Characterization of ADAM10 as a vulnerability and novel potential therapy target of acute leukemia

Schmid, Jan Philipp (2024): Characterization of ADAM10 as a vulnerability and novel potential therapy target of acute leukemia. Dissertation, LMU München: Fakultät für Biologie

Abstract

The interaction of leukemic cells with their surrounding bone marrow (BM) microenvironment is crucial for leukemia formation and maintenance. Especially dormant leukemia stem cells (LSCs) reside in this protective niche, allowing them to evade chemotherapy. As LSCs are main drivers of relapse development in leukemia patients, it is of high clinical relevance to efficiently eradicate them. We aimed at identifying surface molecules which can be targeted to disrupt the interaction between leukemic cells and the BM microenvironment, thereby releasing leukemia cells from their niche and re-sensitizing them towards chemotherapeutic agents. We employed our recently established pipeline for functional in vivo CRISPR/Cas9 knockout (KO) screens to test a customized surface molecule library comprising candidates from the lab’s own previous proteome and secretome analysis of LSC-resembling cells, complemented with candidates from the literature. While performing screens in two B-ALL patient-derived xenograft (PDX) models, we discovered both commonly depleted genes, including the positive controls CXCR4 and ITGB1, but also PDX model specific dropouts. We selected ADAM10 as our candidate gene because it was depleted in both tested PDX models and showed increased expression in primary leukemia cells from patients of diverse subgroups of acute leukemias, which correlated with poorer overall survival in these patients. We confirmed ADAM10 as a broad vulnerability in numerous ALL and AML PDX models in vivo, independently from underlying driver mutations and genetic alterations. In contrast, in vitro most PDX models were insensitive to loss of ADAM10. We could confirm the specificity of the observed phenotype of the KO through in vivo reconstitution assays, which further elucidated ADAM10’s catalytically active metalloproteinase domain to be mainly responsible for its role in leukemic cells. Multi-omics analysis revealed that ADAM10 KO affected diverse biological processes, such as cell cycle, cell death, metabolism including OXPHOS as well as membrane and adhesion associated processes. Proof-of-concept experiments functionally confirmed the effect on the first two pathways. Additional functional characterization of PDX cells subjected to chemical inhibition or genetic KO of ADAM10 found the early engraftment and homing capacity, the frequency of leukemia-initiating cells and the CFU potential to be diminished upon ADAM10 reduction or loss, respectively. Moreover, performing in vivo and in vitro chemotherapy trials in ALL and AML PDX models, using a mixture of PDX cells with and without ADAM10 KO competitively growing within the same mouse, we showed that loss of ADAM10 sensitized the cells towards routinely used chemotherapeutic agents. In summary, we propose ADAM10 as a potential novel target for the treatment of leukemia patients in the future.

• Dokumententyp: Dissertationen (Dissertation, LMU München)
• Themengebiete: 500 Naturwissenschaften und Mathematik ; 500 Naturwissenschaften und Mathematik > 570 Biowissenschaften, Biologie
• Fakultäten: Fakultät für Biologie
• Sprache der Hochschulschrift: Englisch
• Datum der mündlichen Prüfung: 8. Juli 2024
• 1. Bericht­erstatter:in: Leonhardt, Heinrich