Distant metastasis from oral cancer: A review and molecular biologic aspects

The risk and prognostic factors for lung metastases in oral squamous cell carcinoma: A population-based analysis of the SEER database

PURPOSE

This study aimed to describe the risk and prognostic factors associated with lung metastases among oral squamous cell carcinoma (OSCC) patients, further to establish a nomogram model to predict the risk of lung metastases.

METHODS

Data on OSCC patients was retrieved from the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2019. Univariable and multivariable logistic and Cox regression models were used to explore the risk factors for developing lung metastases, further the predictive nomogram was constructed.

RESULTS

19, 606 OSCC patients meets the inclusion criteria and were enrolled into this study. Of which, 221 cases have lung metastases at initial diagnosis. Multivariate logistic regression analysis indicated race, T stage, N stage as well as bone metastases, liver metastases were independently associated the development of lung metastases. The diagnostic nomogram for developing lung metastases was constructed, the c-index for this model was 0.830 (0.804-0.856). Both the ROC curve and calibration curves revealed accurate predictability. DCA curve displayed the established nomogram model had good clinical applicability for the prediction of lung metastases. The median OS of OSCC patients with lung metastases was 7.0 months (6.0-9.0), and the 6-months, 12-months, 24-month OS rates were 54.5%, 30.9%, 17.7%, respectively. The multivariate Cox analysis showed that chemotherapy and liver metastases were independently associated with both OS and CSS.

CONCLUSION

This study determined the risk and prognostic factors for lung metastases among OSCC patients and the established nomogram had good calibration and discrimination for predicting lung metastases.

Oral Health and Older Adults: A Narrative Review

Oral health's association with general health, morbidity, and mortality in older adults highlights its importance for healthy aging. Poor oral health is not an inevitable consequence of aging, and a proactive, multidisciplinary approach to early recognition and treatment of common pathologies increases the likelihood of maintaining good oral health. Some individuals may not have regular access to a dentist, and opportunities to improve oral health may be lost if health professionals fail to appreciate the importance of oral health on overall well-being and quality of life. The authors of this narrative review examined government websites, the American Dental Association Aging and Dental Health website, and the Healthy People 2030 oral objectives and identified xerostomia, edentulism, caries, periodontitis, and oral cancer as five key topics for the non-dental provider. These conditions are associated with nutritional deficiencies, poorer quality of life, increased risk of disease development and poorer outcomes for cardiovascular disease, diabetes, and other systemic conditions prevalent among older adults. It is important to note that there is a bi-directional dimension to oral health and chronic diseases, underscoring the value of a multidisciplinary approach to maintaining oral health in older adults.

Lidocaine induces apoptosis in head and neck squamous cell carcinoma through activation of bitter taste receptor T2R14

Head and neck squamous cell carcinomas (HNSCCs) have high mortality and significant treatment-related morbidity. It is vital to discover effective, minimally invasive therapies that improve survival and quality of life. Bitter taste receptors (T2Rs) are expressed in HNSCCs, and T2R activation can induce apoptosis. Lidocaine is a local anesthetic that also activates bitter taste receptor 14 (T2R14). Lidocaine has some anti-cancer effects, but the mechanisms are unclear. Here, we find that lidocaine causes intracellular Ca2+ mobilization through activation of T2R14 in HNSCC cells. T2R14 activation with lidocaine depolarizes mitochondria, inhibits proliferation, and induces apoptosis. Concomitant with mitochondrial Ca2+ influx, ROS production causes T2R14-dependent accumulation of poly-ubiquitinated proteins, suggesting that proteasome inhibition contributes to T2R14-induced apoptosis. Lidocaine may have therapeutic potential in HNSCCs as a topical gel or intratumor injection. In addition, we find that HPV-associated (HPV+) HNSCCs are associated with increased TAS2R14 expression. Lidocaine treatment may benefit these patients, warranting future clinical studies.

Emerging histological and serological biomarkers in oral squamous cell carcinoma: Applications in diagnosis, prognosis evaluation and personalized therapeutics (Review)

Oral squamous cell carcinoma (OSCC) is the most common malignancy of the oral cavity and accounts for >90% of all oral cancers. Despite advances in diagnostic procedures and therapeutic interventions, overall survival has not improved significantly in recent decades, primarily due to late diagnosis, locoregional recurrence and treatment resistance. Identifying reliable biomarkers for early detection, prognosis evaluation and treatment response prediction is critical for improving clinical outcomes in patients with OSCC. In the present review, the prognostic and predictive utility of circulating biomarkers, such as circulating tumour cells, serological biomarkers and histological and genetic biomarkers, were explored in the context of OSCC. In addition, the potential role of immune checkpoints in the treatment of OSCC was highlighted and the rapidly evolving field of liquid biopsy and its potential to revolutionize diagnosis, prognosis evaluation and treatment were examined. The existing evidence for the clinical utility of these biomarkers was critically evaluated and the challenges and limitations associated with their introduction into routine clinical practice were addressed. In conclusion, the present review highlights the promising role of biomarkers in improving the current understanding of the pathogenesis of OSCC and offers potential avenues for improving patient care through personalized medicine approaches.

Mapping the Scientific Landscape of Bacterial Influence on Oral Cancer: A Bibliometric Analysis of the Last Decade's Medical Progress

The research domain investigating bacterial factors in the development of oral cancer from January 2013 to December 2022 was examined with a bibliometric analysis. A bibliometric analysis is a mathematical and statistical method used to examine extensive datasets. It assesses the connections between prolific authors, journals, institutions, and countries while also identifying commonly used keywords. A comprehensive search strategy identified 167 relevant articles, revealing a progressive increase in publications and citations over time. China and the United States were the leading countries in research productivity, while Harvard University and the University of Helsinki were prominent affiliations. Prolific authors such as Nezar Al-Hebshi, Tsute Chen, and Yaping Pan were identified. The analysis also highlights the contributions of different journals and identifies the top 10 most cited articles in the field, all of which focus primarily on molecular research. The article of the highest citation explored the role of a Fusobacterium nucleatum surface protein in tumor immune evasion. Other top-cited articles investigated the correlation between the oral bacteriome and cancer using 16S rRNA amplicon sequencing, showing microbial shifts associated with oral cancer development. The functional prediction analysis used by recent studies has further revealed an inflammatory bacteriome associated with carcinogenesis. Furthermore, a keyword analysis reveals four distinct research themes: cancer mechanisms, periodontitis and microbiome, inflammation and Fusobacterium, and risk factors. This analysis provides an objective assessment of the research landscape, offers valuable information, and serves as a resource for researchers to advance knowledge and collaboration in the search for the influence of bacteria on the prevention, diagnosis, and treatment of oral cancer.

Evaluation of the cytotoxic, anti-proliferative, anti-metastatic and pro-apoptotic effect of aqueous leaf extract of Annona muricata on oral tongue squamous cell carcinoma cell line (SCC-15): An in vitro study

Background

Oral cancer still represents the leading cause of mortality in India. Due to the drawbacks of current treatment options, a safe, low-cost therapy is the need of the hour. Recently, novel plant extracts with anti-cancer properties have gained greater attention. One among them is Annona muricata and its leaf extract, which has been studied for its anti-cancer effect against various cancers. However, studies on oral cancer cells are very much limited and hence the study.

Aims

To evaluate the cytotoxic, anti-proliferative, anti-metastatic and pro-apoptotic effect of aqueous leaf extract of Annona muricata (ALEAM) against SCC-15 cell lines through in vitro assays.

Materials and Methods

In vitro assays such as MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide], colony formation and wound healing assays were performed. Furthermore, to evaluate the underlying mechanism, gene and protein expression analysis of apoptotic/anti-apoptotic marker genes Bax, P53 and Bcl2, were done using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analysis. Student's t-test has been performed for analysis of experimental data.

Results

The results showed that ALEAM exhibited significant cytotoxic activity in a dose-dependent manner as well as inhibited colony formation and cell migration. The pro-apoptotic properties were affirmed by a highly significant drop in Bcl-2 gene expression and a highly significant rise in P53 and Bax genes in the study group compared to the control (P < 0.05).

Conclusion

The current study provides evidence that ALEAM has the potential to be developed as a novel anti-cancer drug for the treatment of SCC after further clinical studies.

Methyl gallic acid entrapped ethosomal nano-vesicular system augments cytotoxicity against squamous cell carcinoma

Methylated gallic acid (MGA) is a potent anticancer biomolecular entity (BME). Loading MGA into a nano-vesicular (NV) drug delivery system using nanotechnology approaches can increase the efficiency of the drug and its release characteristics. This study aimed to develop an ethosomal nano-vesicular (ENV) system loaded with MGA that shows augmented entrapment efficiency, release rate, and cytotoxic potential against oral cancer. The ENV system was synthesized using Soy lecithin, ethanol, and propylene glycol. The ENV system's characterization (DLS, Zeta potential, TEM, FT-IR) with and without MGA was performed. The cytotoxicity evaluation of MGA alone compared to the MGA-loaded ENV system was performed against the squamous cell carcinoma-9 (SCC-9) cell line. The DLS and zeta potential analysis revealed the size of the ENV system as 58.2 nm and-43.5 mV charge, respectively. MGA loading to ENV system increased size to 63 nm and decreased charge to -2.8 mV. Peaks of FTIR analysis confirmed the encapsulation of MGA in the ENV system. TEM studies revealed the spherical surface morphology of the MGA-loaded ENV system. Compared with conventional MGA alone administration, ENV loaded with MGA showed better drug absorption and bioavailability in vitro. Furthermore, the entrapment efficiency, in vitro drug release, and cytotoxicity results firmly establish the improved therapeutic potential of ENV loaded with MGA against oral cancer cells than MGA alone.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03652-6.

Oral cancer screening knowledge and practices among dental professionals at the University of Toronto

INTRODUCTION

Opportunistic oral cancer screening during visits to the dentist is a non-invasive and accessible option for detection of pre-malignant lesions and early-stage malignancies. The objective of this study was to investigate the knowledge, practices, and attitudes towards oral cancer screening among dentists.

METHODS

A 42-item survey was sent to 650 dental professionals affiliated with the University of Toronto. Data regarding training/practice characteristics, knowledge of oral cavity cancer, current screening practices, attitudes towards screening, and remuneration were collected.

RESULTS

Ninety-one dentists responded. Most obtained their dental degree from Canada (71.4%) and were practicing in large urban centers (87.9%). Most dentists correctly identified the oral tongue (87.8%) and floor of mouth (80%) as the two of most common sites of oral cavity cancer but only 56% correctly identified the most common presentation. 91% performed intra/extra oral examinations at every patient visit. Only 9.9% of dentists discussed the risk factors of oral cancer and 33% were not familiar with resources for smoking cessation and alcohol abuse. International medical graduates were more likely to discuss risk factor management than Canadian medical graduates (p < 0.01). Over 80% of dentists referred to a specialist when a suspected lesion was found. The greatest barrier for oral cancer screening was lack of time. Almost all dentists (98.8%) reported that their screening practices do not differ depending on the patient's insurance status and 63.8% reported compensation would not influence their decision to perform oral examinations.

CONCLUSION

Most dentists have a good knowledge of the presentation and risk factors associated with oral cavity cancer. Most dentists perform screening with every patient, with no influence from compensation and insurance status. Dentists are therefore an excellent first contact for oral cavity cancer screening for the general public and for high-risk populations.

A rare case of cavernous sinus thrombosis following oral squamous cell carcinoma - The etiology and management dilemma

Intracranial cavernous sinus metastases of oral squamous cell carcinoma (OSCC) are rare, with a reported incidence of 0.4 %. Due to their extremely infrequent presentation the etiology and management modalities of such complications are not clearly represented in the literature. Here we present a case of a 58-year-old male diagnosed with OSCC of Right Lower Alveolus with underlying bone invasion, cT4aN1M0, Stage IV. He underwent Right Hemi-mandibulectomy with Modified Neck Dissection, Pectoralis Major Myocutaneous Flap, and 60 Gy/30# adjuvant radiotherapy. Six months later, the patient was diagnosed with recurrence involving the right infratemporal fossa with associated right cavernous sinus thrombosis. Immunohistochemistry block review showed PDL1 - Positive. The patient was subjected to Cisplatin and Pembrolizumab immunotherapy. After receiving 35 cycles of Pembrolizumab over a period of 2 years the patient is doing well with no recurrence.

Therapeutic Potential of BAY-117082, a Selective NLRP3 Inflammasome Inhibitor, on Metastatic Evolution in Human Oral Squamous Cell Carcinoma (OSCC)

Oral squamous cell carcinoma (OSCC) is a commonly occurring head and neck cancer and it is characterized by a high metastasis grade. The aim of this study was to evaluate for the first time the effect of BAY-117082, a selective NLRP3 inflammasome inhibitor, in an in vivo orthotopic model of OSCC and its role in the invasiveness and metastasis processes in neighbor organs such as lymph node, lung, and spleen tissues. Our results demonstrated that BAY-117082 treatment, at doses of 2.5 mg/kg and 5 mg/kg, was able to significantly reduce the presence of microscopic tumor islands and nuclear pleomorphism in tongue tissues and modulate the NLRP3 inflammasome pathway activation in tongue tissues, as well as in metastatic organs such as lung and spleen. Additionally, BAY-117082 treatment modulated the epithelial-mesenchymal transition (EMT) process in tongue tissue as well as in metastatic organs such as lymph node, lung, and spleen, also reducing the expression of matrix metalloproteinases (MMPs), particularly MMP2 and MMP9, markers of cell invasion and migration. In conclusion, the obtained data demonstrated that BAY-117082 at doses of 2.5 mg/kg and 5 mg/kg were able to reduce the tongue tumor area as well as the degree of metastasis in lymph node, lung, and spleen tissues through the NLRP3 inflammasome pathway inhibition.

Inverse correlation of CD3 & vascular endothelial growth factor in incisional oral squamous cell carcinoma biopsies predicts nodal metastasis & poor survival of patients

Background & objectives

Oral squamous cell carcinoma (OSCC) is widely prevalent in the Indian subcontinent mainly due to habit-associated aetiologies. Immune regulation and angiogenesis are the part of tumourigenesis that play a crucial role in metastasis and survival. However, the concurrent expression of vascular endothelial growth factor (VEGF) and CD3 (immune regulator receptor on T-lymphocyte) in the same OSCC tissue samples has not been reported in the Indian population. The present study evaluated the expression of CD3+ T-cells and VEGF in OSCC tissue samples and studied the clinicopathological correlation and survival analysis in an Indian population.

Methods

This was a retrospective study conducted on 30 formalin-fixed and paraffin embedded sections which were histologically diagnosed as OSCC cases comprising of 15 metastatic OSCC and 15 non-metastatic OSCC with available clinical data and survival status.

Results

Reduced expression of CD3+ T-cells and increased VEGF expression were observed in metastatic OSCC samples. The correlation of expression of CD3+ T-cells and VEGF with clinicopathological parameters showed a significant association between these markers with age, nodal status, site of the lesion and survival.

Interpretation & conclusions

Reduced expression of CD3+ T-cells in OSCC was found to be associated with a significantly poor survival. VEGF was found to be over expressed in metastatic OSCC as compared to that in non-metastatic OSCC. The study findings suggest that the evaluation of CD3 and VEGF in incisional OSCC biopsies can be considered for predicting the survival outcome and metastasis.

Fucoidan/hyaluronic acid cross-linked zein nanoparticles loaded with fisetin as a novel targeted nanotherapy for oral cancer

Fisetin (FS) is an anticancer drug having potential role in oral tumors management. However, its clinical application is limited due to its hydrophobicity and instability. Bioactive polymers-based nanosystems have a great potential in cancer therapy. Herein, different biopolymers were selected for their anticancer activity and targeting ability for nanoparticles preparation namely; fucoidan (FU), zein (Zn) and hyaluronic acid (HA). The selected FS-loaded cross-linked Zn nanoparticles (ZFH) which contains HA& FU for Zn nanoparticles stabilization showed the most suitable particle size (196 ± 6.53 nm), mean surface net charge (-38.8 ± 1.47 mV) and entrapment efficiency (98 ± 1.2 %). This is the first study to utilize both HA &FU not only for stabilization but also for dual targeting effect due to their targeting ability to multiple tumor targets. In-vitro anticancer activity of ZHF revealed remarkable uptake by SCC-4 cells with significant cytotoxic action. Further, ZHF was appraised using 4-nitroquinoline 1-oxide (4-NQO)-induced oral cancer in-vivo; ZHF significantly reduced OSCC-specific serum biomarkers levels, histologic tumor grade and increased caspase-3 level. Moreover, potential of destroying two key tumor regulatory cells; TECs and CSCs, was evaluated using their specific markers. The elaborated ZFH nanoparticles could be considered as promising targeted nanotherapy for oral cancer treatment with enhanced efficacy and survival rate.

Imaging Recommendations for Diagnosis, Staging, and Management of Oral Cancer

Oral cavity cancers contribute to a majority of cancers in India. Clinical examination alone cannot determine the deeper extent of the disease; therefore, need for cross-sectional imaging including computed tomography and magnetic resonance imaging becomes indispensable for pre-treatment evaluation to decide optimal plan of management. Oral cavity squamous cell cancers (OSCC) can be treated with surgery alone, whereas deep muscle, neurovascular, osseous, or nodal involvement on imaging suggests advanced disease that requires a combination of surgery, radiation, and/or chemotherapy. Because of the complex anatomy of the oral cavity and its surrounding structures, imaging is crucial for locoregional staging and early detection of distant metastases. Imaging plays indispensable role not only in diagnosis but also in planning the management. An optimal guideline paper for developing countries like India is lacking that not only helps standardize the management but will also assist oncologists make reasonable decisions and reduce the unnecessary imaging. This imaging guideline paper will discuss the optimal imaging in diagnosis and management OSCC for Indian subcontinent.

Injectable catechin-based supramolecular hydrogel for highly efficient application in HPV-associated OSCC

Catechins are a group of natural polyphenols extracted from green tea. Notably, they have been proven to have excellent anti-HPV and anti-tumour properties and to be effective against some HPV-related diseases, showing great potential in the treatment of HPV-associated oral squamous cell carcinoma (HPV⁺ OSCC). However, the poor bioavailability, short half-lives, and stability issues of catechins hamper their clinical application. To overcome these shortcomings of catechins, we innovatively synthesised an injectable supramolecular hydrogel, namely catechin-phenylenebisboronic acid-isoguanosine (CPBisoG), with catechin (one of the simplest catechins) and isoguanosine (isoG), another natural product with self-assembly ability, via dynamic phenylborate diester bonds. The biodegradation and sustained-release time of the CPBisoG hydrogel in mice lasted up to 72 h. This supramolecular hydrogel not only functioned as a good local drug delivery platform with good stability, injectability, self-healing properties, biocompatibility, biodegradability, but also exhibited therapeutic effects toward HPV⁺ OSCC in vitro and in vivo. And interestingly, it also showed selective inhibition against HPV⁺ OSCC cells. In all, these results demonstrate that this catechin-based hydrogel could sustainedly and highly effectively treat HPV⁺ OSCC topically, which could also provide a promising strategy for the management of other HPV-associated diseases in the future.

The 3D's of Neural Phenotypes in Oral Cancer: Distance, Diameter, and Density

Squamous cell carcinoma of the oral cavity (OSCC) is the most common type of head and neck cancer; survival is poor, and response to treatment varies. Metastasis or recurrence in the regional lymph nodes is associated with poor survival. Consequently, overt or occult spread to the lymph nodes is used to identify patients who will receive adjuvant radiation therapy. Perineural invasion and the diameter of nerves exhibiting perineural invasion have also been suggested to be of prognostic significance. The explosion of interest in cancer neuroscience in the last two decades has led to novel biological insights into interactions between nerves and tumor cells. However, the criteria for defining perineural invasion have lagged behind current knowledge. It is important to re-evaluate the concept of perineural invasion and identify other neural phenotypes in OSCC that can impact treatment selection and prognosis. In addition to perineural invasion, neural phenotypes that are of potential relevance to tumor progression include nerve-tumor distance, nerve diameter, and nerve density. This manuscript discusses the translational significance of recent mechanistic studies on the progression of oral cancer.

Naturally Isolated Sesquiterpene Lactone and Hydroxyanthraquinone Induce Apoptosis in Oral Squamous Cell Carcinoma Cell Line

Oral squamous cell carcinoma (OSCC) is one of the most prevalent cancers worldwide, especially in Asian countries. The emergence of its drug resistance and its side effects demands alternatives, to improve prognosis. Since the majority of cancer drugs are derived from natural sources, it provides a window to look for more biocompatible alternatives. In this study, two natural compounds, costunolide (CE) and aloe emodin (AE), were isolated from the stem of Lycium shawii. The compounds were examined for their anticancer and apoptotic potentials against OSCC (CAL 27) cells, using an in vitro analysis, such as a MTT assay, scratch assay, gene, and protein expressions. Both compounds, CE and AE, were found to be cytotoxic against the cancer cells with an IC₅₀ value of 32 and 38 µM, respectively. Moreover, the compounds were found to be non-toxic against normal NIH-3T3 cells and comparable with the standard drug i.e., 5-fluorouracil (IC₅₀ = 97.76 µM). These compounds were active against normal cells at higher concentrations. Nuclear staining displayed the presence of apoptosis-associated morphological changes, i.e., karyopyknosis and karyorrhexis in the treated cancer cells. Flow cytometry results further confirmed that these compounds induce apoptosis rather than necrosis, as the majority of the cells were found in the late apoptotic phase. Gene and protein expression analyses showed an increased expression of apoptotic genes, i.e., BAK, caspase 3, 6, and 9. Moreover, the compounds significantly downregulated the expression of the anti-apoptotic (BCL-2 L1), metastatic (MMP-2), and pro-inflammatory (COX-2) genes. Both compounds have shown promising anticancer, apoptotic, and anti-migratory activities against the OSCC cell line (i.e., CAL-27). However, further in vivo studies are required to explore these compounds as anticancer agents.

Integrating Cutting-Edge Methods to Oral Cancer Screening, Analysis, and Prognosis

Oral cancer (OC) has become a significant barrier to health worldwide due to its high morbidity and mortality rates. OC is among the most prevalent types of cancer that affect the head and neck region, and the overall survival rate at 5 years is still around 50%. Moreover, it is a multifactorial malignancy instigated by genetic and epigenetic variabilities, and molecular heterogeneity makes it a complex malignancy. Oral potentially malignant disorders (OPMDs) are often the first warning signs of OC, although it is challenging to predict which cases will develop into malignancies. Visual oral examination and histological examination are still the standard initial steps in diagnosing oral lesions; however, these approaches have limitations that might lead to late diagnosis of OC or missed diagnosis of OPMDs in high-risk individuals. The objective of this review is to present a comprehensive overview of the currently used novel techniques viz., liquid biopsy, next-generation sequencing (NGS), microarray, nanotechnology, lab-on-a-chip (LOC) or microfluidics, and artificial intelligence (AI) for the clinical diagnostics and management of this malignancy. The potential of these novel techniques in expanding OC diagnostics and clinical management is also reviewed.

The FnBPA from methicillin-resistant Staphylococcus aureus promoted development of oral squamous cell carcinoma

Background

Oral squamous cell carcinoma (OSCC) is the most common tumor in the oral cavity. Methicillin-resistant Staphylococcus aureus (MRSA) were highly detected in OSCC patients; however, the interactions and mechanisms between drug-resistant bacteria (MRSA) and OSCC are not clear.

Aim

The aim of this study was to investigate the promotion of MRSA on the development of OSCC.

Methods

MRSA and MSSA (methicillin-susceptible) strains were employed to investigate the effect on the proliferation of OSCC in vitro and vivo.

Results

All of the MRSA strains significantly increased the proliferation of OSCC cells and MRSA arrested the cell cycles of OSCC cells in the S phase. MRSA activated the expression of TLR-4, NF-κB and c-fos in OSCC cells. MRSA also promoted the development of squamous cell carcinoma in vivo. The virulence factor fnbpA gene was significantly upregulated in all MRSA strains. By neutralizing FnBPA, the promotions of MRSA on OSCC cell proliferation and development of squamous cell carcinoma were significantly decreased. Meanwhile, the activation of c-fos and NF-κB by MRSA was also significantly decreased by FnBPA antibody.

Conclusion

MRSA promoted development of OSCC, and the FnBPA protein was the critical virulence factor. Targeting virulence factors is a new method to block the interaction between a drug-resistant pathogen and development of tumors.

Long noncoding RNA MEG3 inhibits oral squamous cell carcinoma progression via GATA3

Oral squamous cell carcinoma (OSCC) accounts for about 90% of oral cancers. Expression of the long noncoding RNA (lncRNA) maternally expressed 3 (MEG3) has previously been reported to be downregulated in OSCC, and its overexpression can inhibit proliferation, migration, and invasion and promote apoptosis of OSCC cells. However, the mechanism underlying MEG3 downregulation in OSCC has not been well characterized. Here we report that low expression of MEG3 is caused by H3K27me3 modification of the MEG3 gene locus, and this is associated with the poor prognosis of OSCC. Overexpression of MEG3 inhibited the proliferation and invasion of OSCC cells. We observed that MEG3 was modified by m6A and bound to YTHDC1. Enhancer-controlled genes positively regulated by MEG3 were functionally enriched for the 'negative regulation of Wnt signaling pathway' term, as determined using metascape. GATA3 was predicted to be a transcription factor for these genes, and was demonstrated to bind to MEG3. Knockdown of GATA3 countered the effects on proliferation, invasion, and increased transcription of HIC1 and PRICKLE1 induced by MEG3 overexpression. In conclusion, our data suggest that MEG3 is downregulated in OSCC due to trimethylation of H3K27 at the MEG3 gene locus. The inhibitory effect of MEG3 on proliferation and invasion of OSCC cells was dependent on the binding of GATA3.

Improving radiomic model reliability using robust features from perturbations for head-and-neck carcinoma

Background

Using high robust radiomic features in modeling is recommended, yet its impact on radiomic model is unclear. This study evaluated the radiomic model’s robustness and generalizability after screening out low-robust features before radiomic modeling. The results were validated with four datasets and two clinically relevant tasks.

Materials and methods

A total of 1,419 head-and-neck cancer patients’ computed tomography images, gross tumor volume segmentation, and clinically relevant outcomes (distant metastasis and local-regional recurrence) were collected from four publicly available datasets. The perturbation method was implemented to simulate images, and the radiomic feature robustness was quantified using intra-class correlation of coefficient (ICC). Three radiomic models were built using all features (ICC &gt; 0), good-robust features (ICC &gt; 0.75), and excellent-robust features (ICC &gt; 0.95), respectively. A filter-based feature selection and Ridge classification method were used to construct the radiomic models. Model performance was assessed with both robustness and generalizability. The robustness of the model was evaluated by the ICC, and the generalizability of the model was quantified by the train-test difference of Area Under the Receiver Operating Characteristic Curve (AUC).

Results

The average model robustness ICC improved significantly from 0.65 to 0.78 (P&lt; 0.0001) using good-robust features and to 0.91 (P&lt; 0.0001) using excellent-robust features. Model generalizability also showed a substantial increase, as a closer gap between training and testing AUC was observed where the mean train-test AUC difference was reduced from 0.21 to 0.18 (P&lt; 0.001) in good-robust features and to 0.12 (P&lt; 0.0001) in excellent-robust features. Furthermore, good-robust features yielded the best average AUC in the unseen datasets of 0.58 (P&lt; 0.001) over four datasets and clinical outcomes.

Conclusions

Including robust only features in radiomic modeling significantly improves model robustness and generalizability in unseen datasets. Yet, the robustness of radiomic model has to be verified despite building with robust radiomic features, and tightly restricted feature robustness may prevent the optimal model performance in the unseen dataset as it may lower the discrimination power of the model.

Novel prognostic matrisome-related gene signature of head and neck squamous cell carcinoma

Background: Head and neck squamous cell carcinoma (HNSCC) is a common malignancy of the mucosal epithelium of the oral cavity, pharynx, and larynx. Laryngeal squamous cell carcinoma (LSCC) and oral squamous cell carcinoma are common HNSCC subtypes. Patients with metastatic HNSCC have a poor prognosis. Therefore, identifying molecular markers for the development and progression of HNSCC is essential for improving early diagnosis and predicting patient outcomes.

Methods: Gene expression RNA-Seq data and patient clinical traits were obtained from The Cancer Genome Atlas-Head and Neck Squamous Cell Carcinoma (TCGA-HNSC) and Gene Expression Omnibus databases. Differentially expressed gene (DEG) screening was performed using the TCGA-HNSC dataset. Intersection analysis between the DEGs and a list of core matrisome genes obtained from the Matrisome Project was used to identify differentially expressed matrisome genes. A prognostic model was established using univariate and multivariate Cox regression analyses, least absolute shrinkage, and selection operator (LASSO) regression analysis. Immune landscape analysis was performed based on the single-sample gene set enrichment analysis algorithm, Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, prognostic value, receiver operating characteristic curve analysis, and gene mutation analyses. Immunohistochemical results regarding prognostic protein levels were obtained from the Human Protein Atlas. Single-gene RNA-sequencing data were obtained from GSE150321 and GSE172577 datasets. CCK-8 and Transwell assays were used to confirm cell proliferation and migration.

Results: A total of 1,779 DEGs, including 939 upregulated and 840 downregulated genes, between tumor and normal samples were identified using the TCGA-HNSC microarray data. Intersection analysis revealed 52 differentially expressed matrisome-related genes. After performing univariate and multivariate Cox regression and LASSO analyses, a novel prognostic model based on six matrisome genes (FN1, LAMB4, LAMB3, DMP1, CHAD, and MMRN1) for HNSCC was established. This risk model can successfully predict HNSCC survival. The high-risk group had worse prognoses and higher enrichment of pathways related to cancer development than the low-risk group. Silencing LAMB4 in HNSCC cell lines promoted cell proliferation and migration.

Conclusion: This study provides a novel prognostic model for HNSCC. Thus, FN1, LAMB4, LAMB3, DMP1, CHAD, and MMRN1 may be the promising biomarkers for clinical practice.

Circ_0008068 facilitates the oral squamous cell carcinoma development by microRNA-153-3p/acylgycerol kinase (AGK) axis

Oral squamous cell carcinoma (OSCC) is a common cancer with high recurrence, metastasis rates and poor prognosis. Circular RNAs (circRNAs) take part in regulating OSCC. Herein, we examined the role of circ_0008068 in OSCC. The circ_0008068, Katanin p60 ATPase-containing subunit A-like 1 (KATNAL1) mRNA, microRNA-153-3p (miR-153-3p) and acylgycerol kinase (AGK) contents were indicated by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. Moreover, in vitro and in vivo assays were conducted to scrutinize the effects of circ_0008068 on OSCC. Additionally, the contact between miR-153-3p and circ_0008068 or AGK was assessed by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Thereafter, we found that the appearance of circ_0008068 and AGK was increased, and miR-153-3p content was diminished in OSCC. Circ_0008068 lack subdued cell proliferation, migration, invasion, tube formation and glycolysis metabolism, but stimulated cell apoptosis in OSCC. In addition, circ_0008068 bound to miR-153-3p to modulate the expression of its target AGK. Besides, miR-153-3p was validated to act as a tumor suppressor in OSCC tumorigenesis by suppressing AGK. Additionally, circ_0008068 knockdown also attenuated tumor growth in nude mice. In all, circ_0008068 expedited the growth of OSCC by miR-153-3p/AGK axis.

Abbreviations: OSCC: Oral squamous cell carcinoma; AGK: Acylgycerol kinase; CircRNA: Circular RNA; KATNAL1: Katanin p60 ATPase-containing subunit A-like 1; qRT-PCR: Quantitative real-time polymerase chain reaction; miRNAs/miRs: MicroRNAs; RIP: RNA immunoprecipitation; 3′UTR3’: -untranslated region; HK2: Hexokinase 2; LDHA Lactate dehydrogenase A; IHC: Immunohistochemistry; CCK8: Cell counting kit-8; GAPDH: Glyceraldehyde-3-phosphate dehydrogenase

Inhibitor of Growth 4 (ING4) Plays a Tumor-Repressing Role in Oral Squamous Cell Carcinoma via Nuclear Factor kappa-B (NF-kB)/DNA Methyltransferase 1 (DNMT1) Axis-Mediated Regulation of Aldehyde Dehydrogenase 1A2 (ALDH1A2)

BACKGROUND

Inhibitor of growth 4 (ING4) level was reported to be decreased in head and neck squamous cell carcinoma (HNSC) tissue, however, it is unknown whether and how ING4 participates in regulating the development of oral squamous cell carcinoma (OSCC).

OBJECTIVE

To investigate the role and mechanism of ING4 in OSCC.

METHODS

ING4 was forced up-or down-regulated in two OSCC cell lines, and its effects on the malignant behavior of OSCC cells were investigated in vitro. The ubiquitination level of NF-kB p65 in ING4 upregulated cells was measured by co-immunoprecipitation. Moreover, the effects of ING4 on the methylation level of ALDH1A2 were evaluated by methylation-specific polymerase chain reaction (MSP) assay. The role of ING4 in OSCC growth in vivo was observed in nude mice.

RESULTS

Our results showed that the expression of ING4 in OSCC cell lines was lower than that in normal oral keratinocyte cells. In vitro, ING4 overexpression inhibited the proliferation, migration, and invasion of OSCC cell lines and ING4 silencing exhibited opposite results. We also demonstrated that ING4 overexpression promoted the ubiquitination and degradation of P65 and reduced DNA methyltransferase 1 (DNMT1) expression, and Aldehyde dehydrogenase 1A2 (ALDH1A2) methylation. Moreover, overexpression of p65 rescued the suppression of malignant behavior, induced by ING4 overexpression. In addition, ING4 negatively regulated the growth of OSCC xenograft tumors in vivo.

CONCLUSION

Our data evidenced that ING4 played a tumor-repressing role in OSCC in vivo and in vitro via NF-κB/DNMT1/ALDH1A2 axis.

Direct Contact with Platelets Induces Podoplanin Expression and Invasion in Human Oral Squamous Cell Carcinoma Cells

Oral squamous cell carcinoma (OSCC) is mostly diagnosed at an advanced stage, with local and/or distal metastasis. Thus, locoregional and/or local control of the primary tumor is crucial for a better prognosis in patients with OSCC. Platelets have long been considered major players in cancer metastasis. Traditional antiplatelet agents, such as aspirin, are thought to be potential chemotherapeutics, but they need to be used with caution because of the increased bleeding risk. Podoplanin (PDPN)-expressing cancer cells can activate platelets and promote OSCC metastasis. However, the reciprocal effect of platelets on PDPN expression in OSCC has not been investigated. In this study, we found that direct contact with platelets upregulated PDPN and integrin β1 at the protein level and promoted invasiveness of human OSCC Ca9.22 cells that express low levels of PDPN. In another human OSCC HSC3 cell line that express PDPN at an abundant level, silencing of the PDPN gene reduced cell invasiveness. Analysis of the public database further supported the co-expression of PDPN and integrin β1 and their increased expression in metastatic tissues compared to normal and tumor tissues of the oral cavity. Taken together, these data suggest that PDPN is a potential target to regulate platelet-tumor interaction and metastasis for OSCC treatment, which can overcome the limitations of traditional antiplatelet drugs.

Systematic Review: Cardiac Metastasis of Lingual Squamous Cell Carcinoma

INTRODUCTION

Lingual squamous cell carcinoma (LSCC) is an aggressive malignancy that carries significant mortality risk and the potential for cardiac metastasis. The authors performed a systematic review designed to characterize disease progression of LSCC cardiac metastasis by evaluating patient demographics, characteristics, management, and clinical outcomes.

METHODS

Two authors independently screened articles in Embase, PubMed, and Cochrane Database of Systematic Reviews up until December 2019 for study eligibility. Demographic data, patient symptomatology, imaging findings, management strategies, and patient outcomes were obtained and analyzed. The Oxford Centre for Evidence Based Medicine (OCEBM) Levels of Evidence categorization was implemented to determine the quality of studies selected in this review.

RESULTS

From this review, a total of 28 studies met inclusion criteria and received an OCEBM Level 4 evidence designation. Thirty-one patients were identified with cardiac metastasis from LSCC. Shortness of breath (29.0%) and chest pain (29.0%) were the most common presenting symptoms, and pericardial effusion (29.2%) and right ventricular outflow tract obstruction (25.0%) were the predominant echocardiogram findings. Cardiac metastases most often presented in the right ventricle (56.7%), followed by the left ventricle (43.3%). Palliative intervention (68.2%) or chemotherapy (40.9%) were typically implemented as treatments. All sample patients expired within one year of metastatic cancer diagnosis in cases that reported mortality outcomes.

CONCLUSIONS

Patients presenting with shortness of breath, tachycardia, and a history of squamous cell carcinoma of the tongue may indicate evaluation for LSCC cardiac metastasis. Although LSCC cardiac metastases typically favor the right and left ventricles, they are not exclusive to these sites. Palliative care may be indicated as treatment due to high mortality and overall poor outcomes from current interventions.

Salvage surgery for recurrent carcinoma of the oral cavity: assessment of prognostic factors

Salvage surgery is the most acceptable therapeutic option for disease control of loco-regional recurrences in oral cancers. Prognostic factors need to be assessed to select patients for salvage surgery who would benefit the most. This was a single-centre retrospective observational study conducted between 2015 and 2018. A total of 168 patients with recurrent oral cavity carcinoma who underwent salvage surgery were included for analysis. The primary endpoints of the study were to evaluate overall survival (rOS) after salvage surgery and prognostic factors affecting survival. In this study, the median rOS was 18 months and the median disease-free survival (rDFS) was 14 months. Advanced stage (hazard ratio (HR) 2.387, 95% confidence interval (CI) 1.496-3.808; P = 0.001) and multimodality treatment (HR 1.642, 95% CI 1.139-2.367; P = 0.008) in the initial disease, as well as nodal spread (HR 3.794, 95% CI 1.580-9.111; P = 0.008) and perineural invasion (HR 2.167, 95% CI 1.358-3.455; P = 0.001) in the recurrent disease, were found to adversely affect survival after salvage surgery. With thorough assessment of the prognostic factors and appropriate patient selection, survival may be favourable after salvage surgery for recurrent oral cavity carcinoma.

Resveratrol effects in oral cancer cells: a comprehensive review

Oral cancer is a very common tumor worldwide with high incidence and mortality. The treatment of oral cancer involves surgery, radio- and chemotherapy; however, high failure rates and toxicity are noticed. Thus, the search of new drugs aiming a more effective treatment is welcomed. Natural products present chemopreventive and anti-cancer effects. Resveratrol is a naturally occurring antioxidant that contains several health benefits, including anti-inflammatory and antiproliferative activities. This review discusses the different action mechanisms of resveratrol related in the in vitro and in vivo studies using models of oral cancer.

Assessment of Potential Prognostic Value of Peroxiredoxin 1 in Oral Squamous Cell Carcinoma

Purpose

The role of the peroxiredoxin (PRDX) family in oral squamous cell carcinoma (OSCC) remains unclear. This study aimed to investigate the expression of PRDXs and their effects on the prognosis in OSCC.

Methods

The expression of PRDXs and their effects on prognosis were analysed in 216 OSCC samples from The Cancer Genome Atlas (TCGA) database. OSCC tissues and adjacent noncancerous tissues (ANTs) were obtained from 68 clinical patients. Quantitative real-time (qRT)-PCR, Western blot, and immunohistochemical (IHC) staining were used to verify the relationship between the expression level of PRDX1 and different clinical features. Gene set enrichment analysis (GSEA) was used to examine the molecular mechanism of PRDX1 in OSCC.

Results

PRDX1 was found to be the only gene in PRDX family that highly expressed in OSCC samples and affected the prognosis of patients with OSCC. PRDX1 expression was significantly related to tumor stage, lymphatic metastasis, and pathological grade. A nomogram consisting of tumor stage, N stage, and PRDX1 level was constructed. GSEA showed that high expression of PRDX1 involved many cancer-related molecular functions and signaling pathways.

Conclusion

PRDX1 may play an important role in the occurrence and development of OSCC, and may be a potential new target for OSCC treatment.

Metabolically Active Subacute Infarct Masquerading as Metastasis: A Finding not to be overlooked in Asymptomatic Oncology Patients

A 50-year-old man with carcinoma of the right buccal mucosa underwent staging whole-body 18F-fluorodeoxyglucose positron emission tomography–computed tomography, which revealed a hypermetabolic heterogeneously enhancing lobulated primary lesion in the right buccal region and an incidental finding of subacute stroke. The case highlights the importance of discriminating brain neoplasms mimicking stroke from true ischemic stroke, which is crucial for appropriate management of patients in an oncology setting.

Application of the Interaction between Tissue Immunohistochemistry Staining and Clinicopathological Factors for Evaluating the Risk of Oral Cancer Progression by Hierarchical Clustering Analysis: A Case-Control Study in a Taiwanese Population

The aim of this single-center case-control study is to investigate the feasibility and accuracy of oral cancer protein risk stratification (OCPRS) to analyze the risk of cancer progression. All patients diagnosed with oral cancer in Taiwan, between 2012 and 2014, and who underwent surgical intervention were selected for the study. The tissue was further processed for immunohistochemistry (IHC) for 21 target proteins. Analyses were performed using the results of IHC staining, clinicopathological characteristics, and survival outcomes. Novel stratifications with a hierarchical clustering approach and combinations were applied using the Cox proportional hazard regression model. Of the 163 participants recruited, 102 patients were analyzed, and OCPRS successfully identified patients with different progression-free survival (PFS) profiles in high-risk (53 subjects) versus low-risk (49 subjects) groups (p = 0.012). OCPRS was composed of cytoplasmic PLK1, phosphoMet, and SGK2 IHC staining. After controlling for the influence of clinicopathological features, high-risk patients were 2.33 times more likely to experience cancer progression than low-risk patients (p = 0.020). In the multivariate model, patients with extranodal extension (HR = 2.66, p = 0.045) demonstrated a significantly increased risk for disease progression. Risk stratification with OCPRS provided distinct PFS groups for patients with oral cancer after surgical intervention. OCPRS appears suitable for routine clinical use for progression and prognosis estimation.

The prospects of nanotherapeutic approaches for targeting tumor-associated macrophages in oral cancer

OSCC (oral squamous cell carcinoma) is currently one of the most formidable cancers plagued by challenges like low overall survivability, lymph node associated metastasis, drug resistance, and poor diagnostics. The tumor microenvironment (TME) and its constituent stromal elements are crucial modulators of tumor growth and treatment response, more specifically so with regards to resident tumor associated macrophages (TAMs) and their liaison with the different stromal elements in the tumor niche (Figure 1). Interestingly, there isn't much information on TAM-targeted nanotherapy in OSCC where the first line of therapeutics for oral cancer is surgery with other therapeutics such as chemo- and radiotherapy acting only as adjuvant therapy for oral cancer. In the face of this real time situation, there have been some successful attempts at targeted therapy for OSCC cells and we believe they might elicit favorable responses against TAMs as well. Demanding our immediate attention, this review intends to provide a glimpse of the prevailing anti-TAM treatment strategies, which present great prospect for an uncharted territory like OSCC.

Norcantharidin combined with 2-deoxy-d-glucose suppresses the hepatocellular carcinoma cells proliferation and migration

Present study aims to investigate the combined effect of anticancer drug, norcantharidin (NCTD) in combination with glycolytic inhibitor, i.e. 2-deoxy-d-glucose (2-DG) in liver cancer (HepG2 and Hepa 1-6) cells. Cell viability of NCTD and 2-DG exposed cells was determined by MTT assay, whereas, colony-forming efficiency and migration rate was determined by clonogenic assay and wound healing assay, respectively. Nuclear DAPI staining and Annexin V FITC-PI staining were used to study the apoptosis induction in cells. Fluorescence microscopy imaging was performed to detect the intracellular reactive oxygen species (ROS) generation and mitochondrial membrane potential by staining with DCFDA and JC-1 dye, respectively. Cell viability assay revealed that NCTD and 2-DG exposure in combination displays more cytotoxic effect than a single drug. Additionally, cells lose their colony formation efficiency, as well as the reduced migration rate ability was also observed upon combined exposure. Increased nuclear condensation and mitochondrial membrane depolarization are considered as key features for apoptosis induction in cancerous cells. Furthermore, oxidative stress produced in cells due to enhanced intracellular ROS generation is also major probability for cellular damage. Thus, from the initial data it can be concluded that further preclinical studies will be needed to prove the efficacy of NCTD and 2-DG in hepatocellular carcinoma therapy.

A Rare Case of Metastatic Colon Cancer in a Patient With Squamous Cell Carcinoma of the Tongue

Squamous cell carcinoma (SCC) of the colon, both primary and metastatic, are extremely rare malignancies. We present a case of a 60-year-old man with metastatic SCC of the tongue status after radiation and chemotherapy who presented with fatigue and melena. Colonoscopy revealed a 5 cm mass in the transverse colon. Pathology established the diagnosis of poorly differentiated SCC with p16 immunostaining, similar to biopsies from his initially diagnosed lingual cancer. To the best of our knowledge, there are no previously reported cases of primary SCC of the tongue metastasizing to the colon.

New Insights into Oral Cancer-Risk Factors and Prevention: A Review of Literature

The oral cancer constitutes 48% of head and neck cancer cases. Ninety percent of oral cancer cases are histologically diagnosed as oral squamous cell carcinomas (OSCCs). Despite new management strategies, the 5-year survival rate of oral cancer is still below 50% in most countries. Head and neck cancers are heterogeneous tumors, and this characteristic of them provides a challenge to treatment plan. Due to the poor outcomes in oral cancer, prevention is a necessity. In this review, a relevant English Literature search in PubMed, ScienceDirect, and Google Scholar from 2000 to mid-2018 was performed. All published articles related to oral cancer and its prevention were included. The risk factors of oral cancer and strategies of oral cancer prevention will be discussed.

Role of Autophagy in the Microenvironment of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma, the most common type of oral cancer, affects more than 275,000 people per year worldwide. Oral squamous cell carcinoma is very aggressive, as most patients die after 3 to 5 years post-diagnosis. The initiation and progression of oral squamous cell carcinoma are multifactorial: smoking, alcohol consumption, and human papilloma virus infection are among the causes that promote its development. Although oral squamous cell carcinoma involves abnormal growth and migration of oral epithelial cells, other cell types such as fibroblasts and immune cells form the carcinoma niche. An underlying inflammatory state within the oral tissue promotes differential stress-related responses that favor oral squamous cell carcinoma. Autophagy is an intracellular degradation process that allows cancer cells to survive under stress conditions. Autophagy degrades cellular components by sequestering them in vesicles called autophagosomes, which ultimately fuse with lysosomes. Although several autophagy markers have been associated with oral squamous cell carcinoma, it remains unclear whether up- or down-regulation of autophagy favors its progression. Autophagy levels during oral squamous cell carcinoma are both timing- and cell-specific. Here we discuss how autophagy is required to establish a new cellular microenvironment in oral squamous cell carcinoma and how autophagy drives the phenotypic change of oral squamous cell carcinoma cells by promoting crosstalk between carcinoma cells, fibroblasts, and immune cells.

miR-146a Overexpression in Oral Squamous Cell Carcinoma Potentiates Cancer Cell Migration and Invasion Possibly via Targeting HTT

Huntingtin (HTT) is one of the target genes of miR-146-a and regulates various cancer cell activities. This study aims to explore the miR-146a expression pattern in oral squamous cell carcinoma (OSCC) and its role and mechanism in OSCC progression and metastasis via targeting the HTT gene. OSCC tissue and non-cancerous matched tissue (NCMT) were obtained from 14 patients. OSCC cell lines and normal HOK cells were used to analyze migration and invasion assay. OSCC-induced miR-146a knockout mice (B6.Cg-Mir146tm1.1Bal) model was developed. Transwell cell migration/invasion and scratch wound assays were used to investigate the OSCC cell migration and invasion in vitro. Kaplan-Meier survival analysis was used to investigate the association of HTT expression patterns in cancer tissue with patient survival percentage and duration. Pearson's correlation analysis tested the association between miR-146a and HTT expression in OSCC tissues. miR-146a mimic and inhibitor transfection were performed to overexpress and knockdown the miR-146a in OSCC cells, respectively. miR-146a expression was highly upregulated in OSCC tissues and OSCC cell lines. Cancer cell migration/invasion was enhanced in miR-146a overexpressed cells and reduced in mi-R146a knockdowned cells. HTT expression was reduced in OSCC tissues and cell lines compared to NCMT and HOK cells, respectively. HTT expression was downregulated in miR-146a overexpressed OSCC cells and upregulated in miR-146a knockdowned OSCC cells. The expression pattern of miR-146a in OSCC cell lines and tissues was inversely correlated with HTT expression. Prediction of miRNA target analysis showed that HTT possesses the binding sites for miR-146a. HTT overexpression in OSCC tissues was associated with patients' higher survival percentage and duration. HTT knockdown in OSCC cells enhanced miR-146a expression and cell migration/invasion. Inducing OSCC in miR-146a knockout mice increased the HTT expression in tongue tissue and alleviated the cancer aggressiveness and epithelial damage. Overexpressed miR-146a in OSCC targets the HTT gene and enhances cancer cell migration/invasion unraveling the possible role of HTT in miR146a-mediated OSCC cell migration and invasion.

Development of lung metastases in mouse models of tongue squamous cell carcinoma

OBJECTIVE

Oral squamous cell carcinoma (OSCC) represents 3%-4% of all cancers. Despite the increasing incidence of OSCC distant metastasis and poor prognosis, few animal models of OSCC distant metastasis have been reported. In this study, we established mouse models of OSCC lung metastasis by orthotopic and tail vein injection of new OSCC cell lines.

METHODS

For the tail vein model, we used a novel cell line isolated from lung metastases reproduced in vivo after intravenous injection of HSC-3 GFP/luciferase cells and sorted for GFP expression (HSC-3 M1 GFP/luciferase). Lung metastases were assessed by imaging techniques and further confirmed by histology. For the orthotopic model, HSC-3 GFP/luciferase cells were injected into the tongue of athymic nude mice. The primary tumor and metastases were assessed by in vivo imaging, histology, and immunohistochemistry.

RESULTS

The orthotopic model presented spontaneous lung metastases in 50% of the animals and lymph node metastases were present in 83% of cases. In the tail vein model, a lung metastasis rate of 60% was observed.

CONCLUSIONS

Lung metastases were successfully reproduced by orthotopic and tail vein injection. Since lymph node metastases were present, the orthotopic model with HSC-3 GFP/luciferase cells may be suitable to investigate metastatic dissemination in OSCC.

Actin-Associated Gene Expression is Associated with Early Regional Metastasis of Tongue Cancer

OBJECTIVES

We aimed to analyze gene expression profile of tongue cancer associated with early lymph node metastasis using the cancer genome atlas (TCGA) data.

STUDY DESIGN

Basic research.

METHODS

A total of 515 patients with matched RNAseq data of primary tumor and clinical data from TCGA data were extracted. To compare gene expression profile between early T-stage tongue cancer with cervical lymph node metastasis and late T-stage tongue cancer without cervical metastasis, genomic data of following two groups was assessed; 1) group 1: T1/2 and N2/3 (n = 41), 2) group 2: T4 and N0 (n = 65). Using R and limma package in bioconductor program, differentially expressed genes (DEGs) were extracted. Gene ontology and pathway enrichment analysis were performed using the DAVID online tool. FFPE tissue of 285 patients were evaluated for the validation of relevant genes by imunofluorescence (IF) and immunohistochemical (IHC) stain.

RESULTS

A total of 225 DEGs were found, and 50 genes were highly significant with absolute fold change over eight. Gene ontology and pathway enrichment analysis revealed that most of the upregulated genes were associated with actin cytoskeleton and included following genes: ANKRD23, NO3, PDLIM3, MUSTN1, TNNT3, MYBPC1, MB, MYH3, TTN, ACTA1, and ACTC1. When comparing tongue cancer with cN0pN0 vs. pN0pN+ using the total tongue cancer cohort of TCGA, ACTA1 was the only parameter which was associated with hidden lymph node metastasis in T1/2 (P = .019). Perineural invasion was significantly associated with high expression of ACTA1 (P < .001). IF and IHC analysis revealed that actin was overexpressed, while E-cadherin and N-cadherin were not significantly different.

CONCLUSIONS

Actin associated genes, especially overexpression of ACTA1 may be associated with early regional metastasis of tongue cancer.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:813-819, 2021.

CCL18-NIR1 promotes oral cancer cell growth and metastasis by activating the JAK2/STAT3 signaling pathway

BACKGROUND

Chemokine (C-C motif) ligand 18 (CCL18) affects the malignant progression of varying cancers by activating chemokine receptors. Our previous work has shown that CCL18 promotes hyperplasia and invasiveness of oral cancer cells; however, the cognate receptors of CCL18 involved in the pathogenesis of oral squamous cell carcinoma (OSCC) have not yet been identified. This study aimed to investigate the molecular mechanisms which underlie promotive effects of CCL18 on OSCC progression by binding to functional receptors.

METHODS

The expression of CCL18 receptor-NIR1 in OSCC was determined by conducting western blot, immunofluorescence, and immunocytochemistry assays. Chi square test was applied to analyze the relationship between expression levels of NIR1 and clinicopathological variables. Recombinant CCL18 (rCCL18), receptor siRNA and JAK specific inhibitor (AG490) were used in experiments investigating the effects of the CCL18-NIR1 axis on growth of cancer cells (i.e., proliferation, and metastasis), epithelial-mesenchymal transition (EMT) and the activation of the JAK2/STAT3 signaling pathway.

RESULTS

NIR1 as functional receptor of CCL18 in OSCC, was found to be significantly upregulated in OSCC and positively related to the TNM stage of OSCC patients. rCCL18 induced the phenotypical alterations in oral cancer cells including cell growth, metastasis and EMT. The JAK2/STAT3 signaling pathway was confirmed to be a downstream pathway mediating the effects of CCL18 in OSCC. AG490 and knockdown of NIR1 could block the effects of rCCL18-induced OSCC.

CONCLUSION

CCL18 can promote the progression of OSCC by binding NIR1, and the CCL18-NIR1 axis can activate JAK2/STAT3 signaling pathway. The identification of the mechanisms underlying CCL18-mediated promotion of OSCC progression could highlight potential therapeutic targets for treating oral cancer.

The chemokine lymphotactin and its recombinant variants in oral cancer cell regulation

BACKGROUND

The expression of XCR1 receptor and its metamorphic ligand lymphotactin (hLtn) has been shown in cancers but their precise role in tumorigenesis is poorly understood including the significance of the physiologically existing hLtn monomeric (CC3) and dimeric (W55D) confirmations where the latter thought to function as the receptor antagonist. The aim of this study was to explore the functional role of bioengineered hLtn variants and the role of fibroblasts in XCR1/hLtn expression regulation in oral cancer cells (OCCL).

MATERIAL AND METHODS

qRT-PCR and flow cytometry were performed to evaluate mRNA and protein expression of XCR1 and hLtn. Recombinant hLtn variants (wild-type, CC3 and W55D mutant) were designed, expressed, purified and evaluated using proliferation, adhesion and chemotaxis assays. XCR1 and hLtn expression regulation by fibroblasts was determined using indirect co-culture. XCR1 and hLtn expression in primary and metastatic OSCC tissue was assessed using immunohistochemistry.

RESULTS

hLtn caused a significant decrease in OCCL XCR1 surface protein expression. hLtn CC3 mutant was highly functional facilitating proliferation and migration. Conditioned media from primary cancer-associated and senescent fibroblasts significantly upregulated XCR1 and hLtn mRNA expression in OCCL. Immunohistochemistry revealed higher XCR1 and hLtn expression in metastatic tumour deposits and surrounding stroma compared to primary OSCC tissue.

CONCLUSIONS

The development of hLtn biological mutants, regulation of XCR1 expression by its ligand hLtn and crosstalk with fibroblasts are novel findings suggesting an important role for the XCR1/hLtn axis within the OSCC tumour microenvironment. These discoveries build upon previous studies and suggest that the hLtn/XCR1 axis has a significant role in stromal crosstalk and OSCC progression.

Role of VEGFs/VEGFR-1 Signaling and its Inhibition in Modulating Tumor Invasion: Experimental Evidence in Different Metastatic Cancer Models

The vascular endothelial growth factor (VEGF) family members, VEGF-A, placenta growth factor (PlGF), and to a lesser extent VEGF-B, play an essential role in tumor-associated angiogenesis, tissue infiltration, and metastasis formation. Although VEGF-A can activate both VEGFR-1 and VEGFR-2 membrane receptors, PlGF and VEGF-B exclusively interact with VEGFR-1. Differently from VEGFR-2, which is involved both in physiological and pathological angiogenesis, in the adult VEGFR-1 is required only for pathological angiogenesis. Besides this role in tumor endothelium, ligand-mediated stimulation of VEGFR-1 expressed in tumor cells may directly induce cell chemotaxis and extracellular matrix invasion. Furthermore, VEGFR-1 activation in myeloid progenitors and tumor-associated macrophages favors cancer immune escape through the release of immunosuppressive cytokines. These properties have prompted a number of preclinical and clinical studies to analyze VEGFR-1 involvement in the metastatic process. The aim of the present review is to highlight the contribution of VEGFs/VEGFR-1 signaling in the progression of different tumor types and to provide an overview of the therapeutic approaches targeting VEGFR-1 currently under investigation.

Periodontitis and oral cancer - current concepts of the etiopathogenesis

Gingival tissues are attacked by oral pathogens which can induce inflammatory reactions. The immune-inflammatory responses play essential roles in the patient susceptibility to periodontal diseases. There is a wealth of evidence indicating a link between chronic inflammation and risk of malignant transformation of the affected oral epithelium. Periodontitis is associated with an increased risk of developing chronic systemic conditions including autoimmune diseases and different types of cancers. Besides, some risk factors such as smoking, alcohol consumption and human papilloma virus have been found to be associated with both periodontitis and oral cancer. This review article aimed to study the current concepts in pathogenesis of chronic periodontitis and oral cancer by reviewing the related articles.

circRNA_0000140 suppresses oral squamous cell carcinoma growth and metastasis by targeting miR-31 to inhibit Hippo signaling pathway

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies and has a poor prognosis. Circular RNA (circRNA) has been increasingly recognized as a crucial contributor to carcinogenesis. circRNA_0000140 has been aberrantly expressed in OSCC, but its role in tumor growth and metastasis remains largely unclear. Sanger sequencing, actinomycin D, and RNase R treatments were used to confirm head-to-tail junction sequences and the stability of circ_0000140. In vitro cell activities, including proliferation, migration, invasion, and apoptosis, were determined by colony formation, transwell, and flow cytometry assays. The expression levels of circ_0000140, Hippo signaling pathway, and serial epithelial–mesenchymal transition (EMT) markers were measured by quantitative real-time PCR, western blotting, immunofluorescence, and immunohistochemistry. Dual luciferase reporter assays and Argonaute 2-RNA immunoprecipitation assays were performed to explore the interplay among circ_0000140, miR-31, and LATS2. Subcutaneous tumor growth was observed in nude mice, in which in vivo metastasis was observed following tail vein injection of OSCC cells. circ_0000140 is derived from exons 7 to 10 of the KIAA0907 gene. It was down-regulated in OSCC tissues and cell lines, and correlated negatively with poor prognostic outcomes in OSCC patients. Gain-of-function experiments demonstrated that circ_0000140 enhancement suppressed cell proliferation, migration, and invasion, and facilitated cell apoptosis in vitro. In xenograft mouse models, overexpression of circ_0000140 was able to repress tumor growth and lung metastasis. Furthermore, mechanistic studies showed that circ_0000140 could bind with miR-31 and up-regulate its target gene LATS2, thus affecting OSCC cellular EMT. Our findings demonstrated the roles of circ_0000140 in OSCC tumorigenesis as well as in metastasis, and circ_0000140 exerts its tumor-suppressing effect through miR-31/LATS2 axis of Hippo signaling pathway in OSCC.

Expression profile analysis identifies IER3 to predict overall survival and promote lymph node metastasis in tongue cancer

Background

Lymph node metastasis is one of the most important factors affecting the prognosis of tongue cancer, and the molecular mechanism regulating lymph node metastasis of tongue cancer is poorly known.

Methods

The gene expression dataset GSE2280 and The Cancer Genome Atlas (TCGA) tongue cancer dataset were downloaded. R software was used to identify the differentially expressed hallmark gene sets and individual genes between metastatic lymph node tissues and primary tongue cancer tissues, and the Kaplan-Meier method was used to evaluate the association with overall survival. The screening and validation of functional genes was performed using western blot, q-PCR, CCK-8, migration and invasion assays, and lymphangiogenesis was examined by using a tube formation assay.

Results

Thirteen common hallmark gene sets were found based on Gene Set Variation Analysis (GSVA) and then subjected to differential gene expression analysis, by which 76 deregulated genes were found. Gene coexpression network analysis and survival analysis further confirmed that IER3 was the key gene associated with the prognosis and lymph node metastasis of tongue cancer patients. Knockdown of IER3 with siRNA inhibited the proliferation, colony formation, migration and invasion of Tca-8113 cells in vitro and it also inhibited the secretion and expression of VEGF-C in these cells. The culture supernatant of Tca-8113 cells could promote lymphangiogenesis and migration of lymphatic endothelial cells, and knockdown of IER3 in Tca-8113 cells suppressed these processes.

Conclusion

Our study demonstrated that IER3 plays important roles in lymphangiogenesis regulation and prognosis in tongue cancer and might be a potential therapeutic target.

Junction plakoglobin, a potential prognostic marker of oral squamous cell carcinoma, promotes proliferation, migration and invasion

BACKGROUND

Junction plakoglobin (JUP) is an important cell-cell junction protein. Recently, its deregulation has been correlated with the initiation and progression of various malignancies. Our aim was to investigate the expression of JUP in oral squamous cell carcinoma (OSCC) and its correlation with prognosis and to further study the effects of JUP on the proliferation, apoptosis, migration and invasion of OSCC cells.

METHODS

We detected JUP expression in 273 OSCC specimens using immunohistochemistry. We assessed the correlation of JUP expression with clinicopathologic parameters and patient survival by Cox regression. Then, expression levels of JUP in normal oral keratinocytes (NOKs) and OSCC cell lines were detected by Western blotting and quantitative real-time PCR (qPCR). Next, we used HSC3 cells to study the effect of JUP on tumor cell proliferation, apoptosis, migration, and invasion by using cell counting kit-8, flow cytometry, and transwell assays, respectively.

RESULTS

Cox regression showed that high expression of JUP was related to the poor prognosis of OSCC patients. Western blotting and qPCR assays showed that the expression level of JUP in OSCC cell lines was higher than that in NOKs. Overexpression of JUP promoted the proliferation, metastasis, and invasion of HSC3 cells and inhibited apoptosis, while the opposite was observed after JUP knockdown.

CONCLUSION

This study initially revealed that JUP was overexpressed in OSCC, and that JUP promoted the proliferation, migration, and invasion of OSCC cells and inhibited apoptosis. Moreover, high expression of JUP could be used as a potential prognostic marker of OSCC.