Oncogenic and microenvironmental signals drive cell type specific apoptosis resistance in juvenile myelomonocytic leukemia.

Juvenile myelomonocytic leukemia (JMML) is caused by constitutively activated RAS signaling and characterized by increased proliferation and predominant myelomonocytic differentiation of hematopoietic cells. Using MxCre;Ptpn11 mice, which model human JMML, we show that RAS pathway activation affects apoptosis signaling through cell type-dependent regulation of BCL-2 family members. Apoptosis resistance observed in monocytes and granulocytes was mediated by overexpression of the anti-apoptotic and down-regulation of the pro-apoptotic members of the BCL-2 family.

CD21 B cells reveal a unique glycosylation pattern with hypersialylation and hyperfucosylation.

Background: The posttranslational modification of cellular macromolecules by glycosylation is considered to contribute to disease pathogenesis in autoimmune and inflammatory conditions. In a subgroup of patients with common variable immunodeficiency (CVID), the occurrence of such complications is associated with an expansion of naïve-like CD21 B cells during a chronic type 1 immune activation. The glycosylation pattern of B cells in CVID patients has not been addressed to date.

Improved Quantification of Circulating Tumor DNA in Translocation-Associated Myxoid Liposarcoma by Simultaneous Detection of Breakpoints and Single Nucleotide Variants.

Background: Myxoid liposarcomas (MLS) can exhibit a disseminated metastatic pattern, necessitating extensive diagnostics during follow-up. With no tumor markers available, early diagnosis of recurrences and tumor monitoring is difficult. The detection of circulating tumor DNA (ctDNA; liquid biopsy) in MLS with the characteristic translocations t(12;16) and t(12;22) can provide an additional diagnostic.

KDM5C and KDM5D mutations have different consequences in clear cell renal cell carcinoma cells.

KDM5C is commonly mutated in clear cell renal cell carcinomas (ccRCC) in men but rarely in women. Introducing KDM5C mutation into two male and two female KDM5C wild-type ccRCC cell lines caused different phenotypes and non-overlapping transcriptional consequences, indicative of context-dependent functions of KDM5C. We identify that loss of the Y chromosome, harbouring the KDM5C homologue KDM5D, occurs in most male KDM5C mutant ccRCCs.

Adiponectin reduces immune checkpoint inhibitor-induced inflammation without blocking anti-tumor immunity.

Immune-related adverse events (irAEs) in cancer patients receiving immune checkpoint inhibitors (ICIs) cause morbidity and necessitate cessation of treatment. Comparing irAE treatments, we find that anti-tumor immunity is preserved in mice after extracorporeal photopheresis (ECP) but reduced with glucocorticosteroids, TNFα blockade, and α4β7-integrin inhibition. Local adiponectin production elicits a tissue-specific effect by reducing pro-inflammatory T cell frequencies in the colon while sparing tumor-specific T cell development.

Integrated Analysis of Cell-Free DNA and Novel Protein Biomarkers for Stratification and Therapy Monitoring in Stage IV Pancreatic Cancer: A Preliminary Study.

Given the poor prognosis of metastatic pancreatic adenocarcinoma (mPDAC), closer disease monitoring through liquid biopsy, most frequently based on serial measurements of cell-free mutated ( cfDNA), has become a highly active research focus, aimed at improving patients' long-term outcomes. However, most of the available data show only a limited predictive and prognostic value of single-parameter-based methods. We hypothesized that a combined longitudinal analysis of cfDNA and novel protein biomarkers could improve risk stratification and molecular monitoring of patients with mPDAC.

Mutations in tumor suppressor genes Vhl and Rassf1a cause DNA damage, chromosomal instability and induce gene expression changes characteristic of clear cell renal cell carcinoma.

RASSF1A is frequently biallelically inactivated in clear cell renal cell carcinoma (ccRCC) due to loss of chromosome 3p and promoter hypermethylation. Here we investigated the cellular and molecular consequences of single and combined deletion of the Rassf1a and Vhl tumor suppressor genes to model the common ccRCC genotype of combined loss of function of RASSF1A and VHL. In mouse embryonic fibroblasts and in primary kidney epithelial cells, double deletion of Rassf1a and Vhl caused chromosomal segregation defects and increased formation of micronuclei, demonstrating that pVHL and RASSF1A function to maintain genomic integrity.

Efficacy of CTLA-4 checkpoint therapy is dependent on IL-21 signaling to mediate cytotoxic reprogramming of PD-1CD8 T cells.

The mechanisms underlying the efficacy of anti-programmed cell death protein 1 (PD-1) and anti-cytotoxic T lymphocyte-associated protein 4 (CTLA-4) therapy are incompletely understood. Here, by immune profiling responding PD-1CD8 T (T) cell populations from patients with advanced melanoma, we identified differential programming of T cells in response to combination therapy, from an exhausted toward a more cytotoxic effector program. This effect does not occur with anti-PD-1 monotherapy.

Alterations in the microenvironment of junctional epidermolysis bullosa keratinocytes: A gene expression study.

Integrin α6β4 subunits and type XVII collagen are critical transmembrane proteins involved in cell-matrix adhesion in skin, while laminin 332 serves as their ligand in the basement membrane zone (BMZ). Those proteins contribute to the composition of hemidesmosomes (HDs) and pathogenic variants in their corresponding genes cause junctional epidermolysis bullosa (JEB). Although the genotype-phenotype relationships in JEB have been extensively studied, the pathogenetic changes of extracellular matrix (ECM) and cell-matrix adhesion resulting from gene mutations remain unclear.

ZBTB18 regulates cytokine expression and affects microglia/macrophage recruitment and commitment in glioblastoma.

Glioma associated macrophages/microglia (GAMs) play an important role in glioblastoma (GBM) progression, due to their massive recruitment to the tumor site and polarization to a tumor promoting phenotype. GAMs secrete a variety of cytokines, which facilitate tumor cell growth and invasion, and prevent other immune cells from mounting an immune response against the tumor. Here, we demonstrate that zinc finger and BTB containing domain 18 (ZBTB18), a transcriptional repressor with tumor suppressive function in glioblastoma, impairs the production of key cytokines, which function as chemoattractant for GAMs.

Spatial single-cell profiling and neighbourhood analysis reveal the determinants of immune architecture connected to checkpoint inhibitor therapy outcome in hepatocellular carcinoma.

Background: The determinants of the response to checkpoint immunotherapy in hepatocellular carcinoma (HCC) remain poorly understood. The organisation of the immune response in the tumour microenvironment (TME) is expected to govern immunotherapy outcomes but spatial immunotypes remain poorly defined.

Objective: We hypothesised that the deconvolution of spatial immune network architectures could identify clinically relevant immunotypes in HCC.

Cyclin-dependent kinase 4 drives cystic kidney disease in the absence of mTORC1 signaling activity.

Progression of cystic kidney disease has been linked to activation of the mTORC1 signaling pathway. Yet the utility of mTORC1 inhibitors to treat patients with polycystic kidney disease remains controversial despite promising preclinical data. To define the cell intrinsic role of mTORC1 for cyst development, the mTORC1 subunit gene Raptor was selectively inactivated in kidney tubular cells lacking cilia due to simultaneous deletion of the kinesin family member gene Kif3A.

Oncogene-induced TIM-3 ligand expression dictates susceptibility to anti-TIM-3 therapy in mice.

Leukemia relapse is a major cause of death after allogeneic hematopoietic cell transplantation (allo-HCT). We tested the potential of targeting T cell (Tc) immunoglobulin and mucin-containing molecule 3 (TIM-3) for improving graft-versus-leukemia (GVL) effects. We observed differential expression of TIM-3 ligands when hematopoietic stem cells overexpressed certain oncogenic-driver mutations.

Safe and effective liver-directed AAV-mediated homology-independent targeted integration in mouse models of inherited diseases.

Liver-directed adeno-associated viral (AAV) vector-mediated homology-independent targeted integration (AAV-HITI) by CRISPR-Cas9 at the highly transcribed albumin locus is under investigation to provide sustained transgene expression following neonatal treatment. We show that targeting the 3' end of the albumin locus results in productive integration in about 15% of mouse hepatocytes achieving therapeutic levels of systemic proteins in two mouse models of inherited diseases. We demonstrate that full-length HITI donor DNA is preferentially integrated upon nuclease cleavage and that, despite partial AAV genome integrations in the target locus, no gross chromosomal rearrangements or insertions/deletions at off-target sites are found.

Oncogenic Calreticulin Induces Immune Escape by Stimulating TGFβ Expression and Regulatory T-cell Expansion in the Bone Marrow Microenvironment.

Increasing evidence supports the interplay between oncogenic mutations and immune escape mechanisms. Strategies to counteract the immune escape mediated by oncogenic signaling could provide improved therapeutic options for patients with various malignancies. As mutant calreticulin (CALR) is a common driver of myeloproliferative neoplasms (MPN), we analyzed the impact of oncogenic CALRdel52 on the bone marrow (BM) microenvironment in MPN.

Anti-PD-1 cancer immunotherapy induces central nervous system immune-related adverse events by microglia activation.

Cancer treatment with anti-PD-1 immunotherapy can cause central nervous system immune-related adverse events (CNS-irAEs). The role of microglia in anti-PD-1 immunotherapy-induced CNS-irAEs is unclear. We found that anti-PD-1 treatment of mice caused morphological signs of activation and major histocompatibility complex (MHC) class II up-regulation on microglia.

Targeting TGFβ-activated kinase-1 activation in microglia reduces CAR T immune effector cell-associated neurotoxicity syndrome.

Cancer immunotherapy with chimeric antigen receptor (CAR) T cells can cause immune effector cell-associated neurotoxicity syndrome (ICANS). However, the molecular mechanisms leading to ICANS are not well understood. Here we examined the role of microglia using mouse models and cohorts of individuals with ICANS.

[The collaborative project "Personalized medicine for oncology" (PM4Onco) as part of the Medical Informatics Initiative (MII)].

The collaborative project Personalized Medicine for Oncology (PM4Onco) was launched in 2023 as part of the National Decade against Cancer (NKD) and is executed within the Medical Informatics Initiative (MII). Its aim is to establish a sustainable infrastructure for the integration and use of data from clinical and biomedical research and therefore combines the experience and preliminary work of all four consortia of the MII and the leading oncology centers in Germany. The data provided by PM4Onco will be prepared in a suitable form to support decision making in molecular tumor boards.

On- and off-target effects of paired CRISPR-Cas nickase in primary human cells.

Undesired on- and off-target effects of CRISPR-Cas nucleases remain a challenge in genome editing. While the use of Cas9 nickases has been shown to minimize off-target mutagenesis, their use in therapeutic genome editing has been hampered by a lack of efficacy. To overcome this limitation, we and others have developed double-nickase-based strategies to generate staggered DNA double-strand breaks to mediate gene disruption or gene correction with high efficiency.

Lipocalin-2 expression identifies an intestinal regulatory neutrophil population during acute graft-versus-host disease.

Acute graft-versus-host disease (aGVHD) is a life-threatening complication of allogeneic hematopoietic cell transplantation (allo-HCT), for which therapeutic options are limited. Strategies to promote intestinal tissue tolerance during aGVHD may improve patient outcomes. Using single-cell RNA sequencing, we identified a lipocalin-2 (LCN2)-expressing neutrophil population in mice with intestinal aGVHD.