In:
Cancer Research, American Association for Cancer Research (AACR), Vol. 75, No. 15_Supplement ( 2015-08-01), p. 3536-3536
Abstract:
Hepatoblastoma (HB), the commonest pediatric liver tumor is frequently associated with an N-terminal deletion in the CTNNB1 gene, which encodes stable β-catenin and promotes nuclear localization and transactivation activity. In 80% of patients, nuclear localization of β-catenin and Yes Associated Protein (YAP), a Hippo-related transactivator, is seen together. Further, stable hepatic co-expression of Δ90-CTNNB1 and active-YAP in mice causes rapid and aggressive HB. Dicer-substrate siRNAs (DsiRNAs) are potent RNA interference (RNAi) triggers that that are efficacious in preclinical tumor models of diverse origin, and are currently under clinical evaluation. To determine if CTNNB1-targeting DsiRNAs have potential as a therapy in HB, we encapsulated this oligonucleotide payload into lipid nanoparticles (LNPs), and systemically administered into mice bearing CTNNB1/YAP-induced HB. The LNP platform used, termed EnCore (because of its specific Envelope and Core lipid components), enables high encapsulation efficiency, long-term stability, and consistent analytical criteria. Downstream of LNP-mediated DsiRNA delivery, both qPCR and in situ hybridization were used to visualize changes in CTNNB1 expression in both tumor and normal liver. Robust and specific silencing of CTNNB1 mRNA was achieved in the tumors. The distribution of mRNA knockdown within each tumor nodule suggests efficient extravasation and internalization of the LNP and its payload into the tumor parenchyma, in contrast to previous reports of vascular-channel limited nanoparticle accumulation in tumors. Intriguingly, a “liver-centric” LNP formulation, which delivers cargo efficiently to a normal liver due to rapid hepatic extraction and apolipoprotein-mediated internalization, was inactive in the tumors. Further evaluation demonstrated efficacy of β-catenin targeting in this model. In conclusion, we report a highly relevant modality of RNAi delivery in a mouse model of hepatoblastoma to target a classically-undruggable oncogene. Citation Format: Marc T. Abrams, Junyan Tao, Shanthi Ganesh, Wendy Cyr, Bo Ying, Martin Koser, Rokhand Arvan, Girish Chopda, Hank Dudek, Cheng Lai, Weimin Wang, Bob Brown, Satdarshan Monga. Targeting β-catenin with a Dicer-substrate siRNA (DsiRNA) in a sleeping beauty transposon-driven murine hepatoblastoma model. [abstract] . In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3536. doi:10.1158/1538-7445.AM2015-3536
Type of Medium:
Online Resource
ISSN:
0008-5472
,
1538-7445
DOI:
10.1158/1538-7445.AM2015-3536
Language:
English
Publisher:
American Association for Cancer Research (AACR)
Publication Date:
2015
detail.hit.zdb_id:
2036785-5
detail.hit.zdb_id:
1432-1
detail.hit.zdb_id:
410466-3
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