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Background: Oral squamous cell carcinoma (OSCC) is one of the most important types of oral malignancies. DKK gene family members as well as DKK2/4 have critical roles in regulation of Wnt signaling as one of the main determining pathway in oral carcinogenesis. This study aimed to identify promoter methylation status of DKK2/4 genes to provide possible biomarkers for early detection and treatment of OSCC patients. Methods: A case control study was performed on 31 fresh tissues obtained from oral cavity of patients affected by OSCC and 31 fresh corresponding tissues from normal healthy controls in Tehran and, between the years of 2016-2018. Purified DNA from tissue samples was subjected to bisulfite treatment and then methylation specific polymerase chain reaction (MSP-PCR) was carried out on treated DNA samples. Results: DKK4 promoter was methylated in none of OSCC samples while it was methylated in 16.1% of healthy controls. 16.1% of OSCC samples were detected to be semimethylated and 22.6% of healthy normal samples were methylated for DKK2 promoter gene. Meaningful difference was found in DKK4 promoter methylation among OSCC patients and healthy controls. Significant correlation was found between DKK4 promoter methylation and tumor grade. The age of all enrolled samples was demonstrated to have strong effect on promoter methylation of studied genes. Conclusion: Hypomethylation of DKK2 and DKK4 genes in higher grades of OSCC samples may indicate the pivotal role of their expression in tumor cells invasion and progression through modulation of Wnt signaling pathway. Further study required to determine simultaneous expression of those genes and Wnt signaling elements at mRNA and protein levels.

Background:Radiotherapy is one of the oral and pharyngeal cancer treatment methods that can cause damage to the tissues in the radiation area; the purpose of this study is to evaluate the effects of radiotherapy on dental pulp tissue in rats.Materials and Methods:In this interventional, experimental double-blind study, 30 rats were studied in three groups (n = 10 each). The first group received 12 gray (Gy), the second group received 18 Gy in one session, and the third group was not exposed to radiation (control group). The 5 μm sections of mandibular molar tooth were prepared and stained with hematoxylin and eosin. Samples were studied under optical microscope to evaluate and score inflammation, necrosis, hyalinization, and vascular congestion. The data were coded and analyzed by statistical tests of χ2 and Fisher's exact tests. The significant level of P = 0.05.Results:In Group 1, necrosis in two cases, inflammation in one case, hyalinization in one case, and vascular congestion in four cases were observed. In Group 2, inflammation in four cases, hyalinization in two cases, and vascular congestion in five cases were observed. In Group 3, inflammation was observed only in one case. In comparison between the groups, no significant differences were observed in inflammation (P > 0.05), necrosis (P > 0.05), and hyalinization (P > 0.05). However, the difference was significant for vascular congestion (P < 0.05).Conclusion:Radiotherapy with doses of 12 and 18 Gy had no significant effect on inflammation, necrosis, and hyalinization in all groups; however, the difference was significant for vascular congestion.

Background: Despite the notable advances in modern surgery and radiotherapy,no significant increase in the five year survival rate of oral squamous cell carcinoma has been reported. Collecting evidence demonstrates that miR 153 and miR 455-5p play a key role in growth and progression of oral cancer. Early detection of OSCC is important for enhancing patient quality of life and clinical treatment.For this reason, biomarkers or tumour markers offer an opportunity to intervene and avoid development of oral cancer. Methods: A total of 50 blood samples from patients from both genders (25 OSCC and 25 healthy people/control groups) were obtained to determine the expression of miR153 and miR455-5p using Real time Polymerase chain reaction and t test. Results: In general by using the formula Δ ct, it is evident that the miR 153 expression in peripheral blood is lower in patients than in healthy individuals (1.97) while the miR 455-5p expression in peripheral blood is higher in patients than in healthy individuals (2.56). Conclusion: We conclude that miR153 and miR 455-5p expression in serum can function as a diagnostic screening test for the early detection of oral squamous cell carcinoma.

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