Immunohistochemical Expression of Mina53 and Ki67 Proteins in Human Primary Gingival Squamous Cell Carcinoma

Studies have reported the presence of relationships between the Myc target gene Mina53 and poor prognostic factors in several cancers including esophageal cancer. In this study, we investigated the relationships between Mina53 expression in gingival squamous cell carcinoma and clinicopathological factors. Seven samples of normal and dysplastic gingival tissues and 15 samples of gingival squamous cell carcinoma were immunostained for Mina53 and Ki67, and examined for the relationships between their expression and differentiation degree, lymph node metastasis, stage, tumor diameter, and prognosis. In normal and dysplastic gingival tissues, the localization of the expression of Mina53 and Ki67 was similar, but that in gingival squamous cell carcinoma tissue varied depending on the degree of differentiation. In well-differentiated GSCC with pearl formation, Mina53 was negative at the center of the clearly keratinized cancer nest, but positive in the nuclei of cells in the periphery and adjacent area of the cancer nest. In diffusely proliferating undifferentiated and moderately-differentiated GSCC showing no pearl formation, both Mina53 tended to be positive in the nuclei of cancer cells in the entire cancer nest. A significant correlation was found between the expression of Mina53 and that of Ki67 in patients with gingival squamous cell carcinoma or dysplastic gingiva. No significant correlation was noted between the expression of Mina53 or Ki67 and prognostic factors such as the degree of differentiation, lymph node metastasis, stage, and tumor diameter. In gingival squamous cell carcinoma, Mina53 expression was correlated with the proliferation of tumor cells, but unlike esophageal and other squamous cell carcinomas, not with the prognosis. The absence of correlations with prognostic factors suggests that may differ gingival squamous cell carcinoma differs biologically from esophageal squamous cell carcinoma which is correlated with Mina53 in terms of the biological expression of Mina53.