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

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

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

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

[Concurrent simultaneous integrated boost radiotherapy and cetuximab in head and neck squamous cell cancer patients: is it feasible in daily clinical practice?] / Radioterapia a intensità modulata con boost simultaneo più cetuximab in pazienti con carcinoma a cellule squamose in stadio localmente avanzato del distretto testa collo: è fattibile nella pratica clinica quotidiana?

INTRODUCTION AND AIM: Locally advanced head and neck squamous cell carcinoma (LA-Hnscc) is a true therapeutical challenge in the modern era and the scientific community is trying to face this challenge with new therapeutical strategies, including combinations of monoclonal antibodies and radiation therapy. The aim of this study is to evaluate clinical outcomes in LA-Hnscc patients unfit to receive platinum-based chemotherapy, treated with concurrent simultaneous integrated boost-intensity modulated radiotherapy (Sib-Imrt) + cetuximab (Ctx) in daily clinical practice. METHODS: LA-Hnscc patients not included in other prospective studies treated in 4 Italian radiotherapy units (2 Messina, 1 Rome, and 1 Lecce) using Sib-Imrt and Ctx were included in this study. Acute and late toxicities and overall survival (OS) have been evaluated. RESULTS: Data regarding 27 patients with squamous tumour were collected and reviewed. The primary tumour sites were oropharynx in 14 patients (51.9%), oral cavity in 7 (25.9%), larynx in 3 (11%) and other sites in 3(11%). There were 20 (74%) patients had stage IV (16 IVa and 4 IVb). Complete remission was observed in 18 patients (66.7%), a partial remission in 4 (14.8%) whilst 4 had a progression disease (14.8%). After 3 year of follow-up 7/27 patients were deaths. The OS was 95.5%, 62.5% and 52.9% respectively at 1,2 and 3 years. Acute toxicities were observed in all treated patients (mucositis, dermatitis and dysphagia) while 66.7% of patients developed late toxicities. All observed toxicities were grade 1 to 3 and just 1 patient developed a G4 toxicity. CONCLUSION: The concurrent bio-radiotherapy of Sib-Imrt and cetuximab is feasible in real-life daily clinical practice for LA-Hnscc patients unfit for platinum-based chemoradiotherapy.

Systematic evaluation and meta-analysis of the prognosis of down-staging human papillomavirus (HPV) positive oropharyngeal squamous cell carcinoma using cetuximab combined with radiotherapy instead of cisplatin combined with radiotherapy.

Objective: To evaluate the efficacy and safety of cetuximab instead of cisplatin in combination with downstaging radiotherapy for papillomavirus (HPV) positive oropharyngeal squamous cell carcinoma (HPV+ OPSCC). Design: Meta-analysis and systematic evaluation. Data sources: The PubMed, Embase, Web of Science, and Cochrane library databases were searched up to June 8, 2023, as well as Clinicaltrials.gov Clinical Trials Registry, China Knowledge Network, Wanfang Data Knowledge Service Platform, and Wiprojournal.com. Eligibility criteria for selecting studies: Randomized controlled trials reporting results of standard regimens of cetuximab + radiotherapy vs cisplatin + radiotherapy in treating HPV+ OPSCC were included. The primary outcomes of interest were overall survival (OS), progression-free survival (PFS), local regional failure rate (LRF), distant metastasis rate (DM), and adverse events (AE). Data extraction and synthesis: Two reviewers independently extracted data and assessed the risk of bias of the included studies. The HR and its 95% CI were used as the effect analysis statistic for survival analysis, while the OR and its 95% CI were used as the effect analysis statistic for dichotomous variables. These statistics were extracted by the reviewers and aggregated using a fixed-effects model to synthesise the data. Results: A total of 874 relevant papers were obtained from the initial search, and five papers that met the inclusion criteria were included; a total of 1,617 patients with HPV+ OPSCC were enrolled in these studies. Meta-analysis showed that OS and PFS were significantly shorter in the cetuximab + radiotherapy group of patients with HPV+ OPSCC compared with those in the conventional cisplatin + radiotherapy group (HR = 2.10, 95% CI [1.39-3.15], P = 0.0004; HR = 1.79, 95% CI [1.40-2.29], P < 0.0001); LRF and DM were significantly increased (HR = 2.22, 95% CI [1.58-3.11], P < 0.0001; HR = 1.66, 95% CI [1.07-2.58], P = 0.02), but there was no significant difference in overall grade 3 to 4, acute and late AE overall (OR = 0.86, 95% CI [0.65-1.13], P = 0.28). Conclusions: Cisplatin + radiotherapy remains the standard treatment for HPV+ OPSCC. According to the 7th edition AJCC/UICC criteria, low-risk HPV+ OPSCC patients with a smoking history of ≤ 10 packs/year and non-pharyngeal tumors not involved in lymphatic metastasis had similar survival outcomes with cetuximab/cisplatin + radiotherapy. However, further clinical trials are necessary to determine whether cetuximab + radiotherapy can replace cisplatin + radiotherapy for degraded treatment in individuals who meet the aforementioned characteristics, particularly those with platinum drug allergies. Prospero registration number: CRD42023445619.

PPARγ Antagonists Exhibit Antitumor Effects by Regulating Ferroptosis and Disulfidptosis.

Oral squamous cell carcinoma (OSCC) stands as a prevalent subtype of head and neck squamous cell carcinoma, leading to disease recurrence and low survival rates. PPARγ, a ligand-dependent nuclear transcription factor, holds significance in tumor development. However, the role of PPARγ in the development of OSCC has not been fully elucidated. Through transcriptome sequencing analysis, we discovered a notable enrichment of ferroptosis-related molecules upon treatment with PPARγ antagonist. We subsequently confirmed the occurrence of ferroptosis through transmission electron microscopy, iron detection, etc. Notably, ferroptosis inhibitors could not completely rescue the cell death caused by PPARγ inhibitors, and the rescue effect was the greatest when disulfidptosis and ferroptosis inhibitors coexisted. We confirmed that the disulfidptosis phenotype indeed existed. Mechanistically, through qPCR and Western blotting, we observed that the inhibition of PPARγ resulted in the upregulation of heme oxygenase 1 (HMOX1), thereby promoting ferroptosis, while solute carrier family 7 member 11 (SLC7A11) was also upregulated to promote disulfidptosis in OSCC. Finally, a flow cytometry analysis of flight and multiplex immunohistochemical staining was used to characterize the immune status of PPARγ antagonist-treated OSCC tissues in a mouse tongue orthotopic transplantation tumor model, and the results showed that the inhibition of PPARγ led to ferroptosis and disulfidptosis, promoted the aggregation of cDCs and CD8+ T cells, and inhibited the progression of OSCC. Overall, our findings reveal that PPARγ plays a key role in regulating cell death in OSCC and that targeting PPARγ may be a potential therapeutic approach for OSCC.

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

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

Targeting histone deacetylases in head and neck squamous cell carcinoma: molecular mechanisms and therapeutic targets.

The onerous health and economic burden associated with head and neck squamous cell carcinoma (HNSCC) is a global predicament. Despite the advent of novel surgical techniques and therapeutic protocols, there is an incessant need for efficacious diagnostic and therapeutic targets to monitor the invasion, metastasis and recurrence of HNSCC due to its substantial morbidity and mortality. The differential expression patterns of histone deacetylases (HDACs), a group of enzymes responsible for modifying histones and regulating gene expression, have been demonstrated in neoplastic tissues. However, there is limited knowledge regarding the role of HDACs in HNSCC. Consequently, this review aims to summarize the existing research findings and explore the potential association between HDACs and HNSCC, offering fresh perspectives on therapeutic approaches targeting HDACs that could potentially enhance the efficacy of HNSCC treatment. Additionally, the Cancer Genome Atlas (TCGA) dataset, CPTAC, HPA, OmicShare, GeneMANIA and STRING databases are utilized to provide supplementary evidence on the differential expression of HDACs, their prognostic significance and predicting functions in HNSCC patients.

An investigative meta-analysis on the effectiveness and safety of integrating VEGF/VEGFR inhibitors with PD-1/PD-L1 inhibitors in cases with R/M HNSCC.

OBJECTIVES: Exploration into the use of vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR) inhibitors alongside programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) inhibitors has been undertaken for treating recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC). We conducted a meta-analysis to provide a more precise assessment of the efficacy and safety of this integrated approach in managing R/M HNSCC. METHODS: A systematic exploration encompassing PubMed, Embase, the Cochrane Library, and Web of Science databases was undertaken to figure out relevant studies. It was attempted to analyze critical endpoints, such as overall response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and adverse events (AEs) utilizing a random-effects model. RESULTS: Eleven studies, encompassing 413 patients, were analyzed. The combined data revealed an ORR of 41 % (95 % CI: 34-49 %), a DCR of 67 % (95 % CI: 51-83 %), a median PFS of 5.87 months (95 % CI: 3.90-7.85), and a median OS of 9.63 months (95 % CI: 6.78-12.49). Furthermore, the rates for 1-year PFS and OS were 45 % (95 % CI: 27-64 %) and 65 % (95 % CI: 49-81 %), respectively. The occurrence of grade 3 or higher adverse events related to the drugs was 20 % (95 % CI: 10-30 %). Subgroup analysis within the tyrosine kinase inhibitor (TKI) group revealed an ORR of 47 % (95 % CI: 39 %-55 %) and a DCR of 67 % (95 % CI: 46 %-88 %). CONCLUSIONS: In summary, combining VEGF/VEGFR inhibitors with PD-1/PD-L1 inhibitors shows considerable effectiveness with manageable side effects in cases with R/M HNSCC. SYSTEMATIC REVIEW REGISTRATION: Registered with the International Prospective Register of Systematic Reviews, identifier CRD42023486345.

Prognostic and chemotherapeutic implications of a novel four-gene pyroptosis model in head and neck squamous cell carcinoma.

Background: Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancers. Chemotherapy remains one dominant therapeutic strategy, while a substantial proportion of patients may develop chemotherapeutic resistance; therefore, it is particularly significant to identify the patients who could achieve maximum benefits from chemotherapy. Presently, four pyroptosis genes are reported to correlate with the chemotherapeutic response or prognosis of HNSCC, while no study has assessed the combinatorial predicting efficacy of these four genes. Hence, this study aims to evaluate the predictive value of a multi-gene pyroptosis model regarding the prognosis and chemotherapeutic responsiveness in HNSCC. Methods: By utilizing RNA-sequencing data from The Cancer Genome Atlas database and the Gene Expression Omnibus database, the pyroptosis-related gene score (PRGscore) was computed for each HNSCC sample by performing a Gene Set Variation Analysis (GSVA) based on four genes (Caspase-1, Caspase-3, Gasdermin D, Gasdermin E). The prognostic significance of the PRGscore was assessed through Cox regression and Kaplan-Meier survival analyses. Additionally, chemotherapy sensitivity stratified by high and low PRGscore was examined to determine the potential association between pyroptosis activity and chemosensitivity. Furthermore, chemotherapy sensitivity assays were conducted in HNSCC cell lines in vitro. Results: As a result, our study successfully formulated a PRGscore reflective of pyroptotic activity in HNSCC. Higher PRGscore correlates with worse prognosis. However, patients with higher PRGscore were remarkably more responsive to chemotherapy. In agreement, chemotherapy sensitivity tests on HNSCC cell lines indicated a positive association between overall pyroptosis levels and chemosensitivity to cisplatin and 5-fluorouracil; in addition, patients with higher PRGscore may benefit from the immunotherapy. Overall, our study suggests that HNSCC patients with higher PRGscore, though may have a less favorable prognosis, chemotherapy and immunotherapy may exhibit better benefits in this population.

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

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

Enhanced oral versus flank lymph node T cell response parallels anti-PD1 efficacy in head and neck cancer.

OBJECTIVES: Understanding head and neck tissue specific immune responses is important for elucidating immunotherapy resistance mechanisms to head and neck squamous cell carcinoma (HNSCC). In this study, we aimed to investigate HNSCC-specific immune response differences between oral and subcutaneous flank tumor transplantation in preclinical models. MATERIALS AND METHODS: The MOC1 syngeneic mouse oral carcinoma cell line or versions expressing either the H2Kb-restricted SIINFEKL peptide from ovalbumin (MOC1OVA) or ZsGreen (MOC1ZsGreen) were inoculated into mouse oral mucosa (buccal space) or subcutaneous flank and compared for immune cell kinetics in tumors and tumor-draining lymph nodes (TDLNs) and for anti-PD1 response. RESULTS: Compared to subcutaneous flank tumors, orthotopic oral MOC1OVA induced a higher number of OVA-specific T cells, PD1 + or CD69 + activated OVA-specific T cells in both primary tumors and TDLNs. Tumors were also larger in the flank site and CD8 depletion eliminated the difference in tumor weight between the two sites. Oral versus flank SIINFEKL peptide vaccination showed enhanced TDLN lymphocyte response in the former site. Notably, cDC1 from oral TDLN showed enhanced antigen uptake and co-stimulatory marker expression, resulting in elicitation of an increased antigen specific T cell response and increased activated T cells. Parental MOC1 in the oral site showed increased endogenous antigen-reactive T cells in TDLNs and anti-PD1 blockade rejected oral MOC1 tumors but not subcutaneous flank MOC1. CONCLUSION: Collectively, we find distinct immune responses between orthotopic oral and heterotopic subcutaneous models, including priming by cDC1 in TDLN, revealing important implications for head and neck cancer preclinical studies.

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

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

An Acid-Responsive Iron-Based Nanocomposite for OSCC Treatment.

Oral squamous cell carcinoma (OSCC) is the most common type of oral cancer, characterized by invasiveness, local lymph node metastasis, and poor prognosis. Traditional treatment and medications have limitations, making the specific inhibition of OSCC growth, invasion, and metastasis a challenge. The tumor microenvironment exhibits mildly acidity and high concentrations of H2O2, and its exploitation for cancer treatment has been widely researched across various cancers, but research in the oral cancer field is relatively limited. In this study, by loading ultra-small Prussian blue nanoparticles (USPBNPs) into mesoporous calcium-silicate nanoparticles (MCSNs), we developed an acid-responsive iron-based nanocomposite, USPBNPs@MCSNs (UPM), for the OSCC treatment. UPM demonstrated excellent dual enzyme activities, generating toxic ·OH in a mildly acidic environment, effectively killing OSCC cells and producing O2 in a neutral environment to alleviate tissue hypoxia. The results showed that UPM could effectively inhibit the proliferation, migration, and invasion of OSCC cells, as well as the growth of mice solid tumors, without obvious systemic toxicity. The mechanisms may involve UPM inducing ferroptosis of OSCC cells by downregulating the xCT/GPX4/glutathione (GSH) axis, characterized by intracellular iron accumulation, reactive oxygen species accumulation, GSH depletion, lipid peroxidation, and abnormal changes in mitochondrial morphology. Therefore, this study provides empirical support for ferroptosis as an emerging therapeutic target for OSCC and offers a valuable insight for future OSCC treatment.

Tumor growth-arrest effect of tetrahydroquinazoline-derivative human topoisomerase II-alpha inhibitor in HPV-negative head and neck squamous cell carcinoma.

Oral malignancies continue to have severe morbidity with less than 50% long-term survival despite the advancement in the available therapies. There is a persisting demand for new approaches to establish more efficient strategies for their treatment. In this regard, the human topoisomerase II (topoII) enzyme is a validated chemotherapeutics target, as topoII regulates vital cellular processes such as DNA replication, transcription, recombination, and chromosome segregation in cells. TopoII inhibitors are currently used to treat some neoplasms such as breast and small cells lung carcinomas. Additionally, topoII inhibitors are under investigation for the treatment of other cancer types, including oral cancer. Here, we report the therapeutic effect of a tetrahydroquinazoline derivative (named ARN21934) that preferentially inhibits the alpha isoform of human topoII. The treatment efficacy of ARN21934 has been evaluated in 2D cell cultures, 3D in vitro systems, and in chick chorioallantoic membrane cancer models. Overall, this work paves the way for further preclinical developments of ARN21934 and possibly other topoII alpha inhibitors of this promising chemical class as a new chemotherapeutic approach for the treatment of oral neoplasms.

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

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

The potential roles of antibody-drug conjugates in head and neck squamous cell carcinoma.

PURPOSE OF REVIEW: To summarize the actual antibody-drug conjugates (ADCs) tested for patients with advanced head and neck squamous cell carcinoma (HNSCC), outlining the results of safety and efficacy through published clinical trials. RECENT FINDINGS: ADCs combine the specificity of mAbs with the cytotoxic drug (known as payload) via a chemical linker and it is designed to selectively deliver the ultratoxic payload directly to the target cancer cells. To date, various ADCs have been investigated in multiple solid malignancies and others are in clinical development. In this study, we provide an overview of the structure and biology of ADC and we review recent clinical experience with the ADC in patients with advanced HNSCC, followed by a brief discussion of the evolvement of ADC conception, drug resistance and future perspectives. SUMMARY: ADC strategy is emerging as a potential active treatment in previously treated patients with advanced HNSCC. However, the recent improvement in the bioengineering of ADC and a better comprehension of sequencing and association strategies could provide more benefit to HNSCC patients in need of innovative therapy.

Pembrolizumab-based first-line treatment for PD-L1-positive, recurrent or metastatic head and neck squamous cell carcinoma: a retrospective analysis.

BACKGROUND: The KEYNOTE-048 trial showed that pembrolizumab-based first-line treatment for R/M HNSCC led to improved OS in the PD-L1 CPS ≥ 1 population when compared to the EXTREME regimen. However, the R/M HNSCC real-world population is generally frailer, often presenting with multiple comorbidities, worse performance status and older age than the population included in phase III clinical trials. METHODS: This is a retrospective, single-centre analysis of patients with R/M HNSCC treated with pembrolizumab-based first-line treatment. RESULTS: From February 2021 to March 2023, 92 patients were treated with pembrolizumab-based first-line treatment. Patients treated with pembrolizumab-based chemoimmunotherapy had better ECOG PS and younger age than those treated with pembrolizumab monotherapy. Median PFS and OS were 4 months and 8 months, respectively. PFS was similar among patients treated with pembrolizumab-based chemoimmunotherapy and pembrolizumab monotherapy, while patients treated with pembrolizumab monotherapy had worse OS (log-rank p =.001, HR 2.7). PFS and OS were improved in patients with PD-L1 CPS > = 20 (PFS: log-rank p =.005, HR 0.50; OS: log-rank p =.04, HR 0.57). Patients with higher ECOG PS scores had worse PFS and OS (PFS, log-rank p =.004; OS, log-rank p = 6e-04). In multivariable analysis, ECOG PS2 was associated with worse PFS and OS. CONCLUSIONS: PFS in our real-world cohort was similar to the KEYNOTE-048 reference while OS was numerically inferior. A deeper understanding of clinical variables that might affect survival outcomes of patients with R/M HNSCC beyond ECOG PS and PD-L1 CPS is urgently needed.

Polycomb repressive complex 2 and its core component EZH2: potential targeted therapeutic strategies for head and neck squamous cell carcinoma.

The polycomb group (PcG) comprises a set of proteins that exert epigenetic regulatory effects and play crucial roles in diverse biological processes, ranging from pluripotency and development to carcinogenesis. Among these proteins, enhancer of zeste homolog 2 (EZH2) stands out as a catalytic component of polycomb repressive complex 2 (PRC2), which plays a role in regulating the expression of homologous (Hox) genes and initial stages of x chromosome inactivation. In numerous human cancers, including head and neck squamous cell carcinoma (HNSCC), EZH2 is frequently overexpressed or activated and has been identified as a negative prognostic factor. Notably, EZH2 emerges as a significant gene involved in regulating the STAT3/HOTAIR axis, influencing HNSCC proliferation, differentiation, and promoting metastasis by modulating related oncogenes in oral cancer. Currently, various small molecule compounds have been developed as inhibitors specifically targeting EZH2 and have gained approval for treating refractory tumors. In this review, we delve into the epigenetic regulation mediated by EZH2/PRC2 in HNSCC, with a specific focus on exploring the potential roles and mechanisms of EZH2, its crucial contribution to targeted drug therapy, and its association with cancer markers and epithelial-mesenchymal transition. Furthermore, we aim to unravel its potential as a therapeutic strategy for oral squamous cell carcinoma.

[Pembrolizumab plus nab-paclitaxel and platinum as first-line treatment in patients with recurrent or metastatic head and neck squamous-cell carcinoma: a prospective phaseâ ¡study].

Objective: To evaluate the efficacy and safety of pembrolizumab plus nab-paclitaxel and platinum as first-line treatment in patients with recurrent or metastatic head and neck squamous-cell carcinoma (R/M HNSCC). Methods: This was a prospective, single-arm, open label, phase 2 clinical study enrolling patients at the Cancer Hospital of the Chinese Academy of Medical Sciences with R/M HNSCC treated with pembrolizumab plus nab-paclitaxel and cisplatin or carboplatin. After six cycles of treatment, patients received pembrolizumab as maintenance therapy until disease progression or intolerable toxicity or completion of 35 cycles of treatment. The primary endpoint was objective response rate, and secondary endpoints included overall survival, progression-free survival, and safety profile. Efficacy was evaluated according to the response evaluation criteria in solid tumors 1.1, survival analysis was performed using the Kaplan-Meier method, and adverse events were assessed using the America National Cancer Institute Common Terminology Criteria for Adverse Events 5.0. Results: A total of 30 patients with R/M HNSCC were enrolled from 23 April 2021 to 22 March 2023, including 28 males and 2 females, with a median age of 67 years. The median follow-up time was 14.5 months, the objective response rate was 70.0%, the disease control rate was 96.7%, and the median progression-free survival and overall survival of all patients were 11.6 months and 18.8 months, respectively. Median duration of response was up to 17.3 months. Grade≥3 treatment-related adverse events were leukopenia (26.7%), neutropenia (26.7%), peripheral neurotoxicity (3.3%), rash (3.3%), hyperalgesia (3.3%), and immune-related pneumonitis (3.3%). The most common immune-related adverse event was hypothyroidism (40.0%). Conclusion: Pembrolizumab combined with nab-paclitaxel and platinum shows encouraging antitumor activity accompanied with a manageable safety profile in untreated R/M HNSCC patients in China.