Three dimensional reconstruction of the mouse cerebellum in Hedgehog-driven medulloblastoma models to identify Norrin-dependent effects on preneoplasia

Nenad T Pokrajac; Akshay Gurdita; Nobuhiko Tachibana; Nicholas J A Tokarew; Valerie A Wallace

doi:10.1038/s42003-022-03507-5

Three dimensional reconstruction of the mouse cerebellum in Hedgehog-driven medulloblastoma models to identify Norrin-dependent effects on preneoplasia

Commun Biol. 2022 Jun 9;5(1):569. doi: 10.1038/s42003-022-03507-5.

Authors

Nenad T Pokrajac^{1

2}, Akshay Gurdita^{1

2}, Nobuhiko Tachibana^{1

2}, Nicholas J A Tokarew^{1

2}, Valerie A Wallace^{3

4

5}

Affiliations

¹ Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ON, M5T 2S8, Canada.
² Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, M5S 1A8, Canada.
³ Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ON, M5T 2S8, Canada. valerie.wallace@uhnresearch.ca.
⁴ Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, M5S 1A8, Canada. valerie.wallace@uhnresearch.ca.
⁵ Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, M5T 3A9, Canada. valerie.wallace@uhnresearch.ca.

Abstract

Spontaneous mouse models of medulloblastoma (MB) offer a tractable system to study malignant progression in the brain. Mouse Sonic Hedgehog (Shh)-MB tumours first appear at postnatal stages as preneoplastic changes on the surface of the cerebellum, the external granule layer (EGL). Here we compared traditional histology and 3DISCO tissue clearing in combination with light sheet fluorescence microscopy (LSFM) to identify and quantify preneoplastic changes induced by disrupting stromal Norrin/Frizzled 4 (Fzd4) signalling, a potent tumour inhibitory signal in two mouse models of spontaneous Shh-MB. We show that 3DISCO-LSFM is as accurate as traditional histology for detecting Norrin/Fzd4-associated changes in PNL formation in Ptch^+/- mice and EGL hyperplasia in Neurod2-SmoA1^+/- mice. Moreover, we show that the anti-tumour effect of Norrin/Fzd4 signalling is restricted to the posterior region of the cerebellum and is characterized by defective neural progenitor migration away from the EGL. In conclusion, 3DISCO-LSFM is a valid way to monitor tumour initiation events in mouse MB models and reveals an unanticipated regional restriction of stromal signalling in constraining tumour initiation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Cerebellar Neoplasms* / genetics
Cerebellar Neoplasms* / pathology
Cerebellum / metabolism
Disease Models, Animal
Hedgehog Proteins / genetics
Hedgehog Proteins / metabolism
Imaging, Three-Dimensional
Medulloblastoma* / genetics
Medulloblastoma* / pathology
Mice

Substances

Hedgehog Proteins

Grants and funding

CIHR/Canada