Depatment of Craniofacial Biology and Center for Oral Health Research, Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, United States of America.
PLoS One. 2013 Sep 3;8(9):e73348. doi: 10.1371/journal.pone.0073348. eCollection 2013.
Despite a better understanding of the pathogenesis of oral cancer, its treatment outcome remains poor. Thus, there is a need for new therapeutic strategies to improve the prognosis of this disease. RNA interference (RNAi) appears to be a promising therapeutic tool for the treatment of many diseases, including oral cancer. However, an obstacle for RNAi-mediated therapies has been delivery, in particular, the retention of small interfering RNAs (siRNAs) in endosomes and their subsequent degradation in lysosomes, resulting in inefficient gene silencing. Thus, the current study examined the feasibility of designing and utilizing a peptide, termed 599, consisting of a synthetic influenza virus-derived endosome-disruptive fusogenic peptide sequence and a stretch of cationic cell-penetrating nona(D-arginine) residues, to deliver siRNAs into oral cancer cells and induce silencing of the therapeutic target, CIP2A, an oncoprotein overexpressed in various human malignancies including oral cancer. Increasing the 599 peptide-to-siRNA molar ratio demonstrated a higher binding capacity for siRNA molecules and enhanced siRNA delivery into the cytoplasm of oral cancer cells. In fact, quantitative measurements of siRNA delivery into cells demonstrated that a 50∶1 peptide-to-siRNA molar ratio could deliver 18-fold higher amounts of siRNAs compared to cells treated with siRNA alone with no significant long-term cytotoxic effects. Most importantly, the 599 peptide-mediated siRNA delivery promoted significant CIP2A mRNA and protein silencing which resulted in decreased oral cancer cell invasiveness and anchorage-independent growth. Together, these data demonstrate that a chimeric peptide consisting of a fusogenic sequence, in combination with cell-penetrating residues, can be used to effectively deliver siRNAs into oral cancer cells and induce the silencing of its target gene, potentially offering a new therapeutic strategy in combating oral cancer.
尽管人们对口腔癌的发病机制有了更好的理解,但它的治疗效果仍然很差。因此,需要新的治疗策略来改善这种疾病的预后。RNA 干扰 (RNAi) 似乎是治疗许多疾病(包括口腔癌)的一种很有前途的治疗工具。然而,RNAi 介导的治疗的一个障碍是递送,特别是小干扰 RNA (siRNA) 在内涵体中的保留及其随后在溶酶体中的降解,导致基因沉默效率低下。因此,本研究探讨了设计和利用一种肽的可行性,该肽称为 599,由合成流感病毒衍生的内涵体破坏融合肽序列和一段阳离子细胞穿透性九(D-精氨酸)残基组成,将 siRNA 递送到口腔癌细胞中,并诱导治疗靶点 CIP2A 的沉默,CIP2A 是一种在各种人类恶性肿瘤中过度表达的癌蛋白,包括口腔癌。增加 599 肽与 siRNA 的摩尔比表明对 siRNA 分子具有更高的结合能力,并增强了 siRNA 递送到口腔癌细胞的细胞质中。事实上,对细胞内 siRNA 递送的定量测量表明,与单独用 siRNA 处理的细胞相比,50∶1 的肽与 siRNA 的摩尔比可以递送 18 倍更高量的 siRNA,而没有明显的长期细胞毒性作用。最重要的是,599 肽介导的 siRNA 递送促进了 CIP2A mRNA 和蛋白的显著沉默,从而降低了口腔癌细胞的侵袭性和锚定独立性生长。总之,这些数据表明,由融合序列与细胞穿透性残基组成的嵌合肽可有效递送至口腔癌细胞并诱导其靶基因沉默,为防治口腔癌提供了一种新的治疗策略。