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

Identification of novel genetic variants associated with oral squamous cell carcinoma (OSCC) in South-West coast of India using targeted exome sequencing

Oral squamous cell carcinoma (OSCC) is a subset of head and neck squamous cell carcinoma (HNSCC). This study explores the genetic landscape of oral squamous cell carcinoma (OSCC) in a cohort of 33 patients from Southern India using targeted exome sequencing. Our analysis revealed a diverse range of mutations across the cohort, with missense mutations being the most prevalent. Pathogenic mutations, as classified by ClinVar, exhibited significant individual variation, highlighting the heterogeneity of OSCC. Seventy-five genes were identified to harbor pathogenic or potentially pathogenic mutations, with notable recurrence in genes such as TP53, PDGFRA, and RAD50 among others. Comparison with high-frequency mutation genes in HNSCC from TCGA database revealed significant overlap, emphasizing the relevance of these mutations across different populations. Additionally, several novel mutations were identified, including those in CHD8, ITPKB, and HNF1A, shedding light on potential genetic risk factors specific to this population. Functional annotation and pathway analysis underscored the involvement of these mutated genes in various cancer-related pathways. Despite limitations such as sample size and the need for further validation, this study contributes to a deeper understanding of OSCC pathogenesis and highlights potential genetic markers for prognosis and targeted interventions, especially in the Indian context.

Screening Differentially Expressed Proteins in Areca Nut-Related Oral Squamous Cell Carcinoma Using Tandem Mass Tag Proteomics

OBJECTIVE

Areca nut chewing has been associated with a poor prognosis in oral squamous cell carcinoma (OSCC). This study seeks to identify differentially expressed proteins among areca nut-related OSCC,non-areca nut-related OSCC and adjacent normal epithelial tissues, with the aim of providing novel insights for the investigation of areca nut-related OSCC.

METHODS

Using Tandem mass tag (TMT)-based proteomic analysis, a comparative proteomic profiling was conducted among areca nut-related OSCC, non-areca nut-related OSCC, and adjacent normal epithelial tissues (n=15). GO and KEGG enrichment analyses were then employed to identify significant proteins pertinent to the pathogenesis of OSCC for further study. Western Blot (WB) and Immunohistochemistry (IHC) techniques were used to preliminary validate the expression patterns of LZTS1, MMP10, MYH6, MB, and TNNC1 among various groups (n=30).

RESULTS

27 differentially expressed proteins were identified when comparing the areca nut-related OSCC group with both the non-areca nut-related OSCC and normal epithelial tissue groups. Among these, 15 proteins were upregulated, while 12 were downregulated. LZTS1 and MMP10 were included in the upregulated proteins, whereas MYH6, MB, and TNNC1 were downregulated. WB and IHC analyses corroborated the proteomic findings, revealing consistent expression trends for these 5 proteins across the studied groups.

CONCLUSION

LZTS1, MMP10, MYH6, MB and TNNC1 emerge as promising biomarkers for assessing disease progression, prognosis, and potential targeted therapies in areca nut-related OSCC.

Porcupine expression promotes the progression of oral carcinogenesis

Oral squamous cell carcinoma (OSCC) is the most common type of oral cancer, which is usually preceded by a potentially malignant disorder histologically diagnosed as dysplasia. We and others have provided evidence for the pro-carcinogenic role of the Wnt/β-catenin pathway in this context, in which Wnt ligands stabilize and allow relocalization of β-catenin to the nucleus for transcription of pro-survival and pro-proliferation genes. However, the contribution of Porcupine (PORCN), an O-acyltransferase that catalyzes the palmitoylation of Wnt ligands, to OSCC carcinogenesis is not known. Moreover, the effectiveness of LGK974, a novel PORCN inhibitor remains to be elucidated. By using different ex vivo, in vivo and in vitro OSCC carcinogenesis models, we show that PORCN expression is significantly increased in high-grade dysplasia as well as moderately/poorly- differentiated OSCC. Consistent with these observations, expression of key proteins involved in the Wnt/β-catenin pathway are elevated as well. Importantly, the treatment with LGK974, a chemical PORCN inhibitor, reduced the number and size of oral lesions in mice treated with 4-Nitroquinoline 1-oxide (4NQO), a tobacco smoke surrogate. These results highlight the role of PORCN during OSCC carcinogenesis.

Isoorientin: Unveiling the hidden flavonoid's promise in combating cancer development and progression - A comprehensive review

Cancer remains one of the leading causes of mortality worldwide, characterized by uncontrolled cell growth and the ability of tumors to invade surrounding tissues and spread to distant organs. Despite significant advancements in early detection, diagnosis, and treatment, many cancers still present substantial challenges due to their heterogeneity, resistance to conventional therapies, and severe side effects of existing treatments. Consequently, there is an ongoing need for novel therapeutic agents to selectively target cancer cells, enhance the efficacy of current treatments, and minimize adverse effects. Isoorientin (ISO) is a naturally occurring flavonoid known for its anticancer properties. ISO has demonstrated the ability to influence several critical processes in cancer progression, such as cell proliferation, apoptosis, and metastasis. Due to the absence of clinical trials, we included only in vitro studies, reviewing 13 investigations. These studies covered diverse cancer types, including lung, brain, oral, liver, pancreatic, and gastric cancers, and assessed various outcomes related to cell viability, apoptosis, migration, and molecular pathway modulation. By synthesizing data from these investigations, our review seeks to provide a thorough understanding of ISO's anticancer effects, its mechanisms of action, and its potential as a therapeutic agent.

A Review of a Breakdown in the Barrier: Tight Junction Dysfunction in Dental Diseases

The tight junction (TJ), a type of cell-cell junction, regulates the permeability of solutes across epithelial and endothelial cellular sheets and is believed to maintain cell polarity. However, recent studies have provided conflicting views on the roles of TJs in epithelial polarity. Membrane proteins, including occludin, claudin, and the junction adhesion molecule, have been identified as TJ components. TJs are predominantly found at the stratum granulosum and stratum corneum. Although it remains unclear whether the disruption of TJs is the cause or consequence of certain dental diseases, evidence suggests that TJ dysfunction may be a crucial factor in gingival epithelial barrier impairment and the progression of oral diseases. Bacterial infection is among the most specific factors we found that may contribute to the breakdown of the epithelial barrier formed by TJs in dental diseases. Bacteria and their products may weaken the epithelial barrier by directly destroying intercellular junctions or altering the expression of junctional proteins. Additionally, they may induce the production of inflammatory cytokines, which could lead to the downregulation of TJ proteins and, consequently, impair the epithelial barrier. This review introduces a novel perspective by exploring, for the first time, the role of TJs dysfunction in the breakdown of the oral epithelial barrier and its potential link to the progression of dental diseases such as gingivitis, periodontitis, Sjӧgren syndrome, and oral squamous cell carcinoma.

The role of long non-coding RNA LINC00839 in oral squamous cell carcinoma based on bioinformatics and experimental research

This study explores the role of LINC00839 and its potential interaction with the miR-195-5p/cyclin E1 (CCNE1) axis in oral squamous cell carcinoma (OSCC). Using The Cancer Genome Atlas, we analyzed lncRNA, miRNA, and mRNA sequencing data for OSCC. Different online tools were applied to detect lncRNA-related miRNAs and their target mRNAs, forming a lncRNA/miRNA/mRNA axis. Co-expression analysis determined the correlation between lncRNA and mRNA expression. Afterward, protein-protein interaction network and functional enrichment analyses disclosed the biological activity of target genes. The expression and correlations of LINC00839, miR-195-5p, and CCNE1 were examined in 30 pairs of OSCC and noncancerous tissues. A Chi-square test was used to determine clinicopathological associations, and ROC analysis estimated diagnostic value. A total of 66 differentially expressed lncRNAs, 80 miRNAs, and 1149 mRNAs were identified in OSCC versus non-tumor samples. After filtering lncRNAs based on novelty, and predicting lncRNA-miRNA, and miRNA-mRNA interactions, the LINC00839/miR-195-5p/CCNE1 axis was discovered. RT-qPCR showed upregulation of LINC00839 and CCNE1 was accompanied by the downregulation of miR-195-5p. A significant positive correlation was observed between LINC00839 and CCNE1 mRNA expression, along with a significant negative correlation between LINC00839 and miR-195-5p expression. Moreover, increased LINC00839 was associated with tumor grade and lymph node status, while decreased miR-195-5p was correlated with lymph, depth, and vascular invasion (p < 0.05). The combined ROC curve demonstrated a significant area under the curve of 0.93. This discovery reveals a novel regulatory mechanism underlying OSCC tumorigenesis and may provide effective diagnosis and potential therapeutic targets to cure this devastating cancer.

Premalignant lesions of the oral cavity: a narrative review of factors and mechanisms of transformation into cancer

Oral squamous cell carcinoma (OSCC) is the most common type of head and neck cancer. The development and progression of OSCC are closely linked to various aetiological factors. Early signs of OSCC may manifest as oral lesions, genetic abnormalities, and chronic inflammation. Lesions with dysplastic features have a high risk of malignant transformation into OSCC. Moreover, dysplastic lesions are characteristic of many oral potentially malignant disorders (OPMDs). Currently, there is no unified standard of treatment for OPMD patients, due to the variability in risk factors and mechanisms of transformation. Therefore, it is essential to detect and manage OPMDs at an early stage in order to prevent their malignant transformation into OSCC. This necessitates analysing OPMD mechanisms to identify objective markers for predicting the risk of malignant transformation. The aim of this review was to describe the process of OPMD transformation into OSCC under the influence of environmental, immune, microbiome, and molecular factors.

Cytomorphological changes of oral mucosal cells among smokeless tobacco users in low and middle-income country settings: new findings from Pakistan

BACKGROUND

Chronic tobacco use, in any form, induces significant cellular alterations in the oral mucosa. This study investigates four distinct cytomorphological changes in oral mucosal cells among smokeless tobacco users, examining their association across different genders and age groups.

MATERIALS AND METHODS

This cross-sectional study involved collecting mucosal samples from smokeless tobacco (naswar/snuff) users through consecutive sampling. The prepared smears were examined for dysplastic changes. Data analysis was performed using SPSS, with Chi-square tests and logistic regression employed to evaluate proportions and associations.

RESULTS

Among 100 Naswar/snuff users, the labial sulcus mucosa was the most common site affected (47%). The most frequent cytomorphological change was micronuclei (46%), followed by nuclear budding (25%), perinuclear halo (18%), and binucleated cells (14%). In the 51-60 age group, micronuclei (78.9%), nuclear budding (55.3%), binucleation (31.6%), and perinuclear halo (36.8%) were more prevalent (P < 0.005). Gender analysis revealed that micronuclei were more common in females (54.2%) compared to males (43.4%), while nuclear budding was more prevalent in males (27.6%) than females (P < 0.28). Logistic regression indicated that individuals aged 51-60 were more likely to exhibit micronuclei (OR = 1.15, 95% CI: 0.22 to 5.83, P = 0.863) and nuclear budding (OR = 15.34, 95% CI: 9.23 to 30.75, P < 0.05).

CONCLUSION

The dysplastic changes observed included micronuclei, nuclear budding, binucleated cells, and perinuclear halo, with micronuclei being the most prevalent. These findings could facilitate the early diagnosis of oral lesions and their timely management in habitual smokeless tobacco users.

Metabolic targeting of regulatory T cells in oral squamous cell carcinoma: new horizons in immunotherapy

Oral squamous cell carcinoma (OSCC) is a prevalent oral malignancy, which poses significant health risks with a high mortality rate. Regulatory T cells (Tregs), characterized by their immunosuppressive capabilities, are intricately linked to OSCC progression and patient outcomes. The metabolic reprogramming of Tregs within the OSCC tumor microenvironment (TME) underpins their function, with key pathways such as the tryptophan-kynurenine-aryl hydrocarbon receptor, PI3K-Akt-mTOR and nucleotide metabolism significantly contributing to their suppressive activities. Targeting these metabolic pathways offers a novel therapeutic approach to reduce Treg-mediated immunosuppression and enhance anti-tumor responses. This review explores the metabolic dependencies and pathways that sustain Treg function in OSCC, highlighting key metabolic adaptations such as glycolysis, fatty acid oxidation, amino acid metabolism and PI3K-Akt-mTOR signaling pathway that enable Tregs to thrive in the challenging conditions of the TME. Additionally, the review discusses the influence of the oral microbiome on Treg metabolism and evaluates potential therapeutic strategies targeting these metabolic pathways. Despite the promising potential of these interventions, challenges such as selectivity, toxicity, tumor heterogeneity, and resistance mechanisms remain. The review concludes with perspectives on personalized medicine and integrative approaches, emphasizing the need for continued research to translate these findings into effective clinical applications for OSCC treatment.

Expression of mTOR, CD163, α-SMA, FOXp3 as survival predictors and its significance in patients with oral squamous cell carcinoma

BACKGROUND

Oral cancer; categorised under head and neck cancers (HNC) predominantly originates from squamous cells and is referred as oral squamous cell carcinoma (OSCC). Various factors (internal and external) causes OSCC. PI3K/AKT/mTOR pathways are known to be primarily mutated in HNC. mTOR remains as a key regulator for various physiological and developmental processes in normal and cancer cells. Cancer cells are surrounded by tumor microenvironment, majorly composed of immune cells. Cancer associated fibroblasts, macrophages and regulatory T cells controlled by mTOR, plays an important role in the progression of cancer.

METHODS

Two hundred sixty retrospective patient samples were collected along with their demographical and clinic-pathological data. Here, we have analysed expression of mTOR, α-SMA, CD163 and FOXp3 using immunohistochemistry and their survival outcomes were calculated using Kaplan-Meier statistical method.

RESULTS

Overexpression of CD163 and α-SMA was detected in samples of patients compared to mTOR and FOXp3. Their expression was compared with clinico-oncological parameters. We also observed two and three combinations of markers and its association with the prognosis of the cancer. The results suggest, higher the expression of all the four markers in combination correlated to poor prognosis of patients and vice-versa.

CONCLUSION

The study reveals that over expression of CD163 and α-SMA is strongly associated with disease outcome. The combinations of all the four marker expression profile will be emerging strategy towards prognosis and also to determine survival outcomes in patients. This is a pioneering observation of these combinations of markers in OSCC despite certain limitations.

AKR1B10 and digestive tumors development: a review

Aldo-keto reductase family 1 member B10 (AKR1B10) is a member of the AKR1B subfamily. It is mainly found in cytoplasm, and it is typically expressed in the stomach and intestines. Given that its expression is low or absent in other tissues, AKR1B10 is a potential diagnostic and therapeutic biomarker for various digestive system diseases. Here, we review recent research progress on AKR1B10 in digestive system tumors such as hepatocellular carcinoma, gastric carcinoma, colorectal carcinoma, pancreatic carcinoma, oral squamous cell carcinoma, laryngeal squamous cell carcinoma, cholangiocarcinoma, and nasopharyngeal carcinoma, over the last 5 years. We also discuss the current trends and future research directions for AKR1B10 in both oncological and non-oncological diseases to provide a scientific reference for further exploration of this gene.

Dichloroacetate and chloroquine in combination with arsenite suppress ROS-induced oral squamous cell carcinoma (OSCC) development and improve BALB/c mice survival

Oral squamous cell carcinoma (OSCC) is a disabling tumor with poor response to chemotherapy. Here, we sought to explore a new chemotherapeutic approach based on a combined induction of cytotoxic ROS and targeting of autophagy and aerobic glycolysis as central contributors to OSCC carcinogenesis and chemoresistance. To this end, tongue OSCC was generated in BALB/c mice using 4NQO. Treatment of mouse-derived OSSC explants with NaAsO2 resulted in a strong inhibition of MTT activity and Bcl-2 and Ki-67 expression. The addition of chloroquine (CQ) and dichloroacetate (DCA) to arsenite, resulted in additive inhibitory effects on Bcl-2 and Ki-67 expression. Whereas NaAsO2 alone inhibited aerobic glycolysis (LDHA), it also alleviated autophagy (LC3B) and ROS levels (MDA). DCA improved NaAsO2-dependent inhibition of aerobic glycolysis. CQ addition to arsenite, suppressed autophagy without affecting the Warburg effect. NaAsO2 combination with CQ and DCA improved the oxidative status balance by boosting anti-oxidative CAT and SOD and controlling pro-oxidant MDA activity. The administration of the combo to 4NQO-mice resulted in a significant survival advantage over the control group (90 % vs. 35 % survival at week 32, p < 0.02; HR (log-rank) = 0.166, CI 95 % 0.03-0.73). This effect was accompanied by a significant increase in mice's mean body weight (p < 0.009). Contrarily to the control, administration of the combo resulted in the absence of progression towards severe dysplasia and OSCC and an overrepresentation of low/mild dysplasia events (100 %). Interestingly, signs of hepatocellular and renal toxicity following combo administration were limited in comparison to control. Taken together, these results suggest that NaAsO2 combined with CQ and DCA may constitute an interesting alternative to eliminating chemo-resistant OSSC tumors by inhibiting aerobic glycolysis and autophagy and controlling ROS generation. In vivo, the drugs may provide a survival advantage by inhibiting tumor development.

Neutrophil-to-Lymphocyte Ratio and Pembrolizumab Outcomes in Oral Cavity Squamous Cell Carcinoma

OBJECTIVE

To determine the relationship between pretreatment neutrophil-to-lymphocyte ratio (NLR) and 6-month progression-free survival (PFS)/2-year overall survival (OS) among patients with recurrent or metastatic (R/M) oral cavity cancer on pembrolizumab.

STUDY DESIGN

This study was a retrospective, observational study performed at a tertiary care academic center.

SETTING

Participants included patients with oral cavity squamous cell carcinoma (OCSCC) who began pembrolizumab treatment at the University of California, San Francisco between May 2016 and May 2022.

METHODS

The primary outcome was a 6-month PFS. The secondary outcome was a 2-year OS. NLR was treated as a continuous variable. Disease progression was determined using radiographic criteria, adopted from the Response Evaluation Criteria in Solid Tumors.

RESULTS

Fifty-two patients with OCSCC were included. Immune checkpoint inhibitor (ICI) indication was recurrence/metastasis for all patients. The median pretreatment NLR was 5.7 (interquartile range: 3.6-7.6). Twenty-seven (55%) patients received pembrolizumab alone. Of those receiving treatment for R/M prior to ICI, 9 (18%) received salvage surgery and adjuvant therapy, 2 (4%) received chemotherapy alone, 1 (2%) received chemoradiation, and 10 (20%) received salvage surgery. Nineteen (36.5%) patients had distant metastases at the start of ICI. Six-month PFS was 46%. Two-year OS was 44%. NLR was independently associated with 6-month PFS [hazard ratio, HR: 1.05 (95% confidence interval, CI: 1.01-1.11), P = .028] and 2-year OS [HR: 1.12 (95% CI: 1.05-1.20), P < .001].

CONCLUSION

Higher pretreatment NLR was associated with poorer 6-month PFS and 2-year OS in OCSCC patients treated with pembrolizumab.

Estimating the Benefits of Oral Cancer Screening: Challenges and Opportunities

Screening is widely believed to facilitate early detection and improve health outcomes; however, recent evidence questions its overall benefits, highlighting the need for a critical assessment of cancer screening programs. The simplicity of clinical oral examination and the easy accessibility of the oral cavity make oral cancer a suitable candidate for opportunistic screening. Despite this uniqueness, studies that solidly assess the efficacy and cost-effectiveness of oral cancer screening are scanty, and the only large randomized trial undertaken so far shows limited evidence of mortality reduction through population screening. Research indicates that while early detection rates following screening may increase, they do not necessarily translate into decreased oral cancer deaths. This article emphasizes the need for a nuanced understanding of the benefits of screening, awareness of deceptive metrics and inherent biases in the context of early detection, and the importance of improving dentist education and introducing new technologies to enhance clinical decision-making. The review calls for a balanced and evidence-based approach to oral cancer screening, integrating it with broader oral health initiatives to maximize public health outcomes.

DNA hypermethylation of tumor suppressor genes among oral squamous cell carcinoma patients: a prominent diagnostic biomarker

Oral Squamous Cell Carcinoma is a globally revealing form of oral malignancy. Epigenetics, which studies genetic modifications in gene expression without altering the sequence of DNA, is crucial for understanding OSCC. Key epigenetic modifications such as histone modifications, DNA methylation, and microRNA regulation play significant roles in Oral carcinoma. Aberrant methylation of DNA of tumor suppressor genes which leads to their inactivation, promoting cancer development, and specific methylation patterns are emerging as biomarkers for early OSCC detection.Current treatments like surgery, radiotherapy, and chemotherapy often fall short, prompting research into epigenetic therapies. Agents like DNMT and HDAC inhibitors demonstrate the potential for reversing aberrant epigenetic patterns, perhaps reactivating silenced TSGs, and suppressing oncogenes. Despite early promise, the development of effective combination medicines and the identification of reliable biomarkers continue to present challenges.In OSCC, resistance to therapy is also influenced by epigenetic processes. Aberrant DNA methylation and changes in histone modifications impact genes involved in medication metabolism and the survival of cells. Enhancing treatment efficacy and overcoming medication resistance may be possible by recognizing and focusing on these processes. This review explores the interplay between epigenetic changes and OSCC, their role in the disease's initiation and progression, and their impact on diagnosis and treatment. It also discusses the potential of epigenetic drugs (epi-drugs) to improve diagnostic precision and treatment outcomes.

Tumor-Derived GDF15 Induces Tumor Associated Fibroblast Transformation From BMSCs and Fibroblasts in Oral Squamous Cell Carcinoma

Cancer associated fibroblasts (CAFs) are the predominant stromal cell-type in the solid tumor microenvironment, originating from various cell types and playing a crucial role in promoting tumor progression and metastasis The generation of CAFs is influenced by complex factors secreted by tumor cells, with particular emphasis on transforming growth factor-β (TGF-β). However, it remains largely unknown whether growth/differentiation factor-15 (GDF15), as a member of the TGF-β superfamily, exerts similar effects to TGF-β in oral squamous cell carcinoma (OSCC). In this study, we investigated the impact of GDF15 derived from tumor cells on CAF transformation and elucidated the underlying mechanisms. Exogenous GDF15 and OSCC cells induced the transformation of bone marrow mesenchymal stem cells (BMSCs) and human gingival fibroblasts (HGFs) into CAFs, as evidenced by α-smooth muscle actin (α-SMA) as a phenotypic marker and TGF-β, interleukin 6 (IL-6), and vascular endothelial-derived growth factor (VEGF) as functional markers. Conversely, knockdown of GDF15 in OSCC cells reversed CAF transformation. Mechanistically, extracellular signal-regulated kinases 1/2(ERK1/2) pathway was associated with GDF15-mediated promotion of CAF transformation. Furthermore, OSCC-induced CAFs enhanced migration and invasion abilities of OSCC cells; but this pro-cancer effect was abolished upon knockdown of GDF15 in OSCC cells. Subcutaneous coinjection of OSCC cells with BMSCs or HGFs into mice revealed the promoted tumor growth along with increased expression levels of α-SMA and Ki67 compared with alone OSCC cells injection; these effects were attenuated when GDF15 was knocked down in OSCC cells. Collectively, our findings suggest that tumor-derived GDF15 contributes to the progression of OSCC by promoting CAF transformation through activation of the ERK1/2 pathway.

Advances in nanotechnology-based approaches for the treatment of head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC), one of the most common types of cancers occurring in the head and neck region, is often associated with high mortality rates due to its invasiveness and morbidity. The mainstream treatment methods in clinical settings, including surgery, chemotherapy, and radiotherapy, may cause poor overall survival rate and prognosis, with issues such as drug resistance, damage to adjacent healthy tissues, and potential recurrences. Other treatment approaches such as immunotherapy, photodynamic therapy (PDT), and photothermal therapy (PPT) also suffer from inefficient tumor targeting and suboptimal therapeutic outcomes. Early detection is vital for HNSCC patients, but it is always limited by insensitivity and confusing clinical manifestations. Hence, it is highly desirable to develop optimized therapeutic and diagnostic strategies. With the boom in nanomaterials, nanotechnology-conducted HNSCC therapy has attracted widespread attention. Nanoparticles (NPs) are distinguished by their unique morphology and superior physicochemical property, and some can exhibit direct antitumor activity, while others serve as promising candidates for drug delivery. In addition, NPs offer the potential for structural modification for drug delivery and tumor targeting, enabling specific delivery to tumor cells through conjugation with biomarker ligands and improving cargo biocompatibility. This work reviews current therapies and diagnosis methods for HNSCC, highlights the characteristics of the major NPs, surveys their uses and advantages in the treatment of HNSCC, and discusses the obstacles and prospects in clinical applications, aiming to enlighten future research directions for nanotechnology-based therapy for HNSCC.

Integrating omics data and machine learning techniques for precision detection of oral squamous cell carcinoma: evaluating single biomarkers

Introduction

Early detection of oral squamous cell carcinoma (OSCC) is critical for improving clinical outcomes. Precision diagnostics integrating metabolomics and machine learning offer promising non-invasive solutions for identifying tumor-derived biomarkers.

Methods

We analyzed a multicenter public dataset comprising 61 OSCC patients and 61 healthy controls. Plasma metabolomics data were processed to extract 29 numerical and 47 ratio features. The Extra Trees (ET) algorithm was applied for feature selection, and the TabPFN model was used for classification and prediction.

Results

The model achieved an area under the curve (AUC) of 93% and an overall accuracy of 76.6% when using top-ranked individual biomarkers. Key metabolic features significantly differentiated OSCC patients from healthy controls, providing a detailed metabolic fingerprint of the disease.

Discussion

Our findings demonstrate the utility of integrating omics data with advanced machine learning techniques to develop accurate, non-invasive diagnostic tools for OSCC. The study highlights actionable metabolic signatures that have potential applications in personalized therapeutics and early intervention strategies.

Oral squamous cell carcinomas drive monocytes into immunosuppressive CD25+CD163+CD206+ macrophages

Tumor-associated macrophages (TAMs) are major cellular components in the tumor microenvironment of oral squamous cell carcinomas (OSCCs). Most of these TAMs derive from circulating monocytes that differentiate in situ. In this work, we show that cell culture media (CM) derived from two OSCC cell lines, H413 and TR146, promote monocyte differentiation into M2 macrophages, characterized by a high expression of CD163, CD206 and a low expression of CD11c, CD86 and HLA-DR. Monocyte-derived macrophages (moMΦ) differentiated by CM from H413 cells (H413-CM) were also unable to activate allogeneic T cells, and inhibited T cell activation and proliferation induced by CD3/CD28 stimulation. By culturing monocytes with fractionated H413-CM, we found that soluble proteins mediated CD163+CD206+ moMΦ differentiation, discarding a role for small metabolites and extracellular vesicles. Differential proteomic analyses on H413-CM fractions revealed the presence of several proteins, including the complement factor H or plasminogen activator inhibitor 1, as potential candidates to induce CD163+CD206+ moMΦ differentiation. Finally, RNAseq transcriptomic analyses of H413-CM conditioned moMΦ, identified a expression profile signature involving cytokines and cytokine receptors, which surprisingly included IL2RA (encoding CD25). CD25 enhanced expression was confirmed on H143-CM moMΦ. Collectively, these data indicate that the CM from OSCC cell lines promotes the differentiation of functionally immunosuppressive macrophages resembling TAMs, and contributes to the understanding of how OSCCs create an immunosuppressive cellular environment that favors tumor growth.

Metformin radiosensitizes OSCC in 2D and 3D models: possible involvement of CAF-1

Objective

This study investigated metformin as a sensitizer for radiotherapy in oral squamous cell carcinoma (OSCC) to reduce the radiation intensity. It evaluated the drug's effect on Chromatin Assembly Factor-1 (CAF-1) expression, whose high levels correlate with worse prognosis of this cancer.

Methods

The effects of metformin, alone and with radiotherapy, were evaluated on CAL27 (HPV-) and SCC154 (HPV+) OSCC cells. The analyses were performed on cell monolayers by colony-forming assay, motility, and confocal microscopy. In spheroid 3D models, the sensitizing effect of metformin was assessed by measuring areas. CAF-1 expression affected by metformin was evaluated via Western blot, and its role was investigated by siRNAs.

Results

Metformin reduced the cells' ability to form colonies, migrate and invade, and promoted the acquisition of a less aggressive phenotype by increased E-cadherin and decreased N-cadherin expressions. Moreover, metformin lowered the IC50 of radiotherapy and showed strong effects on spheroid growth. Metformin downmodulated the expression of the major subunits of CAF-1, and the knockdown of this protein by siRNAs elicited a metformin-like effect on cell aggressiveness.

Conclusions

Metformin emerged as a promising adjuvant drug in OSCC because of its effects on cell aggressiveness and radiosensitizing action. These activities could be CAF-1-mediated.

Utilizing a Fully Digital Approach for Oral Squamous Cell Carcinoma Treatment and Zygomatic Implant-Based Rehabilitation for Maxillary Defects

This clinical report details the functional and esthetic rehabilitation of a patient with a severe maxillary defect secondary to subtotal maxillectomy for oral squamous cell carcinoma using a maxillary prosthesis anchored by 4 zygomatic implants. The procedure involved meticulous subtotal maxillectomy and defect repair with zygomatic implant support, incorporating advanced digital surgical methods, including 3D reconstruction, computer-guided surgery, and photogrammetry (Icam4D). A 3D finite element analysis was conducted to assess the method's efficacy in analyzing stress distribution around the zygomatic implants. The patient expressed high satisfaction with the prosthesis's functionality, esthetics, speech, and swallowing capabilities, underscoring the value of zygomatic implant-supported maxillofacial prosthetics. This synergy of advanced planning, surgical precision, and biomechanical analysis marks a significant advancement in maxillofacial prosthetics.

Global research on oral cancer: A bibliometric analysis based on 82 highly cited publications from 2014 to 2024

OBJECTIVE

Oral cancer refers to a group of malignancies. The disease's complexity requires a multidisciplinary approach, encompassing oncology, dentistry, epidemiology, molecular biology, and other fields. Given this multifaceted nature, bibliometrics has emerged as a crucial tool to navigate the vast array of academic literature surrounding oral cancer.

METHOD

82 highly cited publications on oral cancer were collected based on the Web of Science Core Collection. For bibliometric visualization and analysis, VOSviewer and R software (4.3.0 version) were used to explore publication trends, collaboration networks, core journals, research hotspots and authors in the field of oral cancer.

RESULTS

This study analyzed 82 publications published over the past 11 years, including 46 published in the United States, 17 in China, 17 in UK, 12 in Canada and 10 in India. Quynh-Thu Le had the most publications (4 publications). Burtness B was the most cited author with 1,926 citations. University of Texas MD Anderson Cancer Center was the most active institution by contributing 7 publications. The most productive journal was journal of clinical oncology. Cluster Analysis of Co-occurrence Keywords revealed that top 10 highest number of core words were squamous-cell carcinoma, cancer, human-papillomavirus, survival, united-states, oropharyngeal cancer, risk, epidemiology, head and risk-factors.

CONCLUSION

Over the past 11 years, studies of oral cancer are increasingly. This bibliometric study may aid researchers in the understanding of the knowledge base and research frontiers associated with oral cancer. Emerging hotspots for research can be used as the subjects of future studies.

Expression and role of methyltransferase 3 in oral malignant transformation

OBJECTIVE

To investigate the expression and role of methyltransferase 3 (METTL3) in oral malignant transformation.

MATERIALS AND METHODS

Immunohistochemical method was used to investigate the expression of METTL3 in the human oral malignant transformation. Bioinformatics analysis was used to explore the role of METTL3 in oral malignant transformation. Oral cancer animal model was used to verify the expression trend of METTL3 in oral malignant transformation. Knockdown of METTL3 expression in human oral mucosal precancerous lesion cells was performed to explore the METTL3 effect on proliferation, migration, apoptosis, and cell cycle.

RESULTS

METTL3 expression was significantly up-regulated in the human oral malignant transformation. Moreover, METTL3 was related to the pathway of "Neuroactive ligand-receptor interaction." In addition, METTL3 expression was also significantly up-regulated in the hamster oral malignant transformation. Finally, the proliferation and migration abilities of human oral mucosal precancerous lesion cells were inhibited after METTL3 knockdown.

CONCLUSIONS

In conclusion, we found that METTL3 was up-regulated in oral malignant transformation, and the role may relate to the pathway of "Neuroactive ligand-receptor interaction."

Abnormal p53 Immunohistochemical Patterns Are Associated with Regional Lymph Node Metastasis in Oral Cavity Squamous Cell Carcinoma at Time of Surgery

Most (60%-80%) of the oral cavity invasive squamous cell carcinoma (OSCC) demonstrate molecular alterations in TP53. The presence of TP53 mutations in multiple organ systems has been associated with a more aggressive clinical course. This study aimed to classify OSCC into p53 wild-type OSCC and p53-abnormal OSCC using p53 immunohistochemistry and to determine if abnormal p53 status correlates with a higher risk of lymph node metastasis at the time of surgery. A total of 101 patients with OSCC resection and cervical lymph node dissection were identified. p53 immunohistochemistry was performed for all cases and scored into p53 wild-type (p53-HPV: midepithelial/basal sparing, markedly reduced [null-like]/basal sparing; p53-conventional: scattered basal, patchy basal/parabasal) and p53-abnormal (overexpression basal/parabasal only, overexpression basal/parabasal to diffuse, null, and cytoplasmic) patterns. p16 immunohistochemistry and high-risk HPV RNA in situ hybridization were used to confirm the HPV status in cases showing midepithelial/basal sparing or markedly reduced (null-like)/basal sparing pattern. Logistic regression analysis was performed to investigate the association of p53 status, tumor size, depth of invasion, and pT stage against lymph node status. We identified 22 cases with p53 wild-type patterns (16 p53-conventional, 6 p53-HPV) and 79 cases with p53-abnormal patterns. Two of 22 p53 wild-type cases had positive lymph nodes (1 p53-conventional, 1 p53-HPV), whereas 40 of 79 p53-abnormal cases had positive lymph nodes (P < .001). Multivariate analysis showed that p53-abnormal pattern was an independent risk factor associated with positive node(s) with an odds ratio of 8.12 (95% CI, 2.10-53.78; P = .008). p53-Abnormal OSCCs were significantly more likely to be associated with positive lymph node status than p53 wild-type OSCCs at the time of surgery. Further investigation with long-term follow-up is required to determine its clinical application before surgery planning.

Achieving negative superficial resection margins with NBI and white light in carcinoma oral cavity: Could it be a norm?

INTRODUCTION

In India, oral cavity cancer rates are the highest, largely due to tobacco and areca nut use. The primary goal of oncologic surgery is complete tumor resection with adequate margins, yet no accepted guidelines exist margin identification. NBI enhances mucosal lesion detection and may improve margin assessment in OSCC.

AIMS

This study aims to evaluate the proportion of negative superficial resection margins using NBI and to compare these results with margins assessed using white light (WL) examination.

MATERIALS AND METHODS

The study at AIIMS, Rishikesh, included 38 patients with T1-T3 biopsy-proven OSCC. Surgical margins were marked using WL and NBI. Histopathology classified margins as clear (>5mm), close (1-5 mm), or involved. Sensitivity, specificity, and predictive values of NBI were calculated.

RESULTS

The average NBI examination duration was 227 s. Negative margins were achieved in 68.42 % (>5mm) and 78.94 % (>3mm) of NBI cases, compared to 71.05 % and 84.21 % for WL. NBI had a sensitivity of 12.50 %, specificity of 96.67 %, and overall accuracy of 78.95 %.

DISCUSSION

NBI showed high specificity but low sensitivity. This could be due to the smaller number of patients in NBI positive group. In the present study, the single positive margin identified with NBI could also have been detected with the combined approach of white light and palpation, ensuring that no positive margins were missed.

CONCLUSION

NBI can complement WL for margin assessment in oral SCC but requires a long learning curve and a dedicated team. Integrating NBI into standard protocols could improve surgical outcomes and reduce recurrence.

Advancements in adoptive CAR immune cell immunotherapy synergistically combined with multimodal approaches for tumor treatment

Adoptive immunotherapy, notably involving chimeric antigen receptor (CAR)-T cells, has obtained Food and Drug Administration (FDA) approval as a treatment for various hematological malignancies, demonstrating promising preclinical efficacy against cancers. However, the intricate and resource-intensive autologous cell processing, encompassing collection, expansion, engineering, isolation, and administration, hamper the efficacy of this therapeutic modality. Furthermore, conventional CAR T therapy is presently confined to addressing solid tumors due to impediments posed by physical barriers, the potential for cytokine release syndrome, and cellular exhaustion induced by the immunosuppressive and heterogeneous tumor microenvironment. Consequently, a strategic integration of adoptive immunotherapy with synergistic multimodal treatments, such as chemotherapy, radiotherapy, and vaccine therapy etc., emerges as a pivotal approach to surmount these inherent challenges. This collaborative strategy holds the key to addressing the limitations delineated above, thereby facilitating the realization of more precise personalized therapies characterized by heightened therapeutic efficacy. Such synergistic strategy not only serves to mitigate the constraints associated with adoptive immunotherapy but also fosters enhanced clinical applicability, thereby advancing the frontiers of therapeutic precision and effectiveness.

Protecting Against Postsurgery Oral Cancer Recurrence with an Implantable Hydrogel Vaccine for In Situ Photoimmunotherapy

Oral squamous cell carcinoma (OSCC) often recurs aggressively and metastasizes despite surgery and adjuvant therapy, driven by postoperative residual cancer cells near the primary tumor site. An implantable in situ vaccine hydrogel was designed to target residual OSCC cells post-tumor removal. This hydrogel serves as a reservoir for the sustained localized release of δ-aminolevulinic acid (δ-ALA), enhancing protoporphyrin IX-mediated photodynamic therapy (PDT), and a polydopamine-hyaluronic acid composite for photothermal therapy (PTT). Additionally, immune adjuvants, including anti-CD47 antibodies (aCD47) and CaCO3 nanoparticles, are directly released into the resected tumor bed. This approach induces apoptosis of residual OSCC cells through sequential near-infrared irradiation, promoting calcium interference therapy (CIT). The hydrogel further stimulates immunogenic cell death (ICD), facilitating the polarization of tumor-associated macrophages from the M2 to the M1 phenotype. This facilitates phagocytosis, dendritic cell activation, robust antigen presentation, and cytotoxic T lymphocyte-mediated cytotoxicity. In murine OSCC models, the in situ vaccine effectively prevents local recurrence, inhibits orthotopic OSCC growth and pulmonary metastases, and provides long-term protective immunity against tumor rechalle nge. These findings support postoperative in situ vaccination with a biocompatible hydrogel implant as a promising strategy to minimize residual tumor burden and reduce recurrence risk after OSCC resection.

Role of ENPP1 in cancer pathogenesis: Mechanisms and clinical implications (Review)

Cancer is a significant societal, public health and economic challenge in the 21st century, and is the primary cause of death from disease globally. Ectonucleotide pyrophosphatase/phosphodiesterase (ENPP) serves a crucial role in several biochemical processes, including adenosine triphosphate hydrolysis, purine metabolism and regulation of signaling pathways. Specifically, ENPP1, a type II transmembrane glycoprotein and key member of the ENPP family, may be upregulated in tumor cells and implicated in the pathogenesis of multiple human cancers. The present review provides an overview of the structural, pathological and physiological roles of ENPP1 and discusses the potential mechanisms of ENPP1 in the development of cancers such as breast, colon, gallbladder, liver and lung cancers, and also summarizes the four major signaling pathways in tumors. Furthermore, the present review demonstrates that ENPP1 serves a crucial role in cell migration, proliferation and invasion, and that corresponding inhibitors have been developed and associated with clinical characterization.

Exploring the anticancer and antioxidant potential of gold nanoparticles synthesized from Pterocarpus marsupium bark extract against oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a disease of significant concern with higher mortality rates. Conventional treatment approaches have several drawbacks, leading to the opening of new research avenues in the field of nanoparticle-based cancer therapeutics. The study aimed at the synthesis of gold nanoparticles (Pm-AuNPs) from the aqueous bark extract of Pterocarpus marsupium, followed by its characterization and in vitro anticancer evaluation against OSCC. The synthesized Pm-AuNPs were characterized using UV-visible spectroscopy, particle size analyser, zeta potential, FTIR and SEM techniques. The anticancer potential of the Pm-AuNPs was evaluated against OSCC cell lines (SCC29b, SSC154 and OECM-1) through in vitro assays. The IC50 value was found to be 25 ± 1.2, 45 ± 1.5 and 75 ± 2.1 µg/mL for the three OSCC cell lines, elucidating Pm-AuNPs cytotoxic effects and mechanism of action. Intracellular ROS and SOX detection, mitochondrial transmembrane potential analysis and apoptosis detection were used to confirm the activity of Pm-AuNPs against OSCC. Acute toxicity studies on Wistar rats confirmed the non-toxic nature of the Pm-AuNPs at a higher dose concentration up to 2000 mg/kg body weight. The findings underscore Pm-AuNPs as promising candidates for future anticancer therapeutics, providing insights into their mechanism of action and therapeutic efficacy against OSCC.

Antihypertensive agent losartan promotes tongue squamous cell carcinoma cell proliferation via EGFR/ERK1/2/cyclin D1 signaling axis

OBJECTIVE

To study the effects of losartan, an angiotensin II receptor blocker, in the SCC4 and SCC25 human tongue squamous cell carcinoma cell lines.

METHODS

Cell proliferation was measured by MTS/PMS activity and trypan blue exclusion assays. The levels of the cell proliferation marker, cyclin D1, were analyzed by western blotting. Apoptosis was assessed by caspase-3 activation and Annexin V-FITC/propidium iodide double staining. Activation of epidermal growth factor receptor (EGFR) and ERK1/2 was validated by western blotting.

RESULTS

Moderate concentrations of losartan enhanced the proliferation of SCC4 and SCC25 cells. However, high losartan concentrations induced apoptosis in SCC4 cells. Losartan activated the EGFR/ERK1/2/cyclin D1 signaling axis, which in turn promoted cell proliferation. Afatinib (EGFR inhibitor) and U0126 (ERK1/2 inhibitor) abolished losartan-induced cell proliferation. In contrast, UC2288 (p21 inhibitor) enhanced it.

CONCLUSIONS

Losartan exhibited dual effects on tongue squamous cell carcinoma cells. Moderate losartan concentrations facilitated cell proliferation, whereas high concentrations induced cytotoxicity in tongue carcinoma cells.

m6A-related genes ALKBH5 and RBMX as prognostic and progression biomarkers in Chinese oral squamous cell carcinoma patients

OBJECTIVE

N6-methyladenosine (m6A) RNA dysregulation is crucial for cancer development. The study aimed to explore the effects of m6A modification in oral squamous cell carcinoma (OSCC) and its potential as a biomarker and therapeutic target.

DESIGN

We first analyzed m6A-related gene expression and its impact on OSCC prognosis and progression using the TCGA database. Subsequently, a Chinese cohort of 134 samples was used for validation. Bioinformatics analysis was conducted with TCGA data, and m6A levels were measured in the validation cohort using a quantification kit. Survival analysis was performed to study the relationship between m6A-related genes and OSCC prognosis in the Chinese population. The expression of m6A-related genes was assessed by using quantitative real-time PCR, Western blot analysis, and immunohistochemistry.

RESULTS

In the TCGA database, we found dysregulated expressions of METTL14, ALKBH5, YTHDF2, HNRNPC, LRPPRC, HNRNPA2B1, IGF2BP2, and RBMX in OSCC. Based on this, we observed significantly elevated total m6A content in OSCC tissues compared to normal controls in the validation cohort. Among the m6A candidate genes, only ALKBH5 and RBMX upregulation were found to be independent prognostic risk factors for poor OSCC survival in the Chinese population. And the inclusion of these two genes had a higher area under the curve for 3-year (0.705, 0.826), and 5-year (0.715, 0.788) overall survival compared to the model that only considered clinical parameters.

CONCLUSIONS

We found the upregulation of m6A status in OSCC, of which, ALKBH5 and RBMX may serve as promising diagnostic and prognostic biomarkers for Chinese patients with OSCC.

Recent Advance on Biological Activity and Toxicity of Arecoline in Edible Areca (Betel) Nut: A Review

Areca nut (Areca catechu L. AN), which is the dried, mature seed of the palm species Areca catechu L., is consumed by over 600 million individuals, predominantly in South Asia, East Africa, and certain regions of the tropical Pacific. The International Agency for Research on Cancer (IARC) has classified it as a species carcinogenic to humans and designated it as a Group 1 human carcinogen. Arecoline, which has attracted attention for its therapeutic potential in the treatment of mental illness and the relief of gastrointestinal disorders, is the main active alkaloid in the areca nut. However, in 2020, the IARC said that arecoline might be a "probable human carcinogen". Arecoline can cause various types of cellular damage, primarily leading to the destruction of cell morphology, reduced survival rates, abnormal physiological functions, and even cell apoptosis. The research on its toxic mechanisms includes several aspects, such as increased levels of reactive oxygen species, autophagy, epigenetic dysregulation, and immune dysfunction, but these research findings are scattered and lack systematic integration. This article summarizes the effect mechanisms of arecoline on the oral cavity, neurological and cardiovascular systems, and other organs, as well as embryogenesis, and provides detailed and valuable insights for the clinical practice and targeted therapy of arecoline.

N6-methyladenosine RNA modification in head and neck squamous cell carcinoma (HNSCC): current status and future insights

N6-methyladenosine (m6A) plays a pivotal role in regulating epitranscriptomic mechanisms and is closely linked to the normal functioning of diverse classes of RNAs, both coding as well as noncoding. Recent research highlights the role of m6A RNA methylation in the onset and progression of several cancers, including head and neck squamous cell carcinoma (HNSCC). HNSCC ranks as the seventh most common cancer globally, with a five-year patient survival rate of just 50%. Elevated m6A RNA methylation levels and deregulated expression of various m6A modifiers, i.e. writers, readers, and erasers, have been reported across nearly all HNSCC subtypes. Numerous studies have demonstrated that m6A modifications significantly impact key hallmarks of HNSCC, such as proliferation, apoptosis, migration, and invasion. Furthermore, m6A impacts epithelial-mesenchymal transition (EMT), drug resistance, and aerobic glycolysis, and disrupts the tumor microenvironment. Additionally, transcripts regulated by m6A in HNSCC present themselves as potential diagnostic and prognostic biomarkers. This review attempts to comprehensively summarize the role of m6A RNA methylation and its modifiers in regulating various facets of HNSCC pathogenesis.

A new perspective on diagnostic strategies concerning the potential of saliva-based miRNA signatures in oral cancer

Oral cancer, the most prevalent cancer worldwide, is far more likely to occur after the age of forty-five, according to the World Health Organization. Although many biomarkers have been discovered over the years using non-invasive saliva samples, biopsies, and human blood, these biomarkers have not been incorporated into standard clinical practice. Investigating the function of microRNAs (miRNAs) in the diagnosis, aetiology, prognosis, and treatment of oral cancer has drawn more attention in recent years. Though salivary microRNA can act as a window into the molecular environment of the tumour, there are challenges due to the heterogeneity of oral squamous cell carcinoma (OSCC), diversity in sample collection, processing techniques, and storage conditions. The up and downregulation of miRNAs has been found to have a profound role in OSCC as it regulates tumour stages by targeting many genes. As a result, the regulatory functions of miRNAs in OSCC underscore their significance in the field of cancer biology. Salivary miRNAs are useful diagnostic and prognostic indicators because their abnormal expression profiles shed light on tumour behaviour and patient prognosis. In addition to their diagnostic and prognostic value, miRNAs hold promise as therapeutic targets for oral cancer intervention. The current review sheds light on the challenges and potentials of microRNA studies that could lead to a better understanding of oral cancer prognosis, diagnosis, and therapeutic intervention. Furthermore, the clinical translation of OSCC biomarkers requires cooperation between investigators, physicians, regulatory bodies, and business partners. There is much potential for improving early identification, tracking therapy response, and forecasting outcomes in OSCC patients by including saliva-based miRNAs as biomarkers.

Photodynamic therapy: An emerging therapeutic modality in dentistry

Photodynamic Therapy (PDT) is a rapidly evolving, non-invasive treatment modality with considerable promise in dental pharmacotherapeutics. This review article comprehensively examines PDT, beginning with its principles and then delving into its diverse applications in dentistry, including periodontal disease, endodontics, oral cancer, dental implants, and dental caries. Each area presents the latest research and discusses the potential benefits and challenges. The unique advantages of PDT are highlighted, such as selective targeting, broad-spectrum antimicrobial effect, lack of resistance development, and its synergistic effect with other treatments. However, challenges such as photosensitizer delivery, light penetration, oxygen availability, and the need to standardize protocols are also acknowledged. The review further explores future perspectives of PDT in dentistry, including advancements in photosensitizer design, overcoming hypoxic limitations, personalized protocols, integration with other therapies, and standardization and regulation. The potential of advanced technologies, such as nanotechnology and synthetic biology, to improve PDT outcomes is also discussed. The review concludes that while PDT has shown immense potential to revolutionize dental pharmacotherapeutics, further high-quality research is needed to translate this potential into everyday dental practice. The promising future of PDT in dentistry suggests a more effective and less invasive treatment option for a range of dental conditions.

LINC01614 Promotes Oral Squamous Cell Carcinoma by Regulating FOXC1

Background: Long non-coding RNAs (lncRNAs) are pivotal mediators during the development of carcinomas; however, it remains to be investigated whether lncRNAs are implicated in oral squamous cell carcinoma (OSCC). Methods: In this study, quantitative real-time PCR was conducted for detecting the expression of LINC01614 in OSCC cell lines. The biological functions of LINC01614 were assessed by loss- and gain-of-function experiments conducted both in vivo and in vitro. Cellular proliferation, migration, and invasion were investigated herein, and dual luciferase reporter assays were additionally performed to explore the relationships among LINC01614, miR-138-5p, and Forkhead box C1 (FOXC1). Results: The research presented herein revealed that OSCC cells express high levels of LINC01614. Functional experiments employing cellular and animal models demonstrated that LINC01614 knockdown repressed the malignant phenotypes of OSCC cells, including their growth, invasiveness, and migration. Further investigation revealed that LINC01614 absorbs miR-138-5p miRNA by functioning as a competing endogenous RNA to downregulate the abundance of FOXC1. Conclusions: The findings revealed that LINC01614 contributes to the progression of OSCC by targeting the FOXC1 signaling pathway. The study provides insights into a novel mechanistic process to regulate the development of OSCC, and established a possible target for the therapeutic management of OSCC.

Heat Shock Protein 70-2 is Overexpressed in Oral Leukoplakia and Oral Squamous Cell Carcinoma

OBJECTIVE

The objective of this study was to assess the correlation between the expression of HSP70-2 and the development of oral potentially malignant disorders (OPMD) and oral squamous cell carcinoma (OSCC). Furthermore, the study evaluates the potential function of HSP70-2 in the pathogenesis of malignant diseases of the oral cavity.

METHODS

Using immunohistochemistry, RT-qPCR, Western blot, indirect immunofluorescence, and flow cytometry, the expression of HSP70-2 mRNA and protein in OPMD and OSCC tissues and cells was investigated. Using liposomal vector transient transfection to specifically knock down HSP70-2 gene expression in pertinent cell lines in vitro, the role of HSP70-2 in the development of oral malignant disorders was further investigated.

RESULTS

Studies on OPMD and OSCC tissues and cell lines revealed that HSP70-2 mRNA and protein were substantially expressed. Furthermore, it was discovered that the expression levels corresponded with the degree of disease development. Downregulating the HSP70-2 gene specifically reduces the proliferation, viability, colony-forming ability, migration, and invasion of OPMD and OSCC cells. Furthermore, it will cause apoptosis and control cell cycle arrest.

CONCLUSION

HSP70-2 exhibited a significantly differential expression in both NM, OPMD, and OSCC tissues and cells. Furthermore, HSP70-2 plays a function in the development of oral malignant illnesses.

CLINICAL RELEVANCE

HSP70-2 is a promising biomarker for predicting the malignant transformation of Oral leukoplakia (OLK) and early diagnosis of OSCC. It is highly anticipated that HSP70-2 will be a potential target for the early intervention and blockage of OLK malignant transformation, given its established role in the development of oral malignant disorders. With regard to the treatment of OSCC, the same provides a referable target for siRNA-based therapeutic modalities.

Near-Infrared Light Photodynamic Therapy with PEI-Capped Up-Conversion Nanoparticles and Chlorin e6 Induces Apoptosis of Oral Cancer Cells

Oral squamous cell carcinoma (OSCC) is a common malignancy in the oral cavity. Photodynamic therapy (PDT) is a new alternative for the treatment of diseases using photosensitizers (PS) and light. In this study, we used a photosensitizer complex (Ce6-MnNPs-Chlorin e6 combined with up-conversion nanoparticles NaYF4:Yb/Er/Mn) to investigate the therapeutic effectiveness of this treatment against oral cancer cells. We also investigated the mechanism of action of near-infrared light PDT (NIR-PDT) combined with the Ce6-MnNPs. After determining a suitable concentration of Ce6-MnNPs using an MTT assay, human oral squamous cell carcinoma cells (HSC-3) were treated with NIR-PDT with Ce6-MnNPs. We examined the characteristics of Ce6-MnNPs by transmission electron microscopy (TEM); a zeta potential and particle size analyzer; Fourier-transform infrared spectroscopy (FTIR); cell viability by MTT assay; and apoptosis by FITC-Annexin V/PI assay. The mitochondrial membrane potential (MMP), apoptosis-related mRNA level (Bax and Bcl-2) and p53 protein were also researched. NIR-PDT with 0.5 ng/µL Ce6-MnNPs inhibited the proliferation of HSC-3 (p < 0.05). After treatment with NIR-PDT, changes in the mitochondrial membrane potential and apoptosis occurred (p < 0.01). The ratio of Bax/Bcl-2 and p53-positive cells increased (p < 0.01). These results suggest that this treatment can induce apoptosis of oral cancer cells.

The Connection Between the Oral Microbiota and the Kynurenine Pathway: Insights into Oral and Certain Systemic Disorders

The oral microbiome, comprising bacteria, fungi, viruses, and protozoa, is essential for maintaining both oral and systemic health. This complex ecosystem includes over 700 bacterial species, such as Streptococcus mutans, which contributes to dental caries through acid production that demineralizes tooth enamel. Fungi like Candida and pathogens such as Porphyromonas gingivalis are also significant, as they can lead to periodontal diseases through inflammation and destruction of tooth-supporting structures. Dysbiosis, or microbial imbalance, is a key factor in the development of these oral diseases. Understanding the composition and functions of the oral microbiome is vital for creating targeted therapies for these conditions. Additionally, the kynurenine pathway, which processes the amino acid tryptophan, plays a crucial role in immune regulation, neuroprotection, and inflammation. Oral bacteria can metabolize tryptophan, influencing the production of kynurenine, kynurenic acid, and quinolinic acid, thereby affecting the kynurenine system. The balance of microbial species in the oral cavity can impact tryptophan levels and its metabolites. This narrative review aims to explore the relationship between the oral microbiome, oral diseases, and the kynurenine system in relation to certain systemic diseases.

Virtual Tumor Mapping: A New Standard for Surgeon-Pathologist Collaboration in Treating Oral Squamous Cell Carcinoma

Background: The histopathological assessment is critical in the comprehensive treatment process for patients diagnosed with oral squamous cell carcinoma (OSCC). A detailed and precise specimen characterization is essential to facilitate effective surgeon-pathologist communication. Methods: In response to this need, a user-friendly virtual communication protocol utilizing a 3D scanner has been developed. This study involved 50 patients with OSCC, whose resected tumors were directly scanned in the operating room and subsequently annotated and characterized using available software. Results: The direct application of annotations and descriptions onto the virtual tumor specimens significantly enhanced the quantity and accuracy of information conveyed to the pathologist. Conclusions: The proposed solution's repeatability and standardized approach make integration into routine clinical practice feasible, thereby establishing a potential new standard in the field.

Challenges and improvements in multi-layer mucosa-adhesive films for oral diseases treatment and prognosis

Due to the complexity of oral physiology and pathology, the treatment of oral diseases faces multiple and complex clinical requirements. Mucosa-adhesive films (MAFs) with a single layer have demonstrated considerable potential in delivering therapeutic bioactive ingredients directly to the site of oral diseases. However, their functions are often hindered by certain factors such as limited loading capacity, poor site specificity, and sensitivity to mechanical stimuli. To overcome these limitations, the development of multi-layer MAFs has become a focal point for recent research. This involves the improvement of construction methods for multi-layer MAFs to minimize potential health risks from residual solvents, and conducting comprehensive in vivo studies to evaluate their safety and therapeutic efficacy more accurately, thus paving the way for their commercialization. Additionally, the exploration of multi-layer MAFs as personalized drug delivery systems could further broaden their application prospect. Precisely, multi-layer MAFs compensate for the shortcomings of current therapeutic strategies for oral diseases to a great extent, indicating a promising future in the market.

A Graphene-Based Lipid Modulation Nanoplatform for Synergetic Lipid Starvation/Chemo/Photothermal Therapy of Oral Squamous Cell Carcinoma

Purpose

Chemotherapy is one of the most commonly used treatments for oral squamous cell carcinoma (OSCC), but its use is limited by drug resistance and severe systemic toxicity. To eliminate these side effects and improve anti-tumor efficacy, several therapeutic approaches have been developed for use with chemotherapy. In this study, we developed a graphene-based lipid modulation nanoplatform (NSD) that carries SB-204990, a small molecule inhibitor specific for ATP citrate lyase (ACLY), and doxorubicin (DOX), a chemotherapeutic agent, and the trio enables synergistic treatment of OSCC with lipid starvation, chemotherapy, and photothermal therapy.

Methods

We first determined whether ACLY expression was upregulated in OSCC, and then assessed the growth inhibitory effects of SB-204990 on SCC-15 cells and changes in lipid (acetyl coenzyme A, free fatty acids, and cholesterol) levels. We characterized NSD and then evaluated the stability, photothermal properties, drug loading, and release ability of NSD. Finally, the therapeutic effects of NSD on OSCC were investigated by in vitro and in vivo experiments, and the changes in lipid levels in OSCC tissues after ACLY inhibition were further evaluated.

Results

The results showed that ACLY was highly expressed in OSCC, and ACLY inhibition produced reproductive suppression and decreased lipid levels in SCC-15 cells. The NSD nanoplatform possessed good stability, photothermal properties, high drug loading capacity and controlled release. In addition, the triple therapy achieved satisfactory anticancer effects in both in vivo and in vitro assays, and the inhibition rate of tumors was as high as 99.4% in the NSD+Laser treatment group.

Conclusion

The changes in tumor cell lipid levels and cell proliferation arrest induced by ACLY inhibition suggest that ACLY may be a promising target for lipid starvation therapy and resistance to chemoresistance, and its inhibitors are expected to become new anticancer drugs. The NSD nanocarrier system enables synergistic treatment with lipid starvation, chemotherapy, and photothermal therapy, which represents an innovative approach to combating tumors.

FADD amplification is associated with CD8+ T-cell exclusion and malignant progression in HNSCC

OBJECTIVE

This study aimed to clarify the relationship between FADD amplification and overexpression and the tumor immune microenvironment.

METHODS

Immunohistochemical staining and bioanalysis were used to analyze the association between FADD expression in tumor cells and cells in tumor microenvironment. RNA-seq analysis was used to detect the differences in gene expression upon FADD overexpression. Flow cytometry and multicolor immunofluorescence staining (mIHC) were used to detect the differences in CD8+ T-cell infiltration in FADD-overexpressed cells or tumor tissues.

RESULTS

Overexpression of FADD significantly promoted tumor growth. Cells with high FADD expression presented high expression of CD276 and FGFBP1 and low expression of proinflammatory factors (such as IFIT1-3 and CXCL8), which reduced the percentage of CD8+ T cells and created a "cold tumor" immune microenvironment, thus promoting tumor progression. In vivo and in vitro experiment confirmed that tumor tissues with excessive FADD expression exhibited CD8+ T-cell exclusion in the microenvironment.

CONCLUSION

Our preliminary investigation has discovered the association between FADD expression and the immunosuppressive microenvironment in HNSCC. Due to the high frequent amplification of the chromosomal region 11q13.3, where FADD is located, targeting FADD holds promise for improving the immune-inactive state of tumors, subsequently inhibiting HNSCC tumor progression.

The interplay between microbiome and host factors in pathogenesis and therapy of head and neck cancer

Heterogeneous cancers that lack strong driver mutations with high penetrance, such as head and neck squamous cell carcinoma (HNSCC), present unique challenges to understanding their aetiology due to the complex interactions between genetics and environmental factors. The interplay between lifestyle factors (such as poor oral hygiene, smoking, or alcohol consumption), the oral and gut microbiome, and host genetics appears particularly important in the context of HNSCC. The complex interplay between the gut microbiota and cancer treatment outcomes has also received increasing attention in recent years. This review article describes the bidirectional communication between the host and the oral/gut microbiome, focusing on microbiome-derived metabolites and their impact on systemic immune responses and the modulation of the tumour microenvironment. In addition, we review the role of host lifestyle factors in shaping the composition of the oral/gut microbiota and its impact on cancer progression and therapy. Overall, this review highlights the rationality of considering the oral/gut microbiota as a critical determinant of cancer therapy outcomes and points to therapeutic opportunities offered by targeting the oral/gut microbiota in the management of HNSCC.

Ferroptosis as a hero against oral cancer

Cancer is an abnormal condition altering the cells to proliferate out of control simultaneously being susceptible to evolution. The lining which is made up of tissues in the lips, upper throat and mouth can undergo mutations, is recognised as mouth cancer or oral cancer. Substantial number of mouth lesions are identified at a point where it is typically not possible to get effective remedial care. Ferroptosis is a cutting-edge instance of cellular destruction which stands out in distinction to other sorts of cell death. It appears to have distinctive cellular, molecular and gene-level attributes and scavenges on deposits of reactive oxygen species triggered via iron-induced lipid peroxidation. It is said to be involved dichotomously in cancer development. Because the ferroptotic tumour cells put out numerous chemicals that alternatively signal for cancer attenuation or growth. There is increasing proof that researchers are now keenly investigating to stimulate ferroptosis through various inducers and pathways in the intent for oral cancer therapeutics, specifically to kill malignant tumours that refuse to respond well to conventional treatments. Also, it has the ability to reverse chemotherapy and radiotherapy resistance in victims maximising the success rate of the treatments. This review centres on the stimulation of ferroptosis as a stand-alone therapy for oral cancer, or in combination with other medicines, agents and pathways.

Cancer-associated fibroblasts-derived CXCL1 activates DEC2-mediated dormancy in oral squamous cell carcinoma

Cancer-associated fibroblasts (CAFs) are known to play an important role in cancer progression, but their effects on tumor cell dormancy and the underlying mechanisms remain to be explored. Here, we aimed to dissect the intercellular communication between CAFs and oral squamous cell carcinoma (OSCC) cells under cellular dormancy. In this study, we investigated 61 OSCC patients and found that low expression of Differentiated Embryonic Chondrocyte gene 2 (DEC2) was closely associated with tumor recurrence, cisplatin chemotherapy administration, and infiltration of CAFs. Overexpression of DEC2 promoted the invasion and migration ability of OSCC cells but inhibited their proliferation and glucose metabolism, and characterized them as dormant and cisplatin-resistant cells. C-X-C motif ligand 1 (CXCL1) from CAFs was found to down-regulate DEC2 expression in OSCC cells, ultimately awakening dormant cells and leading to tumor recurrence, which was validated in vitro and in vivo. In conclusion, CAFs-derived CXCL1 downregulated DEC2 and "interrupted" DEC2-mediated OSCC cell dormancy, which may be a mechanism by which CAFs modulate OSCC cell dormancy and contribute to the development of new therapies for OSCC.

Causal associations of MICB, CTSA, and MMP9 proteins with oral cancer: Mendelian randomization study

Oral cancer (ORCA) is the most prevalent histological subtype of oral malignancies in which immune modulation is relevant. The goal of this work was to employ Mendelian randomization (MR) to investigate the causal connection between the immune-related proteins MICB, CTSA, MMP9, and ORCA. The Open GWAS database of the Integrative Epidemiology Unit (IEU) was accessed to collect GWAS data for ORCA (ieu-b-4961), MICB (prot-a-1898), CTSA (prot-a-717) and MMP9 (prot-a-1921). From 372,373 samples, the ORCA dataset comprises 7,723,107 single nucleotide polymorphisms (SNPs). MICB, CTSA, and MMP9 all have 10,534,735 SNPs and 3,301 sample sizes. Then, the primary SVMR implementation approaches were weighted mode, simple mode, inverse variance weighted (IVW), weighted median, and MR-Egger. IVW was the most effective technique. A sensitivity study was also carried out to assess the correctness of SVMR data, with special focus devoted to heterogeneity, horizontal pleiotropy, and Leave-One-Out (LOO). MVMR was eventually implemented as well. A Mendelian randomization analysis of the three exposure factors in the dataset (ieu-b-94, ebi-a-GCST012237) was also performed to validate the study results. According to the SVMR results, there was a noteworthy causal interaction between ORCA and MICB (P = 0.0014), MMP9 (P = 0.0343), and CTSA (P = 0.0003). Furthermore, odds ratios (ORs) values revealed that MMP9 (OR = 1.0005) was an ORCA risk factor, whereas MICB (OR = 0.9994) and CTSA (OR = 0.9993) were security factors. The robustness of the SVMR findings was confirmed by the p-values of the heterogeneity and horizontal pleiotropy, both of which were greater than 0.05. The MVMR result did not affect any of the safety or hazard features of these three exposure factors. However, the P value for MMP9 was greater than 0.05, implying that MICB and CTSA may have a greater influence on ORCA than MMP9. The validation outcomes in both datasets harmonized with the findings from previous research, thereby solidifying the reliability of results. Our investigation provided a crucial resource for further research on the subject by demonstrating a causal relationship between ORCA and MICB, CTSA, and MMP9.

Identification and validation of a prognostic model based on three TLS-Related genes in oral squamous cell carcinoma

BACKGROUND

The tertiary lymphoid structures (TLSs) have an immunomodulatory function and have a positive impact on the survival outcomes of patients with oral squamous cell carcinoma (OSCC). However, there is a lack of standard approaches for quantifying TLSs and prognostic models using TLS-related genes (TLSRGs). These limitations limit the widespread use of TLSs in clinical practice.

METHODS

A convolutional neural network was used to automatically detect and quantify TLSs in HE-stained whole slide images. By employing bioinformatics and diverse statistical methods, this research created a prognostic model using TCGA cohorts and explored the connection between this model and immune infiltration. The expression levels of three TLSRGs in clinical specimens were detected by immunohistochemistry. To facilitate the assessment of individual prognostic outcomes, we further constructed a nomogram based on the risk score and other clinical factors.

RESULTS

TLSs were found to be an independent predictor of both overall survival (OS) and disease-free survival in OSCC patients. A larger proportion of the TLS area represented a better prognosis. After analysis, we identified 69 differentially expressed TLSRGs and selected three pivotal TLSRGs to construct the risk score model. This model emerged as a standalone predictor for OS and exhibited close associations with CD4 + T cells, CD8 + T cells, and macrophages. Immunohistochemistry revealed high expression levels of CCR7 and CXCR5 in TLS + OSCC samples, while CD86 was highly expressed in TLS- OSCC samples. The nomogram demonstrates excellent predictive ability for overall survival in OSCC patients.

CONCLUSIONS

This is the first prognostic nomogram based on TLSRGs, that can effectively predict survival outcomes and contribute to individual treatment strategies for OSCC patients.

Molecular Targets of Plant-Derived Bioactive Compounds in Oral Squamous Cell Carcinoma

BACKGROUND

With a significant increase in both incidence and mortality, oral cancer-particularly oral squamous cell carcinoma (OSCC)-is one of the main causes of death in developing countries. Even though there is evidence of advances in surgery, chemotherapy, and radiotherapy, the overall survival rate for patients with OSCC has improved, but by a small percentage. This may be due, on the one hand, to the fact that the disease is diagnosed when it is at a too-advanced stage, when metastases are already present.

METHODS

This review explores the therapeutic potential of natural herbal products and their use as adjuvant therapies in the treatment of oral cancer from online sources in databases (PubMed, Web of Science, Google Scholar, Research Gate, Scopus, Elsevier).

RESULTS

Even if classic therapies are known to be effective, they often produce many serious side effects and can create resistance. Certain natural plant compounds may offer a complementary approach by inducing apoptosis, suppressing tumor growth, and improving chemotherapy effectiveness. The integration of these compounds with conventional treatments to obtain remarkable synergistic effects represents a major point of interest to many authors. This review highlights the study of molecular mechanisms and their efficiency in in vitro and in vivo models, as well as the strategic ways in which drugs can be administered to optimize their use in real contexts.

CONCLUSIONS

This review may have a significant impact on the oncology community, creating new inspirations for the development of more effective, safer cancer therapies with less toxic potential.