Immunohistochemical expression of E-Cadherin and Cyclin D1 in different grades of oral squamous cell carcinoma

Background

Oral squamous cell carcinoma (OSCC) is the most common oral malignancy, representing up to 80-90% of all malignant neoplasms of the oral cavity. It results from the multistep accumulation of heterogeneous genetic changes. Important risk factors for OSCC include the use of tobacco or betel quid chewing, alcohol consumption, human papillomavirus and poor nutrition. E-Cadherin as a tumour suppressor gene sets a threshold for Wnt/β-catenin signalling. When expression of E-Cadherin is lost, potentiation of Wnt signalling pathway occurs leading to loss of cell-cell adhesion. The cyclin D1 gene (CCND1) located on chromosome 11q13 encodes a nuclear protein that is the regulatory subunit of Cdk-4 and Cdk-6. Cyclin D1 plays a major role in cell cycle transition from G1 to S phase by contributing to inactivation of the retinoblastoma gene product, and overexpression of CCND1 has been reported in 35-40% cases of OSCC.

Aim

Considering this, we decided to evaluate and compare the expression of CE-Cadherin and Cyclin D1 in different grades of OSCC.

Materials and Methods

A retrospective study was carried out on 60 formalin-fixed paraffin embedded tissue blocks comprising of 20 cases of well-differentiated OSCC, 20 cases of moderately differentiated OSCC and 20 cases of poorly differentiated OSCC. Diagnosed (using H and E), with oral mucosa taken as control.

Results

There was downregulation of E-Cadherin and overexpression of Cyclin D1 in increasing grades of OSCC and the difference was statistically significant. E-Cadherin was localised to membranous and shifted to cytoplasm as the grade worsened. Cyclin D1 was localised to nuclei of cells and the expression was seen more at the peripheral portions of tumour islands depicting the proliferative activity of tumour front.

Conclusion

The study revealed a good prognostic role of both E-Cadherin and Cyclin D1 in OSCC. The markers can be used for prognostic as well as therapeutic purposes.

Assessment of Serum Fucose Level among Oral Squamous Cell Carcinoma Patients: A Case-Control Study

Background

Serum glycoproteins, which are made up of various monosaccharides, are altered in malignancy, a disorder of cellular conduct. L-fucose, a methyl pentose that serves as the last sugar in the majority of plasma glycoproteins, is one of the monosaccharides. Numerous illness conditions and cancers have been linked to increased levels of protein-bound fucose.

Materials and Methods

In the current study, the serum fucose levels of patients with oral squamous cell carcinoma (OSCC) and healthy individuals were assessed and compared. The present study included a total of 30 OSCC patients and 30 healthy controls. The Winzler method was used to estimate the serum L-fucose levels using a spectrophotometer (Spectronic 20, Thermo Fisher Scientific, USA).

Results

Age and sex had no effect on serum fucose levels. In contrast to healthy individuals, OSCC patients' mean serum fucose levels significantly increased. In conclusion, patients with OSCC can benefit from the use of serum fucose as an investigative biomarker.

The potential role of COVID-19 in progression, chemo-resistance, and tumor recurrence of oral squamous cell carcinoma (OSCC)

Numerous studies have revealed that cancer patients are more likely to develop severe Coronavirus disease-2019 (COVID-19), which can cause mortality, as well as cancer progression and treatment failure. Among these patients who may be particularly vulnerable to severe COVID-19 and COVID-19-associated cancer progression are those with oral squamous cell carcinoma (OSCC). In this regard, therapeutic approaches must be developed to lower the risk of cancer development, chemo-resistance, tumor recurrence, and death in OSCC patients with COVID-19. It may be helpful to comprehend the cellular and molecular mechanisms by which the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) contributes to these problems. In this line, in this review, we described the potential cellular and molecular mechanisms that SARS-CoV-2 can exert its role and based on them pharmacological targeted therapies were suggested. However, in this study, we encourage more investigations in the future to uncover other cellular and molecular mechanisms of action of SARS-CoV-2 to develop beneficial therapeutic strategies for such patients.

LAMC2 regulates proliferation, migration, and invasion mediated by the Pl3K/AKT/mTOR pathway in oral

Background

Oral squamous cell carcinoma (OSCC) is a common malignant tumor. Recently, Laminin Gamma 2 (LAMC2) has been shown to be abnormally expressed in OSCC; however, how LAMC2 signaling contributes to the occurrence and development of OSCC and the role of autophagy in OSCC has not been fully explored. This study aimed to analyze the role and mechanism of LAMC2 signaling in OSCC and the involvement of autophagy in OSCC.

Methods

To explore the mechanism by which LAMC2 is highly expressed in OSCC, we used small interfering RNA (siRNA) to knock down LAMC2 to further observe the changes in the signaling pathway. Furthermore, we used cell proliferation assays, Transwell invasion assays, and wound-healing assays to observe the changes in OSCC proliferation, invasion, and metastasis. RFP-LC3 was used to detect the level of autophagy intensity. A cell line-derived xenograft (CDX) model was used to detect the effect of LAMC2 on tumor growth in vivo.

Results

This study found that the level of autophagy was correlated with the biological behavior of OSCC. The downregulation of LAMC2 activated autophagy and inhibited OSCC proliferation, invasion, and metastasis via inhibiting the PI3K/AKT/mTOR pathway. Moreover, autophagy has a dual effect on OSCC, and the synergistic downregulation of LAMC2 and autophagy can inhibit OSCC metastasis, invasion, and proliferation via the PI3K/AKT/mTOR pathway.

Conclusions

LAMC2 interacts with autophagy to regulate OSCC metastasis, invasion, and proliferation via the PI3K/AKT/mTOR pathway. LAMC2 down-regulation can synergistically modulate autophagy to inhibit OSCC migration, invasion, and proliferation.

Evaluation of the expression level of some coding and non-coding genes in oral squamous cell carcinoma

INTRODUCTION

Oral squamous cell carcinoma (OSCC) is the most common cancers arising from the head and neck region. There is growing evidence that lncRNAs play an important role in OSCC progression. The study aims to investigate correlations between the expression levels of LncRNAs of PARROT, MYCNUT, DANCR, and KTN1-AS1 with clinicopathological characteristics and finding suitable biomarkers for OSCC.

MATERIAL AND METHOD

Total lncRNAs related to cancers and HNSC trascriptomics data were downloaded from lncRNADisease v2.0 database and xenabrowser, respectively. Then, ACO was perfomed on shared of LncRNAs between two databases. Finally, some lncRNAs were proposed as potential biomarkers. Thirty biopsies samples from patients with the OSCC and 30 healthy subjects were collected by the surgery. Questionnaires including clinical and demographic data were filled for all cases. Using Real-time PCR, the expression levels of PARROT, MYCNUT, DANCR, and KTN1-AS1 lncRNAs were quantified.

RESULT

According to the results,17 novel gene symbol was identified.All the candidate lncRNAs the expression levels of PARROT, MYCNUT, DANCR, and KTN1-AS1 were remarkably upregulated in OSCC tumors in comparison with control group (RQ: 10.00 (P < 0.0001), RQ: 2.920 (P < 0.0001), RQ: 1.623 (P = 0.002), and 4.467 (P < 0.0001), respectively). Also, we found significant associations between tumor lncRNAs expression of PARRPT and DANCER and tumor metastasis (P = 0.009, and P = 0.005, respectively). Additionally, lncRNA KTN1-AS1 expression level was significantly higher in the patients with tumor size more than 3 cm, in comparison with tumor less than 3 cm (P = 0.005). According ROC analysis, all these candidate lncRNAs can be a significant predictor for OSCC (AUC of PARROT lncRNA = 69.72%, AUC of MYCNUT = 98.22%, AUC of DANCR = 74.83%, and AUC of KTN1-AS1 = 99.22%).

CONCLUSION

we found that overexpression levels of PARROT, MYCNUT, DANCR, and KTN1-AS1 lncRNAs were correlated with poor clinicopathological characteristics in patients with OSCC. Also, PARROT, MYCNUT, DANCR, and KTN1-AS1 are novel biomarker for the detection of OSCC.

Statin Medication Improves Five-Year Survival Rates in Patients with Head and Neck Cancer: A Retrospective Case-Control Study of about 100,000 Patients

INTRODUCTION

The overall survival among head and neck cancer patients is still low, even in a time of new therapy regimes. Regarding cancer patients' survival, statin use has already proven to be associated with favorable survival outcomes. Our objective was to investigate the influence of statin medication on the overall survival of head and neck cancer patients.

METHODS

Retrospective clinical data of patients diagnosed with head and neck cancer (International Classification of Diseases codes: C00-C14) were retrieved from a real-world evidence database. The initial cohort was divided into patients with statin medication, who were assigned to building cohort I, and subjects without statin medication, who were assigned to cohort II, both matched by age, gender, and risk factors (nicotine and alcohol abuse/dependence). Subsequently, Kaplan-Meier and risk analyses were performed, and odds and hazard ratios were calculated.

RESULTS

After matching, each cohort contained 48,626 patients (cohort I = females: 15,409; (31.7%), males 33,212 (68.3%); mean age ± standard deviation (SD) at diagnosis 66.3 ± 11.4 years; cohort II = females: 15,432; (31.7%), males 33,187 (68.2%); mean age ± standard deviation (SD) at diagnosis 66.4 ± 11.5 years). Five-year survival was found to be significantly higher for cohort I, with 75.19%, respectively 70.48% for cohort II. These findings were correlated significantly with a risk of death of 15.9% (cohort I) and 17.2% (cohort II); the odds ratio was 0.91 (95% CI: 0.881-0.942) and the hazard ratio 0.80 (0.777-0.827).

CONCLUSIONS

The results indicate that the five-year survival of head and neck cancer patients is significantly improved by statin medication. As this study was conducted retrospectively, our data must be interpreted with caution, especially since other potential influencing factors and the initial tumor stage were not available.

M2 Macrophages-Derived Exosomal miRNA-23a-3p Promotes the Progression of Oral Squamous Cell Carcinoma by Targeting PTEN

Exosomes from tumor cells and immune cells regulate the tumor microenvironment through the biomolecules or microRNAs (miRNAs) they carry. This research aims to investigate the role of miRNA in exosomes derived from tumor-associated macrophages (TAMs) in the progression of oral squamous cell carcinoma (OSCC). RT-qPCR and Western blotting assays were used to determine the expression of genes and proteins in OSCC cells. CCK-8, Scratch assay and invasion-related proteins were utilized to detect the malignant progression of tumor cells. High-throughput sequencing predicted differentially expressed miRNAs in exosomes secreted by M0 and M2 macrophages. Compared with exosomes from M0 macrophages, exosomes from M2 macrophages led to enhanced proliferation and invasion of OSCC cells and inhibited their apoptosis. High-throughput sequencing results show that miR-23a-3p is differentially expressed in exosomes from M0 and M2 macrophages. MiRNA target gene database predicts that phosphatase and tensin homolog (PTEN) are target genes of miR-23a-3p. Further studies revealed that transfection of miR-23a-3p mimics inhibited PTEN expression in vivo and in vitro and promoted the malignant progression of OSCC cells, which was reversed by miR-23a-3p inhibitors. MiR-23a-3p in exosomes derived from M2 macrophages promotes malignant progression of OSCC. PTEN is a potential intracellular target of miR-23a-3p. MiR-23a-3p, an M2 macrophage-associated exosome, is a promising target for the future treatment of OSCC.

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.

Exosome-mediated long noncoding RNA (lncRNA) PART1 suppresses malignant progression of oral squamous cell carcinoma via miR-17-5p/SOCS6 axis

BACKGROUND

Exosomes derived from oral squamous cell carcinoma (OSCC) could modulate OSCC development. This study aimed to explore effects of exosome-mediated lncRNA PART1 on OSCC cells.

METHODS

This study was performed in Tianjin Medical University Cancer Institute from February 2021 to March 2022. Bioinformatic analysis was performed on the public database GEPIA (http://gepia.cancer-pku.cn/). Exosomes isolated from cell lines squamous cell carcinoma 9 (SCC9) and Centre Antoine Lacassagne-27 (CAL27) were identified by transmission electron microscope and western blot. Exosome-mediated lncRNA PART1, microRNA-17-5p(miR-17-5p) and suppressor of cytokine signaling 6(SOCS6) RNA expressions were assessed by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Cell counting kit8(CCK-8), caspase-3 activity, and flow cytometry were applied to evaluate OSCC cell viabilities and apoptosis. Meanwhile, OSCC cell migratory ability and invasiveness were evaluated using transwell assay. Bindings between miR-17-5p and lncRNA PART1 or SOCS6 were validated using the luciferase reporter test. Western blot was used for detecting the protein levels of SOCS6, phosphorylated signal transducer and activator of transcription 3 (STAT3) and STAT3.

RESULTS

: According to GEPIA, lncRNA PART1 was downregulated in OSCC tissue samples and cells, and it had a positive correlation with the good prognosis of Head and neck squamous cell cancer (HNSCC) patients. After the exosomes from OSCC cells were isolated and verified, PART1 was then confirmed to be secreted by exosomes. Further, overexpression of exosome-mediated lncRNA PART1 inhibited OSCC cell viabilities, migration, and invasiveness but facilitated OSCC cell apoptosis. PART1 upregulated SOCS6 through sponging miR-17-5p. Moreover, exosome-mediated lncRNA PART1 suppressed the phosphorylation of STAT3.

DISCUSSION

Exosome-mediated lncRNA PART1 could mediate the OSCC progression via miR-17-5p/SOCS6 axis in vitro, suggesting that lncRNA PART1 might be a target for treating OSCC.

Genome-wide DNA methylation profiling of HPV-negative leukoplakia and gingivobuccal complex cancers

BACKGROUND

Gingivobuccal complex oral squamous cell carcinoma (GBC-OSCC) is an aggressive malignancy with high mortality often preceded by premalignant lesions, including leukoplakia. Previous studies have reported genomic drivers in OSCC, but much remains to be elucidated about DNA methylation patterns across different stages of oral carcinogenesis.

RESULTS

There is a serious lack of biomarkers and clinical application of biomarkers for early detection and prognosis of gingivobuccal complex cancers. Hence, in search of novel biomarkers, we measured genome-wide DNA methylation in 22 normal oral tissues, 22 leukoplakia, and 74 GBC-OSCC tissue samples. Both leukoplakia and GBC-OSCC had distinct methylation profiles as compared to normal oral tissue samples. Aberrant DNA methylation increases during the different stages of oral carcinogenesis, from premalignant lesions to carcinoma. We identified 846 and 5111 differentially methylated promoters in leukoplakia and GBC-OSCC, respectively, with a sizable fraction shared between the two sets. Further, we identified potential biomarkers from integrative analysis in gingivobuccal complex cancers and validated them in an independent cohort. Integration of genome, epigenome, and transcriptome data revealed candidate genes with gene expression synergistically regulated by copy number and DNA methylation changes. Regularised Cox regression identified 32 genes associated with patient survival. In an independent set of samples, we validated eight genes (FAT1, GLDC, HOXB13, CST7, CYB5A, MLLT11, GHR, LY75) from the integrative analysis and 30 genes from previously published reports. Bisulfite pyrosequencing validated GLDC (P = 0.036), HOXB13 (P < 0.0001) promoter hypermethylation, and FAT1 (P < 0.0001) hypomethylation in GBC-OSCC compared to normal controls.

CONCLUSIONS

Our findings identified methylation signatures associated with leukoplakia and gingivobuccal complex cancers. The integrative analysis in GBC-OSCC identified putative biomarkers that enhance existing knowledge of oral carcinogenesis and may potentially help in risk stratification and prognosis of GBC-OSCC.

Photodynamic Therapy in Oral Cancer: A Narrative Review

Methods: A comprehensive search in PubMed, Scopus, and Google Scholar was performed using relevant keywords to structure this narrative review. Only English articles were included and assessed according to titles, abstracts, and full texts. Background: Photodynamic therapy (PDT) is applied for targeting pre-malignancy and malignancies in the head and neck, skin, lungs, and gastrointestinal tract and has been greatly promising in reducing disfigurement and morbidity. This method includes a light-sensitive medicine known as a photosensitizer and a light source used through a minimally invasive surgical tool. Objective: This study aimed to review the application of PDT in managing head and neck cancers (HNCs) and provide an overview of the most recent advances in PDT and its efficiency in increasing the long-term life quality of patients with HNC. Results: The light source irradiates light at an appropriate wavelength that can be absorbed by the sensitizer and produce cytotoxic free radicals that can kill tumor cells, impair microvasculature in the tumor microenvironment, and stimulate further inflammatory responses of the immune system. Patients with either early lesions or advanced disease conveniently accept to receive PDT in outpatient clinics. Therefore, this simple technique is considered a novel and promising approach that can be used either individually or in association with other methods. However, its application as a management method in oral malignancies has yet to be studied. PDT is also suggested as a promising adjuvant treatment with better functional results. Then, it is possible to conclude that PDT's effectiveness in treating various tumors has been shown to depend on the depth of the lesion location. Its safety is acceptable, but its limited irradiation depth confines its application in the advanced stages of cancer. Conclusions: PDT is critically applicable in the early diagnosed cancers and superficial tumors where many heads and neck lesions settle as an ideal candidate for PDT because of the possibility of accurate evaluation of lesions and providing appropriate irradiation at these sites.

An Insight into Survivin in Relevance to Hematological, Biochemical and Genetic Characteristics in Tobacco Chewers with Oral Squamous Cell Carcinoma

BACKGROUND

Survivin is an inhibitor of apoptosis protein (IAP), encoded by the Baculoviral IAP Repeat Containing 5 (BIRC5) gene located on q arm (25.3) on chromosome 17. It is expressed in various human cancers and involved in tumor resistance to radiation and chemotherapy. The genetic analysis of the BIRC5 gene and its protein survivin levels in buccal tissue related to oral squamous cell carcinoma (OSCC) in South Indian tobacco chewers has not been studied. Hence, the study was designed to quantify survivin in buccal tissue and its association with pretreatment hematological parameters and to analyze the BIRC5 gene sequence.

METHOD

In a single centric case control study, buccal tissue survivin levels were measured by ELISA. A total of 189 study subjects were categorized into Group 1 (n = 63) habitual tobacco chewers with OSCC, Group 2 (n = 63) habitual tobacco chewers without OSCC, and Group 3 (n = 63) healthy subjects as control. Retrospective hematological data were collected from Group 1 subjects and statistically analyzed. The BIRC5 gene was sequenced and data were analyzed using a bioinformatics tool.

RESULTS

Survivin protein mean ± SD in Group 1 was (1670.9 ± 796.21 pg/mL), in Group 2 it was (1096.02 ± 346.17 pg/mL), and in Group 3 it was (397.5 ± 96.1 pg/mL) with significance (p < 0.001). Survivin levels showed significance with cut-off levels of absolute monocyte count (AMC), neutrophil/lymphocyte ratio (NLR), and lymphocyte/monocyte ratio (LMR) at (p = 0.001). The unique variants found only in OSCC patients were T → G in the promoter region, G → C in exon 3, C → A, A → G, G → T, T → G, A → C, G → A in exon 4, C → A, G → T, G → C in the exon 5 region.

CONCLUSIONS

The tissue survivin level increased in OSCC patients compared to controls; pretreatment AMC, LMR, and NLR may serve as add-on markers along with survivin to measure the progression of OSCC. Unique mutations in the promoter and exons 3-5 were observed in sequence analysis and were associated with survivin concentrations.

LINC00525 promotes tumour growth and epithelial-mesenchymal transition as an oncogene in oral squamous cell carcinoma

OBJECTIVE

Oral squamous cell carcinoma (OSCC) is the most common malignant tumour in the oral cavity. OSCC is aggressive and prone to metastasis; it is associated with high mortality and short survival. In this study, we investigated the function of the long non-coding RNA LINC00525 in OSCC progression and the molecular mechanisms through in vitro and in vivo experiments.

MATERIALS AND METHODS

CCK8 assay was used to detect the effect of LINC00525 on cell viability; transwell migration and invasion assays and scratch assay were used to examine the role of LINC00525 in cell migration and invasion. Flow cytometry, RT-PCR and western blot were used to detect apoptosis indexes. Tumorigenic effects were investigated using mouse xenograft tumour models.

RESULTS

LINC00525 was associated with OSCC survival and prognosis. LINC00525 knockdown decreased cell viability and epithelial-mesenchymal transition (EMT) properties and increased apoptosis and also shortened the cell cycle of OSCC cells in vitro. The downregulation of LINC00525 reduced the growth of OSCC tumour in vivo. LINC00525 can regulate OSCC cells via the apoptotic signalling pathway.

CONCLUSION

Our results indicate that LINC00525 exhibits oncogenic functions in OSCC. LINC00525 may be a new promising and potential target for the treatment of OSCC.

Salivary protein biomarkers for diagnosis of oral squamous cell carcinoma

OSCC (Oral Squamous Cell Carcinoma) is a major health challenge in many parts of the world. It occurs most commonly in males and is associated with tobacco, pan, or areca nut consumption. One of the major challenges associated with the management of OSCC is late diagnosis. As a result, the treatment required is more aggressive, expensive, and has poor prognostic value. On the other hand, early diagnosis of OSCC can be life-saving with less aggressive treatment and a better prognosis. A diagnostic method for early diagnosis of OSCC is greatly needed. A lot of research efforts have been made to identify biomarkers that can act as tools to classify the tumor status of the patient. Various biological fluids and tissues have been explored for such studies. Saliva appears to be the most attractive biological sample with many potential advantages over other matrices such as blood or tissue. Saliva as a diagnostic fluid has the advantage of ample availability, being non-invasive and being in the vicinity of the tumor, and having a less complex composition. Our paper provides an updated review of the state of the art of research in the area of salivary biomarkers for oral squamous cell carcinoma. The paper gives an account of methods for saliva collection, followed by a brief description of various protein biomarkers discovered to date, along with their status quo.

A novel T-cell proliferation-associated gene predicts prognosis and reveals immune infiltration in patients with oral squamous cell carcinoma

OBJECTIVE

Oral squamous cell carcinoma (OSCC) is a highly malignant tumour, and the prediction of its prognosis remains challenging. The prognostic value of T-lymphocyte proliferation regulators in OSCC remains to be explored.

DESIGN

We integrated mRNA expression profiles and relevant clinical information of OSCC patients from The Cancer Genome Atlas database. The expression and function of T-lymphocyte proliferation regulators and their relationship with overall survival (OS) were analysed. The T-lymphocyte proliferation regulator signature was screened using univariate Cox regression and least absolute shrinkage and selection operator coefficients and used to construct models for prognosis and staging prediction as well as for immune infiltration analysis. Final validation was performed using single-cell sequencing database and immunohistochemical staining.

RESULTS

Most T-lymphocyte proliferation regulators in the TCGA cohort exhibited different expression levels between OSCC and paracancerous tissues. A prognostic model constructed using the T-lymphocyte proliferation regulator signature (RAN, CDK1, and CDK2) was used to categorise patients into high- and low-risk groups. The OS was significantly lower in the high-risk group than the low-risk group (p < 0.01). The predictive ability of the T-lymphocyte proliferation regulator signature was validated by receiver operating characteristic curve analysis. Immune infiltration analysis revealed different immune statuses in both groups.

CONCLUSIONS

We established a new T-lymphocyte proliferation regulator signature that can predict the prognosis of OSCC. The results of this study will contribute to studies of T-cell proliferation and the immune microenvironment in OSCC to improve prognosis and immunotherapeutic response.

A PKM2 inhibitor induces apoptosis and autophagy through JAK2 in human oral squamous cell carcinoma cells

The enzyme pyruvate kinase M2 (PKM2) is involved in glycolysis, which plays an important role in the regulation of tumor progression. In this study, we investigated the anti-tumor activity of N-(4-(3-(3-(methylamino)-3-oxopropyl)-5-(4'-(prop-2-yn-1-yloxy)-[1,1'-biphenyl]-4-yl)-1H-pyrazol-1-yl)phenyl)propiolamide (MTP), a PKM2 inhibitor, in oral squamous cell carcinoma (OSCC) cells. Our results showed that MTP inhibited cell growth with IC50 values of 0.59 μM and 0.78 μM in SCC2095 and HSC3 OSCC cells, respectively. MTP induced caspase-dependent apoptosis, which was associated with the modulation of PKM2 and oncogenic biomarkers epidermal growth factor receptor and β-catenin. In addition, MTP increased the generation of reactive oxygen species (ROS) and modulated the expression of autophagic gene products, including LC3B-II and p62. Western blotting showed that MTP inhibited Janus kinase 2 (JAK2) signaling, and JAK2 overexpression partially reversed MTP-mediated cytotoxicity. Taken together, these data indicate the potential use of MTP as a therapeutic agent for OSCC.

Knockdown of HMGB1 inhibits the crosstalk between oral squamous cell carcinoma cells and tumor-associated macrophages

Tumor-associated macrophages (TAMs), the major component of the tumor microenvironment (TME), play distinctly different roles in different tumors. High mobility group box 1 (HMGB1), a nonhistone protein in the nucleus, can perform functions during inflammation and cancers. However, the role of HMGB1 in the crosstalk between oral squamous cell carcinoma (OSCC) cells and TAMs remains unclear. Here, we established a coculture system of TAMs and OSCC cells to explore the bidirectional effect and potential mechanism of HMGB1 in OSCC cell-TAM interactions. Our results showed that HMGB1 was significantly upregulated in OSCC tissues and positively associated with tumor progression, immune cell infiltration and macrophage polarization. Then, knocking down HMGB1 in OSCC cells inhibited the recruitment and polarization of cocultured TAMs. Moreover, the knockdown of HMGB1 in macrophages not only suppressed polarization, but also inhibited cocultured OSCC cell proliferation, migration and invasion in vitro and in vivo. Mechanistically, macrophages secreted higher levels of HMGB1 than OSCC cells, and dampening endogenous HMGB1 reduced HMGB1 secretion. Both OSCC cell-generated and macrophage-endogenous HMGB1 may regulate TAM polarization by promoting receptor TLR4 expression and NF-κB/p65 activation and enhancing IL-10/TGF-β expression. HMGB1 in OSCC cells may regulate macrophage recruitment via IL-6/STAT3. In addition, TAM-derived HMGB1 may affect aggressive phenotypes of cocultured OSCC cells by regulating the immunosuppressive microenvironment through the IL-6/STAT3/PD-L1 and IL-6/NF-κB/MMP-9 pathways. In conclusion, HMGB1 may regulate the crosstalk between OSCC cells and TAMs, including modulating macrophage polarization and attraction, enhancing cytokine secretion, and remodeling and creating an immunosuppressive TME to further affect OSCC progression.

Anatomical landscape of oral squamous cell carcinoma: A single cancer center study in UAE

Objectives

This study aimed to present demographic and clinicopathological aspects of OSCC identified in Pathology service in the UAE over a 13-year period and compare these findings to a cohort of 523 cases of Head and neck squamous cell carcinoma using the Cancer Genome Atlas's cBioPortal database (http://cbioportal.org).

Material and methods

Histological examination of all hematoxylin and eosin-stained slides and assessment of all demographic and clinical information from laboratory records were performed on all OSCC diagnosed between 2005 and 2018.

Results

Males made up 71.4% of the sample of 231 OSCCs that were evaluated. The patients' average age was 55.38 years. The two most prevalent afflicted sites were the anterior two-thirds of the tongue (57.6%) and the cheek (28.1%). The most prevalent site among smokers were the floor of mouth, cheek, and jaw bones. There was a link between tumor size and numerous anatomical subsites that was shown to be highly significant. OSCC in the FOM was associated with a 25% mortality rate. Patients with OSCC of the anterior tongue and cheek had the best prognosis, with only 15.7% and 15.3% of patients dying during follow-up.

Conclusion

The present investigation found a correlation between the diverse clinicopathological characteristics of the various anatomical subsites in OSCC. Different anatomical subsites also displayed varying degrees of gene mutation.

FBXW7 promotes autophagy and inhibits proliferation of oral squamous cell carcinoma

BACKGROUND

F-box and WD repeat domain containing 7 (FBXW7) is a critical tumor suppressor. The expression of FBXW7 is decreased in oral squamous cell carcinoma (OSCC) tissues and shows diagnosis value. We aimed to investigate the influence of FBXW7 overexpression on OSCC cell proliferation and autophagy.

METHODS

In Balb/c nude mice, CAL27 xenograft tumor model was established. Western blot was employed to evaluate protein level. Messenger RNA level was analyzed by quantitative reverse transcription-polymerase chain reaction. Colony formation assay and MTT assay were employed to evaluate cell proliferation.

RESULTS

FBXW7 expression was decreased in OSCC cell lines. FBXW7 inhibited cell proliferation of SCC9 and CAL27. FBXW7 increased Autophagy related 7 (Atg7), Beclin1 (BECN1), B-cell lymphoma 2 (BCL2) -associated X (BAX), BCL2 antagonist killer (BAK), and microtubule-associated protein 1 light chain 3 (LC3) levels and decreased MCL1 and BCL2 levels in CAL27 cells. FBXW7 decreased tumor volume and weight in CAL27 xenograft tumor model. FBXW7 increased BECN1, Atg7, and LC3 levels in CAL27 xenograft tumor model.

CONCLUSION

In conclusion, decreased expression of FBXW7 is confirmed in diverse OSCC cell lines. The enhanced FBXW7 expression inhibits cancer cell proliferation and promotes autophagy in both OSCC cells and xenograft tumor model.

Aqueous-soluble components of sporoderm-removed Ganoderma lucidum spore powder promote ferroptosis in oral squamous cell carcinoma

Objective

Ferroptosis is a novel cell death process which displays a promising role in cancer treatment. However, clinically available drugs targeting ferroptosis are rarely used, and yet there are no studies reporting on inducing ferroptosis via Chinese herbal extracts. Here we explored the tumor inhibition effects of Ganoderma lucidum (G. lucidum) on oral squamous cell carcinoma (OSCC). Specifically, we aimed to clarify the biological mechanism of components in the dietary, aqueous-soluble sporoderm-removed G. lucidum spore powder (A-GSP).

Methods

Preliminary transcriptome analysis revealed the significant enrichment of the ferroptosis pathway. Cellular Fe2+, glutathione (GSH), malondialdehyde (MDA), reactive oxygen species (ROS) and lipid peroxide levels were measured to identify ferroptosis occurrence. Western blotting was used to measure ferroptosis-related proteins. Changes in mitochondria morphology and function were observed with transmission electron microscopy (TEM) and ATP detection assays. Ferroptosis inhibitor ferrostatin-1 was then used to verify the anti-tumor effects of A-GSP. Finally, nude mice xenograft models of oral cancer confirmed that A-GSP inhibited tumor growth.

Results

A-GSP promoted ferroptosis in oral cancer cells by inducing Fe2+ influx, GSH depletion, as well as lipid peroxide and ROS accumulation. Ferroptosis-related proteins exhibited corresponding changes, particularly Acyl-coA synthetase long chain family member 4 (ACSL4) increase and glutathione peroxidase 4 (GPX4) decrease. A-GSP considerably lowered mitochondrial volume and ridge number, while significantly decreasing ATP production. Ferrostatin-1 reversed all of these A-GSP-induced changes. In vivo, A-GSP exerted a ferroptosis-mediated tumor-suppressing effect without observable adverse reactions.

Conclusions

Our findings demonstrate the therapeutic potential of A-GSP for treating patients with OSCC by targeting ferroptosis.

Role of Hemidesmosomes in Oral Carcinogenesis: A Systematic Review

BACKGROUND

Oral cancers have limited diagnostic tools to aid clinical management. Current evidence indicates that alterations in hemidesmosomes, the adhesion complexes primarily involved in epithelial attachment to the basement membrane, are correlated to cancer phenotype for multiple cancers. This systematic review aimed to assess the experimental evidence for hemidesmosomal alterations, specifically in relation to oral potentially malignant disorders and oral squamous cell carcinomas.

METHODS

We conducted a systemic review to summarise the available literature on hemidesmosomal components and their role in oral pre-cancer and cancer. Relevant studies were retrieved from a comprehensive search of Scopus, Ovid MEDLINE, Ovid Embase and Web of Science.

RESULTS

26 articles met the inclusion criteria, of which 19 were in vitro studies, 4 in vivo studies, 1 in vitro and in vivo study, and 2 in vitro and cohort studies. Among them, 15 studies discussed individual alpha-6 and/or beta-4 subunits, 12 studies discussed the alpha-6 beta-4 heterodimers, 6 studies discussed the entire hemidesmosome complex, 5 studies discussed bullous pemphigoid-180, 3 studies discussed plectin, 3 studies discussed bullous pemphigoid antigen-1 and 1 study discussed tetraspanin.

CONCLUSION

Heterogeneity in cell type, experimental models, and methods were observed. Alterations in hemidesmosomal components were shown to contribute to oral pre-cancer and cancer. We conclude that there is sufficient evidence for hemidesmosomes and their components to be potential biomarkers for evaluating oral carcinogenesis.

The role of Wnt, ARL4C, and Sema3A in developmental process and disease pathogenesis

Various types of tumors, including malignant and benign ones, occur in the oral cavity. These arise from the mucosal epithelium, odontogenic epithelium, and salivary gland. To date, few major driver events in oral tumors have been identified. Accordingly, molecular targets in anti-tumor therapy for oral tumors are lacking. We focused on elucidating the function of aberrantly activated signal transduction related to oral tumor formation, especially in oral squamous cell carcinoma, ameloblastoma, and adenoid cystic carcinoma, which are raised as common oral tumors. Wnt/β-catenin-dependent pathway is involved in the developmental process, organ homeostasis and disease pathogenesis through regulating various cellular functions by enhancing transcriptional activity. Recently, we identified ADP-ribosylation factor (ARF)-like 4c (ARL4C) and Semaphorin 3A (Sema3A), the expression of which is regulated by Wnt/β-catenin-dependent pathway, and characterized their functions in the developmental process and tumor formation. This review highlights the recent advances in understanding the roles of Wnt/β-catenin-dependent pathway, ARL4C and Sema3A, as determined by pathological and experimental studies.

Targeted blockade of interleukin-8 negates metastasis and chemoresistance via Akt/Erk-NFκB axis in oral cancer

BACKGROUND

The tumor microenvironment plays a significant role in tumor growth, metastasis and chemoresistance via dysregulated signaling pathways. Toward this, an inflammatory chemokine, interleukin-8 (IL-8), is overexpressed in various cancers and is involved in tumor progression and chemoresistance. However, the mechanistic role of IL-8 in mediating metastasis and chemoresistance in oral squamous cell carcinoma (OSCC) is not known.

METHODS AND RESULTS

In the present study, we evaluated the effect of IL-8 in regulating metastasis as well as chemoresistance in OSCC cell lines. For this, IL-8 was blocked exogenously using neutralizing IL-8 monoclonal antibody and IL-8 levels were enhanced by exogenous supply of recombinant human IL-8 (rhIL-8) to OSCC cells. The epithelial-to-mesenchymal transition (EMT) was evaluated using qPCR, migration by scratch/wound healing assay and invasion ability using transwell assay. rIL-8 induced chemoresistance was studied by apoptosis assay and the nuclear localization of NFκB using immunocytochemistry. IL-8 was significantly overexpressed in OSCC patients and cell lines. While exogenous blockade of IL-8 significantly reduced EMT, migration and invasion potential in OSCC cells, IL-8 overexpression upregulated these cellular traits thereby confirming the role of IL-8 in OSCC metastasis. Exogenous blockade of IL-8 also reversed chemoresistance in cisplatin resistant OSCC subline via NFκB signaling.

CONCLUSION

IL-8 plays a crucial role in OSCC metastasis and its targeted blockade can help in management of cisplatin resistance.

Structure based High-Throughput Virtual Screening, Molecular Docking and Molecular Dynamics Study of anticancer natural compounds against fimbriae (FimA) protein of Porphyromonas gingivalis in oral squamous cell carcinoma

Oral cancer is among the most common cancer in the world. Tobacco, alcohol, and viruses have been regarded as a well- known risk factors of OCC however, 15% of OSCC cases occurred each year without these known risk factors. Recently a myriad of studies has shown that bacterial infections lead to cancer. Accumulated shreds of evidence have demonstrated the role of Porphyromonas gingivalis (P. gingivalis) in OSCC. The virulence factor FimA of P. gingivalis activates the oncogenic pathways in OSCC by upregulating various cytokines. It also led to the inactivation of a tumor suppressor protein p53. The present Insilico study uses High-Throughput Virtual Screening, molecular docking, and molecular dynamics techniques to find the potential compounds against the target protein FimA. The goal of this study is to identify the anti-cancer lead compounds retrieved from natural sources that can be used to develop potent drug molecules to treat P.gingivalis-related OSCC. The anticancer natural compounds library was screened to identify the potential lead compounds. Furthermore, these lead compounds were subjected to precise docking, and based on the docking score potential lead compounds were identified. The top docked receptor-ligand complex was subjected to molecular dynamics simulation. A study of this insilico finding provides potent lead molecules which help in the development of therapeutic drugs against the target protein FimA in OSCC. Workflow of Structure based High-Throughput Virtual Screening, Molecular Docking and Molecular Dynamics Study of anticancer natural compounds against Fimbriae (FimA) protein of P. gingivalis in oral squamous cell carcinoma.

Human papillomavirus and Epstein-Barr virus co-infection in oral and oropharyngeal squamous cell carcinomas: A systematic review and meta-analysis

Squamous cell carcinoma of the oral cavity (OSCC) is the most common head and neck malignancy. Importantly, we are experiencing an alarming rise in the incidence of oropharyngeal squamous cell carcinoma (OPSCC) globally. Oncogenic viruses, human papillomavirus (HPV) and Epstein-Barr virus (EBV), are known to be co-associated with OSCC and OPSCC cases. However, the reported incidence of HPV and EBV co-infection in OSCCs and OPSCCs globally is unknown. To address this, we performed a formal meta-analysis and systematic review on published studies that report the detection of both EBV and HPV in OSCCs and OPSCCs. Our analysis revealed 18 relevant studies out of a total of 1820 cases (1181 from the oral cavity and 639 from the oropharynx). Overall, HPV and EBV co-infection was found in 11.9% of OSCC and OPSCC cases combined (95% CI: 8-14.1%). Based on anatomical subsite, dual positivity estimates were 10.5% (95% CI: 6.7- 15.1%) for OSCC and 14.2% (95% CI: 9.1-21.3%) for OPSCC. The highest dual positivity rates described were in European countries: for OSCC 34.7% (95% CI: 25.9 - 44.6%) in Sweden and for OPSCC, 23.4% (95% CI: 16.9 - 31.5%) in Poland. Given these substantive prevalence rates, the value of detecting dual infection in the diagnosis and prognosis of these cancers deserves careful longitudinal studies, as do implications for cancer prevention and therapy. We further proposed molecular mechanisms that could explain how HPV and EBV could co-contribute to the aetiology of OSCCs and OPSCCs. This article is protected by copyright. All rights reserved.

Variations in protein expression associated with oral cancer

BACKGROUND

Differential protein expression of the oral microbiome is related to human diseases, including cancer.

OBJECTIVE

In order to reveal the potential relationship between oral bacterial protein expression in oral squamous cell carcinoma (OSCC), we designed this study.

METHODS

We obtained samples of the same patient from cancer lesion and anatomically matched normal site. Then, we used the label free quantitative technique based on liquid chromatography tandem mass spectrometry (LC-MS/MS) to analyze the bacteria in the samples of oral squamous cell carcinoma at the protein level, so as to detect the functional proteins.

RESULTS

Protein diversity in the cancer samples was significantly greater than in the normal samples. We identified a substantially higher number of the taxa than those detected in previous studies, demonstrating the presence of a remarkable number of proteins in the groups. In particular, proteins involved in energy production and conversion, proton transport, hydrogen transport and hydrogen ion transmembrane transport, ATP-binding cassette (ABC) transporter, PTS system, and L-serine dehydratase were enriched significantly in the experimental group. Moreover, some proteins associated with Actinomyces and Fusobacterium were highly associated with OSCC and provided a good diagnostic outcome.

CONCLUSION

The present study revealed considerable changes in the expression of bacterial proteins in OSCC and enrich our understanding in this point.

Low-dose arecoline regulates distinct core signaling pathways in oral submucous fibrosis and oral squamous cell carcinoma

BACKGROUND

Betel nut chewing plays a role in the pathogenesis of oral submucous fibrosis (OSF) and oral squamous cell carcinoma (OSCC). As the major active ingredient of the betel nut, the effect of arecoline and its underlying mechanism to OSF and OSCC pathogenesis remain unclear.

METHODS

Next-generation sequencing-based transcriptome and dRRBS analysis were performed on OSF and OSCC cells under low-dose arecoline exposure. Functional analyses were performed to compare the different roles of arecoline during OSF and OSCC pathogenesis, and key genes were identified.

RESULTS

In this study, we identified that low-dose arecoline promoted cell proliferation of both NFs and OSCC cells via the acceleration of cell cycle progression, while high-dose arecoline was cytotoxic to both NFs and OSCC cells. We performed for the first time the transcriptome and methylome landscapes of NFs and OSCC cells under low-dose arecoline exposure. We found distinct transcriptome and methylome profiles mediated by low-dose arecoline in OSF and OSCC cells, as well as specific genes and signaling pathways associated with metabolic disorders induced by low-dose arecoline exposure. Additionally, low-dose arecoline displayed different functions at different stages, participating in the modulation of the extracellular matrix via Wnt signaling in NFs and epigenetic regulation in OSCC cells. After exposure to low-dose arecoline, the node roles of FMOD in NFs and histone gene clusters in OSCC cells were found. Meanwhile, some key methylated genes induced by arecoline were also identified, like PTPRM and FOXD3 in NFs, SALL3 and IRF8 in OSCC cells, indicating early molecular events mediated by arecoline during OSF and OSCC pathogenesis.

CONCLUSIONS

This study elucidated the contribution of low-dose arecoline to OSF and OSCC pathogenesis and identified key molecular events that could be targeted for further functional studies and their potential as biomarkers.

Early Diagnosis of Oral Cancer and Lesions in Fanconi Anemia Patients: A Prospective and Longitudinal Study Using Saliva and Plasma

Fanconi anemia (FA) patients display an exacerbated risk of oral squamous cell carcinoma (OSCC) and oral potentially malignant lesions (OPMLs) at early ages. As patients have defects in their DNA repair mechanisms, standard-of-care treatments for OSCC such as radiotherapy and chemotherapy, give rise to severe toxicities. New methods for early diagnosis are urgently needed to allow for treatment in early disease stages and achieve better clinical outcomes. We conducted a prospective, longitudinal study wherein liquid biopsies from sixteen patients with no clinical diagnoses of OPML and/or OSCC were analyzed for the presence of mutations in cancer genes. The DNA from saliva and plasma were sequentially collected and deep-sequenced, and the clinical evaluation followed over a median time of approximately 2 years. In 9/16 FA patients, we detected mutations in cancer genes (mainly TP53) with minor allele frequencies (MAF) of down to 0.07%. Importantly, all patients that had mutations and clinical follow-up data after mutation detection (n = 6) developed oral precursor lesions or OSCC. The lead-time between mutation detection and tumor diagnosis ranged from 23 to 630 days. Strikingly, FA patients without mutations displayed a significantly lower risk of developing precursor lesions or OSCCs. Therefore, our diagnostic approach could help to stratify FA patients into risk groups, which would allow for closer surveillance for OSCCs or precursor lesions.

Tumour Necrosis Factor Alpha (TNF-α) and Oral Squamous Cell Carcinoma

Uncovering the inflammatory mechanisms underpinning initiation, progression, and promotion of oral squamous cell carcinoma (OSCC) development is fundamental to the rational pursuit of targeted therapeutics. Here we present a review of the current knowledge of the role of TNF-α in the aetiology, pathogenesis, and potential therapies with regards to OSCC. TNF-α is worthy of particular attention in OSCC, with its presence demonstrated to enhance cell proliferation and its downregulation demonstrated to inhibit proliferation and migration in other carcinomas in both in vitro and in vivo models and oral cancer patients. Increased TNF-α in the OSCC tumour microenvironment has been demonstrated to favour invasion through promotion of firstly the pro-inflammatory, pro-invasive phenotypes of OSCC cells and secondly its paracrine mechanism mediating recruitment and activation of inflammatory cells. Polymorphisms affecting the gene expression of TNF-α have been strongly associated with an increased risk for oral squamous cell carcinoma. A number of studies have considered TNF-α within biofluids, including saliva and serum, as a potential biomarker for the early detection of OSCC, as well as its staging, differentiation, and prognosis. The broad and multifaceted role that TNF-α plays in many inflammatory states presents an obvious confounder, particularly with demonstrated increased TNF-α levels in common oral disease states. Lastly, biologic agents targeting TNF-α are currently in clinical use for immune-mediated inflammatory rheumatological and gastrointestinal diseases. There is the potential that these biological agents might have an adjunctive role in OSCC prevention and treatment.

Hsa_circ_0009128 mediates progression of oral squamous cell carcinoma by influencing MMP9

OBJECTIVES

The objective of this study was to explore the role and mechanism of an abnormally expressed circRNA (hsa_circ_0009128) in the progression of oral squamous cell carcinoma.

MATERIALS AND METHODS

We conducted quantitative real-time PCR (qRT-PCR) to assess the expression of hsa_circ_0009128 in 51 paired OSCC tissues and analyzed the correlation between clinical features and aberrant expression of hsa_circ_0009128 in OSCC. CCK-8 assays, colony formation assays, transwell assays, and wound healing assays were used to analyze the effect of hsa_circ_0009128 on cell proliferation and migration. Furthermore, epithelial-mesenchymal transition (EMT)-related proteins were evaluated by Western blotting.

RESULTS

Hsa_circ_0009128 was upregulated in both OSCC tissues and cell lines, and high hsa_circ_0009128 correlated with advanced TNM stage (p = 0.046) and lymph node metastasis (p = 0.018) in OSCC patients. Knockdown of hsa_circ_0009128 inhibited cell proliferation and migration. Mechanistically, hsa_circ_0009128 downregulation decreased EMT in OSCC cells as shown by elevated levels of E-cadherin and decreased N-cadherin, vimentin, and MMP9.

CONCLUSIONS

The circRNA hsa_circ_0009128 correlates with malignant progression of OSCC. Hsa_circ_0009128 stimulates proliferation and migration in OSCC cells by targeting MMP9 to activate EMT.

Expression of Minichromosome Maintenance Protein 2 (MCM2) in Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma: A Systematic Review

The histopathological investigations of oral lesions are a basic approach for diagnosing ongoing cancer or pre-cancer associated pathological attributes in the dissected biopsy. The early detection and management of potentially malignant disorders of the lip and oral cavity that require intervention may reduce malignant transformations, or in case any malignancy is detected during surveillance, the appropriate treatment may improve survival rates. This would guide the clinicians to decide the appropriate treatment modality or lesion to achieve a more favorable prognosis. MCM2 protein is involved in DNA replication providing additional information about the prognosis of neoplasms. Some authors have pointed out that MCM proteins have been inversely correlated with salivary tumour differentiation and therefore could be an indicator of proliferation potential. Therefore, it is essential to find the expression of the MCM2 gene in oral leukoplakia and oral squamous cell carcinoma. Electronic databases like Ebscohost, Livivo, Google Scholar and PubMed were searched. Based on the inclusion and exclusion criteria, 2 reviewers (MS and SN) independently selected the relevant articles. Any disagreement was discussed until a consensus was reached. We used the QUADAS-2 tool to assess the quality of the included studies over four key domains: patient selection, index test, reference standard and flow and timing of participants through the study. 10 out of 57 titles were found to meet the eligibility criteria. Biopsied tissue with immunohistochemical staining or advanced diagnostic studies were included. A total of 901 samples were included in the study and different groups were normal oral mucosa (NOM), oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC). MCM2 proteins are useful diagnostic markers for distinguishing malignant from benign epithelial dysplasia and for early detection and diagnosis of OSCC as an adjunct to clinicopathological parameters.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-022-03296-7.

Epstein-Barr Virus Detection and LMP-1 Expression in Thai Patients with Oral Squamous Cell Carcinoma

BACKGROUND

To date, high-risk human papillomavirus (HPV) is primarily linked to oropharyngeal carcinoma, but only a small subset of oral squamous cell carcinoma (OSCC) is truly driven by high-risk HPV. In addition, Epstein-Barr virus (EBV) is another potential oncogenic virus for OSCC development. This study aims to investigate the role of EBV infection in Thai patients with OSCC.

METHODS

Forty-seven formalin-fixed paraffin-embedded specimens of OSCC were obtained. EBV DNA was detected by polymerase chain reaction analysis using primers for LMP-1 region of EBV. EBV-positive OSCC cases were subjected to LMP-1 immunohistochemical analysis and EBV-encoded small RNA (EBER) in situ hybridization to determine EBV cellular localization in OSCC. LMP-1 immunohistochemical analysis was also performed in all EBV-negative OSCC cases.

RESULTS

Of the 47 OSCC specimens, ten (21%) exhibited EBV DNA by PCR analysis. Seven of ten (70%) EBV-positive specimens showed high-grade LMP-1 expression by immunohistochemistry. However, no EBER expression was detected in all EBV-positive OSCC specimens. In EBV-negative specimens, LMP-1 was also negative except in 3 specimens which showed low grade expression of LMP-1.

CONCLUSION

The prevalence of EBV infection in OSCC in this group of Thai patients was 21%. Most of EBV-positive OSCC cases showed LMP-1 expression but a lack of EBER expression. From our findings, we presume that EBV may take some roles in OSCC development in this group of participants.

LINC00173 blocks GATA6-mediated transcription of COL5A1 to affect malignant development of oral squamous cell carcinoma

BACKGROUND

Aberrant expression of collagen type V alpha 1 chain (COL5A1) has been linked to several forms of human cancers. In this work, we focused on the interaction of the LINC00173/GATA binding protein 6 (GATA6)/COL5A1 axis in the malignant property of oral squamous cell carcinoma (OSCC) cells.

METHODS

We analyzed six publicly accessible datasets GSE160042, GSE74530, GSE138206, GSE23558, GSE31853 and GSE146483 to identify aberrantly expressed genes in OSCC. The expression of COL5A1 in OSCC tissues and cell lines was examined by reverse transcription-quantitative polymerase chain reaction and/or immunohistochemistry. The regulatory mechanism responsible for COL5A1 transcription was predicted via bioinformatics systems, and the interactions of LINC00173, GATA6, and COL5A1 were identified by immunoprecipitation and luciferase assays. Overexpression or downregulation of COL5A1, GATA6, and LINC00173 were induced in OSCC cell lines to determine their roles in the malignant phenotype of the OSCC cells in vitro and in vivo.

RESULTS

COL5A1 showed elevated expression in OSCC tissues and cells. The COLA51 knockdown suppressed proliferation, migration and invasiveness, apoptosis resistance, and pro-angiogenic ability of OSCC cells, and it suppressed the growth and dissemination of xenograft tumors in vivo. GATA6 bound to COL5A1 promoter to activate its transcription, whereas LINC00173 bound to GATA6 to block this transcriptional activation. Overexpression of GATA6 or COL5A1 promoted the malignant phenotype of the OSCC cells, which were blocked upon LINC00173 upregulation.

CONCLUSION

This work demonstrates that LINC00173 blocks GATA6-mediated transcription of COL5A1 to affect malignant development of OSCC.

CXCL12 is expressed by skeletal muscle cells in tongue oral squamous cell carcinoma

BACKGROUND

The CXCL12/CXCR4 axis plays a pivotal role in the progression of various malignancies, including oral squamous cell carcinoma (OSCC). In this study, we aimed to clarify the biological and clinical significance of CXCL12 in the tumor microenvironment of OSCCs.

METHODS

Publicly available single-cell RNA-sequencing (RNA-seq) datasets were used to analyze CXCL12 expression in head and neck squamous cell carcinomas (HNSCC). Immunohistochemical analysis of CXCL12, α-smooth muscle antigen (α-SMA), fibroblast activation protein (FAP) and CD8 was performed in a series of 47 surgically resected primary tongue OSCCs. Human skeletal muscle cells were co-cultured with or without OSCC cells, after which CXCL12 expression was analyzed using quantitative reverse-transcription PCR.

RESULTS

Analysis of the RNA-seq data suggested CXCL12 is abundantly expressed in stromal cells within HNSCC tissue. Immunohistochemical analysis showed that in grade 1 primary OSCCs, CXCL12 is expressed in both tumor cells and muscle cells. By contrast, grade 3 tumors were characterized by disruption of muscle structure and reduced CXCL12 expression. Quantitative analysis of CXCL12-positive areas within tumors revealed that reduced CXCL12 expression correlated with poorer overall survival. Levels of CXCL12 expression tended to inversely correlate α-SMA expression and positively correlate with infiltration by CD8+ lymphocytes, though these relations did not reach statistical significance. CXCL12 was significantly upregulated in muscle cells co-cultured with OSCC cells.

CONCLUSION

Our results suggest that tongue OSCC cells activate CXCL12 expression in muscle cells, which may contribute to tumor progression. However, CXCL12 is reduced in advanced OSCCs due to muscle tissue destruction.

Hinokitiol Inhibits the Viability of Oral Squamous Carcinoma Cells by Inducing Apoptosis and Autophagy

BACKGROUND/AIM

Oral squamous cell carcinoma (OSCC) is one of the deadliest cancers, with approximately ~500,000 new diagnosed cases and 145,000 deaths worldwide, per year. The incidence of new cases continues to increase in developing countries. This study aimed to investigate the effect of hinokitiol on cell viability in OSCC cells.

MATERIALS AND METHODS

The anticancer effect and mechanism of action of hinokitiol in OSCC cells were analyzed by cell viability assays and cell cycle analysis using flow cytometry, while apoptosis and autophagy-related protein expression was measured using western blot.

RESULTS

The results showed that hinokitiol concentration-dependently reduced the viability of SCC4 and SCC25 cells by downregulating the levels of cell-cycle mediators, such as cyclin B1, cyclin D1 and cyclin-dependent kinase-1 (CDK1). Furthermore, hinokitiol promoted apoptosis in SCC25 cells based on the presence of active cleaved caspase-3. Hinokitiol also induced autophagy by promoting the accumulation of the microtubule-associated protein light chain 3B (LC3B) and the expression of the sequestosome-1 (p62/SQSTM).

CONCLUSION

Hinokitiol exhibits anti-proliferation activity and has pro-apoptotic effects on OSCC cell lines.

The Emerging Role of MMP12 in the Oral Environment

Matrix metalloproteinase-12 (MMP12), or macrophage metalloelastase, plays important roles in extracellular matrix (ECM) component degradation. Recent reports show MMP12 has been implicated in the pathogenesis of periodontal diseases. To date, this review represents the latest comprehensive overview of MMP12 in various oral diseases, such as periodontitis, temporomandibular joint dysfunction (TMD), orthodontic tooth movement (OTM), and oral squamous cell carcinoma (OSCC). Furthermore, the current knowledge regarding the distribution of MMP12 in different tissues is also illustrated in this review. Studies have implicated the association of MMP12 expression with the pathogenesis of several representative oral diseases, including periodontitis, TMD, OSCC, OTM, and bone remodelling. Although there may be a potential role of MMP12 in oral diseases, the exact pathophysiological role of MMP12 remains to be elucidated. Understanding the cellular and molecular biology of MMP12 is essential, as MMP12 could be a potential target for developing therapeutic strategies targeting inflammatory and immunologically related oral diseases.

Machilin D Promotes Apoptosis and Autophagy, and Inhibits Necroptosis in Human Oral Squamous Cell Carcinoma Cells

Oral squamous cell carcinoma (OSCC) accounts for about 90% of all head and neck cancers, the prognosis is very poor, and there are no effective targeted therapies. Herein, we isolated Machilin D (Mach), a lignin, from the roots of Saururus chinensis (S. chinensis) and assessed its inhibitory effects on OSCC. Herein, Mach had significant cytotoxicity against human OSCC cells and showed inhibitory effects against cell adhesion, migration, and invasion by inhibiting adhesion molecules, including the FAK/Src pathway. Mach suppressed the PI3K/AKT/mTOR/p70S6K pathway and MAPKs, leading to apoptotic cell death. We investigated other modes of programmed cell death in these cells and found that Mach increased LC3I/II and Beclin1 and decreased p62, leading to autophagosomes, and suppressed the necroptosis-regulatory proteins RIP1 and MLKL. Our findings provide evidence that the inhibitory effects of Mach against human YD-10B OSCC cells are related to the promotion of apoptosis and autophagy and inhibition of necroptosis and are mediated via focal adhesion molecules.

Stain color translation of multi-domain OSCC histopathology images using attention gated cGAN

Oral Squamous Cell Carcinoma (OSCC) is the most prevalent type of oral cancer across the globe. Histopathology examination is the gold standard for OSCC examination, where stained histopathology slides help in studying and analyzing the cell structures under a microscope to determine the stages and grading of OSCC. One of the staining methods popularly known as H&E staining is used to produce differential coloration, highlight key tissue features, and improve contrast, which makes cell analysis easier. However, the stained H&E histopathology images exhibit inter and intra-variation due to staining techniques, incubation times, and staining reagents. These variations negatively impact computer-aided diagnosis (CAD) and Machine learning algorithm's accuracy and development. A pre-processing procedure called stain normalization must be employed to reduce stain variance's negative impacts. Numerous state-of-the-art stain normalization methods are introduced. However, a robust multi-domain stain normalization approach is still required because, in a real-world situation, the OSCC histopathology images will include more than two color variations involving several domains. In this paper, a multi-domain stain translation method is proposed. The proposed method is an attention gated generator based on a Conditional Generative Adversarial Network (cGAN) with a novel objective function to enforce color distribution and the perpetual resemblance between the source and target domains. Instead of using WSI scanner images like previous techniques, the proposed method is experimented on OSCC histopathology images obtained by several conventional microscopes coupled with cameras. The proposed method receives the L* channel from the L*a*b* color space in inference mode and generates the G(a*b*) channel, which are color-adapted. The proposed technique uses mappings learned during training phases to translate the source domain to the target domain; mapping are learned using the whole color distribution of the target domain instead of one reference image. The suggested technique outperforms the four state-of-the-art methods in multi-domain OSCC histopathological translation, the claim is supported by results obtained after assessment in both quantitative and qualitative ways.

The expression of ACAT1 in oral squamous cell carcinoma and the adjacent pre-tumour tissue

Background

Altered acetyl CoA acetyltransferase 1 (ACAT1) expression has been reported in diverse cancers. However, the expression of ACAT1 and its prognostic value in oral squamous cell carcinoma (OSCC) has remained unexplored.

Materials and methods

In this study, the expression of ACAT1 was analysed by immunohistochemistry (IHC) in 61 OSCC patients and compared between OSCC and adjacent pre-tumour tissue of 21 patients.

Results

The expression of ACAT1 in OSCC tumours is heterogeneous between patients. More specifically, 52.38% of the patients show low expression of ACAT1 in both tumour and adjacent pre-tumour tissues, 9.52% of the patients show high expression of ACAT1 in both tumour and adjacent pre-tumour, 19.05% of the patients have high expression of ACAT1 in tumour tissue and low expression of ACAT1 in adjacent pre-tumour tissue and another 19.05% of the patients have low expression of ACAT1 in tumour tissue and high expression of ACAT1 in adjacent pre-tumour tissue.

Conclusion

Comparison of ACAT1 expression, one of the key enzymes in the ketone body metabolic pathway, divided OSCC patients into two groups: 1) similar expression and 2) different expression of ACAT1 in tumour and adjacent pre-tumour tissue. No significant association between ACAT1 levels and overall survival was observed.

Tumor Immune Microenvironment Heterogeneity at the Invasion Front and Tumor Center in Oral Squamous Cell Carcinoma as a Perspective of Managing This Cancer Entity

BACKGROUND

Evaluating the tumor microenvironment and its influence on clinical management and therapy response is becoming increasingly important. However, only a few studies deal with the spatial distribution of immune cells within the tumor. This study aimed to describe the topology of immune cells in the microenvironment of oral squamous cell carcinoma (OSCC) sectioned by tumor invasion front and tumor center and to test their prognostic relevance regarding patient survival.

METHODS

A total of 55 OSCC patient specimens were collected retrospectively. The cancer tissue was immunohistochemically stained using an automated tissue stainer Ventana Benchmark Ultra (Roche) and analyzed using discrete expression marker profiles on immune cells. We investigated CD4+ lymphocytes, CD8+ lymphocytes, CD68+ macrophages, CD163+ macrophages, and M1 macrophages regarding their spatial distribution.

RESULTS

The statistical analysis revealed that the quantity and distribution of CD4+ (p = 0.007), CD8+ (p < 0.001), CD68+ (p < 0.001), CD163+ cells (p = 0.004), and M1 (p < 0.001) macrophages were significantly higher at the invasion front compared to the tumor center in all observed cases. However, high and low immune cell counts in the tumor center and invasion front were not associated with overall survival.

CONCLUSION

Our results show two distinct immune microenvironments of the tumor center compared to the invasion front. Future studies are needed to explore how these results can be leveraged to improve patient therapy and outcome.

Screening and identification of miR-181a-5p in oral squamous cell carcinoma and functional verification in vivo and in vitro

BACKGROUND

Oral squamous cell carcinoma (OSCC) is a common malignant tumor associated with poor prognosis. MicroRNAs (miRNAs) play crucial regulatory roles in the cancer development. However, the role of miRNAs in OSCC development and progression is not well understood.

METHODS

We sought to establish a dynamic Chinese hamster OSCC animal model, construct miRNA differential expression profiles of its occurrence and development, predict its targets, and perform functional analysis and validation in vitro.

RESULTS

Using expression and functional analyses, the key candidate miRNA (miR-181a-5p) was selected for further functional research, and the expression of miR-181a-5p in OSCC tissues and cell lines was detected. Subsequently, transfection technology and a nude mouse tumorigenic model were used to explore potential molecular mechanisms. miR-181a-5p was significantly downregulated in human OSCC specimens and cell lines, and decreased miR-181a-5p expression was observed in multiple stages of the Chinese hamster OSCC animal model. Moreover, upregulated miR-181a-5p significantly inhibited OSCC cell proliferation, colony formation, invasion, and migration; blocked the cell cycle; and promoted apoptosis. BCL2 was identified as a target of miR-181a-5p. BCL2 may interact with apoptosis- (BAX), invasion- and migration- (TIMP1, MMP2, and MMP9), and cell cycle-related genes (KI67, E2F1, CYCLIND1, and CDK6) to further regulate biological behavior. Tumor xenograft analysis indicated that tumor growth was significantly inhibited in the high miR-181a-5p expression group.

CONCLUSION

Our findings indicate that miR-181a-5p can be used as a potential biomarker and provide a novel animal model for mechanistic research on oral cancer.

Metformin inhibits oral squamous cell carcinoma progression through regulating RNA alternative splicing

AIMS

Oral squamous cell carcinoma (OSCC) is considered as the sixth most common cancer worldwide characterized by high invasiveness, high metastasis rate and high mortality. It is urgent to explore novel therapeutic strategies to overcome this feature. Metformin is currently a strong candidate anti-tumor drug in multiple cancers. However, whether metformin could inhibit cancer progression by regulating RNA alternative splicing remains largely unknown.

MAIN METHODS

Cell proliferation and growth ability of CAL-27 and UM-SCC6 were analyzed by CCK8 and colony formation assays. Cell migration was judged by wound healing assay. Mechanistically, RNA-seq was applied to systematically identify genes that are regulated by metformin. The expression of metformin-regulated genes was determined by real-time quantitative PCR (RT-qPCR). Metformin-regulated alternative splicing events were confirmed by RT-PCR.

KEY FINDINGS

We demonstrated that metformin could significantly inhibit the proliferation and migration of oral squamous cell carcinoma cells. Mechanistically, in addition to transcriptional regulation, metformin induces a wide range of alternative splicing alteration, including genes involved in centrosome, cellular response to DNA damage stimulus, GTPase binding, histone modification, catalytic activity, regulation of cell cycle process and ATPase complex. Notably, metformin specifically modulates the splicing of NUBP2, a component of the cytosolic iron-sulfur (Fe/S) protein assembly (CIA). Briefly, metformin favors the production of NUBP2-L, the long splicing isoform of NUBP2, thereby inhibiting cancer cell proliferation.

SIGNIFICANCE

Our findings provide mechanistic insights of metformin on RNA alternative splicing regulation, thus to offer a potential novel route for metformin to inhibit cancer progression.

Is CCL2 an Important Mediator of Mast Cell-Tumor Cell Interactions in Oral Squamous Cell Carcinoma?

In this study, we aimed to evaluate the influence of interactions between mast cells (MCs) and oral squamous cell carcinoma (OSCC) tumor cells on tumor proliferation and invasion rates and identify soluble factors mediating this crosstalk. To this end, MC/OSCC interactions were characterized using the human MC cell line LUVA and the human OSCC cell line PCI-13. The influence of an MC-conditioned (MCM) medium and MC/OSCC co-cultures on the proliferative and invasive properties of the tumor cells was investigated, and the most interesting soluble factors were identified by multiplex ELISA analysis. LUVA/PCI-13 co-cultures increased tumor cell proliferation significantly (p = 0.0164). MCM reduced PCI-13 cell invasion significantly (p = 0.0010). CC chemokine ligand 2 (CCL2) secretion could be detected in PCI-13 monocultures and be significantly (p = 0.0161) increased by LUVA/PCI-13 co-cultures. In summary, the MC/OSCC interaction influences tumor cell characteristics, and CCL2 could be identified as a possible mediator.

Photodynamic therapy in oral cancer: a review of clinical studies

A significant mortality rate is associated with oral cancer, particularly in cases of late-stage diagnosis. Since the last decades, oral cancer survival rates have only gradually improved despite advances in treatment. This poor success rate is mainly due to the development of secondary tumors, local recurrence, and regional failure. Invasive treatments frequently have a negative impact on the aesthetic and functional outcomes of survivors. Novel approaches are thus needed to manage this deadly disease in light of these statistics. In photodynamic therapy (PDT), a light-sensitive medication called a photosensitizer is given first, followed by exposure to light of the proper wavelength that matches the absorbance band of the photosensitizer. The tissue oxygen-induced cytotoxic free radicals kill tumor cells directly, harm the microvascular structure, and cause inflammatory reactions at the targeted sites. In the case of early lesions, PDT can be used as a stand-alone therapy, and in the case of advanced lesions, it can be used as adjuvant therapy. The current review article discussed the uses of PDT in oral cancer therapy based on recent advances in this field.

SCARA5 inhibits oral squamous cell carcinoma via inactivating the STAT3 and PI3K/AKT signaling pathways

Oral squamous cell carcinoma (OSCC) is a common tumor in the world. Despite the rapid development of medical care, OSCC is also accompanied by high incidence and mortality every year. Therefore, it is still necessary to continuously develop new methods or find new targets to treat OSCC. Previous research showed that scavenger receptor class A member 5 (SCARA5) was one of the potential biomarkers of OSCC, and its expression is significantly low in OSCC. This study aimed to explore the role and related molecular mechanisms of SCARA5 in OSCC. In this study, we found that the SCARA5 expression was lower in CAL-27 and SCC-9 cells than that in human normal oral epithelial keratinocytes. SCARA5 overexpression significantly inhibited cell proliferation and induced apoptosis of CAL-27 and SCC-9 cells. In addition, SCARA5 repressed OSCC cell epithelial-mesenchymal transformation (EMT), evidenced by increased E-cadherin expression and reduced N-cadherin expression. Finally, we found that SCARA5 could suppress STAT3, PI3K, and AKT phosphorylation. Therefore, SCARA5 was related to STAT3 and PI3K/AKT signaling pathways in OSCC. In conclusion, SCARA5 inhibited the proliferation and EMT and induced the apoptosis of OSCC cells through the inhibition of STAT3 and PI3K/AKT signaling pathways, thereby exerting a tumor suppressor effect.

Therapeutic Potential of Dimethyl Fumarate in Counteract Oral Squamous Cell Carcinoma Progression by Modulating Apoptosis, Oxidative Stress and Epithelial-Mesenchymal Transition

Oral squamous cell carcinoma (OSCC) is a common human tumor, that originates from buccal mucosa and the tongue, associated with a high mortality rate. Currently, the treatment for OSCC involves surgery, chemotherapy and radiotherapy; however, survival outcomes for OSCC patients remain poor. For this reason, it is necessary to investigate new therapeutic strategies to counteract the progression of OSCC. In this study, we aimed to evaluate the role of dimethyl fumarate (DMF) in modulation of OSCC progression, both in vitro and in an in vivo orthotopic xenograft model. In vitro results revealed that DMF was able to reduce the expression of anti-apoptotic factors as BCL-2 and increased the expression of pro-apoptotic factors as Bax, Caspase-3 and BID. DMF appears to be involved in the modulation of oxidative stress mediators, such as MnSOD and HO-1. Furthermore, DMF showed to reduce the migratory ability of tumor cells and to modulate the expression of markers of epithelial-mesenchymal transition (EMT), as N-cadherin and E-cadherin. The in vivo study confirmed the data obtained in vitro significantly decreasing tumor mass and also reducing oxidative stress and apoptosis. Therefore, based on these results, the use of DMF could be considered a promising strategy to counteract oral cancer progression.

Statin Use Ameliorates Survival in Oral Squamous Cell Carcinoma-Data from a Population-Based Cohort Study Applying Propensity Score Matching

The anti-cancer properties of statins have attracted much attention recently, but little is known about the prognostic role of statins in oral squamous cell carcinoma (OSCC). In a retrospective approach, we analyzed a population-based cohort of 602 OSCC patients with primary curative tumor resection to negative margins and concomitant neck dissection between 2005-2017. Long-term medication with statins was correlated with overall survival (OAS) as well as recurrence-free survival (RFS) using uni- and multivariable Cox regression. Additionally, propensity score matching was applied to adjust for confounders. Statin use was present in 96 patients (15.9%) at a median age of 65.7 years. Statin treatment correlated with ameliorated survival in multivariable Cox regression in the complete cohort (OAS: HR 0.664; 95% CI 0.467-0.945, p = 0.023; RFS: HR 0.662; 95% CI 0.476-0.920, p = 0.014) as well as matched-pair cohort of OSCC patients (OAS: HR 0.691; 95% CI 0.479-0.997, p = 0.048; RFS: HR 0.694; 95% CI 0.493-0.976, p = 0.036) when compared to patients not taking statins at time of diagnosis. These findings were even more pronounced by sub-group analysis in the matched-pair cohort (age < 70 years). These data indicate that statin use might ameliorate the oncological outcome in primarily resected OSCC patients, but prospective clinical trials are highly recommended.

LncRNA NEAT2 regulates oral squamous cell carcinoma progression via VEGFB and TGF-β/Smad3 pathway

BACKGROUND

lncRNAs are involved in OSCC. This study investigated the functions and new mechanisms of NEAT2 in OSCC.

METHODS

RT-qPCR detected NEAT2 and VEGFB expression levels in OSCC cells and HOECs. Cellular proliferation, apoptosis and EMT process were evaluated after NEAT2 or VEGFB regulation. TGF-β/Smad3 pathway was evaluated using Western blot. TGF-β/Smad3 inhibitor SIS3 and TGF-βwere used to regulate the signaling pathway. Stably transfected OSCC cells were injected subcutaneously to establish the subcutaneous model, and the cells were injected into the tail veins of nude mice to establish the lung metastasis models.

RESULTS

Expression of NEAT2 and VEGFB were higher in OSCC cells. Knockdown of NEAT2 or VEGFB led to lower cell proliferation and EMT and induced apoptosis in OSCC cells. NEAT2 knockdown could inhibit VEGFB and inactivated the TGF-β/Smad3 signaling pathway. VEGFB inhibition could aggravate the signaling inactivation. Inhibition or activation of the pathway regulated the cell viability and curbed EMT. Knockdown of NEAT2 could inhibit the tumor growth and suppress metastasis.

CONCLUSION

NEAT2 downregulation inhibited cell proliferation and EMT through VEGFB and TGF-β/Smad3 pathway in vitro, disclosing a new regulatory mechanism in OSCC. In addition, downregulation of NEAT2 could inhibit the tumor growth and metastasis.

A20 as a Potential New Tool in Predicting Recurrence and Patient's Survival in Oral Squamous Cell Carcinoma

A20, known as a potent inhibitor of NF-κB signaling, has been characterized in numerous clinical as well as preclinical studies. Recently, especially in various malignant diseases, the prognostic and therapeutic relevance of A20 was investigated. In oral squamous cell carcinoma (OSCC) however, the characterization of A20 is uncharted territory. We analyzed a tissue microarray (TMA) of 229 surgically-treated OSCC patients (2003-2013). Immunohistochemical (IHC) stainings were performed for A20 and CD3; additionally, standard haematoxylin-eosin staining was applied. IHC findings were correlated with a comprehensive dataset, comprising clinical and pathohistological information. A20 expression was analyzed in tumor cells as well as in tumor infiltrating lymphocytes (TILs) and correlated with the overall survival (OS) and recurrence-free survival (RFS) using uni- and multivariable Cox regression. The median follow-up time was 10.9 years and the A20 expression was significantly decreased in CD3+ TILs compared to mucosa-infiltrating lymphocytes (MILs). In the Kaplan-Meier analyses, higher A20 expression in TILs was correlated with better OS (p = 0.017) and RFS (p = 0.020). In the multivariable survival analysis, A20 overexpression correlated with improved OS (HR: 0.582; 95% CI 0.388-0.873, p = 0.009) and RFS (HR 0.605; 95% CI 0.411-0.889, p = 0.011). Our results indicate a novel prognostic role for A20 in OSCC. Due to its elevated expression in TILs, further research is highly desirable, which therefore could offer new therapeutic opportunities for patients suffering from OSCC.

Glycolysis-Related Gene Analyses Indicate That DEPDC1 Promotes the Malignant Progression of Oral Squamous Cell Carcinoma via the WNT/β-Catenin Signaling Pathway

Increasing evidence suggests that aerobic glycolysis is related to the progression of oral squamous cell carcinoma (OSCC). Hence, we focused on glycolysis-related gene sets to screen for potential therapeutic targets for OSCC. The expression profiles of OSCC samples and normal controls were obtained from The Cancer Genome Atlas (TCGA). Then, the differentially expressed gene sets were selected from the official GSEA website following extraction of the differentially expressed core genes (DECGs). Subsequently, we tried to build a risk model on the basis of DECGs to predict the prognosis of OSCC patients via Cox regression analysis. Furthermore, crucial glycolysis-related genes were selected to explore their biological roles in OSCC. Two active glycolysis-related pathways were acquired and 66 DECGs were identified. Univariate Cox regression analysis showed that six genes, including HMMR, STC2, DDIT4, DEPDC1, SLC16A3, and AURKA, might be potential prognostic factors. Subsequently, a risk formula consisting of DEPDC1, DDIT4, and SLC16A3 was established on basis of the six molecules. Furthermore, DEPDC1 was proven to be related to advanced stage cancer and lymph node metastasis. Moreover, functional experiments suggested that DEPDC1 promoted the aerobic glycolysis, migration, and invasion of OSCC via the WNT/β-catenin pathway. The risk score according to glycolysis-related gene expression might be an independent prognostic factor in OSCC. In addition, DEPDC1 was identified as playing a carcinogenic role in OSCC progression, suggesting that DEPDC1 might be a novel biomarker and therapeutic target for OSCC.