选择性COX-2抑制剂逆转肺癌顺铂耐药作用及机制研究

Study on the effect and mechanism of selective COX-2 inhibitors to reverse cisplatin resistance in lung cancer

目的探讨选择性环氧化酶-2(COX-2)抑制剂逆转肺癌对顺铂耐药的作用,并从分子水平研究其机制。方法1.构建肺癌A549/DDP细胞裸鼠移植瘤模型。2.药物干预:将荷瘤裸鼠随机分为4组:对照组(腹腔注射生理盐水和胃内灌注0.5%羟甲基纤维素钠);顺铂(DDP)组(腹腔注射顺铂溶液);尼美舒利(NIM)组(胃内灌注尼美舒利溶液);NIM与DDP联合组(腹腔注射顺铂溶液和胃内灌注尼美舒利溶液)。DDP每4天腹腔注射1次,共5次,NIM连续灌胃21天。给药期间,测量瘤径及鼠重,绘制肿瘤生长曲线。3.计算抑瘤率:给药3周处死裸鼠,剥离移植瘤,检测各组移植瘤重量、体积,计算抑瘤率。4.免疫组化法检测各组肺癌A549/DDP裸鼠移植瘤细胞内耐药相关因子P-gp、LRP、MRP1的蛋白表达水平。结果1.NIM有抑制肺癌生长的作用,瘤体积及瘤重抑瘤率分别为22.63%和15.98%。NIM与DDP联合用药后抑瘤作用更明显,瘤体体积及瘤重抑瘤率分别为60.83%和46.76%,分别明显大于NIM组、DDP组及对照组的抑瘤率,差异有统计学意义(P<0.05),NIM有增强肺癌细胞对DDP敏感性的作用。2.免疫组化结果显示:P-gp、LRP、MRP1耐药基因在肺癌A549/DDP裸鼠移植瘤细胞内均呈阳性表达,在NIM与DDP联合中的阳性表达分别显著低于各自在DDP组及对照组中的表达,差异有统计学意义(P<0.05)。结论1.选择性COX-2抑制剂NIM有抑制肺癌生长的作用;2.选择性COX-2抑制剂NIM有逆转肺癌对DDP耐药的作用;3.选择性COX-2抑制剂NIM逆转肺癌对DDP耐药的机制,可能与下调肺癌细胞耐药因子P-gp、LRP、MRP1蛋白表达有关。

Objective To investigate the reversal effect of selective COX-2 inhibitors on cisplatin resistance in lung cancer,and to study its mechanism from the molecular level.Methods 1.Transplanted tumor model was constructed in nude mice of lung cancer A549/DDP cells.2.The tumor-burdened nude mice were divided into 4 groups randomly:the control group(intraperitoneal injection of normal saline and intragastric infusion of 0.5%sodium carboxymethyl cellulose),the cisplatin group(intraperitoneal injection of cisplatin solution),the nimesulide group(intragastric infusion of nimesulide)and the nimesulide and cisplatin group(intraperitoneal injection of cisplatin solution and intragastric infusion of nimesulide).Cisplatin was intraperitoneally injected every 4 days per time,a total of 5 times.Nimesulide was continuously lavage for 21 days.During the treatment,their tumor size and body weight were measured,and then drew the tumor growth curve.3.The mice were euthanized at 3 weeks after the treatment,and transplanted tumor was stripped,then their weight and volume of each transplanted tumor were tested and the inhibitory rate was calculated.4.It used immunohistochemical method to detect the protein expression level of resistant factor P-gp,LRP and MRP1 in lung cancer A549/DDP nude mouse transplantated tumor cells.Results 1.Nimesulide had the effect to inhibit lung cancer,and the volume of transplanted tumor and the heavy inhibition rate were 22.63%and 15.98%respectively.The tumor suppression effect was more apparent after the combination of nimesulide and cisplatin.The volume of transplanted tumor and the heavy inhibition rate were 60.83%and 46.76%respectively,which were significantly greater than the inhibitory rate of the NIM group,the DDP group and the control group(P<0.05).Nimesulide had the enhancement effect of lung cancer cells to cisplatin sensitivity.2.Immunohistochemical results showed that P-gp,LRP and MRP1 drug-resistant genes in lung cancer A549/DDP nude mice transplanted tumor cells were positive for expression.The positive expression of P-gp,LRP and MRP1 was significantly lower in the combination group than in the DDP group and the control group(P<0.05).Conclusion 1.Selective cox-2 inhibitors nimesulide has the effect to inhibit the growth of lung cancer.2.Selective cox-2 inhibitors nimesulide has a reverse effect on cisplatin resistance of lung cancer.3.The mechanism of selective COX-2 inhibitor nimesulide to reverse the cisplatin resistance of lung cancer was possibly related to the decrease of the protein expression of resistance factor P-gp,LRP and MRP1 in lung cancer cells.