AIM: Nitric oxide (NO) has been studied in a variety of human cancers and is implicated in both tumor promotion and inhibition. Downregulation of the enzyme iNOS by wild-type p53 (but not mutant) protein has been shown to occur in normal cells and some tumors, but the relationship has not been reported in oral epithelial dysplasia. METHODS AND RESULTS: An immunohistochemical study was conducted with antibodies to iNOS and p53 (clone DO-7) in 36 cases of oral dysplasia of varying severity. Statistical analysis showed a significant correlation between iNOS staining and grade of dysplasia (P <.001) and between p53 and iNOS staining (P <.001). CONCLUSIONS: This preliminary study has shown that iNOS expression correlates with severity of dysplasia, and it is also increased in those cases showing positive staining for p53. Further research is required to fully establish the relationship between iNOS and p53 in both dysplasia and oral squamous cell carcinoma.
AIM: Nitric oxide (NO) has been studied in a variety of humancancers and is implicated in both tumor promotion and inhibition. Downregulation of the enzyme iNOS by wild-type p53 (but not mutant) protein has been shown to occur in normal cells and some tumors, but the relationship has not been reported in oral epithelial dysplasia. METHODS AND RESULTS: An immunohistochemical study was conducted with antibodies to iNOS and p53 (clone DO-7) in 36 cases of oral dysplasia of varying severity. Statistical analysis showed a significant correlation between iNOS staining and grade of dysplasia (P <.001) and between p53 and iNOS staining (P <.001). CONCLUSIONS: This preliminary study has shown that iNOS expression correlates with severity of dysplasia, and it is also increased in those cases showing positive staining for p53. Further research is required to fully establish the relationship between iNOS and p53 in both dysplasia and oral squamous cell carcinoma.