RESUMO
Host kinases play essential roles in the host cell cycle, innate immune signaling, the stress response to viral infection, and inflammation. Previous work has demonstrated that coronaviruses specifically target kinase cascades to subvert host cell responses to infection and rely upon host kinase activity to phosphorylate viral proteins to enhance replication. Given the number of kinase inhibitors that are already FDA approved to treat cancers, fibrosis, and other human disease, they represent an attractive class of compounds to repurpose for host-targeted therapies against emerging coronavirus infections. To further understand the host kinome response to betacoronavirus infection, we employed multiplex inhibitory bead mass spectrometry (MIB-MS) following MERS-CoV and SARS-CoV-2 infection of human lung epithelial cell lines. Our MIB-MS analyses revealed activation of mTOR and MAPK signaling following MERS-CoV and SARS-CoV-2 infection, respectively. SARS-CoV-2 host kinome responses were further characterized using paired phosphoproteomics, which identified activation of MAPK, PI3K, and mTOR signaling. Through chemogenomic screening, we found that clinically relevant PI3K/mTOR inhibitors were able to inhibit coronavirus replication at nanomolar concentrations similar to direct-acting antivirals. This study lays the groundwork for identifying broad-acting, host-targeted therapies to reduce betacoronavirus replication that can be rapidly repurposed during future outbreaks and epidemics. The proteomics, phosphoproteomics, and MIB-MS datasets generated in this study are available in the Proteomics Identification Database (PRIDE) repository under project identifiers PXD040897 and PXD040901.
Assuntos
COVID-19 , Hepatite C Crônica , Coronavírus da Síndrome Respiratória do Oriente Médio , Humanos , Antivirais/farmacologia , Inibidores de MTOR , Fosfatidilinositol 3-Quinases , SARS-CoV-2 , Replicação Viral , Coronavírus da Síndrome Respiratória do Oriente Médio/fisiologia , Serina-Treonina Quinases TORRESUMO
Mitochondria are multifaceted organelles which are important for bioenergetics, biosynthesis and signaling in metazoans. Mitochondrial functions are frequently altered in cancer to promote both the energy and the necessary metabolic intermediates for biosynthesis required for tumor growth. Cancer stem cells (CSCs) contribute to chemotherapy resistance, relapse, and metastasis. Recent studies have shown that while non-stem, bulk cancer cells utilize glycolysis, breast CSCs are more dependent on oxidative phosphorylation (OxPhos) and therefore targeting mitochondria may inhibit CSC function. We previously reported that small molecule ONC201, which is an agonist for the mitochondrial caseinolytic protease (ClpP), induces mitochondrial dysfunction in breast cancer cells. In this study, we report that ClpP agonists inhibit breast cancer cell proliferation and CSC function in vitro and in vivo. Mechanistically, we found that OxPhos inhibition downregulates multiple pathways required for CSC function, such as the mevalonate pathway, YAP, Myc, and the HIF pathway. ClpP agonists showed significantly greater inhibitory effect on CSC functions compared with other mitochondria-targeting drugs. Further studies showed that ClpP agonists deplete NAD(P)+ and NAD(P)H, induce redox imbalance, dysregulate one-carbon metabolism and proline biosynthesis. Downregulation of these pathways by ClpP agonists further contribute to the inhibition of CSC function. In conclusion, ClpP agonists inhibit breast CSC functions by disrupting mitochondrial homeostasis in breast cancer cells and inhibiting multiple pathways critical to CSC function. Significance: ClpP agonists disrupt mitochondrial homeostasis by activating mitochondrial matrix protease ClpP. We report that ClpP agonists inhibit cell growth and cancer stem cell functions in breast cancer models by modulating multiple metabolic pathways essential to cancer stem cell function.
Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Peptídeo Hidrolases/metabolismo , NAD/metabolismo , Recidiva Local de Neoplasia/metabolismo , Mitocôndrias , Homeostase , Endopeptidases/metabolismo , Células-Tronco Neoplásicas , Endopeptidase Clp/metabolismoRESUMO
Cytomegalovirus (CMV) reactivation from latency following immune dysregulation remains a serious risk for patients, often causing substantial morbidity and mortality. Here, we demonstrate the CMV-encoded G protein-coupled receptor, US28, in coordination with cellular Ephrin receptor A2, attenuates mitogen-activated protein kinase signaling, thereby limiting viral replication in latently infected primary monocytes. Furthermore, treatment of latently infected primary monocytes with dasatinib, a Food and Drug Association-approved kinase inhibitor used to treat a subset of leukemias, results in CMV reactivation. These ex vivo data correlate with our retrospective analyses of the Explorys electronic health record database, where we find dasatinib treatment is associated with a significant risk of CMV-associated disease (odds ratio 1.58, P = 0.0004). Collectively, our findings elucidate a signaling pathway that plays a central role in the balance between CMV latency and reactivation and identifies a common therapeutic cancer treatment that elevates the risk of CMV-associated disease.
RESUMO
Oncogenic KRAS drives cancer growth by activating diverse signaling networks, not all of which have been fully delineated. We set out to establish a system-wide profile of the KRAS-regulated kinase signaling network (kinome) in KRAS-mutant pancreatic ductal adenocarcinoma (PDAC). We knocked down KRAS expression in a panel of six cell lines and then applied multiplexed inhibitor bead/MS to monitor changes in kinase activity and/or expression. We hypothesized that depletion of KRAS would result in downregulation of kinases required for KRAS-mediated transformation and in upregulation of other kinases that could potentially compensate for the deleterious consequences of the loss of KRAS. We identified 15 upregulated and 13 downregulated kinases in common across the panel of cell lines. In agreement with our hypothesis, all 15 of the upregulated kinases have established roles as cancer drivers (e.g., SRC, TGF-ß1, ILK), and pharmacological inhibition of one of these upregulated kinases, DDR1, suppressed PDAC growth. Interestingly, 11 of the 13 downregulated kinases have established driver roles in cell cycle progression, particularly in mitosis (e.g., WEE1, Aurora A, PLK1). Consistent with a crucial role for the downregulated kinases in promoting KRAS-driven proliferation, we found that pharmacological inhibition of WEE1 also suppressed PDAC growth. The unexpected paradoxical activation of ERK upon WEE1 inhibition led us to inhibit both WEE1 and ERK concurrently, which caused further potent growth suppression and enhanced apoptotic death compared with WEE1 inhibition alone. We conclude that system-wide delineation of the KRAS-regulated kinome can identify potential therapeutic targets for KRAS-mutant pancreatic cancer.
Assuntos
Carcinoma Ductal Pancreático , Proteínas de Ciclo Celular/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Mutação , Neoplasias Pancreáticas , Proteínas Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas p21(ras) , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/enzimologia , Carcinoma Ductal Pancreático/genética , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Humanos , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/enzimologia , Neoplasias Pancreáticas/genética , Proteínas Tirosina Quinases/genética , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismoRESUMO
Neurofibromatosis Type 2 (NF2) is an autosomal dominant genetic syndrome caused by mutations in the NF2 tumor suppressor gene resulting in multiple schwannomas and meningiomas. There are no FDA approved therapies for these tumors and their relentless progression results in high rates of morbidity and mortality. Through a combination of high throughput screens, preclinical in vivo modeling, and evaluation of the kinome en masse, we identified actionable drug targets and efficacious experimental therapeutics for the treatment of NF2 related schwannomas and meningiomas. These efforts identified brigatinib (ALUNBRIG®), an FDA-approved inhibitor of multiple tyrosine kinases including ALK, to be a potent inhibitor of tumor growth in established NF2 deficient xenograft meningiomas and a genetically engineered murine model of spontaneous NF2 schwannomas. Surprisingly, neither meningioma nor schwannoma cells express ALK. Instead, we demonstrate that brigatinib inhibited multiple tyrosine kinases, including EphA2, Fer and focal adhesion kinase 1 (FAK1). These data demonstrate the power of the de novo unbiased approach for drug discovery and represents a major step forward in the advancement of therapeutics for the treatment of NF2 related malignancies.
Assuntos
Neoplasias Meníngeas/genética , Meningioma/genética , Neurilemoma/genética , Neurofibromina 2/deficiência , Neurofibromina 2/genética , Compostos Organofosforados/farmacologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Pirimidinas/farmacologia , Proliferação de Células , Humanos , Mutação , Neurilemoma/patologiaRESUMO
To identify therapeutic targets for KRAS mutant pancreatic cancer, we conduct a druggable genome small interfering RNA (siRNA) screen and determine that suppression of BCAR1 sensitizes pancreatic cancer cells to ERK inhibition. Integrative analysis of genome-scale CRISPR-Cas9 screens also identify BCAR1 as a top synthetic lethal interactor with mutant KRAS. BCAR1 encodes the SRC substrate p130Cas. We determine that SRC-inhibitor-mediated suppression of p130Cas phosphorylation impairs MYC transcription through a DOCK1-RAC1-ß-catenin-dependent mechanism. Additionally, genetic suppression of TUBB3, encoding the ßIII-tubulin subunit of microtubules, or pharmacological inhibition of microtubule function decreases levels of MYC protein in a calpain-dependent manner and potently sensitizes pancreatic cancer cells to ERK inhibition. Accordingly, the combination of a dual SRC/tubulin inhibitor with an ERK inhibitor cooperates to reduce MYC protein and synergistically suppress the growth of KRAS mutant pancreatic cancer. Thus, we demonstrate that mechanistically diverse combinations with ERK inhibition suppress MYC to impair pancreatic cancer proliferation.
Assuntos
Proteína Substrato Associada a Crk/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Microtúbulos/metabolismo , Neoplasias Pancreáticas/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-myc/metabolismo , Acetamidas/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Calpaína/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Sinergismo Farmacológico , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Meia-Vida , Humanos , Microtúbulos/efeitos dos fármacos , Morfolinas/farmacologia , Mutação/genética , Organoides/efeitos dos fármacos , Organoides/metabolismo , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Proteínas Proto-Oncogênicas p21(ras)/genética , Piridinas/farmacologia , Transcrição Gênica/efeitos dos fármacos , Tubulina (Proteína)/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Quinases da Família src/antagonistas & inibidores , Quinases da Família src/metabolismoRESUMO
We address whether combinations with a pan-RAF inhibitor (RAFi) would be effective in KRAS mutant pancreatic ductal adenocarcinoma (PDAC). Chemical library and CRISPR genetic screens identify combinations causing apoptotic anti-tumor activity. The most potent combination, concurrent inhibition of RAF (RAFi) and ERK (ERKi), is highly synergistic at low doses in cell line, organoid, and rat models of PDAC, whereas each inhibitor alone is only cytostatic. Comprehensive mechanistic signaling studies using reverse phase protein array (RPPA) pathway mapping and RNA sequencing (RNA-seq) show that RAFi/ERKi induced insensitivity to loss of negative feedback and system failures including loss of ERK signaling, FOSL1, and MYC; shutdown of the MYC transcriptome; and induction of mesenchymal-to-epithelial transition. We conclude that low-dose vertical inhibition of the RAF-MEK-ERK cascade is an effective therapeutic strategy for KRAS mutant PDAC.
Assuntos
Apoptose/genética , Carcinoma Ductal Pancreático/genética , Sistema de Sinalização das MAP Quinases/genética , Neoplasias Pancreáticas/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Animais , Apoptose/efeitos dos fármacos , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Humanos , Quinases de Proteína Quinase Ativadas por Mitógeno/genética , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Mutação/genética , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Neoplasias PancreáticasRESUMO
The maternal embryonic leucine zipper kinase (MELK) has been implicated in the regulation of cancer cell proliferation. RNAi-mediated MELK depletion impairs growth and causes G2/M arrest in numerous cancers, but the mechanisms underlying these effects are poorly understood. Furthermore, the MELK inhibitor OTSSP167 has recently been shown to have poor selectivity for MELK, complicating the use of this inhibitor as a tool compound to investigate MELK function. Here, using a cell-based proteomics technique called multiplexed kinase inhibitor beads/mass spectrometry (MIB/MS), we profiled the selectivity of two additional MELK inhibitors, NVS-MELK8a (8a) and HTH-01-091. Our results revealed that 8a is a highly selective MELK inhibitor, which we further used for functional studies. Resazurin and crystal violet assays indicated that 8a decreases triple-negative breast cancer cell viability, and immunoblotting revealed that impaired growth is due to perturbation of cell cycle progression rather than induction of apoptosis. Using double-thymidine synchronization and immunoblotting, we observed that MELK inhibition delays mitotic entry, which was associated with delayed activation of Aurora A, Aurora B, and cyclin-dependent kinase 1 (CDK1). Following this delay, cells entered and completed mitosis. Using live-cell microscopy of cells harboring fluorescent proliferating cell nuclear antigen, we confirmed that 8a significantly and dose-dependently lengthens G2 phase. Collectively, our results provide a rationale for using 8a as a tool compound for functional studies of MELK and indicate that MELK inhibition delays mitotic entry, likely via transient G2/M checkpoint activation.
Assuntos
Espectrometria de Massas , Mitose , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Histonas/metabolismo , Humanos , Mitose/efeitos dos fármacos , Proteínas de Neoplasias/metabolismo , Fosforilação/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/metabolismo , Neoplasias de Mama Triplo Negativas/enzimologia , Neoplasias de Mama Triplo Negativas/patologiaRESUMO
Controlling which particular members of a large protein family are targeted by a drug is key to achieving a desired therapeutic response. In this study, we report a rational data-driven strategy for achieving restricted polypharmacology in the design of antitumor agents selectively targeting the TYRO3, AXL, and MERTK (TAM) family tyrosine kinases. Our computational approach, based on the concept of fragments in structural environments (FRASE), distills relevant chemical information from structural and chemogenomic databases to assemble a three-dimensional inhibitor structure directly in the protein pocket. Target engagement by the inhibitors designed led to disruption of oncogenic phenotypes as demonstrated in enzymatic assays and in a panel of cancer cell lines, including acute lymphoblastic and myeloid leukemia (ALL/AML) and nonsmall cell lung cancer (NSCLC). Structural rationale underlying the approach was corroborated by X-ray crystallography. The lead compound demonstrated potent target inhibition in a pharmacodynamic study in leukemic mice.
Assuntos
Antineoplásicos/química , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Sequência de Aminoácidos , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Estrutura Molecular , Neoplasias ExperimentaisRESUMO
Stabilization of the MYC oncoprotein by KRAS signaling critically promotes the growth of pancreatic ductal adenocarcinoma (PDAC). Thus, understanding how MYC protein stability is regulated may lead to effective therapies. Here, we used a previously developed, flow cytometry-based assay that screened a library of >800 protein kinase inhibitors and identified compounds that promoted either the stability or degradation of MYC in a KRAS-mutant PDAC cell line. We validated compounds that stabilized or destabilized MYC and then focused on one compound, UNC10112785, that induced the substantial loss of MYC protein in both two-dimensional (2D) and 3D cell cultures. We determined that this compound is a potent CDK9 inhibitor with a previously uncharacterized scaffold, caused MYC loss through both transcriptional and posttranslational mechanisms, and suppresses PDAC anchorage-dependent and anchorage-independent growth. We discovered that CDK9 enhanced MYC protein stability through a previously unknown, KRAS-independent mechanism involving direct phosphorylation of MYC at Ser62 Our study thus not only identifies a potential therapeutic target for patients with KRAS-mutant PDAC but also presents the application of a screening strategy that can be more broadly adapted to identify regulators of protein stability.
Assuntos
Quinase 9 Dependente de Ciclina/antagonistas & inibidores , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Neoplasias Pancreáticas/genética , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Quinase 9 Dependente de Ciclina/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Estrutura Molecular , Mutação , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/química , Estabilidade Proteica , Proteólise , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologiaRESUMO
ONC201 is a first-in-class imipridone molecule currently in clinical trials for the treatment of multiple cancers. Despite enormous clinical potential, the mechanism of action is controversial. To investigate the mechanism of ONC201 and identify compounds with improved potency, we tested a series of novel ONC201 analogues (TR compounds) for effects on cell viability and stress responses in breast and other cancer models. The TR compounds were found to be â¼50-100 times more potent at inhibiting cell proliferation and inducing the integrated stress response protein ATF4 than ONC201. Using immobilized TR compounds, we identified the human mitochondrial caseinolytic protease P (ClpP) as a specific binding protein by mass spectrometry. Affinity chromatography/drug competition assays showed that the TR compounds bound ClpP with â¼10-fold higher affinity compared to ONC201. Importantly, we found that the peptidase activity of recombinant ClpP was strongly activated by ONC201 and the TR compounds in a dose- and time-dependent manner with the TR compounds displaying a â¼10-100 fold increase in potency over ONC201. Finally, siRNA knockdown of ClpP in SUM159 cells reduced the response to ONC201 and the TR compounds, including induction of CHOP, loss of the mitochondrial proteins (TFAM, TUFM), and the cytostatic effects of these compounds. Thus, we report that ClpP directly binds ONC201 and the related TR compounds and is an important biological target for this class of molecules. Moreover, these studies provide, for the first time, a biochemical basis for the difference in efficacy between ONC201 and the TR compounds.
Assuntos
Antineoplásicos/farmacologia , Endopeptidase Clp/antagonistas & inibidores , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cromatografia de Afinidade , Endopeptidase Clp/genética , Endopeptidase Clp/metabolismo , Ativação Enzimática , Técnicas de Silenciamento de Genes , Compostos Heterocíclicos de 4 ou mais Anéis/química , Humanos , Imidazóis , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/enzimologia , Piridinas , PirimidinasRESUMO
Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease, and at least one-third of its patients relapse after treatment with the current chemotherapy regimen, R-CHOP. By gene-expression profiling, patients with DLBCL can be categorized into two clinically relevant subtypes: activated B-cell (ABC) and germinal center B-cell (GCB) DLBCL. Patients with the ABC subtype have a worse prognosis than those with GCB, and the subtype is defined by chronic, over-active signaling through the B-cell receptor and NF-κB pathways. We examined the effects of the Src family kinase (SFK) inhibitor dasatinib in a panel of ABC and GCB DLBCL cell lines and found that the former are much more sensitive to dasatinib than the latter. However, using multiplexed inhibitor bead coupled to mass spectrometry (MIB/MS) kinome profiling and Western blot analysis, we found that both subtypes display inhibition of the SFKs in response to dasatinib after both short- and long-term treatment. The MIB/MS analyses revealed that several cell-cycle kinases, including CDK4, CDK6, and the Aurora kinases, are down-regulated by dasatinib treatment in the ABC, but not in the GCB, subtype. The present findings have potential implications for the clinical use of dasatinib for the treatment of ABC DLBCL, either alone or in combination with other agents.
Assuntos
Dasatinibe/farmacologia , Centro Germinativo/efeitos dos fármacos , Ativação Linfocitária/efeitos dos fármacos , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Antineoplásicos/uso terapêutico , Linfócitos B/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Dasatinibe/uso terapêutico , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Centro Germinativo/patologia , Humanos , Linfoma Difuso de Grandes Células B/classificaçãoRESUMO
Our recent ERK1/2 inhibitor analyses in pancreatic ductal adenocarcinoma (PDAC) indicated ERK1/2-independent mechanisms maintaining MYC protein stability. To identify these mechanisms, we determined the signaling networks by which mutant KRAS regulates MYC. Acute KRAS suppression caused rapid proteasome-dependent loss of MYC protein, through both ERK1/2-dependent and -independent mechanisms. Surprisingly, MYC degradation was independent of PI3K-AKT-GSK3ß signaling and the E3 ligase FBWX7. We then established and applied a high-throughput screen for MYC protein degradation and performed a kinome-wide proteomics screen. We identified an ERK1/2-inhibition-induced feedforward mechanism dependent on EGFR and SRC, leading to ERK5 activation and phosphorylation of MYC at S62, preventing degradation. Concurrent inhibition of ERK1/2 and ERK5 disrupted this mechanism, synergistically causing loss of MYC and suppressing PDAC growth.
Assuntos
Carcinoma Ductal Pancreático/patologia , MAP Quinase Quinase 5/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Proteína Quinase 7 Ativada por Mitógeno/metabolismo , Neoplasias Pancreáticas/patologia , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Animais , Carcinoma Ductal Pancreático/genética , Linhagem Celular Tumoral , Receptores ErbB/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Neoplasias Pancreáticas/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Quinases da Família src/metabolismoRESUMO
Background: Meningiomas are the most common primary brain tumor in adults, and somatic loss of the neurofibromatosis 2 (NF2) tumor suppressor gene is a frequent genetic event. There is no effective treatment for tumors that recur or continue to grow despite surgery and/or radiation. Therefore, targeted therapies that either delay tumor progression or cause tumor shrinkage are much needed. Our earlier work established mammalian target of rapamycin complex mTORC1/mTORC2 activation in NF2-deficient meningiomas. Methods: High-throughput kinome analyses were performed in NF2-null human arachnoidal and meningioma cell lines to identify functional kinome changes upon NF2 loss. Immunoblotting confirmed the activation of kinases and demonstrated effectiveness of drugs to block the activation. Drugs, singly and in combination, were screened in cells for their growth inhibitory activity. Antitumor drug efficacy was tested in an orthotopic meningioma model. Results: Erythropoietin-producing hepatocellular receptor tyrosine kinases (EPH RTKs), c-KIT, and Src family kinase (SFK) members, which are biological targets of dasatinib, were among the top candidates activated in NF2-null cells. Dasatinib significantly inhibited phospho-EPH receptor A2 (pEPHA2), pEPHB1, c-KIT, and Src/SFK in NF2-null cells, showing no cross-talk with mTORC1/2 signaling. Posttreatment kinome analyses showed minimal adaptive changes. While dasatinib treatment showed some activity, dual mTORC1/2 inhibitor and its combination with dasatinib elicited stronger growth inhibition in meningiomas. Conclusion: Co-targeting mTORC1/2 and EPH RTK/SFK pathways could be a novel effective treatment strategy for NF2-deficient meningiomas.
Assuntos
Antineoplásicos/farmacologia , Biomarcadores Tumorais/antagonistas & inibidores , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Meníngeas/patologia , Meningioma/patologia , Neurofibromina 2/deficiência , Receptores da Família Eph/antagonistas & inibidores , Animais , Apoptose , Proliferação de Células , Humanos , Neoplasias Meníngeas/tratamento farmacológico , Neoplasias Meníngeas/metabolismo , Meningioma/tratamento farmacológico , Meningioma/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Receptores da Família Eph/genética , Receptores da Família Eph/metabolismo , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Continuous exposure of a pancreatic cancer cell line MIA PaCa-2 (MiaS) to gemcitabine resulted in the formation of a gemcitabine-resistant subline (MiaR). In an effort to discover kinase inhibitors that inhibited MiaR growth, MiaR cells were exposed to kinase inhibitors (PKIS-1 library) in a 384-well screening format. Three compounds (UNC10112721A, UNC10112652A, and UNC10112793A) were identified that inhibited the growth of MiaR cells by more than 50% (at 50 nM). Two compounds (UNC10112721A and UNC10112652A) were classified as cyclin-dependent kinase (CDK) inhibitors, whereas UNC10112793A was reported to be a PLK inhibitor. Dose-response experiments supported the efficacy of these compounds to inhibit growth and increase apoptosis in 2D cultures of these cells. However, only UNC10112721A significantly inhibited the growth of 3D spheroids composed of MiaR cells and GFP-tagged cancer-associated fibroblasts. Multiplexed inhibitor bead (MIB)-mass spectrometry (MS) kinome competition experiments identified CDK9, CLK1-4, DYRK1A, and CSNK1 as major kinase targets for UNC10112721A in MiaR cells. Another CDK9 inhibitor (CDK-IN-2) replicated the growth inhibitory effects of UNC10112721A, whereas inhibitors against the CLK, DYRK, or CSNK1 kinases had no effect. In summary, these studies describe a coordinated approach to discover novel kinase inhibitors, evaluate their efficacy in 3D models, and define their specificity against the kinome.
Assuntos
Antineoplásicos/farmacologia , Desoxicitidina/análogos & derivados , Resistencia a Medicamentos Antineoplásicos , Ensaios de Seleção de Medicamentos Antitumorais , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Biomarcadores Tumorais , Linhagem Celular Tumoral , Sobrevivência Celular , Desoxicitidina/química , Desoxicitidina/farmacologia , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Ensaios de Triagem em Larga Escala , Humanos , Modelos Moleculares , Conformação Molecular , Inibidores de Proteínas Quinases/farmacologia , Proteínas Quinases/química , Proteínas Quinases/metabolismo , Relação Estrutura-Atividade , Fluxo de Trabalho , GencitabinaRESUMO
PURPOSE: The EphA2 tyrosine kinase is frequently overexpressed in human tumors that are also treated with radiation. However, few studies have examined the effect of radiation on the EphA2 receptor itself. The purpose of this project was to investigate the impact of radiation on EphA2 to better understand mechanisms of radioresistance. MATERIALS AND METHODS: Cell lines were exposed to X-rays and assayed for changes in EphA2 protein levels and phosphorylation over time by Western blotting. HEK293 cells stably expressing wild-type EphA2 or the S897A mutant were analyzed for cell survival from X-rays. RESULTS: Treatment of different cancer cell lines with 2 Gy of X-rays induced the phosphorylation of EphA2 on S897 but no changes were found in EphA2 total levels or its tyrosine phosphorylation. Radiation-induced S897 phosphorylation was unaffected by an AKT inhibitor but blocked by a MEK or RSK inhibitor. HEK293 cells expressing the EphA2 S897A mutant had a nearly 2-fold lower level of cell survival from X-rays than cells expressing wild-type EphA2. CONCLUSIONS: These findings show that radiation induces S897 EphA2 phosphorylation, an event associated with increased cell survival. Therefore, targeting pathways that mediate EphA2 S897 phosphorylation may be a beneficial strategy to reduce radioresistance.
Assuntos
Sobrevivência Celular/fisiologia , Sobrevivência Celular/efeitos da radiação , Sistema de Sinalização das MAP Quinases/fisiologia , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Fosfosserina/metabolismo , Radiação Ionizante , Receptor EphA2/metabolismo , Relação Dose-Resposta à Radiação , Células HEK293 , Humanos , Fosforilação/efeitos da radiação , Doses de Radiação , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismoRESUMO
Baculoviral IAP repeat containing 6 (BIRC6) is a member of the inhibitors of apoptosis proteins (IAPs), a family of functionally and structurally related proteins that inhibit apoptosis. BIRC6 has been implicated in drug resistance in several different human cancers, however mechanisms regulating BIRC6 have not been extensively explored. Our phosphoproteomic analysis of an imatinib-resistant chronic myelogenous leukemia (CML) cell line (MYL-R) identified increased amounts of a BIRC6 peptide phosphorylated at S480, S482, and S486 compared to imatinib-sensitive CML cells (MYL). Thus we investigated the role of BIRC6 in mediating imatinib resistance and compared it to the well-characterized anti-apoptotic protein, Mcl-1. Both BIRC6 and Mcl-1 were elevated in MYL-R compared to MYL cells. Lentiviral shRNA knockdown of BIRC6 in MYL-R cells increased imatinib-stimulated caspase activation and resulted in a ~20-25-fold increase in imatinib sensitivity, without affecting Mcl-1. Treating MYL-R cells with CDK9 inhibitors decreased BIRC6 mRNA, but not BIRC6 protein levels. By contrast, while CDK9 inhibitors reduced Mcl-1 mRNA and protein, they did not affect imatinib sensitivity. Since the Src family kinase Lyn is highly expressed and active in MYL-R cells, we tested the effects of Lyn inhibition on BIRC6 and Mcl-1. RNAi-mediated knockdown or inhibition of Lyn (dasatinib/ponatinib) reduced BIRC6 protein stability and increased caspase activation. Inhibition of Lyn also increased formation of an N-terminal BIRC6 fragment in parallel with reduced amount of the BIRC6 phosphopeptide, suggesting that Lyn may regulate BIRC6 phosphorylation and stability. In summary, our data show that BIRC6 stability is dependent on Lyn, and that BIRC6 mediates imatinib sensitivity independently of Mcl-1 or CDK9. Hence, BIRC6 may be a novel target for the treatment of drug-resistant CML where Mcl-1 or CDK9 inhibitors have failed.
Assuntos
Antineoplásicos/toxicidade , Apoptose , Resistencia a Medicamentos Antineoplásicos/genética , Mesilato de Imatinib/toxicidade , Proteínas Inibidoras de Apoptose/metabolismo , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Linhagem Celular Tumoral , Quinase 9 Dependente de Ciclina/genética , Quinase 9 Dependente de Ciclina/metabolismo , Humanos , Proteínas Inibidoras de Apoptose/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Quinases da Família src/genética , Quinases da Família src/metabolismoRESUMO
Human cytomegalovirus (HCMV) is a significant cause of disease in immune-compromised adults and immune naïve newborns. No vaccine exists to prevent HCMV infection, and current antiviral therapies have toxic side effects that limit the duration and intensity of their use. There is thus an urgent need for new strategies to treat HCMV infection. Repurposing existing drugs as antivirals is an attractive approach to limit the time and cost of new antiviral drug development. Virus-induced changes in infected cells are often driven by changes in cellular kinase activity, which led us to hypothesize that defining the complement of kinases (the kinome), whose abundance or expression is altered during infection would identify existing kinase inhibitors that could be repurposed as new antivirals. To this end, we applied a kinase capture technique, multiplexed kinase inhibitor bead-mass spectrometry (MIB-MS) kinome, to quantitatively measure perturbations in >240 cellular kinases simultaneously in cells infected with a laboratory-adapted (AD169) or clinical (TB40E) HCMV strain. MIB-MS profiling identified time-dependent increases and decreases in MIB binding of multiple kinases including cell cycle kinases, receptor tyrosine kinases, and mitotic kinases. Based on the kinome data, we tested the antiviral effects of kinase inhibitors and other compounds, several of which are in clinical use or development. Using a novel flow cytometry-based assay and a fluorescent reporter virus we identified three compounds that inhibited HCMV replication with IC50 values of <1 µm, and at doses that were not toxic to uninfected cells. The most potent inhibitor of HCMV replication was OTSSP167 (IC50 <1.2 nm), a MELK inhibitor, blocked HCMV early gene expression and viral DNA accumulation, resulting in a >3 log decrease in virus replication. These results show the utility of MIB-MS kinome profiling for identifying existing kinase inhibitors that can potentially be repurposed as novel antiviral drugs.