Background/Objectives: Recent meta-analyses have established that factors such as sarcopenia, male sex, and low serum albumin significantly correlate with increased postoperative complications in head and neck surgery, with routine neck computed tomography (CT) at the third cervical vertebra (C3) serving as a practical tool for muscle mass assessment. This study aimed to confirm the prognostic value of C3-based sarcopenia and specific clinical comorbidities in predicting early postoperative complications in patients with oral squamous cell carcinoma (OSCC). Methods: A retrospective cohort study was conducted on 167 patients undergoing primary surgery for OSCC. Sarcopenia was assessed using the C3-vertebra skeletal muscle index (SMI) derived from routine preoperative neck CT scans. Clinical and surgical variables, including preoperative serum albumin levels, comorbidities, and flap reconstruction types, were evaluated. A priori multivariate logistic regression models were utilized to identify independent predictors of surgical site and pulmonary and total complications (Clavien-Dindo classification) within 30 days. Results: The overall complication rate was 51%. Multivariate analysis revealed that sarcopenia (aOR: 3.26; 95% CI: 1.11-9.56), male sex (aOR: 3.48; 95% CI: 1.11-10.85), coronary artery disease (CAD) (aOR: 4.30; 95% CI: 1.21-15.36), and free-flap reconstruction (aOR: 15.06; 95% CI: 2.47-92.01) were robust independent predictors of total complications. Male sex (aOR: 4.17; 95% CI: 1.51-11.58) and preoperative hypoalbuminemia (<3.5 g/dL) (aOR: 3.43; 95% CI: 1.20-9.82) were independent predictors of surgical site complications, while regional flap reconstruction was independently associated with pulmonary complications (aOR: 5.97; 95% CI: 1.38-25.97). Conclusions: Sarcopenia, male sex, CAD, and flap reconstruction type are strong independent predictors of postoperative morbidity in OSCC. These findings advocate for "opportunistic screening" of muscle mass via routine preoperative neck CT, alongside rigorous cardiovascular profiling, to identify high-risk phenotypes for targeted perioperative optimization.

OBJECTIVE:The primary objective was to investigate the effect of extra-nodal extension (ENE) grading on the survival of pN-positive patients with laryngeal squamous cell carcinoma (LSCC). STUDY DESIGN:A retrospective cohort study. SETTING:A tertiary referral center. METHODS:The patients with LSCC were retrospectively reviewed. The histopathological slides of patients were re-examined, and ENE was graded. Survival analyses were performed. RESULTS:Seventy-six patients were enrolled in this study. The average age of patients was 61.29 years. 3-year overall survival (OS), disease-specific survival (DSS), and disease-free survival (DFS) rates were 69.7%, 73.7%, and 73.7%, respectively. ENE grading had no statistically significant impact on survival rates. CONCLUSION:While the presence of ENE in more than 4 lymph nodes, lymph node density (LND) greater than 0.2, poor histologic differentiation, and not receiving chemotherapy were identified as independent poor prognosticators in LSCC, the study did not show any effect of ENE grading on survival rates.

Aim: As a result of the array analyses obtained within the scope of the TUBITAK-SBAG-114S497 project conducted by Demokan and his colleagues, STK32C gene was determined as a potential epigenetic biomarker candidate. In this study, the methylation and expression levels of STK32C gene were examined in a larger patient group consisting of oral squamous cell carcinoma (OSCC) cases; the biomarker potential of this gene in terms of early diagnosis/prognosis evaluation was investigated. Method: DNA and RNA were isolated from tissue samples of 15 OSCC patients, and the methylation and expression levels of the STK32C gene were examined using Quantitative Methylation Specific PCR and Real-Time PCR methods, respectively. Results and Conclusions: In tumor samples of OSCC patients, 93.3% methylation was observed in the promoter region of the STK32C gene. When expression levels were evaluated, expression loss was detected in 53.3% of the samples in tumor tissues compared to normal tissues, while expression increase was observed in 13.3%. Hypermethylation was detected in all patients with decreased expression levels. It is suggested that the loss of expression observed in the STK32C gene due to hypermethylation may play a role in the molecular characterization of a certain subgroup of OSCC patients and that this gene may be a significant biomarker candidate for early diagnosis and prognosis. However, further studies covering larger patient populations are needed to confirm this.

Aim: Oral cancer constitutes 2-4% of all cancers and is the most common cancer in the head and neck region after laryngeal cancer. Oral squamous cell carcinoma (OSCC) constitutes more than 90% of all oral cavity carcinomas. While the 5-year survival rate in OSCC is 40%, this rate increases to 95% in early diagnosis. The GABRB3 gene was identified as a potential epigenetic biomarker candidate in the TUBITAK-SBAG-114S497 project conducted by Demokan et al., and in this study, the differing methylation and expression levels in OSCC patients were examined and its biomarker potential in early diagnosis and prognosis was investigated. Methods: DNA and RNA were isolated from tissue samples taken from 15 patients diagnosed with OSCC, then the methylation status and gene expression levels of the GABRB3 gene were evaluated by Quantitative Methylation Specific PCR and Real-Time PCR methods, respectively. Results and Conclusions: Methylation was detected in the promoter region of the GABRB3 gene in 60% of tumor samples from OSCC patients. When expression levels were evaluated, loss of expression of the GABRB3 gene was detected in 46.7% of samples compared to normal tissues in tumor tissues, while increased expression was observed as 13.3%. Methylation was detected in all patients with decreased expression levels. While decreased expression was observed in 33.3% of tumor tissues having no methylation, increased expression was observed in 50%. It is thought that GABRB3 gene may be responsible for a special subgroup of OSCC patients via methylation-related loss of expression and can be used as a potential biomarker candidate in early diagnosis and prognosis determination. Further studies in larger patient groups are needed to confirm these findings.

(1) Background: This study investigated the presence of human papillomavirus (HPV), HPV genotypes, Epstein–Barr virus (EBV), cytomegalovirus (CMV) and herpes simplex virus (HSV) in patients with Head and Neck Cancer (HNC) at both molecular and serological levels. (2) Methods Fifty patients with histopathologically confirmed HNC who were admitted to the Department of Otorhinolaryngology, Istanbul Faculty of Medicine. Viral DNA was detected using quantitative real-time PCR, and serological IgM and IgG antibodies were analyzed using the CMIA method; (3) Results: In blood samples, CMV and HSV DNA were not detected, whereas EBV DNA was identified in 2% and HPV DNA in 4% of patients. In tumor tissues, CMV DNA was detected in 8%, EBV DNA in 10%, and HPV DNA in 6%; HSV DNA is 6%. HPV genotypes 18, 45, and 69 were found in tissue samples. Serologically, IgG positivity for CMV, EBV, and HSV-1 exceeded 90%, whereas IgM positivity was low and not statistically significant; (4) Conclusions: HPV, EBV, and CMV DNA were detected at low frequencies in patients with HNC, while HSV DNA was absent. These findings underline the need for larger multi-center studies and support the consideration of routine viral screening, particularly for HPV, in specific tumor subtypes.

BACKGROUND:Oral squamous cell carcinoma (OSCC) remains a major global health burden, often diagnosed at advanced stages, with limited survival improvement. Epigenetic dysregulation, particularly promoter hypermethylation, plays a significant role in OSCC pathogenesis. Previous study by Demokan et al. identified Gamma-Aminobutyric Acid Receptor Beta-2 (GABRB2) as a candidate gene subject to methylation-dependent transcriptional silencing. This study aimed to evaluate the methylation and expression profiles of GABRB2 in OSCC and to explore its potential as a diagnostic biomarker. METHODS:Tissue and serum samples from 48 OSCC patients and 15 healthy controls were analyzed for GABRB2 promoter methylation via quantitative methylation-specific PCR and for gene expression levels via quantitative real-time PCR. Relationships between methylation, expression levels, clinicopathological parameters, and patient outcomes were statistically assessed. RESULTS:GABRB2 promoter hypermethylation was detected in 14.6% of tumor samples, predominantly in floor of the mouth and buccal tumors. Decreased GABRB2 expression was observed in 52.1% of tumor tissues compared to matched-normal tissues, while 22.9% of tumors exhibited increased expression. Methylation-dependent expression loss was confirmed in 71.4% of methylated tumors. Notably, decreased expression and hypermethylation of GABRB2 were correlated with poor prognosis parameters (p < 0.05). ROC analysis showed moderate discrimination for GABRB2 expression in distinguishing tumor from normal tissues (AUC = 0.635, p = 0.022), while serum-based analysis demonstrated poor diagnostic performance. Survival analysis revealed no statistically significant prognostic impact of GABRB2 expression levels (p > 0.05). However, alcohol consumption (p = 0.006) and recurrence developed (p = 0.030) as independent predictors of poor prognosis in multivariate analysis. CONCLUSION:Our study suggests that there was association between methylation-based expression loss of GABRB2 with OSCC' subgroups. To our knowledge, this is the first study to investigate GABRB2 gene methylation and expression profiling in both invasive/non-invasive samples from OSCC patients. Hypermethylation in the newly identified candidate GABRB2 gene may play a role in the development of tumors originating from the mouth floor and buccal anatomical regions of the oral cavity. However, since the loss of expression seen in the majority of our patients, we thought that only methylation may not the inhibition mechanism for GABRB2 gene decreased expression. The new identified candidate gene may be specific for the OSCC's subgroups.

Objective Immune-related gene expression levels in the tumor microenvironment (TM) of head and neck squamous cell carcinoma (HNSCC) patients was compared. Materials and Methods The CD163, CD274, CD86, FUT4, FOXP3, and ITGAX levels of HNSCC patients in their tumor tissues (n =76) and surrounding tissues adjacent to the tumor (n =76) were determined using quantitative real-time PCR (qRT-PCR). Changes in these genes were also evaluated by associating with demographical data of the patients. Results CD163, CD274, FUT4, and FOXP3 gene expression levels were significantly higher in tumor tissue than in surrounding tissue. FUT4 fold change was statistically higher in patients with lymph node involvement. CD86 expression was statistically lower in smokers of 50 boxes per year or more. CD163, CD274, and FUT4 expressions were increased in response to the presence of extranodal extension (ENE). Conclusions These preliminary results demonstrate the alterations in expression levels of immunologic markers are associated with the clinical presentations of HNSCC. Availability of data and materials The datasets used and/or analysed during the current study available from the corresponding author on reasonable request.

Objective: To evaluate caloric response changes after endolymphatic sac decompression (ESD), together with hearing outcomes and the functional benefit of the operation. Methods: A retrospective chart review of subjects who underwent endolymphatic sac decompression at a tertiary referral centre was performed. Data on audiological results, caloric testing, and functional level scale of the patients were analysed. Results: Twenty-eight patients who met our criteria were eligible for enrolment in the study. The average followup after surgery was 25 months (range, 13-41). Postoperative pure-tone threshold averages and reduced vestibular response values (RVR) were not significantly altered by ESD; whereas, functional level scores improved significantly. Conclusion: Endolymphatic sac decompression is a surgical procedure that preserves hearing and vestibular function, and improves the daily functional level of patients with Meniere's disease. ESD can be preferred both in bilateral and unilateral disease because it does not alter vestibular function and preserves hearing.

Objective: Oral squamous cell carcinoma (OSCC) is a severe form of cancer affecting different anatomic sites of the oral cavity. OSCC ranks as the sixth most common cancer type with an increasing prevalence globally. However, the mechanisms of OSCC process at later stages are not well understood. In this study, we aimed to determine genetic alternations in metastatic OSCC patients to identify genomic changes occurred at metastatic phase of the disease. Material and Methods: The Illumina CytoSNP-12 Array was used to determine copy number variations in OSCC cancer genome. Hybridization procedures were performed according to the manufacturer procedures (Illumina). Arrays were scanned on iScan System (Illumina). Data were analyzed using Illumina Genotyping module of Genome Studio software (version 1.2, Illumina). Multiple CNV algorithms and copy number alternations were accessed by Genome Studio. CNVs in whole genome were investigated by using a chromosomal heat map. Results: We reported that gains in 8q21.11 -ter, 9p21.3, 13q14.11 -ter, 13q13.3 -ter and losses in 5q14.3 -ter, 5q35 and 17p13.3-12 were associated with the development of OSCC. In addition, we also detected that deletion in 2q33.2 -ter and 2q35-37.3 regions were also associated with OSCC metastasis process. Conclusions: Our results were also showed that gains in 11q13.3 -q13.4 and 2q13.2 chromosomal regions could promote the metastatic OSCC process. We believe that results of the study will help to find new biomarkers for diagnosis at later stage of OSCC. (c) 2023 Elsevier Masson SAS. All rights reserved.

In this study, our aim was to investigate the epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) gene polymorphisms in oral squamous cell carcinoma (OSCC) patients and non-OSCC healthy controls. This case-control study comprised 89 OSCC and 107 healthy controls by using polymerase chain reaction (PCR) and restriction fragment length polymorphism methods, the genotypes for EGF + 61 A > G (rs4444903) and EGFR R497K (rs2227983) were analyzed. According to the EGF + 61 A > G genotype distribution, individuals with the GG genotype were more prevalent in the OSCC group when compared to the healthy controls. But the AA genotype frequency was significantly higher in the healthy control group. The frequency of G allele carriers was 2.3 times higher than A allele carriers in OSCC patients (p < .001). For the EGFR R497K genotype, there was no significant difference between the OSCC and healthy control groups. Regarding the study results, the G allele of EGF + 61 A > G polymorphism was associated with OSCC. Larger populations and functional investigations should be used to explore the nature of the interaction between EGF and OSCC.

Antibiotics-chemotherapeutics combination have become on the table for many cancer treatments. For this reason, we thought that further progress and development of studies to support chemotherapeutic approaches with the use of antibiotics may be beneficial in the clinical field. Cell lines (SCC-15, HTB-41, and MRC-5) were treated with 5-100 μM/ml concentrations of cisplatin (cisp) and amoxicillin/clavulanic acid (amx/cla) with combination (amx/cla-cisp) and alone in three different incubation periods. The all-cells viability was examined with WST-1 and apoptotic activity of the drugs were investigated via cell death ELISA assay kit. The cytotoxic impact of the 100 μM amx/cla-cisp combination was found to be reduced by up to 21.8%, which was significant given that the cytotoxic effect of only cisplatin therapy was 86.1%. Because our findings demonstrated that solo amx/cla therapy have almost no impact on proliferation or death, we focused on the amx/cla-cisp combination effect. It was found that the amx/cla-cisp combination has reduced the apoptotic fragment when comparing with the solely cisp-treated cells. Due to amx/cla-cisp combination on both cells but significantly on SCC-15 recovered the sole cisplatin effect, we believe that there might be a second thought when prescribing antibiotics while treating cancer patients. Not only the antibiotic's type but also the cancer type might interact to lessen the chemotherapeutic agent's impact which is clinically a dilemma to focus on.

Background. The sinonasal tract is the second most common site of human papillomavirus (HPV)-related carcinomas in the head and neck. Published data on the association between sinonasal tumors and HPV are quite inconsistent among different regions. Material and methods. We performed high-risk HPV DNA in situ hybridization (ISH) and p16 immunohistochemistry on sinonasal carcinomas diagnosed between 2006 and 2016. Results. Of 105 sinonasal carcinomas, we found only two (2%) HPV-positive cases; both had non-keratinizing morphology and were diffusely positive for p16. By histologic type, HPV DNA positivity rate was 14% in non-keratinizing squamous cell carcinomas, and we did not detect HPV DNA in any other type of sinonasal carcinomas. Thirteen HPV-negative tumors (7 salivary gland carcinomas, 3 sinonasal undifferentiated carcinomas, 2 keratinizing squamous cell carcinomas, and 1 non-keratinizing squamous cell carcinoma) were positive for p16. In nine carcinomas arising from an underlying sinonasal papilloma, p16 and HPV DNA ISH were evaluated in both carcinoma and papilloma areas and all were negative. Follow-up information was available for 104 patients; 46 (44%) were alive and 58 (55%) died of disease. One of the two HPV-positive patients died of the disease; the other was alive at 100 months of follow-up. Conclusions. We detected a much lower percentage of HPV positivity in sinonasal carcinomas when compared to the literature. We believe that our results support various rates of HPV-related carcinomas depending on the geographic and ethnic characteristics.

Background: Tumor Necrosis Factor-Alpha (TNF-alpha) is a proinflammatory cytokine that plays a role in inflam-mation, which is one of the hallmarks of cancer, and its polymorphic variants have been associated with disease risk in many cancers in the literature. This study aimed to investigate four different polymorphic variants in the promoter region of the TNF-alpha gene and to determine the association between these variants and disease risk and clinical parameters. In addition, TNF-alpha promoter methylation and differential expression status were investigated in our study. We purposed to investigate the genetic and epigenetic alterations of the TNF-alpha gene in larynx cancer (LC).Material and Methods: After isolation of DNA/RNA from whole blood and tumor or normal tissue, polymorphic variant alleles, expression, and methylation levels were analyzed by RFLP, semiquantitative RT-PCR, and re-striction enzyme digestion. TNF-alpha expression and methylation levels were calculated using BIO1D software. The frequencies of the variants c.-238 G>A (rs361525), c.-857 C>T (rs1799724), c.-863 C>A (rs1800630), and c.-1031 T > C (rs1799964) in the promoter region of TNF-alpha in LC Turkish patients and healthy individuals were examined using the De-Finetti case-control program. Haplotype frequencies and linkage disequilibrium were analyzed using the SNPStats program.Results: Polymorphism genotype frequency showed that the frequency of genotype -1031 TC was significantly lower in patients than in healthy individuals [TT vs TC: OR (%95CI) = 7.00 (1.75-27.93), p = 0.003, chi 2 = 8.76]. The heterozygous variant of -857 was associated with recurrence [T vs G: OR (%95CI) = 0.15 (0.02-0.95), p = 0.02, chi 2 = 4.86]. For c.-238 G>A, c.-857 C>T, and c.-863 C>A, there is no statistically significant difference between the patient and healthy group in terms of disease risk. A significant association was found between c.-1031 T > C and disease risk of LC. Decreased expression was detected in 46% (23/50) and increased expression in 54% (27/50) of tumor tissue compared to the matched normal tissue of patients. Methylation-related loss of expression was detected in 53.3% (16/30) of patients.Conclusion: Our study is the first to investigate four different polymorphic regions of the TNF-alpha promoter region and the expression/methylation status of TNF-alpha in the same LC patient and healthy cohort. According to our results, the -1031 TC variant was reported to be significantly associated with a reduced risk of LC. In addition, the TNF-alpha variant -857 CT suggests that it may be a potential biomarker for predicting the recurrence of LC. An association between its variant and methylation-based expression status was observed.

Background: The let-7 family of microRNAs regulate multiple oncogenes including the KRAS gene and has been shown to play a critical role in carcinogenesis. In this study, we aimed to investigate polymorphic alterations of the let-7 miRNA binding site (rs61764370) in the 3 ' UTR region of the KRAS gene as a predictive biomarker for head and neck cancer (HNC) and to evaluate its association with clinicopathological parameters.Material and Methods: The frequency of the KRAS-LCS6 variant in 216 Turkish HNC' patients and 85 healthy individuals were evaluated. After extracting DNA from whole blood, the variant allele was analyzed by poly-merase chain reaction and restriction fragment length polymorphism method. Genotype and allele frequencies were evaluated using the De-Finetti case-control program.Results: 85.6 % of the patients were wild type, 13 % heterozygous and 1.4 % homozygous variant. Although the KRAS-LCS6 variant was not associated with the risk of HNC (p > 0.05), G homozygous variant allele was found to be significantly associated with HNC patients having lymph node metastasis [T vs G: OR(%95 CI)= 2.370 (1.03-5.41), p = 0.03, chi 2 = 4.38]. It was found statistical significance between genotype frequencies and smoker patients [TT vs TG: OR(%95 CI)= 0.357 (0.13-0.97), p = 0.03, chi 2 = 4.32] by using De-Finetti analysis. Statistical significance was observed between KRAS-LCS6 genotype frequencies and gender, smoking, alcohol, early/late-stage, lymph node metastasis according to univariate analysis and Cox proportional hazards regression model (p < 0.05).Conclusion: This is the first study to reveal the relationship between KRAS-LCS6 variant and lymph node metastasis in HNC. The LCS6 variant of the KRAS gene may be a candidate predictor risk biomarker for lymph node metastasis in HNC.

Objectives: Oral squamous cell carcinoma (OSCC) has a high morbidity and mortality rates, but there are no reliable biomarkers to define patients in early phases of disease.In our study (TUBITAK-SBAG-114S497), we aimed to investigate the potential epigenetic biomarker candidate genes observed methylation-dependent expression loss via methylation and expression array methods in OSCC patients.Material and Methods: Methylation and expression profiling in tumor and conjugate-normal tissue samples of 6 OSCC patients were analyzed by "IlluminaHumanMethylation450 chips" and "Illumina iScan", respectively.Methylation/expression array data were analyzed and interpreted by R(v3.5.1) environment using ChAMP and limma/lumi packages, and then the significant decreased expression changes due to hypermethylation of the candidate gene was detected.The selected candidate gene was validated in tumor and matched-normal tissues and body fluids (serum and saliva) of 20 OSCC patients by QRT-PCR/QMSP methods.Results: According to the array results, it was determined that the expression levels of the candidate gene were decreased due to methylation (DiffScore:13.18826;FoldChange:-1.08345).This candidate gene (unpublished data), which plays an important role in ubiquitin-ligase activity, was found to be methylated in 45% tumor, 40% matched-normal tissue, 10% serum and 30% saliva samples.50% of the patients observed methylation in the tumor tissue showed the differentially decreased expression levels.Conclusion: It is thought that this candidate gene, whose expression level decreased due to methylation, will be a candidate epigenetic biomarker for the early diagnosis of the subtypes of OSCC.Further validation of this candidate gene will be needed in the larger OSCC cohorts.

Introduction: Our previously study (TUBITAK-SBAG-114S497) showed hypermethylation of the PAX1 gene in Turkish oral squamous cell carcinoma (OSCC) patients via methylation-array results.In this study, we aimed to validate its potential as an epigenetic biomarker for OSCC by analyzing the methylation status and the changes in methylation-related gene expression of the PAX1 gene in Turkish OSCC patient and healthy groups.Material and Methods: Expression and methylation levels of PAX1 gene were analyzed by Quantitative Real Time-PCR and Quantitative Methylation Specific PCR methods respectively, in tissues and body-fluid samples of 30 OSCC patients and 30 healthy individuals.Results: The methylation rates of the PAX1 gene in matched-normal tissue, tumors, serum and saliva samples of OSCC patients were 50%, 73%, 40%, and 66%, respectively.The methylation rates of the PAX1 gene in normal mucosa, serum and saliva samples of healthy individuals were found to be 6%, 0 and 10%, respectively.In the malignant group, 59% patients in whom methylation was observed in the promoter region of the PAX1 gene in the tumor tissue was found to have decreased expression levels in the tumor tissues compared to the matched-normal tissues.Conclusion: DNA hypermethylation of PAX1 gene may play a role in oral carcinogenesis and may be used as an epigenetic biomarker.

Objectives: DNA methylation, which is the most frequently observed epigenetic change, is very important because it is seen in the early stages of cancer.Abnormal methylation of promoter regions and silencing of tumor suppressor genes play a key role in the development of oral squamous cell carcinoma (OSCC).In our study*, it was aimed to identify and validate new biomarker candidates via epigenomics/transcriptomics approaches, to understand the molecular mechanisms of OSCC and to discover new biomarkers for early diagnosis.Materials and Methods: After DNA/RNA isolation of tumor/matched-normal tissue samples from 6 OSCC patients, BC-DNA/cDNA synthesis was performed, respectively.The methylation and expression profiles were analyzed by the R(v3.5.1) environment methods using IlluminaHumanMethylation450chips and IlluminaiScan, respectively.A candidate gene showing methylation-dependent expression loss after bioinformatic analysis was validated by QRT-PCR AND QMSP methods in tissues and body fluids of 20 OSCC and 20 oral premalignant lesions (OPML) patients, respectively.Results: To identify epigenetic biomarker candidate, we selected gene which show either hypermethylation and lower expression patterns.This candidate gene (unpublished data), which is belong subfamily of the protein-tyrosine kinase, was found to be methylated in 65% of tumors, 20% of matched-normal tissues of OSCC.The methylation rates of the candidate gene in tumor, matched-normal tissues and saliva of OPML patients were found to be 55%, 40% and 10%, respectively.The decreased expression levels of candidate gene were observed in 55% OSCC and 35% OPML tumors, respectively.Conclusions: Our candidate gene could be a biomarker for early detection of OSCC.

Objective: Demokan et.al idetified G/Protein/Coupled/Receptor/Class-C/Group-5/Member-C (GPRC5C) as a candidate gene in OSCC via expression and methylation array results (logFC:0.59663; DeltaBeta: -0.130984561) from their previous unpublished data. In our study, the methylation and expression status of GPRC5C gene was investigated in a larger group of OSCC patients and healthy cohort for further validation. Its potential candidate biomarker was evaluated for early diagnosis of OSCC by non-invasive methods. Materials and Methods: DNA and RNA were isolated from tissues/body fluid samples of 30 patients OSCC and 15 healthy individuals. The methylation and expression levels were analyzed by using QMSP and QRT-PCR methods, respectively. The data were compared with clinical parameters and evaluated by statistical analysis. Results: Decreased expression levels were observed in 43% and increased expression levels were observed in 33% in the tumor tissues compared to corresponding-normal tissues of OSCC patients. Methylation-based expression loss was observed in 4 patients having the ratio between 3.4 and 12.2%. We also observed a decrease in expression in OSCC patients with observed methylation. There was statistical significance between differentiation degree and expression in OSCC. Conclusion: It was concluded that GPRC5C may play a role as a potential methylation biomarker candidate of specific subgroups of the oral cavity. Other mechanisms need to be explored to understand the differences in expression levels.

Oral squamous cell carcinoma patients are exhausted against the powerful chemotherapies, radiotherapies after the surgery, and their immune system is devastated during the process and antibiotic usage become inescapable. Although prescribing an antibiotic might be fraught for such as drug interaction and undesirable proliferation danger, studies still look for the new ideas such as antibiotic combinations that might be safe to use. The antiproliferative and apoptotic outcomes of levofloxacin with cisplatin combination as well as their single usage were examined with WST-1, Caspase-3/BCA and Annexin V methods on SCC-15 cells and a healthy cell line (MRC-5). 24 h treatment of 50 mM single levofloxacin, 50 mM single cisplatin and 50 mM levofloxacin-cisplatin combination resulted in viability rates of SCC-15 cells as 90%, 67% and 80.8%, respectively. Caspase-3 enzyme activity was enhanced 0.92-fold for single levofloxacin, 13.05-fold for single cisplatin and 9.73-fold for the combination of levofloxacin-cisplatin, the total apoptotic activity of single levofloxacin, single cisplatin and levofloxacin-cisplatin combination were observed as 4.88%, 21.14%, 16.21%, respectively on SCC-15. The apoptotic effect of cisplatin on MRC-5 has been shown to be suppressed when combined with levofloxacin. Considering the cell viability, caspase-3, and apoptotic activity results, it's conclude that the levofloxacin-cisplatin combination was also effective compared to the only cisplatin treatment on OSCC cells. The combination has shown less toxicity for healthy cells than single cisplatin treatment. Therefore, our apoptotic findings suggest that the different dosage combinations are necessary to understand the interaction for the treatment of tongue squamous cell carcinoma.