Small RNAs in metastatic and non-metastatic oral squamous cell carcinoma

MiRNAs as non-invasive biomarkers in the serum of Oral Squamous Cell Carcinoma (OSCC) and Oral Potentially Malignant Disorder (OPMD) patients

OBJECTIVE

Cell-free microRNAs have shown differential levels in the serum of individuals under disease conditions suggesting its potential to act as biomarkers. A population specific miRNA signature in oral cancer is reported in different studies. We aim to identify a set of serum specific miRNAs that may differentiate oral cancer, oral pre-malignant conditions from the healthy individuals.

DESIGN

We investigated the levels of 24 miRNAs in the serum of 47 Oral squamous cell carcinoma (OSCC) patients, 20 patients with Oral potentially malignant disorders (OPMD) and 42 healthy controls from Eastern India. Small RNAs were isolated from serum samples followed by cDNA synthesis. Levels of miRNAs were determined using qRT-PCR. The sources of serum specific miRNAs were evaluated using GTEx-RNAseq and TCGA-HNSCC database.

RESULTS

Five miRNAs, miR-483-5p, miR-31-5p, Let-7b-5p, miR-486-5p and miR-30e-5p showed significant elevation in OSCC patients. An Elastic-Net model with 4 miRNAs classified OSCC from healthy controls with 80 % sensitivity, 64.3 % specificity, and 72.4 % accuracy. Mir-483-5p and miR-31-5p was significantly overexpressed in OSCC tissues as well as significantly higher in the serum of Leukoplakia and Verrucous carcinoma patients suggesting their potential as early disease markers. MiR-483-5p showed a consistent elevated level in the serum/plasma of oral cancer patients across different population and was found to be tumour specific while, the rest of the miRNAs showed variable results across different studies.

CONCLUSIONS

Our study suggested that the serum miRNAs in oral cancer and pre-malignant disorder conditions can be used as a non-invasive marker for screening of these oral conditions.

MicroRNAs’ Crucial Role in Salivary Gland Cancers’ Onset and Prognosis

Simple Summary

Salivary gland cancers are incredibly heterogeneous, both in the physical onset and in the aggressiveness. Setting up a novel diagnostic and prognostic detection method based on the noninvasive microRNAs’ profiling might represent a goal for the clinical management of those particular malignancies, saving precious time for the patients.

Abstract

Salivary gland cancer (SGC) is an uncommon and heterogeneous disease that accounts for around 8.5% of all head and neck cancers. MicroRNAs (miRNAs) consist of a class of highly conserved, short, single-stranded segments (18–25 nucleotides) of noncoding RNA that represent key gene-transcription regulators in physiological and pathological human conditions. However, their role in SGC development and progression is not completely clear. This review aims to compile and summarize the recent findings on the topic, focusing on the prognostic and diagnostic value of the major modulated and validated microRNAs in SGC. Their differential expression could possibly aid the clinician in delivering an early diagnosis, therapeutic strategy and precision medicine.

MicroRNA-31: a pivotal oncogenic factor in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) continuously constitutes a major challenge for treatment and prognosis due to approximately half of treated OSCC patients dying from locoregional recurrences and distant metastases. MicroRNA-31 (miR-31), an early mammalian miRNA identified, has been gaining importance in the field of OSCC research in recent years. This comprehensive review was conducted for the first time to summarize the current evidence on the association between miR-31 and OSCC. The vast majority of relevant studies (20/21, 95%) demonstrated that miR-31 was an oncogenic factor in the tumorigenesis and progression of OSCC. miR-31 expression is significantly upregulated in plasma, saliva, and tumor tissue of OSCC. miR-31 played an essential role in OSCC development by constituting a complex network with its targeted genes (e.g. RhoA, FIH, ACOX1, VEGF, SIRT3, LATS2, KANK1, and NUMB) and the signaling cascades (e.g. EGF-AKT signaling axis, ERK-MMP9 cascade, Hippo pathway, Wnt signaling, and MCT1/MCT4 regulatory cascade). This review highlights that miR-31 might function as a potential diagnostic, prognostic, and predictive biomarker for OSCC. Further studies are still warranted to better illuminate the clinicopathological features and the molecular mechanisms of miR-31-mediated OSCC development.

Application of liquid biopsy as multi-functional biomarkers in head and neck cancer

Head and neck squamous cell carcinoma (HNSCC) is a molecularly heterogeneous disease, with a 5-year survival rate that still hovers at ~60% despite recent advancements. The advanced stage upon diagnosis, limited success with effective targeted therapy and lack of reliable biomarkers are among the key factors underlying the marginally improved survival rates over the decades. Prevention, early detection and biomarker-driven treatment adaptation are crucial for timely interventions and improved clinical outcomes. Liquid biopsy, analysis of tumour-specific biomarkers circulating in bodily fluids, is a rapidly evolving field that may play a striking role in optimising patient care. In recent years, significant progress has been made towards advancing liquid biopsies for non-invasive early cancer detection, prognosis, treatment adaptation, monitoring of residual disease and surveillance of recurrence. While these emerging technologies have immense potential to improve patient survival, numerous methodological and biological limitations must be overcome before their implementation into clinical practice. This review outlines the current state of knowledge on various types of liquid biopsies in HNSCC, and their potential applications for diagnosis, prognosis, grading treatment response and post-treatment surveillance. It also discusses challenges associated with the clinical applicability of liquid biopsies and prospects of the optimised approaches in the management of HNSCC.

miRNA-214-5p inhibits prostate cancer cell proliferation by targeting SOX4

Background

Prostate cancer is the most common malignant tumor in men. Due to the lack of theoretical research on its pathogenic mechanism, the current cure rate is still low. miRNAs play an important role in the pathogenesis of various cancers. miRNA-214-5p plays an important role in the development of a variety of cancers. This study aims to explore the expression level of miR-214-5p in prostate cancer and make a preliminary study of its molecular mechanism in the development of prostate cancer to provide effective new strategies for the treatment of prostate cancer.

Methods

The target genes of miRNA-214-5p were predicted with bioinformatics technology, and the target relationship between miRNA-214-5p and its target genes was verified with dual luciferase reporter assay. RT-qPCR and Western blot were used to detect the expression levels of miRNA-214-5p and target genes in 50 clinical samples and two common prostate continuous cell lines, respectively. The targeting relationship between miRNA-214-5p and its target genes was verified with clinical data. miRNA-214-5p and miRNA-214-5p inhibitor was over-expressed in DU-145 cell lines to verify the effect of miRNA-214-5p on prostate cancer cell proliferation and SOX4 gene expression. And the mechanism of miRNA-214-5p inhibiting the proliferation of prostate cancer cells were analyzed by detecting the expression difference of downstream factors of SOX4 pathway. Bioinformatics analysis showed that miRNA-214-5p combined with SOX4 3′UTR region, and dual luciferase reporter assay further verified the reliability of the predicted results. The low expression of miRNA-214-5p was observed in prostate cancer tissues and cells, while high expression of SOX4 was observed in prostate cancer tissues and cells.

Results

Overexpression of miRNA-214-5p to prostate cancer cells significantly inhibited the proliferation of cancer cells, and the expression of SOX4 was inhibited in the transfected cell line. After transfection of miRNA-214-5p inhibitor into prostate cancer cells, the cell proliferation rate further increased. Meanwhile, overexpression of miRNA-214-5p effectively inhibited the expression of SOX4 downstream factors, including c-Myc, eIF4E, and CDK4. However, the specific knockdown of SOX4 through SOX4 shRNA significantly reduced the proliferation of prostate cancer cell lines.

Conclusions

miRNA-214-5 can inhibit the proliferation of prostate cancer cells by specifically targeting S0X4 and inhibiting the expression of growth factors downstream of this pathway.

1. Low expression of miRNA-214-5p is observed in prostate cancer cells.

2. miRNA-214-5p inhibits the proliferation of prostate cancer cells in vitro by targeting SOX4.

Expression of miR-31 in saliva-liquid biopsy in patients with oral squamous cell carcinoma

OBJECTIVES

Oral squamous cell carcinoma (OSCC) is a commonly reported cancer in men and is second only to breast cancer in women in Pakistan.. Investigations for identifying biomarkers of OSCC are essential for diagnostic, therapeutic, or prognostic significance. This study aims to examine the miR-31 expression in the pre- and post-operative OSCC patients and correlate this expression with clinicopathological characteristics.

METHODS

Patients with histopathologically confirmed OSCC who had undergone surgical resections of tumours were recruited. A total of 40 saliva samples (pre- and post-operative) were collected from 19 patients and two healthy individuals. Levels of salivary miR-31 expressions were examined through quantitative reverse transcription polymerase chain reaction.

RESULTS

The salivary miR-31 expression was significantly higher in the preoperative patients than in postoperative patients (p < 0.001). However, no significant correlation had been found between the salivary miR-31 expression and clinicopathological characteristics (p > 0.05).

CONCLUSION

Our data suggest that miR-31 can be used as an adjunct non-invasive marker to monitor surgery outcomes during postoperative follow-up in patients with OSCC.

microRNAs deregulation in head and neck squamous cell carcinoma

Head and neck (HN) squamous cell carcinoma (SCC) is the eighth most common human cancer worldwide. Besides tobacco and alcohol consumption, genetic and epigenetic alterations play an important role in HNSCC occurrence and progression. microRNAs (miRNAs) are small noncoding RNAs that regulate cell cycle, proliferation, development, differentiation, and apoptosis by interfering in gene expression. Expression profiling of miRNAs showed that some miRNAs are upregulated or downregulated in tumor cells when compared with the normal cells. The present review focuses on the role of miRNAs deregulations in HNSCC, enrolled in risk, development, outcome, and therapy sensitivity. Moreover, the influence of single nucleotide variants in miRNAs target sites, miRNAs seed sites, and miRNAs-processing genes in HNSCC was also revised. Due to its potential for cancer diagnosis, progression, and as a therapeutic target, miRNAs may bring new perspectives in HNSCC understanding and therapy, especially for those patients with no or insufficient treatment options.

Pre-Operative Evaluation of DNA Methylation Profile in Oral Squamous Cell Carcinoma Can Predict Tumor Aggressive Potential

BACKGROUND

Prognosis of oral squamous cell carcinoma (OSCC) is difficult to exactly assess on pre-operative biopsies. Since OSCC DNA methylation profile has proved to be a useful pre-operative diagnostic tool, the aim of the present study was to evaluate the prognostic impact of DNA methylation profile to discriminate OSCC with high and low aggressive potential.

METHODS

36 OSCC cases underwent neoplastic cells collection by gentle brushing of the lesion, before performing a pre-operative biopsy. The CpG islands methylation status of 13 gene (ZAP70, ITGA4, KIF1A, PARP15, EPHX3, NTM, LRRTM1, FLI1, MiR193, LINC00599, MiR296, TERT, GP1BB) was studied by bisulfite Next Generation Sequencing (NGS). A Cox proportional hazards model via likelihood-based component-wise boosting was used to evaluate the prognostic power of the CpG sites.

RESULTS

The boosting estimation identified five CpGs with prognostic significance: EPHX3-24, EPHX3-26, ITGA4-3, ITGA4-4, and MiR193-3. The combination of significant CpGs provided promising results for adverse events prediction (Brier score = 0.080, C-index = 0.802 and AUC = 0.850). ITGA4 had a strong prognostic power in patients with early OSCC.

CONCLUSIONS

These data confirm that the study of methylation profile provides new insights into the molecular mechanisms of OSCC and can allow a better OSCC prognostic stratification even before surgery.

Low expression of miR-let-7a promotes cell growth and invasion through the regulation of c-Myc in oral squamous cell carcinoma

In oral squamous cell carcinoma (OSCC), abnormal expression of microRNAs has been extensively reported. MiR-let-7a has been validated as a critical regulator of multiple cancers, but the biological process involved and its potential role in OSCC remain unknown.We first analyzed the differential expression of miR-let-7a in cancer tissues, adjacent noncancerous tissues and cell lines. The functional role of miR-let-7a in OSCC cell lines was evaluated by using colony formation assays, cell proliferation and transwell invasion assays in vitro. In addition, subcutaneous xenotransplantation of miR-let-7a transfected cells into nude mouse model was carried out to explore the potential function of miR-let-7a in vivo.miR-let-7a levels were found to be significantly downregulated in OSCC tissues compared with matched normal tissues (n = 60), and lower expression of miR-let-7a was related to poor prognosis in OSCC patients. Overexpression of MiR-let-7a induced a suppression in proliferation, invasion and migration and inhibited tumourigenesis in the nude mouse model. We also determined that c-Myc may serve as a direct target of miR-let-7a; furthermore, upregulated c-Myc expression could partially rescue the effects caused by miR-let-7a overexpression. miR-let-7a is low expression in OSCC, and promotes tumor development by directly targeting c-Myc. Our results may provide a potential therapeutic role for miR-let-7a in human OSCC.

Extracellular Vesicles of Human Periodontal Ligament Stem Cells Contain MicroRNAs Associated to Proto-Oncogenes: Implications in Cytokinesis

The human Periodontal Ligament Stem Cells (hPDLSCs) exhibit self-renewal capacity and clonogenicity potential. The Extracellular Vesicles (EVs) secreted by hPDLSCs are particles containing lipids, proteins, mRNAs, and non-coding RNAs, among which microRNAs, that are important in intercellular communication. The purpose of this study was the analysis of the non-coding RNAs contained in the EVs derived from hPDLSCs using Next Generation Sequencing. Moreover, our data were enriched using bioinformatic tools. The analysis highlighted the presence of non-coding RNAs and five microRNAs: MIR24-2, MIR142, MIR335, MIR490, and MIR296. Our results show that these miRNAs target the genes classified in two terms of the Gene Ontology: "Ras protein signal transduction" and "Actin/microtubule cytoskeleton organization." Noteworthy, the in-deep analysis of our EVs highlights that the miRNAs could be implicated in the silencing of proto-oncogenes involved in 12 different types of tumors.

Extracellular miRNAs as Biomarkers of Head and Neck Cancer Progression and Metastasis

Head and neck squamous cell carcinomas (HNSCCs) contribute to over 300,000 deaths every year worldwide. Although the survival rates have improved in some groups of patients, mostly due to new treatment options and the increasing percentage of human papillomavirus (HPV)-related cancers, local recurrences and second primary tumors remain a great challenge for the clinicians. Presently, there is no biomarker for patient surveillance that could help identify patients with HNSCC that are more likely to experience a relapse or early progression, potentially requiring closer follow-up or salvage treatment. MicoRNAs (miRNAs) are non-coding RNA molecules that posttranscriptionally modulate gene expression. They are highly stable and their level can be measured in biofluids including serum, plasma, and saliva, enabling quick results and allowing for repeated analysis during and after the completion of therapy. This has cemented the role of miRNAs as biomarkers with a huge potential in oncology. Since altered miRNA expression was described in HNSCC and many miRNAs play a role in radio- and chemotherapy resistance, cancer progression, and metastasis, they can be utilized as biomarkers of these phenomena. This review outlines recent discoveries in the field of extracellular miRNA-based biomarkers of HNSCC progression and metastasis, with a special focus on HPV-related cancers and radioresistance.

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.

Heat shock factor 1 in cancer-associated fibroblasts is a potential prognostic factor and drives progression of oral squamous cell carcinoma

Heat shock factor 1 (HSF1) is highly expressed in various malignancies and is a potential modulator of tumor progression. Emerging evidence suggests that HSF1 activation in stromal cells is closely related to poor patient prognosis. However, the role of HSF1 in oral squamous cell carcinoma (OSCC) remains elusive. We aimed to investigate the function of HSF1 in cancer‐associated fibroblasts (CAFs) of the tumor microenvironment (TME) and in tumor development. In the present study, we found that HSF1 was highly expressed in both CAFs and tumor cells, and was significantly correlated with poor prognosis and overall survival. Moreover, HSF1 overexpression in CAFs resulted in a fibroblast‐like phenotype of Cal27 cells, induced epithelial‐mesenchymal transition (EMT), and promoted proliferation, migration and invasion in Cal27 cells. HSF1 knockdown attenuated features of CAFs and reduced EMT, proliferation, migration and invasion in Cal27 cells. Furthermore, HSF1 in CAFs promoted tumor growth in nude mice. Taken together, these data suggest that HSF1 expression in CAFs drive OSCC progression, and could serve as an independent prognostic marker of patients with OSCC. Thus, HSF1 is a potent mediator of OSCC malignancy.

Molecular pathways of oral cancer that predict prognosis and survival: A systematic review

Several genes and pathways associated with oral squamous cell carcinoma (OSCC) are significant in terms of early detection and prognosis. The objective of this literature review is to evaluate the current research on molecular pathways and genes involved in oral cancer. Articles on the genes involved in oral cancer pathways were evaluated to identify potential biomarkers that can predict survival. In total, 36 articles were retrieved from internet databases, including EBSCO Host, Google Scholar, PubMed, and Science Direct, using the keywords "biomarker of oral cancer," "pathways of oral cancer," "genes involved in oral cancer," and "oral cancer pathways." A total of 36 studies related to OSCC were chosen. Most of the studies used cell lines, while others used archival tissues, few studies followed up the cases. Three major interlinked pathways found were the nuclear factor kappa B (NF-kB), PI3K-AKT, and Wnt pathways. The commonly mutated genes were cyclin D1 (CCND1), Rb, p53, FLJ10540, and TC21. The NF-kB, PI3K-AKT, and Wnt pathways are most frequently involved in the molecular pathogenesis of oral cancer. However, the CCND1, Rb, p53, FLJ10540, and TC21 genes were found to be more accurate in determining patients' overall survival. Polymerase chain reaction, immunohistochemistry, and immunoblotting were the commonly used detection methods.

Liquid biopsy: miRNA as a potential biomarker in oral cancer

Oral cancer is one of the leading cancers in South-Asian countries. Despite the easy access of the oral cavity, the detection and five year survival rates of OSCC patients are dismal. Identification of non-invasive biomarkers to determine the progression and recurrence of OSCC could be of immense help to patients. Recent studies on oral cancer suggest the importance of non-invasive biomarker development. Micro-RNAs (miRNAs) are one of the important components of the cell-free nucleic acids available in different body fluids. Here, we have reviewed the current understanding of circulating miRNAs as non-invasive biomarkers in different body fluids of oral cancer patients. A number of circulating miRNAs are found to be common in the body fluids of OSCC patients, while many of these are study specific, the possible sources of this variability could be due to differences in sample processing, assay procedure, clinical stage of the disease, oral habit and environmental factors. The prognostic and therapeutic significance of these circulating miRNAs are suggested by several studies. Mir-371, mir-150, mir-21 and mir-7d were found to be potential prognostic markers, while mir-134, mir-146a, mir-338 and mir-371 were associated with metastases. The prognostic markers, mir-21 and mir-7d were also found to be significantly correlated with resistance to chemotherapy, while mir-375, mir-196 and mir-125b were significantly correlated with sensitivity to radiotherapy. Despite the promising roles of circulating miRNAs, challenges still remain in unravelling the exact regulation of these miRNAs before using them for targeted therapy.

MicroRNA induction by copy number gain is associated with poor outcome in squamous cell carcinoma of the lung

Copy number gains in cancer genomes have been shown to induce oncogene expression and promote carcinogenesis; however, their role in regulating oncogenic microRNAs (onco-miRNAs) remains largely unknown. Our aim was to identify onco-miRNAs induced by copy number gains in human squamous cell carcinoma (Sq) of the lung. We performed a genome-wide screen of onco-miRNAs from 245 Sqs using data sets from RNA-sequencing, comparative genomic hybridization, and the corresponding clinical information from The Cancer Genome Atlas. Among 1001 miRNAs expressed in the samples, 231 were correlated with copy number alternations, with only 11 of these being highly expressed in Sq compared to adenocarcinoma and normal tissues. Notably, miR-296-5p, miR-324-3p, and miR-3928-3p expression was significantly associated with poor prognosis. Multivariate analysis using the Cox proportional hazards model showed that miRNA expression and smoking were independent prognostic factors and were associated with poor prognosis. Furthermore, the three onco-miRNAs inhibited FAM46C to induce MYC expression, promoting proliferation of Sq cells. We found that copy number gains in Sq of the lung induce onco-miRNA expression that is associated with poor prognosis.

MicroRNA-based classifiers for diagnosis of oral cavity squamous cell carcinoma in tissue and plasma

BACKGROUND

MicroRNAs (miRNAs) hold promise as diagnostic cancer biomarkers. Here we aimed to define the miRNome in oral squamous cell carcinoma (OSCC) and normal oral mucosa (NOM), and to identify and validate new diagnostic miRNAs and miRNA combinations in formalin-fixed paraffin-embedded (FFPE) tissue samples and plasma samples.

METHODS

We performed next-generation miRNA sequencing in FFPE tissue samples of OSCC (n = 80) and NOM (n = 8). Our findings were validated by quantitative polymerase chain reaction (qPCR) analysis of OSCC (n = 195) and NOM (n = 103) FFPE tissue samples, and plasma samples from OSCC patients (n = 55) and healthy persons (n = 18).

RESULTS

The OSCC miRNome included 567 miRNAs, 66 of which were differentially expressed between OSCC and NOM. Using qPCR data, we constructed receiver operating curves to classify patients as NOM or OSCC based on miRNA combinations. The area under the curve was of 0.92 from FFPE tissue (miR-204-5p, miR-370, miR-1307, miR-193b-3p, and miR-144-5p), and 1.0 from plasma samples (miR-30a-5p and miR-769-5p). Model calibration and discrimination were evaluated using 10-fold cross-validation.

CONCLUSIONS

Analysis of the miRNome from many OSCC cases improves our knowledge of the importance of individual miRNAs and their predictive potential in OSCC. We successfully identified miRNA classifiers in FFPE OSCC tissue and plasma with a high discriminatory ability between OSCC and NOM. The proposed combination of miR-30a-5p and miR-769-5p in plasma from OSCC patients could serve as a minimal invasive biomarker for diagnosis and control of T-site recurrences.

Circulating miR-31 as an effective biomarker for detection and prognosis of human cancer: a meta-analysis

PURPOSE

Circulating miR-31 was found to be associated with cancers detection and prognosis. The present meta-analysis aimed to explore the effect of circulating miR-31 on cancer detection and prognosis.

METHOD

The studies were accessed using multiple databases. RevMan5.3, Meta-DiSc 1.4, and STATA14.0 were used to estimate the pooled effects, heterogeneity among studies, and publication bias.

RESULTS

A total of 14 studies with 1397 cancer patients and 1039 controls were included. For the 12 prognostic tests, the adjusted pooled-AUC was 0.79 (95% CI: 0.73-0.86) as the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odd ratio (DOR) from 10 tests was 0.79 (95% CI: 0.76-0.82), 0.79 (95% CI: 0.76-0.82), 3.81 (95% CI: 2.90-5.01), 0.26 (95% CI: 0.20-0.35), and 16.81 (95% CI: 9.67-29.25), respectively. For the 5 prognosis analyses, the pooled HR (hazard ratio) of overall survival (OS) was 1.55 (95% CI 1.30-1.86) for high versus low circulating miR-31 expression. However, high expression of circulating miR-31 did not significantly increase the risk of poor differentiation (pooled OR=1.39, 95% CI: 0.56-3.47) and LNM (pooled OR=3.46, 95% CI: 0.96-12.42) in lung cancer.

CONCLUSION

Circulating miR-31 is an effective biomarker and could be used as a component of miRs signature for cancer detection and prognosis surveillance.

Screening pathogenic genes in oral squamous cell carcinoma based on the mRNA expression microarray data

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies and its survival rate has barely improved over the past few decades. The purpose of this study was to screen pathogenic genes of OSCC via microarray analysis. The mRNA expression microarray datasets (GSE2280 and GSE3524) were downloaded from the Gene Expression Omnibus (GEO) database. In GSE2280, there were 22 OSCC samples without metastasis and 5 OSCC samples with lymph node metastasis. In GSE3524, there were 16 OSCC samples and 4 normal tissue samples. The differentially expressed genes (DEGs) in OSCC samples with lymph node metastasis compared with those without metastasis (named as DEGs-1), and the DEGs in OSCC samples compared with normal tissue samples (named as DEGs-2), were obtained via limma package. The Database for Annotation, Visualization and Integrated Discovery (DAVID) was used to perform the functional enrichment analyses of DEGs-1 and DEGs-2. The miRNA-gene pairs of overlaps among DEGs were screened out with the TargetScan database, and the miRNA-gene regulated network was constructed by Cytoscape software. A total of 233 and 410 DEGs were identified in the sets of DEGs-1 and DEGs-2, respectively. DEGs-1 were enriched in 188 Gene Ontology (GO) terms and 8 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, and DEGs-2 were enriched in 228 GO terms and 6 KEGG pathways. In total, 126 nodes and 135 regulated pairs were involved in the miRNA-gene regulated network. Our study indicated that transglutaminase 2 (TGM2) and Islet 1 (ISL1) may be biomarkers of OSCC and their metastases. Moreover, it provided some potential pathogenic genes (e.g. P2RY2 and RAPGEFL1) in OSCC.

Human salivary microRNAs in Cancer

Circulating microRNAs (miRNAs) have emerged as excellent candidates for cancer biomarkers. Several recent studies have highlighted the potential use of saliva for the identification of miRNAs as novel biomarkers, which represents a great opportunity to improve diagnosis and monitor general health and disease. This review summarises the mechanisms of miRNAs deregulation in cancer, the value of targeting them with a therapeutic intention and the evidence of the potential clinical use of miRNAs expressed in saliva for the detection of different cancer types. We also provide a comprehensive review of the different methods for normalising the levels of specific miRNAs present in saliva, as this is a critical step in their analysis, and the challenge to validate salivary miRNAs as a reality to manage cancer patients.

Serum, plasma and saliva biomarkers for head and neck cancer

INTRODUCTION

Head and neck squamous cell carcinoma (HNSCC) encompasses tumors arising from several locations (oral and nasal cavities, paranasal sinuses, salivary glands, pharynx, and larynx) and currently stands as the sixth most common cancer worldwide. The most important risk factors identified so far are tobacco and alcohol consumption, and, for a subgroup of HNSCCs, infection with high-risk types of human papillomavirus (HPV). Despite several improvements in the treatment of these tumors in the last decades, overall survival rates have only improved marginally, mainly due to the advanced clinical stage at diagnosis and the high rates of treatment failure associated with this late diagnosis. Areas covered: This review will focus on the feasibility of evaluating molecular-based biomarkers (mRNA, microRNA, lncRNA, DNA methylation and protein expression) in body fluids (serum, plasma, and saliva) as markers for diagnosis, prognosis, and surveillance. Expert commentary: The potential use of those markers in the clinical setting would allow for early diagnosis, prediction of treatment response, improvement in treatment selection and provide disease monitoring for early detection of tumor recurrence. It can ultimately be translated into better survival rates and improved quality of life for HNSCC patients.

Improving accuracy of RNA-based diagnosis and prognosis of oral cancer by using noninvasive methods

RNA-based diagnosis and prognosis of squamous cell carcinoma has been slow to come to the clinic. Improvements in RNA measurement, statistical evaluation, and sample preservation, along with increased sample numbers, have not made these methods reproducible enough to be used clinically. We propose that, in the case of squamous cell carcinoma of the oral cavity, a chief source of variability is sample dissection, which leads to variable amounts of stroma mixed in with tumor epithelium. This heterogeneity of the samples, which requires great care to avoid, makes it difficult to see changes in RNA levels specific to tumor cells. An evaluation of the data suggests that, paradoxically, brush biopsy samples of oral lesions may provide a more reproducible method than surgical acquisition of samples for miRNA measurement. The evidence also indicates that body fluid samples can show similar changes in miRNAs with oral squamous cell carcinoma (OSCC) as those seen in tumor brush biopsy samples - suggesting much of the miRNA in these samples is coming from the same source: tumor epithelium. We conclude that brush biopsy or body fluid samples may be superior to surgical samples in allowing miRNA-based diagnosis and prognosis of OSCC in that they feature a rapid method to obtain homogeneous tumor cells and/or RNA.

Downregulation of miR-377 Promotes Oral Squamous Cell Carcinoma Growth and Migration by Targeting HDAC9

microRNAs are the post-transcriptional regulators implicated in the initiation and progression of various cancer types, including oral squamous cell carcinoma (OSCC). Here, we investigated the role of miR-377 in OSCC tumorigenesis. miR-377 expression was reduced in OSCC samples and cell line (UPCI-SCC-116), and was associated with patient survival. In vitro restoration of miR-377 repressed cell growth, induced apoptosis, and reduced cell migration. We identified HDAC9 as a target of miR-377 and found miR-377 to regulate HDAC9 and its pro-apoptotic target, NR4A1/Nur77. Our findings show that miR-377 targets HDAC9 pathway in OSCC, suggesting that miR-377-HDAC9 axis may provide a novel therapeutic target for OSCC therapy.

Persistent Exposure to Porphyromonas gingivalis Promotes Proliferative and Invasion Capabilities, and Tumorigenic Properties of Human Immortalized Oral Epithelial Cells

Recent epidemiological studies revealed a significant association between oral squamous cell carcinoma (OSCC) and Porphyromonas gingivalis, a major pathogen of periodontal disease. As a keystone pathogen of periodontitis, P. gingivalis is known not only to damage local periodontal tissues, but also to evade the host immune system and eventually affect systemic health. However, its role in OSCC has yet to be defined. To explore the underlying effect of chronic P. gingivalis infection on OSCC and to identify relevant biomarkers as promising targets for therapy and prevention, we established a novel model by exposing human immortalized oral epithelial cells (HIOECs) to P. gingivalis at a low multiplicity of infection (MOI) for 5–23 weeks. The P. gingivalis infected HIOECs were monitored for tumor biological alteration by proliferation, wound healing, transwell invasion, and gelatin zymography assays. Microarray and proteomic analyses were performed on HIOECs infected with P. gingivalis for 15 weeks, and some selected data were validated by quantitative real-time PCR and (or) western blot on cells infected for 15 and 23 weeks. Persistent exposure to P. gingivalis caused cell morphological changes, increased proliferation ability with higher S phase fraction in the cell cycle, and promoted cell migratory and invasive properties. In combining results of bioinformatics analyses and validation assays, tumor-related genes such as NNMT, FLI1, GAS6, lncRNA CCAT1, PDCD1LG2, and CD274 may be considered as the key regulators in tumor-like transformation in response to long-time exposure of P. gingivalis. In addition, some useful clinical biomarkers and novel proteins were also presented. In conclusion, P. gingivalis could promote tumorigenic properties of HIOECs, indicating that chronic P. gingivalis infection may be considered as a potential risk factor for oral cancer. The key regulators detected from the present model might be used in monitoring the development of OSCC with chronic periodontal infection.

Circulating miRNAs from blood, plasma or serum as promising clinical biomarkers in oral squamous cell carcinoma: A systematic review of current findings

The purpose of this systematic review was to summarize current findings on the use of circulating miRNAs from blood, serum and plasma as cancer biomarkers in patients with oral squamous cell carcinoma. Studies were gathered after searching four different electronic databases: PUBMED, SCOPUS, Cochrane Library and Web of Science. Additional search was carried out through cross check on bibliography of selected articles. After the selection process made by two of the authors, 16 articles met the inclusion criteria and were included in the review. Results showed that circulating miRNAs from blood, serum or plasma represent promising candidates as cancer biomarkers in patients suffering from oral cancer. The possibility to predict recurrences and metastases through follow-up quantification of candidate miRNAs represents another potential feature to be addressed in future studies. However, methodological standardization and uniform sampling is needed to increase the power and accuracy of results.

Six Serum-Based miRNAs as Potential Diagnostic Biomarkers for Gastric Cancer

BACKGROUND

Circulating miRNAs in serum may serve as promising diagnostic biomarkers for patients with gastric cancer.

METHODS

Using qRT-PCR-based Exiqon panel, we identified 58 differentially expressed miRNAs from three gastric cancer pool samples and one normal control (NC) pool in the initial screening phase. Identified miRNAs were further validated in the training (49 gastric cancer vs. 47 NCs) and validation phases (154 gastric cancer vs. 120 NCs) using qRT-PCR. The expression levels of the miRNAs were also determined in tissues, arterial serum, and exosomes.

RESULTS

Consequently, six serum miRNAs (miR10b-5p, miR132-3p, miR185-5p, miR195-5p, miR-20a3p, and miR296-5p) were significantly overexpressed in gastric cancer compared with NCs. The areas under the receiver operating characteristic curve of the six-miRNA panel were 0.764 and 0.702 for the training and validation phases, respectively. miR10b-5p and miR296-5p were significantly upregulated in gastric cancer tissues (n = 188). In addition, patients who did not receive adjuvant chemotherapy with high expression of miR10b-5p or miR296-5p in tissues tended to suffer worse overall survival. Furthermore, the expression levels of miR10b-5p, miR195-5p, miR20a-3p, and miR296-5p were significantly elevated in exosomes from gastric cancer serum samples (n = 30).

CONCLUSIONS

We identified a six-miRNA panel in serum for the detection of gastric cancer.

IMPACT

Our findings provide a novel serum miRNA signature for gastric cancer diagnosis, and will serve as the basis of the application of circulating miRNAs in clinical for the detection of gastric cancer in the future. Cancer Epidemiol Biomarkers Prev; 26(2); 188-96. ©2016 AACR.

Mesenchymal to Epithelial Transition Induced by Reprogramming Factors Attenuates the Malignancy of Cancer Cells

Epithelial to mesenchymal transition (EMT) is a biological process of metastatic cancer. However, an effective anticancer therapy that directly targets the EMT program has not yet been discovered. Recent studies have indicated that mesenchymal to epithelial transition (MET), the reverse phenomenon of EMT, is observed in fibroblasts during the generation of induced pluripotent stem cells. In the present study, we investigated the effects of reprogramming factors (RFs) on squamous cell carcinoma (SCC) cells. RFs-introduced cancer cells (RICs) demonstrated the enhanced epithelial characteristics in morphology with altered expression of mRNA and microRNAs. The motility and invasive activities of RICs in vitro were significantly reduced. Furthermore, xenografts of RICs exhibited no lymph node metastasis, whereas metastasis was detected in parental SCC-inoculated mice. Thus, we concluded that RICs regained epithelial properties through MET and showed reduced cancer malignancy in vitro and in vivo. Therefore, the understanding of the MET process in cancer cells by introduction of RFs may lead to the designing of a novel anticancer strategy.