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Objective Head and neck squamous cell carcinoma ( HNSCC) progression and metastasis have previously been associated with the activation of phosphatidylinositol 3-kinase-protein kinase B ( PI3 K- Akt) and Wnt signalling pathways, which lead to the activation of pro-proliferative genes, such as cyclin D1. The current study aims to investigate whether there is a crosstalk between these pathways in HNSCC and which pathway is more likely to regulate cyclin D1. Material and Methods Two HNSCC and a control keratinocyte cell lines were treated with EGF and wortmannin to respectively activate and block the PI3 K- Akt and Wnt pathways. Partial and total levels of cyclin D1, beta-catenin and Akt were evaluated by Western blotting and immunofluorescence. Twenty-four paraffin-embedded samples of human HNSCC, as well as normal oral mucosa biopsies, were also immunohistochemically evaluated for beta-catenin and cyclin D1 expression. Results Following both treatments, change in cyclin D1 protein was correlated with Akt levels only. Cytoplasmic staining for beta-catenin and loss of its membranous expression in the HNSCC invasive areas were found in 92% of the HNSCC biopsies. Conclusion Taken together, we show that the change in cyclin D1 levels is more likely to be due to the EGFR- Akt pathway activation than due to beta-catenin nuclear translocation. [ABSTRACT FROM AUTHOR]

The molecular circuitries controlling the process of skin wound healing have gained new significant insights in recent years. This knowledge is built on landmark studies on skin embryogenesis, maturation, and differentiation. Furthermore, the identification, characterization, and elucidation of the biological roles of adult skin epithelial stem cells and their influence in tissue homeostasis have provided the foundation for the overall understanding of the process of skin wound healing and tissue repair. Among numerous signaling pathways associated with epithelial functions, the PI3 K/ Akt/m TOR signaling route has gained substantial attention with the generation of animal models capable of dissecting individual components of the pathway, thereby providing a novel insight into the molecular framework underlying skin homeostasis and tissue regeneration. In this review, we focus on recent findings regarding the mechanisms involved in wound healing associated with the upregulation of the activity of the PI3 K/ Akt/m TOR circuitry. This review highlights critical findings on the molecular mechanisms controlling the activation of mTOR, a downstream component of the PI3 K- PTEN pathway, which is directly involved in epithelial migration and proliferation. We discuss how this emerging information can be exploited for the development of novel pharmacological intervention strategies to accelerate the healing of critical size wounds. [ABSTRACT FROM AUTHOR]

Management of skin injuries imposes a substantial financial burden on patients and hospitals, leading to diminished quality of life. Periostin (rhOSF), an extracellular matrix component, regulates cell function, including a proliferative healing phase, representing a key protein to promote wound healing. Despite its proven efficacy in vitro , there is a lack of scaffolds that facilitate the in situ delivery of rhOSF. In addition, there is a need for a scaffold to not only support cell growth, but also to resist the mechanical forces involved in wound healing. In this work, we synthesized rhOSF-loaded mesoporous nanoparticles (MSNs) and incorporated them into a cell-laden gelatin methacryloyl (GelMA) ink that was bioprinted into melt electrowritten poly(ε-caprolactone) (PCL) microfibrous (MF-PCL) meshes to develop mechanically competent constructs. Diffraction light scattering (DLS) analysis showed a narrow nanoparticle size distribution with an average size of 82.7 ± 13.2 nm. The rhOSF-loaded hydrogels showed a steady and controlled release of rhOSF over 16 days at a daily dose of ∼40 ng/mL. Compared with blank MSNs, the incorporation of rhOSF markedly augmented cell proliferation, underscoring its contribution to cellular performance. Our findings suggest a promising approach to address challenges such as prolonged healing, offering a potential solution for developing robust, biocompatible, and cell-laden grafts for burn wound healing applications.

This review article critically examines the pivotal role of chromatin organization in gene regulation, cellular differentiation, disease progression and aging. It explores the dynamic between the euchromatin and heterochromatin, coded by a complex array of histone modifications that orchestrate essential cellular processes. We discuss the pathological impacts of chromatin state misregulation, particularly in cancer and accelerated aging conditions such as progeroid syndromes, and highlight the innovative role of epigenetic therapies and artificial intelligence (AI) in comprehending and harnessing the histone code toward personalized medicine. In the context of aging, this review explores the use of AI and advanced machine learning (ML) algorithms to parse vast biological datasets, leading to the development of predictive models for epigenetic modifications and providing a framework for understanding complex regulatory mechanisms, such as those governing cell identity genes. It supports innovative platforms like CEFCIG for high-accuracy predictions and tools like GridGO for tailored ChIP-Seq analysis, which are vital for deciphering the epigenetic landscape. The review also casts a vision on the prospects of AI and ML in oncology, particularly in the personalization of cancer therapy, including early diagnostics and treatment optimization for diseases like head and neck and colorectal cancers by harnessing computational methods, AI advancements and integrated clinical data for a transformative impact on healthcare outcomes.

The aim of this study was to evaluate the expression of the EZH2 protein and describe the clinical and microscopic characteristics of adenoid cystic carcinoma (ACC) and pleomorphic adenoma (PA). The study included 16 ACC cases and 12 PA. All ACC and PA cases were positive for EZH2 and the ACC samples showed significantly higher EZH2 expression. The clinical and microscopic covariates were described in relation to EZH2 staining in ACC samples. The highest mean values of EZH2 were observed in cases with local metastasis, recurrence, perineural invasion, and predominantly cribriform growth pattern without solid areas. EZH2 is a potential marker of malignancy.

Burn injuries are observed throughout a wide range of ages, with over 1.1 million Americans suffering burns yearly, and half of these require hospitalization. Epigenetic modifications are fast-acting mechanisms that allow the human body to respond and adapt to environmental changes, including burn injuries. There is a lack of understanding of the epigenetic role during burn-induced tissue repair. Here, we characterize the histone modifications that follow burn injury, aiming at future pharmacological intervention using drugs capable of targeting epigenetic events. A clinically relevant porcine burn model was used to recapitulate the skin healing process after the burn. Isolated skin tissues at different time points were used to detect the acetylation levels of histones H3K27, H4K5, H4K8, and H4K12 as significant players of gene transcription using MetaXpress High-Content Imaging Analysis. We observed that the acetylation of histones is dynamically adjusted throughout healing, and its modifications are uniquely expressed according to the anatomical location and time of healing. We also observed that histone H4K5 is the most widely expressed during healing, followed by histone H3K27. We observed that histones expressed in intact skin tissue adjacent to the burn site could sense the burn injury by changing its histone acetylation pattern compared to control skin from uninjured and distant skin. Using a clinically relevant animal model, we have generated a comprehensive landscape of epigenetic modifications during burn healing. Our data will help us identify novel epi-drugs capable of manipulating histone modifications during healing to accelerate the healing process., (© The Author(s) 2023. Published by Oxford University Press on behalf of the American Burn Association.)

Background: There is no consensus about effective systemic therapy for salivary gland carcinomas (sgcs). Our aim was summarized the clinical trials assessing the systemic therapies (ST) on sgcs., Material and Methods: Electronic searches were carried out through MEDLINE/pubmed, EMBASE, Scopus, Web of Science, and the Cochrane Library databases, and gray literature., Results: Seventeen different drugs were evaluated, and the most frequent histological subtype was adenoid cystic carcinoma (n=195, 45.5%). Stable disease, observed in 11 ST, achieved the highest rate in adenoid cystic carcinoma treated with sunitinib. The highest complete (11.1%) and partial response (30.5%) rates were seen in androgen receptor-positive tumors treated with leuprorelin acetate., Conclusions: Despite all the advances in this field, there is yet no effective evidence-based regimen of ST, with all the clinical trials identified showing low rates of complete and partial responses. Further, translational studies are urgently required to characterize molecular targets and effective ST.

Wound healing can be influenced by genes that control the circadian cycle, including Per2 and BMAL1, which coordinate the functions of several organs, including the skin. The aim of the study was to evaluate the role of PER2 during experimental skin wound healing. Two groups (control and Per2-KO), consisting of 14 male mice each, were anesthetized by inhalation, and two 6 mm wounds were created on their dorsal skin using a punch biopsy. A silicone ring was sutured around the wound perimeter to restrict contraction. The wound healing process was clinically measured daily (closure index) until complete wound repair. On Day 6, histomorphometric analysis was performed using the length and thickness of the epithelial migration tongue, in addition to counting vessels underlying the lesion by immunofluorescence assay and maturation of collagen fibers through picrosirius staining. Bromodeoxyuridine (BrdU) incorporation and quantification were performed using the subcutaneous injection technique 2 h before euthanasia and through immunohistochemical analysis of the proliferative index. In addition, the qualitative analysis of myofibroblasts and periostin distribution in connective tissue was performed by immunofluorescence. Statistically significant differences were observed in the healing time between the experimental groups (means: 15.5 days for control mice and 13.5 days for Per2-KO; p = 0.001). The accelerated healing observed in the Per2-KO group (p < 0.05) was accompanied by statistical differences in wound diameter and length of the migrating epithelial tongue (p = 0.01) compared to the control group. Regarding BrdU immunoreactivity, higher expression was observed in the intact epithelium of Per2-KO animals (p = 0.01), and this difference compared to control was also present, to a lesser extent, at the wound site (p = 0.03). Immunofluorescence in the connective tissue underlying the wound showed a higher angiogenic potential in the Per2-KO group in the intact tissue area and the wound region (p < 0.01), where increased expression of myofibroblasts was also observed. Qualitative analysis revealed the distribution of periostin protein and collagen fibers in the connective tissue underlying the wound, with greater organization and maturation during the analyzed period. Our research showed that the absence of the Per2 gene positively impacts the healing time of the skin in vivo. This acceleration depends on the increase of epithelial proliferative and angiogenic capacity of cells carrying the Per2 deletion., (© 2024 The Authors. Journal of Cellular Biochemistry published by Wiley Periodicals LLC.)

Tumor resistance remains an obstacle to successfully treating oral squamous cell carcinoma (OSCC). Cisplatin is widely used as a cytotoxic drug to treat solid tumors, including advanced OSCC, but with low efficacy due to chemoresistance. Therefore, identifying the pathways that contribute to chemoresistance may show new possibilities for improving the treatment. This work explored the role of the tumor necrosis factor-alpha (TNF-alpha)/NFkB signaling in driving the cisplatin resistance of OSCC and its potential as a pharmacological target to overcome chemoresistance. Differential accessibility analysis demonstrated the enrichment of opened chromatin regions in members of the TNF-alpha/NFkB signaling pathway, and RNA-Seq confirmed the upregulation of TNF-alpha/NFkB signaling in cisplatin-resistant cell lines. NFkB was accumulated in cisplatin-resistant cell lines and in cancer stem cells (CSC), and the administration of TNF-alpha increased the CSC, suggesting that TNF-alpha/NFkB signaling is involved in the accumulation of CSC. TNF-alpha stimulation also increased the histone deacetylases HDAC1 and SIRT1. Cisplatin-resistant cell lines were sensitive to the pharmacological inhibition of NFkB, and low doses of the NFkB inhibitors, CBL0137, and emetine, efficiently reduced the CSC and the levels of SIRT1, increasing histone acetylation. The NFkB inhibitors decreased stemness potential, clonogenicity, migration, and invasion of cisplatin-resistant cell lines. The administration of the emetine significantly reduced the tumor growth of cisplatin-resistant xenograft models, decreasing NFkB and SIRT1, increasing histone acetylation, and decreasing CSC. TNF-alpha/NFkB/SIRT1 signaling regulates the epigenetic machinery by modulating histone acetylation, CSC, and aggressiveness of cisplatin-resistant OSCC and the NFkB inhibition is a potential strategy to treat chemoresistant OSCC., (© 2023 Wiley Periodicals LLC.)

Adenoid cystic carcinoma (ACC) is a rare neoplasm known for its indolent clinical course, risk of perineural invasion, and late onset of distant metastasis. Due to the scarcity of samples and the tumor's rarity, progress in developing effective treatments has been historically limited. To tackle this issue, a high-throughput screening of epigenetic drugs was conducted to identify compounds capable of disrupting the invasive properties of the tumor and its cancer stem cells (CSCs). ACC cells were screened for changes in tumor viability, chromatin decondensation, Snail inhibition along tumor migration, and disruption of cancer stem cells. Seven compounds showed potential clinical interest, and further validation showed that Scriptaid emerged as a promising candidate for treating ACC invasion. Scriptaid demonstrated a favorable cellular toxicity index, effectively inhibited Snail expression, induced hyperacetylation of histone, reduced cell migration, and effectively disrupted tumorspheres. Additionally, LMK235 displayed encouraging results in four out of five validation assays, further highlighting its potential in combating tumor invasion in ACC. By targeting the invasive properties of the tumor and CSCs, Scriptaid and LMK235 hold promise as potential treatments for ACC, with the potential to improve patient outcomes and pave the way for further research in this critical area.

Objective: Emerging evidence suggests that the modest response of head and neck squamous cell carcinoma (HNSCC) to treatment is associated with cancer stem cells (CSC). However, the signaling pathways that play a role in HNSCC CSC maintenance and therapy response are not well-understood. In this study, we investigate the response of CSCs to phosphatase and tensin homolog (PTEN) modulation and its potential dependency on the mammalian target of rapamycin (mTOR) signaling., Design: PTEN deficiency was stably induced using short hairpin RNA (shRNA). Downregulation of RPTOR/mTORC1 and RICTOR/mTORC2 was achieved using small interfering RNA (siRNA). CSCs were evaluated through tumorsphere formation and were classified into various subtypes: parasphere, merosphere, and holosphere. We investigated the effect of rapamycin on CSC properties in both control and PTEN-deficient HNSCC cells., Results: PTEN deficiency led to an accumulation of CSCs and enhanced a favorable response to rapamycin treatment. The viability of HNSCC CSCs was dependent on mTOR signaling. Deficiencies in both mTORC1 and mTORC2 reduced the number of CSCs. However, CSCs with PTEN deficiency had a greater reliance on mTORC1 signaling. Interestingly, when considering CSC subtypes, a deficiency in mTORC2 led to an increased number of paraspheres in both the control and PTEN-deficient groups., Conclusions: Loss of PTEN signaling increased the HNSCC CSC population, which can be targeted by rapamycin. However, the mTORC2 deficiency can induce a problematic selection of paraspheres CSCs subtype., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Despite many progresses in the development of new systemic therapies for oral squamous cell carcinoma (OSCC), the five-year survival rate of OSCC is low. The traditional chemotherapies approach (cisplatin - CDDP) shows some limitations like drug toxicity, limited efficacy, and drug resistance. Promising studies suggested OSCC cancer stem cells (CSC) presented resistance to CDDP. We have previously studied many targets, and we extensively showed the efficacy of the NFκB signaling and the role of histones acetylation, on different malignant tumors, including adenoid cystic carcinoma and mucoepidermoid carcinoma, but until then the effects of the NFkB inhibitor and histone deacetylase (HDAC) inhibitor on the biology of OSCC were not evaluated. Here we assessed the pharmacological inhibitor of NFκB emetine and HDAC inhibitor SAHA on the behavior of CSC derived from OSCC. Our data suggested that CDDP administration resulted in reduced viability of bulk OSCC cells and increased CSC. A single and isolated shot of emetine and SAHA were able to disrupt CSC by inhibiting the NFκB pathway and increasing the histone acetylation levels, respectively. Further, the combined administration of emetine and SAHA presented the same CSC disruption as seen in emetine alone., Competing Interests: None., (AJCR Copyright © 2023.)

Central giant cell granuloma (CGCG) is a benign jaw lesion with variable clinical behavior. Cell cannibalism is a cellular process associated with aggressiveness and invasion in malignant neoplasms. Here, we morphologically investigated cell cannibalism as an auxiliary method to predict CGCG clinical behavior. Cell cannibalism was quantitatively evaluated in 19 cases of peripheral giant cell granuloma (PGCG), 38 cases of CGCG (non-aggressive and aggressive), and 19 cases of giant cell tumor of bone (GCT) stained with hematoxylin and eosin. T-test was performed to assess the differences between the variables analyzed (p ≤ 0.05). Cell cannibalism was identified in 21% of non-aggressive CGCGs and 68.4% of aggressive CGCGs. A significantly higher amount of cannibal multinucleated giant cells (CMGC) was observed in aggressive CGCG compared to PGCG and non-aggressive CGCG (p = 0.042; p = 0.044, respectively). There were no significant differences in the CMGC index between non-aggressive CGCG and PGCG (p = 0.858) and between aggressive CGCG and GCT (p = 0.069). CGGC cases that exhibited rapid growth and tooth displacement and/or root resorption had a higher amount of CMGC (p = 0.035; p = 0.041, respectively). Cell cannibalism can be identified in CGCG through routine anatomopathological examination. The quantification of CMGC can help to predict the clinical behavior of central giant cell granuloma., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier GmbH. All rights reserved.)

Human papillomavirus (HPV) infection has recently been linked to a subset of cancers affecting the oral cavity. However, the molecular mechanisms underlying HPV-driven oral squamous cell carcinoma (OSCC) onset and progression are poorly understood., Methods: We performed MS-based proteomics profiling based on HPV status in OSCC in young patients, following biological characterization and cell assays to explore the proteome functional landscape., Results: Thirty-nine proteins are differentially abundant between HPV (+) and HPV (-) OSCC. Among them, COPS3, DYHC1, and S100A8 are unfavorable for tumor recurrence and survival, in contrast to A2M and Serpine1, low levels of which show an association with better DFS. Remarkably, S100A8 is considered an independent prognostic factor for lower survival rates, and at high levels, it alters tumor-associated immune profiling, showing a lower proportion of M1 macrophages and dendritic cells. HPV (+) OSCC also displayed the pathogen-associated patterns receptor that, when activated, triggered the S100A8 and NFκB inflammatory responses., Conclusion: HPV (+) OSCC has a peculiar microenvironment pattern distinctive from HPV (-), involving the expression of pathogen-associated pattern receptors, S100A8 overexpression, and NFκB activation and responses, which has important consequences in prognosis and may guide therapeutic decisions.

Drug resistance remains a major obstacle in the treatment of mucoepidermoid carcinomas (MEC) leading to tumor recurrence, disease progression, and metastasis. Emerging evidence suggests that drug resistance is mediated by the presence of a highly adaptative subpopulation of cancer cells known as cancer stem cells (CSC). We have previously reported that solid tumors use NFkB signaling as a chemotherapy-resistant mechanism. We have also shown that interfering with the epigenome of solid tumors is an effective strategy to control the population of CSC. Here, we sought to investigate the effects of the NFkB inhibitor emetine and the HDAC inhibitor SAHA on the biology of MEC CSC and assessed whether this combination therapy would favor the standard of care therapy comprised of the administration of Cisplatin (CDDP). Our findings suggested that the administration of low concentrations of emetine and SAHA is more effective in disrupting CSC in MEC, while the administration of emetine in combination with CDDP constitutes an effective therapy to target non-CSC MEC tumor cells., Competing Interests: None., (AJCR Copyright © 2023.)

Adenoid cystic carcinoma (ACC) patients face a highly infiltrative and metastatic disease characterized by poor survival rates and suboptimal response to available therapies. We have previously shown that sensitization of ACC tumors to chemotherapy using histone deacetylase inhibitors (HDACi) constitutes a promising therapeutic strategy to manage tumor growth. Here, we used patient-derived xenografts (PDX) from ACC tumors to evaluate the effects of in vivo administration of the HDAC inhibitor Entinostat combined with Cisplatin over tumor growth. RNA from PDX tumor samples receiving the proposed therapy were analyzed using NanoString technology to identify molecular signatures capable of predicting ACC response to the therapy. We also used an RNAseq dataset from 68 ACC patients to validate the molecular signature identified by the NanoString platform. We found that the administration of Entinostat combined with Cisplatin resulted in a potent tumor growth inhibition (TGI) ranging from 38% to 106% of the original tumor mass. Enhanced response to therapy is consistent with the reactivation of tumor suppressor genes, including SFRP1, and the downregulation of oncogenes like FGF8 and CCR7. Nanostring data from PDX tumors identified a genetic signature capable of predicting tumor response to therapy. We further stratified 68 ACC patients containing RNAseq data accordingly to the activity levels of the identified genetic signature. We found that 23% of all patients exhibit a genetic signature consistent with a high ACC tumor response rate to Entinostat and Cisplatin. Our study provides compelling preclinical data supporting the deployment of a powerful systemic anticancer therapy crafted and explicitly tested for ACC tumors., Competing Interests: None., (AJCR Copyright © 2023.)

Introduction: The continual evolution of dental education, dental practice and the delivery of optimal oral health care is rooted in the practice of leadership. This paper explores opportunities and challenges facing dental education with a specific focus on incorporating the use of artificial intelligence (AI)., Methods: Using the model in Bolman and Deal's Reframing Organizations, the Four Frames model serves as a road map for building infrastructure within dental schools for the adoption of AI., Conclusion: AI can complement and boost human tasks and have a far-reaching impact in academia and health care. Its adoption could enhance educational experiences and the delivery of care, and support current functions and future innovation. The framework suggested in this paper, while specific to AI, could be adapted and applied to a myriad of innovations and new organizational ideals and goals within institutions of dental education., (© 2022 The Authors. Journal of Dental Education published by Wiley Periodicals LLC on behalf of American Dental Education Association.)

Adenoid cystic carcinoma (ACC) is a biphasic malignant lesion that can develop at various anatomical sites. Salivary and lacrimal ACC lesions have a high risk of local invasion, metastasis, and poor prognosis. In more distant organs, such as the breast, ACC is a rarer and less aggressive lesion. One of the major predictors of mortality of ACC is perineural invasion, which can be seen in 30 % of breast lesions, 85% of salivary lesions, and almost 100 % of lacrimal gland tumors. The biological differences between these three ACC tumors are still poorly understood. We focused on the current understanding of the genetic variations observed on ACC tumors and prognostic differences associated with distinct anatomical sites. A special effort was made to present the currently available therapies alongside the emerging strategies under development., Competing Interests: Conflict of interest statement The authors have no conflict of interest., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Aim: To evaluate the potential use of Cephaeline as a therapeutic strategy to manage mucoepidermoid carcinomas (MEC) of the salivary glands., Material and Methods: UM-HMC-1, UM-HMC-2, and UM-HMC-3A MEC cell lines were used to establish the effects of Cephaeline over tumor viability determined by MTT assay. In vitro wound healing scratch assays were performed to address cellular migration while immunofluorescence staining for histone H3 lysine 9 (H3k9ac) was used to identify the acetylation status of tumor cells upon Cephaeline administration. The presence of cancer stem cells was evaluated by the identification of ALDH enzymatic activity by flow cytometry and through functional assays using in vitro tumorsphere formation., Results: A single administration of Cephaeline resulted in reduced viability of MEC cells along with the halt on tumor growth and cellular migration potential. Administration of Cephaeline resulted in chromatin histone acetylation as judged by the increased levels of H3K9ac and disruption of tumorspheres formation. Interestingly, ALDH levels were increased in UM-HMC-1 and UM-HMC-3A cell lines, while UM-HMC-2 showed a reduced enzymatic activity., Conclusion: Cephaeline has shown anti-cancer properties in all MEC cell lines tested by regulating tumor cells' viability, migration, proliferation, and disrupting the ability of cancer cells to generate tumorspheres., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

For decades, the link between poor oral hygiene and the increased prevalence of oral cancer has been suggested. Most recently, emerging evidence has suggested that chronic inflammatory diseases from the oral cavity (e.g., periodontal disease), to some extent, play a role in the development of oral squamous cell carcinoma (OSCC). The present study aimed to explore the direct impact of biofilm‑induced periodontitis in the carcinogenesis process using a tobacco surrogate animal model for oral cancer. A total of 42 Wistar rats were distributed into four experimental groups: Control group, periodontitis (Perio) group, 4‑nitroquinoline 1‑oxide (4‑NQO) group and 4NQO/Perio group. Periodontitis was stimulated by placing a ligature subgingivally, while oral carcinogenesis was induced by systemic administration of 4NQO in the drinking water for 20 weeks. It was observed that the Perio, 4NQO and 4NQO/Perio groups presented with significantly higher alveolar bone loss compared with that in the control group. Furthermore, all groups receiving 4NQO developed lesions on the dorsal surface of the tongue; however, the 4NQO/Perio group presented larger lesions compared with the 4NQO group. There was also a modest overall increase in the number of epithelial dysplasia and OSCC lesions in the 4NQO/Perio group. Notably, abnormal focal activation of cellular differentiation (cytokeratin 10‑positive cells) that extended near the basal cell layer of the mucosa was observed in rats receiving 4NQO alone, but was absent in rats receiving 4NQO and presenting with periodontal disease. Altogether, the presence of periodontitis combined with 4NQO administration augmented tumor size in the current rat model and tampered with the protective mechanisms of the cellular differentiation of epithelial cells.

The human body is endowed with an extraordinary ability to maintain different oxygen levels in various tissues and organs. The maintenance of physiological levels of oxygen is known as physoxia. The development of hypoxic conditions plays an important role in the biology of several pathologies, including cancer. In vitro studies using normal and neoplastic cells require that culture conditions be carried out under appropriate oxygen levels, either physoxic or hypoxic conditions. Such requirements are difficult to widely implement in laboratory practice, mainly due to the high costs of specialized equipment. In this work, we present and characterize a cost-effective method to culture cells under a range of oxygen levels using deoxidizing pouches. Our results show that physoxic and hypoxic levels using deoxidizing absorbers can be achieved either by implementing a gradual change in oxygen levels or by a regimen of acute depletion of oxygen. This approach triggers the activation of an epithelial-mesenchymal transition in cancer cells while stimulating the expression of HIF-1α. Culturing cancer cells with deoxidizing agent pouches revealed PI3K oncogenic pathway exacerbations compared to tumor cells growing under atmospheric levels of oxygen. Similar to the PI3K signaling disturbance, we also observed augmented oxidative stress and superoxide levels and increased cell cycle arrest. Most interestingly, the culture of cancer cells under hypoxia resulted in the accumulation of cancer stem cells in a time-dependent manner. Overall, we present an attractive, cost-effective method of culturing cells under appropriate physoxic or hypoxic conditions that is easily implementable in any wet laboratory equipped with cell culture tools.

Parathyroid tumors are very prevalent conditions among endocrine tumors, being the second most common behind thyroid tumors. Secondary hyperplasia can occur beyond benign and malignant neoplasia in parathyroid glands. Adenomas are the leading cause of hyperparathyroidism, while carcinomas represent less than 1% of the cases. Tumor suppressor gene mutations such as MEN1 and CDC73 were demonstrated to be involved in tumor development in both familiar and sporadic types; however, the epigenetic features of the parathyroid tumors are still a little-explored subject. We present a review of epigenetic mechanisms related to parathyroid tumors, emphasizing advances in histone modification and its perspective of becoming a promising area in parathyroid tumor research.

Objectives: To modify the surface of denture base material by coating it with cinnamon-laden nanofibers to reduce Candida albicans (C. albicans) adhesion and/or proliferation., Materials and Methods: Heat-cured poly(methyl methacrylate) (PMMA) specimens were processed and coated, or not, with cinnamon-laden polymeric nanofibers (20 or 40 wt.% of cinnamon relative to the total polymer weight). Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) analyses of the nanofibers were performed. Antifungal activity was assessed through agar diffusion and colony-forming unit (CFU/mL) assays. Representative SEM morphological analysis was carried out to observe the presence/absence of C. albicans on the fibers. Alamar blue assay was used to determine cell toxicity. Analysis of variance and the Tukey's test were used to analyze the data (α = 0.05)., Results: SEM imaging revealed nanofibers with adequate (i.e., bead-free) morphological characteristics and uniform microstructure. FTIR confirmed cinnamon incorporation. The cinnamon-laden nanofibers led to growth inhibition of C. albicans. Viable fungal counts support a significant reduction on CFU/mL also directly related to cinnamon concentration (40 wt.%: mean log 6.17 CFU/mL < 20 wt.%: mean log 7.12 CFU/mL), which agrees with the SEM images. Cinnamon-laden nanofibers at 40 wt.% led to increased cell death., Conclusions: The deposition of 20 wt.% cinnamon-laden nanofibers onto PMMA surfaces led to a significant reduction of the adhesive and/or proliferative ability of C. albicans, while maintaining epithelial cells' viability., Clinical Relevance: The high recurrence rates of denture stomatitis are associated with patient non-adherence to treatments and contaminated prostheses use. Here, we provide the non-patients' cooperation sensible method, which possesses antifungal action, hence improving treatment effectiveness., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: The phosphatidylinositol 3-kinase/protein kinase-B/mammalian target of the rapamycin (PI3K-AKT-mTOR) signaling pathway is an important regulator of cell proliferation, survival, and motility. The gain or loss of function of proteins related to this pathway results in the neoplastic transformation in several types of cancers. This study aimed to evaluate the expression profile of the PI3K-AKT-mTOR pathway in patients with head and neck squamous cell carcinoma (HNSCC) and HNSCC cell lines., Study Design: The study involved 26 formalin-fixed paraffin-embedded tissue samples from patients with HNSCC. The analysis of immunohistochemical expression of PI3K, AKT, p-mTOR, and phosphatase and tensin homolog (PTEN) proteins was performed by a quantitative assessment. The in vitro gene and protein expression evaluation was performed by real-time polymerase chain reaction and Western blot assay, respectively, in the human cell lines SCC-9 and FaDu., Results: High levels of PI3K, AKT, and p-mTOR were found in most HNSCC tumors. Following this result, we observed low amounts or absence of PTEN in most samples. Additionally, the FaDu cells (pharynx) showed higher AKT expression but lower expression of p-mTOR compared with SCC-9 cells (oral cavity), which hints at a loco-anatomical relevance., Conclusion: Overall, this study found increased expression of the PI3K-AKT-mTOR pathway along with evident PTEN reduction in head and neck cancer., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Epithelial to mesenchymal transition promotes cell adhesion loss, enabling invasion and metastasis. MicroRNAs are a class of small non-codifying RNAs that regulate gene expression., Objectives: The aim of this study was to evaluate the expression of microRNAs that could regulate the expression of EMT factors in salivary gland tumors (SGTs)., Methods and Results: The expression of microRNAs miR-9, miR-34a, miR-101, miR-138, miR-155, and miR-200c-described in the literature to target EMT factors-was evaluated by Real-time RT-PCR (qPCR) in pleomorphic adenoma (PA), mucoepidermoid carcinoma (MEC) and adenoid cystic carcinoma (ACC) samples. Bioinformatics tools were applied to identify miR targets and immunohistochemistry was used to examine the expression of the proteins E-cadherin, Twist, ZEB-1, β-Catenin, and c-Kit. Comparing miR expression among SGT types, we observed increased expression of miR-9, and miR-138 in PAs, and increased miR-155 expression in MECs. Low-grade MECs exhibited increased miR-155 expression (p = 0.032). MECs that generated lymph node metastases had increased miR-200c levels (p = 0.018). MECs tended to have decreased expression of EMT-related proteins when compared to the other SGT types (c-Kit p < 0.001, Twist p = 0.014, and ZEB p = 0.012). Notably, increased c-Kit expression was associated with the presence of perineural infiltration in ACC (p = 0.050)., Conclusions: This study provides evidence of alterations in the expression of EMT-factors regulating miRs, especially of miR-9, miR-138, miR-155, and miR-200c. No significant relationships were found between the expression of these miRs and proteins associated with EMT in SGTs., (© 2021. The Author(s), under exclusive licence to Springer Nature B.V.)

A systematic review (SR) and meta-analysis were conducted to determine the prevalence of PI3K-AKT-mTOR signaling pathway mutations in patients with head and neck cancer (HNC). Overall, 105 studies comprising 8630 patients and 1306 mutations were selected. The estimated mutations prevalence was 13 % for PIK3CA (95 % confidence interval [CI] = 11-14; I 2 = 82 %; p < 0.0001), 4% for PTEN (95 % CI = 3-5; I 2 = 55 %; p < 0.0001), 3% for MTOR (95 % CI = 2-4; I 2 = 5%; p = 0.40), and 2% for AKT (95 % CI = 1-2; I 2 = 50 %; p = 0.0001). We further stratified the available data of the participants according to risk factors and tumor characteristics, including HPV infection, tobacco use, alcohol exposure, TNM stage, and histological tumor differentiation, and performed subgroup analysis. We identified significant associations between PI3K-AKT-mTOR pathway-associated mutations and advanced TNM stage (odds ratio [OR] = 0.20; 95 % CI = 0.09-0.44; I² = 71 %; p = 0.0001) and oropharyngeal HPV-positive tumors and PIK3CA mutations (OR = 17.48; 95 % CI = 4.20-72.76; I² = 69 %; p < 0.0002). No associations were found between alcohol and tobacco exposure, and tumor differentiation grade. This SR demonstrated that the PI3K-AKT-mTOR pathway emerges as a potential prognostic factor and could offer a molecular basis for future studies on therapeutic targeting in HNC patients., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Introduction: Head and neck cancer is a deadly cancer that ranks among the six most common cancers worldwide. The HPV vaccine has been used to prevent head and neck cancer of the oropharynx, and changes in health policies and state law are impacting the role of dental professionals in HPV vaccination. However, relatively little is known about dental professionals' attitudes regarding the vaccine., Objectives: Our study assesses dental professionals' willingness to administer the HPV vaccine, their confidence discussing HPV with patients, beliefs about the vaccine's efficacy, perceived barriers to administering it, and sites of referral., Methods: We surveyed 623 dental professionals, including dentists, hygienists, dental students, and hygiene students across Michigan. Attitudes toward the vaccine and predictive characteristics were evaluated by logistic regression, ANOVAs, and t-tests., Results: The majority of the respondents (51% of dentists, 63% of hygienists, 82% of dental students, and 71% of hygiene students) were willing to administer the HPV vaccine if allowed by law. The role of dental and dental hygiene students would be one of advocacy, educating and recommending the vaccine, and the dental students administering it once licensed. Dental professionals were variably confident discussing HPV with patients and generally believed it enhanced patients' health. Stronger confidence and beliefs were associated with greater willingness to administer the vaccine. Barriers among professionals opposing the HPV vaccine included lack of knowledge on the subject, liability concerns, and personal beliefs., Conclusion: Dental professionals can become leaders in preventing HPV-related cancers. Training and continuing education courses could enhance their confidence and willingness to recommend and administer the HPV vaccine., Policy Implications: Legislation that permits dental professionals to administer the vaccine could increase the vaccine's accessibility to patients, improve vaccination rates, and population health., Competing Interests: The authors have declared that no competing interests exist.

Emerging evidence indicates the clinical benefits of photobiomodulation therapy (PBMT) in the management of skin and mucosal wounds. Here, we decided to explore the effects of different regiments of PBMT on epithelial cells and stem cells, and the potential implications over the epigenetic circuitry during healing. Scratch-wound migration, immunofluorescence (anti-acetyl-Histone H3, anti-acetyl-CBP/p300 and anti-BMI1), nuclear morphometry and western blotting (anti-Phospho-S6, anti-methyl-CpG binding domain protein 2 [MBD2]) were performed. Epithelial stem cells were identified by the aldehyde dehydrogenase enzymatic levels and sphere-forming assay. We observed that PBMT-induced accelerated epithelial migration and chromatin relaxation along with increased levels of histones acetylation, the transcription cofactors CBP/p300 and mammalian target of rapamycin. We further observed a reduction of the transcription repression-associated protein MBD2 and a reduced number of epithelial stem cells and spheres. In this study, we showed that PBMT could induce epigenetic modifications of epithelial cells and control stem cell fate, leading to an accelerated healing phenotype., (© 2020 Wiley-VCH GmbH.)

Curcumin, a polyphenol isolated from the rhizome of Curcuma longa, has been studied because of its antioxidant, antimicrobial, and antiinflammatory properties. This study aimed to evaluate the effects of curcumin on head and neck cancer (HNC) cell lines and how it modulates the PI3K-AKT-mTOR signaling pathway. Dose-response curves for curcumin were established for hypopharynx carcinoma (FaDu), tongue carcinoma (SCC-9), and keratinocytes (HaCaT) cell lines and IC 50 values were calculated. Cell cycle and cell death were investigated through flow cytometry. Cytoskeleton organization was assessed through phalloidin+FITC staining. qPCR array and western blot were performed to analyze gene and protein expression. Curcumin reduced cell viability in a dose-dependent and selective manner, induced cell death on SCC-9 cells (necrosis/late apoptosis: 44% curcumin vs. 16.4% vehicle), and arrested cell cycle at phase G 2 /M on SCC-9 and FaDu (G 2 : SCC-9-19.1% curcumin vs. 13.4% vehicle; FaDu-37.8% curcumin vs. 12.9% vehicle). Disorganized cytoskeleton and altered cell morphology were observed. Furthermore, curcumin downregulated the PI3K-AKT-mTOR signaling pathway by modifying the expression of key genes and proteins. These findings highlight the promising therapeutic potential of curcumin to inhibit HNC growth and progression and to modulate the PI3K-AKT-mTOR pathway., (© 2020 John Wiley & Sons, Ltd.)

Objectives: To analyze the expression profile of DNA repair proteins (XRCC1 and APE1) and histone acetylation (H3K9) in oral and cutaneous lichen planus, in order to investigate potential biological markers that can clarify pathogenesis of these lesions., Design and Results: The total sample consisted of 89 lichen planus cases (66 oral and 23 cutaneous). Analysis of APE1 and XRCC1 expression was performed by immunohistochemistry in 44 oral and 20 cutaneous lichen planus, whereas the analysis of H3K9 acetylation was performed by immunofluorescence in 42 oral and 11 cutaneous lichen planus., Results: Immunoreactivity for APE1 and XRCC1 was significantly higher in cutaneous lichen planus than in oral lichen planus (P = 0.003 and P = 0.034, respectively). There was a significant and moderate positive correlation between APE1 and XRCC1 in the oral group (Rho = 0.544; P < 0.0001). In oral cases, there were no statistically significant results comparing APE1 and XRCC1 expression between reticular and erosive cases (P > 0.05). Evaluation of H9K3 histone acetylation levels did not reveal significant results comparing oral to cutaneous lichen planus, neither comparing erosive to reticular (P > 0.05)., Conclusions: Changes in the expression profile of the DNA repair proteins exerted greater influence in pathogenesis of cutaneous lichen planus than oral lichen planus, in addition, H3K9 histone acetylation is an epigenetic event found in both lesions., (Copyright © 2020. Published by Elsevier Ltd.)

Introduction: Alterations of the epigenome may influence cancer initiation and progression. At the cellular level, histones are key regulators of chromatin accessibility and gene transcription; thus, the inhibition of histone deacetylase enzymes (HDACs) constitutes an attractive target for therapy. In this study, we investigated the effects of the HDAC inhibitor entinostat on oral squamous cell carcinoma (OSCC)., Materials and Methods: We tested the effects of entinostat on OSCC cell lines. Cell viability and growth were analyzed using MTT assay. Cell cycle analysis, cell apoptosis, cancer stem cell (CSC) content, and the concentration of reactive oxygen species (ROS) in OSCC tumor cells were assessed using flow cytometry. The expression of histones and cell cycle regulatory proteins was examined by Western blot., Results: The administration of entinostat resulted in reduced proliferation of OSCC cells, followed by cell cycle arrest at the G0/G1 phase, as well as substantial tumor apoptosis. We found an increase in ROS production and significant reductions in CSCs. We also found that entinostat caused increased acetylation histone H3 and histone H4, and changes in the expression of cell cycle-associated proteins such as p21., Conclusion: This study indicates that entinostat is a potential novel therapeutic agent for OSCC by halting tumor proliferation, inducing cytotoxicity and intracellular ROS, and attacking the CSCs., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: Head and neck squamous cell carcinoma (HNSCC) is an aggressive cancer associated with poor survival. Phosphatase and tensin homolog (PTEN) is a tumor suppressor gene involved in the maintenance of stem cells. DNA methylation is a known epigenetic modification involved in tumor progression. In this study, we investigated the effect of the DNA demethylation agent 5-AZA-2'-deoxycytidine (5-AZA) over HNSCC and its population of cancer stem cells (CSCs) presenting dysfunctional PTEN., Study Design: The effects of 5-AZA on HNSCC were evaluated by using WSU-HN13 cells. CSC was assessed by sphere-forming assays, along with the endogenous levels of aldehyde dehydrogenase. The clonogenic potential of tumors was evaluated, along with the protein expression of mTOR signaling and the identification of nuclear factor-κB (NF-κB) and epithelial-mesenchymal transition (EMT)-associated genes, using real-time polymerase chain reaction (PCR)., Results: We observed that loss of PTEN enhances tumor biologic behavior, including colony- and tumor sphere-forming abilities. We also found that 5-AZA has an inhibitory effect over the CSCs and molecular markers associated with the NF-κB and EMT pathways., Conclusions: Our findings suggest that the stratification of treatment of HNSCC based on PTEN status may identify a subset of patients who can benefit from the coadministration of 5-AZA., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Photobiomodulation therapy (PBMT) is an emerging therapeutic modality designed to prevent and treat chemotherapy-driven oral mucositis (OM). However, the response of tumor cells to the effects of PBMT remains poorly understood. Our study explores the effects of PBMT in head and neck squamous cell carcinoma (HNSCC) based on cellular proliferation, migration, and survival of tumor cells and its population of cancer stem cells (CSC). We explored the behavior of two HNSCC cell lines (HN6 and HN13) under two distinct conditions, a physiological growing condition (10% FBS), and under stress growing condition (2% FBS) prior to irradiation using diode laser (InGaAlP; MM Optics, São Carlos, SP, Brazil). Diode laser (660 nm) was applied with a power of 100 mW delivering a total energy per point of 0.24 J. MTT and wound healing test (scratch assay) were performed to evaluate, respectively, proliferation and migration of tumor cells. Clonogenic and spheres formation assays were also performed to evaluate the survival and percentage of CSC upon irradiation. Overall, we observed that PBMT does not exacerbate the behavior of HNSCC. We could only observe a decrease in cellular proliferation of one cell line (HN6) when cultured under nutritional stress conditions (p < .05). There were no significant differences between the control and the PBMT groups regarding cell migration, survival and the percentage of CSC. Collectively, our results suggest that in vitro administration of PBMT to HNSCC does not modify the behavior of tumor cells., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: Despite multiple modalities used to management of head and neck squamous cell carcinoma (HNSCC), disease control remains unsatisfactory. Immunotherapy is emerging as a novel therapeutic approach. This systematic review assesses clinical data regarding immunotherapy efficacy and safety., Methods: Data from 11 clinical trials testing immunotherapy in HNSCC were assessed. We performed the meta-analysis to correlate the overall survival (OS), response rate (RR), adverse effects, HPV status, and PD-L1 expression., Results: Immunotherapy extended OS (hazard ratio = 0.77, p < 0.0001) and RR significantly (risk ratio = 1.41, p = 0.02). Patients with HPV-positive HNSCC exhibited a better RR (risk ratio = 1.29, p = 0.24) and OS (11.5 vs. 6.3 months). PD-L1 positive tumors showed a higher OS (9.9 vs. 6.5 months). Moreover, immunotherapy caused less adverse effects than standard therapy., Conclusion: Our results indicate the benefit of immunotherapy for improving RR and OS of HNSCC patients. The benefit is higher in patients with HPV and PD-L1 positive tumors., Competing Interests: Declaration of Competing Interest The authors (M.M.G, G.A.B, I.P.T, R.M.C, E.N.S.G, L.P.K, and C.H.S) declare no commercial or financial conflict of interest. The co-author T.B.O is a consultant (advisory board) for Bristol Myers Squibb (BMS), Merck Sharp Dohme (MSD) and Merck Serono (MS). BMS, MSD and MS had no role in study design, data collection, analysis, preparation and decision to publish this systematic review and metanalysis., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Asparaginase is fundamental to the treatment of haematological malignancies. However, little has been studied on the effects that asparaginase could exert on solid tumours. Thus, this study aimed to evaluate the effects of asparaginase on an oral carcinoma cell line. The cytotoxicity of asparaginase in SCC-9 (tongue squamous cell carcinoma) and HaCaT (human keratinocyte) cell lines was evaluated with MTT cell viability assay. The cells were treated with asparaginase at 0.04, 0.16, 0.63, 1.0, 1.5, 2.5, and 5.0 IU/mL. Dose-response curves and IC 50 values were obtained and the Tumour Selectivity Index (TSI) was calculated. The effect of asparaginase on procaspase-3 and nuclear factor κB (NFκB) expression was evaluated with western blot because it was reported that the overexpression of NFκB has been shown to contribute to tumour cell survival, proliferation, and migration. Caspase 3/7 staining was performed to identify cell death using flow cytometry. Effective asparaginase concentrations were lower for SCC-9 cells when compared to HaCaT cells. The cytotoxicity results at 48 and 72 hours were significantly different for SCC-9 cells. The TSI indicated that asparaginase was selective for the tumour cells. A decrease in procaspase-3 and NFκB protein levels was observed in SCC-9 cells. Furthermore, asparaginase resulted in significant apoptosis after 48 and 72 hours. Based on these results, asparaginase was cytotoxic in a dose- and time-dependent manner, induces apoptosis, and reduces NFκB expression in oral cancer cells. These results encourage further studies on the effectiveness of this enzyme as a treatment for solid tumours, especially head and neck cancer., (© 2020 John Wiley & Sons Australia, Ltd.)

Background: The skin is the largest organ of the human body. Upon injury, the skin triggers a sequence of signaling pathways that induce epithelial proliferation, migration, and ultimately, the re-establishment of the epithelial barrier. Our study explores the unknown epigenetic regulations of wound healing from a histone perspective. Posttranslational modifications of histones enhance chromatin accessibility and modify gene transcription., Methods: Full-thickness wounds were made in the dorsal skin of twenty-four C57/B6 mice (C57BL/6J), followed by the use of ring-shaped silicone splints to prevent wound contraction. Tissue samples were collected at three time points (post-operatory day 1, 4, and 9), and processed for histology. Immunofluorescence was performed in all-time points using markers for histone H4 acetylation at lysines K5, K8, K12, and K16., Results: We found well-defined histone modifications associated with the stages of healing. Most exciting, we showed that the epidermis located at a distance from the wound demonstrated changes in histone acetylation, particularly the deacetylation of histone H4K5, H4K8, and H4K16, and hyperacetylation of H4K12. The epidermis adjacent to the wound revealed the deacetylation of H4K5 and H4K8 and hyperacetylation of H4K12. Conversely, the migratory epithelium (epithelial tongue) displayed significant acetylation of H4K5 and H4K12. The H4K5 and H4K8 were decreased in the newly formed epidermis, which continued to display high levels of H4K12 and H4K16., Conclusions: This study profiles the changes in histone H4 acetylation in response to injury. In addition to the epigenetic changes found in the healing tissue, these changes also took place in tissues adjacent and distant to the wound. Furthermore, not only deacetylation but also hyperacetylation occurred during tissue repair and regeneration.

Objectives: The mechanisms involved in the initiation and progression of peri-implantitis lesions are poorly understood. It was the aim to determine the content and activation status of macrophages present in human peri-implantitis lesions and compare the current findings with the macrophage polarization associated with periodontitis lesions., Material and Methods: A total of 14 patients were studied in this investigation. Seven were soft tissue biopsies from dental implants affected by peri-implantitis that required explantation. Seven biopsies were from chronic periodontal disease. Immunofluorescence stains were performed using biomarkers to identify macrophages (CD68 + ) undergoing M1 polarization (iNOS + ) and M2 polarization (CD206 + ), along with Hoechst 33,342 to identify DNA content. All samples were stained and photographed, and double-positive cells for CD68 and iNOS or CD68 and CD206 were quantified., Results: All peri-implantitis biopsies examined revealed a mixed population of macrophages undergoing M1 polarization and M2 polarization. Further analysis demonstrated the co-expression of iNOS and CD206, which indicates the presence of a heterogenic immune response on peri-implantitis lesions. Macrophage polarization in peri-implantitis lesions presents a distinct pattern than in periodontitis. We observed a significant increase in the population of M1 macrophages on peri-implantitis samples compared to periodontal disease samples., Conclusion: Our results demonstrate that peri-implantitis has higher numbers of macrophages displaying a distinct macrophage M1 polarization signature compared to periodontitis lesions. This pattern may explain, in part, the distinct nature of peri-implantitis progression vs. periodontitis in humans., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Although the human body can heal, it takes time, and slow healing and chronic wounds often occur. Thus, identifying novel therapies to aid regeneration is needed. Here, we conducted a systematic review following the Preferred Reporting Items for Systematic Reviews guidelines and assessed preclinical studies on phosphatase and tensin homolog (PTEN) inhibitors and their effects on tissue repair and regeneration. In conditions associated with neurodegeneration, tissue injury and ischemia, the PTEN-regulated PI3K/AKT signaling pathway is activated. The use of PTEN inhibitors resulted in better tissue response by reducing the healing time and lesion sizes or inducing neuronal regeneration. Notably, all studies included in this systematic review indicated that pharmacological inhibition of PTEN enhanced the repair process of the eye, lung, muscle and nervous system.

The circadian rhythm regulates the physiology and behavior of living organisms in a time-dependent manner. Clock genes have distinct roles including the control over gene expression mediated by the transcriptional activators CLOCK and BMAL1, and the suppression of gene expression mediated by the transcriptional repressors PER1/2 and CRY1/2. The balance between gene expression and repression is key to the maintenance of tissue homeostasis that is disrupted in the event of an injury. In the skin, a compromised epithelial barrier triggers a cascade of events that culminate in the mobilization of epithelial cells and stem cells. Recruited epithelial cells migrate towards the wound and reestablish the protective epithelial layer of the skin. Although we have recently demonstrated the involvement of BMAL and the PI3K signaling in wound healing, the role of the circadian clock genes in tissue repair remains poorly understood. Here, we sought to understand the role of BMAL1 on skin healing in response to injury. We found that genetic depletion of BMAL1 resulted in delayed healing of the skin as compared to wild-type control mice. Furthermore, we found that loss of Bmal1 was associated with the accumulation of Reactive Oxygen Species Modulator 1 (ROMO1), a protein responsible for inducing the production of intracellular reactive oxygen species (ROS). The slow healing was associated with ROS and superoxide dismutase (SOD) production, and pharmacological inhibition of the oxidative stress signaling (ROS/SOD) led to cellular proliferation, upregulation of Sirtuin 1 (SIRT1), and rescued the skin healing phenotype of Bmal1 -/- mice. Overall, our study points to BMAL1 as a key player in tissue regeneration and as a critical regulator of ROMO1 and oxidative stress in the skin.

Oral leukoplakia (OL) is a white lesion of an indeterminate risk not related to any excluded (other) known diseases or disorders that carry no increased risk for cancer. Many biological markers have been used in an attempt to predict malignant transformation; however, no reliable markers have been established so far. Objective To evaluate cell proliferation and immortalization in OL, comparing non-dysplastic (Non-dys OL) and dysplastic OL (Dys OL). Methodology This is a cross-sectional observational study. Paraffin-embedded tissue blocks of 28 specimens of Non-dys OL, 33 of Dys OL, 9 of normal oral mucosa (NOM), 17 of inflammatory hyperplasia (IH), and 19 of oral squamous cell carcinomas (OSCC) were stained for Ki-67 and BMI-1 using immunohistochemistry. Results A gradual increase in BMI-1 and K-i67 expression was found in oral carcinogenesis. The immunolabeling for those markers was higher in OSCC when compared with the other groups (Kruskal-Wallis, p<0.05). Ki-67 expression percentage was higher in OL and in IH when compared with NOM (Kruskal-Wallis/Dunn, p<0.05). Increased expression of BMI-1 was also observed in OL when compared with NOM (Kruskal-Wallis/Dunn, p<0.05). No differences were observed in expression of both markers when non-dysplastic and dysplastic leukoplakias were compared. A significant positive correlation between Ki-67 and BMI-1 was found (Spearman correlation coefficient, R=0.26, p=0.01). High-grade epithelial dysplasia was associated with malignant transformation (Chi-squared, p=0.03). Conclusions These findings indicate that BMI-1 expression increases in early oral carcinogenesis and is possibly associated with the occurrence of dysplastic changes. Furthermore, our findings indicate that both Ki-67 and BMI-1 are directly correlated and play a role in initiation and progression of OSCC.

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide and is characterized by a fast-paced growth. Like other solid tumors, the HNSCC growth rate results in the development of hypoxic regions identified by the expression of hypoxia-inducible factor 1α (HIF-1α). Interestingly, clinical data have shown that pharmacological induction of intratumoral hypoxia caused an unexpected rise in tumor metastasis and the accumulation of cancer stem cells (CSCs). However, little is known on the molecular circuitries involved in the presence of intratumoral hypoxia and the augmented population of CSCs. Here we explore the impact of hypoxia on the behavior of HNSCC and define that the controlling function of phosphatase and tensin homolog (PTEN) over HIF-1α expression and CSC accumulation are de-regulated during hypoxic events. Our findings indicate that hypoxic niches are poised to accumulate CSCs in a molecular process driven by the loss of PTEN activity. Furthermore, our data suggest that targeted therapies aiming at the PTEN/PI3K signaling may constitute an effective strategy to counteract the development of intratumoral hypoxia and the accumulation of CSCs.-Nascimento-Filho, C. H. V., Webber, L. P., Borgato, G. B., Goloni-Bertollo, E. M., Squarize, C. H., Castilho, R. M. Hypoxic niches are endowed with a protumorigenic mechanism that supersedes the protective function of PTEN.

Head and neck cancer (HNSCC) are one of the most common solid malignancies of the world, being responsible for over 350,000 deaths every year. Much of the complications in managing and treating HNSCC advent from the complex genetic and epigenetic landscape of the disease. Emerging information has shown promising results in targeting BRD4, an epigenetic regulator bromodomain that functions as a scaffold for transcription factors at promoters and super-enhancers. Here we show that by disrupting the interaction between BRD4 and histones using the bromodomain inhibitor JQ1, HNSCC cells undergo cell growth arrest followed by cellular senescence. Mechanistically, JQ1 negatively impacted the phosphorylation levels of SIRT1 along with the acetylation levels of mutant p53 (active). In vivo administration of JQ1 resulted in disruption of HNSCC growth along with the activation of cellular senescence, observed by the accumulation of DNA double-strand breaks, p16 ink4 , accumulation of senescence-associated beta-galactosidase, and loss of phosphorylated Sirt1 ser47 . Furthermore, we also demonstrate that JQ1 was efficient in reducing the population of cancer stem cells from HNSCC xenografts., (Copyright © 2019. Published by Elsevier B.V.)

Aim: To explore the M1/M2 status of macrophage polarization from healthy, gingivitis, and periodontitis patient samples., Materials and Methods: Gingival biopsies were collected from 42 individuals (14 gingivitis, 18 periodontitis, and 10 healthy samples) receiving periodontal therapy. Histomorphology analysis was performed with haematoxylin and eosin staining. Immunofluorescence was performed using a combination of CD68 (macrophages), iNOS (M1), and CD206 (M2) in order to acquire changes in macrophage polarization at a single-cell resolution. Macrophages were quantified under microscopy using narrow wavelength filters to detect Alexa 488, Alexa 568, Alexa 633 fluorophores, and Hoechst 33342 to identify cellular DNA content., Results: Gingivitis and periodontitis samples showed higher levels of macrophages compared with healthy samples. Unexpectedly, periodontitis samples displayed lower levels of macrophages dispersed in the stromal tissues compared with gingivitis samples; however, it remained higher than healthy tissues. The polarization of macrophages appears to be reduced in periodontitis and showed similar levels to those observed in healthy tissues., Conclusions: Our study found that gingivitis and periodontitis differ from each other by the levels of macrophage infiltrate, but not by changes in macrophage polarization., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Purpose: Emerging evidence indicates that bromodomains comprise a conserved class of epigenome readers involved in cancer development and inflammation. Bromodomains are associated with epigenetic modifications of gene transcription through interactions with lysine residues of histone tails. Particularly, the bromodomain and extra-terminal domain (BET) family member BRD4 has been found to be involved in the control over oncogenes, including c-MYC, and in the maintenance of downstream inflammatory processes. The objective of this study was to evaluate the effect of pharmacologically displacing BRD4 in mucoepidermoid carcinoma (MEC) cells., Methods: We assessed the presence of BRD4 levels in a panel of human MEC tissue samples in conjunction with histological grading and clinical information. In vitro studies were carried out using human MEC-derived cell lines. The BET inhibitor iBET762 was administered to MEC cells to assess the impact of disrupted BRD4 signaling on colony forming capacities and cell cycle status. The activation of cellular senescence induced by iBET762 was determined by immunohistochemical staining for p16 ink4 . Flow cytometry was used to identify populations of cancer stem cells in MEC-derived cell lines., Results: We found that primary human MECs and MEC-derived cell lines are endowed with high BRD4 expression levels compared to those in normal salivary glands. We also found that, by displacing BRD4 from chromatin using the BET inhibitor iBET762, MEC cells lose their colony forming capacities and undergo G1 cell cycle arrest and senescence. Finally, we found that targeted displacement of BRD4 from chromatin results in depletion of cancer stem cells from the overall MEC cell populations., Conclusions: Our findings indicate that bromodomain-mediated gene regulation constitutes an epigenetic mechanism that is deregulated in MEC cells and that the use of BET inhibitors may serve as a feasible therapeutic strategy to manage MECs.

Objectives: The presence of titanium (Ti) particles around dental implants has been reported in the literature for decades. The prospective presence of Ti debris on soft tissues surrounding dental implants has not been systematically investigated and remains to be explored. Hence, this review aimed to evaluate the origin, presence, characteristics, and location of Ti particles in relation to dental implants., Material and Methods: Literature searches were conducted by two reviewers independently based on the PRISMA guidelines. The systematic review identified studies on Ti particles derived from dental implants. We evaluated several parameters, including anatomical location, and the suspected methods of Ti particles release., Results: The search resulted in 141 articles, of which 26 were eligible and included in the systematic review of the literature. The investigations reported Ti and metal-like particles in the soft (i.e., epithelial cells, connective tissue, and inflammatory cells) and hard (bone crest and bone marrow) tissues around the dental implants. Shape and size of the particles varied. The current literature reported a size range from 100 nm to 54 µm identified by multiple particles identification methods., Conclusion: Ti particles surrounding peri-implant tissues are a common finding. Peri-implantitis sites presented a higher number of particles compared to healthy implants. The particles were mostly around the implants and inside epithelial cells, connective tissue, macrophages, and bone. Various mechanisms were described as causes of Ti release, including friction during implant insertion, corrosion of the implant surface, friction at the implant-abutment interface, implantoplasty, and several methods used for implant surface detoxification., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)