patients.

LOXL1-AS1 communicating with TIAR modulates vasculogenic mimicry in glioma via regulation of the miR-374b-5p/MMP14 axis

At present, growing evidence indicates that long non‐coding RNAs (lncRNAs) participate in the progression of glioma. The function of LOXL1‐AS1 in vasculogenic mimicry (VM) in glioma remains unclear. First, the expressions of TIAR, the lncRNA LOXL1‐AS1, miR‐374b‐5p and MMP14 were examined by qRT‐PCR and Western blot in both, glioma tissues and glioma cell lines. Proliferation, migration, invasion and tube formation assays were conducted to evaluate the roles of TIAR, LOXL1‐AS1, miR‐374b‐5p and MMP14 in malignant cellular behaviours in glioma cells. A nude mouse xenograft model and dual staining for CD34 and PAS were used to assess whether VM was affected by TIAR, LOXL1‐AS1 or miR‐374b‐5p in vivo. In this study, low levels of TIAR and high levels of LOXL1‐AS1 were found in glioma cells and tissues. TIAR downregulated the expression of LOXL1‐AS1 by destabilizing it. LOXL1‐AS1 acted like a miRNA sponge towards miR‐374b‐5p so that downregulation of the former greatly inhibited cell proliferation, migration, invasion and VM. Additionally, miR‐374b‐5p overexpression repressed malignant biological behaviours and VM in glioma by modifying MMP14. In summary, we demonstrated that TIAR combined with LOXL1‐AS1 modulates VM in glioma via the miR‐374b‐5p/MMP14 axis, revealing novel targets for glioma therapy.

MicroRNA and cyclooxygenase-2 in breast cancer

Cancer remains a major public health problem worldwide and the latest statistics show that breast cancer (BC) is among the most frequent in women. MicroRNAs (miRNAs; miRs) and cyclooxygenase-2 (COX-2) are new diagnostic and therapeutic biomarkers for monitoring BC. COX-2 is a prominent tumor-associated inflammatory factor highly expressed in human tumor cells, including BC. Expression of COX-2 contributes to tumor growth, metastasis and recurrence. MiRs are a group of short (~22 nucleotides), noncoding regulatory RNAs that downregulate gene expression post-transcriptionally and play vital roles in regulating cancer development and progression. Interestingly, there are a group of miRNAs differentially expressed in breast tumor tissue. Understanding the pathway linking miRNAs to COX-2 can provide novel insight for suppressing COX-2 expression via gene silencing thereby leading to the development of selective miRNA inhibitors. Further research can also reveal key intermediate players and their potential as therapeutic targets. Given the association between different miRNAs and COX-2 expression in BC, this review presents a comprehensive overview of the current literature concerning how miRNAs and COX-2 signaling interact in BC progression.

An updated review of the role of lncRNAs and their contribution in various molecular subtypes of breast cancer

Introduction: Breast cancer (BC) is the most significant threat to women's life. To demonstrate its molecular mechanisms, which results in BC progression, it is crucial to develop approaches to enhance prognosis and survival in BC cases.Areas covered: In the current study, we aimed to highlight the updated data on the oncogenic and tumor suppressive roles of lncRNAs in the progression of various subtypes of BC by specifically putting importance on the functional characteristics, modulatory agents, therapeutic potential, future perspectives and challenges of lncRNAs in BC. We reviewed recent studies published between 2019 and 2020.Expert opinion: The latest investigations have demonstrated that the long non-coding RNAs (lncRNAs) participate in different BC molecular subtypes via different molecular mechanisms; however, the exact functional information of the lncRNAs has yet to be elucidated. The studied lncRNAs could be more applicable as therapeutic targets in BC treatment after pre-clinical and clinical studies.

Vitamin D and Non-coding RNAs: New Insights into the Regulation of Breast Cancer

Breast cancer, a life-threatening serious disease with a high incident rate among women, is responsible for thousands of cancer-associated death worldwide. Numerous investigations have evaluated the possible mechanisms related to this malignancy. Among them, non-coding RNAs (ncRNAs), i.e., microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs have recently attracted attention of researchers. In addition to recent studies for evaluating the role of ncRNAs in breast cancer etiology, some investigations have revealed that vitamin D has regulatory and therapeutic roles in breast cancer. Moreover, an important link between vitamin D and ncRNAs in cancer therapy has been highlighted. Herein, the aim of this study was to discuss the available data on the mentioned link in breast cancer.

Regulation of Nuclear Factor-KappaB (NF-κB) signaling pathway by non-coding RNAs in cancer: Inhibiting or promoting carcinogenesis?

The nuclear factor-kappaB (NF-κB) signaling pathway is considered as a potential therapeutic target in cancer therapy. It has been well established that transcription factor NF-κB is involved in regulating physiological and pathological events including inflammation, immune response and differentiation. Increasing evidences suggest that deregulated NF-κB signaling can enhance cancer cell proliferation, metastasis and also mediate radio-as well as chemo-resistance. On the contrary, non-coding RNAs (ncRNAs) have been found to modulate NF-κB signaling pathway under different settings. MicroRNAs (miRNAs) can dually inhibit/induce NF-κB signaling thereby affecting the growth and migration of cancer cells. Furthermore, the response of cancer cells to radiotherapy and chemotherapy may also be regulated by miRNAs. Regulation of NF-κB by miRNAs may be mediated via binding to 3^/-UTR region. Interestingly, anti-tumor compounds can increase the expression of tumor-suppressor miRNAs in inhibiting NF-κB activation and the progression of cancers. Long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) can also effectively modulate NF-κB signaling thus affecting tumorigenesis. It is noteworthy that several studies have demonstrated that lncRNAs and circRNAs can affect miRNAs in targeting NF-κB activation. They can act as competing endogenous RNA (ceRNA) thereby reducing miRNA expression to induce NF-κB activation that can in turn promote cancer progression and malignancy.

LncRNA SNHG8 Serves as an Oncogene in Breast Cancer Through miR-634/ZBTB20 Axis

Background

Small nucleolus RNA Host Gene 8 (SNHG8) belongs to a subgroup with long non-coding RNAs. LncRNA SNHG8 presents up-regulated in miscellaneous cancers, like gastric cancer, liver cancer, and esophageal squamous cell cancer. Nevertheless, the expression pattern and the pathological function of lncRNA SNHG8 in breast cancer remain obscure.

Methods

We examined the expression levels of lncRNA SNHG8 in the tissue samples and cell lines from breast cancer via RT-qPCR in the present study. The functions of lncRNA SNHG8 on the progression of breast cancer cell were examined by CCK-8, EdU, Transwell chamber assays, and flow cytometry analyses. The expression of proteins was assessed using Western blot assay.

Results

We found that proliferation, migration, and invasion of breast cancer cells were significantly inhibited due to knockdown of lncRNA SNHG8, while inducing apoptosis of these cells. Mechanistically, SNHG8 functioned as an inhibitor of miR-634 in tumor tissues.

Conclusion

LncRNA SNHG8 sponged the miR-634 to increase the expression level of ZBTB20, thus further aggravating the malignancy of breast cancer. Hence, the lncRNA SNHG8-miR-634-ZBTB20 axis may be a promising therapeutic target to treat breast cancers.

Schisandrin B Inhibits Cell Viability and Migration, and Induces Cell Apoptosis by circ_0009112/miR-708-5p Axis Through PI3K/AKT Pathway in Osteosarcoma

Osteosarcoma is a primary tumor of bone and its incidence is increasing. Schisandrin B (Sch B), a generally used lignan in Chinese medicine, has been found to repress cancer progression. This study aims to reveal the effects and regulatory mechanism of Sch B in the viability, apoptosis and migration of osteosarcoma cells. In this study, we found circ_0009112 expression was higher and miR-708-5p expression was lower in SaOS2 and U2OS cells than in hFOB1.19 cells. Circ_0009112 expression was downregulated, but miR-708-5p was upregulated by Sch B treatment in a dose-dependent manner in SaOS2 and U2OS cells. Sch B exposure inhibited osteosarcoma development in vitro and in vivo; however, these effects were restored by circ_0009112. Furthermore, circ_0009112 acted as a sponge of miR-708-5p. Circ_0009112 regulated PI3K/AKT pathway after Sch B treatment by associating with miR-708-5p. Sch B exposure inhibited cell viability and migration, whereas promoted cell apoptosis by regulating circ_0009112/miR-708-5p axis through PI3K/AKT pathway in osteosarcoma cells. This study provided a theoretical basis for further studying osteosarcoma therapy with Sch B.

LncRNA LOXL1-AS1 promotes esophageal squamous cell carcinoma progression by targeting DESC1

Recently, ample evidence indicated that numerous aberrantly expressed long non-coding RNAs (lncRNAs) participated in the development of multiple malignancies. However, the expression and function of lncRNA LOXL1-AS1 in mediating esophageal squamous cell carcinoma (ESCC) carcinogenesis remains largely elusive. Here we validated that LOXL1-AS1 was significantly upregulated in ESCC tissues compared with the corresponding adjacent non-neoplastic tissues, and LOXL1-AS1 expression was positively correlated with ESCC patients' lymph node metastasis. Besides, LOXL1-AS1 knockdown impaired ESCC cells proliferation, migration and invasion capabilities in vitro. Furthermore, inhibiting LOXL1-AS1 in ESCC cells increased the percentage of cells at the G1 phase, accompanied by reducing in S phase in contrast to scramble control, and silencing of LOXL1-AS1 evoked ESCC cell apoptosis. From high throughput RNA sequencing (RNA-seq) analysis, we identified that differentially expressed in squamous cell carcinoma 1 (DESC1) was a critical downstream target of LOXL1-AS1. Taken together, we demonstrated the function and mechanism of LOXL1-AS1 in contributing ESCC progression for the first time, and indicated LOXL1-AS1 may be a novel therapeutic biomarker of ESCC.

The Long Noncoding RNA LOXL1-AS1 Promotes the Proliferation, Migration, and Invasion in Hepatocellular Carcinoma

Objective

To investigate the expression of long noncoding RNA lysyl oxidase-like 1-antisense 1 (LOXL1-AS1) in hepatocellular carcinoma tissues and its effect on cell proliferation, migration, and invasion.

Methods

Quantitative real-time PCR was used to analyze the expression of LOXL1-AS1 RNA in tumor tissues, adjacent normal tissues, and cell lines. MTT assay, colony formation assay, flow cytometry analysis, transwell assays, and lentivirus-mediated RNA interference (RNAi) technology were used to evaluate cell proliferation and migration.

Results

In the present study, we observed that the expression level of LOXL1-AS1 in hepatocellular carcinoma tissue was significantly higher than that in adjacent nontumor tissues, and its expression in three hepatic carcinoma cell lines was obviously higher than that in a normal cell line. In addition, in the Hep-G2 cell line, LOXL1-AS1 downregulation significantly inhibited cell proliferation in the light of the MTT and colony formation assays in vitro, which was consistent with animal experiment in vivo. What is more, cell migration was also inhibited in vitro in Matrigel Transwell Assay by LOXL1-AS1 knockdown, which might be partly attributed to the reduction of MMP-2 and MMP-9 protein expressions. Finally, cell cycle analysis revealed that knockdown of LOXL1-AS1 induced significantly a G0/G1 phase cell cycle arrest, which might be partly attributed to the downregulation of Cdc2, Cdc25A, and cyclin B1 protein expression.

Conclusion

In conclusion, we demonstrated that reduced LOXL1-AS1 expression could inhibit hepatocellular carcinoma cell proliferation, migration, and invasion. The application of RNAi targeting LOXL1-AS1 might be a potential treatment strategy in advanced cases.

Long non-coding RNAs MACC1-AS1 and FOXD2-AS1 mediate NSD2-induced cisplatin resistance in esophageal squamous cell carcinoma

The nuclear receptor-binding SET domain (NSD) protein family encoding histone lysine methyltransferases is involved in cancer progression. However, the role of NSDs in esophageal squamous cell carcinoma (ESCC) remains unclear. Here we examined the expression of NSDs in cisplatin-resistant and parental ESCC cells and revealed the upregulation of NSD2 in cisplatin-resistant cells. Ectopic expression of NSD2 increased cisplatin resistance and attenuated cisplatin-induced apoptosis. Colony formation assay indicated that NSD2 overexpression enhanced long-term survival of ESCC cells after treatment with cisplatin. In contrast, knockdown of NSD2 inhibited ESCC cell proliferation and sensitized ESCC cells to cisplatin. Depletion of NSD2 augmented the cytotoxic effect of cisplatin on EC109 xenograft tumors. NSD2 stimulated long non-coding RNA MACC1-AS1 in ESCC cells. Knockdown of MACC1-AS1 impaired NSD2-induced cisplatin resistance. Moreover, MACC1-AS1 overexpression promoted ESCC cell proliferation and cisplatin resistance. Clinically, MACC1-AS1 was upregulated in ESCC relative to adjacent noncancerous tissues. High MACC1-AS1 levels were significantly associated with reduced overall survival of ESCC patients. There was a positive correlation between MACC1-AS1 and NSD2 expression in ESCC specimens. Taken together, MACC1-AS1 induced by NSD2 mediates resistance to cisplatin in ESCC and may represent a novel target to improve cisplatin-based chemotherapy.

Molecular characterization of breast cancer: a potential novel immune-related lncRNAs signature

Background

Accumulating evidence has demonstrated that immune-related lncRNAs (IRLs) are commonly aberrantly expressed in breast cancer (BC). Thus, we aimed to establish an IRL-based tool to improve prognosis prediction in BC patients.

Methods

We obtained IRL expression profiles in large BC cohorts (N = 911) from The Cancer Genome Atlas (TCGA) database. Then, in light of the correlation between each IRL and recurrence-free survival (RFS), we screened prognostic IRL signatures to construct a novel RFS nomogram via a Cox regression model. Subsequently, the performance of the IRL-based model was evaluated through discrimination, calibration ability, risk stratification ability and decision curve analysis (DCA).

Results

A total of 52 IRLs were obtained from TCGA. Based on multivariate Cox regression analyses, four IRLs (A1BG-AS1, AC004477.3, AC004585.1 and AC004854.2) and two risk parameters (tumor subtype and TNM stage) were utilized as independent indicators to develop a novel prognostic model. In terms of predictive accuracy, the IRL-based model was distinctly superior to the TNM staging system (AUC: 0.728 VS 0.673, P = 0.010). DCA indicated that our nomogram had favorable clinical practicability. In addition, risk stratification analysis showed that the IRL-based tool efficiently divided BC patients into high- and low-risk groups (P < 0.001).

Conclusions

A novel IRL-based model was constructed to predict the risk of 5-year RFS in BC. Our model can improve the predictive power of the TNM staging system and identify high-risk patients with tumor recurrence to implement more appropriate treatment strategies.

Long non-coding RNA TMPO-AS1 promotes tumor progression via sponging miR-140-5p in breast cancer

Long non-coding RNAs (lncRNAs) are involved in carcinogenesis and tumor suppression, and are novel biological tumor regulators. However, the functional roles of lncRNAs and their underlying dysregulation mechanisms in breast cancer are not completely understood. The aim of the present study was to investigate the clinical significance and biological functions of lncRNA TMPO antisense RNA 1 (TMPO-AS1) in breast cancer. TMPO-AS1 levels were measured in human cancer tissues and breast cancer cell lines, and the functional roles of TMPO-AS1 in breast cancer cells were investigated by performing in vitro and in vivo assays. Additionally, luciferase reporter assays were conducted to detect the association between microRNA (miR)-140-5p and TMPO-AS1. TMPO-AS1 expression levels were significantly increased in breast cancer tissues and cell lines compared with adjacent non-cancerous tissues and MCF-10A cells, respectively. In vitro and in vivo studies indicated that TMPO-AS1 knockdown significantly suppressed breast cancer cell viability at 48 and 72 h compared with the small interfering (si)RNA negative control group (NC; siNC). TMPO-AS1 knockdown in vitro inhibited MCF-7 and T47D cell migration and invasion compared with the siNC group. TMPO-AS1 knockdown in metastatic breast cancer cells also decreased metastatic colonization in the mouse lung compared with the short hairpin RNA NC group. Mechanistically, TMPO-AS1 promoted cellular viability and migration as a competing endogenous RNA by sponging miR-140-5p. The results suggested that TMPO-AS1 may serve as a potential therapeutic target in patients with breast cancer.

LncRNA LOXL1-AS1 controls osteogenic and adipocytic differentiation of bone marrow mesenchymal stem cells in postmenopausal osteoporosis through regulating the miR-196a-5p/Hmga2 axis

INTRODUCTION

Exploring molecular mechanisms of human bone marrow mesenchymal stem cells (hBMMSCs) differentiation, a crucial step for bone formation, is a new direction for treating postmenopausal osteoporosis. LncRNAs are involved in lots of biological processes including hBMMSCs differentiation. The present study aimed to explore the effect of LOXL1-AS1 on hBMMSCs differentiation.

MATERIALS AND METHODS

We examined the expression levels of LOXL1-AS1, miR-196a-5p and Hmga2 in peripheral blood from postmenopausal osteoporosis patients by RT-qPCR, and detected their changes during the osteogenic differentiation of hBMMSCs by RT-qPCR. RT-qPCR and western blot measured the level of biomarkers of bone formation and osteogenic differentiation (osteopontin, OPN; Alkaline phosphatase, ALP; Runt-related transcription factor-2, Runx-2). The effects of LOXL1-AS1 on the osteogenic and adipocytic differentiation of hBMMSCs were, respectively, determined by ALP, ARS staining assays and oil red O staining assay.

RESULTS

The abnormal high expression of LOXL1-AS1 was found in patients. LOXL1-AS1 expression showed a gradual decrease during the osteogenic differentiation of hBMMSCs. However, LOXL1-AS1 overexpression inhibited the hBMMSCs osteogenic differentiation but promoted adipocytic differentiation. Furthermore, LOXL1-AS1 was identified to be a sponge of miR-196a-5p and Hmga2 as a target gene of miR-196a-5p. Besides, LOXL1-AS1 sponged miR-196a-5p to mediate Hmga2 expression, which played contrary effects on regulating osteogenic and adipocytic differentiation of hBMMSCs. Moreover, LOXL1-AS1/miR-196a-5p/Hmga2 axis regulated hBMMSCs differentiation through controlling C/EBPβ-mediated PPARγ expression.

CONCLUSION

These findings facilitate understanding the molecular mechanism of hBMMSCs differentiation and bring up a novel sight for postmenopausal osteoporosis therapy.

LOXL1-AS1 contributes to the proliferation and migration of laryngocarcinoma cells through miR-589-5p/TRAF6 axis

Background

LOXL1-AS1 is a long non-coding RNA (lncRNA) that plays crucial roles in various cancers. However, the functional role of LOXL1-AS1 in laryngocarcinoma remains unclear. Thus we planned to probe into the function and underlying mechanism of LOXL1-AS1 in laryngocarcinoma.

Methods

Gene expression was evaluated in laryngocarcinoma cells using RT-qPCR. The ability of cell proliferation and migration was assessed by CCK8, colony formation, wound healing and transwell assays. The interaction among LOXL1-AS1, miR-589-5p and TRAF6 was detected by Ago2-RIP, RNA pull down and luciferase reporter assays.

Results

LOXL1-AS1 was overexpressed in laryngocarcinoma cells. Silencing of LOXL1-AS1 suppressed cell proliferation, migration and EMT in laryngocarcinoma. Moreover, miR-589-5p, the downstream of LOXL1-AS1, directly targeted TRAF6 in laryngocarcinoma. Importantly, LOXL1-AS1 augmented TRAF6 expression in laryngocarcinoma cells by sequestering miR-589-5p. Besides, miR-589-5p worked as a tumor-inhibitor while TRAF6 functioned as a tumor-facilitator in laryngocarcinoma. Of note, rescue experiments both in vitro and in vivo validated that LOXL1-AS1 aggravated the malignancy in laryngocarcinoma by targeting miR-589-5p/TRAF6 pathway.

Conclusions

LOXL1-AS1 promotes the proliferation and migration of laryngocarcinoma cells through absorbing miR-589-5p to upregulate TRAF6 expression.

Long Non-Coding RNA LOXL1-AS1 Enhances Colorectal Cancer Proliferation, Migration and Invasion Through miR-708-5p/CD44-EGFR Axis

Introduction

Colorectal cancer (CRC), the third most common cancer worldwide, involves a physiological and pathological long non-coding RNA (lncRNA) paradigm shift. It has been reported that the lncRNA LOXL1-AS1 affects tumor development for many kinds of cancers, but its functions and mechanisms in CRC remain unknown.

Methods

Expression levels of LOXL1-AS1 and miR-708-5p within CRC tissues and cell lines were measured using qRT-PCR. The performance of gain-of-function and loss-of-function assays was aimed at examining the effects of LOXL1-AS1 and miR-708-5p; colony formation and cell viability assays were carried out to measure cell multiplication; and Transwell migration and wound-healing assays were carried out for the measurement of cell migration and invasion. Luciferase reporter assay was used to verify the interactions between LOXL1-AS1 and miR-708-5p and between miR-708-5p and the CD44-EGFR signaling pathway. Finally, expression of CD44 and EGFR proteins was measured by Western blot and immunofluorescence assays.

Results

In this study, we reveal that the regulation of lncRNA LOXL1-AS1 occurs within CRC based on the correlation with poor clinical outcomes. LOXL1-AS1 knockdown along with miR-708-5p overpresentation in CRC cell lines inhibited cell multiplication, migration, and invasion. The inhibiting effect of LOXL1-AS1 knockdown on CRC was reversed by upregulating the CD44-EGFR signal pathway. From the perspective of mechanism, LOXL1-AS1 imposes sponging upon miR-708-5p and thereby promotes the CD44-EGFR signal pathway in CRC cells.

Discussion

This study demonstrated that lncRNA LOXL1-AS1 enhances multiplication, migration, invasion, and progression of CRC by sponging miR-708-5p to regulate the CD44-EGFR signal pathway.

Long Non-Coding RNA NEAT1 Promotes the Proliferation, Migration, and Metastasis of Human Breast-Cancer Cells by Inhibiting miR-146b-5p Expression

Background

Breast cancer (BC) is the most commonly diagnosed cancer in women. Tumor recurrence and metastasis are the key causes of death in BC patients. Long non-coding RNA (lncRNA) is closely associated with BC progression. lncRNA nuclear-enriched abundant transcript (NEAT)1 has been reported to regulate the proliferation and mobility of several types of cancer cells. However, how lncRNA NEAT1 affects the proliferation and invasion of BC cells is not known.

Methods

Quantitative real time-polymerase chain reaction (qRT-PCR) was used to measure expression of lncRNA NEAT1 and microRNA (miR)-146b-5p in BC tissues and cell lines. Cell Counting Kit (CCK)-8, cell colony-formation, wound-healing, and Transwell™ assays were undertaken to determine the effects of lncRNA NEAT1 and miR-146b-5p on progression of BC cells. The interaction between lncRNA NEAT1 and miR-146b-5p was examined by luciferase reporter, RNA-binding protein immunoprecipitation (RIP), and RNA-pulldown assays.

Results

Expression of lncRNA NEAT1 was upregulated in BC tissues and cell lines. High expression of lncRNA NEAT1 predicted poor overall survival in BC patients. Silencing of expression of lncRNA NEAT1 inhibited epithelial–mesenchymal transition (EMT) and suppressed the proliferation, migration and invasion of BC cells. Ectopic expression of lncRNA NEAT1 induced EMT and promoted BC progression. Mechanistic investigations revealed that miR-146b-5p was a direct target of lncRNA NEAT1, and its expression was correlated negatively with expression of lncRNA NEAT1 in BC tissues.

Conclusion

lncRNA NEAT1 could (i) serve as a novel prognostic marker for BC and (ii) be a potential therapeutic target for BC.

Long non-coding RNA MINCR aggravates colon cancer via regulating miR-708-5p-mediated Wnt/β-catenin pathway

BACKGROUND

Increasing evidence has found that the dysregulation of long non-coding RNAs (lncRNAs) may be important indicators in tumorigenesis. MYC-induced long non-coding RNA (MINCR) has been found to be related with some cancers, such as non-small cell lung cancer and gallbladder cancer. Besides, MINCR has potentially prognostic value for colon cancer (CC) patients' prognosis, yet its function and molecular mechanism in CC are not explored.

METHODS

qRT-PCR evaluated gene expression, and western blot detected protein level. In vitro and in vivo experiments were adopted to understand the biological role of MINCR in CC. TOP/FOP Flash assay was performed to measure the activity of Wnt/β-catenin pathway. RNA pull down, luciferase reporter and RIP assays were utilized to analyze the relationship among genes. Immunohistochemistry and HE staining techniques were utilized to evaluate Ki67 staining in xenografts.

RESULTS

MINCR was up-regulated in CC cells. Knockdown of MINCR suppressed cell proliferation and migration. MINCR could up-regulate CTNNB1 via sequestering miR-708-5p, resulting in activated Wnt/β-catenin pathway. The addition of LiCl treatment, miR-708-5p inhibitor or pcDNA3.1/CTNNB1 abolished the inhibitory impacts induced by MINCR silence in CC progression.

CONCLUSION

MINCR sponges miR-708-5p to up-regulate CTNNB1 and activate Wnt/β-catenin pathway, thus promoting the development CC. Targeting MINCR might shed new light on the therapeutic strategies of CC.