The role of ferroptosis in radiotherapy and combination therapy for head and neck squamous cell carcinoma (Review).

Head and neck squamous cell carcinoma (HNSCC) is a highly aggressive, heterogeneous tumour usually caused by alcohol and tobacco consumption, making it one of the most common malignancies worldwide. Despite the fact that various therapeutic approaches such as surgery, radiation therapy (RT), chemotherapy (CT) and targeted therapy have been widely used for HNSCC in recent years, its recurrence rate and mortality rate remain high. RT is the standard treatment choice for HNSCC, which induces reactive oxygen species production and causes oxidative stress, ultimately leading to tumour cell death. CT is a widely recognized form of cancer treatment that treats a variety of cancers by eliminating cancer cells and preventing them from reproducing. Immune checkpoint inhibitor and epidermal growth factor receptor are important in the treatment of recurrent or metastatic HNSCC. Iron death, a type of cell death regulated by peroxidative damage to phospholipids containing polyunsaturated fatty acids in cell membranes, has been found to be a relevant death response triggered by tumour RT in recent years. In the present review, an overview of the current knowledge on RT and combination therapy and iron death in HNSCC was provided, the mechanisms by which RT induces iron death in tumour cells were summarized, and therapeutic strategies to target iron death in HNSCC were explored. The current review provided important information for future studies of iron death in the treatment of HNSCC.

CHD4 acts as a prognostic factor and drives radioresistance in HPV negative HNSCC.

Despite great efforts in improving existing therapies, the outcome of patients with advanced radioresistant HPV-negative head and neck squamous cell carcinoma (HNSCC) remains poor. The chromatin remodeler Chromodomain helicase DNA binding protein 4 (CHD4) is involved in different DNA-repair mechanisms, but the role and potential in HNSCC has not been explored yet. In the present study, we evaluated the prognostic significance of CHD4 expression using in silico analysis of the pan-cancer dataset. Furthermore, we established a monoclonal HNSCC CHD4 knockdown cell clone utilizing the CRISPR/Cas9 system. Effects of lower CHD4 expression on radiosensitivity after increasing doses of ionizing radiation were characterized using clonogenic assays and cell numbers. The in silico analysis revealed that high CHD4 expression is associated with significant poorer overall survival of HPV-negative HNSCC patients. Additionally, the knockdown of CHD4 significantly increased the radiosensitivity of HNSCC cells. Therefore, CHD4 might be involved in promoting radioresistance in hard-to-treat HPV-negative HNSCC entities. We conclude that CHD4 could serve as a prognostic factor in HPV-negative HNSCC tumors and is a potential target protein overcoming radioresistance in HNSCC. Our results and the newly established cell clone laid the foundation to further characterize the underlying mechanisms and ultimately use CHD4 in HNSCC therapies.

Association of adjuvant radiation and survival in human papilloma virus-positive oropharynx squamous cell carcinoma with lymphovascular invasion as the sole adverse pathologic feature.

BACKGROUND: Postoperative radiotherapy radiation therapy (PORT) for early-stage human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) with positive lymphovascular invasion (LVI) has an unclear association with overall survival (OS). METHODS: This retrospective cohort study queried the National Cancer Database for surgically treated, T1-2, N0-1 HPV+ OPSCC from 2010 to 2019. Primary exposures were LVI and PORT, and the main outcome was 5-year OS. Odds ratios and hazard ratios (HR) with 95% confidence intervals (CIs) were generated using multivariable models and Cox proportional hazard models, respectively. RESULTS: Of 2768 patients, average age was 59.3 years, 2207 (79.7%) were male, and 386 (13.9%) had LVI. Of patients with LVI as their sole adverse pathologic feature, 220 (57.0%) received PORT, which was not associated with 5-year OS (HR, 1.13; CI, 0.65-1.19). CONCLUSIONS: Patients with surgically treated, early-stage HPV+ OPSCC and positive LVI as their only pathologic adverse feature may not require PORT.

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

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

IL7 in combination with radiotherapy stimulates a memory T-cell response to improve outcomes in HNSCC models.

Clinically approved head and neck squamous cell carcinoma (HNSCC) immunotherapies manipulate the immune checkpoint blockade (ICB) axis but have had limited success outside of recurrent/metastatic disease. Interleukin-7 (IL7) has been shown to be essential for effector T-cell survival, activation, and proliferation. Here, we show that IL7 in combination with radiotherapy (RT) is effective in activating CD8 + T-cells for reducing tumor growth. Our studies were conducted using both human papillomavirus related and unrelated orthotopic HNSCC murine models. Immune populations from the tumor, draining lymph nodes, and blood were compared between treatment groups and controls using flow cytometry, proteomics, immunofluorescence staining, and RNA sequencing. Treatment with RT and IL7 (RT + IL7) resulted in significant tumor growth reduction, high CD8 T-cell tumor infiltration, and increased proliferation of T-cell progenitors in the bone marrow. IL7 also expanded a memory-like subpopulation of CD8 T-cells. These results indicate that IL7 in combination with RT can serve as an effective immunotherapy strategy outside of the conventional ICB axis to drive the antitumor activity of CD8 T-cells.

Glutamine inhibition combined with CD47 blockade enhances radiotherapy-induced ferroptosis in head and neck squamous cell carcinoma.

Head and neck squamous cell carcinoma (HNSCC) is a formidable cancer type that poses significant treatment challenges, including radiotherapy (RT) resistance. The metabolic characteristics of tumors present substantial obstacles to cancer therapy, and the relationship between RT and tumor metabolism in HNSCC remains elusive. Ferroptosis is a type of iron-dependent regulated cell death, representing an emerging disease-modulatory mechanism. Here, we report that after RT, glutamine levels rise in HNSCC, and the glutamine transporter protein SLC1A5 is upregulated. Notably, blocking glutamine significantly enhances the therapeutic efficacy of RT in HNSCC. Furthermore, inhibition of glutamine combined with RT triggers immunogenic tumor ferroptosis, a form of nonapoptotic regulated cell death. Mechanistically, RT increases interferon regulatory factor (IRF) 1 expression by activating the interferon signaling pathway, and glutamine blockade augments this efficacy. IRF1 drives transferrin receptor expression, elevating intracellular Fe2+ concentration, disrupting iron homeostasis, and inducing cancer cell ferroptosis. Importantly, the combination treatment-induced ferroptosis is dependent on IRF1 expression. Additionally, blocking glutamine combined with RT boosts CD47 expression and hinders macrophage phagocytosis, attenuating the treatment effect. Dual-blocking glutamine and CD47 promote tumor remission and enhance RT-induced ferroptosis, thereby ameliorating the tumor microenvironment. Our work provides valuable insights into the metabolic and immunological mechanisms underlying RT-induced ferroptosis, highlighting a promising strategy to augment RT efficacy in HNSCC.

A diagnostic algorithm for sinonasal papillary non-keratinizing squamous cell carcinoma with DEK:: AFF2 fusion and mimickers / Algoritmo diagnóstico para carcinoma sinonasal papilar de células escamosas no queratinizante con fusión e imitadores de DEK:: AFF2

Sinonasal carcinomas represent a rare and diverse group of tumors, presenting diagnostic complexities due to their varied histological and molecular features. To ensure accurate differentiation among these malignancies, a systematic and stepwise approach is paramount. Even with the morphological similarities between poorly differentiated (non) keratinizing sinonasal squamous cell carcinoma (SNSCC) and DEK::AFF2 SNSCC, the two lesions are distinguishable using the surrogate immunohistochemical marker AFF2 or molecular testing for DEK::AFF2 mutation. We report a rare case of SMARCB1-retained DEK::AFF2 papillary non-keratinizing SNSCC in a 53-year-old female, who presented with a polypoid mass corresponding to the left middle turbinate. Following the surgical resection of the tumor and locoregional lymph nodes, adjuvant radiotherapy was administered to eradicate any residual cancer cells that may have remained after surgery. (AU)

Los carcinomas sinonasales representan un grupo diverso e infrecuente de tumores que presentan complejidades diagnósticas debidas a la variedad de sus características histológicas y moleculares. Para asegurar una diferenciación precisa entre estas neoplasias es esencial un enfoque sistemático paso a paso. Incluso con similitudes morfológicas entre carcinoma sinonasal escamoso pobremente diferenciado, no queratinizante (CSNE) y DEK::AFF2 se puede distinguir entre las lesiones con el uso del marcador inmunohistoquímico sustitutivo AFF2 o la mutación molecular DEK::AFF2. Comunicamos un raro caso de CSNE no queratinizante SMARCB1-retained DEK::AFF2 en una mujer de 53 años con una masa polipoide en pliegue turbinado medio izquierdo. Tras la resección quirúrgica del tumor y de los ganglios linfáticos, se administró radioterapia adyuvante para eliminar el tumor residual. (AU)

A diagnostic algorithm for sinonasal papillary non-keratinizing squamous cell carcinoma with DEK:: AFF2 fusion and mimickers / Algoritmo diagnóstico para carcinoma sinonasal papilar de células escamosas no queratinizante con fusión e imitadores de DEK:: AFF2

Sinonasal carcinomas represent a rare and diverse group of tumors, presenting diagnostic complexities due to their varied histological and molecular features. To ensure accurate differentiation among these malignancies, a systematic and stepwise approach is paramount. Even with the morphological similarities between poorly differentiated (non) keratinizing sinonasal squamous cell carcinoma (SNSCC) and DEK::AFF2 SNSCC, the two lesions are distinguishable using the surrogate immunohistochemical marker AFF2 or molecular testing for DEK::AFF2 mutation. We report a rare case of SMARCB1-retained DEK::AFF2 papillary non-keratinizing SNSCC in a 53-year-old female, who presented with a polypoid mass corresponding to the left middle turbinate. Following the surgical resection of the tumor and locoregional lymph nodes, adjuvant radiotherapy was administered to eradicate any residual cancer cells that may have remained after surgery. (AU)

Los carcinomas sinonasales representan un grupo diverso e infrecuente de tumores que presentan complejidades diagnósticas debidas a la variedad de sus características histológicas y moleculares. Para asegurar una diferenciación precisa entre estas neoplasias es esencial un enfoque sistemático paso a paso. Incluso con similitudes morfológicas entre carcinoma sinonasal escamoso pobremente diferenciado, no queratinizante (CSNE) y DEK::AFF2 se puede distinguir entre las lesiones con el uso del marcador inmunohistoquímico sustitutivo AFF2 o la mutación molecular DEK::AFF2. Comunicamos un raro caso de CSNE no queratinizante SMARCB1-retained DEK::AFF2 en una mujer de 53 años con una masa polipoide en pliegue turbinado medio izquierdo. Tras la resección quirúrgica del tumor y de los ganglios linfáticos, se administró radioterapia adyuvante para eliminar el tumor residual. (AU)

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.

Quantitative US Delta Radiomics to Predict Radiation Response in Individuals with Head and Neck Squamous Cell Carcinoma.

Purpose To investigate the role of quantitative US (QUS) radiomics data obtained after the 1st week of radiation therapy (RT) in predicting treatment response in individuals with head and neck squamous cell carcinoma (HNSCC). Materials and Methods This prospective study included 55 participants (21 with complete response [median age, 65 years {IQR: 47-80 years}, 20 male, one female; and 34 with incomplete response [median age, 59 years {IQR: 39-79 years}, 33 male, one female) with bulky node-positive HNSCC treated with curative-intent RT from January 2015 to October 2019. All participants received 70 Gy of radiation in 33-35 fractions over 6-7 weeks. US radiofrequency data from metastatic lymph nodes were acquired prior to and after 1 week of RT. QUS analysis resulted in five spectral maps from which mean values were extracted. We applied a gray-level co-occurrence matrix technique for textural analysis, leading to 20 QUS texture and 80 texture-derivative parameters. The response 3 months after RT was used as the end point. Model building and evaluation utilized nested leave-one-out cross-validation. Results Five delta (Δ) parameters had statistically significant differences (P < .05). The support vector machines classifier achieved a sensitivity of 71% (15 of 21), a specificity of 76% (26 of 34), a balanced accuracy of 74%, and an area under the receiver operating characteristic curve of 0.77 on the test set. For all the classifiers, the performance improved after the 1st week of treatment. Conclusion A QUS Δ-radiomics model using data obtained after the 1st week of RT from individuals with HNSCC predicted response 3 months after treatment completion with reasonable accuracy. Keywords: Computer-Aided Diagnosis (CAD), Ultrasound, Radiation Therapy/Oncology, Head/Neck, Radiomics, Quantitative US, Radiotherapy, Head and Neck Squamous Cell Carcinoma, Machine Learning Clinicaltrials.gov registration no. NCT03908684 Supplemental material is available for this article. © RSNA, 2024.

HSP90 inhibition suppresses tumor glycolytic flux to potentiate the therapeutic efficacy of radiotherapy for head and neck cancer.

Glycolytic metabolism may account for antitumor immunity failure. Pyruvate kinase M2 (PKM2) and platelet phosphofructokinase (PFKP), two key enzymes involved in the glycolytic pathway, are hyperactivated in head and neck squamous cell carcinoma (HNSCC). Using ganetespib as a drug model for heat shock protein 90 (HSP90) inhibition and combining results from clinical trials and animal treatment, we demonstrated that HSP90 inhibition leads to a blockade of glycolytic flux in HNSCC cells by simultaneously suppressing PKM2 and PFKP at both the transcriptional and posttranslational levels. Down-regulation of tumor glycolysis facilitates tumor infiltration of cytotoxic T cells via suppression of glycolysis-dependent interleukin-8 signaling. The addition of ganetespib to radiation attenuates radiation-induced up-regulation of PKM2 and PFKP and potentiates T cell-mediated antitumor immunity, resulting in a more potent antitumor effect than either treatment alone, providing a molecular basis for exploring the combination of HSP90 inhibitors with radiotherapy to improve outcomes for patients with HNSCC.

SALL4 promotes cancer stem-like cell phenotype and radioresistance in oral squamous cell carcinomas via methyltransferase-like 3-mediated m6A modification.

Radioresistance imposes a great challenge in reducing tumor recurrence and improving the clinical prognosis of individuals having oral squamous cell carcinoma (OSCC). OSCC harbors a subpopulation of CD44(+) cells that exhibit cancer stem-like cell (CSC) characteristics are involved in malignant tumor phenotype and radioresistance. Nevertheless, the underlying molecular mechanisms in CD44( + )-OSCC remain unclear. The current investigation demonstrated that methyltransferase-like 3 (METTL3) is highly expressed in CD44(+) cells and promotes CSCs phenotype. Using RNA-sequencing analysis, we further showed that Spalt-like transcription factor 4 (SALL4) is involved in the maintenance of CSCs properties. Furthermore, the overexpression of SALL4 in CD44( + )-OSCC cells caused radioresistance in vitro and in vivo. In contrast, silencing SALL4 sensitized OSCC cells to radiation therapy (RT). Mechanistically, we illustrated that SALL4 is a direct downstream transcriptional regulation target of METTL3, the transcription activation of SALL4 promotes the nuclear transport of ß-catenin and the expression of downstream target genes after radiation therapy, there by activates the Wnt/ß-catenin pathway, effectively enhancing the CSCs phenotype and causing radioresistance. Herein, this study indicates that the METTL3/SALL4 axis promotes the CSCs phenotype and resistance to radiation in OSCC via the Wnt/ß-catenin signaling pathway, and provides a potential therapeutic target to eliminate radioresistant OSCC.

Role of primary tumor volume and metastatic lymph node volume in response to curative effect of definitive radiotherapy for locally advanced head and neck cancer.

BACKGROUND: Studies have shown mixed results concerning the role of primary tumor volume (TV) and metastatic lymph node (NV) volume in response to the curative effect of definitive radiotherapy for locally advanced head and neck squamous cell carcinoma (LAHNSCC). OBJECTIVE: We aimed to evaluate the impact of TV and NV on the efficacy of radical radiotherapy in LAHNSCC patients, with the goal of guiding individualized therapy. PATIENTS AND METHODS: Patients with LAHNSCC who received radical radiation therapy and were reexamined within 6 months post-therapy from January 2012 to December 2021 were selected. The volumes of the primary tumors and metastatic lymph nodes were calculated by software and then were divided into a large TV group vs small TV group and a large NV group vs small NV group according to the relationship with the median. Additionally, patients who received concurrent chemoradiotherapy (CCRT) or not were divided into the CCRT group and the radiotherapy (RT) group. Patients with lymph node metastasis were divided into node concurrent chemotherapy (N-CCRT) group and a node metastatic chemotherapy (N-RT) group according to whether they received concurrent chemotherapy or not. The volume shrinkage rate (VSR), objective response rate (ORR), local control rate (LCR) and overall survival (OS) were recorded and analyzed. RESULTS: 96 patients were included in the primary tumor volume group, and 73 patients were included in the metastatic lymph node group. Receiver operating characteristic (ROC) curves were constructed for objective remission (OR) endpoints, and a volume threshold was defined for TV and NV patients. The threshold primary tumor volume was 32.45 cm3, and the threshold metastatic lymph node volume was 6.05 cm3.The primary TV shrinkage rates of the small TV and the large TV groups were basically the same, P = 0.801. Similarly, the ORR and LCR were not significantly different between the small TV group and the large TV group (PORR = 0.118, PLCR = 0.315). Additionally, the TV shrinkage rate did not significantly differ between the CCRT group and the RT group, P = 0.133. Additionally, there was no significant difference in ORR or LCR in CCRT group (PORR = 0.057, PLCR = 0.088). However, the metastatic lymph node volume shrinkage rate in the small NV group was significantly greater than that in the large NV group (P = 0.001). The ORR and LCR of the small NV subgroup were significantly greater than those of the large NV subgroup (PORR = 0.002, PLCR = 0.037). Moreover, compared with that of the N-RT group, the NV shrinkage rate of the N-CCRT group was 84.10 ± s3.11%, and the shrinkage rate was 70.76 ± s5.77% (P = 0.047). For the ORR and LCR, the N-CCRT group and N-RT group were significantly different (PORR = 0.030, PLCR = 0.037). The median OS of the whole group was 26 months. However, neither TV/NV nor concurrent chemotherapy seemed to influence OS. CONCLUSION: Primary tumor volume is not a prognostic factor for the response to curative effect radiotherapy in LAHNSCC patients. Nevertheless, metastatic lymph nodes are a prognostic factor for the response to curative effect radiotherapy in LAHNSCC patients. Patients with smaller lymph nodes have better local control.

Impact of Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography on Therapeutic Decisions and Radiotherapy Planning in Head and Neck Squamous Carcinoma: A Retrospective Study of 46 Patients.

BACKGROUND Positron emission tomography/computed tomography (PET/CT) using fluorodeoxyglucose (FDG) is essential in oncology for precise tumor delineation. This study evaluated FDG PET/CT's impact on therapeutic decisions in head and neck cancer, comparing metabolic tumor volumes (MTV) measured by different methods with radiotherapy targets, crucial for treatment planning and patient outcomes. MATERIAL AND METHODS We retrospectively analyzed 46 patients with histologically confirmed head and neck cancer who underwent FDG PET/CT examination before radiotherapy. The mean age was 62 years (46-78 years). Then, we calculated MTV of the primary tumor or local recurrence using a local threshold of 41% of the standard uptake volume (SUV) corrected for lean body mass (SULmax) of the lesion and absolute threshold of SUV 2.5. Descriptive analysis of the recruited patients was assessed based on the clinical database (Medsol). RESULTS The study included 45 patients with squamous carcinoma and 1 with sarcoid cell carcinoma. PET/CT examination led to therapeutic decision changes in 11 cases. No significant difference was found in median values of Gross Tumor Volume (GTV) and MTV absolute (p=0.130). However, significant differences were observed in MTV local, MTV absolute, and GTV median values (p<0.001), with both MTVs showing significant correlation with GTV (p<0.01), especially MTV absolute (r=0.886). CONCLUSIONS FDG PET/CT examination prior to radiotherapy significantly influences therapeutic decisions in head and neck cancer patients. Based on our findings, the absolute threshold method (SUV: 2.5) appears to be an effective approach for calculating MTV for radiotherapy planning purposes.

MTDH enhances radiosensitivity of head and neck squamous cell carcinoma by promoting ferroptosis based on a prognostic signature.

Ionizing radiation (IR) induces ferroptosis in head and neck squamous cell carcinoma (HNSCC). But, it remains unclear whether ferroptosis affects the prognosis of HNSCC patients after receiving radiotherapy. This study aims to develop a ferroptosis signature to predict the radiosensitivity and prognosis of HNSCC. Ferroptosis-related genes, clinical data and RNA expression profiles were obtained from the FerrDb database, The Cancer Genome Atlas and GEO database. Prognostic genes were identified by random survival forest, univariate Cox regression, Kaplan-Meier and ROC analyses. Principal component analysis, multivariate Cox regression, nomogram and DCA analyses were conducted to estimate its predictive ability. Functional enrichment and immune-related analyses were performed to explore potential biological mechanisms and tumor immune microenvironment. The effect of the hub gene on ferroptosis and radiosensitivity was verified using flow cytometry, quantitative real-time PCR and clonogenic survival assay. We constructed a ferroptosis-related signature, including IL6, NCF2, metadherin (MTDH) and CBS. We classified patients into high-risk (HRisk) and low-risk groups according to the risk scores. The risk score was confirmed to be an independent predictor for overall survival (OS). Combining the clinical stage with the risk score, we established a predictive nomogram for OS. Furthermore, pathways related to tumorigenesis and tumor immune suppression were mainly enriched in HRisk. MTDH was verified to have a potent effect on IR-induced ferroptosis and consequently promoted radiosensitivity. We constructed a ferroptosis-related signature to predict radiosensitivity and OS in HNSCC patients. MTDH was identified as a promising therapeutic target in radioresistant HNSCC patients.

Season of radiotherapy and outcomes of head & neck cancer patients in the MACH-NC & MARCH meta-analyses.

BACKGROUND: A single institution retrospective study suggested that head and neck squamous cell cancer (HNSCC) patients receiving radiotherapy (RT) during "dark" season (fall/winter) may have better outcomes than those treated during "light" season (spring/summer), possibly secondary to seasonal variations in cell cycle progression. We investigated the impact of season of RT in two large, multi-institutional, prospective datasets of randomized trials. METHODS: Individual patient data from the MACH-NC and MARCH meta-analyses were analyzed. Dark season was defined as mid-radiotherapy date during fall or winter and light the reverse, using equinoxes to separate the two periods. Primary endpoint was progression-free survival (PFS) and secondary endpoint was locoregional failure (LRF). The effect of season was estimated with a Cox model stratified by trial and adjusted on sex, tumor site, stage, and treatment. Planned sensitivity analyses were performed on patients treated around solstices, who received "complete radiotherapy", patients treated with concomitant radio-chemotherapy and on trials performed in Northern countries. RESULTS: 11320 patients from 33 trials of MARCH and 6276 patients from 29 trials of MACH-NC were included. RT during dark season had no benefit on PFS in the MARCH (hazard ratio[HR]: 1.01 [95%CI 0.97;1.05],p=0.72) or MACH-NC dataset (HR:1.00 [95%CI 0.94;1.06],p=1.0. No difference in LRF was observed in the MARCH (HR:1.00 [95%CI 0.94;1.06,p=0.95) or MACH-NC dataset (HR:0.99 [95%CI 0.91; 1.07],p=0.77). Sensitivity analyses showed similar results. CONCLUSION: Season of RT had no impact on PFS or LRF in two large databases of HNSCC.

Differential Formation of Stress Granules in Radiosensitive and Radioresistant Head and Neck Squamous Cell Carcinoma Cells.

PURPOSE: Stress granules (SGs) are cytoplasmic aggregates in which mRNAs and specific proteins are trapped in response to a variety of damaging agents. They participate in the cellular defense mechanisms. Currently, their mechanism of formation in response to ionizing radiation and their role in tumor-cell radiosensitivity remain elusive. METHODS AND MATERIALS: The kinetics of SG formation was investigated after the delivery of photon irradiation at different doses to head and neck squamous cell carcinoma cell lines with different radiosensitivities and the HeLa cervical cancer cell line (used as reference). In parallel, the response to a canonical inducer of SGs, sodium arsenite, was also studied. Immunolabeling of SG-specific proteins and mRNA fluorescence in situ hybridization enabled SG detection and quantification. Furthermore, a ribopuromycylation assay was used to assess the cell translational status. To determine whether reactive oxygen species were involved in SG formation, their scavenging or production was induced by pharmacologic pretreatment in both SCC61 and SQ20B cells. RESULTS: Photon irradiation at different doses led to the formation of cytoplasmic foci that were positive for different SG markers. The presence of SGs gradually increased from 30 minutes to 2 hours postexposure in HeLa, SCC61, and Cal60 radiosensitive cells. In turn, the SQ20B and FaDu radioresistant cells did not form SGs. These results indicated a correlation between sensitivity to photon irradiation and SG formation. Moreover, SG formation was significantly reduced by reactive oxygen species scavenging using dimethyl sulfoxide in SCC61 cells, which supported their role in SG formation. However, a reciprocal experiment in SQ20B cells that depleted glutathione using buthionine sulfoximide did not restore SG formation in these cells. CONCLUSIONS: SGs are formed in response to irradiation in radiosensitive, but not in radioresistant, head and neck squamous cell carcinoma cells. Interestingly, compared with sodium arsenite-induced SGs, photon-induced SGs exhibited a different morphology and cellular localization. Moreover, photon-induced SGs were not associated with the inhibition of translation; rather, they depended on oxidative stress.

Definitive weekly hypofractionated radiotherapy in surgery-ineligible older adults with cutaneous squamous cell carcinoma of the head and neck region.

This study intends to address the impact of weekly hypofractionated radiation therapy with curative intent for cutaneous squamous cell carcinoma of the head and neck region in the elderly population.

Bromodomain-containing protein 4 inhibition improves the efficacy of cisplatin and radiotherapy in oral squamous cell carcinoma by suppressing programmed cell death-ligand 1 expression.

The bromodomain-containing protein 4 (BRD4) is highly expressed in oral squamous cell carcinoma (OSCC) and plays a crucial role in tumour progression. However, the impact of BRD4 on the efficacy of chemotherapy and radiotherapy by regulating the expression of programmed cell death-ligand 1 (PD-L1) in OSCC remains unclear. In this study, we found that the BRD4 inhibitor JQ1 effectively enhanced the inhibitory effects of cisplatin and radiotherapy on cell proliferation and promoted the apoptosis of OSCC cells by cisplatin and radiotherapy. Furthermore, treatment with JQ1 reversed the increase of the expression of PD-L1 by cisplatin and radiotherapy, whereas the overexpression of PD-L1 partially countered the beneficial effects of JQ1 on the anticancer efficacy of cisplatin and radiotherapy. These results demonstrate that the inhibition of BRD4 improves the anticancer effect of chemotherapy and radiotherapy by suppressing the expression of PD-L1 in OSCC, suggesting that targeting BRD4 could be a promising therapeutic approach for chemo/radioresistant OSCC.

Preclinical Evaluation of the ATR Inhibitor BAY 1895344 as a Radiosensitizer for Head and Neck Squamous Cell Carcinoma.

PURPOSE: Despite aggressive multimodal treatment that typically includes definitive or adjuvant radiation therapy (RT), locoregional recurrence rates approach 50% for patients with locally advanced human papillomavirus (HPV)-negative head and neck squamous cell carcinoma (HNSCC). Thus, more effective therapeutics are needed to improve patient outcomes. We evaluated the radiosensitizing effects of ataxia telangiectasia and RAD3-related (ATR) inhibitor (ATRi) BAY 1895344 in preclinical models of HNSCC. METHODS AND MATERIALS: Murine and human HPV-negative HNSCC cells (MOC2, MOC1, JHU-012) were treated with vehicle or ATRi with or without 4 Gy. Checkpoint kinase 1 phosphorylation and DNA damage (γH2AX) were evaluated by Western blot, and ATRi half-maximal inhibitory concentration was determined by MTT assay for HNSCC cells and immortalized murine oral keratinocytes. In vitro radiosensitization was tested by clonogenic assay. Cell cycle distribution and mitotic catastrophe were evaluated by flow cytometry. Mitotic aberrations were quantified by fluorescent microscopy. Tumor growth delay and survival were assessed in mice bearing MOC2 or JHU-012 transplant tumors treated with vehicle, ATRi, RT (10 Gy × 1 or 8 Gy × 3), or combined ATRi + RT. RESULTS: ATRi caused dose-dependent reduction in checkpoint kinase 1 phosphorylation at 1 hour post-RT (4 Gy) and dose-dependent increase in γH2AX at 18 hours post-RT. Addition of RT to ATRi led to decreased BAY 1895344 half-maximal inhibitory concentration in HNSCC cell lines but not in normal tissue surrogate immortalized murine oral keratinocytes. Clonogenic assays demonstrated radiosensitization in the HNSCC cell lines. ATRi abrogated the RT-induced G2/M checkpoint, leading to mitosis with unrepaired DNA damage and increased mitotic aberrations (multinucleated cells, micronuclei, nuclear buds, nucleoplasmic bridges). ATRi and RT significantly delayed tumor growth in MOC2 and JHU-012 in vivo models, with improved overall survival in the MOC2 model. CONCLUSIONS: These findings demonstrated that BAY 1895344 increased in vitro and in vivo radiosensitivity in HPV-negative HNSCC preclinical models, suggesting therapeutic potential warranting evaluation in clinical trials for patients with locally advanced or recurrent HPV-negative HNSCC.