抗疟药氯喹增强胃癌裸鼠移植瘤对顺铂的化疗敏感性

Chloroquine sensitizes cisplatin cytotoxicity in human gastric cancer xenografts

目的探讨抗疟药氯喹(CQ)增强顺铂(DDP)抑制胃癌SGC7901细胞裸鼠移植瘤生长的作用。方法建立胃癌SGC7901细胞裸鼠异位移植瘤模型,将24只荷瘤鼠随机分为对照组、DDP组、CQ组和CQ+DDP组。腹腔注射给药,给药后每3日测量肿瘤体积。给药结束时处死裸鼠,剥离移植瘤,称重。Western Blot检测肿瘤组织beclin-1、LC3Ⅱ/Ⅰcaspase3和P-gp表达,RT-PCR技术检测MDR1 mRNA水平。结果与对照组相比,DDP组移植瘤生长缓慢,体积较小,抑瘤率为47.6%,而且Beclin1和LC3表达增加,LCⅠ转换LCⅡ增多。联合氯喹后,抑瘤率提高至84.7%(P<0.01),LC3Ⅱ/Ⅰ比值下降;检测到caspase3蛋白水平升高,MDR1/P-gp表达下降(均P<0.05)。结论氯喹能增强胃癌裸鼠移植瘤对顺铂的化疗敏感性,这一作用可能与抑制自噬活性和下调多药耐药基因MDR1/P-gp的表达有关。

Objective To investigate the enhanced effect of cisplatin on chloroquine in SGC7901 xenografts. Methods The models of SGC7901 xenograft on athymic mouse were established and randomized to four groups with intraperitoneal injection of different drugs： control, cisplatin（DDP）, chloroquine（CQ） and DDP＋CQ. Drugs were injected once every 3 days, 10 times in all. The tumor volume were measured during the process of drug therapy. The mice were sacrificed 3 days after the last injection,and then the weight of tumor were measured. Western Blot was performed to detect the expression of beclin-1, LC3Ⅱ/Ⅰ, Caspase3 and P-gp, RT-PCR was performed to detect the expression of MDR1 mRNA. Results Compared to group control,the growth of tumor were more slowly and the tumor volume were much smaller in group DDP, the inhibition of tumor rate was 47.6%;and the expression of Beclin1 and LC3 were up-regulated. After combined with CQ, the inhibition of tumor rate was increased to 84.7%（P〈0.01）, and the ratio between LC3Ⅱ/Ⅰ was decreased;the expression of MDR1 and P-gp were also down-regulated. Conclusion Chloroquine can enhance the anti-tumor effect of cisplatin on gastric cancer xenografts, inhibition of autophagy and down-regulation of MDR1/P-gp expression are possibly the related mechanisms.