Oral cancer: Deregulated molecular events and their use as biomarkers

Differences among oral carcinomas arising de novo from those associated with oral potentially malignant disorders: a systematic review and meta-analysis

OBJECTIVE

To analyze the frequency of sequential oral squamous cell carcinomas (s-OSCC), preceded by oral potentially malignant disorders, and OSCC de novo (OSCC-dn) and explore differences in their clinicopathologic presentations.

STUDY DESIGN

A structured electronic search strategy identified studies that analyzed frequency, clinical, biological, demographic, biomarkers, and prognostic features of s-OSCC and OSCC-dn according to PRISMA guidelines in PubMed, Scopus, Cochrane Library, and Google Scholar, up to January 31, 2023. Inclusion criteria were original English, Spanish, Portuguese, French, Italian, and German cross-sectional, cohort, and case-control studies. The quality of studies was assessed using the Agency for Research and Health Quality tool and the Newcastle-Ottawa Scale tool.

RESULTS

The final selection included 40 studies. OSCC-dn and s-OSCC represent, respectively, 71% and 29% of cases of OSCC (P = .00), showing a higher percentage of T1 or of T1+T2 in s-OSCC (P < .0001). The association meta-analysis showed OSCC-dn with a significant association. The meta-analysis showed that s-OSCC was significantly associated with smaller tumor size, absence of distant metastases, relapses, male sex, and tumor sites different from tongue; and OSCC-dn was associated with more advanced tumor size, more regional and distant metastases, more advanced stages, and worse survival.

CONCLUSIONS

S-OSCC was less frequent than expected. OSCC-dn seems to have specific clinical, biological, and prognostic features. Future perspectives on oral cancer prevention should address novel approaches and alternatives to screening, such as urgent referral of OSCC-dn.

Bioactive gelatin-sheets as novel biopapers to support prevascularization organized by laser-assisted bioprinting for bone tissue engineering

Despite significant advances in the management of patients with oral cancer, maxillofacial reconstruction after ablative surgery remains a clinical challenge. In bone tissue engineering, biofabrication strategies have been proposed as promising alternatives to solve issues associated with current therapies and to produce bone substitutes that mimic both the structure and function of native bone. Among them, laser-assisted bioprinting (LAB) has emerged as a relevant biofabrication method to print living cells and biomaterials with micrometric resolution onto a receiving substrate, also called 'biopaper'. Recent studies have demonstrated the benefits of prevascularization using LAB to promote vascularization and bone regeneration, but mechanical and biological optimization of the biopaper are needed. The aim of this study was to apply gelatin-sheet fabrication process to the development of a novel biopaper able to support prevascularization organized by LAB for bone tissue engineering applications. Gelatin-based sheets incorporating bioactive glasses (BGs) were produced using various freezing methods and crosslinking (CL) parameters. The different formulations were characterized in terms of microstructural, physical, mechanical, and biological properties in monoculture and coculture. Based on multi-criteria analysis, a rank scoring method was used to identify the most relevant formulations. The selected biopaper underwent additional characterization regarding its ability to support mineralization and vasculogenesis, its bioactivity potential andin vivodegradability. The biopaper 'Gel5wt% BG1wt%-slow freezing-CL160 °C 24 h' was selected as the best candidate, due to its suitable properties including high porosity (91.69 ± 1.55%), swelling ratio (91.61 ± 0.60%), Young modulus (3.97 × 104± 0.97 × 104Pa) but also its great cytocompatibility, osteogenesis and bioactivity properties. The preorganization of human umbilical vein endothelial cell using LAB onto this new biopaper led to the formation of microvascular networks. This biopaper was also shown to be compatible with 3D-molding and 3D-stacking strategies. This work allowed the development of a novel biopaper adapted to LAB with great potential for vascularized bone biofabrication.

Oral squamous cell carcinomas: state of the field and emerging directions

Oral squamous cell carcinoma (OSCC) develops on the mucosal epithelium of the oral cavity. It accounts for approximately 90% of oral malignancies and impairs appearance, pronunciation, swallowing, and flavor perception. In 2020, 377,713 OSCC cases were reported globally. According to the Global Cancer Observatory (GCO), the incidence of OSCC will rise by approximately 40% by 2040, accompanied by a growth in mortality. Persistent exposure to various risk factors, including tobacco, alcohol, betel quid (BQ), and human papillomavirus (HPV), will lead to the development of oral potentially malignant disorders (OPMDs), which are oral mucosal lesions with an increased risk of developing into OSCC. Complex and multifactorial, the oncogenesis process involves genetic alteration, epigenetic modification, and a dysregulated tumor microenvironment. Although various therapeutic interventions, such as chemotherapy, radiation, immunotherapy, and nanomedicine, have been proposed to prevent or treat OSCC and OPMDs, understanding the mechanism of malignancies will facilitate the identification of therapeutic and prognostic factors, thereby improving the efficacy of treatment for OSCC patients. This review summarizes the mechanisms involved in OSCC. Moreover, the current therapeutic interventions and prognostic methods for OSCC and OPMDs are discussed to facilitate comprehension and provide several prospective outlooks for the fields.

Immunohistochemical expression of COX-2, Ki-67, Bcl-2, Bax, VEGF and CD105 according to histological grading in oral squamous cell carcinoma

INTRODUCTION

Oral squamous cell carcinoma (OSCC) is the most prevalent head and neck cancer. Few studies have analyzed the expression of proteins related to inflammation (COX-2) and tumor progression according to the histological grade of OSCC.

OBJECTIVE

Analyze the immunohistochemical expression of COX-2, Ki-67 (cell proliferation), Bcl-2/Bax (apoptosis), VEGF, and CD105 (angiogenesis) according to histological grades of OSCC.

MATERIAL AND METHODS

The immunohistochemical expression of COX-2, Ki-67, Bcl-2, Bax, VEGF, and CD105 of 58 cases of OSCC was analyzed. 13 cases of oral mucosa (OM) were analyzed as controls.

RESULTS

COX-2, VEGF, CD105, and Ki-67 were higher in OSCC than in OM, particularly in poorly differentiated OSCC (p<0.05). Bax expression was lower in poorly differentiated OSCC (p<0.001). The Bcl-2/Bax ratio was higher in OSCC compared to MO (p<0.05).

CONCLUSION

There are immunohistochemical differences according to histological grades of OSCC, which could influence clinical behavior.

Stepwise activation of p63 and the MEK/ERK pathway induces the expression of ARL4C to promote oral squamous cell carcinoma cell proliferation

Carcinogenesis is a multistep process wherein cells accumulate multiple genetic alterations and progress to a more malignant phenotype. It has been proposed that sequential accumulation of gene abnormalities in specific genes drives the transition from non-tumorous epithelia through a preneoplastic lesion/benign tumor to cancer. Histologically, oral squamous cell carcinoma (OSCC) progresses in multiple ordered steps that begin with mucosal epithelial cell hyperplasia, which is followed by dysplasia, carcinoma in situ and invasive carcinoma. It is therefore hypothesized that genetic alteration-mediated multistep carcinogenesis would be involved in the development of OSCC; however, the detailed molecular mechanisms are unknown. We clarified the comprehensive gene expression patterns and carried out an enrichment analysis using DNA microarray data from a pathological specimen of OSCC (including a non-tumor region, carcinoma in situ lesion and invasive carcinoma lesion). The expression of numerous genes and signal activation were altered in the development of OSCC. Among these, the p63 expression was increased and the MEK/ERK-MAPK pathway was activated in carcinoma in situ lesion and in invasive carcinoma lesion. Immunohistochemical analyses revealed that p63 was initially upregulated in carcinoma in situ and ERK was sequentially activated in invasive carcinoma lesions in OSCC specimens. ADP-ribosylation factor (ARF)-like 4c (ARL4C), the expression of which is reportedly induced by p63 and/or the MEK/ERK-MAPK pathway in OSCC cells, has been shown to promote tumorigenesis. Immunohistochemically, in OSCC specimens, ARL4C was more frequently detected in tumor lesions, especially in invasive carcinoma lesions, than in carcinoma in situ lesions. Additionally, ARL4C and phosphorylated ERK were frequently merged in invasive carcinoma lesions. Loss-of-function experiments using inhibitors and siRNAs revealed that p63 and MEK/ERK-MAPK cooperatively induce the expression of ARL4C and cell growth in OSCC cells. These results suggest that the stepwise activation of p63 and MEK/ERK-MAPK contributes to OSCC tumor cell growth through regulation of ARL4C expression.

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

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Effects of tobacco on the DNA of smokers and non-smokers affected by OSCC: systematic review and meta-analysis

Scientific evidence about genetic and molecular changes in oral squamous cell carcinoma (OSCC) among smokers and non-smokers is inconclusive. This systematic review and meta-analysis assessed the effects of tobacco on the DNA of individuals with OSCC based on protein mutations. Electronic searches were conducted on PubMed, Ovid, Web of Science, and Scopus to identify observational studies published up to January/2022. The Joanna Briggs Institute tool was used for the critical appraisal of studies. The certainty of the evidence was evaluated. Twenty-three studies assessing 4,060 individuals (2,967 smokers vs. 1,093 non-smokers) were included in this review. Fifteen groups of proteins/genes were investigated. Analysis of the quality of articles revealed low risk of bias in most studies. The certainty of the evidence was very low. The meta-analysis confirmed no significant difference between smokers and non-smokers with respect to damage to GSTM1 (OR: 0.60; 95%CI: 0.30-1.18), GSTT1 (OR: 1.18; 95%CI:0.49-2.83), hydrolase proteins (Ku70 and Ku80) (OR: 0.74; 95%CI: 0.18-3.05), and transferase proteins (GSTM1, GSTT1, GSTM3) (OR: 0.74; 95%CI: 0.47-1.18). Most of the studies included showed that smokers are more likely to exhibit genetic instability. However, the meta-analysis revealed that smokers do not necessarily have more genetic alterations in the DNA than non-smokers.

Tumor microenvironment and immunotherapy of oral cancer

Oral cancer is one of the most common malignant tumors of the head and neck, not only affects the appearance, but also affects eating and even endangers life. The clinical treatments of oral cancer mainly include surgery, radiotherapy, and chemotherapy. However, unsatisfactory therapeutic effect and toxic side effects are still the main problems in clinical treatment. Tumor microenvironment (TME) is not only closely related to the occurrence, growth, and metastasis of tumor but also works in the diagnosis, prevention, and treatment of tumor and prognosis. Future studies should continue to investigate the relationship of TME and oral cancer therapy. This purpose of this review was to analyze the characteristics of oral cancer microenvironment, summarize the traditional oral cancer therapy and immunotherapy strategies, and finally prospect the development prospects of oral cancer immunotherapy. Immunotherapy targeting tumor microenvironment is expected to provide a new strategy for clinical treatment of oral cancer.

Correlation of H3K9ac and H4K12ac With Cell Proliferation Marker Ki-67 in Oral Leukoplakia: An Immunohistochemical Study

This study aimed to analyze the immunohistochemical expression of H3K9ac and H4K12ac in oral leukoplakia (OL) and its association with cell proliferation marker Ki-67 and clinicopathologic data. Paraffin-embedded, formalin-fixed tissue samples from 50 OLs and 15 fragments of the normal oral mucosa (NOM) were submitted to immunohistochemical assay using the streptavidin-biotin-peroxidase method. Quantitative analysis of the antigen-antibody reaction was performed by obtaining integrated optical density (IOD) and the percentage of positive nuclei (PPN) with ImageJ software. OL samples presented higher PPN ( P =0.02) and lower IOD values ( P =0.007) for H4K12ac in comparison to NOM. The area under the receiver operating characteristic curve for PPN and IOD values of H4K12ac immunostaining were 0.70 ( P =0.02) and 0.73 ( P =0.007), respectively. No differences were found between OL and NOM for H3K9ac. Cell proliferation marker Ki-67 had a positive correlation with PPN ( P <0.0001) and IOD ( P =0.0007) for H3K9ac expression and with IOD values ( P =0.002) for H4K12ac expression. The present findings suggest that alterations in the acetylation pattern of H4K12 occur in the early stages of oral carcinogenesis and that both H3K9ac and H4K12ac might have a role in the regulation of epithelial cell proliferation of OL.

Histopathologic Oral Cancer Prediction Using Oral Squamous Cell Carcinoma Biopsy Empowered with Transfer Learning

Oral cancer is a dangerous and extensive cancer with a high death ratio. Oral cancer is the most usual cancer in the world, with more than 300,335 deaths every year. The cancerous tumor appears in the neck, oral glands, face, and mouth. To overcome this dangerous cancer, there are many ways to detect like a biopsy, in which small chunks of tissues are taken from the mouth and tested under a secure and hygienic microscope. However, microscope results of tissues to detect oral cancer are not up to the mark, a microscope cannot easily identify the cancerous cells and normal cells. Detection of cancerous cells using microscopic biopsy images helps in allaying and predicting the issues and gives better results if biologically approaches apply accurately for the prediction of cancerous cells, but during the physical examinations microscopic biopsy images for cancer detection there are major chances for human error and mistake. So, with the development of technology deep learning algorithms plays a major role in medical image diagnosing. Deep learning algorithms are efficiently developed to predict breast cancer, oral cancer, lung cancer, or any other type of medical image. In this study, the proposed model of transfer learning model using AlexNet in the convolutional neural network to extract rank features from oral squamous cell carcinoma (OSCC) biopsy images to train the model. Simulation results have shown that the proposed model achieved higher classification accuracy 97.66% and 90.06% of training and testing, respectively.

Early-onset oral cancer as a clinical entity: aetiology and pathogenesis

Oral squamous cell carcinoma (OSCC) is one of the most important medical and socio-economic problems in many of the developed countries worldwide, due to the high mortality. The incidence of OSCC among individuals under 45 years of age is growing every year; however, the aetiological factors and pathogenetic mechanisms are poorly understood. This review summarizes the available information regarding clinicopathological features, extrinsic and intrinsic aetiological factors, and the molecular and immune landscape of early-onset OSCC. This cancer shows high recurrence rates and is not associated with the aetiological factors specific to adult-onset OSCC. Young adults with OSCC are not infected with human papillomavirus and rarely consume alcohol or tobacco, but more frequently use smokeless tobacco. Data from single studies indicate the hereditary nature of early-onset OSCC: the KIR2DL1⁺-HLA-C2⁺ genotype and MMP-1 2 G allele are frequently detected in young patients. Early-onset OSCC shows specific genetic, epigenetic, transcriptomic, and proteomic changes. The tumour microenvironment in early-onset OSCC is tolerogenic rather than immunogenic. All of the data suggest that OSCC in young patients is a separate clinical entity with a specific aetiology and pathogenesis. Further studies are needed to reveal the causes and molecular targets of early-onset OSCC for the development of preventive and therapeutic strategies.

JAK/STAT Signaling: Molecular Targets, Therapeutic Opportunities, and Limitations of Targeted Inhibitions in Solid Malignancies

JAK/STAT signaling pathway is one of the important regulatory signaling cascades for the myriad of cellular processes initiated by various types of ligands such as growth factors, hormones, and cytokines. The physiological processes regulated by JAK/STAT signaling are immune regulation, cell proliferation, cell survival, apoptosis and hematopoiesis of myeloid and non-myeloid cells. Dysregulation of JAK/STAT signaling is reported in various immunological disorders, hematological and other solid malignancies through various oncogenic activation mutations in receptors, downstream mediators, and associated transcriptional factors such as STATs. STATs typically have a dual role when explored in the context of cancer. While several members of the STAT family are involved in malignancies, however, a few members which include STAT3 and STAT5 are linked to tumor initiation and progression. Other STAT members such as STAT1 and STAT2 are pivotal for antitumor defense and maintenance of an effective and long-term immune response through evolutionarily conserved programs. The effects of JAK/STAT signaling and the persistent activation of STATs in tumor cell survival; proliferation and invasion have made the JAK/STAT pathway an ideal target for drug development and cancer therapy. Therefore, understanding the intricate JAK/STAT signaling in the pathogenesis of solid malignancies needs extensive research. A better understanding of the functionally redundant roles of JAKs and STATs may provide a rationale for improving existing cancer therapies which have deleterious effects on normal cells and to identifying novel targets for therapeutic intervention in solid malignancies.

18F-FDG PET cannot predict expression of clinically relevant histopathological biomarkers in head and neck squamous cell carcinoma: a meta-analysis

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is a common cancer. Positron emission tomography (PET) with 18F-fluorodeoxyglucose (18F-FDG) is a widely used imaging modality in HNSCC.

PURPOSE

To provide evident data about associations between 18F-FDG PET and histopathology in HNSCC.

MATERIAL AND METHODS

The MEDLINE database was screened for associations between maximum standard uptake values (SUV_max) derived from 18F-FDG PET and histopathological features in HNSCC up to May 2020. Only papers containing correlation coefficients between SUV_max and histopathology were acquired. Overall, 23 publications were collected.

RESULTS

The following correlations were calculated: KI 67: 12 studies (345 patients), pooled correlation coefficient (PCC): 0.23 (95% confidence interval [CI] 0.06-0.40); hypoxia-inducible factor-1α: eight studies (240 patients), PCC: 0.24 (95% CI 0.06-0.42); microvessel density: three studies (64 patients), PCC: 0.33 (95% CI 0.02-0.65); vascular endothelial growth factor: two studies (59 cases), PCC: 0.27 (95% CI 0.02-0.51); tumor suppressor protein p53: four studies (159 patients), PCC: 0.05 (95% CI -0.41 to 0.51); epidermal growth factor receptor: two studies (124 patients), PCC: 0.21 (95% CI 0.05-0.37); tumor cell count: three studies (67 patients), PCC: 0.18 (95% CI -0.06 to 0.42); tumor cell apoptosis: two studies (40 patients), PCC: 0.07 (95% CI = -0.85 to 0.99); B-cell lymphoma-2 protein: two studies (118 patients); PCC: 0.04 (95% CI -0.65 to 0.74); glucose-transporter 1: 10 studies (317 patients), PCC: 0.20 (95% CI 0.10-0.30).

CONCLUSION

SUV_max derived from 18F-FDG PET cannot reflect relevant histopathological features in HNSCC.

Downregulated microRNA-149-3p triggers malignant development and predicts worse prognosis in oral squamous cell carcinoma

OBJECTIVE

Accumulating evidence reveals that aberrant expression of microRNAs contributes to the tumorigenesis and development of diverse human cancers. In the current study, we aimed to evaluate the functional role and prognostic value of miR-149-3p in oral squamous cell carcinoma (OSCC).

METHODS

Real-time polymerase chain reaction (PCR) analysis was performed to detect the expression of miR-149-3p in 70 OSCC patients (64.10 ± 11.97 years; 31 males and 39 females). The prognostic ability of miR-149-3p in OSCC patients was assessed by Kaplan-Meier survival analysis. Transwell assays and cell adhesion assays were used to investigate the impact of miR-149-3p on cell migration and invasion. The regulation of MMP2 expression by miR-149-3p was determined by real-time PCR, western blotting and dual luciferase reporter assay.

RESULTS

Our results revealed a lower level of miR-149-3p in OSCC tissues than in adjacent normal tissues. Downregulation of miR-149-3p was correlated with malignant development and poor outcomes in patients with OSCC. MiR-149-3p repressed the migratory and invasive abilities of OSCC cells. We confirmed that miR-149-3p targeted the 3'-untranslated region of MMP2 mRNA to suppress MMP2 expression. Moreover, the miR-149-3p-mediated decrease in metastasis was reversed by overexpression of MMP2 in OSCC cells.

CONCLUSION

Our findings provide an important molecular mechanism by which miR-149-3p inhibits OSCC cell migration and invasion via negative regulation of MMP2 and implicate miR-149-3p as a prospective biomarker and therapeutic target for OSCC.

Silencing of LncRNA AFAP1-AS1 Inhibits Cell Proliferation in Oral Squamous Cancer by Suppressing CCNA2

Background

Evidence has indicated that dysregulation of long noncoding RNAs (lncRNA) is a critical factor in the occurrence of many diseases, including cancer. The lncRNA AFAP1-AS1 has been shown to participate in oncogenesis, metastasis, or drug resistance in many types of cancer. However, the potential role of AFAP1-AS1 in oral squamous cell carcinoma (OSCC) has not been fully elucidated.

Methods

Bioinformatics analysis was performed to compare AFAP1-AS1 expression levels in OSCC cancer samples and in normal controls. The biological function of AFAP1-AS1 was studied through loss-of-function assays. To study the potential mechanisms, high-throughput sequencing was applied to OSCC cancer samples and a series of bioinformatics analyses were performed. The effects of AFAP1-AS1 on OSCC tumor growth was evaluated by in vivo xenograft tumor formation assays.

Results

Bioinformatics analyses indicated that AFAP1-AS1 was upregulated in OSCC. Overexpression of AFAP1-AS1 was positively correlated with lymph node metastasis, tumor stage, and pathological grade. Down-regulation of AFAP1-AS1 in OSCC led to decreased proliferation in vitro and, notably, inhibition of tumor growth in vivo. Further research indicated that AFAP1-AS1 regulated OSCC cell proliferation by targeting CCNA2.

Conclusion

AFAP1-AS1 promotes tumor proliferation and indicates a poor prognosis in OSCC, providing a potential therapeutic strategy.

The scope of liquid biopsy in the clinical management of oral cancer

Oral squamous cell carcinoma (OSCC) is one of the most prevalent forms of head and neck cancer, and it remains a leading cause of death in developing countries. Failure to detect the disease at an early stage is the main reason for the lack of improvement in the overall survival rate over the decades. Even though tissue biopsy is considered as the gold standard for diagnosis and molecular workup, it is an invasive, expensive and time-consuming procedure. Besides, it may not indicate the genetic status of the entire tumour owing to the heterogeneity of the cancer. In this context, liquid biopsy could be quite useful as it provides a more representative picture of the circulating tumour cells, circulating tumour DNA, circulating RNA, and tumour-derived exosomes obtained from all types of body fluids. This technique provides real-time assessment of variations in the molecular profile of the whole tumour and enables the serial monitoring of the disease status. The method has many advantages, such as easy accessibility, reliability, reproducibility and the possibility for early detection of the disease. However, the concept is still in its infancy, and the research on its application in various tumours including OSCC is rapidly progressing.

Identification of latent biomarkers in connection with progression and prognosis in oral cancer by comprehensive bioinformatics analysis

Background

Oral cancer (OC) is a common and dangerous malignant tumor with a low survival rate. However, the micro level mechanism has not been explained in detail.

Methods

Gene and miRNA expression micro array data were extracted from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) and miRNAs (DE miRNAs) were identified by R software. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of genes and genomes (KEGG) pathway analysis were used to assess the potential molecular mechanisms of DEGs. Cytoscape software was utilized to construct protein–protein interaction (PPI) network and miRNA-gene network. Central genes were screened out with the participation of gene degree, molecular complex detection (MCODE) plugin, and miRNA-gene network. Then, the identified genes were checked by The Cancer Genome Atlas (TCGA) gene expression profile, Kaplan-Meier data, Oncomine, and the Human Protein Atlas database. Receiver operating characteristic (ROC) curve was drawn to predict the diagnostic efficiency of crucial gene level in normal and tumor tissues. Univariate and multivariate Cox regression were used to analyze the effect of dominant genes and clinical characteristics on the overall survival rate of OC patients.

Results

Gene expression data of gene expression profiling chip(GSE9844, GSE30784, and GSE74530) were obtained from GEO database, including 199 tumor and 63 non-tumor samples. We identified 298 gene mutations, including 200 upregulated and 98 downregulated genes. GO functional annotation analysis showed that DEGs were enriched in extracellular structure and extracellular matrix containing collagen. In addition, KEGG pathway enrichment analysis demonstrated that the DEGs were significantly enriched in IL-17 signaling pathway and PI3K-Akt signaling pathway. Then, we detected three most relevant modules in PPI network. Central genes (CXCL8, DDX60, EIF2AK2, GBP1, IFI44, IFI44L, IFIT1, IL6, MMP9,CXCL1, CCL20, RSAD2, and RTP4) were screened out with the participation of MCODE plugin, gene degree, and miRNA-gene network. TCGA gene expression profile and Kaplan-Meier analysis showed that high expression of CXCL8, DDX60, IL6, and RTP4 was associated with poor prognosis in OC patients, while patients with high expression of IFI44L and RSAD2 had a better prognosis. The elevated expression of CXCL8, DDX60, IFI44L, RSAD2, and RTP44 in OC was verified by using Oncomine database. ROC curve showed that the mRNA levels of these five genes had a helpful diagnostic effect on tumor tissue. The Human Protein Atlas database showed that the protein expressions of DDX60, IFI44L, RSAD2, and RTP44 in tumor tissues were higher than those in normal tissues. Finally, univariate and multivariate Cox regression showed that DDX60, IFI44L, RSAD2, and RTP44 were independent prognostic indicators of OC.

Conclusion

This study revealed the potential biomarkers and relevant pathways of OC from publicly available GEO database, and provided a theoretical basis for elucidating the diagnosis, treatment, and prognosis of OC.

Tumor-Associated Trypsin Inhibitor (TATI) as a Biomarker of Poor Prognosis in Oropharyngeal Squamous Cell Carcinoma Irrespective of HPV Status

BACKGROUND

We studied the role of tumor-associated trypsin inhibitor (TATI) in serum and in tumor tissues among human papillomavirus (HPV)-positive and HPV-negative OPSCC patients.

MATERIALS AND METHODS

The study cohort included 90 OPSCC patients treated at the Helsinki University Hospital (HUS), Helsinki, Finland, in 2012-2016. TATI serum concentrations (S-TATIs) were determined by an immunofluorometric assay. Immunostaining was used to assess tissue expression. HPV status was determined with a combination of p16 immunohistochemistry and HPV DNA PCR genotyping. The survival endpoints were overall survival (OS) and disease-specific survival (DSS).

RESULTS

A significant correlation was found between S-TATI positivity and poor OS (p < 0.001) and DSS (p = 0.04) in all patients. In HPV-negative cases, S-TATI positivity was linked to poor OS (p = 0.01) and DSS (p = 0.05). In HPV-positive disease, S-TATI positivity correlated with poor DSS (p = 0.01). S-TATI positivity was strongly associated with HPV negativity. TATI serum was negatively linked to a lower cancer stage. TATI expression in peritumoral lymphocytes was associated with favorable OS (p < 0.025) and HPV positivity. TATI expression in tumor and in peritumoral lymphocytes correlated with lower cancer stages.

CONCLUSION

Our results suggest that S-TATI positivity may be a biomarker of poor prognosis in both HPV-positive and HPV-negative OPSCC.

Application and Performance of Artificial Intelligence Technology in Oral Cancer Diagnosis and Prediction of Prognosis: A Systematic Review

Oral cancer (OC) is a deadly disease with a high mortality and complex etiology. Artificial intelligence (AI) is one of the outstanding innovations in technology used in dental science. This paper intends to report on the application and performance of AI in diagnosis and predicting the occurrence of OC. In this study, we carried out data search through an electronic search in several renowned databases, which mainly included PubMed, Google Scholar, Scopus, Embase, Cochrane, Web of Science, and the Saudi Digital Library for articles that were published between January 2000 to March 2021. We included 16 articles that met the eligibility criteria and were critically analyzed using QUADAS-2. AI can precisely analyze an enormous dataset of images (fluorescent, hyperspectral, cytology, CT images, etc.) to diagnose OC. AI can accurately predict the occurrence of OC, as compared to conventional methods, by analyzing predisposing factors like age, gender, tobacco habits, and bio-markers. The precision and accuracy of AI in diagnosis as well as predicting the occurrence are higher than the current, existing clinical strategies, as well as conventional statistics like cox regression analysis and logistic regression.

2-phenylethynesulfonamide inhibits growth of oral squamous cell carcinoma cells by blocking the function of heat shock protein 70

Oral squamous cell carcinoma (OSCC) is the most common malignancy in the oral cavity, which accounts for >90% of all diagnosed oral cancers. 2-phenylethynesulfonamide (PES) was known as a selective heat shock protein 70 (Hsp70) function inhibitor, which induced cytotoxic effects on various tumor cell types, but showed to be less toxic to normal cells. However, no associated evaluation of PES on OSCC was found. In the present study, the proliferation of OSCC cells treated with PES was analyzed using a CCK-8 assay. The effects of PES on the cell cycle and apoptosis of OSCC cells were determined by flow cytometric analyses. Expression of associated protein was determined by Western blot analysis. The results of the present study showed that PES inhibited the proliferation of OSCC cell lines in vivo and in vitro. PES induced apoptosis and arrested the cell cycle of OSCC cells. PES inhibited the expression of X-linked inhibitor of apoptosis protein (XIAP), baculoviral IAP repeat containing 2 (c-IAP1), phosphorylated AKT (p-AKT), and phosphorylated extracellular signal-regulated kinase (p-ERK). Additionally, knockdown of Hsp70 enhanced the effects of PES. By contrast, overexpression of Hsp70 attenuated the inhibitory effects of PES on cell viability. PES disrupted the interaction between Hsp70 and XIAP. In conclusion, the present study demonstrated that PES suppresses the growth of OSCC cells through Hsp70-dependent mechanism.

MicroRNA-487a-3p inhibits the growth and invasiveness of oral squamous cell carcinoma by targeting PPM1A

Oral squamous cell carcinoma (OSCC) forms the majority of the entire cancerous tumors which occur in the mouth. Current treatment advances, such as surgical resection, chemotherapy, and radiotherapy, have significantly helped reduce OSCC. However, the overall patient survival rate remains relatively low. MiRNAs, a non-coding RNA group, are essential for multiple biological functions, which are essential for the progression of cancer, including survival of the cell, migration, multiplication, differentiation, and apoptosis. The study aimed to explore the existing association between miR-487a-3p and PPM1A and elucidating their role in modulation of proliferation in OSCC cell lines. In this study, we used CAL-27 and TCA-8113 OSCC cell lines and human samples to validate our results. The manifestation of miR-487a-3p and PPM1A was checked using quantitative real-time PCR. The miR-487a-3p and PPM1A binding was investigated through western blot assay and dual-luciferase reporter gene. Functional experiments, including colony formation, CCK-8, and transwell experimentations, were undertaken to validate cells' growth and invasion activities. According to the results, the expression of miR-487a-3p is regulated in the OSCC cell lines compared to normal cells. Moreover, the mimicking of miR-487a-3p significantly reduces the OSCC cell growth and invasion, and PPM1A overexpression exerts oncogenic effects and hinders the anti-oncogenic effects of miR-487a-3p. In conclusion, the study demonstrated that miR-487a-3p might act as a tumor suppressor by inhibiting the growth and invasion of OSCC via regulating PPM1A expression.

Prognosis and predictive value of heat-shock proteins expression in oral cancer: A PRISMA-compliant meta-analysis

BACKGROUND

Heat-shock proteins (HSP) is a key chaperone protein which maintains intracellular proteostasis and is expressed on the surface of solid and hematological malignancies. Several studies have reported paradoxical evidence of the association between HSP expression and prognosis of oral cancer. To address the discrepancy, we carried out the meta-analysis to assess the role of HSP such as: HSP70, HSP90, HSP27, HSP60, and HSP105 in susceptibility, progression, and prognosis of oral cancer.

MATERIALS AND METHODS

We retrieved the PubMed, Embase, Web of science, China National Knowledge Infrastructure (CNKI), and Wanfang databases to acquire the eligible studies which were associated with HSP70, HSP90, HSP27, HSP60, and HSP105 protein expression and oral cancer. We applied hazard ratio (HR) and its 95% confidence interval (95% CI) to assess the value of HSP protein expression in overall survival of oral cancer; odds ratio (OR) and its 95% CI were used to evaluate the association of risk and clinical features of oral cancer. Funnel plot, Begg test, and Egger line regression test were utilized to observe publication bias among studies. All statistical analysis was performed with Stata 14.0 software (Stata Corporation, College Station, TX).

RESULTS

A total of 26 studies were included in the present meta-analysis. On based of the results, HSP70 and HSP27 had no significant association with progression of oral cancer. However, the pooled HR and 95% CI revealed a significant well effects of HSP70 and HSP27 expression on survival of oral cancer. Moreover, the susceptibility of oral cancer was significantly associated with HSP70 and HSP60 overexpression.

CONCLUSION

HSP70 and HSP27 protein overexpression might be valuable biomarkers for the prognosis of oral cancer. And HSP70 and HSP60 might have potential predictive effects on the risk of oral cancer.

Curcumin suppresses the proliferation of oral squamous cell carcinoma through a specificity protein 1/nuclear factor-κB-dependent pathway

Oral squamous cell carcinoma (OSCC) is the most common cancer of the oral cavity. Curcumin (Cur), a naturally derived compound, is reported to have broad-spectrum anticancer activity and is considered as an effective nuclear factor-κB (NF-κB) inhibitor. The present study aimed to clarify the detailed molecular mechanism though which Cur regulates NF-κB pathway activity in OSCC. The viability of HSC3 and CAL33 cells following treatment with Cur was determined using a Cell Counting Kit-8 assay. The protein and mRNA expression of specificity protein 1 (Sp1), p65 and heat shock factor 1 (HSF1) was determined by western blotting and reverse transcription-quantitative PCR analysis, respectively. The NF-κB activity was measured by Dual-Luciferase reporter assay. Short hairpin RNA targeting Sp1 or control RNA was transfected into HSC3 cells using X-treme GENE HP DNA Transfection System. Colony formation assays were performed using crystal violet staining. The results demonstrated that Cur significantly inhibited the viability and colony formation ability of HSC3 and CAL33 cells. In addition, Cur decreased the expression of Sp1, p65 and HSF1 by suppressing their transcription levels. Cur decreased NF-κB activity in OSCC cells, and Sp1 downregulation enhanced the effect of Cur. The findings from the present study suggested that Cur may inhibit the proliferation of OSCC cells via a Sp1/NF-κB-dependent mechanism.

Screening and validation of plasma long non-coding RNAs as biomarkers for the early diagnosis and staging of oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC), characterized by a high recurrence rate, a poor prognosis and high morbidity, is the most prevalent malignancy of the oral cavity. The aberrant expression of long non-coding RNAs (lncRNAs) may lead to the development of various diseases, including cancer. Delayed diagnosis is the main reason for the poor prognosis. Therefore, the present study aimed to investigate the differential expression profiles of plasma lncRNAs in OSCC in order to screen target lncRNAs as biomarkers for the early diagnosis and staging of OSCC. The expression profiles of lncRNAs and mRNAs in OSCC were analyzed by microarray analysis. A total of 14 candidate lncRNAs were selected and analyzed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) using the array homologous samples. Subsequently, 4 target lncRNAs were measured by RT-qPCR in a large cohort, including 28 cases with TNM I/II [early-stage squamous cell carcinoma (ESCC) group], 36 cases with TNM III/IV [advanced-stage squamous cell carcinoma (ASCC) group], 16 cases with dysplasia [oral premalignant lesion (OPL) group] and 16 healthy controls (H group). Receiver operating characteristic (ROC) curves and logistic regression analysis were used to evaluate the diagnostic effects of the combined lncRNAs. In total, 6,606 differentially expressed lncRNAs and 4,196 mRNAs were identified in OSCC. The expression trend of the 14 candidate lncRNAs was consistent with the microarray data. The expression level of ENST00000412740, NR_131012, ENST00000588803 and NR_038323 exhibited significant differences in the H, OPL, ESCC and ASCC groups (P<0.05). ROC curve and logistic regression analyses revealed that the diagnostic efficacy of the combined lncRNAs was more prominent than that of a single lncRNA, particularly in the ESCC and ASCC groups. In conclusion, the present study identified the differential expression profiles of plasma lncRNAs in OSCC and demonstrated that ENST00000412740, NR_131012, ENST00000588803 and NR_038323 may be promising biomarkers for the early diagnosis and staging of OSCC. These findings may provide novel targets for the early diagnosis and staging of OSCC, which may provide an objective basis for clinical decision-making.

EZB-ICR Cell Line: A New Established and Characterized Oral Squamous Cell Carcinoma Cell Line From Tongue

Background:

Tongue cancer is one of the most aggressive forms of oral squamous cell carcinoma which needs more investigations. Herein, we aimed to establish and characterize a tongue cancer cell line.

Methods:

Tumor tissue was obtained from a 70-year-old woman with tongue cancer. The established cell line named as EZB-ICR and characterized for doubling time, expression of specific markers, HPV corporation and migration status using flow cytometry, immunofluorescence staining, multiplex PCR, and migration assay.

Results:

EZB-ICR was negative for expression of mesenchymal specific markers, cytokeratin19, pan-cytokeratin, vimentin and EPCAM, but was positive for S100 and Nestin. No appearance of human papilloma virus DNA was seen. The doubling time of EZB-ICR was 31 hours and migration assay confirmed its metastatic nature.

Conclusion:

To the best of our knowledge, EZB-ICR is the first tongue human cancer cell line established in Iran, and its features make it appropriate for cancer-based in vitro studies and contribute to more studies on tongue cancer.

Suppression of miR-886-3p mediated by arecoline (ARE) contributes to the progression of oral squamous cell carcinoma

Previous studies have reported that as the main extract of areca nut, arecoline (ARE) causes DNA damage and in turn contributes to the carcinogenesis of oral epithelial cells. It has been reported that ARE can inhibit the expression of miR-886-3p. In the current study, we aimed to explore the expression and biological functions of miR-886-3p in oral squamous cell carcinoma (OSCC). Herein, we demonstrated that in OSCC cells treated with ARE, the expression level of miR-886-3p was negatively correlated with the concentration of ARE. Compared with adjacent tissue, the expression level of miR-886-3p in OSCC tissue was remarkably downregulated. Transfection of miR-886-3p mimics markedly decreased viability, migration and invasion of OSCC cells. These experimental data implied that miR-886-3p suppression mediated by ARE took part in the proliferation and metastasis of OSCC. This study can help elucidate the mechanism by which areca nut chewing contributes to the malignant transformation of oral epithelial cells.

Tumor associated tissue eosinophilia in oral squamous cell carcinoma: A systematic review and meta-analysis

Background

Oral squamous cell carcinoma (OSCC) still lacks the valid prognosticator for survival. Tumor associated tissue eosinophilia (TATE) have been widely investigated in the literature but still there is no consensus viewpoint on its role as prognostic marker. With this view in mind, a systematic review and meta-analysis of studies that evaluated the overall risk of elevated TATE and survival in OSCC was conducted.

Methodology

A systematic literature search conducted to identify studies that have evaluated TATE in OSCC. Overall survival (OS), Disease Free Survival (DFS) Hazard ratio (HR) with 95% confidence interval) was extracted. HR was extrapolated if direct HR was not given in publication. Studies were pooled and combined hazard ratios (HRs) of High TATE for OS and DFS were calculated.

Results

6 out of 874 articles were found eligible for systematic review and meta-analysis. High TATE was predictor of OS (pooled HR 0.45 (95% CI, 030-0.65, P ​< ​0.0001)) and DFS (pooled HR 2.33 (95% CI, 0.74-7.37)) in OSCC patients.

Conclusion

High TATE positively predicts OS and DFS in OSCC and thus can be regarded as an important survival prognosticator. Standardization of counting and reporting methodology for TATE count is recommended on future cohort studies.

Development and Validation of Autophagy-Related Gene Signature and Nomogram for Predicting Survival in Oral Squamous Cell Carcinoma

Background

Autophagy, a highly conserved self-digesting process, has been deeply involved in the development and progression of oral squamous cell carcinoma (OSCC). However, the prognostic value of autophagy-related genes (ARGs) for OSCC still remains unclear. Our study set out to develop a multigene expression signature based on ARGs for individualized prognosis assessment in OSCC patients.

Methods

Based on The Cancer Genome Atlas (TCGA) database, we identified prognosis-related ARGs through univariate COX regression analysis. Then we performed the least absolute shrinkage and selection operator (LASSO) regression analysis to identify an optimal autophagy-related multigene signature with the subsequent validation in testing set, GSE41613 and GSE42743 datasets.

Results

We identified 36 prognosis-related ARGs for OSCC. Subsequently, the multigene signature based on 13 prognostic ARGs was constructed and successfully divided OSCC patients into low and high-risk groups with significantly different overall survival in TCGA training set (p < 0.0001). The autophagy signature remained as an independent prognostic factor for OSCC in univariate and multivariate Cox regression analyses. The area under the curve (AUC) values of the receiver operating characteristic (ROC) curves for 1, 3, and 5-year survival were 0.758, 0.810, 0.798, respectively. Then the gene signature was validated in TCGA testing set, GSE41613 and GSE42743 datasets. Moreover, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, and single-sample gene set enrichment analysis (ssGSEA) revealed the underlying biological characteristics and signaling pathways associated with this signature in OSCC. Finally, we constructed a nomogram by combining the gene signature with multiple clinical parameters (age, gender, TNM-stage, tobacco, and alcohol history). The concordance index (C-index) and calibration plots demonstrated favorable predictive performance of our nomogram.

Conclusion

In summary, we identified and verified a 13-ARGs prognostic signature and nomogram, which provide individualized prognosis evaluation and show insight for potential therapeutic targets for OSCC.

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

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

Ilimaquinone Induces Apoptosis and Autophagy in Human Oral Squamous Cell Carcinoma Cells

In this study, the anti-tumor activity of ilimaquinone (IQ), a sesquiterpene quinone isolated from marine sponge Halichondria sp., in oral squamous cell carcinoma (OSCC) cells, was investigated. IQ suppressed the viability of the OSCC cell lines SCC4 and SCC2095 with IC₅₀ values of 7.5 and 8.5 μM, respectively. Flow cytometric analysis demonstrated that IQ induced caspase-dependent apoptosis in SCC4 cells and modulated the expression of several cell growth-related gene products, including Akt, p38, Mcl-1, and p53. Notably, p53 knockdown caused higher resistance to IQ’s anti-tumor activity. In addition, IQ increased reactive oxygen species generation, which was partially reversed by the addition of antioxidants. Furthermore, it triggered autophagy, as evidenced by acidic organelle formation and LC3B-II and Atg5 expression in SCC4 cells. Pretreatment with the autophagy inhibitor 3-methyladenine or chloroquine partially decreased IQ-induced apoptosis, suggesting that IQ induced protective autophagy. In summary, IQ has potential to be used in OSCC therapy.

Downregulation of Jumonji-C domain-containing protein 5 inhibits proliferation by silibinin in the oral cancer PDTX model

Dysregulation of histone demethylase Jumonji-C domain-containing protein 5 (JMJD5) has been identified as a great effect on tumorigenesis. Silibinin is a commonly used anti-hepatotoxic drug and exhibits anticancer effect in various cancers. However, the antitumor mechanism between silibinin and JMJD5 in oral squamous cell carcinoma (OSCC) remains unclear. In this study, the clinical significance of JMJD5 on OSCC patients was assessed through tissue microarray. Furthermore, mice bearing patient-derived tumor xenografts (PDTXs) and tongue cancer cell lines were treated with silibinin and evaluated for tumor growth and JMJD5 expression. High expression of JMJD5 in oral cancer was significantly associated with tumor size (P = 0.0241), cervical node metastasis (P = 0.0001) and clinical stage (P = 0.0002), was associated with worse survival rate compared with that of the total cohort (P = 0.0002). Collectively the data indicate that JMJD5 expression may be suitable for detection of unfavorable prognosis in OSCC patients, based in part on its apparent role as a marker of metastasis. In addition, silibinin inhibits cancer growth in vitro and in PDTX models. Furthermore, metastasis-associated protein 1 (MTA1) could regulate the expression for JMJD5 and had a positive correlation with JMJD5. Moreover, silibinin could downregulate JMJD5 and MTA1 in oral cancer. Present study thus identifies that JMJD5 might be an essential prognostic indicator and therapeutic target against OSCC progression. In addition, silibinin is a potential candidate among novel chemotherapeutic agents or adjuvants for modulating JMJD5 in OSCC, through a mechanism likely involving MTA1/JMJD5 axis.

Epithelial cell infection by Epstein-Barr virus

Epstein-Barr Virus (EBV) is etiologically associated with multiple human malignancies including Burkitt lymphoma and Hodgkin disease as well as nasopharyngeal and gastric carcinoma. Entry of EBV into target cells is essential for virus to cause disease and is mediated by multiple viral envelope glycoproteins and cell surface associated receptors. The target cells of EBV include B cells and epithelial cells. The nature and mechanism of EBV entry into these cell types are different, requiring different glycoprotein complexes to bind to specific receptors on the target cells. Compared to the B cell entry mechanism, the overall mechanism of EBV entry into epithelial cells is less well known. Numerous receptors have been implicated in this process and may also be involved in additional processes of EBV entry, transport, and replication. This review summarizes EBV glycoproteins, host receptors, signal molecules and transport machinery that are being used in the epithelial cell entry process and also provides a broad view for related herpesvirus entry mechanisms.

Long non-coding RNA SAMMSON as a novel potential diagnostic and prognostic biomarker for oral squamous cell carcinoma

Background/purpose

Oral squamous cell carcinoma (OSCC) is one of the most lethal malignancies which accounts for approximately 90% of all malignant oral tumours. SAMMSON is a lncRNA located on chromosome 3p13–3p14 and is known to act as an oncogene in several malignancies. However, its expression and clinical significance in oral squamous cell carcinoma (OSCC) remain mostly unclear. In this study, we investigated the expression and clinical relevance of lncRNA SAMMSON in human OSCC.

Materials and methods

Human OSCC cell lines (Tca8113, SCC9, SCC25, CAL27, HN12, HSU3, FADU) and a human normal oral keratinocyte cell line (HNOK) were used to detect the difference of SAMMSON expression. A total of 90 OSCC patients confirmed by pathological and clinical diagnoses at the Hospital of Stomatology, Department of Periodontology, Shandong University were enrolled. The mRNA expression level was analyzed by reverse transcription PCR (QRT-PCR). Statistical analyses including Student's t-test, chi-square method, Kaplan-Meier method, Univariate and, Multivariate Cox regression analysis were performed to analyse all data.

Results

This study showed that the expression of SAMMSON was significantly increased in OSCC tissues and cell lines. High SAMMSON expression was significantly associated with TMN stage, tumour differentiation, lymph node metastasis distant metastasis and neighboring tissue infiltration. Patients with high expression of SAMMSON had poor overall survival and disease-free survival compared to those with low levels. Cox regression analysis showed that SAMMSON could act as an independent prognostic factor in OSCC.

Conclusion

Serum SAMMSON expression was associated with tumour SAMMSON expression. ROC curve analysis indicated the high diagnostic sensitivity and specificity of serum SAMMSON expression in OSCC patients as compared to other traditional serum biomarker SCCA, TSGF, and CEA. These results indicated that SAMMSON might play an essential role in OSCC progression and could serve as a novel prognostic and diagnostic biomarker in OSCC.

The TRPV4-AKT axis promotes oral squamous cell carcinoma cell proliferation via CaMKII activation

Most human malignant tumor cells arise from epithelial tissues, which show distinctive characteristics, such as polarization, cell-to-cell contact between neighboring cells, and anchoring to a basement membrane. When tumor cells invaginate into the stroma, the cells are exposed to extracellular environments, including the extracellular matrix (ECM). Increased ECM stiffness has been reported to promote cellular biological activities, such as excessive cellular growth and enhanced migration capability. Therefore, tumorous ECM stiffness is not only an important clinical tumor feature but also plays a pivotal role in tumor cell behavior. Transient receptor potential vanilloid 4 (TRPV4), a Ca²⁺-permeable nonselective cation channel, has been reported to be mechano-sensitive and to regulate tumorigenesis, but the underlying molecular mechanism in tumorigenesis remains unclear. The function of TRPV4 in oral squamous cell carcinoma (OSCC) is also unknown. The current study was conducted to investigate whether or not TRPV4 might be involved in OSCC tumorigenesis. TRPV4 mRNA levels were elevated in OSCC cell lines compared with normal oral epithelial cells, and its expression was required for TRPV4 agonist-dependent Ca²⁺ entry. TRPV4-depleted tumor cells exhibited decreased proliferation capabilities in three-dimensional culture but not in a low-attachment plastic dish. A xenograft tumor model demonstrated that TRPV4 expression was involved in cancer cell proliferation in vivo. Furthermore, loss-of-function experiments using siRNA or an inhibitor revealed that the TRPV4 expression was required for CaMKII-mediated AKT activation. Immunohistochemical analyses of tissue specimens obtained from 36 OSCC patients showed that TRPV4 was weakly observed in non-tumor regions but was strongly expressed in tumor lesions at high frequencies where phosphorylated AKT expression was frequently detected. These results suggest that the TRPV4/CaMKII/AKT axis, which might be activated by extracellular environments, promotes OSCC tumor cell growth.

Progress in Drug and Formulation Development for the Chemoprevention of Oral Squamous Cell Carcinoma: A Review

BACKGROUND

Cancer is a life-threatening global problem with high incidence rates. Prioritizing the prevention of cancer, chemopreventive agents have drawn much attention from the researchers.

OBJECTIVE

This review focuses on the discussion of the progress in the development of chemopreventive agents and formulations related to the prevention of oral cancer.

METHODS

In this perspective, an extensive literature survey was carried out to understand the mechanism, control and chemoprevention of oral cancer. Different patented agents and formulations have also exhibited cancer preventive efficacy in experimental studies. This review summarizes the etiology of oral cancer and developments in prevention strategies.

RESULTS

The growth of oral cancer is a multistep activity necessitating the accumulation of genetic as well as epigenetic alterations in key regulatory genes. Many risk factors are associated with oral cancer. Genomic technique for sequencing all tumor specimens has been made available to help detect mutations. The recent development of molecular pathway and genetic tools has made the process of diagnosis easier, better forecast and efficient therapeutic management. Different chemical agents have been studied for their efficacy to prevent oral cancer and some of them have shown promising results.

CONCLUSION

Use of chemopreventive agents, either synthetic or natural origin, to prevent carcinogenesis is a worthy concept in the management of cancers. Preventive measures are helpful in controlling the occurrence or severity of the disease. The demonstrated results of preventive agents have opened an arena for the development of promising chemopreventive agents in the management of oral squamous cell carcinoma.

MicroRNA-140-5p inhibits the tumorigenesis of oral squamous cell carcinoma by targeting p21-activated kinase 4

Oral squamous cell carcinoma (OSCC) is a serious global health problem. Recently, accumulating microRNA (miRNA) has emerged as crucial players in the development and progression of carcinomas including OSCC. Our study aimed to further investigate the roles of miR-140-5p in OSCC tumorigenesis and related molecular basis. In this study, OSCC tissues and adjacent normal tissues were isolated from 34 OSCC patients who suffered from surgical resection at our hospital. MiR-140-5p level was measured by reverse-transcription quantitative polymerase chain reaction assay. p21-activated kinase 4 (PAK4) protein level was determined by western blot assay in OSCC cells at 48 h posttransfection or OSCC xenograft tumors at day 35 after OSCC cell injection. The cell proliferative ability was assessed by cell counting kit-8 assay in OSCC cells at 0, 24, 48, 72 h after transfection. Cell apoptosis and cell-cycle analysis was conducted using a flow cytometry in OSCC cells at 48 h after transfection. The interaction between miR-140-5p and PAK4 3'-untranslated region was tested by bioinformatics analysis and luciferase reporter assay in OSCC cells at 48 h after transfection. Mouse xenograft models of OSCC were established to examine the influence of miR-140-5p on OSCC tumorigenesis in vivo during 35 days after OSCC cell injection. Our data showed that miR-140-5p expression was notably downregulated in OSCC tissues and cell lines. MiR-140-5p inhibited the expression of PAK4 by direct interaction in OSCC cells. Functional analysis disclosed that miR-140-5p overexpression or PAK4 knockdown suppressed cell proliferation, promoted cell apoptosis, and induced cell-cycle arrest in OSCC. Moreover, PAK4 upregulation rescued the detrimental effects of miR-140-5p on cell proliferation and cell-cycle progression and hampered cell apoptosis induced by miR-140-5p in OSCC. In vivo experiments demonstrated that miR-140-5p overexpression suppressed the growth of OSCC xenograft tumors by downregulating PAK4. In conclusion, our data revealed miR-140-5p suppressed OSCC tumorigenesis by targeting PAK4 in vitro and in vivo, deepening our understanding on the function and molecular basis of miR-140-5p in the development of OSCC.

Baicalein inhibits the growth of oral squamous cell carcinoma cells by downregulating the expression of transcription factor Sp1

Oral squamous cell carcinoma (OSCC), the most common malignancy of the oral cavity, accounts for >90% of all diagnosed oral cancer cases. Baicalein, a naturally derived compound, has been shown to alter p65 and the nuclear factor (NF)‑κB pathway, thus exerting cytotoxic effects on various tumor cell types. However, the mechanism of action of baicalein in OSCC has not been fully elucidated. In the present study, the proliferation of OSCC cells treated with baicalein was examined using a CCK‑8 assay. The effects of baicalein on the cell cycle and apoptosis of OSCC cells were determined by flow cytometric analyses. The expression of specificity protein 1 (Sp1), p65 and p50 at the mRNA and protein levels was determined by reverse transcription‑quantitative PCR and western blot analysis, respectively. The results of the present study demonstrated that baicalein suppresses the proliferation of OSCC cell lines in vivo and in vitro. Baicalein also induced apoptosis of OSCC cells and arrested the cell cycle at the G0/G1 phase. Baicalein inhibited the expression of Sp1, p65 and p50 by downregulating the relative mRNA levels. Baicalein reduced the activity of NF‑κB in OSCC cells. Knockdown of Sp1 also resulted in reduced expression of p65 and p50. In addition, Sp1 silencing enhanced the effects of baicalein. In conclusion, the present study demonstrated that baicalein suppresses the growth of OSCC cells through an Sp1/NF‑κB‑dependent mechanism.

Autophagy modulators for the treatment of oral and esophageal squamous cell carcinomas

Oral squamous cell carcinomas (OSCC) and esophageal squamous cell carcinomas (ESCC) exhibit a survival rate of less than 60% and 40%, respectively. Late-stage diagnosis and lack of effective treatment strategies make both OSCC and ESCC a significant health burden. Autophagy, a lysosome-dependent catabolic process, involves the degradation of intracellular components to maintain cell homeostasis. Targeting autophagy has been highlighted as a feasible therapeutic strategy with clinical utility in cancer treatment, although its associated regulatory mechanisms remain elusive. The detection of relevant biomarkers in biological fluids has been anticipated to facilitate early diagnosis and/or prognosis for these tumors. In this context, recent studies have indicated the presence of specific proteins and small RNAs, detectable in circulating plasma and serum, as biomarkers. Interestingly, the interplay between biomarkers (eg, exosomal microRNAs) and autophagic processes could be exploited in the quest for targeted and more effective therapies for OSCC and ESCC. In this review, we give an overview of the available biomarkers and innovative targeted therapeutic strategies, including the application of autophagy modulators in OSCC and ESCC. Additionally, we provide a viewpoint on the state of the art and on future therapeutic perspectives combining the early detection of relevant biomarkers with drug discovery for the treatment of OSCC and ESCC.

Changes in oncogenic protein levels in peri-implant oral malignancy: a case report

Background

Oral squamous cell carcinoma (OSCC) constitutes a group of tumors that exhibit heterogeneous biology, histopathology, and clinical behaviors.

Case presentation

A 73-year-old male had a whitish leukoplakia-like lesion around inflamed peri-implant area (#42, #43, and #44), and this lesion had transformed to OSCC within 3 years. He underwent mass resection, selective neck dissection, and reconstructive surgery. To detect any carcinogenesis progression, we examined the removed tumor tissue as well as the patient’s preoperative and postoperative sera to identify causative oncogenic proteins using immunoprecipitation high-performance liquid chromatography (IP-HPLC).

Conclusions

The protein expression levels of p53, E-cadherin, β-catenin, MMP-10, HER2, NRAS, Met, HER2, and ERb were significantly lower in the serum collected on postoperative day 10 than in the preoperative serum, and if these proteins are consistently not elevated in the serum 3 months after surgery compared with the preoperative serum, these proteins can be potential oncogenic proteins. However, we also found that the serum extracted 3 months after the operation had elevated levels of oncogenic proteins compared with that of the preoperative and 10-day postoperative serum indicating the possibility of tumor recurrence. At postoperative follow-up period, ipsilateral neck metastasis and second primary lesion were found and additional surgery was performed to the patient. IP-HPLC using the patient’s serum shows the possibility of oncogenic protein detection. However, follow-up IP-HPLC data is needed to find out patient-specific prognostic factors.

Early mortality after diagnosis of cancer of the head and neck - A population-based nationwide study

Background

Cancers of the head and neck have a high mortality rate, and roughly 10% of the patients die within six months of diagnosis. To our knowledge little has been written about this group.

We wished to identify risk factors for early death, to predict and monitor patients at risk better and, if possible, avoid unjustified major treatment.

Methods and findings

This population-based nationwide study from the Swedish Head and Neck Cancer Register (SweHNCR) included data from 2008–2015 and 9733 patients at potential risk of early death.

A total of 925 (9.5%) patients died within six months. For every year older the patients became, the risk of early death increased by 2.3% (p<0.001). The relative risk of death was 3.37 times higher (237%) for patients with WHO score 1 compared with WHO score 0. A primary tumour in the hypopharynx correlated with a 24% increased risk over the oral cavity (p<0.024). Patients with stage IV disease had a 3.7 times greater risk of early death than those with stage I (p<0.001). As expected, a 12 times increased risk of early death was noted in the palliative treatment group, compared to the curative group.

Limitations to this study were that the actual cause of death was not recorded in the SweHNCR, and that socioeconomic factors, alcohol consumption, smoking habits, and HPV status, were not reported in SweHNCR until 2015. However, the fact that this is a population-based nationwide study including 9733 patients compensates for some of these limitations.

Conclusions

Identification of patients at increased risk of early death shows that older patients with advanced disease, increased WHO score, primary tumour in the hypopharynx, and those given palliative treatment, are more likely than the others to die from head and neck cancer within six months of diagnosis.

Compositional and Functional Analysis of the Microbiome in Tissue and Saliva of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is affected by the interaction between oral pathogen and holobionts, or the combination of the host and its microbial communities. Studies have indicated the structure and feature of the microbiome in OSCC tissue and saliva, the relationships between microbiota and OSCC sites, stages remain unclear. In the present study, OSCC tissue (T), saliva (S) and mouthwash (W) samples were collected from the same subjects and carried out the microbiome study by 16S sequencing. The results showed the T group was significantly different from the S and W groups with the character of lower richness and diversity. Proteobacteria were most enriched in the T group at the phylum level, while Firmicutes were predominant in groups S and W. At the genus level, the predominant taxa of group T were Acinetobacter and Fusobacterium, and for group S and W, the predominant taxa were Streptococcus and Prevotella. The genera related to late stage tumors were Acinetobacter and Fusobacterium, suggesting microbiota may be implicated in OSCC developing. Both compositional and functional analyses indicated that microbes in tumor tissue were potential indicator for the initiation and development of OSCC.

The therapeutic potential of epigallocatechin‑3‑gallate against human oral squamous cell carcinoma through inhibition of cell proliferation and induction of apoptosis: In vitro and in vivo murine xenograft study

Oral squamous cell carcinoma (OSCC) is one of the most common malignant tumors in the oral region. Despite current therapeutic strategies, the survival rate has not been improved for several decades. Thus, it is important to develop a novel approach for the treatment of OSCC. Epigallocatechin-3-gallate (EGCG) is a major constituent of green tea and has previously been demonstrated to inhibit the growth of several types of cancer cells. However, few studies have investigated the effect of EGCG on human OSCC cells, especially in experimental animal models. The aim of the present study was to evaluate the therapeutic potential of EGCG for targeting human OSCC in vitro and in vivo. In the in vitro experiments, EGCG suppressed HSC-3 cell viability in a time- and dose-dependent manner. Cell cycle analysis revealed that EGCG induced G1 phase arrest of the tumor cells. Apoptosis was examined by Annexin V and propidium iodide staining, assays of caspase-3 and −7 activity and TdT-mediated dUTP nick end labeling (TUNEL) staining. Treatment with EGCG significantly increased caspase-3 and −7 activities, and the percentage of apoptotic cells when compared with control cells. In the in vivo xenograft experiment on mice, EGCG treatment resulted in a 45.2% reduction in tumor size as compared with the control group without weight loss. In vivo cell proliferation and apoptosis were assessed by immunohistochemical Ki-67 staining and the TUNEL staining. There were significant differences in Ki-67 expression between the EGCG treatment group and control group, and the percentage of apoptotic cells in the EGCG treatment group was significantly greater than that in the control group. These results indicated that EGCG significantly inhibited cell proliferation by affecting the cell cycle progression and apoptosis in vitro and in vivo. These findings suggest that EGCG may have clinical applications as a novel approach to oral-cancer therapy.

Salivary LDOC1 is a gender-difference biomarker of oral squamous cell carcinoma

Background

The X-linked tumor suppressor gene LDOC1 is reported to be involved in oral cancer. The detection of biomarkers in salivary RNA is a non-invasive strategy for diagnosing many diseases. The aim of the present study was to investigate the potential of salivary LDOC1 as a biomarker of oral cancer.

Methods

We determined the expression levels of LDOC1 in the saliva of oral squamous cell carcinoma (OSCC) subjects, and investigated its correlation with various clinicopathological characteristics. The expression levels of salivary LDOC1 were detected in 53 OSCC subjects and 43 healthy controls using quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis. We used Fisher’s exact test to analyze the correlations between expression levels and clinicopathological characteristics.

Results

Salivary LDOC1 was significantly upregulated in females with OSCC (p = 0.0072), and significantly downregulated in males with OSCC (p = 0.0206). Eighty-nine percent of male OSCC subjects who smoked expressed low levels of LDOC1. OSCC cell lines derived from male OSCC subjects expressed low levels of LDOC1.

Conclusions

A high level of salivary LDOC1 expression is a biomarker of OSCC in females. A high percentage of male OSCC subjects who smoke express low levels of salivary LDOC1. A low level of salivary LDOC1 expression is a biomarker of OSCC in males.

Oral mucosal mesenchymal stem cell‑derived exosomes: A potential therapeutic target in oral premalignant lesions

Emerging evidence indicates that mesenchymal stem cells (MSCs) serve an indispensable role in the tumor microenvironment. However, whether MSCs participate in the development of oral carcinogenesis remains unclear. The present study isolated MSCs from clinical tissues and investigated the differences of MSCs derived from normal oral mucosa (N-MSC), oral leukoplakia with dysplasia (LK-MSC) and oral carcinoma (Ca-MSC). The results revealed that the LK-MSCs exhibited reduced proliferation and migration, compared with the N-MSCs and Ca-MSCs. Furthermore, it was demonstrated that the exosomes secreted by LK-MSCs have significant roles in promoting proliferation, migration and invasion in vitro, which was similar to the Ca-MSC-derived exosomes. The promoting effect was also demonstrated in a 3D coculture model. When the secretion of exosomes was blocked, the promoting effect of LK-MSCs was reversed. Based on a microarray analysis of MSC-derived exosomes, microRNA-8485 (miR-8485) was identified to be ectopically expressed. The exosomal miR-8485 was capable of promoting the proliferation, migration and invasion of tumor cells. Therefore, the present study highlights the significance of MSC-derived exosomes and exosomal miR-8485 in premalignant lesions and carcinogenesis. Intervention with the secretion of MSC-derived-exosomes may be an innovative strategy to retard the carcinogenesis.