College of Life Science, Jilin University, Changchun, Jilin 130012, People's Republic of China.
Key Laboratory for Molecular Enzymology and Engineering, Ministry of Education, Jilin University, Changchun 130012, People's Republic of China.
Int J Nanomedicine. 2020 Mar 2;15:1397-1408. doi: 10.2147/IJN.S227289. eCollection 2020.
siRNA-mediated polo-like kinase 1 (PLK1) silencing has been proposed as a promising therapeutic method for multiple cancers. However, the clinic application of this method is still hindered by the low specific delivery of siPLK1 to desired tumor lesions. Herein, folate (FA)-modified and leucine-bearing polyethylenimine was successfully synthesized and showed excellent targeted silencing to folate receptor overexpressed cells.
The condensation of siPLK1 by FA-N-Ac-L-Leu-PEI (NPF) was detected by the gel retardation assay. The targeted and silencing efficiency was evaluated by flow cytometry and confocal laser scanning microscope. The PLK1 expressions at gene or protein levels were detected by quantitative real-time PCR and Western blotting assay. Further impacts of the PLK1 silencing on cell viability, cell cycle, migration, and invasion were studied by MTT, colony formation, wound healing and transwell assays.
The NPF and siPLK1 could efficiently assemble to stable nanoparticles at a weight ratio of 3.0 and showed excellent condensation and protection effect. Owing to the FA-mediated targeted delivery, the uptake and silencing efficiency of NPF/siPLK1 to SGC-7901 cells was higher than that without FA modification. Moreover, NPF-mediated PLK1 silencing showed significant antitumor activity in vitro. The anti-proliferation effect of PLK1 silencing was induced via the mitochondrial-dependent apoptosis pathway with the cell cycle arrest of 45% at G2 phase and the apoptotic ratio of 28.3%.
FA-N-Ac-L-Leu-PEI (NPF) could generate targeted delivery siPLK1 to FA receptor overexpressed cells and dramatically downregulate the expression of PLK1 expression.
siRNA 介导的 polo 样激酶 1（PLK1）沉默被认为是治疗多种癌症的一种很有前途的治疗方法。然而，这种方法的临床应用仍然受到 siPLK1 向所需肿瘤病变部位的低特异性传递的限制。在此，成功合成了叶酸（FA）修饰和亮氨酸肽聚亚胺，并显示出对叶酸受体过表达细胞的出色靶向沉默作用。
通过凝胶阻滞试验检测 FA-N-Ac-L-Leu-PEI（NPF）对 siPLK1 的凝聚作用。通过流式细胞术和共聚焦激光扫描显微镜评估靶向性和沉默效率。通过定量实时 PCR 和 Western blot 分析检测基因或蛋白水平的 PLK1 表达。进一步通过 MTT、集落形成、划痕愈合和 Transwell 测定研究 PLK1 沉默对细胞活力、细胞周期、迁移和侵袭的影响。
NPF 和 siPLK1 可以在重量比为 3.0 时有效地组装成稳定的纳米颗粒，并表现出出色的凝聚和保护作用。由于 FA 介导的靶向递送，NPF/siPLK1 对 SGC-7901 细胞的摄取和沉默效率高于没有 FA 修饰的情况。此外，NPF 介导的 PLK1 沉默在体外显示出显著的抗肿瘤活性。PLK1 沉默的抗增殖作用是通过线粒体依赖性凋亡途径诱导的，细胞周期停滞在 G2 期 45%，凋亡率为 28.3%。
FA-N-Ac-L-Leu-PEI（NPF）可以生成靶向递送至 FA 受体过表达细胞的 siPLK1，并显著下调 PLK1 表达。
