Evaluation of apoptotic pathway in oral mucosa by smoking in a Brazilian Outpatient Smoking Cessation Program

PTHLH Predicts the Prognosis of Patients with Oral Leukoplakia

Background

Oral leukoplakia is the most common oral mucosal disease. A proportion of such cases can progress to oral squamous cell carcinoma (OSCC). The mechanism of oral leukoplakia malignant transformation is still unclear. In this study, we analyzed the expression of parathyroid hormone-like hormone (PTHLH) in oral leukoplakia and the effect on prognosis, so as to find reliable molecular markers that can predict oral leukoplakia malignant transformation.

Methods

We measured PTHrP which is coded by PTHLH in oral leukoplakia tissues of 79 cases (30 cases progressed to OSCC and 49 did not) and analyzed the clinical outcomes. Then, PTHLH expression was reduced using lentivirus-mediated small hairpin RNA (shRNA) interference to determine the biological role of PTHLH in DOK cells.

Results

PTHrP was found to be highly expressed in 38% of tissues of oral leukoplakia. There was weak or no PTHrP expression in 25 patients, moderate expression in 24 patients, and strong in 30 patients with oral leukoplakia. The expression level was associated with the degree of atypical hyperplasia and poor prognosis. The cell proliferation, invasion, migration, cell cloning, and cell cycle were affected after reducing PTHLH expression.

Conclusion

Our data suggest that either PTHLH or PTHrP plays a key role in the malignant transformation of oral leukoplakia and might be a reliable biomarker for predicting the carcinogenesis of oral leukoplakia.

Expression of E-cadherin and involucrin in leukoplakia and oral cancer: an immunocytochemical and immunohistochemical study

To assess the immunocytochemical and immunohistochemical correlation of adhesion (E-cadherin) and cell differentiation (involucrin) molecules in oral leukoplakia and oral squamous cell carcinoma. Cytological samples and biopsies were obtained from male and female patients aged over 30 years with oral leukoplakia (n = 30) and oral squamous cell carcinoma (n = 22). Cell scrapings and the biopsy were performed at the site of the lesion and histological slides were prepared for the immunocytochemical analysis of exfoliated oral mucosal cells and for the immunohistochemical analysis of biopsy tissues using E-cadherin and involucrin. Spearman's correlation and kappa coefficients were used to assess the correlation and level of agreement between the techniques. Immunostaining for E-cadherin and involucrin by both techniques was similar in the superficial layers of the histological sections compared with cell scrapings. However, there was no statistical correlation and agreement regarding the immunocytochemical and immunohistochemical expression of E-cadherin and involucrin in oral leukoplakia (R = 0.01, p = 0.958) (Kappa = 0.017, p = 0.92) or in oral squamous cell carcinoma (R = 0.26, p = 0.206) (Kappa = 0.36, p = 0.07). The immunoexpression of E-cadherin and involucrin in tissues is consistent with the expression patterns observed in exfoliated oral mucosal cells, despite the lack of a statistically significant correlation. There is an association of the histopathological characteristics of leukoplakia with the expression E-cadherin and of the microscopic aspects of oral squamous cell carcinoma with immunohistochemical expression of involucrin.

Effect of smoking cessation in saliva compounds by FTIR spectroscopy

INTRODUCTION

Smoking is currently considered one of the biggest risk factors for the development of various diseases and early death. Fourier transform infrared (FTIR) spectroscopy is a valuable tool for analysis of biofluids such as saliva and is considered useful for diagnostic purposes. The aim of this study was to evaluate the effect of smoking cessation on saliva composition by FTIR spectroscopy.

METHODS

We analyzed the saliva of participants in two groups: a smoker group made up of 10 chronic smokers and a former smoker group made up of 10 individuals who had stopped smoking. Members of both groups had similar smoking history.

RESULTS

The results showed few differences in spectral intensity between the groups; however, spectral peaks were slightly increased in the group of smokers in the bands for DNA, indicating modification of its content or cell necrosis. They were also increased for the mannose-6-phosphatase molecule, which is expressed in prostate and breast carcinomas. In the former smoker group, the peak of thyociante was decreased and the band referring to collagen increased in intensity, which indicates a better tissue regeneration capacity.

CONCLUSION

Considering these results and the fact that tobacco intake was similar between the groups, it can be concluded that there was recovery of tissue regeneration capacity with smoking cessation during the study period, although the effects found in smokers persisted in the bodies of those who had given up smoking.