Entwicklung von EpCAM Adapter-siRNAs für die therapeutische Genstilllegung in einem orthotopischen Bauchspeicheldrüsenkrebs-Mausmodell
Biomaterialien
Zusammenfassung der Projektergebnisse
Small interfering RNA (siRNA)-based therapeutics have been developed with considerable promise as a new therapeutic tool in cancer treatments. However, systemic delivery of siRNA remains a challenging hurdle for its widespread application in cancer therapy. Notably, epithelial cell adhesion molecule (EpCAM) is over-expressed in epithelial cancer tissues, which distributed along the cell membrane. In contrast, in normal epithelia, EpCAM is only weakly expressed on non-druggable basolateral gap junctions. To facilitate tumor-specific uptake, in this study, siRNA is linked with an RNA aptamer that binds to EpCAM to generate antitumoral EpCAM aptamer-siRNA chimeras (AsiCs). We establish two epithelial cancer mouse models, pancreatic cancer and breast cancer, to evaluate the therapeutic efficacy of EpCAM-AsiCs. In the development of EpCAM-AsiCs for pancreatic cancer, we verified the overexpression of EpCAM in pancreatic cancer, and EpCAM aptamer can be efficiently internalized by pancreatic cancer cells. We used EpCAM-AsiCs to target genes participating in mitosis (PLK1), mitochondrial apoptotic pathway (MCL1, BCL-XL), tumorigenesis and progression (PTPN2) in cancer cells. All of the AsiCs mediated significant in vitro toxicity in compared to EpCAM aptamer-treated controls, validating the efficacy resulting from the siRNA-based gene silencing. In addition, in the in vivo therapeutic study, PLK1 AsiC lead to the stronger tumor suppression over MCL1 and PTPN2 AsiCs. In aggressive mouse triple-negative breast cancer (TNBC) model, we showed that tumor cell-targeted gene knockdown with immune-modulating EpCAM-AsiC improves tumor immunogenicity and inhibits tumor growth. We designed EpCAM-AsiCs to knock down apoptotic pathway (Mcl1), RNA quality control (Upf2), and DNA damage repair genes (Parp1) to induce tumor neoantigens, and a “don’t eat me” signal that inhibits tumor phagocytosis (Cd47). These EpCAM-AsiCs significantly improved immune responses to the tumor and inhibited tumor growth. Encouragingly, combination of EpCAM AsiCs performed better than individual AsiC and could synergize with anti-PD-1 checkpoint inhibition. Combination of EpCAM AsiCs also effectively inhibited the growth of metastatic tumors. Hopefully, the design of such EpCAM-targeting siRNA delivery system may represent a novel approach for translating RNA-based cancer therapeutics to the clinics.
Projektbezogene Publikationen (Auswahl)
- Immunotherapy for breast cancer using EpCAM aptamer tumor-targeted gene knockdown. PNAS. 2021; 118 (9) e2022830118
Y Zhang, X Xie, PN Yeganeh, DJ Lee et al.
(Siehe online unter https://doi.org/10.1073/pnas.2022830118)
