口腔扁平上皮癌の頸部リンパ節転移巣における細胞増殖活性と細胞間接着分子の発現に関する病理学的研究

抄録

The expression of intercellular adhesion molecules and the cell proliferative activity were analyzed in metastatic focus of lymph node and compared with those in primary oral squamous cell carcinomas in the present study. Immunohistochemistry was performed for E-cadherin, α-catenin and β-catenin in the primary lesions of 11 oral squamous cell carcinomas, and 36 tissues of 18 metastatic foci. The PCNA (proliferative cell nuclear antigen) labeling index was calculated as the percent of immunostain-positive cells to anti-PCNA antibody. Immunostaining of adhesion molecules was categorized as one of three types: preserved, reduced, and lost compared with that in normal oral epithelium. These three adhesion molecules were clearly expressed in the cell-cell contact sites of normal oral epithelium. In the expression of E-cadherin, 8 primary tumors showed reduced type (72.7%), which was the highest ratio. In contrast, in metastatic foci, 25 tumors showed lost-type as the highest (69.4%). Furthermore, in metastatic focus, the expression of E-cadherin was significantly (ANOVA, p<0.05) decreased, and that of β-catenin was also decreased as the tumor expanded in the lymph node. However, the expression of α-catenin did not change with tumor progression. Although the PCNA labeling index in metastatic foci was significantly lower than that in primary tumors (Student t-test, p<0.01), it increased as the tumor advanced in the lymph node. In metastatic foci, as the expression of E-cadherin reduced, the PCNA labeling index was increased conversely. In conclusion, in metastatic oral squamous cell carcinoma of the lymph node, reduction of E-cadherin was involved in the growth and migration of oral squamous cell carcinoma.