MiR-34 by targeting p53 induces apoptosis and DNA damage in paclitaxel-resistant human oral squamous carcinoma cells

MicroRNA-34 (miR-34) is one the most important tumor suppressor miRNAs involving in the various aspects of oral cancer. The present study aimed to evaluate the effects of miR-34 restoration in OECM-1 oral cancer resistant to paclitaxel (OECM-1/PTX) and its underlying mechanisms through p53-mediated DNA damage and apoptosis. OECM-1 and OECM-1/PTX were transfected with miR-34 mimic and inhibitor. Cellular proliferation and apoptosis were evaluated through MTT assay and flow cytometry, respectively. The mRNA and protein expression levels of p53, p-glycoprotein (P-gp), ATM, ATR, CHK1, and CHK2 were assessed through qRT-PCR and western blotting. Rhodamin123 uptake assay was used to measure the P-gp activities. P53 expression was also suppressed by sing a siRNA transfection of cells. The expression levels of miR-34 were downregulated in OECM-1/PTX. Restoration of miR-34 led to increase in cytotoxic effects of paclitaxel in cells. In addition, the expression levels and activities of P-gp were reduced following miR-34 transfection. miR-34 transfection upregulated the p53, ATM, ATR, CHK1, and CHK2 expression levels in OECM-1/PTX cells. Furthermore, cells transfected with miR-34 showed higher levels of apoptosis. miR-34 restoration reverses paclitaxel resistance in OECM-1 oral cancer. The chemosensitive effects of miR-34 is mediated through increasing DNA damage and apoptosis in a p53 depended manner.

MicroRNAs and Periodontal Disease: Helpful Therapeutic Targets?

Periodontal disease is the most common oral disease. This disease can be considered as an inflammatory disease. The immune response to bacteria accumulated in the gum line plays a key role in the pathogenesis of periodontal disease. In addition to immune cells, periodontal ligament cells and gingival epithelial cells are also involved in the pathogenesis of this disease. miRNAs which are small RNA molecules with around 22 nucleotides have a considerable relationship with the immune system affecting a wide range of immunological events. These small molecules are also in relation with periodontium tissues especially periodontal ligament cells. Extensive studies have been performed in recent years on the role of miRNAs in the pathogenesis of periodontal disease. In this review paper, we have reviewed the results of these studies and discussed the role of miRNAs in the immunopathogenesis of periodontal disease comprehensively. miRNAs play an important role in the pathogenesis of periodontal disease and maybe helpful therapeutic targets for the treatment of periodontal disease.

The salivary exosomal microRNA as a potential biomarker in patients with periodontitis and oral cancers

Periodontitis and oral cancers are the most common oral diseases in the human population. The early diagnosis of oral diseases allows the efficient therapy of the patient. During oral diseases, resident cells in the affected tissue secrete exosomal microRNAs (miRNAs) into saliva. As these miRNAs have a crucial role in the pathogenesis of oral diseases, they have been suggested as non-invasive and validated biomarkers in predicting periodontitis severity and cancer progression. Several attempts have been performed to evaluate the expression of salivary exosomal miRNAs in patients with periodontitis and oral cancers. Some miRNAs are differentially expressed in the saliva of the affected patients when compared to healthy individuals. These miRNAs are reviewed in this narrative review. Collectively, it seems that salivary exosomal microRNAs could be used as a diagnostic biomarker in oral diseases. However, further studies are required to validate them.

Correlation of exposure to environmental tobacco smoke and periodontitis in passive smokers; a systematic review

Introduction: Smoking is a major health hazard. Cigarette smoke is produced by burning of complex organic compounds that include highly toxic components. Passive smokers are non-smoker individuals that are exposed to second-hand smoke (SHS) or environmental tobacco smoke (ETS). Passive or involuntary smoking is currently a major public health dilemma worldwide. Considering the increasing number of passive smokers in today’s world, it is imperative to assess the potential adverse effects of passive smoking on oral health and periodontal tissue. Objectives: This study aimed to assess the correlation between exposure to ETS and periodontitis in passive smokers. Methods: In this systematic review, the Google Scholar, PubMed and Scopus databases were searched for relevant articles published from 1990 to 2020. The extracted data were tabulated. Results: Search of the literature yielded 77 articles based on the searched keywords. After assessing the abstracts and excluding the duplicates, 68 articles remained. After accurate assessment by the examiners, 21 articles were selected for the full-text review. Finally, seven eligible articles remained in the study for the final review. Conclusion: Cigarette smoke affects the immune system and aggravates periodontal destruction as such. Despite the available evidence regarding the correlation of periodontal parameters and exposure to ETS in passive smokers, more comprehensive studies on this topic are still required to achieve a definite therapeutic protocol considering the small number of available studies on this topic, methodological flaws and the existing controversies.

Canalicular adenoma of the hard palate: A rare case report

Canalicular adenoma (CA) is a rare, benign salivary gland tumor that has special tendency to occur in the upper lip. Buccal mucosa is the second most common site. It occurs more often in older patients with peak prevalence in the seventh decade of life. A definitive female predominance has been reported. According to the latest English published literature, 531 cases of CA have been reported. We present a case of CA of the hard palate that presented in a 29-year-old female patient. The histopathological and immunohistochemical findings showed typical features of CA and intense expression of pan-cytokeratin and S-100 protein. We also review its differential diagnosis from other salivary gland tumors.

IL-4 induces the formation of multinucleated giant cells and expression of β5 integrin in central giant cell lesion

Background

It is now well established that IL-4 has a central role in the development of monocytes to multinucleated giant cells (MGCs) by inducing the expression of integrins on the surface of monocytes. The aim of this study was to investigate the potential role of IL-4 in induction of β5 integrin expression in the peripheral blood samples of patients with giant cell granuloma.

Material and Methods

Monocytes were isolated from peripheral blood samples of patients with central giant cell granuloma (CGCG) and healthy controls using human Monocyte Isolation Kit II. Isolated monocytes were then cultured in the absence or presence of IL-4 (10 and 20 ng/mL), and following RNA extraction and cDNA synthesis, Real-time PCR was performed to determine the level of β5 integrin expression. The formation of CGCGs and morphological analyses were done under light microscopy. For confirmation of CGCGs, immunocytochemistry technique was also carried out by anti-RANK (receptor-activator of NF-κB ligand) antibody.

Results

In both patient and control groups, β5 levels were significantly enhanced by increasing the IL-4 dose from 10 to 20 ng/mL. In addition, these differences were significant between patient and control groups without IL-4 treatment. On the other hand, the number of cells which expressed RANK and therefore the number of giant cells were significantly higher in the patient group in comparison to controls, as assessed by immunohistochemistry evaluations.

Conclusions

In this study, we showed an elevation in the expression levels of β5 integrin when stimulated by IL-4. It is strongly indicated that this integrin acts as an important mediator during macrophage to macrophage fusion and development of giant cells.

Key words:β5 integrin, giant cell, Il-4, monocyte, rank.