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Biology subjects

Maher, S. E.

Publications and source records attributed to Maher, S. E..

2 recordsLinked to original sources

Optimizing in utero electroporation of the developing mouse pons to model diffuse midline glioma

The leading cause of brain cancer-related death in children is diffuse midline glioma (DMG). A particularly aggressive DMG subtype is pediatric diffuse intrinsic pontine glioma (DIPG), which is caused by the histone mutation H3.3K27M. Because of its diffuse growth and location in a critical brainstem structure, therapeutic options are limited and DIPG is considered universally fatal. Lack of appropriate animal models has hindered our understanding of the developmental origins and progression of DIPG, which in turn has limited development of effective therapeutics. To address this barrier, we optimized an in utero electroporation method to model DIPG in vivo in the developing mouse pons. In this protocol, we use in utero electroporation to express canonical DIPG mutant oncogenes in neural progenitors lining the 4th ventricle, which give rise to cells in the pons. As the embryos continue to develop in utero and then postnatally, they develop large diffuse brainstem tumors with molecular characteristics of pediatric DIPG, allowing us to model the formation and progression of this deadly pediatric brain cancer.

cancer biology↗

Metastasis of colon cancer requires Dickkopf-2 to generate cancer cells with Paneth cell properties

Metastasis is the leading cause of cancer-related mortality. Paneth cells provide stem cell niche factors in homeostatic conditions, but the underlying mechanisms of cancer stem cell niche development are unclear. Here we report that Dickkopf-2 (DKK2) is essential for the generation of cancer cells with Paneth cell properties during colon cancer metastasis. Splenic injection of Dkk2-knockout (KO) cancer organoids into C57BL/6 mice resulted in a significant reduction of liver metastases. Transcriptome analysis showed reduction of Paneth cell markers such as lysozymes in KO organoids. Single cell RNA sequencing analyses of murine metastasized colon cancer cells and patient samples identified the presence of lysozyme positive cells with Paneth cell properties including enhanced glycolysis. Further analyses of transcriptome and chromatin accessibility suggested Hepatocyte nuclear factor 4-alpha (HNF4A) as a downstream target of DKK2. Chromatin immunoprecipitation followed by sequencing analysis revealed that HNF4A binds to the promoter region of Sox9, a well-known transcription factor for Paneth cell differentiation. In the liver metastatic foci, DKK2 knockout rescued HNF4A protein levels followed by reduction of lysozyme positive cancer cells. Taken together, DKK2-mediated reduction of HNF4A protein promotes the generation of lysozyme positive cancer cells with Paneth cell properties in the metastasized colon cancers.

cancer biology↗