Extracellular Targets Research Articles

Investigation of antibacterial mode of action of ω-aminoalkoxylxanthones by NMR-based metabolomics and molecular docking.

The knowledge of the mode of action of an antimicrobial is essential for drug development and helps to fight against bacterial resistance. Thus, it is crucial to use analytical techniques to study the mechanism of action of substances that have potential to act as antibacterial agents OBJECTIVE: To use NMR-based metabolomics combined with chemometrics and molecular docking to identify the metabolic responses of Staphylococcus aureus following exposure to commercial antibiotics and some synthesized ω-aminoalkoxylxanthones. Intracellular metabolites of S. aureus were extracted after treatment with four commercial antibiotics and three synthesized ω-aminoalkoxylxanthones. NMR spectra were obtained and 1HNMR data was analyzed using both unsupervised and supervised algorithms (PCA and PLS-DA, respectively). Docking simulations on DNA topoisomerase IV protein were also performed for the ω-aminoalkoxylxanthones. Through chemometric analysis, we distinguished between the control group and antibiotics with extracellular (ampicillin) and intracellular targets (kanamycin, tetracycline, and ciprofloxacin). We identified 21 metabolites, including important metabolites that differentiate the groups, such as betaine, acetamide, glutamate, lysine, alanine, isoleucine/leucine, acetate, threonine, proline, and ethanol. Regarding the xanthone-type derivatives (S6, S7 and S8), we observed a greater similarity between S7 and ciprofloxacin, which targets bacterial DNA replication. The molecular docking analysis showed high affinity of the ω-aminoalkoxylxanthones with the topoisomerase IV enzyme, as well as ciprofloxacin. NMR-based metabolomics has shown to be an effective technique to assess the metabolic profile of S. aureus after treatment with certain antimicrobial compounds, helping the investigation of their mechanism of action.

Abstract C012: Dissemination of retrotransposable elements from the non-coding genome in tumor-derived extracellular vesicles target stromal and immune cells to induce local and systemic inflammation

Abstract The majority of the human genome (>70%) contains non-coding DNA consisting of retrotransposable elements (RTE), such as LINE-1, SINE/Alu elements, human endogenous retroviruses (HERV), and satellite repeat DNA (Hsat2 and Hsat3). The expression of these elements is suppressed in normal adult tissues but are abnormally expressed in many cancers. Another key mechanism in cancer initiation and progression is the release of tumor-derived extracellular vesicles (EV) that are long-distance communication vehicles propagating signals from tumors inducing metabolic changes, immune dysregulation and promoting metastases across the body. Our work has uncovered a link between RTE, HERV and Hsat expression in cancer and EV in driving tumor progression and immune dysregulation. W hole transcriptome sequencing of EV derived from several different cancer cell lines and patient samples, including Ewing sarcoma, osteosarcoma, prostate, pancreatic, and breast cancer found that RTE, HERV and Hsat2,3 transcripts are highly enriched in EV versus coding region transcripts and in much higher abundance than in the tumor cell themselves. Tumor-derived EV contained dsRNA, dsDNA and RNA:DNA hybrids from these non-coding regions. Plasma EV isolated from both metastatic and non-metastatic patients also showed an enrichment of these RTE, HERV and Hsat2,3 elements and clearly differentiated healthy, normal donor EV that had little or no detectable signal. Evidence of local dissemination of these non-coding elements in EV was also found in vivo in tumor xenografts that showed transfer of Hsat2,3 transcripts into the murine stroma that naturally lack these satellite repeats. Treatment of fibroblasts and myeloid cells with tumor-derived EV triggered innate immune responses via type I IFN and pro-inflammatory cytokines, including IL-1beta, IL-6, IL-8, and TNFalpha owing to the pathogen-like nucleic acid sequences (viral mimicry) of these elements. These EV-induced chronic inflammatory effects were mainly induced through the cGAS-STING nucleic acid sensing pathway. Evidence of DNA damage in stromal fibroblasts and induced senescence was also found as a result of EV treatment. A key element of RTE is the expression of LINE-1 and HERV derived reverse transcriptase (RT) that propagates the action of RTE via RNA:DNA hybrids, dsDNA and retrotransposition in the genome. In a spontaneous estradiol-driven breast cancer model in ACI rats, long-term treatment with an HIV RT inhibitor (lamivudine/3TC) inhibited breast tumor development associated with reduced RTE activation in the mammary gland and in circulating immune cells as well as reduced chronic systemic innate inflammation. Our results suggest that RTE, HERV and Hsat activation, together with their local and systemic dissemination in EV plays an important role in cancer initiation and progression associated with chronic inflammation. We also suggest that abnormal dissemination of these activated non-coding elements in EV may also play a role in "inflammaging" facilitating not only cancer but also other chronic diseases. Citation Format: Laszlo Radvanyi, Valentina Evdokimova, Peter Ruzanov, Zhenbo Zhang, Poul Sorenson, Hendrik Gassmann, Stefan Burdach, Lincoln D. Stein. Dissemination of retrotransposable elements from the non-coding genome in tumor-derived extracellular vesicles target stromal and immune cells to induce local and systemic inflammation [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C012.

Architectural dissection of adhesive bacterial cell surface appendages from a "molecular machines" viewpoint.

The ability of bacteria to interact with and respond to their environment is crucial to their lifestyle and survival. Bacterial cells routinely need to engage with extracellular target molecules, in locations spatially separated from their cell surface. Engagement with distant targets allows bacteria to adhere to abiotic surfaces and host cells, sense harmful or friendly molecules in their vicinity, as well as establish symbiotic interactions with neighboring cells in multicellular communities such as biofilms. Binding to extracellular molecules also facilitates transmission of information back to the originating cell, allowing the cell to respond appropriately to external stimuli, which is critical throughout the bacterial life cycle. This requirement of bacteria to bind to spatially separated targets is fulfilled by a myriad of specialized cell surface molecules, which often have an extended, filamentous arrangement. In this review, we compare and contrast such molecules from diverse bacteria, which fulfil a range of binding functions critical for the cell. Our comparison shows that even though these extended molecules have vastly different sequence, biochemical and functional characteristics, they share common architectural principles that underpin bacterial adhesion in a variety of contexts. In this light, we can consider different bacterial adhesins under one umbrella, specifically from the point of view of a modular molecular machine, with each part fulfilling a distinct architectural role. Such a treatise provides an opportunity to discover fundamental molecular principles governing surface sensing, bacterial adhesion, and biofilm formation.

Collagen VI and endotrophin: potential extracellular matrix targets to attenuate adverse cardiac remodeling post-infarction

Abstract Background The extracellular matrix (ECM) is a key component of cardiac repair after myocardial infarction (post-MI). After tissue damage following myocardial ischaemia, the ECM becomes enriched in proteases that are known to induce partial enzymatic cleavage and fragmentation of native structural and fibrillar macromolecules such as collagens. While some of the resulting protein fragments (matrikines) may have beneficial effects by mediating an active scar formation, other such as the collagen VI (COL6) proteolytic component "endothrophin" has been related to deleterious evolution and fibrosis, particularly in the presence of cardiovascular risk factors. Purpose We aimed to investigate the collagen profile in the structural fraction of ECM (enriched in fibrillar and structural proteins) of post-MI hearts at late evolution stages after MI. Methods The ECM protein profile was investigated in the ischemic (ISCH) and non-ischemic (NISCH) zones of the post-MI myocardium in pigs. MI was induced by closed-chest balloon occlusion of the LAD for 90 minutes. Studies were performed in normo- and hypercholesterolemic (diet induced) animals. Myocardial tissue was obtained 30d after MI. ECM proteins were selectively extracted, identified by LC/MS-MS and validated by Western Blot. Plasma levels of endothrophin were quantified by ELISA. Myocardial tissue from the same areas was characterized by immunohistochemistry. Results The ECM in the ISCH zone showed a differential signature of 39 proteins (14 upregulated / 25 downregulated) 30 days after MI compared to the NISCH area of the same animals. In the ISCH region, significant changes in collagen referring to COL6A3 and COL6A1 (increase) and COL6A2 and COL6A6 (decrease) were detected. COL6A3 protein content was 1.8fold higher (p=0.01) in the ISCH-ECM. A similar increase was found in normo- and hypercholesterolemic animals. A higher trend in COL6A3 levels was found in the ISCH- vs, the NISCH-zone in the myocardial cellular fraction suggesting that the COL6 ECM-related increase in ISCH is produced at a transcript level. Importantly, the COL6A3 found in the ECM did not contain the protein peptide (C5 domain) corresponding to endotrophin matrikine, suggesting its cleavage and release. Using a specific ELISA, hypercholesterolemic animals showed significantly higher endothrophin plasma levels than normolipemic controls (p=0.003) even in the absence of MI. Conclusion Our results evidence an increase in COL6A3 content in the ECM of the ischemic myocardium at 30 days post-MI. COL6A3 is depleted in a peptide of the C5 domain corresponding to endotrophin, found to be enhanced in hypercholesterolemia. These findings support a role for collagen type VI in adverse cardiac remodeling post-MI.

Targeted protein degradation via cellular trafficking of nanoparticles.

Strategies that selectively bind proteins of interest and target them to the intracellular protein recycling machinery for targeted protein degradation have recently emerged as powerful tools for undruggable targets in biomedical research and the pharmaceutical industry. However, targeting any new protein of interest with current degradation tools requires a laborious case-by-case design for different diseases and cell types, especially for extracellular targets. Here we observe that nanoparticles can mediate specific receptor-independent internalization of a bound protein and further develop a general strategy for degradation of extracellular proteins of interest by making full use of clinically approved components. This extremely flexible strategy aids in targeted protein degradation tool development and provides knowledge for targeted drug therapies and nanomedicine design.

Histone deacetylase inhibition disrupts the molecular signature of the glioblastoma secretome related to extracellular vesicle-associated proteins and targets RAB7a and RAB14 in vitro

Glioblastoma (GBM) is the most aggressive brain tumor with a poor prognosis. While Histone Deacetylase inhibitors have shown promising results in inhibiting cancer cell invasion and promoting apoptosis, their effects on GBM secretion, specifically focusing on extracellular vesicles (EVs) secretion, remain largely unexplored. Using label-free NANOLC-MS/MS methodology, we identified significant changes in the abundance of membrane traffic regulatory proteins in the secretome of U87MG cells after the treatment with the HDAC inhibitor Trichostatin A (TSA). In silico analysis showed that TSA treatment disrupted the secretion pattern of EVs-associated proteins and cellular signaling pathways, both qualitatively and quantitatively. Notably, RAB14/RAB7a interaction was only observed in the secretome of cells treated with TSA. In vitro assays revealed that TSA treatment of glioma cells increased EVs secretion and intracellular protein levels of RAB7a and RAB14 without affecting gene expression, suggesting a role of these two EVs-associated proteins in grade IV glioma cells. Additionally, an integrative approach using clinical data highlighted a correlation between DNA mutations affecting vesicle traffic coding-genes and clinical and phenotypic outcomes in glioma patients. These findings provide insights into the interplay between epigenetics and GBM intracellular trafficking, potentially leading to improved strategies for targeting and modifying the complex signaling network established between GBM cells and the tumor cell microenvironment.

CYpHER: catalytic extracellular targeted protein degradation with high potency and durable effect

Many disease-causing proteins have multiple pathogenic mechanisms, and conventional inhibitors struggle to reliably disrupt more than one. Targeted protein degradation (TPD) can eliminate the protein, and thus all its functions, by directing a cell’s protein turnover machinery towards it. Two established strategies either engage catalytic E3 ligases or drive uptake towards the endolysosomal pathway. Here we describe CYpHER (CatalYtic pH-dependent Endolysosomal delivery with Recycling) technology with potency and durability from a catalytic mechanism that shares the specificity and straightforward modular design of endolysosomal uptake. By bestowing pH-dependent release on the target engager and using the rapid-cycling transferrin receptor as the uptake receptor, CYpHER induces endolysosomal delivery of surface and extracellular targets while re-using drug, potentially yielding increased potency and reduced off-target tissue exposure risks. The TfR-based approach allows targeting to tumors that overexpress this receptor and offers the potential for transport to the CNS. CYpHER function was demonstrated in vitro with EGFR and PD-L1, and in vivo with EGFR in a model of EGFR-driven non-small cell lung cancer.

MANF serves as a novel hepatocyte factor to promote liver regeneration after 2/3 partial hepatectomy via doubly targeting Wnt/β-catenin signaling

Liver regeneration is an intricate pathophysiological process that has been a subject of great interest to the scientific community for many years. The capacity of liver regeneration is very critical for patients with liver diseases. Therefore, exploring the mechanisms of liver regeneration and finding good ways to improve it are very meaningful. Mesencephalic astrocyte-derived neurotrophic factor (MANF), a member of newly identified neurotrophic factors (NTFs) family, extensively expresses in the liver and has demonstrated cytoprotective effects during ER stress and inflammation. However, the role of MANF in liver regeneration remains unclear. Here, we used hepatocyte-specific MANF knockout (MANFHep−/−) mice to investigate the role of MANF in liver regeneration after 2/3 partial hepatectomy (PH). Our results showed that MANF expression was up-regulated in a time-dependent manner, and the peak level of mRNA and protein appeared at 24 h and 36 h after 2/3 PH, respectively. Notably, MANF knockout delayed hepatocyte proliferation, and the peak proliferation period was delayed by 24 h. Mechanistically, our in vitro results showed that MANF physically interacts with LRP5 and β-catenin, two essential components of Wnt/β-catenin pathway. Specifically, as a cofactor, MANF binds to the extracellular segment of LRP5 to activate Wnt/β-catenin signaling. On the other hand, MANF interacts with β-catenin to stabilize cytosolic β-catenin level and promote its nuclear translocation, which further enhance the Wnt/β-catenin signaling. We also found that MANF knockout does not affect the c-Met/β-catenin complex after 2/3 PH. In summary, our study confirms that MANF may serve as a novel hepatocyte factor that is closely linked to the activation of the Wnt/β-catenin pathway via intracellular and extracellular targets.

Small molecule innate immune modulators in cancer therapy.

Immunotherapy has proved to be a breakthrough in cancer treatment. So far, a bulk of the approved/late-stage cancer immunotherapy are antibody-based. Although these antibody-based drugs have demonstrated great promise, a majority of them are limited due to their access to extracellular targets, lack of oral bioavailability, tumor microenvironment penetration, induction of antibody dependent cytotoxicity etc. In recent times, there has been an increased research focus on the development of small molecule immunomodulators since they have the potential to overcome the aforementioned limitations posed by antibodies. Furthermore, while most biologics based therapeutics that are in clinical use are limited to modulating the adaptive immune system, very few clinically approved therapeutic modalities exist that modulate the innate immune system. The innate immune system, which is the body's first line of defense, has the ability to turn cold tumors hot and synergize strongly with existing adaptive immune modulators. In preclinical studies, small molecule innate immune modulators have demonstrated synergistic efficacy as combination modalities with current standard-of-care immune checkpoint antibodies. In this review, we highlight the recent advances made by small molecule innate immunomodulators in cancer immunotherapy.

Netrin-1 and UNC5B Cooperate with Integrins to Mediate YAP-Driven Cytostasis.

Netrins are widely perceived as procancer proteins; however, we uncover an anticancer function for Netrin-1 and its receptor UNC5B.

A plug-and-play monofunctional platform for targeted degradation of extracellular proteins and vesicles

Existing strategies use bifunctional chimaeras to mediate extracellular protein degradation. However, these strategies rely on specific lysosome-trafficking receptors to facilitate lysosomal delivery, which may raise resistance concerns due to intrinsic cell-to-cell variation in receptor expression and mutations or downregulation of the receptors. Another challenge is establishing a universal platform applicable in multiple scenarios. Here, we develop MONOTAB (MOdified NanOparticle with TArgeting Binders), a plug-and-play monofunctional degradation platform that can drag extracellular targets into lysosomes for degradation. MONOTAB harnesses the inherent lysosome-targeting ability of certain nanoparticles to obviate specific receptor dependency and the hook effect. To achieve high modularity and programmable target specificity, we utilize the streptavidin-biotin interaction to immobilize antibodies or other targeting molecules on nanoparticles, through an antibody mounting approach or by direct binding. Our study reveals that MONOTAB can induce efficient degradation of diverse therapeutic targets, including membrane proteins, secreted proteins, and even extracellular vesicles.

Transcriptomic observations of intra and extracellular immunotherapy targets for pediatric brain tumors

ABSTRACT Objectives Despite surgical resection, chemoradiation, and targeted therapy, brain tumors remain a leading cause of cancer-related death in children. Immunotherapy has shown some promise and is actively being investigated for treating childhood brain tumors. However, a critical step in advancing immunotherapy for these patients is to uncover targets that can be effectively translated into therapeutic interventions. Methods In this study, our team performed a transcriptomic analysis across pediatric brain tumor types to identify potential targets for immunotherapy. Additionally, we assessed components that may impact patient response to immunotherapy, including the expression of genes essential for antigen processing and presentation, inhibitory ligands and receptors, interferon signature, and overall predicted T cell infiltration. Results We observed distinct expression patterns across tumor types. These included elevated expression of antigen genes and antigen processing machinery in some tumor types while other tumors had elevated inhibitory checkpoint receptors, known to be associated with response to checkpoint inhibitor immunotherapy. Conclusion These findings suggest that pediatric brain tumors exhibit distinct potential for specific immunotherapies. We believe our findings can guide investigators in their assessment of appropriate immunotherapy classes and targets in pediatric brain tumors.

Antimicrobial activity of curcuma longa and mimosa pudica: a comprehensive review

The active ingredient in turmeric, Curcuma longa, and the traditional medicinal plant, Mimosa pudica, have both been the subject of intensive research due to their wide range of therapeutic applications. The antibacterial, anti-inflammatory, and wound-healing qualities of Mimosa pudica have long been employed, whereas curcumin is well known for its anti-inflammatory, antioxidant, and anticancer benefits. The pharmacological advantages of these two naturally occurring substances are summarized in this article, which also discusses their possible synergistic effects, modes of action, and therapeutic uses. Our goal in examining the complimentary qualities of Mimosa pudica and curcumin is to present a through analysis that bolsters their application in integrative medicine and offers ideas for further research. Curcumin is known for its powerful anti-inflammatory, antioxidant, and anticancer properties. Its therapeutic success is related to its capacity to affect numerous cellular pathways, such as inhibiting NF-KB and activating AREs. These pathways play a vital role in reducing inflammation and oxidative stress, which contribute to chronic diseases like cancer, cardiovascular disease, and neurodegeneration. Curcumin's antibacterial characteristics make it a promising medicinal agent with broad-spectrum applications. Mimosa pudica, often known as the "sensitive plant" for its quick responsiveness to physical stimuli, has a long history in traditional medicine, especially in Ayurvedic and folk treatments. It is used for wound healing,anti-inflammatory, antibacterial, and anti-ulcer properties. The pharmacological actions of Mimosa pudica are primarily due to its rich composition of bioactive compounds, including alkaloids,flavonoids, tannins, and phenolic acids.These compounds collectively contribute to the plant's ability to modulate immune responses, promote tissue regeneration, and inhibit microbial growth.Curcumin and Mimosa pudica have complimentary mechanisms that can lead to synergistic effects. Curcumin modulates intracellular signaling pathways and transcription factors, while Mimosa pudica's bioactive ingredients also interact with extracellular targets and microbial cell walls, indicating a multimodal approach to illness management.

Extracellular matrix markerLAMC2 targets ZEB1 to promote TNBC malignancy via up-regulating CD44/STAT3 signaling pathway.

Triple negative breast cancer (TNBC) is a heterogeneous and aggressive disease characterized by a high risk of mortality and poor prognosis. It has been reported that Laminin γ2 (LAMC2) is highly expressed in a variety of tumors, and its high expression is correlated with cancer development and progression. However, the function and mechanism by which LAMC2 influences TNBC remain unclear. Kaplan-Meier survival analysis and Immunohistochemical (IHC) staining were used to examine the expression level of LAMC2 in TNBC. Subsequently, cell viability assay, wound healing and transwell assay were performed to detect the function of LAMC2 in cell proliferation and migration. A xenograft mouse model was used to assess tumorigenic function of LAMC2 in vivo. Luciferase reporter assay and western blot were performed to unravel the underlying mechanism. In this study, we found that higher expression of LAMC2 significantly correlated with poor survival in the TNBC cohort. Functional characterization showed that LAMC2 promoted cell proliferation and migration capacity of TNBC cell lines via up-regulating CD44. Moreover, LAMC2 exerted oncogenic roles in TNBC through modulating the expression of epithelial-mesenchymal transition (EMT) markers. Luciferasereporterassay verified that LAMC2 targeted ZEB1to promote its transcription.Interestingly, LAMC2 regulated cell migration in TNBC via STAT3 signaling pathway. LAMC2 targeted ZEB1 via activating CD44/STAT3 signaling pathway to promote TNBC proliferation and migration, suggesting that LAMC2 could be a potential therapeutic target in TNBC patients.

Abstract PO5-14-10: Dynamics and prognostic value of subtype specific TROP2 expression in matched pair samples of primary (PBC) and metastatic breast cancer (MBC) tissues

Abstract Background: The genotype and phenotype of breast cancer may change during disease progression. This is of particular interest in the advent of targeted treatment adressing extracellular targets such as TROP2, which serves as chemotherapy carrier rather than being required for tumor cell survival. In addition, technical issues may affect biomarker assessment when comparing primary breast cancer (PBC) tissues with biopsies of metastatic breast cancer (MBC) tissues at distant sites. Here we analyzed TROP2 expression on mRNA level by RT-qPCR in primary tumor and metastatic tissues on basis of molecular subtyping to determine subtype specificity and target gene stability/dynamics. Methods: The tumor bank of a single institution was screened for paraffin-embedded pairs of PBC and MBC tissue samples and a total of 34 matched PBC and MBC pairs were retrieved. RNA was extracted using a bead-based extraction method (RNXtract® IVD kits, Cerca Biotech). Multiplex RT-qPCR was performed using TaqMan® based primer probe sets for ESR1/PGR/ERBB2 and MKI67 (MammaTyper® IVD kits, Cerca Biotech) as well as TROP2 (TargetTyper RUO kits, STRATIFYER Molecular Pathology GmbH). Correlation analysis, Scatter Plots, Partitioning tests and Kaplan Meier analysis were performed using the SAS JMP® 9.0.0 software. Results: Samples from 34 patients with MBC and PBC were available. Positivity of PBC RT-qPCR for ESR1, PGR and HER2 was 78%, 70% and 3%. The overall agreement between matched primary and metastatic lesions 90%, 70% and 100% for RT-qPCR of ESR1, PGR and HER2. Median expression of TROP2 was 2 fold lower in metastatic tissues compared to matched primary tumor tissues, while the lower quartile of mRNA expression dropped 4 fold. In primary tumor tissues TROP2 expression was significantly associated with PGR and HER2 expression (Spearman r=0.5284 p=0.0013 and r=0.3950 p=0.0208; respectively), while no significant association was found for ESR1 and MKI67. In contrast, no significant association with neither PGR nor HER2 was found (Spearman r=0.0461 p=0.8041 and r=0.0461 p=0.7955; respectively), while TROP2 trended to be associated with MKI67 in metastatic lesions (Spearman r=0.3247 p=0.0610). In line with the strong positive association of TROP2 with PGR in primary tumor tissues, elevated TROP2 levels were associated with substantially longer median distant metastasis free survival of 72 months, while TROP2 negative tumors exhibited a median DDFS of only 24 months (p=0,0091). In contrast, no prognostic value for TROP2 mRNA level could be determined from metastatic lesions and determining the time from initial metastasis until death. Conclusion: In this selected matched pair, metastatic cohort, TROP2 mRNA in primary tumors is strongly associated with luminal type of breast cancer expressing higher levels of PGR mRNA, while no such correlation was found in matched metastatic tissues. Moreover, TROP2 is significantly downregulated in metastatic lesions. As TROP2 is expressed in luminal tumors, it may serve as a valuable target for luminal tumors of higher progression risk. However, TROP2 expression is unstable and requires careful decision making on actual biopsies rather than archival tissue samples. Citation Format: Thomas Deutsch, Ralph Wirtz, Stefan Stefanovic, Andreas Hartkopf, Hans-Peter Sinn, Andreas Schneeweiss, Markus Wallwiener. Dynamics and prognostic value of subtype specific TROP2 expression in matched pair samples of primary (PBC) and metastatic breast cancer (MBC) tissues [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-14-10.

Improving the pharmacokinetics, biodistribution and plasma stability of monobodies.

Cancer is a leading cause of death worldwide. Several targeted anticancer drugs entered clinical practice and improved survival of cancer patients with selected tumor types, but therapy resistance and metastatic disease remains a challenge. A major class of targeted anticancer drugs are therapeutic antibodies, but their use is limited to extracellular targets. Hence, alternative binding scaffolds have been investigated for intracellular use and better tumor tissue penetration. Among those, monobodies are small synthetic protein binders that were engineered to bind with high affinity and selectivity to central intracellular oncoproteins and inhibit their signaling. Despite their use as basic research tools, the potential of monobodies as protein therapeutics remains to be explored. In particular, the pharmacological properties of monobodies, including plasma stability, toxicity and pharmacokinetics have not been investigated. Here, we show that monobodies have high plasma stability, are well-tolerated in mice, but have a short half-life in vivo due to rapid renal clearance. Therefore, we engineered monobody fusions with an albumin-binding domain (ABD), which showed enhanced pharmacological properties without affecting their target binding: We found that ABD-monobody fusions display increased stability in mouse plasma. Most importantly, ABD-monobodies have a dramatically prolonged in vivo half-life and are not rapidly excreted by renal clearance, remaining in the blood significantly longer, while not accumulating in specific internal organs. Our results demonstrate the promise and versatility of monobodies to be developed into future therapeutics for cancer treatment. We anticipate that monobodies may be able to extend the spectrum of intracellular targets, resulting in a significant benefit to patient outcome.

Extracellular Purine Metabolism-Potential Target in Multiple Sclerosis.

The purinergic signaling system comprises a complex network of extracellular purines and purine-metabolizing ectoenzymes, nucleotide and nucleoside receptors, ATP release channels, and nucleoside transporters. Because of its immunomodulatory function, this system is critically involved in the pathogenesis of multiple sclerosis (MS) and its best-characterized animal model, experimental autoimmune encephalomyelitis (EAE). MS is a chronic neuroinflammatory demyelinating and neurodegenerative disease with autoimmune etiology and great heterogeneity, mostly affecting young adults and leading to permanent disability. In MS/EAE, alterations were detected in almost all components of the purinergic signaling system in both peripheral immune cells and central nervous system (CNS) glial cells, which play an important role in the pathogenesis of the disease. A decrease in extracellular ATP levels and an increase in its downstream metabolites, particularly adenosine and inosine, were frequently observed at MS, indicating a shift in metabolism toward an anti-inflammatory environment. Accordingly, upregulation of the major ectonucleotidase tandem CD39/CD73 was detected in the blood cells and CNS of relapsing-remitting MS patients. Based on the postulated role of A2A receptors in the transition from acute to chronic neuroinflammation, the association of variants of the adenosine deaminase gene with the severity of MS, and the beneficial effects of inosine treatment in EAE, the adenosinergic system emerged as a promising target in neuroinflammation. More recently, several publications have identified ADP-dependent P2Y12 receptors and the major extracellular ADP producing enzyme nucleoside triphosphate diphosphohydrolase 2 (NTPDase2) as novel potential targets in MS.

Chimeric Antigen Receptor (CAR)-T Cell Therapy for Non-Hodgkin's Lymphoma.

This review focuses on the use of chimeric antigen receptor (CAR)-T cell therapy to treat non-Hodgkin's lymphoma (NHL), a classification of heterogeneous malignant neoplasms of the lymphoid tissue. Despite various conventional and multidrug chemotherapies, the poor prognosis for NHL patients remains and has prompted the utilization of groundbreaking personalized therapies such as CAR-T cells. CAR-T cells are T cells engineered to express a CAR that enables T cells to specifically lyse tumor cells with extracellular expression of a tumor antigen of choice. A CAR is composed of an extracellular antibody fragment or target protein binding domain that is conjugated to activating intracellular signaling motifs common to T cells. In general, CAR-T cell therapies for NHL are designed to recognize cellular markers ubiquitously expressed on B cells such as CD19+, CD20+, and CD22+. Clinical trials using CAR-T cells such as ZUMA-7 and TRANSFORM demonstrated promising results compared to standard of care and ultimately led to FDA approval for the treatment of relapsed/refractory NHL. Despite the success of CAR-T therapy for NHL, challenges include adverse side effects as well as extrinsic and intrinsic mechanisms of tumor resistance that lead to suboptimal outcomes. Overall, CAR-T cell therapies have improved clinical outcomes in NHL patients and generated optimism around their future applications.

Recent Advances in Non‐Standard Macrocyclic Peptide Ligand Discovery using mRNA Display

AbstractAdvancements in platform technologies have facilitated the production of libraries consisting of macrocyclic peptides composed of natural and non‐canonical amino acids for more drug‐like characteristics. Identification of macrocyclic peptide ligands against targets of interest can be accomplished using mRNA display. Despite numerous successful in vitro selections for macrocyclic peptide ligands against extracellular targets, identifying macrocyclic peptide hits that can reach intracellular targets continue to be a challenge. Breakthroughs in defining the features of a macrocyclic peptide that promote cell permeability have recently been disclosed. Here, we review the successful selections of non‐standard macrocyclic peptide ligands using mRNA display in the last five years and chemical optimization of a drug‐like macrocyclic peptide ligand for targeting intracellular KRAS.

Multivalent Aptamer-Based Lysosome-Targeting Chimeras (LYTACs) Platform for Mono- or Dual-Targeted Proteins Degradation on Cell Surface.

Selective protein degradation platforms have opened novel avenues in therapeutic development and biological inquiry. Antibody-based lysosome-targeting chimeras (LYTACs) have emerged as a promising technology that extends the scope of targeted protein degradation to extracellular targets. Aptamers offer an advantageous alternative owing to their potential for modification and manipulation toward a multivalent state. In this study, a chemically engineered platform of multivalent aptamer-based LYTACs (AptLYTACs) is established for the targeted degradation of either single or dual protein targets. Leveraging the biotin-streptavidin system as a molecular scaffold, this investigation reveals that trivalently mono-targeted AptLYTACs demonstrate optimum efficiency in degrading membrane proteins. The development of this multivalent AptLYTACs platform provides a principle of concept for mono-/dual-targets degradation, expanding the possibilities of targeted protein degradation.