PA28γ induces dendritic cell maturation and activates T-cell immune responses in oral lichen planus.

Oral lichen planus (OLP) is a common chronic inflammatory disease of the oral mucosa, the mechanism of its inflammatory progression has not yet been fully elucidated. PA28γ plays a significant role in a variety of immune-related diseases. However, the exact role of PA28γ in the pathogenesis of OLP remains unclear. Here, we demonstrated that PA28γ is overexpressed in epithelial cells and inflammatory cells of OLP tissues but has no significant relationship with OLP subtypes. Functionally, keratinocytes with high PA28γ expression could induce dendritic cell (DC) maturation and promote the T-cell differentiation into Th1 cells in response to the immune response. In addition, we found that a high level of PA28γ expression is associated with high numbers of infiltrating mature DCs and activated T-cells in OLP tissues. Mechanistically, keratinocytes with high PA28γ expression could promote the secretion of C-C motif chemokine (CCL)5, blocking CCL5 or/and its receptor CD44 could inhibit the induction of T-cell differentiation by keratinocytes with high PA28γ expression. In conclusion, we reveal that keratinocytes with high expression of PA28γ in OLP can induce DC maturation and promote T-cell differentiation through the CCL5-CD44 pathway, providing previously unidentified mechanistic insights into the mechanism of inflammatory progression in OLP.

DRP1 inhibition-mediated mitochondrial elongation abolishes cancer stemness, enhances glutaminolysis, and drives ferroptosis in oral squamous cell carcinoma.

BACKGROUND: Mitochondrial dynamics play a fundamental role in determining stem cell fate. However, the underlying mechanisms of mitochondrial dynamics in the stemness acquisition of cancer cells are incompletely understood. METHODS: Metabolomic profiling of cells were analyzed by MS/MS. The genomic distribution of H3K27me3 was measured by CUT&Tag. Oral squamous cell carcinoma (OSCC) cells depended on glucose or glutamine fueling TCA cycle were monitored by 13C-isotope tracing. Organoids and tumors from patients and mice were treated with DRP1 inhibitors mdivi-1, ferroptosis inducer erastin, or combination with mdivi-1 and erastin to evaluate treatment effects. RESULTS: Mitochondria of OSCC stem cells own fragment mitochondrial network and DRP1 is required for maintenance of their globular morphology. Imbalanced mitochondrial dynamics induced by DRP1 knockdown suppressed stemness of OSCC cells. Elongated mitochondria increased α-ketoglutarate levels and enhanced glutaminolysis to fuel the TCA cycle by increasing glutamine transporter ASCT2 expression. α-KG promoted the demethylation of histone H3K27me3, resulting in downregulation of SNAI2 associated with stemness and EMT. Significantly, suppressing DRP1 enhanced the anticancer effects of ferroptosis. CONCLUSION: Our study reveals a novel mechanism underlying mitochondrial dynamics mediated cancer stemness acquisition and highlights the therapeutic potential of mitochondria elongation to increase the susceptibility of cancer cells to ferroptosis.

Acetyl-11-keto-beta-boswellic acid inhibits cell proliferation and growth of oral squamous cell carcinoma via RAB7B-mediated autophagy.

Natural products can overcome the limitations of conventional chemotherapy. Acetyl-11-keto-beta-boswellic acid (AKBA) as a natural product extracted from frankincense, exhibited chemotherapeutic activities in different cancers. However, whether AKBA exerts inhibiting effect of oral squamous cell carcinoma (OSCC) cells growth and the mechanism need to be explored. We attempted to investigate the therapeutic effects of AKBA against OSCC and explore the mechanism involved. Here we attempt to disclose the cell-killing effect of AKBA on OSCC cell lines and try to figure out the specifical pathway. The presence of increase autophagosome and the production of mitochondrial reactive oxygen species were confirmed after the application of AKBA on OSCC cells, and RAB7B inhibition enhanced autophagosome accumulation. Though the increase autophagosome was detected induced by AKBA, autophagic flux was inhibited as the failure fusion of autophagosome and lysosome. Cal27 xenografts were established to verify the role of anti-OSCC cells of AKBA in vivo. Based above findings, we speculate that natural product AKBA suppresses OSCC cells growth via RAB7B-mediated autophagy and may serve as a promising strategy for the therapy of OSCC.

Loss of PA28γ exacerbates imbalanced differentiation of bone marrow stromal cells during bone formation and bone healing in mice.

Proteasome activator subunit 3 (PA28γ) is a member of the proteasome activator family, which mainly regulates the degradation and stability of proteins. Studies have shown that it plays crucial roles in lipid formation, stemness maintenance, and blood vessel formation. However, few studies have clarified the association between PA28γ and bone diseases. Herein, we identified PA28γ as a previously unknown regulator of bone homeostasis that coordinates bone formation and lipid accumulation. PA28γ-knockout mice presented with the characteristics of low bone mass and accumulation of lipids. Suppressed expression of PA28γ restrained the osteogenic differentiation and enhanced the adipogenic differentiation of bone marrow stromal cells (BMSCs). Overexpression of PA28γ promoted osteogenic differentiation and inhibited adipogenic differentiation of BMSCs. Mechanistically, PA28γ interacted with Wnt5α, and the two interactors appeared to be positively correlated. PA28γ mainly activated the downstream Wnt/ß-catenin signaling pathway, which affects BMSCs differentiation homeostasis. Deletion of Wnt5α significantly delayed the promotion of osteogenic differentiation and partially alleviated the inhibitory effect of adipogenic differentiation of BMSCs in the PA28γ-overexpressing group. Furthermore, we demonstrated that PA28γ-knockout mice had an inhibited rate of bone healing in a drill-hole femoral bone defect model in vivo. Therefore, our results confirm the effects of PA28γ on bone formation and bone defect repair, indicating that PA28γ mainly interacts with Wnt5α to activate the Wnt/ß-catenin signaling pathway regulating BMSCs differentiation homeostasis. Our results reveal the function of PA28γ in bone diseases and provide a new theoretical basis for expanding the treatment of bone diseases.

Thioredoxin (Trx): A redox target and modulator of cellular senescence and aging-related diseases.

Thioredoxin (Trx) is a compact redox-regulatory protein that modulates cellular redox state by reducing oxidized proteins. Trx exhibits dual functionality as an antioxidant and a cofactor for diverse enzymes and transcription factors, thereby exerting influence over their activity and function. Trx has emerged as a pivotal biomarker for various diseases, particularly those associated with oxidative stress, inflammation, and aging. Recent clinical investigations have underscored the significance of Trx in disease diagnosis, treatment, and mechanistic elucidation. Despite its paramount importance, the intricate interplay between Trx and cellular senescence-a condition characterized by irreversible growth arrest induced by multiple aging stimuli-remains inadequately understood. In this review, our objective is to present a comprehensive and up-to-date overview of the structure and function of Trx, its involvement in redox signaling pathways and cellular senescence, its association with aging and age-related diseases, as well as its potential as a therapeutic target. Our review aims to elucidate the novel and extensive role of Trx in senescence while highlighting its implications for aging and age-related diseases.

Emerging roles of circular RNAs in the invasion and metastasis of head and neck cancer: Possible functions and mechanisms.

Head and neck cancer (HNC) is the seventh most prevalent malignancy worldwide in 2020. Cancer metastasis is the main cause of poor prognosis in HNC patients. Recently, circular RNAs (circRNAs), initially thought to have no biological function, are attracting increasing attention, and their crucial roles in mediating HNC metastasis are being extensively investigated. Existing studies have shown that circRNAs primarily function through miRNA sponges, transcriptional regulation, interacting with RNA-binding proteins (RBPs) and as translation templates. Among these functions, the function of miRNA sponge is the most prominent. In this review, we summarized the reported circRNAs involved in HNC metastasis, aiming to elucidate the regulatory relationship between circRNAs and HNC metastasis. Furthermore, we summarized the latest advances in the epidemiological information of HNC metastasis and the tumor metastasis theories, the biogenesis, characterization and functional mechanisms of circRNAs, and their potential clinical applications. Although the research on circRNAs is still in its infancy, circRNAs are expected to serve as prognostic markers and effective therapeutic targets to inhibit HNC metastasis and significantly improve the prognosis of HNC patients.

Natural product piperlongumine inhibits proliferation of oral squamous carcinoma cells by inducing ferroptosis and inhibiting intracellular antioxidant capacity.

Background: As a new form of cell death, ferroptosis has been shown to have inhibitory effects on a variety of tumor cells except oral squamous cell carcinoma (OSCC). There were few investigations on the effects and molecular mechanisms of piperlongumine (PL, a ferroptosis inducer) and CB-839 (a GLS1 inhibitor which promotes ferroptosis) on OSCC cells. This article assesses the anticancer effect and mechanism of PL as well as combined with CB-839. Methods: OSCC cells were treated with specified concentration of PL alone or with ferroptosis inhibitor Ferrostatin-1 (Fer-1) and antioxidant N-Acetylcysteine (NAC) to assess their effects on biological characteristics such as cell proliferation, cell death and intracellular ferroptosis related pathways. Also, cells were treated with PL combined with CB-839 to evaluate the synergistic effect of CB-839 on PL's anticancer effects. Results: The results showed that the proliferation rate of PL-treated OSCC cells were decreased in a dose- and time-dependent manner. PL can induce OSCC cells apoptosis. Lipid peroxidation (LPO) and intracellular reactive oxygen species (ROS) were accumulated after PL treatment. We found some protein changes significantly such as the expression of DMT1 increased, and the expression of FTH1, SLC7A11 and GPX4 decreased. In addition, the anti-proliferation effect of PL can be reversed by Fer-1 and NAC and the level of LPO and ROS was decreased accordingly. Importantly, we found that PL and CB-839 in combination could decrease the cell viability and the LPO level synergistically, accompanied by a large consumption of glutathione (GSH). These evidences prove that PL can induce ferroptosis of OSCC cells, which can be enhanced by CB-839. Conclusions: Our study suggested that the nature product PL can induce the ferroptotic death of OSCC cells, which is further enhanced when combined with CB-839. The synergistic anticancer effect of these two may prove new strategy for OSCC treatment.

Extracellular vesicles modulate key signalling pathways in refractory wound healing.

Chronic wounds are wounds that cannot heal properly due to various factors, such as underlying diseases, infection or reinjury, and improper healing of skin wounds and ulcers can cause a serious economic burden. Numerous studies have shown that extracellular vesicles (EVs) derived from stem/progenitor cells promote wound healing, reduce scar formation and have significant advantages over traditional treatment methods. EVs are membranous particles that carry various bioactive molecules from their cellular origins, such as cytokines, nucleic acids, enzymes, lipids and proteins. EVs can mediate cell-to-cell communication and modulate various physiological processes, such as cell differentiation, angiogenesis, immune response and tissue remodelling. In this review, we summarize the recent advances in EV-based wound healing, focusing on the signalling pathways that are regulated by EVs and their cargos. We discuss how EVs derived from different types of stem/progenitor cells can promote wound healing and reduce scar formation by modulating the Wnt/ß-catenin, phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin, vascular endothelial growth factor, transforming growth factor ß and JAK-STAT pathways. Moreover, we also highlight the challenges and opportunities for engineering or modifying EVs to enhance their efficacy and specificity for wound healing.

Mitochondrial DNA-targeted therapy: A novel approach to combat cancer.

Mitochondrial DNA (mtDNA) encodes proteins and RNAs that are essential for mitochondrial function and cellular homeostasis, and participates in important processes of cellular bioenergetics and metabolism. Alterations in mtDNA are associated with various diseases, especially cancers, and are considered as biomarkers for some types of tumors. Moreover, mtDNA alterations have been found to affect the proliferation, progression and metastasis of cancer cells, as well as their interactions with the immune system and the tumor microenvironment (TME). The important role of mtDNA in cancer development makes it a significant target for cancer treatment. In recent years, many novel therapeutic methods targeting mtDNA have emerged. In this study, we first discussed how cancerogenesis is triggered by mtDNA mutations, including alterations in gene copy number, aberrant gene expression and epigenetic modifications. Then, we described in detail the mechanisms underlying the interactions between mtDNA and the extramitochondrial environment, which are crucial for understanding the efficacy and safety of mtDNA-targeted therapy. Next, we provided a comprehensive overview of the recent progress in cancer therapy strategies that target mtDNA. We classified them into two categories based on their mechanisms of action: indirect and direct targeting strategies. Indirect targeting strategies aimed to induce mtDNA damage and dysfunction by modulating pathways that are involved in mtDNA stability and integrity, while direct targeting strategies utilized molecules that can selectively bind to or cleave mtDNA to achieve the therapeutic efficacy. This study highlights the importance of mtDNA-targeted therapy in cancer treatment, and will provide insights for future research and development of targeted drugs and therapeutic strategies.

Computer especially AI-assisted drug virtual screening and design in traditional Chinese medicine.

BACKGROUND: Traditional Chinese medicine (TCM), as a significant part of the global pharmaceutical science, the abundant molecular compounds it contains is a valuable potential source of designing and screening new drugs. However, due to the un-estimated quantity of the natural molecular compounds and diversity of the related problems drug discovery such as precise screening of molecular compounds or the evaluation of efficacy, physicochemical properties and pharmacokinetics, it is arduous for researchers to design or screen applicable compounds through old methods. With the rapid development of computer technology recently, especially artificial intelligence (AI), its innovation in the field of virtual screening contributes to an increasing efficiency and accuracy in the process of discovering new drugs. PURPOSE: This study systematically reviewed the application of computational approaches and artificial intelligence in drug virtual filtering and devising of TCM and presented the potential perspective of computer-aided TCM development. STUDY DESIGN: We made a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Then screening the most typical articles for our research. METHODS: The systematic review was performed by following the PRISMA guidelines. The databases PubMed, EMBASE, Web of Science, CNKI were used to search for publications that focused on computer-aided drug virtual screening and design in TCM. RESULT: Totally, 42 corresponding articles were included in literature reviewing. Aforementioned studies were of great significance to the treatment and cost control of many challenging diseases such as COVID-19, diabetes, Alzheimer's Disease (AD), etc. Computational approaches and AI were widely used in virtual screening in the process of TCM advancing, which include structure-based virtual screening (SBVS) and ligand-based virtual screening (LBVS). Besides, computational technologies were also extensively applied in absorption, distribution, metabolism, excretion and toxicity (ADMET) prediction of candidate drugs and new drug design in crucial course of drug discovery. CONCLUSIONS: The applications of computer and AI play an important role in the drug virtual screening and design in the field of TCM, with huge application prospects.

Identification of a Novel Cuproptosis-Related Gene Signature for Prognostic Implication in Head and Neck Squamous Carcinomas.

Head and neck squamous carcinoma (HNSC) is a frequent and deadly malignancy that is challenging to manage. The existing treatment options have considerable efficacy limitations. Hence, the identification of new therapeutic targets and the development of efficacious treatments are urgent needs. Cuproptosis, a non-apoptotic programmed cell death caused by excess copper, has only very recently been discovered. The present study investigated the prognostic importance of genes involved in cuproptosis through the mRNA expression data and related clinical information of HNSC patients downloaded from public databases. Our results revealed that many cuproptosis-related genes were differentially expressed between normal and HNSC tissues in the TCGA cohort. Moreover, 39 differentially expressed genes were associated with the prognosis of HNSC patients. Then, a 24-gene signature was identified in the TCGA cohort utilizing the LASSO Cox regression model. HNSC expression data used for validation were obtained from the GEO database. Consequently, we divided patients into high- and low-risk groups based on the 24-gene signature. Furthermore, we demonstrated that the high-risk group had a worse prognosis when compared to the low-risk group. Additionally, significant differences were found between the two groups in metabolic pathways, immune microenvironment, etc. In conclusion, we found a cuproptosis-related gene signature that can be used effectively to predict OS in HNSC patients. Thus, targeting cuproptosis might be an alternative and promising strategy for HNSC patients.

Identification of key miRNAs and targeted genes involved in the progression of oral squamous cell carcinoma.

Background/purpose: Oral squamous cell carcinoma (OSCC) is one of the most common types of head and neck squamous cell carcinoma. Accurate biomarkers are needed for early diagnosis and prognosis of OSCC. MicroRNAs (miRNAs) have shown great values in different types of cancers including OSCC. However, most of the miRNAs involved in the development of OSCC remain uncovered. This study aimed to identify hub miRNAs and mRNAs in OSCC. Materials and methods: We explored the roles of key miRNAs, target genes and their relationships in OSCC using an integrated bioinformatics approach. Initially, Two OSCC microarray datasets from the Gene Expression Omnibus database were obtained to analyze miRNA expression. MiRNA-targeted mRNAs were acquired, and gene ontology/kyoto encyclopedia of genes and genomes analyses were performed. Thereafter, we constructed a protein-protein interaction (PPI) network to identify hub genes and a miRNA-mRNA interaction network was used to identify key miRNAs. Furthermore, differential gene expression and Kaplan-Meier Plotter survival analysis was performed to evaluate their potential clinical application values. Results: Four upregulated, two downregulated miRNAs and 608 target genes of the differentially expressed miRNAs were identified. The PPI and miRNA-mRNA interaction networks highlighted 10 hub genes and two key miRNAs, and pathway analyses showed their correlative involvement in tumorigenesis-related processes. Of these miRNAs and genes, miR-125b, ß-actin, vinculin and histone deacetylase 1 were correlated with overall survival (P < 0.05). Conclusion: These findings indicate that miR-21 and miR-125b, associated with the 10 hub genes, jointly participate in OSCC tumorigenesis, offering insight into the molecular mechanisms underlying OSCC as potential targets for early diagnosis, treatment and prognosis.

Photodynamic treatment as a promising strategy applied in lichenoid tissue reaction/interface dermatitis with moderate-to-severe dysplasia: A case report.

Lichenoid tissue reaction/interface dermatitis represents a class of mucocutaneous inflammatory diseases which share common histopathological manifestations. One patient presented to our clinic whose oral lesions could not categorized into a definitely clinical or pathological diagnosis, but could be ascribed to lichenoid tissue reaction/interface dermatitis with moderate-to-severe dysplasia. Photodynamic treatment was applied in this case and a satisfactory result was eventually achieved. Signs of recurrence were not revealed at the follow-up of the tenth month.

Predisposition of hypersensitivity in patients with exfoliative cheilitis.

BACKGROUND/PURPOSE: Exfoliative cheilitis (EC) is a chronic and reversible inflammatory disease of the lips without definite etiology. Clinically, different types of allergens can be found in exfoliative cheilitis patients, however, few studies have focused on the relationship between exfoliative cheilitis and hypersensitivity. This research aimed to investigate the prevalence of hypersensitivity in EC patients. MATERIALS AND METHODS: A prospective study was conducted in 30 patients with exfoliative cheilitis and 30 healthy controls, matched in age and sex. Laboratory tests included serum total IgE, allergen-specific IgE, and food-specific IgG. RESULTS: Increased serum total IgE level, positive food-specific IgG were seen more frequently in exfoliative cheilitis patients than in healthy control (P < 0.05). Special IgE level to FX5 and the degree of food-specific IgG to wheat were seen higher in exfoliative cheilitis patients than in healthy control (P < 0.05). CONCLUSION: This study suggests that patients with exfoliative cheilitis may have predisposition of hypersensitivity. The detection of allergens should be strengthened in the future clinical work.

The Balance Between the Effectiveness and Safety for Chemotherapy-Induced Nausea and Vomiting of Different Doses of Olanzapine (10 mg Versus 5 mg): A Systematic Review and Meta-Analysis.

INTRODUCTION: The aim of this study is to rigorously review the efficacy and safety of olanzapine in chemotherapy-induced nausea and vomiting (CINV) settings including (1) at 5- and 10-mg doses, and (2) the setting of highly emetogenic chemotherapy (HEC) and moderately emetogenic chemotherapy (MEC). METHODS: Embase, Pubmed, and Cochrane Library were searched from the establishment of the database through April 18, 2021. The primary efficacy endpoints were the rate of complete response (CR; no emesis and no rescue), in the acute (0-24 h post-chemotherapy), delayed (24-120 h post-chemotherapy), and overall (0-120 h post-chemotherapy) phases. The secondary efficacy endpoints were the rates of complete control (CC, no nausea, and no emesis), for each phase. Safety endpoints were the rate of somnolence, as assessed by Common Terminology Criteria for Adverse Events (CTCAE) criteria. The Mantel-Haenszel, random, or fixed-effect analysis model was used to compute risk ratios and accompanying 95% confidence intervals for each endpoint. For endpoints that statistically favored one arm, absolute risk differences were computed to assess whether there is a 10% or greater difference, used as the threshold for clinical significance by MASCC/ESMO. RESULT: Nine studies reported the use of 10 mg olanzapine to prevent CINV; three studies reported the use of 5 mg olanzapine to prevent CINV. When olanzapine was administered at 10 mg for HEC patients, the six endpoints were statistically and clinically better than the control group. For MEC patients, four out of six endpoints were better than the control group. When olanzapine is administered at 5 mg for MEC patients, four endpoints have statistical and clinical advantages. The sedative effects of 10 and 5 mg olanzapine were statistically more significant than those of the control group. The sedative effect of the 10-mg olanzapine group was more significant than that of the 5-mg olanzapine group, both statistically and clinically. CONCLUSION: 5 mg olanzapine may be as effective as 10 mg olanzapine for patients with HEC and MEC, and its sedative effect is lower than 10 mg olanzapine. Fewer studies on 5 mg olanzapine have led to uncertain data. In the future, more randomized controlled trials of 5 mg olanzapine are needed to study the balance between the effectiveness and safety of olanzapine.

A pan-cancer analysis of the prognostic and immunological role of ß-actin (ACTB) in human cancers.

Beta-actin (ACTB), a highly conserved cytoskeleton structural protein, has been regarded as a common housekeep gene and used as a reference gene for years. However, accumulating evidence indicates that ACTB is abnormally expressed in multiple cancers and hence changes the cytoskeleton to affect the invasiveness and metastasis of tumors. This study aimed to investigate the function and clinical significance of ACTB in pan-cancer. The role of ACTB for prognosis and immune regulation across 33 tumors was explored based on the datasets of gene expression omnibus and the cancer genome atlas. Differential expression of ACTB was found between cancer and adjacent normal tissues, and significant associations was found between ACTB expression and prognosis of tumor patients. In most cancers, ACTB expression was associated with immune cells infiltration, immune checkpoints and other immune modulators. Relevance between ACTB and metastasis and invasion was identified in various types of cancers by CancerSEA. Moreover, focal adhesion and actin regulation-associated pathways were included in the functional mechanisms of ACTB. The expression of ACTB was verified by quantitative real-time polymerase chain reaction. Knockdown of ACTB inhibited head and neck squamous carcinoma cell migration and invasion by NF-κB and Wnt/ß-catenin pathways. Our first pan-cancer study of ACTB offers insight into the prognostic and immunological roles of ACTB across different tumors, indicating ACTB may be a potential biomarker for poor prognosis and immune infiltration in cancers, and the role of ACTB as a reference gene in cancers was challenged.

Adrenergic Blockade by Nebivolol to Suppress Oral Squamous Cell Carcinoma Growth via Endoplasmic Reticulum Stress and Mitochondria Dysfunction.

Adrenergic nerve fibers in the tumor microenvironment promote tumor growth and represent a potential target for cancer therapy. However, the effectiveness of targeting adrenergic nerve fibers for oral squamous cell carcinoma (OSCC) therapy needs to be evaluated by preclinical data. Herein, the 4NQO-induced and orthotopic xenograft OSCC mice models were established. We demonstrated that using 6OHDA chemical denervation as well as using nebivolol adrenergic blockade could halt the oral mucosa carcinogenesis. Our preclinical studies suggested that nebivolol, which is widely used to treat cardiovascular diseases, can be repositioned as a potential candidate to treat OSCC. Remarkably, we revealed the precise effect and mechanism of nebivolol on OSCC cells proliferation, cell cycle, and cell death. Administration of nebivolol could activate the endoplasmic reticulum (ER) stress signaling pathway through increasing the expression of inducible nitric oxide synthase, which subsequently triggers the integrated stress response and cell growth arrest. Simultaneously, ER stress also induced mitochondrial dysfunction in OSCC cells. We found that the accumulation of dysfunctional mitochondria with the impaired electron transport chain caused increasing reactive oxygen species production, which ultimately resulted in OSCC cell death. Altogether, our finding suggested a novel therapeutic opportunity for OSCC by targeting adrenergic nerve fibers, and repurposing nebivolol to treat OSCC can be represented as an effective strategy.

Melatonin Targets Metabolism in Head and Neck Cancer Cells by Regulating Mitochondrial Structure and Function.

Metabolic reprogramming, which is characteristic of cancer cells that rapidly adapt to the hypoxic microenvironment and is crucial for tumor growth and metastasis, is recognized as one of the major mechanisms underlying therapeutic resistance. Mitochondria, which are directly involved in metabolic reprogramming, are used to design novel mitochondria-targeted anticancer agents. Despite being targeted by melatonin, the functional role of mitochondria in melatonin's oncostatic activity remains unclear. In this study, we aim to investigate the role of melatonin in mitochondrial metabolism and its functional consequences in head and neck cancer. We analyzed the effects of melatonin on head and neck squamous cell carcinoma (HNSCC) cell lines (Cal-27 and SCC-9), which were treated with 100, 500, and 1500 µM of melatonin for 1, 3, and 5 days, and found a connection between a change of metabolism following melatonin treatment and its effects on mitochondria. Our results demonstrate that melatonin induces a shift to an aerobic mitochondrial metabolism that is associated with changes in mitochondrial morphology, function, fusion, and fission in HNSCC. We found that melatonin increases oxidative phosphorylation (OXPHOS) and inhibits glycolysis in HNSCC, resulting in increased ROS production, apoptosis, and mitophagy, and decreased cell proliferation. Our findings highlight new molecular pathways involved in melatonin's oncostatic activity, suggesting that it could act as an adjuvant agent in a potential therapy for cancer patients. We also found that high doses of melatonin, such as those used in this study for its cytotoxic impact on HNSCC cells, might lead to additional effects through melatonin receptors.

Isorhamnetin induces the paraptotic cell death through ROS and the ERK/MAPK pathway in OSCC cells.

OBJECTIVE: There were rarely investigations on the effects and molecular mechanisms of oral squamous cell carcinoma (OSCC) cells when treated with isorhamnetin. This article assesses the anti-cancer effect of isorhamnetin. METHODS AND MATERIALS: Oral squamous cell carcinoma cells were treated with or without isorhamnetin. Cell proliferation, cell cycle arrest, cell migration, cell death, and the related signaling pathways were evaluated. RESULTS: The results revealed that cell proliferation was inhibited in a dose- and time-dependent manner, which was confirmed by diminished cell viability and revealed by decreased in the number of cell colonies. In addition, the cell cycle arrested in the G2/M phase, and the protein levels of cyclin B1 and CDC2 were suppressed. Moreover, the cell migration was inhibited, and the protein levels of related proteins were modulated. Furthermore, it could be observed that abundant cytoplasmic vacuoles existed which that were derived from mitochondria and the endoplasmic reticulum. It was confirmed that cell death did not result from apoptosis and may have which may be apt to paraptosis. Isorhamnetin was observed to upregulate phosphorylated ERK cascades and increase intracellular reactive oxygen species levels. CONCLUSIONS: Our study suggested that the anti-cancer effect of isorhamnetin might trigger paraptosis, which may indicate a new therapeutic approach to OSCC.

Repurposing disulfiram to induce OSCC cell death by cristae dysfunction promoted autophagy.

OBJECTIVE: Disulfiram has been repurposed as a potential candidate to suppress various cancers. However, its anti-tumor effects and molecular mechanisms of oral squamous cell carcinoma remain unclear. In this study, we aimed to assess the anti-cancer activity and underlying mechanisms of disulfiram in the context of oral squamous cell carcinoma. MATERIALS AND METHODS: We tested the cytotoxicity of disulfiram in oral squamous cell carcinoma using a 3D culture model and a PDX model. Cell proliferation, cell death, and related signaling pathways were evaluated. Mitochondrial DNA copy number, mitochondrial respiration, mitochondrial mass, and mitochondrial complexes were analyzed. RESULTS: Disulfiram can induce excessive autophagy in oral squamous cell carcinoma cells as a result of OXPHOS deficiency. Disulfiram-induced OPA1 degradation can impair the functional cristae structure, which results in a dramatic reduction in mitochondrial respiration capability as well as ATP production. Subsequently, energy deprivation leads to excessive autophagy through AMPK activation. In addition, exogenous ATP blocked the activation of AMPK and rescued disulfiram-induced cell death. CONCLUSION: DSF targets mitochondrial inner membrane protein OPA1 to disturb the energy supply, triggering excessive autophagy, and cell death in OSCC. Our study suggests OPA1-dependent ATP generation is pharmacologically targetable in OSCC treatment.