scholarly journals Partitioning of cancer therapeutics in nuclear condensates

Science ◽  
2020 ◽  
Vol 368 (6497) ◽  
pp. 1386-1392 ◽  
Author(s):  
Isaac A. Klein ◽  
Ann Boija ◽  
Lena K. Afeyan ◽  
Susana Wilson Hawken ◽  
Mengyang Fan ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Small Molecules ◽  
Tumor Cells ◽  
Drug Target ◽  
Cancer Therapeutics ◽  
Specific Protein ◽  
Antineoplastic Drugs ◽  
Disease Therapy ◽  
Drug Partitioning

The nucleus contains diverse phase-separated condensates that compartmentalize and concentrate biomolecules with distinct physicochemical properties. Here, we investigated whether condensates concentrate small-molecule cancer therapeutics such that their pharmacodynamic properties are altered. We found that antineoplastic drugs become concentrated in specific protein condensates in vitro and that this occurs through physicochemical properties independent of the drug target. This behavior was also observed in tumor cells, where drug partitioning influenced drug activity. Altering the properties of the condensate was found to affect the concentration and activity of drugs. These results suggest that selective partitioning and concentration of small molecules within condensates contributes to drug pharmacodynamics and that further understanding of this phenomenon may facilitate advances in disease therapy.

scholarly journals Partitioning of cancer therapeutics in nuclear condensates.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 3131-3131
Author(s):  
Isaac Klein ◽  
Ann Boija ◽  
Lena Afeyan ◽  
Susana Hawken ◽  
Mengyang Fan ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Small Molecule ◽  
Cancer Therapeutics ◽  
Therapeutic Index ◽  
Regulatory Elements ◽  
Specific Protein ◽  
Target Engagement ◽  
Membrane Bound ◽  
In Cells

3131 Background: The molecules of the cell are compartmentalized into membrane- and non-membrane-bound organelles. Many non-membrane-bound organelles are phase-separated biomolecular condensates with distinct physicochemical properties that can absorb and concentrate specific proteins and nucleic acids involved in discrete biochemical processes. We reasoned that selective condensate partitioning might also occur with small molecule drugs whose targets occur within condensates, and that the therapeutic index and efficacy of such compounds might therefore relate to their ability to partition into condensates. Methods: To study the behavior of drugs within condensates, these were modeled in cells and in vitro with purified proteins and visualized by fluorescent confocal microscopy. The functional outcomes of condensate partitioning were queried in cells. Results: We found that cisplatin, tamoxifen, JQ1, THZ1, and mitoxantrone are concentrated in specific protein condensates in vitro, and that this occurs through physicochemical properties independent of the drug target. A screen of a chemically diverse fluorescent probes and mutant-protein condensates demonstrated that pi-system interactions between aromatic moieties in the protein and small molecule govern concentration in condensates. These results show that clinically important drugs partition into specific protein condensates in vitro by virtue of defined chemical properties, thereby altering their local concentration. In vitro droplet assays revealed that cisplatin is selectively concentrated in transcriptional condensates, and that this ability is required for efficient platination of target DNA. In cell studies revealed that cisplatin preferentially targets DNA contained within MED1 condensates, and disrupts the genetic regulatory elements that compose phase-separated transcriptional condensates. Live cell imaging demonstrated that transcriptional condensates are dissolved by cisplatin, whereas other condensates remain intact. Conclusions: Our results show that antineoplastic drugs partition selectively into biomolecular condensates, that this can occur through physicochemical properties independent of their molecular targets, and that drug activity may occur through condensate-related mechanisms. These results have implications for development of efficacious cancer therapeutics; effective target engagement will depend on factors such as drug partitioning in condensates. Assays of the type described here may thus help optimize condensate partitioning, target engagement, and the therapeutic index of drugs for cancer treatment.

scholarly journals Peptide-tags for site-specific protein labelling in vitro and in vivo

2016 ◽  
Vol 12 (6) ◽  
pp. 1731-1745 ◽  
Author(s):  
Jonathan Lotze ◽  
Ulrike Reinhardt ◽  
Oliver Seitz ◽  
Annette G. Beck-Sickinger
Keyword(s):  
Metal Ions ◽  
Small Molecules ◽  
Protein Localization ◽  
Specific Protein ◽  
Site Specific ◽  
Protein Labelling ◽  
Peptide Interactions ◽  
Peptide Tags

Peptide-tag based labelling can be achieved by (i) enzymes (ii) recognition of metal ions or small molecules and (iii) peptide–peptide interactions and enables site-specific protein visualization to investigate protein localization and trafficking.

scholarly journals Identification of inhibitors of SARS-CoV-2 3CL-Pro enzymatic activity using a small molecule in-vitro repurposing screen

2020 ◽  
Author(s):  
Maria Kuzikov ◽  
Elisa Costanzi ◽  
Jeanette Reinshagen ◽  
Francesca Esposito ◽  
Laura Vangeel ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Small Molecules ◽  
Drug Target ◽  
Treatment Options ◽  
Cleavage Sites ◽  
X Ray ◽  
Binding Characteristics ◽  
Main Protease ◽  
Ic50 Values

Compound repurposing is an important strategy for the identification of effective treatment options against SARS-CoV-2 infection and COVID-19 disease. In this regard, SARS-CoV-2 main protease (3CL-Pro), also termed M-Pro, is an attractive drug target as it plays a central role in viral replication by processing the viral polyproteins pp1a and pp1ab at multiple distinct cleavage sites. We here report the results of a repurposing program involving 8.7 K compounds containing marketed drugs, clinical and preclinical candidates, and small molecules regarded as safe in humans. We confirmed previously reported inhibitors of 3CL-Pro, and have identified 62 additional compounds with IC50 values below 1 uM and profiled their selectivity towards Chymotrypsin and 3CL-Pro from the MERS virus. A subset of 8 inhibitors showed anti-cytopathic effect in a Vero-E6 cell line and the compounds thioguanosine and MG-132 were analysed for their predicted binding characteristics to SARS-CoV-2 3CL-Pro. The X-ray crystal structure of the complex of myricetin and SARS-Cov-2 3CL-Pro was solved at a resolution of 1.77 Angs., showing that myricetin is covalently bound to the catalytic Cys145 and therefore inhibiting its enzymatic activity.

scholarly journals PLEKHA4 Promotes Wnt/β-catenin Signaling-Mediated G1/S Transition and Proliferation in Melanoma

2020 ◽  
Author(s):  
Adnan Shami Shah ◽  
Xiaofu Cao ◽  
Andrew C. White ◽  
Jeremy M. Baskin
Keyword(s):  
Small Molecules ◽  
Ubiquitin Ligase ◽  
Targeted Therapies ◽  
Drug Target ◽  
Binding Partners ◽  
Xenograft Models ◽  
Melanoma Patients ◽  
Cell Cycle Transition ◽  
Braf Mutant

ABSTRACTMelanoma patients incur substantial mortality, despite promising recent advances in targeted therapies and immunotherapies. In particular, inhibitors targeting BRAF-mutant melanoma can lead to resistance, and no targeted therapies exist for NRAS-mutant melanoma, motivating the search for additional therapeutic targets and vulnerable pathways. Here, we identify a regulator of Wnt/β-catenin signaling, PLEKHA4, as a factor required for melanoma proliferation and survival. PLEKHA4 knockdown in vitro leads to lower Dishevelled levels, attenuated Wnt/β-catenin signaling, and a block of progression through the G1/S cell cycle transition. In mouse xenograft models, inducible PLEKHA4 knockdown attenuated tumor growth in BRAF- and NRAS-mutant melanomas and synergized with the clinically used inhibitor encorafenib in a BRAF-mutant model. As an E3 ubiquitin ligase regulator with both lipid and protein binding partners, PLEKHA4 presents several opportunities for targeting with small molecules. Our work identifies PLEKHA4 as a promising drug target for melanoma and clarifies a controversial role for Wnt/β-catenin signaling in the control of melanoma proliferation.

scholarly journals Spatiotemporal depletion of tumor-associated immune checkpoint PD-L1 with near-infrared photoimmunotherapy promotes antitumor immunity

2021 ◽  
Vol 9 (11) ◽  
pp. e003036
Author(s):  
Shunichi Taki ◽  
Kohei Matsuoka ◽  
Yuko Nishinaga ◽  
Kazuomi Takahashi ◽  
Hirotoshi Yasui ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Immune Checkpoint ◽  
Antitumor Immunity ◽  
Near Infrared ◽  
Specific Antigen ◽  
Cancer Therapeutics ◽  
Antitumor Effects ◽  
Nir Light

BackgroundNear-infrared photoimmunotherapy (NIR-PIT) is a new modality for treating cancer, which uses antibody-photoabsorber (IRDye700DX) conjugates that specifically bind to target tumor cells. This conjugate is then photoactivated by NIR light, inducing rapid necrotic cell death. NIR-PIT needs a highly expressed targeting antigen on the cells because of its reliance on antibodies. However, using antibodies limits this useful technology to only those patients whose tumors express high levels of a specific antigen. Thus, to propose an alternative strategy, we modified this phototechnology to augment the anticancer immune system by targeting the almost low-expressed immune checkpoint molecules on tumor cells.MethodsWe used programmed death-ligand 1 (PD-L1), an immune checkpoint molecule, as the target for NIR-PIT. Although the expression of PD-L1 on tumor cells is usually low, PD-L1 is almost expressed on tumor cells. Intratumoral depletion with PD-L1-targeted NIR-PIT was tested in mouse syngeneic tumor models.ResultsAlthough PD-L1-targeted NIR-PIT showed limited effect on tumor cells in vitro, the therapy induced sufficient antitumor effects in vivo, which were thought to be mediated by the ‘photoimmuno’ effect and antitumor immunity augmentation. Moreover, PD-L1-targeted NIR-PIT induced antitumor effect on non-NIR light-irradiated tumors.ConclusionsLocal PD-L1-targeted NIR-PIT enhanced the antitumor immune reaction through a direct photonecrotic effect, thereby providing an alternative approach to targeted cancer immunotherapy and expanding the scope of cancer therapeutics.

DEVELOPMENT OF A PHOTOSENSITIZER DELIVERY SYSTEM FOR THERAPY AND DIAGNOSTICS IN ONCOLOGY

2020 ◽  
pp. 124-125
Author(s):  
A.Semkina Semkina ◽  
M.Abakumov Abakumov ◽  
P.Ostroverkhov Ostroverkhov ◽  
M. Grin
Keyword(s):  
Photodynamic Therapy ◽  
Physicochemical Properties ◽  
Tumor Cells ◽  
Therapeutic Effect ◽  
Delivery System ◽  
Biological Studies ◽  
Kinetics Of ◽  
Ct26 Tumor

In this work, the MNP-HSA-PEG-PS@4 complex was obtained and its physicochemical properties were studied. Biological studies have also been conducted. Namely, the ability of the drug to accumulate in CT26 tumor cells in vitro and the kinetics of drug accumulation in the tumor in vivo were studied. Then, the effectiveness of photodynamic therapy was studied under different conditions. The maximum therapeutic effect was achieved with irradiation at 1 hour after injection of the drug.

Inhibitors of bacterial H2S biogenesis targeting antibiotic resistance and tolerance

Science ◽  
2021 ◽  
Vol 372 (6547) ◽  
pp. 1169-1175
Author(s):  
Konstantin Shatalin ◽  
Ashok Nuthanakanti ◽  
Abhishek Kaushik ◽  
Dmitry Shishov ◽  
Alla Peselis ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Hydrogen Sulfide ◽  
Small Molecules ◽  
Biofilm Formation ◽  
Drug Target ◽  
Human Pathogens ◽  
Defense System

Emergent resistance to all clinical antibiotics calls for the next generation of therapeutics. Here we report an effective antimicrobial strategy targeting the bacterial hydrogen sulfide (H2S)–mediated defense system. We identified cystathionine γ-lyase (CSE) as the primary generator of H2S in two major human pathogens, Staphylococcus aureus and Pseudomonas aeruginosa, and discovered small molecules that inhibit bacterial CSE. These inhibitors potentiate bactericidal antibiotics against both pathogens in vitro and in mouse models of infection. CSE inhibitors also suppress bacterial tolerance, disrupting biofilm formation and substantially reducing the number of persister bacteria that survive antibiotic treatment. Our results establish bacterial H2S as a multifunctional defense factor and CSE as a drug target for versatile antibiotic enhancers.

scholarly journals Novel enhancers of guanylyl cyclase-A activity via allosteric modulation

2022 ◽  
Author(s):  
Henriette Andresen ◽  
Cristina Pérez-Ternero ◽  
Jerid Robinson ◽  
Deborah M Dickey ◽  
Adrian J Hobbs ◽  
...  
Keyword(s):  
Small Molecules ◽  
Natriuretic Peptide ◽  
Guanylyl Cyclase ◽  
Drug Target ◽  
Ex Vivo ◽  
Cyclic Guanosine Monophosphate ◽  
Guanosine Monophosphate ◽  
Allosteric Binding Sites ◽  
Small Molecule Modulators

Natriuretic peptide receptor (NPR)-A (also known as NPR-A, NPR1 or guanylyl cyclase-A, GC-A) is an attractive but challenging target to activate with small molecules. GC-A is activated by endogenous atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP), and this activation leads to the production of cyclic guanosine monophosphate (cGMP). This system plays an important role in the regulation of cardiovascular and renal homeostasis. However, utilization of this receptor as a drug target has so far been limited to peptides, even though small molecule modulators allow oral administration and longer half-life. We have identified small molecular allosteric enhancers of GC-A, which strengthened ANP or BNP activation in various in vitro and ex vivo systems. These compounds do not mediate their actions through previously described allosteric binding sites or via known mechanisms of action. In addition, their selectivity and activity are dependent on only one amino acid in GC-A. Our findings show that there is a novel allosteric binding site on GC-A, which can be targeted by small molecules that increase the signaling effects of ANP and BNP.

scholarly journals Fluorescent and quantitative mitochondrial redox imaging of tumor targeted by Octa-RGD probe

2016 ◽  
Vol 09 (04) ◽  
pp. 1642002
Author(s):  
Shuang Sha ◽  
Fei Yang ◽  
Anle Wang ◽  
Honglin Jin ◽  
Zhihong Zhang ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Fluorescent Protein ◽  
Cancer Therapeutics ◽  
Tumor Metabolism ◽  
Confocal Imaging ◽  
Metabolic Imaging ◽  
Tumor Biomarker ◽  
Rgd Peptides

Integrins, over-expressed in a broad range of cancer diseases, are widely utilized as a tumor biomarker. Metabolism investigation also plays important roles in tumor theranostics. Developing simple integrin-targetting probe and monitoring tumor metabolism will give opportunities to find ways for cancer treatment, however, the investigation of tumor metabolism with integrin receptor based probes has been rarely reported so far. Here, we developed an octavalent fluorescent probe Octa-RGD by convenient genetic method, based on one tetrameric far-red fluorescent protein (fRFP) linked with RGD peptides. We validated its intergin targeting by confocal imaging in vitro. Then we screened a variety of tumor cells, and differentiated their binding affinity based on the fluorescence of the probe via flow cytometry. Among these cells, CNE-2 cells had the highest uptake of the probe, while B16 cells had the lowest, corresponding with their intergin expression levels. Next, the fluorescent and metabolic imaging was performed in HT1080 (intergin postive) tumor, where nicotinamide adenine dinucleotide hydrogen (NADH), flavoprotein (Fp) and fRFP fluorescent signals were collected. The tumor from mice intravenously injected with Octa-RGD probe displayed obviously higher NADH redox ratio NADH/(Fp+NADH) and fRFP signal, than those with fRFP protein. It suggested that integrin targeting may have influence on the target cell metabolism, and further demonstrated Octa-RGD probe facilitated its uptake in the targeted tumor in vivo. This paper developed a useful probe, which can bind integrins specifically and efficiently in tumor cells, and together with tumor metabolic information, it may provide new insight for RGD targeting-based cancer therapeutics.

EBNA1-specific luminescent small molecules for the imaging and inhibition of latent EBV-infected tumor cells

2014 ◽  
Vol 50 (49) ◽  
pp. 6517-6519 ◽  
Author(s):  
Lijun Jiang ◽  
Yin-Lai Lui ◽  
Hongguang Li ◽  
Chi-Fai Chan ◽  
Rongfeng Lan ◽  
...  
Keyword(s):  
Small Molecules ◽  
Tumor Cells ◽  
Small Molecule ◽  
Anticancer Agent ◽  
Selective Binding ◽  
Infected Tumor

An EBNA1-specific small molecule (JLP2) has been synthesized and shown selective binding and inhibition of EBNA1 in vitro as potential anticancer agent.

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