聚酰胺-氨纳米微粒介导5-氟尿嘧啶联合小RNA-21抑制乳腺癌细胞生长的研究

目的 观察聚酰胺-氨(PAMAM)纳米微粒介导5-氟尿嘧啶(5-Fu)联合小RNA-21抑制乳腺癌细胞MCF-7生长的效果.方法 透析法制备5-Fu/PAMAM,孵育法同载miR-21抑制剂;透射电镜观察形貌;紫外分光光度计检测载药率和包封率;流式细胞仪检测转染效率及细胞凋亡;噻唑蓝(MTT)比色法检测细胞增殖;Transwell检测细胞侵袭能力变化.结果 5-Fu/PAMAM形貌规整,包封率为(66.21±4.11)%,载药率为(31.77±0.73)%,转染效率为(60.54±6.97)%;联合治疗组肿瘤细胞生长缓慢,在观察截止期时生存率(55.85±3.71)%;联合治疗组细胞凋亡率(18.32±2.42)%,与对照组比较明显增多(F=58.326,P<0.01);联合治疗组视野内细胞数目仅为(18.96±3.14)个,侵袭能力显著降低(F=16.409,P<0.01).结论 PAMAM可以实现5-Fu和miR-21的同载,并有效抑制乳腺癌细胞的体外生长.

Inhibitory effects of PAMAM nanoparticle-mediated 5-fluorouracil combined with microRNA-21 inhibitor on breast cancer cells growth in vitro

Objective To study the effect of PAMAM-mediated 5-fluorouracil combined with miR-21 inhibitor gene therapy to suppress MCF-7 human breast cancer cell growth in vitro. Methods 5-Fu/PAMAM complex was prepared by dialysis method and then incubated with miR-21 inhibitor at room temperature. Transmission electronic microscopy (TEM) was performed to observe the morphology of the nanoparticles. The drug loading efficiency and encapsulation efficiency was determined by ultraviolet spectroscopy (UV). The transfection of PAMAM dendrimer was detected by flow cytometry. MTT assay was carried out to determine MCF-7 cell growth survival rate. Cell apoptosis was analyzed by flow-cytometry. Transwell assay was performed to detect invasion ability after MCF-7 cells treated with 5-Fu chemotherapy combined with miR-21 inhibitor gene therapy. Results The morphology of the complex was sphere observed under TEM. Encapsulation efficiency and loading efficiency of drug were (66. 21±4. 11)% and (31.77±0. 73)% , respectively. Flow cytometry revealed that 5-Fu/PAMAM transfection efficiency was (60.54 ±6. 97)%. 5-Fu combined with miR-21 inhibitor treatment significantly suppressed cell growth, and the survival rate was only (55. 85±3. 71)% on the 6th day of the observation period. The apoptosis rate in combined treatment group was (18. 32±2.42)% , dramatically higher than in control group (F=58. 326,P<0. 01). In combined treatment group, the number of invasion cells was only 18. 96 ±3. 14, suggesting the greatly decreased invasion ability of MCF-7 cells (F=16. 409,P < 0. 01). Conclusion PAMAM could effectively deliver miR-21 inhibitor and 5-Fu simultaneously, and combined therapy can suppress growth of MCF-7 cells effectively in vitro.