Connexin 43, Bcl-2, Bax, Ki67, and E-cadherin patterns in oral squamous cell carcinoma and its relationship with GJA1 rs12197797 C/G.

BACKGROUND: To our knowledge, there is no useful and accurate prognostic biomarker or biomarkers for patients with oral squamous cell carcinoma (OSCC), a tumor with uncertain biological behavior, and unpredictable clinical progress. The purposes of this study were: a) to determine the expresión profile of Connexin 43, Bcl-2, Bax, E-cadherin, and Ki67 in patients with OSCC; b) identify the GJCA1 rs12197797 genotypic composition. MATERIAL AND METHODS: A cross-sectional study using genomic DNA and biopsy samples extracted from the oral mucosa with/without OSCC, older than 18 years, both genders, attended at Facultad de Odontología, Universidad Nacional Córdoba. Immunostaining for Cx43, Bcl-2, Bax, E-cadherin, and Ki67 and genotyping GJA1 rs12197797 by RFLP were performed. Odds Ratio (95% CI), Spearman Coefficient were estimated. Mann-Whitney test was applied to analyze immunostaining between controls/cases (p <0.05 was set for statistical significance). RESULTS: GG (mutant) was the most frequent genotype in patients with OSCC diagnosis (53.2%) in relation to CC "healthy" genotype (p=0.00487; OR=7.33; CI95% [1.1-54.7]). And, the allele G (mutant) had a presence in 75.5% of OSCC patients. However, no significant association was observed between alleles C/G and diagnosis (p=0.0565). The heterozygous genotype was the most frequent in the patients of both groups Cx43 and E-cadherin markers were lower in OSCCs in relation to controls. Ki67 and Bcl-2 immunolabeling were high on OSCC, and Bax immunomarker was diminished in OSCC. CONCLUSIONS: We hypothesized that the oral epithelium losses Connexin 43 and E-cadherin in the membrane, which modifies cell differentiation. The Ki67 and Bcl2 overexpression would increase the cell density in the tissue, by promoting proliferation and decreasing apoptosis. And, this study shows evidence that patients who carry on allele G of GJA1rs12197797 could be at risk of developing OSCC.

Oral cancer associated with chronic mechanical irritation of the oral mucosa.

BACKGROUND: Most of the studies dealing with Chronic Mechanical Irritation (CMI) and Oral Cancer (OC) only considered prosthetic and dental variables separately, and CMI functional factors are not registered. Thus, the aim of this study was to assess OC risk in individuals with dental, prosthetic and functional CMI. Also, we examined CMI presence in relation to tumor size. MATERIAL AND METHODS: A case-control study was carried out from 2009 to 2013. Study group were squamous cell carcinoma cases; control group was patients seeking dental treatment in the same institution. RESULTS: 153 patients were studied (Study group n=53, Control group n=100). CMI reproducibility displayed a correlation coefficient of 1 (p<0.0001). Bivariate analysis showed statistically significant associations for all variables (age, gender, tobacco and alcohol consumption and CMI). Multivariate analysis exhibited statistical significance for age, alcohol, and CMI, but not for gender or tobacco. Relationship of CMI with tumor size showed no statistically significant differences. CONCLUSIONS: CMI could be regarded as a risk factor for oral cancer. In individuals with other OC risk factors, proper treatment of the mechanical injuring factors (dental, prosthetic and functional) could be an important measure to reduce the risk of oral cancer.

[Human papillomavirus detection in oral cancer lesions in the city of Córdoba]. / Detección del virus papiloma humano en lesiones cancerosas orales en la ciudad de Córdoba.

Oral cancer is a process that involves different etiological factors and mechanisms in the light of current view of viral cocarcinogenesis. Evidence from histology and DNA hybridization studies suggests that HPV is engaged in oral carcinogenesis. The Pathology Laboratory of the Dentistry School, National University of Córdoba, admits approximately 20% of all patients with cancerous lesions in this city. In the January 1992-December 1997 lapse, we examined 1950 biopsies with oral lesions, 4.77% (93/1950) of which were malignant neoplasms, 79.57% (74/93) were oral carcinomas. Thirty-three oral carcinomas (44.6%; 33/74) were selected at random and included in this study, 33 cells smears of normal oral mucosa of controls individuals were included. They were analyzed by conventional light microscopy and an in situ hybridization technique for the detection of HPV. Data were analyzed with chi square test. The prevalence of HPV among the 33 cancer samples studied was 27.27%, 9/33 tested positive for HPV in low stringent conditions. Only one was positive in high stringent condition for HPV16, a verrugous carcinoma. No HPV-DNA was detected in cells smears of controls. Among the HPV positive, 3/9 (33.33%) were squamous carcinomas and 5/9 (55.56%) were verrugous carcinomas. Only one was a melanoma. Verrugous carcinoma was the carcinoma most associated with the HPV infection (x2 = 20.5; 95% level of confidence). This would indicate a major role of HPV in the pathogenesis of verrucous carcinomas. The viral prevalence found in cancerous lesions reinforces the concept of heterogenic natures of oral cancer. HPV is a circumstance that increase the probability of malignancy, and when reducing, diminish the frequency of cancer.