Evaluation of squamous cell carcinoma antigen 1 expression in oral squamous cell carcinoma (tumor cells and peritumoral T-lymphocytes) and verrucous carcinoma and comparison with normal oral mucosa

Abstract Background: Squamous cell carcinoma antigen (SCCA) is used as a prognostic marker for recurrence of squamous cell carcinoma in various sites, including head and neck. Studies suggest that its high serum levels are correlated to some clinical features, such as nodal metastasis. However, it is still unknown if high SCCA in patients with SCCA tissue expression in tumor cells are related to peripheral T-lymphocytes. Therefore, we did this study to evaluate SCCA expression in squamous cell carcinoma and verrucous carcinoma and to compare it with normal oral mucosa, also investigating the correlation between serum-based and tissue-based antigen levels. Methodology: In this study, the immunohistochemistry (IHC) technique was used to determine the SCCA1 expression pattern in 81 specimens divided into 3 groups, including oral squamous cell carcinoma, verrucous carcinoma, and normal oral mucosa. Serum-based and tissue-based antigen levels of 20 oral squamous cell carcinoma cases were compared by the western blot assay. SCCA expression was also evaluated and compared in both tumor cells and peripheral T-lymphocytes by the immunofluorescence assay. Results: Our results showed that the SCCA levels in SCC specimens were significantly lower than in verrucous carcinoma and normal and hyperplastic oral mucosa specimens. We found no correlation between the IHC expression of SCCA and serum levels. SCCA was well expressed in both tumor cells and peripheral T-lymphocytes. Conclusion: Decreasing SCCA in SCC specimens suggested that SCC tumor cells may affect more than the serum levels of SCCA in some patients. In addition, expression of SCCA in peripheral T-lymphocytes showed that both tumor cells and T-lymphocytes may cause serum SCCA.

P53 protein expression in dental follicle, dentigerous cyst, odontogenic keratocyst, and inflammatory subtypes of cysts: an immunohistochemical study

Objectives: An odontogenic keratocyst [OKC] is a developmental odontogenic cyst with aggressive clinical behavior. This cyst shows a different growth mechanism from the more common dentigerous cyst and now has been renamed as a keratocystic odontogenic tumor [KCOT]. Inflammation can assist tumor growth via different mechanisms including dysregulation of the p53 gene. This study aims to assess and compare the expression of tumor suppressor gene p53 in inflamed and non-inflamed types of OKC and dentigerous cyst

Methods: Immunohistochemical expression of p53 was assessed in 14 cases of dental follicle, 34 cases of OKC [including 18 inflamed OKCs], and 31 cases of dentigerous cyst [including 16 inflamed cysts]

Results: The mean percentage of p53 positive cells was 0.7% in dental follicles, 5.4% in non-inflamed OKCs, 17.3% in inflamed OKCs, 1.2% in non-inflamed dentigerous cysts, and 2.2% in inflamed dentigerous cysts. The differences between the groups were statistically significant [p < 0.050] except for the difference between inflamed and non-inflamed dentigerous cysts, and between dental follicle and non-inflamed dentigerous cyst

Conclusions: The difference in p53 expression in OKC and dentigerous cyst can explain their different growth mechanism and clinical behavior. Inflammation is responsible for the change in behavior of neoplastic epithelium of OKC via p53 overexpression