Effect of bone marrow transplantation on the immunolocalization of p53, hMSH2, and hMLH1 proteins on oral mucosa.

Considering that hMSH2, hMLH1 and p53 are important in maintaining genomic stability of the oral mucosa epithelium, the purpose of the present study was to investigate the immunolocalization of these proteins in the epithelium of the oral mucosa of patients submitted to bone marrow transplantation (BMT) compared with controls. Twenty-one samples of lip biopsies from BMT recipients were retrieved. Twenty samples of normal lower labial mucosa associated with mucocele in non-transplanted patients were included as control group. The streptavidin­biotin complex stain was used to detect the human DNA mismatch repair proteins hMSH2, hMLH1 and p53 protein. RESULTS: The main findings demonstrated that the mean number of suprabasal epithelial cells positive for MSH2 was statistically higher than the control group. The immunostaining of hMLH1 and p53 at the basal and suprabasal epithelial layers were statistically higher in the oral labial mucosa of the BMT patients compared with controls. CONCLUSION: The present study shows that oral epithelial cells of BMT patients show increased immunolocalization of the DNA repair related proteins. [ABSTRACT FROM AUTHOR]