The Study Of MDR Produced By X Radiation Exposure In NPC CNE2 Cell

Objeet:1. To detect the changes of expression of P-gp in NPC(nasopharyngeal carcinoma) CNE2 cell after X radiation exposureand the different inhibition chemotherapy drug ratios of in CNE2cell among before,after X radiation exposure,giving simultaneo-usly X radiation exposure and chemotherapy drug, for providing thetheory bases of sequence arrangement about radiotherapy and chem-otherapy for the clinical NPC combined therapy.Methods: Detecting the changes of positive expression of P-gpin CNE2 cell following X radiation in the method of immunocyto-logy 2.Examining the differences of chemotherapy drug inhibitionratios in NPC CNE2 cell, among before, after X radiation exposure,giving simultaneously X radiation exposure and chemotherapy drugin the method of MTT.Results: 1.The expression ratios of P—gp in CNE2 cell is 7％before X radiation,it becomes 72.7％after it(P＜0.05). 2.The chemot-herapy drug inhibition ratios of CNE2 cell after X radiation expos-ure is lower than before it and giving simultaneously X radiationexposure and chemotherapy drug in PTX,DDP,5—FU(P＜0.05).Thechemotherapy drug inhibition ratios of CNE2 cell are almost the sa-me in DDP,5-FU,PTX between giving simultaneously X radiation exposure,chemotherapy drug and before X radiation exposure(p＞0.05).Conclusions: The results show that X radiation exposure canmake the expression of P-gp in CNE2 cell increase, then the sensi-tivity of chemotherapy decreases.2.We should give the patients che-motherapy before raidiotherapy or giving simultaneously chemothera-py and raidiotherapy in NPC's clinical combined therapy.