Head And Neck Squamous Cell Carcinoma Research Articles

RGIE: A Gene Selection Method Related to Radiotherapy Resistance in Head and Neck Squamous Cell Carcinoma.

Head and Neck Squamous Cell Carcinoma (HNSCC) is a malignant tumor with a high degree of malignancy, invasiveness, and metastasis rate. Radiotherapy, as an important adjuvant therapy for HNSCC, can reduce the postoperative recurrence rate and improve the survival rate. Identifying the genes related to HNSCC radiotherapy resistance (HNSCC-RR) is helpful in the search for potential therapeutic targets. However, identifying radiotherapy resistance-related genes from tens of thousands of genes is a challenging task. While interactions between genes are important for elucidating complex biological processes, the large number of genes makes the computation of gene interactions infeasible. We propose a gene selection algorithm, RGIE, which is based on ReliefF, Gene Network Inference with Ensemble of Trees (GENIE3) and Feature Elimination. ReliefF was used to select a feature subset that is discriminative for HNSCC-RR, GENIE3 constructed a gene regulatory network based on this subset to analyze the regulatory relationship among genes, and feature elimination was used to remove redundant and noisy features. Nine genes (SPAG1, FIGN, NUBPL, CHMP5, TCF7L2, COQ10B, BSDC1, ZFPM1, GRPEL1) were identified and used to identify HNSCC-RR, which achieved performances of 0.9730, 0.9679, 0.9767, and 0.9885 in terms of accuracy, precision, recall, and AUC, respectively. Finally, qRT-PCR validated the differential expression of the nine signature genes in cell lines (SCC9, SCC9-RR). RGIE is effective in screening genes related to HNSCC-RR. This approach may help guide clinical treatment modalities for patients and develop potential treatments.

Dynamic change of gut microbiota in head and neck concurrent chemoradiotherapy patients and its potential value in the prediction of acute oral mucositis grade as well as quality of life.

Radiotherapy is the major therapy for head and neck squamous cell carcinoma (HNSCC). However, whether gut microbiota changes in HNSCC patients who received concurrent chemoradiotherapy remains unclear. This study aimed to investigate the dynamic change of gut microbiota composition, construct the first radiotherapy-related gut microbiota database in these patients and identify the potential value of the gut microbiota changing in the prediction of acute oral mucositis grade as well as patients' life quality. We enrolled 47 HNSCC patients who scheduled with concurrent chemoradiotherapy. The field was irradiated with a total dose of 66-70Gy in 33-35 fractions. All the patients received 2-3 cycles of platinum-based chemotherapy. After feces specimens collected, bacterial genomic DNA was isolated using magnetic beads and then analyzed by the Illumina MiSeq Sequencing System based on the V3-V4 hypervariable regions of the 16S rRNA gene. 194 genera which belonged to 27 phyla were found in 141 samples. Increased abundance of microbiota in diversity and richness was observed in mid-radiotherapy group. Bacteroides, Blautia, Phascolarctobacterium were three main genera in all three groups and the mid-radiotherapy group had the highest relative abundance of Phascolarctobacterium. What is more, most significantly altered bacteria shared the same variation pattern which was increased in mid-radiotherapy while decreased to the almost same level of as pre-radiotherapy in post-radiotherapy group. Further analysis indicated that Bacteroidetes showing an upward trend while Proteobacteria declining in higher grade of acute mucositis. Moreover, relatively low abundant Proteobacteria was significantly correlated with high-grade acute oral mucositis. As for the quality of life, Lactobacillales and Actinomycetales were specifically found in better life quality group. However, Clostridia_UCG_014, Eubacteriaceae, UCG_010 and Moraxellaceae were unique abundantly present in worse life quality group. Chemoradiotherapy can affect the composition of the gut microbiota in HNSCC patients during the mid-term of treatment. Yet self-stabilized ability maintained the gut microbiota homeostasis. Dynamic change of specific species could help predict acute oral mucositis grade and characterize different quality of life group in these patients.

Phase 1/2 Study of the Aurora Kinase A Inhibitor Alisertib and Pembrolizumab in Refractory, Rb-Deficient Head and Neck Squamous Cell Carcinomas.

Effective therapy for recurrent head and neck squamous cell carcinoma (HNSCC) that is refractory to chemotherapy and immunotherapy is a considerable need. Aurora kinase A inhibition leads to apoptosis and immunogenic cell death in preclinical models of human papilloma virus (HPV)-driven cancers. Alisertib was administered orally twice daily on days 1-7 and pembrolizumab on day 1 of a 21-day cycle to adults with advanced solid tumors (phase 1) or with immunotherapy- and platinum-resistant, HPV-positive HNSCC (phase 2). The recommended phase 2 alisertib dose was 40 mg which had only the expected toxicity including cytopenia that led to dose reductions in two phase 2 patients at cycles 13 and 16. We saw no objective responses, but the combination led to prolonged stable disease (SD) in several patients, including 2 of 10 phase 1 patients (8 and 27 months). Eight of the 15 HPV-positive patients had SD; four of them (heavily pretreated) for ≥6 months, with median overall and progression-free survival durations of 16.8 and 1.4 months, respectively. In circulating immune cells and plasma patients with SD had markedly higher levels of HLA-DR-expressing natural killer cells than did progressive disease patients who demonstrated a more immunosuppressive and inflammatory profile. Pharmacokinetics did not indicate any significant drug-drug interactions between pembrolizumab and alisertib. The combination of alisertib and pembrolizumab was well tolerated and led to prolonged SD in some immunotherapy-resistant patients, supporting our hypothesis that Aurora kinase A inhibition can reverse immunotherapy resistance of retinoblastoma protein-deficient HNSCC.

Frailty and Overall Survival of Older Patients Undergoing Radiotherapy for Head and Neck Cancer: A Prospective Analysis

Background/Objectives: Over 60% of diagnoses of head and neck squamous cell carcinoma (HNSCC) occur in patients aged over 65. The benefits of radiotherapy (RT) combined with chemotherapy remain controversial in geriatric patients. Frailty stratification is underutilized in clinical practice despite evidence suggesting its predictive power. We aimed to assess the impact of pre-treatment frailty stratification on overall survival (OS) and acute radiation-related toxicity in a cohort of older patients with HNSCC. Methods: A prospective cohort of 117 patients aged ≥65 years with newly diagnosed HNSCC was enrolled between 2017 and 2022. Patients received RT with or without chemotherapy. Frailty was assessed using the 40-item Frailty Index (FI) as part of a comprehensive geriatric assessment. The primary outcomes were OS and acute RT toxicity, defined as a grade ≥ 3 based on CTCAE 5.0. Cox proportional hazard models and logistic regression models, adjusted for age, tumor stage, and chemotherapy, were used. Results: After a median follow-up of 819 days, FI (HR 1.478, 95% CI 1.182–1.848, p < 0.001) was an independent predictor of OS. Grade ≥ 3 toxicities were observed in 38% of patients, but frailty was not significantly associated with toxicity. A sub-analysis of oropharyngeal carcinoma patients demonstrated improved OS in HPV-positive patients (HR 0.231, 95% CI 0.078–0.686, p = 0.008). Conclusions: the standardized introduction of frailty assessment in the evaluation of older HNSCC patients holds great promise for predicting long-term survival. This approach could be crucial in tailoring treatment protocols that account for the biological heterogeneity of older adults.

Effect of immortal time bias on the association between immune-related adverse events and oncological outcomes following immune checkpoint inhibitors therapy for head and neck squamous cell carcinoma.

Immune checkpoint inhibitors (ICIs) are pharmacological agents indicated for recurrent and metastatic head and neck squamous cell carcinoma (HNCSCC). Immune-related adverse events (irAEs) have been reported as predictors of therapeutic response to ICIs. However, previous studies have not adequately addressed the immortal time bias. Therefore, we aimed to investigate the association between the onset of irAEs and oncological outcomes, accounting for immortal time bias. We conducted a retrospective study involving 130 patients with HNSCC who were treated with ICIs. The objective response, progression-free survival (PFS), and overall survival (OS) were assessed using logistic regression analysis, the Kaplan-Meier method, and the Cox proportional hazard (PH) model. The immortal time bias was considered using a landmark analysis and an extended Cox (EC) model. The odds ratios for response and disease control were smaller in the landmark than in the naïve analyses. In the landmark analysis, the 1-year PFS rates were 47.6% and 27.2% for irAE+ and irAE- patients, respectively (p = 0.049), and the 1-year OS rates were 85.7% and 66.5%, respectively (p = 0.006). Regarding PFS, the adjusted HRs for irAEs were 0.49 (95% confidence interval (CI) 0.28-0.85) in the PH analysis and 0.75 (95% CI 0.40-1.40) in the EC analysis. As for OS, the adjusted HRs for irAEs were 0.36 (95% CI 0.19-0.66) in the PH analysis and 0.51 (95% CI 0.27-0.95) in the EC analysis. IrAEs were an independent prognostic factor for OS but not PFS. Without considering the immortal time bias, the association between irAEs and oncologic outcomes in patients with HNSCC treated with ICIs was overestimated. Therefore, the balance between the benefits and risks of ICI therapy must be carefully weighed in clinical settings.

TRIM47 promotes hypopharyngeal and laryngeal cancers progression through promoting K63-linked ubiquitination of vimentin.

Hypopharyngeal and laryngeal cancers which belong to head and neck squamous cell carcinoma (HNSCC) are the two most malignant types of head and neck cancer, characterized by a low 5-year survival rate, high recurrence and metastasis rate. It is vital to explore strategies to suppress metastasis and improve prognosis for patients with these cancers. In this research, we analyzed the clinical data and found that E3 ubiquitin ligase TRIM47 was upregulated in cancer tissues of hypopharyngeal cancer and was closely associated with poor survival outcomes. In terms of mechanism, we performed tandem affinity chromatography and denatured Ni-NTA Agarose pulldown. As a result, TRIM47 was found to interact with vimentin and control vimentin stabilization through ubiquitination, specifically in the form of K63 chains. Importantly, through experiments of cancer cell viability and migration, we found that TRIM47 could enhance the proliferation and metastasis abilities of cancer cells in a vimentin-dependent manner, thus promoting the advancement of hypopharyngeal and laryngeal cancers. TRIM47 was verified to regulate cancer cells metastasis invivo using metastasis models. All these results imply that TRIM47 emerges as a potential biomarker for early diagnosis and metastasis prediction of hypopharyngeal and laryngeal cancers and represents a promising therapeutic target.

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

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

Nucleus-targeted Silencer nanoplatform regulating ZEB1-AS1 in head and neck squamous cell carcinoma therapy

Long noncoding RNAs have emerged as key players in the progression of head and neck squamous cell carcinoma (HNSC). Among them, ZEB1-AS1 was identified as an upregulated candidate in HNSC through comprehensive analysis of RNA-sequencing datasets. Here, elevated ZEB1-AS1 expression was correlated with poor prognosis in HNSC patients. Further investigations demonstrated that downregulation of ZEB1-AS1 induced epithelial-mesenchymal transition and increased sensitivity to cisplatin in Cal27 cells, while its upregulation reversed these effects, underscoring its pivotal role in tumor metastasis and cisplatin resistance in Cal27 cells. Mechanistically, ZEB1-AS1, located in cytoplasm and nucleus, directly regulated the expression of ZEB1, thereby influencing the expression of μ opioid receptor (MOR) and implicating in cancer progression. To advance clinical translation, we employed a nucleus-targeting nanoparticle platform for efficient delivery of a mixture of antisense oligonucleotides and siRNA (Silencer), effectively manipulating ZEB1-AS1 expression in vitro and in vivo. Besides, a predictive model for HNSC patients was developed by analyzing the expression levels of ZEB1-AS1, ZEB1, and MOR in the HNSC datasets. Our study underscored the critical role of ZEB1-AS1 in HNSC and its potential as a therapeutic target. By elucidating its functional mechanisms and utilizing a nucleus-targeting nanoparticle platform for efficient delivery, we proved the potential of ZEB1-AS1-targeted therapies in HNSC.

LINC02154 promotes cell cycle and mitochondrial function in oral squamous cell carcinoma.

Long noncoding RNAs (lncRNAs) play pivotal roles in the development of human malignancies, though their involvement in oral squamous cell carcinoma (OSCC) remains incompletely understood. Using The Cancer Genome Atlas (TCGA) dataset, we analyzed expression of 7840 lncRNAs in primary head and neck squamous cell carcinoma (HNSCC) and found that upregulation of LINC02154 is associated with a poorer prognosis. LINC02154 knockdown in OSCC cell lines induced cell cycle arrest and apoptosis, and significantly attenuated tumor growth invitro and invivo. Notably, depletion of LINC02154 downregulated FOXM1, a master regulator of cell cycle-related genes. RNA pulldown and mass spectrometry analyses identified a series of proteins that could potentially interact with LINC02154, including HNRNPK and LRPPRC. HNRNPK stabilizes FOXM1 expression by interacting with the 3'-UTR of FOXM1 mRNA, which suggests LINC02154 and HNRNPK promote cell cycling by regulating FOXM1 expression. Additionally, LINC02154 positively regulates HNRNPK expression by inhibiting microRNAs targeting HNRPNK. Moreover, LINC02154 affects mitochondrial function by interacting with LRPPRC. Depletion of LINC02154 suppressed expression of mitochondrial genes, including MTCO1 and MTCO2, and inhibited mitochondrial respiratory function in OSCC cells. These results suggest that LINC02154 exerts its oncogenic effects by modulating the cell cycle and oxidative phosphorylation in OSCC, highlighting LINC02154 as a potential therapeutic target.

Complex IIa formation and ABC transporters determine sensitivity of OSCC to Smac mimetics

Small molecule inhibitors of apoptosis proteins (IAPs) antagonists, known as Smac mimetics (SMs), activate non-canonical NF-κB and sensitize cancer cells to TNF-induced cell death. SMs are currently in phase III clinical trials for head and neck squamous cell carcinoma (HNSCC) after promising phase II trials. To explore the utility of SMs in oral squamous cell carcinoma (OSCC), we tested nine human OSCC cell lines and correlated SM sensitivity with both IAP mutation and expression levels. cIAP1 protein expression was shown to be higher in OSCC and a predictor of poor prognosis. However, our in vitro and in vivo testing demonstrated differential sensitivity to SMs, which did not correlate with cIAP1 and cIAP2 expression in these OSCC cell lines. Exogenous TNF failed to effectively increase the sensitivity of SM-resistant OSCC cells to SM-induced cell death. SM resistance was associated with a deficiency in Complex IIa formation, but activation of non-canonical NF-κB was not a determinant of SM efficacy. Finally, metabolic analysis revealed that the ABC transporter pathway was activated in SM-resistant OSSC cells, and SMs combined with ABC transporter inhibitors improved cell death sensitivity to overcome SM resistance. These studies highlight the therapeutic potential of SMs in OSCC and support patient stratification to improve efficacy with the addition of adjuvant therapy.

Pulrodemstat, a selective inhibitor of KDM1A, suppresses head and neck squamous cell carcinoma growth by triggering apoptosis

BackgroundChemotherapy is often ineffective as a first-line treatment for head and neck squamous cell carcinoma (HNSCC), and a more precise and effective therapeutic option is urgently needed.MethodsHigh-throughput screening of a histone demethylase inhibitor library was performed to identify potential drugs for treating HNSCC. The Cancer Genome Atlas (TCGA) and single-cell sequencing were used to evaluate the potential diagnostic value and expression distribution of candidate drug targets. Colony formation, transwell assays, and flow cytometry analyses were used to assess the antitumor function of the potential drugs. The CCK-8 assay was used to compare the antitumor activity of the candidate drug and the traditional chemotherapy drug. Bioinformatic analysis based on TCGA database was used for unveiling the upstream signaling.ResultsPulrodemstat, a selective KDM1A inhibitor that is ongoing clinical trial, stood out as the most effective candidate anti-HNSCC drug based on the high-throughput screening. IC50 analysis revealed that Pulrodemstat might possess stronger anti-tumor activity than 5-Fu. Additionally, Pulrodemstat dramatically suppressed HNSCC cell proliferation and migration without inducing toxicity in normal cells. TCGA analysis revealed that KDM1A is positively associated with tumor proliferation, DNA repair, and DNA replication in HNSCC. Consistent with these results, Pulrodemstat substantially induced apoptosis in the HNSCC cells. Furthermore, TCGA analysis revealed that KDM1A was aberrantly overexpressed in HNSCC, positively correlated with malignancy, and negatively associated with the clinical outcomes of HNSCC patients. Notably, single-cell analysis indicated that KDM1A was mainly distributed in the malignant cells of HNSCC samples, highlighting that Pulrodemstat may be a more precise therapeutic option for HNSCC. In addition, methylation occupancies in the KDM1A promoter were substantially low in HNCC tumors, and low methylation occupancies in the KDM1A promoter predicted poor clinical outcomes in HNSCC. These data are consistent with the KDM1A expression in HNSCC. Moreover, TET3, a DNA demethylase, was strongly and positively correlated with KDM1A expression.ConclusionsPulrodemstat is an effective therapeutic drug for HNSCC. Thus, the TET3/KDM1A axis may account for the malignant phenotype of HNSCC.

Transcriptome Analysis of HNSCC by Aggregatibacter actinomycetemcomitans Extracellular Vesicles.

The role of extracellular vesicles (EVs), also known as outer membrane vesicles (OMVs), secreted by oral bacteria in the progression of head and neck squamous cell carcinomas (HNSCCs), is largely unexplored. This study aimed to investigate the influence of bacterial EVs, specifically those derived from Aggregatibacter actinomycetemcomitans (Aa), on the progression of HNSCC. FaDu and UMSCC1 cell lines were treated with Aa-derived EVs, and oncogenic activities were assessed. Comprehensive cellular and RNA-sequencing transcriptome analyses were conducted to assess the impact of these EVs on cell cycle progression and gene expression. Our findings reveal that Aa-derived EVs accelerate cell cycle progression through the S and G2 phases and enhance invasion in HNSCC cell lines. RNA-sequencing analysis showed that Aa-derived EVs exert a more significant effect on general transcript expression than on microRNA profiles, except for miR-146a, which is recognized as a key factor in both carcinogenesis and immune modulation. Bacterial EVs, particularly from periodontal pathogens like Aa, are significant modulators within the oral cancer environment, potentially affecting cellular behavior and gene expression profiles. This study highlights the complex relationship between periodontal health and oral carcinogenesis, emphasizing the significant role of bacterial EVs in HNSCC progression.

Combination Effect of Radiotherapy and Targeted Therapy with NK Cell-Based Immunotherapy in head and Neck Squamous Cell Carcinoma

ABSTRACT Background Head and neck squamous cell carcinoma (HNSCC) has a poor prognosis, and current treatments are limited by high toxicity and low survival rates, highlighting the need for new therapeutic approaches. Natural killer (NK) cells can identify and eliminate cancer cells without prior antigen exposure. Radiotherapy directly targets tumors and increases activating ligands on tumor cells, promoting NK cell interactions. Cetuximab, an EGFR-targeting antibody, enhances NK cell cytotoxicity. Additionally, anti-PD-1 antibodies may further boost NK cell function by blocking inhibitory signals. The study aimed to enhance HNSCC treatment efficacy by combining radiotherapy and targeted therapy with expanded NK cells. Methods NK cells were isolated, activated, and expanded from healthy donors. The FaDu and SCC-47 cell lines were inoculated into NOD/SCID mice. The mice were treated with PD-1 inhibitors, cetuximab, and radiation, followed by intravenous injection of NK cells. Results Radiation increased ligands that regulate NK cell sensitivity. The combination of cetuximab, radiotherapy, and expanded NK cells significantly suppressed cancer progression and improved survival rates. However, adding anti-PD-1 antibodies did not further enhance outcomes. Conclusion This study suggests that a multimodal approach combining cetuximab, radiotherapy, and NK cells can significantly improve HNSCC therapy efficacy, offering a novel and promising treatment strategy.

E2F1 Promotes the Occurrence of Head and Neck Squamous Cell Carcinoma and Serves as a Prognostic Biomarker.

Head and neck squamous cell carcinoma (HNSCC) is a common malignant tumor occurring in various sites such as the oral cavity, pharynx, larynx, and nasal cavity. This study aimed to explore the biological functions and prognostic value of E2F transcription factor 1 (E2F1) in HNSCC. Transcriptome and single-cell sequencing (scRNA-seq) data of HNSCC patients were analyzed using data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). All samples were divided into high and low expression groups based on the expression levels of E2F1. A risk model was constructed based on Lasso-Cox regression, and the differences between the two groups in terms of prognosis were explored. The scRNA-seq data of HNSCC samples were analyzed using the Seurat package to identify cell types. AUCell was used to score different types of cells, and subsequently, the interaction pathways between the high-scoring cell population and other cell populations were explored using the CellChat package. The expression level of E2F1 in tumor tissues was higher than that in normal tissues, which was confirmed by in vitro experiments. Analysis of transcriptome data from TCGA revealed significant differences in overall survival (OS) between the high and low expression groups. Prognostic genes were selected based on DEGs between the two groups, and a risk model was constructed. Subsequently, a nomogram model was constructed based on clinical factors and risk scores, which exhibited good predictive performance. The expression landscape of prognostic genes in different cell types was explored using scRNA-seq data of HNSCC samples. Dendritic cell populations were identified as high-scoring cell populations, and the pathways of interaction between this cell population and other cell populations were explored. We identified E2F1 as an independent prognostic factor closely associated with the prognosis and immune response of HNSCC.

Changes in the tumor microenvironment in recurrent head and neck squamous cell carcinoma and its implication on efficacy of immune checkpoint inhibitors

Little is known about changes in the abundance of tumor-infiltrating lymphocytes (TILs) and immune phenotype (IP) in recurrent and/or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC). We aimed to compare the TILs and IP between initial and recurrent HNSCCs using paired analysis. Thirty-seven patients who experienced recurrence after surgical resection and received treatment with immune checkpoint inhibitors (ICIs) between June 2014 and June 2023 were included. Changes in intratumoral TIL (iTILs), stromal TIL (sTILs), and IPs were subjected to paired analysis between the initial and recurrent tumors. We investigated their relationship with the outcomes of ICIs. The density of iTIL and sTIL in the recurrent tumors was significantly lower compared to initial tumors. IP was significantly different; the proportion of desert IP was higher in recurrent tumors (83.8% vs. 35.1%, P < 0.001). Increased sTIL was a favorable indicator for overall response to ICIs and progression-free survival. Our findings suggest TILs decrease during recurrence compared with the initial tumor, resulting in a transition toward desert IP. Therefore, careful evaluation of TIL density in both initial and recurrent tumors is recommended when using ICIs in patients with R/M HNSCC.

Contrast-Enhanced Computed Tomography (CT) With Concordant Sonography as Sufficient Early Detection Tools for Recurrent and Persistent Cervical Metastases After (Chemo)radiotherapy (CRT).

Most challenging treatment needs are in recurrent or persisting head and neck squamous cell carcinoma (HNSCC) patients after (((chemo-)radiotherapy) (C)RT). This 10-year retrospective study included 100 patients, who initially received (C)RT followed by neck dissection (ND). The results of computed tomography (CT) and sonography were evaluated for residual/recurrent cervical lymph nodes and compared to the histopathology. On this basis we calculate the sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV). A total of 144 ND specimens were analyzed. The combination of CT and sonography (n = 103) reached values 97% sensitivity, 71% specificity, 98% NPV, 66% PPV, and 81% overall accuracy. For patients who received as primary treatment CRT the values for the combined imaging were: 100.0%, 73.5%, 100.0%, 66.7% and 82.7% respectively. Our study demonstrates that the combined use of CT and sonography reliably detects lymph node metastases, particularly in patients previously treated with CRT, even after a long time after treatment.

Abstract C009: MK2 knockout and radiation enhances immune cell influx in a mouse model of HPV+ head and neck squamous cell carcinoma

Abstract Introduction: HPV mediated head and neck squamous cell carcinoma (HNSCC) has an immunosuppressive microenvironment which contributes to local and distant failures. We have previously shown that MAPKAPK2 (MK2) inhibition (MK2i) in HNSCC results in improved response to irradiation (RT). MK2i was synergistic with RT resulting in better control than monotherapy. To understand the mechanism behind the improvement of RT in MK2i treated mice we tested the hypothesis that MK2 ablation can enhance the radiotherapy mediated immunogenic response in a solid tumor. Methods: We used CRISPR gene editing to knockout the MK2 gene in the highly metastatic murine cell line, MLM3 (KO). We implanted tumors into c57bl6 and NSG mice and compared tumor growth compared to wild type (WT) with and without radiation. At end point, tumors were excised, digested and immunophenotyped utilizing labelled antibodies and flow cytometry. Before immunophenotyping, 8 mgs of tumor were cut off and incubated in media for 24 hours to assess cytokine release by cytokine array analysis. Results: We found that the differences in tumor growth between WT and KO cells in c57bl6 mice were significantly greater than those seen in NSG mice. Survival studies with c57bl6 mice implanted with WT or KO tumors with and without RT showed that MLM3 KO implanted mice had significantly greater survival (58.5 days) compared to WT (35.5 days). WT tumors treated with RT improved median overall survival with the WT + RT group surviving longer than WT (56 days) and the MK2 KO + RT had the longest survival overall (65 days). Immunophenotyping WT v KO tumors grown in c57bl6 mice showed an increase in CD45 cells in the KO tumors compared to WT. The cells that were increased in number in the KO tumors were labelled by Ly6G (neutrophils), F4/80 (macrophages), CD14+MD11c (dendritic cells), CD4 (Th), CD8 (Tc), CD3+NK1.1 (NKt) and NK1.1 (NK cells). Irradiating the tumors accentuated the influx of immune cells causing a greater influx of CD45 cells at 3 days post-RT which included increases in F4/80+CD80 (M1 macrophages), CD14 (monocytes), CD11c+MHCII, NK1.1, NK1.1+CD3 and CD4 cells. However, the influx of CD8 cells were reduced at 3 days. At 8 days post RT, many cell types remained elevated in the KO tumors compared to wildtype and there was a partial recovery of CD8 cell influx. However, there was also an increase in immune suppressor cells into the tumors including Ly6C+arginase (M-MDSCs), Ly6C+arginase (PMN-MDSCs) and CD4+T-bet (Th1) cells. The cytokine analysis showed that six cytokines were differentially secreted from tumors: Dkk-1, IL-2, IGFBP-5, IL-3, IL-17a and CD14. All these cytokines were suppressed in the KO with respect to the WT tumors. Conclusion: Here we show evidence that genetic ablation of MK2 in a mouse model of HPV mediated HNSCC results in an increase in immune cells infiltrate into tumors. Irradiation enhances this difference by stimulating a greater influx of immune cells. These data suggest that tumoral MK2 may aid in the immunosuppression of tumors in HNSCC. Citation Format: Deri Morgan, Colby Spiess, Alyssa Schmidt, Dakota D.D. Okuwone, Harmony Saunders, Chris E. Lominska, Mary A. Markiewicz, Yelder Tonia, Devin Shrock, Yuting Lin, Hao Gao, Gregory N Gan. MK2 knockout and radiation enhances immune cell influx in a mouse model of HPV+ head and neck squamous cell carcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C009.

Abstract C010: Tumor MK2 drives tumor progression and an immunosuppressive microenvironment in head and neck squamous cell carcinoma

Abstract Background: Head and neck squamous carcinoma (HNSCC) results in poor patient outcomes driven primarily by locoregional and distant metastatic tumor spread. We have demonstrated that highly phosphorylated/active MAPKAPK-2 (MK2) is a poor prognostic factor in HNSCC patients. MK2 is associated with the expression of pro-inflammatory cytokines that are linked with creating a pro-tumorigenic microenvironment. Nevertheless, how MK2 contributes to HNSCC development has not been established. In this study, we aimed to identify the effect of MK2 on cancer progression, immune infiltration, and cytokine secretion. Method: To assess the effect of tumor MK2 in vivo, we used CRISPR-Cas9 to knock out (KO) MK2 in a metastatic murine HNSCC cell line, Ly2, and orthotopically implanted wildtype (WT) or MK2 KO cells into the floor-of-mouth of Balb/c mice. At the endpoint of the experiment, the tumors were excised, and myeloid and lymphocyte immune profiling was done via flow cytometry. Mouse lungs and cervical lymph nodes were dissected, paraffin-fixed, sectioned, and H&amp;E stained, and the presence/quantity of metastatic foci was evaluated by a blinded board-certified pathologist. We broadly evaluated the tumor secretome via a 105-cytokine dot blot array using 8 mg of the same resected tumor sample and performed densitometric analysis comparing WT and KO tumors. Results: Loss of MK2 significantly reduced primary tumor growth, as well as lymph node and lung metastasis, compared to WT tumors. Tumor immunophenotyping by flow cytometry revealed that MK2 KO tumors had increased overall immune cell (CD45+) infiltration, but decreased quantities of immunosuppressive neutrophils (CD11b+Ly6G+Arg1+Ly6C-) and a shift in macrophage polarity favoring M1 (anti-tumor) macrophages (CD11b+Ly6G-F4-80+CD80+). In addition, there were increased quantities of anti-tumor immune cells including natural killer (NK)-T, CD4+, and CD8+ T cells in the MK2-KO tumors, while the proportion of CD4+CD25+ Tregs and exhausted CD8 T cells (CD8+PD1+) was decreased compared to WT tumors. Furthermore, cytokine array analysis revealed that secreted levels of several cytokines, including CXCL1, CXCL2, GM-CSF, G-CSF, IL-1alpha, and IL-6, were significantly lower in MK2 KO tumors compared to WT tumors. Conclusion: These results show that tumoral MK2 signaling promotes tumor growth, metastasis, immunosuppressive inflammation, and pro-tumorigenic cytokine release which substantiates future therapeutic targeting of this pathway. Citation Format: Dakota D.D. Okwuone, Deri Morgan, Alyssa Schmidt, Devin Shrock, Yuting Lin, Hao Gao, Sufi M. Thomas, Gregory N. Gan. Tumor MK2 drives tumor progression and an immunosuppressive microenvironment in head and neck squamous cell carcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C010.

Systematic comparison of fluorescence imaging in the near-infrared and shortwave-infrared spectral range using clinical tumor samples containing cetuximab-IRDye800CW.

Shortwave-infrared (SWIR) imaging is reported to yield better contrast in fluorescence-guided surgery than near-infrared (NIR) imaging, due to a reduction in scattering. This benefit of SWIR was shown in animal studies, however not yet in clinical studies with patient samples. We investigate the potential benefit of SWIR to NIR imaging in clinical samples containing cetuximab-IRDye800CW in fluorescence-guided surgery. The potential of the epidermal growth factor-targeted NIR dye cetuximab-IRDye800CW in the shortwave range was examined by recording the absorption and emission spectrum. An ex vivo comparison of NIR and SWIR images using clinical tumor samples of patients with penile squamous cell carcinoma (PSCC) and head and neck squamous cell carcinoma (HNSCC) containing cetuximab-IRDye800CW was performed. The comparison was based on the tumor-to-background ratio and an adapted contrast-to-noise ratio (aCNR) using the standard of care pathology tissue assessment as the golden standard. Based on the emission spectrum, cetuximab-IRDye800CW can be detected in the SWIR range. In clinical PSCC samples, overall SWIR imaging was found to perform similarly to NIR imaging (NIR imaging is better than SWIR in the 2/7 criteria examined, and SWIR is better than NIR in the 3/7 criteria). However, when inspecting HNSCC data, NIR is better than SWIR in nearly all (5/7) examined criteria. This difference seems to originate from background autofluorescence overwhelming the off-peak SWIR fluorescence signal in HNSCC tissue. SWIR imaging using the targeted tracer cetuximab-IRDye800CW currently does not provide additional benefit over NIR imaging in ex vivo clinical samples. Background fluorescence in the SWIR region, resulting in a higher background signal, limits SWIR imaging in HNSCC samples. However, SWIR shows potential in increasing the contrast of tumor borders in PSCC samples, as shown by a higher aCNR over a line.

Tumor suppressor ACER1 correlates with prognosis and Immune Infiltration in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is notorious for poor prognoses, and effective biomarkers are urgently needed for early diagnosis of HNSCC patients. We investigate the role of alkaline ceramidase 1 (ACER1) and its relationship with immune infiltration in HNSCC. The differential expression and clinical prognostic significance of ACER1 in HNSCC patients are explored using bioinformatics methods and verified in human HNSCC samples. Genetic mutation, DNA methylation and drug sensitivity linked with ACER1 are examined. The potential biological function of ACER1 co-expression genes is assessed, and a series of functional assays are performed on ACER1in vitro. The results comprehensively reveal a relationship between ACER1 and immune infiltration in HNSCC patients. ACER1 expression is significantly downregulated in HNSCC tissues and closely correlated with better prognoses for HNSCC patients, and this prognostic significance is determined by distinct clinical characteristics. Genetic alteration and promoter hypomethylation of ACER1 are involved in progression of HNSCC, and ACER1 expression is significantly related to several drug sensitivities. Functional analysis shows that ACER1 co-expression genes are mainly enriched in the sphingolipid signaling pathway associated with inhibition of tumorigenesis, leading to better prognoses for HNSCC patients. In vitro, ACER1 overexpression inhibits proliferation and migration, induces apoptosis, and promotes adhesion of Fadu and SCC9 cells. In addition, high ACER1 expression is closely linked with infiltration levels of immune cells, and strongly associated with biomarkers of immune cells in HNSCC, suggesting the important role of ACER1 in regulating tumor immunity in HNSCC patients. In summary, ACER1 may be a useful indicator for diagnosis and prognosis, and may regulate immune infiltration in HNSCC patients, thus promising targeted immunotherapy for HNSCC.