Periodic Reporting for period 4 - ONCOMECHAML (Common Oncogenic Mechanisms in Multi-Partner Translocation Families in Acute Myeloid Leukemia)
Reporting period: 2019-01-01 to 2020-05-31
In this project, we aim to delineate critical common components of oncogenic mechanisms in AML driven by MPT families through a comparative analysis of 20 MLL-, RUNX1- and NUP98-fusion proteins. First, we will describe how fusion proteins interact with their partner proteins and how they regulate the expression of target genes. Second, we will identify critical components within the fusion-protein-dependent regulatory landscapes by systematic loss-of-function screening. High-confidence candidates will be further analysed in detail in AML cells via different molecular approaches.
This project will contribute to the clarification of molecular mechanisms underlying fusion-protein-dependent oncogenic transformation. We are convinced that knowledge about the oncogenic mechanisms can be translated into clinical approaches for better patient management strategies for AML patients.
The functional relevance of protein interactors and/or target genes is systematically interrogated using functional genomics approaches in clinically relevant model systems. While we initially started to use RNAi loss-of-function screening to validate small lists of candidate proteins, we have recently begun to leverage the CRISPR/Cas9 technology to identify critical effectors of MPT families at a genomic scale. First genome-wide CRISPR/Cas9 screens in fusion-protein-dependent cellular models are currently being analysed. High-confidence hits are subsequently validated using a variety of experimental approaches.
We have recently completed a first study to apply this experimental pipeline to conserved interactors of seven MLL fusion proteins. Functional investigation of 128 conserved MLL-fusion-interactors identified a specific role for the lysine methyltransferase SETD2 in MLL-leukemia. SETD2 loss caused growth arrest and differentiation of AML cells, and led to increased DNA damage. These results uncover a dependency for SETD2 during MLL-leukemogenesis, revealing a novel actionable vulnerability in this disease.