[The expression and prognosis prediction of CFL-1 in head and neck squamous cell carcinoma].

PURPOSE: The purpose of this study was to explore the expression, prognostic value and immune correlation of Cofilin 1 protein(CFL-1) in head and neck squamous cell carcinoma(HNSCC). METHODS: The expression and prognostic value of CFL-1 in head and neck squamous cell carcinoma(HNSCC) was explored in the cancer genome map database (TCGA) and gene expression total databases (GEO), and the potential immune pathway of CFL-1 in HNSCC was revealed by GESA and cibersoft analysis. The data were statistically analyzed using SPSS 26.0 software package. RESULTS: CFL-1 was significantly up-regulated in HNSCC tissue. The expression level of CFL-1 was significantly correlated with the overall survival status of HNSCC. High expression of CFL-1 was significantly associated with a lower overall survival rate. In addition, multivariate Cox survival analysis showed that CFL-1 expression was independent predictors of poor prognosis of HNSCC. GESA and cibersoft analysis showed that the imbalance of CFL-1 expression affected multiple signal pathways and infiltration of immune cells. CONCLUSIONS: CFL-1 is highly expressed in HNSCC and is significantly associated with poor prognosis of NHSCC. It is a potential prognostic marker of HNSCC.

Identification of tumor stemness and immunity related prognostic factors and sensitive drugs in head and neck squamous cell carcinoma.

The presence of cancer stem cells (CSCs) contributes significantly to treatment resistance in various cancers, including head and neck squamous cell carcinoma (HNSCC). Despite this, the relationship between cancer stemness and immunity remains poorly understood. In this study, we aimed to identify potential immunotherapeutic targets and sensitive drugs for CSCs in HNSCC. Using data from public databases, we analyzed expression patterns and prognostic values in HNSCC. The stemness index was calculated using the single-sample gene set enrichment analysis (ssgsea) algorithm, and weighted gene co-expression network analysis (WGCNA) was employed to screen for key stemness-related modules. Consensus clustering was then used to group samples for further analysis, and prognosis-related key genes were identified through regression analysis. Our results showed that tumor samples from HNSCC exhibited higher stemness indices compared to normal samples. WGCNA identified a module highly correlated with stemness, comprising 187 genes, which were significantly enriched in protein digestion and absorption pathways. Furthermore, we identified sensitive drugs targeting prognostic genes associated with tumor stemness. Notably, two genes, HLF and CCL11, were found to be highly associated with both stemness and immunity. In conclusion, our study identifies a stemness-related gene signature and promising drug candidates for CSCs of HNSCC. Additionally, HLF and CCL11, which are associated with both stemness and immunity, represent potential targets for immunotherapy in HNSCC.

Differential Immune Checkpoint Protein Expression in HNSCC: The Role of HGF/MET Signaling.

Although inhibitors targeting the PD1/PD-L1 immune checkpoint are showing comparably good outcomes, a significant percentage of head and neck squamous cell carcinoma (HNSCC) patients do not respond to treatment. Apart from using different treatment strategies, another possibility would be to target other immune checkpoints operating in these non-responding tumors. To obtain an overview of which checkpoint ligands are expressed on HNSCC tumor cells and if these ligands are affected by HGF/MET signaling, we used mRNA sequencing and antibody-based techniques for identifying checkpoint ligands in six HNSCC tumor cell lines. Furthermore, we compared our results to mRNA sequencing data. From the checkpoint ligands we investigated, VISTA was expressed the highest at the RNA level and was also the most ubiquitously expressed. PD-L2 and B7-H3 were expressed comparably lower and were not present in all cell lines to the same extent. B7-H4, however, was only detectable in the Detroit 562 cell line. Concerning the effect of HGF on the ligand levels, PD-L2 expression was enhanced with HGF stimulation, whereas other checkpoint ligand levels decreased with stimulation. B7-H4 levels in the Detroit 562 cell line drastically decreased with HGF stimulation. This is of interest because both the checkpoint ligand and the growth factor are reported to be connected to epithelial-mesenchymal transition in the literature.

The immunomodulatory ballet of tumour-derived extracellular vesicles and neutrophils orchestrating the dynamic CD73/PD-L1 pathway in cancer.

Head and neck squamous cell carcinoma (HNSCC) is a global cancer burden with a 5-year overall survival rate of around 50%, stagnant for decades. A tumour-induced immunosuppressive microenvironment contributes to HNSCC progression, with the adenosine (ADO) pathway and an upregulated expression of inhibitory immune checkpoint regulators playing a key role in this context. The correlation between high neutrophil-to-lymphocyte ratio (NLR) with advanced tumour staging suggests involvement of neutrophils (NØ) in cancer progression. Interestingly, we associated a high NLR with an increased intracellular PD-L1 localization in primary HNSCC samples, potentially mediating more aggressive tumour characteristics and therefore synergistically favouring tumour progression. Still, further research is needed to harness this knowledge for effective treatments and overcome resistance. Since it is hypothesized that the tumour microenvironment (TME) may be influenced by small extracellular vesicles (sEVs) secreted by tumours (TEX), this study aims to investigate the impact of HNSCC-derived TEX on NØ and blockade of ADO receptors as a potential strategy to reverse the pro-tumour phenotype of NØ. UMSCC47-TEX exhibited CD73 enzymatic activity involved in ADO signalling, as well as the immune checkpoint inhibitor PD-L1. Data revealed that TEX induce chemotaxis of NØ and the sustained interaction promotes a shift into a pro-tumour phenotype, dependent on ADO receptors (P1R), increasing CD170high subpopulation, CD73 and PD-L1 expression, followed by an immunosuppressive secretome. Blocking A3R reduced CD73 and PD-L1 expression. Co-culture experiments with HNSCC cells demonstrated that TEX-modulated NØ increase the CD73/PD-L1 axis, through Cyclin D-CDK4/6 signalling. To support these findings, the CAM model with primary tumour was treated with NØ supernatant. Moreover, these NØ promoted an increase in migration, invasion, and reduced cell death. Targeting P1R on NØ, particularly A3R, exhibited potential therapeutic strategy to counteract immunosuppression in HNSCC. Understanding the TEX-mediated crosstalk between tumours and NØ offers insights into immunomodulation for improving cancer therapies.

Stabilization of EREG via STT3B-mediated N-glycosylation is critical for PDL1 upregulation and immune evasion in head and neck squamous cell carcinoma.

Dysregulated Epiregulin (EREG) can activate epidermal growth factor receptor (EGFR) and promote tumor progression in head and neck squamous cell carcinoma (HNSCC). However, the mechanisms underlying EREG dysregulation remain largely unknown. Here, we showed that dysregulated EREG was highly associated with enhanced PDL1 in HNSCC tissues. Treatment of HNSCC cells with EREG resulted in upregulated PDL1 via the c-myc pathway. Of note, we found that N-glycosylation of EREG was essential for its stability, membrane location, biological function, and upregulation of its downstream target PDL1 in HNSCC. EREG was glycosylated at N47 via STT3B glycosyltransferases, whereas mutations at N47 site abrogated N-glycosylation and destabilized EREG. Consistently, knockdown of STT3B suppressed glycosylated EREG and inhibited PDL1 in HNSCC cells. Moreover, treatment of HNSCC cells with NGI-1, an inhibitor of STT3B, blocked STT3B-mediated glycosylation of EREG, leading to its degradation and suppression of PDL1. Finally, combination of NGI-1 treatment with anti-PDLl therapy synergistically enhanced the efficacy of immunotherapy of HNSCC in vivo. Taken together, STT3B-mediated N-glycosylation is essential for stabilization of EREG, which mediates PDL1 upregulation and immune evasion in HNSCC.

Type I conventional dendritic cells and CD8+ T cells predict favorable clinical outcome of head and neck squamous cell carcinoma patients.

Head and neck squamous cell carcinoma (HNSCC) is one of the most common tumor entities worldwide, with human papillomavirus (HPV) infection contributing to cancer development. Conventional therapies achieve only limited efficiency, especially in recurrent or metastatic HNSCC. As the immune landscape decisively impacts the survival of patients and treatment efficacy, this study comprehensively investigated the immunological tumor microenvironment (TME) and its association with patient outcome, with special focus on several dendritic cell (DC) and T lymphocyte subpopulations. Therefore, formalin-fixed paraffin-embedded tumor samples of 56 HNSCC patients, who have undergone resection and adjuvant radiotherapy, were analyzed by multiplex immunohistochemistry focusing on the detailed phenotypic characterization and spatial distribution of DCs, CD8+ T cells, and T-helper cell subsets in different tumor compartments. Immune cell densities and proportions were correlated with clinical characteristics of the whole HNSCC cohort and different HPV- or hypoxia-associated subcohorts. Tumor stroma was highly infiltrated by plasmacytoid DCs and T lymphocytes. Among the T-helper cells and CD8+ T cells, stromal regulatory T cells and intraepithelial exhausted CD8+ T cells expressing programmed cell death protein-1 (PD-1+) and/or lymphocyte-activation gene-3 (LAG-3+) were the predominant phenotypes, indicating an immunosuppressive TME. HPV-associated tumors showed significantly higher infiltration of type I and type II conventional DCs (cDC1, cDC2) as well as several CD8+ T cell phenotypes including exhausted, activated, and proliferating T cells. On the contrary, tumors with hypoxia-associated gene signatures exhibited reduced infiltration for these immune cells. By multivariate Cox regression, immune-related prognostic factors were identified. Patient clusters defined by high infiltration of DCs and T lymphocytes combined with HPV positivity or low hypoxia showed significantly prolonged survival. Thereby, cDC1 and CD8+ T cells emerged as independent prognostic factors for local and distant recurrence. These results might contribute to the implementation of an immune cell infiltration score predicting HNSCC patients' survival and such patient stratification might improve the design of future individualized radiochemo-(immuno)therapies.

CTHRC1 is a prognostic biomarker correlated with immune infiltration in head and neck squamous cell carcinoma.

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide, characterized by high morbidity, high mortality, and poor prognosis. Collagen triple helix repeat containing 1 (CTHRC1) has been shown to be highly expressed in various cancers. However, its biological functions, potential role as a biomarker, and its relationship with immune infiltrates in HNSCC remain unclear. Our principal objective was to analyze CTHRC1 expression, its prognostic implications, biological functions, and its effects on the immune system in HNSCC patients using bioinformatics analysis. METHODS: The expression matrix was obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). CTHRC1 expression in HNSCC was analyzed between tumor and adjacent normal tissues, different stages were compared, and its impact on clinical prognosis was assessed using Kaplan-Meier analysis. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Variation Analysis (GSVA) were employed for enrichment analysis. The Search Tool for the Retrieval of Interacting Genes database (STRING) was used to analyze protein-protein interactions. Pearson correlation tests were used to investigate the association between CTHRC1 expression and immune checkpoints. The correlation between CTHRC1 and immune infiltration was investigated using CIBERSORT, TIMER, and ESTIMATE. RESULTS: Compared to adjacent normal tissues, CTHRC1 was found to be highly overexpressed in tumors. Increased expression of CTHRC1 was more evident in the advanced stage of HNSCC and predicted a poor prognosis. Most genes related to CTHRC1 in HNSCC were enriched in physiological functions of Extracellular matrix(ECM) and tumor. Furthermore, several immune checkpoints, such as TNFSF4 and CD276 have been shown to be associated with CTHRC1 expression. Notably, the level of CTHRC1 expression correlated significantly with immune infiltration levels, particularly activated macrophages in HNSCC. CONCLUSIONS: High expression of CTHRC1 predicts poor prognosis and is associated with immune infiltration in HNSCC, confirming its utility as a tumor marker for HNSCC. TRIAL REGISTRATION: Not applicable. All data are from public databases and do not contain any clinical trials.

Cancer Cell Small Molecule Secretome Induces the Immune Checkpoint NKG2A and Dysfunction of Human CD8+ T Cells.

PD-1 blockade has been approved for head and neck squamous cell carcinoma (HNSCC) patients. However, many HNSCC patients do not respond to this treatment, and other tumor microenvironmental factors may promote resistance to PD-1 blockade. We previously identified increased expression of the inhibitory receptor NKG2A on CD8+ T cells in HNSCC tumors compared with T cells in matching PBMC samples. Mechanisms that promote NKG2A expression and the role of NKG2A on human T cells in the tumor microenvironment, however, are uncertain. In this study, we show that tumor-conditioned media (TCM) of HNSCC cancer cell lines or ascites fluid from colorectal carcinoma patients is sufficient to induce the expression of NKG2A and other inhibitory receptors on activated CD8+ T cells isolated from PBMCs of healthy donors. Boiling or small molecular mass cutoff filtering did not eliminate the effect of TCM, suggesting that a small molecule promotes NKG2A. T cell activation in TCM decreased the basal and maximal mitochondrial respiration to metabolically restrain CD8+ T cells. Functionally, T cell activation in TCM reduced CD8+ T cell cytotoxicity as shown by lower production of cytokines, granzyme B, and perforin. Furthermore, TCM prevented CD8+ T cells from killing cancer cells in response to an anti-CD19/anti-CD3 bispecific T cell engager. Thus, a small secreted molecule from HNSCC cells can induce NKG2A expression and promote T cell dysfunction. Our findings may lead to targets for novel cancer therapies or biomarkers for NKG2A blockade response and provide a model to study T cell dysfunction and impaired metabolism.

Predictive capacity of immune-related adverse events and cytokine profiling in neoadjuvant immune checkpoint inhibitor trials for head and neck squamous cell carcinoma.

OBJECTIVES: Certain low-level immune-related adverse events (irAEs) have been associated with survival benefits in patients with various solid tumors on immune checkpoint inhibitors (ICIs). We aimed to investigate the association between irAEs and response to neoadjuvant ICIs in patients with head and neck squamous cell carcinoma (HNSCC) and to identify differences in circulating cytokine levels based on irAE status. METHODS: This was a retrospective cohort study including three neoadjuvant clinical trials from July 2017 to January 2022: NCT03238365 (nivolumab ± tadalafil), NCT03854032 (nivolumab ± BMS986205), NCT03618654 (durvalumab ± metformin). The presence and type of irAEs, pathologic treatment response, and survival were compared. Canonical linear discriminant analysis (LDA) was performed to identify combinations of circulating cytokines predictive of irAEs using plasma sample multiplex assay. RESULTS: Of 113 participants meeting inclusion criteria, 32 (28.3%) developed irAEs during treatment or follow-up. Positive p16 status was associated with irAEs (odds ratio [OR] 2.489; 95% CI 1.069-6.119; p = 0.043). irAEs were associated with pathologic treatment response (OR 3.73; 95% CI 1.34-10.35; p = 0.011) and with higher OS in the combined cohort (HR 0.319; 95% CI 0.113-0.906; p = 0.032). Patients with irAEs within the nivolumab cohort had significant elevations of select cytokines pre-treatment. Canonical LDA identified key drivers of irAEs among all trials, which were highly predictive of future irAE status. CONCLUSIONS: irAEs are associated with response to neoadjuvant ICI therapy in HNSCC and can serve as clinical indicators for improved clinical outcomes. irAEs can be predicted by concentrations of several circulating cytokines prior to treatment.

Multi omics analysis of mitophagy subtypes and integration of machine learning for predicting immunotherapy responses in head and neck squamous cell carcinoma.

Mitophagy serves as a critical mechanism for tumor cell death, significantly impacting the progression of tumors and their treatment approaches. There are significant challenges in treating patients with head and neck squamous cell carcinoma, underscoring the importance of identifying new targets for therapy. The function of mitophagy in head and neck squamous carcinoma remains uncertain, thus investigating its impact on patient outcomes and immunotherapeutic responses is especially crucial. We initially analyzed the differential expression, prognostic value, intergene correlations, copy number variations, and mutation frequencies of mitophagy-related genes at the pan-cancer level. Through unsupervised clustering, we divided head and neck squamous carcinoma into three subtypes with distinct prognoses, identified the signaling pathway features of each subtype using ssGSEA, and characterized subtype B as having features of an immune desert using various immune infiltration calculation methods. Using multi-omics data, we identified the genomic variation characteristics, mutated gene pathway features, and drug sensitivity features of the mitophagy subtypes. Utilizing a combination of 10 machine learning algorithms, we have developed a prognostic scoring model called Mitophagy Subgroup Risk Score (MSRS), which is used to predict patient survival and the response to immune checkpoint blockade therapy. Simultaneously, we applied MSRS to single-cell analysis to explore intercellular communication. Through laboratory experiments, we validated the biological function of SLC26A9, one of the genes in the risk model. In summary, we have explored the significant role of mitophagy in head and neck tumors through multi-omics data, providing new directions for clinical treatment.

PPP1R14A is Associated with Immunotherapy Resistance in Head and Neck Squamous Cell Carcinoma Identified by Single-Cell and Bulk RNA-Sequencing.

Objective To identify nivolumab resistance-related genes in patients with head and neck squamous cell carcinoma (HNSCC) using single-cell and bulk RNA-sequencing data. Methods The single-cell and bulk RNA-sequencing data downloaded from the Gene Expression Omnibus database were analyzed to screen out differentially expressed genes (DEGs) between nivolumab resistant and nivolumab sensitive patients using R software. The Least Absolute Shrinkage Selection Operator (LASSO) regression and Recursive Feature Elimination (RFE) algorithm were performed to identify key genes associated with nivolumab resistance. Functional enrichment of DEGs was analyzed with Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses. The relationships of key genes with immune cell infiltration, differentation trajectory, dynamic gene expression profiles, and ligand-receptor interaction were explored. Results We found 83 DEGs. They were mainly enriched in T-cell differentiation, PD-1 and PD-L1 checkpoint, and T-cell receptor pathways. Among six key genes identified using machine learning algorithms, only PPP1R14A gene was differentially expressed between the nivolumab resistant and nivolumab sensitive groups both before and after immunotherapy (P < 0.05). The high PPP1R14A gene expression group had lower immune score (P < 0.01), higher expression of immunosuppressive factors (such as PDCD1, CTLA4, and PDCD1LG2) (r > 0, P < 0.05), lower differentiation of infiltrated immune cells (P < 0.05), and a higher degree of interaction between HLA and CD4 (P < 0.05). Conclusions PPP1R14A gene is closely associated with resistance to nivolumab in HNSCC patients. Therefore, PPP1R14A may be a target to ameliorate nivolumab resistance of HNSCC patients.

Obesity enhances the response to neoadjuvant anti-PD1 therapy in oral tongue squamous cell carcinoma.

OBJECTIVES: Previous studies have demonstrated that obesity may impact the efficacy of anti-PD1 therapy, but the underlying mechanism remains unclear. In this study, our objective was to determine the prognostic value of obesity in patients with oral tongue squamous cell carcinoma (OTSCC) treated with pembrolizumab and establish a subtype based on fatty acid metabolism-related genes (FAMRGs) for immunotherapy. MATERIALS AND METHODS: We enrolled a total of 56 patients with OTSCC who underwent neoadjuvant anti-PD1 therapy. Univariate and multivariate Cox regression analyses, Kaplan-Meier survival analysis, and immunohistochemistry staining were performed. Additionally, we acquired the gene expression profiles of pan-cancer samples and conducted GSEA and KEGG pathway analysis. Moreover, data from TCGA, MSigDB, UALCAN, GEPIA and TIMER were utilized to construct the FAMRGs subtype. RESULTS: Our findings indicate that high Body Mass Index (BMI) was significantly associated with improved PFS (HR = 0.015; 95% CI, 0.001 to 0.477; p = 0.015), potentially attributed to increased infiltration of PD1 + T cells. A total of 91 differentially expressed FAMRGs were identified between the response and non-response groups in pan-cancer patients treated with immunotherapy. Of these, 6 hub FAMRGs (ACSL5, PLA2G2D, PROCA1, IL4I1, UBE2L6 and PSME1) were found to affect PD-1 expression and T cell infiltration in HNSCC, which may impact the efficacy of anti-PD1 therapy. CONCLUSION: This study demonstrates that obesity serves as a robust prognostic predictor for patients with OTSCC undergoing neoadjuvant anti-PD1 therapy. Furthermore, the expression of 6 hub FAMRGs (ACSL5, PLA2G2D, PROCA1, IL4I1, UBE2L6 and PSME1) plays a pivotal role in the context of anti-PD1 therapy and deserves further investigation.

Enhancement of Tumor Antigen-specific T-cell Responses by Immune Checkpoint Blockade in Human Papillomavirus-related Head and Neck Squamous Cell Carcinoma.

BACKGROUND/AIM: Human papillomavirus (HPV)-positive head and neck squamous cell carcinoma (HNSCC) is clinically and immunologically distinct from HPV-negative HNSCC. Herein, we investigated the presence of tumor antigens HPV E6/E7 and wild-type p53-specific T-cell responses, and the impact of immune checkpoint blockade in patients with HPV-positive HNSCC. MATERIALS AND METHODS: Peripheral blood mononuclear cells (PBMCs) from patients with HPV-positive HNSCC were stimulated with HPV E6/E7 or wild-type p53-derived peptide mixture and evaluated using the interferon-γ enzyme-linked immunosorbent spot assay. Flow cytometry was performed to analyze the proportion of T-cell subsets and T cells expressing immune checkpoint molecules. RESULTS: HPV E6/E7-specific T cells were detected in 22 (95.7%) of 23 patients, whereas wild-type p53-specific T cells were detected in 3 (15.0%) of 20 patients. Seven (43.8%) of 16 patients exhibited wild-type p53-specific T-cell responses, as determined using whole proteins instead of peptides. Immune checkpoint blockade enhanced wild-type p53-specific T-cell responses in 9 (45.0%) of 20 patients. Flow cytometric analysis of PBMCs revealed that responders exhibiting enhanced wild-type p53-specific T-cell responses following immune checkpoint blockade had a significantly higher proportion of Ki-67+CD4+ T cells, Ki-67+CD8+ T cells, regulatory T cells, PD-1+CD4+ T cells, and TIM-3+CD4+ T cells than non-responders. CONCLUSION: Our findings indicate that tumor antigen-specific T cells are present in the peripheral blood of patients with HPV-positive HNSCC. Blockade of checkpoint pathways can enhance T-cell responses in certain patients, probably via activated T cells, Tregs, and/or exhausted CD4+ T cells.

Comparative analysis of the tumor microbiome, molecular profiles, and immune cell abundances by HPV status in mucosal head and neck cancers and their impact on survival.

Head and Neck Squamous Cell Carcinoma (HNSCC) comprises a diverse group of tumors with variable treatment response and prognosis. The tumor microenvironment (TME), which includes microbiome and immune cells, can impact outcomes. Here, we sought to relate the presence of specific microbes, gene expression, and tumor immune infiltration using tumor transcriptomics from The Cancer Genome Atlas (TCGA) and associate these with overall survival (OS). RNA sequencing (RNAseq) from HNSCC tumors in TCGA was processed through the exogenous sequences in tumors and immune cells (exotic) pipeline to identify and quantify low-abundance microbes. The detection of the Papillomaviridae family of viruses assessed HPV status. All statistical analyses were performed using R. A total of 499 RNAseq samples from TCGA were analyzed. HPV was detected in 111 samples (22%), most commonly Alphapapillomavirus 9 (90.1%). The presence of Alphapapillomavirus 9 was associated with improved OS [HR = 0.60 (95%CI: 0.40-0.89, p = .01)]. Among other microbes, Yersinia pseudotuberculosis was associated with the worst survival (HR = 3.88; p = .008), while Pseudomonas viridiflava had the best survival (HR = 0.05; p = .036). Microbial species found more abundant in HPV- tumors included several gram-negative anaerobes. HPV- tumors had a significantly higher abundance of M0 (p < .001) and M2 macrophages (p = .035), while HPV+ tumors had more T regulatory cells (p < .001) and CD8+ T-cells (p < .001). We identified microbes in HNSCC tumor samples significantly associated with survival. A greater abundance of certain anaerobic microbes was seen in HPV tumors and pro-tumorigenic macrophages. These findings suggest that TME can be used to predict patient outcomes and may help identify mechanisms of resistance to systemic therapies.

m1A inhibition fuels oncolytic virus-elicited antitumor immunity via downregulating MYC/PD-L1 signaling.

N1-methyladenosine (m1A) RNA methylation is critical for regulating mRNA translation; however, its role in the development, progression, and immunotherapy response of head and neck squamous cell carcinoma (HNSCC) remains largely unknown. Using Tgfbr1 and Pten conditional knockout (2cKO) mice, we found the neoplastic transformation of oral mucosa was accompanied by increased m1A modification levels. Analysis of m1A-associated genes identified TRMT61A as a key m1A writer linked to cancer progression and poor prognosis. Mechanistically, TRMT61A-mediated tRNA-m1A modification promotes MYC protein synthesis, upregulating programmed death-ligand 1 (PD-L1) expression. Moreover, m1A modification levels were also elevated in tumors treated with oncolytic herpes simplex virus (oHSV), contributing to reactive PD-L1 upregulation. Therapeutic m1A inhibition sustained oHSV-induced antitumor immunity and reduced tumor growth, representing a promising strategy to alleviate resistance. These findings indicate that m1A inhibition can prevent immune escape after oHSV therapy by reducing PD-L1 expression, providing a mutually reinforcing combination immunotherapy approach.

Metabolic landscape of head and neck squamous cell carcinoma informs a novel kynurenine/Siglec-15 axis in immune escape.

BACKGROUND: Metabolic reprograming and immune escape are two hallmarks of cancer. However, how metabolic disorders drive immune escape in head and neck squamous cell carcinoma (HNSCC) remains unclear. Therefore, the aim of the present study was to investigate the metabolic landscape of HNSCC and its mechanism of driving immune escape. METHODS: Analysis of paired tumor tissues and adjacent normal tissues from 69 HNSCC patients was performed using liquid/gas chromatography-mass spectrometry and RNA-sequencing. The tumor-promoting function of kynurenine (Kyn) was explored in vitro and in vivo. The downstream target of Kyn was investigated in CD8+ T cells. The regulation of CD8+ T cells was investigated after Siglec-15 overexpression in vivo. An engineering nanoparticle was established to deliver Siglec-15 small interfering RNA (siS15), and its association with immunotherapy response were investigated. The association between Siglec-15 and CD8+ programmed cell death 1 (PD-1)+ T cells was analyzed in a HNSCC patient cohort. RESULTS: A total of 178 metabolites showed significant dysregulation in HNSCC, including carbohydrates, lipids and lipid-like molecules, and amino acids. Among these, amino acid metabolism was the most significantly altered, especially Kyn, which promoted tumor proliferation and metastasis. In addition, most immune checkpoint molecules were upregulated in Kyn-high patients based on RNA-sequencing. Furthermore, tumor-derived Kyn was transferred into CD8+ T cells and induced T cell functional exhaustion, and blocking Kyn transporters restored its killing activity. Accroding to the results, mechanistically, Kyn transcriptionally regulated the expression of Siglec-15 via aryl hydrocarbon receptor (AhR), and overexpression of Siglec-15 promoted immune escape by suppressing T cell infiltration and activation. Targeting AhR in vivo reduced Kyn-mediated Siglec-15 expression and promoted intratumoral CD8+ T cell infiltration and killing capacity. Finally, a NH2-modified mesoporous silica nanoparticle was designed to deliver siS15, which restored CD8+ T cell function status and enhanced anti-PD-1 efficacy in tumor-bearing immunocompetent mice. Clinically, Siglec-15 was positively correlated with AhR expression and CD8+PD-1+ T cell infiltration in HNSCC tissues. CONCLUSIONS: The findings describe the metabolic landscape of HNSCC comprehensively and reveal that the Kyn/Siglec-15 axis may be a novel potential immunometabolism mechanism, providing a promising therapeutic strategy for cancers.

A systematic review of antibody-drug conjugates and bispecific antibodies in head and neck squamous cell carcinoma and nasopharyngeal carcinoma: Charting the course of future therapies.

INTRODUCTION: There is a need to improve the outcomes of patients with head and neck squamous cell carcinoma (HNSCC) and nasopharyngeal carcinoma (NPC), especially in recurrent unresectable and metastatic (R/M) setting. Antibody-drug conjugates (ADC) and bispecific antibodies (BsAb) may deliver promising results. METHODS: We conducted a systematic literature review to identify ADC and BsAb clinical trials, involving patients with HNSCC and NPC, from database creation to December 2023. We reported trial characteristics, overall response rate (ORR), overall survival (OS), and grade ≥ 3 treatment-related adverse events (trAEs). RESULTS: 23 trials (65 % phase I) were found, involving 540 R/M patients (355 [20trials] HNSCC and 185 [5trials] NPC). There were 13 ADC (n = 343) and 10 BsAb (n = 197) trials. 96 % patients were refractory to standard of care treatments. ORR ranged from 0 to 100 %, with the highest ORR for GEN1042 plus chemoimmunotherapy. ORRs for monotherapies were 47 % for ADC, and 0-37 % for BsAb. MRG003 reached in HNSCC 43 % and NPC 47 %. BL-B01D1 54 % in NPC. Longest median OS was seen with MRG003 and KN046. Grade ≥ 3 trAEs were 28-60 % in ADC trials, and 3-33 % BsAb. Grade ≥ 3 myelosuppressive trAEs were typically seen in 8 ADC trials, while 4 BsAb showed infusion-related reactions (IRR). Four treatment-related deaths were reported (1 pneumonitis), all ADC trials. CONCLUSION: ADC and BsAb antibodies show promise in R/M HNSCC and NPC. Results are premature by small sample sizes and lack of control arm. ADC mainly caused myelosuppression and a pneumonitis case, and BsAb IRR. Further research is warranted in this setting.

Neoadjuvant immunotherapy for head and neck squamous cell carcinoma. / Neoadjuvante Immuntherapie bei Kopf-Hals- Plattenepithelkarzinomen.

The neoadjuvant immunotherapy approach marks a significant shift in the treatment paradigm of potentially curable HNSCC. Here, current therapies, despite being highly individualized and advanced, often fall short in achieving satisfactory long-term survival rates and are frequently associated with substantial morbidity.The primary advantage of this approach lies in its potential to intensify and enhance treatment regimens, offering a distinct modality that complements the existing triad of surgery, radiotherapy, and chemotherapy. Checkpoint inhibitors have been at the forefront of this evolution. Demonstrating moderate yet significant survival benefits in the recurrent-metastatic setting with a relatively better safety profile compared to conventional treatments, these agents hold promise when considered for earlier stages of HNSCC.On the other hand, a significant potential benefit of introducing immunotherapy in the neoadjuvant phase is the possibility of treatment de-escalation. By reducing the tumor burden before surgery, this strategy could lead to less invasive surgical interventions. The prospect of organ-sparing protocols becomes a realistic and highly valued goal in this context. Further, the early application of immunotherapy might catalyze a more effective and durable immune response. The induction of an immune memory may potentially lead to a more effective surveillance of residual disease, decreasing the rates of local, regional, and distant recurrences, thereby enhancing overall and recurrence-free survival.However, neoadjuvant immunotherapy is not without its challenges. One of the primary concerns is the safety and adverse events profile. While data suggest that adverse events are relatively rare and manageable, the long-term safety profile in the neoadjuvant setting, especially in the context of curative intent, remains a subject for ongoing research. Another unsolved issue lies in the accurate assessment of treatment response. The discrepancy between radiographic assessment using RECIST criteria and histological findings has been noted, indicating a gap in current imaging techniques' ability to accurately reflect the true efficacy of immunotherapy. This gap underscores the necessity for improved imaging methodologies and the development of new radiologic and pathologic criteria tailored to evaluate the response to immunotherapy accurately.Treatment combinations and timing represent another layer of complexity. There is a vast array of possibilities in combining immunotherapy agents with conventional chemotherapy, targeted therapy, radiation, and other experimental treatments. Determining the optimal treatment regimen for individual patients becomes an intricate task, especially when comparing small, single-arm, non-randomized trials with varying regimens and outcome measures.Moreover, one needs to consider the importance of pre- and intraoperative decision-making in the context of neoadjuvant immunotherapy. As experience with this treatment paradigm grows, there is potential for more tailored surgical approaches based on the patient's remaining disease post-neoadjuvant treatment. This consideration is particularly relevant in extensive surgeries, where organ-sparing protocols could be evaluated.In practical terms, the multi-modal nature of this treatment strategy introduces complexities, especially outside clinical trial settings. Patients face challenges in navigating the treatment landscape, which involves coordination across multiple medical disciplines, highlighting the necessity for streamlined care pathways at specialized centers to facilitate effective treatment management if the neoadjuvant approach is introduced to the real-world.These potential harms and open questions underscore the critical need for meticulously designed clinical trials and correlational studies to ensure patient safety and efficacy. Only these can ensure that this new treatment approach is introduced in a safe way and fulfils the promise it theoretically holds.

Breaking Ground in Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma: Novel Therapies Beyond PD-L1 Immunotherapy.

The treatment for recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) with immune checkpoint inhibitors (anti-PD1) with or without chemotherapy has led to an improvement in survival. Yet, despite this therapeutic advancement, only 15%-19% of patients remain alive at four years, highlighting the poor survival and unmet need for improved therapies for this patient population. Some of the key evolving novel therapeutics beyond anti-PD1 in R/M HNSCC have included therapeutic vaccine therapies, bispecific antibodies/fusion proteins and multitargeted kinase inhibitors, and antibody-drug conjugates (ADCs). Multiple concurrent investigations of novel therapeutics for patients with R/M HNSCC beyond anti-PD(L)1 inhibition are currently underway with some promising early results. Beyond immune checkpoint inhibition, novel immunotherapeutic strategies including therapeutic vaccines ranging from targeting human papillomavirus-specific epitopes to personalized neoantigen vaccines are ongoing with some early efficacy signals and large, randomized trials. Other novel weapons including bispecific antibodies, fusion proteins, and multitargeted kinase inhibitors leverage multiple concurrent targets and modulation of the tumor microenvironment to harness antitumor immunity and inhibition of protumorigenic signaling pathways with emerging promising results. Finally, as with other solid tumors, ADCs remain a promising therapeutic intervention either alone or in combination with immunotherapy for patients with R/M HNSCC. With early enthusiasm across novel therapies in R/M HNSCC, results of larger randomized trials in R/M HNSCC are eagerly awaited.

Engineering Dimeric EGFR-directed IgA Antibodies Reveals a Central Role of CD147 during Neutrophil-mediated Tumor Cell Killing of Head and Neck Squamous Cancer Cells.

Human IgA Abs engage neutrophils for cancer immunotherapy more effectively than IgG Abs. Previous studies demonstrated that engineering approaches improved biochemical and functional properties. In this study, we report a novel, to our knowledge, IgA2 Ab against the epidermal growth factor receptor generated by protein engineering and polymerization. The resulting molecule demonstrated a covalent linkage of L and H chains and an effective polymerization by the joining chain. The engineered dimer outperformed its monomeric variant in functional experiments on Fab-mediated modes of action and binding to the Fc receptor. The capacity to engage neutrophils for Ab-dependent cell-mediated cytotoxicity (ADCC) of adherent growing target cancer cells was cell line dependent. Although the engineered dimer displayed a long-term efficacy against the vulva carcinoma cell line A431, there was a notable in-efficacy against human papillomavirus (HPV)- head and neck squamous cell carcinoma (HNSCC) cell lines. However, the highly engineered IgA Abs triggered a neutrophil-mediated cytotoxicity against HPV+ HNSCC cell lines. Short-term ADCC efficacy correlated with the target cells' epidermal growth factor receptor expression and the ability of cancer cell-conditioned media to enhance the CD147 surface level on neutrophils. Notably, the HPV+ HNSCC cell lines demonstrated a significant increment in releasing soluble CD147 and a reduced induction of membranous CD147 on neutrophils compared with HPV- cells. Although membranous CD147 on neutrophils may impair proper IgA-Fc receptor binding, soluble CD147 enhanced the IgA-neutrophil-mediated ADCC in a dose-dependent manner. Thus, engineering IgA Abs and impedance-based ADCC assays provided valuable information regarding the target-effector cell interaction and identified CD147 as a putative critical parameter for neutrophil-mediated cytotoxicity.