Kyung Bo Kim

University of Kentucky, Lexington, KY, United States

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Publications (36)155.27 Total impact

  • Zachary Miller, Wooin Lee, Kyung Bo Kim
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    ABSTRACT: Remarkable successes with the FDA-approved proteasome inhibitors bortezomib (Velcade®) and carfilzomib (Kyprolis®) have proved that the proteasome is an effective target for the treatment of multiple myeloma. In other hematological malignancies, however, clinical trials of proteasome-targeting drugs have shown generally disappointing results to date. Additionally, existing proteasome inhibitors have significant issues with toxicity, poor response rate, and the emergence of resistance for many patients. A new generation of small-molecule therapies specifically targeting the immunoproteasome may have the potential to overcome the drawbacks of bortezomib and carfilzomib in multiple myeloma and to bring significant benefits of proteasome inhibitor therapies to many more patients. In this article, we describe the potential of the immunoproteasome as a therapeutic target for hematological malignancies and the recent progress in the development of useful immunoproteasome inhibitors.
    Current Cancer Drug Targets 07/2014; · 4.00 Impact Factor
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    ABSTRACT: Mammalian genomes encode seven catalytic proteasome subunits, namely β1c, β2c, β5c (assembled into constitutive 20S proteasome core particles), β1i, β2i, β5i (incorporated into immunoproteasomes) and the thymoproteasome-specific subunit, β5t. Extensive research in the past decades has yielded numerous potent proteasome inhibitors including compounds currently used in the clinic to treat multiple myeloma and mantle cell lymphoma. Proteasome inhibitors that selectively target combinations of β1c/β1i, β2c/β2i or β5c/β5i are available, yet ligands truly selective for a single proteasome activity are scarce. In this work we report the development of cell-permeable β1i as well as β5i selective inhibitors, which outperform existing leads in terms of selectivity and/or potency. These compounds are the result of a rational design strategy using known inhibitors as starting points and introducing structural features according to the X-ray structures of the murine constitutive and immunoproteasome 20S core particles.
    Journal of Medicinal Chemistry 07/2014; · 5.61 Impact Factor
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    ABSTRACT: The purpose of this work was to optimize the structure of codrugs for extended delivery across microneedle treated skin. Naltrexone, the model compound was linked with diclofenac, a nonspecific cyclooxygenase inhibitor to enhance the pore lifetime following microneedle treatment and develop a 7 day transdermal system for naltrexone. Four different codrugs of naltrexone and diclofenac were compared in terms of stability and solubility. Transdermal flux, permeability and skin concentration of both parent drugs and codrugs were quantified to form a structure permeability relationship. The results indicated that all codrugs bioconverted in the skin. The degree of conversion was dependent on the structure, phenol linked codrugs were less stable compared to the secondary alcohol linked structures. The flux of naltrexone across microneedle treated skin and the skin concentration of diclofenac were higher for the phenol linked codrugs. The polyethylene glycol link enhanced solubility of the codrugs, which translated into flux enhancement. The current studies indicated that formulation stability of codrugs and the flux of naltrexone can be enhanced via structure design optimization. The polyethylene glycol linked naltrexone diclofenac codrug is better suited for a 7 day drug delivery system both in terms of stability and drug delivery.
    Pharmaceutical Research 08/2013; · 4.74 Impact Factor
  • Kimberly Cornish Carmony, Kyung Bo Kim
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    ABSTRACT: Over the years, the proteasome has been extensively investigated due to its crucial roles in many important signaling pathways and its implications in diseases. Two proteasome inhibitors-bortezomib and carfilzomib-have received FDA approval for the treatment of multiple myeloma, thereby validating the proteasome as a chemotherapeutic target. As a result, further research efforts have been focused on dissecting the complex biology of the proteasome to gain the insight required for developing next-generation proteasome inhibitors. It is clear that chemical probes have made significant contributions to these efforts, mostly by functioning as inhibitors that selectively block the catalytic activity of proteasomes. Analogues of these inhibitors are now providing additional tools for visualization of catalytically active proteasome subunits, several of which allow real-time monitoring of proteasome activity in living cells as well as in in vivo settings. These imaging probes will provide powerful tools for assessing the efficacy of proteasome inhibitors in clinical settings. In this review, we will focus on the recent efforts towards developing imaging probes of proteasomes, including the latest developments in immunoproteasome-selective imaging probes.
    Cell biochemistry and biophysics 05/2013; · 3.34 Impact Factor
  • Kyung Bo Kim, Craig M Crews
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    ABSTRACT: Covering: 1992 to 2012The initial enthusiasm following the discovery of a pharmacologically active natural product is often fleeting due to the poor prospects for its ultimate clinical application. Despite this, the ever-changing landscape of modern biology has a constant need for molecular probes that can aid in our understanding of biological processes. After its initial discovery by Bristol-Myers Squibb as a microbial anti-tumor natural product, epoxomicin was deemed unfit for development due to its peptide structure and potentially labile epoxyketone pharmacophore. Despite its drawbacks, epoxomicin's pharmacophore was found to provide unprecedented selectivity for the proteasome. Epoxomicin also served as a scaffold for the generation of a synthetic tetrapeptide epoxyketone with improved activity, YU-101, which became the parent lead compound of carfilzomib (Kyprolis™), the recently approved therapeutic agent for multiple myeloma. In this era of rational drug design and high-throughput screening, the prospects for turning an active natural product into an approved therapy are often slim. However, by understanding the journey that began with the discovery of epoxomicin and ended with the successful use of carfilzomib in the clinic, we may find new insights into the keys for success in natural product-based drug discovery.
    Natural Product Reports 04/2013; · 10.18 Impact Factor
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    ABSTRACT: The proteasome is a key regulator of cellular protein homeostasis and is a clinically validated anticancer target. The immunoproteasome, a subtype of proteasome expressed mainly in hematopoietic cells, was initially recognized for its role in antigen presentation during the immune response. Recently, the immunoproteasome has been implicated in several disease conditions including cancer and autoimmune disorders, but many of the factors contributing to these pathological processes remain unknown. In particular, the codon 60 polymorphism of the PSMB9 gene encoding the β1i immunoproteasome catalytic subunit has been investigated in the context of a variety of diseases. Despite this, previous studies have so far reported inconsistent findings regarding the impact of this polymorphism on proteasome activity. Thus, we set out to investigate the impact of the PSMB9 codon 60 polymorphism on the expression and activity of the β1i immunoproteasome subunit in a panel of human cancer cell lines. The β1i-selective fluorogenic substrate Acetyl-Pro-Ala-Leu-7-amino-4-methylcoumarin was used to specifically measure β1i catalytic activity. Our results indicate that the codon 60 Arg/His polymorphism does not significantly alter the expression and activity of β1i among the cell lines tested. Additionally, we also examined the expression of β1i in clinical samples from colon and pancreatic cancer patients. Our immunohistochemical analyses showed that ∼70% of clinical colon cancer samples and ∼53% of pancreatic cancer samples have detectable β1i expression. Taken together, our results indicate that the β1i subunit of the immunoproteasome is frequently expressed in colon and pancreatic cancers but that the codon 60 genetic variants of β1i display similar catalytic activities and are unlikely to contribute to the significant inter-cell-line and inter-individual variabilities in the immunoproteasome activity.
    PLoS ONE 01/2013; 8(9):e73732. · 3.53 Impact Factor
  • Zachary Miller, Lin Ao, Kyung Bo Kim, Wooin Lee
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    ABSTRACT: The ubiquitin-proteasome system (UPS) plays a vital role in maintaining protein homeostasis and regulating numerous cellular processes. The proteasome, a multi-protease complex, is the key component of the UPS that has been validated as a therapeutic target by the FDA's approval of bortezomib and carfilzomib. These proteasome inhibitor drugs have substantially improved outcomes in patients with hematological malignancies and are currently being investigated for other types of cancer as well as several other diseases. These approved proteasome inhibitors target the catalytic activity of both the constitutive proteasome and immunoproteasome indiscriminately and their inhibitory effects on the constitutive proteasome in normal cells are believed to contribute to unwanted side effects. In addition, selective immunoproteasome inhibition has been proposed to have unique effects on other diseases, including those involving aberrant immune function. Initially recognized for its role in the adaptive immune response, the immunoproteasome is often upregulated in disease states such as inflammatory diseases and cancer, suggesting functions beyond antigen presentation. In an effort to explore the immunoproteasome as a potential therapeutic target in these diseases, the development of immunoproteasome-specific inhibitors has become the focus of recent studies. Owing to considerable efforts by both academic and industry groups, immunoproteasome-selective inhibitors have now been identified and tested against several disease models. These inhibitors also provide a valuable set of chemical tools for investigating the biological function of the immunoproteasome. In this review, we will focus on the recent efforts towards the development of immunoproteasome-selective inhibitors.
    Current pharmaceutical design 11/2012; · 4.41 Impact Factor
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    ABSTRACT: To evaluate the significance of C-C chemokine receptor type 5 (CCR5) in lung tumor development, we compared carcinogen-induced tumor growth in CCR5 knockout (CCR5(-/-)) mice and wild-type (CCR5(+/+)) mice. CCR5(-/-) mice showed reduced urethane (1g/kg)-induced tumor incidence when compared with those of CCR5(+/+) mice. We investigated the activation of nuclear factor-kappaB/STAT3 since these are implicated transcription factors in the regulation of genes involving tumor growth. Significant inhibition of DNA-binding activity of nuclear factor-kappaB and STAT3, and the translocation of p50 and p65 into the nucleus and the phosphorylation of IĸB were found in the lungs of CCR5(-/-) mice compared with the lungs of CCR5(+/+) mice. Expression of apoptotic protein such as cleaved caspase-3, cleaved PARP and Bax was elevated, whereas the expression levels of survival protein such as Bcl-2 and cIAP1 was decreased in the lungs of CCR5(-/-) mice. Interestingly, we found that the level of monocyte chemoattractant protein-1 (MCP-1), a tumor growth-promoting cytokine, was significantly reduced in the lung tumor tissue and blood of CCR5(-/-) mice compared with the level in CCR5(+/+) mice. In addition, CCR5 small interfering RNA (siRNA) and inhibitor of MCP-1 blocked lung cancer cell growth, which was abolished by the addition of MCP-1 protein in cultured lung cancer cells. Moreover, inactivation of CD8(+) cytotoxic T cell and dendritic cells was significantly increased in the blood, lung tumors and spleens of CCR5(-/-) mice compared with that of CCR5(+/+) mice. Therefore, these results showed that CCR5 deficiency suppressed lung tumor development through the inhibition of nuclear factor-kappaB/STAT3 pathways and the downregulation of MCP-1 in the carcinogen-induced lung tumor model.
    Carcinogenesis 08/2012; · 5.64 Impact Factor
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    ABSTRACT: Carfilzomib is a novel class of peptidyl epoxyketone proteasome inhibitor and has demonstrated promising activity in multiple clinical trials to treat patients with multiple myeloma and other types of cancers. Here, we investigated molecular mechanisms underlying acquired resistance to carfilzomib and a potential strategy to restore cellular sensitivity to carfilzomib. H23 and DLD-1 cells (human lung and colon adenocarcinoma cell lines) with acquired resistance to carfilzomib displayed marked cross-resistance to YU-101, a closely related proteasome inhibitor, and paclitaxel, a known substrate of Pgp. However, carfilzomib-resistant cells remained sensitive to bortezomib, a clinically used dipeptide with boronic acid pharmacophore. In accordance with these observations, carfilzomib-resistant H23 and DLD-1 cells showed marked upregulation of P-glycoprotein (Pgp) as compared to their parental controls, and coincubation with verapamil, a Pgp inhibitor, led to an almost complete restoration of cellular sensitivity to carfilzomib. These results indicate that Pgp upregulation plays a major role in the development of carfilzomib resistance in these cell lines. In developing a potential strategy to overcome carfilzomib resistance, we as a proof of concept prepared a small library of peptide analogues derived from the peptide backbone of carfilzomib and screened these molecules for their activity to restore carfilzomib sensitivity when cotreated with carfilzomib. We found that compounds as small as dipeptides are sufficient in restoring carfilzomib sensitivity. Taken together, we found that Pgp upregulation plays a major role in the development of resistance to carfilzomib in lung and colon adenocarcinoma cell lines and that small peptide analogues lacking the pharmacophore can be used as agents to reverse acquired carfilzomib resistance. Our findings may provide important information in developing a potential strategy to overcome drug resistance.
    Molecular Pharmaceutics 06/2012; · 4.57 Impact Factor
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    ABSTRACT: The discovery of NF-κB signaling pathways has greatly enhanced our understanding of inflammatory and immune responses. In the canonical NF-κB pathway, the proteasomal degradation of IκBα, an inhibitory protein of NF-κB, is widely accepted to be a key regulatory step. However, contradictory findings have been reported as to whether the immunoproteasome plays an obligatory role in the degradation of IκBα and activation of the canonical NF-κB pathway. Such results were obtained mainly using traditional gene deletion strategies. Here, we have revisited the involvement of the immunoproteasome in the canonical NF-κB pathway using small molecule inhibitors of the immunoproteasome, namely UK-101 and LKS01 targeting β1i and β5i, respectively. H23 and Panc-1 cancer cells were pretreated with UK-101, LKS01 or epoxomicin (a prototypic inhibitor targeting both the constitutive proteasome and immunoproteasome). We then examined whether these pretreatments lead to any defect in activating the canonical NF-κB pathway following TNFα exposure by monitoring the phosphorylation and degradation of IκBα, nuclear translocation of NF-κB proteins and DNA binding and transcriptional activity of NF-κB. Our results consistently indicated that there is no defect in activating the canonical NF-κB pathway following selective inhibition of the immunoproteasome catalytic subunits β1i, β5i or both using UK-101 and LKS01, in contrast to epoxomicin. In summary, our current results using chemical genetic approaches strongly support that the catalytic activity of the immunoproteasome subunits β1i and β5i is not required for canonical NF-κB activation in lung and pancreatic adenocarcinoma cell line models.
    Molecular BioSystems 06/2012; 8(9):2295-302. · 3.35 Impact Factor
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    ABSTRACT: The type III intermediate filaments (IFs) are essential cytoskeletal elements of mechanosignal transduction and serve critical roles in tissue repair. Mice genetically deficient for the IF protein vimentin (Vim−/−) have impaired wound healing from deficits in myofibroblast development. We report a surprising finding made in Vim−/− mice that corneas are protected from fibrosis and instead promote regenerative healing after traumatic alkali injury. This reparative phenotype in Vim−/− corneas is strikingly recapitulated by the pharmacological agent withaferin A (WFA), a small molecule that binds to vimentin and down-regulates its injury-induced expression. Attenuation of corneal fibrosis by WFA is mediated by down-regulation of ubiquitin-conjugating E3 ligase Skp2 and up-regulation of cyclin-dependent kinase inhibitors p27Kip1 and p21Cip1. In cell culture models, WFA exerts G2/M cell cycle arrest in a p27Kip1- and Skp2-dependent manner. Finally, by developing a highly sensitive imaging method to measure corneal opacity, we identify a novel role for desmin overexpression in corneal haze. We demonstrate that desmin down-regulation by WFA via targeting the conserved WFA-ligand binding site shared among type III IFs promotes further improvement of corneal transparency without affecting cyclin-dependent kinase inhibitor levels in Vim−/− mice. This dissociates a direct role for desmin in corneal cell proliferation. Taken together, our findings illuminate a previously unappreciated pathogenic role for type III IF overexpression in corneal fibrotic conditions and also validate WFA as a powerful drug lead toward anti-fibrosis therapeutic development.
    Journal of Biological Chemistry 01/2012; 287(2):989-1006. · 4.65 Impact Factor
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    ABSTRACT: The cover picture shows a fluorescent image of the immunoproteasome captured in living cells by using LKS01‐B650, an immunoproteasome‐selective activity‐based fluorescent probe. The image at the bottom shows the binding mode of LKS01‐B650 to the β5i‐catalytic subunit of the immunoproteasome. Considering recent studies that suggest an important role of the immunoproteasome in multiple disease states, this imaging probe could help us to understand immunoproteasome functions better and to explore its therapeutic potential. On p. 1899 ff., W. Lee, K.‐B. Kim et al. describe the structure‐based design, synthesis and characterization of a near‐infra‐red fluorescent probe that targets the immunoproteasome subunit β5i. Cell‐based binding studies, in‐gel fluorescence and competition assays all clearly demonstrate the ability of this probe to visualize the immunoproteasome catalytic subunit LMP7/β5i in living cells, thus providing a valuable tool for immunoproteasome biology. The cover picture was prepared by Chitra Saini.
    ChemBioChem 01/2012; 13(13). · 3.74 Impact Factor
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    ABSTRACT: The type III intermediate filaments (IFs) are essential cytoskeletal elements of mechanosignal transduction and serve critical roles in tissue repair. Mice genetically deficient for the IF protein vimentin (Vim(-/-)) have impaired wound healing from deficits in myofibroblast development. We report a surprising finding made in Vim(-/-) mice that corneas are protected from fibrosis and instead promote regenerative healing after traumatic alkali injury. This reparative phenotype in Vim(-/-) corneas is strikingly recapitulated by the pharmacological agent withaferin A (WFA), a small molecule that binds to vimentin and down-regulates its injury-induced expression. Attenuation of corneal fibrosis by WFA is mediated by down-regulation of ubiquitin-conjugating E3 ligase Skp2 and up-regulation of cyclin-dependent kinase inhibitors p27(Kip1) and p21(Cip1). In cell culture models, WFA exerts G(2)/M cell cycle arrest in a p27(Kip1)- and Skp2-dependent manner. Finally, by developing a highly sensitive imaging method to measure corneal opacity, we identify a novel role for desmin overexpression in corneal haze. We demonstrate that desmin down-regulation by WFA via targeting the conserved WFA-ligand binding site shared among type III IFs promotes further improvement of corneal transparency without affecting cyclin-dependent kinase inhibitor levels in Vim(-/-) mice. This dissociates a direct role for desmin in corneal cell proliferation. Taken together, our findings illuminate a previously unappreciated pathogenic role for type III IF overexpression in corneal fibrotic conditions and also validate WFA as a powerful drug lead toward anti-fibrosis therapeutic development.
    Journal of Biological Chemistry 11/2011; 287(2):989-1006. · 4.65 Impact Factor
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    ABSTRACT: An environmentally benign microwave-assisted solvent-free self-condensation of carbonyl compounds was developed using catalytic amounts of triethylamine and lithium perchlorate. Changing the amount of lithium perchlorate helps in controlling the ratio of the single-condensation and double-condensation products. The effect of other additives and microwave activation was also investigated. The optimized conditions were then applied to various cyclic/acyclic ketones and aldehydes, with selectivity observed in many cases.
    Green Chemistry 10/2011; 13:1546-1549. · 6.83 Impact Factor
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    ABSTRACT: Aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that regulates genes involved in drug/xenobiotic metabolism, cell cycle progression, cell fate determination, immune function, and inflammatory response. Increasing evidence that AHR plays a role in the pathophysiology of a number of human disease states is driving the need for improved pharmacological tools to be used for understanding the in vivo impact of AHR modulation. In this study, we have characterized and used structure-activity relationship analyses of a newly synthesized library of derivatives of the potent AHR antagonist 2-methyl-2H-pyrazole-3-carboxylic acid (2-methyl-4-o-tolylazo-phenyl)-amide (CH223191). Initial screening of these compounds revealed that those bearing groups with strong electronegativity at the R1 position (i.e., CHD-5, CHD-11, and CHD-12) versus those that are more electron-poor at this position (i.e., CHD-7 and CHD-8) elicited the most potent AHR antagonistic properties. The ability of these derivatives to inhibit agonist (2,3,7,8-tetrachlorodibenzo-p-dioxin) binding, nuclear translocation of AHR, and agonist-induced enzyme activity also were determined and support the initial findings. Furthermore, CH223191, but not CHD-5, CHD-11, or CHD-12, was found to exhibit AHR-independent proproliferative properties. These results contribute to our understanding of the structural requirements of potent AHR antagonists and the development of effective pharmacological tools to be used for studying the pathophysiological role of AHR.
    Molecular pharmacology 10/2011; 81(1):3-11. · 4.53 Impact Factor
  • Wooin Lee, Kyung Bo Kim
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    ABSTRACT: The proteasome, a large multisubunit protease complex, has been extensively investigated over the years, greatly enhancing our understanding of critical roles that the proteasome plays in cells. The FDA approval of bortezomib for the treatment of multiple myeloma and mantle cell lymphoma has validated the proteasome as an anticancer target. However, the undesirable toxicities of these agents limit their broad utility. The immunoproteasome, an alternative form of the constitutive proteasome, has recently been explored as a therapeutic target. While the immunoproteasome, normally expressed in cells of hematopoietic origin, has been shown to be associated with various types of cancer and inflammatory diseases, its multifaceted function is not fully understood due to the lack of appropriate molecular probes. In this review, recent advances in the immunoproteasome field are covered, including potential implications in disease states. In particular, recent developments in immunoproteasome-specific inhibitors are emphasized.
    Current topics in medicinal chemistry 08/2011; 11(23):2923-30. · 4.47 Impact Factor
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    ABSTRACT: Introduction: Lung cancer, although not the most commonly diagnosed form of cancer, is the leading cause of cancer deaths in the US. Unfortunately, standard chemotherapeutic treatments for lung cancer are largely ineffective and, thus, novel approaches are urgently needed to improve clinical outcomes. Targeted therapies are currently being explored, including combining bortezomib, a general proteasome inhibitor, with other therapies. The immunoproteasome is an alternative form of the proteasome and has been shown to play an important role in a number of diseases including cancer. We have previously developed ‘UK-101’, a small molecule that selectively inhibits the immunoproteasome catalytic subunit LMP2. In our present study, we investigate the therapeutic potential of the LMP2-targeting approach in lung cancer. Experimental Procedures: The expression and cellular localization of LMP2 was evaluated in primary non-small cell lung cancer (NSCLC) tissues via immunohistochemistry (IHC). Established lung cancer cell lines were likewise examined using western blotting (WB) and immunofluorescence (IF). A panel of NSCLC cell lines were selected for further analysis using UK-101 and the general proteasome inhibitors epoxomicin and bortezomib. Upon treatment with these inhibitors, cell viability was measured using the MTS assay while proteasome activity was interrogated using Suc-LLVY-aminoluciferin. Apoptosis markers were examined to determine the mechanism of UK-101-induced loss of cell viability. Finally, the presence of a naturally occurring LMP2 genetic polymorphism (Arg>His at codon 60) in the NSCLC cell lines was determined using restriction fragment length polymorphism analysis. Data Summary: Our WB and IHC analyses indicated that LMP2 is substantially upregulated in primary NSCLC tissues as well as established NSCLC cell lines compared to nonmalignant lung tissues and small cell lung cancer cell lines. IF and IHC analyses showed LMP2 localization throughout the cells, including overlap with nuclear staining in both. UK-101 treatment led to a covalent modification of LMP2 and decreased proteasomal activity. In addition, UK-101 decreased cell viability and induced apoptotic cell death in NSCLC cells expressing LMP2. The LMP2 polymorphism at codon 60 did not appear to influence the proteasomal activity or cellular sensitivity to UK-101, epoxomicin, or bortezomib in these NSCLC cell lines. Conclusion: Our results show that LMP2 is upregulated in NSCLC and that the targeted inhibition of LMP2 using UK-101 induces apoptotic cell death in NSCLC cell lines. Taken together, these results suggest that LMP2 may be a potential therapeutic target for the treatment of NSCLC with lesser systemic toxicity than general proteasome inhibitors. Further studies are warranted to identify molecular factors impacting the effectiveness of the immunoproteasome-targeting approaches in NSCLC.
    American Association of Cancer Research Annual Meeting 2011; 04/2011
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    ABSTRACT: Introduction: This study was conducted to develop the first activity-based fluorescent probe targeting the immunoproteasome subunit LMP2. The immunoproteasome is an alternate form of the constitutive proteasome which is composed of unique catalytic subunits. While immunoproteasomes were believed to primarily function in generating peptides for antigen presentation on MHC class I molecules, antibody-based studies have revealed the expression of immunoproteasome catalytic subunits in a variety of cancers. However, antibodies are incapable of distinguishing between active and inactive forms of these proteins, a limitation that can be overcome using activity-based probes. Experimental Procedures: Fluorescent compounds were synthesized by derivatization of the LMP2-specific inhibitor UK-101 at the P2 position, where lysine was substituted for alanine. The free amino group on the side chain of lysine was coupled to linkers of various lengths. Fluorescein was then coupled to each linker to yield the fluorescent probes. These compounds were characterized in prostate cancer cell lines via sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunofluorescence (IF) microscopy. One analog was selected for further characterization. Prostate cancer cells were treated with an LMP2-selective dose of this analog, Fluoro-UK-101, and the co-localization of this fluorescent probe with antibodies specific for proteasome subunits and intracellular organelles was examined via IF. Data Summary: The structures of the synthesized fluorescent derivatives of UK-101 were confirmed via mass spectrometry and nuclear magnetic resonance spectroscopy. Treatment of prostate cancer cells with these compounds gave punctate staining in a dose-dependent manner, indicating the cell permeability and activity of these probes. The impact of the linker length on LMP2 binding specificity and fluorescent signal strength was determined via SDS-PAGE and IF microscopy. Doses at which these fluorescent analogs specifically target LMP2, but not other proteasome subunits, were identified via SDS-PAGE. One analog, Fluoro-UK-101, was selected based on binding specificity and IF intensity. Additionally, IF microscopy techniques using the selected fluorescent analog, Fluoro-UK-101, revealed differences in LMP2 localization patterns among prostate cancer cell lines. Conclusions: We have successfully developed Fluoro-UK-101, an activity-based fluorescent probe that selectively binds the immunoproteasome catalytic subunit LMP2. Fluoro-UK-101 allows the visualization of catalytically active immunoproteasomes in intact cells. Modification of the fluorophore will facilitate its application in a rapid readout assay to detect tumors in animal models using LMP2 as a biomarker.
    American Association of Cancer Research Annual Meeting 2011; 04/2011
  • Jayhyuk Myung, Kyung Bo Kim, Craig M. Crews
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    ABSTRACT: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
    ChemInform 09/2010; 32(36).
  • ChemInform 07/2010; 31(29).

Publication Stats

454 Citations
155.27 Total Impact Points

Institutions

  • 2005–2013
    • University of Kentucky
      • • Department of Pharmaceutical Sciences
      • • Department of Ophthalmology and Visual Sciences
      Lexington, KY, United States
  • 1999–2010
    • Yale University
      • Department of Molecular, Cellular and Developmental Biology
      New Haven, Connecticut, United States
  • 2008
    • Lexington College
      Lexington, Kentucky, United States
  • 2001
    • Molecular and Cellular Biology Program
      Seattle, Washington, United States
  • 1997–2000
    • The Ohio State University
      • Department of Chemistry and Biochemistry
      Columbus, Ohio, United States