Search

Periodontitis is a disease characterized by tooth-associated microbial biofilms that drive chronic inflammation and destruction of periodontal-supporting tissues. In some individuals, disease progression can lead to tooth loss. A similar condition can occur around dental implants in the form of peri-implantitis. The immune response to bacterial challenges is not only influenced by genetic factors, but also by environmental factors. Epigenetics involves the study of gene function independent of changes to the DNA sequence and its associated proteins, and represents a critical link between genetic and environmental factors. Epigenetic modifications have been shown to contribute to the progression of several diseases, including chronic inflammatory diseases like periodontitis and peri-implantitis. This review aims to present the latest findings on epigenetic influences on periodontitis and to discuss potential mechanisms that may influence peri-implantitis, given the paucity of information currently available.

Purpose: There are no effective treatment options for patients with advanced adenoid cystic carcinoma (ACC). Here, we evaluated the effect of a new small molecule inhibitor of the MDM2–p53 interaction (MI-773) in preclinical models of ACC.Experimental Design: To evaluate the anti-tumor effect of MI-773, we administered it to mice harboring three different patient-derived xenograft (PDX) models of ACC expressing functional p53. The effect of MI-773 on MDM2, p53, phospho-p53, and p21 was examined by Western blots in 5 low passage primary human ACC cell lines and in MI-773-treated PDX tumors.Results: Single-agent MI-773 caused tumor regression in the 3 PDX models of ACC studied here. For example, we observed a tumor growth inhibition index of 127% in UM-PDX-HACC-5 tumors that was associated with an increase in the fraction of apoptotic cells (P = 0.015). The number of p53-positive cells was increased in MI-773-treated PDX tumors (P < 0.001), with a correspondent shift in p53 localization from the nucleus to the cytoplasm. Western blots demonstrated that MI-773 potently induced expression of p53 and its downstream targets p21, MDM2, and induced phosphorylation of p53 (serine 392) in low passage primary human ACC cells. Notably, MI-773 induced a dose-dependent increase in the fraction of apoptotic ACC cells and in the fraction of cells in the G1 phase of cell cycle (P < 0.05).Conclusions: Collectively, these data demonstrate that therapeutic inhibition of the MDM2–p53 interaction with MI-773 activates downstream effectors of apoptosis and causes robust tumor regression in preclinical models of ACC. Clin Cancer Res; 22(14); 3550–9. ©2016 AACR.

Table S1: (Table depicting patient demographics and tumor characteristics); Table S2: (Table depicting STR profiles of experimental models used here); Figure S1: (Characterization of UM-PDX-HACC-5, a PDX model of adenoid cystic carcinoma); Figure S2: (MI-773 induces ACC tumor regression); Figure S3: (MI-773 induces ACC tumor regression in an additional model of ACC); Figure S4: (Effect of MI-773 is p53-dependent); Figure S5: (Histopathology of UM-PDX-HACC-5 tumors treated with MI-773); Figure S6: (Aminoacid sequence of p53 in the ACC models used in this project)

Supplementary Figure Legends 1-2 from Chemoprevention and Treatment of Experimental Cowden's Disease by mTOR Inhibition with Rapamycin

Supplementary Figure 2 from Chemoprevention and Treatment of Experimental Cowden's Disease by mTOR Inhibition with Rapamycin

Supplementary Figure 1 from Chemoprevention and Treatment of Experimental Cowden's Disease by mTOR Inhibition with Rapamycin

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.

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.

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.

Background Aim of the pilot study was the histologic classification of the inflamed peri-implant soft tissue around ceramic implants (CI) in comparison with titanium implants (TI). Methods Peri-implant tissue were retrieved from 15 patients (aged 34 to 88 years, seven males/eight females) with severe peri-implantitis (eight CI, seven TI). The peri-implant soft tissue samples were retrieved from the sites during scheduled removal of the implant and prepared for immunohistochemical analysis. Monoclonal antibodies (targeting CD3, CD20, CD138, and CD68) were used to identify T- and B-cells, plasma cells and macrophages. Quantitative assessment was performed by one histologically trained investigator. Linear mixed regression models were used. Results A similar numerical distribution of the cell population was found in peri-implantitis around CI compared with TI. CD3 (TI, 17% to 85% versus CI, 20% to 70% of total cell number) and CD138 (TI, 1% to 73% versus CI, 12% to 69% of total cell number) were predominantly expressed. Notably, patient-individual differences of numerical cell distribution were detected. Co-localization of B- and T-lymphocytes was observed. Conclusions Peri-implantitis around CI in comparison with TI seems to have a similar histological appearance. Differences in cellular composition of peri-implantitis lesions might also depend on the patient's specific immune status and not only on the material used.

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 IC50 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 G2 /M on SCC-9 and FaDu (G2 : 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.

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.

Purpose The purpose of this study was to provide sufficient information on the clinical outcome of zirconia implants, mainly observing the survival rate and marginal bone loss (MBL), with a minimum follow-up of 12 months, to verify the adoption of ceramics as a rational possibility for dental implants. Materials and methods A systematic electronic search through the PubMed (MEDLINE) and EMBASE databases was performed by two independent reviewers to identify clinical studies published between January 2005 and April 2019 containing a minimum of 10 patients per study and 12 months of follow-up after functional loading. References from the selected articles were manually reviewed for further studies. Results From the initial 1,225 articles retrieved, 19 met all the inclusion criteria. The marginal bone remodeling accounted for mean losses of 0.8 mm (95% CI: 0.60 to 1.00 mm) and 1.01 mm (95% CI: 0.72 to 1.29 mm) at 1 year and 2 years postloading, respectively. The failure rate of 6.8% was calculated for a mean follow-up period of 2.75 years, where the prevalence of early failure, late failure, and implant fracture was 3.4%, 1.7%, and 1.7%, respectively. The meta-analysis associated with the survival rate of one- and two-piece zirconia dental implants was hindered due to the lack of confidence interval or standard deviation information in most of the included articles. Conclusion Zirconia implants presented MBL values consistent with the standard in the global consensus, high survival rates, and considerable clinical results at short-term observation periods following prosthetic delivery.

Despite major progress in elucidating the pathobiology of head and neck squamous cell carcinoma (HNSCC), the high frequency of disease relapse correlates with unacceptably deficient patient survival. We previously showed that cancer stem-like cells (CSCs) drive tumorigenesis and progression of HNSCC. Although CSCs constitute only 2–5% of total tumor cells, CSCs contribute to tumor progression by virtue of their high tumorigenic potential and their resistance to chemo-, radio-, and immunotherapy. Not only are CSCs resistant to therapy, but cytotoxic agents actually enhance cancer stemness by activating transcription of pluripotency factors and by inducing expression of Bmi-1, a master regulator of stem cell self-renewal. We hypothesized therapeutic inhibition of interleukin-6 receptor (IL-6R) suppresses Bmi-1 to overcome intrinsic chemoresistance of CSCs. We observed that high Bmi-1 expression correlates with decreased (p = 0.04) recurrence-free survival time in HNSCC patients (n = 216). Blockade of IL-6R by lentiviral knockdown or pharmacologic inhibition with a humanized monoclonal antibody (Tocilizumab) is sufficient to inhibit Bmi-1 expression, secondary sphere formation, and to decrease the CSC fraction even in Cisplatin-resistant HNSCC cells. IL-6R inhibition with Tocilizumab abrogates Cisplatin-mediated increase in CSC fraction and induction of Bmi-1 in patient-derived xenograft (PDX) models of HNSCC. Notably, Tocilizumab inhibits Bmi-1 and suppresses growth of xenograft tumors generated with Cisplatin-resistant HNSCC cells. Altogether, these studies demonstrate that therapeutic blockade of IL-6R suppresses Bmi-1 function and inhibits cancer stemness. These results suggest therapeutic inhibition of IL-6R might be a viable strategy to overcome the CSC-mediated chemoresistance typically observed in HNSCC patients.

AIM: To Evaluate the potential use of Cephaeline as a therapeutic strategy to manage mucoepidermoid carcinomas of the salivary glands. MATERIAL AND METHODS: Mucoepidermoid carcinoma cell lines UM-HMC-1, UM-HMC-2, and UM-HMC-3A MEC 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 CSC 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 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 shown a reduced enzimatic activity. CONCLUSION: Cephaeline has shown anti-cancer properties in all MEC cell lines tested by regulating tumor cells viablity, migration, proliferation, and by disrupting the ability of cancer cells in generate tumorspheres.

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.

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.

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.

Objectives Mucoepidermoid carcinoma (MEC) is the most common type of salivary gland malignancy. Advanced or high-grade MECs are refractory to chemotherapy, often leading to tumor recurrence/metastasis and abysmal ~35% 5-year survival. Causal links have been established between Epithelial Growth Factor Receptor (EGFR) activation and poor outcome. Herein we investigated the therapeutic efficacy of EGFR inhibition against MEC using in vitro pre-clinical models. Materials and Methods Five human MEC cell lines were used in cell viability, cytotoxicity, apoptosis, cell cycle, 2D-clonogenicity, and 3D-spheroid formation assays following treatment with Erlotinib (EGFR inhibitor), SAHA (Histone Deacetylase inhibitor; HDAC) and CUDC-101 (dual EGFR-HDAC inhibitor). Effects on MEC cancer stem cells were evaluated using flow cytometry. Gene expression and pathway regulation were evaluated via qPCR and Western blot, respectively. Results MEC cells enter a quiescent, non-proliferative yet rapidly reversible drug tolerant state upon EGFR inhibition. Despite robust suppression of MEC cell proliferation, no discernable apoptosis is detected. Combination of EGFR and HDAC inhibitors exhibits synergistic effects, exerting ~5-fold more potent cell cytotoxicity compared to HDAC or EGFR monotherapy. CUDC-101, a single molecule with dual EGFR-HDAC inhibitor moieties, exerts irreversible and potent cytotoxic activity against MEC cells and blunts MEC cancer stem-cell tumorigenicity. Conclusion MEC cells are intrinsically tolerant to EGFR inhibition. Combining EGFR and HDAC inhibitors exerts synergistic and potent cytotoxic effects, suggesting that EGFR inhibitors still hold significant promise against MEC. Future studies are needed to assess the applicability and efficacy of dual EGFR-HDAC inhibitors for the clinical management of MEC.

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.

INTRODUCTION: The maintenance of a stem cell pool is imperative to enable healing processes in the dental pulp tissue throughout life. As such, knowing mechanisms underlying stem cell self-renewal is critical to understand pulp pathophysiology and pulp regeneration. The purpose of this study was to evaluate the impact of stem cell factor (SCF) signaling through its receptor tyrosine kinase (c-Kit) on the self-renewal of human dental pulp stem cells (hDPSC). METHODS: hDPSC were stably transduced with lentiviral vectors expressing shRNA-c-Kit or vector control. The impact of the SCF/c-Kit axis on hDPSC self-renewal was evaluated using a pulpsphere assay in low attachment conditions and by evaluating the expression of polycomb complex protein Bmi-1 (master regulator of self-renewal) by western blot and flow cytometry. RESULTS: c-Kit-silenced hDPSC formed less pulpspheres when compared to hDPSC transduced with control vector (p

Made available in DSpace on 2021-06-25T12:39:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-04-01 National Institutes of Health (NIH) /National Institute of Dental and Craniofacial Research (NIDCR) The aim of this investigation was to engineer metformin (MF)-loaded mesoporous silica nanospheres (MSNs)laden gelatin methacryloyl (GelMA) photocrosslinkable hydrogels and test their effects on the mechanical properties, swelling ratio, drug release, cytocompatibility, and osteogenic differentiation of stem cells from human exfoliated deciduous teeth (SHEDs). As-received and carboxylated MSNs (MSNs-COOH) were characterized by scanning and transmission electron microscopies (SEM and TEM), as well as Fourier-transform infrared spectroscopy (FTIR) prior to hydrogel modification. MF-MSNs-COOH were obtained by loading MF into MSNs at a 1:1 mass ratio. Upon MSNs-COOH laden-hydrogels fabrication, the mechanical properties, swelling ratio and MF release were evaluated. SHEDs were seeded on the hydrogels and cytocompatibility was examined. The effects of the MF-MSNs-COOH/GelMA on the osteogenic differentiation of SHEDs were measured by ALP activity, Alizarin Red assay, and Real-time PCR. Statistics were performed using one-way ANOVA (alpha = 0.05). Morphological (SEM and TEM) analyses of pristine and carboxylated MSNs revealed a mean particle size of 200 nm and 218 nm, respectively. Importantly, an intrinsic nanoporous structure was noticed. Incorporation of MSNs-COOH at 1.5 mg/mL in GelMA led to the highest compressive modulus and swelling ratio. The addition of MSNs-COOH (up to 3 mg/mL) in GelMA did not impact cell viability. The presence of MF in MSNs-COOH/GelMA significantly promoted cell proliferation. Significant upregulation of osteogenic-related genes (except OCN) were seen for modified (MSNs-COOH and MF-MSNs-COOH) hydrogels when compared to GelMA. Altogether, the engineered MF-MSNs-COOH/GelMA shows great promise in craniomaxillofacial applications as an injectable, cell-free and bioactive therapeutics for bone regeneration. Univ Michigan, Sch Dent, Dept Cariol Restorat Sci & Endodont, 1011 N Univ,Room 5223, Ann Arbor, MI 48109 USA China Med Univ, Sch & Hosp Stomatol, Dept Endodont, Liaoning Prov Key Lab Oral Dis, Shenyang, Peoples R China Univ Fed Pelotas, Sch Dent, Dept Restorat Dent, Pelotas, RS, Brazil Sao Paulo State Univ, Sch Dent, Dept Dent Mat & Prosthodont, Araraquara, SP, Brazil Univ Michigan, Sch Dent, Dept Periodont & Oral Med, Ann Arbor, MI 48109 USA Sao Paulo State Univ, Sch Dent, Dept Dent Mat & Prosthodont, Araraquara, SP, Brazil National Institutes of Health (NIH) /National Institute of Dental and Craniofacial Research (NIDCR): R01DE026578

Several epidemiological investigations have found associations between poor oral health and different types of cancer, including colorectal, lung, pancreatic, and oral malignancies. The oral health parameters underlying these relationships include deficient oral hygiene, gingival bleeding, and bone and tooth loss. These parameters are related to periodontal diseases, which are directly and indirectly mediated by oral bacteria. Given the increased accessibility of microbial sequencing platforms, many recent studies have investigated the link between the oral microbiome and these cancers. Overall, it seems that oral dysbiotic states can contribute to tumorigenesis in the oral cavity as well as in distant body sites. Further, it appears that certain oral bacterial species can contribute to carcinogenesis, in particular, Fusobacterium nucleatum and Porphyromonas gingivalis, based on results from epidemiological as well as mechanistic studies. Yet, the strength of the findings from these investigations is hampered by the heterogeneity of the methods used to measure oral diseases, the treatment of confounding factors, the study design, the platforms employed for microbial analysis, and types of samples analyzed. Despite these limitations, there is an overall indication that the presence of oral dysbiosis that leads to oral diseases may directly and/or indirectly contribute to carcinogenesis. Proper methodological standardized approaches should be implemented in future epidemiological studies as well as in the mechanistic investigations carried out to explore these results.

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.

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.

Malignancies from the salivary glands are rare and represent 11% of all cancers from the oropharyngeal anatomical area. Mucoepidermoid Carcinomas (MEC) is the most common malignancy from the salivary glands. Low survival rates of high-grade Mucoepidermoid Carcinomas (MEC) are particularly associated with the presence of positive lymph nodes, extracapsular lymph node spread, and perineural invasion. Most recently, the presence of cancer stem cells (CSC), and the activation of the NFκB signaling pathway have been suggested as cues for an acquired resistance phenotype. We have previously shown that NFκB signaling is very active in MEC tumors. Herein, we explore the efficacy of NFκB inhibition in combination with class I and II HDAC inhibitor to deplete the population of CSC and to destroy MEC tumor cells. Our finding suggests that disruption of NFκB signaling along with the administration of HDAC inhibitors constitute an effective strategy to manage MEC tumors.

((3RS,5SR)- and ((3RS,5RS)-2-(2-methoxybenzyl)-3-(1,10-phenanthrolin-2-yl)isoxazolidin-5-yl)methanol have been synthesized, according to 1,3-dipolar cycloaddition methodology, as DNA intercalating agents and evaluated for their anticancer activity against human cervical carcinoma HeLa and head and neck squamous cells carcinoma cell lines. The synthesized compounds exhibited good cytotoxic activity with IC50 better than cisplatin, used as the main and effective treatment for HNSCC, and a 24.3–72.0-fold selectivity respect to the 184B5 non-cancerous immortalized breast epithelial cell lines. Unwinding assay, circular dichroism data, and Uv-vis melting experiments confirmed that these compounds act as DNA intercalators with a binding constant in the order of 104 M−1. Docking studies showed that both compounds can interact as intercalating agent with both poly-d(AT)2 and poly-d(GC)2, preferring an entrance by the minor groove of the poly-d(AT)2.

Histone deacetylase inhibitors (HDACis) play an important role as valuable drugs targeted to cancer therapy: several HDACis are currently being tested in clinical trials. Two new potential HDACis 1a and 1d, characterized by the presence of a biphenyl-4-sulfonamide group as a connection unit between the N-{4-[(E)-(2-formylhydrazinylidene)methyl]-3-hydroxyphenyl} and the 2-hydroxy-N-(trifluoroacetyl)benzamide moiety, respectively, as two zinc-binding group (ZBG), have been designed, synthesized and tested for their biological activity. Surprisingly, compounds 1a and 12, this last exclusively obtained in place of 1d, exhibited a very low HDAC inhibitory activity. A serendipitous assay of these two compounds, conducted on three chemoresistant cell lines of head and neck squamous cell carcinoma (HNSCC), showed their antiproliferative activity at low nanomolar concentrations, better than cisplatin. In vitro, biological assays indicated that compounds 1a and 12 are able to increase acetylation of histone H3 and to interfere with the PI3K/Akt/mTOR pathway by inducing the accumulation of PTEN protein.

Head and neck cancer is globally challenging due to the resistance to therapy and aggressive behavior leading to high rates of mortality. Recent findings show that the tumor microenvironment plays a role in the maintenance and progression of many solid tumors, including head and neck cancer. The mechanisms involved in the modulation and regulation of the tumor microenvironment remain poorly understood. Increasing evidence suggests that epigenetic events can modulate the crosstalk between neoplastic and non-neoplastic cells during tumor progression. In this review, we explore the current understanding of the involvement of epigenetic events in the modulation of the tumor microenvironment and its impact on head and neck cancer behavior. We also explore the latest therapeutic strategies that use epigenetic-modulating drugs to manage tumor growth and progression.

Objective To evaluate the influence of periodontal therapy on DNA methylation in chronic periodontitis patients as compared to healthy individuals. Materials & Methods Twenty patients were enrolled into two groups: 1) 10 diagnosed as clinically healthy; and 2) 10 diagnosed with chronic periodontitis. Clinical measures were recorded and gingival biopsies were harvested at baseline (both patient groups) and at 2 and 8 weeks post-baseline for diseased individuals. Molecular DNA methylation analysis was performed by pyrosequencing for the putative inflammation-associated genes LINE-1, COX-2 IFN-γ, and TNF-α. Random-intercept linear regression models were applied to evaluate methylation levels across groups at baseline and the methylation changes over time in the diseased and normal tissues. Results Periodontal therapy did not influence gene expression methylation of TNF-α, IFN-γ and LINE-1 levels at normal and periodontitis sites over time. However, it significantly reduced COX-2 methylation levels comparable to healthy individuals at both 2 and 8 weeks post-treatment (P < 0.05). Conclusions Periodontal therapy resets the DNA methylation status of inflammatory gene for COX-2 in periodontal disease patients. DNA methylation levels of TNF-α, IFN-γ and LINE-1 were sustained in periodontitis sites despite therapy. Future studies should consider an expanded panel of inflammatory genes over time. (ClinicalTrials. gov NCT02835898). This article is protected by copyright. All rights reserved.

The field of tissue engineering and regenerative medicine (TE/RM) involves regeneration of tissues and organs using implantable biomaterials. The term epigenetics refers to changes in gene expression that are not encoded in the DNA sequence, leading to remodeling of the chromatin and activation or inactivation of gene expression. Recently, studies have demonstrated that these modifications are influenced not only by biological cues but also by mechanical and topographical signals. This review highlights the current knowledge on emerging approaches in TE/RM with a focus on the effect of materials and topography on the epigenetic expression pattern in cells with potential impacts on modulating regenerative biology. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017.

Summary Tissue integrity requires constant maintenance of a quiescent, yet responsive, population of stem cells. In the skin, hair follicle stem cells (HFSCs) that reside within the bulge maintain tissue homeostasis in response to activating cues that occur with each new hair cycle or upon injury. We found that PTEN, a major regulator of the PI3K-AKT pathway, controlled HFSC number and size in the bulge and maintained genomically stable pluripotent cells. This regulatory function is central for HFSC quiescence, where PTEN-deficiency phenotype is in part regulated by BMAL1. Furthermore, PTEN ablation led to downregulation of BMI-1, a critical regulator of adult stem cell self-renewal, and elevated senescence, suggesting the presence of a protective system that prevents transformation. We found that short- and long-term PTEN depletion followed by activated BMAL1, a core clock protein, contributed to accumulation of HFSC., Graphical Abstract, Highlights • PTEN downregulation leads to the enrichment of stem cells in the niche • PTEN activates core clock protein BMAL1 • BMAL1 plays a role in PTEN-associated stem cell accumulation via AKT, Controlling stem cell number and function holds promise for the development of new therapeutic strategies aiming at tissue regeneration. However, little is known about the molecular mechanisms that control stem cells. In this article, Zagni and colleagues discovered that PTEN controls stem cell accumulation mediated by the core clock gene BMAL1 and PI3K signaling pathway.

Aims Epigenetics refers to changes in cell characteristics that occur independently of modifications to the DNA sequence. Oral carcinogenesis is influenced by modifications in epigenetic mechanisms, including changes in histones, which are proteins that support chromatin remodelling for the dynamic regulation of gene expression and silencing. The dysregulation of histone acetylation can lead to the uncontrolled activity of different genes, thereby triggering events associated with malignant transformation. The aim of this study was to analyse the expression of acetyl-histone H3 at lys9 (H3K9ac) in oral leucoplakia (OL) and oral squamous cell carcinoma (OSCC) in addition to its association with cell proliferation, epithelial–mesenchymal transition (EMT) and clinical-pathological findings. Methods and results Samples of normal oral mucosa (NOM), OL and OSCC were submitted to immunohistochemical analysis using anti-H3K9ac, Ki67 and vimentin. Slides were submitted to quantitative analysis regarding the percentage of positive cells. OSCC presented less expression of H3K9ac in comparison to OL (P < 0.01), whereas Ki67 and vimentin levels increased from OL to OSCC (P < 0.001 and P = 0.03, respectively). OSCC patients with poor prognosis had less H3K9ac expression (P = 0.04). The Kaplan–Meier cumulative survival curves also revealed lower survival rates in patients with less H3K9ac expression (P < 0.01). Conclusions The present findings suggest that changes in H3K9ac occur during the process of oral carcinogenesis along with an increase in cell proliferation and EMT. The results demonstrate that H3K9ac may be a useful novel prognostic marker for OSCC.

Adenoid cystic carcinoma (ACC) is an uncommon malignancy of the salivary glands that is characterized by local recurrence and distant metastasis due to its resistance to conventional therapy. Platinum-based therapies have been extensively explored as a treatment for ACC, but they show little effectiveness. Studies have shown that a specific group of tumor cells, harboring characteristics of cancer stem cells (CSCs), are involved in chemoresistance of myeloid leukemias, breast, colorectal and pancreatic carcinomas. Therapeutic strategies that target CSCs improve the survival of patients by decreasing the rates of tumor relapse, and epigenetic drugs, such as histone deacetylase inhibitors (HDACi), have shown promising results in targeting CSCs. In this study, we investigated the effect of the HDACi Suberoylanilide hydroxamic acid (Vorinostat), and cisplatin, alone or in combination, on CSCs and non-CSCs from ACC. We used CSCs as a biological marker for tumor resistance to therapy in patient-derived xenograft (PDX) samples and ACC primary cells. We found that cisplatin reduced tumor viability, but enriched the population of CSCs. Systemic administration of Vorinostat reduced the number of detectable CSCs in vivo and in vitro, and a low dose of Vorinostat decreased tumor cell viability. However, the combination of Vorinostat and cisplatin was extremely effective in depleting CSCs and reducing tumor viability in all ACC primary cells by activating cellular senescence. These observations suggest that HDACi and intercalating agents act more efficiently in combination to destroy tumor cells and their stem cells.

Background Epigenetic changes refer to any heritable modification in gene expression independent of alterations in the DNA sequence. Currently, it is well established that epigenetics represents a crucial player for tumor development. Nevertheless, the epigenetic mechanisms involved in the development and progression of salivary gland tumors (SGTs) remain poorly understood. Methods In this study, we analyzed the pattern of acetyl-histone H3 (lys9) expression in benign and malignant SGTs and further correlate our results with tumors' proliferative activity and clinical outcomes. We assembled tissue microarrays (TMAs) of 84 cases of SGTs and analyzed for acetyl-histone H3 (lys9) and Ki-67 using immunohistochemistry. The study comprised 42 benign and 42 malignant SGTs. Results All cases included in this study were positive to acetyl-H3 (lys9). We observed that malignant SGTs were hypoacetylated compared with benign (P = 0.04). Moreover, acetyl-H3 (lys9) expression was inversely correlated with Ki67 (**P = 0.02). Conclusion This study provides the first insight regarding histone modifications in SGTs. Our results suggest that epigenetic mechanism, particularly hypoacetylation of histone H3 (lys9), might play a role in the behavior of salivary gland tumors. Also, our findings suggest that interfering with the acetylation pattern of tumor histones represents a potential novel therapeutic strategy for the treatment of SGTs.

A mass spectrometry-based proteomics study carried out on 20 oral squamous cell carcinoma (OSCC) samples identified 26 differentially expressed proteins between high-risk human papillomavirus DNA (HR-HPV DNA) positive (+) and negative (-) tumors. Among these proteins, S100-A8 was upregulated in HR-HPV + cases and presented the most relevant correlation with survival rates. Objective: Validate the expression of S100-A8 in an expanded number of OSCC and correlate it with clinicopathological features and survival outcomes. Study Design: Immunofluorescence for S100-A8 was performed on a 91 OSCC tissue microarray. Additionally, The Cancer Genome Atlas data set of 338 OSCC samples was analyzed for S100-A8 mRNA levels. Results: Higher expression of S100-A8 protein and mRNA levels in HR-HPV DNA + tumors were confirmed. The up-regulated S100-A8 was correlated with T3/T4 tumors, advanced clinical stage and positive surgical margins. Furthermore, a high level of S100-A8 was associated with decreased disease-free survival, cancer specific, and overall survival. Conclusions: S100-A8 may play a role in HR-HPV DNA-related OSCC onset and progression. Acknowledgments: This work was supported by FAPESP grants: 2016/03248-1 and 2017/16347-0. We acknowledge the Mass Spectrometry Laboratory at Brazilian Biosciences National Laboratory, CNPEM, Campinas, Brazil for their support with the mass spectrometry analysis.

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.

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 IC50 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.

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.

A frequent observation in several malignancies is the development of resistance to therapy that results in frequent tumor relapse and metastasis. Much of the tumor resistance phenotype comes from its heterogeneity that halts the ability of therapeutic agents to eliminate all cancer cells effectively. Tumor heterogeneity is, in part, controlled by cancer stem cells (CSC). CSC may be considered the reservoir of cancer cells as they exhibit properties of self-renewal and plasticity and the capability of reestablishing a heterogeneous tumor cell population. The endowed resistance mechanisms of CSC are mainly attributed to several factors including cellular quiescence, accumulation of ABC transporters, disruption of apoptosis, epigenetic reprogramming, and metabolism. There is a current need to develop new therapeutic drugs capable of targeting CSC to overcome tumor resistance. Emerging in vitro and in vivo studies strongly support the potential benefits of combination therapies capable of targeting cancer stem cell-targeting agents. Clinical trials are still underway to address the pharmacokinetics, safety, and efficacy of combination treatment. This review will address the main characteristics, therapeutic implications, and perspectives of targeting CSC to improve current anticancer therapeutics.