Hypoxia reduces the E-cadherin expression and increases OSCC cell migration regardless of the E-cadherin methylation profile

Metformin Radiosensitizing Effect on Hypoxic Oral Squamous Cell Carcinoma Cells by GAPDH and TAGLN2

OBJECTIVE

Tumor hypoxia is associated with a poorer prognosis in cancer patients and can diminish the efficacy of radiation therapy (RT). This study investigates the potential of metformin to enhance radiosensitivity in hypoxic cancer cells.

METHODS

Preliminary experiments were conducted to validate the impact of hypoxia on radiation response. Reactive oxygen species (ROS) levels, cell migration, and cell death were assessed in hypoxic, radiated cells treated with metformin. Proteomic and ontological analyses were employed to identify molecular targets associated with the radiosensitizing effect of metformin. Proteomic and ontological findings were validated through patient samples and in vitro studies.

RESULTS

Metformin amplified cell death, induced DNA fragmentation, decreased cell migration, and elevated ROS levels in hypoxic, radiated cells. Proteomic analyses revealed that GAPDH and TAGLN2 were identified as pivotal targets linked to the radiosensitizing effect of metformin. Oral cancer patients exhibited elevated levels of TAGLN2 and reduced levels of GAPDH. Metformin downregulated TAGLN2 and upregulated GAPDH in hypoxic, radiated cells. Additionally, metformin reduced levels of mutated p53.

CONCLUSIONS

This study suggests that metformin can enhance radiosensitivity in hypoxic cells, operating through modulation of GAPDH and TAGLN2. Furthermore, metformin effectively reduces mutated p53 levels in radiated cells under hypoxic conditions.

Oral squamous cell carcinomas: state of the field and emerging directions

Oral squamous cell carcinoma (OSCC) develops on the mucosal epithelium of the oral cavity. It accounts for approximately 90% of oral malignancies and impairs appearance, pronunciation, swallowing, and flavor perception. In 2020, 377,713 OSCC cases were reported globally. According to the Global Cancer Observatory (GCO), the incidence of OSCC will rise by approximately 40% by 2040, accompanied by a growth in mortality. Persistent exposure to various risk factors, including tobacco, alcohol, betel quid (BQ), and human papillomavirus (HPV), will lead to the development of oral potentially malignant disorders (OPMDs), which are oral mucosal lesions with an increased risk of developing into OSCC. Complex and multifactorial, the oncogenesis process involves genetic alteration, epigenetic modification, and a dysregulated tumor microenvironment. Although various therapeutic interventions, such as chemotherapy, radiation, immunotherapy, and nanomedicine, have been proposed to prevent or treat OSCC and OPMDs, understanding the mechanism of malignancies will facilitate the identification of therapeutic and prognostic factors, thereby improving the efficacy of treatment for OSCC patients. This review summarizes the mechanisms involved in OSCC. Moreover, the current therapeutic interventions and prognostic methods for OSCC and OPMDs are discussed to facilitate comprehension and provide several prospective outlooks for the fields.

Whey Derivatives and Galactooligosaccharides Stimulate the Wound Healing and the Function of Human Keratinocytes through the NF-kB and FOXO-1 Signaling Pathways

Skin repair requires the activation of keratinocytes and is mediated by controlled inflammation and cell migration and proliferation, ending with the regeneration of well-differentiated cell layers. Whey derivatives contain galactooligosaccharides (GOS), which have potential beneficial effects on wound healing due to their activity as toll-like receptor ligands, although their direct nonprebiotic effects in the skin have not yet been described. In this study, we investigated the effects of different whey-derived products and purified GOS on a human keratinocyte cell line. We found that the inflammatory cytokine interleukin-8 (IL-8) was upregulated by nuclear factor kappa B (NF-kB) signaling triggered by whey derivatives and GOS and that wound healing was accelerated by promoting cell migration and the loss of E-cadherin in the absence of epithelial–mesenchymal transition. Interestingly, the treatments enhanced the mitochondrial function in association with the translocation of the Forkhead Box O1 (FOXO-1) transcription factor. Finally, we detected the increased expression of the differentiation markers induced by GOS and whey derivatives. All together, our results show that GOS-containing products can promote wound closure and skin health by direct activity on keratinocyte functions. Among the preparations tested, the fermented compound produced by autochthonous microorganisms was the most active in modulating keratinocyte activity, supporting the biological value of whey derivatives for health.

Identification and Validation of a Hypoxia-Immune-Based Prognostic mRNA Signature for Oral Squamous Cell Carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) is a commonly encountered head and neck malignancy. Increasing evidence shows that there are abnormal immune response and chronic cell hypoxia in the development of OSCC. However, there is a lack of a reliable hypoxia-immune-based gene signature that may serve to accurately prognosticate OSCC.

METHODS

The mRNA expression data of OSCC patients were extracted from the TCGA and GEO databases. Hypoxia status was identified using the t-distributed Stochastic Neighbor Embedding (t-SNE) algorithm. Both ESTIMATE and single-sample gene-set enrichment analysis (ssGSEA) were used for further evaluation of immune status. The DEGs in different hypoxia and immune status were determined, and univariate Cox regression was used to identify significantly prognostic genes. A machine learning method, least absolute shrinkage and selection operator (LASSO) Cox regression analysis, allowed us to construct prognostic gene signature to predict the overall survival (OS) of OSCC patients.

RESULTS

A total of 773 DEGs were identified between hypoxia high and low groups. According to immune cell infiltration, patients were divided into immune high, medium, and low groups and immune-associated DEGs were identified. A total of 193 overlapped DEGs in both immune and hypoxia status were identified. With the univariate and LASSO Cox regression model, eight signature mRNAs (FAM122C, RNF157, RANBP17, SOWAHA, KIAA1211, RIPPLY2, INSL3, and DNAH1) were selected for further calculation of their respective risk scores. The risk score showed a significant association with age and perineural and lymphovascular invasion. In the GEO validation cohort, a better OS was observed in patients from the low-risk group in comparison with those in the high-risk group. High-risk patients also demonstrated different immune infiltration characteristics from the low-risk group and the low-risk group showed potentially better immunotherapy efficacy in contrast to high-risk ones.

CONCLUSION

The hypoxia-immune-based gene signature has prognostic potential in OSCC.

Photodynamic therapy mediated by nanoparticles Aluminum Chloro Phthalocyanine in oral squamous carcinoma cells

The aim of this study is to investigate the antineoplastic potential of photodynamic therapy (PDT) mediated by an aluminum-phthalocyanine chloride nanoemulsion (AlPc-NE), against an oral squamous cell carcinoma (OSCC) cell line in vitro. Both OSCC (SCC9) and A431 cell lines were studied in vitro. Four study groups were used: Group 1 (phosphate-buffered saline [PBS]), Group 2 (PBS + 28.3 J/cm² irradiation), Group 3 (AlPc-NE alone), and Group 4 (AlPc-NE + 28.3 J/cm² irradiation). To test the effect of PDT with AlPc-NE, cell viability, migration, and cell death assays were performed. Moreover, the expressions of Ki-67 and TP53 were evaluated using immunoassays. The results showed that PDT mediated by all AlPc-NE concentrations evaluated (i.e., 0.7, 0.35, and 0.17 nM AlPc) significantly reduced the viability of SCC9 cells. Migration and cell death assays also revealed that PDT with AlPc-NE significantly reduced the rate of migration and increased cell death compared to the control groups. In addition, it was found that PDT with AlPc-NE reduced Ki-67 and mutated TP53 immunoexpression. PDT with AlPc-NE is effective in reducing the viability and migration of SCC9. Moreover, PDT with AlPc-NE nanoemulsions reduces the cell proliferation and expression of mutant TP53.

Exploring the Mechanism of Scutellaria baicalensis Georgi Efficacy against Oral Squamous Cell Carcinoma Based on Network Pharmacology and Molecular Docking Analysis

BACKGROUND

Scutellaria baicalensis Georgi (SBG) has been widely shown to induce apoptosis and inhibit invasion and migration of various cancer cells. Increased evidence shows that SBG may be useful to treat oral squamous cell carcinoma (OSCC). However, the biological activity and possible mechanisms of SBG in the treatment of OSCC have not been fully elucidated. This study aimed to clarify the bioactive component and multitarget mechanisms of SBG against OSCC using network pharmacology and molecular docking.

METHODS

Traditional Chinese Medicine Systems Pharmacology (TCMSP) database was used to predict the active components in SBG, and putative molecular targets of SBG were identified using the Swiss Target Prediction database. OSCC-related targets were screened by GeneCards, Online Mendelian Inheritance in Man (OMIM), and Therapeutic Target Database (TTD). Then, we established protein-protein interaction (PPI), compound-target-disease (C-T-D), and compound-target-pathway (C-T-P) networks by Cytoscape to identify the main components, core targets, and pharmacological pathways of SBG against OSCC via applying data mining techniques and topological parameters. Metascape database was utilized for Gene Ontology (GO) and pathway enrichment analysis. The potential interaction of the main components with core targets was revealed by molecular docking simulation, and for the correlation between core targets and OSCC prognosis analysis, the Kaplan-Meier Plotter online database was used.

RESULTS

There were 25 active compounds in SBG and 86 genes targeted by OSCC. A total of 141 signaling pathways were identified, and it was found that the PI3K-Akt signaling pathway may occupy core status in the anti-OSCC system. GO analysis revealed that the primary biological processes were related to apoptosis, proliferation, and migration. Molecular docking results confirmed that core targets of OSCC had a high affinity with the main compounds of SBG.

CONCLUSION

Our study demonstrated multicomponent, multitarget, and multipathway characteristics of SBG in the treatment of OSCC and provided a foundation for further drug development research.

Epithelial-Mesenchymal Transition Associated with Head and Neck Squamous Cell Carcinomas: A Review

Head and neck squamous cell carcinomas (HNSCCs) are aggressive, recurrent, and metastatic neoplasms with a high occurrence around the world and can lead to death when not treated appropriately. Several molecules and signaling pathways are involved in the malignant conversion process. Epithelial-mesenchymal transition (EMT) has been described in HNSCCs, a major type of aggressive carcinoma. EMT describes the development of epithelial cells into mesenchymal cells, which depends on several molecular interactions and signaling pathways that facilitate mesenchymal conversion. This is related to interactions with the microenvironment of the tumor, hypoxia, growth factors, matrix metalloproteinases, and the presence of viral infections. In this review, we focus on the main molecules related to EMT, their interactions with the tumor microenvironment, plasticity phenomena, epigenetic regulation, hypoxia, inflammation, their relationship with immune cells, and the inhibition of EMT in the context of HNSCCs.

Intersecting Mechanisms of Hypoxia and Prostaglandin E2-Mediated Inflammation in the Comparative Biology of Oral Squamous Cell Carcinoma

The importance of inflammation in the pathogenesis of cancer was first proposed by Rudolph Virchow over 150 years ago, and our understanding of its significance has grown over decades of biomedical research. The arachidonic acid pathway of inflammation, including cyclooxygenase (COX) enzymes, PGE2 synthase enzymes, prostaglandin E2 (PGE2) and PGE2 receptors has been extensively studied and has been associated with different diseases and different types of cancers, including oral squamous cell carcinoma (OSCC). In addition to inflammation in the tumour microenvironment, low oxygen levels (hypoxia) within tumours have also been shown to contribute to tumour progression. Understandably, most of our OSCC knowledge comes from study of this aggressive cancer in human patients and in experimental rodent models. However, domestic animals develop OSCC spontaneously and this is an important, and difficult to treat, form of cancer in veterinary medicine. The primary goal of this review article is to explore the available evidence regarding interaction between hypoxia and the arachidonic acid pathway of inflammation during malignant behaviour of OSCC. Overlapping mechanisms in hypoxia and inflammation can contribute to tumour growth, angiogenesis, and, importantly, resistance to therapy. The benefits and controversies of anti-inflammatory and anti-angiogenic therapies for human and animal OSCC patients will be discussed, including conventional pharmaceutical agents as well as natural products.

Might anxiety disorders promote head and neck cancer development?

Cancer patients present a higher risk of experiencing anxiety disorders (AD). However, it is not clear if AD might be associated with cancer development. Thus, our study aimed to evaluate if AD might be related to head and neck squamous cell carcinoma (HNSCC) development. The combination of an applied animal basic study and a retrospective diagnostic case and control study in patients was performed. As a result, we obtained that stress reduced the locomotor activity of the animals in the group stress and stress + 4NqO (p < 0.0001). The stress showed no influence on the progression of neoplasia in mice. In the same way, the case group did not present differences in anxiety scores in comparison to control. Moreover, no association between HNSCC staging and anxiety scores was observed. In conclusion, our in vivo findings in humans and animals have shown that there is no relationship between AD and oral squamous cell carcinoma.

Caveolin-1-Mediated Tumor Suppression Is Linked to Reduced HIF1α S-Nitrosylation and Transcriptional Activity in Hypoxia

Caveolin-1 (CAV1) is a well-established nitric oxide synthase inhibitor, whose function as a tumor suppressor is favored by, but not entirely dependent on, the presence of E-cadherin. Tumors are frequently hypoxic and the activation of the hypoxia-inducible factor-1α (HIF1α) promotes tumor growth. HIF1α is regulated by several post-translational modifications, including S-nitrosylation. Here, we evaluate the mechanisms underlying tumor suppression by CAV1 in cancer cells lacking E-cadherin in hypoxia. Our main findings are that CAV1 reduced HIF activity and Vascular Endothelial Growth Factor expression in vitro and in vivo. This effect was neither due to reduced HIF1α protein stability or reduced nuclear translocation. Instead, HIF1α S-nitrosylation observed in hypoxia was diminished by the presence of CAV1, and nitric oxide synthase (NOS) inhibition by Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME) reduced HIF1α transcriptional activity in cells to the same extent as observed upon CAV1 expression. Additionally, arginase inhibition by (S)-(2-Boronoethyl)-L-cysteine (BEC) partially rescued cells from the CAV1-mediated suppression of HIF1α transcriptional activity. In vivo, CAV1-mediated tumor suppression was dependent on NOS activity. In summary, CAV1-dependent tumor suppression in the absence of E-cadherin is linked to reduced HIF1α transcriptional activity via diminished NOS-mediated HIF1α S-nitrosylation.

Epigenetic Modifications in Head and Neck Cancer

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common human malignancy in the world, with high mortality and poor prognosis for patients. Among the risk factors are tobacco and alcohol intake, human papilloma virus, and also genetic and epigenetic modifications. Many studies show that epigenetic events play an important role in HNSCC development and progression, including DNA methylation, chromatin remodeling, histone posttranslational covalent modifications, and effects of non-coding RNA. Epigenetic modifications may influence silencing of tumor suppressor genes by promoter hypermethylation, regulate transcription by microRNAs and changes in chromatin structure, or induce genome instability through hypomethylation. Moreover, getting to better understand aberrant patterns of methylation may provide biomarkers for early detection and diagnosis, while knowledge about target genes of microRNAs may improve the therapy of HNSCC and extend overall survival. The aim of this review is to present recent studies which demonstrate the role of epigenetic regulation in the development of HNSCC.

The peculiarities of cancer cell metabolism: A route to metastasization and a target for therapy

The last decade has witnessed the peculiarities of metabolic reprogramming in tumour onset and progression, and their relevance in cancer therapy. Also, it has been indicated that the metastatic process may depend on the metabolic rewiring and adaptation of cancer cells to the pressure of tumour microenvironment and limiting nutrient availability. The present review gatherers the existent knowledge on the influence of tumour microenvironment and metabolic routes driving metastasis. A focus will be given to glycolysis, fatty acid metabolism, glutaminolysis, and amino acid handling. In addition, the role of metabolic waste driving metastasization will be explored. Finally, we discuss the status of cancer treatment approaches targeting metabolism. This knowledge revision will highlight the critical metabolic targets in metastasis and the chemicals already used in preclinical studies and clinical trials, providing clues that would be further exploited in medicinal chemistry research.

CoCl2 , a mimic of hypoxia, enhances bone marrow mesenchymal stem cells migration and osteogenic differentiation via STAT3 signaling pathway

Mesenchymal stem cells homing and migration is a crucial step during bone fracture healing. Hypoxic environment in fracture site induces bone marrow mesenchymal stem cells (BMSCs) migration, but its mechanism remains unclear. Our previous study and studies by other groups have reported the involvement of signal transducer and activator of transcription 3 (STAT3) pathway in cell migration. However, the role of STAT3 pathway in hypoxia-induced cell migration is still unknown. In this study, we investigated the role of STAT3 signaling in hypoxia-induced BMSCs migration and osteogenic differentiation. BMSCs isolated from C57BL/6 male mice were cultured in the presence of cobalt chloride (CoCl₂ ) to simulate intracellular hypoxia. Hypoxia enhanced BMSCs migration, and upregulated cell migration related gene expression, that is, metalloproteinase (MMP) 7, MMP9, and C-X-C motif chemokine receptor 4. Hypoxia enhanced the phosphorylation of STAT3, and cell migration related proteins: c-jun n-terminal kinase (JNK), focal of adhesion kinase (FAK), extracellular regulated protein kinases, and protein kinase B 1/2 (ERK1/2). Moreover, hypoxia enhanced expression of osteogenic differentiation marker. Inhibition of STAT3 suppressed the hypoxia-induced BMSCs migration, cell migration related signaling molecules phosphorylation, and osteogenic differentiation related gene expression. In conclusion, our result indicates that hypoxia-induced BMSCs migration and osteogenic differentiation is via STAT3 phosphorylation and involves the cooperative activity of the JNK, FAK, and MMP9 signaling pathways.

Hypoxia induced EMT: A review on the mechanism of tumor progression and metastasis in OSCC

Hypoxia, a condition of low oxygen tension in tissues, has emerged as a crucial factor in tumor pathophysiology. Hypoxic microenvironment gives rise to altered cellular metabolism and triggers varied molecular responses. These responses promote tumor progression and confer radiation resistance and chemo resistance to tumors. The predominant molecules that are associated with hypoxia research are the hypoxia inducible factors (HIFs). HIFs are known to regulate a large group of genes that are involved in cell survival, proliferation, motility, metabolism, pH regulation, extracellular matrix function, inflammatory cell recruitment and angiogenesis by inducing the expression of their downstream target genes. The process of epithelial to mesenchymal transition (EMT) has been associated with metastasis in cancer. Reports also suggest that hypoxia triggers EMT in several types of cancer including breast cancer, prostate cancer and oral cancer. Oral cancer is a predominant cancer in Central and South East Asia. However, in the recent times, the incidence rates of oral cancer have been increasing in Northern and Eastern Europe as well. This review articulates the role of hypoxia and the associated factors like HIFs in inducing EMT in oral cancer (OSCC).