Expression of CD44v6 and COX-2 in pleomorphic adenomas and carcinomas of parotid gland

Abstract

To investigate the correlation between CD44v6 and cyclooxygenase-2(COX-2) expression and recurrence and deterioration of pleomorphic adenoma of parotid gland. Immunohistochemistry was used to detect the expression of CD44v6 and COX-2 in 19 normal parotid tissues, 25 primary pleomorphic adenomas, 15 first recurrent pleomorphic adenoma, 15 second recurrent pleomorphic adenoma and 13 cancer in pleomorphic adenomas. The correlation between CD44v6 and COX-2 and the recurrence and deterioration of pleomorphic adenomas was evaluated using SPSS 15.0 software package. The positive expression rate of CD44v6 in normal parotid gland, primary pleomorphic adenoma, first recurrent pleomorphic adenoma, second recurrent pleomorphic adenoma and cancer was 5.26%, 44.00%, 60.00%, 93.37% and 100.00%, respectively;and the positive expression rate of COX-2 was 10.53%, 40.00%, 63.33%, 93.37% and 100.00%, respectively. There was significant difference in the positive expression intensity of CD44v6 and COX-2 among the groups (P<0.05). The positive expression rate and intensity of CD44v6 and COX-2 in normal parotid gland tissue were significantly lower than those in other groups (P<0.05). There was no significant difference in the positive expression rate and intensity of CD44v6 between primary pleomorphic adenoma and first recurrent pleomorphic adenoma (P>0.05). There was no significant difference in the expression intensity of COX-2 between the two groups (P>0.05), but the positive expression rate of COX-2 between the two groups was not significant(P>0.05). The positive expression rate and intensity of CD44v6 and COX-2 in the second recurrent pleomorphic adenoma were significantly higher than those in the first recurrent pleomorphic adenoma(P<0.05), but there was no significant difference between the two groups(P>0.05). CD44v6 in the second recurrent pleomorphic adenoma and cancer was significantly higher than that in the first recurrent pleomorphic adenoma(P<0.05). There was no significant difference in the expression rate and intensity of COX-2 (P>0.05). CD44v6 and COX-2 may play an important role in promoting occurrence, invasion, recurrence and deterioration of pleomorphic adenoma through synergistic action.