RESUMEN
NXP900 is a selective and potent SRC family kinase (SFK) inhibitor, currently being dosed in a phase 1 clinical trial, that locks SRC in the "closed" conformation, thereby inhibiting both kinase-dependent catalytic activity and kinase-independent functions. In contrast, several multi-targeted kinase inhibitors that inhibit SRC, including dasatinib and bosutinib, bind their target in the active "open" conformation, allowing SRC and other SFKs to act as a scaffold to promote tumorigenesis through non-catalytic functions. NXP900 exhibits a unique target selectivity profile with sub-nanomolar activity against SFK members over other kinases. This results in highly potent and specific SFK pathway inhibition. Here, we demonstrate that esophageal squamous cell carcinomas (ESCC) and head and neck squamous cell carcinomas (HNSCC) are exquisitely sensitive to NXP900 treatment in cell culture and in vivo, and we identify a patient population that could benefit from treatment with NXP900.
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Most patients with lung squamous cell carcinoma (LSCC) undergo chemotherapy, radiotherapy, and adjuvant immunotherapy for locally advanced disease. The efficacy of these treatments is still limited because of dose-limiting toxicity or locoregional recurrence. New combination approaches and targets such as actionable oncogenic drivers are needed to advance treatment options for patients with LSCC. Moreover, other options for chemotherapy-ineligible patients are limited. As such, there is a critical need for the development of selective and potent chemoradiosensitizers for locally advanced LSCC. In this study, we investigated inhibiting TRAF2- and NCK-interacting protein kinase (TNIK), which is amplified in 40% of patients with LSCC, as a strategy to sensitize LSCC tumors to chemotherapy and radiotherapy. Employing a range of human LSCC cell lines and the TNIK inhibitor NCB-0846, we investigated the potential of TNIK as a chemo- and radiosensitizing target with in vitro and in vivo preclinical models. The combination of NCB-0846 with cisplatin or etoposide was at best additive. Interestingly, pre-treating LSCC cells with NCB-0846 prior to ionizing radiation (IR) potentiated the cytotoxicity of IR in a TNIK-specific fashion. Characterization of the radiosensitization mechanism suggested that TNIK inhibition may impair the DNA damage response and promote mitotic catastrophe in irradiated cells. In a subcutaneous xenograft in vivo model, pretreatment with NCB-0846 significantly enhanced the efficacy of IR and caused elevated necrosis in TNIKhigh LK2 tumors but not TNIKlow KNS62 tumors. Overall, these results indicate that TNIK inhibition may be a promising strategy to increase the efficacy of radiotherapy in patients with LSCC with high TNIK expression.
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Most patients with lung squamous cell carcinoma (LSCC) undergo chemotherapy, radiotherapy, and adjuvant immunotherapy for locally advanced disease. The efficacy of these treatments is still limited due to dose-limiting toxicity or locoregional recurrence. New combination approaches and targets such as actionable oncogenic drivers are needed to advance treatment options for LSCC patients. Moreover, other options for chemotherapy-ineligible patients are also limited. As such there is a critical need for the development of selective and potent chemoradiosensitizers for locally advanced LSCC. Here, we investigated inhibiting TRAF2 and NCK-interacting protein kinase (TNIK), which is amplified in 40% of LSCC patients, as a strategy to sensitize LSCC tumors to chemo- and radiotherapy. Employing a range of human LSCC cell lines and the TNIK inhibitor NCB-0846, we investigated the potential of TNIK as a chemo- and radiosensitizing target with in vitro and in vivo preclinical models. The combination of NCB-0846 with cisplatin or etoposide was at best additive. Interestingly, pre-treating LSCC cells with NCB-0846 prior to ionizing radiation (IR) potentiated the cytotoxicity of IR in a TNIK-specific fashion. Characterization of the radiosensitization mechanism suggested that TNIK inhibition may impair the DNA damage response and promote mitotic catastrophe in irradiated cells. In a subcutaneous xenograft in vivo model, pretreatment with NCB-0846 significantly enhanced the efficacy of IR and caused elevated necrosis in TNIKhigh LK2 tumors but not TNIKlow KNS62 tumors. Overall, these results indicate that TNIK inhibition may be a promising strategy to increase the efficacy of radiotherapy in LSCC patients with high TNIK expression.
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PIM kinases have important pro-tumorigenic roles and mediate several oncogenic traits, including cell proliferation, survival, and chemotherapeutic resistance. As a result, multiple PIM inhibitors have been pursued as investigational new drugs in cancer; however, response to PIM inhibitors in solid tumors has fallen short of expectations. We found that inhibition of PIM kinase activity stabilizes protein levels of all three PIM isoforms (PIM1/2/3), and this can promote resistance to PIM inhibitors and chemotherapy. To overcome this effect, we designed PIM proteolysis targeting chimeras (PROTACs) to target PIM for degradation. PIM PROTACs effectively downmodulated PIM levels through the ubiquitin-proteasome pathway. Importantly, degradation of PIM kinases was more potent than inhibition of catalytic activity at inducing apoptosis in prostate cancer cell line models. In conclusion, we provide evidence of the advantages of degrading PIM kinases versus inhibiting their catalytic activity to target the oncogenic functions of PIM kinases.
Asunto(s)
Resistencia a Antineoplásicos , Neoplasias de la Próstata , Masculino , Humanos , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/patología , Fosforilación , Apoptosis , Proliferación Celular , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Proto-Oncogénicas c-pim-1RESUMEN
Amplification of pro-oncogenic kinases is a common genetic alteration driving tumorigenic phenotypes. Cancer cells rely on the amplified kinases to sustain cell proliferation, survival, and growth, presenting an opportunity to develop therapies targeting the amplified kinases. Utilizing small molecule catalytic inhibitors as therapies to target amplified kinases is plagued by de novo resistance driven by increased expression of the target, and amplified kinases can drive tumorigenic phenotypes independent of catalytic activity. Here, we discuss the emergence of proteolysis-targeting chimeras that provide an opportunity to target these oncogenic drivers effectively. SIGNIFICANCE STATEMENT: Protein kinases contribute to tumorigenesis through catalytic and noncatalytic mechanisms, and kinase gene amplifications are well described mechanisms of resistance to small molecule catalytic inhibitors. Repurposing catalytic inhibitors for the development of protein degraders will offer improved clinical benefits by targeting noncatalytic functions of kinases that promote tumorigenesis and overcoming resistance due to amplification.
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Neoplasias , Carcinogénesis/genética , Proliferación Celular , Amplificación de Genes , Humanos , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Proteínas Quinasas/genéticaRESUMEN
Poly(ADP-ribose) polymerase 1 (PARP1) and PARP2 are recruited and activated by DNA damage, resulting in ADP-ribosylation at numerous sites, both within PARP1 itself and in other proteins. Several PARP1 and PARP2 inhibitors are currently employed in the clinic or undergoing trials for treatment of various cancers. These drugs act primarily by trapping PARP1 on damaged chromatin, which can lead to cell death, especially in cells with DNA repair defects. Although PARP1 trapping is thought to be caused primarily by the catalytic inhibition of PARP-dependent modification, implying that ADP-ribosylation (ADPr) can counteract trapping, it is not known which exact sites are important for this process. Following recent findings that PARP1- or PARP2-mediated modification is predominantly serine-linked, we demonstrate here that serine ADPr plays a vital role in cellular responses to PARP1/PARP2 inhibitors. Specifically, we identify three serine residues within PARP1 (499, 507, and 519) as key sites whose efficient HPF1-dependent modification counters PARP1 trapping and contributes to inhibitor tolerance. Our data implicate genes that encode serine-specific ADPr regulators, HPF1 and ARH3, as potential PARP1/PARP2 inhibitor therapy biomarkers.
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Proteínas Portadoras/metabolismo , Daño del ADN , Reparación del ADN , Neoplasias/tratamiento farmacológico , Proteínas Nucleares/metabolismo , Poli(ADP-Ribosa) Polimerasa-1/antagonistas & inhibidores , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Serina/metabolismo , ADP-Ribosilación , Línea Celular , Línea Celular Tumoral , Humanos , Neoplasias/enzimología , Poli(ADP-Ribosa) Polimerasa-1/metabolismo , Poli(ADP-Ribosa) Polimerasas/química , Poli(ADP-Ribosa) Polimerasas/metabolismo , Procesamiento Proteico-PostraduccionalRESUMEN
Squamous cell carcinomas of the lung, head and neck, esophagus, and cervix account for more than two million cases of cancer per year worldwide with very few targetable therapies available and minimal clinical improvement in the past three decades. Although these carcinomas are differentiated anatomically, their genetic landscape shares numerous common genetic alterations. Amplification of the third chromosome's distal portion (3q) is a distinguishing genetic alteration in most of these carcinomas and leads to copy-number gain and amplification of numerous oncogenic proteins. This area of the chromosome harbors known oncogenes involved in squamous cell fate decisions and differentiation, including TP63, SOX2, ECT2, and PIK3CA. Furthermore, novel targetable oncogenic kinases within this amplicon include PRKCI, PAK2, MAP3K13, and TNIK. TCGA analysis of these genes identified amplification in more than 20% of clinical squamous cell carcinoma samples, correlating with a significant decrease in overall patient survival. Alteration of these genes frequently co-occurs and is dependent on 3q-chromosome amplification. The dependency of cancer cells on these amplified kinases provides a route toward personalized medicine in squamous cell carcinoma patients through development of small-molecules targeting these kinases.
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Antineoplásicos/uso terapéutico , Carcinoma de Células Escamosas/tratamiento farmacológico , Neoplasias Esofágicas/tratamiento farmacológico , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/uso terapéutico , Neoplasias del Cuello Uterino/tratamiento farmacológico , Carcinoma de Células Escamosas/enzimología , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/mortalidad , Ensayos Clínicos como Asunto , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Quinasas Ciclina-Dependientes/genética , Quinasas Ciclina-Dependientes/metabolismo , Neoplasias Esofágicas/enzimología , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/mortalidad , Femenino , Regulación Neoplásica de la Expresión Génica , Neoplasias de Cabeza y Cuello/enzimología , Neoplasias de Cabeza y Cuello/genética , Neoplasias de Cabeza y Cuello/mortalidad , Humanos , Neoplasias Pulmonares/enzimología , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/mortalidad , Masculino , Fosfatidilinositol 3-Quinasa/genética , Fosfatidilinositol 3-Quinasa/metabolismo , Medicina de Precisión/métodos , Receptores de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Receptores de Factores de Crecimiento Endotelial Vascular/genética , Receptores de Factores de Crecimiento Endotelial Vascular/metabolismo , Análisis de Supervivencia , Neoplasias del Cuello Uterino/enzimología , Neoplasias del Cuello Uterino/genética , Neoplasias del Cuello Uterino/mortalidadRESUMEN
Lung squamous cell carcinoma (LSCC) is the second most prevalent type of lung cancer. Despite extensive genomic characterization, no targeted therapies are approved for the treatment of LSCC. Distal amplification of the 3q chromosome is the most frequent genomic alteration in LSCC, and there is an urgent need to identify efficacious druggable targets within this amplicon. We identify the protein kinase TNIK as a therapeutic target in LSCC. TNIK is amplified in approximately 50% of LSCC cases. TNIK genetic depletion or pharmacologic inhibition reduces the growth of LSCC cells in vitro and in vivo. In addition, TNIK inhibition showed antitumor activity and increased apoptosis in established LSCC patient-derived xenografts. Mechanistically, we identified the tumor suppressor Merlin/NF2 as a novel TNIK substrate and showed that TNIK and Merlin are required for the activation of focal adhesion kinase. In conclusion, our data identify targeting TNIK as a potential therapeutic strategy in LSCC. SIGNIFICANCE: Targeted therapies have not yet been approved for the treatment of LSCC, due to lack of identification of actionable cancer drivers. We define TNIK catalytic activity as essential for maintaining LSCC viability and validate the antitumor efficacy of TNIK inhibition in preclinical models of LSCC.This article is highlighted in the In This Issue feature, p. 1307.
Asunto(s)
Antineoplásicos/uso terapéutico , Carcinoma de Células Escamosas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Animales , Antineoplásicos/farmacología , Carcinoma de Células Escamosas/genética , Línea Celular Tumoral/efectos de los fármacos , Células Epiteliales/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Pulmonares/genética , Ratones , Terapia Molecular Dirigida , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Serina-Treonina Quinasas/genéticaRESUMEN
Identifying additional mitogen-activated protein kinase (MAPK) pathway regulators is invaluable in aiding our understanding of the complex signaling networks that regulate cellular processes, including cell proliferation and survival. Here, using in vitro kinase assays and by expressing WT or kinase-dead MAPK kinase kinase 19 (MAP3K19) in the HEK293T cell line and assessing activation of the extracellular signal-regulated kinase (ERK) and JUN N-terminal kinase (JNK) signaling pathways, we defined MAP3K19 as a novel regulator of MAPK signaling. We also observed that overexpression of WT MAP3K19 activates both the ERK and JNK pathways in a panel of cancer cell lines. Furthermore, MAP3K19 sustained ERK pathway activation in the presence of inhibitors targeting the RAF proto-oncogene Ser/Thr protein kinase (RAF) and MAPK/ERK kinase, indicating that MAP3K19 activates ERK via a RAF-independent mechanism. Findings from in vitro and in-cell kinase assays demonstrate that MAP3K19 is a kinase that directly phosphorylates both MAPK/ERK kinase (MEK) and MAPK kinase 7 (MKK7). Results from an short-hairpin RNA screen indicated that MAP3K19 is essential for maintaining survival in KRAS-mutant cancers; therefore, we depleted or inhibited MAP3K19 in KRAS-mutant cancer cell lines and observed that this reduces viability and decreases ERK and JNK pathway activation. In summary, our results reveal that MAP3K19 directly activates the ERK and JNK cascades and highlight a role for this kinase in maintaining survival of KRAS-mutant lung cancer cells.
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Quinasas Quinasa Quinasa PAM/metabolismo , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Proteínas Proto-Oncogénicas p21(ras)/genética , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Resistencia a Antineoplásicos , Humanos , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Quinasas Quinasa Quinasa PAM/antagonistas & inhibidores , Quinasas Quinasa Quinasa PAM/genética , Sistema de Señalización de MAP Quinasas , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Quinasas de Proteína Quinasa Activadas por Mitógenos/antagonistas & inhibidores , Fosforilación/efectos de los fármacos , Inhibidores de Proteínas Quinasas/farmacología , Proto-Oncogenes Mas , Proteínas Proto-Oncogénicas c-raf/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-raf/metabolismo , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Interferencia de ARN , ARN Interferente Pequeño/metabolismoRESUMEN
Protein kinases are critical regulators of signaling cascades that control cellular proliferation, growth, survival, metabolism, migration, and invasion. Deregulation of kinase activity can lead to aberrant regulation of biological processes and to the onset of diseases, including cancer. In this review, we focus on oncogenic kinases and the signaling pathways they regulate that underpin tumor development. We highlight genomic biomarker-based precision medicine intervention strategies that match kinase inhibitors alone or in combination to mutationally activated kinase drivers, as well as progress towards implementation of these treatment strategies in the clinic. We also discuss the challenges for identification of novel protein kinase cancer drivers in the genomic era.
RESUMEN
For many decades, kinases have predominantly been characterized as oncogenes and drivers of tumorigenesis, because activating mutations in kinases occur in cancer with high frequency. The oncogenic functions of kinases relate to their roles as growth factor receptors and as critical mediators of mitogen-activated pathways. Indeed, some of the most promising cancer therapeutic agents are kinase inhibitors. However, cancer genomics studies, especially screens that utilize high-throughput identification of loss-of-function somatic mutations, are beginning to shed light on a widespread role for kinases as tumor suppressors. The initial characterization of tumor-suppressing kinases- in particular members of the protein kinase C (PKC) family, MKK4 of the mitogen-activated protein kinase kinase family, and DAPK3 of the death-associated protein kinase family- laid the foundation for bioinformatic approaches that enable the identification of other tumor-suppressing kinases. In this review, we discuss the important role that kinases play as tumor suppressors, using several examples to illustrate the history of their discovery and highlight the modern approaches that presently aid in the identification of tumor-suppressing kinases. © 2018 IUBMB Life, 71(6):738-748, 2019.
Asunto(s)
Proteínas Quinasas Asociadas a Muerte Celular/genética , MAP Quinasa Quinasa 4/genética , Neoplasias/genética , Proteínas Supresoras de Tumor/genética , Carcinogénesis/genética , Humanos , Proteína Quinasa C/genética , Transducción de Señal , Proteínas Supresoras de Tumor/químicaRESUMEN
Metastasis to distant organs is a major cause for solid cancer mortality, and the acquisition of migratory and invasive phenotype is a key factor in initiation of malignancy. In this study we investigated the contribution of Mixed-Lineage Kinase 4 (MLK4) to aggressive phenotype of breast cancer cells. Our TCGA cancer genomic data analysis revealed that amplification or mRNA upregulation of MLK4 occurred in 23% of invasive breast carcinoma cases. To find the association between MLK4 expression and the specific subtype of breast cancer, we performed a transcriptomic analysis of multiple datasets, which showed that MLK4 is highly expressed in triple-negative breast cancer compared to other molecular subtypes. Depletion of MLK4 in cell lines with high MLK4 expression impaired proliferation and anchorage-dependent colony formation. Moreover, silencing of MLK4 expression significantly reduced the migratory potential and invasiveness of breast cancer cells as well as the number of spheroids formed in 3D cultures. These in vitro findings translate into slower rate of tumor growth in mice upon MLK4 knock-down. Furthermore, we established that MLK4 activates NF-κB signaling and promotes a mesenchymal phenotype in breast cancer cells. Immunohistochemical staining of samples obtained from breast cancer patients revealed a strong positive correlation between high expression of MLK4 and metastatic potential of tumors, which was predominantly observed in TNBC subgroup. Taken together, our results show that high expression of MLK4 promotes migratory and invasive phenotype of breast cancer and may represent a novel target for anticancer treatment.
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Movimiento Celular/ética , Quinasas Quinasa Quinasa PAM/genética , Invasividad Neoplásica/genética , Neoplasias de la Mama Triple Negativas/genética , Regulación hacia Arriba/genética , Animales , Línea Celular , Línea Celular Tumoral , Proliferación Celular/genética , Femenino , Células HEK293 , Humanos , Células MCF-7 , Ratones , FN-kappa B/genética , Invasividad Neoplásica/patología , Transducción de Señal/genética , Transcriptoma/genética , Neoplasias de la Mama Triple Negativas/patologíaRESUMEN
RAS is one of the most frequently altered oncogenes, yet RAS-driven tumors are largely refractory to anticancer therapies. Fedele and colleagues demonstrate that SHP2 inhibitors prevent adaptive MEK inhibitor resistance; therefore, combining MEK and SHP2 inhibitors represents an exciting new therapeutic approach for the treatment of RAS-driven cancers. Cancer Discov; 8(10); 1210-2. ©2018 AACR. See related article by Fedele et al., p. 1237.
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Inhibidores de Proteínas Quinasas , Línea Celular TumoralRESUMEN
Precision medicine aims to tailor cancer therapies to target specific tumor-promoting aberrations. For tumors that lack actionable drivers, which occurs frequently in the clinic, extensive molecular characterization and pre-clinical drug efficacy studies will be required. A cell line maintained at low passage and a patient- derived xenograft model (PDX) were generated using a fresh biopsy from a patient with a poorly-differentiated neuroendocrine tumor of unknown primary origin. Next-generation sequencing, high throughput signaling network analysis, and drug efficacy trials were then conducted to identify actionable targets for therapeutic intervention. No actionable mutations were identified after whole exome sequencing of the patient's DNA. However, whole genome sequencing revealed amplification of the 3q and 5p chromosomal arms, that include the PIK3CA and RICTOR genes, respectively. We then conducted pathway analysis, which revealed activation of the AKT pathway. Based on this analysis, efficacy of PIK3CA and AKT inhibitors were evaluated in the tumor biopsy-derived cell culture and PDX, and response to the AKT inhibitor AZD5363 was observed both in vitro and in vivo indicating the patient would benefit from targeted therapies directed against the serine/threonine kinase AKT. In conclusion, our study demonstrates that high throughput signaling pathway analysis will significantly aid in identifying actionable alterations in rare tumors and guide patient stratification into early-phase clinical trials.
RESUMEN
Conventional protein kinase C (PKC) family members are reversibly activated by binding to the second messengers Ca2+ and diacylglycerol, events that break autoinhibitory constraints to allow the enzyme to adopt an active, but degradation-sensitive, conformation. Perturbing these autoinhibitory constraints, resulting in protein destabilization, is one of many mechanisms by which PKC function is lost in cancer. Here, we address how a gain-of-function germline mutation in PKCα in Alzheimer's disease (AD) enhances signaling without increasing vulnerability to down-regulation. Biochemical analyses of purified protein demonstrate that this mutation results in an â¼30% increase in the catalytic rate of the activated enzyme, with no changes in the concentrations of Ca2+ or lipid required for half-maximal activation. Molecular dynamics simulations reveal that this mutation has both localized and allosteric effects, most notably decreasing the dynamics of the C-helix, a key determinant in the catalytic turnover of kinases. Consistent with this mutation not altering autoinhibitory constraints, live-cell imaging studies reveal that the basal signaling output of PKCα-M489V is unchanged. However, the mutant enzyme in cells displays increased sensitivity to an inhibitor that is ineffective toward scaffolded PKC, suggesting the altered dynamics of the kinase domain may influence protein interactions. Finally, we show that phosphorylation of a key PKC substrate, myristoylated alanine-rich C-kinase substrate, is increased in brains of CRISPR-Cas9 genome-edited mice containing the PKCα-M489V mutation. Our results unveil how an AD-associated mutation in PKCα permits enhanced agonist-dependent signaling via a mechanism that evades the cell's homeostatic down-regulation of constitutively active PKCα.
Asunto(s)
Enfermedad de Alzheimer/genética , Regulación hacia Abajo/genética , Mutación con Ganancia de Función/genética , Proteína Quinasa C-alfa/genética , Enfermedad de Alzheimer/metabolismo , Animales , Encéfalo/metabolismo , Células COS , Sistemas CRISPR-Cas/genética , Calcio/metabolismo , Catálisis , Dominio Catalítico/genética , Línea Celular , Chlorocebus aethiops , Activación Enzimática/genética , Humanos , Ratones , Ratones Endogámicos C57BL , Mutación/genética , Fosforilación/genética , Transducción de Señal/genéticaRESUMEN
A major challenge in cancer genomics is identifying "driver" mutations from the many neutral "passenger" mutations within a given tumor. To identify driver mutations that would otherwise be lost within mutational noise, we filtered genomic data by motifs that are critical for kinase activity. In the first step of our screen, we used data from the Cancer Cell Line Encyclopedia and The Cancer Genome Atlas to identify kinases with truncation mutations occurring within or before the kinase domain. The top 30 tumor-suppressing kinases were aligned, and hotspots for loss-of-function (LOF) mutations were identified on the basis of amino acid conservation and mutational frequency. The functional consequences of new LOF mutations were biochemically validated, and the top 15 hotspot LOF residues were used in a pan-cancer analysis to define the tumor-suppressing kinome. A ranked list revealed MAP2K7, an essential mediator of the c-Jun N-terminal kinase (JNK) pathway, as a candidate tumor suppressor in gastric cancer, despite its mutational frequency falling within the mutational noise for this cancer type. The majority of mutations in MAP2K7 abolished its catalytic activity, and reactivation of the JNK pathway in gastric cancer cells harboring LOF mutations in MAP2K7 or the downstream kinase JNK suppressed clonogenicity and growth in soft agar, demonstrating the functional relevance of inactivating the JNK pathway in gastric cancer. Together, our data highlight a broadly applicable strategy to identify functional cancer driver mutations and define the JNK pathway as tumor-suppressive in gastric cancer.
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Regulación Neoplásica de la Expresión Génica , Genómica/métodos , Mutación con Pérdida de Función , MAP Quinasa Quinasa 7/genética , Sistema de Señalización de MAP Quinasas/genética , Neoplasias Gástricas/genética , Secuencia de Aminoácidos , Línea Celular Tumoral , Genes Supresores de Tumor , Humanos , MAP Quinasa Quinasa 7/química , MAP Quinasa Quinasa 7/metabolismo , Simulación de Dinámica Molecular , Homología de Secuencia de Aminoácido , Neoplasias Gástricas/enzimología , Neoplasias Gástricas/patologíaRESUMEN
Head and neck squamous cell carcinoma (HNSCC) includes epithelial cancers of the oral and nasal cavity, larynx, and pharynx and accounts for â¼350,000 deaths per year worldwide. Smoking-related HNSCC is associated with few targetable mutations but is defined by frequent copy-number alteration, the most common of which is gain at 3q. Critical 3q target genes have not been conclusively determined for HNSCC. Here, we present data indicating that MAP3K13 (encoding LZK) is an amplified driver gene in HNSCC. Copy-number gain at 3q resulted in increased MAP3K13 mRNA in HNSCC tumor samples and cell lines. Silencing LZK reduced cell viability and proliferation of HNSCC cells with 3q gain but not control cell lines. Inducible silencing of LZK caused near-complete loss of colony-forming ability in cells harboring 3q gain. These results were validated in vivo by evidence that LZK silencing was sufficient to reduce tumor growth in a xenograft model of HNSCC. Our results establish LZK as critical for maintaining expression of mutant stabilized p53. Cancer Res; 77(18); 4961-72. ©2017 AACR.
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Carcinoma de Células Escamosas/patología , Proliferación Celular , Neoplasias de Cabeza y Cuello/patología , Quinasas Quinasa Quinasa PAM/metabolismo , Proteínas Mutantes/metabolismo , Mutación/genética , Proteína p53 Supresora de Tumor/metabolismo , Animales , Apoptosis , Biomarcadores de Tumor , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Femenino , Neoplasias de Cabeza y Cuello/genética , Neoplasias de Cabeza y Cuello/metabolismo , Humanos , Quinasas Quinasa Quinasa PAM/genética , Ratones , Ratones Endogámicos NOD , Ratones SCID , Proteínas Mutantes/química , Proteínas Mutantes/genética , Estabilidad Proteica , Células Tumorales Cultivadas , Proteína p53 Supresora de Tumor/química , Proteína p53 Supresora de Tumor/genética , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
The discovery in the 1980s that protein kinase C (PKC) is a receptor for the tumor-promoting phorbol esters fueled the dogma that PKC is an oncoprotein. Yet 30+ years of clinical trials for cancer using PKC inhibitors not only failed, but in some instances worsened patient outcome. The recent analysis of cancer-associated mutations, from diverse cancers and throughout the PKC family, revealed that PKC isozymes are generally inactivated in cancer, supporting a tumor suppressive function. In keeping with a bona fide tumor suppressive role, germline causal loss-of-function (LOF) mutations in one isozyme have recently been identified in lymphoproliferative disorders. Thus, strategies in cancer treatment should focus on restoring rather than inhibiting PKC.
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Neoplasias/enzimología , Neoplasias/genética , Proteína Quinasa C/genética , Proteína Quinasa C/metabolismo , Animales , Genes Supresores de Tumor , Mutación de Línea Germinal , HumanosRESUMEN
The lack of actionable mutations in patients with non-small cell lung cancer (NSCLC) presents a significant hurdle in the design of targeted therapies for this disease. Here, we identify somatically mutated ABL1 as a genetic dependency that is required to maintain NSCLC cell survival. We demonstrate that NSCLC cells with ABL1 mutations are sensitive to ABL inhibitors and we verify that the drug-induced effects on cell viability are specific to pharmacological inhibition of the ABL1 kinase. Furthermore, we confirm that imatinib suppresses lung tumor growth in vivo, specifically in lung cancer cells harboring a gain-of-function (GOF) mutation in ABL1. Consistent with structural modeling, we demonstrate that mutations in ABL1 identified in primary NSCLC tumors and a lung cancer cell line increase downstream pathway activation compared to wild-type ABL1. Finally, we observe that the ABL1 cancer mutants display an increased cytosolic localization, which is associated with the oncogenic properties of the ABL1 kinase. In summary, our results suggest that NSCLC patients with ABL1 mutations could be stratified for treatment with imatinib in combination with other therapies.