Effect of different doses of cyclophosphamide on drug-resistance of implanted human lung cancer in nude mice / 第三军医大学学报

ABSTRACT

Objective To explore the effect of different doses of cyclophosphamide(CTX) on the drug-resistance of implanted human A549 lung cancer in nude mice,and investigate the anti-tumor effect and toxicity.Methods BALB/c nude mice bearing A549 lung carcinoma were randomized into low-dose metronomic(LDM) CTX group,maximum tolerate dose(MTD) CTX group and normal saline group.The changes of tumor volume,weight and toxicity were observed.Expression of glutathione S-transferase-?(GST-?) and lung resistance-related protein(LRP) in the tumor were detected by immunohistochemistry SP method.Results In LDM CTX group,the tumor grew fast at first,then slowed down gradually and grew slowly for a long time,while in MTD CTX group tumor grew slowly at first,then it accelerated.Side effects of chemotherapythe weight of nude mice was lost persistently in MTD CTX group,while lost insignificantly in LDM CTX group.No obvious toxicity was observed in LDM CTX group.GST-? and LRP expression in LDM CTX group were not significantly different from those in the control,but significance was seen in MTD CTX group compared with those in the control(P