外放射对鼻咽鳞癌P糖蛋白的影响

Effect of Radiation on p-glycoprotein Expression in Nasopharyngeal Squamous Carcinoma

目的初步探讨放射治疗前、后鼻咽鳞癌组织P-糖蛋白(P-gp)的表达及变化特点。方法应用免疫组织化学SP法检测了48例初治鼻咽鳞癌患者放射治疗前、后P-gp的表达。结果48例初治鼻咽鳞癌组织P-gp阳性表达率放射治疗前为18.75%(9例/48例),其中低分化鳞癌和中高分化鳞癌分别为17.65%(6例/34例)和21.43%(3例/14例);放射治疗后P-gp阳性表达率为75.00%(36例/48例),其中低分化鳞癌和中高分化鳞癌分别为79.41%(27例/34例)和64.29%(9例/14例)。放射治疗后P-gp阳性表达率较放射治疗前呈增高趋势,放射治疗后P-gp阳性率和放射治疗前相比有显著性差异(P<0.001)。结论放射治疗可诱导和加强鼻咽鳞癌组织中P-gp表达,这可能是引起放、化疗交叉耐药的原因之一。

Objective To investigate preliminarily the expression of p-glycoprotein（P-gp） in patients with nasopharyngeal squamous carcinoma （NPSC） pre- and post-radiotherapy. Methods The immunohistochemistry with one monoclonal antibody JSB-1 staining was performed to test the expression of pgp in pre- and post-radiotherapy NPSC specimens from 48 patients. Results The positive rate of P-gp expression in the patients with NPSC pre-radiotherapy was 18. 75 % （9/48）. Among them, the positive expression rate was 17. 65 % （6/34） and 21.43% （3/14）in low grade differentiation squamous cell carcinoma and mid-high grade differentiation squamous cell carcinoma, respectively. The positive expression rate of post-radiotherapy was 75. 00% （36/48）and among them, the positive expression rate was 79. 41% （27/ 34） ,64. 29 % （9/14）in low grade differentiation squamous cell carcinoma and mid-high grade differentiation squamous cell carcinoma, respectively. P-gp expression rate post-radiotherapy was significantly higher than that of pre-radiotherapy （P〈0. 001 ）. Conclusion Our study indicates that pgp expression in NPSC was significantly induced by radiation and increases the overexpression of P-gp. Therefore, irradiation may be one of the reasons of crossed resistance to chemotherapy and radiotherapy.