Abstract 298: Targeting KRAS mutant non-small cell lung cancer with EGFR aptamer displaying 3WJ pRNA nanoparticles

Abstract

Abstract Background and Purpose: KRAS mutations are one of the most common oncogenic mutations in human cancers, including non-small cell lung cancer (NSCLC), and have established roles in cancer pathogenesis and therapeutic resistance. Development of effective inhibitors of mutant KRAS represent a significant challenge. The field of three-way junction (3WJ) based RNA nanoparticles has advanced rapidly and shows promise as an effective in vivo siRNA delivery system. This aim of this study is to explore the potential of 3WJ-pRNA nanoparticles for specific and efficient delivery of KRASG12C siRNA to NSCLC cells harboring a KRASG12C mutation to effectively silence KRAS oncogenic activity. Experimental design: Multifunctional EGFRapt-3WJ-siKRASG12C nanoparticles were prepared using bottom-up self-assembly approach, and characterized by agarose gel shift assay, dynamic light scattering (DLS), and temperature gradient gel electrophoresis system (TGGE). Three NSCLC cell lines, H2122 and H2030 carrying KRASG12C, and H1299 with wild type KRAS were used in this study. Binding specificity and delivery efficiency of EGFRapt-3WJ-siKRASG12C nanoparticles in NSCLC cells were evaluated in vitro and in vivo. Biological effects of KRAS mutant silencing were assessed by in vitro functional assays, and in vivo tumor xenograft experiments. Results: Characterization of EGFRapt-3WJ-siKRASG12C by DLS showed 7.2 ± 0.5 nm average size, and TGGE indicated a melting temperature (Tm) of 51.77°C. Flow cytometry, IVIS lumina imaging assay, real-time quantitative PCR, western blot, and KRAS activity assay confirmed that EGFRapt-3WJ-siKRASG12C potently and selectively depleted cellular KRAS expression, resulting in suppression of downstream MAPK pathway signaling in KRASG12C NSCLC cells and in heterotopic tumor models. In addition, in vitro cell proliferation, migration/invasion, and chemotherapy and radiotherapy sensitivity assays, demonstrated that KRAS silencing by EGFRapt-3WJ-siKRASG12C suppressed NSCLC cell growth, migration/invasion ability, and sensitized NSCLC cells to chemotherapy or radiotherapy. In vivo, these nanoparticles led to regression of tumor growth in heterotopic models. Conclusions: Together, this study suggests that 3WJ pRNA based platform has clinical potential to suppress mutant KRAS activity for the treatment of KRAS driven human cancers, and warrants further development. Citation Format: Linlin Yang, Zhefeng Li, Peixuan Guo, Terence M. Williams. Targeting KRAS mutant non-small cell lung cancer with EGFR aptamer displaying 3WJ pRNA nanoparticles [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 298.