The Expression of Cell Cycle Regulators in Primary and Relapsing Nasopharyngeal Carcinoma / 中山大学学报(医学科学版)

ABSTRACT

【Objective】To explore the role of cell cycle regulators in nasopharyngeal carcinoma (NPC) relapse.【Method】To assay p53,MDM2,p21ras and p21WAF1 proteins by LsAB immunohistochemical technique in 69 cases of primary and relapsing NPC tissues.【Results】As compared with primary NPC,the expression rate of p53 or MDM2 protein in relapsing NPC was similar (78% to 80%,84% to 83%),and the expression rate of p21ras or p21WAF1 protein in relapsing NPC was obviously descended (73% to 93%,52% to 84% );the high-expression rate of p53 protein in relapsing NPC was similar (42% to 51%),the high-expression rate of MDM2 protein in relapsing NPC was obviously risen (57% to 32%),and the high-expression rate of p21ras or p21WAF1 protein in relapsing NPC was obviously descended (16% to 65%,17% to 46%).Among of them,the significant rise of MDM2 protein expression level in relapsing NPC mainly occurred in the patients of group 2 which relapsing-interval was shorter than 34 months,P<0.05;the significant descent of p21ras or p21WAF1 protein expression level in relapsing NPC occurred in the patients of group 2 and group 1 which relapsing-interval was equal to or longer than 34 months,P<0.02,respectively.【Conclusions】The overexpression of p53 and MDM2 proteins and the low or negative expression of p21WAF1 protein after clinical cure might still play an important role in NPC relapse,the obvious rise of MDM2 protein level and the obvious descent of p21WAF1 protein level might further accelarate the process of NPC relapse.