PAMAM-NK4纳米复合物对乳腺癌裸鼠移植瘤生长的抑制作用

Inhibitory effect of PAMAM-NK4 nanocomposite on the growth of breast cancer xenografts in nude mice

目的:探讨新型纳米材料聚酰胺-胺型树枝状高聚合物(polyamidoamine dendrimer,PAMAM)介导NK4基因对乳腺癌MDA-MB-231、MCF-7细胞生长的抑制作用及对MDA-MB-231细胞移植瘤裸鼠模型的治疗作用。方法:制备PAMAM-NK4纳米复合物颗粒,纳米复合物和空载体PAMAM分别转染MDA-MB-231和MCF-7细胞作为实验组和对照组。MTT实验、Western blotting和流式细胞术分别检测转染PAMAM-NK4对细胞增殖、NK4蛋白表达和细胞凋亡的影响。40只雌性裸鼠经皮下注射建立MDA-MB-231细胞移植瘤裸鼠模型,随机分成4组,每组10只裸鼠:空白组肿瘤接种部位旁皮下注射0.2 ml 0.9%Na Cl溶液、空载体组注射0.2 ml含100μg PAMAM-Lac Z质粒的溶液、给药组注射0.2 ml含100μg PAMAM-NK4质粒的溶液、阳性对照组腹腔注射0.2 ml多柔比星(100μg)溶液。连续注射7 d,第30天处死裸鼠,完整摘除肿瘤,测量肿瘤体积和质量。Western blotting检测各组移植瘤组织NK4蛋白表达。结果:PAMAM-NK4纳米粒转染MDA-MB-231、MCF-7细胞后能够稳定表达NK4蛋白、抑制细胞增殖和增加细胞凋亡率。成功建立MDA-MB-231细胞移植瘤裸鼠模型,给药组和阳性对照组肿瘤体积及质量显著低于空白组(P<0.05),且安全性良好;给药组NK4蛋白表达显著高于空白组(P<0.05)。结论:PAMAMNK4纳米粒对乳腺癌MDA-MB-231、MCF-7细胞生长具有抑制作用,并对人乳腺癌细胞移植瘤裸鼠模型具有治疗作用。

Objective： To explore the inhibitory effect of polyamidoamine dendrimer（ PAMAM）-mediated NK4 gene on the growth of breast cancer cell lines MDA-MB-231 and MCF-7,and its therapeutic effect on MDA-MB-231 cell transplantation tumor in nude mouse model. Methods： PAMAM-NK4 nanoparticles and blank plamids were prepared and respectively transfected into MDA-MB-231 and MCF-7 cells as the experiment group（ PAMAM-NK4 group） and the control group（ PAMAM group）. MTT,Western blotting and flow cytometry assays were used to examine effect of the PAMAMNK4 transfection on proliferation of the cells,expression of NK4 protein and apoptosis of the cells,respectively. Forty female nude mice were subcutaneous injected with human breast cancer MDA-MB-231 cell to establish nude mouse model with the xenograft tumor. The mice were randomly divided into 4 groups with 10 mice in each. Mice of the blank control group were subcutaneously injected with 0. 2 ml of 0. 9% Na Cl surrounding the xenograft tumor,those of the blank plasmid group with 0. 2 ml of plasmid solution containing 100 μg PAMAM-Lac Z,those of the PAMAM-NK4 group with 0. 2 ml of plasmid solution containing 100 μg PAMAM-NK4 and those of the positive control group with 0. 2 ml of solution containing 100 μg adriamycin,respectively. All of the nude mice were continuously injected for 7 d and then sacrificed on 30 th day. The xenograft tumors were removed completely to measure their weights and sizes. Expressions of the NK4 protein in the xenograft tissues were detected by Western blotting assay. Results： The transfection of PAMAM-NK4 nanocomposites,could result in stable expression of the NK4 protein,and inhibition of the cell proliferation and promotion of the cell apoptosis. The nude mouse models with human breast carcinoma xenogragts were successfully constructed. The volumes and weights of the carcinoma xenografts in the PAMAM-NK4 and the positive control groups were significantly smaller than those in the blank control group（ P〈0. 05） with a fairly good safety. The expression of NK4 protein in the PAMAM-NK4 group significantly increased,comparing with that in the blank control group（ P〈0. 05）. Conclution： PAMAM-NK4 nanocomposites could inhibit growth of the breast cancer MDA-MB-231 and MCF-7 cells,and have therapeutic effect on the human breast carcinoma xenografts in nude mouse model.