鼻咽低分化鳞癌细胞X射线照射后多药耐药基因的表达及功能

Expression and function of multidrug resistance gene in poorly differentiated squamous cell of nasopharyngeal carcinoma after irradiation exposure

目的:检测鼻咽癌CNE2细胞射线照射前后多药耐药基因(mdr1基因)及其编码产物P糖蛋白(P-glycoprotein,P-gp)的表达及其功能的变化。方法:利用RT-PCR、Westernblot和流式细胞仪检测CNE2细胞射线照射前后的mdr1基因和P-gp的表达及对柔红霉素的外排功能。结果:鼻咽癌CNE2细胞射线照射前mdr1基因、P-gp不表达;射线照射后较长时间内mdr1基因、P-gp均明显表达,对柔红霉素的摄取较射线照射前高。结论:鼻咽癌低分化鳞癌细胞CNE2射线照射后化疗敏感性增高,除了多药耐药机制外可能尚存在其他耐药机制。

Objective To test the changes in the function and expression of muhidrng resistance gene （mdrl gene） and its coding product P-glycoprotein （P-gp） in nasopharyngeal carcinoma （NPC） CNE2 cell following irradiation. Methods The expression of mdrl gene and its protein P-gp as well as the efflux function of P-gp for daunorubicin were examined in the CNE2 cell before and after irradiation exposure by reverse transcription-polymerase chain reaction, Western blotting and flow cytometry, respectively. Results No expressions of mdrl gene and P-gp were found before irradiation of CNE2 ceils. However, a significant expression of mdrl gene and P-gp occurred and maintained for a longer time and intraceUular daunornbicin accumulation was elevated after irradiation of CNE2 cells. Conclusions The sensitivity of the NPC CNE2 cell to chemotherapy is enhanced after irradiation. Other drug resistance mechanisms may exist besides the present mechanism of multidrng resistance.