RESUMEN
Human genetic evidence suggests a protective role of loss-of-function variants in 17-beta hydroxysteroid dehydrogenase 13 (HSD17B13) for liver fibrotic diseases. Although there is limited preclinical experimental data on Hsd17b13 antisense oligonucleotide (ASO) or siRNA in a fibrosis model, several ASO and siRNA approaches are being tested clinically as potential therapies for nonalcoholic steatohepatitis (NASH). The aim of this study was to assess the therapeutic potential of Hsd17b13 ASO in a preclinical advanced NASH-like hepatic fibrosis in vivo model. In vitro testing on primary hepatocytes demonstrated that Hsd17b13 ASO exhibited strong efficacy and specificity for knockdown of the Hsd17b13 gene. In choline-deficient, L-amino acid-defined, HFD (CDAHFD)-induced steatotic and fibrotic mice, therapeutic administration of Hsd17b13 ASO resulted in a significant and dose-dependent reduction of hepatic Hsd17b13 gene expression. The CDAHFD group exhibited considerably elevated liver enzyme levels, hepatic steatosis score, hepatic fibrosis, and increased fibrotic and inflammatory gene expression, indicating an advanced NASH-like hepatic fibrosis phenotype. Although Hsd17b13 ASO therapy significantly affected hepatic steatosis, it had no effect on hepatic fibrosis. Our findings demonstrate, for the first time, that Hsd17b13 ASO effectively suppressed Hsd17b13 gene expression both in vitro and in vivo, and had a modulatory effect on hepatic steatosis in mice, but did not affect fibrosis in the CDAHFD mouse model of NASH.
Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Animales , Ratones , Modelos Animales de Enfermedad , Hígado/metabolismo , Cirrosis Hepática/tratamiento farmacológico , Cirrosis Hepática/genética , Ratones Endogámicos C57BL , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/genética , Oligonucleótidos Antisentido/genética , Oligonucleótidos Antisentido/farmacología , Oligonucleótidos Antisentido/uso terapéutico , ARN Interferente Pequeño/metabolismoRESUMEN
Calcitonin gene-related peptide (CGRP) receptor antagonists have been shown clinically to be effective treatments for migraine. Zavegepant (BHV-3500, BMS-742413) is a high affinity antagonist of the CGRP receptor (hCGRP Ki = 0.023 nM) that has demonstrated efficacy in the acute treatment of migraine with intranasal delivery in a Phase 2/3 trial, despite showing low oral bioavailability in rats (FPO = 1.7%). Using zavegepant as a template, we sought to improve oral bioavailability through a series of azepinones which were designed in an attempt to reduce the number of rotatable bonds. These efforts led to the discovery of compound 21 which was able to mostly maintain high affinity binding (hCGRP Ki = 0.100 nM) and in vivo efficacy in the marmoset facial blood flow assay, while greatly improving oral bioavailability (rat FPO = 17%).
Asunto(s)
Azepinas/farmacología , Antagonistas del Receptor Peptídico Relacionado con el Gen de la Calcitonina/farmacología , Indazoles/farmacología , Receptores de Péptido Relacionado con el Gen de Calcitonina/metabolismo , Azepinas/química , Antagonistas del Receptor Peptídico Relacionado con el Gen de la Calcitonina/química , Relación Dosis-Respuesta a Droga , Humanos , Indazoles/química , Estructura Molecular , Relación Estructura-ActividadRESUMEN
BACKGROUND: Atypical spiradenoma and spiradenocarcinoma present a diagnostic challenge. We aim to assess the significance of certain histologic features, which may facilitate diagnosis of these tumors. METHODS: A natural language search for cases of "atypical spiradenoma" and "spiradenocarcinoma" diagnosed between 2009 and 2018 was performed. Original slides were retrieved and a subset of cases (n = 5) were stained for Ki-67, p53, carcinoembryonic antigen (CEA), and S100. All cases (n = 7) were assessed for overall architecture, atypical mitotic figures, abnormal cytology, necrosis, ductal proliferation, dilated vessels, and loss of dual cell population. RESULTS: All our cases showed an abrupt transition from benign to malignant morphology, nuclear atypia, atypical mitotic figures, and a monomorphic loss of the dual cell population (7/7; 100%). The majority also had dilated vessels (6/7; 85.7%), and ductal dilation or proliferation (5/7; 71.4%). Fewer cases showed tumor encapsulation (3/7; 43%), massive necrosis (3/7; 43%), and focal cellular necrosis (1/7; 14%). All cases showed a relatively increased Ki-67 proliferation index at the transitional interface (5/5; 100%). Almost all cases stained positively for p53 (4/5; 80%). Malignant areas of tumor or at the transitional interface showed more intense S100 staining (3/5; 60%). All cases were negative for CEA. CONCLUSION: Histologic features that strongly favor atypical spiradenoma or spiradenocarcinoma include abrupt transition to malignant foci, atypical mitotic figures, and monomorphic loss of the dual cell population. Ki-67, p53, and S100 may help delineate areas of atypical or malignant transformation in spiradenomas.
Asunto(s)
Adenocarcinoma/diagnóstico , Adenocarcinoma/patología , Adenoma de las Glándulas Sudoríparas/diagnóstico , Adenoma de las Glándulas Sudoríparas/patología , Neoplasias de las Glándulas Sudoríparas/diagnóstico , Neoplasias de las Glándulas Sudoríparas/patología , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/análisis , Femenino , Humanos , Persona de Mediana EdadRESUMEN
The authors report 2 cases of measles demonstrating novel skin pathology that may be useful in establishing early diagnosis. Syncytial epithelial giant cells, which are characteristic of measles, were found to be present in the dermis, indicating that these cells are not specific to the lymphoid tissue and epithelia of which they are classically attributed to. The cells were not prominent, and required step sectioning to observe. These results were confirmed by electron microscopy, which showed virus capsid particles within the endoplasmic reticulum, secretory vesicles, and cytoplasm of multinucleated cells. One of the cases also demonstrated an unusual mixed infiltrate of eosinophils and fibrin thrombi, which has not been previously described. Both patients in this report recovered with supportive therapy.
Asunto(s)
Dermis/patología , Células Gigantes/ultraestructura , Sarampión/patología , Enfermedades Cutáneas Virales/patología , Cápside/ultraestructura , Dermis/ultraestructura , Femenino , Humanos , Masculino , Virus del Sarampión , Persona de Mediana Edad , Adulto JovenRESUMEN
Calcitonin gene-related peptide (CGRP) receptor antagonists have been shown to be efficacious as abortive migraine therapeutics with the absence of cardiovascular liabilities that are associated with triptans. Herein, we report the discovery of a highly potent CGRP receptor antagonist, BMS-742413, with the potential to provide rapid onset of action through intranasal delivery. The compound displays excellent aqueous solubility, oxidative stability, and toxicological profile. BMS-742413 has good intranasal bioavailability in the rabbit and shows a robust, dose-dependent inhibition of CGRP-induced increases in marmoset facial blood flow.
Asunto(s)
Amidas/química , Antagonistas del Receptor Peptídico Relacionado con el Gen de la Calcitonina , Indazoles/química , Quinolonas/química , Administración Intranasal , Amidas/farmacología , Amidas/uso terapéutico , Animales , Células CACO-2 , Callithrix , Vasos Coronarios/efectos de los fármacos , Evaluación Preclínica de Medicamentos , Cara/irrigación sanguínea , Humanos , Indazoles/farmacología , Indazoles/uso terapéutico , Trastornos Migrañosos/tratamiento farmacológico , Quinolonas/farmacología , Quinolonas/uso terapéutico , Conejos , Ratas , Receptores de Péptido Relacionado con el Gen de Calcitonina/metabolismo , Mucosa Respiratoria/efectos de los fármacos , Mucosa Respiratoria/patologíaRESUMEN
Acquired Perforating Dermatosis (APD) is a perforating disease characterized by transepidermal elimination of dermal material [1,2]. This disease usually develops in adulthood. APD has been reported to occur in association with various diseases, but is most commonly associated with dialysis-dependent chronic renal failure (CRF) or diabetes mellitus (DM) [1,2,3,4]. Morton et al found that APD occurs in up to 10% of patients undergoing hemodialysis [5]. Additionally, Saray et al found that sixteen of twenty-two cases with APD were associated with CRF [3].
Asunto(s)
Dermoscopía , Foliculitis/patología , Hiperpigmentación/patología , Queratosis/patología , Anciano , Femenino , Foliculitis/complicaciones , Foliculitis/tratamiento farmacológico , Humanos , Hiperpigmentación/complicaciones , Hiperpigmentación/tratamiento farmacológico , Queratosis/complicaciones , Queratosis/tratamiento farmacológico , Prurito/etiologíaRESUMEN
Histiocytic/dendritic cell sarcomas are rare tumors, a few of which have been reported in association with B-cell lymphoma/leukemia. Isolated reports have documented identical immunoglobulin gene rearrangements suggesting a common clonal origin for both the sarcoma and the B-cell neoplasm from individual patients. We report a case of a 75-year-old male with hairy cell leukemia who subsequently developed Langerhans cell sarcoma 1 year after his primary diagnosis of leukemia. The bone marrow biopsy containing hairy cell leukemia and skin biopsies of Langerhans cell sarcoma were evaluated by routine histology, immunohistochemistry, flow cytometric immunophenotyping and PCR-based gene rearrangement studies of the immunoglobulin heavy chain and kappa genes. The hairy cell leukemia showed characteristic morphologic, immunohistochemical and flow cytometric features. The Langerhans cell sarcoma showed pleomorphic cytology, a high mitotic rate and characteristic immunohistochemical staining for Langerin, S100 and CD1a. There was no evidence of B-cell differentiation or a background B-cell infiltrate based on the absence of immunoreactivity with antibodies to multiple B-cell markers. Identical immunoglobulin gene rearrangements were identified in both the hairy cell leukemia and Langerhans cell sarcoma specimens. Despite the phenotypic dissimilarity of the two neoplasms, identical immunoglobulin gene rearrangements indicate a common origin.
Asunto(s)
Linfocitos B , Sarcoma de Células de Langerhans , Leucemia de Células Pilosas , Neoplasias Primarias Secundarias , Neoplasias Cutáneas , Hipermutación Somática de Inmunoglobulina/genética , Anciano , Linfocitos B/metabolismo , Linfocitos B/patología , Biomarcadores de Tumor/biosíntesis , Biomarcadores de Tumor/genética , Médula Ósea , Diferenciación Celular/genética , Humanos , Inmunohistoquímica , Sarcoma de Células de Langerhans/genética , Sarcoma de Células de Langerhans/metabolismo , Sarcoma de Células de Langerhans/patología , Leucemia de Células Pilosas/genética , Leucemia de Células Pilosas/metabolismo , Leucemia de Células Pilosas/patología , Masculino , Proteínas de Neoplasias/biosíntesis , Proteínas de Neoplasias/genética , Neoplasias Primarias Secundarias/genética , Neoplasias Primarias Secundarias/metabolismo , Neoplasias Primarias Secundarias/patología , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/metabolismo , Neoplasias Cutáneas/patología , Factores de TiempoRESUMEN
Melanonychia is a black, tan, or brown streak within the nail plate subsequent to activation of melanocytes in the nail matrix. We present a case of a Haitian girl who presented with transverse melanonychia involving all 10 fingernails in the setting of hyperthyroidism and acute liver injury. Melanonychia has been described only one time in the literature in the setting of hyperthyroidism though this patient also underwent radium treatment which could have led to nail changes.
Asunto(s)
Enfermedad de Graves/diagnóstico , Hepatitis/diagnóstico , Enfermedades de la Uña/diagnóstico , Trastornos de la Pigmentación/diagnóstico , Adolescente , Biopsia , Femenino , Enfermedad de Graves/complicaciones , Enfermedad de Graves/cirugía , Hepatitis/complicaciones , Humanos , Enfermedades de la Uña/etiología , Trastornos de la Pigmentación/etiología , TiroidectomíaRESUMEN
Antisense oligonucleotides are a relatively new therapeutic modality and safety evaluation is still a developing area of research. We have observed that some oligonucleotides can produce acute, nonhybridization dependent, neurobehavioral side effects after intracerebroventricular (ICV) dosing in mice. In this study, we use a combination of in vitro, in vivo, and bioinformatics approaches to identify a sequence design algorithm, which can reduce the number of acutely toxic molecules synthesized and tested in mice. We find a cellular assay measuring spontaneous calcium oscillations in neuronal cells can predict the behavioral side effects after ICV dosing, and may provide a mechanistic explanation for these observations. We identify sequence features that are overrepresented or underrepresented among oligonucleotides causing these reductions in calcium oscillations. A weighted linear combination of the five most informative sequence features predicts the outcome of ICV dosing with >80% accuracy. From this, we develop a bioinformatics tool that allows oligonucleotide designs with acceptable acute neurotoxic potential to be identified, thereby reducing the number of toxic molecules entering drug discovery pipelines. The informative sequence features we identified also suggest areas in which to focus future medicinal chemistry efforts.
Asunto(s)
Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Oligonucleótidos Antisentido , Animales , Encéfalo , Ratones , Oligonucleótidos Antisentido/farmacologíaRESUMEN
Tau is a microtubule-associated protein (MAPT, tau) implicated in the pathogenesis of tauopathies, a spectrum of neurodegenerative disorders characterized by accumulation of hyperphosphorylated, aggregated tau. Because tau pathology can be distinct across diseases, a pragmatic therapeutic approach may be to intervene at the level of the tau transcript, as it makes no assumptions to mechanisms of tau toxicity. Here we performed a large library screen of locked-nucleic-acid (LNA)-modified antisense oligonucleotides (ASOs), where careful tiling of the MAPT locus resulted in the identification of hot spots for activity in the 3' UTR. Further modifications to the LNA design resulted in the generation of ASO-001933, which selectively and potently reduces tau in primary cultures from hTau mice, monkey, and human neurons. ASO-001933 was well tolerated and produced a robust, long-lasting reduction in tau protein in both mouse and cynomolgus monkey brain. In monkey, tau protein reduction was maintained in brain for 20 weeks post injection and corresponded with tau protein reduction in the cerebrospinal fluid (CSF). Our results demonstrate that LNA-ASOs exhibit excellent drug-like properties and sustained efficacy likely translating to infrequent, intrathecal dosing in patients. These data further support the development of LNA-ASOs against tau for the treatment of tauopathies.
RESUMEN
Amyloidosis cutis dyschromica is a rare form of cutaneous amyloidosis in which there is deposition of keratinocyte-derived amyloid with involvement of almost the entire integument, leading to diffuse dyschromia without associated systemic abnormalities. We report the case of a 40-year-old female who presented with the onset of diffuse hyperpigmentation shortly after birth, which was followed by the widespread development of numerous 2-5 mm hypopigmented macules. Biopsy of the one of these macules revealed eosinophilic globular material in the papillary dermis with Congo red birefringence which also stained positively for high-molecular weight cytokeratin. Electron microscopy confirmed the presence of 11 nm hollow fibrils, consistent with amyloid. Similar clinical changes were noted in a younger male sibling. Both patients also suffered from an unexplained neurological disorder characterized by atypical Parkinsonism, spasticity and motor weakness. This association has not been shown before and may represent a heretofore unreported contiguous gene syndrome.
Asunto(s)
Amiloidosis Familiar/complicaciones , Espasticidad Muscular/complicaciones , Enfermedades Neuromusculares/complicaciones , Enfermedad de Parkinson/complicaciones , Enfermedades de la Piel/complicaciones , Adulto , Amiloidosis Familiar/genética , Amiloidosis Familiar/patología , Biopsia , Femenino , Humanos , Masculino , Espasticidad Muscular/genética , Espasticidad Muscular/patología , Debilidad Muscular/etiología , Debilidad Muscular/patología , Enfermedades Neuromusculares/genética , Enfermedades Neuromusculares/patología , Pakistán , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/patología , Enfermedades de la Piel/genética , Enfermedades de la Piel/patologíaRESUMEN
We report a 50-year-old woman who presented with a six-month history of recurrent retiform purpura of uncertain etiology. Laboratory findings included neutropenia, positive anticardiolipin IgM antibody, and a weakly positive p-ANCA. Histopathology revealed a leukocytoclastic vasculitis with intravascular thrombi. Urine toxicology screen was positive for cocaine. These findings are similar to recent reports of agranulocytosis and purpura induced by levamisole-tainted cocaine. A review of the clinical and histopathological findings associated with levamisole-induced purpura will be discussed.
Asunto(s)
Trastornos Relacionados con Cocaína/complicaciones , Contaminación de Medicamentos , Levamisol/efectos adversos , Púrpura/patología , Vasculitis/patología , Anticuerpos Anticitoplasma de Neutrófilos/sangre , Oído Externo/patología , Femenino , Humanos , Persona de Mediana Edad , Púrpura/inducido químicamente , Vasculitis/inducido químicamenteRESUMEN
The promise of gene-based therapies is being realized at an accelerated pace, with more than 155 active clinical trials and multiple U.S. Food and Drug Administration approvals for therapeutic oligonucleotides, by far most of which contain modified phosphate linkages. These unnatural linkages have desirable biological and physical properties but are often accessed with difficulty using phosphoramidite chemistry. We report a flexible and efficient [P(V)]based platform that can install a wide variety of phosphate linkages at will into oligonucleotides. This approach uses readily accessible reagents and can install not only stereodefined or racemic thiophosphates but any combination of (S, R or rac)PS with native phosphodiester (PO2) and phosphorodithioate (PS2) linkages into DNA and other modified nucleotide polymers. This platform easily accesses this diversity under a standardized coupling protocol with sustainably prepared, stable P(V) reagents.
Asunto(s)
Oligonucleótidos/síntesis químicaRESUMEN
We describe a 60-year-old man with a history of primary cutaneous anaplastic large cell lymphoma on the chest, who presented with a new scaly red plaque on the same site 11 years after radiation therapy. Histological examination revealed a dense epidermotropic infiltrate of atypical mononuclear cells consistent with pagetoid reticulosis. Immunohistochemistry revealed the infiltrate to be CD4, CD8, and CD30. Remarkably, all the atypical cells were strongly CD30, and furthermore, the CD30 cells were found exclusively in the epidermis. In the initial cutaneous anaplastic large cell lymphoma lesion, the CD4, CD8, and focally CD30 atypical cells were well confined within the dermis with no epidermal component. To our knowledge, the present case seems to be the first description of pagetoid reticulosis presenting at the site of a previously treated dermal anaplastic large cell lymphoma. This case also represents an extreme presentation of epidermotropism and CD30 expression in pagetoid reticulosis.
Asunto(s)
Linfoma Anaplásico de Células Grandes/radioterapia , Neoplasias Primarias Secundarias/patología , Reticulosis Pagetoide/patología , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/radioterapia , Antígenos CD/metabolismo , Biomarcadores de Tumor/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Primarias Secundarias/metabolismo , Reticulosis Pagetoide/metabolismo , Neoplasias Cutáneas/metabolismoRESUMEN
As reflected in the literature, the use of dermal filler agents has increased substantially over the last decade. Consequently, these agents are more frequently encountered on histopathologic examination. A variety of dermal fillers can be readily identified histopathologically, and the accurate identification of these agents is a critical task for dermatopathologists. Furthermore, a basic understanding of the histological features of fillers has relevance to dermatologists and dermatologic surgeons. The identification of filler substances may have important diagnostic, medico-legal and medical management considerations. This concise review aims to provide a pragmatic approach to distinguishing the agents most frequently encountered in routine practice and in the literature.
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Materiales Biocompatibles/efectos adversos , Materiales Biocompatibles/análisis , Técnicas Cosméticas/efectos adversos , Piel/patología , Colágeno/efectos adversos , Colágeno/análisis , Durapatita/efectos adversos , Durapatita/análisis , Humanos , Hidrogeles/efectos adversos , Hidrogeles/análisis , Inyecciones Intradérmicas , Ácido Láctico/efectos adversos , Ácido Láctico/análisis , Parafina/efectos adversos , Parafina/análisis , Poliésteres , Polímeros/efectos adversos , Polímeros/análisis , Polimetil Metacrilato/efectos adversos , Polimetil Metacrilato/análisis , Siliconas/análisis , Piel/químicaRESUMEN
Acquired digital fibrokeratoma is a rare benign fibroepithelial tumor that typically presents as a solitary asymptomatic nodule on the finger or toe. Middle-aged adults are most commonly affected. Here we discuss an unusual case of acquired digital fibrokeratoma presenting as a cluster of multiple nodules on the sole of a 15-year-old boy.
Asunto(s)
Dermatosis del Pie/patología , Queratosis/patología , Neoplasias Cutáneas/patología , Adolescente , Dermatosis del Pie/cirugía , Humanos , Queratosis/cirugía , Masculino , Neoplasias Cutáneas/cirugíaRESUMEN
The calcitonin gene-related peptide (CGRP) receptor has been implicated in the pathogenesis of migraine. A class of urethanamide derivatives has been identified as potent inhibitors of the CGRP receptor. Compound 20 was found to be among the most potent (IC(50)=17pM). It was shown to retain excellent aqueous solubility (>50mg/mL, pH 7) while dramatically improving solution stability as compared to our previously disclosed development candidate, BMS-694153 (1).
Asunto(s)
Antagonistas del Receptor Peptídico Relacionado con el Gen de la Calcitonina , Carbamatos/química , Indazoles/química , Quinazolinonas/química , Quinolonas/química , Carbamatos/síntesis química , Carbamatos/farmacología , Estabilidad de Medicamentos , Humanos , Trastornos Migrañosos/tratamiento farmacológico , Quinolonas/síntesis química , Quinolonas/farmacología , Receptores de Péptido Relacionado con el Gen de Calcitonina/metabolismoRESUMEN
The role of the intestine in the elimination of (2R)-2-{(3R)-3-amino-3-[4-(2-methylquinolin-4-ylmethoxy)phenyl]-2-oxopyrrolidin-1-yl}-N-hydroxy-4-methylpentanamide (DPC 333), a potent inhibitor of tissue necrosis factor alpha-converting enzyme, was investigated in mice and rats in vivo and in vitro. In Madine-Darby canine kidney cells stably transfected with P-glycoprotein (P-gp) and DPC 333, the transport from B-->A reservoirs exceeded the transport from A-->B by approximately 7-fold. In Caco-2 monolayers and isolated rat ileal mucosa, DPC 333 was transported from basolateral to apical reservoirs in a concentration-dependent, saturable manner, and transport was blocked by N-(4-[2-(1,2,3,4-tetrahydro-6,7-dimethoxy-2-isoquinolinyl)ethyl]-phenyl)-9,10-dihydro-5-methoxy-9-oxo-4-acridine carboxamide (GF120918), confirming the contribution of P-gp/breast cancer resistance protein in B-->A efflux of DPC 333. In quantitative whole body autoradiography studies with [(14)C]DPC 333 in mice and rats, radioactivity was distributed throughout the small intestine in both species. In GF120918-pretreated bile duct-cannulated rats, radioactivity in feces was reduced 60%. Using the in situ perfused rat intestine model, approximately 20% of an i.v. dose of [(14)C]DPC 333 was measured in the intestinal lumen within 3 h postdose, 12% as parent. Kinetic analysis of data suggested that excreted DPC 333 may be further metabolized in the gut. Intestinal clearance was 0.2 to 0.35 l/h/kg. The above data suggest that in the rodent the intestine serves as an organ of DPC 333 excretion, mediated in part by the transporter P-gp.
Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Mucosa Intestinal/metabolismo , Quinolinas/farmacocinética , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Animales , Células CACO-2 , Línea Celular , Perros , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Quinolinas/sangre , Ratas , Ratas Sprague-Dawley , TransfecciónRESUMEN
Rhabdomyosarcoma is the most common sarcoma in children and is difficult to treat if the primary tumor is nonresectable or if the disease presents with metastases. The function of the serine/threonine kinase Mirk was investigated in this cancer. Mirk has both growth arrest and survival functions in terminally differentiating skeletal myoblasts. Maintenance of Mirk growth arrest properties would cause down-regulation of Mirk in transformed myoblasts. Alternatively, Mirk expression would be retained if rhabdomyosarcoma cells used Mirk survival capability. Mirk expression was significant in 12 of 16 clinical cases of rhabdomyosarcoma. Mirk was detected in each rhabdomyosarcoma cell line examined. Mirk was a functional kinase in each of three rhabdomyosarcoma cell lines, where it proved to be more active than in C2C12 skeletal myoblasts. Mirk mediated survival of the majority of clonogenic rhabdomyosarcoma cells. Knockdown of Mirk by RNA interference reduced the fraction of RD and of Rh30 rhabdomyosarcoma cells capable of colony formation 3- to 4-fold in multiple experiments. Depletion of Mirk induced cell death by apoptosis, as shown by increased numbers of terminal deoxynucleotidyl transferase-mediated nick-end labeling-positive cells and by increased binding of Annexin V. Mirk is a stress-activated kinase that mediates expression of contractile proteins in differentiating myoblasts, but Mirk is not essential for muscle formation in the embryo. It is likely that Mirk also facilitates survival of satellite cell-derived rhabdomyoblasts in regenerating skeletal muscle and aids their differentiation. This survival function is maintained in rhabdomyosarcoma, where Mirk may be a novel therapeutic target.
Asunto(s)
Proteínas Quinasas Activadas por Mitógenos/fisiología , Rabdomiosarcoma Alveolar/enzimología , Rabdomiosarcoma Embrionario/enzimología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Apoptosis/fisiología , Línea Celular Tumoral , Supervivencia Celular/fisiología , Niño , Preescolar , Citoplasma/enzimología , Femenino , Humanos , Inmunohistoquímica , Masculino , Ratones , Persona de Mediana Edad , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Mioblastos/citología , Mioblastos/patología , Proteínas Serina-Treonina Quinasas , Proteínas Tirosina Quinasas , Rabdomiosarcoma Alveolar/patología , Rabdomiosarcoma Embrionario/patología , Factores de Transcripción , Quinasas DyrKRESUMEN
Ductal adenocarcinoma of the pancreas is almost uniformly lethal as this cancer is invariably detected at an advanced stage and is resistant to treatment. The serine/threonine kinase Mirk/Dyrk1B has been shown to be antiapoptotic in rhabdomyosarcomas. We have now investigated whether Mirk might mediate survival in another cancer in which Mirk is widely expressed, pancreatic ductal adenocarcinoma. Mirk was an active kinase in each pancreatic cancer cell line where it was detected. Mirk knockdown by RNA interference (RNAi) reduced the clonogenicity of Panc1 pancreatic cancer cells 4-fold and decreased tumor cell number, showing that Mirk mediates survival in these cells. Mirk knockdown by synthetic duplex RNAis in Panc1, AsPc1, and SU86.86 pancreatic cancer cells induced apoptosis and enhanced the apoptosis induced by gemcitibine. Mirk knockdown did not increase the abundance or activation of Akt. However, four of five pancreatic carcinoma cell lines exhibited either elevated Mirk activity or elevated Akt activity, suggesting that pancreatic cancer cells primarily rely on Mirk or Akt for survival signaling. Mirk protein was detected by immunohistochemistry in 25 of 28 cases (89%) of pancreatic ductal adenocarcinoma, with elevated expression in 11 cases (39%). Increased expression of Mirk was seen in pancreatic carcinomas compared with primary cultures of normal ductal epithelium by serial analysis of gene expression and by immunohistochemistry. Thus, Mirk is a survival factor for pancreatic ductal adenocarcinoma. Because knockout of Mirk does not cause embryonic lethality, Mirk is not essential for normal cell growth and may represent a novel therapeutic target.