Campothecin suppresses cell proliferation and migration in head and neck squamous cell carcinoma by blocking RAB27A-mediated phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT) pathway.

Camptothecin (CPT), a naturally occurring alkaloid derived from the Camptotheca acuminate plant, exerts anti-tumor properties. However, its specific impact on head and neck squamous cell carcinoma (HNSCC) remains uncertain. The study was to explore the action and mechanism of CPT on HNSCC cells. First, two HNSCC cell lines (FaDu and TU686) and a normal immortalized keratinocyte (HEK001) cell line, were exposed to a spectrum of CPT concentrations (ranging from 10 to 50 µM) for durations of 24 h and 48 h. Cell viability, proliferation, migration, and invasion were assessed by CCK-8 assay, EdU incorporation assay, wound healing assay and transwell assay. Subsequently, si-RAB27A or negative control (NC) was introduced into FaDu and TU686 cells through transfection, and the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway was manipulated with L740Y-P, an activator of this pathway. The expression of proliferating cell nuclear antigen (PCNA), E-cadherin, PI3K/AKT signaling factors and RAB27A were determined by Western blot analysis. RAB27A was detected by immunofluorescence assay. It was found that CPT significantly hindered the viability, proliferation (p<0.01), migration (p<0.001), and invasion (p<0.001) of FaDu and TU686 cells. At the molecular level, administration of CPT caused a decline in the expression of PCNA, P-PI3K, P-AKT, and RAB27A, alongside an elevation in E-cadherin levels within HNSCC cells (p<0.05, p<0.01 and p<0.001). Reducing RAB27A expression enhanced the suppressive impacts of CPT on HNSCC cell viability (p<0.05 and p<0.01), migration (p<0.001) and invasion (p<0.01), these effects that were reversed upon treatment with L740Y-P in HNSCC cells (p<0.001). In summary, our study highlights the efficacy of CPT in HNSCC, demonstrating its influence on cell processes via the RAB27A-mediated PI3K/AKT pathway.

Mitochondrial outer membrane protein MTUS1/ATIP1 exerts antitumor effects through ROS-induced mitochondrial pyroptosis in head and neck squamous cell carcinoma.

We showed that microtubule-associated tumor suppressor gene (MTUS1/ATIP) downregulation correlated with poor survival in head and neck squamous cell carcinoma (HNSCC) patients and that MTUS1/ATIP1 was the most abundant isoform in HNSCC tissue. However, the location and function of MTUS1/ATIP1 have remain unclear. In this study, we confirmed that MTUS1/ATIP1 inhibited proliferation, growth and metastasis in HNSCC in cell- and patient-derived xenograft models in vitro and in vivo. MTUS1/ATIP1 localized in the outer mitochondrial membrane, influence the morphology, movement and metabolism of mitochondria and stimulated oxidative stress in HNSCC cells by directly interacting with MFN2. MTUS1/ATIP1 activated ROS, recruiting Bax to mitochondria, facilitating cytochrome c release to the cytosol to activate caspase-3, and inducing GSDME-dependent pyroptotic death in HNSCC cells. Our findings showed that MTUS1/ATIP1 localized in the outer mitochondrial membrane in HNSCC cells and mediated anticancer effects through ROS-induced pyroptosis, which may provide a novel therapeutic strategy for HNSCC treatment.

Aspartate ß-Hydroxylase Is Upregulated in Head and Neck Squamous Cell Carcinoma and Regulates Invasiveness in Cancer Cell Models.

Aspartate ß-hydroxylase (ASPH) is a protein associated with malignancy in a wide range of tumors. We hypothesize that inhibition of ASPH activity could have anti-tumor properties in patients with head and neck cancer. In this study, we screened tumor tissues of 155 head and neck squamous cell carcinoma (HNSCC) patients for the expression of ASPH using immunohistochemistry. We used an ASPH inhibitor, MO-I-1151, known to inhibit the catalytic activity of ASPH in the endoplasmic reticulum, to show its inhibitory effect on the migration of SCC35 head and neck cancer cells in cell monolayers and in matrix-embedded spheroid co-cultures with primary cancer-associated fibroblast (CAF) CAF 61137 of head and neck origin. We also studied a combined effect of MO-I-1151 and HfFucCS, an inhibitor of invasion-blocking heparan 6-O-endosulfatase activity. We found ASPH was upregulated in HNSCC tumors compared to the adjacent normal tissues. ASPH was uniformly high in expression, irrespective of tumor stage. High expression of ASPH in tumors led us to consider it as a therapeutic target in cell line models. ASPH inhibitor MO-I-1151 had significant effects on reducing migration and invasion of head and neck cancer cells, both in monolayers and matrix-embedded spheroids. The combination of the two enzyme inhibitors showed an additive effect on restricting invasion in the HNSCC cell monolayers and in the CAF-containing co-culture spheroids. We identify ASPH as an abundant protein in HNSCC tumors. Targeting ASPH with inhibitor MO-I-1151 effectively reduces CAF-mediated cellular invasion in cancer cell models. We propose that the additive effect of MO-I-1151 with HfFucCS, an inhibitor of heparan 6-O-endosulfatases, on HNSCC cells could improve interventions and needs to be further explored.

Identification of immunogenic cell death-related damage-related molecular patterns (DAMPs) to predict outcomes in patients with head and neck squamous cell carcinoma.

PURPOSE: Head and neck cancer is the sixth most common type of cancer worldwide, wherein the immune responses are closely associated with disease occurrence, development, and prognosis. Investigation of the role of immunogenic cell death-related genes (ICDGs) in adaptive immune response activation may provide cues into the mechanism underlying the outcome of HNSCC immunotherapy. METHODS: ICDGs expression patterns in HNSCC were analyzed, after which consensus clustering in HNSCC cohort conducted. A 4-gene prognostic model was constructed through LASSO and Cox regression analyses to analyze the prognostic index using the TCGA dataset, followed by validation with two GEO datasets. The distribution of immune cells and the response to immunotherapy were compared between different risk subtypes through multiple algorithms. Moreover, immunohistochemical (IHC) analyses were conducted to validate the prognostic value of HSP90AA1 as a predictor of HNSCC patient prognosis. In vitro assays were performed to further detect the effect of HSP90AA1 in the development of HNSCC. RESULTS: A novel prognostic index based on four ICDGs was constructed and proved to be useful as an independent factor of HNSCC prognosis. The risk score derived from this model grouped patients into high- and low-risk subtypes, wherein the high-risk subtype had worse survival outcomes and poorer immunotherapy response. IHC analysis validated the applicability of HSP90AA1 as a predictor of prognosis of HNSCC patients. HSP90AA1 expression in tumor cells promotes the progression of HNSCC. CONCLUSIONS: Together, these results highlight a novel four-gene prognostic signature as a valuable tool to assess survival status and prognosis of HNSCC patients.

EP4-induced mitochondrial localization and cell migration mediated by CALML6 in human oral squamous cell carcinoma.

Lymph node metastasis, primarily caused by the migration of oral squamous cell carcinoma (OSCC) cells, stands as a crucial prognostic marker. We have previously demonstrated that EP4, a subtype of the prostaglandin E2 (PGE2) receptor, orchestrates OSCC cell migration via Ca2+ signaling. The exact mechanisms by which EP4 influences cell migration through Ca2+ signaling, however, is unclear. Our study aims to clarify how EP4 controls OSCC cell migration through this pathway. We find that activating EP4 with an agonist (ONO-AE1-473) increased intracellular Ca2+ levels and the migration of human oral cancer cells (HSC-3), but not human gingival fibroblasts (HGnF). Further RNA sequencing linked EP4 to calmodulin-like protein 6 (CALML6), whose role remains undefined in OSCC. Through protein-protein interaction network analysis, a strong connection is identified between CALML6 and calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2), with EP4 activation also boosting mitochondrial function. Overexpressing EP4 in HSC-3 cells increases experimental lung metastasis in mice, whereas inhibiting CaMKK2 with STO-609 markedly lowers these metastases. This positions CaMKK2 as a potential new target for treating OSCC metastasis. Our findings highlight CALML6 as a pivotal regulator in EP4-driven mitochondrial respiration, affecting cell migration and metastasis via the CaMKK2 pathway.

The predictive role of PD-L1 in head and neck cancer: A systematic review and meta-analysis.

This systematic review and meta-analysis investigates the predictive and prognostic role of PD-L1 expression in treating head and neck squamous cell carcinoma (HNSCC). Recognizing the importance of PD-L1 in patient response to treatment, the main objective was to assess its impact on overall survival and progression-free survival in HNSCC patients. A thorough search of databases such as PubMed, Scopus, and Web of Science from 2010 to 2022, along with relevant articles and references, yielded 120 studies. Of these, 7 met the criteria focusing on HNSCC patients, PD-L1 expression evaluation, and treatment with PD-1 or PD-L1 inhibitors. Data extraction followed PRISMA guidelines and involved independent review and consensus for discrepancies. The primary outcomes analyzed were overall survival and progression-free survival in relation to PD-L1 expression levels in patients undergoing immunotherapy.Theseven randomized controlled trials selected had a total of 4,477 participants. Results showed that patients with positive PD-L1 expression experienced improved overall survival when treated with PD-1 or PD-L1 inhibitors, particularly those with high PD-L1 expression. However, PD-L1 expression did not significantly affect progression-free survival. These findings suggest that PD-L1 expression can be a predictive marker for better overall survival in HNSCC patients treated with immunotherapy. However, its influence on progression-free survival remains unclear, indicating the need for further research.

USP39 Promotes the Viability and Migration of Head and Neck Squamous Cell Carcinoma Cell by Regulating STAT1.

Objective: Ubiquitin-specific peptidase 39 (USP39) plays a carcinogenic role in many cancers, but little research has been conducted examining whether it is involved in head and neck squamous cell carcinoma (HNSCC). Therefore, this study explored the functional role of USP39 in HNSCC. Method: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to identify differentially expressed proteins (DEPs) between the HNSCC tumor and adjacent healthy tissues. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were used to assess the functional enrichment of DEPs. Immunohistochemistry was used to detect protein expression. The viability and migration of two HNSCC cell lines, namely CAL27 and SCC25, were detected using the cell counting kit-8 assay and a wound healing assay, respectively. Quantitative real-time PCR was used to detect the expression level of signal transducer and activator of transcription 1 (STAT1) mRNA. Results: LC-MS/MS results identified 590 DEPs between HNSCC and adjacent tissues collected from 4 patients. Through GO and KEGG pathway analyses, 34 different proteins were found to be enriched in the spliceosome pathway. The expression levels of USP39 and STAT1 were significantly higher in HNSCC tumor tissue than in adjacent healthy tissue as assessed by LC-MS/MS analysis, and the increased expression of USP39 and STAT1 protein was confirmed by immunohistochemistry in clinical samples collected from 7 additional patients with HNSCC. Knockdown of USP39 or STAT1 inhibited the viability and migration of CAL27 and SCC25 cells. In addition, USP39 knockdown inhibited the expression of STAT1 mRNA in these cells. Conclusion: Our findings indicated that USP39 knockdown may inhibit HNSCC viability and migration by suppressing STAT1 expression. The results of this study suggest that USP39 may be a potential new target for HNSCC clinical therapy or a new biomarker for HNSCC.

WNT3 promotes chemoresistance to 5-Fluorouracil in oral squamous cell carcinoma via activating the canonical ß-catenin pathway.

BACKGROUND: 5-Fluorouracil (5FU) is a primary chemotherapeutic agent used to treat oral squamous cell carcinoma (OSCC). However, the development of drug resistance has significantly limited its clinical application. Therefore, there is an urgent need to determine the mechanisms underlying drug resistance and identify effective targets. In recent years, the Wingless and Int-1 (WNT) signaling pathway has been increasingly studied in cancer drug resistance; however, the role of WNT3, a ligand of the canonical WNT signaling pathway, in OSCC 5FU-resistance is not clear. This study delved into this potential connection. METHODS: 5FU-resistant cell lines were established by gradually elevating the drug concentration in the culture medium. Differential gene expressions between parental and resistant cells underwent RNA sequencing analysis, which was then substantiated via Real-time quantitative PCR (RT-qPCR) and western blot tests. The influence of the WNT signaling on OSCC chemoresistance was ascertained through WNT3 knockdown or overexpression. The WNT inhibitor methyl 3-benzoate (MSAB) was probed for its capacity to boost 5FU efficacy. RESULTS: In this study, the WNT/ß-catenin signaling pathway was notably activated in 5FU-resistant OSCC cell lines, which was confirmed through transcriptome sequencing analysis, RT-qPCR, and western blot verification. Additionally, the key ligand responsible for pathway activation, WNT3, was identified. By knocking down WNT3 in resistant cells or overexpressing WNT3 in parental cells, we found that WNT3 promoted 5FU-resistance in OSCC. In addition, the WNT inhibitor MSAB reversed 5FU-resistance in OSCC cells. CONCLUSIONS: These data underscored the activation of the WNT/ß-catenin signaling pathway in resistant cells and identified the promoting effect of WNT3 upregulation on 5FU-resistance in oral squamous carcinoma. This may provide a new therapeutic strategy for reversing 5FU-resistance in OSCC cells.

Lectin-like Transcript-1 (LLT1) Expression in Oral Squamous Cell Carcinomas: Prognostic Significance and Relationship with the Tumor Immune Microenvironment.

Lectin-like transcript-1 (LLT1) expression is detected in different cancer types and is involved in immune evasion. The present study investigates the clinical relevance of tumoral and stromal LLT1 expression in oral squamous cell carcinoma (OSCC), and relationships with the immune infiltrate into the tumor immune microenvironment (TIME). Immunohistochemical analysis of LLT1 expression was performed in 124 OSCC specimens, together with PD-L1 expression and the infiltration of CD20+, CD4+, and CD8+ lymphocytes and CD68+ and CD163+-macrophages. Associations with clinicopathological variables, prognosis, and immune cell densities were further assessed. A total of 41 (33%) OSCC samples showed positive LLT1 staining in tumor cells and 55 (44%) positive LLT1 in tumor-infiltrating lymphocytes (TILs). Patients harboring tumor-intrinsic LLT1 expression exhibited poorer survival, suggesting an immunosuppressive role. Conversely, positive LLT1 expression in TILs was significantly associated with better disease-specific survival, and also an immune-active tumor microenvironment highly infiltrated by CD8+ T cells and M1/M2 macrophages. Furthermore, the combination of tumoral and stromal LLT1 was found to distinguish three prognostic categories (favorable, intermediate, and adverse; p = 0.029, Log-rank test). Together, these data demonstrate the prognostic relevance of tumoral and stromal LLT1 expression in OSCC, and its potential application to improve prognosis prediction and patient stratification.

Identification of MUC1-C as a Target for Suppressing Progression of Head and Neck Squamous Cell Carcinomas.

The MUC1-C protein is aberrantly expressed in adenocarcinomas of epithelial barrier tissues and contributes to their progression. Less is known about involvement of MUC1-C in the pathogenesis of squamous cell carcinomas (SCC). Here, we report that the MUC1 gene is upregulated in advanced head and neck SCCs (HNSCC). Studies of HNSCC cell lines demonstrate that the MUC1-C subunit regulates expression of (i) RIG-I and MDA5 pattern recognition receptors, (ii) STAT1 and IFN regulatory factors, and (iii) downstream IFN-stimulated genes. MUC1-C integrates chronic activation of the STAT1 inflammatory pathway with induction of the ∆Np63 and SOX2 genes that are aberrantly expressed in HNSCCs. In extending those dependencies, we demonstrate that MUC1-C is necessary for NOTCH3 expression, self-renewal capacity, and tumorigenicity. The findings that MUC1 associates with ∆Np63, SOX2 and NOTCH3 expression by single-cell RNA sequencing analysis further indicate that MUC1-C drives the HNSCC stem cell state and is a target for suppressing HNSCC progression. SIGNIFICANCE: This work reports a previously unrecognized role for MUC1-C in driving STAT1-mediated chronic inflammation with the progression of HNSCC and identifies MUC1-C as a druggable target for advanced HNSCC treatment.

A prognostic model built on amino acid metabolism patterns in HPV-associated head and neck squamous cell carcinoma.

OBJECTIVES: To compare amino acid metabolism patterns between HPV-positive and HPV-negative head and neck squamous cell carcinoma (HNSCC) patients and identify key genes for a prognostic model. DESIGN: Utilizing the Cancer Genome Atlas dataset, we analyzed amino acid metabolism genes, differentiated genes between HPV statuses, and selected key genes via LASSO regression for the prognostic model. The model's gene expression was verified through immunohistochemistry in clinical samples. Functional enrichment and CIBERSORTx analyses explored biological functions, molecular mechanisms, and immune cell correlations. The model's prognostic capability was assessed using nomograms, calibration, and decision curve analysis. RESULTS: We identified 1157 key genes associated with amino acid metabolism in HNSCC and HPV status. The prognostic model, featuring genes like IQCN, SLC22A1, SYT12, and TLX3, highlighted functions in development, metabolism, and pathways related to receptors and enzymes. It significantly correlated with immune cell infiltration and outperformed traditional staging in prognosis prediction, despite immunohistochemistry results showing limited clinical identification of HPV-related HNSCC. CONCLUSIONS: Distinct amino acid metabolism patterns differentiate HPV-positive from negative HNSCC patients, underscoring the prognostic model's utility in predicting outcomes and guiding therapeutic strategies.

Identification of ACAA1 and HADHB as potential prognostic biomarkers based on a novel fatty acid oxidation-related gene model in head and neck squamous cell carcinoma: A retrospective study.

OBJECTIVES: To investigate the importance of fatty acid oxidation (FAO)-related genes in predicting the progression and prognosis of head and neck squamous cell carcinoma (HNSCC). METHODS: The FAO-related gene prognostic model was established employing Cox regression analyses, during which accuracy and sensitivity of the gene model were evaluated in The Cancer Genome Atlas (TCGA) internal testing and Gene Expression Omnibus (GEO) external validation cohorts. Ultimately, hub genes were identified among 13 model genes using STRING and Cytoscape, with preliminary validation carried out through immunohistochemistry. RESULTS: The model, which comprised 13 genes (ABCD2, ACAA1, ACACB, AKT1, CNR1, CPT1C, CROT, ECHDC2, ETFA, HADHB, IRS2, LONP2, and SLC25A17), was established. On the basis of the median risk score, the two cohorts were grouped into low-and high-risk groups in the subsequent test and validation, and the former exhibited significantly higher survival rates than the latter. Nomograms were established based on prognostic factors, including stage and risk score, and individualized for the prediction of HNSCC patients. Ultimately, immunohistochemical staining showed that ACAA1 and HADHB were significantly under-expressed in HNSCC, with a favorable prognosis associated with low HADHB and high ACAA1. CONCLUSIONS: The gene prognostic model has illustrated promising capability in predicting the prognosis, and ACAA1 and HADHB might serve as potential therapeutic biomarkers for HNSCC patients.

Identification of AURKA as a Biomarker Associated with Cuproptosis and Ferroptosis in HNSCC.

Cuproptosis and ferroptosis represent copper- and iron-dependent forms of cell death, respectively, and both are known to play pivotal roles in head and neck squamous cell carcinoma (HNSCC). However, few studies have explored the prognostic signatures related to cuproptosis and ferroptosis in HNSCC. Our objective was to construct a prognostic model based on genes associated with cuproptosis and ferroptosis. We randomly assigned 502 HSNCC samples from The Cancer Genome Atlas (TCGA) into training and testing sets. Pearson correlation analysis was utilized to identify cuproptosis-associated ferroptosis genes in the training set. Cox proportional hazards (COX) regression and least absolute shrinkage operator (LASSO) were employed to construct the prognostic model. The performance of the prognostic model was internally validated using single-factor COX regression, multifactor COX regression, Kaplan-Meier analysis, principal component analysis (PCA), and receiver operating curve (ROC) analysis. Additionally, we obtained 97 samples from the Gene Expression Omnibus (GEO) database for external validation. The constructed model, based on 12 cuproptosis-associated ferroptosis genes, proved to be an independent predictor of HNSCC prognosis. Among these genes, the increased expression of aurora kinase A (AURKA) has been implicated in various cancers. To further investigate, we employed small interfering RNAs (siRNAs) to knock down AURKA expression and conducted functional experiments. The results demonstrated that AURKA knockdown significantly inhibited the proliferation and migration of HNSCC cells (Cal27 and CNE2). Therefore, AURKA may serve as a potential biomarker in HNSCC.

Therapeutic targeting of thioredoxin reductase 1 causes ferroptosis while potentiating anti-PD-1 efficacy in head and neck cancer.

Head and neck squamous cell carcinoma (HNSCC) faces low response rates to anti-PD-1 immunotherapies, highlighting the need for enhanced treatment strategies. Auranofin, which inhibits thioredoxin reductase (TrxR) through its gold-based composition, has shown potential in cancer treatment. It targets the TrxR system, essential for safeguarding cells from oxidative stress. The overproduction of TrxR in cancerous cells supports their proliferation. However, auranofin's interference with this system can upset the cellular redox equilibrium, boost levels of reactive oxygen species, and trigger the death of cancer cells. This study is the first to highlight TXNRD1 as a crucial factor contributing to resistance to anti-PD-1 treatment in HNSCC. In this study, we identified targetable regulators of resistance to immunotherapy-induced ferroptosis in HNSCC. We observed a link of thioredoxin reductase 1 (TXNRD1) with tumoral PD-L1 expression and ferroptosis suppression in HNSCC. Moreover, HNSCC tumors with aberrant TXNRD1 expression exhibited a lack of PD-1 response, NRF2 overexpression, and PD-L1 upregulation. TXNRD1 inhibition promoted ferroptosis in HNSCC cells with NRF2 activation and in organoid tumors derived from patients lacking a PD-1 response. Mechanistically, TXNRD1 regulated PD-L1 transcription and maintained the redox balance by binding to ribonucleotide reductase regulatory subunit M2 (RRM2). TXNRD1 expression disruption sensitized HNSCC cells to anti-PD-1-mediated Jurkat T-cell activation, promoting tumor killing through ferroptosis. Moreover, TXNRD1 inhibition through auranofin cotreatment synergized with anti-PD-1 therapy to potentiate immunotherapy-mediated ferroptosis by mediating CD8+ T-cell infiltration and downregulating PD-L1 expression. Our findings indicate that targeting TXNRD1 is a promising therapeutic strategy for improving immunotherapy outcomes in patients with HNSCC.

Low-Level Expression of p-S6 Is Associated with Nodal Metastasis in Patients with Head and Neck Cutaneous Squamous Cell Carcinoma.

Cutaneous squamous cell carcinoma (cSCC) is the second most common form of skin cancer. The incidence of metastasis for cSCC is estimated to be around 1.2-5%. Ribosomal protein S6 (p-S6) and the p21 protein (p21) are two proteins that play central roles in other cancers. These proteins may be equally important in cSCC, and together, these could constitute a good candidate for metastasis risk assessment of these patients. We investigate the relationship of p-S6 and p21 expression with the impact on the prognosis of head and neck cSCC (cSCCHN). p-S6 and p21 expression was analyzed by immunohistochemistry on paraffin-embedded tissue samples from 116 patients with cSCCHN and associations sought with clinical characteristics. Kaplan-Meier estimators and Cox proportional hazard regression models were also used. The expression of p-S6 was significantly inversely associated with tumor thickness, tumor size, desmoplastic growth, pathological stage, perineural invasion and tumor buds. p21 expression was significantly inversely correlated with >6 mm tumor thickness, desmoplastic growth, and perineural invasion. p-S6-negative expression significantly predicted an increased risk of nodal metastasis (HR = 2.63, 95% CI 1.51-4.54; p < 0.001). p21 expression was not found to be a significant risk factor for nodal metastasis. These findings demonstrate that p-S6-negative expression is an independent predictor of nodal metastasis. The immunohistochemical expression of p-S6 might aid in better risk stratification and management of patients with cSCCHN.

Prevotella intermedia boosts OSCC progression through ISG15 upregulation: a new target for intervention.

PURPOSE: Periodontitis-associated bacteria, such as Porphyromonas gingivalis and Fusobacterium nucleatum, are closely linked to the risk of oral squamous cell carcinoma (OSCC). Emerging studies have indicated that another common periodontal pathogen, Prevotella intermedia (P. intermedia), is enriched in OSCC and could affect the occurrence and progression of OSCC. Our aim is to determine the effects of P. intermedia on the progression of OSCC and the role of antibiotics in reversing these effects. METHODS: In this study, a murine xenograft model of OSCC was established, and the mice were injected intratumorally with PBS (control group), P. intermedia (P.i group), or P. intermedia combined with an antibiotic cocktail administration (P.i + ABX group), respectively. The effects of P. intermedia and ABX administration on xenograft tumor growth, invasion, angiogenesis, and metastasis were investigated by tumor volume measurement and histopathological examination. Enzyme-linked immunosorbent assay (ELISA) was used to investigate the changes in serum cytokine levels. Immunohistochemistry (IHC) was adopted to analyze the alterations in the levels of inflammatory cytokines and infiltrated immune cells in OSCC tissues of xenograft tumors. Transcriptome sequencing and analysis were conducted to determine differential expression genes among various groups. RESULTS: Compared with the control treatment, P. intermedia treatment significantly promoted tumor growth, invasion, angiogenesis, and metastasis, markedly affected the levels of inflammatory cytokines, and markedly altered M2 macrophages and regulatory T cells (Tregs) infiltration in the tumor microenvironment. However, ABX administration clearly abolished these effects of P. intermedia. Transcriptome and immunohistochemical analyses revealed that P. intermedia infection increased the expression of interferon-stimulated gene 15 (ISG15). Correlation analysis indicated that the expression level of ISG15 was positively correlated with the Ki67 expression level, microvessel density, serum concentrations and tissue expression levels of inflammatory cytokines, and quantities of infiltrated M2 macrophages and Tregs. However, it is negatively correlated with the quantities of infiltrated CD4+ and CD8+ T cells. CONCLUSION: In conclusion, intratumoral P. intermedia infection aggravated OSCC progression, which may be achieved through upregulation of ISG15. This study sheds new light on the possible pathogenic mechanism of intratumoral P. intermedia in OSCC progression, which could be a prospective target for OSCC prevention and treatment.

CDK1 and CCNA2 play important roles in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is a malignant tumor that occurs in oral cavity and is dominated by squamous cells. The relationship between CDK1, CCNA2, and OSCC is still unclear. The OSCC datasets GSE74530 and GSE85195 configuration files were downloaded from the Gene Expression Omnibus (GEO) database and were derived from platforms GPL570 and GPL6480. Differentially expressed genes (DEGs) were screened. The weighted gene co-expression network analysis, functional enrichment analysis, gene set enrichment analysis, construction and analysis of protein-protein interaction (PPI) network, Comparative Toxicogenomics Database analysis were performed. Gene expression heatmap was drawn. TargetScan was used to screen miRNAs that regulate central DEGs. A total of 1756 DEGs were identified. According to Gene Ontology (GO) analysis, they were predominantly enriched in processes related to organic acid catabolic metabolism, centromeric, and chromosomal region condensation, and oxidoreductase activity. In Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, the DEGs were mainly concentrated in metabolic pathways, P53 signaling pathway, and PPAR signaling pathway. Weighted gene co-expression network analysis was performed with a soft-thresholding power set at 9, leading to the identification of 6 core genes (BUB1B, CCNB1, KIF20A, CCNA2, CDCA8, CDK1). The gene expression heatmap revealed that core genes (CDK1, CCNA2) were highly expressed in OSCC samples. Comparative Toxicogenomics Database analysis demonstrated associations between the 6 genes (BUB1B, CCNB1, KIF20A, CCNA2, CDCA8, CDK1) and oral tumors, precancerous lesions, inflammation, immune system disorders, and tongue tumors. The associated miRNAs for CDK1 gene were hsa-miR-203a-3p.2, while for CCNA2 gene, they were hsa-miR-6766-3p, hsa-miR-4782-3p, and hsa-miR-219a-5p. CDK1 and CCNA2 are highly expressed in OSCC. The higher the expression of CDK1 and CCNA2, the worse the prognosis.

KAT7 enhances the proliferation and metastasis of head and neck squamous carcinoma by promoting the acetylation level of LDHA.

Lysine acetyltransferase 7 (KAT7), a histone acetyltransferase, has recently been identified as an oncoprotein and has been implicated in the development of various malignancies. However, its specific role in head and neck squamous carcinoma (HNSCC) has not been fully elucidated. Our study revealed that high expression of KAT7 in HNSCC patients is associated with poor survival prognosis and silencing KAT7 inhibits the Warburg effect, leading to reduced proliferation, invasion, and metastatic potential of HNSCC. Further investigation uncovered a link between the high expression of KAT7 in HNSCC and tumor-specific glycolytic metabolism. Notably, KAT7 positively regulates Lactate dehydrogenase A (LDHA), a key enzyme in metabolism, to promote lactate production and create a conducive environment for tumor proliferation and metastasis. Additionally, KAT7 enhances LDHA activity and upregulates LDHA protein expression by acetylating the lysine 118 site of LDHA. Treatment with WM3835, a KAT7 inhibitor, effectively suppressed the growth of subcutaneously implanted HNSCC cells in mice. In conclusion, our findings suggest that KAT7 exerts pro-cancer effects in HNSCC by acetylating LDHA and may serve as a potential therapeutic target. Inhibiting KAT7 or LDHA expression holds promise as a therapeutic strategy to suppress the growth and progression of HNSCC.

Spatiotemporal characteristics of tissue derived small extracellular vesicles is associated with tumor relapse and anti-PD-1 response.

Small extracellular vesicles (sEVs) residing at tumor tissues are valuable specimens for biopsy. Tumor heterogeneity is common across all cancer types, but the heterogeneity of tumor tissue-derived sEVs (Ti-sEVs) is undefined. This study aims to discover the spatial distributions of Ti-sEVs in oral squamous cell carcinoma (OSCC) tissues and explore how these vesicle distributions affect the patients' prognosis. Multi-regional sampling enabled us to uncover that Ti-sEVs' accumulation at peritumoral sites correlates with a higher disease-free survival rate, and conversely, sparse peritumoral Ti-sEVs tend to forecast a higher risk of relapse. Of those relapsed patients, Ti-sEVs strongly bind to extracellular matrix and subsequently degrade it for allowing themselves enter the bloodstream rather than staying in situ. In advanced OSCC patients, the quantity and spatial distribution of Ti-sEVs prior to anti-PD-1 treatment, as well as the temporal variance of Ti-sEVs before and after immunotherapy, strongly map the clinical response and can help to distinguish the patients with shrinking tumors from those with growing tumors. Our work elucidates the correlation of spatiotemporal features of Ti-sEVs with patients' therapeutic outcomes and exhibit the potential for using Ti-sEVs as a predictor to forecast prognosis and screen the responders to anti-PD-1 therapy.