Abstract: PO0506
Modeling Rare Human Tuberous Sclerosis Complex-Associated Kidney Angiomyolipomas In Vivo with Induced Pluripotent Stem Cell-Derived Renal Organoid Xenografts
Session Information
- Bioengineering: Organoids and Organs-on-a-Chip
November 04, 2021 | Location: On-Demand, Virtual Only
Abstract Time: 10:00 AM - 12:00 PM
Category: Bioengineering
- 300 Bioengineering
Author
- Lemos, Dario R., Brigham and Women's Hospital, Boston, Massachusetts, United States
Group or Team Name
- Lemos Lab
Background
Currently there are no animal models of renal angiomyolipoma (AML) for the study of tumor mechanisms in vivo. This is partly due to the fact that biallelic inactivation of TSC1 or TSC2 during development causes embryonic lethality, while previous attempts to ablate TSC1 or TSC2 by means of tissue-specific Cre-mediated recombination have not succeeded in recapitulating the lesions.
Methods
We induced nephric differentiation of isogenic TSC2−/−, TSC2+/-, and TSC2+/+ human iPSCs derived from a TSC patient, under three-dimensional tissue culture conditions for 21 days. Next we transplanted the resulting renal organoids under the kidney capsule of immunodeficient RNU Nude rats. We next tested the a novel formulation for delivery of the mTOR inhibitor rapamycin using nanocarriers, on xenograft growth and ablation.
Results
Orthotopically transplanted TSC2−/− AML organoids displayed significantly higher growth rate compared to TSC2+/- or TSC2+/+ kidney organoids, at Day 14 post-transplantation. Histological analysis of organoid xenograft tissues using antibodies against human nuclear antigen (HNA) or the human isoform of Lamin A/C (hLamin A/C), revealed prominent presence of human AML-like cells expressing smooth muscle and melanocyte markers in TSC2-/- but not in TSC2+/- or TSC2+/+ organoid xenografts, indicating that the myomelanocytic phenotype of TSC2-/- AML organoids was maintained in vivo. mTOR activation was observed in ACTA2+ PMEL+ cells of TSC2-/- AML organoid graft cells, but not in the adjacent normal rat tissue or in TSC2+/+ or TSC2+/- organoid xenografts, indicating that metabolic activation in the absence of TSC2 was consistent with xenograft growth. The rat kidney critically provided vascularization, supporting the growth of TSC2-/- organoids, and promoting the proliferation of AML cells. In our drug testing experiments, 3mg/kg rapamycin delivered orally significantly slowed TSC2-/- organoid xenograft growth, while local injections of low-dose rapamaycin-loaded nanoparticles resulted in organoid AML cell apoptosis and xenograft abrogation after 7 days, without affecting the rat kidney.
Conclusion
TSC2-/- hiPSC-derived AML organoid xenografts recapitulate key features of human TSC-associated AML in vivo with a high degree of anatomical and molecular fidelity. This model can be used to study tumor mechanisms and to test new therapies.
Funding
- NIDDK Support