MicroRNAs as Important Players and Biomarkers in Oral Carcinogenesis. Biomed Res Int. 2015;2015:186904. [PMID: 26504785 DOI: 10.1155/2015/186904]

Exploring miR-155-5p and miR-1246 as Diagnostic and Prognostic Markers in Oral Squamous cell carcinoma

INTRODUCTION

Oral Squamous Cell Carcinoma (OSCC) is one of the leading cancers worldwide, significantly impacting developing nations. This study aimed to explore the diagnostic and prognostic potential of miR-155-5p and miR-1246 in OSCC in the Indian population, as their comparative roles in this context remain unexplored.

MATERIAL AND METHODS

The present cross-sectional study comprised 50 histopathologically confirmed OSCC cases, with adjacent normal mucosa as controls. MiRNA expression was assessed via qRT-PCR and correlated with clinicopathological factors. MiRwalk and miRTargetlink were used for miRNA:mRNA interaction prediction, and gprofiler was employed to analyze validated targets for functional insights.

RESULTS

The expression analysis showed a significant upregulation of miR-155-5p and miR-1246 in OSCC tissues compared to adjacent controls. Receiver operating curve analysis revealed that miR-1246 exhibited excellent diagnostic accuracy (AUC = 0.94) compared to miR-155-5p (AUC = 0.69). Higher miRNA levels were associated with age and extracapsular extension while overexpression of miR-1246 was correlated significantly with increased tumor size, tumor grade, TNM staging, and depth of invasion. The analysis for target prediction unveiled a set of validated targets, among which were WNT5A, TP53INP1, STAT3, CTNNB1, PRKAR1A, and NFIB.

CONCLUSION

miR-155-5p and miR-1246 may be used as potential prognostic biomarkers in OSCC, with miR-1246 demonstrating superior diagnostic accuracy.

Enhancing oral squamous cell carcinoma prediction: the prognostic power of the worst pattern of invasion and the limited impact of molecular resection margins

Objective

Oral squamous cell carcinoma (OSCC) originates from the mucosal lining of the oral cavity. Almost half of newly diagnosed cases are classified as advanced stage IV disease, which makes resection difficult. In this study, we investigated the pathological features and mutation profiles of tumor margins in OSCC.

Methods

We performed hierarchical clustering of principal components to identify distinct patterns of tumor growth and their association with patient prognosis. We also used next-generation sequencing to analyze somatic mutations in tumor and marginal tissue samples.

Results

Our analyses uncovered that the grade of worst pattern of invasion (WPOI) is strongly associated with depth of invasion and patient survival in multivariable analysis. Mutations were primarily detected in the DNA isolated from tumors, but several mutations were also identified in marginal tissue. In total, we uncovered 29 mutated genes, mainly tumor suppressor genes involved in DNA repair including BRCA genes; however none of these mutations significantly correlated with a higher chance of relapse in our medium-size cohort. Some resection margins that appeared histologically normal harbored tumorigenic mutations in TP53 and CDKN2A genes.

Conclusion

Even histologically normal margins may contain molecular alterations that are not detectable by conventional histopathological methods, but NCCN classification system still outperforms other methods in the prediction of the probability of disease relapse.

Potential of melatonin to reverse epigenetic aberrations in oral cancer: new findings

It is now an accepted principle that epigenetic alterations cause cellular dyshomeostasis and functional changes, both of which are essential for the initiation and completion of the tumor cycle. Oral carcinogenesis is no exception in this regard, as most of the tumors in the different subsites of the oral cavity arise from the cross-reaction between (epi)genetic inheritance and the huge challenge of environmental stressors. Currently, the biochemical machinery is put at the service of the tumor program, halting the cell cycle, triggering uncontrolled proliferation, driving angiogenesis and resistance to apoptosis, until the archetypes of the tumor phenotype are reached. Melatonin has the ability to dynamically affect the epigenetic code. It has become accepted that melatonin can reverse (epi)genetic aberrations present in oral and other cancers, suggesting the possibility of enhancing the oncostatic capacity of standard multimodal treatments by incorporating this indolamine as an adjuvant. First steps in this direction confirm the potential of melatonin as a countermeasure to mitigate the detrimental side effects of conventional first-line radiochemotherapy. This single effect could produce synergies of extraordinary clinical importance, allowing doses to be increased and treatments not to be interrupted, ultimately improving patients' quality of life and prognosis. Motivated by the urgency of improving the medical management of oral cancer, many authors advocate moving from in vitro and preclinical research, where the bulk of melatonin cancer research is concentrated, to systematic randomized clinical trials on large cohorts. Recognizing the challenge to improve the clinical management of cancer, our motivation is to encourage comprehensive and robust research to reveal the clinical potential of melatonin in oral cancer control. To improve the outcome and quality of life of patients with oral cancer, here we provide the latest evidence of the oncolytic activity that melatonin can achieve by manipulating epigenetic patterns in oronasopharyngeal tissue.

Prospective study: expression levels of microRNA-7-3p and its target STAT3 in head and neck cancer

BACKGROUND

Head and neck cancer (HNC) is the seventh most prevalent type of cancer in the globe, and it encompasses a wide range of tumors that affect the oral, facial and neck region. Despite breakthroughs in treatment strategies, patients survival has not increased substantially in the last few decades. Therefore, there is need for quick and reliable biomarkers and therapeutic targets for the treatment of HNC. Interestingly, microRNAs (miRNAs) are a small non-coding RNAs (ncRNAs) that have a role in the post-transcriptional regulation of gene expression. Thus, the aim of the study is to evaluate the role of miR-7-3p in the HNC and normal tissues.

METHODS

A total of 25 HNC and normal tissues were collected from the Department of Oral and Maxillofacial Surgery, Saveetha Dental College and Hospitals. Bioinformatic tool (TargetScan) was used to predict the target for miR-7-3p. The tissue samples were processed for Hematoxylin and Eosin staining and following that total RNA was extracted and analyzed for expression studies using RT-qPCR.

RESULTS

The bioinformatic analysis of the current study have revealed that STAT3 is a direct target for miR-7-3p. The histopathological examination showed damaged epithelial cells and keratin pool formation was observed in HNC tissue. Our results have also revealed that the miR-7-3p levels were significantly reduced and STAT3 levels were significantly higher in the HNC tissues when compared to the normal tissues.

CONCLUSIONS

MiR-7-3p can be used as a prognostic, diagnostic biomarker and therapeutic target for the treatment of HNC.

MicroRNA-1289 Functions as a Novel Tumor Suppressor in Oral Squamous Cell Carcinoma

Recently, numerous tumor-suppressive microRNAs (TS-miRs) have been identified in human malignancies. Here, we attempted to identify novel TS-miRs in oral squamous cell carcinoma (OSCC). First, we transfected human OSCC cells individually with 968 synthetic miRs mimicking human mature miRs individually, and the growth of these cells was evaluated using the WST-8 assay. Five miR mimics significantly reduced the cell growth rate by less than 30%, and the miR-1289 mimic had the most potent growth inhibitory effect among these miRs. Subsequently, we assessed the in vivo growth-inhibitory effects of miR-1289 using a mouse model. The administration of the miR-1289 mimic-atelocollagen complex significantly reduced the size of subcutaneously xenografted human OSCC tumors. Next, we investigated the expression of miR-1289 in OSCC tissues using reverse transcription-quantitative PCR. The expression level of miR-1289 was significantly lower in OSCC tissues than in the adjacent normal oral mucosa. Furthermore, 15 genes were identified as target genes of miR-1289 via microarray and Ingenuity Pathway Analysis (IPA) microRNA target filtering. Among these genes, the knockdown of magnesium transporter 1 (MAGT1) resulted in the most remarkable cell growth inhibition in human OSCC cells. These results suggested that miR-1289 functions as a novel TS-miR in OSCC and may be a useful therapeutic tool for patients with OSCC.

LncRNA SOX21-AS1 accelerates endometrial carcinoma progression through the miR-7-5p/RAF1 pathway

BACKGROUND

Endometrial carcinoma (EC) is one of the world's typical female reproductive tract malignancies, mostly occurring in postmenopausal women. Many reports have confirmed that long non-coding RNA SOX21 antisense RNA1 (lncRNA SOX21-AS1) is associated with the progressions of various cancer. However, the mechanism of SOX21-AS1 in EC remains unclear. Our study is intended to probe the mechanisms of SOX21-AS1 on EC progression.

METHODS

The CCK-8 assay and colony formation detected cell proliferation. Cell migration and invasion were assessed by transwell analysis. Apoptosis was measured by flow cytometry assay. Bioinformatics software predicted target binding and confirmed using a luciferase reporter analysis.

RESULTS

SOX21-AS1 expression was upregulated in EC tumor tissues and cells. High expression of SOX21-AS1 was associated with poor overall survival. Silencing of SOX21-AS1 restrained cell proliferation, migration, invasion, and increased apoptosis in HEC-1A and Ishikawa cells. Additionally, bioinformatics analysis demonstrated that SOX21-AS1 modulated RAF1 expression by competitively binding to miR-7-5p. Functionally, silencing of RAF1 reversed the functions of miR-7-5p inhibitor in the proliferation, invasion, and apoptosis of HEC-1A/sh-SOX21-AS1 and Ishikawa/sh-SOX21-AS1 cells.

CONCLUSIONS

SOX21-AS1 promoted the pathological development of EC by regulating the miR-7-5p/RAF1 pathway. This research may provide a novel target for EC therapy.

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.

Melatonin: Emerging Player in the Management of Oral Cancer

Oral cancer (OC) has emerged as a major medical and social issue in many industrialized nations due to the high death rate. It is becoming increasingly common in people under the age of 45, although the underlying causes and mechanisms of this increase remain unclear. Melatonin, as a pleiotropic hormone, plays a pivotal role in a wide variety of cellular and physiological functions. Mounting evidence supports melatonin's ability to modify/influence oral carcinogenesis, help in the reduction of the incidence of OC, and increase chemo- and radiosensitivity. Despite its potential anti-carcinogenic effects, the precise function of melatonin in the management of OC is not well understood. This review summarizes the current knowledge regarding melatonin function in anti-carcinogenesis mechanisms for OC. In addition, clinical assessment and the potential therapeutic utility of melatonin in OC are discussed. This review will provide a basis for researchers to create new melatonin-based personalized medicines for treating and preventing OC.

LncRNA KCNQ1OT1 accelerates ovarian cancer progression via miR-125b-5p/CD147 axis

BACKGROUND

Ovarian cancer (OC) is one of the most common gynecological malignancies with a high incidence. Researches showed that lncRNA KCNQ1OT1 (KCNQ1OT1) was involved various tumors progression, including OC. However, the precise mechanism of KCNQ1OT1 in OC needs to be further clarified.

OBJECTIVE

For investigate the underlying mechanism of KCNQ1OT1 regulating OC progression.

METHODS

CCK-8 assay, colony formation assay, Transwell assay, Western blot and quantitative real-time PCR (qRT-PCR) were performed to examine viability, proliferation, migration and invasion, genes and proteins' level. To identify KCNQ1OT1 as a regulator of miR-125b-5p and miR-125b-5p as a regulator of CD147, we used miRNA target prediction algorithms, Pearson's correlation analysis and dual-luciferase reporter gene assay.

RESULTS

KCNQ1OT1 was high expression and miR-125b-5p was low expression in OC, and KCNQ1OT1 was negatively correlated with that of miR-125b-5p in OC specimens. KCNQ1OT1 promoted OC cell proliferation and metastasis by binding to miR-125b-5p. miR-125b-5p targeted CD147, and which was negatively correlated with that of miR-125b-5p in OC specimens. KCNQ1OT1 was positively correlated with that of CD147 in OC specimens, and KCNQ1OT1 accelerated OC progression via miR-125b-5p/CD147 axis.

CONCLUSION

KCNQ1OT1 accelerated OC progression via miR-125b-5p/CD147 axis indicating KCNQ1OT1 serve as a novel biomarker for OC treatment. Our research provides a new direction for OC treatment.

MicroRNA-613 Enhances Nasopharyngeal Carcinoma Cell Radiosensitivity via the DNA Methyltransferase 3B/Tissue Inhibitor of Matrix Metalloproteinase-3/Signal Transducer and Activator of Transcription-1/Forkhead Box O-1 Axis

Nasopharyngeal carcinoma (NPC) is a common malignancy of the nasopharynx, and radioresistant represents the main obstacle in NPC treatment. Malignant transformation of normal cells is driven by genetic and epigenetic changes, which are primarily manifested as changes in miRNA levels and DNA methylation status. microRNA (miR)-613 plays an inhibitory role in several types of cancer. Herein, the current study sought to explore the roles of miR-613 in NPC cell radiosensitivity. miR-613 expression patterns in NPC tissues were detected, and its correlation with clinical indexes was analyzed. NP-69 and C666-1 cell lines were selected for cellular experimentation. Radioresistant cell line C666-1R was obtained by fractionated radiation. Cell viability, survival fraction, and apoptosis were detected by CCK-8, colony formation assay, and flow cytometry. The binding relation between miR-613 and DNMT3B was verified by dual-luciferase and RIP assays. miR-613 was lowly expressed in NPC tissues and cells, with lower expression levels in C666-1R than C666-1, and further correlated with lymph node metastasis, tumor size, and tumor metastasis. miR-613 overexpression reduced C666-1R cell viability and survival fraction and increased apoptosis, while C666-1 cells with silencing miR-613 presented the opposite trends. miR-613 targeted DNMT3B. miR-613 and DNMT3B overexpression led to enhanced C666-1R cell viability and survival fraction and decreased apoptosis. miR-613 reduced TIMP3 methylation and elevated TIMP3 protein level by inhibiting DNMT3B. miR-613 enhanced NPC radiosensitivity by inhibiting the DNMT3B/TIMP3/STAT1/FOXO1 pathway. Collectively, miR-613 inhibited DNMT3B, reduced TIMP3 methylation, and increased TIMP3 protein level, thus inhibiting the STAT1/FOXO1 pathway and enhancing the radiosensitivity of NPC cells.

Long non-coding RNA TFAP2A-AS1 plays an important role in oral squamous cell carcinoma: research includes bioinformatics analysis and experiments

BACKGROUND

Oral squamous cell carcinoma (OSCC) is the most common neck and head malignancies, and the prognosis is not good. Studies shown that the long non-coding RNA (lncRNA) TFAP2A-AS1 is involved in the progression of multiple cancers. However, the role of lncRNA TFAP2A-AS1 in OSCC remains unclear. We aimed to explore the functions and expression in OSCC.

METHODS

The lncRNA profiles for OSCC patients were acquired from the TCGA. Based on these data, the data mining of TFAP2A-AS1 in patients with OSCC were performed. The functions of TFAP2A-AS1 were determined by bioinformatics analysis. The expression and roles in cell growth were tested by RT-qPCR and MTS assay. Cell invasion and migration were tested by wound healing and transwell assays.

RESULTS

The consequences displayed that TFAP2A-AS1 was upregulated in the TCGA datasets. The expression of TFAP2A-AS1 was higher in OSCC samples. Bioinformatics analysis shown that TFAP2A-AS1 might be associated with the P53 signaling pathway. Cell culture experiments indicated that deficiency of TFAP2A-AS1 inhibited cell growth, invasion, and migration, and overexpression of it could opposite results in SCC-25 cells.

CONCLUSION

The results suggested that TFAP2A-AS1 was overexpressed in OSCC cells, which could facilitate OSCC cell proliferation, migration, and invasion.

MicroRNA-138 Abates Fibroblast Motility With Effect on Invasion of Adjacent Cancer Cells

Background

Recent studies have shown aberrant expression of micro-RNAs in cancer-associated fibroblasts (CAFs). This study aimed to investigate miR-138 dysregulation in CAFs in oral squamous cell carcinoma (OSCC) and its effects on their phenotype and invasion of adjacent OSCC cells.

Methods

Expression of miR-138 was first investigated in OSCC lesions (n = 53) and OSCC-derived CAFs (n = 15). MiR-138 mimics and inhibitors were used to functionally investigate the role of miR-138 on CAF phenotype and the resulting change in their ability to support OSCC invasion.

Results

Expression of miR-138 showed marked heterogeneity in both OSCC tissues and cultured fibroblasts. Ectopic miR-138 expression reduced fibroblasts’ motility and collagen contraction ability and suppressed invasion of suprajacent OSCC cells, while its inhibition resulted in the opposite outcome. Transcript and protein examination after modulation of miR-138 expression showed changes in CAF phenotype-specific molecules, focal adhesion kinase axis, and TGFβ1 signaling pathway.

Conclusions

Despite its heterogeneous expression, miR-138 in OSCC-derived CAFs exhibits a tumor-suppressive function.

Versatile role of miR-24/24-1*/24-2* expression in cancer and other human diseases

MiRNAs (miRs) have been proven to be well-validated therapeutic targets. Emerging evidence has demonstrated that intricate, intrinsic and paradoxical functions of miRs are context-dependent because of their multiple upstream regulators, broad spectrum of downstream molecular targets and distinct expression in various tissues, organs and disease states. Targeted therapy has become an emerging field of research. One key for the development of successful miR-based/targeted therapy is to acquire integrated knowledge of its regulatory network and its association with disease phenotypes to identify critical nodes of the underlying pathogenesis. Herein, we systematically summarized the comprehensive role of miR-24-3p (miR-24), along with its passenger strands miR-24-1-5p* (miR-24-1) and miR-24-2-5p* (miR-24-2), emphasizing their microenvironment, intracellular targets, and associated gene networks and regulatory phenotypes in 18 different cancer types and 13 types of other disorders. MiR-24 targets and regulates numerous genes in various cancer types and enhances the expression of several oncogenes (e.g., cMyc, BCL2 and HIF1), which are challenging in terms of druggability. In contrast, several tumor suppressor proteins (p21 and p53) have been reported to be downregulated by miR-24. MiR-24 also regulates the cell cycle and is associated with numerous cancer hallmarks such as apoptosis, proliferation, metastasis, invasion, angiogenesis, autophagy, drug resistance and other diseases pathogenesis. Overall, miR-24 plays an emerging role in the diagnosis, prognosis and pathobiology of various diseases. MiR-24 is a potential target for targeted therapy in the era of precision medicine, which expands the landscape of targetable macromolecules, including undruggable proteins.

Investigation of miR-21-5p Key Target Genes and Pathways in Head and Neck Squamous Cell Carcinoma Based on TCGA Database and Bioinformatics Analysis

Aim: Head and neck squamous cell carcinoma (HNSCC) is the sixth most commonly diagnosed malignancy worldwide. Overexpressed of microRNA-21-5p (miR-21-5p) has been reported to be involved in the development of HNSCC. However, the role of miR-21-5p in HNSCC is still not fully elucidated. The purpose of this study was to explore the underlying molecular mechanisms of miR-21-5p in HNSCC. Methods: RT-qPCR was used to determine the differential expression levels of miR-21-5p in tissue samples of HNSCC patients. Meta-analysis was performed based on miRNA expression data collected from the Gene Expression Omnibus (GEO) database, The Cancer Genome Atlas (TCGA), and published articles to evaluate the expression of miR-21-5p in HNSCC. We investigated the biological function of miR-21-5P by gene ontology enrichment and target prediction analysis. Furthermore, RT-qPCR and IHC were conducted to verify the expression of target genes. Finally, Kaplan–Meier survival analysis was performed to assessed the prognostic value of the putative miR-21-5p target genes. Results: MiR-21-5p was significantly overexpressed in HNSCC compared to healthy tissues (P < .05) and showed potent predictive power with a summary receiver operating characteristic of 0.90. Meanwhile, the expression of miR-21-5p was significantly correlated with tumor stage, T stage and smoking in HNSCC (P < .05). A total of 71 down-regulated genes, both HNSCC-related and miR-21-p5-related, were obtained from the analytical integration. Two predicted genes (ADH7, RDH12) were down-regulated in HNSCC, and significantly negatively correlated with miR-21-5p. IHC and RT-qPCR demonstrated that the expression of ADH7 and RDH12 in HNSCC samples was significantly lower than control. And high expression of ADH7 was associated with better DFS of HNSCC patients. Conclusions: miR-21-5p may target at ADH7, RDH12 and participate in regulation of retinol metabolism, which might affect the prognosis of HNSCC. High expression of ADH7 may indicate better prognosis in HNSCC patients.

A Systematic Review of MicroRNA Signatures Associated with the Progression of Leukoplakia with and without Epithelial Dysplasia

Oral cancer is a significant public health issue, being the eighth most common cancer worldwide with over 300,000 cases diagnosed annually. Early diagnosis and adequate management of oral potentially malignant disorders (OPMDs) before transformation into oral squamous cell carcinoma (OSCC) is critical to reduce deaths, morbidity, and to improve overall prognosis. MicroRNAs (miRNAs) are small noncoding RNAs involved in the post-transcriptional regulation of protein expression and implicated in the control of numerous cellular pathways and impacting physiological, developmental, and pathological processes. Dysregulation of miRNAs has been reported in many cancers and has been demonstrated to play a critical role in cancer initiation, progression, apoptosis, invasion and metastasis. This systematic review provides a comprehensive summary of the prevailing literature on miRNA signatures in OPMDs, specifically leukoplakia with or without oral epithelial dysplasia, and their utility in predicting malignant transformation into OSCC. Eighteen articles describing 73 unique and differentially expressed microRNAs met the criteria for inclusion in this review. We reviewed the characteristics and methodology for each of these studies and assessed the sensitivity and specificity of the studied miRNAs in predicting malignant transformation. This systematic review highlights the significant interest in miRNAs and their tremendous potential as prognostic markers for predicting the malignant transformation of OPMDs into OSCC.

LncRNA MNX1-AS1 promotes ovarian cancer process via targeting the miR-744-5p/SOX12 axis

Purpose

Ovarian cancer (OC) is the most common malignancy in women with high mortality. Increasing studies have revealed that long non-coding RNA (lncRNA) MNX1-AS1 has a promoting effect on various cancers. However, the mechanisms of MNX1-AS1 in OC are still unclear. Therefore, this study focused on exploring the mechanisms of MNX1-AS1 in OC.

Materials and methods

The expression of SOX12 at the protein level was detected by western blot. Cell proliferation was detected by CCK8 assay and colony formation assay. Cell cycle and cell apoptosis were detected by flow cytometry. Wound-healing assay, transwell assay and western blot were used to detect the ability of cell migration and invasion. The target binding was confirmed through the luciferase reporter assay.

Results

The expression of MNX1-AS1 was increased in OC tumor tissues and cells. Elevated MNX1-AS1 expression is associated with advanced stage and lower overall survival rate. Knockdown of MNX1-AS1 inhibited cell proliferation, migration and invasion, blocked cell cycle, and promoted cell apoptosis in SKOV-3 and OVCAR-3 cells. MNX1-AS1 was competitively binding with miR-744-5p, and its downstream target gene was SOX12. miR-544-5p expression was decreased, while SOX12 expression was increased in OC tumor tissues and cells. Overexpression of miR-744-5p inhibited cell proliferation, migration, invasion and promoted cell apoptosis in SKOV-3 and OVCAR-3 cells.

Conclusion

MNX1-AS1 promoted the development of OC through miR-744-5p/SOX12 axis. This study revealed a novel mechanism of MNX1-AS1 in OC, which may provide a new treatment or scanning target for OC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-021-00910-0.

Long noncoding RNA KCNQ1 opposite strand/antisense transcript 1 promotes osteosarcoma progression through miR-154-3p/KLF12

OBJECTIVE

Osteosarcoma (OS) is a common bone cancer that usually influences children. Metastasis and recurrence are the main reasons for the poor prognosis. In this study, we investigated the functions and mechanisms of KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1) in OS.

METHODS

Cell viability and proliferation were detected using the CCK-8 assay and the 5-Ethynyl-2'-deoxyuridine (EdU) assay. Wound-healing assays, transwell assay and flow cytometry were used to identify cell migration, invasion, and apoptosis, respectively. The relationship among KCNQ1OT1, miR-154-3p, and KLF12 was verified by luciferase reporter assay and restricting protein immunoprecipitation (RIP) assay. Xenograft models were established to confirm the function of KCNQ1OT1 in vivo.

RESULTS

The expression of KCNQ1OT1 was higher in OS than in non-tumor tissues and cells. Knockdown of KCNQ1OT1 could reduce OS cell proliferation, migration, and invasion and promoted cell death. Mechanistically, KCNQ1OT1 contributed to OS formation by acting as a competitive endogenous RNA (ceRNA) and influencing miR-154-3p expression. Furthermore, we confirmed that miR-154-3p affected KLF12 expression through binding the 3'UTR region. Finally, rescue experiments determined that KCNQ1OT1 exerted major roles in OS through the miR-154-3p/KLF12 axis.

CONCLUSION

In conclusion, our research explains the mechanism of KCNQ1OT1 in OS progression, which could serve as a new therapeutic target.

Profiling and Functional Analysis of microRNA Deregulation in Cancer-Associated Fibroblasts in Oral Squamous Cell Carcinoma Depicts an Anti-Invasive Role of microRNA-204 via Regulation of Their Motility

Background: Knowledge on the role of miR changes in tumor stroma for cancer progression is limited. This study aimed to investigate the role of miR dysregulation in cancer-associated fibroblasts (CAFs) in oral squamous cell carcinoma (OSCC). Methodology: CAF and normal oral fibroblasts (NOFs) were isolated from biopsies of OSCC patients and healthy individuals after informed consent and grown in 3D collagen gels. Total RNA was extracted. Global miR expression was profiled using Illumina version 2 panels. The functional impact of altered miR-204 expression in fibroblasts on their phenotype and molecular profile was investigated using mimics and inhibitors of miR-204. Further, the impact of miR-204 expression in fibroblasts on invasion of adjacent OSCC cells was assessed in 3D-organotypic co-cultures. Results: Unsupervised hierarchical clustering for global miR expression resulted in separate clusters for CAF and NOF. SAM analysis identified differential expression of twelve miRs between CAF and NOF. Modulation of miR-204 expression did not affect fibroblast cell proliferation, but resulted in changes in the motility phenotype, expression of various motility-related molecules, and invasion of the adjacent OSCC cells. 3′ UTR miR target reporter assay showed ITGA11 to be a direct target of miR-204. Conclusions: This study identifies differentially expressed miRs in stromal fibroblasts of OSCC lesions compared with normal oral mucosa and it reveals that one of the significantly downregulated miRs in CAF, miR-204, has a tumor-suppressive function through inhibition of fibroblast migration by modulating the expression of several different molecules in addition to directly targeting ITGA11.

MiRNA-146a/AKT/β-Catenin Activation Regulates Cancer Stem Cell Phenotype in Oral Squamous Cell Carcinoma by Targeting CD24

CD44^highCD24^low population has been previously reported as cancer stem cells (CSCs) in Oral Squamous Cell Carcinoma (OSCC). Increasing evidence suggests potential involvement of microRNA (miRNA) network in modulation of CSC properties. MiRNAs have thus emerged as crucial players in tumor development and maintenance. However, their role in maintenance of OSCC stem cells remains unclear. Here we report an elevated expression of miR-146a in the CD44^highCD24^low population within OSCC cells and primary HNSCC tumors. Moreover, over-expression of miR-146a results in enhanced stemness phenotype by augmenting the CD44^highCD24^low population. We demonstrate that miR-146a stabilizes β-catenin with concomitant loss of E-cadherin and CD24. Interestingly, CD24 is identified as a novel functional target of miR-146a and ectopic expression of CD24 abrogates miR-146a driven potential CSC phenotype. Mechanistic analysis reveals that higher CD24 levels inhibit AKT phosphorylation leading to β-catenin degradation. Using stably expressing miR-146a/CD24 OSCC cell lines, we also validate that the miR-146a/CD24/AKT loop significantly alters tumorigenic ability in vivo. Furthermore, we confirmed that β-catenin trans-activates miR-146a, thereby forming a positive feedback loop contributing to stem cell maintenance. Collectively, our study demonstrates that miR-146a regulates CSCs in OSCC through CD24-AKT-β-catenin axis.

Knockdown of circ_0011946 targets miR-216a-5p/BCL2L2 axis to regulate proliferation, migration, invasion and apoptosis of oral squamous cell carcinoma cells

Background

Circular RNAs (circRNAs) are implicated in the development of oral squamous cell carcinoma (OSCC). The aim of current research is to elucidate the role and mechanism of circ_0011946 in the functional behaviors of OSCC cells.

Methods

Circ_0011946, microRNA (miR)-216a-5p, B cell lymphoma-2-like 2 protein (BCL2L2) abundances were exposed by quantitative reverse transcription polymerase chain reaction (qRT-PCR) or western blot. Cell proliferation, migration, invasion and apoptosis were detected by MTT, colony formation assay, transwell, wound-healing and flow cytometry assays, respectively. Target correlation was tested by dual-luciferase reporter and RNA pull-down assays. An in vivo xenograft experiment was employed to investigate the function of circ_0011946 on tumor growth in vivo.

Results

Circ_0011946 and BCL2L2 levels were increased, while miR-216a-5p level was decreased in OSCC tissues and cells. Circ_0011946 knockdown impeded proliferation, migration, and invasion, but promoted apoptosis in OSCC cells. Circ_0011946 functioned as a sponge for miR-216a-5p, and BCL2L2 was targeted by miR-216a-5p. Besides, miR-216a-5p or BCL2L2 knockdown partly attenuated the inhibitory influences of circ_0011946 silence or miR-216a-5p overexpression on OSCC cell progression. Furthermore, circ_0011946 post-transcriptionally regulated BCL2L2 through sponging miR-216a-5p. Moreover, circ_0011946 knockdown constrained OSCC tumor growth in vivo.

Conclusion

Circ_0011946 silence repressed OSCC cell proliferation, migration, and invasion, but promoted apoptosis through the regulation of the miR-216a-5p/BCL2L2 axis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08779-4.

Human microRNA-182-5p and kinectin 1: Potential biomarkers for prognosis in oral squamous cell carcinoma

BACKGROUND

The prognostic impact of hsa-miRNA-182-5p in oral cancer remains unexplored. Therefore, the aim of this study was to investigate the prognostic value of hsa-miRNA-182-5p and its predicted target kinectin 1 (KTN1) in oral squamous cell carcinoma (OSCC).

METHOD

Expression level of hsa-miRNA-182-5p was analyzed in tumor tissue (n = 36) and healthy oral mucosal tissue (n = 17) using quantitative real-time polymerase chain reaction. Protein level of the predicted target KTN1 was detected via immunohistochemistry. Results were validated in a cohort of The Cancer Genome Atlas (TCGA).

RESULTS

After dividing the data into a subgroup with high and low hsa-miRNA-182-5p expression level, a significant better overall (p = 0.016), recurrence-free (p = 0.009), and progression-free survival (p = 0.004) was observed in an upregulation of hsa-miRNA-182-5p. Staining intensity of KTN1 showed a reciprocal impact on the prognosis. Validation in a TCGA cohort confirmed these results.

CONCLUSION

Our results indicate hsa-miRNA-182-5p and KTN1 as potential biomarkers for OSCC.

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.

Site specificity and expression profile of miR-21 in oral squamous cell carcinoma

Background:

Oral Squamous Cell Carcinoma (OSCC) is the most common epithelial malignancy of the oral cavity which has evolved globally as a grave and growing health problem. It shares a wide geographic variation with respect to the incidence rate and exhibits anatomic adaptation to oral environment with varied clinical presentation along with a spectrum of histological mélange. Besides, in recent cancer research, both genetics and epigenetics add on at the molecular level and accounts for this diversification and tumor heterogeneity of OSCC and thereby substantiates to the miRNA expression profiling in OSCC.

Aims and Objectives:

In the present study, subsite specificity of miR-21 expression in tissue specimens of OSCC of Tongue, Buccal mucosa, and Gingivo buccal (GB) sulcus were analyzed.

Materials and Methods:

Quantification of miR-21 was done on 30 tissue samples of OSCC using real-time polymerase chain reaction (RT-PCR).

Results:

Results indicated that miR-21 expression was significantly expressed at the subsites. Out of 30 samples, 22 showed upregulation, and 8 showed down-regulation with reference to endogenous control. The comparative Ct method was used to analyze the differences in subsite specific expression of miR-21 in OSCC cases. It was significantly upregulated in the buccal mucosa (p=0.002), followed by GB sulcus (p=0.01) and Tongue (p=0.25).

Conclusion:

In conclusion, the study could identify the differential miR-21 expression at sub-sites, indicating that it may serve as a diagnostic marker with further elaboration on a larger sample size..

MIR137/MIR2682 locus is associated with perineural invasiveness in head and neck cancer

BACKGROUND

Head and neck cancer (HNSCC) is one of the most lethal cancers characterized by high relapse and poor prognosis. Several miRNAs have been implicated in HNSCC, including the tumor suppressor miR-137. A large CpG island (CpG73) spans most of the miR-137 gene sequence and stretches 659-bp downstream, ending just upstream of miR-2682 in the same host gene. Here, we assessed the role of the MIR137/MIR2682 locus in HNSCC.

METHODS

MiRNA expression was analyzed in paired cancerous and normal tissues from 77 HNSCC patients by Quantitative Reverse-Transcription PCR. CpG73 methylation in paired tissues from 48 patients was determined by combined bisulfite restriction analysis. Associations between expression and methylation levels and patient clinicopathological parameters were investigated.

RESULTS

Decreased expression of miR-137 (P<0.01) and miR-2682 (P<0.01) precursors was observed in cancerous tissues, most significantly in oropharyngeal tumors. Lower miR-137 levels correlated with increased perineural invasiveness (P = 0.04). Predicted common miRNA targets MTDH and Notch1 were upregulated in tumor tissues. The CpG73 region between miR-137 and miR-2682 was hypermethylated in tumors. Methylation was observed in 60.4% of cancerous compared to 31.6% of normal tissues, and methylation levels were significantly higher (P<0.01) in tumors. Increased methylation correlated with decreased disease-free patient survival (P = 0.024).

CONCLUSION

The MIR137/MIR2682 locus correlated with HNSCC perineural invasiveness. This is the first report showing miR-2682 downregulation in head and neck cancer. Our results support the tumor suppressive role of miR-137 and miR-2682. The inverse correlation between CpG73 hypermethylation and disease-free survival suggests this epigenetic mark may have prognostic value in HNSCC.

Combined In Situ Hybridization and Immunohistochemistry on Archival Tissues Reveals Stromal microRNA-204 as Prognostic Biomarker for Oral Squamous Cell Carcinoma

Simple Summary

In addition to the transformation of epithelial cells, dysfunction of stroma is crucial in carcinogenesis; cancer-associated stroma can regulate the phenotype of cancer cells and thereby influence the clinical outcome. Our study aimed to investigate the correlation of stromal miR-204 with progression of oral squamous cell carcinoma (OSCC) and assert its clinical utility. We first established a chromogen-based method that combined immunohistochemistry and in situ hybridization for exact delimitation of stroma from the tumor islands and concomitant visualization of miRs, and have developed a guide to digital miR quantification using the publicly available tool ImageJ and the licensed software Aperio ImageScope. We have then applied the method for investigating stromal miR-204 as a putative prognostic biomarker on an OSCC cohort and identified expression of miR204 in the stroma at tumor front as an independent prognostic biomarker for this disease.

Abstract

Micro-RNAs (miRs) are emerging as important players in carcinogenesis. Their stromal expression has been less investigated in part due to lack of methods to accurately differentiate between tumor compartments. This study aimed to establish a robust method for dual visualization of miR and protein (pan-cytokeratin) by combining chromogen-based in situ hybridization (ISH) and immunohistochemistry (IHC), and to apply it to investigate stromal expression of miR204 as a putative prognostic biomarker in oral squamous cell carcinoma (OSCC). Four different combinations of methods were tested and ImageJ and Aperio ImageScope were used to quantify miR expression. All four dual ISH-IHC methods tested were comparable to single ISH in terms of positive pixel area percentage or integrated optical density of miRs staining. Based on technical simplicity, one of the methods was chosen for further investigation of miR204 on a cohort of human papilloma virus (HPV)-negative primary OSCC (n = 169). MiR204 stromal expression at tumor front predicted recurrence-free survival (p = 0.032) and overall survival (p = 0.036). Multivariate Cox regression further confirmed it as an independent prognostic biomarker in OSCC. This study provides a methodological platform for integrative biomarker studies based on simultaneous detection and quantification of miRs and/or protein and reveals stromal miR204 as a prognostic biomarker in OSCC.

LINC00958 promotes the proliferation of TSCC via miR-211-5p/CENPK axis and activating the JAK/STAT3 signaling pathway

Background

Tongue squamous cell carcinoma (TSCC) is one of the most common oral tumors. Recently, long intergenic noncoding RNA 00958 (LINC00958) has been identified as an oncogene in human cancers. Nevertheless, the role of LINC00958 and its downstream mechanisms in TSCC is still unknown.

Methods

The effect of LINC00958 on TSCC cells proliferation and growth were assessed by CCK-8, colony formation, 5-Ethynyl-2′-deoxyuridline (EdU) assay and flow cytometry assays in vitro and tumor xenograft model in vivo. Bioinformatics analysis was used to predict the target of LINC00958 in TSCC, which was verified by RNA immunoprecipitation and luciferase reporter assays.

Results

LINC00958 was increased in TSCC tissues, and patients with high LINC00958 expression had a shorter overall survival. LINC00958 knockdown significantly decreased the growth rate of TSCC cells both in vitro and in vivo. In mechanism, LINC00958 acted as a ceRNA by competitively sponging miR-211-5p. In addition, we identified CENPK as a direct target gene of miR-211-5p, which was higher in TSCC tissues than that in adjacent normal tissues. Up-regulated miR-211-5p or down-regulated CENPK could abolish LINC00958-induced proliferation promotion in TSCC cells. Furthermore, The overexpression of CENPK promoted the expression of oncogenic cell cycle regulators and activated the JAK/STAT3 signaling.

Conclusions

Our findings suggested that LINC00958 is a potential prognostic biomarker in TSCC.

New Insights Into Oral Squamous Cell Carcinoma: From Clinical Aspects to Molecular Tumorigenesis

Oral squamous cell carcinoma (SCC) is a prevalent malignant disease worldwide, especially so in Taiwan. Early- or even preclinical-stage detection is critical for reducing morbidity and mortality from oral SCC. Epidemiological and genome association studies are useful for identifying clinicopathological risk factors for preventive, diagnostic, and therapeutic approaches of oral SCC. For advanced oral SCC, effective treatments are critical to prolonging survival and enhancing quality of life. As oral SCC is characteristic of regional invasion with lymph node metastases, understanding the aggressive features of oral SCC, particularly in lymphangiogenesis, is essential for determining effective treatments. Emerging evidence has demonstrated that the tumor microenvironment (TME) plays a pivotal role in tumor growth, invasion, and metastases. Recent clinical successes in immune checkpoint inhibitors either alone or combined with chemotherapy have also supported the therapeutic value of immunotherapy in oral SCC. This review summarizes critical advances in basic knowledge of oral SCC from the perspective of clinicopathological risk factors, molecular tumorigenesis, and the TME. We also highlight our recent investigations on the microbiome, genome association studies, lymphangiogenesis, and immunomodulation in oral SCC. This review may provide new insights for oral SCC treatment by systematically interpreting emerging evidence from various preclinical and clinical studies.

MicroRNAs and Long Non-Coding RNAs as Regulators of NANOG Expression in the Development of Oral Squamous Cell Carcinoma

NANOG is a stem cell transcription factor that is believed to play an important role in the development of oral squamous cell carcinoma (OSCC), but there is limited data regarding the role of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) in the regulation of NANOG expression. We therefore analyzed expression of NANOG, NANOG-regulating miRNAs and lncRNAs in OSCC cancerogenesis, using oral biopsy samples from 66 patients including normal mucosa, dysplasia, and OSCC. Expression analysis of NANOG, miR-34a, miR-145, RoR, SNHG1, AB209630, and TP53 was performed using qPCR and immunohistochemistry for NANOG protein detection. NANOG protein showed no staining in normal mucosa, very weak in low-grade dysplasia, and strong staining in high-grade dysplasia and OSCC. NANOG, miR-145, RoR, and SNHG1 showed up-regulation, TP53 and miR-34a showed down-regulation, and AB209630 showed variable expression during cancerogenesis. NANOG mRNA was up-regulated early in cancerogenesis, before strong protein expression can be detected. NANOG was in correlation with miR-145 and RoR. Our results suggest that miRNAs and lncRNAs, particularly miR-145 and RoR, might be important post-transcription regulatory mechanisms of NANOG in OSCC cancerogenesis. Furthermore, NANOG protein detection has a diagnostic potential for oral high-grade dysplasia, distinguishing it from low-grade dysplasia and non-neoplastic reactive lesions.

circBICD2 targets miR-149-5p/IGF2BP1 axis to regulate oral squamous cell carcinoma progression

BACKGROUND

Circular RNAs (circRNAs) are related to oral squamous cell carcinoma (OSCC) progression. circRNA bicaudal D cargo adaptor 2 (circBICD2) has been reported to be abnormally expressed in OSCC. However, the function and mechanism of this circRNA in OSCC progression remain largely unknown.

METHODS

circBICD2, microRNA-149-5p (miR-149-5p), and insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) abundances were examined via quantitative reverse transcription polymerase chain reaction or Western blot. The function of circBICD2 was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation, flow cytometry, wound healing, transwell, specific kits, Western blot, and xenograft analyses. Dual-luciferase reporter analysis and RNA immunoprecipitation were carried out to analyze the binding interaction.

RESULTS

circBICD2 expression was enhanced in OSCC tissues and cells. circBICD2 silence suppressed OSCC cell proliferation, migration, invasion, and glutaminolysis and facilitated apoptosis. miR-149-5p was targeted via circBICD2 and decreased in OSCC tissues and cells. miR-149-5p knockdown attenuated silence of circBICD2 on the influence of OSCC cell proliferation, apoptosis, migration, invasion, and glutaminolysis. IGF2BP1 was targeted via miR-149-5p, and circBICD2 could regulate IGF2BP1 via miR-149-5p. IGF2BP1 interference constrained OSCC cell proliferation, migration, invasion, and glutaminolysis and promoted apoptosis. circBICD2 silence reduced OSCC cell growth in xenograft model.

CONCLUSION

circBICD2 knockdown repressed OSCC cell proliferation, migration, invasion, and glutaminolysis and increased apoptosis via modulating miR-149-5p/IGF2BP1 axis, which might act as a potential target for OSCC treatment.

Circulating microRNA Panel as a Potential Novel Biomarker for Oral Squamous Cell Carcinoma Diagnosis

Simple Summary

Although early detection of oral squamous cell carcinoma (OSCC) is considered vital, classical biomarkers have shown poor sensitivity and specificity for early detection and monitoring of OSCC. Therefore, identification of reliable and sensitive biomarkers allowing for early detection and monitoring of OSCC is of the utmost importance. In this study, we successfully identified significantly upregulated or downregulated microRNAs in OSCC patients, and reported that a combination of six microRNAs could distinguish between OSCC and the control group with a higher degree of accuracy. Furthermore, compared with serum squamous cell carcinoma (SCC) antigen, the miRNA panel reflected the presence of OSCC accurately. The present results suggest that the combined microRNA panel based on serum microRNA levels shows potential as a novel diagnostic biomarker of OSCC.

Abstract

A lack of reliable biomarkers for oral squamous cell carcinoma (OSCC) poses a major clinical issue. The sensitivity and specificity of classical serum tumor markers, such as the squamous cell carcinoma antigen (SCC-Ag), are quite poor, especially for early detection. This study aimed to identify specific serum miRNAs potentially serving as OSCC biomarkers. The expression levels of candidate miRNAs in serum samples from 40 OSCC patients and 40 healthy controls were quantitatively analyzed via microarray and reverse transcription PCR (RT-PCR) analyses. To enhance the accuracy of detection, we used Fisher’s linear discriminant analysis to establish a diagnostic model that incorporated a combination of selected miRNAs. Consequently, miR-19a and miR-20a were significantly upregulated in the patient group (p = 0.014 and 0.036, respectively), whereas miR-5100 was downregulated (p = 0.001). We found that a combination of six miRNAs (miR-24, miR-20a, miR-122, miR-150, miR-4419a, and miR-5100) could distinguish between OSCC and the control group with a higher degree of accuracy (Area Under the Curve, AUC: 0.844, sensitivity: 55%, and specificity: 92.5%). Furthermore, compared to serum SCC antigen, the 6-miRNA panel could accurately detect the presence of OSCC. The present specific miRNAs panel may serve as a novel candidate biomarker of oral cancer.

The relevance of miRNAs as promising biomarkers in lip cancer

OBJECTIVES

This study aimed to analyze the expression of miR-181b, miR-21, miR-31, and miR-345 in actinic cheilitis with and without epithelial dysplasia and lower lip squamous cell carcinomas, and to verify if the deregulated expression of these miRNAs would be indicative of malignant transformation.

MATERIALS AND METHODS

The sample was selected from formalin-fixed paraffin-embedded tissues of 19 actinic cheilitis without epithelial dysplasia, 32 actinic cheilitis with epithelial dysplasia, 42 lower lip squamous cell carcinomas, and 10 nonaltered oral mucosa of the lip. The microRNA (miR, miRNA) expression was quantified by real-time RT-PCR and the expression of the selected miRNAs among the groups of actinic cheilitis and lower lip cancer was compared by chi-square.

RESULTS

A higher expression of miR-181b, miR-31, and miR-345 was found in actinic cheilitis without epithelial dysplasia in comparison to that in actinic cheilitis with epithelial dysplasia and with lower lip cancer. There were no differences in miR-21 expression between actinic cheilitis and lower lip cancer. Hierarchical clustering analysis showed a tendency for a downregulation of miR-181b, miR-21, miR-31, and miR-345 in most patients with lower lip cancers.

CONCLUSIONS

The upregulation of miR-181b, miR-31, and miR-345 expression in actinic cheilitis without epithelial dysplasia and the decrease in the expression of these miRNAs in actinic cheilitis with epithelial dysplasia and in lower lip cancer are potential biomarkers of malignant progression.

CLINICAL RELEVANCE

This miRNA signature can help to identify actinic cheilitis with potential to progress to lip cancer.

Role of miR153 and miR455-5p Expression in Oral Squamous Cell Carcinoma Isolated from Plasma

Background:

Despite the notable advances in modern surgery and radiotherapy,no significant increase in the five year survival rate of oral squamous cell carcinoma has been reported. Collecting evidence demonstrates that miR 153 and miR 455-5p play a key role in growth and progression of oral cancer. Early detection of OSCC is important for enhancing patient quality of life and clinical treatment.For this reason, biomarkers or tumour markers offer an opportunity to intervene and avoid development of oral cancer.

Methods:

A total of 50 blood samples from patients from both genders (25 OSCC and 25 healthy people/control groups) were obtained to determine the expression of miR153 and miR455-5p using Real time Polymerase chain reaction and t test.

Results:

In general by using the formula Δ ct, it is evident that the miR 153 expression in peripheral blood is lower in patients than in healthy individuals (1.97) while the miR 455-5p expression in peripheral blood is higher in patients than in healthy individuals (2.56).

Conclusion:

We conclude that miR153 and miR 455-5p expression in serum can function as a diagnostic screening test for the early detection of oral squamous cell carcinoma.

Tumor Suppressor LINC02487 Inhibits Oral Squamous Cell Carcinoma Cell Migration and Invasion Through the USP17-SNAI1 Axis

Purpose

The aim of this study was to explore the functions and associated mechanisms of long noncoding RNA LINC02487 in oral squamous cell carcinoma (OSCC).

Methods

The relative expression levels of LINC02487 in OSCC cell lines and tissue samples were examined by RT-qPCR. Intracellular localization was determined using RNA fluorescence in situ hybridization. LINC02487 was cloned into the pCMV-puro vector and then introduced into OSCC cells using lentiviral transfection. Cell processes, such as proliferation, apoptosis, migration, and invasion, were subsequently examined. LINC02487-binding proteins were identified by ChIRP-MS and confirmed by RNA immunoprecipitation. Protein expression was determined by western blotting assay.

Results

LINC02487 has been reported to be downregulated in OSCC. Here, we confirmed that the expression of LINC02487 was reduced in 6 OSCC cell lines compared with that in immortalized normal oral epithelial cells and in 50 OSCC samples compared with paired adjacent normal tissue in a Chinese population and that LINC02487 expression levels were associated with cancer metastasis. We further identified that LINC02487 was localized to the cytoplasm, aggregated around the nuclear membrane. Functional studies demonstrate that overexpression of LINC02487 significantly suppresses cell migration and invasion and also inhibits cell proliferation. For the mechanism, we reveal that LINC02487 directly binds to USP17, a deubiquitinating enzyme, and regulates cell migration and invasion through the USP17-SNAI1 axis in a process that involves epithelial-mesenchymal transition (EMT).

Conclusion

Our results confirm that long noncoding RNA LINC02487 is downregulated in OSCC tissue samples and cell lines. We also find that LINC02487 acts as a tumor suppressor through the USP17-SNAI1 axis.

Identification of Prognosis Associated microRNAs in HNSCC Subtypes Based on TCGA Dataset

Background and Objectives: Head and Neck Squamous Cell Carcinoma (HNSCC) includes cancers from the oral cavity, larynx, and oropharynx and is the sixth-most common cancer worldwide. MicroRNAs are small non-coding RNAs for which altered expression has been demonstrated in pathological processes, such as cancer. The objective of our study was to evaluate the different expression profile in HNSCC subtypes and the prognostic value that one or several miRNAs may have. Materials and Methods: Data from The Cancer Genome Atlas Program-Head and Neck Squamous Cell Carcinoma (TCGA-HNSCC) patients were collected. Differential expression analysis was conducted by edge R-powered TCGAbiolinks R package specific function. Enrichment analysis was developed with Diana Tool miRPath 3.0. Kaplan-Meier survival estimators were used, followed by log-rank tests to compute significance. Results: A total of 127 miRNAs were identified with differential expression level in HNSCC; 48 of them were site-specific and, surprisingly, only miR-383 showed a similar deregulation in all locations studied (tonsil, mouth, floor of mouth, cheek mucosa, lip, tongue, and base of tongue). The most probable affected pathways based on miRNAs interaction levels were protein processing in endoplasmic reticulum, proteoglycans in cancer (p < 0.01), Hippo signaling pathway (p < 0.01), and Transforming growth factor-beta (TGF-beta) signaling pathway (p < 0.01). The survival analysis highlighted 38 differentially expressed miRNAs as prognostic biomarkers. The miRNAs with a greater association between poor prognosis and altered expression (p < 0.001) were miR-137, miR-125b-2, miR-26c, and miR-1304. Conclusions: In this study we have determined miR-137, miR-125b-2, miR-26c, and miR-1304 as novel powerful prognosis biomarkers. Furthermore, we have depicted the miRNAs expression patterns in tumor patients compared with normal subjects using the TCGA-HNSCC cohort.

The roles of microRNAs in the stemness of oral cancer cells

Oral cancer (OC), which is the most common form of head and neck cancers, has one of the lowest (~50%) overall 5-year survival rates. The main reasons for this high mortality rate are diagnosis of OC in advanced stages in most patients and spread to distant organs via lymph node metastasis. Many studies have shown that a small population of cells within the tumor plays vital roles in the initiation, progression, and metastasis of the tumor, resistance to chemotherapeutic agents, and recurrence. These cells, identified as cancer stem cells (CSCs), are the main reasons for the failure of current treatment modalities. Deregulated expressions of microRNAs are closely related to tumor prognosis, metastasis and drug resistance. In addition, microRNAs play important roles in regulating the functions of CSCs. Until now, the roles of microRNAs in the acquisition and maintenance of OC stemness have not been elucidated in detail yet. Here in this review, we summarized significant findings and the latest literature to better understand the involvement of CSCs in association with dysregulated microRNAs in oral carcinogenesis. Possible roles of these microRNAs in acquisition and maintenance of CSCs features during OC pathogenesis were summarized.

microRNAs in oral cancer: Moving from bench to bed as next generation medicine

Oral cancer is the thirteenth most common cancer in the world, with India contributing to 33% of the global burden. Lack of specific non-invasive markers, non-improvement in patient survival and tumor recurrence remain a major clinical challenge in oral cancer. Epigenetic regulation in the form of microRNAs (miRs) that act as tumor suppressor miRs or oncomiRs has gained significant momentum with the advancement in the field, suggesting the potential for clinical application of miRs in oral cancer. The current review of literature identified miR-21, miR-27a(-3p), miR-31, miR-93, miR-134, miR-146, miR-155, miR-196a, miR-196b, miR-211, miR-218, miR-222, miR-372 and miR-373 to be up-regulated and let-7a, let-7b, let-7c, let-7d, let-7e, let-7f, let-7g, let-7i, miR-26a, miR-99a-5p, miR-137, miR-139-5p, miR-143-3p, miR-184 and miR-375 to be down-regulated in oral cancer. Mechanistic studies have uncovered several miRs that are deregulated at varying levels and in different stages of oral cancer progression, thus providing clinical utility in better diagnosis as well as usefulness in prognosis by identifying patients with poor prognosis or stratifying patients based on responsiveness to chemo- and radio-therapy. Lastly, exogenous modulation of miR expression using miRNA-based drugs in combination with first-line agents may be adopted as a new therapeutic modality to treat oral cancer. Knowledge of miRs and their involvement in key molecular processes, clinical association, responsiveness to therapy and clinical advancement may highlight additional avenues in order to improve patient morbidity and mortality. Furthermore, combinatorial approaches with miR-therapy may be efficacious in oral cancer.

Evaluating the role of microRNAs alterations in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) accounts for nearly 90 percent of oral cavity malignancies and is one of the most widespread oral cancers in the world. The microRNAs (miRNAs or miRs) have an important role in cellular processes comprising cell cycle, differentiation, and also apoptosis. MiRNAs are also implicated in the progression of cancers, including OSCC, through a variety of signaling pathways. One of the most significant signaling pathways in OSCC is the PI3K / Akt pathway that has been illustrated to be under the tight regulation of miRNAs. Deregulation or activation of the PI3K / Akt pathway due to mutations has been revealed to be implicated in the development of oral cancer. According to studies, more than 47% of HNSCC and around 38% of OSCC samples indicate at least one molecular alteration in this signaling pathway. The potential of miRNAs for their use as therapeutic tools in the diagnosis as well as treatment of numerous diseases have been confirmed. In the current review, we summarize miRNAs and their possible mechanisms as well as their functions in OSCC advancement and progression.

MiR-142-3p enhances chemosensitivity of breast cancer cells and inhibits autophagy by targeting HMGB1

MiR-142-3p has been reported to act as a tumor suppressor in breast cancer. However, the regulatory effect of miR-142-3p on drug resistance of breast cancer cells and its underlying mechanism remain unknown. Here, we found that miR-142-3p was significantly downregulated in the doxorubicin (DOX)-resistant MCF-7 cell line (MCF-7/DOX). MiR-142-3p overexpression increased DOX sensitivity and enhanced DOX-induced apoptosis in breast cancer cells. High-mobility group box 1 (HMGB1) is a direct functional target of miR-142-3p in breast cancer cells and miR-142-3p negatively regulated HMGB1 expression. Moreover, overexpression of HMGB1 dramatically reversed the promotion of apoptosis and inhibition of autophagy mediated by miR-142-3p up-regulation. In conclusion, miR-142-3p overexpression may inhibit autophagy and promote the drug sensitivity of breast cancer cells to DOX by targeting HMGB1. The miR-142-3p/HMGB1 axis might be a novel target to regulate the drug resistance of breast cancer patients.

[Effect of miR-204-5p on the proliferation, migration, and invasion on tongue squamous cell carcinoma SCC25 cells by targeting bromodomain-containing protein 4]

OBJECTIVE

This study aimed to explore the target relationship between miR-204-5p and bromodomain-containing protein (BRD) 4, as well as their effects on cell proliferation, migration, and invasion in tongue squamous cell carcinoma SCC25.

METHODS

Real-time quantitative polymerase chain reaction (RT-qPCR) was performed to detect miR-204-5p and BRD4 expression levels in tongue squamous cell carcinoma and different cell lines. TargetScan and dual luciferase reporter assay were used to confirm the target relationship between miR-204-5p and BRD4. The effects of miR-204-5p on SCC25 cell proliferation were examined by cell counting kit (CCK) 8 assay, whereas those on SCC25 cell migration and invasion were determined by Transwell assay. RT-qPCR and Western blot were used to detect the effects of miR-204-5p mimics and inhibitors on BRD4 expression. Transwell and CCK8 assays were used to detect the effects of miR-204-5p on proliferation, migration, and invasion through BRD4 regulation.

RESULTS

miR-204-5p was significantly downregulated in the tissues and cells of squamous cell carcinoma, and BRD4 showed the opposite result. The increase in miR-204-5p expression can inhibit the proliferation, migration, and invasion of SCC25 cells. TargetScan and luciferase test confirmed that miR-204-5p and BRD4 had a negative regulatory relationship with BRD4, respectively. Moreover, miR-204-5p mimics can inhibit BRD4 expression, and miR-204-5p inhibitors can promote BRD4 expression upregulation. When miR-204-5p and BRD4 were overexpressed in SCC25 cells, BRD4 can make up for the inhibitory effect of miR-204-5p on SCC25 cells.

CONCLUSIONS

miR-204-5p could inhibit proliferation, migration and invasion in tongue squamous cell carcinoma SCC25 cells by targeting BRD4 gene.

Mir-5100 Mediates Proliferation, Migration and Invasion of Oral Squamous Cell Carcinoma Cells Via Targeting SCAI

PURPOSE

We aimed to investigate the role of microRNA-5100 (miRNA-5100) in oral squamous cell carcinoma (OSCC) and its underlying mechanisms.Material/Methods: The expression of miR-5100 and suppressor of cancer cell invasion (SCAI) in OSCC cell lines were examined. A luciferase reporter assay was applied to confirm the combination between miR-5100 and SCAI. Then, miR-5100 inhibitor or small hairpin RNA (shRNA)-SCAI were transfected into cells. Cell Counting Kit-8 assay was executed for testing cell proliferation ability. Flow cytometry assay was exploited for measuring cell cycle. Invasion and migration of OSCC cells were assessed using Transwell assay and wound healing assay. The expression of proteins were detected using western blotting.

RESULTS

The results demonstrated that the level of miR-5100 was upregulated while SCAI was downregulated in OSCC cells. SCAI was verified as a direct target of miR-5100. MiR-5100 silencing suppressed proliferation of OSCC cells, increased cells in the G1 and G2 phases, and reduced those in the S phase, which was reversed after transfection with shRNA-SCAI. Moreover, miR-5100 inhibitor downregulated the expression of cyclin-dependent kinase-2 (CDK-2) and cyclinD1, accompanied by upregulation in p27 expression, whereas SCAI silencing had the opposite results. The invasion and migration abilities of OSCC cells were reduced after treatment with miR-5100 inhibitor, whereas SCAI silencing suppressed the effects of miR-5100 inhibitor on OSCC cell behaviors.

CONCLUSION

These findings suggested that miR-5100 silencing inhibit proliferation, invasion and migration of OSCC cells via upregulating the expression of SCAI, which provides theoretical basis and treatment strategies for the treatment of OSCC.

Potential of Melatonin as Adjuvant Therapy of Oral Cancer in the Era of Epigenomics

The wide variety of epigenetic controls available is rapidly expanding the knowledge of molecular biology even overflowing it. At the same time, it can illuminate unsuspected ways of understanding the etiology of cancer. New emerging therapeutic horizons, then, promise to overcome the current antitumor strategies need. The translational utility of this complexity is particularly welcome in oral cancer (OC), in which natural history is alarmingly disappointing due to the invasive and mutilating surgery, the high relapsing rate, the poor quality of life and the reduced survival after diagnosis. Melatonin activates protective receptor-dependent and receptor-independent processes that prevent tissue cancerisation and inhibit progressive tumor malignancy and metastasis. Related evidence has shown that melatonin pleiotropy encompasses gene expression regulation through all the three best-characterized epigenetic mechanisms: DNA methylation, chromatin modification, and non-coding RNA. OC has received less attention than other cancers despite prognosis is usually negative and there are no significant therapy improvements recorded in the past decade. However, a large research effort is being carried out to elucidate how melatonin´s machinery can prevent epigenetic insults that lead to cancer. In the light of recent findings, a comprehensive examination of biochemistry through which melatonin may reverse epigenetic aberrations in OC is an extraordinary opportunity to take a step forward in the clinical management of patients.

MicroRNA expression patterns in oral squamous cell carcinoma: hsa-mir-99b-3p and hsa-mir-100-5p as novel prognostic markers for oral cancer

BACKGROUND

MicroRNAs (miRNA) recently evolved as potential cancer biomarkers. Therefore, the aim of the present study was to evaluate the prognostic impact of eight miRNAs connected to oral squamous cell carcinoma (OSCC).

METHOD

Expression levels of hsa-mir-21-5p, hsa-mir-29b-3p, hsa-mir-31-5p, hsa-mir-99a-5p, hsa-mir-99b-3p, hsa-mir-100-5p, hsa-mir-143-3p and hsa-mir-155-5p were analyzed in tumor tissue (n = 36) and healthy oral mucosal tissue (n = 17) and correlated with clinical variables. Results of the study cohort were validated in an OSCC cohort of The Cancer Genome Atlas.

RESULTS

Increased hsa-mir-99b-3p expression level showed a tendency toward advanced tumor stages, and high levels of hsa-mir-100-5p expression were associated with extracapsular extension. While a high expression level of hsa-mir-99b-3p was associated with better survival, a high expression level of hsa-mir-100-5p was correlated with a poorer survival in the study cohort.

CONCLUSION

Our results indicate that hsa-mir-99b-3p and hsa-mir-100-5p may serve as novel prognostic biomarkers in OSCC.

miR‑543 acts as a novel oncogene in oral squamous cell carcinoma by targeting CYP3A5

MicroRNAs (miRNAs/miRs) are small non-coding RNAs that can act as oncogenes or tumor-suppressor genes in human cancer. Previous studies have revealed that abnormal expression of miRNAs is closely associated with tumor cell cycle, differentiation, growth and apoptosis. miR-543 is expressed abnormally in a wide variety of cancers and has been associated with cellular proliferation, apoptosis, and invasion; however, the effect of miR-543 remains unknown in oral squamous cell carcinoma (OSCC). In the present study, the expression level of miR-543 in OSCC cell lines and tissues was investigated by RT-qPCR. A series of experiments was then performed to elucidate the functions of miR-543 in OSCC, such as CCK-8 assay, colony formation assay, flow cytometry, cell cycle distribution assay and cell apoptosis assay and Transwell assay. miR-543 expression was significantly upregulated in tumors from patients with OSCC and in OSCC cell lines. Overexpression of miR-543 promoted the proliferation, invasion and migration of OSCC cell lines, and inhibited cell apoptosis. In addition, the present study identified cytochrome P450 family 3 subfamily A member 5 (CYP3A5) as a direct target of miR-543 using software analysis and dual-luciferase reporter assays. In conclusion, the results of the present study suggest that miR-543 acts as a tumor promoter and serves a vital role in OSCC proliferation and invasion. These results confirm that miR-543 may serve as a potential novel target for the treatment of OSCC.

Genome-wide miRNA methylome analysis in oral cancer: possible biomarkers associated with patient survival

AIM

The methylome associated with miRNA loci was investigated in oral cancer to explore tobacco specific methylation and potential biomarkers for patient survival.

METHODS

Methylome data was generated from 16 pairs of cancer-normal tissues by reduced representation bisulfite sequencing method. Differentially methylated regions were identified using the DMAP pipeline. In silico validation and Kaplan-Meier survival analyses were performed on The Cancer Genome Atlas data based on our miRNA methylome data.

RESULTS

A total of 4310 unique differentially methylated regions, mapping to 144 miRNA loci, were identified. Three distinct groups of miRNAs were differentially methylated in cancer tissues from smokers, chewers and mixed habitués. Hypermethylation of miR-503, miR-200a/b, miR-320b and miR-489 was associated with worse 5-year survival.

CONCLUSION

Differential methylation patterns in miRNA loci are associated with poor survival underscoring their potential as predictive and prognostic biomarkers in oral cancer.

miRNAs expression of oral squamous cell carcinoma patients: Validation of two putative biomarkers

microRNA expression patterns have provided new directions in the search of biomarkers with prognostic value and even in the search of novel therapeutic targets for several neoplasms. Specifically, miRNAs profiling in oral squamous cell carcinoma (OSCC) represents a web of intrigue in the study of oral carcinogenesis. The objective of the present study was twofold:The first study phase comprised case-control groups: A) 8 OSCC-affected patients and 8 healthy controls. Microarray technology (Affymetrix miRNA Array Plate 4.1) was used for miRNAs expression profile. Deregulated miRNAs were studied using Diana Tools miRPath 3.0 to associate miRNA targets with molecular pathways via Kyoto Encyclopedia of Genes and Genomes (KEGG). In a second phase, 2 miRNAs chosen for the subsequent RT-qPCR validation were studied in a second OSSC cohort (n = 8).Microarray analysis identified 80 deregulated miRNAs (35 over-expressed and 45 under-expressed). Two miRNAs (miR-497-5p and miR-4417) were chosen for further validation via RT-qPCR. Prognostic analysis did not ascertain relevant relation between miR-497-5p or miR-4417 expression and clinical or pathological parameters, except high miR-4417 in the case of nodular affectation (P = .035) and diminished miR-497-5p radiotherapy-treated patients (P = .05). KEGG analysis revealed that deregulated miRNAs were implicated in several biological pathways such as Proteoglycans in cancer.Our data suggest an altered miRNAs profiling in OSCC-affected patients. We have verified the altered expression of miR-497-5p and miR-4417 in OSCC samples and related the deregulated miRNAs with the 'proteoglycans in cancer' pathway. Further longitudinal studies with large samples are warranted to confirm the present findings.

MicroRNA-137 inhibits autophagy and chemosensitizes pancreatic cancer cells by targeting ATG5

PURPOSE

Autophagy play an important role in tumor chemotherapy resistance. It has been reported that miR-137 expression was reducedand involved in the regulation of sensitivity of PC cells to chemotherapy. However, little is known about the underlying molecular mechanisms. In this study, we hypothesized that miR-137 might sensitize PC cells to chemotherapy thought regulating cell autophagy.

METHODS

Cell survival was determined with MTT assay. Apoptotic cells were assessed with flow cytometric analysis. Fluorescence intensity of GFP-LC3 and RFP-GFP-LC3 were examined with immunofluorescence analysis to determine the autophagy and autophagic flux level. Western blotting assay was used to determine protein expression levels of LC3II/LC3I, P62, FUNDC1 and ATG5. mRNA expression level of miR-137 was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Dual-luciferase reporter assay was used to evaluate the directly binding of miR-137 with its targets. Xenograft model was setup to evaluate tumor growth.

RESULTS

The results showed that doxorubicin (Dox) induced autophagy but downregulated the expression level of miR-137 in pancreatic cancer (PC) cells. In turn, overexpression of miR-137 enhanced the effect of Dox on decreasing cell survival, inducing cell apoptosis and inhibiting autophagy rather than influencing autophagic flux in PC cells. Further mechanistic study identified that ATG5 was a direct target of miR-137. Moreover, overexpression of ATG5 dramatically reversed the promotion of apoptosis and inhibition of autophagy mediated by higher expression level of miR-137. We also demonstrated that miR-137 sensitized PANC-1 cells to Dox through inhibiting ATG5 and autophagy in vivo.

CONCLUSIONS

Our findings demonstrated for the first time that miR-137 was able to promote sensitivity of PC cells to chemotherapy via inhibition of autophagy mediated by ATG5. Therefore, miR-137 may act as a potential therapeutic target for pancreatic cancer.