Head And Neck Squamous Cell Carcinoma Tissues Research Articles

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

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. 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. 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. 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.

PiR-hsa-23533 promotes malignancy in head and neck squamous cell carcinoma via USP7

BackgroundWith regard to head and neck squamous cell carcinoma (HNSCC), its occurrence and advancement are controlled by genetic and epigenetic anomalies. PIWI-interacting RNAs (piRNAs) are recognized with significance in tumor, but the precise molecular mechanisms of piRNAs in HNSCC largely remain undisclosed. MethodsDifferentially expressed piRNAs were identified by RNA sequencing. The expression of piR-hsa-23533 was evaluated using quantitative real-time PCR and RNA in situ hybridization. The impacts of piR-hsa-23533 on the proliferation and apoptosis of HNSCC cells were investigated by a series of in vitro and in vivo assays. ResultspiR-hsa-23533 exhibits upregulation within HNSCC cells and tissues. Besides, piR-hsa-23533 overexpression promotes proliferation while inhibiting apoptosis in vitro and in vivo, while piR-hsa-23533 silencing has an opposite function. From the mechanistic perspective, piR-hsa-23533 can bind to Ubiquitin-specific protease 7 (USP7), as shown through RNA pull-down and RNA immunoprecipitation assays, promoting USP7 mRNA and protein expression. ConclusionsThese findings highlight the functional importance of piR-hsa-23533 in HNSCC and may assist in the development of anti-HNSCC therapeutic target.

A novel SLC3A2-targeting antibody-drug conjugate exerts potent antitumor efficacy in head and neck squamous cell cancer

The development of innovative therapeutic strategies for head and neck squamous cell carcinoma (HNSCC) is a critical medical requirement. Antibody-drug conjugates (ADC) targeting tumor-specific surface antigens have demonstrated clinical effectiveness in treating hematologic and solid malignancies. Our investigation revealed high expression levels of SLC3A2 in HNSCC tissue and cell lines. This study aimed to develop a novel anti-SLC3A2 ADC and assess its antitumor effects on HNSCC both in vitro and in vivo. This study developed a potent anti-SLC3A2 ADC (19G4-MMAE) and systematically investigated its drug delivery potential and antitumor efficacy in preclinical models. This study revealed that 19G4-MMAE exhibited specific binding to SLC3A2 and effectively targeted lysosomes. Moreover, 19G4-MMAE induced a significant accumulation of reactive oxygen species (ROS) and apoptosis in SLC3A2-positive HNSCC cells. The compound demonstrated potent antitumor effects derived from MMAE against SLC3A2-expressing HNSCC in preclinical models, displaying a favorable safety profile. These findings suggest that targeting SLC3A2 with an anti-SLC3A2 ADC could be a promising therapeutic approach for treating HNSCC patients.

Role of mitophagy in head and neck squamous cell carcinoma: Prognosis and immune insights

ObjectiveTo explore the correlation between mitophagy and the tumor microenvironment (TME) in patients with head and neck squamous cell carcinoma (HNSCC), with an aim to enhance therapeutic efficacy for HNSCC. MethodsA machine learning-based multigene prognostic signature was developed based on mitophagy-related differentially expressed genes (MRGs) identified in The Cancer Genome Atlas cohort. This signature was correlated with the TME using gene set enrichment analysis. The association between this prognostic signature and various immunological features of the TME was explored, including status of tumor-infiltrating immune cells, expression of immune checkpoint molecules, and the immunoscore. Immunohistochemistry validated the expression of hub gene CSNK2A2 and assessed its relationship with immunomarker expression. Quantitative PCR validated CSNK2A2 knockdown in HNSCC cell lines. Functional experiments including Transwell assays to determine cell migration and invasion, Cell Counting Kit 8 assay, and 5-ethynyl-2-deoxyuridine assay were performed to confirm the role of CSNK2A2 in HNSCC. Finally, a subcutaneous xenograft model was generated in C3H mice to validate our findings. ResultsThe MRG-based prognostic signature showed excellent predictive performance. High-risk patients had significantly shorter progression-free and overall survival (P ​< ​0.0001) than low-risk patients. CD8+ T cell infiltration was lower in high-risk groups, whereas low-risk groups showed higher immunological marker expression. Thus, the low-risk HNSCC subtype may benefit from immune therapy, while high-risk subtypes may benefit from chemotherapy (P ​< ​0.001). CSNK2A2 was highly expressed and strongly correlated with CD8 and PD-L1 based on immunohistochemistry of the HNSCC tissue microarray. CSNK2A2 knockdown reduced cell migration, invasion, and proliferation, and arrested cells in G1 phase. In vivo, it led to slower tumor growth and smaller tumor volumes. ConclusionWe established a potential prognostic signature that could improve HNSCC management in the future. CSNK2A2 may be a new biomarker to predict immunotherapy efficacy in HNSCC.

Study of head and neck squamous cell carcinoma transcriptome after proton therapy

Aim. To evaluate changes in the transcriptome of head and neck squamous cell carcinoma (HNSCC) tissue cells in patients after proton therapy.Materials and methods. Biopsy material obtained from 3 HNSCC patients before and after proton therapy at a total dose of 10 isoGy was homogenized, purified, and concentrated. Then total RNA was isolated with further purification and concentration with the RNA Clean &amp; Concentrator kit (Zymo Research). Library quantitation was assessed using the Qubit 2.0 instrument (Invitrogen, Life Technologies). After isolation of 1 μg total RNA for sequencing, libraries were prepared on the Illumina platform using the TruSeq RNA Sample Prep Kit v2 with a 10-cycle enrichment step according to the manufacturer’s recommendations. The quality of RNA and the resulting libraries was checked using the Agilent 2100 Bioanalyzer system (Agilent Tec. Inc., USA). The RIN parameter for RNA was at least 7. The library concentration was assessed by real-time PCR on the CFX96 Touch Real-Time PCR Detection System (Bio-Rad, USA). Final libraries were pooled in equimolar ratios before sequencing on the Illumina HiSeq 2500 platform using 50 base-pair paired-end reads. The Q20 parameter for all samples was &gt; 97%, and the number of reads averaged 60.2 million per sample. Raw reads were processed using the RTA 1.17.21.3 and Casava 1.8.2 (Illumina). The enrichment analysis was performed using the PANTHER 17.0 software.Results. The transcriptome analysis of HNSCC after proton radiation therapy (5 x 2 isoGy) at a total dose of 10 isoGy revealed 1,414 significantly differentially expressed genes. The 10 most and least expressed genes and their associated signaling pathways were identified. A number of signaling pathways associated with the underexpressed genes were detected in HNSCC after proton therapy, such as: STAT5; PD-1 signaling pathway; marked MET-mediated activation of PTK2 signaling pathway, PDGF signaling; CD22-mediated regulation of BCR; and FCERI-mediated MAPK activation. In addition to the above signaling pathways, activation of collagen degradation, FCGR3A-mediated phagocytosis, and FCGR3A-mediated interleukin (IL)-10 synthesis are of interest. In the enrichment analysis among highly expressed genes, keratinization and biological oxidation processes were activated in HNSCC tissues after proton therapy.Conclusion. Proton therapy in HNSCC leads to overexpression of genes involved in the regulation of keratinization and biological oxidation processes as well as to underexpression of genes associated with suppression of signaling pathways: STAT5, PD-1, MET-mediated activation of PTK2 signaling pathway, PDGF signaling; CD22-mediated regulation of BCR; FCERI-mediated MAPK activation, collagen degradation, FCGR3A-mediated phagocytosis activation, and FCGR3A-mediated IL-10 synthesis. All signaling pathways of underexpressed genes function in HNSCC cells if there is no negative influence on the tumor from outside (irradiation or delivery of antitumor drugs). The predominance of suppressed signaling pathways over activated ones most likely indicates a decrease in the functional potential of cells after proton therapy. The dose-dependence of PT effects necessitates further study of changes in cellular and molecular-genetic signatures of HNSCC after proton irradiation with different doses.

Systematic analysis of expression and prognostic significance for MCM family in head and neck squamous cell carcinoma.

Head and neck squamous cell carcinoma (HNSC) is a common malignant tumor in the world and has a poor prognosis. The family of minichromosome maintenance proteins (MCM) improves the stability of genome replication by inhibiting the rate of DNA replication in eukaryotic cells, thus, small changes in physiological MCM levels would increase the instability of gene replication and increase the incidence of tumor formation, most of which are significantly elevated in multiple cancers. However, the expression of different MCM families in HNSC and their prognostic value remain unclear. ONCOMINE and GEPIA databases were used to analyze the expression of MCMs in HNSC. The Kaplan-Meier plotter database was used to identify molecules with prognostic values. We collected 77 HNSC tissues and 50 normal tissues to validate the results of the bioinformatics analysis by immunohistochemical staining. The expression of MCM3, MCM5 and MCM6 in mRNA and protein levels were higher in HNSC. Moreover, the increased expression of MCM3, MCM5 and MCM6 in mRNA and protein levels predicted better prognosis of HNSC patients. Furthermore, multivariate analysis showed that high expressions of MCM3, MCM5 and MCM6 in protein level may be independent prognostic factors for HNSC patients. The results of this study indicated that MCM3, MCM5 and MCM6 play an important role in occurrence and development in HNSC and might be risk factors for the survival of HNSC patients.

Investigating diagnostic potential of long non-coding RNAs in head and neck squamous cell carcinoma using TCGA database and clinical specimens

Head and neck squamous cell carcinoma (HNSCC) is a prevalent and prognostically challenging cancer worldwide. The role of long non-coding RNAs (lncRNAs) in cancer regulation is progressively being understood. This study aims to identify lncRNAs with diagnostic potential as biomarkers for HNSCC. Statistical analysis was performed on expression data from the Cancer Genome Atlas (TCGA) database to identify potential lncRNAs associated with HNSCC. Four selected lncRNAs were validated using real-time quantitative reverse transcription polymerase chain reaction and correlated with clinical factors. Functional roles were further investigated. A total of 488 differentially expressed lncRNAs were identified in TCGA-HNSC. After rigorous evaluation based on p-values, survival analysis, and ROC analysis, 24 lncRNAs were prioritized for additional investigation. LINC00460, LINC00941, CTC-241F20.4, and RP11-357H14.17 were established as candidate diagnostic biomarkers. These lncRNAs exhibited elevated expression in HNSCC tissues and were associated with poor prognosis. Combining them showed high diagnostic accuracy. Notably, LINC00460 and CTC-241F20.4 demonstrated a significant elevation in the advanced stages of HNSCC. We constructed an lncRNA-mRNA regulatory network, and the array of significant regulatory pathways identified included focal adhesion, regulation of epithelial cell migration, and others. Additionally, these lncRNAs were found to influence immune responses by modulating immune cell infiltration in the HNSCC microenvironment. Our research indicates that LINC00460, LINC00941, RP11-357H14.17, and CTC-241F20.4 may have diagnostic and prognostic importance in HNSCC. Furthermore, we have gained insights into their potential functional roles, particularly about immune responses and interactions in the microenvironment.

LncRNA RASAL2-AS1 promotes METTL14-mediated m6A methylation in the proliferation and progression of head and neck squamous cell carcinoma

BackgroundLong non-coding RNAs (lncRNAs) are key regulators of the 6-methyladenosine (m6A) epigenetic modification, playing a role in the initiation and progression of tumors. However, the regulatory mechanisms in head and neck squamous cell carcinoma (HNSCC) remain elusive. In this study, we investigated the molecular regulatory mechanisms of the lncRNA RASAL2-AS1 in the occurrence and development of HNSCC tumors.MethodsA bioinformatics analysis was conducted to analyze the expression level of RASAL2-AS1 in HNSCC and normal tissues. RASAL2-AS1 mRNA and protein levels were detected using RT-PCR and Western blotting. Wound healing, transwell assays, flow cytometry, M6A dot blot, and RNA immunoprecipitation experiments were conducted to explore the regulatory role of the RASAL2-AS1 and downstream targets METTL14/LIS1 signaling pathway in HNSCC. Immunohistochemical examination was conducted to evaluate the expression of METTL14 and LIS1 in HNSCC and normal tissues. A tumor xenograft model of BALB/c nude mice was established to assess the impact of RASAL2-AS1 on cell proliferation and growth.ResultsRASAL2-AS1 high expression in HNSCC and cells deteriorated with survival rates of HNSCC. RASAL2-AS1 overexpression in HNSCC accelerated cell migration, colony formation, cell proliferation, cell cycle in S stage, while RASAL2-AS1 knockdown in HNSC cells inhibited cell cycle in G1 stage. After silencing METTL14, the above effects induced by overexpression of the RASAL2-AS1 were reversed. RASAL2-AS1 overexpression prompted LIS1 expression, whereas RASAL2-AS1 silencing reduced LIS1 levels in HNSCC cells, which was confirmed by immunohistological staining. Results demonstrated elevated expression of METTL14 or LIS1 in tongue cancer tissues. Overexpression of RASAL2-AS1 promoted tumor weight and tumor volume, which was counteracted by pcDNA3.1 RASAL2-AS1 plus silencing METTL14 and METTL14 and LIS1 were significantly decreased.ConclusionOur study highlights the functional importance of the LncRNA RASAL2-AS1 in HNSCC and might assist in the development of a prognostic stratification and therapeutic approach. Which regulates HNSCC with the dependence of m6a manner.

Abstract 7585: Targeting of 7 or 24 dehydrocholesterol reductase decreases cancer progression in head and neck cancer

Abstract The elevated expression of cholesterol metabolism has been associated with many cancer including head and neck squamous cell carcinoma (HNSCC). However, the molecular mechanisms between cholesterol biosynthesis and head and neck cancer have not yet been studied. In this study, we identified upregulation of dehydrocholesterol reductase such as DHCR7 or DHCR24 in HNSCC compared with adjacent normal tissues from the same patients using RNA sequencing data. We observed protein expression level of DHCR7 or DHCR24 in head and neck cancer cell lines through Western blotting. We also checked high expression of DHCR7 or DHCR24 in HNSCC tissues from patients using immunohistochemistry assays. Yet, when DHCR7 or DHCR24 was knocked down using siRNA, the viability of HNSCC cells was decreased in MTT assays. In parallel, we adapted small inhibitory drugs; AY9944 for DHCR7 inhibition and Triparanol or SH-42 for DHCR24 inhibition. Treatment of AY9944, Triparanol, or SH-42 also resulted in decreased viability of HNSCC cells. Moreover, when we used a cholesterol blocker, MCD, the cell viability was decreased, whereas the cells overcame cell death by adding the combination of cholesterol and LDL. Taken together, we concluded that head and neck cancer requires DHCR7 and DHCR24 activity involved in cholesterol metabolism for cancer growth. Our data suggest that targeting DHCR7 or DHCR24 using AY9944, Triparanol or SH-42 is one of the potential strategies that will definitely help with cancer treatment for head and neck cancer. Citation Format: Bok-Soon Lee, Ji-Hye Choi, Hyo Jeong Kim, Jin Roh, Joselyn Padilla, Kennedy Davis Brock, Jeon Yeob Jang, Hyun Goo Woo, Chul-Ho Kim, Jiyoung Lee. Targeting of 7 or 24 dehydrocholesterol reductase decreases cancer progression in head and neck cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7585.

Abstract 1154: Spatial profiling of the tumor microenvironment in head and neck squamous cell carcinoma revealed immune cell type infiltration into the TME as a predictor of immunotherapy response

Abstract Background: Immunotherapy has shown promising results in advanced head and neck cancer patients, however, only a subset of patients are responsive to immune checkpoint blockade therapy. The molecular and cellular characterization of the tumor microenvironment (TME) may reveal clues as to why some head and neck tumors are responsive or resistant to the therapy. Methods: Formalin-fixed paraffin-embedded (FFPE) tissue samples were collected from 34 patients at two major Queensland Hospitals with advanced head and neck squamous cell carcinoma (HNSCC), prior to immunotherapy. To investigate the cellular and molecular characteristics of the HNSCC TME, we used the Nanostring GeoMx Digital Spatial Profiler (DSP) spanning modules in an immune-oncology panel, which included immune cell typing and profiling, cell death, PI3K/AKT signaling, drug target, immune activation, and pan tumor protein biomarkers. A deeper structural analysis was performed using the Nanostring whole transcriptome atlas (WTA) panel of tertiary lymphoid structures (TLSs) and germinal centers (GCs). Results: Out of 34 patients, 3 had a complete response (CR), 7 had a partial response (PR), 5 had stable disease (SD), and 19 had progressive disease (PD), based on the Response Evaluation Criteria in Solid Tumors (RECIST). When we compared patient responders (patients with CR, PR, and SD) to patient non-responders (patients with PD), we found that the former had a higher infiltration of immune cell type markers representatives of CD8+ T cells, dendritic cells, and macrophages, into their tumor microenvironment than the latter. Then, to investigate differentially expressed genes between patients with complete response and patients with partial response to immunotherapy, we performed DE analyses and we found that patients with PR had higher Ki-67 expression than those with CR. Spatial transcriptomic mapping of TLS’s (peripheral, intra-tumoral) and normal germinal centers revealed interferon pathway enrichment in the TLS’s. In a subset, these appear to be linked with HPV viral infection. Conclusion: In this study, we found that immune cell type infiltration into the tumor microenvironment of head and neck cancers could be predictive of response to immunotherapy. Furthermore, it was revealed that patients with a high expression of Ki-67 might be less likely to respond completely to immunotherapy. Spatially resolved whole transcriptome analysis of HNSCC tissues revealed the presence of tertiary lymphoid structures with a higher enrichment of interferon pathway genes. Citation Format: Habib Sadeghirad, Chin Wee Tan, Ning Liu, James Monkman, Caroline Cooper, Ken O’Byrne, Melissa Davis, Brett Hughes, Arutha Kulasinghe. Spatial profiling of the tumor microenvironment in head and neck squamous cell carcinoma revealed immune cell type infiltration into the TME as a predictor of immunotherapy response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1154.

CELSR3 is a prognostic marker in HNSCC and correlates with immune cell infiltration in the tumor microenvironment

PurposeTo look at the diagnostic value of the CELSR receptor 3 (CELSR3) gene in head and neck squamous cell carcinoma (HNSCC) and its effect on tumor immune invasion, which is important for enhancing HNSCC treatment.MethodsSeveral bioinformatics tools were employed to investigate CELSR3’s putative oncogenic pathway in HNSCC, and datasets from The Tumor Genome Atlas (TCGA), Tumor Immune Estimation Resource (TIMER), Gene Expression Profile Interaction Analysis (GEPIA) and LinkedOmics were extracted and evaluated. CELSR3 has been linked to tumor immune cell infiltration, immunological checkpoints, and immune-related genes. CELSR3’s putative roles were investigated using Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and pathway enrichment analysis. The expression level of CELSR3 in HNSCC tissues and cells was detected by RT-qPCR. The effects of CELSR3 on proliferation of HNSCC cells were detected by CCK-8 assay.ResultsCELSR3 was shown to be expressed differently in different types of cancer and normal tissues. CELSR3 gene expression was linked to pN-stage and pM-stage. Patients with high CELSR3 expression also have a well prognosis. CELSR3 expression was found to be an independent predictive factor for HNSCC in both univariate and multivariate Cox regression analyses. We discovered the functional network of CELSR3 in HNSCC using GO and KEGG analysis. CELSR3 expression levels were found to be favorably associated with immune cell infiltration levels. Furthermore, CELSR3 expression levels were significantly correlated with the expression levels of many immune molecules, such as MHC genes, immune activation genes, chemokine receptors, and chemokines. CELSR3 is highly expressed in HNSCC tissues and cells. CELSR3 overexpression significantly inhibited the proliferation of HNSCC cells. CELSR3 expression may affect the immune microenvironment and, as a result, the prognosis of HNSCC.ConclusionCELSR3 expression is elevated in HNSCC tumor tissues, and high CELSR3 expression is associated with well prognosis, which inhibited the proliferation of NHSCC cells. CELSR3 has the potential to influence tumor formation by controlling tumor-infiltrating cells in the tumor microenvironment (TME). As a result, CELSR3 may have diagnostic significance in HNSCC.

The circRNA hsa-circ-0013561 regulates head and neck squamous cell carcinoma development via the miR-7-5p/PDK3 axis

BackgroundCircular RNAs (circRNAs) belong to a class of covalently closed single stranded RNAs that have been implicated in cancer progression. Former investigations showed that hsa-circ-0013561 is abnormally expressed in head and neck squamous cell carcinoma (HNSCC). Nevertheless, the role of hsa-circ-0013561 during the progress of HNSCC still unclear.MethodsPresent study applied FISH and qRT-PCR to examine hsa-circ-0013561 expression in HNSCC cells and tissue samples. Dual-luciferase reporter assay was employed to identify downstream targets of hsa-circ-0013561. Transwell migration, 5-ethynyl-2′-deoxyuridine incorporation, CCK8 and colony formation assays were utilized to test cell migration and proliferation. A mouse tumor xenograft model was utilized to determine the hsa-circ-0013561 roles in HNSCC progression and metastasis in vivo.ResultsWe found that hsa-circ-0013561 was upregulated in HNSCC tissue samples. hsa-circ-0013561 downregulation inhibited HNSCC cell proliferation and migration to promote apoptosis and G1 cell cycle arrest. The dual-luciferase reporter assay revealed that miR-7-5p and PDK3 are hsa-circ-0013561 downstream targets. PDK3 overexpression or miR-7-5p suppression reversed the hsa-circ-0013561-induced silencing effects on HNSCC cell proliferation and migration. PDK3 overexpression reversed miR-7-5p-induced effects on HNSCC cell proliferation and migration.ConclusionThe findings suggest that hsa-circ-0013561 downregulation inhibits HNSCC metastasis and progression through PDK3 expression and miR-7-5p binding modulation.

ELOVL6 promotes the progression of head and neck squamous cell carcinoma via activating WNT/β-catenin pathway.

This study was to explore the role of ELOVL6 in the development of head and neck squamous cell carcinoma (HNSCC). Considering its previously identified oncogenic role in hepatocellular carcinoma. ELOVL6 gene expression, clinicopathological analysis, enrichment analysis, and immune infiltration analysis were based on the data from Gene Expression Omnibus and The Cancer Genome Atlas, with additional bioinformatics analyses performed. Human HNSCC tissue microarray and cell lines were used. The expression of ELOVL6 in HNSCC was detected by quantitative polymerase chain reaction, immunohistochemistry assay, and western blot analysis. The proliferation ability of HNSCC cells, invasion, and apoptosis were evaluated using cell counting kit-8 method, Transwell assay, and flow cytometry, respectively. Based on the data derived from the cancer databases and our HNSCC cell and tissue studies, we found that ELOVL6 was overexpressed in HNSCC. Moreover, ELOVL6 expression level had a positive correlation with clinicopathology of HNSCC. Gene set enrichment analysis showed that ELOVL6 affected the occurrence of HNSCC through WNT signaling pathway. Functional experiments demonstrated that ELOVL6 knockdown inhibited the proliferation and invasion of HNSCC cells while promoting apoptosis. Additionally, compound 3f, an agonist of WNT/β-catenin signaling pathway, enhances the effect of ELOVL6 on the progression of HNSCC cells. ELOVL6 is upregulated in HNSCC and promotes the development of HNSCC cells by inducing WNT/β-catenin signaling pathway. ELOVL6 stands a potential target for the treatment of HNSCC and a prognosis indicator of human HNSCC.

SLC20A1 is a prospective prognostic and therapy response predictive biomarker in head and neck squamous cell carcinoma.

SLC20A1, a prominent biomarker in several cancers, has been understudied in its predictive role in head and neck squamous cell carcinoma (HNSCC). The Cancer Genome Atlas (TCGA) database was used to analyze HNSCC prognosis, SLC20A1 overexpression, and clinical characteristics. Quantitative real-time PCR and Western blot analysis confirmed SLC20A1 expression in HNSCC tissues. Cellular behaviors such as invasion, migration and proliferation were assessed using Transwell, wound healing and colony formation assays. Immune system data were obtained from the Tumor Immune Estimation Resource (TIMER) and CIBERSORT databases. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA) were used to explore biological parameters and pathways associated with SLC20A1 overexpression in HNSCC. In 499 HNSCC samples, SLC20A1 mRNA and protein expression were significantly higher than in 44 normal counterparts, confirmed by 24 paired samples. Patients were categorized based on SLC20A1 levels, survival status and overall survival. High SLC20A1 expression correlated with advanced T stage, increased risk scores and decreased survival. Stage, age and SLC20A1 expression emerged as independent predictive factors for HNSCC in univariate and multivariate analyses. SLC20A1 overexpression, which is associated with poor prognosis, may influence cell proliferation, migration, invasion, chemotherapy response, and the immune milieu. SLC20A1 overexpression in HNSCC, characterized by increased cellular invasion, migration and proliferation, is a potential prognostic biomarker and therapeutic response indicator.

Monoamine oxidase B inhibits epithelial-mesenchymal transition and trigger apoptosis via targeting ERK1/2 signaling pathway in head and neck squamous cell carcinoma.

Monoamine oxidase B (MAOB), a flavin monoamine oxidase, regulates biogenic and xenobiotic amine oxidative deaminization. We demonstrate MAOB expression in head and neck epithelium and its biological importance in head and neck squamous cell carcinoma (HNSCC) development. First, we found a possible MAOB downregulation in HNSCC using bioinformatic analysis. Second, we validated MAOB expression changes in vitro and assessed its tumorigenicity in HNSCC. Finally, preclinical xenograft models further confirmed our findings. Results proved that MAOB was significantly reduced in HNSCC tissues and cell lines. By comparing MAOB localization in patient specimens, we found that epithelial basal cells express MAOB and that it changes throughout HNSCC development. We observed that MAOB overexpression inhibited HNSCC cell malignancy via lentiviral transfection. We additionally discovered that selegiline partly counter-regulated MAOB overexpression-induced phenotypes in HNSCC cells. We found that MAOB is a potent biomarker and a unique and essential indication of HNSCC carcinogenesis.

Dickkopf-1 is an immune infiltration-related prognostic biomarker of head and neck squamous cell carcinoma.

Immunotherapy is currently one of the most viable therapies for head and neck squamous cell carcinoma (HNSCC), characterized by high immune cell infiltration. The Wnt-signaling inhibitor and immune activation mediator, Dickkopf-1 (DKK1), has a strong correlation with tumor growth, tumor microenvironment, and, consequently, disease prognosis. Nevertheless, it is still unclear how DKK1 expression, HNSCC prognosis, and tumor-infiltrating lymphocytes are related. To better understand these associations, we examined how DKK1 expression varies across different tumor and normal tissues. In our study, we investigated the association between DKK1 mRNA expression and clinical outcomes. Next, we assessed the link between DKK1 expression and tumor immune cell infiltration. Additionally, using immunohistochemistry, we evaluated the expression of DKK1 in 15 healthy head and neck tissue samples, and the expression of CD3, CD4, and DKK1 in 27 HNSCC samples. We also explored aberrant DKK1 expression during tumorigenesis. DKK1 expression was remarkably higher in HNSCC tissues than in healthy tissues, and was shown to be associated with tumor stage, grade, lymph node metastasis, histology, and a dismal clinical prognosis in HNSCC. DKK1 expression in HNSCC tissues was inversely correlated with CD3+ (P < 0.0001) and CD4+ (P < 0.0001) immune cell infiltration, while that in immune cells was inversely associated with HNSCC prognosis. These findings offer a bioinformatics perspective on the function of DKK1 in HNSCC immunotherapy and provide justification for clinical research on DKK1-targeted HNSCC treatments. DKK1 is a central target for improving the efficacy of HNSCC immunotherapy.

Depletion of PHLDB2 Suppresses Epithelial-Mesenchymal Transition and Enhances Anti-Tumor Immunity in Head and Neck Squamous Cell Carcinoma.

The role of Pleckstrin homology-like domain family B member 2 (PHLDB2) in the regulation of cell migration has been extensively studied. However, the exploration of PHLDB2 in head and neck squamous cell carcinoma (HNSCC) is still limited in terms of expression, function, and therapeutic potential. In this study, we discovered an upregulation of PHLDB2 expression in HNSCC tissues which was correlated with a negative prognosis in patients with HNSCC. Additionally, we determined that a high level of expression of PHLDB2 is crucial for maintaining cell migration through the regulation of the epithelial-mesenchymal transition (EMT). Furthermore, we demonstrated that the ablation of PHLDB2 in tumor cells inhibited tumorigenicity in a C3H syngeneic tumor-bearing mouse model. Mechanistically, PHLDB2 was found to be involved in the regulation of T cell anti-tumor immunity, primarily by enhancing the activation and infiltration of CD8+ T cells. In light of these findings, PHLDB2 emerges as a promising biomarker and therapeutic target for interventions in HNSCC.

Prognostic significance and immune escape implication of tumor-infiltrating neutrophil plasticity in human head and neck squamous cell carcinoma.

Tumor-infiltrating neutrophils play a crucial role in the progression of head and neck squamous cell carcinoma (HNSCC). Here, we aimed to statistically quantify the plasticity of HNSCC-infiltrating N2/N1 neutrophils and examine its impacts on survival and immune infiltration landscape. A retrospective study of 80 patients who underwent curative surgical resection for HNSCC between 2014 and 2017 was conducted in this study. HNSCC-infiltrating neutrophil phenotypes were classified using immunofluorescence staining, and the N2/N1 neutrophil plasticity was evaluated via the ratio of N2/N1 neutrophils. We then assessed the correlations between N2/N1 neutrophil plasticity, clinicopathological characteristics, and immune infiltration landscape using rigorous statistical methods. Infiltration variations of N1 and N2 neutrophils were observed between the tumor nest (TN) and tumor stroma (TS), with TN exhibiting higher N2 neutrophil infiltration and lower N1 neutrophil infiltration. High ratios of N2/N1 neutrophils were correlated with advanced TNM stage, large tumor size and invasion of adjacent tissue. High infiltration of N2 neutrophils was associated with decreased overall and relapse-free survival, which were opposite for N1 neutrophils. The independent prognostic role of N2/N1 neutrophil plasticity, particularly within the TN region, was confirmed by multivariate analyses. Moreover, the ratio of N2/N1 neutrophils within the TN region showed correlations with high CD8+ T cells infiltration and low FOXP3+ Tregs infiltration. We identify HNSCC-infiltrating N2/N1 neutrophil plasticity as a crucial prognostic indictor which potentially reflects the tumor microenvironment (TME) and immune escape landscape within HNSCC tissues. Further investigations and validations may provide novel therapeutic strategies for personalized immunomodulation in HNSCC patients.

Different Impacts of DNA-PK and mTOR Kinase Inhibitors in Combination with Ionizing Radiation on HNSCC and Normal Tissue Cells.

Despite substantial advancements in understanding the pathomechanisms of head and neck squamous cell carcinoma (HNSCC), effective therapy remains challenging. The application of kinase inhibitors (KIs) in HNSCC, specifically mTOR and DNA-PK inhibitors, can increase radiosensitivity and therefore presents a promising strategy when used simultaneously with ionizing radiation (IR) in cancer treatment. Our study focused on the selective DNA-PK-inhibitor AZD7648; the selective mTOR-inhibitor Sapanisertib; and CC-115, a dual inhibitor targeting both mTOR and DNA-PK. The impact of these KIs on HNSCC and normal tissue cells was assessed using various analytical methods including cell death studies, cell cycle analysis, real-time microscopy, colony-forming assays and immunohistochemical staining for γH2AX and downstream mTOR protein p-S6. We detected a strong inhibition of IR-induced DNA double-strand break (DSB) repair, particularly in AZD7648-treated HNSCC, whereas normal tissue cells repaired DNA DSB more efficiently. Additionally, AZD7648 + IR treatment showed a synergistic decline in cell proliferation and clonogenicity, along with an elevated G2/M arrest and cell death in the majority of HNSCC cell lines. CC-115 + IR treatment led to an elevation in G2/M arrest, increased cell death, and a synergistic reduction in cell proliferation, though the effect was notably lower compared to the AZD7648 + IR- treated group. Sapanisertib led to a high cellular toxicity in both HNSCC and normal tissue cells, even in non-irradiated cells. Regarding cell proliferation and the induction of apoptosis and necrosis, Sapanisertib + IR was beneficial only in HPV+ HNSCC. Overall, this study highlights the potential of AZD7648 as a radiosensitizing agent in advanced-stage HPV-positive and negative HNSCC, offering a promising therapeutic strategy. However, the dual mTOR/DNA-PK-I CC-115 did not provide a distinct advantage over the use of selective KIs in our investigations, suggesting limited benefits for its application in KI + IR therapy. Notably, the selective mTOR-inhibitor Sapanisertib was only beneficial in HPV+ HNSCC and should not be applied in HPV- cases.

DTL promotes head and neck squamous cell carcinoma progression by mediating the degradation of ARGLU1 to regulate the Notch signaling pathway

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide, with a high incidence in squamous epithelium. The E3 ubiquitin ligase DTL is a component of the CRL4A complex and is widely involved in tumor progression. We aimed to analyze the role of DTL in HNSCC and to explore its mechanism of action. Through clinical analysis, we found that DTL is upregulated in HNSCC tissues and is associated with the tumor microenvironment and poor survival in patients. Through gain-of-function and loss-of-function assays, we showed that DTL promotes cell proliferation and migration in vitro and tumor growth in vivo. Mass spectrometry analysis and immunoprecipitation assays showed that DTL interacts with ARGLU1 to promote K11-linked ubiquitination-mediated degradation of ARGLU1, thereby promoting the activation of the CSL-dependent Notch signaling pathway. Furthermore, siARGLU1 blocks the inhibitory effects of DTL knockdown on HNSCC cells. In this study, we showed that DTL promotes HNSCC progression through K11-linked ubiquitination of ARGLU1 to activate the CSL-dependent Notch pathway. These findings identify a promising therapeutic target for HNSCC.