Detection of Candida albicans ADH1 and ADH2 mRNAs in human archival oral biopsy samples

ObjectivesThe aim of this study was to investigate the relationship between expression of Candida albicans alcohol dehydrogenases (ADH) genes in archival formalin-fixed paraffin-embedded (FFPE) samples from biopsies of leukoplakia. Materials and MethodsArchival FFPE samples were obtained from four sample groups: normal oral mucosa, non-dysplastic leukoplakia, chronic hyperplastic candidosis (CHC), and non-CHC dysplastic leukoplakia. The presence of C.albicans was determined by periodic acid Schiff staining and by immunocytochemistry. C.albicans ADH1 and ADH2 mRNAs were detected using reverse transcription PCR. ResultsCandida albicans was detected in FFPE samples diagnosed as CHC (the histological diagnoses had been made by specialist oral pathologists, using uniform criteria), but not in any other sample group, including the non-dysplastic leukoplakias. RT-PCR confirmed a significant correlation between the expression of CaADH1 mRNA (P=0.000), but not for CaADH2 mRNA (P=0.056) in archival FFPE samples (n=31) from biopsies of leukoplakia. ConclusionsCandida albicans was the predominant species in the lesions diagnosed as CHC, and the presence of C.albicans in CHC lesions was associated with a high expression of C.albicans ADH1 mRNA. There was no association between the presence of Candida and malignant transformation in the cases examined; however, the number of cases was limited and further studies are needed to further elucidate the role of C.albicans ADH1 in the pathogenesis of oral squamous cell carcinoma.