Direct Pharmacological Inhibition of β-Catenin by RNA Interference in Tumors of Diverse Origin.


The Wnt/β-catenin pathway is among the most frequently altered signaling networks in human cancers. Despite decades of preclinical and clinical research, efficient therapeutic targeting of Wnt/β-catenin has been elusive. RNA interference (RNAi) technology silences genes at the mRNA level and therefore can be applied to previously undruggable targets. Lipid nanoparticles (LNP) represent an elegant solution for the delivery of RNAi-triggering oligonucleotides to disease-relevant tissues, but have been mostly restricted to applications in the liver. In this study, we systematically tuned the composition of a prototype LNP to enable tumor-selective delivery of a Dicer-substrate siRNA (DsiRNA) targeting CTNNB1, the gene encoding β-catenin. This formulation, termed EnCore-R, demonstrated pharmacodynamic activity in subcutaneous human tumor xenografts, orthotopic patient-derived xenograft (PDX) tumors, disseminated hematopoietic tumors, genetically induced primary liver tumors, metastatic colorectal tumors, and murine metastatic melanoma. DsiRNA delivery was homogeneous in tumor sections, selective over normal liver and independent of apolipoprotein-E binding. Significant tumor growth inhibition was achieved in Wnt-dependent colorectal and hepatocellular carcinoma models, but not in Wnt-independent tumors. Finally, no evidence of accelerated blood clearance or sustained liver transaminase elevation was observed after repeated dosing in nonhuman primates. These data support further investigation to gain mechanistic insight, optimize dose regimens, and identify efficacious combinations with standard-of-care therapeutics. Mol Cancer Ther; 15(9); 2143-54. ©2016 AACR.

DOI: 10.1158/1535-7163.MCT-16-0309

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@article{Ganesh2016DirectPI, title={Direct Pharmacological Inhibition of β-Catenin by RNA Interference in Tumors of Diverse Origin.}, author={Shanthi Ganesh and Martin L. Koser and Wendy A Cyr and Girish R Chopda and Junyan Tao and Xue Shui and Bo Ying and Dongyu Chen and Purva Pandya and Edmond Chipumuro and Zakir Siddiquee and Kevin Craig and Chengjung Lai and Henryk Dudek and Satdarshan Pal Singh Monga and Weimin Wang and Bob D. Brown and Marc Abrams}, journal={Molecular cancer therapeutics}, year={2016}, volume={15 9}, pages={2143-54} }