Translocator protein (TSPO) analysis in saliva of adults with oral mucosal lesions: A preliminary study

Abstract

Background: The analysis of translocator protein (TSPO) in saliva could elucidate its potential role as biomarker in oral mucosal lesions associated to early-stage oral cancer. We compared the TSPO protein signal intensity from saliva samples of adults with and without oral mucosal lesions suspected of being potentially malignant disorders. Methods: Saliva samples were collected from 28 participants with and without oral mucosal lesions, recruited from dental clinics in Cartagena, Colombia. A biopsy was performed at the lesion site for each case, and a histopathological diagnosis was obtained. A protein precipitation method for saliva and the Dot blot technique were used to detect and analyze TSPO protein in saliva samples. The signal intensity for TSPO protein was determined by optical densitometry analysis using the software Image Lab. Kruskal-Wallis test was used to compare the intensity of TSPO protein signal by type of histopathological diagnosis; while linear regression analysis was used for the association between TSPO protein signal intensity and the presence or absence of oral mucosal lesions, adjusting by age and sex. Results: Comparing TSPO protein signal intensity from saliva samples of participants with and without oral mucosal lesions, a higher median was observed in the group of cases with oral mucosal lesions (p-value = 0.0141), even after adjusting by age and sex. TSPO protein signal intensity from saliva samples of participants with dysplasia showed the highest median compared with other histopathological findings (p-value = 0.0596). Conclusions: A high signal intensity or presence of TSPO protein in saliva samples of participants with oral mucosal lesions may indicate its potential as marker for malignant transformation; therefore, further research should be performed to investigate TSPO expression in oral carcinogenesis.