Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta , Edmonton, AB , Canada.
Department of Chemical and Materials Engineering, Faculty of Engineering, University of Alberta , Edmonton, AB , Canada ; School of Pharmacy, Chapman University , Irvine, CA , USA.
Front Bioeng Biotechnol. 2015 Feb 16;3:14. doi: 10.3389/fbioe.2015.00014. eCollection 2015.
The cell cycle proteins are key regulators of cell cycle progression whose deregulation is one of the causes of breast cancer. RNA interference (RNAi) is an endogenous mechanism to regulate gene expression and it could serve as the basis of regulating aberrant proteins including cell cycle proteins. Since the delivery of small interfering RNA (siRNA) is a main barrier for implementation of RNAi therapy, we explored the potential of a non-viral delivery system, 2.0 kDa polyethylenimines substituted with linoleic acid and caprylic acid, for this purpose. Using a library of siRNAs against cell cycle proteins, we identified cell division cycle protein 20 (CDC20), a recombinase RAD51, and serine-threonine protein kinase CHEK1 as effective targets for breast cancer therapy, and demonstrated their therapeutic potential in breast cancer MDA-MB-435, MDA-MB-231, and MCF7 cells with respect to another well-studied cell cycle protein, kinesin spindle protein. We also explored the efficacy of dicer-substrate siRNA (DsiRNA) against CDC20, RAD51, and CHEK1, where a particular DsiRNA against CDC20 showed an exceptionally high inhibition of cell growth in vitro. There was no apparent effect of silencing selected cell cycle proteins on the potency of the chemotherapy drug doxorubicin. The efficacy of DsiRNA against CDC20 was subsequently assessed in a xenograft model, which indicated a reduced tumor growth as a result of CDC20 DsiRNA therapy. The presented study highlighted specific cell cycle protein targets critical for breast cancer therapy, and provided a polymeric delivery system for their effective down-regulation.
细胞周期蛋白是细胞周期进程的关键调节因子，其失调是乳腺癌的原因之一。RNA 干扰 (RNAi) 是一种调节基因表达的内源性机制，它可以作为调节异常蛋白（包括细胞周期蛋白）的基础。由于小干扰 RNA (siRNA) 的递送是 RNAi 治疗实施的主要障碍，我们为此探索了非病毒递送系统，2.0 kDa 聚亚乙基亚胺用亚油酸和辛酸取代的潜在用途。使用针对细胞周期蛋白的 siRNA 文库，我们确定了细胞分裂周期蛋白 20 (CDC20)、重组酶 RAD51 和丝氨酸-苏氨酸蛋白激酶 CHEK1 是乳腺癌治疗的有效靶点，并证明了它们在乳腺癌 MDA-MB-435、MDA-MB-231 和 MCF7 细胞中的治疗潜力，相对于另一种研究充分的细胞周期蛋白，驱动蛋白纺锤体蛋白。我们还探索了针对 CDC20、RAD51 和 CHEK1 的双链 RNA 酶底物 siRNA (DsiRNA) 的功效，针对 CDC20 的特定 DsiRNA 在体外显示出对细胞生长的异常高抑制作用。沉默选定的细胞周期蛋白对化疗药物阿霉素的效力没有明显影响。随后在异种移植模型中评估了针对 CDC20 的 DsiRNA 的功效，结果表明 CDC20 DsiRNA 治疗导致肿瘤生长减少。本研究强调了针对乳腺癌治疗至关重要的特定细胞周期蛋白靶标，并提供了一种有效的下调这些靶标的聚合物递送系统。
