title: Unraveling Therapeutic Strategies and Tumor Suppressor Functions in EML4-ALK-Driven Lung Tumorigenesis
creator: Diaz Jimenez, Alberto
subject: ddc-570
subject: 570 Life sciences
description: EML4-ALK is an oncogenic chromosomal rearrangement found in 5% of non-small-cell lung cancer. This fusion involves the echinoderm microtubule-associated protein-like 4 (EML4) and the anaplastic lymphoma kinase (ALK) genes. Interestingly, up to 15 different EML4-ALK variants have been described, with variant 1 and variant 3 accounting for over 70% of the cases. The discovery of the EML4-ALK oncogene represents a critical milestone in precision medicine, providing important insights into targeted therapies. However, despite exhibiting a favorable prognosis, EML4-ALK-driven tumors become resistant to available ALK inhibitors. Additionally, co-occurring genetic alterations can often shape tumor development and treatment response. Beyond the role of TP53 in therapy response, very little is known about the impact of other genetic alterations. Therefore, this thesis aims to improve the therapeutic response of EML4-ALK tumor cells and to uncover the fitness landscape of EML4-ALK lung tumors across various genetic alterations.  To investigate the therapeutic response of variant 1 and variant 3, I established cell lines derived from corresponding murine lung tumors. These cell lines accurately reproduce histopathological markers of lung adenocarcinomas and respond to ALK inhibitors, rendering them appropriate as a preclinical tool. The results indicate that variant 3 exhibits lower sensitivity to brigatinib and lorlatinib, two potent ALK inhibitors used as standard-of care for the treatment. Importantly, this enhanced resistance could be overcome by the use of SRC inhibitors. In-depth (phospho)proteomic analyses revealed a synergistic effect primarily driven by a strong inhibition of pathways crucially linked to lung cancer, particularly inhibiting the mTOR pathway.  Due to the genomic heterogeneity of cancer and its impact on patient outcomes, I coupled CRISPR/Cas9 gene editing with tumor barcoding sequencing to the impact of 29 tumor suppressor genes in an Eml4-Alk variant-specific manner. This work identified unexpectedly diverse genetic interactions that strongly and specifically influence tumorigenesis driven by either EML4-ALK variant 1 or variant 3. These findings suggest that the underlying biology of V1 and V3-driven lung tumors is very different and show that different variants can significantly alter the effects of other pathways on tumor progression. Furthermore, I demonstrated that loss of Lkb1 or Setd2 significantly enhanced V3-tumor growth, reducing mouse survival. These findings highlight the essential role of these genes in cancer progression in an EML4-ALK variant-specific manner. Finally, this mouse model is a valuable preclinical tool for investigating pharmacological responses in various tumor genotypes.
date: 2025
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/34876/1/Alberto_Diaz_Jimenez_UNI.pdf
identifier: DOI:10.11588/heidok.00034876
identifier: urn:nbn:de:bsz:16-heidok-348764
identifier:   Diaz Jimenez, Alberto  (2025) Unraveling Therapeutic Strategies and Tumor Suppressor Functions in EML4-ALK-Driven Lung Tumorigenesis.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/34876/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng