Heterogeneity of the Head and Neck Squamous Cell Carcinoma Immune Landscape and Its Impact on Immunotherapy

Light-activated photosensitizer/quercetin co-loaded extracellular vesicles for precise oral squamous cell carcinoma therapy

Oral squamous cell carcinoma (OSCC) is the most common subtype of head and neck malignancies, characterized by a five-year survival rate that remains persistently below 50%, indicative of limited progress in therapeutic interventions. There is an urgent imperative to develop innovative therapeutic strategies, warranting the investigation of advanced treatment modalities. Nanocarriers offer a promising avenue by significantly enhancing drug properties and pharmacokinetics. Extracellular vesicles (EVs) are naturally occurring nanocarriers produced by cells and have become a focal point in drug delivery research. Quercetin, one of the most abundant dietary flavonoids, exhibits potent anticancer effects. However, its pharmaceutical application is hampered by poor water solubility, instability under physiological conditions, and low bioavailability. To overcome these obstacles, we propose using bio-derived EVs as carriers to co-encapsulate quercetin with the photosensitizer chlorin e6. This strategy leverages the intrinsic targeting capabilities of EVs for precise drug delivery to tumors, along with light-activated drug release, enabling rapid quercetin release under near-infrared light, effectively inhibiting cellular proliferation and inducing apoptosis in tumor cells. In vivo studies demonstrated that drug-loaded EVs exhibited robust tumor-targeting efficacy, resulting in effective and selective tumor ablation upon photoactivation in mice bearing subcutaneous MOC2 tumors.

EMILIN-1 Suppresses Cell Proliferation through Altered Cell Cycle Regulation in Head and Neck Squamous Cell Carcinoma

Extracellular matrix (ECM) proteins play an important role in the pathological processes of tumor development and progression. Elastic microfibril interface located protein-1 (EMILIN-1), an ECM glycoprotein, has been linked to cell adhesion and migration. It was previously identified from head and neck squamous cell carcinoma (HNSCC) tissues that down-regulated EMILIN-1 is associated with an increased risk of secondary primary malignancy development in HNSCC and hypothesized that EMILIN-1 functions as a tumor suppressor in HNSCC. This study shows EMILIN-1 expression in HNSCC tissues is specific to the stromal area, and secreted-EMILIN-1 level is higher in fibroblasts isolated from HNSCC tissues than in HNSCC cells. EMILIN-1 overexpression decreased cell proliferation, migration, and invasion in FaDu and CAL27 cells. Knockdown of EMILIN-1 in HNSCC cancer-associated fibroblasts induced cell proliferation and migration. The conditioned medium from EMILIN-1 knockdown cancer-associated fibroblasts increased HNSCC cell proliferation, and the co-culture system enhanced cancer cell migration and invasion. RNA-sequencing analysis revealed that the cell cycle and aurora kinase signaling are the most significant enrichment pathways, confirmed at the protein level. Furthermore, using an in ovo chick chorioallantoic membrane model, overexpression of EMILIN-1 in FaDu cells reduced tumor size and Ki-67-positivity and increased cleaved caspase-3-positive cells. These findings suggest that EMILIN-1 suppresses HNSCC growth partly through the down-regulation of cell cycle and aurora kinase signaling pathways.

Mesenchymal stem cell-mediated adipogenic transformation: a key driver of oral squamous cell carcinoma progression

BACKGROUND

Interaction between mesenchymal stem cells (MSCs) and oral squamous cell carcinoma (OSCC) cells plays a major role in OSCC progression. However, little is known about adipogenic differentiation alteration in OSCC-derived MSCs (OSCC-MSCs) and how these alterations affect OSCC growth.

METHODS

MSCs were successfully isolated and cultured from normal gingival tissue, OSCC peritumoral tissue, and OSCC tissue. This included gingiva-derived MSCs (GMSCs), OSCC adjacent noncancerous tissues-derived MSCs (OSCCN-MSCs), and OSCC-MSCs. The adipogenic and osteogenic differentiation capabilities of these cells were evaluated using Oil Red O and Alizarin Red S staining, respectively. OSCC cells were then co-cultured with either OSCC-MSCs or GMSCs to assess the impact on OSCC cell proliferation and migration. Subcutaneous xenograft experiments were conducted in BALB/c-nu mice to further investigate the effects in vivo. Additionally, immunohistochemical staining was performed on clinical samples to determine the expression levels of fatty acid synthase (FASN) and the proliferation marker Ki67.

RESULTS

OSCC-MSCs exhibited enhanced adipogenic differentiation and reduced osteogenic differentiation compared to GMSCs. OSCC-MSCs significantly increased the proliferation and migration of OSCC cells relative to GMSCs and promoted tumor growth in mouse xenografts. Lipid droplet accumulation in the stroma was significantly more pronounced in OSCC + OSCC-MSCs xenografts compared to OSCC + GMSCs xenografts. Free fatty acids (FFAs) levels were elevated in OSCC tissues compared to normal gingival tissues. Moreover, OSCC-MSCs consistently secreted higher levels of FFAs in condition medium than GMSCs. Knockdown of FASN in OSCC-MSCs reduced their adipogenic potential and inhibited their ability to promote OSCC cell proliferation and migration. Clinical sample analysis confirmed higher FASN expression in OSCC stroma, correlating with larger tumor size and increased Ki67 expression in cancer tissues, and was associated with poorer overall survival.

CONCLUSIONS

OSCC-MSCs promoted OSCC proliferation and migration by upregulating FASN expression and facilitating FFAs secretion. Our results provide new insight into the mechanism of OSCC progression and suggest that the FASN of OSCC-MSCs may be potential targets of OSCC in the future.

MYC Overexpression Enhances Sensitivity to MEK Inhibition in Head and Neck Squamous Cell Carcinoma

MEK inhibitors, such as trametinib, have shown therapeutic potential in head and neck squamous cell carcinoma (HNSCC). However, the factors influencing cancer cell sensitivity and resistance to MEK inhibition remain poorly understood. In our study, we observed that MEK inhibition significantly reduced the expression of MYC, a transcription factor critical for the therapeutic response. MYC overexpression markedly enhanced the sensitivity of HNSCC cells to trametinib, as evidenced by delayed wound healing and reduced colony formation. Cell cycle analysis revealed that trametinib induced a G1 phase arrest, whereas MYC overexpression accelerated cell cycle progression, with a reduced induction of p27 and p21 and diminished decreases in E2F1 and phospho-Ser2/5 levels. Flow cytometry and protein analyses demonstrated that MYC overexpression amplified trametinib-induced apoptosis and DNA damage, as evidenced by elevated levels of pro-apoptotic markers (p53, cleaved PARP, and BIM) and γH2AX. In vivo xenograft models confirmed these findings, showing increased sensitivity to trametinib in MYC-overexpressing tumors. Moreover, MEK inhibition increased autophagy in HNSCC cells, a factor critical for therapeutic resistance. Inhibiting trametinib-induced autophagy further enhanced apoptotic cell death. These findings suggest that MYC expression and autophagy play crucial roles in HNSCC's response to MEK inhibition. Combining trametinib with autophagy inhibition may improve therapeutic outcomes in HNSCC.

Exploring PANoptosis in head and neck cancer: A novel approach to cancer therapy

PANoptosis is a newly discovered complex programmed cell death (PCD) form. In the field of cancer research, PANoptosis is involved in multiple cell death pathways that affect tumor cell survival, proliferation, and response to treatment, serving as an innovative strategy for cancer therapy. Endocrine-disrupting chemicals (EDCs) impact the endocrine system, including cancer. However, research on their influence on head and neck carcinoma (HNSC) through PANoptosis genes remains limited. This study utilises transcriptomic and clinical data related to HNSC from the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases. We developed a risk model based on PANoptosis-related genes through LASSO Cox regression analysis. Finally, we utilized a Sankey diagram to depict the relationships between EDCs and key genes, identifying DSCAM, IL-6, and SYCP2 as critical predictors of HNSC PANoptosis. These essential genes identified 214 EDCs potentially influencing HNSC, including 3 (Aroclor 1242, Pentachlorobenzene, and Propanil) previously unreported to HNSC. These findings elucidate novel relationships between PANoptosis-related genes mediated by EDCs and the pathogenesis of HNSC.

Identification of B Cell Subpopulations with Pro- and Anti-Tumorigenic Properties in an Immunocompetent Mouse Model of Head and Neck Squamous Cell Carcinoma

Due to their high developmental diversity and different regulatory and functional roles, B cell subpopulations can promote or inhibit tumor growth. An orthotopic murine HNSCC model was applied to investigate the B cell composition and function in HNSCCs. Using flow cytometry approaches, cells from the spleen, lymph nodes and tumors were analyzed. Additionally, immunoglobulin (Ig) levels post-tumor induction were tracked via enzyme-linked immunosorbent assays (ELISA). Following tumor induction, GCs, as well as increasing numbers of GL7+CD95+ GC B cells in the spleen and tumor tissues, were detected. In parallel, we observed CD39+CD73+ B cells in tumors and spleens of tumor-bearing mice. Notably, CD39+CD73+ expression was primarily detected on MZ B cells and to a lesser extent on follicular (FO) and non-follicular, newly formed (NF) B cells, supposing an immunosuppressive function of MZ B cells in the TME. Parallel to increased MZ B cell numbers in secondary lymphoid organs (SLOs) as well as in the tumor tissue, IgM antibody (Ab) levels rose continuously. In contrast, IgG1, IgG2, and IgG3 levels increased at later time points. Understanding the complex interactions between B cell subsets and the TME could lead to new strategies for enhancing the treatment and prognosis of HNSCC patients.

Regorafenib enhances M1/M2 macrophage polarization by inhibiting the secretion of plasminogen activator inhibitor-1 in head and neck squamous cell carcinoma

AIMS

Regorafenib, an oral multikinase inhibitor, is approved for the treatment of various metastatic/advanced cancers. Although clinical trials have reported the efficacy of regorafenib in multiple cancer types, its immunomodulatory activity in head and neck squamous cell carcinoma (HNSCC) remains unclear.

MAIN METHODS

This study investigated the effects of regorafenib on tumorigenesis by using two mouse models of HNSCC. The distribution of immune cells in tumor tissues was assessed through flow cytometry, RNA sequencing, and multiplex immunofluorescence staining.

KEY FINDINGS

Regorafenib exhibited significant antitumor activity in our HNSCC mouse models. Tumor-infiltrating lymphocyte isolation and RNA sequencing revealed that regorafenib can activate immune functions. Moreover, regorafenib-treated tumor-conditioned medium regulated macrophage proliferation ex vivo. Our data suggests that regorafenib modulates immune function by regulating both tumor and immune cells. Specifically, regorafenib induced the polarization of macrophages toward the proinflammatory M1 phenotype by suppressing the production of plasminogen activator inhibitor 1 (PAI-1), a macrophage regulator. In addition, regorafenib suppressed the secretion of PAI-1 from ex vivo human HNSCC organoids.

SIGNIFICANCE

Regorafenib enhances M1/M2 macrophage polarization and suppresses PAI-1 secretion from cancer cells, leading to a shift from M2 to M1 macrophages in the HNSCC tumor microenvironment.

CCDC71L as a novel prognostic marker and immunotherapy target via lipid metabolism in head and neck squamous cell carcinoma

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is the sixth most widespread cancer globally with high rate and poor prognosis. Coiled-coil domain containing 71 like (CCDC71L) exerts an important role in cellular lipid metabolic process. However, its function in HNSCC remains unclear. To this end, we examined the CCDC71L implications for prognosis and tumor microenvironment in HNSCC.

MATERIALS AND METHODS

First, CCDC71L expression was explored through The Cancer Genome Atlas (TCGA), Human Protein Atlas (HPA), the Gene Expression Profiling Interactive Analysis 2 (GEPIA2), Clinical Proteomic Tumor Analysis Consortium (CPTAC) and the Gene Expression Omnibus (GEO) databases. The clinicpathological information were obtained from the dataset of TCGA. The Kaplan-Meier Plotter databases and Cox model were performed for the determination of prognostic values of CCDC71L, including the overall survival (OS), progress free interval (PFI), recurrence-free survival (RFS) and disease specific survival (DSS). Then, the potential mechanism of CCDC71L in HNSCC development was elucidated by means of Gene set enrichment analysis (GSEA) and Metascape databases. Furthermore, the relevance of CCDC71L to immune cells infiltration and immune checkpoints was assessed. The correlations among CCDC71L expression, mutational landscape and genome heterogeneity [mutant-allele tumor heterogeneity (MATH) and tumor purity] were detected by the data in TCGA.

RESULTS

CCDC71L expression was significantly upregulated in HNSCC, and positively associated with age, gender and N stage. Higher CCDC71L expression resulted in poor OS, RFS, DSS and PFI. Multivariate Cox regression analysis showed CCDC71L would be an independent prognostic marker in patients with HNSCC. Moreover, CCDC71L and the level of macrophage and neutrophil cells infiltration were significantly correlated in HNSCC. High expression of CCDC71L was related to immune checkpoint genes, oncogene mutations and genome heterogeneity markers.

CONCLUSION

These results implied that CCDC71L plays vital roles in HNSCC progression, which could be used as a underlying biomarker for the diagnosis and prognosis of HNSCC. Meanwhile, CCDC71L participates in immune regulation, which has a potential value for the immunotherapy of HNSCC patients.

Identification and analysis of a cell communication prognostic signature for oral squamous cell carcinoma at bulk and single-cell levels

Head and neck squamous cancer (HNSC) is a heterogenous malignant tumour disease with poor prognosis and has become the current major public health concern worldwide. Oral squamous cell carcinoma (OSCC) is the majority of HNSC. It is still in lack of comprehensive tumour immune microenvironment analysis and prognostic model development for OSCC's clinic practice. Single-cell sequencing data analysis was conducted to identify immune cell subtypes and illustrate cell-cell interaction status in OSCC via R package 'Seurat', 'Harmony', 'elldex' and 'CellChat'. Base on the bulk sequencing data, WGCNA analysis was employed to identify the CD8+ T cell related gene module. XGBoost was used to construct the gene prognostic model for OSCC. Validation sets and immunotherapy data sets were analysed to further evaluate the model's effectiveness and immunotherapy responsiveness predicting potential. siRNA was used to down regulate FCRL4 expression. Real-time PCR and Western blot were used to validate target gene expression. The effects of FCRL4 on OSCC cells were detected by wound healing, Trans well and clone formation assays. Communication between epithelial cells and tissue stem cells may be the potential key regulators for OSCC progression. By integrating single-cell sequencing data analysis and bulk sequencing data analysis, we constructed a novel immune-related gene prognostic model. The model can effectively predict the prognosis and immunotherapy responsiveness of OSCC patients. In addition, the effects of FCRL4 on OSCC cells were validated. We comprehensively interpreted the immune microenvironment pattern of OSCC based on the single-cell sequencing data and bulk sequencing data analysis. A robust immune feature-based prognostic model was developed for the precise treatment and prognosis evaluation of OSCC.

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.

Navigating the landscape of HPV-associated cancers: From epidemiology to prevention

Human Papillomavirus (HPV) is a widespread infection associated with various cancers, including cervical, oropharyngeal, anal, and genital cancers. This infection contributes to 5 % of global cancer cases annually, affecting approximately 625,600 women and 69,400 men. Cervical cancer remains the most prevalent HPV-linked cancer among females, with the highest incidence seen in low and middle-income countries (LMICs). While most HPV infections are transient, factors such as HPV variants, age, gender, and socioeconomic status influence transmission risks. HPV is categorized into high-risk (HR-HPV) and low-risk types, with strains like HPV 16 and 18 displaying distinct demographic patterns. The intricate pathogenesis of HPV involves genetic and epigenetic interactions, with HPV oncogenes (E6 and E7) and integration into host DNA playing a pivotal role in driving malignancies. Early diagnostics, utilizing HPV DNA testing with surrogate markers such as p16, and advanced molecular techniques like PCR, liquid biopsy, and NGS, significantly impact the management of HPV-induced cancers. Effectively managing HPV-related cancers demands a multidisciplinary approach, including immunotherapy, integrating current therapies, ongoing trials, and evolving treatments. Prevention via HPV vaccination and the inclusion of cervical cancer screening in national immunization programs by conventional Pap smear examination and HPV DNA testing remains fundamental.Despite the preventability of HPV-related cancers, uncertainties persist in testing, vaccination, and treatment. This review article covers epidemiology, pathogenesis, diagnostics, management, prevention strategies, challenges, and future directions. Addressing issues like vaccine hesitancy, healthcare disparities, and advancing therapies requires collaboration among researchers, healthcare providers, policymakers, and the public. Advancements in understanding the disease's molecular basis and clinical progression are crucial for early detection, proper management, and improved outcomes.

Advances in ferroptosis in head and neck cancer (Review)

Ferroptosis is an iron-dependent form of cell death that was discovered in 2012. It encompasses the coordinated orchestration of three fundamental biological pathways: Iron homeostasis, glutathione regulation and lipid metabolism. Head and neck cancer (HNC) is a heterogeneous group of cancers occurring on the mucosal surfaces of the upper respiratory and digestive tracts. Head and neck squamous cell carcinoma is the most common type of HNC, accounting for >90% of HNC cases, and has high morbidity and mortality rates. Despite improvements in diagnosis and treatment, the 5-year survival rate hovers at a dismal 50-60%, with recurrence afflicting nearly 30% of patients, highlighting the inadequacies of currently available treatments. Of note, research exploring the nexus between ferroptosis and HNC remains scarce; however, the present review endeavors to synthesize current knowledge surrounding ferroptosis. The present review elaborated on the normal physiological role of ferroptosis and discussed its potential involvement in HNC pathogenesis. Therapeutic strategies and prognostic paradigms for HNC that target ferroptosis were also reviewed. This review aims to provide direction to catalyze future investigations into ferroptosis in HNC.

Tumor-related IGF2BP1-derived molecular subtypes to predict prognosis and immune microenvironment in head and neck squamous cell carcinoma

Background

Recent studies have underscored the biological significance of RNA modifications in tumorigenicity and progression. However, the potential roles of RNA modifications in immune regulation and the formation of the tumor microenvironment (TME) in head and neck squamous carcinoma (HNSC) remain unclear.

Methods

We collected 199 untreated HNSC samples and clinicopathological data from Fujian Provincial Cancer Hospital. MeRIP-seq and RNA-seq were performed to generate methylation and gene expression profiles, respectively. Consensus molecular subtyping was employed to identify prognosis-related genes and RNA modification patterns in HNSC. Experiments confirmed the potential oncogenic behavior influenced by key genes. Molecular subtypes were identified through consensus clustering and validated using external cohort validation sets.

Results

Among the RNA modification-related genes, IGF2BP1 emerged as the most prognostic. HNSC patients were categorized into high and low IGF2BP1 expression groups. High-expressing patients exhibited poorer survival and reduced chemosensitivity, coupled with increased tumor mutational burden, low PD-L1 expression, and limited immune cell infiltration, indicative of aggressive disease. Analysis revealed two distinct RNA modification patterns associated with IGF2BP1 expression: biosynthetically intense type (BIT) and oncogenically active type (OAT), each characterized by distinct clinical features, outcomes, and biological pathways. In an independent immunotherapy cohort, BIT patients displayed enhanced immune responses and sustained clinical benefits.

Conclusions

This study highlights the crucial link between RNA modification and TME diversity. Evaluating RNA modification in tumors improves our understanding of TME features and supports the development of effective immunotherapy strategies.

Prognosis prediction of head and neck squamous cell carcinoma through the basement membrane-related lncRNA risk model

Background

Head and neck squamous cell carcinoma (HNSCC) ranks among the most widespread and significantly heterogeneous malignant tumors globally. Increasing evidence suggests that the basement membrane (BM) and associated long non-coding RNAs (lncRNA) are correlated with the onset of HNSCC and its prognosis. Our study aims to construct a basement membrane-associated lncRNAs (BMlncRNAs) marker to accurately predict the prognosis of HNSCC patients and find novel immunotherapy targets.

Methods

The Cancer Genome Atlas (TCGA) database was accessed to acquire the transcriptome expression matrices, somatic mutation data, and clinical follow-up data of HNSCC patients. Utilizing co-expression analysis, the BMlncRNAs were identified and the differentially expressed lncRNAs (DEBMlncRNA) were then filtered, The filtering thresholds are FDR<0.05 and |log2FC|≥1. Furthermore, univariate analysis, least absolute shrinkage and selection operator (LASSO), and multivariable Cox regression were utilized to develop the risk model. The model then underwent thorough evaluation across diverse perspectives, encompassing tumor immune infiltration, tumor mutation burden (TMB), functional enrichment, and chemotherapy sensitivity.

Results

The risk assessment model consists of 14 BMlncRNA pairs. The acquired data is indicative of the reliability of the risk score in its capacity as a prognostic factor. Individuals at high risk exhibited a poorer prognosis, and a statistically significant variance was noted in TMB and tumor immune infiltration compared to the low-risk group. Additionally, heightened sensitivity to paclitaxel and docetaxel was evident in the patients at high risk.

Conclusion

We have established a BMLncRNA-based prognostic model that can provide clinical guidance for future laboratory and clinical studies of HNSCC.

Biomarkers in head and neck squamous cell carcinoma: unraveling the path to precision immunotherapy

Recent strides in understanding the molecular underpinnings of head and neck cancers have sparked considerable interest in identifying precise biomarkers that can enhance prognostication and enable personalized treatment strategies. Immunotherapy has particularly revolutionized the therapeutic landscape for head and neck squamous cell carcinoma, offering new avenues for treatment. This review comprehensively examines the application and limitations of the established and emerging/novel biomarkers for head and neck squamous cell carcinoma. Established biomarkers, including well-characterized genetic mutations, protein expressions, and clinical factors, have been extensively studied and validated in clinical practice. Novel biomarkers identified through molecular analyses, including novel genetic alterations, immune-related markers, and molecular signatures, are currently being investigated and validated in preclinical and clinical settings. Biomarkers hold the potential to deepen our understanding of head and neck squamous cell carcinoma biology and guide therapeutic strategies. The evolving paradigm of predictive biomarkers facilitates the study of individual responses to specific treatments, including targeted therapy and immunotherapy.

BANF1 is a novel prognostic biomarker linked to immune infiltration in head and neck squamous cell carcinoma

Background

Barrier-to-autointegration factor 1 (BANF1) is an abundant and ubiquitously expressed postnatal mammalian protein that is overexpressed in numerous human cancers and can promote cancer cell proliferation. However, the role of BANF1 in prognosis remains unclear in head and neck squamous cell carcinoma (HNSCC).

Methods

BANF1 expression data were obtained from the GEO and TCGA databases. We used Cox regression and Kaplan-Meier curves to assess the prognostic potential of BANF1. The role of BANF1-related genes was investigated using Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analyses. In addition, we explored the link between BANF1, drug sensitivity, and the tumor immune microenvironment. Finally, functional in vitro and in vivo assays were used to explore the effects of BANF1 on tumor growth and metastasis of HNSCC.

Results

BANF1 was markedly overexpressed in HNSCC and was correlated with clinicopathological characteristics. According to survival analysis, BANF1 can be inversely correlated with patient survival and can act as a prognostic risk indicator. IC50 values for chemotherapeutic treatments indicated that the group with high BANF1 expression was more responsive to most antitumor treatments. Furthermore, higher TIDE scores were observed in the low BANF1 expression group, indicating a decline in the efficacy of immune checkpoint inhibitor therapy. Functionally, the malignant biological behavior of HNSCC cell lines was inhibited when BANF1 expression was knocked down.

Conclusion

BANF1 can promote tumor progression in patients with HNSCC. BANF1 shows great promise as a potential biomarker to assess the prognosis.

Unravelling the Complexity of HNSCC Using Single-Cell Transcriptomics

BACKGROUND/OBJECTIVES

Head and neck squamous cell carcinoma (HNSCC) is a highly heterogeneous and the most common form of head and neck cancer, posing significant challenges for disease management. The objective of this review is to assess the utility of single-cell RNA sequencing (scRNAseq) in addressing these challenges by enabling a detailed characterization of the tumor microenvironment (TME) at the cellular level.

METHODS

This review compiles and analyzes current strategies that utilize scRNAseq and other single-cell technologies in HNSCC research.

RESULTS

For HNSCC etiology, scRNAseq allows for the construction of cellular atlases, characterization of different cell types, and investigation of genes and processes involved in cancer initiation, development, and progression within the TME. In terms of HNSCC diagnosis and prognosis, the resolution offered by scRNAseq enables the identification of cell type-specific signatures, enhancing prognostic models and disease stratifiers for patient outcome assessments. Regarding HNSCC treatment, scRNAseq provides insights into cellular responses to various treatments, including radiotherapy, chemotherapy, and immunotherapy, contributing to a better understanding of treatment efficacy and patient outcomes.

CONCLUSIONS

This review highlights the contributions of scRNAseq to HNSCC research, addressing its cellular and biological complexity, and emphasizes its potential for advancing research and clinical practice in other cancer types.

Type 2-like polarization and elevated CXCL4 secretion of monocyte derived macrophages upon internalization of plasma-derived exosomes from head and neck cancer patients

BACKGROUND

Exosomes are closely associated with different aspects of tumor-progression in patients with head and neck squamous cell carcinoma (HNSCC), such as angiogenesis or immune regulation. As extracellular vesicles they are involved in the intercellular communication by transferring their cargo such as proteins and nucleic acids from one cell to another. However, the influence of tumor related plasma-derived exosomes on the polarization and characteristics of monocyte derived macrophages is not fully understood.

METHODS

Exosomes were isolated from plasma samples of healthy donors (HD) and HNSCC patients and further evaluated with regard to morphology, size and protein composition via transmission electron microscopy, nanoparticle tracking, western blot analysis and cytokine assays. Differentiation and characteristics of monocyte derived macrophages upon exosome internalization were analyzed using flow cytometry and fluorescence microscopy. Macrophage cytokine secretion patterns were analyzed by human cytokine antibody arrays and ELISA measurements.

RESULTS

Our data revealed elevated overall plasma levels of CTLA-4, PD-L1, and TIM-3 as well as elevated exosome-associated CTLA-4, PD-L2, TIM-3, and LAG-3 levels in HNSCC patients compared to HD. Furthermore, we observed a significant type 2-like polarization and elevated CXCL4 secretion of monocyte derived macrophages upon internalization of plasma-derived exosomes from HNSCC patients, which could be visualized by fluorescence microcopy of membrane stained exosomes.

CONCLUSIONS

The study provides new insights regarding exosome driven pro-tumorigenic immune regulation in the circulation of patients with head and neck cancer and could help to better understand the individual immunologic situation.

Prognostic Significance of SASP-Related Gene Signature of Radiation Therapy in Head and Neck Squamous Cell Carcinoma

In this study, we developed and validated the clinical significance of senescence-associated secretory phenotype (SASP)-related gene signature and explored its association with radiation therapy (RT) in patients with head and neck squamous cell carcinoma (HNSCC). First, we searched the three published review literature associated with SASP and selected all 81 genes to develop SASP-related gene signature. Then, 81 SASP-related genes were adapted to gene expression dataset from The Cancer Genome Atlas (TCGA). Patients with HNSCC of TCGA were classified into clusters 1 and 2 via unsupervised clustering according to SASP-related gene signature. Kaplan-Meier plot survival analysis showed that cluster 1 had a poorer prognosis than cluster 2 in 5-year overall survival and recurrence-free survival. Similarly, cluster 1 showed a worse prognosis than cluster 2 in three validation cohorts (E-MTAB-8588, FHCRC, and KHU). Cox proportional hazards regression observed that the SASP-related signature was an independent prognostic factor for patients with HNSCC. We also established a nomogram using a relevant clinical parameter and a risk score. Time-dependent receiver operating characteristic analysis was carried out to assess the accuracy of the prognostic risk model and nomogram. Senescence SASP-related gene signature was associated with the response to RT. Therefore, subsequent, in vitro experiments further validated the association between SASP-related gene signature and RT in HNSCC. In conclusion, we developed a SASP-related gene signature, which could predict survival of patients with HNSCC, and this gene signature provides new clinical evidence for the accurate diagnosis and targeted RT of HNSCC.

Primary cilia-associated signalling in squamous cell carcinoma of head and neck region

Squamous cell carcinoma (SCC) of the head and neck originates from the mucosal lining of the upper aerodigestive tract, including the lip, tongue, nasopharynx, oropharynx, larynx and hypopharynx. In this review, we summarise what is currently known about the potential function of primary cilia in the pathogenesis of this disease. As primary cilia represent a key cellular structure for signal transduction and are related to cell proliferation, an understanding of their role in carcinogenesis is necessary for the design of new treatment approaches. Here, we introduce cilia-related signalling in head and neck squamous cell carcinoma (HNSCC) and its possible association with HNSCC tumorigenesis. From this point of view, PDGF, EGF, Wnt and Hh signalling are discussed as all these pathways were found to be dysregulated in HNSCC. Moreover, we review the clinical potential of small molecules affecting primary cilia signalling to target squamous cell carcinoma of the head and neck area.

Bufalin Suppresses Head and Neck Cancer Development by Modulating Immune Responses and Targeting the β-Catenin Signaling Pathway

Bufalin, a cardiotonic steroid derived from the Chinese toad (Bufo gargarizans), has demonstrated potent anticancer properties across various cancer types, positioning it as a promising therapeutic candidate. However, comprehensive mechanistic studies specific to head and neck cancers have been lacking. Our study aimed to bridge this gap by investigating bufalin's mechanisms of action in head and neck cancer cells. Using several methods, such as Western blotting, immunofluorescence, and flow cytometry, we observed bufalin's dose-dependent reduction in cell viability, disruption of cell membrane integrity, and inhibition of colony formation in both HPV-positive and HPV-negative cell lines. Bufalin induces apoptosis through the modulation of apoptosis-related proteins, mitochondrial function, and reactive oxygen species production. It also arrests the cell cycle at the G2/M phase and attenuates cell migration while affecting epithelial-mesenchymal transition markers and targeting pivotal signaling pathways, including Wnt/β-catenin, EGFR, and NF-κB. Additionally, bufalin exerted immunomodulatory effects by polarizing macrophages toward the M1 phenotype, bolstering antitumor immune responses. These findings underscore bufalin's potential as a multifaceted therapeutic agent against head and neck cancers, targeting essential pathways involved in proliferation, apoptosis, cell cycle regulation, metastasis, and immune modulation. Further research is warranted to validate these mechanisms and optimize bufalin's clinical application.

Role of Mesenchymal Stem/Stromal Cells in Head and Neck Cancer-Regulatory Mechanisms of Tumorigenic and Immune Activity, Chemotherapy Resistance, and Therapeutic Benefits of Stromal Cell-Based Pharmacological Strategies

Head and neck cancer (HNC) entails a heterogenous neoplastic disease that arises from the mucosal epithelium of the upper respiratory system and the gastrointestinal tract. It is characterized by high morbidity and mortality, being the eighth most common cancer worldwide. It is believed that the mesenchymal/stem stromal cells (MSCs) present in the tumour milieu play a key role in the modulation of tumour initiation, development and patient outcomes; they also influence the resistance to cisplatin-based chemotherapy, the gold standard for advanced HNC. MSCs are multipotent, heterogeneous and mobile cells. Although no MSC-specific markers exist, they can be recognized based on several others, such as CD73, CD90 and CD105, while lacking the presence of CD45, CD34, CD14 or CD11b, CD79α, or CD19 and HLA-DR antigens; they share phenotypic similarity with stromal cells and their capacity to differentiate into other cell types. In the tumour niche, MSC populations are characterized by cell quiescence, self-renewal capacity, low reactive oxygen species production and the acquisition of epithelial-to-mesenchymal transition properties. They may play a key role in the process of acquiring drug resistance and thus in treatment failure. The present narrative review examines the links between MSCs and HNC, as well as the different mechanisms involved in the development of resistance to current chemo-radiotherapies in HNC. It also examines the possibilities of pharmacological targeting of stemness-related chemoresistance in HNSCC. It describes promising new strategies to optimize chemoradiotherapy, with the potential to personalize patient treatment approaches, and highlights future therapeutic perspectives in HNC.

Pembrolizumab plus epacadostat in patients with recurrent/metastatic head and neck squamous cell carcinoma (KEYNOTE-669/ECHO-304): a phase 3, randomized, open-label study

BACKGROUND

Advanced head and neck squamous cell carcinoma (HNSCC) has a poor prognosis, and new treatment options are needed. Combining immunotherapies with differing mechanisms of action may enhance clinical benefits compared with single-agent immunotherapy. Epacadostat, an indoleamine 2,3 dioxygenase 1 inhibitor, plus pembrolizumab, a PD-1 inhibitor, showed promising activity in advanced HNSCC in the phase 1/2 KEYNOTE-037/ECHO-202 trial.

METHODS

KEYNOTE-669/ECHO-304 is a randomized, open-label, phase 3 study evaluating the efficacy and safety of pembrolizumab plus epacadostat, pembrolizumab monotherapy, and the EXTREME regimen (cetuximab with a platinum [carboplatin or cisplatin] and 5-fluorouracil) in recurrent/metastatic (R/M) HNSCC. Participants had no prior systemic therapy for R/M HNSCC and were randomly assigned (2:1:2) to pembrolizumab 200 mg intravenously every 3 weeks plus epacadostat 100 mg orally twice daily, pembrolizumab monotherapy, or EXTREME. The primary endpoint was objective response rate (ORR; investigator assessment). Secondary endpoints were safety and tolerability. Change in serum kynurenine was an exploratory endpoint. Study enrollment was discontinued early as a strategic decision on May 2, 2018, and response assessment was discontinued after first on-study imaging assessment at week 9. Data cut-off was January 17, 2019.

RESULTS

Between December 1, 2017, and May 2, 2018, 89 patients were randomly allocated to pembrolizumab plus epacadostat (n = 35), pembrolizumab monotherapy (n = 19), or EXTREME (n = 35). ORR (95% CI) was 31% (17%-49%) for pembrolizumab plus epacadostat, 21% (6%-46%) for pembrolizumab monotherapy, and 34% (19%-52%) for EXTREME. Treatment-related adverse events (TRAEs) occurred in 82% (n = 28) of patients receiving pembrolizumab plus epacadostat, 63% (n = 12) receiving pembrolizumab monotherapy, and 100% (n = 34) receiving EXTREME. Grade 3-4 TRAEs occurred in 24% (n = 8) of patients receiving pembrolizumab plus epacadostat, 16% (n = 3) receiving pembrolizumab monotherapy, and 82% (n = 28) receiving EXTREME. No deaths occurred due to AEs. Pembrolizumab plus epacadostat treatment reduced kynurenine levels but not to that of healthy subjects.

CONCLUSIONS

Pembrolizumab plus epacadostat and pembrolizumab monotherapy provided a similar response rate to EXTREME and demonstrated a manageable safety profile in patients with R/M HNSCC.

TRIAL REGISTRATION

NCT03358472. Date of trial registration: November 30, 2017.

Prognosis Prediction in Head and Neck Squamous Cell Carcinoma by Radiomics and Clinical Information

(1) Background: head and neck squamous cell carcinoma (HNSCC) is a common cancer whose prognosis is affected by its heterogeneous nature. We aim to predict 5-year overall survival in HNSCC radiotherapy (RT) patients by integrating radiomic and clinical information in machine-learning models; (2) Methods: HNSCC radiotherapy planning computed tomography (CT) images with RT structures were obtained from The Cancer Imaging Archive. Radiomic features and clinical data were independently analyzed by five machine-learning algorithms. The results were enhanced through a voted ensembled approach. Subsequently, a probability-weighted enhanced model (PWEM) was generated by incorporating both models; (3) Results: a total of 299 cases were included in the analysis. By receiver operating characteristic (ROC) curve analysis, PWEM achieved an area under the curve (AUC) of 0.86, which outperformed both radiomic and clinical factor models. Mean decrease accuracy, mean decrease Gini, and a chi-square test identified T stage, age, and disease site as the most important clinical factors in prognosis prediction; (4) Conclusions: our radiomic-clinical combined model revealed superior performance when compared to radiomic and clinical factor models alone. Further prospective research with a larger sample size is warranted to implement the model for clinical use.

Differential tumor immune microenvironment coupled with tumor progression or tumor eradication in HPV-antigen expressing squamous cell carcinoma (SCC) models

Human papilloma virus (HPV) is an etiological factor of head and neck squamous cell carcinoma (HNSCC). To investigate the role of HPV antigen in anti-tumor immunity, we established mouse models by expressing HPV16 E6 and E7 in a SCC tumor cell line. We obtained two HPV antigen-expressing clones (C-225 and C-100) transplantable into C57BL/6 recipients. We found that C-225 elicited complete eradication in C57BL/6 mice (eradicated), whereas C-100 grew progressively (growing). We examined immune tumor microenvironment (TME) using flow cytometry and found that eradicated or growing tumors exhibited differential immune profiles that may influence the outcome of anti-tumor immunity. Surprisingly, the percentage of CD8 and CD4 tumor-infiltrating lymphocytes (TILs) was much higher in growing (C-100) than eradicated (C-225) tumor. However, the TILs upregulated PD-1 and LAG-3 more potently and exhibited impaired effector functions in growing tumor compared to their counterparts in eradicated tumor. C-225 TME is highly enriched with myeloid cells, especially polymorphonuclear (PMN) myeloid-derived suppressor cells (MDSC), whereas the percentage of M-MDSC and tumor-associated macrophages (TAMs) was much higher in C-100 TME, especially M2-TAMs (CD206+). The complete eradication of C-225 depended on CD8 T cells and elicited anti-tumor memory responses upon secondary tumor challenge. We employed DNA sequencing to identify differences in the T cell receptor of peripheral blood lymphocytes pre- and post-secondary tumor challenge. Lastly, C-225 and C-100 tumor lines harbored different somatic mutations. Overall, we uncovered differential immune TME that may underlie the divergent outcomes of anti-tumor immunity by establishing two SCC tumor lines, both of which express HPV16 E6 and E7 antigens. Our experimental models may provide a platform for pinpointing tumor-intrinsic versus host-intrinsic differences in orchestrating an immunosuppressive TME in HNSCCs and for identifying new targets that render tumor cells vulnerable to immune attack.

Navigating therapeutic strategies: HPV classification in head and neck cancer

The World Health Organisation recognised human papillomavirus (HPV) as the cause of multiple cancers, including head and neck cancers. HPV is a double-stranded DNA virus, and its viral gene expression can be controlled after infection by cellular and viral promoters. In cancer cells, the HPV genome is detected as either integrated into the host genome, episomal (extrachromosomal), or a mixture of integrated and episomal. Viral integration requires the breakage of both viral and host DNA, and the integration rate correlates with the level of DNA damage. Interestingly, patients with HPV-positive head and neck cancers generally have a good prognosis except for a group of patients with fully integrated HPV who show worst clinical outcomes. Those patients present with lowered expression of viral genes and limited infiltration of cytotoxic T cells. An impediment to effective therapy applications in the clinic is the sole testing for HPV positivity without considering the HPV integration status. This review will discuss HPV integration as a potential determinant of response to therapies in head and neck cancers and highlight to the field a novel therapeutic avenue that would reduce the cancer burden and improve patient survival.

The impact of the tumor immune microenvironment and tumor-infiltrating lymphocyte subgroups on laryngeal cancer prognosis

The absence of improvement in survival rates across various cancers, including laryngeal cancer, has led to an increasing interest in understanding the immune response to cancer. In head and neck cancers, immune modulatory mechanisms such as immune microenvironment and immune infiltration are important in cancer pathogenesis. This study aims to explore the distribution of tumor-infiltrating lymphocyte (TIL) subgroups in the immune microenvironment and evaluate their impact on tumor histopathological characteristics and prognosis. The study included 50 patients who underwent laryngectomy for laryngeal squamous cell carcinoma, in Istanbul University - Cerrahpaşa, Faculty of Medicine Department of Otorhinolaryngology, between January 2016 and January 2018. Pathology specimens were evaluated using immunohistochemistry to assess the expressions of the CD3, CD20, CD8, CD4, CD25, and FoxP3 markers, identifying subgroups of TILs. The investigation aimed to uncover how these subgroups influence tumor histopathological features and survival outcomes. The high infiltration of CD3, CD20, and CD4 had a positive impact on disease-specific survival, disease-free survival, and recurrence-free survival. In addition, overall survival was positively affected by high CD3 and CD4 infiltrations. However, no significant relationship was observed between the expressions of CD8, FoxP3, and CD25 and any of the survival parameters. The infiltration of CD3, CD20, and CD4 positive cells indicative of a robust antitumoral immune response-emerged as favorable prognostic factors in laryngeal cancer. These findings suggest that enhancing the infiltration of CD3, CD20, and CD4 lymphocytes could be a therapeutic strategy worth exploring in clinical trials.

Early detection and diagnosis of cancer with interpretable machine learning to uncover cancer-specific DNA methylation patterns

Cancer, a collection of more than two hundred different diseases, remains a leading cause of morbidity and mortality worldwide. Usually detected at the advanced stages of disease, metastatic cancer accounts for 90% of cancer-associated deaths. Therefore, the early detection of cancer, combined with current therapies, would have a significant impact on survival and treatment of various cancer types. Epigenetic changes such as DNA methylation are some of the early events underlying carcinogenesis. Here, we report on an interpretable machine learning model that can classify 13 cancer types as well as non-cancer tissue samples using only DNA methylome data, with 98.2% accuracy. We utilize the features identified by this model to develop EMethylNET, a robust model consisting of an XGBoost model that provides information to a deep neural network that can generalize to independent data sets. We also demonstrate that the methylation-associated genomic loci detected by the classifier are associated with genes, pathways and networks involved in cancer, providing insights into the epigenomic regulation of carcinogenesis.

The intratumor microbiome varies by geographical location and anatomical site in head and neck squamous cell carcinoma

Head and Neck Squamous Cell Carcinoma (HNSCC) is a highly heterogeneous cancer that is characterized by distinct phenotypes based on anatomical site and etiological agents. Recently, the intratumor microbiome has been implicated in cancer pathogenesis and progression. Although it is well established that the gut microbiome varies with geographical location and is highly influenced by factors such as diet, environment, and genetics, the intratumor microbiome is not very well characterized. In this review, we aim to characterize the HNSCC intratumor microbiome by geographical location and anatomical site. We conducted a review of primary literature from PubMed and assessed studies based on relevancy and recency. To the best of our knowledge, we are the first to comprehensively examine the tumor microenvironment of HNSCC with respect to these two primary factors on a large scale. Our results suggest that there are unique bacterial and fungal biomarkers for HNSCC for each of the following geographical locations: North America, Asia, Europe, Australia, and Africa. We also identified a panel of microbial biomarkers that are unique to two primary HNSCC anatomic sites, as well as microbial biomarkers associated with various etiological agents of HNSCC. Future study of these microbes may improve HNSCC diagnostic and therapeutic modalities by accounting for differences based on geographic regions and anatomical sites.

High Intraepithelial Mast Cell Density in Warthin's Tumor

BACKGROUND/AIM

Warthin's tumor, the second most frequent neoplasia of the parotid gland, is characterized by a proliferation of both epithelial and lymphoid components. In addition to epithelial and lymphoid cells, various other cell types are implicated to varying degrees in the immune response. Notably, mast cells have long been recognized as a consistent cell population within this tumor. Despite the historical acknowledgment of mast cell presence, their true distribution and significance within Warthin's tumor remain unclear. In this study, we aimed to elucidate the distribution and significance of mast cells in Warthin's tumor.

MATERIALS AND METHODS

Histochemical and immunohistochemical methods were employed for the evaluation of mast cells within tumor specimens.

RESULTS

Our study revealed a notable concentration of mast cells in the epithelial component of Warthin's tumor. Microscopic examination showed predominant lymphoid and epithelial elements with occasional cystic formations. Immunohistochemical analysis identified mast cells in both components, emphasizing their role in the tumor microenvironment. Double immunostaining (mast cell tryptase and CD34) revealed no significant correlation between mast cells and blood vessels. Intraepithelial mast cells (IEMCs) had a significantly higher density in the epithelial component, suggesting a potential association with the tumor's benign nature. The relationship between IEMCs and epithelial cells, especially in the presence of cystic structures, offers valuable insights into the unique features of Warthin's tumor.

CONCLUSION

Our study contributes to the understanding of mast cells in Warthin's tumor, highlighting a substantial concentration within the epithelial component. This knowledge may pave the way for further investigations into the roles of mast cells in the pathogenesis and treatment of Warthin's tumor.

Integrative analysis in head and neck cancer reveals distinct role of miRNome and methylome as tumour epigenetic drivers

Head and neck cancer is the sixth most common malignancy worldwide, with the relatively low 5-year survival rate, mainly because it is diagnosed at a late stage. Infection with HPV is a well known aetiology, which affects the nature of these cancers and patients' survival. Besides, it is considered that the main driving force for this type of cancer could be epigenetics. In this study we aimed to find potential epigenetic biomarkers, by integrating miRNome, methylome, and transcriptome analyses. From the fresh head and neck cancer tissue samples, we chose a group for miRNome, methylome and transcriptome profiling, in comparison to adequate control samples. Bioinformatics analyses are performed in R v4.2.2. Count normalisation and group differential expression for mRNA and the previously obtained miRNA count data was performed with DESeq2 v1.36. Gene set enrichment analysis was performed and visualised using gProfiler2 v0.2.1 Identification of miRNA targets was performed by querying in miRTarBase using multiMiR v1.18.0. Annotation of CpG sites merging into islands was obtained from RnBeads.hg19 v1.28.0. package. For the integrative analysis we performed kmeans clustering using stats v4.2.2 package, using 8-12 clusters and nstart 100. We found that transcriptome analysis divides samples into cancers and controls clusters, with no relation to HPV status or cancer anatomical location. Differentially expressed genes (n = 2781) were predominantly associated with signalling pathways of tumour progression. We identified a cluster of genes under the control of the transcription factor E2F that are significantly underexpressed in cancer tissue, as well as T cell immunity genes and genes related to regulation of transcription. Among overexpressed genes in tumours we found those that belong to cell cycle regulation and vasculature. A small number of genes were found significantly differentially expressed in HPV-positive versus HPV-negative tumours (for example NEFH, ZFR2, TAF7L, ZNF541, and TYMS). In this comprehensive study on an overlapping set of samples where the integration of miRNome, methylome and transcriptome analysis were performed for head and neck cancer, we demonstrated that the majority of genes were associated exclusively with miRNome or methylome and, to a lesser extent, under the control of both epigenetic mechanisms.

Spatial heterogeneity of tumor cells and the tissue microenvironment in oral squamous cell carcinoma

PURPOSE

This study describes the morphologic and phenotypic spatial heterogeneity of tumor cells and the tissue microenvironment (TME), focusing on immune infiltration in OSCCs.

STUDY DESIGN

Patients with OSCCs and planned surgical tumor resection were eligible for the study. Two biopsies each from the tumor center and the tumor rim were obtained. Immunohistochemical characterization of tumor and immune cells was performed using a panel of immunohistochemical markers.

RESULTS

Thirty-six biopsies were obtained from the 9 patients. All patients showed an individual marker expression profile with ITH. Within the same biopsy, the CPS and TPS scores showed relevant variations in PD-L1 expression. Comparisons between the tumor center and rim revealed significant differences in the up/downregulation of p53. Marker expression of patients with recurrences clustered similarly, with the higher expression of FoxP3, IDO, CD4, CD68, and CD163 at the tumor rim.

CONCLUSION

OSCCs were found to exhibit relevant ITH involving both tumor cells and TME, suggesting that biomarker analysis of multiple tumor regions may be helpful for clinical decision making and tumor characterization. The analysis of multiple spots within a biopsy is recommended for a reliable determination of PD-L1 expression and other biomarkers, impacting current clinical assessments.

Gene-Expression Patterns of Tumor and Peritumor Tissues of Smoking and Non-Smoking HPV-Negative Patients with Head and Neck Squamous Cell Carcinoma

We studied the gene-expression patterns in specimens of tumor and peritumor tissue biopsies of 26 patients with head and neck carcinomas depending on smoking status. Histological and immunohistochemical examinations verified that all tumors belonged to the "classical" subgroup of head and neck carcinomas, and the HPV-negative tumor status was confirmed. The expression of 28 tumor-associated genes determined by RT-PCR was independent of patients' sex or age, TNM status, degree of differentiation, or tissue localization. Moreover, in peritumor tissue, none of the 28 genes were differentially expressed between the groups of smoking and nonsmoking patients. During oncotransformation in both studied groups, there were similar processes typical for HNSCC progression: the expression levels of paired keratins 4 and 13 were reduced, while the expression levels of keratin 17 and CD44 were significantly increased. However, further investigation revealed some distinctive features: the expression of the genes EGFR and TP63 increased significantly only in the nonsmoking group, and the expression of IL6, CDKN2A, EGF, and PITX1 genes changed only in the smoking group. In addition, correlation analysis identified several clusters within which genes displayed correlations in their expression levels. The largest group included 10 genes: TIMP1, TIMP2, WEE1, YAP, HIF1A, PI3KCA, UTP14A, APIP, PTEN, and SLC26A6. The genetic signatures associated with smoking habits that we have found may serve as a prerequisite for the development of diagnostic panels/tests predicting responses to different therapeutic strategies for HNSCC.

Effect of radiotherapy on head and neck cancer tissues in patients receiving radiotherapy: a bioinformatics analysis-based study

Radiotherapy is pivotal in treating head and neck cancers including nasopharyngeal, tongue, hypopharyngeal, larynx, maxillary sinus, parotid gland, and oral cancers. It holds the potential for curative effects and finds application in conjunction with chemotherapy, either as a radical method to preserve organ function or as an adjuvant postoperative treatment. We used bioinformatics analysis to investigate the effects of radiotherapy on head and neck cancer tissues in patients who had received radiotherapy. In this study, the expression and mutation profiles of The Cancer Genome Atlas-Head-Neck Squamous Cell Carcinoma were downloaded from the UCSC-Xena database, categorizing patients into two groups-those receiving radiotherapy and those not receiving radiotherapy. Subsequently, differential expression analysis and gene set enrichment analysis (GSEA) were performed. Following this, single-sample GSEA (ssGSEA) scores related to glucose and lipid metabolism were compared between the two groups. Additionally, immune cell infiltration analysis and single-cell verification were performed. Finally, the mutation profiles of the two groups were compared. The analyses revealed that patients receiving radiotherapy exhibited prolonged survival, enhanced apoptosis in head and neck cancer tissue, and diminished keratinocyte proliferation and migration. A comparison of ssGSEA scores related to glucose and lipid metabolism between the two groups indicated a reduction in glycolysis, tricarboxylic acid cycle activity, and fat synthesis in tissues treated with radiotherapy, suggesting that radiotherapy can effectively inhibit tumour cell energy metabolism. Analyses of immune cell infiltration and single-cell verification suggested decreased infiltration of immune cells post-radiotherapy in head and neck cancer tissues. A comparison of mutation profiles revealed a higher frequency of TP53, TTN, and CDKN2A mutations in patients receiving radiotherapy for head and neck cancer. In conclusion, the bioinformatics analyses delved into the effect of radiotherapy on patients with head and neck carcinoma. This study provides a theoretical framework elucidating the molecular mechanisms underlying radiotherapy's efficacy in treating head and neck cancer and presents scientific recommendations for drug therapy following radiotherapy.

A radiomics model to predict γδ T-cell abundance and overall survival in head and neck squamous cell carcinoma

γδ T cells are becoming increasingly popular because of their attractive potential for antitumor immunotherapy. However, the role and assessment of γδ T cells in head and neck squamous cell carcinoma (HNSCC) are not well understood. We aimed to explore the prognostic value of γδ T cell and predict its abundance using a radiomics model. Computer tomography images with corresponding gene expression data and clinicopathological data were obtained from online databases. After outlining the volumes of interest manually, the radiomic features were screened using maximum melevance minimum redundancy and recursive feature elimination algorithms. A radiomics model was developed to predict γδ T-cell abundance using gradient boosting machine. Kaplan-Meier survival curves and univariate and multivariate Cox regression analyses were used for the survival analysis. In this study, we confirmed that γδ T-cell abundance was an independent predictor of favorable overall survival (OS) in patients with HNSCC. Moreover, a radiomics model was built to predict the γδ T-cell abundance level (the areas under the operating characteristic curves of 0.847 and 0.798 in the training and validation sets, respectively). The calibration and decision curves analysis demonstrated the fitness of the model. The high radiomic score was an independent protective factor for OS. Our results indicated that γδ T-cell abundance was a promising prognostic predictor in HNSCC, and the radiomics model could discriminate its abundance levels and predict OS. The noninvasive radiomics model provided a potentially powerful prediction tool to aid clinical judgment and antitumor immunotherapy.

Treatment response of advanced HNSCC towards immune checkpoint inhibition is associated with an activated effector memory T cell phenotype

Locally advanced or metastatic head and neck squamous cell carcinoma (HNSCC) is associated with a poor prognosis. The introduction of PD-1 inhibitors has led to a significant improvement in survival, but only a subpopulation of patients responds to therapy. Current biomarkers cannot reliably identify these patients. The identification of biomarkers for the prediction and monitoring of immunotherapy is therefore of great importance. In this study, we characterized lymphocyte subsets in the peripheral blood of HNSCC patients under PD-1 inhibition. Patients with primary response (n=11) to PD-1 inhibition showed an increase of the CD3+ effector memory (CD3/EM) population and an elevated expression of the activation marker CD69 in CD3+ T cells, particularly in the CD3/EM subpopulation at 3 months when treatment response was assessed. In contrast, patients with primary treatment failure and progressive disease (n=9) despite PD-1 inhibition had lower absolute lymphocyte counts and an increased expression of CTLA-4 in CD3+ T cells at the time of treatment failure compared with baseline, particularly in CD4+ and CD8+ effector memory populations. Our results demonstrate that HNSCC patients' response to immune checkpoint inhibition shows a distinct immune signature in peripheral blood, which could help identify refractory patients earlier. Furthermore, strategies to overcome primary therapy failure by inducing a beneficial T cell phenotype or adding alternative immune checkpoint inhibitors could improve response rates and survival of HNSCC patients.

Tumor budding to investigate local invasion, metastasis, and prognosis of head and neck carcinoma: A systematic review

The aim of this systematic review is to shed light on the role of tumor budding (TB) in the biology, behavior, and prognosis of head and neck squamous cell carcinoma (HNSCC). A search was run in PubMed, Scopus, and Embase databases following PRISMA guidelines. After full-text screening and application of inclusion/exclusion criteria, 36 articles were included. Several investigations support the prognostic role of TB, which might play a role in selecting rational treatment strategies. To achieve this goal, further research is needed for greater standardization in TB quantification. Although TB is not included as a negative prognostic factor in the current management guidelines, it might be reasonable to consider a closer follow-up for HNSCC cases with high histopathological evidence of TB.

Dual anti-HER2/EGFR inhibition synergistically increases therapeutic effects and alters tumor oxygenation in HNSCC

Epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), and hypoxia are associated with radioresistance. The goal of this study is to study the synergy of anti-HER2, trastuzumab, and anti-EGFR, cetuximab, and characterize the tumor microenvironment components that may lead to increased radiation sensitivity with dual anti-HER2/EGFR therapy in head and neck squamous cell carcinoma (HNSCC). Positron emission tomography (PET) imaging ([89Zr]-panitumumab and [89Zr]-pertuzumab) was used to characterize EGFR and HER2 in HNSCC cell line tumors. HNSCC cells were treated with trastuzumab, cetuximab, or combination followed by radiation to assess for viability and radiosensitivity (colony forming assay, immunofluorescence, and flow cytometry). In vivo, [18F]-FMISO-PET imaging was used to quantify changes in oxygenation during treatment. Bliss Test of Synergy was used to identify combination treatment synergy. Quantifying EGFR and HER2 receptor expression revealed a 50% increase in heterogeneity of HER2 relative to EGFR. In vitro, dual trastuzumab-cetuximab therapy shows significant decreases in DNA damage response and increased response to radiation therapy (p < 0.05). In vivo, tumors treated with dual anti-HER2/EGFR demonstrated decreased tumor hypoxia, when compared to single agent therapies. Dual trastuzumab-cetuximab demonstrates synergy and can affect tumor oxygenation in HNSCC. Combination trastuzumab-cetuximab modulates the tumor microenvironment through reductions in tumor hypoxia and induces sustained treatment synergy.

NSD1 supports cell growth and regulates autophagy in HPV-negative head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. Despite advances in therapeutic management and immunotherapy, the 5-year survival rate for head and neck cancer remains at ~66% of all diagnosed cases. A better definition of drivers of HPV-negative HNSCC that are targetable points of tumor vulnerability could lead to significant clinical advances. NSD1 is a histone methyltransferase that catalyzes histone H3 lysine 36 di-methylation (H3K36me2); mutations inactivating NSD1 have been linked to improved outcomes in HNSCC. In this study, we show that NSD1 induces H3K36me2 levels in HNSCC and that the depletion of NSD1 reduces HNSCC of cell growth in vitro and in vivo. We also find that NSD1 strongly promotes activation of the Akt/mTORC1 signaling pathway. NSD1 depletion in HNSCC induces an autophagic gene program activation, causes accumulation of the p62 and LC3B-II proteins, and decreases the autophagic signaling protein ULK1 at both protein and mRNA levels. Reflecting these signaling defects, the knockdown of NSD1 disrupts autophagic flux in HNSCC cells. Taken together, these data identify positive regulation of Akt/mTORC1 signaling and autophagy as novel NSD1 functions in HNSCC, suggesting that NSD1 may be of value as a therapeutic target in this cancer.

CTC together with Shh and Nrf2 are prospective diagnostic markers for HNSCC

BACKGROUND

The lack of appropriate prognostic biomarkers remains a significant obstacle in the early detection of Head and Neck Squamous Cell Carcinoma (HNSCC), a cancer type with a high mortality rate. Despite considerable advancements in treatment, the success in diagnosing HNSCC at an early stage still needs to be improved. Nuclear factor erythroid 2-related factor 2 (Nrf2) and Sonic Hedgehog (Shh) are overexpressed in various cancers, including HNSCC, and have recently been proposed as possible therapeutic targets for HNSCC. Circulating Tumor Cell (CTC) is a novel concept used for the early detection of cancers, and studies have suggested that a higher CTC count is associated with the aggressiveness of HNSCC and poor survival rates. Therefore, we aimed to establish molecular markers for the early diagnosis of HNSCC considering Shh/Nrf2 overexpression in the background. In addition, the relation between Shh/Nrf2 and CTCs is still unexplored in HNSCC patients.

METHODS

In the present study, we selected a cohort of 151 HNSCC patients and categorized them as CTC positive or negative based on the presence or absence of CTCs in their peripheral blood. Data on demographic and clinicopathological features with the survival of the patients were analyzed to select the patient cohort to study Shh/Nrf2 expression. Shh and Nrf2 expression was measured by qRT-PCR.

RESULTS

Considering significant demographic [smoking, betel leaf (p-value < 0.0001)] and clinicopathological risk factors [RBC count (p < 0.05), Platelet count (p < 0.05), Neutrophil count (p < 0.005), MCV (p < 0.0001), NLR (p < 0.05), MLR (p < 0.05)], patients who tested positive for CTC also exhibited significant overexpression of Shh/Nrf2 in both blood and tissue compared to CTC-negative patients. A strong association exists between CTCs and tumor grade. Following chemotherapy (a combination of Cisplatin, 5FU, and Paclitaxel), the frequency of CTCs was significantly decreased in patients with HNSCC who had tested positive for CTCs. The Kaplan-Meier plot illustrated that a higher number of CTCs is associated with poorer overall survival (OS) in patients with HNSCC.

CONCLUSIONS

Detecting CTCs, and higher expression of Shh and Nrf2 in HNSCC patients' blood, can be a promising tool for diagnosing and prognosticating HNSCC.

Pancancer analysis reveals the role of disulfidptosis in predicting prognosis, immune infiltration and immunotherapy response in tumors

Disulfidptosis has been reported as a novel cell death process, suggesting a therapeutic strategy for cancer treatment. Herein, we constructed a multiomics data analysis to reveal the effects of disulfidptosis in tumors. Data for 33 kinds of tumors were downloaded from UCSC Xene, and disulfidptosis-related genes (DRGs) were selected from a previous study. After finishing processing data by the R packages, the expression and coexpression of DRGs in different tumors were assessed as well as copy number variations. The interaction network was drawn by STRING, and the activity of disulfidptosis was compared to the single-sample gene set enrichment analysis algorithm. Subsequently, the differences in DRGs for prognosis and clinicopathological features were evaluated, and the tumor immune microenvironment was assessed by the TIMER and TISCH databases. Tumor mutation burden, stem cell features and microsatellite instability were applied to predict drug resistance, and the expression of checkpoints was identified for the prediction of immunotherapy. Moreover, the TCIA, CellMiner and Enrichr databases were also utilized for selecting potential agents. Ten DRGs were differentially expressed in tumors, and the plots of coexpression and interaction revealed their correlation. Survival analysis suggested SLC7A11 as the most prognosis-related DRG with the most significant results. Additionally, the comparison also reflected the differences in DRGs in the status of pathologic lymph node metastasis for 5 types of tumors. The tumor immune microenvironment showed commonality among tumors based on immune infiltration and single-cell sequencing, and the analysis of tumor mutation burden, stemness and microsatellite instability showed a mostly positive correlation with DRGs. Moreover, referring to the prediction about clinical treatment, most DRGs can enhance sensitivity to chemotherapeutic agents but decrease the response to immune inhibitors with increasing expression. In this study, a primarily synthetic landscape of disulfidptosis in tumors was established and provided guidance for further exploration and investigation.

GABA regulates the proliferation and apoptosis of head and neck squamous cell carcinoma cells by promoting the expression of CCND2 and BCL2L1

Gamma-aminobutyric acid (GABA) is a multifunctional molecule that is widely present in the nervous system and nonneuronal tissues. It plays pivotal roles in neurotransmission, regulation of secretion, cell differentiation, proliferation, and tumorigenesis. However, the exact mechanisms of GABA in head and neck squamous cell carcinomas (HNSCCs) are unknown. We took advantage of RNA sequencing in this work and uncovered the potential gene expression profiles of the GABA-treated HNSCC cell line HN4-2. We found that the expression of CCND2 and BCL2L1 was significantly upregulated. Furthermore, GABA treatment inhibited the cell apoptosis induced by cisplatin and regulated the cell cycle after treatment with cisplatin in HN4-2 cells. Moreover, we also found that GABA could upregulate the expression of CCND2 and BCL2L1 after treatment with cisplatin. Our results not only reveal the potential pro-tumorigenic effect of GABA on HNSCCs but also provide a novel therapeutic target for HNSCC treatment.

Clinical implication of genetic intratumor heterogeneity for targeted therapy in head and neck cancer

BACKGROUND

Genomic profiling is increasingly used both in therapeutic decision-making and as inclusion criteria for trials testing targeted therapies. However, the mutational landscape may vary across different areas of a tumor and intratumor heterogeneity will challenge treatments or clinical decisions based on single tumor biopsies. The purpose of this study was to assess the clinical relevance of genetic intratumor heterogeneity in head and neck squamous cell carcinomas (HNSCC) using the ESMO Scale for Clinical Actionability of Molecular Targets (ESCAT).

MATERIALS AND METHODS

This prospective study included 33 whole tumor specimens from 28 patients with primary or recurrent HNSCC referred for surgery. Three tumor blocks were selected from central, semi-peripheral, and peripheral positions, mimicking biopsies in three different locations. Genetic analysis of somatic copy number alterations (SCNAs) was performed on the three biopsies using Oncoscan, focusing on 45 preselected HNSCC genes of interest. Clinical relevance was assessed using the ESCAT score to investigate whether and how treatment decisions would change based on the three biopsies from the same tumor.

RESULTS

The SCNAs identified among 45 preselected genes within the three tumor biopsies derived from the same tumor revealed distinct variations. The detected discrepancies could potentially influence treatment approaches or clinical decisions in 36% of the patients if only one tumor biopsy was used. Recurrent tumors exhibited significantly higher variation in SCNAs than primary tumors (p = .024). No significant correlation between tumor size and heterogeneity (p = .7) was observed.

CONCLUSION

In 36% of patients diagnosed with HNSCC, clinically significant intratumor heterogeneity was observed which may have implications for patient management. This finding substantiates the need for future studies that specifically investigate the clinical implications associated with intratumor heterogeneity.

Head and Neck Squamous Cell Carcinoma Vaccine: Current Landscape and Perspectives

The treatment of unresectable or metastatic Head and Neck Squamous Cell Carcinoma (HNSCC) has traditionally relied on chemotherapy or radiotherapy, yielding suboptimal outcomes. The introduction of immunotherapy has significantly improved HNSCC treatment, even if the long-term results cannot be defined as satisfactory. Its mechanism of action aims to counteract the blockade of tumor immune escape. This result can also be obtained by stimulating the immune system with vaccines. This review scope is to comprehensively gather existing evidence and summarize ongoing clinical trials focused on therapeutic vaccines for HNSCC treatment. The current landscape reveals numerous promising drugs in the early stages of experimentation, along with a multitude of trials that have been suspended or abandoned for years. Nonetheless, there are encouraging results and ongoing experiments that instill hope for potential paradigm shifts in HNSCC therapy.

Changes of immune microenvironment in head and neck squamous cell carcinoma in 3D-4-culture compared to 2D-4-culture

BACKGROUND

The immune system plays a crucial role in initiating, progressing, and disseminating HNSCC. This study aims to investigate the differences in immune microenvironments between 2D-4-culture and 3D-4-culture models of head and neck squamous cell carcinoma (HNSCC) cells (FaDu), human fibroblasts (HF), human monocytes (THP-1), and human endothelial cells (HUVEC).

METHODS

For the 3D-4-culture model, FaDu:HF:THP-1 (2:1:1) were inoculated in an ultra-low attachment culture plate, while HUVECs were placed in a transwell chamber. The ordinary culture plate was used for the 2D-4-culture model. Tumor-associated macrophage markers (CD163), tumor-associated fibroblast markers (FAP), and epithelial-mesenchymal transition (EMT) were detected by western blot. Inflammatory cytokines (IL-4, IL-2, CXCL 10, IL-1 β, TNF-α, CCL 2, IL-17 A, IL-6, IL-10, IFN-γ, IL-12 p 70, CXCL 8, TGFβ1) in the supernatant were measured by flow cytometry. HUVEC migration was observed under a microscope. The 3D spheres were stained and observed with a confocal microscope. CCK8 assay was used to detect the resistance of mixed cells to cisplatin in both 2D-4-culture and 3D-4-culture.

RESULTS

After three days of co-culture, the 3D-4-culture model showed increased expression levels of CD163 and FAP proteins (both P < 0.001), increased expression of E-cadherin protein and N-cadherin protein expression (P < 0.001), decreased expression of vimentin (P < 0.01) and Twist protein (P < 0.001). HUVEC migration significantly increased (P < 0.001), as did the concentrations of IP-10, MCP-1, IL-6, and IL-8 (all P < 0.001). Confocal microscopy showed that 3D-4-culture formed loose cell clusters on day 1, which gradually became a dense sphere surrounded by FaDu cells invading the inside. After co-culturing for 24 h, 48 h, and 72 h, the resistance of mix cells to cisplatin in 3D-4-culture was significantly higher than in 2D-4-culture (P < 0.01 for all).

CONCLUSION

Compared to 2D-4-culture, 3D-4-culture better simulates the in vivo immune microenvironment of HNSCC by promoting fibroblast transformation into tumor-associated fibroblasts, monocyte transformation into tumor-associated macrophages, enhancing endothelial cell migration ability, partial EMT formation in HNSCC cells, and is more suitable for studying the immunosuppressive microenvironment of HNSCC.

Recombinant immunotoxin induces tumor intrinsic STING signaling against head and neck squamous cell carcinoma

The innate immune stimulator of interferon genes (STING) pathway is known to activate type I interferons (IFN-I) and participate in generating antitumor immunity. We previously produced hDT806, a recombinant diphtheria immunotoxin, and demonstrated its efficacy against head and neck squamous cell carcinoma (HNSCC). However, it's unknown whether the tumor-intrinsic STING plays a role in the anti-HNSCC effects of hDT806. In this study, we investigated the innate immune modulation of hDT806 on HNSCC. hDT806 significantly upregulated the level of STING and the ratio of p-TBK1/TBK1 in the HNSCC cells. Moreover, intratumoral hDT806 treatment increased the expression of STING-IFN-I signaling proteins including IFNA1, IFNB, CXCL10 and MX1, a marker of IFN-I receptor activity, in the HNSCC xenografts. Overexpression of STING mimicked the hDT806-induced upregulation of the STING-IFN-I signaling and induced apoptosis in the HNSCC cells. In the mouse xenograft models of HNSCC with STING overexpression, we observed a significant suppression of tumor growth and reduced tumor weight with increased apoptosis compared to their control xenograft counterparts without STING overexpression. Collectively, our data revealed that hDT806 may act as a stimulator of tumor-intrinsic STING-IFN-I signaling to inhibit tumor growth in HNSCC.

The Prediction of Biological Features Using Magnetic Resonance Imaging in Head and Neck Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

Magnetic resonance imaging (MRI) is an indispensable, routine technique that provides morphological and functional imaging sequences. MRI can potentially capture tumor biology and allow for longitudinal evaluation of head and neck squamous cell carcinoma (HNSCC). This systematic review and meta-analysis evaluates the ability of MRI to predict tumor biology in primary HNSCC. Studies were screened, selected, and assessed for quality using appropriate tools according to the PRISMA criteria. Fifty-eight articles were analyzed, examining the relationship between (functional) MRI parameters and biological features and genetics. Most studies focused on HPV status associations, revealing that HPV-positive tumors consistently exhibited lower ADCmean (SMD: 0.82; p < 0.001) and ADCminimum (SMD: 0.56; p < 0.001) values. On average, lower ADCmean values are associated with high Ki-67 levels, linking this diffusion restriction to high cellularity. Several perfusion parameters of the vascular compartment were significantly associated with HIF-1α. Analysis of other biological factors (VEGF, EGFR, tumor cell count, p53, and MVD) yielded inconclusive results. Larger datasets with homogenous acquisition are required to develop and test radiomic-based prediction models capable of capturing different aspects of the underlying tumor biology. Overall, our study shows that rapid and non-invasive characterization of tumor biology via MRI is feasible and could enhance clinical outcome predictions and personalized patient management for HNSCC.

Neoadjuvant PD-1/PD-L1 inhibitors combined with chemotherapy had a higher ORR than mono-immunotherapy in untreated HNSCC: Meta-analysis

BACKGROUND

HNSCC is one of the most common types of cancer worldwide and immune checkpoint inhibitor has shown favorable therapeutic effect in R/M HNSC. However, the application of immunotherapy in untreated HNSCC still needs to be discovered since most R/M HNSCC patients have been treated before and their drug susceptibility and immune tumor microenvironment have changed. This meta-analysis tries to compare immunotherapy and immunochemotherapy in untreated HNSCC and give a reference for clinic application.

METHODS

Electronic databases, including PubMed, Embase, and Web of Science, were systematically searched from inception through August 31, 2022. The primary outcomes were efficacy, evaluated by objective response rate, 1-year OS and 1-year PFS, and safety, evaluated by grade 3-4 adverse reaction rate.

RESULTS

A total of 1092 patients from twenty-four studies were included, 282 (25.8%) of which had ORR reported. The average ORR was 37% (95%CI = 26%-49%). Immunochemotherapy could have higher ORR than immunotherapy patients (ORR: 61% vs 22%), and favorable 1-year overall survival from PD-L1 inhibitor (OS = 84%, 95%CI 76%-93%). Radiotherapy after neoadjuvant immunotherapy was equal with the other treatments like chemotherapy and surgery (84% vs 88%, subgroup df p = 0.7). There was no apparent difference between immunotherapy and immunochemotherapy (32% vs 42%, subgroup df p = 0.60).

CONCLUSION

HNSCC patients could benefit more from neoadjuvant immunochemotherapy.

NSD1 supports cell growth and regulates autophagy in HPV-negative head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. Despite advances in therapeutic management and immunotherapy, the five-year survival rate for head and neck cancer remains at ~66% of all diagnosed cases. A better definition of drivers of HPV-negative HNSCC that are targetable points of tumor vulnerability could lead to significant clinical advances. NSD1 is a histone methyltransferase which catalyzes histone H3 lysine 36 di-methylation (H3K36me2); mutations inactivating NSD1 have been linked to improved outcomes in HNSCC. In this study, we show that NSD1 induces H3K36me2 levels in HNSCC, and that the depletion of NSD1 reduces HNSCC of cell growth in vitro and in vivo. We also find that NSD1 strongly promotes activation of the Akt/mTORC1 signaling pathway. NSD1 depletion in HNSCC induces an autophagic gene program activation, causes accumulation of the p62 and LC3B-II proteins, and decreases the autophagic signaling protein ULK1 at both protein and mRNA levels. Reflecting these signaling defects, knockdown of NSD1 disrupts autophagic flux in HNSCC cells. Taken together, these data identify positive regulation of Akt/mTORC1 signaling and autophagy as novel NSD1 functions in HNSCC, suggesting that NSD1 may be of value as a therapeutic target in this cancer.