Project Details
Projekt
Identification of functional dependencies to prevent MPN disease progression
Applicant
Professor Dr. Florian Heidel
Subject Area
Hematology, Oncology
Term
since 2024
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 517204983
While Jak-inhibitors (JAK-i) reduce inflammatory activity and hyperproliferation of myeloid progenitors, the disease-maintaining Jak2-mutated clones persist or even progress. Using phopho-proteomic analysis of JAK2-mutated cells, we have recently identified functionally relevant proteins responsible for maintenance of MPN cells (Jayavelu et al. Nature 2020). Following these observations, we have focused on cellular mechanisms with particular relevance for clonal development and disease progression. Using JAK2-mutated human cell lines of blast-phase (BP-) MPN we have identified transcriptional regulator CER1 (Cerberus 1) as a highly expressed molecule and have confirmed its status as a unique dependency in JAK2-mutated cells by targeted in vitro and in vivo CIRSPR-Cas9 screens. CER1 is part of a group of bone morphogenetic protein (BMP) modulating molecules with confirmed impact on proliferative capacity of JAK2-mutated cells. Most recently, a key role for the BMP/SMAD pathway has been described in the pathogenesis of p53 mutant leukemic transformation. In this model, deregulation of the BMP/SMAD pathway, enhances self-renewal and HSPC expansion. Therefore, we hypothesize that the identified molecule CER1 is functionally relevant for disease persistence and progression of JAK2-mutated MPN. To characterize its functional relevance and translational applicability, we will use genetic and pharmacologic perturbation in vitro and in vivo. Using genetically engineered reporter cell lines, we aim to identify regulators of CER1 expression. Also, we will assess for CER1-binding partners by interactome analyses and investigate pathways that are globally affected by induced degradation of CER1 in vitro. To investigate how disease persistence and progression is influenced by CER1, we will explore its transformation potential in normal and JAK2-muated primary murine and human cells by genetic modulation and study its cell-intrinsic versus cell-extrinsic functions. Finally, we aim to define secondary genetic dependencies on CER1 by global CRISPR-Cas9 screens and to validate relevant molecules in primary murine and human MPN cells. Taken together, experiments described in our research proposal will produce a detailed characterization of the functional role and mechanistic impact of CER1 in the context of MPN persistence and progression in close and synergistic collaborations within a Research Unit.
DFG Programme
Research Units
