German Cancer Research Center

Therapy-induced senescence (TIS) is a stable cell cycle arrest in cancerous cells favoring immune control upon immune cell recruitment and activation via a senescence-associated secretory phenotype (SASP). Numerous studies have investigated the therapeutic applicability of TIS in hepatocellular carcinoma (HCC), a frequent cancer with high morbidity and mortality. Despite these efforts, a comprehensive understanding of how TIS may expose vulnerabilities specifically for immunotherapies, a potent means of cancer therapy, in HCC remains incomplete. Therefore, we conducted systematic studies to carefully characterize actionable and shared SASP- or other senescence-associated molecular parameters of TIS. We systematically compared the TIS inducers, etoposide and alisertib with a novel TIS inducer, CX5461, for their effects on SASP, surfaceome and innate immune clearance of representative human HCC cell lines. Surprisingly, all three compounds induced both metastasis surface antigens but also immunotherapeutically tractable antigens like CD95 (Fas), CD276 (B7-H3) and CD340 (Her2). This was verified in four representative HCC cell lines and publicly available datasets of HCC. Interestingly, alisertib, etoposide and CX5461 rendered senescent HCC vulnerable to be targeted by either T-cell-engaging bispecific antibodies or CAR NK cells. Collectively, our study indicates that heterogenous, but selective features of HCC senescence may be exploited by different immunotherapeutic approaches.

Centriole duplication is regulated by polo-like kinase 4 (PLK4) and several conserved initiator proteins. The precise timing and regulation of PLK4 activation are critical for ensuring that centriole duplication occurs only once per cell cycle. While significant progress has been made in understanding how PLK4 is activated, many aspects remain unclear. Here, we show how CEP152 contributes to the activation of PLK4. We utilize human cell lines that have been genetically engineered to rapidly degrade CEP152. Upon degradation of CEP152, localization of PLK4 at the proximal end of the centriole is disrupted. We show that binding of CEP152 N-terminal part to PLK4 increases phosphorylation and kinase activation. CEP152 controls the localization and levels of phosphorylated PLK4 at the proximal end of the centriole. CEP152 binding to PLK4 leads to phosphorylation and activation of PLK4 which might stabilize PLK4 dimer formation, thus allowing autophosphorylation. We propose that CEP152 activates PLK4 to ensure proper centriole duplication at the onset of S-phase.

Background Inflammatory bowel disease (IBD) is a group of chronic inflammatory disorders, including ulcerative colitis (UC) and Crohn’s disease, affecting the gastrointestinal tract and is associated with high morbidity and mortality. Accumulating evidence indicates that IBD not only impacts the gastrointestinal tract but also affects multiple extraintestinal organs, which may manifest prior to the diagnosis of IBD. Among these extraintestinal manifestations associated with IBD, primary sclerosing cholangitis (PSC) stands out as a prominent example. PSC is recognized as a progressive cholestatic disorder, characterized by the narrowing of bile ducts, eventual development of liver cirrhosis, end-stage liver disease, and the potential emergence of cholangiocarcinoma. This study aimed to identify the molecular contributors in UC-induced PSC by detecting the essential regulatory genes that are differentially expressed in both diseases. Materials and methods The common single-nucleotide polymorphisms (SNPs) and differentially expressed genes (DEGs) were detected using DisGeNET and GEO databases, respectively. Then, the top module and hub genes within the protein–protein interaction network were identified. Furthermore, the co-expression network of the top module was constructed using the HIPPIE database. Additionally, the gene regulatory network was constructed based on miRNAs and circRNAs. Finally, we searched the DGIdb database for possible interacting drugs with UC-PSC top module genes. Results A total of 132 SNPs and their associated genes were found to be shared between UC and PSC. Gene expression analysis identified 56 common DEGs between the two diseases. Following functional enrichment analysis, 207 significant biological processes (BP), 48 molecular functions (MF), and 8 KEGG pathways, with notable enrichment in mRNA-related processes such as mRNA splicing and RNA binding, were defined. Particularly, the PTPN2 gene was the only gene common between UC and PSC at both the SNP level and the expression level. Additionally, the top cluster of PPI network analysis was consisted of PABPC1, SNRPA1, NOP56, NHP2L1, and HNRNPA2B1 genes. Finally, ceRNA network involving 4 mRNAs, 94 miRNAs, and 200 selected circRNAs was constructed. Conclusion The present study provides novel potential candidate genes that may be involved in the molecular association between ulcerative colitis and primary sclerosing cholangitis, resulting in the development of diagnostic tools and therapeutic targets to prevent the progression of PSC from UC.

Embryonic macrophages emerge before the onset of definitive hematopoiesis, seed into discrete tissues and contribute to specialized resident macrophages throughout life. Presence of embryonic macrophages in the bone marrow and functional impact on hematopoietic stem cells (HSC) or the niche remains unclear. Here we show that bone marrow macrophages consist of two ontogenetically distinct cell populations from embryonic and adult origin. Newborn mice lacking embryonic macrophages have decreased HSC numbers in the bone marrow suggesting an important function for embryo-derived macrophages in orchestrating HSC trafficking around birth. The establishment of a normal cellular niche space in the bone marrow critically depends on embryonic macrophages that are important for the development of mesenchymal stromal cells, but not other non-hematopoietic niche cells, providing evidence for a specific role for embryo-derived macrophages in the establishment of the niche environment pivotal for the establishment of a normally sized HSC pool.

Durable clinical responses to immune checkpoint inhibitors (ICI) are limited to a minority of patients, and molecular pathways that modulate their efficacy remain incompletely defined. We have recently shown that activation of the innate RNA-sensing receptor RIG-I and associated apoptotic tumor cell death can facilitate tumor immunosurveillance and -therapy, but the mechanism that drives its immunogenicity remained unclear. We here show that intratumoral activity of the pore-forming protein gasdermin E (GSDME) links active RIG-I signaling and apoptotic cell death in tumor cells to inflammatory pyroptosis. Activation of tumor-intrinsic RIG‑I triggered cleavage of GSDME, pore formation, loss of cell membrane integrity and leakage of cytosolic components from dying tumor cells. Tumor antigen cross-presentation by dendritic cells and subsequent expansion of cytotoxic T cells strongly relied on tumor-intrinsic GSDME activity. In preclinical murine cancer models, defective GSDME signaling rendered tumors resistant to ICI therapy. Epigenetic reprogramming with upregulation of Gdsme enhanced the susceptibility of tumor cells to inflammatory cell death and immunotherapy. In humans, transcriptome analysis of melanoma samples showed strong correlation between genetic activity of the RIG-I and pyroptosis pathways. In melanoma patients, high transcriptional activity of a pyroptosis gene set was associated with prolonged survival and beneficial response to ICI therapy. In summary, our data show that GSDME links RIG-I and apoptotic signaling to inflammatory cell death, thereby driving its immunogenicity and responsiveness to ICI. A deeper understanding of these pathways may allow for the development of novel combined modality approaches to improve ICI treatment responses in cancer patients.

Background While metabolic pathway alterations are linked to colorectal cancer (CRC), the predictive value of pre-diagnostic metabolomic profiling in CRC risk assessment remains to be clarified. This study evaluated the predictive performance of a metabolomics risk panel (MRP) both independently and in combination with established risk factors. Methods We derived, internally validated (IV), and externally validated (EV) a metabolomics risk panel (MRP) for CRC from data of the UK Biobank (UKB) and the German ESTHER cohort. Baseline blood samples were assessed for 249 metabolites using nuclear magnetic resonance spectroscopy analysis. We applied LASSO Cox proportional hazards regression to identify metabolites for inclusion in the MRP and evaluated the model performance using the concordance index (C-index). We compared the performance of the MRP to an environmental risk panel (ERP; sex, age, body mass index, smoking status, and alcohol consumption) and a genetic risk panel (GRP; polygenic risk score). Results The study included 154,892 participants of the UKB cohort (mean age at baseline 54.5 years; 55.5% female) with 1879 incident CRC and 3242 participants of the ESTHER cohort (mean age 61.5 years; 52.2% female) with 103 CRC cases. Twenty-three metabolites, primarily amino acid and lipid-related metabolites, were selected for the MRP, showing moderate predictive performance (C-index 0.60 [IV] and 0.54 [EV]). The ERP and GRP showed superior performance, with C-index values of 0.73 (IV) and 0.69 (EV). Adding the MRP to these risk models did not change the C-indices in both cohorts. Conclusions Genetic and environmental risk information provided strong predictive accuracy for CRC risk, with no improvements from adding metabolomics data. These findings suggest that metabolomics data may have limited impact on enhancing established CRC risk models in clinical practice.

Background Cancer-related fatigue (CRF) is a common symptom in breast cancer patients and survivors, which can substantially impair quality of life. Previous studies suggested that CRF may be associated with poorer survival outcomes, but had limited follow-up duration or insufficient adjustment for established prognostic factors. The aim of this analysis was to assess the prognostic value of CRF at the end of radiotherapy for overall survival in a cohort of women with breast cancer with a median follow-up time of 19 years. Methods Data from the prospective ISE study, which enrolled women with non-metastatic breast cancer between 1998 and 2001, were analysed. Patients did not receive chemotherapy. A vital status follow-up was conducted in 2019. CRF was collected at the end of radiotherapy using the EORTC QLQ-C30 and classified using the threshold of clinical importance. Cox regression models adjusted for CRF, age, body mass index (BMI), tumour size, nodal involvement, grading and receptor status were calculated. Results Of 437 patients with fatigue assessments, 164 (38%) reported CRF. During 10 years of follow-up, 25 patients without and 27 patients with CRF died. Tumour size, nodal involvement and age were statistically significantly associated with 10-year overall survival. For CRF, a statistically significant effect was observed for ≥ 5 years of follow-up (HR: 2.44), but not within the first 5 years of follow-up (HR: 1.26). Conclusions CRF assessments at the end of radiotherapy showed prognostic value for long-term survival beyond established factors and could potentially be used to identify patients that require monitoring in risk-adapted aftercare programmes in order to improve survival.

Introduction Sexually transmitted infections caused by Chlamydia trachomatis and Mycoplasma genitalium can have significant implications during early childhood. This study aimed to assess maternal antibodies to C. trachomatis and M. genitalium in newborns, their vanishing, and offspring's own seroconversion to these pathogens during the first 3 years of life. Material and Methods Altogether, 309 mother‐neonate pairs originally enrolled in the prospective Finnish Family HPV (FFHPV) cohort study at Turku University Hospital, Finland, were analyzed for serum IgG antibodies to plasmid protein gene 3 (pGP3) for C. trachomatis and M. genitalium protein of adhesion (MgPa N‐term) and recombinant MgPa for M. genitalium using multiplex serology, by serial sampling during a 3‐year follow‐up. Results A significant correlation between maternal and neonate antibodies to both C. trachomatis and M. genitalium was evident up to 2 months after birth and to C. trachomatis also at 6 months (p < 0.001). During the first 3 years of life, three children seroconverted IgG antibodies to C. trachomatis and one to M. genitalium. At the last (36‐month) follow‐up visit, five (2.1%) children were seropositive for C. trachomatis and only one (0.4%) for M. genitalium. Conclusions Both C. trachomatis and M. genitalium IgG antibodies are transferred from the mother to her offspring during pregnancy; similarly, this is shown for nearly all maternal IgG antibodies. Seroconversion for both C. trachomatis and M. genitalium in early childhood was a rare event. Further studies are required to elucidate the significance of C. trachomatis and M. genitalium antibodies acquired in early life.

Head and neck (HN) tumors are responsible for approximately 4% of annual new cancer cases worldwide. Besides surgery, radiochemotherapy, particularly fractionated radiotherapy (RT), is the gold-standard treatment modality for these cancers. However, there is currently no reliable early measure of success available to further personalize treatment plans. This work aims to address this critical bottleneck by pioneering the use of photoacoustic imaging (PAI) to measure treatment response in HN cancer patients undergoing RT. PAI leverages the photoacoustic effect in order to non-invasively recover functional tissue properties in depths of up to several centimeters. We hypothesized that oxygen saturation ([Formula: see text]), hemoglobin concentration, and water content, as measured by PAI, would non-invasively reflect expected RT treatment effects, namely reoxygenation of lymph nodes (hypothesis H1), inflammation of surrounding organs (H2) and xerostomia (H3). Our study with n = 30 human subjects showed notable changes in [Formula: see text], hemoglobin concentration, and water levels in HN tumor patients resulting from disease treatment. Our data confirmed hypotheses H2 and H3, while an observed decrease in [Formula: see text] over the treatment course contradicted our prior assumptions (H1). A comprehensive analysis based on device and tissue digital twins, however, revealed that low blood volume fraction as encountered in malignant nodes, can lead to particularly high [Formula: see text] prediction errors, indicating that the measured [Formula: see text] values cannot be trusted within these regions. We conclude that our study is the first to show that PAI is capable of measuring early molecular changes induced by RT in human tissue non-invasively. Further studies are now needed to convert the potential of the new imaging technique into patient benefit.

Purpose Shortcut learning has been identified as a source of algorithmic unfairness in medical imaging artificial intelligence (AI), but its impact on photoacoustic tomography (PAT), particularly concerning sex bias, remains underexplored. This study investigates this issue using peripheral artery disease (PAD) diagnosis as a specific clinical application. Methods To examine the potential for sex bias due to shortcut learning in convolutional neural network (CNNs) and assess how such biases might affect diagnostic predictions, we created training and test datasets with varying PAD prevalence between sexes. Using these datasets, we explored (1) whether CNNs can classify the sex from imaging data, (2) how sex-specific prevalence shifts impact PAD diagnosis performance and underdiagnosis disparity between sexes, and (3) how similarly CNNs encode sex and PAD features. Results Our study with 147 individuals demonstrates that CNNs can classify the sex from calf muscle PAT images, achieving an AUROC of 0.75. For PAD diagnosis, models trained on data with imbalanced sex-specific disease prevalence experienced significant performance drops (up to 0.21 AUROC) when applied to balanced test sets. Additionally, greater imbalances in sex-specific prevalence within the training data exacerbated underdiagnosis disparities between sexes. Finally, we identify evidence of shortcut learning by demonstrating the effective reuse of learned feature representations between PAD diagnosis and sex classification tasks. Conclusion CNN-based models trained on PAT data may engage in shortcut learning by leveraging sex-related features, leading to biased and unreliable diagnostic predictions. Addressing demographic-specific prevalence imbalances and preventing shortcut learning is critical for developing models in the medical field that are both accurate and equitable across diverse patient populations.

BACKGROUND Clinical management of heart failure with preserved ejection fraction (HFpEF) is hindered by a lack of disease-modifying therapies capable of altering its distinct pathophysiology. Despite the widespread implementation of a 2-hit model of cardiometabolic HFpEF to inform precision therapy, which utilizes ad libitum high-fat diet and 0.5% N(ω)-nitro-L-arginine methyl ester, we observe that C57BL6/J mice exhibit less cardiac diastolic dysfunction in response to high-fat diet and 0.5% N(ω)-nitro-L-arginine methyl ester. METHODS Genetic strain-specific single-nucleus transcriptomic analysis identified disease-relevant genes that enrich oxidative metabolic pathways within cardiomyocytes. Because C57BL/6J mice are known to harbor a loss-of-function mutation affecting the inner mitochondrial membrane protein Nnt (nicotinamide nucleotide transhydrogenase), we used an isogenic model of Nnt loss-of-function to determine whether intact NNT is necessary for the pathological cardiac manifestations of high-fat diet and 0.5% N(ω)-nitro-L-arginine methyl ester. Twelve-week-old mice cross-bred to isolate wild-type ( Nnt +/+ ) or loss-of-function ( Nnt ⁻ / ⁻ ) Nnt in the C57BL/6N background were challenged with high-fat diet and 0.5% N(ω)-nitro-L-arginine methyl ester for 9 weeks (n=6–10). RESULTS Nnt +/+ mice exhibited impaired ventricular diastolic relaxation and pathological remodeling, as assessed via E/e′ (42.8 versus 21.5, P =1.2×10 ⁻ ¹⁰ ), E/A (2.3 versus 1.4, P =4.1×10 ⁻ ² ), diastolic stiffness (0.09 versus 0.04 mm Hg/μL, P =5.1×10 ⁻ ³ ), and myocardial fibrosis ( P =2.3×10 ⁻ ² ). Liquid chromatography and mass spectroscopy exposed a 40.0% reduction in NAD ⁺ ( P =8.4×10 ⁻ ³ ) and a 38.8% reduction in glutathione:GSSG ( P =2.6×10 ⁻ ² ) among Nnt +/+ mice after high-fat diet and 0.5% N(ω)-nitro-L-arginine methyl ester feeding. Using single-nucleus ligand-receptor analysis, we implicate Fgf1 (fibroblast growth factor 1) as a putative NNT-dependent mediator of cardiomyocyte-to-fibroblast signaling of myocardial fibrosis. CONCLUSIONS Together, these findings underscore the pivotal role of mitochondrial dysfunction in HFpEF pathogenesis, implicating both NNT and Fgf1 as novel therapeutic targets.