# Mechanisms and therapeutic evaluation of splicing modulation for cohesin-mutant myelodysplastic syndromes

> **NIH NIH F32** · DANA-FARBER CANCER INST · 2021 · $65,994

## Abstract

PROJECT SUMMARY
Myelodysplastic syndromes (MDS) are the most common form of bone marrow failure disorders with more than
30,000 new cases diagnosed each year in the United States. These disorders are characterized by ineffective
hematopoiesis as a result of mutations acquired in the hematopoietic stem and progenitor cells that clonally
expand over time. Mutations in the cohesin complex, most commonly STAG2, are found in the high-risk subset
of MDS patients with poor overall survival and for whom there are currently no targeted therapeutic options.
Therefore, it is critical to gain a better understanding of the cellular mechanisms that drive cohesin-mutant MDS
which can be therapeutically targeted. Our preliminary work has revealed that under normal conditions, the
cohesin complex interacts with the spliceosome through an RNA-intermediate. Interestingly, this interaction is
lost upon mutation of STAG2 in cells. Furthermore, STAG2-mutant cells are selectively killed compared to wild-
type when treated with splicing modulators that target the SF3B complex, drugs that are currently undergoing
clinical testing for splicing-factor mutant MDS. Based on our preliminary work, our central hypothesis is that
regulatory RNAs mediate the interaction between cohesin and the spliceosome at enhancer-promoter loops that
are either lost or altered in cohesin-mutant cells. Furthermore, we believe the loss of this interaction renders
cohesin-mutant cells more sensitive to splicing modulation than normal, healthy cells. The overall objective of
this work is to fully characterize the RNA and protein components that allow cohesin to interact with the
spliceosome and test the in vivo efficacy of splicing modulation in cohesin-mutant MDS mouse models. In Aim1,
we will determine the RNAs that mediate the interaction between cohesin and the spliceosome that are lost in
cohesin-mutant MDS. We will perform enhanced cross-linking immunoprecipitation (eCLIP) on the cohesin
complex to identify bound RNAs and use precision run-on sequencing (PRO-Seq) and total RNA-Seq to quantify
both nascent and steady-state levels of bound RNAs in wild-type and STAG2-mutant cells. In Aim2, we will
quantify the alternative splicing burden observed in cohesin-mutant MDS mouse models and determine the
efficacy of splicing modulators to reverse disease phenotypes and expansion of mutant clones in vivo. Our in
vivo model develops MDS phenotypes upon sequential acquisition of Tet2 and Stag2 mutations, a process that
mimics disease progression in patients. Our long-term goal is to contribute to a mechanistic understanding of
how the interaction between cohesin and the spliceosome is disrupted in disease and potentially offer cohesin-
mutant MDS patients a new therapeutic option of splicing modulation. This work will be carried out under the
guidance of Dr. Zuzana Tothova and Dr. Ben Ebert in the Dana-Farber Cancer Institute, with our local
collaborators Dr. Karen Adelman and Dr. Chris Burge. Together...

## Key facts

- **NIH application ID:** 10313199
- **Project number:** 1F32HL159905-01
- **Recipient organization:** DANA-FARBER CANCER INST
- **Principal Investigator:** Emily Wheeler
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $65,994
- **Award type:** 1
- **Project period:** 2021-09-01 → 2024-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10313199

## Citation

> US National Institutes of Health, RePORTER application 10313199, Mechanisms and therapeutic evaluation of splicing modulation for cohesin-mutant myelodysplastic syndromes (1F32HL159905-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10313199. Licensed CC0.

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