R. Kozomara

Gene hypermethylation in tumor tissue of advanced oral squamous cell carcinoma patients.

Oral squamous cell carcinoma (OSCC) is characterized by high mortality rate and rising incidence. The aim of this study was to examine the methylation of particular tumor suppressor genes promoters in OSCC and to correlate the methylation status with the tumor-host features and patients survival. The genes selected for our investigation are involved in key cellular processes of malignant transformation, including cell cycle control (p16), apoptosis (Death Associated Protein Kinase, DAPK), Wnt signaling (Adenomatous Polyposis Coli, APC), cell-cell adhesion (E-cadherin, E-cad), and DNA repair (O(6)-methylguanine-DNA methyltransferase, MGMT, Werner syndrome gene, WRN). In 77 patients with OSCC, hypermethylation was determined by nested methylation-specific PCR method. Methylation of p16 gene promoter was detected in 58.4% of samples, E-cad in 42.9%, DAPK in 36.8%, MGMT in 33.8%, WRN in 23.8%, and APC in 18.2% of OSCC samples. Patients with E-cad promoter methylation had significantly worse overall survival (p=0.039, log-rank test), while hypermethylation of other genes did not have prognostic significance. Stratified analysis by the lymph node involvement and tumor stage showed that E-cad promoter methylation is associated to poor survival in N positive (p=0.024), and stage III tumors (p=0.027), as an opposite to N0 and stage II tumors, where E-cad methylation did not have prognostic significance (p=0.849, p=0.794, respectively). Our findings indicate that multiple genes are frequently aberrantly methylated in OSCC, and that E-cad promoter methylation should be considered as a potential molecular marker for the poor survival in advanced OSCC.

Interaction between the MTHFR C677T Polymorphism and Alcohol—Impact on Oral Cancer Risk and Multiple DNA Methylation of Tumor-related Genes:

Several studies have reported Oral Squamous Cell Carcinoma (OSCC) association with etiological factors, such as smoking and alcohol. The aim of the present study was to establish whether the methylenetetrahydrofolate reductase (MTHFR) C677T genotype and a high alcohol intake, solely or in interaction, have an impact on the oral cancer risk, DNA methylation, or multiple methylation of tumor-related genes. MTHFR C677T genetic polymorphism was determined by the PCR/RFLP method, and DNA methylation was assessed by nested methylation-specific PCR. The risk for multiple methylation was significantly increased in heavy-drinking patients with the TT genotype, compared with CC and CT patients (OR = 10.873; 95% CI, 1.134-104.24). Multiple methylation was significantly associated with tumor stage (p = 0.018), and showed a trend of association with the presence of nodal metastases (p = 0.058). A significant association was found between TT genotype and methylation status of the RASSF1A gene in OSCC patients (p = 0.012). Heavy-drinking individuals with the TT genotype showed increased oral cancer risk compared with the CC genotype (OR = 3.601; 95% CI, 1.036-12.513), and compared with the CC and CT genotypes (OR = 4.288; 95% CI, 1.325-13.877). Our study suggested gene-environment interactions between high alcohol intake and the MTHFR 677TT genotype for elevated oral cancer risk, with a significant impact on multiple methylation of cancer-related genes.

Association of TLR2, TLR3, TLR4 and CD14 genes polymorphisms with oral cancer risk and survival

OBJECTIVES The aim of this study is to investigate association between polymorphisms in TLR2, TLR3, TLR4 and CD14 genes or their haplotypes with oral squamous cell carcinomas (OSCC) risk and survival. METHODS The study was conducted on 93 OSCC patients and 104 cancer-free controls. Polymorphisms were genotyped by real-time PCR or PCR-RFLP method. RESULTS Significant increase in oral cancer risk was observed in individuals with mutated genotype of TLR3 rs3775291 polymorphism (OR = 1.096, P = 0.036) compared to wild-type. The heterozygous and mutated genotype of TLR3 rs5743312 polymorphism had worse survival in group of patients with stage III tumours (P = 0.043). Multivariate Cox regression analysis revealed that TLR3 rs5743312 polymorphism could be considered as prognostic marker in advanced III stage OSCC (HR = 2.456, P = 0.007), but not independently of nodal status. TLR3 rs3775291 and rs5743312 polymorphisms were in strong linkage disequilibrium. Haplotype TG was associated with worse prognosis in OSCC patients in comparison with common CG haplotype (HR = 1.717, P = 0.042). Interaction among polymorphisms in TLR2, TLR3 and CD14 genes was observed (P = 0.010). CONCLUSIONS TLR3 rs5743312 polymorphism could be considered as potential predictor of worse overall survival in advanced oral cancer, but not independently of nodal status. Haplotypes in TLR3 gene might be associated with poor prognosis in OSCC patients.

Hypermethylation of RUNX3 but not WIF1 gene and its association with stage and nodal status of tongue cancers

OBJECTIVES Recent studies indicate various molecular abnormalities in oral squamous cell carcinomas (OSCC), including DNA methylation of tumor-associated genes. Although promoter hypermethylation of Wnt pathway antagonists RUNX3 (Runt-related transcription factor 3) and Wnt inhibitory factor 1 (WIF1) has been identified as a common event in a number of carcinomas, methylation status and the role of RUNX3 as a possible tumor suppressor in oral and head and neck cancer are yet controversial. The aim of our study is to determine the occurrence of RUNX3 and WIF1 genes hypermethylation and correlation with tumor and host-related factors and prognosis in tongue carcinomas. MATERIAL AND METHODS In 76 patients with tongue carcinoma, RUNX3 and WIF1 genes promoter hypermethylation analysis was assessed by nested methylation-specific PCR method. RESULTS Hypermethylation of WIF1 and RUNX3 genes promoters was observed in 35% and 25% of carcinomas, respectively. RUNX3 gene promoter hypermethylation was significantly associated with lymph node involvement (P = 0.013) and tumor stage (P = 0.006), but not with the overall survival. Occurrence of RUNX3 and WIF1 genes comethylation was associated with nodal status (P = 0.058) and tumor stage (P = 0.055). CONCLUSIONS Our findings indicate that RUNX3 and WIF1 are frequently aberrantly methylated and that RUNX3 promoter methylation could be considered as a potential prognostic marker in tongue carcinoma.

HMGB1 genetic polymorphisms in oral squamous cell carcinoma and oral lichen planus patients

OBJECTIVES This study examined the single nucleotide polymorphisms (SNPs) in high-mobility group box 1 (HMGB1) gene in patients with oral squamous cell carcinoma (OSCC) and oral lichen planus (OLP). MATERIALS AND METHODS The study was conducted on 93 patients with OSCC, 53 patients with OLP, and 100 controls, all Caucasians of the same ethnicity, matched by age. HMGB1 genotypes for 4 SNPs, 2262G/A (rs1045411), 1177G/C (rs3742305), 3814C/G (rs2249825), and rs4540927, were assessed using TaqMan SNP Genotyping Assays, Applied Biosystems. RESULTS The HMGB1 1177GG genotype was associated with lymph-node metastasis and tumor stage in OSCCs (P = 0.016 and P = 0.030, respectively). Genotype 1177GG resulted in poorer recurrence-free survival (RFS), P = 0.000. The 1177G/C polymorphism was an independent predictor of RFS compared to GG genotype, P = 0.001. The three polymorphisms were in linkage disequilibrium (LD). The AGC and GGC haplotypes were associated with an increased oral cancer risk, determined over the haplotype odds ratios (HOR = 13.316, P = 0.015, and HOR = 5.769, P = 0.029, respectively). The AGC haplotype was related to erosive OLP progression to OSCC (HOR = 12.179, P = 0.001). CONCLUSIONS HMGB1 polymorphism 1177G/C could be associated with tumor progression and recurrence-free survival in patients with OSCC. The haplotypes of HMGB1 gene might be associated with susceptibility to OSCC and OLP progression to OSCC.

Temporomandibular disorders after orthognathic surgery in patients with mandibular prognathism with depression as a risk factor

OBJECTIVE To examine the prevalence of temporomandibular disorders (TMD) after orthodontic-surgical treatment in patients with mandibular prognathism and analyze psychosocial variables related to TMD. MATERIALS AND METHODS The case-control study comprised 40 patients with mandibular prognathism who underwent combined orthodontic-surgical treatment (orthognathic surgery group). Forty-two patients with untreated mandibular prognathism served as a control group. Research diagnostic criteria for temporomandibular disorders was used in order to assess the clinical diagnosis of TMD (Axis I) and to estimate depression, somatization and patients disability related to chronic pain (Axis II). RESULTS The overall prevalence of TMD was not significantly different between the groups. Myofascial pain was significantly higher, while arthralgia, arthritis and arthrosis was significantly lower in the orthognathic group compared with the controls (90.5% vs 50.0%, 0.0% vs 27.8%, respectively) (p < 0.05). Females in orthognathic surgery group showed higher prevalence of TMD (p < 0.05) and myofascial pain (p < 0.01) and increased level of chronic pain (p < 0.05) in comparison with post-operative males. No significant difference in chronic pain, somatization and depression scores was found between investigated groups. With respect to presence of TMD within the groups depression was higher in untreated subjects with dysfunction (p < 0.05). CONCLUSION Prevalence of TMD immediately after completion of orthodontic-surgical treatment for mandibular prognathism is similar to frequency of dysfunction in untreated subjects, is significantly higher in females and is most commonly myogenic. Furthermore, females show an increased level of chronic pain post-operatively. Somatization and depression levels do not differ between patients with corrected prognathism and untreated prognathic patients.

TMD in class III patients referred for orthognathic surgery: Psychological and dentition-related aspects

OBJECTIVE To investigate temporomandibular disorders (TMD), psychosocial, and occlusal variables in class III orthognathic surgery patients with respect to the control subjects, and to compare psychosocial and occlusal features in class III patients with different Research Diagnostic Criteria for TMD (RDC/TMD) diagnoses. MATERIALS AND METHODS The study enrolled 44 class III patients referred for orthognathic surgery and 44 individuals without a malocclusion. TMD, depression and somatization were assessed by RDC/TMD. Occlusal analysis included Helkimos Occlusal Index items, overjet and overbite. RESULTS In the controls, patients with class III deformities had higher prevalence of myogenic TMD, increased grade of chronic pain, and more occlusal deviations. Within the study group, TMD patients reported higher depression score (P < 0.01), myofascial pain was related to higher depression and somatization grades (P < 0.01, P < 0.05 respectively), and disc displacement showed relation with RCP-ICP slide interferences (P < 0.05). CONCLUSION With respect to subjects without a malocclusion, TMD in class III dentofacial deformities is similar in prevalence, but differs in clinical appearance. Occlusal, but not psychosocial features deviate from those in the controls. While psychosocial variables accompanied TMD and myofascial pain, increased RCP-ICP slide was related to disc displacement in class III patients.

Prognostic significance of TP53 mutations in oral squamous cell carcinoma with human papilloma virus infection.

PURPOSE The aim of this study was to analyze the prognostic impact of mutated TP53 in patients with oral squamous cell carcinoma (OSCC) whose tumors were infected with human papillomavirus (HPV). METHODS Thirty-two HPV-positive OSCC patients were included. Most of them were clinically classified as stage III (n=29). All patients underwent postoperative radiotherapy (follow-up from 12 to 60 months, median 32). There were 21 relapses. DNA was isolated by phenol extraction from tumor tissue. HPV DNA (type 16, 18, 31, 33) was detected in genomic DNA of the tumors by the PCR-PAGE method. TP53 mutations (exons 4-8) were detected by the PCR-SSCP method. RESULTS A statistically significant difference in the number of relapses in HPV-infected (13/21) versus HPV-infected and TP53-mutated (8/8) patients was observed. Patients with both TP53 mutation and HPV infection had a significantly shorter disease-free interval than patients with HPV infection only (median 6 versus 31 months, respectively). CONCLUSIONS TP53 mutations are associated with a higher risk of relapse and contribute to an even worse prognosis of patients with OSCC when the tumors are HPV infected. The shorter disease-free interval in patients with TP53 mutations indicates that the response to postoperative radiotherapy may be influenced by TP53 status. The presence of both HPV infection and TP53 mutations may define a particular group of tumors with a more aggressive phenotype in advanced OSCC.

Brown tumor of the maxilla in patient with secondary hyperparathyroidism

Brown tumor or parathyroid osteopathy is a kind of bony lesion caused by hyperparathyroidism. It appears as an expansive osteolytic lesion mostly in mandible, ribs, pelvis and femur, but rarely in the upper jaw. Bone resorption is the result of osteoclastic activity due to an increased activity of parathyroid hormone. A 25-years-old male patient was operated on due to clinicaly and radiographicaly obvious maxillary tumor and increased values of parathyroid hormon (PTH-1 050 ng/l). The level of calcium in blood was normal (Ca 2.34 mEq/L). The patient was dialyzed for years because of the chronic renal failure. Histopathologic analysis confirmed brown tumor, that appeared as bony lesion of secondary hyperparathyroidism due to the chronic renal failure. The operation of the upper jaw had been performed before parathyroidectomy, due to an excessive growth of tumor followed by heavy epistaxes. The subsequent parathyroidectomy was followed by the regression of remaining bony lesions.