542 results on '"Radu, Caius G."'
Search Results
2. Targeting host deoxycytidine kinase mitigates Staphylococcus aureus abscess formation
- Author
-
Winstel, Volker, Abt, Evan R, Le, Thuc M, and Radu, Caius G
- Subjects
Biological Sciences ,Biomedical and Clinical Sciences ,Microbiology ,Clinical Sciences ,Medical Microbiology ,Oncology and Carcinogenesis ,Infectious Diseases ,Biotechnology ,Emerging Infectious Diseases ,5.1 Pharmaceuticals ,2.2 Factors relating to the physical environment ,2.1 Biological and endogenous factors ,Development of treatments and therapeutic interventions ,Aetiology ,Infection ,Good Health and Well Being - Abstract
Host-directed therapy (HDT) is an emerging approach to overcome antimicrobial resistance in pathogenic microorganisms. Specifically, HDT targets host-encoded factors required for pathogen replication and survival without interfering with microbial growth or metabolism, thereby eliminating the risk of resistance development. By applying HDT and a drug repurposing approach, we demonstrate that (R)-DI-87, a clinical-stage anti-cancer drug and potent inhibitor of mammalian deoxycytidine kinase (dCK), mitigates Staphylococcus aureus abscess formation in organ tissues upon invasive bloodstream infection. Mechanistically, (R)-DI-87 shields phagocytes from staphylococcal death-effector deoxyribonucleosides that target dCK and the mammalian purine salvage pathway-apoptosis axis. In this manner, (R)-DI-87-mediated protection of immune cells amplifies macrophage infiltration into deep-seated abscesses, a phenomenon coupled with enhanced pathogen control, ameliorated immunopathology, and reduced disease severity. Thus, pharmaceutical blockade of dCK represents an advanced anti-infective intervention strategy against which staphylococci cannot develop resistance and may help to fight fatal infectious diseases in hospitalized patients.
- Published
- 2023
3. Immunization of Mice with Virus-Like Vesicles of Kaposi Sarcoma-Associated Herpesvirus Reveals a Role for Antibodies Targeting ORF4 in Activating Complement-Mediated Neutralization
- Author
-
Lam, Alex K, Roshan, Romin, Miley, Wendell, Labo, Nazzarena, Zhen, James, Kurland, Andrew P, Cheng, Celine, Huang, Haigen, Teng, Pu-Lin, Harelson, Claire, Gong, Danyang, Tam, Ying K, Radu, Caius G, Epeldegui, Marta, Johnson, Jeffrey R, Zhou, Z Hong, Whitby, Denise, and Wu, Ting-Ting
- Subjects
Medical Microbiology ,Biomedical and Clinical Sciences ,Immunology ,Cancer ,Vaccine Related ,Immunization ,HIV/AIDS ,Prevention ,Biotechnology ,Infectious Diseases ,Rare Diseases ,Emerging Infectious Diseases ,2.1 Biological and endogenous factors ,2.2 Factors relating to the physical environment ,Aetiology ,Prevention of disease and conditions ,and promotion of well-being ,3.4 Vaccines ,Infection ,Animals ,Humans ,Mice ,Antibodies ,Neutralizing ,Herpesviridae Infections ,Herpesvirus 8 ,Human ,Open Reading Frames ,Vaccination ,Viral Proteins ,KSHV ,vaccine ,antibody function ,complement ,neutralizing antibodies ,Biological Sciences ,Agricultural and Veterinary Sciences ,Medical and Health Sciences ,Virology ,Agricultural ,veterinary and food sciences ,Biological sciences ,Biomedical and clinical sciences - Abstract
Infection by Kaposi sarcoma-associated herpesvirus (KSHV) can cause severe consequences, such as cancers and lymphoproliferative diseases. Whole inactivated viruses (WIV) with chemically destroyed genetic materials have been used as antigens in several licensed vaccines. During KSHV productive replication, virus-like vesicles (VLVs) that lack capsids and viral genomes are generated along with virions. Here, we investigated the immunogenicity of KSHV VLVs produced from a viral mutant that was defective in capsid formation and DNA packaging. Mice immunized with adjuvanted VLVs generated KSHV-specific T cell and antibody responses. Neutralization of KSHV infection by the VLV immune serum was low but was markedly enhanced in the presence of the complement system. Complement-enhanced neutralization and complement deposition on KSHV-infected cells was dependent on antibodies targeting viral open reading frame 4 (ORF4). However, limited complement-mediated enhancement was detected in the sera of a small cohort of KSHV-infected humans which contained few neutralizing antibodies. Therefore, vaccination that induces antibody effector functions can potentially improve infection-induced humoral immunity. Overall, our study highlights a potential benefit of engaging complement-mediated antibody functions in future KSHV vaccine development. IMPORTANCE KSHV is a virus that can lead to cancer after infection. A vaccine that prevents KSHV infection or transmission would be helpful in preventing the development of these cancers. We investigated KSHV VLV as an immunogen for vaccination. We determined that antibodies targeting the viral protein ORF4 induced by VLV immunization could engage the complement system and neutralize viral infection. However, ORF4-specific antibodies were seldom detected in the sera of KSHV-infected humans. Moreover, these human sera did not potently trigger complement-mediated neutralization, indicating an improvement that immunization can confer. Our study suggests a new antibody-mediated mechanism to control KSHV infection and underscores the benefit of activating the complement system in a future KSHV vaccine.
- Published
- 2023
4. Targeting deoxycytidine kinase improves symptoms in mouse models of multiple sclerosis
- Author
-
Chen, Bao Ying, Salas, Jessica R, Trias, Alyssa O, Rodriguez, Arely Perez, Tsang, Jonathan E, Guemes, Miriam, Le, Thuc M, Galic, Zoran, Shepard, H Michael, Steinman, Lawrence, Nathanson, David A, Czernin, Johannes, Witte, Owen N, Radu, Caius G, Schultz, Kenneth A, and Clark, Peter M
- Subjects
Biomedical and Clinical Sciences ,Immunology ,Autoimmune Disease ,Neurodegenerative ,Neurosciences ,Brain Disorders ,Multiple Sclerosis ,2.1 Biological and endogenous factors ,Aetiology ,Inflammatory and immune system ,Neurological ,Animals ,Mice ,Deoxycytidine Kinase ,Encephalomyelitis ,Autoimmune ,Experimental ,Lymphocytes ,Disease Models ,Animal ,Mice ,Inbred C57BL ,autoimmunity ,EAE ,MS ,imaging ,nucleotide metabolism ,EAE/MS ,Paediatrics and Reproductive Medicine - Abstract
Multiple sclerosis (MS) is an autoimmune disease driven by lymphocyte activation against myelin autoantigens in the central nervous system leading to demyelination and neurodegeneration. The deoxyribonucleoside salvage pathway with the rate-limiting enzyme deoxycytidine kinase (dCK) captures extracellular deoxyribonucleosides for use in intracellular deoxyribonucleotide metabolism. Previous studies have shown that deoxyribonucleoside salvage activity is enriched in lymphocytes and required for early lymphocyte development. However, specific roles for the deoxyribonucleoside salvage pathway and dCK in autoimmune diseases such as MS are unknown. Here we demonstrate that dCK activity is necessary for the development of clinical symptoms in the MOG35-55 and MOG1-125 experimental autoimmune encephalomyelitis (EAE) mouse models of MS. During EAE disease, deoxyribonucleoside salvage activity is elevated in the spleen and lymph nodes. Targeting dCK with the small molecule dCK inhibitor TRE-515 limits disease severity when treatments are started at disease induction or when symptoms first appear. EAE mice treated with TRE-515 have significantly fewer infiltrating leukocytes in the spinal cord, and TRE-515 blocks activation-induced B and T cell proliferation and MOG35-55 -specific T cell expansion without affecting innate immune cells or naïve T and B cell populations. Our results demonstrate that targeting dCK limits symptoms in EAE mice and suggest that dCK activity is required for MOG35-55 -specific lymphocyte activation-induced proliferation.
- Published
- 2023
5. 18F-FDG PET Visualizes Systemic STING Agonist-Induced Lymphocyte Activation in Preclinical Models
- Author
-
Le, Thuc M, Lee, Hailey R, Abt, Evan R, Rashid, Khalid, Creech, Amanda L, Liang, Keke, Cui, Jing, Cho, Arthur, Wei, Liu, Labora, Amanda, Chan, Charlotte, Sanchez, Eric, Kriti, Kriti, Karin, Daniel, Li, Luyi, Wu, Nanping, Mona, Christine, Carlucci, Giuseppe, Hugo, Willy, Wu, Ting-Ting, Donahue, Timothy R, Czernin, Johannes, and Radu, Caius G
- Subjects
Biomedical and Clinical Sciences ,Clinical Sciences ,Oncology and Carcinogenesis ,Immunology ,Immunotherapy ,Cancer ,Biomedical Imaging ,Genetics ,Inflammatory and immune system ,Male ,Animals ,Mice ,Fluorodeoxyglucose F18 ,Lymphocyte Activation ,Mice ,Inbred C57BL ,Positron-Emission Tomography ,Signal Transduction ,STING agonists ,F-18-FDG PET ,lymphocytes ,immune activation ,immunometabolism ,18F-FDG PET ,Nuclear Medicine & Medical Imaging ,Clinical sciences - Abstract
Stimulator of interferon genes (STING) is a mediator of immune recognition of cytosolic DNA, which plays important roles in cancer, cytotoxic therapies, and infections with certain pathogens. Although pharmacologic STING activation stimulates potent antitumor immune responses in animal models, clinically applicable pharmacodynamic biomarkers that inform of the magnitude, duration, and location of immune activation elicited by systemic STING agonists are yet to be described. We investigated whether systemic STING activation induces metabolic alterations in immune cells that can be visualized by PET imaging. Methods: C57BL/6 mice were treated with systemic STING agonists and imaged with 18F-FDG PET after 24 h. Splenocytes were harvested 6 h after STING agonist administration and analyzed by single-cell RNA sequencing and flow cytometry. 18F-FDG uptake in total splenocytes and immunomagnetically enriched splenic B and T lymphocytes from STING agonist-treated mice was measured by γ-counting. In mice bearing prostate or pancreas cancer tumors, the effects of STING agonist treatment on 18F-FDG uptake, T-lymphocyte activation marker levels, and tumor growth were evaluated. Results: Systemic delivery of structurally distinct STING agonists in mice significantly increased 18F-FDG uptake in the spleen. The average spleen SUVmax in control mice was 1.90 (range, 1.56-2.34), compared with 4.55 (range, 3.35-6.20) in STING agonist-treated mice (P < 0.0001). Single-cell transcriptional and flow cytometry analyses of immune cells from systemic STING agonist-treated mice revealed enrichment of a glycolytic transcriptional signature in both T and B lymphocytes that correlated with the induction of immune cell activation markers. In tumor-bearing mice, STING agonist administration significantly delayed tumor growth and increased 18F-FDG uptake in secondary lymphoid organs. Conclusion: These findings reveal hitherto unknown functional links between STING signaling and immunometabolism and suggest that 18F-FDG PET may provide a widely applicable approach toward measuring the pharmacodynamic effects of systemic STING agonists at a whole-body level and guiding their clinical development.
- Published
- 2023
6. Purine nucleoside phosphorylase enables dual metabolic checkpoints that prevent T cell immunodeficiency and TLR7-dependent autoimmunity
- Author
-
Abt, Evan R, Rashid, Khalid, Le, Thuc M, Li, Suwen, Lee, Hailey R, Lok, Vincent, Li, Luyi, Creech, Amanda L, Labora, Amanda N, Mandl, Hanna K, Lam, Alex K, Cho, Arthur, Rezek, Valerie, Wu, Nanping, Abril-Rodriguez, Gabriel, Rosser, Ethan W, Mittelman, Steven D, Hugo, Willy, Mehrling, Thomas, Bantia, Shanta, Ribas, Antoni, Donahue, Timothy R, Crooks, Gay M, Wu, Ting-Ting, and Radu, Caius G
- Subjects
Biochemistry and Cell Biology ,Biomedical and Clinical Sciences ,Biological Sciences ,Immunology ,Autoimmune Disease ,1.1 Normal biological development and functioning ,Underpinning research ,Inflammatory and immune system ,Animals ,Autoimmunity ,Humans ,Immunologic Deficiency Syndromes ,Mice ,Purine Nucleosides ,Purine-Nucleoside Phosphorylase ,T-Lymphocytes ,Toll-Like Receptor 7 ,Autoimmune diseases ,Immunotherapy ,Metabolism ,T cell development ,Medical and Health Sciences ,Biological sciences ,Biomedical and clinical sciences ,Health sciences - Abstract
Purine nucleoside phosphorylase (PNP) enables the breakdown and recycling of guanine nucleosides. PNP insufficiency in humans is paradoxically associated with both immunodeficiency and autoimmunity, but the mechanistic basis for these outcomes is incompletely understood. Here, we identify two immune lineage-dependent consequences of PNP inactivation dictated by distinct gene interactions. During T cell development, PNP inactivation is synthetically lethal with downregulation of the dNTP triphosphohydrolase SAMHD1. This interaction requires deoxycytidine kinase activity and is antagonized by microenvironmental deoxycytidine. In B lymphocytes and macrophages, PNP regulates Toll-like receptor 7 signaling by controlling the levels of its (deoxy)guanosine nucleoside ligands. Overriding this regulatory mechanism promotes germinal center formation in the absence of exogenous antigen and accelerates disease in a mouse model of autoimmunity. This work reveals that one purine metabolism gene protects against immunodeficiency and autoimmunity via independent mechanisms operating in distinct immune lineages and identifies PNP as a potentially novel metabolic immune checkpoint.
- Published
- 2022
7. Porcupine Inhibition Disrupts Mitochondrial Function and Homeostasis in WNT Ligand-Addicted Pancreatic Cancer.
- Author
-
Aguilera, Kristina Y, Le, Thuc, Riahi, Rana, Lay, Anna R, Hinz, Stefan, Saadat, Edris A, Vashisht, Ajay A, Wohlschlegel, James, Donahue, Timothy R, Radu, Caius G, and Dawson, David W
- Subjects
Biochemistry and Cell Biology ,Biomedical and Clinical Sciences ,Biological Sciences ,Genetics ,Cancer ,Digestive Diseases ,Rare Diseases ,Pancreatic Cancer ,Development of treatments and therapeutic interventions ,Aetiology ,5.1 Pharmaceuticals ,2.1 Biological and endogenous factors ,Good Health and Well Being ,Acyltransferases ,Carcinoma ,Pancreatic Ductal ,Cell Line ,Tumor ,Cell Proliferation ,Homeostasis ,Humans ,Ligands ,Membrane Proteins ,Mitochondria ,Pancreatic Neoplasms ,Proteomics ,Wnt Signaling Pathway ,Oncology and Carcinogenesis ,Pharmacology and Pharmaceutical Sciences ,Oncology & Carcinogenesis ,Biochemistry and cell biology ,Oncology and carcinogenesis - Abstract
WNT signaling promotes pancreatic ductal adenocarcinoma (PDAC) through diverse effects on proliferation, differentiation, survival, and stemness. A subset of PDAC with inactivating mutations in ring finger protein 43 (RNF43) show growth dependency on autocrine WNT ligand signaling and are susceptible to agents that block WNT ligand acylation by Porcupine O-acyltransferase, which is required for proper WNT ligand processing and secretion. For this study, global transcriptomic, proteomic, and metabolomic analyses were performed to explore the therapeutic response of RNF43-mutant PDAC to the Porcupine inhibitor (PORCNi) LGK974. LGK974 disrupted cellular bioenergetics and mitochondrial function through actions that included rapid mitochondrial depolarization, reduced mitochondrial content, and inhibition of oxidative phosphorylation and tricarboxylic acid cycle. LGK974 also broadly altered transcriptional activity, downregulating genes involved in cell cycle, nucleotide metabolism, and ribosomal biogenesis and upregulating genes involved in epithelial-mesenchymal transition, hypoxia, endocytosis, and lysosomes. Autophagy and lysosomal activity were augmented in response to LGK974, which synergistically inhibited tumor cell viability in combination with chloroquine. Autocrine WNT ligand signaling dictates metabolic dependencies in RNF43-mutant PDAC through a combination of transcription dependent and independent effects linked to mitochondrial health and function. Metabolic adaptations to mitochondrial damage and bioenergetic stress represent potential targetable liabilities in combination with PORCNi for the treatment of WNT ligand-addicted PDAC.
- Published
- 2022
8. The cardiomyocyte disrupts pyrimidine biosynthesis in non-myocytes to regulate heart repair
- Author
-
Li, Shen, Yokota, Tomohiro, Wang, Ping, Hoeve, Johanna ten, Ma, Feiyang, Le, Thuc M, Abt, Evan R, Zhou, Yonggang, Wu, Rimao, Nanthavongdouangsy, Maxine, Rodriguez, Abraham, Wang, Yijie, Lin, Yen-Ju, Muranaka, Hayato, Sharpley, Mark, Braddock, Demetrios T, MacRae, Vicky E, Banerjee, Utpal, Chiou, Pei-Yu, Seldin, Marcus, Huang, Dian, Teitell, Michael, Gertsman, Ilya, Jung, Michael, Bensinger, Steven J, Damoiseaux, Robert, Faull, Kym, Pellegrini, Matteo, Lusis, Aldons, Graeber, Thomas G, Radu, Caius G, and Deb, Arjun
- Subjects
Biochemistry and Cell Biology ,Medical Physiology ,Biomedical and Clinical Sciences ,Biological Sciences ,Biotechnology ,Heart Disease ,Heart Disease - Coronary Heart Disease ,Regenerative Medicine ,Cardiovascular ,2.1 Biological and endogenous factors ,Underpinning research ,Aetiology ,1.1 Normal biological development and functioning ,Adenosine Monophosphate ,Adenosine Triphosphate ,Animals ,Heart Injuries ,Mice ,Myocardium ,Myocytes ,Cardiac ,Phosphoric Diester Hydrolases ,Pyrimidines ,Pyrophosphatases ,Regeneration ,Signal Transduction ,Cardiology ,Cardiovascular disease ,Medical and Health Sciences ,Immunology ,Biological sciences ,Biomedical and clinical sciences ,Health sciences - Abstract
Various populations of cells are recruited to the heart after cardiac injury, but little is known about whether cardiomyocytes directly regulate heart repair. Using a murine model of ischemic cardiac injury, we demonstrate that cardiomyocytes play a pivotal role in heart repair by regulating nucleotide metabolism and fates of nonmyocytes. Cardiac injury induced the expression of the ectonucleotidase ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1), which hydrolyzes extracellular ATP to form AMP. In response to AMP, cardiomyocytes released adenine and specific ribonucleosides that disrupted pyrimidine biosynthesis at the orotidine monophosphate (OMP) synthesis step and induced genotoxic stress and p53-mediated cell death of cycling nonmyocytes. As nonmyocytes are critical for heart repair, we showed that rescue of pyrimidine biosynthesis by administration of uridine or by genetic targeting of the ENPP1/AMP pathway enhanced repair after cardiac injury. We identified ENPP1 inhibitors using small molecule screening and showed that systemic administration of an ENPP1 inhibitor after heart injury rescued pyrimidine biosynthesis in nonmyocyte cells and augmented cardiac repair and postinfarct heart function. These observations demonstrate that the cardiac muscle cell regulates pyrimidine metabolism in nonmuscle cells by releasing adenine and specific nucleosides after heart injury and provide insight into how intercellular regulation of pyrimidine biosynthesis can be targeted and monitored for augmenting tissue repair.
- Published
- 2022
9. Reprogramming of nucleotide metabolism by interferon confers dependence on the replication stress response pathway in pancreatic cancer cells
- Author
-
Abt, Evan R, Le, Thuc M, Dann, Amanda M, Capri, Joseph R, Poddar, Soumya, Lok, Vincent, Li, Luyi, Liang, Keke, Creech, Amanda L, Rashid, Khalid, Kim, Woosuk, Wu, Nanping, Cui, Jing, Cho, Arthur, Lee, Hailey Rose, Rosser, Ethan W, Link, Jason M, Czernin, Johannes, Wu, Ting-Ting, Damoiseaux, Robert, Dawson, David W, Donahue, Timothy R, and Radu, Caius G
- Subjects
Biochemistry and Cell Biology ,Biological Sciences ,Rare Diseases ,Genetics ,Cancer ,Digestive Diseases ,Human Genome ,Pancreatic Cancer ,Good Health and Well Being ,Adenocarcinoma ,Animals ,Ataxia Telangiectasia Mutated Proteins ,Carcinoma ,Pancreatic Ductal ,Cell Cycle Checkpoints ,Cell Line ,Tumor ,DNA Damage ,Female ,Humans ,Interferon Type I ,Male ,Membrane Proteins ,Mice ,Mice ,Inbred NOD ,Nucleotides ,Pancreatic Neoplasms ,Protein Kinase Inhibitors ,Signal Transduction ,Xenograft Model Antitumor Assays ,STING ,interferon ,nucleotide metabolism ,pancreas cancer ,replication stress ,Medical Physiology ,Biological sciences - Abstract
We determine that type I interferon (IFN) response biomarkers are enriched in a subset of pancreatic ductal adenocarcinoma (PDAC) tumors; however, actionable vulnerabilities associated with IFN signaling have not been systematically defined. Integration of a phosphoproteomic analysis and a chemical genomics synergy screen reveals that IFN activates the replication stress response kinase ataxia telangiectasia and Rad3-related protein (ATR) in PDAC cells and sensitizes them to ATR inhibitors. IFN triggers cell-cycle arrest in S-phase, which is accompanied by nucleotide pool insufficiency and nucleoside efflux. In combination with IFN, ATR inhibitors induce lethal DNA damage and downregulate nucleotide biosynthesis. ATR inhibition limits the growth of PDAC tumors in which IFN signaling is driven by stimulator of interferon genes (STING). These results identify a cross talk between IFN, DNA replication stress response networks, and nucleotide metabolism while providing the rationale for targeted therapeutic interventions that leverage IFN signaling in tumors.
- Published
- 2022
10. STING-driven interferon signaling triggers metabolic alterations in pancreas cancer cells visualized by [18F]FLT PET imaging
- Author
-
Liang, Keke, Abt, Evan R, Le, Thuc M, Cho, Arthur, Dann, Amanda M, Cui, Jing, Li, Luyi, Rashid, Khalid, Creech, Amanda L, Wei, Liu, Ghukasyan, Razmik, Rosser, Ethan W, Wu, Nanping, Carlucci, Giuseppe, Czernin, Johannes, Donahue, Timothy R, and Radu, Caius G
- Subjects
Biomedical and Clinical Sciences ,Oncology and Carcinogenesis ,Immunology ,Rare Diseases ,Genetics ,Cancer ,Pancreatic Cancer ,Biomedical Imaging ,Digestive Diseases ,Animals ,Cell Line ,Tumor ,Dideoxynucleosides ,Female ,Fluorine Radioisotopes ,Humans ,Interferon Type I ,Male ,Membrane Proteins ,Mice ,Mice ,Inbred NOD ,Pancreatic Neoplasms ,Positron-Emission Tomography ,Signal Transduction ,Xenograft Model Antitumor Assays ,interferon ,STING ,PET imaging ,nucleotide metabolism ,pancreatic cancer - Abstract
Type I interferons (IFNs) are critical effectors of emerging cancer immunotherapies designed to activate pattern recognition receptors (PRRs). A challenge in the clinical translation of these agents is the lack of noninvasive pharmacodynamic biomarkers that indicate increased intratumoral IFN signaling following PRR activation. Positron emission tomography (PET) imaging enables the visualization of tissue metabolic activity, but whether IFN signaling-induced alterations in tumor cell metabolism can be detected using PET has not been investigated. We found that IFN signaling augments pancreatic ductal adenocarcinoma (PDAC) cell nucleotide metabolism via transcriptional induction of metabolism-associated genes including thymidine phosphorylase (TYMP). TYMP catalyzes the first step in the catabolism of thymidine, which competitively inhibits intratumoral accumulation of the nucleoside analog PET probe 3'-deoxy-3'-[18F]fluorothymidine ([18F]FLT). Accordingly, IFN treatment up-regulates cancer cell [18F]FLT uptake in the presence of thymidine, and this effect is dependent upon TYMP expression. In vivo, genetic activation of stimulator of interferon genes (STING), a PRR highly expressed in PDAC, enhances the [18F]FLT avidity of xenograft tumors. Additionally, small molecule STING agonists trigger IFN signaling-dependent TYMP expression in PDAC cells and increase tumor [18F]FLT uptake in vivo following systemic treatment. These findings indicate that [18F]FLT accumulation in tumors is sensitive to IFN signaling and that [18F]FLT PET may serve as a pharmacodynamic biomarker for STING agonist-based therapies in PDAC and possibly other malignancies characterized by elevated STING expression.
- Published
- 2021
11. Mechanisms of Resistance to Prostate-Specific Membrane Antigen–Targeted Radioligand Therapy in a Mouse Model of Prostate Cancer
- Author
-
Stuparu, Andreea D, Capri, Joseph R, Meyer, Catherine AL, Le, Thuc M, Evans-Axelsson, Susan L, Current, Kyle, Lennox, Mark, Mona, Christine E, Fendler, Wolfgang P, Calais, Jeremie, Eiber, Matthias, Dahlbom, Magnus, Czernin, Johannes, Radu, Caius G, Lückerath, Katharina, and Slavik, Roger
- Subjects
Biomedical and Clinical Sciences ,Clinical Sciences ,Oncology and Carcinogenesis ,Prostate Cancer ,Urologic Diseases ,Aging ,Cancer ,2.1 Biological and endogenous factors ,5.1 Pharmaceuticals ,Animals ,Male ,Mice ,Prostatic Neoplasms ,Disease Models ,Animal ,Cell Line ,Tumor ,Glutamate Carboxypeptidase II ,Ligands ,Humans ,Antigens ,Surface ,Phosphoproteins ,Proteome ,[Ac-225]Ac-PSMA ,[Lu-177]Lu-PSMA ,prostatecancer ,proteomics/phosphoproteomics ,DNA damage response ,[177Lu]Lu-PSMA ,[225Ac]Ac-PSMA ,prostate cancer ,Nuclear Medicine & Medical Imaging ,Clinical sciences - Abstract
Prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT) is effective against prostate cancer (PCa), but all patients relapse eventually. Poor understanding of the underlying resistance mechanisms represents a key barrier to development of more effective RLT. We investigate the proteome and phosphoproteome in a mouse model of PCa to identify signaling adaptations triggered by PSMA RLT. Methods: Therapeutic efficacy of PSMA RLT was assessed by tumor volume measurements, time to progression, and survival in C4-2 or C4-2 TP53-/- tumor-bearing nonobese diabetic scid γ-mice. Two days after RLT, the proteome and phosphoproteome were analyzed by mass spectrometry. Results: PSMA RLT significantly improved disease control in a dose-dependent manner. Proteome and phosphoproteome datasets revealed activation of genotoxic stress response pathways, including deregulation of DNA damage/replication stress response, TP53, androgen receptor, phosphatidylinositol-3-kinase/AKT, and MYC signaling. C4-2 TP53-/- tumors were less sensitive to PSMA RLT than were parental counterparts, supporting a role for TP53 in mediating RLT responsiveness. Conclusion: We identified signaling alterations that may mediate resistance to PSMA RLT in a PCa mouse model. Our data enable the development of rational synergistic RLT-combination therapies to improve outcomes for PCa patients.
- Published
- 2021
12. NAD+ depletion by type I interferon signaling sensitizes pancreatic cancer cells to NAMPT inhibition
- Author
-
Moore, Alexandra M, Zhou, Lei, Cui, Jing, Li, Luyi, Wu, Nanping, Yu, Alice, Poddar, Soumya, Liang, Keke, Abt, Evan R, Kim, Stephanie, Ghukasyan, Razmik, Khachatourian, Nooneh, Pagano, Kristina, Elliott, Irmina, Dann, Amanda M, Riahi, Rana, Le, Thuc, Dawson, David W, Radu, Caius G, and Donahue, Timothy R
- Subjects
Biochemistry and Cell Biology ,Biomedical and Clinical Sciences ,Oncology and Carcinogenesis ,Biological Sciences ,Cancer ,Rare Diseases ,Digestive Diseases ,Pancreatic Cancer ,Animals ,Apoptosis ,Biomarkers ,Tumor ,Carcinoma ,Pancreatic Ductal ,Cell Proliferation ,Cytokines ,Gene Expression Regulation ,Neoplastic ,Humans ,Interferon Type I ,Male ,Mice ,Mice ,Inbred NOD ,Mice ,SCID ,NAD ,Neoplasm Proteins ,Nicotinamide Phosphoribosyltransferase ,Pancreatic Neoplasms ,Poly(ADP-ribose) Polymerases ,Proto-Oncogene Proteins ,Signal Transduction ,Tumor Cells ,Cultured ,Xenograft Model Antitumor Assays ,pancreatic cancer ,interferon ,NAMPT ,PARP - Abstract
Emerging evidence suggests that intratumoral interferon (IFN) signaling can trigger targetable vulnerabilities. A hallmark of pancreatic ductal adenocarcinoma (PDAC) is its extensively reprogrammed metabolic network, in which nicotinamide adenine dinucleotide (NAD) and its reduced form, NADH, are critical cofactors. Here, we show that IFN signaling, present in a subset of PDAC tumors, substantially lowers NAD(H) levels through up-regulating the expression of NAD-consuming enzymes PARP9, PARP10, and PARP14. Their individual contributions to this mechanism in PDAC have not been previously delineated. Nicotinamide phosphoribosyltransferase (NAMPT) is the rate-limiting enzyme in the NAD salvage pathway, a dominant source of NAD in cancer cells. We found that IFN-induced NAD consumption increased dependence upon NAMPT for its role in recycling NAM to salvage NAD pools, thus sensitizing PDAC cells to pharmacologic NAMPT inhibition. Their combination decreased PDAC cell proliferation and invasion in vitro and suppressed orthotopic tumor growth and liver metastases in vivo.
- Published
- 2021
13. Genetic signature of prostate cancer mouse models resistant to optimized hK2 targeted α-particle therapy
- Author
-
Bicak, Mesude, Lückerath, Katharina, Kalidindi, Teja, Phelps, Michael E, Strand, Sven-Erik, Morris, Michael J, Radu, Caius G, Damoiseaux, Robert, Peltola, Mari T, Peekhaus, Norbert, Ho, Austin, Veach, Darren, Malmborg Hager, Ann-Christin, Larson, Steven M, Lilja, Hans, McDevitt, Michael R, Klein, Robert J, and Ulmert, David
- Subjects
Biomedical and Clinical Sciences ,Clinical Sciences ,Oncology and Carcinogenesis ,Cancer ,Genetics ,Urologic Diseases ,Prostate Cancer ,Biotechnology ,5.1 Pharmaceuticals ,Development of treatments and therapeutic interventions ,Actinium ,Alpha Particles ,Animals ,Biomarkers ,Tumor ,Humans ,Immunoconjugates ,Male ,Mice ,Mice ,Nude ,Neoplasms ,Experimental ,Prostate-Specific Antigen ,Prostatic Neoplasms ,Tissue Kallikreins ,hu11B6 ,225Ac ,radiommunotherapy ,prostate cancer ,hK2 - Abstract
Hu11B6 is a monoclonal antibody that internalizes in cells expressing androgen receptor (AR)-regulated prostate-specific enzyme human kallikrein-related peptidase 2 (hK2; KLK2). In multiple rodent models, Actinium-225-labeled hu11B6-IgG1 ([225Ac]hu11B6-IgG1) has shown promising treatment efficacy. In the present study, we investigated options to enhance and optimize [225Ac]hu11B6 treatment. First, we evaluated the possibility of exploiting IgG3, the IgG subclass with superior activation of complement and ability to mediate FC-γ-receptor binding, for immunotherapeutically enhanced hK2 targeted α-radioimmunotherapy. Second, we compared the therapeutic efficacy of a single high activity vs. fractionated activity. Finally, we used RNA sequencing to analyze the genomic signatures of prostate cancer that progressed after targeted α-therapy. [225Ac]hu11B6-IgG3 was a functionally enhanced alternative to [225Ac]hu11B6-IgG1 but offered no improvement of therapeutic efficacy. Progression-free survival was slightly increased with a single high activity compared to fractionated activity. Tumor-free animals succumbing after treatment revealed no evidence of treatment-associated toxicity. In addition to up-regulation of canonical aggressive prostate cancer genes, such as MMP7, ETV1, NTS, and SCHLAP1, we also noted a significant decrease in both KLK3 (prostate-specific antigen ) and FOLH1 (prostate-specific membrane antigen) but not in AR and KLK2, demonstrating efficacy of sequential [225Ac]hu11B6 in a mouse model.
- Published
- 2020
14. Investigating PSMA-Targeted Radioligand Therapy Efficacy as a Function of Cellular PSMA Levels and Intratumoral PSMA Heterogeneity
- Author
-
Current, Kyle, Meyer, Catherine, Magyar, Clara E, Mona, Christine E, Almajano, Joel, Slavik, Roger, Stuparu, Andreea D, Cheng, Chloe, Dawson, David W, Radu, Caius G, Czernin, Johannes, and Lueckerath, Katharina
- Subjects
Biomedical and Clinical Sciences ,Oncology and Carcinogenesis ,Immunology ,Cancer ,Good Health and Well Being ,Animals ,Antigens ,Surface ,DNA Damage ,Ligands ,Male ,Mice ,Prostate-Specific Antigen ,Prostatic Neoplasms ,Tumor Cells ,Cultured ,Oncology & Carcinogenesis ,Clinical sciences ,Oncology and carcinogenesis - Abstract
PurposeProstate-specific membrane antigen (PSMA) targeting radioligands deliver radiation to PSMA-expressing cells. However, the relationship between PSMA levels and intralesion heterogeneity of PSMA expression, and cytotoxic radiation by radioligand therapy (RLT) is unknown. Here we investigate RLT efficacy as function of PSMA levels/cell, and the fraction of PSMA+ cells in a tumor.Experimental designRM1 cells expressing different levels of PSMA (PSMA-, PSMA+, PSMA++, PSMA+++; study 1) or a mix of PSMA+ and PSMA- RM1 (study 2, 4) or PC-3/PC-3-PIP (study 3) cells at various ratios were injected into mice. Mice received 177Lu- (studies 1-3) or 225Ac- (study 4) PSMA617. Tumor growth was monitored. Two days post-RLT, tumors were resected in a subset of mice. Radioligand uptake and DNA damage were quantified.Results177Lu-PSMA617 efficacy increased with increasing PSMA levels (study 1) and fractions of PSMA positive cells (studies 2, 3) in both, the RM1 and PC-3-PIP models. In tumors resected 2 days post-RLT, PSMA expression correlated with 177Lu-PSMA617 uptake and the degree of DNA damage. Compared with 177Lu-PSMA617, 225Ac-PSMA617 improved overall antitumor effectiveness and tended to enhance the differences in therapeutic efficacy between experimental groups.ConclusionsIn the current models, both the degree of PSMA expression and the fraction of PSMA+ cells correlate with 177Lu-/225Ac-PSMA617 tumor uptake and DNA damage, and thus, RLT efficacy. Low or heterogeneous PSMA expression represents a resistance mechanism to RLT.See related commentary by Ravi Kumar and Hofman, p. 2774.
- Published
- 2020
15. 18F-FAC PET Visualizes Brain-Infiltrating Leukocytes in a Mouse Model of Multiple Sclerosis
- Author
-
Chen, Bao Ying, Ghezzi, Chiara, Villegas, Brendon, Quon, Andrew, Radu, Caius G, Witte, Owen N, and Clark, Peter M
- Subjects
Biomedical and Clinical Sciences ,Immunology ,Brain Disorders ,Bioengineering ,Biomedical Imaging ,Neurosciences ,Multiple Sclerosis ,Neurodegenerative ,Clinical Research ,Autoimmune Disease ,Neurological ,Animals ,Blood-Brain Barrier ,Brain ,Cytarabine ,Encephalomyelitis ,Autoimmune ,Experimental ,Female ,Immunologic Factors ,Leukocytes ,Mice ,Mice ,Inbred C57BL ,Positron-Emission Tomography ,PET imaging ,autoimmune disease ,leukocytes ,brain ,Clinical Sciences ,Nuclear Medicine & Medical Imaging ,Clinical sciences - Abstract
Brain-infiltrating leukocytes contribute to multiple sclerosis (MS) and autoimmune encephalomyelitis and likely play a role in traumatic brain injury, seizure, and stroke. Brain-infiltrating leukocytes are also primary targets for MS disease-modifying therapies. However, no method exists for noninvasively visualizing these cells in a living organism. 1-(2'-deoxy-2'-18F-fluoroarabinofuranosyl) cytosine (18F-FAC) is a PET radiotracer that measures deoxyribonucleoside salvage and accumulates preferentially in immune cells. We hypothesized that 18F-FAC PET could noninvasively image brain-infiltrating leukocytes. Methods: Healthy mice were imaged with 18F-FAC PET to quantify if this radiotracer crosses the blood-brain barrier (BBB). Experimental autoimmune encephalomyelitis (EAE) is a mouse disease model with brain-infiltrating leukocytes. To determine whether 18F-FAC accumulates in brain-infiltrating leukocytes, EAE mice were analyzed with 18F-FAC PET, digital autoradiography, and immunohistochemistry, and deoxyribonucleoside salvage activity in brain-infiltrating leukocytes was analyzed ex vivo. Fingolimod-treated EAE mice were imaged with 18F-FAC PET to assess if this approach can monitor the effect of an immunomodulatory drug on brain-infiltrating leukocytes. PET scans of individuals injected with 2-chloro-2'-deoxy-2'-18F-fluoro-9-β-d-arabinofuranosyl-adenine (18F-CFA), a PET radiotracer that measures deoxyribonucleoside salvage in humans, were analyzed to evaluate whether 18F-CFA crosses the human BBB. Results: 18F-FAC accumulates in the healthy mouse brain at levels similar to 18F-FAC in the blood (2.54 ± 0.2 and 3.04 ± 0.3 percentage injected dose per gram, respectively) indicating that 18F-FAC crosses the BBB. EAE mice accumulate 18F-FAC in the brain at 180% of the levels of control mice. Brain 18F-FAC accumulation localizes to periventricular regions with significant leukocyte infiltration, and deoxyribonucleoside salvage activity is present at similar levels in brain-infiltrating T and innate immune cells. These data suggest that 18F-FAC accumulates in brain-infiltrating leukocytes in this model. Fingolimod-treated EAE mice accumulate 18F-FAC in the brain at 37% lower levels than control-treated EAE mice, demonstrating that 18F-FAC PET can monitor therapeutic interventions in this mouse model. 18F-CFA accumulates in the human brain at 15% of blood levels (0.08 ± 0.01 and 0.54 ± 0.07 SUV, respectively), indicating that 18F-CFA does not cross the BBB in humans. Conclusion: 18F-FAC PET can visualize brain-infiltrating leukocytes in a mouse MS model and can monitor the response of these cells to an immunomodulatory drug. Translating this strategy into humans will require exploring additional radiotracers.
- Published
- 2020
16. Isoquinoline thiosemicarbazone displays potent anticancer activity with in vivo efficacy against aggressive leukemias
- Author
-
Sun, Daniel L, Poddar, Soumya, Pan, Roy D, Rosser, Ethan W, Abt, Evan R, Van Valkenburgh, Juno, Le, Thuc M, Lok, Vincent, Hernandez, Selena P, Song, Janet, Li, Joanna, Turlik, Aneta, Chen, Xiaohong, Cheng, Chi-An, Chen, Wei, Mona, Christine E, Stuparu, Andreea D, Vergnes, Laurent, Reue, Karen, Damoiseaux, Robert, Zink, Jeffrey I, Czernin, Johannes, Donahue, Timothy R, Houk, Kendall N, Jung, Michael E, and Radu, Caius G
- Subjects
Medicinal and Biomolecular Chemistry ,Organic Chemistry ,Chemical Sciences ,Rare Diseases ,Hematology ,Cancer ,Development of treatments and therapeutic interventions ,5.1 Pharmaceuticals ,Pharmacology and Pharmaceutical Sciences ,Medicinal and biomolecular chemistry ,Organic chemistry - Abstract
A potent class of isoquinoline-based α-N-heterocyclic carboxaldehyde thiosemicarbazone (HCT) compounds has been rediscovered; based upon this scaffold, three series of antiproliferative agents were synthesized through iterative rounds of methylation and fluorination modifications, with anticancer activities being potentiated by physiologically relevant levels of copper. The lead compound, HCT-13, was highly potent against a panel of pancreatic, small cell lung carcinoma, prostate cancer, and leukemia models, with IC50 values in the low-to-mid nanomolar range. Density functional theory (DFT) calculations showed that fluorination at the 6-position of HCT-13 was beneficial for ligand-copper complex formation, stability, and ease of metal-center reduction. Through a chemical genomics screen, we identify DNA damage response/replication stress response (DDR/RSR) pathways, specifically those mediated by ataxia-telangiectasia and Rad3-related protein kinase (ATR), as potential compensatory mechanism(s) of action following HCT-13 treatment. We further show that the cytotoxicity of HCT-13 is copper-dependent, that it promotes mitochondrial electron transport chain (mtETC) dysfunction, induces production of reactive oxygen species (ROS), and selectively depletes guanosine nucleotide pools. Lastly, we identify metabolic hallmarks for therapeutic target stratification and demonstrate the in vivo efficacy of HCT-13 against aggressive models of acute leukemias in mice.
- Published
- 2020
17. Metabolic Modifier Screen Reveals Secondary Targets of Protein Kinase Inhibitors within Nucleotide Metabolism
- Author
-
Abt, Evan R, Rosser, Ethan W, Durst, Matthew A, Lok, Vincent, Poddar, Soumya, Le, Thuc M, Cho, Arthur, Kim, Woosuk, Wei, Liu, Song, Janet, Capri, Joseph R, Xu, Shili, Wu, Nanping, Slavik, Roger, Jung, Michael E, Damoiseaux, Robert, Czernin, Johannes, Donahue, Timothy R, Lavie, Arnon, and Radu, Caius G
- Subjects
Biochemistry and Cell Biology ,Biological Sciences ,Binding Sites ,Cell Line ,Tumor ,Cell Survival ,Crystallography ,X-Ray ,Dihydroorotate Dehydrogenase ,Drug Design ,Equilibrative Nucleoside Transporter 1 ,Humans ,Molecular Dynamics Simulation ,Oxidoreductases Acting on CH-CH Group Donors ,Protein Kinase Inhibitors ,Pyrimidine Nucleosides ,Small Molecule Libraries ,cancer metabolism ,phenotypic screening ,pyrimidine metabolism ,target identification ,Pyrimidine metabolism ,Biochemistry and cell biology ,Medicinal and biomolecular chemistry - Abstract
Biosynthesis of the pyrimidine nucleotide uridine monophosphate (UMP) is essential for cell proliferation and is achieved by the activity of convergent de novo and salvage metabolic pathways. Here we report the development and application of a cell-based metabolic modifier screening platform that leverages the redundancy in pyrimidine metabolism for the discovery of selective UMP biosynthesis modulators. In evaluating a library of protein kinase inhibitors, we identified multiple compounds that possess nucleotide metabolism modifying activity. The JNK inhibitor JNK-IN-8 was found to potently inhibit nucleoside transport and engage ENT1. The PDK1 inhibitor OSU-03012 (also known as AR-12) and the RAF inhibitor TAK-632 were shown to inhibit the therapeutically relevant de novo pathway enzyme DHODH and their affinities were unambiguously confirmed through in vitro assays and co-crystallization with human DHODH.
- Published
- 2020
18. Targeted alpha therapy in a systemic mouse model of prostate cancer - a feasibility study
- Author
-
Stuparu, Andreea D, Meyer, Catherine AL, Evans-Axelsson, Susan L, Lückerath, Katharina, Wei, Liu H, Kim, Woosuk, Poddar, Soumya, Mona, Christine E, Dahlbom, Magnus, Girgis, Mark D, Radu, Caius G, Czernin, Johannes, and Slavik, Roger
- Subjects
Biomedical and Clinical Sciences ,Clinical Sciences ,Oncology and Carcinogenesis ,Liver Disease ,Urologic Diseases ,Digestive Diseases ,Prostate Cancer ,Prevention ,Cancer ,Good Health and Well Being ,Actinium ,Alpha Particles ,Animals ,Cell Line ,Tumor ,Dipeptides ,Disease Models ,Animal ,Feasibility Studies ,Heterocyclic Compounds ,1-Ring ,Humans ,Male ,Mice ,Prostate-Specific Antigen ,Prostatic Neoplasms ,Castration-Resistant ,Radiopharmaceuticals ,PSMA ,targeted alpha therapy ,prostate cancer ,metastatic mouse model ,actinium ,Oncology and carcinogenesis - Abstract
225Ac-PSMA-617 targeted-therapy has demonstrated efficacy in 75-85% of patients; however, responses are not durable. We aimed to establish translatable mouse models of disseminated prostate cancer (PCa) to evaluate effectiveness of 225Ac-PSMA-617 at various disease stages. Methods: C4-2, C4-2B, or 22Rv1 cells were injected into the left ventricle of male NSG mice. Disease progression was monitored using bioluminescence imaging (BLI). For treatment, mice were injected with 40 kBq 225Ac-PSMA-617 at one (early treatment cohort) or three weeks (late treatment cohort) post-inoculation. Treatment efficacy was monitored by BLI of whole-body tumor burden. Mice were sacrificed based on body conditioning score. Results: C4-2 cells yielded metastases in liver, lungs, spleen, stomach, bones, and brain - achieving a clinically relevant model of widespread metastatic disease. The disease burden in the early treatment cohort was stable over 27 weeks in 5/9 mice and progressive in 4/9 mice. These mice were sacrificed due to brain metastases. Median survival of the late treatment cohort was superior to controls (13 vs. 7 weeks; p
- Published
- 2020
19. Histone deacetylase inhibition is synthetically lethal with arginine deprivation in pancreatic cancers with low argininosuccinate synthetase 1 expression
- Author
-
Kim, Stephanie S, Xu, Shili, Cui, Jing, Poddar, Soumya, Le, Thuc M, Hayrapetyan, Hovhannes, Li, Luyi, Wu, Nanping, Moore, Alexandra M, Zhou, Lei, Yu, Alice C, Dann, Amanda M, Elliott, Irmina A, Abt, Evan R, Kim, Woosuk, Dawson, David W, Radu, Caius G, and Donahue, Timothy R
- Subjects
Biomedical and Clinical Sciences ,Oncology and Carcinogenesis ,Genetics ,Cancer ,Digestive Diseases ,Rare Diseases ,Orphan Drug ,Pancreatic Cancer ,Biotechnology ,Development of treatments and therapeutic interventions ,5.1 Pharmaceuticals ,Animals ,Antineoplastic Agents ,Arginine ,Argininosuccinate Synthase ,Carcinoma ,Pancreatic Ductal ,Cell Line ,Tumor ,Female ,Histone Deacetylase Inhibitors ,Histone Deacetylases ,Humans ,Hydrolases ,Male ,Mice ,Mice ,Inbred NOD ,Mice ,SCID ,Middle Aged ,Molecular Targeted Therapy ,Pancreatic Neoplasms ,Panobinostat ,Polyethylene Glycols ,Prognosis ,Synthetic Lethal Mutations ,HDAC inhibitor ,arginine deprivation ,pancreatic cancer ,DNA damage ,synthetic lethality ,Oncology and carcinogenesis - Abstract
Arginine (Arg) deprivation is a promising therapeutic approach for tumors with low argininosuccinate synthetase 1 (ASS1) expression. However, its efficacy as a single agent therapy needs to be improved as resistance is frequently observed. Methods: A tissue microarray was performed to assess ASS1 expression in surgical specimens of pancreatic ductal adenocarcinoma (PDAC) and its correlation with disease prognosis. An RNA-Seq analysis examined the role of ASS1 in regulating the global gene transcriptome. A high throughput screen of FDA-approved oncology drugs identified synthetic lethality between histone deacetylase (HDAC) inhibitors and Arg deprivation in PDAC cells with low ASS1 expression. We examined HDAC inhibitor panobinostat (PAN) and Arg deprivation in a panel of human PDAC cell lines, in ASS1-high and -knockdown/knockout isogenic models, in both anchorage-dependent and -independent cultures, and in multicellular complex cultures that model the PDAC tumor microenvironment. We examined the effects of combined Arg deprivation and PAN on DNA damage and the protein levels of key DNA repair enzymes. We also evaluated the efficacy of PAN and ADI-PEG20 (an Arg-degrading agent currently in Phase 2 clinical trials) in xenograft models with ASS1-low and -high PDAC tumors. Results: Low ASS1 protein level is a negative prognostic indicator in PDAC. Arg deprivation in ASS1-deficient PDAC cells upregulated asparagine synthetase (ASNS) which redirected aspartate (Asp) from being used for de novo nucleotide biosynthesis, thus causing nucleotide insufficiency and impairing cell cycle S-phase progression. Comprehensively validated, HDAC inhibitors and Arg deprivation showed synthetic lethality in ASS1-low PDAC cells. Mechanistically, combined Arg deprivation and HDAC inhibition triggered degradation of a key DNA repair enzyme C-terminal-binding protein interacting protein (CtIP), resulting in DNA damage and apoptosis. In addition, S-phase-retained ASS1-low PDAC cells (due to Arg deprivation) were also sensitized to DNA damage, thus yielding effective cell death. Compared to single agents, the combination of PAN and ADI-PEG20 showed better efficacy in suppressing ASS1-low PDAC tumor growth in mouse xenograft models. Conclusion: The combination of PAN and ADI-PEG20 is a rational translational therapeutic strategy for treating ASS1-low PDAC tumors through synergistic induction of DNA damage.
- Published
- 2020
20. Development of Hematopoietic Stem Cell-Engineered Invariant Natural Killer T Cell Therapy for Cancer
- Author
-
Zhu, Yanni, Smith, Drake J, Zhou, Yang, Li, Yan-Ruide, Yu, Jiaji, Lee, Derek, Wang, Yu-Chen, Di Biase, Stefano, Wang, Xi, Hardoy, Christian, Ku, Josh, Tsao, Tasha, Lin, Levina J, Pham, Alexander T, Moon, Heesung, McLaughlin, Jami, Cheng, Donghui, Hollis, Roger P, Campo-Fernandez, Beatriz, Urbinati, Fabrizia, Wei, Liu, Pang, Larry, Rezek, Valerie, Berent-Maoz, Beata, Macabali, Mignonette H, Gjertson, David, Wang, Xiaoyan, Galic, Zoran, Kitchen, Scott G, An, Dong Sung, Hu-Lieskovan, Siwen, Kaplan-Lefko, Paula J, De Oliveira, Satiro N, Seet, Christopher S, Larson, Sarah M, Forman, Stephen J, Heath, James R, Zack, Jerome A, Crooks, Gay M, Radu, Caius G, Ribas, Antoni, Kohn, Donald B, Witte, Owen N, and Yang, Lili
- Subjects
Biochemistry and Cell Biology ,Biomedical and Clinical Sciences ,Biological Sciences ,Immunology ,Medical Biotechnology ,Oncology and Carcinogenesis ,Stem Cell Research - Nonembryonic - Human ,Regenerative Medicine ,Genetics ,Biotechnology ,Cancer ,Stem Cell Research ,Stem Cell Research - Nonembryonic - Non-Human ,Hematology ,Gene Therapy ,Development of treatments and therapeutic interventions ,5.1 Pharmaceuticals ,5.2 Cellular and gene therapies ,Animals ,Cells ,Cultured ,Genetic Engineering ,Hematopoietic Stem Cells ,Humans ,Immunotherapy ,Adoptive ,Mice ,Mice ,SCID ,Natural Killer T-Cells ,Neoplasms ,Receptors ,Antigen ,T-Cell ,Xenograft Model Antitumor Assays ,HSC ,HSC transfer ,HSCT ,T cell receptor ,TCR ,cancer immunotherapy ,cell therapy ,gene therapy ,hematopoietic stem cell ,iNKT ,invariant natural killer T cell ,preclinical development ,sr39TK suicide gene ,stem cell therapy ,Medical and Health Sciences ,Developmental Biology ,Biological sciences ,Biomedical and clinical sciences - Abstract
Invariant natural killer T (iNKT) cells are potent immune cells for targeting cancer; however, their clinical application has been hindered by their low numbers in cancer patients. Here, we developed a proof-of-concept for hematopoietic stem cell-engineered iNKT (HSC-iNKT) cell therapy with the potential to provide therapeutic levels of iNKT cells for a patient's lifetime. Using a human HSC engrafted mouse model and a human iNKT TCR gene engineering approach, we demonstrated the efficient and long-term generation of HSC-iNKT cells in vivo. These HSC-iNKT cells closely resembled endogenous human iNKT cells, could deploy multiple mechanisms to attack tumor cells, and effectively suppressed tumor growth in vivo in multiple human tumor xenograft mouse models. Preclinical safety studies showed no toxicity or tumorigenicity of the HSC-iNKT cell therapy. Collectively, these results demonstrated the feasibility, safety, and cancer therapy potential of the proposed HSC-iNKT cell therapy and laid a foundation for future clinical development.
- Published
- 2019
21. STING-driven interferon signaling triggers metabolic alterations in pancreas cancer cells visualized by [ 18 F]FLT PET imaging
- Author
-
Liang, Keke, Abt, Evan R., Le, Thuc M., Cho, Arthur, Dann, Amanda M., Cui, Jing, Li, Luyi, Rashid, Khalid, Creech, Amanda L., Wei, Liu, Ghukasyan, Razmik, Rosser, Ethan W., Wu, Nanping, Carlucci, Giuseppe, Czernin, Johannes, Donahue, Timothy R., and Radu, Caius G.
- Published
- 2021
22. Lysosome inhibition sensitizes pancreatic cancer to replication stress by aspartate depletion
- Author
-
Elliott, Irmina A, Dann, Amanda M, Xu, Shili, Kim, Stephanie S, Abt, Evan R, Kim, Woosuk, Poddar, Soumya, Moore, Alexandra, Zhou, Lei, Williams, Jennifer L, Capri, Joseph R, Ghukasyan, Razmik, Matsumura, Cynthia, Tucker, D Andrew, Armstrong, Wesley R, Cabebe, Anthony E, Wu, Nanping, Li, Luyi, Le, Thuc M, Radu, Caius G, and Donahue, Timothy R
- Subjects
Biochemistry and Cell Biology ,Biological Sciences ,Digestive Diseases ,Cancer ,Pancreatic Cancer ,Rare Diseases ,Development of treatments and therapeutic interventions ,5.1 Pharmaceuticals ,Animals ,Aspartic Acid ,Carcinoma ,Pancreatic Ductal ,Cell Line ,Tumor ,Chloroquine ,Female ,Humans ,Lysosomes ,Male ,Mice ,Mitochondria ,Pancreatic Neoplasms ,Stress ,Physiological ,Xenograft Model Antitumor Assays ,lysosome ,autophagy ,replication stress ,pancreatic cancer ,nucleotide metabolism - Abstract
Functional lysosomes mediate autophagy and macropinocytosis for nutrient acquisition. Pancreatic ductal adenocarcinoma (PDAC) tumors exhibit high basal lysosomal activity, and inhibition of lysosome function suppresses PDAC cell proliferation and tumor growth. However, the codependencies induced by lysosomal inhibition in PDAC have not been systematically explored. We performed a comprehensive pharmacological inhibition screen of the protein kinome and found that replication stress response (RSR) inhibitors were synthetically lethal with chloroquine (CQ) in PDAC cells. CQ treatment reduced de novo nucleotide biosynthesis and induced replication stress. We found that CQ treatment caused mitochondrial dysfunction and depletion of aspartate, an essential precursor for de novo nucleotide synthesis, as an underlying mechanism. Supplementation with aspartate partially rescued the phenotypes induced by CQ. The synergy of CQ and the RSR inhibitor VE-822 was comprehensively validated in both 2D and 3D cultures of PDAC cell lines, a heterotypic spheroid culture with cancer-associated fibroblasts, and in vivo xenograft and syngeneic PDAC mouse models. These results indicate a codependency on functional lysosomes and RSR in PDAC and support the translational potential of the combination of CQ and RSR inhibitors.
- Published
- 2019
23. Preclinical evaluation of PSMA expression in response to androgen receptor blockade for theranostics in prostate cancer
- Author
-
Lückerath, Katharina, Wei, Liu, Fendler, Wolfgang P, Evans-Axelsson, Susan, Stuparu, Andreea D, Slavik, Roger, Mona, Christine E, Calais, Jeremie, Rettig, Matthew, Reiter, Robert E, Herrmann, Ken, Radu, Caius G, Czernin, Johannes, and Eiber, Matthias
- Subjects
Biomedical and Clinical Sciences ,Clinical Sciences ,Oncology and Carcinogenesis ,Clinical Research ,Aging ,Urologic Diseases ,Clinical Trials and Supportive Activities ,Biomedical Imaging ,Prostate Cancer ,Radiation Oncology ,Cancer ,5.1 Pharmaceuticals ,PSMA ,Prostate cancer ,Ga-68-PSMA PET ,CT ,Androgen receptor blockade ,Radioligand therapy ,68Ga-PSMA PET/CT ,Medical Biochemistry and Metabolomics ,Clinical sciences ,Oncology and carcinogenesis - Abstract
BackgroundProstate-specific membrane antigen (PSMA)-directed radioligand therapy (RLT) is a promising yet not curative approach in castration-resistant (CR) prostate cancer (PC). Rational combination therapies may improve treatment efficacy. Here, we explored the effect of androgen receptor blockade (ARB) on PSMA expression visualized by PET and its potential additive effect when combined with 177Lu-PSMA RLT in a mouse model of prostate cancer.MethodsMice bearing human CRPC (C4-2 cells) xenografts were treated with 10 mg/kg enzalutamide (ENZ), with 50 mg/kg bicalutamide (BIC), or vehicle (control) for 21 days. PSMA expression was evaluated by 68Ga-PSMA11 PET/CT and quantified by flow cytometry of tumor fine needle aspirations before treatment and on days 23, 29, 34, and 39 post-therapy induction. For the RLT combination approach, mice bearing C4-2 tumors were treated with 10 mg/kg ENZ or vehicle for 21 days before receiving either 15 MBq (84 GBq/μmol) 177Lu-PSMA617 or vehicle. DNA damage was assessed as phospho-γH2A.X foci in tumor biopsies. Reduction of tumor volume on CT and survival were used as study endpoints.ResultsTumor growth was delayed by ARB while 68Ga-PSMA11 uptake increased up to 2.3-fold over time when compared to controls. ABR-induced upregulation of PSMA expression was confirmed by flow cytometry. Phospho-γH2A.X levels increased 1.8- and 3.4-fold at 48 h in response to single treatment ENZ or RLT and ENZ+RLT, respectively. Despite significantly greater DNA damage and persistent increase of PSMA expression at the time of RLT, no additional tumor growth retardation was observed in the ENZ+RLT group (vs. RLT only, p = 0.372 at day 81). Median survival did not improve significantly when ENZ was combined with RLT.ConclusionARB-mediated increases in PSMA expression in PC xenografts were evident by 68Ga-PSMA11 PET imaging and flow cytometry. 177Lu-PSMA617 effectively decreased C4-2 tumor size. However, while pre-treatment with ARB increased DNA damage significantly, it did not result in synergistic effects when combined with RLT.
- Published
- 2018
24. Metabolic characterization of isocitrate dehydrogenase (IDH) mutant and IDH wildtype gliomaspheres uncovers cell type-specific vulnerabilities
- Author
-
Garrett, Matthew, Sperry, Jantzen, Braas, Daniel, Yan, Weihong, Le, Thuc M, Mottahedeh, Jack, Ludwig, Kirsten, Eskin, Ascia, Qin, Yue, Levy, Rachelle, Breunig, Joshua J, Pajonk, Frank, Graeber, Thomas G, Radu, Caius G, Christofk, Heather, Prins, Robert M, Lai, Albert, Liau, Linda M, Coppola, Giovanni, and Kornblum, Harley I
- Subjects
Medical Biochemistry and Metabolomics ,Biomedical and Clinical Sciences ,Cancer ,Genetics ,Brain Disorders ,Rare Diseases ,Brain Cancer ,2-hydroxyglutarate ,Metabolism ,Nucleotide ,Radiation ,Glioma ,Medical biochemistry and metabolomics ,Oncology and carcinogenesis - Abstract
BackgroundThere is considerable interest in defining the metabolic abnormalities of IDH mutant tumors to exploit for therapy. While most studies have attempted to discern function by using cell lines transduced with exogenous IDH mutant enzyme, in this study, we perform unbiased metabolomics to discover metabolic differences between a cohort of patient-derived IDH1 mutant and IDH wildtype gliomaspheres.MethodsUsing both our own microarray and the TCGA datasets, we performed KEGG analysis to define pathways differentially enriched in IDH1 mutant and IDH wildtype cells and tumors. Liquid chromatography coupled to mass spectrometry analysis with labeled glucose and deoxycytidine tracers was used to determine differences in overall cellular metabolism and nucleotide synthesis. Radiation-induced DNA damage and repair capacity was assessed using a comet assay. Differences between endogenous IDH1 mutant metabolism and that of IDH wildtype cells transduced with the IDH1 (R132H) mutation were also investigated.ResultsOur KEGG analysis revealed that IDH wildtype cells were enriched for pathways involved in de novo nucleotide synthesis, while IDH1 mutant cells were enriched for pathways involved in DNA repair. LC-MS analysis with fully labeled 13C-glucose revealed distinct labeling patterns between IDH1 mutant and wildtype cells. Additional LC-MS tracing experiments confirmed increased de novo nucleotide synthesis in IDH wildtype cells relative to IDH1 mutant cells. Endogenous IDH1 mutant cultures incurred less DNA damage than IDH wildtype cultures and sustained better overall growth following X-ray radiation. Overexpression of mutant IDH1 in a wildtype line did not reproduce the range of metabolic differences observed in lines expressing endogenous mutations, but resulted in depletion of glutamine and TCA cycle intermediates, an increase in DNA damage following radiation, and a rise in intracellular ROS.ConclusionsThese results demonstrate that IDH1 mutant and IDH wildtype cells are easily distinguishable metabolically by analyzing expression profiles and glucose consumption. Our results also highlight important differences in nucleotide synthesis utilization and DNA repair capacity that could be exploited for therapy. Altogether, this study demonstrates that IDH1 mutant gliomas are a distinct subclass of glioma with a less malignant, but also therapy-resistant, metabolic profile that will likely require distinct modes of therapy.
- Published
- 2018
25. Detection Threshold and Reproducibility of 68Ga-PSMA11 PET/CT in a Mouse Model of Prostate Cancer
- Author
-
Lückerath, Katharina, Stuparu, Andreea D, Wei, Liu, Kim, Woosuk, Radu, Caius G, Mona, Christine E, Calais, Jeremie, Rettig, Matthew, Reiter, Robert E, Czernin, Johannes, Slavik, Roger, Herrmann, Ken, Eiber, Matthias, and Fendler, Wolfgang P
- Subjects
Biomedical and Clinical Sciences ,Clinical Sciences ,Oncology and Carcinogenesis ,Cancer ,Urologic Diseases ,Biomedical Imaging ,Bioengineering ,Prostate Cancer ,Good Health and Well Being ,Animals ,Biological Transport ,Cell Line ,Tumor ,Disease Models ,Animal ,Edetic Acid ,Gallium Isotopes ,Gallium Radioisotopes ,Gene Expression Regulation ,Neoplastic ,Image Processing ,Computer-Assisted ,Male ,Mice ,Mice ,Inbred C57BL ,Oligopeptides ,Positron Emission Tomography Computed Tomography ,Prostatic Neoplasms ,Reproducibility of Results ,PSMA ,prostate cancer ,PET ,threshold ,reproducibility ,Nuclear Medicine & Medical Imaging ,Clinical sciences - Abstract
To improve prostate-specific membrane antigen (PSMA)-targeted theranostic approaches, robust murine models of prostate cancer are needed. However, important characteristics of preclinical PSMA imaging-that is, the reproducibility of the imaging signal and the relationship between quantitative cell surface PSMA expression and lesion detectability with small-animal PET/CT-have not been defined yet. Methods: Murine prostate cancer RM1 sublines (ras myc transformed cells of C57BL/6 prostate origin) expressing varying levels of human PSMA were injected into the shoulder of C57BL/6 mice on day 0. 68Ga-PSMA11 PET/CT was performed on days 7 and 8 and interpreted by 2 masked readers to determine interday and interreader reproducibility. PSMA expression was quantified on days 7 and 8 by flow cytometry of fine-needle aspiration tumor biopsy samples. Cell surface PSMA expression was correlated with PET signal. The threshold for PET positivity was based on the clinical Prostate Cancer Molecular Imaging Standardized Evaluation (PROMISE) criteria. Results: The maximum and average percentages of injected 68Ga-PSMA11 activity per gram of tissue (%IA/g) correlated nearly perfectly as determined by 2 independent readers and on 2 separate days (intraclass correlation coefficient, 1.00/0.89 and 0.95/0.88, respectively). The number of PSMA molecules per cell increased from the RM1-yellow fluorescent protein subline (PSMA-; 2,000/cell) to the RM1-low subline (PSMA+; 17,000/cell), the RM1-medium subline (PSMA++; 22,000/cell), and the RM1-PGLS subline (PSMA-positive, green fluorescent protein-positive, and luciferase-positive; PSMA+++; 45,000/cell). Expression levels correlated with the visual positivity rate on 68Ga-PSMA11 PET and with the PSMA PET %IA/g. The PSMA threshold for PET positivity was approximately 20,000 per cell. Signal correlation was close at lower PSMA levels (RM1-low to RM1-medium; 10-23 %IA/g) but was lost at higher PSMA levels (RM1-medium to RM1-PGLS; 23-27 %IA/g). Conclusion: The in vivo relationship between 68Ga-PSMA11 PET/CT and PSMA expression level in a murine model of prostate cancer was robust for lower cell surface PSMA expression levels (≤22,000/cell). Thus, preclinical 68Ga-PSMA11 PET/CT can be used as an imaging biomarker to test PSMA-targeted interventions in murine models.
- Published
- 2018
26. Establishing 177Lu-PSMA-617 Radioligand Therapy in a Syngeneic Model of Murine Prostate Cancer
- Author
-
Fendler, Wolfgang P, Stuparu, Andreea D, Evans-Axelsson, Susan, Lückerath, Katharina, Wei, Liu, Kim, Woosuk, Poddar, Soumya, Said, Jonathan, Radu, Caius G, Eiber, Matthias, Czernin, Johannes, Slavik, Roger, and Herrmann, Ken
- Subjects
Biomedical and Clinical Sciences ,Clinical Sciences ,Oncology and Carcinogenesis ,Prostate Cancer ,Cancer ,Biomedical Imaging ,Urologic Diseases ,Animals ,Cell Line ,Tumor ,DNA Breaks ,Double-Stranded ,Dipeptides ,Fluorodeoxyglucose F18 ,Heterocyclic Compounds ,1-Ring ,Humans ,Immunohistochemistry ,Lutetium ,Male ,Mice ,Mice ,Inbred C57BL ,Neoplasm Transplantation ,Positron-Emission Tomography ,Prostate-Specific Antigen ,Prostatic Neoplasms ,Radiopharmaceuticals ,Tissue Distribution ,Tumor Burden ,syngeneic ,PSMA ,prostate cancer ,Lu-177 ,specific activity ,177Lu ,Nuclear Medicine & Medical Imaging ,Clinical sciences - Abstract
Clinical 177Lu-PSMA-617 radioligand therapy (RLT) is applied in advanced-stage prostate cancer. However, to the best of our knowledge murine models to study the biologic effects of various activity levels have not been established. The aim of this study was to optimize specific and total activity for 177Lu-PSMA-617 RLT in a syngeneic model of murine prostate cancer. Methods: Murine-reconstituted, oncogene-driven prostate cancer cells (0.1 × 106) (RM1), transduced to express human prostate-specific membrane antigen (PSMA), were injected into the left flank of C57Bl6 immunocompetent mice. RLT was performed by administering a single tail vein injection of 177Lu-PSMA-617 at different formulations for specific (60 MBq at high, 62 MBq/nmol; intermediate, 31 MBq/nmol; or low 15 MBq/nmol specific activity) or total activity (30, 60, or 120 MBq). Organ distribution was determined by ex vivo γ-counter measurement. DNA double-strand breaks were measured using anti-gamma-H2A.X (phospho S139) immunohistochemistry. Efficacy was assessed by serial CT tumor volumetry and 18F-FDG PET metabolic volume. Toxicity was evaluated 4 wk after the start of RLT. Results: Mean tumor-to-kidney ratios ± SEM were 19 ± 5, 10 ± 5, and 2 ± 0 for high, intermediate, and low (each n = 3) specific activity, respectively. Four of 6 (67%) mice treated with intermediate or high specific activity and none of 6 (0%) mice treated with low specific activity or formulation demonstrated significant DNA double-strand breaks (≥5% γ-H2A.X-positive cells). High when compared with intermediate or low specific activity resulted in a lower mean ± SEM tumor load by histopathology (vital tissue, 4 ± 2 vs. 8 ± 3 mm2; n = 3 vs. 6), day-4 18F-FDG PET (metabolic volume, 87 ± 23 vs. 118 ± 14 mm3; n = 6 vs. 12), and day-7 CT (volume, 323 ± 122 vs. 590 ± 46 mm3; n = 3 vs. 6; P = 0.039). 177Lu-PSMA-617 (120 MBq) with high specific activity induced superior tumor growth inhibition (P = 0.021, n = 5/group) without subacute hematologic toxicity (n = 3/group). Conclusion:177Lu-PSMA-617 (120 MBq) and high specific activity resulted in the highest efficacy in a syngeneic model of murine prostate cancer. The model will be useful for studying the effects of PSMA-directed RLT combined with potentially synergistic pharmacologic approaches.
- Published
- 2017
27. Targeting host deoxycytidine kinase mitigates Staphylococcus aureus abscess formation
- Author
-
Winstel, Volker, primary, Abt, Evan R., additional, Le, Thuc M., additional, and Radu, Caius G., additional
- Published
- 2024
- Full Text
- View/download PDF
28. Author Response: Targeting host deoxycytidine kinase mitigates Staphylococcus aureus abscess formation
- Author
-
Winstel, Volker, primary, Abt, Evan R., additional, Le, Thuc M., additional, and Radu, Caius G., additional
- Published
- 2024
- Full Text
- View/download PDF
29. ATR inhibition facilitates targeting of leukemia dependence on convergent nucleotide biosynthetic pathways.
- Author
-
Le, Thuc M, Poddar, Soumya, Capri, Joseph R, Abt, Evan R, Kim, Woosuk, Wei, Liu, Uong, Nhu T, Cheng, Chloe M, Braas, Daniel, Nikanjam, Mina, Rix, Peter, Merkurjev, Daria, Zaretsky, Jesse, Kornblum, Harley I, Ribas, Antoni, Herschman, Harvey R, Whitelegge, Julian, Faull, Kym F, Donahue, Timothy R, Czernin, Johannes, and Radu, Caius G
- Subjects
Animals ,Mice ,Inbred C57BL ,Humans ,Mice ,Ribonucleotide Reductases ,Deoxycytidine Kinase ,Nucleotides ,DNA Replication ,Female ,Biosynthetic Pathways ,Precursor Cell Lymphoblastic Leukemia-Lymphoma ,Ataxia Telangiectasia Mutated Proteins ,Rare Diseases ,Biotechnology ,Childhood Leukemia ,Pediatric ,Pediatric Cancer ,Orphan Drug ,Cancer ,Hematology ,5.1 Pharmaceuticals ,2.1 Biological and endogenous factors - Abstract
Leukemia cells rely on two nucleotide biosynthetic pathways, de novo and salvage, to produce dNTPs for DNA replication. Here, using metabolomic, proteomic, and phosphoproteomic approaches, we show that inhibition of the replication stress sensing kinase ataxia telangiectasia and Rad3-related protein (ATR) reduces the output of both de novo and salvage pathways by regulating the activity of their respective rate-limiting enzymes, ribonucleotide reductase (RNR) and deoxycytidine kinase (dCK), via distinct molecular mechanisms. Quantification of nucleotide biosynthesis in ATR-inhibited acute lymphoblastic leukemia (ALL) cells reveals substantial remaining de novo and salvage activities, and could not eliminate the disease in vivo. However, targeting these remaining activities with RNR and dCK inhibitors triggers lethal replication stress in vitro and long-term disease-free survival in mice with B-ALL, without detectable toxicity. Thus the functional interplay between alternative nucleotide biosynthetic routes and ATR provides therapeutic opportunities in leukemia and potentially other cancers.Leukemic cells depend on the nucleotide synthesis pathway to proliferate. Here the authors use metabolomics and proteomics to show that inhibition of ATR reduced the activity of these pathways thus providing a valuable therapeutic target in leukemia.
- Published
- 2017
30. Human Biodistribution and Radiation Dosimetry of 18F-Clofarabine, a PET Probe Targeting the Deoxyribonucleoside Salvage Pathway
- Author
-
Barrio, Martin J, Spick, Claudio, Radu, Caius G, Lassmann, Michael, Eberlein, Uta, Allen-Auerbach, Martin, Schiepers, Christiaan, Slavik, Roger, Czernin, Johannes, and Herrmann, Ken
- Subjects
Biomedical and Clinical Sciences ,Clinical Sciences ,Oncology and Carcinogenesis ,Biomedical Imaging ,Urologic Diseases ,Digestive Diseases ,Cancer ,Liver Disease ,Clinical Research ,Bioengineering ,5.1 Pharmaceuticals ,4.1 Discovery and preclinical testing of markers and technologies ,Generic health relevance ,Absorption ,Radiation ,Adenine Nucleotides ,Aged ,Arabinonucleosides ,Clofarabine ,Deoxycytidine Kinase ,Deoxyribonucleosides ,Female ,Fluorine Radioisotopes ,Humans ,Male ,Metabolic Clearance Rate ,Middle Aged ,Molecular Imaging ,Organ Specificity ,Positron-Emission Tomography ,Radiation Dosage ,Radiopharmaceuticals ,Signal Transduction ,Tissue Distribution ,Whole-Body Counting ,PET ,dosimetry ,clofarabine ,Nuclear Medicine & Medical Imaging ,Clinical sciences - Abstract
18F-clofarabine, a nucleotide purine analog, is a substrate for deoxycytidine kinase (dCK), a key enzyme in the deoxyribonucleoside salvage pathway. 18F-clofarabine might be used to measure dCK expression and thus serve as a predictive biomarker for tumor responses to dCK-dependent prodrugs or small-molecule dCK inhibitors, respectively. As a prerequisite for clinical translation, we determined the human whole-body and organ dosimetry of 18F-clofarabine. Methods: Five healthy volunteers were injected intravenously with 232.4 ± 1.5 MBq of 18F-clofarabine. Immediately after tracer injection, a dynamic scan of the entire chest was acquired for 30 min. This was followed by 3 static whole-body scans at 45, 90, and 135 min after tracer injection. Regions of interest were drawn around multiple organs on the CT scan and copied to the PET scans. Organ activity was determined and absorbed dose was estimated with OLINDA/EXM software. Results: The urinary bladder (critical organ), liver, kidney, and spleen exhibited the highest uptake. For an activity of 250 MBq, the absorbed doses in the bladder, liver, kidney, and spleen were 58.5, 6.6, 6.3, and 4.3 mGy, respectively. The average effective dose coefficient was 5.1 mSv. Conclusion: Our results hint that 18F-clofarabine can be used safely in humans to measure tissue dCK expression. Future studies will determine whether 18F-clofarabine may serve as a predictive biomarker for responses to dCK-dependent prodrugs or small-molecule dCK inhibitors.
- Published
- 2017
31. Inhibition of Nucleotide Synthesis Targets Brain Tumor Stem Cells in a Subset of Glioblastoma
- Author
-
Laks, Dan R, Ta, Lisa, Crisman, Thomas J, Gao, Fuying, Coppola, Giovanni, Radu, Caius G, Nathanson, David A, and Kornblum, Harley I
- Subjects
Biological Sciences ,Biomedical and Clinical Sciences ,Oncology and Carcinogenesis ,Neurosciences ,Rare Diseases ,Brain Disorders ,Cancer ,Brain Cancer ,Animals ,Brain Neoplasms ,Cell Line ,Tumor ,Cell Proliferation ,Cell Survival ,Deoxycytidine Kinase ,Drug Resistance ,Neoplasm ,Enzyme Inhibitors ,Glioblastoma ,Humans ,Mice ,Neoplastic Stem Cells ,PAX3 Transcription Factor ,PTEN Phosphohydrolase ,Pyrimidines ,Signal Transduction ,Sulfonamides ,Thymidine ,Xenograft Model Antitumor Assays ,Pharmacology and Pharmaceutical Sciences ,Oncology & Carcinogenesis ,Biochemistry and cell biology ,Oncology and carcinogenesis - Abstract
Inhibition of both the de novo (DNP) and salvage (NSP) pathways of nucleoside synthesis has been demonstrated to impair leukemia cells. We endeavored to determine whether this approach would be efficacious in glioblastoma. To diminish nucleoside biosynthesis, we utilized compound DI-39, which selectively targets NSP, in combination with thymidine (dT), which selectively targets DNP. We employed in vitro and ex vivo models to determine the effects of pretreatment with dT + DI-39 on brain tumor stem cells (BTSC). Here, we demonstrate that this combinatorial therapy elicits a differential response across a spectrum of human patient-derived glioblastoma cultures. As determined by apoptotic markers, most cultures were relatively resistant to treatment, although a subset was highly sensitive. Sensitivity was unrelated to S-phase delay and to DNA damage induced by treatment. Bioinformatics analysis indicated that response across cultures was associated with the transcription factor PAX3 (associated with resistance) and with canonical pathways, including the nucleotide excision repair pathway, PTEN (associated with resistance), PI3K/AKT (associated with sensitivity), and ErbB2-ErbB3. Our in vitro assays demonstrated that, in sensitive cultures, clonal sphere formation was reduced upon removal from pretreatment. In contrast, in a resistant culture, clonal sphere formation was slightly increased upon removal from pretreatment. Moreover, in an intracranial xenograft model, pretreatment of a sensitive culture caused significantly smaller and fewer tumors. In a resistant culture, tumors were equivalent irrespective of pretreatment. These results indicate that, in the subset of sensitive glioblastoma, BTSCs are targeted by inhibition of pyrimidine synthesis. Mol Cancer Ther; 15(6); 1271-8. ©2016 AACR.
- Published
- 2016
32. [18F]CFA as a clinically translatable probe for PET imaging of deoxycytidine kinase activity
- Author
-
Kim, Woosuk, Le, Thuc M, Wei, Liu, Poddar, Soumya, Bazzy, Jimmy, Wang, Xuemeng, Uong, Nhu T, Abt, Evan R, Capri, Joseph R, Austin, Wayne R, Van Valkenburgh, Juno S, Steele, Dalton, Gipson, Raymond M, Slavik, Roger, Cabebe, Anthony E, Taechariyakul, Thotsophon, Yaghoubi, Shahriar S, Lee, Jason T, Sadeghi, Saman, Lavie, Arnon, Faull, Kym F, Witte, Owen N, Donahue, Timothy R, Phelps, Michael E, Herschman, Harvey R, Herrmann, Ken, Czernin, Johannes, and Radu, Caius G
- Subjects
Biomedical and Clinical Sciences ,Oncology and Carcinogenesis ,Biomedical Imaging ,Orphan Drug ,Cancer ,Rare Diseases ,Hematology ,Adenine Nucleotides ,Animals ,Antineoplastic Agents ,Arabinonucleosides ,Biomarkers ,Tumor ,Cell Line ,Tumor ,Clofarabine ,Contrast Media ,Deoxycytidine Kinase ,Humans ,Leukemia ,Mice ,Neoplasms ,Positron-Emission Tomography ,Prodrugs ,Rats ,nucleotide metabolism ,deoxycytidine kinase ,PET imaging ,cancer - Abstract
Deoxycytidine kinase (dCK), a rate-limiting enzyme in the cytosolic deoxyribonucleoside (dN) salvage pathway, is an important therapeutic and positron emission tomography (PET) imaging target in cancer. PET probes for dCK have been developed and are effective in mice but have suboptimal specificity and sensitivity in humans. To identify a more suitable probe for clinical dCK PET imaging, we compared the selectivity of two candidate compounds-[(18)F]Clofarabine; 2-chloro-2'-deoxy-2'-[(18)F]fluoro-9-β-d-arabinofuranosyl-adenine ([(18)F]CFA) and 2'-deoxy-2'-[(18)F]fluoro-9-β-d-arabinofuranosyl-guanine ([(18)F]F-AraG)-for dCK and deoxyguanosine kinase (dGK), a dCK-related mitochondrial enzyme. We demonstrate that, in the tracer concentration range used for PET imaging, [(18)F]CFA is primarily a substrate for dCK, with minimal cross-reactivity. In contrast, [(18)F]F-AraG is a better substrate for dGK than for dCK. [(18)F]CFA accumulation in leukemia cells correlated with dCK expression and was abrogated by treatment with a dCK inhibitor. Although [(18)F]CFA uptake was reduced by deoxycytidine (dC) competition, this inhibition required high dC concentrations present in murine, but not human, plasma. Expression of cytidine deaminase, a dC-catabolizing enzyme, in leukemia cells both in cell culture and in mice reduced the competition between dC and [(18)F]CFA, leading to increased dCK-dependent probe accumulation. First-in-human, to our knowledge, [(18)F]CFA PET/CT studies showed probe accumulation in tissues with high dCK expression: e.g., hematopoietic bone marrow and secondary lymphoid organs. The selectivity of [(18)F]CFA for dCK and its favorable biodistribution in humans justify further studies to validate [(18)F]CFA PET as a new cancer biomarker for treatment stratification and monitoring.
- Published
- 2016
33. Looking for the unexpected in purine and pyrimidine metabolism
- Author
-
Jordheim, Lars Petter, primary, Radu, Caius G., additional, and Peters, Godefridus J., additional
- Published
- 2023
- Full Text
- View/download PDF
34. Targeting host deoxycytidine kinase attenuates Staphylococcus aureus virulence
- Author
-
Winstel, Volker, primary, Abt, Evan R., additional, and Radu, Caius G., additional
- Published
- 2023
- Full Text
- View/download PDF
35. A high-throughput screen of inactive X chromosome reactivation identifies the enhancement of DNA demethylation by 5-aza-2′-dC upon inhibition of ribonucleotide reductase
- Author
-
Minkovsky, Alissa, Sahakyan, Anna, Bonora, Giancarlo, Damoiseaux, Robert, Dimitrova, Elizabeth, Rubbi, Liudmilla, Pellegrini, Matteo, Radu, Caius G, and Plath, Kathrin
- Subjects
Biological Sciences ,Genetics ,Rare Diseases ,Hematology ,Cancer ,Human Genome ,X chromosome inactivation ,DNA methylation ,5-aza-2 '-dC ,Ribonucleotide reductase ,Hydroxyurea ,5-aza-2′-dC - Abstract
BackgroundDNA methylation is important for the maintenance of the silent state of genes on the inactive X chromosome (Xi). Here, we screened for siRNAs and chemicals that reactivate an Xi-linked reporter in the presence of 5-aza-2'-deoxycytidine (5-aza-2'-dC), an inhibitor of DNA methyltransferase 1, at a concentration that, on its own, is not sufficient for Xi-reactivation.ResultsWe found that inhibition of ribonucleotide reductase (RNR) induced expression of the reporter. RNR inhibition potentiated the effect of 5-aza-2'-dC by enhancing its DNA incorporation, thereby decreasing DNA methylation levels genome-wide. Since both 5-aza-2'-dC and RNR-inhibitors are used in the treatment of hematological malignancies, we treated myeloid leukemia cell lines with 5-aza-2'-dC and the RNR-inhibitor hydroxyurea, and observed synergistic inhibition of cell growth and a decrease in genome-wide DNA methylation.ConclusionsTaken together, our study identifies a drug combination that enhances DNA demethylation by altering nucleotide metabolism. This demonstrates that Xi-reactivation assays can be used to optimize the epigenetic activity of drug combinations.
- Published
- 2015
36. Purine nucleoside phosphorylase enables dual metabolic checkpoints that prevent T cell immunodeficiency and TLR7-associated autoimmunity
- Author
-
Abt, Evan R., Rashid, Khalid, Le, Thuc M., Li, Suwen, Lee, Hailey R., Lok, Vincent, Li, Luyi, Creech, Amanda L., Labora, Amanda N., Mandl, Hanna K., Lam, Alex K., Cho, Arthur, Rezek, Valerie, Wu, Nanping, Abril-Rodriguez, Gabriel, Rosser, Ethan W., Mittelman, Steven D., Hugo, Willy, Mehrling, Thomas, Bantia, Shanta, Ribas, Antoni, Donahue, Timothy R., Crooks, Gay M., Wu, Ting-Ting, and Radu, Caius G.
- Subjects
Purine nucleotides -- Physiological aspects -- Health aspects ,Immunological deficiency syndromes -- Genetic aspects -- Prevention ,Phosphorylase -- Physiological aspects -- Health aspects ,TLR7 -- Health aspects -- Physiological aspects ,Autoimmune diseases -- Genetic aspects -- Prevention ,Health care industry - Abstract
Purine nucleoside phosphorylase (PNP) enables the breakdown and recycling of guanine nucleosides. PNP insufficiency in humans is paradoxically associated with both immunodeficiency and autoimmunity, but the mechanistic basis for these outcomes is incompletely understood. Here, we identify two immune lineage-dependent consequences of PNP inactivation dictated by distinct gene interactions. During T cell development, PNP inactivation is synthetically lethal with downregulation of the dNTP triphosphohydrolase SAMHD1. This interaction requires deoxycytidine kinase activity and is antagonized by microenvironmental deoxycytidine. In B lymphocytes and macrophages, PNP regulates Toll-like receptor 7 signaling by controlling the levels of its (deoxy)guanosine nucleoside ligands. Overriding this regulatory mechanism promotes germinal center formation in the absence of exogenous antigen and accelerates disease in a mouse model of autoimmunity. This work reveals that one purine metabolism gene protects against immunodeficiency and autoimmunity via independent mechanisms operating in distinct immune lineages and identifies PNP as a potentially novel metabolic immune checkpoint., Introduction Nucleotide metabolism controls immune cell development and function through diverse mechanisms (1). The purine nucleoside adenosine is sensed by A2a/b receptors, which mediate immunosuppressive effects in various immune cell [...]
- Published
- 2022
- Full Text
- View/download PDF
37. Regulation of nucleotide metabolism by mutant p53 contributes to its gain-of-function activities.
- Author
-
Kollareddy, Madhusudhan, Dimitrova, Elizabeth, Vallabhaneni, Krishna C, Chan, Adriano, Le, Thuc, Chauhan, Krishna M, Carrero, Zunamys I, Ramakrishnan, Gopalakrishnan, Watabe, Kounosuke, Haupt, Ygal, Haupt, Sue, Pochampally, Radhika, Boss, Gerard R, Romero, Damian G, Radu, Caius G, and Martinez, Luis A
- Subjects
Cell Line ,Tumor ,Animals ,Humans ,Mice ,Breast Neoplasms ,Brain Neoplasms ,Neoplasm Invasiveness ,Deoxycytidine Kinase ,Nucleosides ,Nucleotides ,Guanosine Triphosphate ,Blotting ,Western ,Prognosis ,Tumor Stem Cell Assay ,Proportional Hazards Models ,Immunoprecipitation ,Neoplasm Transplantation ,Cell Cycle ,Cell Proliferation ,Gene Expression Regulation ,Neoplastic ,Mutation ,Female ,Tumor Suppressor Protein p53 ,Promoter Regions ,Genetic ,Gene Knockdown Techniques ,Kaplan-Meier Estimate ,Cell Line ,Tumor ,Blotting ,Western ,Gene Expression Regulation ,Neoplastic ,Promoter Regions ,Genetic ,Genetics ,Cancer ,Breast Cancer ,2.1 Biological and endogenous factors - Abstract
Mutant p53 (mtp53) is an oncogene that drives cancer cell proliferation. Here we report that mtp53 associates with the promoters of numerous nucleotide metabolism genes (NMG). Mtp53 knockdown reduces NMG expression and substantially depletes nucleotide pools, which attenuates GTP-dependent protein activity and cell invasion. Addition of exogenous guanosine or GTP restores the invasiveness of mtp53 knockdown cells, suggesting that mtp53 promotes invasion by increasing GTP. In addition, mtp53 creates a dependency on the nucleoside salvage pathway enzyme deoxycytidine kinase for the maintenance of a proper balance in dNTP pools required for proliferation. These data indicate that mtp53-harbouring cells have acquired a synthetic sick or lethal phenotype relationship with the nucleoside salvage pathway. Finally, elevated expression of NMG correlates with mutant p53 status and poor prognosis in breast cancer patients. Thus, mtp53's control of nucleotide biosynthesis has both a driving and sustaining role in cancer development.
- Published
- 2015
38. Structure-Guided Development of Deoxycytidine Kinase Inhibitors with Nanomolar Affinity and Improved Metabolic Stability
- Author
-
Nomme, Julian, Li, Zheng, Gipson, Raymond M, Wang, Jue, Armijo, Amanda L, Le, Thuc, Poddar, Soumya, Smith, Tony, Santarsiero, Bernard D, Nguyen, Hien-Anh, Czernin, Johannes, Alexandrova, Anastassia N, Jung, Michael E, Radu, Caius G, and Lavie, Arnon
- Subjects
Medicinal and Biomolecular Chemistry ,Chemical Sciences ,Rare Diseases ,Orphan Drug ,Hematology ,Cancer ,5.1 Pharmaceuticals ,Development of treatments and therapeutic interventions ,Animals ,Antineoplastic Agents ,Binding Sites ,Chemistry ,Pharmaceutical ,Computer Simulation ,Crystallography ,X-Ray ,Deoxycytidine ,Deoxycytidine Kinase ,Drug Design ,Female ,Humans ,Inhibitory Concentration 50 ,Mice ,Mice ,Inbred C57BL ,Microsomes ,Phosphorylation ,Positron-Emission Tomography ,Precursor Cell Lymphoblastic Leukemia-Lymphoma ,Protein Kinase Inhibitors ,Stereoisomerism ,Thiazoles ,Organic Chemistry ,Pharmacology and Pharmaceutical Sciences ,Medicinal & Biomolecular Chemistry ,Pharmacology and pharmaceutical sciences ,Medicinal and biomolecular chemistry ,Organic chemistry - Abstract
Recently, we have shown that small molecule dCK inhibitors in combination with pharmacological perturbations of de novo dNTP biosynthetic pathways could eliminate acute lymphoblastic leukemia cells in animal models. However, our previous lead compound had a short half-life in vivo. Therefore, we set out to develop dCK inhibitors with favorable pharmacokinetic properties. We delineated the sites of the inhibitor for modification, guided by crystal structures of dCK in complex with the lead compound and with derivatives. Crystal structure of the complex between dCK and the racemic mixture of our new lead compound indicated that the R-isomer is responsible for kinase inhibition. This was corroborated by kinetic analysis of the purified enantiomers, which showed that the R-isomer has >60-fold higher affinity than the S-isomer for dCK. This new lead compound has significantly improved metabolic stability, making it a prime candidate for dCK-inhibitor based therapies against hematological malignancies and, potentially, other cancers.
- Published
- 2014
39. INDs for PET Molecular Imaging Probes—Approach by an Academic Institution
- Author
-
Mosessian, Sherly, Duarte-Vogel, Sandra M, Stout, David B, Roos, Kenneth P, Lawson, Gregory W, Jordan, Maria C, Ogden, Amanda, Matter, Cheryl, Sadeghi, Saman, Mills, George Q, Schelbert, Heinrich R, Radu, Caius G, Czernin, Johannes, Couto, Marcelo, and Phelps, Michael E
- Subjects
Pharmacology and Pharmaceutical Sciences ,Biomedical and Clinical Sciences ,Biotechnology ,Bioengineering ,Biomedical Imaging ,Academies and Institutes ,Animals ,Cytarabine ,Drug Approval ,Drugs ,Investigational ,Female ,Humans ,Male ,Molecular Imaging ,Molecular Probes ,Positron-Emission Tomography ,Rats ,Sprague-Dawley ,United States ,United States Food and Drug Administration ,PET probes ,Investigational New Drug application ,FDA regulations ,Cost-effective ,Clinical trial ,Physiology ,Clinical Sciences ,Nuclear Medicine & Medical Imaging ,Clinical sciences - Abstract
We have developed an efficient, streamlined, cost-effective approach to obtain Investigational New Drug (IND) approvals from the Food and Drug Administration (FDA) for positron emission tomography (PET) imaging probes (while the FDA uses the terminology PET drugs, we are using "PET imaging probes," "PET probes," or "probes" as the descriptive terms). The required application and supporting data for the INDs were collected in a collaborative effort involving appropriate scientific disciplines. This path to INDs was successfully used to translate three [(18) F]fluoro-arabinofuranosylcytosine (FAC) analog PET probes to phase 1 clinical trials. In doing this, a mechanism has been established to fulfill the FDA regulatory requirements for translating promising PET imaging probes from preclinical research into human clinical trials in an efficient and cost-effective manner.
- Published
- 2014
40. Adoptive Transfer of MART-1 T-Cell Receptor Transgenic Lymphocytes and Dendritic Cell Vaccination in Patients with Metastatic Melanoma
- Author
-
Chodon, Thinle, Comin-Anduix, Begoña, Chmielowski, Bartosz, Koya, Richard C, Wu, Zhongqi, Auerbach, Martin, Ng, Charles, Avramis, Earl, Seja, Elizabeth, Villanueva, Arturo, McCannel, Tara A, Ishiyama, Akira, Czernin, Johannes, Radu, Caius G, Wang, Xiaoyan, Gjertson, David W, Cochran, Alistair J, Cornetta, Kenneth, Wong, Deborah JL, Kaplan-Lefko, Paula, Hamid, Omid, Samlowski, Wolfram, Cohen, Peter A, Daniels, Gregory A, Mukherji, Bijay, Yang, Lili, Zack, Jerome A, Kohn, Donald B, Heath, James R, Glaspy, John A, Witte, Owen N, Baltimore, David, Economou, James S, and Ribas, Antoni
- Subjects
Biomedical and Clinical Sciences ,Oncology and Carcinogenesis ,Immunology ,Cancer ,Gene Therapy ,Genetics ,Immunization ,Prevention ,Vaccine Related ,Biotechnology ,Clinical Research ,5.2 Cellular and gene therapies ,Development of treatments and therapeutic interventions ,Adult ,Cancer Vaccines ,Dendritic Cells ,Female ,Humans ,Immunotherapy ,Adoptive ,MART-1 Antigen ,Male ,Melanoma ,Middle Aged ,Neoplasm Metastasis ,Neoplasm Staging ,Peptide Fragments ,Positron-Emission Tomography ,Receptors ,Antigen ,T-Cell ,T-Lymphocytes ,Tomography ,X-Ray Computed ,Transduction ,Genetic ,Treatment Outcome ,Vaccination ,Oncology & Carcinogenesis ,Clinical sciences ,Oncology and carcinogenesis - Abstract
PurposeIt has been demonstrated that large numbers of tumor-specific T cells for adoptive cell transfer (ACT) can be manufactured by retroviral genetic engineering of autologous peripheral blood lymphocytes and expanding them over several weeks. In mouse models, this therapy is optimized when administered with dendritic cell (DC) vaccination. We developed a short 1-week manufacture protocol to determine the feasibility, safety, and antitumor efficacy of this double cell therapy.Experimental designA clinical trial (NCT00910650) adoptively transferring MART-1 T-cell receptor (TCR) transgenic lymphocytes together with MART-1 peptide-pulsed DC vaccination in HLA-A2.1 patients with metastatic melanoma. Autologous TCR transgenic cells were manufactured in 6 to 7 days using retroviral vector gene transfer, and reinfused with (n = 10) or without (n = 3) prior cryopreservation.ResultsA total of 14 patients with metastatic melanoma were enrolled and 9 of 13 treated patients (69%) showed evidence of tumor regression. Peripheral blood reconstitution with MART-1-specific T cells peaked within 2 weeks of ACT, indicating rapid in vivo expansion. Administration of freshly manufactured TCR transgenic T cells resulted in a higher persistence of MART-1-specific T cells in the blood as compared with cryopreserved. Evidence that DC vaccination could cause further in vivo expansion was only observed with ACT using noncryopreserved T cells.ConclusionDouble cell therapy with ACT of TCR-engineered T cells with a very short ex vivo manipulation and DC vaccines is feasible and results in antitumor activity, but improvements are needed to maintain tumor responses.
- Published
- 2014
41. Co-targeting of convergent nucleotide biosynthetic pathways for leukemia eradication
- Author
-
Nathanson, David A, Armijo, Amanda L, Tom, Michelle, Li, Zheng, Dimitrova, Elizabeth, Austin, Wayne R, Nomme, Julian, Campbell, Dean O, Ta, Lisa, Le, Thuc M, Lee, Jason T, Darvish, Ryan, Gordin, Ari, Wei, Liu, Liao, Hsiang-I, Wilks, Moses, Martin, Colette, Sadeghi, Saman, Murphy, Jennifer M, Boulos, Nidal, Phelps, Michael E, Faull, Kym F, Herschman, Harvey R, Jung, Michael E, Czernin, Johannes, Lavie, Arnon, and Radu, Caius G
- Subjects
Biomedical and Clinical Sciences ,Health Sciences ,Pediatric Cancer ,Hematology ,Genetics ,Orphan Drug ,Pediatric ,Biomedical Imaging ,Childhood Leukemia ,Rare Diseases ,Cancer ,Aetiology ,2.1 Biological and endogenous factors ,Animals ,Biosynthetic Pathways ,Deoxycytidine Kinase ,Deoxycytosine Nucleotides ,Disease Eradication ,Mice ,Positron-Emission Tomography ,Precursor Cell Lymphoblastic Leukemia-Lymphoma ,Thymidine ,Medical and Health Sciences ,Immunology ,Biomedical and clinical sciences ,Health sciences - Abstract
Pharmacological targeting of metabolic processes in cancer must overcome redundancy in biosynthetic pathways. Deoxycytidine (dC) triphosphate (dCTP) can be produced both by the de novo pathway (DNP) and by the nucleoside salvage pathway (NSP). However, the role of the NSP in dCTP production and DNA synthesis in cancer cells is currently not well understood. We show that acute lymphoblastic leukemia (ALL) cells avoid lethal replication stress after thymidine (dT)-induced inhibition of DNP dCTP synthesis by switching to NSP-mediated dCTP production. The metabolic switch in dCTP production triggered by DNP inhibition is accompanied by NSP up-regulation and can be prevented using DI-39, a new high-affinity small-molecule inhibitor of the NSP rate-limiting enzyme dC kinase (dCK). Positron emission tomography (PET) imaging was useful for following both the duration and degree of dCK inhibition by DI-39 treatment in vivo, thus providing a companion pharmacodynamic biomarker. Pharmacological co-targeting of the DNP with dT and the NSP with DI-39 was efficacious against ALL models in mice, without detectable host toxicity. These findings advance our understanding of nucleotide metabolism in leukemic cells, and identify dCTP biosynthesis as a potential new therapeutic target for metabolic interventions in ALL and possibly other hematological malignancies.
- Published
- 2014
42. Deoxycytidine kinase augments ATM-Mediated DNA repair and contributes to radiation resistance.
- Author
-
Bunimovich, Yuri L, Nair-Gill, Evan, Riedinger, Mireille, McCracken, Melissa N, Cheng, Donghui, McLaughlin, Jami, Radu, Caius G, and Witte, Owen N
- Subjects
B-Lymphocytes ,T-Lymphocytes ,Cell Line ,Tumor ,Animals ,Mice ,Inbred BALB C ,Mice ,Knockout ,Humans ,Mice ,DNA Damage ,Genomic Instability ,Deoxycytidine Kinase ,Deoxyribonucleosides ,Deoxycytidine ,Mutagenesis ,Site-Directed ,Hematopoiesis ,DNA Repair ,Protein Processing ,Post-Translational ,Substrate Specificity ,Phosphorylation ,Ataxia Telangiectasia Mutated Proteins ,Cell Line ,Tumor ,Inbred BALB C ,Knockout ,Mutagenesis ,Site-Directed ,Protein Processing ,Post-Translational ,General Science & Technology - Abstract
Efficient and adequate generation of deoxyribonucleotides is critical to successful DNA repair. We show that ataxia telangiectasia mutated (ATM) integrates the DNA damage response with DNA metabolism by regulating the salvage of deoxyribonucleosides. Specifically, ATM phosphorylates and activates deoxycytidine kinase (dCK) at serine 74 in response to ionizing radiation (IR). Activation of dCK shifts its substrate specificity toward deoxycytidine, increases intracellular dCTP pools post IR, and enhances the rate of DNA repair. Mutation of a single serine 74 residue has profound effects on murine T and B lymphocyte development, suggesting that post-translational regulation of dCK may be important in maintaining genomic stability during hematopoiesis. Using [(18)F]-FAC, a dCK-specific positron emission tomography (PET) probe, we visualized and quantified dCK activation in tumor xenografts after IR, indicating that dCK activation could serve as a biomarker for ATM function and DNA damage response in vivo. In addition, dCK-deficient leukemia cell lines and murine embryonic fibroblasts exhibited increased sensitivity to IR, indicating that pharmacologic inhibition of dCK may be an effective radiosensitization strategy.
- Published
- 2014
43. Targeting host deoxycytidine kinase mitigates Staphylococcus aureus abscess formation.
- Author
-
Winstel, Volker, Abt, Evan R., Le, Thuc M., and Radu, Caius G.
- Published
- 2024
- Full Text
- View/download PDF
44. Targeting host deoxycytidine kinase mitigatesStaphylococcus aureusabscess formation
- Author
-
Winstel, Volker, primary, Abt, Evan R., additional, Le, Thuc M., additional, and Radu, Caius G., additional
- Published
- 2023
- Full Text
- View/download PDF
45. Data from MEK Inhibition Sensitizes Pancreatic Cancer to STING Agonism by Tumor Cell–intrinsic Amplification of Type I IFN Signaling
- Author
-
Ghukasyan, Razmik, primary, Liang, Keke, primary, Chau, Kevin, primary, Li, Luyi, primary, Chan, Charlotte, primary, Abt, Evan R., primary, Le, Thuc, primary, Park, Joon Y., primary, Wu, Nanping, primary, Premji, Alykhan, primary, Damoiseaux, Robert, primary, Luu, Tony, primary, Labora, Amanda, primary, Rashid, Khalid, primary, Link, Jason M., primary, Radu, Caius G., primary, and Donahue, Timothy R., primary
- Published
- 2023
- Full Text
- View/download PDF
46. Supplementary Fig. 2 from MEK Inhibition Sensitizes Pancreatic Cancer to STING Agonism by Tumor Cell–intrinsic Amplification of Type I IFN Signaling
- Author
-
Ghukasyan, Razmik, primary, Liang, Keke, primary, Chau, Kevin, primary, Li, Luyi, primary, Chan, Charlotte, primary, Abt, Evan R., primary, Le, Thuc, primary, Park, Joon Y., primary, Wu, Nanping, primary, Premji, Alykhan, primary, Damoiseaux, Robert, primary, Luu, Tony, primary, Labora, Amanda, primary, Rashid, Khalid, primary, Link, Jason M., primary, Radu, Caius G., primary, and Donahue, Timothy R., primary
- Published
- 2023
- Full Text
- View/download PDF
47. Supplementary Fig. 5 from MEK Inhibition Sensitizes Pancreatic Cancer to STING Agonism by Tumor Cell–intrinsic Amplification of Type I IFN Signaling
- Author
-
Ghukasyan, Razmik, primary, Liang, Keke, primary, Chau, Kevin, primary, Li, Luyi, primary, Chan, Charlotte, primary, Abt, Evan R., primary, Le, Thuc, primary, Park, Joon Y., primary, Wu, Nanping, primary, Premji, Alykhan, primary, Damoiseaux, Robert, primary, Luu, Tony, primary, Labora, Amanda, primary, Rashid, Khalid, primary, Link, Jason M., primary, Radu, Caius G., primary, and Donahue, Timothy R., primary
- Published
- 2023
- Full Text
- View/download PDF
48. Supplementary Fig. 1 from MEK Inhibition Sensitizes Pancreatic Cancer to STING Agonism by Tumor Cell–intrinsic Amplification of Type I IFN Signaling
- Author
-
Ghukasyan, Razmik, primary, Liang, Keke, primary, Chau, Kevin, primary, Li, Luyi, primary, Chan, Charlotte, primary, Abt, Evan R., primary, Le, Thuc, primary, Park, Joon Y., primary, Wu, Nanping, primary, Premji, Alykhan, primary, Damoiseaux, Robert, primary, Luu, Tony, primary, Labora, Amanda, primary, Rashid, Khalid, primary, Link, Jason M., primary, Radu, Caius G., primary, and Donahue, Timothy R., primary
- Published
- 2023
- Full Text
- View/download PDF
49. Supplementary Fig. 4 from MEK Inhibition Sensitizes Pancreatic Cancer to STING Agonism by Tumor Cell–intrinsic Amplification of Type I IFN Signaling
- Author
-
Ghukasyan, Razmik, primary, Liang, Keke, primary, Chau, Kevin, primary, Li, Luyi, primary, Chan, Charlotte, primary, Abt, Evan R., primary, Le, Thuc, primary, Park, Joon Y., primary, Wu, Nanping, primary, Premji, Alykhan, primary, Damoiseaux, Robert, primary, Luu, Tony, primary, Labora, Amanda, primary, Rashid, Khalid, primary, Link, Jason M., primary, Radu, Caius G., primary, and Donahue, Timothy R., primary
- Published
- 2023
- Full Text
- View/download PDF
50. Supplementary Fig. 3 from MEK Inhibition Sensitizes Pancreatic Cancer to STING Agonism by Tumor Cell–intrinsic Amplification of Type I IFN Signaling
- Author
-
Ghukasyan, Razmik, primary, Liang, Keke, primary, Chau, Kevin, primary, Li, Luyi, primary, Chan, Charlotte, primary, Abt, Evan R., primary, Le, Thuc, primary, Park, Joon Y., primary, Wu, Nanping, primary, Premji, Alykhan, primary, Damoiseaux, Robert, primary, Luu, Tony, primary, Labora, Amanda, primary, Rashid, Khalid, primary, Link, Jason M., primary, Radu, Caius G., primary, and Donahue, Timothy R., primary
- Published
- 2023
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.