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.

Improving dental epithelial junction on dental implants with bioengineered peptides.

Introduction: The functionalization of titanium (Ti) and titanium alloys (Ti6Al4V) implant surfaces via material-specific peptides influence host/biomaterial interaction. The impact of using peptides as molecular linkers between cells and implant material to improve keratinocyte adhesion is reported. Results: The metal binding peptides (MBP-1, MBP-2) SVSVGMKPSPRP and WDPPTLKRPVSP were selected via phage display and combined with laminin-5 or E-cadherin epithelial cell specific peptides (CSP-1, CSP-2) to engineer four metal-cell specific peptides (MCSPs). Single-cell force spectroscopy and cell adhesion experiments were performed to select the most promising candidate. In vivo tests using the dental implant for rats showed that the selected bi functional peptide not only enabled stable cell adhesion on the trans-gingival part of the dental implant but also arrested the unwanted apical migration of epithelial cells. Conclusion: The results demonstrated the outstanding performance of the bioengineered peptide in improving epithelial adhesion to Ti based implants and pointed towards promising new opportunities for applications in clinical practice.

A novel panel of clinically relevant miRNAs signature accurately differentiates oral cancer from normal mucosa.

Introduction: Although a considerable body of knowledge has been accumulated regarding the early diagnosis and treatment of oral squamous cell carcinoma (OSCC), its survival rates have not improved over the last decades. Thus, deciphering the molecular mechanisms governing oral cancer will support the development of even better diagnostic and therapeutic strategies. Previous studies have linked aberrantly expressed microRNAs (miRNAs) with the development of OSCC. Methods: We combined bioinformatical and molecular methods to identify miRNAs with possible clinical significance as biomarkers in OSCC. A set of 10 miRNAs were selected via an in silico approach by analysing the 3'untranslated regions (3'UTRs) of cancer-related mRNAs such as FLRT2, NTRK3, and SLC8A1, TFCP2L1 and etc. RT-qPCR was used to compare the expression of in silico identified miRNAs in OSCC and normal tissues (n=32). Results: Among the screened miRNAs, miR-21-5p (p < 0.0001), miR-93-5p (p < 0.0197), miR-146b-5p (p <0.0012), miR-155-5p (p < 0.0001), miR-182-5p (p < 0.0001) were significantly overexpressed, whereas miR-133b (p < 0.05) was significantly downregulated in OSCC tissues, a scenario confirmed in two additional OSCC validation cohorts: Regina Elena National Cancer Institute (IRE cohort, N=74) and The Cancer Genome Atlas Data Portal (TCGA cohort, N=354). Initial stage tumors (T1, T2) expressed significantly higher levels of miR-133b (p < 0.0004) compared to more advanced ones (T3, T4). Also, we identified miR-93-5p (p < 0.0003), miR-133b (p < 0.0017) and miR-155-5p (p < 0.0004) as correlated with HPV-induced OSCC. The high expression of these 6 miRNAs as a signature predicted shorter disease-free survival (DFS) and could efficiently distinguish OSCC cases from healthy controls with areas under the curve (AUC) of 0.91 with sensitivity and specificity of 0.98 and 0.6, respectively. Further target identification analysis revealed enrichment of genes involved in FOXO, longevity, glycan biosynthesis and p53 cancer-related signaling pathways. Also, the selected targets were underexpressed in OSCC tissues and showed clinical significance related to overall survival (OS) and DFS. Discussion: Our results demonstrate that a novel panel consisting of miR-21-5p, miR-93-5p, miR-133b, miR-146b-5p, miR-155-5p and miR-182-5p could be used as OSCC-specific molecular signature with diagnostic and prognostic significance related to OS and DFS.

Salivary miR-30c-5p as Potential Biomarker for Detection of Oral Squamous Cell Carcinoma.

The levels of different classes of extracellular RNAs (exRNAs) remain stable in bodily fluids. The detection of either enriched or depleted specific subsets of salivary microRNAs (miRNAs) has the potential to serve as a non-invasive approach for biomarker development. Thus, salivary miRNAs have emerged as a promising molecular tool for early diagnosis and screening of oral squamous cell carcinoma (OSCC). Total RNA was extracted from saliva supernatant of 33 OSCC patients and 12 controls (discovery set), and the differential expression of 8 cancer-related miRNAs was detected by TaqMan assay. Among the screened miRNAs, miR-30c-5p (p < 0.04) was significantly decreased in OSCC saliva. The same transcriptional behavior of miR30c-5p was observed in an additional validation set. miR-30c-5p showed a significant statistical difference between cases and controls with areas under the curve (AUC) of 0.82 (95% CI: 0.71-0.89). The sensitivity and the specificity of miR-30c-5p were 86% and 74%, respectively. The target identification analysis revealed enrichment of miR-30c-5p targets in p53 and Wnt signaling pathways in OSCC. Additionally, the miR-30c-5p targets had clinical significance related to overall survival. In conclusion, these findings show that downregulated miR-30c-5p has the potential to serve as a novel, non-invasive biomarker for early OSCC detection.

Alternative RNA Splicing-The Trojan Horse of Cancer Cells in Chemotherapy.

Almost all transcribed human genes undergo alternative RNA splicing, which increases the diversity of the coding and non-coding cellular landscape. The resultant gene products might have distinctly different and, in some cases, even opposite functions. Therefore, the abnormal regulation of alternative splicing plays a crucial role in malignant transformation, development, and progression, a fact supported by the distinct splicing profiles identified in both healthy and tumor cells. Drug resistance, resulting in treatment failure, still remains a major challenge for current cancer therapy. Furthermore, tumor cells often take advantage of aberrant RNA splicing to overcome the toxicity of the administered chemotherapeutic agents. Thus, deciphering the alternative RNA splicing variants in tumor cells would provide opportunities for designing novel therapeutics combating cancer more efficiently. In the present review, we provide a comprehensive outline of the recent findings in alternative splicing in the most common neoplasms, including lung, breast, prostate, head and neck, glioma, colon, and blood malignancies. Molecular mechanisms developed by cancer cells to promote oncogenesis as well as to evade anticancer drug treatment and the subsequent chemotherapy failure are also discussed. Taken together, these findings offer novel opportunities for future studies and the development of targeted therapy for cancer-specific splicing variants.

Nutrigenomics in cancer: Revisiting the effects of natural compounds.

Nutrigenomics effects have an important role in the manipulation of dietary components for human benefit, particularly in cancer prevention or treatment. The impact of dietary components, including phytochemicals, is largely studied by nutrigenomics, looking at the gene expression and molecular mechanisms interacting with bioactive compounds and nutrients, based on new 'omics' technologies. The high number of preclinical studies proves the relevant role of nutrigenomics in cancer management. By deciphering the network of nutrient-gene connections associated with cancer, relevant data will be transposed as therapeutic interventions for this devastating pathology and for fulfilling the concept of personalized nutrition. All these are presented under the nutrigenomics canopy for a better comprehension of the relation between ingested phytochemicals and chemoprevention or chemotherapy. The profits from the nutrigenomics progress, with a particular focus on the coding and noncoding genes related to the exposure of natural compounds need to be validated. A precise attention receives the evaluation of the role of natural compounds in tandem with conventional therapy using genomic approaches, with emphasis on the capacity to inhibit drug resistance mechanisms. All these relevant nutrigenomics aspects are summarized in the present review paper. It is concluded that further nutrigenomics studies are required to improve our understanding related to the complex mechanisms of action of the natural compounds and for their appropriate application as gears in cancer therapy.

Strategies For Immobilization Of Bioactive Organic Molecules On Titanium Implant Surfaces - A Review.

Numerous approaches have been used to improve the tissue-implant interface of titanium (Ti) and titanium alloy (Ti6Al4V). They all aim at increasing cell migration and attachment to the metal, preventing unspecific protein adsorption and improving post-implantation healing process. Promising methods for titanium and titanium alloy surface modification are based on the immobilization of biologically active organic molecules. New and interesting biochemical approaches to such surface modification include layer-by-layer deposition of polyelectrolyte films, phage display-selected surface binding peptides and self-assembled DNA monolayer systems. The present review summarizes the scientific information about these methods, which are at in vitro or in vivo development stages, and hopes to promote their future application in dental implantology and in oral and maxillofacial surgery.

Sprayed cells and polyelectrolyte films for biomaterial functionalization: the influence of physical PLL-PGA film treatments on dental pulp cell behavior.

Further development of biomaterials is expected as advanced therapeutic products must be compliant to good manufacturing practice regulations. A spraying method for building-up polyelectrolyte films followed by the deposition of dental pulp cells by spraying is presented. Physical treatments of UV irradiation and a drying/wetting process are applied to the system. Structural changes and elasticity modifications of the obtained coatings are revealed by atomic force microscopy and by Raman spectroscopy. This procedure results in thicker, rougher and stiffer film. The initially ordered structure composed of mainly α helices is transformed into random/ß-structures. The treatment enhanced dental pulp cell adhesion and proliferation, suggesting that this system is promising for medical applications.

Bisphosphonate-associated osteonecrosis of the jaws -- report of three cases in Bulgaria and review of the literature.

A severe complication of the administration of bisphosphonate-containing medications is known as bisphosphonate-associated osteonecrosis of the jaws (BONJ). A case series of three patients affected by BONJ is presented. These patients currently represent the only described cases of BONJ in Bulgaria. Exposed necrotic bone of the mandible was observed in two patients and the maxilla was affected in the third case. Two of the patients had been treated with zoledronate for metastatic prostate cancer and one patient for metastatic endometrioid cancer. All three patients underwent surgical treatment. One of the patients received conservative surgical debridement, i.e. removal of necrotic bone only, and primary wound closure. Conservative surgical debridement and application of local medications without wound closure were used in the other two patients. All three patients received systemic antibiotic treatment. No evidence of disease progression was observed during the follow-up period of 3 to 12 months. The surgical approach utilized in the present study is discussed in the light of the etiopathogenesis, prevention and treatment of BONJ.

A retrospective study on the approach to the tooth in the fracture line of the mandible.

UNLABELLED: The presence of a tooth in the fracture line constitutes a specific problem in mandibular fractures. Therefore, our objective was to characterize the approach to teeth in the fracture line used in the Department of Maxillofacial Surgery, Plovdiv, by retrospectively investigating the association between various preoperative factors and the decision to extract or preserve the tooth. MATERIAL AND METHODS: The following variables were studied based on data from available hospital records: 1) gender and age of patients; 2) local preoperative infections; 3) time from trauma to treatment; 4) degree of fracture displacement; 5) relationship between tooth and fracture line; 6) periapical pathology; 7) periodontal diseases; 8) type of tooth in the fracture line; 9) degree of eruption; 10) method of treatment. RESULTS: 593 fractures with a tooth in the fracture line were included in the study. The tooth was preserved in 69.90 +/- 0.14% of the cases, it was extracted in 29.30 +/- 1.91% and exarticulated in 0.80 +/- 0.38% of all fracture lines. The results demonstrated the existing association between the studied variables and the decision to extract or preserve the tooth. Extraction was generally preferred in the following cases: if a local preoperative infection was present; the time from trauma to treatment was more than 72 hours; there was a significant displacement of the fracture; the dental root was fractured; periapical pathology or periodontal disease was present; the tooth was multi-rooted; or treatment consisted of open reduction and internal fixation. CONCLUSIONS: Making a decision to extract or preserve the tooth in the fracture line is a complex process. Each case, therefore, should be approached individually.

Growth factors--importance and possibilities for enhancement of the healing process in bone fractures.

UNLABELLED: The healing process after bone fractures is subject to complex regulation. A major part in it is played by biologically active molecules, called growth factors. The most important of these are the bone morphogenetic proteins (BMPs), transforming growth factor--beta (TGF-beta), platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), insulin-like growth factor (IGF), vascular endothelial growth factor (VEGF), and epidermal growth factor (EGF). AIM: The aim of the present study was to do a short review of data in the scientific literature about the specific role of each factor in reparative osteogenesis in relation to the healing of bone fractures, as well as the possibilities for enhancement of this process by growth factors. MATERIAL AND METHODS: A detailed Medline search was conducted with emphasis on reports from the last ten years. CONCLUSION: The information gathered demonstrated the key role of growth factors and their potential for stimulation of healing of fractures and their complications. This conclusion is supported by results from numerous animal experiments.