Knockdown of lncRNA LEF1-AS1 inhibited the progression of oral squamous cell carcinoma (OSCC) via Hippo signaling pathway

Interaction of noncoding RNAs with hippo signaling pathway in cancer cells and cancer stem cells

The Hippo signaling pathway has a regulatory function in the organogenesis process and cellular homeostasis, switching the cascade reactions of crucial kinases acts to turn off/on the Hippo pathway, altering the downstream gene expression and thereby regulating proliferation, apoptosis, or stemness. Disruption of this pathway can lead to the occurrence of various disorders and different types of cancer. Recent findings highlight the importance of ncRNAs, such as microRNA, circular RNA, and lncRNAs, in modulating the Hippo pathway. Defects in ncRNAs can disrupt Hippo pathway balance, increasing tumor cells, tumorigenesis, and chemotherapeutic resistance. This review summarizes ncRNAs' inhibitory or stimulatory role in - Hippo pathway regulation in cancer and stem cells. Identifying the relation between ncRNAs and the components of this pathway could pave the way for developing new biomarkers in the treatment and diagnosis of cancers.

Non-coding RNAs in oral cancer: Emerging biomarkers and therapeutic frontier

Around the world, oral cancer (OC) is a major public health problem, resulting in a significant number of deaths each year. Early detection and treatment are crucial for improving patient outcomes. Recent progress in DNA sequencing and transcriptome profiling has revealed extensive non-coding RNAs (ncRNAs) transcription, underscoring their regulatory importance. NcRNAs influence genomic transcription and translation and molecular signaling pathways, making them valuable for various clinical applications. Combining spatial transcriptomics (ST) and spatial metabolomics (SM) with single-cell RNA sequencing provides deeper insights into tumor microenvironments, enhancing diagnostic and therapeutic precision for OC. Additionally, the exploration of salivary biomarkers offers a non-invasive diagnostic avenue. This article explores the potential of ncRNAs as diagnostic and therapeutic tools for OC.

Ferroptosis as a hero against oral cancer

Cancer is an abnormal condition altering the cells to proliferate out of control simultaneously being susceptible to evolution. The lining which is made up of tissues in the lips, upper throat and mouth can undergo mutations, is recognised as mouth cancer or oral cancer. Substantial number of mouth lesions are identified at a point where it is typically not possible to get effective remedial care. Ferroptosis is a cutting-edge instance of cellular destruction which stands out in distinction to other sorts of cell death. It appears to have distinctive cellular, molecular and gene-level attributes and scavenges on deposits of reactive oxygen species triggered via iron-induced lipid peroxidation. It is said to be involved dichotomously in cancer development. Because the ferroptotic tumour cells put out numerous chemicals that alternatively signal for cancer attenuation or growth. There is increasing proof that researchers are now keenly investigating to stimulate ferroptosis through various inducers and pathways in the intent for oral cancer therapeutics, specifically to kill malignant tumours that refuse to respond well to conventional treatments. Also, it has the ability to reverse chemotherapy and radiotherapy resistance in victims maximising the success rate of the treatments. This review centres on the stimulation of ferroptosis as a stand-alone therapy for oral cancer, or in combination with other medicines, agents and pathways.

The roles of lncRNAs in the development of drug resistance of oral cancers

Oral cancers are a significant global health concern, with a high incidence of treatment failure primarily due to the development of drug resistance. Long non-coding RNAs (lncRNAs) have emerged as critical regulators of gene expression, playing pivotal roles in various cellular processes, including tumor progression and response to therapy. This review explores the multifaceted roles of lncRNAs in the development of drug resistance in oral cancers. We highlight the mechanisms by which lncRNAs modulate drug efflux, apoptosis, epithelial-mesenchymal transition (EMT), and other pathways associated with chemoresistance. Key lncRNAs implicated in resistance to commonly used chemotherapeutic agents in oral cancers are discussed, along with their potential as therapeutic targets. Understanding the involvement of lncRNAs in drug resistance mechanisms offers promising avenues for overcoming treatment barriers and improving patient outcomes. This review underscores the need for further research to elucidate the precise roles of lncRNAs in oral cancer resistance and their translation into clinical interventions.

Novel insights on oral squamous cell carcinoma management using long non-coding RNAs

Oral squamous cell carcinoma (OSCC) is one of the most prevalent forms of head and neck squamous cell carcinomas (HNSCC) with a poor overall survival rate (about 50%), particularly in cases of metastasis. RNA-based cancer biomarkers are a relatively advanced concept, and non-coding RNAs currently have shown promising roles in the detection and treatment of various malignancies. This review underlines the function of long non-coding RNAs (lncRNAs) in the OSCC and its subsequent clinical implications. LncRNAs, a class of non-coding RNAs, are larger than 200 nucleotides and resemble mRNA in numerous ways. However, unlike mRNA, lncRNA regulates multiple druggable and non-druggable signaling molecules through simultaneous interaction with DNA, RNA, proteins, or microRNAs depending on concentration and localization in cells. Upregulation of oncogenic lncRNAs and down-regulation of tumor suppressor lncRNAs are evident in OSCC tissues and body fluids such as blood and saliva indicating their potential as valuable biomarkers. Targeted inhibition of candidate oncogenic lncRNAs or over-expression of tumor suppressor lncRNAs showed potential therapeutic roles in in-vivo animal models. The types of lncRNAs that are expressed differentially in OSCC tissue and bodily fluids have been systematically documented with specificity and sensitivity. This review thoroughly discusses the biological functions of such lncRNAs in OSCC cell survival, proliferation, invasion, migration, metastasis, angiogenesis, metabolism, epigenetic modification, tumor immune microenvironment, and drug resistance. Subsequently, we addressed the diagnostic and therapeutic importance of lncRNAs in OSCC pre-clinical and clinical systems, providing details on ongoing research and outlining potential future directions for advancements in this field. In essence, this review could be a valuable resource by offering comprehensive and current insights into lncRNAs in OSCC for researchers in fundamental and clinical domains.

Epidemiology, Diagnostics, and Therapy of Oral Cancer-Update Review

Oral cavity and lip cancers are the 16th most common cancer in the world. It is widely known that a lack of public knowledge about precancerous lesions, oral cancer symptoms, and risk factors leads to diagnostic delay and therefore a lower survival rate. Risk factors, which include drinking alcohol, smoking, HPV infection, a pro-inflammatory factor-rich diet, and poor oral hygiene, must be known and avoided by the general population. Regular clinical oral examinations should be enriched in an oral cancer search protocol for the most common symptoms, which are summarized in this review. Moreover, new diagnostic methods, some of which are already available (vital tissue staining, optical imaging, oral cytology, salivary biomarkers, artificial intelligence, colposcopy, and spectroscopy), and newly researched techniques increase the likelihood of stopping the pathological process at a precancerous stage. Well-established oral cancer treatments (surgery, radiotherapy, chemotherapy, and immunotherapy) are continuously being developed using novel technologies, increasing their success rate. Additionally, new techniques are being researched. This review presents a novel glance at oral cancer-its current classification and epidemiology-and will provide new insights into the development of new diagnostic methods and therapies.

Relationship between long non-coding RNAs and Hippo signaling pathway in gastrointestinal cancers; molecular mechanisms and clinical significance

Long non-coding RNAs (lncRNAs) play a significant biological role in the regulation of various cellular processes such as cell proliferation, differentiation, apoptosis and migration. In various malignancies, lncRNAs interplay with some main cancer-associated signaling pathways, including the Hippo signaling pathway to regulate the various cellular processes. It has been revealed that the cross-talking between lncRNAs and Hippo signaling pathway involves in gastrointestinal (GI) cancers development and progression. Considering the clinical significance of these lncRNAs, they have also been introduced as potential biomarkers in diagnostic, prognostic and therapeutic strategies in GI cancers. Herein, we review the mechanisms of lncRNA-mediated regulation of Hippo signaling pathway and focus on the corresponding molecular mechanisms and clinical significance of these non-coding RNAs in GI cancers.

Mechanism of LEF1-AS1 regulating HUVEC cells by targeting miR-489-3p/S100A11 axis

Background

The venous malformation is the most common congenital vascular malformation and exhibits the characteristics of local invasion and lifelong progressive development. Long noncoding RNA (lncRNA) regulates endothelial cells, vascular smooth muscle cells, macrophages, vascular inflammation, and metabolism and also affects the development of venous malformations. This study aimed to elucidate the role of the lncRNA LEF1-AS1 in the development of venous malformations and examine the interaction among LEF1-AS1, miR-489-3p, and S100A11 in HUVEC cells.

Methods

Venous malformation tissues, corresponding normal venous tissues, and HUVEC cells were used. Agilent human lncRNA microarray gene chip was used to screen differential genes, RNA expression was detected using quantitative reverse transcription PCR, and protein expression was detected using Western blotting. The proliferation, migration, and angiogenesis of HUVEC cells were assessed using CCK8, transwell, and in vitro angiogenesis tests.

Results

A total of 1,651 lncRNAs were screened using gene chip analysis, of which 1015 were upregulated and 636 were downregulated. The lncRNA LEF1-AS1 was upregulated with an obvious difference multiple, and the fold-change value was 11.03273. The results of the analysis performed using the StarBase bioinformatics prediction website showed that LEF1-AS1 and miR-489-3p possessed complementary binding sites and that miR-489-3p and S100A11 also had complementary binding sites. The findings of tissue experiments revealed that the expressions of LEF1-AS1 and S100A11 were higher in tissues with venous malformations than in normal tissues, whereas the expression of miR-489-3p was lower in venous malformations than in normal tissues. Cell culture experiments indicated that LEF1-AS1 promoted the proliferation, migration, and angiogenesis of HUVEC cells. In these cells, LEF1-AS1 targeted miR-489-3p, which in turn targeted S100A11. LEF1-AS1 acted as a competitive endogenous RNA and promoted the expression of S100A11 by competitively binding to miR-489-3p and enhancing the proliferation, migration, and angiogenesis of HUVEC cells. Thus, LEF1-AS1 participated in the occurrence and development of venous malformation.

Conclusions

The expression of LEF1-AS1 was upregulated in venous malformations, and the expression of S100A11 was increased by the adsorption of miR-489-3p to venous endothelial cells, thus enhancing the proliferation, migration, and angiogenesis of HUVEC cells. In conclusion, LEF1-AS1 is involved in the occurrence and development of venous malformations by regulating the miR-489-3p/S100A11 axis, which provides valuable insights into the pathogenesis of this disease and opens new avenues for its treatment.

HCG18, LEF1AS1 and lncCEACAM21 as biomarkers of disease severity in the peripheral blood mononuclear cells of COVID-19 patients

BACKGROUND

Even after 3 years from SARS-CoV-2 identification, COVID-19 is still a persistent and dangerous global infectious disease. Significant improvements in our understanding of the disease pathophysiology have now been achieved. Nonetheless, reliable and accurate biomarkers for the early stratification of COVID-19 severity are still lacking. Long noncoding RNAs (LncRNAs) are ncRNAs longer than 200 nucleotides, regulating the transcription and translation of protein-coding genes and they can be found in the peripheral blood, thus holding a promising biomarker potential. Specifically, peripheral blood mononuclear cells (PBMCs) have emerged as a source of indirect biomarkers mirroring the conditions of tissues: they include monocytes, B and T lymphocytes, and natural killer T cells (NKT), being highly informative for immune-related events.

METHODS

We profiled by RNA-Sequencing a panel of 2906 lncRNAs to investigate their modulation in PBMCs of a pilot group of COVID-19 patients, followed by qPCR validation in 111 hospitalized COVID-19 patients.

RESULTS

The levels of four lncRNAs were found to be decreased in association with COVID-19 mortality and disease severity: HLA Complex Group 18-242 and -244 (HCG18-242 and HCG18-244), Lymphoid Enhancer Binding Factor 1-antisense 1 (LEF1-AS1) and lncCEACAM21 (i.e. ENST00000601116.5, a lncRNA in the CEACAM21 locus). Interestingly, these deregulations were confirmed in an independent patient group of hospitalized patients and by the re-analysis of publicly available single-cell transcriptome datasets. The identified lncRNAs were expressed in all of the PBMC cell types and inversely correlated with the neutrophil/lymphocyte ratio (NLR), an inflammatory marker. In vitro, the expression of LEF1-AS1 and lncCEACAM21 was decreased upon THP-1 monocytes exposure to a relevant stimulus, hypoxia.

CONCLUSION

The identified COVID-19-lncRNAs are proposed as potential innovative biomarkers of COVID-19 severity and mortality.

Non-Coding RNAs in Oral Cancer: Emerging Roles and Clinical Applications

Oral cancer (OC) is among the most prevalent cancers in the world. Certain geographical areas are disproportionately affected by OC cases due to the regional differences in dietary habits, tobacco and alcohol consumption. However, conventional therapeutic methods do not yield satisfying treatment outcomes. Thus, there is an urgent need to understand the disease process and to develop diagnostic and therapeutic strategies for OC. In this review, we discuss the role of various types of ncRNAs in OC, and their promising clinical implications as prognostic or diagnostic markers and therapeutic targets. MicroRNA (miRNA), long ncRNA (lncRNA), circular RNA (circRNA), PIWI-interacting RNA (piRNA), and small nucleolar RNA (snoRNA) are the major ncRNA types whose involvement in OC are emerging. Dysregulated expression of ncRNAs, particularly miRNAs, lncRNAs, and circRNAs, are linked with the initiation, progression, as well as therapy resistance of OC via modulation in a series of cellular pathways through epigenetic, transcriptional, post-transcriptional, and translational modifications. Differential expressions of miRNAs and lncRNAs in blood, saliva or extracellular vesicles have indicated potential diagnostic and prognostic importance. In this review, we have summarized all the promising aspects of ncRNAs in the management of OC.

Noncoding RNAs in oral cancer

Oral cancer (OC) is the most prevalent subtype of cancer arising in the head and neck region. OC risk is mainly attributed to behavioral risk factors such as exposure to tobacco and excessive alcohol consumption, and a lesser extent to viral infections such as human papillomaviruses and Epstein-Barr viruses. In addition to these acquired risk factors, heritable genetic factors have shown to be associated with OC risk. Despite the high incidence, biomarkers for OC diagnosis are lacking and consequently, patients are often diagnosed in advanced stages. This delay in diagnosis is reflected by poor overall outcomes of OC patients, where 5-year overall survival is around 50%. Among the biomarkers proposed for cancer detection, noncoding RNA (ncRNA) can be considered as one of the most promising categories of biomarkers due to their role in virtually all cellular processes. Similar to other cancer types, changes in expressions of ncRNAs have been reported in OC and a number of ncRNAs have diagnostic, prognostic, and therapeutic potential. Moreover, some ncRNAs are capable of regulating gene expression by various mechanisms. Therefore, elucidating the current literature on the four main types of ncRNAs namely, microRNA, lncRNA, snoRNA, piwi-RNA, and circular RNA in the context of OC pathogenesis is timely and would enable further improvements and innovations in diagnosis, prognosis, and treatment of OC. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA in Disease and Development > RNA in Development.

Vaspin alleviates the lncRNA LEF1-AS1-induced osteogenic differentiation of vascular smooth muscle cells via the Hippo/YAP signaling pathway

Vascular calcification (VC) is closely related to higher cardiovascular mortality and morbidity, and vascular smooth muscle cell (VSMC) switching to osteogenic-like cells is crucial for VC. LncRNA LEF1-AS1 promotes atherosclerosis and dental pulp stem cells calcification, while its role in VC remains unknown. Visceral adipose tissue-derived serine protease inhibitor (vaspin) is an adipokine regulating bone metabolism. However, the relationship between vaspin and VC is still unclear. We aimed to explore the role of LEF1-AS1 on VSMC osteogenic transition, whether vaspin inhibited LEF1-AS1-mediated osteogenic differentiation of VSMCs, and the responsible mechanism. In this study, quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting analysis indicated that LEF1-AS1 overexpression significantly upregulated osteogenic marker Runt-related transcription factor-2 (RUNX2) level and downregulated VSMC contractile marker α-smooth muscle actin (α-SMA) level. Alizarin red staining, alkaline phosphatase (ALP) staining, ALP activity assay, and calcium content assay also suggested that LEF1-AS1 overexpression promoted calcium deposition in VSMCs. However, vaspin treatment abolished this phenomenon. Mechanistically, LEF1-AS1 markedly decreased phosphorylated YAP level, while vaspin reversed LEF1-AS1-induced phosphorylated YAP decline. Our results revealed that LEF1-AS1 accelerated the osteogenic differentiation of VSMCs by regulating the Hippo/YAP pathway, while vaspin eliminated the LEF1-AS1-meditated VSMCs osteogenic phenotype switch.

Circulating Long Non-Coding RNAs Could Be the Potential Prognostic Biomarker for Liquid Biopsy for the Clinical Management of Oral Squamous Cell Carcinoma

Long non-coding RNA (lncRNA) have little or no coding potential. These transcripts are longer than 200 nucleotides. Since lncRNAs are master regulators of almost all biological processes, recent evidence proves that aberrantly expressed lncRNAs are pathogenic for oral squamous cell carcinoma (OSCC) and other diseases. LncRNAs influence chromatin modifications, transcriptional modifications, post-transcriptional modifications, genomic imprinting, cell proliferation, invasion, metastasis, and apoptosis. Consequently, they have an impact on the disease transformation, progression, and morbidity in OSCC. Therefore, circulating lncRNAs could be the potential cancer biomarker for the better clinical management (diagnosis, prognosis, and monitoring) of OSCC to provide advanced treatment strategies and clinical decisions. In this review, we report and discuss the recent understandings and perceptions of dysregulated lncRNAs with a focus on their clinical significance in OSCC-disease monitoring and treatment. Evidence clearly indicates that a specific lncRNA expression signature could act as an indicator for the early prediction of diagnosis and prognosis for the initiation, progression, recurrence, metastasis and other clinical prognostic-factors (overall survival, disease-free survival, etc.) in OSCC. The present review demonstrates the current knowledge that all potential lncRNA expression signatures are molecular biomarkers for the early prediction of prognosis in OSCC. Finally, the review provides information about the clinical significance, challenges and limitations of the clinical usage of circulating lncRNAs in a liquid biopsy method in early, pre-symptomatic, sub-clinical, accurate OSCC prognostication. More studies on lncRNA are required to unveil the biology of the inherent mechanisms involved in the process of the development of differential prognostic outcomes in OSCC.

The role of long noncoding RNAs as regulators of the epithelial–Mesenchymal transition process in oral squamous cell carcinoma cells

Oral squamous cell carcinoma (OSCC) is a highly invasive and relatively prevalent cancer, accounting for around 3% of all cancers diagnosed. OSCC is associated with bad outcomes, with only 50% overall survival (OS) after five years. The ability of OSCC to invade local and distant tissues relies on the induction of the epithelial–mesenchymal transition (EMT), wherein epithelial cells shed their polarity and cell-to-cell contacts and acquire mesenchymal characteristics. Consequently, a comprehensive understanding of how tumor cell EMT induction is regulated has the potential of direct attempts to prevent tumor progression and metastasis, resulting in better patient outcomes. Several recent studies have established the significance of particular long noncoding RNAs (lncRNAs) in the context of EMT induction. Moreover, lncRNAs regulate a vast array of oncogenic pathways. With a focus on the mechanisms by which the underlined lncRNAs shape the metastatic process and a discussion of their potential utility as clinical biomarkers or targets for therapeutic intervention in patients with OSCC, the present review thus provides an overview of the EMT-related lncRNAs that are dysregulated in OSCC.

LINC01063 functions as an oncogene in melanoma through regulation of miR-5194-mediated SOX12 expression

Melanoma is one of the most aggressive skin cancers and a major cause of cancer-linked deaths worldwide. As the morbidity and mortality of melanoma are increasing, it is necessary to elucidate the potential mechanism influencing melanoma progression. Tumor tissues and adjacent normal tissues (5 cm away from tumors) from 22 melanoma patients at the I-II stage and 39 patients at the III-VI stage were acquired. The expression of LINC01063 in melanoma was estimated by quantitative PCR. Functional assays were employed to investigate the function of LINC01063 in melanoma. Mechanism assays were adopted to explore the mechanism of LINC01063. LINC01063 knockdown impeded melanoma cell proliferation, migration, invasion, and epithelial-mesenchymal transition as well as melanoma tumor growth. Mechanistically, LINC01063 acted as an miR-5194 sponge to upregulate SOX12 expression. Finally, LINC01063 was tested to facilitate the malignant behaviors of melanoma cells via targeting miR-5194/SOX12. LINC01063 was significantly upregulated in melanoma. Specifically, LINC01063 displayed a higher level in patients at an advanced stage or with metastasis than those at an early stage or without metastasis. Our study revealed the oncogenic effects of LINC01063 on melanoma cell/tumor growth and its molecular mechanism involving miR-5194/SOX12, which might support LINC01063 to be the potential prognostic or therapeutic biomarker against melanoma.

The interplay between noncoding RNA and YAP/TAZ signaling in cancers: molecular functions and mechanisms

The Hippo signaling pathway was found coordinately modulates cell regeneration and organ size. Its dysregulation contributes to uncontrolled cell proliferation and malignant transformation. YAP/TAZ are two critical effectors of the Hippo pathway and have been demonstrated essential for the initiation or growth of most tumors. Noncoding RNAs (ncRNAs), including miRNAs, lncRNAs, and circRNAs, have been shown to play critical roles in the development of many cancers. In the past few decades, a growing number of studies have revealed that ncRNAs can directly or indirectly regulate YAP/TAZ signaling. YAP/TAZ also regulate ncRNAs expression in return. This review summarizes the interactions between YAP/TAZ signaling and noncoding RNAs together with their biological functions on cancer progression. We also try to describe the complex feedback loop existing between these components.

Transcriptome sequencing and lncRNA-miRNA-mRNA network construction in cardiac fibrosis and heart failure

Cardiac fibrosis (CF) and heart failure (HF) are common heart diseases, and severe CF can lead to HF. In this study, we tried to find their common potential molecular markers, which may help the diagnosis and treatment of CF and HF. RNA library construction and high-throughput sequencing were performed. The DESeq2 package in R was used to screen differentially expressed mRNAs (DEmRNAs), differentially expressed lncRNA (DElncRNAs) and differentially expressed miRNA (DEmiRNAs) between different samples. The common DEmRNAs, DElncRNAs and DEmiRNAs for the two diseases were obtained. The ConsensusPathDB (CPDB) was used to perform biological function enrichment for common DEmRNAs. Gene interaction network was constructed to screen out key genes. Subsequently, real-time polymerase chain reaction (RT-PCR) verification was performed. Lastly, GSE104150 and GSE21125 data sets were utilized for expression validation and diagnostic analysis. There were 1477 DEmRNAs, 502 DElncRNAs and 36 DEmiRNAs between CF and healthy control group. There were 607 DEmRNAs, 379DElncRNAs,s and 42 DEmiRNAs between HF and healthy control group. CH and FH shared 146 DEmRNAs, 80 DElncRNAs, and 6 DEmiRNAs. Hsa-miR-144-3p, CCNE2, C9orf72, MAP3K20-AS1, LEF1-AS1, AC243772.2, FLJ46284, and AC239798.2 were key molecules in lncRNA-miRNA-mRNA network. In addition, hsa-miR-144-3p and CCNE2 may be considered as potential diagnostic gene biomarkers in HF. In this study, the identification of common biomarkers of CF and HF may help prevent CF to HF transition as early as possible.

Current Research Progress of the Role of LncRNA LEF1-AS1 in a Variety of Tumors

Long non-coding RNAs (lncRNA), as key regulators of cell proliferation and death, are involved in the regulation of various processes in the nucleus and cytoplasm, involving biological developmental processes in the fields of immunology, neurobiology, cancer, and stress. There is great scientific interest in exploring the relationship between lncRNA and tumors. Many researches revealed that lymph enhancer-binding factor 1-antisense RNA 1 (LEF1-AS1), a recently discovered lncRNA, is downregulated in myeloid malignancy, acting mainly as a tumor suppressor, while it is highly expressed and carcinogenic in glioblastoma (GBM), lung cancer, hepatocellular carcinoma (HCC), osteosarcoma, colorectal cancer (CRC), oral squamous cell carcinoma (OSCC), prostatic carcinoma, retinoblastoma, and other malignant tumors. Furthermore, abnormal LEF1-AS1 expression was associated with tumorigenesis, development, survival, and prognosis via the regulation of target genes and signaling pathways. This review summarizes the existing data on the expression, functions, underlying mechanism, relevant signaling pathways, and clinical significance of LEF1-AS1 in cancer. It is concluded that LEF1-AS1 can serve as a novel biomarker for the diagnosis and prognosis of various tumors, thus deserves further attention in the future.

Development of a novel five-lncRNA prognostic signature for predicting overall survival in elderly patients with breast cancer

Background

Breast cancer (BC) is an age‐related disease. Long noncoding RNAs (lncRNAs) have been proven to be crucial contributors in tumorigenesis. This study aims to develop a novel lncRNA‐based signature to predict elderly BC patients’ prognosis.

Methods

The RNA expression profiles and corresponding clinical information of 182 elderly BC patients were retrieved from The Cancer Genome Atlas (TCGA). Differentially expressed lncRNAs (DElncRNAs) between BC and adjacent normal samples were used to construct the signature in the training set through univariate Cox regression analysis, LASSO regression analysis, and multivariate Cox regression analysis. Kaplan–Meier analysis and time‐dependent receiver operating characteristic (ROC) analysis were used to evaluate the predictive performance. Besides, we developed the nomogram. Gene set enrichment analysis (GSEA) was performed to reveal the underlying molecular mechanisms.

Results

We constructed the five‐lncRNA signature (including LEF1‐AS1, MEF2C‐AS1, ST8SIA6‐AS1, LINC01224, and LINC02408) in the training set, which successfully divided the patients into low‐ and high‐risk groups with significantly different prognosis (p = 0.000049), and the AUC at 3 and 5 years of the signature was 0.779 and 0.788, respectively. The predictive performance of this signature was validated in the test and entire set. The 5‐lncRNA signature was an independent prognostic factor of OS (p = 0.007) and the nomogram constructed by independent prognostic factors was an accurate predictor of predicting overall survival probability. Besides, several pathways associated with tumorigenesis have been identified by GSEA.

Conclusions

The 5‐lncRNA signature and nomogram are reliable in predicting elderly BC patients’ prognosis and provide clues for clinical decision‐making.

Long Non-Coding RNA (lncRNA) in Oral Squamous Cell Carcinoma: Biological Function and Clinical Application

Simple Summary

Increasing evidence has revealed the regulatory roles of long non-coding RNAs (lncRNAs) in the initiation and progress of oral squamous cell carcinoma (OSCC). As some novel lncRNA-targeted techniques combined with immune checkpoint therapies have emerged, they provide a new strategy for OSCC treatment. This review summarizes current knowledge regarding the involvement of lncRNAs in OSCC along with their possible use as diagnostic and prognostic biomarker and therapeutic targets.

Abstract

Oral squamous cell carcinoma (OSCC) is a type of malignancy with high mortality, leading to poor prognosis worldwide. However, the molecular mechanisms underlying OSCC carcinogenesis have not been fully understood. Recently, the discovery and characterization of long non-coding RNAs (lncRNAs) have revealed their regulatory importance in OSCC. Abnormal expression of lncRNAs has been broadly implicated in the initiation and progress of tumors. In this review, we summarize the functions and molecular mechanisms regarding these lncRNAs in OSCC. In addition, we highlight the crosstalk between lncRNA and tumor microenvironment (TME), and discuss the potential applications of lncRNAs as diagnostic and prognostic tools and therapeutic targets in OSCC. Notably, we also discuss lncRNA-targeted therapeutic techniques including CRISPR-Cas9 as well as immune checkpoint therapies to target lncRNA and the PD-1/PD-L1 axis. Therefore, this review presents the future perspectives of lncRNAs in OSCC therapy, but more research is needed to allow the applications of these findings to the clinic.

Knockdown of lncRNA IGF2BP2-AS1 inhibits proliferation and migration of oral squamous cell carcinoma cells via the Wnt/β-catenin pathway

BACKGROUND

Long non-coding RNA IGF2BP2 antisense RNA1 (lncRNA IGF2BP2-AS1) has been used to predict the overall survival rate of lung squamous cell carcinoma. This research aims to investigate the effect of IGF2BP2-AS1 in oral squamous cell carcinoma (OSCC).

METHODS

The TCGA database was applied to evaluate the level of IGF2BP2-AS1 and its correlation with the clinicopathological characteristics of OSCC. The levels of IGF2BP2-AS1 in 30 OSCC and 20 normal tissue samples were detected by RT-qPCR. The distributions of IGF2BP2-AS1 in two OSCC cell lines (ie, Cal27 and SCC9) were detected by FISH. Colony formation, flow cytometry, wound-healing, transwell, and Western blotting analyses were used for evaluating the effect of IGF2BP2-AS1 on OSCC progression.

RESULTS

In comparison with the normal tissue samples, OSCC showed higher expression of IGF2BP2-AS1. High expression of IGF2BP2-AS1 was associated with poor survival in OSCC patients. Results of FISH showed that IGF2BP2-AS1 was mainly present in the cytoplasm. Further in vitro functional tests demonstrated that downregulation of IGF2BP2-AS1 in Cal27 and SCC9 cells significantly inhibited cell proliferation and migration, leading to cell-cycle arrest and cell apoptosis. Western blotting showed that expressions of β-catenin, Cyclin D1, Bcl-2, and MMP2 were downregulated, whereas Bax was upregulated following knockdown of IGF2BP2-AS1. The inhibitory effect of knockdown of IGF2BP2-AS1 on migration could be partially reversed by the Wnt/β-catenin pathway stimulator LiCl.

CONCLUSION

Our results suggest that knockdown of IGF2BP2-AS1 suppresses cell growth, migration and promotes apoptosis in OSCC cells, providing a new molecular target for OSCC.

lncRNA DCST1-AS1 Facilitates Oral Squamous Cell Carcinoma by Promoting M2 Macrophage Polarization through Activating NF-κB Signaling

lncRNAs are related to the progression of various diseases, including oral squamous cell carcinoma (OSCC), which is a common squamous cell carcinoma of the head and neck. Tumor-associated macrophages and tumor cells are significant components of tumor microenvironment. M2 polarization of tumor-associated macrophages is a crucial actor in tumor malignancy and metastasis. In this study, we studied the molecular mechanism of lncRNA DCST1-AS1 in OSCC. Here, we reported that DCST1-AS1 was significantly increased in OSCC cells. We found that loss of DCST1-AS1 obviously inhibited the proliferation, migration, and invasion of OSCC cells and xenograft tumor growth. Meanwhile, silencing of DCST1-AS1 also repressed the percentage of macrophages expressing M2 markers CD206 and CD11b. DCST1-AS1 shRNA enhanced the percentage of macrophages expressing M1 markers CD80 and CD11c. Then, we observed that loss of DCST1-AS1 suppressed OSCC progression via inactivating NF-κB signaling. As well established, NF-κB signaling exerts critical roles in tumor progression, and our study proved that DCST1-AS1 could regulate NF-κB signaling. We proved that blocking the NF-κB pathway using antagonists greatly downregulated OSCC progression and M2 macrophage polarization induced by the overexpression of DCST1-AS1. To sum up, we reported that DCST1-AS1 plays an important role in modulating OSCC tumorigenicity and M2 macrophage polarization through regulating the NF-κB pathway.

lncRNA TSPEAR-AS2, a Novel Prognostic Biomarker, Promotes Oral Squamous Cell Carcinoma Progression by Upregulating PPM1A via Sponging miR-487a-3p

Background

Long noncoding RNA (lncRNA) critically impacts the modulation of tumor developments and progressions. Our study is aimed at investigating the expressing patterns, clinical significance, and biological roles of lncRNA TSPEAR-AS2 (TSPEAR-AS2) in oral squamous cell carcinoma (OSCC). Material and Approach. The expressing states achieved by TSPEAR-AS2 were examined in OSCC specimens and cell lines by RT-PCR. The clinical significance of TSPEAR-AS2 was statistically analyzed. OSCC proliferating, invading, and migrating processes were examined with the use of wound healing assays, transwell, colony formation, and cell counting kit-8. Additionally, the downstream molecular mechanism of TSPEAR-AS2 in OSCC was explored.

Results

TSPEAR-AS2 was overexpressed in OSCC tumors and cells. High TSPEAR-AS2 was associated with advanced TNM stage. Patients with high TSPEAR-AS2 expression displayed a shorter disease-free survival and total survival of OSCC patients than those with low TSPEAR-AS2 expressing level. It was found that knockdown of TSPEAR-AS2 could inhibit the proliferating, invading, and migrating processes pertaining to OSCC cells. Luciferase reporter tests and RNA pull-down results revealed that TSPEAR-AS2 enhanced the expressions of PPM1A by regulating miR-487a-3p, and TSPEAR-AS2 could be adopted as a miR-487a-3p sponge to inhibit PPM1A expression.

Conclusion

Our study highlighted the significance of the TSPEAR-AS2/miR-487a-3p/PPM1A axis within OSCC progression and offered a novel biomarker and novel strategies for OSCC treatments.

Integrative profiling analysis identifies the oncogenic long noncoding RNA DUXAP8 in oral cancer

A growing number of studies have revealed the critical roles of long noncoding RNAs (lncRNAs) in the tumorigenesis and cancer progression. Recently, next-generation sequencing technologies combined with bioinformatic have demonstrated that a great number of dysregulated lncRNAs are associated with diverse cancers. However, lots of lncRNAs' function and their underlying molecular mechanisms in oral carcinoma (OC) cancer remain unclear. In this study, we performed integrative lncRNA profiling analysis using the TCGA RNA sequencing data and gene microarray data from Gene Expression Omnibus to identify more OC associated lncRNAs. A total of 619 differentially expressed lncRNAs were identified between the five data sets, and only the double homeobox A pseudogene 8 (DUXAP8) was screened among the up-regulated lncRNAs in all the five groups. Meanwhile, univariate Cox regression analyses disclosed that some lncRNAs are associated with the outcome of OC patients, such as DUXAP8, LINC00152, MIR4435-2HG and LINC00582. Furthermore, we uncovered that silenced DUXAP8 expression exerted suppressive impact on the proliferation of OC cells through interacting with histone-lysine N-methyltransferase enzyme Enhancer of zeste homolog 2 (EZH2) and repressing KLF2 expression. In a word, we identified a lot of unreported OC associated lncRNAs, which may provide a useful resource of lncRNAs for other studies.

Long Non-Coding RNAs as Functional Codes for Oral Cancer: Translational Potential, Progress and Promises

Oral cancer is one of the leading malignant tumors worldwide. Despite the advent of multidisciplinary approaches, the overall prognosis of patients with oral cancer is poor, mainly due to late diagnosis. There is an urgent need to develop valid biomarkers for early detection and effective therapies. Long non-coding RNAs (lncRNAs) are recognized as key elements of gene regulation, with pivotal roles in various physiological and pathological processes, including cancer. Over the past few years, an exponentially growing number of lncRNAs have been identified and linked to tumorigenesis and prognosis outcomes in oral cancer, illustrating their emerging roles in oral cancer progression and the associated signaling pathways. Herein, we aim to summarize the most recent advances made concerning oral cancer-associated lncRNA, and their expression, involvement, and potential clinical impact, reported to date, with a specific focus on the lncRNA-mediated molecular regulation in oncogenic signaling cascades and oral malignant progression, while exploring their potential, and challenges, for clinical applications as biomarkers or therapeutic targets for oral cancer.

Long non-coding RNAs in head and neck squamous cell carcinoma: Diagnostic biomarkers, targeted therapies, and prognostic roles

At present, emerging evidence shows that non-coding RNAs (ncRNAs) play crucial roles for development of multiple tumors. Amongst these ncRNAs, long non-coding RNAs (lncRNAs) play prominent roles in physiological and pathological processes. LncRNAs are RNA transcripts larger than 200 nucleotides and have been shown to serve important regulatory roles in different types of cancer via interactions with DNA, RNA and proteins. Head and neck squamous cell carcinoma (HNSCC) is one of the most malignant tumors with low survival rates in advanced stages. Recently, lncRNAs have been demonstrated to be involved in a wide range of biological processes, including proliferation, metastasis, and prognosis of HNSCC. Therefore, this review describes molecular mechanisms of up- or down-regulation of lncRNAs and expounds their functions in pathology and clinical practices in HNSCC. It also highlights their potential clinical applications as biomarkers for the diagnosis, prognosis, and treatment of HNSCC. However, studies on lncRNAs are still not comprehensive, and more investigations are needed in the future.

Long Non-Coding RNA LINC01929 Accelerates Progression of Oral Squamous Cell Carcinoma by Targeting the miR-137-3p/FOXC1 Axis

Recently, additional long noncoding RNAs (lncRNAs) have been identified and their possible roles were investigated in a variety of human tumors. One of these lncRNAs, LINC01929, promoted the progression of some cancers, whereas its expression and biological function in human oral squamous cell carcinoma (OSCC) remains still mostly uncertain. The LINC01929 expression in OSCC tissues or cell lines was identified via quantitative real-time polymerase chain reaction. The cell counting kit-8, transwell migration, wound-healing, and flow cytometry assays were utilized to characterize the functions of LINC01929 in OSCC cells. The interactive relationships between LINC01929 and miR-137-3p, miR-137-3p and Forkhead box C1 (FOXC1) were investigated by the dual-luciferase activity assay. Our findings demonstrated that LINC01929 was highly expressed in OSCC tissue samples and cell lines, whereas miR-137-3p expression was downregulated. LINC01929 acted as a carcinogenic lncRNA with accelerated OSCC cell proliferation, migration and invasion, and suppression of apoptosis. We further indicated that LINC01929 facilitated tumor growth in xenograft mouse models. Mechanistically, LINC01929 acted as a sponge for miR-137-3p to elevate FOXC1 expression, which is the target of miR-137-3p. In addition, downregulated miR-137-3p expression rescued the suppressive behaviors of LINC01929 knockdown on the biological behaviors of OSCC cells. Taken together, LINC01929 functioned as a tumor-promoting lncRNA via the miR-137-3p/FOXC1 axis in OSCC, suggesting novel targets for OSCC therapy.

Advances in Understanding the LncRNA-Mediated Regulation of the Hippo Pathway in Cancer

Long noncoding RNAs (lncRNAs) are a class of RNA molecules that are longer than 200 nucleotides and cannot encode proteins. Over the past decade, lncRNAs have been defined as regulatory elements of multiple biological processes, and their aberrant expression contributes to the development and progression of various malignancies. Recent studies have shown that lncRNAs are involved in key cancer-related signaling pathways, including the Hippo signaling pathway, which plays a prominent role in controlling organ size and tissue homeostasis by regulating cell proliferation, apoptosis, and differentiation. However, dysregulation of this pathway is associated with pathological conditions, especially cancer. Accumulating evidence has revealed that lncRNAs can modulate the Hippo signaling pathway in cancer. In this review, we elaborate on the role of the Hippo signaling pathway and the advances in the understanding of its lncRNA-mediated regulation in cancer. This review provides additional insight into carcinogenesis and will be of great clinical value for developing novel early detection and treatment strategies for this deadly disease.

MiRNA expression profiling and emergence of new prognostic signature for oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC), the most common type of head and neck cancers, is associated with high recurrence, metastasis, low long-term survival rates and poor treatment outcome. As deregulated miRNA expression plays a crucial role in malignant transformation and cancer progression, the present study is aimed at profiling the miRNA expression pattern in OSCC and developing a new miRNA prognostic signature for oral cancer. MiRNA expression profiling was performed using MiRNA microarray in 30 tumor and 18 normal samples. MiRNA signature obtained was validated with quantitative real time PCR (qRT-PCR) in 144 tumor and 36 normal samples. The potential targets, clinical implications and prognostic value of the miRNA signature were elucidated by various bioinformatics and statistical analyses. Microarray profiling identified a set of 105 miRNAs to be differentially expressed in OSCC, out of which a subset of 19 most dysregulated miRNAs were validated by qRT-PCR. In silico analysis revealed the signature miRNAs to be involved in various cancer associated pathways. Up-regulation of miR-196a, miR-21, miR-1237 and downregulation of miR-204, miR-144 was associated with poor prognosis of OSCC patients. The mir-196a/miR-204 expression ratio emerged as best predictor for disease recurrence and patient survival. Altogether, our study identified a miRNA signature for OSCC with prognostic significance.

The clinical significance, prognostic value and biological role of lncRNA LINC01793 in oral squamous cell carcinoma

OBJECTIVE

The present study aimed to investigate the clinical significance and prognostic value of LINC01793 in OSCC patients, and to explore its role in the modulation of OSCC development.

METHODS

LINC01793 expression was analyzed in 80 cases of OSCC patients and SCC9, SCC25, Cal27, and HN6 cell lines by qRT-PCR. The association of LINC01793 expression with clinicopathological features and prognosis in OSCC patients was analyzed. The effects of LINC01793 on cell proliferation, cell cycle, migration, and invasion of SCC9 and Cal27 cells were detected by MTT, flow cytometry, and Transwell assays in vitro, respectively.

RESULTS

LINC01793 level was upregulated in cancer tissues and cell lines of OSCC, and its expression was increased in cancer tissues from patients with lymph node metastasis. ROC curve for LINC01793 expression and lymph node metastasis revealed a significant AUC of 0.84 (95 % CI: 0.75-0.93), with 76.51 % sensitivity and 83.69 % specificity. Moreover, high LINC01793 level was positively correlated with T category, TNM stage, lymph node metastasis, and local recurrence. OSCC patients with high level of LINC01793 was followed by low overall survival rate, and LINC01793 expression was an independent prognostic indicator for overall survival in patients with OSCC. Functionally, cell proliferation, invasion and migration of SCC9 and Cal27 cells were decreased after knockdown of LINC01793. Consistently, silence of LINC01793 induced G0/G1 cell cycle arrest in OSCC cells.

CONCLUSION

High LINC01793 level is correlated with adverse clinicopathological features and poor prognosis of patients with OSCC. LINC01793 act as an oncogenic role in the development of OSCC.

Long non-coding RNA OIP5-AS1 contributes to cisplatin resistance of oral squamous cell carcinoma through the miR-27b-3p/TRIM14 axis

Oral squamous cell carcinoma (OSCC) accounts for 90% of oral cavity cancer types, but the overall prognosis for patients with OSCC remains unfavorable. Cisplatin (DDP) is an effective drug in OSCC treatment, but DDP resistance weakens its therapeutic effect. Opa-interacting protein 5 antisense RNA 1 (OIP5-AS1) can trigger DDP resistance. The purpose of the current study was to explore the role and mechanism ofOIP5-AS1 in OSCC DDP resistance. In the present study, the expression levels of OIP5-AS1, microRNA (miR)-27b-3p and tripartite motif-containing 14 (TRIM14) were detected by reverse transcription-quantitative PCR. DDP resistance was measured using an MTT assay. Moreover, cell proliferation, migration and invasion were assessed by MTT, Transwell, and Matrigel assays. Protein expression levels of TRIM14, E-cadherin, N-cadherin and Vimentin were detected by western blot analysis. Putative binding sites between miR-27b-3p andOIP5-AS1 or TRIM14werepredicted with starBase and verified using a dual-luciferase reporter assay. The role of OIP5-AS1 in DDP resistance of OSCC in vivo was measured using a xenograft tumor model. It was observed that OIP5-AS1 was upregulated in DDP-resistant OSCC cells, and the knockdown of OIP5-AS1 improved DDP sensitivity in DDP-resistant OSCC cells. The present study identified that miR-27b-3p was a target of OIP5-AS1. Furthermore, miR-27b-3p silencing reversed the effect of OIP5-AS1 knockdown on DDP sensitivity in DDP-resistant OSCC cells. TRIM14was shown to be a direct target of miR-27b-3p, and TRIM14 overexpression abolished the effect of miR-27b-3p on DDP sensitivity in DDP-resistant OSCC cells. The results suggested that OIP5-AS1 increased TRIM14 expression by sponging miR-27b-3p. In addition, OIP5-AS1 knockdown enhanced DDP sensitivity of OSCC in vivo. Data from the present study indicated that OIP5-AS1 may improve DDP resistance through theupregulationTRIM14 mediated bymiR-27b-3p, providing a possible therapeutic strategy for OSCC treatment.

LncRNA FER1L4 Promotes Oral Squamous Cell Carcinoma Progression via Targeting miR-133a-5p/Prx1 Axis

Background

Oral squamous cell carcinoma (OSCC) is a common cancer especially young people in the world. The long non-coding RNA Fer-1-like protein 4 (FER1L4) has been reported to be closely associated with the progression of various human cancers. However, the role of FER1L4 in OSCC remains unclear.

Methods

The expression level of FER1L4 in OSCC tissues and cancer cell lines was detected by using quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was evaluated by cell counting kit-8 (CCK-8) assay and EdU staining assay. Cell invasion and migration were evaluated by Transwell assay. Cell apoptosis was detected by flow cytometry. Luciferase reporter assay was performed to determine the targeting relationship between FER1L4, miR-133a-5p and Prx1. The protein expression of Prx1 was detected by Western blot. In addition, a xenograft tumor model in vivo was constructed to confirm the function of FER1L4.

Results

FERIL4 was significantly upregulated in OSCC tissues and cancer cell lines. Moreover, high level of FER1L4 predicted a poor prognosis of OSCC patients. Silencing of FER1L4 not only significantly inhibited cell growth, invasion, migration and induced apoptosis in SCC-9 and HN4 cells in vitro, but also effectively suppressed the tumorigenesis of OSCC cells in vivo. Knockdown of FER1L4 significantly enhanced the expression of miR-133a-5p by sponging it, and then downregulated Prx1 expression.

Conclusion

Our study elucidated a new mechanism of lncRNA FER1L4 that promoting OSCC progression by directly targeting miR-133a-5p/Prx1 axis and provided novel therapeutic targets for OSCC.

Long Noncoding RNAs in the Metastasis of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is a common malignant tumor worldwide. Metastasis is the main cause of the death of OSCC patients. Long noncoding RNAs (lncRNAs), one of the key factors affecting OSCC metastasis, are a subtype of RNA with a length of more than 200 nucleotides that has little or no coding potential. In recent years, the important role played by lncRNAs in biological processes, such as chromatin modification, transcription regulation, RNA stability regulation, and mRNA translation, has been gradually revealed. More and more studies have shown that lncRNAs can regulate the metastasis of various tumors including OSCC at epigenetic, transcriptional, and post-transcriptional levels. In this review, we mainly discussed the role and possible mechanisms of lncRNAs in OSCC metastasis. Most lncRNAs act as oncogenes and only a few lncRNAs have been shown to inhibit OSCC metastasis. Besides, we briefly introduced the research status of cancer-associated fibroblasts-related lncRNAs in OSCC metastasis. Finally, we discussed the research prospects of lncRNAs-mediated crosstalk between OSCC cells and the tumor microenvironment in OSCC metastasis, especially the potential research value of exosomes and lymphangiogenesis. In general, lncRNAs are expected to be used for screening, treatment, and prognosis monitoring of OSCC metastasis, but more work is still required to better understand the biological function of lncRNAs.

Knockdown of long non-coding RNA LEF1-AS1 attenuates apoptosis and inflammatory injury of microglia cells following spinal cord injury

BACKGROUND

Spinal cord injury (SCI) is associated with health burden both at personal and societal levels. Recent assessments on the role of lncRNAs in SCI regulation have matured. Therefore, to comprehensively explore the function of lncRNA LEF1-AS1 in SCI, there is an urgent need to understand its occurrence and development.

METHODS

Using in vitro experiments, we used lipopolysaccharide (LPS) to treat and establish the SCI model primarily on microglial cells. Gain- and loss of function assays of LEF1-AS1 and miR-222-5p were conducted. Cell viability and apoptosis of microglial cells were assessed via CCK8 assay and flow cytometry, respectively. Adult Sprague-Dawley (SD) rats were randomly divided into four groups: Control, SCI, sh-NC, and sh-LEF-AS1 groups. ELISA test was used to determine the expression of TNF-α and IL-6, whereas the protein level of apoptotic-related markers (Bcl-2, Bax, and cleaved caspase-3) was assessed using Western blot technique.

RESULTS

We revealed that LncRNA LEF1-AS1 was distinctly upregulated, whereas miR-222-5p was significantly downregulated in LPS-treated SCI and microglial cells. However, LEF1-AS1 knockdown enhanced cell viability, inhibited apoptosis, as well as inflammation of LPS-mediated microglial cells. On the contrary, miR-222-5p upregulation decreased cell viability, promoted apoptosis, and inflammation of microglial cells. Mechanistically, LEF1-AS1 served as a competitive endogenous RNA (ceRNA) by sponging miR-222-5p, targeting RAMP3. RAMP3 overexpression attenuated LEF1-AS1-mediated protective effects on LPS-mediated microglial cells from apoptosis and inflammation.

CONCLUSION

In summary, these findings ascertain that knockdown of LEF1-AS1 impedes SCI progression via the miR-222-5p/RAMP3 axis.

LncRNA LEF1-AS1 promotes metastasis of prostatic carcinoma via the Wnt/β-catenin pathway

BACKGROUND

Long noncoding RNAs (lncRNAs) are important functional regulators of many biological processes of cancers. However, the mechanisms by which lncRNAs modulate androgen-independent prostate cancer (AIPC) development remain largely unknown.

METHODS

Next-generation sequencing technology and RT-qPCR were used to assess LEF1-AS1 expression level in AIPC tissues and adjacent normal tissues. Functional in vitro experiments, including colony formation, EDU and transwell assays were performed to assess the role of LEF1-AS1 in AIPC. Xenograft assays were conducted to assess the effect of LEF1-AS1 on cell proliferation in vivo. Chromatin immunoprecipitation (ChIP) and RNA binding protein immunoprecipitation (RIP) assays were performed to elucidate the regulatory network of LEF1-AS1.

RESULTS

The next-generation sequencing results showed that LEF1-AS1 is significantly overexpressed in AIPC. Furthermore, our RT-qPCR assay data showed that LEF1-AS1 is overexpressed in AIPC tissues. Functional experiments showed that LEF1-AS1 promotes the proliferation, migration, invasion and angiogenic ability of AIPC cells in vitro and tumour growth in vivo by recruiting the transcription factor C-myb to the promoter of FZD2, inducing its transcription. Furthermore, LEF1-AS1 was shown to function as a competing endogenous RNA (ceRNA) that sponges miR-328 to activate CD44.

CONCLUSION

In summary, the results of our present study revealed that LEF1-AS1 acts as a tumour promoter in the progression of AIPC. Furthermore, the results revealed that LEF1-AS1 functions as a ceRNA and regulates Wnt/β-catenin pathway activity via FZD2 and CD44. Our results provide new insights into the mechanism that links the function of LEF1-AS1 with AIPC and suggests that LEF1-AS1 may serve as a novel potential target for the improvement of AIPC therapy.

LINC01315 Impairs microRNA-211-Dependent DLG3 Downregulation to Inhibit the Development of Oral Squamous Cell Carcinoma

Recent studies have revealed that long non-coding RNAs (lncRNAs) involve in the progression of oral squamous cell carcinoma (OSCC). These lncRNAs have emerged as biomarkers or therapeutic targets for OSCC. We here aimed to investigate the role of lncRNA LINC01315 in OSCC and the related mechanisms. LINC01315 and DLG3 were determined to be poorly expressed while microRNA-211 (miR-211) was highly expressed in OSCC tissues and cells using RT-qPCR and western blot analysis. Based on the results obtained from dual-luciferase reporter gene, RIP, and FISH assays, LINC01315 was found to upregulate DLG3 expression by competitively binding to miR-211. Upon altering the expression of LINC01315, and/or miR-211 in OSCC cells with shRNA, mimic, or an inhibitor, we assessed their effects on OSCC cell proliferation, migration, invasion, and apoptosis. LINC01315 knockdown enhanced OSCC cell proliferation, migration and invasion, but dampened their apoptosis, all of which could be reversed by miR-211 inhibition. Elevation of DLG3, a target gene of miR-211, activated the Hippo signaling pathway, whereby suppressing OSCC progression in vitro. Finally, their roles in tumor growth were validated in vivo. These findings suggest that LINC01315 elevates DLG3 expression by competitively binding to miR-211, thereby suppressing OSCC progression.

lncRNA MALAT1 promotes cell proliferation and invasion by regulating the miR-101/EZH2 axis in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is the most common malignant tumor of the oral cavity. Emerging evidence indicates that long non-coding (lnc)RNAs play a key role in the cellular processes of tumor cells, including glycolysis, growth and movement. Here, the purpose of this study was to explore the biological functions and potential mechanism of lncRNA metastasis associated lung adenocarcinoma transcript 1 (MALAT1) in OSCC. OSCC tissues and adjacent matched paraneoplastic normal tissues were collected from 20 OSCC patients. The expression of MALAT1 and miR-101 in OSCC tissues and cell lines (HSC3, SCC9, SCC15 and SCC25) were determined by real-time-polymerase chain reaction (qPCR). Caspase-3, xaspase-8 and EZH2 protein levels were determined by western blot analysis. MALAT1-mediated miRNAs were verified by bioinformatics analysis of StarBase and Luciferase reporter assay. Cell Counting Kit-8 (CCK-8) and Transwell assays were used for investigating MALAT1 effect on cell proliferation and invasion in the OSCC cells. qPCR analysis indicated that MALAT1 expression was obviously increased, and miR-101 was decreased in the OSCC tissues and cell lines. Functional studies revealed that overexpression of MALAT1 promoted OSCC cell proliferation and invasion. Further experiments revealed that miR-101 was a target of MALAT1 and that the miR-101 inhibitor abolished the effect of MALAT1 on OSCC cell proliferation and invasion. Enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) acted as a downstream effecter of MALAT1 in the OSCC cells. Collectively, these findings revealed that upregulation of MALAT1 facilitated OSCC proliferation and invasion by targeting the miR-101/EZH2 axis.

Interaction of non-coding RNAs and Hippo signaling: Implications for tumorigenesis

Hippo signaling is an evolutionarily conserved pathway that controls organ size by regulating cell proliferation, apoptosis, and stem cell self-renewal by "turning off" or "turning on" the kinase cascade chain reaction to manipulate the expression of downstream genes. Dysregulation of the Hippo pathway contributes to cancer development and metastasis. Emerging evidence has revealed new insights into tumorigenesis through the interplay between the Hippo pathway and non-coding RNAs (ncRNAs), especially microRNA, long non-coding RNA and circular RNA. Here, we reviewed the interactions between the Hippo pathway and ncRNAs and their implication for a variety of tumor-promoting or tumor-repressing effects. These interactions have the potential to serve as cancer biomarkers and therapeutic targets in clinical applications.

LEF1-AS1 accelerates tumorigenesis in glioma by sponging miR-489-3p to enhance HIGD1A

Long non-coding (lncRNA) lymphoid enhancer-binding factor 1 antisense RNA 1 (LEF1-AS1) has been validated to be implicated in manifold cancers, whereas its function in glioma has not been understood thoroughly. Hence, in this study, we tested that LEF1-AS1 expression was significantly upregulated in glioma tissues and cell lines. Besides, knockdown of LEF1-AS1 repressed cell proliferation while activated apoptosis in glioma cells in vitro, and also suppressed tumor growth in vivo. RNA pull-down and luciferase reporter assays affirmed that LEF1-AS1 could bind with miR-489-3p. In addition, miR-489-3p expression was downregulated in glioma cells. Moreover, miR-489-3p depletion partly offset LEF1-AS1 knockdown-mediated function on proliferation and apoptosis. Further, HIGD1A identified as the target gene of miR-489-3p was upregulated in glioma cells. HIGD1A silence could restrict the process of glioma. In rescue assays, upregulation of HIGD1A remedied the inhibitory impacts of LEF1-AS1 silence on glioma cell growth. In summary, our studies corroborated the regulatory mechanism of LEF1-AS1/miR-489-3p/HIGD1A axis in glioma, suggesting that targeting LEF1-AS1 might be a promising method for glioma therapy in the future.

The crosstalk between lncRNAs and the Hippo signalling pathway in cancer progression

LncRNAs play a pivotal role in the regulation of epigenetic modification, cell cycle, differentiation, proliferation, migration and other physiological activities. In particular, considerable studies have shown that the aberrant expression and dysregulation of lncRNAs are widely implicated in cancer initiation and progression by acting as tumour promoters or suppressors. Hippo signalling pathway has attracted researchers’ attention as one of the critical cancer‐related pathways in recent years. Increasing evidences have demonstrated that lncRNAs could interact with Hippo cascade and thereby contribute to acquisition of multiple malignant hallmarks, including proliferation, metastasis, relapse and resistance to anti‐cancer treatment. Specifically, Hippo signalling pathway is reported to modulate or be regulated by widespread lncRNAs. Intriguingly, certain lncRNAs could form a reciprocal feedback loop with Hippo signalling. More speculatively, lncRNAs related to Hippo pathway have been poised to become important putative biomarkers and therapeutic targets in human cancers. Herein, this review focuses on the crosstalk between lncRNAs and Hippo pathway in carcinogenesis, summarizes the comprehensive role of Hippo‐related lncRNAs in tumour progression and depicts their clinical diagnostic, prognostic or therapeutic potentials in tumours.

lncRNA LEF1-AS1 Promotes Proliferation and Induces Apoptosis of Non-Small-Cell Lung Cancer Cells by Regulating miR-221/PTEN Signaling

Introduction

LEF1-AS1 is a characterized oncogenic lncRNA in oral cancer. Analysis of TCGA dataset revealed the upregulation of LEF1-AS1 in non-small-cell lung cancer (NSCLC). This study was therefore carried out to investigate the involvement of LEF1-AS1 in NSCLC.

Methods

A total of 62 NSCLC patients were included to collect paired cancer and non-tumor tissues. RT-qPCR was performed to measure levels of LEF1-AS1 and miR-221 expression. Transient transfections were performed to explore the interactions between LEF1-AS1, miR-221 and PTEN. Cell proliferation and apoptosis were analyzed by cell proliferation assay and cell apoptosis assay, respectively.

Results

We found that LEF1-AS1 was upregulated in NSCLC patients. In addition, expression of LEF1-AS1 was negatively correlated with the expression of PTEN but positively correlated with the expression of miR-221 in NSCLC tissue samples. In NSCLC cells, overexpression of LEF1-AS1 led to downregulated expression of PTEN but upregulated expression of miR-221, which can directly target PTEN. Overexpression of LEF1-AS1 and miR-221 promoted cancer cell proliferation and inhibited apoptosis. PTEN played an opposite role and reduced the effects of overexpressing LEF1-AS1 and miR-221.

Conclusion

LEF1-AS1 may promote the proliferation and induce apoptosis of NSCLC cells by regulating miR-221/PTEN signaling.

Long noncoding RNA UCA1 promotes cell growth, migration, and invasion by targeting miR-143-3p in oral squamous cell carcinoma

BACKGROUND

The long noncoding RNA (lncRNA) urothelial carcinoma-associated 1 (UCA1) is dysregulated in many types of tumors; however, its role in oral squamous cell carcinoma (OSCC) remains unclear. This study aims to determine the effect of lncRNA UCA1 on OSCC.

METHODS

Fifty-six paired OSCC and adjacent nontumorous tissues were collected and the levels of UCA1, miR-143-3p, and MYO6 in the tissues were evaluated by qRT-PCR. In in vitro experiments, cell viability, migration, and invasion were measured by, respectively, performing CCK-8, wound healing, and transwell assays. The target relationships among UCA1, miR-143-3p, and MYO6 were verified by dual-luciferase assay. Western blot and immunohistochemistry were carried out to determine the protein levels. Xenograft mouse model was established to explore the effects of UCA1 in vivo.

RESULTS

Levels of UCA1 and MYO6 were increased significantly in OSCC, while the level of miR-143-3p was decreased compared with the adjacent nontumorous tissues. UCA1 promoted OSCC cell growth, migration, and invasion both in vitro and in vivo, while miR-143-3p reversed the progression. MYO6 was validated as a target for miR-143-3p, and MYO6 overexpression reversed the effects of miR-143-3p mimic on OSCC cells.

CONCLUSION

LncRNA UCA1 contributes to the proliferation and metastasis of OSCC cells by targeting miR-143-3p and upregulating its downstream gene MYO6. UCA1 could serve as a promising novel target therapy for treatment of OSCC.

Identification and Validation of Novel Long Non-coding RNA Biomarkers for Early Diagnosis of Oral Squamous Cell Carcinoma

Long non-coding RNAs (lncRNAs) are recently emerging as a novel promising biomarker for cancer diagnosis and prognosis. Despite these previous investigations, the expression pattern and diagnostic role of lncRNAs in oral squamous cell carcinoma (OSCC) remain unclear. In this study, we identified six novel lncRNA biomarkers (LINC01697, LINC02487, LOC105376575, AC005083.1, SLC8A1-AS1, and U62317.1) from a list of 29 differentially expressed lncRNAs using the least absolute shrinkage and selection operator (LASSO) method in the discovery dataset of 167 OSCC samples and 45 normal oral tissues. Using the logistic regression method, we constructed a six lncRNAs-based diagnostic risk model (6lncRNAScore) which was able to differentiate between OSCC samples and control samples with high performance with AUC of 0.995 and high diagnostic specificity of 88.9% and sensitivity of 98.2% in the discovery dataset. The diagnostic performance of the 6lncRNAScore was further validated in another two independent OSCC dataset with AUC of 0.968 and 1.0. Functional enrichment analysis for lncRNA biomarkers-related mRNAs suggested that lncRNAs biomarkers tended to be involved in the lipid metabolic process. Together, our study highlighted the importance of lncRNAs in OSCC and demonstrated the utility of lncRNA expression as a promising biomarker for early diagnosis of OSCC.

Long Non-Coding RNA LEF1-AS1 Promotes Migration, Invasion and Metastasis of Colon Cancer Cells Through miR-30-5p/SOX9 Axis

INTRODUCTION

Aberrant expression of long non-coding RNAs (lncRNAs) has been implicated in the tumorigenesis and progression of colon cancer. Lymphoid enhancer-binding factor 1 antisense RNA 1 (LEF1-AS1), a highly conserved and newly discovered long non-coding RNA, has been reported to be upregulated and correlated with poor prognosis in colon cancer, but the exact role of it remains uncertain.

MATERIALS AND METHODS

In our study, the biological functions of LEF1-AS1 in colon cancer were analyzed by cell viability assay, colony formation assay, scratch wound healing assay, transwell cell invasion assay, soft agar assay, luciferase reporter assay, pull down assay, tumor xenograft model and Western blot.

RESULTS

We found that LEF1-AS1 was upregulated in colon cancer patients and correlated with poor overall survival and recurrent-free survival. Besides, enforced expression of LEF1-AS1 in HT29 and T84 cells promoted migration, invasion, anchorage-independent growth, tumor xenograft formation and lung metastasis, while knockdown of LEF1-AS1 in COLO320 cells suppressed cell migration, invasion, anchorage-independent growth and tumor xenograft formation. In addition, LEF1-AS1 was directly interacted and inversely correlated with miR-30-5p in colon cancer, and SOX9 was a downstream target for miR-30-5p. LEF1-AS1 overexpression increased the expression level of SOX9, and restoration of SOX9 attenuated the effects caused by LEF1-AS1 knockdown in cell migration, invasion, anchorage-independent growth and tumor xenograft formation.

CONCLUSION

Our results indicated that LEF1-AS1 promoted migration, invasion and metastasis of colon cancer cells partially through miR-30-5p/SOX9 axis. The oncogenic LEF1-AS1 could be a potential prognostic biomarker for colon cancer.

CREB1-induced lncRNA LEF1-AS1 contributes to colorectal cancer progression via the miR-489/DIAPH1 axis

Long non-coding RNAs (lncRNAs) have been identified as new regulatory factors in tumor progression. Lymphoid enhancer-binding factor 1 antisense RNA 1 (LEF1-AS1) was a recently identified lncRNA. This research aimed to investigate the roles and mechanisms of LEF1-AS1 in colorectal cancer (CRC). We firstly showed that LEF1-AS1 expression was upregulated in human CRC tissues and cell lines. LEF1-AS1 upregulation was demonstrated to be induced by CREB1. Clinical study revealed that high LEF1-AS1 expression was positively associated with histological grade, lymph nodes metastasis, and decreased survivals of CRC patients. Functionally, down-regulation of LEF1-AS1 using si-LEF1-AS1 decreased cell growth, migration and invasion, as well as increased apoptosis in CRC cells. Mechanically, LEF1-AS1 functioned as competing endogenous RNA (ceRNA) for miR-489 to positively recover DIAPH1, thus playing an oncogenic role in CRC pathogenesis. Overall, our observations identified a novel CRC-related lncRNA LEF1-AS1 and discovered a critical role for this lncRNA as a ceRNA in CRC pathogenesis, suggesting that it may serve as a novel biomarker for prognosis and act as a therapeutic target for CRC treatment.

Long non-coding RNA LEF1-AS1 is involved in the progression of retinoblastoma through regulating the Wnt/β-catenin pathway

The lymphoid enhancer binding factor 1 antisense RNA 1 (LEF1-AS1) has been suggested to function as a tumour-associated lncRNA in several types of human cancers, but there is no study to date about the role of LEF1-AS1 in retinoblastoma. In our study, LEF1-AS1 expression was increased in retinoblastoma tissues and cell lines compared with paired adjacent normal tissues and the retinal pigment epithelial cell line, respectively. Meanwhile, we found that patients with retinoblastoma with IIRC D-E or undifferentiated type had notably higher levels of LEF1-AS1 expression than those with IIRC A-C or differentiated type. High LEF1-AS1 expression predicted poor disease-free survival in patients with retinoblastoma. The in vitro assays suggested that silencing of LEF1-AS1 suppressed retinoblastoma cell proliferation, migration, and invasion through regulating the Wnt/β-catenin pathway. In conclusion, LEF1-AS1 functions as an oncogenic lncRNA in retinoblastoma.

Silencing of long noncoding RNA LEF1-AS1 prevents the progression of hepatocellular carcinoma via the crosstalk with microRNA-136-5p/WNK1

Long noncoding RNAs (lncRNAs) have been recognized as cancer-associated biological molecules, favoring hepatocellular carcinoma (HCC) progression. This study was conducted to elucidate the effects lncRNA lymphoid enhancer-binding Factor 1 antisense RNA (LEF1-AS1) on the pathological development of HCC, along with the crosstalk involving microRNA-136-5p (miR-136-5p) and with-no-K (lysine) kinase 1 (WNK1). The study recruited primary HCC tissues and their corresponding nonneoplastic liver tissues. The gain- and loss-of-function studies were performed in HCC cells HuH-7 and tumor xenografts in nude mice. The dual luciferase reporter gene assay system, RNA pull-down, and radioimmunoprecipitation assays were applied to detect their interactions among lncRNA LEF1-AS1, miR-136-5p, and WNK1. 5-Ethynyl-2'-deoxyuridine staining, scratch test, Transwell assays, and in vitro tube formation assays were conducted to examine HCC cell proliferation, migration, and invasion and HUVEC angiogenesis. HCC tissues and cells contained high lncRNA LEF1-AS1 expression. LncRNA LEF1-AS1 upregulation triggered markedly increased HCC cell proliferation, migration, and invasion and human umbilical vein endothelial cell angiogenesis. In vivo silencing lncRNA LEF1-AS1 resulted in reduced tumor cell vitality and matrix metalloproteinase-9 and the vascular endothelial growth factor expression. Additionally, the role of lncRNA LEF1-AS1 was found to be largely dependent on WNK1. Association of lncRNA LEF1-AS1 with WNK1 blocked the inhibitory effect of miR-136-5p on WNK1, which was confirmed by in vivo experiments. Altogether, our results revealed an important role of lncRNA LEF1-AS1 in regulating the HCC progression by regulating WNK1, providing a potential biomarker for the therapeutic modalities regarding HCC.

Linc01234 promotes cell proliferation and metastasis in oral squamous cell carcinoma via miR-433/PAK4 axis

Background

Increasing studies have demonstrated that long non-coding RNAs (lncRNAs) play an important role in tumor progression. However, the potential biological functions and clinical importance of Linc01234 in oral squamous cell carcinoma (OSCC) remain unclear.

Methods

We evaluated the expression profile and prognostic value of Linc01234 in OSCC tissues by RT-qPCR. Then, functional in vitro experiments were performed to investigate the effects of Linc01234 on tumor growth, migration and invasion in OSCC. Mechanistically, RT-qPCR, bioinformatic analysis and dual luciferase reporter assays were performed to identify a competitive endogenous RNA (ceRNA) mechanism involving Linc01234, miR-433-3p and PAK4.

Results

We found that Linc01234 was clearly upregulated in OSCC tissues and cell lines, and its level was positively associated with T stage, lymph node metastasis, differentiation and poor prognosis of patients with OSCC. Our results shown that Linc01234 inhibited cell proliferation and metastatic abilities in CAL27 and SCC25 cells following its knockdown. Mechanistic analysis indicated that Linc01234 may act as a ceRNA (competing endogenous RNA) of miR-433-3p to relieve the repressive effect of miR-433-3p on its target PAK4.

Conclusions

Our results indicated that Linc01234 promotes OSCC progression through the Linc01234/miR-433/PAK4 axis and might be a potential therapeutic target for OSCC.