Epigenetic methylation changes: implication as biomarkers in oral and maxillofacial area cancers.

Background/Aim: Squamous cell carcinoma (SCC) is the most frequent cancer of the head and neck area in the oral cavity. Epigenetic alterations in oral and maxillofacial area cancers are urgently needed to be investigated, as the observed changes might have crucial diagnostic value for personalized medicine. Methods: Our study aimed to identify the most frequently hypermethylated tumor suppressor gene promoters in OSCC, followed by correlation analysis with the patients' survival. We evaluated the methylation status of the promoters in a panel of 22 tumor suppressor genes in Romanian (n=9) and Bulgarian (n=12) patient groups suffering from oral and maxillofacial area cancers. The extracted DNA was further digested through EpiTect Methyl II PCR Array System containing methylation-sensitive and methylation-dependent restriction enzymes, followed by specific amplification of the products obtained by qPCR and data analysis using the online platform provided by the producer. Results: Different methylation patterns were observed in the tumor suppressor genes' promoters. Among them, the methylation profile of Cccnd2, Chd1, Cdh13, Cdkn1c, Neurog1, Gstp1, and Runx3 genes further correlated with overall survival rates. Conclusions: Our data emphasize that epigenetic alterations are responsible for the clinical heterogeneity of oral and maxillofacial area cancers and significantly impact on patient survival. Additional investigation on a larger patient cohort should validate these potential biomarkers.

Periodontal disease might be a risk factor for graft versus host disease. A systematic review.

PURPOSE: The aim of this systematic review was to determine a potential association between periodontal disease and graft versus host disease (GVHD). DESIGN: PubMed, Scopus and Web of Science databases were searched to identify all relevant articles. The eligibility criteria were prospective, retrospective, cross-sectional, cohort, case-control studies and interventional studies that assessed periodontal parameters in GVHD adults' patients. RESULTS: Seven studies, published between 2000 and 2018, were eligible. The aggravation of periodontal tissues is due to inadequate oral hygiene, dental plaque, decays, gum recession, retained roots, tooth loss, periodontally infected teeth. Several studies have indicated that periodontitis treatment performed before transplantation showed the reduction of gingival inflammation and maintenance of periodontal health. CONCLUSIONS: Periodontitis might be a risk factor for GVHD. However, due to the limited number of studies included in the review and their heterogeneity, more data are needed to sustain the correlation between periodontitis and GVHD.

SERS-based differential diagnosis between multiple solid malignancies: breast, colorectal, lung, ovarian and oral cancer.

PURPOSE: Surface-enhanced Raman scattering (SERS) spectroscopy on serum and other biofluids for cancer diagnosis represents an emerging field, which has shown promising preliminary results in several types of malignancies. The purpose of this study was to demonstrate that SERS spectroscopy on serum can be employed for the differential diagnosis between five of the leading malignancies, ie, breast, colorectal, lung, ovarian and oral cancer. PATIENTS AND METHODS: Serum samples were acquired from healthy volunteers (n=39) and from patients diagnosed with breast (n=42), colorectal (n=109), lung (n=33), oral (n=17), and ovarian cancer (n=13), comprising n=253 samples in total. SERS spectra were acquired using a 532 nm laser line as excitation source, while the SERS substrates were represented by Ag nanoparticles synthesized by reduction with hydroxylamine. The classification accuracy yielded by SERS was assessed by principal component analysis-linear discriminant analysis (PCA-LDA). RESULTS: The sensitivity and specificity in discriminating between cancer patients and controls was 98% and 91%, respectively. Cancer samples were correctly assigned to their corresponding cancer types with an accuracy of 88% for oral cancer, 86% for colorectal cancer, 80% for ovarian cancer, 76% for breast cancer and 59% for lung cancer. CONCLUSION: SERS on serum represents a promising strategy of diagnosing cancer which can discriminate between cancer patients and controls, as well as between cancer types such as breast, colorectal, lung ovarian and oral cancer.

Role of Key Micronutrients from Nutrigenetic and Nutrigenomic Perspectives in Cancer Prevention.

Regarding cancer as a genetic multi-factorial disease, a number of aspects need to be investigated and analyzed in terms of cancer's predisposition, development and prognosis. One of these multi-dimensional factors, which has gained increased attention in the oncological field due to its unelucidated role in risk assessment for cancer, is diet. Moreover, as studies advance, a clearer connection between diet and the molecular alteration of patients is becoming identifiable and quantifiable, thereby replacing the old general view associating specific phenotypical changes with the differential intake of nutrients. Respectively, there are two major fields concentrated on the interrelation between genome and diet: nutrigenetics and nutrigenomics. Nutrigenetics studies the effects of nutrition at the gene level, whereas nutrigenomics studies the effect of nutrients on genome and transcriptome patterns. By precisely evaluating the interaction between the genomic profile of patients and their nutrient intake, it is possible to envision a concept of personalized medicine encompassing nutrition and health care. The list of nutrients that could have an inhibitory effect on cancer development is quite extensive, with evidence in the scientific literature. The administration of these nutrients showed significant results in vitro and in vivo regarding cancer inhibition, although more studies regarding administration in effective doses in actual patients need to be done.

The Epigenetics of Triple-Negative and Basal-Like Breast Cancer: Current Knowledge.

Breast cancer has the highest incidence among all malignancies diagnosed in women. Therapies have significantly improved over the years due to extensive molecular and clinical research; in a large number of cases, targeted therapies have provided better prognosis. However, one specific subtype remains elusive to targeted therapies-the triple-negative breast cancer. This immunohistochemically defined subtype is resistant to both endocrine and targeted therapies, leading to its poor prognosis. A field that is of great promise in current cancer research is epigenetics. By studying the epigenetic mechanisms underlying tumorigenesis-DNA methylation, histone modifications, and noncoding RNAs-advances in cancer treatment, diagnosis, and prevention are possible. This review aims to synthesize the epigenetic discoveries that have been made related to the triple-negative breast cancer.

Differential Effect of Smoking on Gene Expression in Head and Neck Cancer Patients.

Smoking is a well-known behavior that has an important negative impact on human health, and is considered to be a significant factor related to the development and progression of head and neck squamous cell carcinomas (HNSCCs). Use of high-dimensional datasets to discern novel HNSCC driver genes related to smoking represents an important challenge. The Cancer Genome Atlas (TCGA) analysis was performed in three co-existing groups of HNSCC in order to assess whether gene expression landscape is affected by tobacco smoking, having quit, or non-smoking status. We identified a set of differentially expressed genes that discriminate between smokers and non-smokers or based on human papilloma virus (HPV)16 status, or the co-occurrence of these two exposome components in HNSCC. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways classification shows that most of the genes are specific to cellular metabolism, emphasizing metabolic detoxification pathways, metabolism of chemical carcinogenesis, or drug metabolism. In the case of HPV16-positive patients it has been demonstrated that the altered genes are related to cellular adhesion and inflammation. The correlation between smoking and the survival rate was not statistically significant. This emphasizes the importance of the complex environmental exposure and genetic factors in order to establish prevention assays and personalized care system for HNSCC, with the potential for being extended to other cancer types.

RNA interference: new mechanistic and biochemical insights with application in oral cancer therapy.

Over the last few decades, the incidence of oral cancer has gradually increased, due to the negative influence of environmental factors and also abnormalities within the genome. The main issues in oral cancer treatment consist in surpassing resistance and recurrence. However, continuous discovery of altered signaling pathways in these tumors provides valuable information for the identification of novel gene candidates targeted in personalized therapy. RNA interference (RNAi) is a natural mechanism that involves small interfering RNA (siRNA); this can be exploited in biomedical research by using natural or synthetic constructs for activation of the mechanism. Synthetic siRNA transcripts were developed as a versatile class of molecular tools that have a diverse range of programmable roles, being involved in the regulation of several biological processes, thereby providing the perspective of an alternative option to classical treatment. In this review, we summarize the latest information related to the application of siRNA in oral malignancy together with molecular aspects of the technology and also the perspective upon the delivery system. Also, the emergence of newer technologies such as clustered regularly interspaced short palindromic repeats/Cas9 or transcription activator-like effector nucleases in comparison with the RNAi approach is discussed in this paper.

The Unforeseen Non-Coding RNAs in Head and Neck Cancer.

Previously ignored non-coding RNAs (ncRNAs) have become the subject of many studies. However, there is an imbalance in the amount of consideration that ncRNAs are receiving. Some transcripts such as microRNAs (miRNAs) or small interfering RNAs (siRNAs) have gained much attention, but it is necessary to investigate other "pieces of the RNA puzzle". These can offer a more complete view over normal and pathological cell behavior. The other ncRNA species are less studied, either due to their recent discovery, such as stable intronic sequence RNA (sisRNA), YRNA, miRNA-offset RNAs (moRNA), telomerase RNA component (TERC), natural antisense transcript (NAT), transcribed ultraconserved regions (T-UCR), and pseudogene transcript, or because they are still largely seen as non-coding transcripts with no relevance to pathogenesis. Moreover, some are still considered housekeeping RNAs, for instance small nucleolar RNAs (snoRNAs) and TERC. Our review summarizes the biogenesis, mechanism of action and potential role of less known ncRNAs in head and neck cancer, with a particular focus on the installment and progress for this particular cancer type.

Current Insights into Oral Cancer Epigenetics.

Epigenetic modifications have emerged into one of the cancer hallmarks, replacing the concept of malignant pathologies as being solely genetic-based conditions. The epigenetic landscape is responsible for normal development but also for the heterogeneity among tissues in terms of gene expression patterns. Dysregulation in these mechanisms has been associated with disease stage, and increased attention is now granted to cancer in order to take advantage of these modifications in terms of novel therapeutic strategies or diagnosis/prognosis tools. Oral cancer has also been subjected to epigenetic analysis with numerous studies revealing that the development and progression of this malignancy are partially induced by an altered epigenetic substrate together with genetic alterations and prolonged exposure to environmental risk factors. The present review summarizes the most important epigenetic modifications associated with oral cancer and also their potential to be used as new therapeutic targets.

Exosomes-Small Players, Big Sound.

Incipiently named extracellular vesicles, exosomes are forming now a separate class of cellular mediators with important functions in physiological and pathological states. Their ability to transfer information between cells through encapsulation of proteins, nucleic acids and lipids for the preservation of the homeostatic equilibrium is translated also in pathological conditions. The recipient cells react to the reception of foreign molecules adjusting their molecular state according to the enclosed message. Cancer cells, in order to influence the microenvironment and facilitate the malignant expanding, exploit this intercellular trafficking. Immune cells are also producing exosomes that ensure the transportation of immune mediators and signaling molecules between cells. Current experimental attempts are concentrated on the adjustment of exosomes level for therapeutic purposes, enrolment of these vesicles as diagnosis or prognosis tools and also exosomes' use as drug delivery vehicles or immune stimulatory agents.

A Looking-Glass of Non-coding RNAs in oral cancer.

Oral cancer is a multifactorial pathology and is characterized by the lack of efficient treatment and accurate diagnostic tools. This is mainly due the late diagnosis; therefore, reliable biomarkers for the timely detection of the disease and patient stratification are required. Non-coding RNAs (ncRNAs) are key elements in the physiological and pathological processes of various cancers, which is also reflected in oral cancer development and progression. A better understanding of their role could give a more thorough perspective on the future treatment options for this cancer type. This review offers a glimpse into the ncRNA involvement in oral cancer, which can help the medical community tap into the world of ncRNAs and lay the ground for more powerful diagnostic, prognostic and treatment tools for oral cancer that will ultimately help build a brighter future for these patients.

Future trends and emerging issues for nanodelivery systems in oral and oropharyngeal cancer.

Oral cancer is a prevalent cancer type on a global scale, whose traditional treatment strategies have several drawbacks that could in the near future be overcome through the development of novel therapeutic and prognostic strategies. Nanotechnology provides an alternative to traditional therapy that leads to enhanced efficiency and less toxicity. Various nanosystems have been developed for the treatment of oral cancer, including polymeric, metallic, and lipid-based formulations that incorporate chemotherapeutics, natural compounds, siRNA, or other molecules. This review summarizes the main benefits of using these nanosystems, in parallel with a particular focus on the issues encountered in medical practice. These novel strategies have provided encouraging results in both in vitro and in vivo studies, but few have entered clinical trials. The use of nanosystems in oral cancer has the potential of becoming a valid therapeutic option for patients suffering from this malignancy, considering that clinical trials have already been completed and others are currently being developed.

Dietary Intervention by Phytochemicals and Their Role in Modulating Coding and Non-Coding Genes in Cancer.

Phytochemicals are natural compounds synthesized as secondary metabolites in plants, representing an important source of molecules with a wide range of therapeutic applications. These natural agents are important regulators of key pathological processes/conditions, including cancer, as they are able to modulate the expression of coding and non-coding transcripts with an oncogenic or tumour suppressor role. These natural agents are currently exploited for the development of therapeutic strategies alone or in tandem with conventional treatments for cancer. The aim of this paper is to review the recent studies regarding the role of these natural phytochemicals in different processes related to cancer inhibition, including apoptosis activation, angiogenesis and metastasis suppression. From the large palette of phytochemicals we selected epigallocatechin gallate (EGCG), caffeic acid phenethyl ester (CAPE), genistein, morin and kaempferol, due to their increased activity in modulating multiple coding and non-coding genes, targeting the main hallmarks of cancer.

Knocking down of p53 triggers apoptosis and autophagy, concomitantly with inhibition of migration on SSC-4 oral squamous carcinoma cells.

Oral squamous cell carcinoma (OSCC) is a malignancy with elevated prevalence and somber prognosis due to the fact that most of the patients are diagnosed at an advanced stage. p53 has a crucial role in proliferation and apoptosis during the occurrence and development of numerous malignant tumors. The impact of mutated p53 on the development and progression of OSCC is unclear and might have therapeutic implications. Using an in vitro RNA interference experiment, we have evaluated the impact of p53 knockdown on cell viability, apoptosis, migration, and gene expression for key genes involved in apoptosis and angiogenesis. We observed that inhibiting the expression of p53 decreased the proliferation ability and induced apoptosis/autophagy in SSC-4 cells. Moreover, we observed that this has decreased migration and has blocked the expression of VEGF. In conclusion, our research provides a proof that a direct connection between p53 knockdown and OSCC cell death can be established, therefore opening new potential directions in OSCC molecular therapeutics and management.

Epigallocatechin-3-gallate suppresses cell proliferation and promotes apoptosis and autophagy in oral cancer SSC-4 cells.

Epigallocatechin-3-gallate (EGCG) is the major bioactive component of green tea. Our experimental data indicated that EGCG treatment suppresses cell proliferation of SSC-4 human oral squamous cell carcinoma (OSCC), the effect being dose- and time-dependent. In parallel was observed the activation of apoptosis and autophagy, in response to EGCG exposure in SSC-4 cells. Treatment with EGCG activates the expression of the BAD, BAK, FAS, IGF1R, WNT11, and ZEB1 genes and inhibits CASP8, MYC, and TP53. All of these results suggest that EGCG has an excellent potential to become a therapeutic compound for patients with OSCC, by inducing tumor cell death via apoptosis and autophagy.

Novel technologies for oral squamous carcinoma biomarkers in diagnostics and prognostics.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is a highly prevalent malignant pathology of the oral cavity. Despite the significant progress accomplished in the field of OSCC, the diagnosis is performed mostly in advanced stages; thus, novel biomarkers need to be developed for the diagnostic and prognostic of this malignancy. Many new technologies are used to provide indispensable information related to the pathogenesis of OSCC. The molecular profiling studies that incorporate genetic and epigenetic alterations need to be integrated in clinical practice as routine approaches to facilitate a better diagnostic and prognostic. REVIEW: In this review, the authors present a summary of these novel technologies in the field of genomics, transcriptomics or proteomics, capable of generating data related to personalized diagnostic and treatment.