Exosomal PD-L1 contributes to immunosuppression and is associated with anti-PD-1 response.

Tumour cells evade immune surveillance by upregulating the surface expression of programmed death-ligand 1 (PD-L1), which interacts with programmed death-1 (PD-1) receptor on T cells to elicit the immune checkpoint response1,2. Anti-PD-1 antibodies have shown remarkable promise in treating tumours, including metastatic melanoma2-4. However, the patient response rate is low4,5. A better understanding of PD-L1-mediated immune evasion is needed to predict patient response and improve treatment efficacy. Here we report that metastatic melanomas release extracellular vesicles, mostly in the form of exosomes, that carry PD-L1 on their surface. Stimulation with interferon-γ (IFN-γ) increases the amount of PD-L1 on these vesicles, which suppresses the function of CD8 T cells and facilitates tumour growth. In patients with metastatic melanoma, the level of circulating exosomal PD-L1 positively correlates with that of IFN-γ, and varies during the course of anti-PD-1 therapy. The magnitudes of the increase in circulating exosomal PD-L1 during early stages of treatment, as an indicator of the adaptive response of the tumour cells to T cell reinvigoration, stratifies clinical responders from non-responders. Our study unveils a mechanism by which tumour cells systemically suppress the immune system, and provides a rationale for the application of exosomal PD-L1 as a predictor for anti-PD-1 therapy.

BRAF V600E mutation mediates invasive and growth features in ameloblastoma.

OBJECTIVES: Ameloblastoma (AM), a locally aggressive tumor with extensive growth capacity, causes significant damage to the jaw and affects facial appearance. Although the high prevalence of BRAF V600E mutation in AM is known, its specific impacts on patients with AM remain unclear. Thus, the present study investigated the role of BRAF V600E mutation, thereby focusing on its impact on AM invasion and growth. MATERIALS AND METHODS: Immunohistochemical analysis was used to compare BRAF V600E, MMP2, MMP9, and Ki-67 expressions in AM (n = 49), normal oral mucosa (NOM) (n = 10), and odontogenic keratocyst (OKC) (n = 15) tissues. AM was further classified according to the presence or absence of BRAF V600E. The relationship between BRAF V600E and invasion as well as growth was evaluated. In addition, correlation analysis was performed using immunohistochemistry and confirmed via double-labeling immunofluorescence. Finally, comparative analyses using mass spectrometry, immunohistochemistry, and immunofluorescence were performed to explore and identify underlying mechanisms. RESULTS: AM exhibited a higher incidence of BRAF V600E mutation than NOM and OKC. BRAF V600E expression was positively correlated with the invasion-associated proteins MMP2 and MMP9 and the growth-related protein Ki-67. Proteomic data revealed that BRAF V600E primarily activates the MAPK signaling pathway in AM, particularly driving the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2). CONCLUSIONS: In summary, the findings suggested that the BRAF V600E mutation enhances the invasion and growth abilities of AM via the MAPK/ERK signaling pathway. Thus, targeting BRAF V600E or the MAPK/ERK pathway may be a potential AM therapy.

Single-cell RNA sequencing reveals tumor heterogeneity within salivary gland pleomorphic adenoma: A preliminary study.

BACKGROUND: Salivary gland pleomorphic adenoma (SPA) is a common neoplasm of salivary glands that displays remarkable histological diversity. Previous studies have demonstrated the involvement of gene rearrangements and cytoskeleton-remodeling-related myoepithelial cells in SPA tumorigenesis. Cytoskeleton remodeling is necessary for epithelial-mesenchymal transition (EMT), a key process in tumor progression. However, the heterogeneity of tumor cells and cytoskeleton remodeling in SPA has not been extensively investigated. METHODS: An analysis of single-cell RNA sequencing (scRNA-seq) was performed on 27 810 cells from two donors with SPA. Bioinformatic tools were used to assess differentially expressed genes, cell trajectories, and intercellular communications. Immunohistochemistry and double immunofluorescence staining were used to demonstrate FOXC1 and MYLK expression in SPA tissues. RESULTS: Our analysis revealed five distinct cell subtypes within the tumor cells of SPA, indicating a high level of intra-lesional heterogeneity. Cytoskeleton-remodeling-related genes were highly enriched in subtype 3 of the tumor cells, which showed a close interaction with mesenchymal cells. We found that tumoral FOXC1 expression was closely related to MYLK expression in the tumor cells of SPA. CONCLUSION: Tumor cells enriched with cytoskeleton-remodeling-related genes play a crucial role in SPA development, and FOXC1 may partially regulate this process.

Single-cell analysis reveals immune cellular components in odontogenic keratocysts.

OBJECTIVES: Various types of cells comprising a complex and diverse cell population are required for the biological activities of odontogenic keratocyst (OKC). Immune and non-immune cells collaborate via cytokine- or chemokine-mediated communication and direct cell-cell interactions. This study aimed to characterize the immune ecosystem and understand the potential chemotactic role of OKC fibroblasts in immune cell migration. MATERIALS AND METHODS: Mass cytometry of 41 markers was employed for the classification of OKC cells from six OKC samples. Immunofluorescence staining and single-cell RNA sequencing (GSE176351) were used for the detection of fibroblast subpopulations. Enzyme-linked immunosorbent assay and immunofluorescence staining were employed for chemokine detection in hypoxia- and/or HIF-1α inhibitor-treated OKC fibroblasts and tissues. Chemotaxis assay was employed to determine the chemotactic effect of fibroblasts via co-culture with peripheral blood mononuclear cells. A cell communication network was constructed based on the single-cell RNA sequencing data. RESULTS: The characterization of the immune cell types of OKC evidenced the enrichment of macrophages, neutrophils and B cells. The majority (41.5%) of fibroblast subsets consisted of chemokine ligand-enriched myofibroblasts. The activation of the HIF-1α signaling pathway in fibroblasts was associated with chemokine release. The chemokines released by OKC fibroblasts remarkably promoted the migration of peripheral blood mononuclear cells in the co-culture system. Close interactions between myofibroblasts and immune cells were validated by cell-cell interaction analysis. Increased RANKL expression was detected in OKC fibroblasts in the co-culture system with peripheral blood mononuclear cells. CONCLUSIONS: Our results provided deep insights into the immune ecosystem and highlighted the potential chemotactic effects of chemokine-enriched myofibroblasts within OKCs. The close interaction between immune cells and fibroblasts demonstrated in this study may be responsible for the osteoclastogenic effects of OKC fibroblasts.

Identification of Immune Infiltration in Odontogenic Keratocyst by Integrated Bioinformatics Analysis.

BACKGROUND: Odontogenic keratocyst (OKC) is a relatively common odontogenic lesion characterized by local invasion in the maxillary and mandibular bones. In the pathological tissue slices of OKC, immune cell infiltrations are frequently observed. However, the immune cell profile and the molecular mechanism for immune cell infiltration of OKC are still unclear. We aimed to explore the immune cell profile of OKC and to explore the potential pathogenesis for immune cell infiltration in OKC. METHODS: The microarray dataset GSE38494 including OKC and oral mucosa (OM) samples were obtained from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) in OKC were analyzed by R software. The hub genes of OKC were performed by protein-protein interaction (PPI) network. The differential immune cell infiltration and the potential relationship between immune cell infiltration and the hub genes were performed by single-sample gene set enrichment analysis (ssGSEA). The expression of COL1A1 and COL1A3 were confirmed by immunofluorescence and immunohistochemistry in 17 OKC and 8 OM samples. RESULTS: We detected a total of 402 differentially expressed genes (DEGs), of which 247 were upregulated and 155 were downregulated. DEGs were mainly involved in collagen-containing extracellular matrix pathways, external encapsulating structure organization, and extracellular structure organization. We identified ten hub genes, namely FN1, COL1A1, COL3A1, COL1A2, BGN, POSTN, SPARC, FBN1, COL5A1, and COL5A2. A significant difference was observed in the abundances of eight types of infiltrating immune cells between the OM and OKC groups. Both COL1A1 and COL3A1 exhibited a significant positive correlation with natural killer T cells and memory B cells. Simultaneously, they demonstrated a significant negative correlation with CD56dim natural killer cells, neutrophils, immature dendritic cells, and activated dendritic cells. Immunohistochemistry analysis showed that COL1A1 (P = 0.0131) and COL1A3 (P < 0.001) were significantly elevated in OKC compared with OM. CONCLUSIONS: Our findings provide insights into the pathogenesis of OKC and illuminate the immune microenvironment within these lesions. The key genes, including COL1A1 and COL1A3, may significantly impact the biological processes associated with OKC.

Salivary non-apoptotic tumoral microvesicles: A potential progressive marker in oral cancer patients.

Tumour cell-secreted microvesicles (MVs) contribute immensely to tumour progression. However, the role of tumoral salivary MVs in oral squamous cell carcinoma (OSCC) remains unclear. Herein, we elucidated the role of non-apoptotic salivary tumoral MVs in OSCC development, especially relating to the migration ability. We purified and compared non-apoptotic salivary tumoral MVs from 63 OSCC patients and orthotopic OSCC mice model. Next, we compared the protein difference between apoptotic and non-apoptotic MVs by Western blot, proteomics and flow cytometry from saliva and CAL27 cells. Finally, we collected the non-apoptotic MVs and co-cultured with normal oral epithelial cells, the migration ability was examined by wound healing assay and Western blot assay. Our results indicated that the levels of non-apoptotic tumoral S-MVs were significantly higher in OSCC patients with T3 to T4 stages than in patients with T1 to T2 stages or healthy donors. In OSCC mice model, we found elevations of non-apoptotic tumoral MVs associated with tumoral volume. EGFR overexpression increased the generation of non-apoptotic tumoral MVs which could significantly promote normal epithelial cell migration. In conclusion, elevated levels of non-apoptotic tumoral S-MVs are associated with clinicopathologic features of OSCC patients, implying that non-apoptotic tumoral S-MVs are a potential progressive marker of OSCC.

ENO1 Binds to ApoC3 and Impairs the Proliferation of T Cells via IL-8/STAT3 Pathway in OSCC.

Lymph node metastasis is associated with poor prognosis of oral squamous cell carcinoma (OSCC), and few studies have explored the relevance of postoperative lymphatic drainage (PLD) in metastatic OSCC. Alpha-enolase (ENO1) is a metabolic enzyme, which is related to lymphatic metastasis of OSCC. However, the role of ENO1 in PLD in metastatic OSCC has not been elucidated. Herein, we collected lymphatic drainage after lymphadenectomy between metastatic and non-metastatic lymph nodes in OSCC patients to investigate the relationship between ENO1 expression and metastasis, and to identify the proteins which interacted with ENO1 in PLD of patients with metastatic OSCC by MS/GST pulldown assay. Results revealed that the metabolic protein apolipoprotein C-III (ApoC3) was a novel partner of ENO1. The ENO1 bound to ApoC3 in OSCC cells and elicited the production of interleukin (IL)-8, as demonstrated through a cytokine antibody assay. We also studied the function of IL-8 on Jurkat T cells co-cultured with OSCC cells in vitro. Western blot analysis was applied to quantitate STAT3 (signal transducer and activator of transcription 3) and p-STAT3 levels. Mechanistically, OSCC cells activated the STAT3 signaling pathway on Jurkat T cells through IL-8 secretion, promoted apoptosis, and inhibited the proliferation of Jurkat T cells. Collectively, these findings illuminate the molecular mechanisms underlying the function of ENO1 in metastasis OSCC and provide new strategies for targeting ENO1 for OSCC treatment.

Increased salivary microvesicles are associated with the prognosis of patients with oral squamous cell carcinoma.

Microvesicles (MVs), which are cell-derived membrane vesicles present in body fluids, are closely associated with the development of malignant tumours. Saliva, one of the most versatile body fluids, is an important source of MVs. However, the association between salivary MVs (SMVs) and oral squamous cell carcinoma (OSCC), which is directly immersed in the salivary milieu, remains unclear. SMVs from 65 patients with OSCC, 21 patients with oral ulcer (OU), and 42 healthy donors were purified, quantified and analysed for their correlations with the clinicopathologic features and prognosis of OSCC patients. The results showed that the level of SMVs was significantly elevated in patients with OSCC compared to healthy donors and OU patients. Meanwhile, the level of SMVs showed close correlations with the lymph node status, and the clinical stage of OSCC patients. Additionally, the ratio of apoptotic to non-apoptotic SMVs was significantly decreased in OSCC patients with higher pathological grade. Consistently, poorer overall survival was observed in patients with lower ratio of apoptotic to non-apoptotic SMVs. In conclusion, the elevated level of SMVs is associated with clinicopathologic features and decreased survival in patients with OSCC, suggesting that SMVs are a potential biomarker and/or regulator of the malignant progression of OSCC.

Treatment of Multiple Odontogenic Keratocysts Involving Chinese Patients.

PURPOSE: The optimal treatment of odontogenic keratocysts (OKCs) remains a matter of debate in reported studies. The present study aimed to estimate the postoperative recurrence rates of multiple OKCs (MOKCs) in Chinese patients. MATERIALS AND METHODS: A retrospective cohort study of histologically confirmed MOKCs treated from 2003 to 2017 using enucleation, marsupialization alone, enucleation and peripheral ostectomy, or marsupialization followed by secondary enucleation was performed. Patients with MOKCs who had undergone follow-up for 12 or more months with panoramic radiographs and radiographs of the chest and skull available from the first visit and had been treated by the same team using the same treatment protocol were included in the study. Patients were excluded if the lesion had been treated previously, they had a solitary OKC, or their medical records were not available for review. The treatment methods, recurrence rate, and interval to recurrence were evaluated. The Kaplan-Meier method was used to estimate the survival rate and median time to recurrence. Univariate analysis was used to identify the risk factors associated with recurrence. Significant differences were determined at an α level of 5%. RESULTS: The sample included 81 patients with MOKCs; 21 (25.6%) were male and 60 (74.07%) were female. The age range was 7 to 63 years (mean ± standard deviation, 18.4 ± 4). The overall recurrence rate was 26.63%, with an overall recurrence-free interval of 26.85 months. The average length of follow-up was 55.68 months. No association was found between the treatment method used and the risk of recurrence (P = .178). Although the interval to recurrence was not affected by any of the study variables, the average interval to the recurrence of MOKCs involving the maxilla was short compared with that of MOKCs involving the mandible. CONCLUSIONS: The surgical treatment method did not influence the risk of recurrence in patients with MOKCs, and the interval to recurrence was not associated with any of the study variables.

Overexpression of Fra-1, c-Jun and c-Fos in odontogenic keratocysts: potential correlation with proliferative and anti-apoptotic activity.

AIMS: The purpose of this study was to explore the potential involvement of Fra-1, c-Jun and c-Fos, three vital members of the AP-1 complex, in the pathogenesis of odontogenic keratocysts (OKCs). METHODS AND RESULTS: Tissue samples, containing 10 normal oral mucosa (OM), 10 dentigerous cysts (DC) and 32 OKC specimens, were applied to investigate the expression levels of Fra-1, c-Jun and c-Fos by immunohistochemistry and real-time-quantitative polymerase chain reaction (RT-qPCR). The association between Fra-1, c-Jun and c-Fos expression levels and markers of proliferation [Ki-67, proliferating cell nuclear antigen (PCNA)], anti-apoptosis (Bcl-2) was then investigated in the OKC serial tissue sections. The results showed that Fra-1, c-Jun and c-Fos expression levels were increased significantly in OKCs compared to these in OM and DC tissue samples. Meanwhile, the expression levels of Fra-1, c-Jun and c-Fos were associated positively with the expression levels of Ki-67, PCNA and Bcl-2, as confirmed further by double-labelling immunofluorescence analysis and hierarchical analysis. CONCLUSIONS: This study revealed for the first time that Fra-1, c-Jun and c-Fos were overexpressed in OKCs and had a close correlation with proliferation and anti-apoptosis potential of OKCs.

Three-Dimensional Printed Plate-Guided 125I Brachytherapy for Malignant Parotid Tumors.

PURPOSE: The treatment of malignant parotid tumors with 125I brachytherapy is rarely reported. This study evaluated the efficacy and dose and response of 125I brachytherapy in patients with malignant tumors. MATERIALS AND METHODS: From July 2014 through August 2017, 39 patients with malignant parotid tumors were treated with 125I brachytherapy. Thirty-five patients were treated with conservative surgical resection before brachytherapy. Four patients were treated with brachytherapy alone. Clinical outcomes and side effects were evaluated. Clinical factors were investigated to determine correlations with local control (LC) and side effects. RESULTS: Mean follow-up was 25 months (range, 7 to 47 months). The LC rate was 87.2% and the overall survival rate was 97.4%. High tumor grade and large tumor showed a propensity for local recurrence. Acute skin toxicity occurred in 87.2% of patients and grade 3 and 4 radioepidermitis was found in 20.5% of patients. In total, 89.7% of patients with facial nerve dysfunction recovered within 12 months. CONCLUSIONS: 125I brachytherapy was a feasible treatment option for patients with malignant parotid tumors. Although side effects were minimal, strict follow-up was necessary for patients treated with a high dose.

Secondary reconstruction for mandibular osteoradionecrosis defect with fibula osteomyocutaneous flap flowthrough from radial forearm flap using stereolithographic 3-dimensional printing modeling technology.

Osteoradionecrosis (ORN) is one of the most serious complications of oral and nasopharyngeal malignant neoplasms after radiotherapy. The incidence of mandibular ORN is significantly higher than that of maxilla. A radical surgical intervention such as mandibulectomy for advanced ORN is appropriate and effective to relieve pain and control infection. However, recovery of functionality and aesthetics is usually not the primary purpose of the one-stage radical surgery. Some patients often need a 2-stage operation owing to the bone defect, scar contracture, or recurrence. Although free flap has been proven as a reliable way to repair the complex maxillofacial defects, it is still a great challenge for surgeons to reconstruct the secondary complex mandibular ORN defects. Here, we report a case of secondary composite mandibular ORN reconstruction using the preoperative 3-dimensional biomodel planning and flowthrough radial forearm flap for free fibula osteocutaneous flap.

Proteomics study of bone tissue around ameloblastoma and the potential mechanism of CD36 in bone remodelling.

Ameloblastoma (AM) is characterised by local aggressiveness and bone resorption. To our knowledge, the proteomic profile of bone adjacent to AM has not previously been explored. We therefore looked at the differential proteins in cancellous bone (CB) adjacent to AM and normal CB from the mandible. CB proteins were extracted, purified, quantified, and analysed by liquid chromatography-mass spectrometry (LC-MS) using samples from five patients with AM. These proteins were further investigated using gene ontology for additional functional annotation and enrichment. Proteins that met the screening requirements of expression difference ploidy > 1.5-fold (upregulation and downregulation) and p < 0.05 were subsequently deemed differential proteins. Immunohistochemical staining was performed to confirm the above findings. Compared with normal mandibular CB, 151 differential proteins were identified in CB adjacent to the mandibular AM. These were mainly linked to cellular catabolic processes, lipid metabolism, and fatty acids (FA) metabolism. LC-MS and immunohistochemistry showed that CD36 was one of the notably decreased proteins in CB bordering the AM compared with normal mandibular CB (p = 0.0066 and p = 0.0095, respectively). CD36 expression in CB correlates with bone remodelling in AM, making CD36 a viable target for therapeutic approaches.

Proteomic profile of tissue-derived extracellular vesicles from benign odontogenic lesions.

BACKGROUND: Benign odontogenic lesions (BOLs) can cause severe jaw bone defects and compromise the quality of life of patients. Extracellular vesicles (EVs) are well-established and versatile players in mediating pathophysiological events. EVs in the interstitial space (tissue-derived EVs or Ti-EVs) possess higher specificity and sensitivity in disease-related biomarker discovery. However, the role of Ti-EV-loaded proteins in mediating the development of BOLs has remained untapped. Herein, we aim to explore the contribution of Ti-EV-loaded proteins to the development of BOLs. METHODS: Samples were obtained from 3 with dental follicle, 3 with dentigerous cyst (DC), 7 with odontogenic keratocyst (OKC), and 3 patients with ameloblastoma (AM). Tissue-derived EVs were then extracted, purified, and validated using ultracentrifugation, transmission electron microscopy, and western blotting. Proteins from Ti-EVs were analyzed using LC-ESI tandem mass spectroscopy and differentially expressed proteins were screened, which was then validated by immunohistochemistry and immunofluorescence assays. RESULTS: The protein profile of Ti-EVs in each group was mapped by LC-MS analysis. The top 10 abundant proteins in BOL-derived Ti-EVs were COL6A3, COL6A1, ALB, HIST1H4A, HBB, ACTB, HIST1H2BD, ANXA2, COL6A2 and FBN1. Additionally, unique proteins in the Ti-EVs from various lesions were identified. Moreover, focal adhesion kinase (FAK) and myeloid differentiation primary response 88 (MyD88) showed higher expressions in Ti-EVs derived from OKC and AM, which were confirmed by immunohistochemistry and immunofluorescence staining. CONCLUSIONS: Ti-EVs containing FAK and MyD88 might be related to the development of OKC and AM, which can be potential therapeutic targets.

Application of PRI-E-a combined learning method in oral and maxillofacial oncology education.

The traditional lecture-based learning (LBL) method is facing great challenges due to its low efficiency and single proceeding form. We designed a PRI-E learning mode that combined and modified problem-based, case-based, and evidence-based learning with a step-by-step approach. We evaluated the practical learning outcomes of using the PRI-E mode by comparing it with traditional lecture-based learning in oral and maxillofacial oncology education. "PRI-E" consists of the first letters of the English words Passion, Research, Innovation, and Education, and it means "the best Education". This prospective randomized controlled trial included 40 participants. We evenly divided the participants into the PRI-E (n = 20) and LBL group (n = 20) based on the entrance test scores. The same staff group designed and then taught the learning content with different group measures. The evaluation included the final test scores and questionnaire assessments. Without affecting the examination results, the PRI-E teaching method was more satisfactory and popular with participants in terms of ability development and classroom participation. Enacting the PRI-E teaching method required more time, but this did not affect its popularity among the participants. Compared with the LBL learning mode, the PRI-E learning mode was more organized and efficient in oral and maxillofacial oncology education without affecting academic performance. This model has a high degree of satisfaction, which is conducive to training students' comprehensive ability.

Advances in CAR-T Cell Therapy in Head and Neck Squamous Cell Carcinoma.

Surgery with the assistance of conventional radiotherapy, chemotherapy and immunotherapy is the basis for head and neck squamous cell carcinoma (HNSCC) treatment. However, with these treatment modalities, the recurrence and metastasis of tumors remain at a high level. Increasingly, the evidence indicates an excellent anti-tumor effect of chimeric antigen receptor T (CAR-T) cells in hematological malignancy treatment, and this novel immunotherapy has attracted researchers' attention in HNSCC treatment. Although several clinical trials have been conducted, the weak anti-tumor effect and the side effects of CAR-T cell therapy against HNSCC are barriers to clinical translation. The limited choices of targeting proteins, the barriers of CAR-T cell infiltration into targeted tumors and short survival time in vivo should be solved. In this review, we introduce barriers of CAR-T cell therapy in HNSCC. The limitations and current promising strategies to overcome barriers in solid tumors, as well as the applications for HNSCC treatment, are covered. The perspectives of CAR-T cell therapy in future HNSCC treatment are also discussed.

Prognostic Value of CAV1 and CAV2 in Head and Neck Squamous Cell Carcinoma.

BACKGROUND: The CAV family, especially CAV1 and CAV2, is significantly associated with tumor development. In this study, we aimed to explore the pathogenic and prognostic roles of CAV1 and CAV2 in head and neck squamous cell carcinoma (HNSCC) through bioinformatic analysis and verified in human tissue. METHODS: We analyzed expression profiles of CAV1 and CAV2 in HNSCC and in normal tissues via data from The Cancer Genome Altas. Prognostic significance was examined by Kaplan-Meier survival curve obtained from the Xena browser together with Cox regression analysis. Co-expressed genes were uploaded to GeneMANIA and applied to Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses, showing interaction networks. Signaling pathways of CAV1 and CAV2 in HNSCC were analyzed by Gene Set Enrichment Analysis to elucidate potential regulatory mechanisms. Gene-drug interaction network was explored via Comparative Toxicogenomics Database. Immunohistochemistry was performed to verify theoretical results. RESULTS: Compared with normal tissues, expression levels of CAV1 and CAV2 were remarkably higher in HNSCC (p < 0.0001), which independently implies poor OS (CAV1: HR: 1.146, p = 0.027; CAV2: HR: 1.408, p = 0.002). Co-expressed genes (PXN, ITGA3, TES, and MET) were identified and analyzed by FunRich with CAV1 and CAV2, revealing a significant correlation with focal adhesion (p < 0.001), which has a vital influence on cancer progression. GSEA also showed cellular protein catabolic process (ES = 0.42) and proteasome complex (ES = 0.72), which is a key degradation system for proteins involved in oxidatively damaging and cell cycle and transcription, closely correlated with high expression of CAV2 in HNSCC. More importantly, we found the relationship between different immune cell infiltration degrees in the immune micro-environment in HNSCC and expression levels of CAV1/CAV2 (p < 0.0001). Gene-drug interaction network was checked via CTD. Moreover, tissue microarrays verified higher expression levels of CAV1/CAV2 in HNSCC (p < 0.0001), and the high expression subgroup indicated significantly poorer clinical outcomes (p < 0.05). CONCLUSIONS: The results revealed that CAV1 and CAV2 are typically upregulated in HNSCC and might predict poor prognosis.

Development and validation of a novel hypoxia-related signature for prognostic and immunogenic evaluation in head and neck squamous cell carcinoma.

Hypoxia plays a critical role in head and neck squamous cell carcinoma (HNSCC) prognosis. However, till now, robust and reliable hypoxia-related prognostic signatures have not been established for an accurate prognostic evaluation in HNSCC patients. This article focused on establishing a risk score model to evaluate the prognosis and guide treatment for HNSCC patients. RNA-seq data and clinical information of 502 HNSCC patients and 44 normal samples were downloaded from The Cancer Genome Atlas (TCGA) database. 433 samples from three Gene Expression Omnibus (GEO) datasets were incorporated as an external validation cohort. In the training cohort, prognostic-related genes were screened and LASSO regression analyses were performed for signature establishment. A scoring system based on SRPX, PGK1, STG1, HS3ST1, CDKN1B, and HK1 showed an excellent prediction capacity for an overall prognosis for HNSCC patients. Patients were divided into high- and low-risk groups, and the survival status of the two groups exhibited a statistically significant difference. Subsequently, gene set enrichment analysis (GSEA) was carried out to explore the underlying mechanisms for the prognosis differences between the high- and low-risk groups. The tumor immune microenvironment was evaluated by CIBERSORT, ESTIMATE, TIDE, and xCell algorithm, etc. Then, we explored the relationships between this prognostic model and the levels of immune checkpoint-related genes. Cox regression analysis and nomogram plot indicated the scoring system was an independent predictor for HNSCC. Moreover, a comparison of predictive capability has been made between the present signature and existing prognostic signatures for HNSCC patients. Finally, we detected the expression levels of proteins encoded by six-HRGs via immunohistochemical analysis in tissue microarray. Collectively, a novel integrated signature considering both HRGs and clinicopathological parameters will serve as a prospective candidate for the prognostic evaluation of HNSCC patients.