# TET2-mediated transcriptional and epigenetic control of normal and malignant hematopoiesis

> **NIH NIH R01** · UNIVERSITY OF TEXAS HLTH SCIENCE CENTER · 2021 · $413,488

## Abstract

TET2 is one of the most commonly mutated genes in adult myeloid malignancies and in normal 
individuals over 70 years of age. Tet2-loss leads to increased expansion of hematopoietic 
stem/progenitor cells (HSPCs) and subsequent development of myeloid malignancies in mice. 
Thus, TET2 mutations constitute a suitable target for intervention at the early stages of HSPC 
clonal expansion. To exploit TET2 mutations therapeutically, a better understanding of the 
mechanisms by which Tet2-loss leads to premalignant HSPC dysregulation and myeloid malignancy 
development is essential. As a member of the methylcytosine dioxygenase family, TET2 converts 5mC 
to 5hmC, which can be relatively stable or be further oxidized to 5fC and 5caC. We 
have reported the requirement of catalytic activity of TET2 in its tumor-suppressive functions in 
HSPCs. Recently, we identified a novel mechanism of hematological malignancy via the increased 
mutational burden at genomic sites where TET2 binds and, counterintuitively, with gained 5hmC upon 
TET2-loss. In addition, we discovered a novel role of TET2 in RNA hydroxymethylation (hm5C) and 
target transcripts destabilization via its partner and RNA-binding protein (RBP) PSPC1 in mouse 
embryonic stem cells. Importantly, we found that PSPC1 and its heterodimer partner NONO are 
both abundantly expressed in HSPCs. Our studies raise two critical questions on TET2 
biology in normal and malignant hematopoiesis: 1) How does gained 5hmC contribute to the 
pathogenesis of myeloid malignancy? 2) Is catalytic activity of TET2 relevant and functional at 
the RNA hm5C level in HSPCs? We hypothesize that TET2 may exert enzymatic functions through 
preferential 5hmC- to-5fC/5caC oxidation leading to DNA demethylation and transcriptional 
activation of tumor suppressor genes and through RNA hm5C modification and consequent 
destabilization of oncogenic RNAs. We will study how dysregulation of DNA-5hmC and RNA-hm5C 
mediated epigenetic control upon TET2 mutations can lead to malignant hematopoiesis by three 
specific aims. Aim 1) Define preferential TET2-mediated 5hmC-5fC/5caC oxidation for DNA 
demethylation in HSPCs and its dysregulation for the pathogenesis of myeloid malignancy using our 
newly created 5hmC stalling and catalytically inactive knock-in mutant Tet2 mouse models. Aim 2) 
Determine the functional significance of the TET2-RUNX1 partnership for TET2 genomic localization 
and target gene expression in HSPCs. RUNX1, a TET2 binding partner, is reported to be enriched in 
regions of increased 5hmC, but not in hypo-5hmC regions in TET2 mutant AML. We will study RUNX1 
functions in regulating TET2 genomic occupancy in HSPCs and examine the potential role of RUNX1 in 
imparting unique TET2 functions in preferential 5hmC-to-5fC/5caC oxidation during normal and 
malignant hematopoiesis. Aim 3) Investigate RBP- mediated TET2 recruitment for RNA hm5C 
modification and destabilization of oncogenic RNAs in HSPCs and its dysregulation i...

## Key facts

- **NIH application ID:** 10129996
- **Project number:** 5R01HL146664-04
- **Recipient organization:** UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
- **Principal Investigator:** Jianlong Wang
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $413,488
- **Award type:** 5
- **Project period:** 2019-05-01 → 2023-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10129996

## Citation

> US National Institutes of Health, RePORTER application 10129996, TET2-mediated transcriptional and epigenetic control of normal and malignant hematopoiesis (5R01HL146664-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10129996. Licensed CC0.

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