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Pancreatic ductal adenocarcinoma (PDAC) has limited treatment options, emphasizing the urgent need for effective therapies. The predominant driver in PDAC is mutated KRAS proto-oncogene, KRA, present in 90% of patients. The emergence of direct KRAS inhibitors presents a promising avenue for treatment, particularly those targeting the KRAS G12C mutated allele, which show encouraging results in clinical trials. However, the development of resistance necessitates exploring potent combination therapies. Our objective was to identify effective KRAS G12C -inhibitor combination therapies through unbiased drug screening. Results revealed synergistic effects with son of sevenless homolog 1 (SOS1) inhibitors, tyrosine-protein phosphatase non-receptor type 11 (PTPN11)/Src homology region 2 domain-containing phosphatase-2 (SHP2) inhibitors, and broad-spectrum multi-kinase inhibitors. Validation in a novel and unique KRAS G12C -mutated patient-derived organoid model confirmed the described hits from the screening experiment. Our findings propose strategies to enhance KRAS G12C -inhibitor efficacy, guiding clinical trial design and molecular tumor boards., (© 2024 The Author(s). Molecular Oncology published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)

Cardiomyocytes can be implanted to remuscularize the failing heart 1-7 . Challenges include sufficient cardiomyocyte retention for a sustainable therapeutic impact without intolerable side effects, such as arrhythmia and tumour growth. We investigated the hypothesis that epicardial engineered heart muscle (EHM) allografts from induced pluripotent stem cell-derived cardiomyocytes and stromal cells structurally and functionally remuscularize the chronically failing heart without limiting side effects in rhesus macaques. After confirmation of in vitro and in vivo (nude rat model) equivalence of the newly developed rhesus macaque EHM model with a previously established Good Manufacturing Practice-compatible human EHM formulation 8 , long-term retention (up to 6 months) and dose-dependent enhancement of the target heart wall by EHM grafts constructed from 40 to 200 million cardiomyocytes/stromal cells were demonstrated in macaques with and without myocardial infarction-induced heart failure. In the heart failure model, evidence for EHM allograft-enhanced target heart wall contractility and ejection fraction, which are measures for local and global heart support, was obtained. Histopathological and gadolinium-based perfusion magnetic resonance imaging analyses confirmed cell retention and functional vascularization. Arrhythmia and tumour growth were not observed. The obtained feasibility, safety and efficacy data provided the pivotal underpinnings for the approval of a first-in-human clinical trial on tissue-engineered heart repair. Our clinical data confirmed remuscularization by EHM implantation in a patient with advanced heart failure., Competing Interests: Competing interests: W.-H.Z. is the founder, equity holder and advisor of Repairon GmbH. M.T. is advisor of Repairon GmbH. Repairon is working towards market authorization of EHM as advanced therapy medicinal product for applications in heart failure. Repairon had no influence on the design, conduct and interpretation of the study. The other authors declare no competing interests., (© 2025. The Author(s), under exclusive licence to Springer Nature Limited.)

The MCL1 gene is frequently amplified in cancer and codes for the antiapoptotic protein myeloid cell leukemia 1 (MCL1), which confers resistance to the current standard of care. Therefore, MCL1 is an attractive anticancer target. Here we describe BRD-810 as a potent and selective MCL1 inhibitor and its key design principle of rapid systemic clearance to potentially minimize area under the curve-driven toxicities associated with MCL1 inhibition. BRD-810 induced rapid cell killing within 4 h in vitro but, in the same 4-h window, had no impact on cell viability or troponin I release in human induced pluripotent stem cell-derived cardiomyocytes, even at suprapharmacologic concentrations. In vivo BRD-810 induced efficacy in xenograft hematological and solid tumor models despite the short residence time of BRD-810 in plasma. In totality, our data support the hypothesis that short-term inhibition of MCL1 with BRD-810 can induce apoptosis in tumor cells while maintaining an acceptable safety profile. We, therefore, intend to advance BRD-810 to clinical trials., (© 2024. The Author(s).)

A subset of phosphodiesterase 3 (PDE3) inhibitors kills cancer cells that express both PDE3A and SLFN12 by inducing a protein-protein interaction between the two, triggering SLFN12 tRNase activity. Following discovery of the prototypical tool compound, DNMDP , an improved compound, BRD9500 , was discovered to be potent in cells and active in several tumor models in vivo . More analogs were prepared and tested with the goal of increasing metabolic stability and decreasing PDE3 inhibition while maintaining the cellular activity of BRD9500 . This led to the discovery of BAY 2666605 , a compound optimized for clinical testing., Competing Interests: The authors declare the following competing financial interest(s): T.L., L.d.W., X.W., H.G., and M.M. received past research funding from Bayer A.G. relevant to this work. T.L., L.d.W., X.W., H.G., and M.M also receive an inventor's share of license revenue as part of their employment for certain patent filings, which relate to aspects of the work described in this manuscript. The co-owners of those patent filings are The Broad Institute, Inc., Dana-Farber Cancer Institute, Inc., and Bayer Pharma A.G. M.M. is the scientific advisory board chair of Isabl; consults for Bayer, DelveBio, and Interline; and is an inventor of patents licensed to LabCorp and Bayer., (© 2024 American Chemical Society.)

Developmental and epileptic encephalopathies (DEEs) feature altered brain development, developmental delay and seizures, with seizures exacerbating developmental delay. Here we identify a cohort with biallelic variants in DENND5A, encoding a membrane trafficking protein, and develop animal models with phenotypes like the human syndrome. We demonstrate that DENND5A interacts with Pals1/MUPP1, components of the Crumbs apical polarity complex required for symmetrical division of neural progenitor cells. Human induced pluripotent stem cells lacking DENND5A fail to undergo symmetric cell division with an inherent propensity to differentiate into neurons. These phenotypes result from misalignment of the mitotic spindle in apical neural progenitors. Cells lacking DENND5A orient away from the proliferative apical domain surrounding the ventricles, biasing daughter cells towards a more fate-committed state, ultimately shortening the period of neurogenesis. This study provides a mechanism for DENND5A-related DEE that may be generalizable to other developmental conditions and provides variant-specific clinical information for physicians and families., (© 2024. The Author(s).)

This study describes the identification and target deconvolution of small molecule inhibitors of oncogenic Yes-associated protein (YAP1)/TAZ activity with potent anti-tumor activity in vivo. A high-throughput screen (HTS) of 3.8 million compounds was conducted using a cellular YAP1/TAZ reporter assay. Target deconvolution studies identified the geranylgeranyltransferase-I (GGTase-I) complex as the direct target of YAP1/TAZ pathway inhibitors. The small molecule inhibitors block the activation of Rho-GTPases, leading to subsequent inactivation of YAP1/TAZ and inhibition of cancer cell proliferation in vitro. Multi-parameter optimization resulted in BAY-593, an in vivo probe with favorable PK properties, which demonstrated anti-tumor activity and blockade of YAP1/TAZ signaling in vivo., Competing Interests: Declaration of interests K.G., B.B, S.P., J.N., J.W., R.L., K.B, B.N., W.B., S.G., S.K., C.K., H.S., N.B., K.N-R., C.S., P.S., M.L. are/were employees of Nuvisan ICB GmbH and Bayer Pharma AG. P.L., J.K., L.P., A.M., S.P., S.H., A.K., A.St., A.Sc., P.B., N.A.F., T.H., L.K., A.O.W., S.B., M.O., A. L., F.v.N., D.M., K.E. are/were employees of Bayer Pharma AG. This study was funded by Bayer Pharma AG. The following patent applications in relation to this study have been submitted: WO-2020048826-A1, WO-2020048830-A1, WO-2020048829-A1, WO-2020048828-A1, WO-2020048831-A1, WO-2020048827-A1. S.P. served as consultant for Bayer in relation to this study., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The fibroblast growth factor receptors comprise a family of related but individually distinct tyrosine kinase receptors. Within this family, FGFR2 is a key regulator in many biological processes, e.g., cell proliferation, tumorigenesis, metastasis, and angiogenesis. Heterozygous activating non-mosaic germline variants in FGFR2 have been linked to numerous autosomal dominantly inherited disorders including several craniosynostoses and skeletal dysplasia syndromes. We report on a girl with cutaneous nevi, ocular malformations, macrocephaly, mild developmental delay, and the initial clinical diagnosis of Schimmelpenning-Feuerstein-Mims syndrome, a very rare mosaic neurocutaneous disorder caused by postzygotic missense variants in HRAS, KRAS, and NRAS. Exome sequencing of blood and affected skin tissue identified the mosaic variant c.1647=/T > G p.(Asn549=/Lys) in FGFR2, upstream of the RAS signaling pathway. The variant is located in the tyrosine kinase domain of FGFR2 in a region that regulates the activity of the receptor and structural mapping and functional characterization revealed that it results in constitutive receptor activation. Overall, our findings indicate FGFR2-associated neurocutaneous syndrome as the accurate clinical-molecular diagnosis for the reported individual, and thereby expand the complex genotypic and phenotypic spectrum of FGFR-associated disorders. We conclude that molecular analysis of FGFR2 should be considered in the genetic workup of individuals with the clinical suspicion of a mosaic neurocutaneous condition, as the knowledge of the molecular cause might have relevant implications for genetic counseling, prognosis, tumor surveillance and potential treatment options., (© 2024. The Author(s).)

Background & Aims: The highly heterogeneous cellular and molecular makeup of pancreatic ductal adenocarcinoma (PDAC) not only fosters exceptionally aggressive tumor biology, but contradicts the current concept of one-size-fits-all therapeutic strategies to combat PDAC. Therefore, we aimed to exploit the tumor biological implication and therapeutic vulnerabilities of a clinically relevant molecular PDAC subgroup characterized by SMAD4 deficiency and high expression of the nuclear factor of activated T cells (SMAD4 -/- /NFATc1 High )., Methods: Transcriptomic and clinical data were analyzed to determine the prognostic relevance of SMAD4 -/- /NFATc1 High cancers. In vitro and in vivo oncogenic transcription factor complex formation was studied by immunoprecipitation, proximity ligation assays, and validated cross model and species. The impact of SMAD4 status on therapeutically targeting canonical KRAS signaling was mechanistically deciphered and corroborated by genome-wide gene expression analysis and genetic perturbation experiments, respectively. Validation of a novel tailored therapeutic option was conducted in patient-derived organoids and cells and transgenic as well as orthotopic PDAC models., Results: Our findings determined the tumor biology of an aggressive and chemotherapy-resistant SMAD4 -/- /NFATc1 High subgroup. Mechanistically, we identify SMAD4 deficiency as a molecular prerequisite for the formation of an oncogenic NFATc1/SMAD3/cJUN transcription factor complex, which drives the expression of RRM1/2. RRM1/2 replenishes nucleoside pools that directly compete with metabolized gemcitabine for DNA strand incorporation. Disassembly of the NFATc1/SMAD3/cJUN complex by mitogen-activated protein kinase signaling inhibition normalizes RRM1/2 expression and synergizes with gemcitabine treatment in vivo to reduce the proliferative index., Conclusions: Our results suggest that PDAC characterized by SMAD4 deficiency and oncogenic NFATc1/SMAD3/cJUN complex formation exposes sensitivity to a mitogen-activated protein kinase signaling inhibition and gemcitabine combination therapy., (Copyright © 2024 AGA Institute. Published by Elsevier Inc. All rights reserved.)

The branched-chain amino acid transaminases (BCATs) are enzymes that catalyze the first reaction of catabolism of the essential branched-chain amino acids to branched-chain keto acids to form glutamate. They are known to play a key role in different cancer types. Here, we report a new structural class of BCAT1/2 inhibitors, (trifluoromethyl)pyrimidinediones, identified by a high-throughput screening campaign and subsequent optimization guided by a series of X-ray crystal structures. Our potent dual BCAT1/2 inhibitor BAY-069 displays high cellular activity and very good selectivity. Along with a negative control (BAY-771), BAY-069 was donated as a chemical probe to the Structural Genomics Consortium.

Proteus syndrome is a very rare disorder with progressive, asymmetrical, and disproportionate overgrowth of body parts with a highly variable phenotype. It is associated with mosaicism for the recurrent heterozygous somatic gain-of-function variant c.49G>A (p.Glu17Lys) in the protein kinase AKT1. We report on a girl with a progressive intraosseous lipoma of the frontal bone and additional, nonspecific features including mild developmental delay, strabism, and a limbal dermoid of the left eye. She did not fulfill the criteria for a clinical diagnosis of Proteus syndrome. However, mutation analysis of AKT1 in a lipoma biopsy revealed this specific activating variant. Several cases of progressive intraosseous lipoma of the frontal bone have been reported in the literature. Only in two of these observations, a tentative diagnosis of Proteus syndrome was made, based on additional clinical features, although without molecular-genetic verification. We conclude that oligosymptomatic Proteus syndrome should be considered in progressive intraosseous lipoma, as recognition of this diagnosis has relevant implications for genetic counseling and opens novel treatment options with AKT1 inhibitors rather than surgical procedures., (© 2022 The Authors. Clinical Genetics published by John Wiley & Sons Ltd.)

Background: Benefits and challenges resulting from advances in genetic diagnostics are two sides of the same coin. Facilitation of a correct and timely diagnosis is paralleled by challenges in interpretation of variants of unknown significance (VUS). Focusing on an individual VUS-re-classification pipeline, this study offers a diagnostic approach for clinically suspected hereditary muscular dystrophy by combining the expertise of an interdisciplinary team., Methods: In a multi-step approach, a thorough phenotype assessment including clinical examination, laboratory work, muscle MRI and histopathological evaluation of muscle was performed in combination with advanced Next Generation Sequencing (NGS). Different in-silico tools and prediction programs like Alamut, SIFT, Polyphen, MutationTaster and M-Cap as well as 3D- modeling of protein structure and RNA-sequencing were employed to determine clinical significance of the LAMA2 variants., Results: Two previously unknown sequence alterations in LAMA2 were detected, a missense variant was classified initially according to ACMG guidelines as a VUS (class 3) whereas a second splice site variant was deemed as likely pathogenic (class 4). Pathogenicity of the splice site variant was confirmed by mRNA sequencing and nonsense mediated decay (NMD) was detected. Combination of the detected variants could be associated to the LGMDR23-phenotype based on the MRI matching and literature research., Discussion: Two novel variants in LAMA2 associated with LGMDR23-phenotype are described. This study illustrates challenges of the genetic findings due to their VUS classification and elucidates how individualized diagnostic procedure has contributed to the accurate diagnosis in the spectrum of LGMD., Competing Interests: Unrelated to this study SM has received payments for travel expenses from Alnylam, Kedrion, Momenta Pharmaceuticals, and Biogen. JS has received payments for advisory boards, speakers honoraria, travel expenses, research projects from Alnylam, Argenx, Biogen, BioMarin, Biotest, CSL Behring, Kezar, LFB, Novartis, Octapharma, Pfizer, and UCB. JZ has received payments for advisory boards, speakers honoraria, travel expenses, research projects from Alnylam, Biogen, Biotest, CSL Behring, Octapharma, Kedrion, Grifols, UCB, Hormosan, Alexion, and Sanofi. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Meyer, Kaulfuß, Zechel, Kummer, Seif Amir Hosseini, Ernst, Schmidt, Pauli and Zschüntzsch.)

Pancreatic Ductal Adenocarcinoma (PDAC) represents a lethal malignancy with a consistently poor outcome. Besides mutations in PDAC driver genes, the aggressive tumor biology of the disease and its remarkable therapy resistance are predominantly installed by potentially reversible epigenetic dysregulation. However, epigenetic regulators act in a context-dependent manner with opposing implication on tumor progression, thus critically determining the therapeutic efficacy of epigenetic targeting. Herein, we aimed at exploring the molecular prerequisites and underlying mechanisms of oncogenic Enhancer of Zeste Homolog 2 (EZH2) activity in PDAC progression. Preclinical studies in EZH2 proficient and deficient transgenic and orthotopic in vivo PDAC models and transcriptome analysis identified the TP53 status as a pivotal context-defining molecular cue determining oncogenic EZH2 activity in PDAC. Importantly, the induction of pro-apoptotic gene signatures and processes as well as a favorable PDAC prognosis upon EZH2 depletion were restricted to p53 wildtype (wt) PDAC subtypes. Mechanistically, we illustrate that EZH2 blockade de-represses CDKN2A transcription for the subsequent posttranslational stabilization of p53wt expression and function. Together, our findings suggest an intact CDKN2A -p53wt axis as a prerequisite for the anti-tumorigenic consequences of EZH2 depletion and emphasize the significance of molecular stratification for the successful implementation of epigenetic targeting in PDAC.

Rare variants in at least 10 genes, including BRCA1, BRCA2, PALB2, ATM, and CHEK2, are associated with increased risk of breast cancer; however, these variants, in combination with common variants identified through genome-wide association studies, explain only a fraction of the familial aggregation of the disease. To identify further susceptibility genes, we performed a two-stage whole-exome sequencing study. In the discovery stage, samples from 1528 breast cancer cases enriched for breast cancer susceptibility and 3733 geographically matched unaffected controls were sequenced. Using five different filtering and gene prioritization strategies, 198 genes were selected for further validation. These genes, and a panel of 32 known or suspected breast cancer susceptibility genes, were assessed in a validation set of 6211 cases and 6019 controls for their association with risk of breast cancer overall, and by estrogen receptor (ER) disease subtypes, using gene burden tests applied to loss-of-function and rare missense variants. Twenty genes showed nominal evidence of association (p-value < 0.05) with either overall or subtype-specific breast cancer. Our study had the statistical power to detect susceptibility genes with effect sizes similar to ATM, CHEK2, and PALB2, however, it was underpowered to identify genes in which susceptibility variants are rarer or confer smaller effect sizes. Larger sample sizes would be required in order to identify such genes.

Background: Developmental and epileptic encephalopathies (DEEs) represent a group of severe neurological disorders characterised by an onset of refractory seizures during infancy or early childhood accompanied by psychomotor developmental delay or regression. DEEs are genetically heterogeneous with, to date, more than 80 different genetic subtypes including DEE31 caused by heterozygous missense variants in DNM1 ., Methods: We performed a detailed clinical characterisation of two unrelated patients with DEE and used whole-exome sequencing to identify causative variants in these individuals. The identified variants were tested for cosegregation in the respective families., Results: We excluded pathogenic variants in known, DEE-associated genes. We identified homozygous nonsense variants, c.97C>T; p.(Gln33*) in family 1 and c.850C>T; p.(Gln284*) in family 2, in the DNM1 gene, indicating that biallelic, loss-of-function pathogenic variants in DNM1 cause DEE., Conclusion: Our finding that homozygous, loss-of-function variants in DNM1 cause DEE expands the spectrum of pathogenic variants in DNM1 . All parents who were heterozygous carriers of the identified loss-of-function variants were healthy and did not show any clinical symptoms, indicating that the type of mutation in DNM1 determines the pattern of inheritance., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Bloom syndrome (BS) is an autosomal recessive disorder with characteristic clinical features of primary microcephaly, growth deficiency, cancer predisposition, and immunodeficiency. Here, we report the clinical and molecular findings of eight patients from six families diagnosed with BS. We identified causative pathogenic variants in all families including three different variants in BLM and one variant in RMI1. The homozygous c.581&#95;582delTT;p.Phe194* and c.3164G>C;p.Cys1055Ser variants in BLM have already been reported in BS patients, while the c.572&#95;573delGA;p.Arg191Lysfs*4 variant is novel. Additionally, we present the detailed clinical characteristics of two cases with BS in which we previously identified the biallelic loss-of-function variant c.1255&#95;1259delAAGAA;p.Lys419Leufs*5 in RMI1. All BS patients had primary microcephaly, intrauterine growth delay, and short stature, presenting the phenotypic hallmarks of BS. However, skin lesions and upper airway infections were observed only in some of the patients. Overall, patients with pathogenic BLM variants had a more severe BS phenotype compared to patients carrying the pathogenic variants in RMI1, especially in terms of immunodeficiency, which should be considered as one of the most important phenotypic characteristics of BS., (© 2022 The Authors. Clinical Genetics published by John Wiley & Sons Ltd.)