Triblock polymer PDMAEMA-co-PNIPAM-co-PMPC to deliver siKRAS for gene therapy in pancreatic cancer

Abstract

Mutant KRAS sustained KRAS-GTP conformation and activated downstream signaling in pancreatic cancer. Inhibition of KRAS expression has been widely utilized for gene therapy of pancreatic cancer. In this study, a triblock cationic polymer, PDMAEMA-co-PNIPAM-co-PMPC (PDNM), was designed and synthesized as a gene carrier through photoinitiated free radical polymerization. The PDNM/siKRAS delivery system exhibited efficient cellular uptake and low bio-toxicity, as confirmed by fluorescence microscopy and flow cytometry. In vitro experiments using AsPC-1 cells showed that the nanoparticle transfection with PDNM/siKRAS demonstrated favorable anti-tumor effect, including enhanced apoptosis, inhibition of mitosis by arresting the cell cycle at the S phase, reduced Ki67 expression, and impaired cell migration ability. The anti-tumor effect was achieved primarily through KRAS inhibition and caspase 3 activation following siKRAS transfection. Additionally, in vivo experiments showed that the PDNM/siKRAS nanoparticles resulted in reduced tumor volumes and decreased Ki67 expression without apparent impairment of other organs. Notably, the transfection of nanoparticles in patient-derived organoids also demonstrated a similar inhibitory effect. Overall, PDNM holds promise as a potential carrier for siKRAS delivery and gene therapy, both in experimental and clinical applications.