Expression and significance of KAI1/CD82 in nasopharyngeal carcinoma

Abstract

Objective To explore the expression levels of KAI1/CD82 gene in the cell lines of human nasopharyngeal carcinoma(NC) with different metastatic potency,and to determine the expression of KAI1/CD82 proteins in both nontumorous nasopharyngeal tissue and NC.Methods Immunohistochemical technique and Western blot were used to detect the location and expression of KAI1/CD82 protein in 5 cell lines of NC.The expression levels of KAI1/CD82 protein were assessed in 70 NC cases and 30 cases of nontumorous nasopharyngeal tissues by immunohistochemistry.Results Western blotting indicated that the expression level of KAI1/CD82 protein decreased gradually(P < 0.05) with the increased metastatic potentiality.Immunohistochemical detection revealed that KAI1/CD82 was expressed in plasma membrane and/or cytoplasm of NC cells.The expression of KAI1/CD82 protein was lower in NC(44.3%) than in nontumorous nasopharyngeal tissues(70.0%) with significant difference(P < 0.05).4.No correlation existed in the expression level of KAI1/CD82 protein in NC tissues with the following factors: sex,age,pathological type,T stage and other clinical parameters(P > 0.05).The positive expression rate of KAI1/CD82 protein in NC stage of N0,N1,N2 and N3 was 68.4%,43.8%,33.3% and 25%,respectively,and it gradually declined with the progression of N stage.The expression rates were significantly higher(P < 0.05) in the group without lymph node metastasis(N0)(68.4%) than in those groups with lymph node metastasis(N1-3)(35.3%).No significant difference(P > 0.05) was found in the expression rate of KAI1/CD82 protein among the 3 groups with lymph node metastasis(N1,N2,N3).Conclusions KAI1/CD82 gene may play an important role in inhibiting the tumor metastasis.The expression rate of KAI1/CD82 gene is lower in NC tissue than in normal nasopharyngeal tissue,implying that the gene may have played an important role on the development of NC.For NC cases,the expression of KAI1/CD82 protein may be inhibited and the expressive level declines along with NC metastasis and the progression of the N stage,implying that the expression of KAI1/CD82 protein may closely related with metastasis of NC.