DAZAP1 promotes OSCC progression via phase separation.

Oxygen consumption rate (OCR) and Extracellular acidification rate (ECAR) analysis in DAZAP1-overexpression and -knockdown Cal27 and HN6 cell lines.

CYTOR promotes DAZAP1 nuclear translocation and phase separation.

Alternative splicing of COX16 in OSCC cells.

DAZAP1 promotes OSCC cell migration, invasion and EMT progression.

Supplementary Materials and Methods

Targeting DAZAP1 suppresses tumor growth and metastasis in OSCC.

Detection of Dazap1 knockdown efficiency in 4MOSC2 cells after transduced by Tet-on lentivirus.

COX16 enhances invasion and mitochondrial respiration in OSCC cells.

The COX16 overexpression rescues the DAZAP1-knockdown induced phenotypes of OSCC cell lines.

Tumor invasion and metastasis are the underlying causes of high mortality rate due to oral squamous cell carcinoma (OSCC). Energy metabolism reprogramming has been identified as a crucial process mediating tumor metastasis, thus indicating an urgent need for an in-depth investigation of the specific mechanisms of tumor energy metabolism. Here, we identified an RNA-binding protein, DAZ-associated protein 1 (DAZAP1), as a tumor-promoting factor with an important role in OSCC progression. DAZAP1 was significantly upregulated in OSCC, which enhanced the migration and invasion of OSCC cells and induced the epithelial-mesenchymal transition (EMT). RNA sequencing analysis and experimental validation demonstrated that DAZAP1 regulates mitochondrial energy metabolism in OSCC. Mechanistically, DAZAP1 underwent liquid-liquid phase separation to accumulate in the nucleus where it enhanced cytochrome c oxidase 16 (COX16) expression by regulating pre-mRNA alternative splicing, thereby promoting OSCC invasion and mitochondrial respiration. In mouse OSCC models, loss of DAZAP1 suppressed EMT, downregulated COX16, and reduced tumor growth and metastasis. In samples from patients with OSCC, expression of DAZAP1 positively correlated with COX16 and a high expression of both proteins was associated with poor patient prognosis. Together, these findings revealed a mechanism by which DAZAP1 supports mitochondrial metabolism and tumor development of OSCC, suggesting the potential of therapeutic strategies targeting DAZAP1 to block OSCC invasion and metastasis. Significance: The RNA-binding protein DAZAP1 undergoes phase separation to enhance COX16 expression and mediate metabolic reprogramming that enables tumor metastasis, highlighting DAZAP1 as a potential metabolic target for cancer therapy.

OBJECTIVESTo investigate the role of oral microbiome in promoting oral squamous cell carcinoma (OSCC) development.MATERIALS AND METHODSWe investigated the salivary microbiome of 108 controls and 70 OSCC cases by16S rRNA gene sequencing and detected the fluorescence signal of OSCC-related pathological bacteria by fluorescence in situ hybridization assay (FISH). The invasion and migration assays were used to show the differences of invasive and migrative abilities between control and experimental groups. Quantitative real-time PCR and western blotting were used to verify the epithelial-to-mesenchymal transition (EMT).RESULTSIn our study, the overall microbiome abundance and composition were richer in the 108 controls than in the 70 OSCC cases. We demonstrated that Streptococcus, Capnocytophaga, Peptostreptococcus and Lactobacillus were highly abundant in the saliva of OSCC patients by 16S rDNA sequencing and FISH. Moreover, we found that Capnocytophaga gingivalis (C. gingivalis) was highly presented in OSCC tissues by FISH. We focused on C. gingivalis and found that its supernatant induced OSCC cells to undergo EMT, causing the cells to acquire a mesenchymal phenotype associated with highly invasive and metastatic properties.CONCLUSIONTaken together, these results indicated that C. gingivalis might invade OSCC tissues and played an important role in OSCC by promoting OSCC invasion and metastasis by inducing EMT. Hence, the role of C. gingivalis in cancer progression revealed a new direction for the research of OSCC.

Neutrophil extracellular traps (NETs) are reticular structures composed of neutrophil elastase (NE), cathepsin G (CG) and DNA-histone enzyme complexes. Accumulating evidence has revealed that NETs play important roles in tumor progression, metastasis, and thrombosis. However, our understanding of its clinical value and mechanism of action in oral squamous cell carcinoma (OSCC) is limited and has not yet been systematically described. Here, we aimed to investigate the clinical significance of NETs in OSCC and the mechanisms by which they affect its invasive and metastatic capacity. Our results demonstrated that high enrichment of NETs is associated with poor prognosis in OSCC, and mechanistic studies have shown that NE in NETs promotes invasion and metastasis via NLRP3-mediated inhibition of pyroptosis in OSCC. These findings may provide a new therapeutic approach for OSCC.

PURPOSE:Head and neck cancer is the sixth most common type of cancer worldwide, wherein the immune responses are closely associated with disease occurrence, development, and prognosis. Investigation of the role of immunogenic cell death-related genes (ICDGs) in adaptive immune response activation may provide cues into the mechanism underlying the outcome of HNSCC immunotherapy.METHODS:ICDGs expression patterns in HNSCC were analyzed, after which consensus clustering in HNSCC cohort conducted. A 4-gene prognostic model was constructed through LASSO and Cox regression analyses to analyze the prognostic index using the TCGA dataset, followed by validation with two GEO datasets. The distribution of immune cells and the response to immunotherapy were compared between different risk subtypes through multiple algorithms. Moreover, immunohistochemical (IHC) analyses were conducted to validate the prognostic value of HSP90AA1 as a predictor of HNSCC patient prognosis. In vitro assays were performed to further detect the effect of HSP90AA1 in the development of HNSCC.RESULTS:A novel prognostic index based on four ICDGs was constructed and proved to be useful as an independent factor of HNSCC prognosis. The risk score derived from this model grouped patients into high- and low-risk subtypes, wherein the high-risk subtype had worse survival outcomes and poorer immunotherapy response. IHC analysis validated the applicability of HSP90AA1 as a predictor of prognosis of HNSCC patients. HSP90AA1 expression in tumor cells promotes the progression of HNSCC.CONCLUSIONS:Together, these results highlight a novel four-gene prognostic signature as a valuable tool to assess survival status and prognosis of HNSCC patients.

Tertiary lymphoid structures (TLSs) are formed in long-term chronic inflammation, promoting the local recruitment of lymphocytes, antigen presentation and regulation of immune response, correlated with a better prognosis for cancer patients. Although studies have been conducted to explore methods that accelerate the establishment of TLSs, related research in head and neck squamous cell carcinoma (HNSCC) is still lacking. In this study, we analysed data from The Cancer Genome Atlas and performed immunohistochemical staining analyses of 188 patient samples. The results showed that TLSs promoted the infiltration of immune cells. Patients with TLSs with high infiltration of CD8+ cells showed the best prognosis. Since lymphotoxin α (LTα) was significantly increased in tissues with TLSs, we overexpressed LTα in SCC7 cells (a mouse-derived HNSCC cell line) and established tongue-tumour-bearing models. The polychromatic observation of tissue sections showed that T-cell aggregation increased in the LTα cell group, and a grade 1 TLS was formed on the 12th day after inoculating the cells. Moreover, the tumour volume in the LTα group was significantly less than that of the control group, whereas both the number and the proportion of infiltrated CD8+ T cells were increased. The peripheral CD8+ cells in mice were removed, and no difference was observed in tumour size or TLS formation. Remarkably, we found that TLS led to an increase in the antitumour effect by recruiting CD8+ T cells in HNSCC, showing a CD8+ T-cell-dependent antitumour effect. Moreover, LTα overexpression in the tumour promoted the formation of TLSs.

Oral squamous cell carcinoma (OSCC), the most common malignancy of the oral and maxillofacial region, severely affects human health. However, current treatments for OSCC commonly show only a ~60% 5-year survival rate of patients with distant metastases, indicating an urgent need for targeted treatments for patients with advanced metastases. Here, we report a survival-related long non-coding RNA, CYTOR, which is highly expressed in the lesions of oral cancer patients. We found that CYTOR can promote both migration and invasion in oral cancer cells as well as the epithelial–mesenchymal transition (EMT). RNA-sequencing of CYTOR-knockdown oral cancer cells revealed that CYTOR can regulate mitochondrial respiration and RNA splicing. Mechanistically, we found that nuclear-localized CYTOR interacts with HNRNPC, resulting in stabilization of ZEB1 mRNAs by inhibiting the nondegradative ubiquitination of HNRNPC. By synthesizing CYTOR-targeting small interfering RNAs (siRNAs) encapsulated in Nanoscale Metal Organic Frameworks (NMOFs), we demonstrate the targeted suppression of CYTOR to inhibit invasion and metastasis of oral cancer cells in a nude mouse model. Cumulatively, this study reveals the potential role of the CYTOR-HNRNPC-ZEB1 axis in regulating mitochondrial metabolism and glycolysis of oral cancer cells, and illustrates the effective use of lncRNA targeting in anti-metastatic cancer therapies.

Purpose: The identification of biomarkers and effective therapeutic targets for gastric cancer (GC), the most common cause of cancer-related deaths around the world, is currently a major focus in research. Here, we examined the utility of LHFPL6 as a prognostic biomarker and therapeutic target for GC. Methods: We explored the clinical relevance, function, and molecular role of LHFPL6 in GC using the MethSurv, cBioPortal, TIMER, Gene Expression Profiling Interactive Analysis, ONCOMINE, MEXPRESS, and EWAS Atlas databases. The GSE118919, GSE29272, and GSE13861 datasets were used for differential expression analysis. Using The Cancer Genome Atlas, we developed a Cox regression model and assessed the clinical significance of LHFPLs. In addition, we used the “CIBERSORT” algorithm to make reliable immune infiltration estimations. Western blot and immunohistochemistry were used to examine protein expression. Cell migration and invasion were assessed using transwell experiments. THP-1-derived macrophages and GC cells were co-cultured in order to model tumor–macrophage interactions in vitro. The levels of CD206 and CD163 were measured using immunofluorescence assays. The results were visualized with the “ggplot2” and “circlize” packages. Results: Our results showed that in GC, LHFPL6 overexpression was significantly associated with a poor prognosis. Our findings also suggested that LHFPL6 may be involved in the activation of the epithelial–mesenchymal transition. Furthermore, LHFPL6 expression showed a positive correlation with the abundance of M2 macrophages, which are potent immunosuppressors. Conclusion: LHFPL6 could be a prognostic biomarker and therapeutic target for GC.