# Role of WT1 in mixed phenotype acute leukemia

> **NIH NIH F32** · ST. JUDE CHILDREN'S RESEARCH HOSPITAL · 2021 · $66,390

## Abstract

PROJECT SUMMARY/ABSTRACT
Pediatric mixed phenotype acute leukemia (MPAL) is a rare, high-risk leukemia that accounts for 2-3% of
pediatric leukemia cases and has a particularly poor prognosis (<50% survival). This is primarily due to lack of
tailored therapies that target the unique genetic and developmental basis of this disease, highlighting a critical
need to better understand MPAL biology. We recently discovered that the WT1 gene is mutated in nearly half of
all pediatric T/myeloid MPAL patients, with most mutations causing premature termination codons that remove
the C-terminal DNA binding domain of the WT1 protein. This particular alteration is predicted to have functional
consequences, as WT1 encodes a DNA binding transcription factor important for early hematopoietic
development. Furthermore, WT1 plays important roles in the regulation of gene expression, chromatin structure,
and DNA methylation through interactions with other molecular complexes, highlighting the multiple pathways
that may be disrupted in WT1-mutant hematopoietic cells. Importantly, each of these pathways represent
potential vulnerabilities that can be exploited or directly targeted with rationally-designed therapy. The research
proposed in this Fellowship will identify the developmental and molecular consequences of WT1 mutations in
early hematopoiesis, providing a critical first step towards developing new strategies to combat this difficult to
treat childhood disease. Aim 1 of this research proposal will address the role of truncating WT1 mutations in
perturbing early hematopoiesis. A CRISPR/Cas9-based approach will be used to introduce patient-relevant
mutations at the endogenous WT1 locus in human hematopoietic stem and progenitor cells (HSPCs) which will
faithfully model the genetic and developmental origin of T/myeloid MPAL. Wild-type and WT1-mutant cells will
be differentiated in vitro using colony forming assays and in vivo through transplantation into humanized mice.
Flow cytometry and gene expression profiling will identify distinct hematopoietic populations and gene
expression programs that are disrupted by WT1 alterations. Aim 2 of this research proposal will use proteomics
and functional genomics assays to identify the molecular alterations induced by truncating WT1 mutations in
human HSPCs, complementing the developmental alterations identified in Aim 1. Specifically, these assays will
map dynamic protein-protein interactions, chromatin modifications, and DNA methylation patterns in wild-type
and WT1-mutant HSPCs. Integration of these data will enable identification of the molecular mechanisms
underlying transcriptional changes that deregulate early hematopoiesis in WT1-mutant MPAL. Overall, these
studies will elucidate the developmental and molecular consequences of recurrent WT1 alterations in
T/myeloid MPAL and reveal new pathways and dependencies that may be interrogated for therapeutic
benefit.

## Key facts

- **NIH application ID:** 10314019
- **Project number:** 5F32CA254140-02
- **Recipient organization:** ST. JUDE CHILDREN'S RESEARCH HOSPITAL
- **Principal Investigator:** Lindsey Montefiori
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $66,390
- **Award type:** 5
- **Project period:** 2020-07-01 → 2023-09-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10314019

## Citation

> US National Institutes of Health, RePORTER application 10314019, Role of WT1 in mixed phenotype acute leukemia (5F32CA254140-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10314019. Licensed CC0.

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