Patients with advanced oral squamous cell carcinoma have high levels of soluble E-cadherin in the saliva.

BACKGROUND: The objective of this study was to assess the potential clinical value of the concentration of soluble salivary E-cadherin (sE-cadherin) compared with the clinical value of the presence of membranous E-cadherin (mE-cadherin) in oral squamous cell carcinoma tumor tissues. MATERIAL AND METHODS: Data regarding patient demographics, clinical stage, saliva and tumor tissue samples were collected. The saliva was analyzed for sE-cadherin protein levels and was compared to the mE-cadherin immunohistochemical expression levels in tumor tissues, which were assessed via the HercepTest® method. Patients without cancer were included in the study as a control group for comparisons of the sE-cadherin levels. RESULTS: sE-cadherin levels in the saliva of patients without cancer were lower than those in patients with cancer, and the difference was statistically significant (p=0.031). Low mE-cadherin expression was statistically significantly associated with lymph node positivity (p=0.015) and advanced clinical stage (p=0.001). The inverse relationship between mE-cadherin and sE-cadherin was significant in terms of lymph node positivity (p=0.014) and advanced clinical stage (p=0.037). CONCLUSIONS: The results suggest that sE-cadherin levels are significantly increased in patients with oral cancer and that its low expression within the membrane as well as the progression of the disease appear to be inversely associated with levels of sE-cadherin in the saliva.

Increased micronuclei and nuclear abnormalities in buccal mucosa and oxidative damage in saliva from patients with chronic and aggressive periodontal diseases.

BACKGROUND AND OBJECTIVE: Periodontal disease is a chronic bacterial infection characterized by connective tissue breakdown and alveolar bone destruction because of inflammatory and immune response caused by periodontopathogens and long-term release of reactive oxygen species. A high number of reactive oxygen species result in periodontal tissue damage through multiple mechanisms such as lipid peroxidation, protein denaturation and DNA damage. The aim of this study was to evaluate DNA and oxidative damage in subjects with chronic or aggressive periodontitis and healthy controls. MATERIAL AND METHODS: Buccal mucosa cells and whole saliva were collected from 160 subjects, who were divided into three groups: subjects with chronic periodontitis (CP) (n = 58), subjects with aggressive periodontitis (AgP) (n = 42) and a control group (n = 60). DNA damage was determined by counting micronuclei (MN) and nuclear abnormalities (NAs) in exfoliated cells, including binucleated cells, cells with nuclear buds and karyolitic, karyorrhectic, condensed chromatin and pyknotic cells. The degree of oxidative stress was determined by quantifying 8-hydroxy-2'-deoxyguanosine (8-OHdG) in whole saliva. RESULTS: Subjects with CP or AgP presented significantly more ( p < 0.05) MN and NAs and higher levels of 8-OHdG ( p < 0.05) compared with the control group. CONCLUSION: Our results indicate that subjects with periodontitis (CP or AgP) exhibited an increase in the frequency of MN, NAs and 8-OHdG, which is directly related to DNA damage. In addition, a positive correlation exists between oxidative stress produced by periodontitis disease and MN.

Positive association between vascular endothelial growth factor (VEGF) -2578 C/A variant and prostate cancer.

BACKGROUND: Vascular endothelial growth factor (VEGF) gene is an important angiogenesis regulator related to cancer development and progression. We evaluated the association between -2578 C/A (rs699947) VEGF polymorphism and PCa in Mexican subjects, to contribute to knowledge of VEGF role in genetic epidemiology of prostate cancer (PCa). OBJECTIVE: The aim of this study was to evaluate the association between -2578 C/A VEGF variant and PCa in Mexican population. METHODS: A total of 249 men (77 PCa cases and 172 controls) from the Northwestern region of Mexico were screened for the -2578 C/A VEGF variant. The polymorphism was determined by polymerase chain reaction-based restriction analysis. RESULTS: Genotype frequencies for C/C, C/A, and A/A, were 0.48, 0.49, 0.03 for cases and 0.41, 0.45, 0.14 for controls respectively. Genotype A/A of -2578 VEGF variant reduces the risk of PCa in an 84% among studied population (Odds Ratio 0.16; 95% CI: 0.04-0.71, P=0.007). C/C carriers showed an increased PCa risk of 6.1 times among the study population. CONCLUSIONS: Inheritance of -2578 A/A genotype of VEGF gene may modify PCa susceptibility risk in Mexican population.

Forensic parameters for 15 STRs in eight Amerindian populations from the north and west of Mexico.

Allele frequency distributions for 15 STR loci (AmpFlSTR Identifiler kit) were estimated in 825 volunteers of the following eight Mexican-Amerindian populations from two geographical regions: (1) North: Tarahumara (204), Mayo (45), Seri (28), and Guarijío (17); (2) Northwest: Tepehuano (123), Mexicanero (84), Cora (85), and Huichol (239). Genotype frequency distribution was in agreement with Hardy-Weinberg expectations for all 15 STRs, excepting for two loci (D13S317 and FGA) in the Huichol population. The power of discrimination and power of exclusion values were both larger than 0.99999. These STR databases will support the correct interpreting of DNA profiles in paternity testing and forensic cases in Mexican-Amerindian groups from these regions, until know poorly studied. Genetic distances and pairwise comparisons were estimated between populations. A significant genetic differentiation was observed between these Mexican-Amerindian groups (F(ST)=3.43%; p=0.0000) that was 10 times larger than the observed between Mestizos (F(ST)=0.34%), which represent most of the Mexican population (~90%). This result was in agreement with the incapability to cluster these Native American populations by geographic criteria. Pre-Colombian descriptions of Aridoamerica, including the North region of Mexico, suggest genetic drift effects to explain this noticeable population differentiation of Mexican-Amerindian groups.

Influence of admixture components on CYP2C9*2 allele frequency in eight indigenous populations from Northwest Mexico.

We previously documented the lowest frequency of CYP2C9*2 in Mexican indigenous Tepehuanos followed by Mestizos and Mexican-Americans populations, suggesting a negative correlation between the CYP2C9*2 frequency and the degree of Asian ancestry in indigenous Americans. We determined the influence of ethnic admixture components on the CYP2C9 allele distribution in 505 Amerindian from eight indigenous populations through genotyping CYP2C9*2, *3 and *6 alleles by real-time PCR and molecular evaluation of ancestry. The frequencies for CYP2C9*2 were 0.026 in Seris and 0.057 in Mayos, being higher than in Asians (P<0.001). CYP2C9*3 was found in Tarahumaras (0.104), Mayos (0.091), Tepehuanos (0.075), Guarijíos (0.067), Huicholes (0.033) and Coras (0.037), with East Asians having lower frequencies than the former three groups (P<0.001). CYP2C9*6 was not found. The frequency of CYP2C9*2 was lower in Amerindians than in European populations, and higher than their Asian ancestors. The presence of this allele in ethnic groups in Mexico can be explained by European admixture.