聚酰胺树形分子递送Survivin反义寡核苷酸诱导结肠癌细胞凋亡的研究

目的 观察聚酰胺(PAMAM)树形分子高聚合物介导Survivin反义寡核苷酸(Sur-vivin-asODN)转染结直肠癌SW620细胞的可行性以及对结直肠癌SW620细胞凋亡的影响.方法 制备PAMAM反义基因复合物和阳离子脂质体反义基因复合物,透射电镜观察复合物的形态,激光散射粒径分析仪测定粒径,zeta电位分析仪测定zeta电位,离心法和紫外分光分度仪测定复合物的的包封率、载药率和体外DNA释放速度.将上述两种基因转染复合物转染结直肠癌细胞,测定其转染效率;检测转染后细胞中Survivin蛋白的表达和细胞的凋亡率.结果 PAMAM-Survivin-asODN复合物的粒径小于脂质体-Survivin-asODN复合物的粒径(P<0.01),但zeta电位高于后者(P<0.05);基因载药率、包封率两组差异无统计学意义;PAMAM对DNA持续释放14 d,但脂质体只持续5 d.PAMAM.Survivin-asODN转染结直肠癌细胞的效果强于脂质体-SurvivinasODN(P<0.05).转染后结直肠癌细胞Survivin蛋白的表达低于脂质体复合物(P<0.05),细胞的凋亡率高于脂质体复合物(P<0.05).结论 PAMAM能将Survivin-asODN高效递送到结直肠癌SW620细胞,降低Survivin蛋白表达并诱导结直肠癌细胞凋亡.

Survivin antisense oligonucleotide mediated by polyamidoamine dendrimer induces apoptosis of colorectal cancer cells

Objective To investigate the possibility of polyamidoamine dendrimer for Survivin Antisense Oligonucleotide delivery system and explore the effects of polyamidoamine dendrimer-Survivin antisense oligonucleotide on the Survivin expression and apoptosis of human colorectal cancer cell line SW620. Methods The PAMAM anti-gene transfection complex and the liposome anti-gene transfection complex was manufactured. The shape of the complex were observed by transmission electron microscope, the size was determined by laser particle size analysator and the zeta potential was measured by analytical tool. The encapsulating efficiency, DNA loading level, release progress in vitro were determined by ultravio- let spectrophotometer in centrifuging method. The transfection efficiency of Survivin-asODN in SW620 cells was mearsured. The protein expression of Survivin was measured by Western blot analysis and the apoptosis rate of SW620 cells was assessed by flow cytometry. Results The diameter of PAMAM-Survivin-asODN complex was less than that of liPosome-Survivin-asODN complex(P < 0.01 ), the zeta potential was high than that for liposome-Survivin-asODN complex(P < 0.05 ). There was no significant difference between two groups for envelopment ratio and loaded dosage. The PAMAM' s release progress in vitro lasted 14 days and 5 days for the liposome. The transfection efficiency for PAMAM-Survivin-asODN was higher than that for liposome-Survivin-asODN (P < 0.05 ). The expression of Survivin protein for PAMAM-Survivin-asODN was less than that for liposome-Survivin-asODN(P <0. 05)and the cell apoptosis rate was higher than that for liposome-Survivin-asODN (P < 0. 01 ). Conclusion The polyamidoamine dendrimer can delivery Sur-vivin-asODN into SW620 cells effectively and induce SW620 cells apoptosis.