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result(s) for
"Oehler, Sebastian"
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Phenylalanine‐Based DNA‐Encoded Chemical Libraries for the Discovery of Potent and Selective Small Organic Ligands Against Markers of Cancer and Immune Cells
by
Migliorini, Francesca
,
Sabato, Emanuela
,
Cazzamalli, Samuele
in
Acids
,
Antigens
,
Biomarkers, Tumor - metabolism
2025
DNA‐encoded chemical libraries (DELs) are powerful tools for drug discovery, enabling the high‐throughput screening of vast libraries of small molecules against target proteins of pharmaceutical interest. Here, the synthesis of two new DELs, named FM‐DEL1 and FM‐DEL2, including 7′710 and 5′697’690 compounds, respectively is described. These libraries are constructed by installing one or two sets of building blocks on a phenylalanine central scaffold. FM‐DELs are screened against markers of prostate cancer, and renal cell carcinoma, and against an immunological target expressed on the surface of natural killer cells. Highly potent and selective binders with affinity constants in the nanomolar range are obtained from DEL screenings against those targets. Small‐molecule ligands against tumor‐associated antigens are used to develop small‐molecule radiopharmaceuticals that selectively accumulate at cancer sites after systemic administration. FM‐DEL1 and FM‐DEL2 are constructed by installing one or two sets of building blocks on a phenylalanine central scaffold. FM‐DELs are screened against markers of prostate, and renal cell carcinoma, and against an immunological target expressed on the surface of natural killer cells. Highly potent and selective binders with affinity constants in the nanomolar range are isolated for those targets.
Journal Article
Impact of the Ferroelectric Stack Lamination in Si Doped Hafnium Oxide (HSO) and Hafnium Zirconium Oxide (HZO) Based FeFETs: Toward High-Density Multi-Level Cell and Synaptic Storage
by
Müller, Johannes
,
Kühnel, Kati
,
Zimmermann, Katrin
in
Alumina
,
Chemical vapor deposition
,
Electrodes
2021
A multi-level cell (MLC) operation as a 1–3 bit/cell of the FeFET emerging memory is reported by utilizing optimized Si doped hafnium oxide (HSO) and hafnium zirconium oxide (HZO) based on ferroelectric laminates. An alumina interlayer was used to achieve the thickness independent of the HSO and HZO-based stack with optimal ferroelectric properties. Various split thicknesses of the HSO and HZO were explored with lamination to increase the FeFET maximum memory window (MW) for a practical MLC operation. A higher MW occurred as the ferroelectric stack thickness increased with lamination. The maximum MW (3.5 V) was obtained for the HZO-based laminate; the FeFETs demonstrated a switching speed (300 ns), 10 years MLC retention, and 104 MLC endurance. The transition from instant switching to increased MLC levels was realized by ferroelectric lamination. This indicated an increased film granularity and a reduced variability through the interruption of ferroelectric columnar grains. The 2–3 bit/cell MLC levels and maximum MW were studied in terms of the size-dependent variability to indicate the impact of the ferroelectric area scaling. The impact of an alumina interlayer on the ferroelectric phase is outlined for HSO in comparison to the HZO material. For the same ferroelectric stack thickness with lamination, a lower maximum MW, and a pronounced wakeup effect was observed in HSO laminate compared to the HZO laminate. Both wakeup effect and charge trapping were studied in the context of an MLC operation. The merits of ferroelectric stack lamination are considered for an optimal FeFET-based synaptic device operation. The impact of the pulsing scheme was studied to modulate the FeFET current to mimic the synaptic weight update in long-term synaptic potentiation/depression.
Journal Article
Cross-reactivity to glutamate carboxypeptidase III causes undesired salivary gland and kidney uptake of PSMA-targeted small-molecule radionuclide therapeutics
2023
PurposeRecently, Pluvicto™ ([177Lu]Lu-PSMA-617), a small-molecule prostate-specific membrane antigen (PSMA) radioligand therapeutic, has been approved by the FDA in metastatic castration-resistant prostate cancer. Pluvicto™ and other PSMA-targeting radioligand therapeutics (RLTs) have shown side effects due to accumulation in certain healthy tissues, such as salivary glands and kidney. Until now, the molecular mechanism underlying the undesired accumulation of PSMA-targeting RLTs had not been elucidated.MethodsWe compared the sequence of PSMA with the entire human proteome to identify proteins closely related to the target. We have identified glutamate carboxypeptidase III (GCPIII), N-acetylated alpha-linked acidic dipeptidase like 1 (NAALADL-1), and transferrin receptor 1 (TfR1) as extracellular targets with the highest similarity to PSMA. The affinity of compound 1 for PSMA, GCPIII, NAALADL-1, and TfR1 was measured by fluorescence polarization. The expression of the putative anti-target GCPIII was assessed by immunofluorescence on human salivary glands and kidney, using commercially available antibodies.ResultsA fluorescent derivative of Pluvicto™ (compound 1) bound tightly to PSMA and to GCPIII in fluorescence polarization experiments, while no interaction was observed with NAALADL-1 and TfR1. Immunofluorescence analysis revealed abundant expression of GCPIII both in healthy human kidney and salivary glands.ConclusionWe conclude that the membranous expression of GCPIII in kidney and salivary gland may be the underlying cause for unwanted accumulation of Pluvicto™ and other Glu-ureido PSMA radio pharmaceuticals in patients.
Journal Article
A DNA-encoded chemical library based on chiral 4-amino-proline enables stereospecific isozyme-selective protein recognition
by
Puglioli, Sara
,
Matasci, Mattia
,
Prati, Luca
in
Antigen (tumor-associated)
,
Antigens
,
Carboxylic acids
2023
DNA-encoded chemical libraries (DELs) consist of large chemical compound collections individually linked to DNA barcodes, facilitating pooled construction and screening. However, screening campaigns often fail if the molecular arrangement of the building blocks is not conducive to an efficient interaction with a protein target. Here we postulated that the use of rigid, compact and stereo-defined central scaffolds for DEL synthesis may facilitate the discovery of very specific ligands capable of discriminating between closely related protein targets. We synthesized a DEL comprising 3,735,936 members, featuring the four stereoisomers of 4-aminopyrrolidine-2-carboxylic acid as central scaffolds. The library was screened in comparative selections against pharmaceutically relevant targets and their closely related protein isoforms. Hit validation results revealed a strong impact of stereochemistry, with large affinity differences between stereoisomers. We identified potent isozyme-selective ligands against multiple protein targets. Some of these hits, specific to tumour-associated antigens, demonstrated tumour-selective targeting in vitro and in vivo. Collectively, constructing DELs with stereo-defined elements contributed to high library productivity and ligand selectivity.The design and construction of a stereo-defined DNA-encoded chemical library, featuring the four different 4-amino-proline stereoisomers as a central scaffold, has now enabled the discovery of potent ligands to proteins of pharmaceutical interest. Parallel screening with closely related isoforms (anti-targets) facilitated the isolation of hits with high selectivity ratios.
Journal Article
A deep learning approach for the discovery of tumor-targeting small organic ligands from DNA-Encoded Chemical Libraries
by
Watson, Ian
,
Prati, Luca
,
Cazzamalli, Samuele
in
Bioinformatics
,
Clear cell-type renal cell carcinoma
,
Deep learning
2023
DNA-Encoded Chemical Libraries (DELs) emerged as efficient and cost-effective ligand discovery tools, which enable the generation of protein-ligand interaction data of unprecedented size. In this article, we present an approach that combines DEL screening and instance-level deep learning modeling to identify tumor-targeting ligands against Carbonic Anhydrase IX (CAIX), a clinically validated marker of hypoxia and clear cell Renal Cell Carcinoma. We present a new ligand identification and HIT-to-LEAD strategy driven by Machine Learning (ML) models trained on DELs, which expand the scope of DEL-derived chemical motifs. CAIX screening datasets obtained from three different DELs were used to train ML models for generating novel HITs, dissimilar to elements present in the original DELs. Out of the 152 novel potential HITs that were identified with our approach and screened in an in vitro enzymatic inhibition assay, 70% displayed submicromolar activities (IC50 < 1 uM). Based on the first HIT set, the model was further used to prioritize and generate LEAD compounds with nanomolar affinity for in vivo tumor-targeting applications. Three LEAD candidates showed accumulation on the surface of CAIX-expressing tumor cells in cellular binding assays. The best compound displayed in vitro KD of 5.7 nM and selectively targeted tumors in mice bearing human Renal Cell Carcinoma lesions. Our results demonstrate the synergy between DEL and machine learning for the identification of novel HITs and for the successful translation of LEAD candidates for in vivo targeting applications.Competing Interest StatementD.N. is the cofounder, C.E.O. and C.S.O. of Philogen S.p.A.. I.B., S.O., L.P., G.B., N.F. and S.C. are employees of Philochem AG, the Research and Development unit of the Philogen group. B.M. performed work related to this article during his internship at Philochem AG. W.T., J.X., I.W., J.F. are current or former employees at Google LLC.
Anti-CSF-1R therapy with combined immuno-chemotherapy coordinate an adaptive immune response to eliminate macrophage enriched triple negative breast cancers
2026
Women diagnosed with metastatic triple negative breast cancer (mTNBC) have limited treatment options, are more prone to develop resistance and are associated with high mortality. A cold tumor immune microenvironment (TIME) characterized by low T cells and high tumor associated macrophages (TAMs) in mTNBC is associated with the failure of standard-of-care chemotherapy and immune checkpoint blockade (ICB) treatment. We demonstrate that the combination of immunomodulatory low-dose Cyclophosphamide (CTX) coupled with anti-CSF-1R antibody targeted therapy (SNDX-ms6352) and anti-PD-1 (ICB), was highly effective against aggressive metastatic
Trp53
null TNBC transplantable syngeneic models that present with high macrophage infiltration. Mechanistically, CSF-1R inhibition along with CTX disrupted the M-CSF/CSF-1R axis which upregulated IL-17, IL-5 and type II interferon resulting in elevated B- and T cell infiltration. Addition of an anti-PD-1 maintenance dose helped overcome de novo PD-L1 intra-tumoral heterogeneity (ITH) associated recurrence in lung and liver mTNBC.
Metastatic triple negative breast cancer (mTNBC) has limited treatments options. Here, this group presents a combination of low-dose cyclophosphamide, anti-CSF1R, and anti-PD-1 therapies to boost immune cell infiltration and reduce recurrence in aggressive TNBC models.
Journal Article
Bone microstructure is significantly altered in CRPS-affected distal tibiae as detected by HR-pQCT: a retrospective cross-sectional study
by
Oehler, Nicola
,
Rolvien, Tim
,
Butscheidt, Sebastian
in
25-Hydroxyvitamin D
,
Alkaline phosphatase
,
Atrophy
2019
In the course of complex regional pain syndrome (CRPS), local osteopenia in the subchondral/subcortical areas of the affected limb represents a central manifestation. Mechanistic aspects of CRPS-associated pathologies remain unclear, and knowledge about bone morphology in CRPS-affected areas is rare. The aim of this study was to assess trabecular and cortical bone microstructure in patients with CRPS of the distal tibiae. We retrospectively analysed 14 women diagnosed with unilateral CRPS type I of the lower limb whose affected and unaffected distal tibiae were examined by high-resolution peripheral quantitative computed tomography (HR-pQCT). Laboratory tests included serum levels of calcium, phosphate, 25-hydroxyvitamin D, bone alkaline phosphatase, parathyroid hormone, osteocalcin and urinary levels of deoxypyridinoline (DPD). Bone mineral density was measured by dual-energy X-ray absorptiometry (DXA) at the lumbar spine and both proximal femurs. Average urinary DPD levels, a biochemical marker of bone resorption, were elevated in the examined patient cohort (7.1 ± 1.9 nmol/mmol, reference 3.0–7.0 nmol/mmol). According to HR-pQCT, CRPS-affected distal tibiae showed significantly lower values of cortical BMD and cortical thickness compared to the unaffected contralateral side. Also, bone volume relative to total volume was significantly lower. Trabecular number and trabecular thickness tended to be lower in the affected tibiae. CRPS is associated with significant alterations in bone microstructure of the affected tibiae. Increased bone resorption seems to play a crucial role within a multifactorial process of CRPS-mediated bone atrophy. HR-pQCT could possibly serve as a diagnostic tool in specific CRPS therapy.
Journal Article
Effectiveness of Self-guided Tailored Implementation Strategies in Integrating and Embedding Internet-Based Cognitive Behavioral Therapy in Routine Mental Health Care: Results of a Multicenter Stepped-Wedge Cluster Randomized Trial
2023
Internet-based cognitive behavioral therapy (iCBT) services for common mental health disorders have been found to be effective. There is a need for strategies that improve implementation in routine practice. One-size-fits-all strategies are likely to be ineffective. Tailored implementation is considered as a promising approach. The self-guided integrated theory-based Framework for intervention tailoring strategies toolkit (ItFits-toolkit) supports local implementers in developing tailored implementation strategies. Tailoring involves identifying local barriers; matching selected barriers to implementation strategies; developing an actionable work plan; and applying, monitoring, and adapting where necessary.
This study aimed to compare the effectiveness of the ItFits-toolkit with implementation-as-usual (IAU) in implementing iCBT services in 12 routine mental health care organizations in 9 countries in Europe and Australia.
A stepped-wedge cluster randomized trial design with repeated measures was applied. The trial period lasted 30 months. The primary outcome was the normalization of iCBT delivery by service providers (therapists, referrers, IT developers, and administrators), which was measured with the Normalization Measure Development as a proxy for implementation success. A 3-level linear mixed-effects modeling was applied to estimate the effects. iCBT service uptake (referral and treatment completion rates) and implementation effort (hours) were used as secondary outcomes. The perceived satisfaction (Client Satisfaction Questionnaire), usability (System Usability Scale), and impact of the ItFits-toolkit by implementers were used to assess the acceptability of the ItFits-toolkit.
In total, 456 mental health service providers were included in this study. Compared with IAU, the ItFits-toolkit had a small positive statistically significant effect on normalization levels in service providers (mean 0.09, SD 0.04; P=.02; Cohen d=0.12). The uptake of iCBT by patients was similar to that of IAU. Implementers did not spend more time on implementation work when using the ItFits-toolkit and generally regarded the ItFits-toolkit as usable and were satisfied with it.
The ItFits-toolkit performed better than the usual implementation activities in implementing iCBT services in routine practice. There is practical utility in the ItFits-toolkit for supporting implementers in developing and applying effective tailored implementation strategies. However, the effect on normalization levels among mental health service providers was small. These findings warrant modesty regarding the effectiveness of self-guided tailored implementation of iCBT services in routine practice.
ClinicalTrials.gov NCT03652883; https://clinicaltrials.gov/ct2/show/NCT03652883.
RR2-10.1186/s13063-020-04686-4.
Journal Article
Mutant huntingtin impairs neurodevelopment in human brain organoids through CHCHD2-mediated neurometabolic failure
2024
Expansion of the glutamine tract (poly-Q) in the protein huntingtin (HTT) causes the neurodegenerative disorder Huntington’s disease (HD). Emerging evidence suggests that mutant HTT (mHTT) disrupts brain development. To gain mechanistic insights into the neurodevelopmental impact of human mHTT, we engineered male induced pluripotent stem cells to introduce a biallelic or monoallelic mutant 70Q expansion or to remove the poly-Q tract of HTT. The introduction of a 70Q mutation caused aberrant development of cerebral organoids with loss of neural progenitor organization. The early neurodevelopmental signature of mHTT highlighted the dysregulation of the protein coiled-coil-helix-coiled-coil-helix domain containing 2 (CHCHD2), a transcription factor involved in mitochondrial integrated stress response. CHCHD2 repression was associated with abnormal mitochondrial morpho-dynamics that was reverted upon overexpression of CHCHD2. Removing the poly-Q tract from HTT normalized CHCHD2 levels and corrected key mitochondrial defects. Hence, mHTT-mediated disruption of human neurodevelopment is paralleled by aberrant neurometabolic programming mediated by dysregulation of CHCHD2, which could then serve as an early interventional target for HD.
Using brain organoids models, Prigione and colleagues uncovered the impact of Huntington’s disease on human brain developmental and identified early dysregulation of CHCHD2, which disrupted mitochondria and might serve as a therapeutic target.
Journal Article