# Dissecting innate immune signaling in pre-leukemia evolution

> **NIH NIH R01** · CINCINNATI CHILDRENS HOSP MED CTR · 2022 · $652,991

## Abstract

Abstract
Clonal hematopoiesis (CH) is an aging associated condition characterized by the clonal outgrowth of
mutated pre-leukemic cells. Although individuals with CH are healthy, they are at an increased risk of
developing hematopoietic malignancies. To identify cooperating molecular alterations required for
malignant transformation of clonal pre-leukemic HSPC, we performed an in vivo shRNA screen and found
that shRNAs targeting Traf6 were overwhelmingly enriched in following transformation to overt myeloid
leukemias. TRAF6 is an ubiquitin E3 ligase that synthesizes Lysine (K) 63-linked ubiquitin chains on
substrates leading to Toll-like receptor (TLR) superfamily pathway activation. In support of our in vivo
shRNA screen, promoter hypermethylation and reduced expression of TRAF6 is observed in subsets of
myeloid malignancy patients, including ~40-50% of acute myeloid leukemia (AML). Moreover, our
preliminary data shows that deletion of Traf6 in pre-leukemic Tet2-deficient HSPC results in an aggressive
myeloid neoplasm in part through a novel MYC-dependent mechanism. Based on our findings, we
hypothesize that loss of TRAF6 drives subsets of genetically-defined myeloid malignancies, specifically
via a novel post-translational modification of MYC resulting in its activation. The objectives of the proposal
are to uncover the molecular and cellular basis of TRAF6 deletion on pre-leukemic HSPC function with the
long-term goal of uncovering improved therapeutic approaches by investigating the consequences of
TRAF6 deletion in models of CH and on leukemia development (Aim 1), identifying the molecular basis of
the tumor suppressor-like function of TRAF6 in AML (Aim 2), and evaluating the oncogenic potential of a
novel TRAF6-dependent MYC post-translational modification (Aim 3). These studies are highly significant
as they will provide critical insight into the progression of pre-leukemic states to overt leukemia as a result
of subverting select innate immune pathways, describe a novel disease-modifying role of TLR-TRAF6, and
reveal an unreported mechanism of MYC regulation. These studies have direct translational implications
and fill an unmet clinical need for genetically- and phenotypically-defined subtypes of AML/MPN.

## Key facts

- **NIH application ID:** 10462192
- **Project number:** 1R01CA271455-01
- **Recipient organization:** CINCINNATI CHILDRENS HOSP MED CTR
- **Principal Investigator:** Iannis Aifantis
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $652,991
- **Award type:** 1
- **Project period:** 2022-03-04 → 2027-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10462192

## Citation

> US National Institutes of Health, RePORTER application 10462192, Dissecting innate immune signaling in pre-leukemia evolution (1R01CA271455-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10462192. Licensed CC0.

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