Precision cancer therapy through nanoparticle delivery of siRNA against KRAS.

260 Background: Small interfering RNA (siRNA) has potential for highly specific gene manipulation, making it attractive for delivering precision therapy to cancer patients. However, efforts to employ siRNA therapeutically have been limited by its short half-life in circulation, low target tissue specificity, and cellular entrapment within endosomes. We utilized serum-stable, cell-penetrating, and endosomolytic peptide-based nanoparticles (NPs) to overcome these obstacles and deliver siRNA against KRAS to KRAS-mutant human and mouse pancreas and colorectal cancers. Methods: Human and mouse pancreas and colorectal cancer cell lines were tested for NP uptake in vitro utilizing fluorescent siRNAs. Uptake was assessed via fluorescent microscopy and flow cytometry (FC). Mice bearing tumors from these cells were injected IV with the same NP, and uptake was assessed with an in vivo imaging system (IVIS), and FC. Cell lines were treated with KRAS-siRNA NP and KRAS knockdown was assessed by real-time PCR. Results: ...