Paediatric high grade glioma (pHGG) is the most common malignant childhood brain tumour with standard-of-care inevitably resulting in therapy-resistant relapse or disease progression. The need for new combinatorial treatments is universally acknowledged; however, modern combination therapies are sparse, include at most two modalities and have so far not been able to significantly improve the dismal prognosis of the disease. In this proposal, I conceptualize a highly targeted multimodal treatment strategy for pHGG (4D-therapy) based on complementary precision medicine approaches. The system leverages multiple inter-modal synergies, overcomes resistance to individual therapies and disperses off-targeting to different cell populations, thereby creating a large therapeutic window. Initially, we will conduct a comprehensive screen to evaluate a novel regimen of combined upfront targeted drug- and radiotherapy (RT), followed by functional validation in vitro and in vivo. In-depth molecular profiling will allow us to unravel mechanisms of radiosensitization. Further, we aim to establish an innovative gene therapy approach with unprecedented, highly specific tropism for tumour cells by combining elaborately selected adeno-associated viruses and nanocapsules with newly identified Cas-nucleases. Ultimately, we will systematically combine drug-RTs, gene therapies and existing tumour-specific CAR-T cells within a rationally designed, multimodal treatment regimen and evaluate its efficacy in a series of preclinical studies. A broad representation of patient-derived xenografts, complemented by immunocompetent allograft models will provide leading-edge predictive power and a unique dataset to investigate multimodal interactions. I expect this project to provide pioneering insights into inter-modal treatment synergies, to produce stratified treatment protocols for pHGG, directly informing clinical trials and to become a pathbreaking feasibility study for multimodal cancer therapy.

How does a cell with unstable, complex genomic rearrangements stay alive, and even give rise to aggressive, highly resistant malignancies? This question remains an ultimate research challenge for cancers with highly aberrant genomes, such as acute myeloid leukemia with complex karyotype (CK-AML). Its etiology, time-resolved clonal dynamics, molecular heterogeneity, and treatment resistance mechanisms are still largely elusive. In particular, the genetic and non-genetic dynamics that drive cancer progression under treatment are elusive to current technologies and escape single-cell resolution. SHATTER-AML will tackle the genomic enigma of CK-AML by analyzing longitudinally obtained triplicate (diagnosis, treated, relapse) samples to examine intra-patient genetic and non-genetic heterogeneity using scNOVA-CITE, a newly developed multi-modal single-cell omics approach. This approach combines (i) structural variation discovery with nucleosome occupancy and cis-regulatory element accessibility profiling (scNOVA) with (ii) cellular indexing of transcriptomes and epitome sequencing (CITE-seq). We will uncover multi-level disease dynamics at single-cell and subclonal levels along the disease course, providing a blueprint for studies of other structurally instable cancers. Identified molecular insights into the networks mediating therapy resistance, leukemic stem cell activity and immune escape will be further explored functionally in patient-derived in vivo models. Pharmacological interference and CRISPRi are used to engineer deregulated signaling pathways for precision oncology, and CRISPRa screens are applied to sensitize CK-AML stem cells to natural killer cell-mediated elimination. • SHATTER-AML will fundamentally transform our understanding of the impact of clonal evolutionary dynamics of malignancies triggered by aberrant genomes and aims to develop novel preclinical strategies to combat CK-AML resistance via immunological and precision oncology approaches.

Transcription factors are often mutated or aberrantly expressed in cancer and drive carcinogenesis. HOXA9 is a master transcription factor that controls a network of genes critical for hematopoiesis. It shows increased expression levels in more than 50% of patients with acute myeloid leukemia (AML), and is strongly associated with poor clinical outcome. Since the initiation and progression of AML depend on elevated HOXA9 levels, it represents an attractive therapeutic target to combat this aggressive malignancy. However, transcription factors are often not amenable to direct pharmacologic inhibition. To overcome this limitation, an alternative strategy aiming at interference with the transcription factor-specific 'degradome' - the degradation machinery regulates HOXA9 stability. To this end, we aim to elucidate the HOXA9 degradome with the goal of identifying its druggable nodes. Specifically, we plan to (1) identify regulatory proteins involved in the degradation of HOXA9 by performing a FACS-based positive selection screen with a focused CRISPR/Cas9 library as perturbation tool, (2) validate candidate proteins involved in the control of HOXA9 stability, and (3) characterize hits suitable for pharmacologic targeting. For the most promising HOXA9 regulators, we will determine their specificity by assessing global changes of protein abundance by proteomics. The potential of employing hits for pharmaceutical targeting will be evaluated by integrating molecular information with clinical data. In summary, this project aims to establish novel strategies for the dissection of the transcription factor HOXA9 degradome by developing a flexible screening platform. Through this project, I will not only acquire new skills but also establish a scientific network, which is expected to intensify the collaboration between DKFZ and Harvard Medical School. Two years’ experience in USA followed by one year in Heidelberg will be undoubtedly a milestone in my career development.

During vertebrate development, genes are regulated by distal regulatory elements, presumably via physical contacts between enhancers and transcription start sites. Alterations in enhancer sequences and/or their interactions with gene promoters can perturb gene expression, leading to developmental disorders and cancers, which argues for their pivotal role in transcription. Conversely, enhancer-promoter contacts can also be uncoupled from gene activation during developmental transitions and in single cells, where they are highly heterogeneous. Thus, the relationship between enhancer-promoter interactions and transcription is frequently indirect and the mechanisms that dictate when promoter-enhancer contacts can result in gene expression differences remain unknown. The core hypothesis of this proposal is that it is the timing of promoter-enhancer communication that instructs gene activation. Aim1 will examine whether and how the precise timing of enhancer-promoter interactions contributes to transcription. My group will determine which molecular mechanisms during transcriptional activation are regulated by enhancers contacting their target genes at different time points during embryonic stem cell differentiation. Aim2 will investigate how present and preceding enhancer-promoter contacts relate to transcriptional activity and transcription factor binding in single cells. My group will develop a genomic approach to trace the memory of preceding interactions at gene regulatory elements, thus adding a novel temporal dimension to current single-cell methods. By longitudinally combining cutting-edge genomic, single-cell and activity perturbation assays, my group will uncover how genes integrate regulatory inputs from several enhancers and assess how the timing of genome folding mechanistically contributes to this process. This research plan will newly elucidate temporality as a powerful feature that shapes the regulatory potential of enhancers and promoters.