LncRNA HOTAIR promotes the invasion and metastasis of oral squamous cell carcinoma through metastasis-associated gene 2

Decoding Salivary ncRNAomes as Novel Biomarkers for Oral Cancer Detection and Prognosis

Oral cancer (OC) ranks among the most prevalent head and neck cancers, becoming the eleventh most common cancer worldwide with ~350,000 new cases and 177,000 fatalities annually. The rising trend in the occurrence of OC among young individuals and women who do not have tobacco habits is escalating rapidly. Surgical procedures, radiation therapy, and chemotherapy are among the most prevalent treatment options for oral cancer. To achieve better therapy and an early detection of the cancer, it is essential to understand the disease's etiology at the molecular level. Saliva, the most prevalent body fluid obtained non-invasively, holds a collection of distinct non-coding RNA pools (ncRNAomes) that can be assessed as biomarkers for identifying oral cancer. Non-coding signatures, which are transcripts lacking a protein-coding function, have been identified as significant in the progression of various cancers, including oral cancer. This review aims to examine the role of various salivary ncRNAs (microRNA, circular RNA, and lncRNA) associated with disease progression and to explore their functions as potential biomarkers for early disease identification to ensure better survival outcomes for oral cancer patients.

Circulating lncRNA HOTAIR is a biomarker for pediatric acute lymphoblastic leukemia and mediator of miR-326 exosomal export

Acute Lymphoblastic Leukemia (ALL) is the most common cancer in children worldwide. In the present investigation, the circulating RNAs (circRNAs) HOTAIR, NEAT1, H19, PCAT1, and SNHG1 were selected as potential biomarkers for childhood ALL (pALL) based on their predicted interactions with miR-326, a recognized tumor suppressor implicated in pALL, along with comprehensive in silico analyses. Subsequently, the expression levels of the circRNAs were examined in 50 pALL samples and 20 healthy controls using RT-qPCR. Notably, HOTAIR was identified as a 95% specific biomarker of cancer susceptibility, exhibiting a substantial increase in expression within the bone marrow plasma and peripheral blood samples. 22 B-ALL patients with elevated relative expression levels of circHOTAIR (≥ 1.87) were then monitored at three distinct time intervals during chemotherapy. Results demonstrated a significant decrease in HOTAIR expression only among treatment-sensitive patients (P < 0.0001). This finding positions HOTAIR as a novel prognostic factor (AUC = 0.955), which may be used for monitoring the efficacy of chemotherapy in a non-invasive, cost-effective manner. Additionally, the regulatory inter-connection between HOTAIR and miR-326 was investigated by transfecting B-ALL RN-95 cells with exogenous miR-326. Data showed a time-dependent increase in cytoplasmic HOTAIR levels, alongside RAB35, resulting in a corresponding reduction in the cytoplasmic and exosomal miR-326 levels. While the results are preliminary due to the sample size, this study is the first to identify circHOTAIR as both a prognostic and diagnostic biomarker in B-ALL. Furthermore, it elucidates the role of HOTAIR as a sponge for miR-326, orchestrating its efflux from the cell via exosomes through RAB35.

Competing endogenous RNAs network dysregulation in oral cancer: a multifaceted perspective on crosstalk and competition

Oral cancer progresses from asymptomatic to advanced stages, often involving cervical lymph node metastasis, resistance to chemotherapy, and an unfavorable prognosis. Clarifying its potential mechanisms is vital for developing effective theraputic strategies. Recent research suggests a substantial involvement of non-coding RNA (ncRNA) in the initiation and advancement of oral cancer. However, the underlying roles and functions of various ncRNA types in the growth of this malignant tumor remain unclear. Competing endogenous RNAs (ceRNAs) refer to transcripts that can mutually regulate each other at the post-transcriptional level by vying for shared miRNAs. Networks of ceRNAs establish connections between the functions of protein-coding mRNAs and non-coding RNAs, including microRNA, long non-coding RNA, pseudogenic RNA, and circular RNA, piwi-RNA, snoRNA. A growing body of research has indicated that imbalances in ceRNAs networks play a crucial role in various facets of oral cancer, including development, metastasis, migration, invasion, and inflammatory responses. Hence, delving into the regulatory pathways of ceRNAs in oral cancer holds the potential to advance our understanding of the pathological mechanisms, facilitate early diagnosis, and foster targeted drug development for this malignancy. The present review summarized the fundamental role of ceRNA network, discussed the limitations of current ceRNA applications, which have been improved through chemical modification and carrier delivery as new biomarkers for diagnosis and prognosis is expected to offer a groundbreaking therapeutic approach for individuals with oral cancer.

LncRNA PVT1 promotes malignant progression by regulating the miR-7-5p/CDKL1 axis in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC), one of the most common types of head and neck squamous cell carcinoma (HNSCC), is characterized by high incidence and mortality. PVT1 is a long non-coding RNA (lncRNA) that plays an oncogenic role in various cancer types. This study aims to reveal the role and underlying molecular mechanism of PVT1 in OSCC progression. The expression levels of PVT1, miR-7-5p, and CDKL1 mRNA were evaluated using qRT-PCR. Western blot and IHC analysis were conducted to determine the protein expression of CDKL1. The biological functions of PVT1, miR-7-5p, and CDKL1 in OSCC were investigated through CCK-8, transwell migration and invasion assays. In vivo experiments utilized a xenograft model to examine the impact of PVT1 on OSCC. Furthermore, the interaction among PVT1, miR-7-5p, and CDKL1 was explored using RNA pull down assay and luciferase reporter assays. We found that PVT1 enhanced cell proliferation, migration, and invasion by targeting CDKL1. In addition, PVT1 functions as a sponge to modulate miR-7-5p, thereby influencing the expression of CDKL1 and the progression of OSCC. In conclusion, this study illustrates that the "PVT1/miR-7-5p/CDKL1" pathway is capable of promoting the progression of OSCC and may serve as a promising target for developing treatment strategies for OSCC.

LncRNAs and the cancer epigenome: Mechanisms and therapeutic potential

Long non-coding RNAs (lncRNAs) have emerged as critical regulators of epigenome, modulating gene expression through DNA methylation, histone modification, and/or chromosome remodeling. Dysregulated lncRNAs act as oncogenes or tumor suppressors, driving tumor progression by shaping the cancer epigenome. By interacting with the writers, readers, and erasers of the epigenetic script, lncRNAs induce epigenetic modifications that bring about changes in cancer cell proliferation, apoptosis, epithelial-mesenchymal transition, migration, invasion, metastasis, cancer stemness and chemoresistance. This review analyzes and discusses the multifaceted role of lncRNAs in cancer pathobiology, from cancer genesis and progression through metastasis and therapy resistance. It also explores the therapeutic potential of targeting lncRNAs through innovative diagnostic, prognostic, and therapeutic strategies. Understanding the dynamic interplay between lncRNAs and epigenome is crucial for developing personalized therapeutic strategies, offering new avenues for precision cancer medicine.

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.

The role of HOTAIR in the modulation of resistance to anticancer therapy

Leading anti-tumour therapeutic strategies typically involve surgery and radiotherapy for locally advanced (non-metastatic) cancers, while hormone therapy, chemotherapy, and molecular targeted therapy are the current treatment options for metastatic cancer. Despite the initially high sensitivity rate to anticancer therapies, a large number of patients develop resistance, leading to a poor prognosis. The mechanisms related to drug resistance are highly complex, and long non-coding RNAs appear to play a crucial role in these processes. Among these, the lncRNA homeobox transcript antisense intergenic RNA (HOTAIR), widely implicated in cancer initiation and progression, likewise plays a significant role in anticancer drug resistance. It can modulate cell activities such as proliferation, apoptosis, hypoxia, autophagy, as well as epithelial-mesenchymal transition, thereby contributing to the development of resistant tumour cells. In this manuscript, we describe different mechanisms of antitumor drug resistance in which HOTAIR is involved and suggest its potential as a therapeutic predictive biomarker for the management of cancer patients.

Tumor-suppressive action of miR-30a-5p in lung adenocarcinoma correlates with ABL2 inhibition and PI3K/AKT pathway inactivation

INTRODUCTION

ABL2 contributes to the oncogenic potential of cancers, pointing to its inhibition as a possible strategy against malignant diseases. Bioinformatics prediction of upstream effector miR-30a-5p for ABL2 allowed us to hypothesize and then validate mechanistic actions of miR-30a-5p in lung adenocarcinoma (LUAD).

MATERIALS AND METHODS

The ABL2 expression in LUAD was analyzed in the TCGA data, clinical samples, and cell lines. The shRNA-mediated silencing of ABL2 was introduced to illustrate its effect on malignant phenotypes of LUAD cells. The binding affinity between ABL2 and miR-30a-5p was verified by luciferase activity and RNA pull-down assay. Ectopic expression, knockdown methods, and PI3K inhibitor LY294002 were used to investigate their effects on in vitro biological characteristics and in vivo tumor growth of LUAD cells. Using nude mouse lung adenocarcinoma in situ and brain metastasis models to validate the inhibitory effect of miR-30a-5p on LUAD by regulating the ABL2/PI3K/AKT signaling axis.

RESULTS

High expression of ABL2 and poor expression of miR-30a-5p were noticed in LUAD tissues and cell lines. Importantly, miR-30a-5p was demonstrated to target and downregulate ABL2, subsequently inactivating the PI3K/AKT pathway. miR-30a-5p inhibited the malignant phenotypes of LUAD cells by inhibiting ABL2 expression and inactivating the PI3K/AKT pathway. For in vivo experiments, miR-30a-5p was substantiated to thwart tumor tumorigenesis by regulating the ABL2/PI3K/AKT axis. In addition, miR-30a-5p suppresses the occurrence and development of in situ lung cancer and brain metastasis via the ABL2/PI3K/AKT signaling pathway.

CONCLUSION

This study underscores the inhibitory role of miR-30a-5p in LUAD through the ABL2/PI3K/AKT axis, which may be a viable target for LUAD treatment.

A snapshot of miRNAs in oral squamous cell carcinoma: Difference between cancer cells and corresponding normal cells

Oral squamous cell carcinoma (OSCC) constitutes the most aggressive tumors of the oral cavity and is one of the leading causes of cancer mortality worldwide. Although recent clinical treatment strategies have improved the survival rate, the outcome of OSCC patients still remains dismal because of the lack of efficient diagnostic and treatment tools. As one of the main actors of OSCC scenario, microRNAs (miRNAs) are involved in triggering, progression and metastasis through the regulation of various cancer-related signaling pathways. Identification followed by precise study of the biology and mechanism of action of miRNAs will greatly help to provide valuable insights regarding OSCC development and can be considered as an anti-OSCC target. In the current review, we have provided a focused summary of the latest published papers on the role of miRNAs in apoptosis, cell cycle, proliferation, EMT and metastasis of OSCC as well as the role of long noncoding RNAs in the modulation of miRNAs in OSCC.

Mutual Regulation of ncRNAs and Chromatin Remodeling Complexes in Normal and Pathological Conditions

Chromatin remodeling is the one of the main epigenetic mechanisms of gene expression regulation both in normal cells and in pathological conditions. In recent years, a growing number of investigations have confirmed that epigenetic regulators are tightly connected and form a comprehensive network of regulatory pathways and feedback loops. Genes encoding protein subunits of chromatin remodeling complexes are often mutated and change their expression in diseases, as well as non-coding RNAs (ncRNAs). Moreover, different mechanisms of their mutual regulation have already been described. Further understanding of these processes may help apply their clinical potential for establishment of the diagnosis, prognosis, and treatment of the diseases. The therapeutic targeting of the chromatin structure has many limitations because of the complexity of its regulation, with the involvement of a large number of genes, proteins, non-coding transcripts, and other intermediary molecules. However, several successful strategies have been proposed to target subunits of chromatin remodeling complexes and genes encoding them, as well as the ncRNAs that regulate the operation of these complexes and direct them to the target gene regions. In our review, we focus on chromatin remodeling complexes and ncRNAs, their mutual regulation, role in cellular processes and potential clinical application.

FOXD1-AS1 upregulates FOXD1 to promote oral squamous cell carcinoma progression

OBJECTIVES

Recently, increasing attention has been concentrated on decrypting the potential of long non-coding RNAs (lncRNAs) in influencing the progression of human tumors, oral squamous cell carcinoma (OSCC) included. The role of a novel lncRNA, forkhead box D1 antisense RNA 1 (FOXD1-AS1), has been discussed in multiple cancers. Nevertheless, its function and relevant mechanism in OSCC have been not probed yet.

MATERIALS AND METHODS

FOXD1-AS1 expression was detected via RT-qPCR. Colony formation, EdU, transwell and Western blot analyses tested the functional role of FOXD1-AS1 in OSCC cells. The relationship between RNAs was assessed by a series of mechanical assays.

RESULTS

FOXD1-AS1 was expressed at a high level in head and neck squamous cell carcinoma (HNSC). Knockdown of FOXD1-AS1 exerted repressive impacts on OSCC cell proliferation, migration, invasion, and EMT. Moreover, FOXD1-AS1 positively regulated its nearby gene FOXD1 via interacting with miR-369-3p. In addition, adenosine deaminase RNA specific (ADAR), known as a RNA-binding protein (RBP), was capable to bind with FOXD1-AS1 and FOXD1 simultaneously, and could regulate the stability of FOXD1 mRNA. Aside from that, rescue assays delineated that FOXD1-AS1 promoted OSCC progression via upregulating FOXD1.

CONCLUSIONS

FOXD1-AS1 elevates FOXD1 expression to promote OSCC malignant phenotypes through miR-369-3p and ADAR.

Long Non-Coding RNAs as Novel Targets for Phytochemicals to Cease Cancer Metastasis

Metastasis is a multi-step phenomenon during cancer development leading to the propagation of cancer cells to distant organ(s). According to estimations, metastasis results in over 90% of cancer-associated death around the globe. Long non-coding RNAs (LncRNAs) are a group of regulatory RNA molecules more than 200 base pairs in length. The main regulatory activity of these molecules is the modulation of gene expression. They have been reported to affect different stages of cancer development including proliferation, apoptosis, migration, invasion, and metastasis. An increasing number of medical data reports indicate the probable function of LncRNAs in the metastatic spread of different cancers. Phytochemical compounds, as the bioactive agents of plants, show several health benefits with a variety of biological activities. Several phytochemicals have been demonstrated to target LncRNAs to defeat cancer. This review article briefly describes the metastasis steps, summarizes data on some well-established LncRNAs with a role in metastasis, and identifies the phytochemicals with an ability to suppress cancer metastasis by targeting LncRNAs.

HOX cluster-embedded lncRNAs and epithelial-mesenchymal transition in cancer: Molecular mechanisms and therapeutic opportunities

Although there has been substantial improvement in the treatment modalities, cancer remains the major cause of fatality worldwide. Metastasis, recurrence, and resistance to oncological therapies are the leading causes of cancer mortality. Epithelial-mesenchymal transition (EMT) is a complex biological process that allows cancer cells to undergo morphological transformation into a mesenchymal phenotype to acquire invasive potential. It encompasses reversible and dynamic ontogenesis by neoplastic cells during metastatic dissemination. Hence, understanding the molecular landscape of EMT is imperative to identify a reliable clinical biomarker to combat metastatic spread. Accumulating evidence reveals the role of HOX (homeobox) cluster-embedded long non-coding RNAs (lncRNAs) in EMT and cancer metastasis. They play a crucial role in the induction of EMT, modulating diverse biological targets. The present review emphasizes the involvement of HOX cluster-embedded lncRNAs in EMT as a molecular sponge, chromatin remodeler, signaling regulator, and immune system modulator. Furthermore, the molecular mechanisms behind therapy resistance and the potential use of novel drugs targeting HOX cluster-embedded lncRNAs in the clinical management of distant metastasis will be discussed.

The Role and Mechanism of Long Non-Coding RNA HOTAIR in the Oncogenesis, Diagnosis, and Treatment of Head and Neck Squamous Cell Carcinoma

The most frequent malignant tumor of the head and neck is head and neck squamous cell carcinoma (HNSCC), which has a high frequency, a poor prognosis in the late stages, and subpar therapeutic results. As a result, early HNSCC diagnosis and treatment are urgently needed; however, there are no good diagnostic biomarkers or efficient therapeutic targets at this time. The long-stranded non-coding RNA HOTAIR may be important in the pathogenesis of cancer, according to recent research. By interactions with DNA, RNA, and proteins, it has been demonstrated that HOTAIR, a >200 nucleotide RNA transcript, plays a role in the biological processes of many types of tumor cells, including proliferation, metastasis, and prognosis of HNSCC. Hence, this review discusses HOTAIR's function and molecular mechanisms in HNSCC.

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 lncRNAs and XIST in oral cancer

Long non-coding RNA (lncRNA) plays a significant role in the pathogenesis of many human malignant tumors, including oral cancer. LncRNA can act as a gene regulator in a variety of cancers. It regulates the growth of malignant cells via many cellular signal pathways such as the PI3K (phosphoinositide 3-kinase)/AKT (α-serine/threonine-protein kinase) pathway. In this review, we have analyzed the role of lncRNAs, such as lncRNA X inactive specific transcript (XIST), in oral cancer, including its effects on the proliferation, apoptosis, invasion, migration, and resistance to chemotherapy of oral cancer. We have also focused on the role of lncRNA XIST as the core of X chromosome inactivation. Here, we provide a brief overview of the role of many kinds of lncRNAs, including XIST, which provides a theoretical basis for the study of the role of XIST in oral cancer. Our review may provide a new direction for the study of the occurrence, development, and prognosis of oral cancer and provide a new target for its treatment.

Clinical Perspectives of Non-Coding RNA in Oral Inflammatory Diseases and Neuropathic Pain: A Narrative Review

Non-coding RNAs (ncRNAs) represent a research hotspot by playing a key role in epigenetic and transcriptional regulation of diverse biological functions and due to their involvement in different diseases, including oral inflammatory diseases. Based on ncRNAs' suitability for salivary biomarkers and their involvement in neuropathic pain and tissue regeneration signaling pathways, the present narrative review aims to highlight the potential clinical applications of ncRNAs in oral inflammatory diseases, with an emphasis on salivary diagnostics, regenerative dentistry, and precision medicine for neuropathic orofacial pain.

LINC01116 Promotes Migration and Invasion of Oral Squamous Cell Carcinoma by Acting as a Competed Endogenous RNA in Regulation of MMP1 Expression

Oral squamous cell carcinoma (OSCC) has increasingly become a worldwide health concern, and its survival rate has not been much improved partially due to a deficiency of precise molecular markers. Dysregulation of LINC01116, a long noncoding RNA sequence, has been observed in several types of cancer. However, the role played by LINC01116 in OSCC has not yet been fully elaborated. This study explored how LINC01116 was involved in the regulation of OSCC progression by analyzing expressions of LINC01116 in OSCC patients. The findings demonstrated upregulation of LINC01116 in OSCC tissues as opposed to regular oral mucosa, and overexpression of LINC01116 was correlated with advanced tumor status. LINC01116 knockdown using shRNA markedly reduced the OSCC cell invasion and migration in vitro. Moreover, the expression of LINC01116 was negatively correlated with that of microRNA-9-5p (miR-9). Luciferase reporter and loss-of-function assays demonstrated that LINC01116 functioned as a competing endogenous RNA (ceRNA) that could effectively sponge miR-9, thus regulating the derepression of matrix metalloproteinase 1 (MMP1). Furthermore, we confirmed that LINC01116 knockdown did not affect the expression of MMP1 messenger RNA (mRNA). Collectively, it is demonstrated in this study that overexpression of LINC01116 can promote the OSCC progression. The LINC01116-miR-9-MMP1 axis provides a novel insight into the OSCC pathogenesis and offers potential therapeutic targets against OSCC.

Long non-coding RNAs involved in different steps of cancer metastasis

Non-proteincoding transcripts bearing 200 base pairs known as long non-coding RNAs (lncRNAs) play a role in a variety of molecular mechanisms, including cell differentiation, apoptosis and metastasis. Previous studies have suggested that frequently dysregulated lncRNAs play a crucial role in various aspects of cancer metastasis. Metastasis is the main leading cause of death in cancer. The role of lncRNAs in different stages of metastasis is the subject of this review. Based on in vitro and in vivo investigations on metastasis, we categorized lncRNAs into distinct stages of metastasis including angiogenesis, invasion, intravasation, survival in circulation, and extravasation. The involvement of lncRNAs in angiogenesis and invasion has been extensively studied. Here, we comprehensively discuss the role and functions of these lncRNAs with a particular focus on the molecular mechanisms.

Co-Culture of MSCs with miR-496 Prompts Epithelial-Mesenchymal Transformation of Oral Squamous Cell Carcinoma (OSCC)

This study discusses the molecular mechanism of co-culture of MSCs with miR-496 in the EMT of OSCC. miR-496 expression in OSCC tissues and cells was detected by qRT-PCR. The MSCs+si-NC, MSCs+pc-DNA-NC, MSCs+si-miR-496, MSCs+pc-DNA-miR-496 was transfected into SCC-PKUs to analyze cell apoptosis, proliferation and clone formation as well as the expression of proteins related with EMT. miR-496 in OSCC tissues was elevated and positively related with the clinical stage of OSCC patients. The cell activity and invasive ability of SCC-PKU was increased after co-culture of MSCs and pc-DNA-miR-496 along with increased expression of EMT-related proteins. However, all above changes were reversed after treatment with MSCs and si-miR-496. In conclusion, co-culture of MSCs and miR-495 prompts the occurrence and development of OSCC through regulating EMT processes, indicating that they might be novel targets for the treatment of OSCC.

miR-653 Induces Bone Marrow Mesenchymal Stem Cells Proliferation via Activating Epithelial-Mesenchymal Transition in Oral Squamous Cell Carcinoma

This study intends to assess miR-653’s expression in MSCs and OSCC and discuss molecular biological mechanism of changes of EMT in MSCs through activating miR-653 in OSCC. miR-653 expression in MSCs and OSCC was detected. si-miR-653 was transfected into MSCs followed by analysis of cell proliferation by CCK-8 and clone formation assay, cell apoptosis and cycle by FCM, and the changes of transcription factor as ZEB1 and Snail by qRT-PCR. miR-653 expression in OSCC cell was up-regulated significantly from the result of q-RT-PCR detection. The proliferation of MSCs induced by miR-653 was restrained and apoptotic rate was increased after treatment with si-miR-653 along with stagnated cycle of G1/G0 staging cell. The expression of transcription factor of EMT type as ZEB1 and Snail was elevated significantly after intervention using si-miR-653. In conclusion, the proliferation of OSCC could be induced by MSCs through activation with miR-653 which might be through regulation of EMT process.

In silico interaction of HOX cluster-embedded microRNAs and long non-coding RNAs in oral cancer

The essential role HOX-associated non-coding RNAs play in chromatin dynamics and gene regulation has been well documented. The potential roles of these microRNAs and long non-coding RNAs in oral cancer development, with their attendant involvement in various cellular processes including proliferation, invasion, migration, epithelial-mesenchymal transition and metastasis is gaining credence. An interaction network of HOX-embedded non-coding RNAs was constructed to identify the RNA interaction landscape using the arena-Idb platform and visualized using Cytoscape. The miR-10a was shown to interact with HOXA1, miR-10b with HOXD10, miR-196a1 with HOXA5, HOXA7, HOXB8, HOXC8, HOXD8, and miR-196a2 with HOXA5. The lncRNAs, HOTAIR interacted with HOXC11, HOTAIRM1 with HOXA1 and HOXA4, HOTTIP with HOXA13, HOXA-AS2 with HOXA3, HOXA11-AS with HOXA11 and HOXD-AS1 with HOXB8. Changes in the HOX cluster-embedded non-coding RNAs have implications for prognosis and overall disease survival. Our review aims to analyze the functional significance and clinical relevance of non-coding RNAs within the HOX cluster in the context of oral carcinogenesis. Elucidating these interactions between the non-coding RNAs and HOX genes in oral cancer development and progression could pave the way for the identification of reliable biomarkers and potential therapeutic targets.

Long noncoding RNA ENST00000508435 promotes migration of breast cancer via FXR 1

LncRNA plays a critical role in tumor progression. However, the role it executes in breast cancer is still unclear. Here, we report a newly discovered lncRNA, ENST00000508435, which could be remarkably up-regulated in breast cancer cells and tissues. We found that the expression of ENST00000508435 was positively correlated with tumor size, lymph node metastasis and HER2. More interesting, overexpression of ENST00000508435 significantly increased cell migration, while specific knockdown led to the opposite. RNA pull-down and RNA immunoprecipitation assays demonstrated that ENST00000508435 could directly bind to FXR1 to promote tumor metastasis. ENST00000508435 and FXR1 were positively correlated. FXR1 was also significantly up-regulated in breast tumors. Taken together, we propose that ENST00000508435 regulates FXR1 to promote breast cancer metastasis.

Long non-coding RNA HOXA-AS3 promotes cell proliferation of oral squamous cell carcinoma through sponging microRNA miR-218-5p

Increasing evidence demonstrated long non-coding RNAs (lncRNAs) play important roles in the occurrence and development of oral squamous cell carcinoma (OSCC). This study aimed to explore the role and molecular mechanism of lncRNA HOXA-AS3 in the progression of OSCC. Here, we found that the expression of lncRNA HOXA-AS3 was upregulated in OSCC tissues and cell lines compared with the para-cancerous tissues and normal human oral keratinocyte (NHOK), respectively. Inhibition of HOXA-AS3 significantly inhibited the proliferation and colony formation of OSCC cells. Further, the luciferase reporter assay showed that HOXA-AS3 was directly bound to miR-218-5p. Moreover, the expression of miR-218-5p was negatively regulated by HOXA-AS3, and miR-218-5p could inhibit the expression of collagen type I alpha1 (COL1A1) and lysophosphatidylcholine acyltransferase 1 (LPCAT1). In addition, silencing miR-218-5p reversed the inhibitory effect of HOXA-AS3 knockdown on the proliferative potential of OSCC cells. In summary, our study illustrated that HOXA-AS3 promoted cancer cell proliferation in OSCC, possibly by sponging miR-218-5p for the first time, which provides a new target or a potential diagnostic biomarker for OSCC.

The role of non-coding RNAs in drug resistance of oral squamous cell carcinoma and therapeutic potential

Oral squamous cell carcinoma (OSCC), the eighth most prevalent cancer in the world, arises from the interaction of multiple factors including tobacco, alcohol consumption, and betel quid. Chemotherapeutic agents such as cisplatin, 5-fluorouracil, and paclitaxel have now become the first-line options for OSCC patients. Nevertheless, most OSCC patients eventually acquire drug resistance, leading to poor prognosis. With the discovery and identification of non-coding RNAs (ncRNAs), the functions of dysregulated ncRNAs in OSCC development and drug resistance are gradually being widely recognized. The mechanisms of drug resistance of OSCC are intricate and involve drug efflux, epithelial-mesenchymal transition, DNA damage repair, and autophagy. At present, strategies to explore the reversal of drug resistance of OSCC need to be urgently developed. Nano-delivery and self-cellular drug delivery platforms are considered as effective strategies to overcome drug resistance due to their tumor targeting, controlled release, and consistent pharmacokinetic profiles. In particular, the combined application of new technologies (including CRISPR systems) opened up new horizons for the treatment of drug resistance of OSCC. Hence, this review explored emerging regulatory functions of ncRNAs in drug resistance of OSCC, elucidated multiple ncRNA-meditated mechanisms of drug resistance of OSCC, and discussed the potential value of drug delivery platforms using nanoparticles and self-cells as carriers in drug resistance of OSCC.

HOTAIR regulates colorectal cancer stem cell properties and promotes tumorigenicity by sponging miR-211-5p and modulating FLT-1

We intended to investigate the underlying mechanism of action of long noncoding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR) in colorectal cancer (CRC) progression, especially in tumor cell stemness. For that purpose, different assays were performed such as real-time PCR and western blotting to determine the expression of target genes. Cell stemness was determined by sphere formation assay, flow cytometry assay, and the analysis of stemness-related markers. The interplay among target genes was evaluated using bioinformatics analyses, luciferase reporter and biotin-labeled RNA pull down assays. We found that HOTAIR was highly expressed and predicted poor prognosis survival in CRC. Downregulation of HOTAIR repressed tumor malignant behaviors and cancer stemness. Mechanistically, HOTAIR facilitated the expression of the microRNA (miR)-211-5p target gene fms-like tyrosine kinase-1 (FLT-1), thereby modulating cancer stem cell (CSC) properties in CRC. We conclude that HOTAIR/miR-211-5p/FLT-1 axis contributes to CRC cancer stemness.

Oncogenic circDHTKD1 promotes tumor growth and metastasis of oral squamous cell carcinoma in vitro and in vivo via upregulating miR-326-mediated GAB1

Circular RNAs (circRNAs) have been extensively elucidated with regard to their significant implications in oral squamous cell carcinoma (OSCC). This study performed the functional investigation of circRNA dehydrogenase E1 and transketolase domain containing 1 (circDHTKD1) in OSCC. RNA expression levels of different molecules were measured via quantitative real-time polymerase chain reaction (qRT-PCR). Cellular behaviors were detected by 3-(4, 5-dimethylthiazol-2-y1)-2,5-diphenyl tetrazolium bromide (MTT) for cell viability, colony formation assay for clonal capacity, flow cytometry for cell apoptosis, wound healing assay for migration, and transwell assay for migration/invasion. Western blot was used for analyzing protein expression. RNA pull-down and dual-luciferase reporter assays were applied to assess the binding between targets. A xenograft tumor model was established in nude mice for in vivo experiments. Our expression analysis revealed that circDHTKD1 was upregulated in OSCC tissues and cells. circDHTKD1 knockdown was shown to impede OSCC cell growth and metastasis but motivate apoptosis. Additionally, circDHTKD1 served as a microRNA-326 (miR-326) sponge and the function of circDHTKD1 was achieved by sponging miR-326 in OSCC cells. Also, miR-326 inhibited OSCC development via targeting GRB2-associated-binding protein 1 (GAB1). circDHTKD1 could sponge miR-326 to alter GAB1 expression. Furthermore, circDHTKD1 contributed to OSCC progression in vivo via the miR-326/GAB1 axis. These data disclosed a specific circDHTKD1/miR-326/GAB1 signal axis in governing the malignant progression of OSCC, showing the considerable possibility of circDHTKD1 as a predictive and therapeutic target for clinical diagnosis and treatment of OSCC.

A novel lncRNA LOLA1 may predict malignant progression and promote migration, invasion, and EMT of oral leukoplakia via the AKT/GSK-3β pathway

Although dysregulation and dysfunction of long noncoding RNAs (lncRNAs) have been implicated in malignant behavior of oral squamous cell carcinoma (OSCC), whether aberrant lncRNAs play a role in the carcinogenesis of oral leukoplakia (OL) as the best-known precursor of OSCC remains undetermined. Differentially expressed lncRNAs in the occurrence and progression of OL were studied by microarray and quantitative reverse-transcription polymerase chain reaction (qRT-PCR). We found a novel key lncRNA n386251 that we named LOLA1 (lncRNA oral leukoplakia progressed associated 1) in the OL progression. The results of qRT-PCR revealed that LOLA1 aberrant expression was validated in tissue samples and cell lines from the normal oral mucosa, OL to OSCC. Fluorescent in situ hybridization showed that LOLA1 expression localized predominately at the cytoplasm of Leuk1 cells. Cell function assays showed that LOLA1 significantly influenced cell migration, invasion, and epithelial-mesenchymal transition (EMT) protein expression. Potential mechanism experiments revealed that AKT/GSK-3β signaling was involved in the regulatory mechanism of LOLA1 in OL progression. Remarkably, Kaplan-Meier analysis revealed that LOLA1 overexpression could predict malignant events of OL progression to OSCC. In conclusion, the current study for the first time profiled and validated the key lncRNAs related to OL progression. Importantly, we demonstrated that a novel lncRNA LOLA1 upregulation was associated with OL malignant progression, suggesting LOLA1 may be a predictive biomarker. Moreover, LOLA1 may promote migration, invasion, and EMT process in OL malignant progression via AKT/GSK-3β pathway.

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.

Circular RNA circ-NCOR2 accelerates papillary thyroid cancer progression by sponging miR-516a-5p to upregulate metastasis-associated protein 2 expression

Objective

Papillary thyroid cancer (PTC) is one of the most prevalent endocrine malignancies and the fifth most common cancer in women. Circular RNAs (circRNAs) have been shown to play vital functions in cancers, but few studies have focused on the functions and mechanism of dysregulated circRNAs in PTC.

Methods

Quantitative reverse transcription PCR was used to measure circ-NCOR2 levels in PTC tissues and cell lines. The functions of circ-NCOR2 in PTC were examined by analysis using the cell counting kit-8, clone forming, flow cytometry, and Transwell experiments. Bioinformatic analysis and dual luciferase reporter gene testing were used to identify the mechanisms of circ-NCOR2.

Results

Circ-NCOR2 overexpression was observed in PTC tissues and cells. Silenced or overexpressed expression of circ-NCOR2 strikingly attenuated or facilitated, respectively, the growth, migration, and invasion of PTC cells. Mechanistically, miR-615a-5p was identified as the target of circ-NCOR2. Moreover, circ-NCOR2 enhanced the expression of metastasis-associated protein 2 (MTA2) by sponging miR-615a-5p, thereby facilitating PTC cell progression.

Conclusions

Taken together, our findings reveal a novel circ-NCOR2/miR-615a-5p/MTA2 axis in PTC, which could become a potential therapeutic target for this disease.

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 RNAs: the tentacles of chromatin remodeler complexes

Chromatin remodeler complexes regulate gene transcription, DNA replication and DNA repair by changing both nucleosome position and post-translational modifications. The chromatin remodeler complexes are categorized into four families: the SWI/SNF, INO80/SWR1, ISWI and CHD family. In this review, we describe the subunits of these chromatin remodeler complexes, in particular, the recently identified members of the ISWI family and novelties of the CHD family. Long non-coding (lnc) RNAs regulate gene expression through different epigenetic mechanisms, including interaction with chromatin remodelers. For example, interaction of lncBRM with BRM inhibits the SWI/SNF complex associated with a differentiated phenotype and favors assembly of a stem cell-related SWI/SNF complex. Today, over 50 lncRNAs have been shown to affect chromatin remodeler complexes and we here discuss the mechanisms involved.

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.

Roles of the HOX Proteins in Cancer Invasion and Metastasis

Invasion and metastasis correspond to the foremost cause of cancer-related death, and the molecular networks behind these two processes are extremely complex and dependent on the intra- and extracellular conditions along with the prime of the premetastatic niche. Currently, several studies suggest an association between the levels of HOX genes expression and cancer cell invasion and metastasis, which favour the formation of novel tumour masses. The deregulation of HOX genes by HMGA2/TET1 signalling and the regulatory effect of noncoding RNAs generated by the HOX loci can also promote invasion and metastasis, interfering with the expression of HOX genes or other genes relevant to these processes. In this review, we present five molecular mechanisms of HOX deregulation by which the HOX clusters products may affect invasion and metastatic processes in solid tumours.

The Role of lncRNA Crosstalk in Leading Cancer Metastasis of Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common type of human malignancy. For decades, research into HNSCC invasion and metastasis has been dedicated to the study of protein-coding genes. Along with whole-genome and transcriptome sequencing development, long non-coding RNA (lncRNA) has attracted greater attention. Compelling evidence has proven the critical role of lncRNAs in the occurrence and development of HNSCC by means of epigenetic modifications, regulation of gene transcription, and post-transcription level. More importantly, crosstalk between lncRNAs and microRNAs was recently proven to regulate HNSCC metastasis through EMT modification. Based on these, this review summarizes the critical roles of lncRNAs in HNSCC metastasis and the crosstalk between lncRNAs and microRNAs as well as the detailed regulatory mechanism of the interaction. Thus, a deeper understanding of the lncRNA network in cancer metastasis is finally uncovered in order to provide a rationale and innovative concepts toward new therapeutic strategies for the highly metastatic HNSCC.

Hsa_circRNA_0000518 facilitates breast cancer development via regulation of the miR-326/FGFR1 axis

Background

Breast cancer (BC) is a heterogeneous malignant tumor that threatens the health of women worldwide. Hsa_circRNA_0000518 (circ_0000518) has been revealed to be upregulated in BC tissues. However, the role and mechanism of circ_0000518 in BC are indistinct.

Methods

Quantitative real‐time polymerase chain reaction (qRT‐PCR) was implemented to detect the levels of circ_0000518, microRNA (miR)‐326, and fibroblast growth factor receptor 1 (FGFR1) mRNA in BC tissues and cells. Cell counting kit‐8 (CCK‐8), colony formation, flow cytometry, and transwell assays were executed to estimate BC cell proliferation, cell cycle progression, apoptosis, migration, and invasion. The relationship between circ_0000518 or FGFR1 and miR‐326 was verified by dual‐luciferase reporter and/or RNA immunoprecipitation (RIP) assays. The role of circ_0000518 in vivo was confirmed by xenograft assay.

Results

Circ_0000518 and FGFR1 were upregulated while miR‐326 was downregulated in BC tissues and cells. Circ_0000518 silencing impeded tumor growth in vivo and induced cell cycle arrest, apoptosis, cured proliferation, colony formation, migration, and invasion of BC cells in vitro. Circ_0000518 regulated FGFR1 expression via competitively binding to miR‐326 in BC cells. MiR‐326 inhibitor reversed the inhibitory influence of circ_0000518 knockdown on the malignant behaviors of BC cells. FGFR1 overexpression abolished miR‐326 mimic‐mediated influence on the malignant behaviors of BC cells.

Conclusions

Circ_0000518 facilitated BC development via regulation of the miR‐326/FGFR1 axis, suggesting that circ_0000518 might be a promising target for BC treatment.