RESUMEN
The development of a wider range of therapeutic options is a key objective in drug discovery for chronic obstructive pulmonary disease (COPD). Fundamental advances in lung biology have the potential to greatly expand the number of therapeutic targets in COPD. The recently reported successful Phase 3 clinical trial of the first biologic agent for COPD, the monoclonal antibody dupilumab, adds additional support to the importance of targeting inflammatory pathways in COPD. However, numerous other cellular mechanisms are important targets in COPD therapeutics, including airway remodeling, the CFTR ion channel, and mucociliary function. Some of these emerging targets can be exploited by the expanded use of existing COPD drugs, such as roflumilast, while targeting others will require the development of novel molecular entities. The identification of additional therapeutic targets and agents has the potential to greatly expand the value of using clinical and biomarker data to classify COPD into specific subsets, each of which can be predictive of an enhanced response to specific subset(s) of targeted therapies. The author reviews established and emerging drug targets in COPD and uses this as a framework to define a novel classification of COPD based on therapeutic targets. This novel classification has the potential to enhance precision medicine in COPD patient care and to accelerate clinical trials and pre-clinical drug discovery efforts.
Asunto(s)
Medicina de Precisión , Enfermedad Pulmonar Obstructiva Crónica , Humanos , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Pulmón/metabolismo , Inflamación/tratamiento farmacológico , Aminopiridinas/uso terapéutico , Ciclopropanos/uso terapéutico , Canales IónicosRESUMEN
The cAMP-signaling cancers, which are defined by functionally-significant somatic mutations in one or more elements of the cAMP signaling pathway, have an unexpectedly wide range of cell origins, clinical manifestations, and potential therapeutic options. Mutations in at least 9 cAMP signaling pathway genes (TSHR, GPR101, GNAS, PDE8B, PDE11A, PRKARA1, PRKACA, PRKACB, and CREB) have been identified as driver mutations in human cancer. Although all cAMP-signaling pathway cancers are driven by mutation(s) that impinge on a single signaling pathway, the ultimate tumor phenotype reflects interactions between five critical variables: (1) the precise gene(s) that undergo mutation in each specific tumor type; (2) the effects of specific allele(s) in any given gene; (3) mutations in modifier genes (mutational "context"); (4) the tissue-specific expression of various cAMP signaling pathway elements in the tumor stem cell; and (5) and the precise biochemical regulation of the pathway components in tumor cells. These varying oncogenic mechanisms reveal novel and important targets for drug discovery. There is considerable diversity in the "druggability" of cAMP-signaling components, with some elements (GPCRs, cAMP-specific phosphodiesterases and kinases) appearing to be prime drug candidates, while other elements (transcription factors, protein-protein interactions) are currently refractory to robust drug-development efforts. Further refinement of the precise driver mutations in individual tumors will be essential for directing priorities in drug discovery efforts that target these mutations.
Asunto(s)
Neoplasias , Transducción de Señal , Humanos , Transducción de Señal/genética , Mutación , Neoplasias/genética , FenotipoRESUMEN
The phosphodiesterase (PDE)-opathies, an expanding set of disorders caused by germline mutations in cyclic nucleotide PDEs, present an intriguing paradox. The enzymes encoded by the PDE family all hydrolyze cAMP and/or cGMP, but mutations in different family members produce very divergent phenotypes. Three interacting factors have been shown recently to contribute to this phenotypic diversity: (i) the 21 genes encode over 80 different isoforms, using alternative mRNA splicing and related mechanisms; (ii) the various isoforms have different regulatory mechanisms, mediated by their unique amino-terminal regulatory domains; (iii) the isoforms differ widely in their pattern of tissue expression. These mechanisms explain why many PDE-opathies are gain-of-function mutations and how they exemplify uniqueness and redundancy within a multigene family.
Asunto(s)
Empalme Alternativo/genética , Familia de Multigenes/genética , Hidrolasas Diéster Fosfóricas/genética , ARN Mensajero/genética , AMP Cíclico/genética , GMP Cíclico/genética , Mutación con Ganancia de Función/genética , Mutación de Línea Germinal/genética , Humanos , Fenotipo , Hidrolasas Diéster Fosfóricas/clasificación , Hidrolasas Diéster Fosfóricas/deficienciaRESUMEN
PDE4 cyclic nucleotide phosphodiesterases reduce 3', 5' cAMP levels in the CNS and thereby regulate PKA activity and the phosphorylation of CREB, fundamental to depression, cognition, and learning and memory. The PDE4 isoform PDE4D5 interacts with the signaling proteins ß-arrestin2 and RACK1, regulators of ß2-adrenergic and other signal transduction pathways. Mutations in PDE4D in humans predispose to acrodysostosis, associated with cognitive and behavioral deficits. To target PDE4D5, we developed mice that express a PDE4D5-D556A dominant-negative transgene in the brain. Male transgenic mice demonstrated significant deficits in hippocampus-dependent spatial learning, as assayed in the Morris water maze. In contrast, associative learning, as assayed in a fear conditioning assay, appeared to be unaffected. Male transgenic mice showed augmented activity in prolonged (2 h) open field testing, while female transgenic mice showed reduced activity in the same assay. Transgenic mice showed no demonstrable abnormalities in prepulse inhibition. There was also no detectable difference in anxiety-like behavior, as measured in the elevated plus-maze. These data support the use of a dominant-negative approach to the study of PDE4D5 function in the CNS and specifically in learning and memory.
Asunto(s)
Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/metabolismo , Hipocampo/fisiología , Aprendizaje/fisiología , Memoria/fisiología , Transducción de Señal/fisiología , Animales , Ansiedad/genética , Ansiedad/fisiopatología , Ansiedad/psicología , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/genética , Femenino , Hipocampo/metabolismo , Humanos , Masculino , Ratones , Ratones Transgénicos , Transducción de Señal/genéticaRESUMEN
Cyclic AMP (cAMP) phosphodiesterase-4 (PDE4) enzymes degrade cAMP and underpin the compartmentalization of cAMP signaling through their targeting to particular protein complexes and intracellular locales. We describe the discovery and characterization of a small-molecule compound that allosterically activates PDE4 long isoforms. This PDE4-specific activator displays reversible, noncompetitive kinetics of activation (increased Vmax with unchanged Km), phenocopies the ability of protein kinase A (PKA) to activate PDE4 long isoforms endogenously, and requires a dimeric enzyme assembly, as adopted by long, but not by short (monomeric), PDE4 isoforms. Abnormally elevated levels of cAMP provide a critical driver of the underpinning molecular pathology of autosomal dominant polycystic kidney disease (ADPKD) by promoting cyst formation that, ultimately, culminates in renal failure. Using both animal and human cell models of ADPKD, including ADPKD patient-derived primary cell cultures, we demonstrate that treatment with the prototypical PDE4 activator compound lowers intracellular cAMP levels, restrains cAMP-mediated signaling events, and profoundly inhibits cyst formation. PDE4 activator compounds thus have potential as therapeutics for treating disease driven by elevated cAMP signaling as well as providing a tool for evaluating the action of long PDE4 isoforms in regulating cAMP-mediated cellular processes.
Asunto(s)
Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/metabolismo , Animales , Línea Celular , AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/efectos de los fármacos , Perros , Activación Enzimática/efectos de los fármacos , Humanos , Células de Riñón Canino Madin Darby , Fosforilación , Enfermedades Renales Poliquísticas/metabolismo , Isoformas de ProteínasRESUMEN
Human phosphodiesterases (PDEs) comprise a complex superfamily of enzymes derived from 24 genes separated into 11 PDE gene families (PDEs 1-11), expressed in different tissues and cells, including heart and brain. The isoforms PDE4, PDE7, and PDE8 are specific for the second messenger cAMP, which is responsible for mediating diverse physiological actions involving different hormones and neurotransmitters. The cAMP pathway plays an important role in the development and function of endocrine tissues while phosphodiesterases are responsible for ensuring the appropriate intensity of the actions of this pathway by hydrolyzing cAMP to its inactive form 5'-AMP. PDE1, PDE2, PDE4, and PDE11A are highly expressed in the pituitary, and overexpression of some PDE4 isoforms have been demonstrated in different pituitary adenoma subtypes. This observed over-expression in pituitary adenomas, although of unknown etiology, has been considered a compensatory response to tumorigenesis. PDE4A4/5 has a unique interaction with the co-chaperone aryl hydrocarbon receptor-interacting protein (AIP), a protein implicated in somatotroph tumorigenesis via germline loss-of-function mutations. Based on the association of low PDE4A4 expression with germline AIP-mutation-positive samples, the available data suggest that lack of AIP hinders the upregulation of PDE4A4 protein seen in sporadic somatotrophinomas. This unique disturbance of the cAMP-PDE pathway observed in the majority of AIP-mutation positive adenomas could contribute to their well-described poor response to somatostatin analogs and may support a role in tumorigenesis.
RESUMEN
Type 4 phosphodiesterases (PDE4s) of the large PDE enzyme superfamily have unique specificity for cAMP and may, therefore, be relevant for somatotroph tumorigenesis. Somatotroph adenomas typically overexpress PDEs probably as part of a compensatory mechanism to reduce cAMP levels. The rat PDE4A5 isoform (human homolog PDE4A4) interacts with the AIP protein, coded by a tumour suppressor gene mutated in a subgroup of familial isolated pituitary adenomas (FIPAs). PDE4A8 is the closest related isoform of PDE4A4. We aimed to evaluate the expression of both PDE4A4 and PDE4A8 in GH cells of AIP-mutated adenomas and compare their expression with that in GH cells from sporadic AIP-mutation negative GH-secreting adenomas, where we had shown previously that both PDE4A4 and PDE4A8 isoforms had been over-expressed. Confocal immunofluorescence analysis showed that both PDE4A8 and PDE4A4 had lower expression in AIP-mutated somatotropinoma samples compared to sporadic GH-secreting tumours (Pâ¯<â¯0.0001 for both). Based on the association of low PDE4A4 and PDE4A8 expression with germline AIP-mutations positive samples we suggest that lack of AIP hinders the upregulation of PDE4A8 and PDE4A4 protein seen in sporadic somatotrophinomas. These data point to a unique disturbance of the cAMP-PDE pathway in AIP-mutation positive adenomas, which may help to explain their well-described poor response to somatostatin analogues.
Asunto(s)
Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/metabolismo , Adenoma Hipofisario Secretor de Hormona del Crecimiento/enzimología , Adenoma Hipofisario Secretor de Hormona del Crecimiento/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Mutación/genética , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND: PDE4 cyclic nucleotide phosphodiesterases regulate 3', 5' cAMP abundance in the CNS and thereby regulate PKA activity and phosphorylation of CREB, which has been implicated in learning and memory, depression and other functions. The PDE4 isoform PDE4B1 also interacts with the DISC1 protein, implicated in neural development and behavioral disorders. The cellular functions of PDE4B1 have been investigated extensively, but its function(s) in the intact organism remained unexplored. RESULTS: To specifically disrupt PDE4B1, we developed mice that express a PDE4B1-D564A transgene in the hippocampus and forebrain. The transgenic mice showed enhanced phosphorylation of CREB and ERK1/2 in hippocampus. Hippocampal neurogenesis was increased in the transgenic mice. Hippocampal electrophysiological studies showed increased baseline synaptic transmission and enhanced LTP in male transgenic mice. Behaviorally, male transgenic mice showed increased activity in prolonged open field testing, but neither male nor female transgenic mice showed detectable anxiety-like behavior or antidepressant effects in the elevated plus-maze, tail-suspension or forced-swim tests. Neither sex showed any significant differences in associative fear conditioning or showed any demonstrable abnormalities in pre-pulse inhibition. CONCLUSIONS: These data support the use of an isoform-selective approach to the study of PDE4B1 function in the CNS and suggest a probable role of PDE4B1 in synaptic plasticity and behavior. They also provide additional rationale and a refined approach to the development of small-molecule PDE4B1-selective inhibitors, which have potential functions in disorders of cognition, memory, mood and affect.
Asunto(s)
Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/metabolismo , Hipocampo/metabolismo , Potenciación a Largo Plazo/fisiología , Actividad Motora/fisiología , Neurogénesis/fisiología , Transmisión Sináptica/fisiología , Animales , Ansiedad/metabolismo , Aprendizaje por Asociación/fisiología , Condicionamiento Psicológico/fisiología , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/genética , Depresión/metabolismo , Miedo/fisiología , Femenino , Isoenzimas/genética , Isoenzimas/metabolismo , Masculino , Memoria/fisiología , Ratones Transgénicos , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Mutación , Fosforilación/fisiologíaRESUMEN
The PDE4 cyclic nucleotide phosphodiesterases are essential regulators of cAMP abundance in the CNS through their ability to regulate PKA activity, the phosphorylation of CREB, and other important elements of signal transduction. In pre-clinical models and in early-stage clinical trials, PDE4 inhibitors have been shown to have antidepressant and memory-enhancing activity. However, the development of clinically-useful PDE4 inhibitors for CNS disorders has been limited by variable efficacy and significant side effects. Recent structural studies have greatly enhanced our understanding of the molecular configuration of PDE4 enzymes, especially the "long" PDE4 isoforms that are abundant in the CNS. The new structural data provide a rationale for the development of a new generation of PDE4 inhibitors that specifically act on long PDE4 isoforms. These next generation PDE4 inhibitors may also be capable of targeting the interactions of select long forms with their "partner" proteins, such as RACK1, ß-arrestin, and DISC1. They would therefore have the ability to affect cAMP levels in specific cellular compartments and target localized cellular functions, such as synaptic plasticity. These new agents might also be able to target PDE4 populations in select regions of the CNS that are implicated in learning and memory, affect, and cognition. Potential therapeutic uses of these agents could include affective disorders, memory enhancement, and neurogenesis.
Asunto(s)
Antidepresivos/uso terapéutico , Trastorno Depresivo/tratamiento farmacológico , Trastornos de la Memoria/tratamiento farmacológico , Nootrópicos/uso terapéutico , Inhibidores de Fosfodiesterasa 4/uso terapéutico , Animales , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/metabolismo , Trastorno Depresivo/metabolismo , Humanos , Aprendizaje , Memoria , Trastornos de la Memoria/metabolismo , Trastornos del Humor/tratamiento farmacológico , Trastornos del Humor/metabolismo , NeurogénesisRESUMEN
The RACK1 protein interacts with numerous proteins involved in signal transduction, the cytoskeleton, and mRNA splicing and translation. We used the 2-hybrid system to identify additional proteins interacting with RACK1 and isolated the RNA-binding protein SERBP1. SERPB1 shares amino acid sequence homology with HABP4 (also known as Ki-1/57), a component of the RNA spicing machinery that has been shown previously to interact with RACK1. Several different isoforms of SERBP1, generated by alternative mRNA splicing, interacted with RACK1 with indistinguishable interaction strength, as determined by a 2-hybrid beta-galactosidase assay. Analysis of deletion constructs of SERBP1 showed that the C-terminal third of the SERBP1 protein, which contains one of its two substrate sites for protein arginine N-methyltransferase 1 (PRMT1), is necessary and sufficient for it to interact with RACK1. Analysis of single amino acid substitutions in RACK1, identified in a reverse 2-hybrid screen, showed very substantial overlap with those implicated in the interaction of RACK1 with the cAMP-selective phosphodiesterase PDE4D5. These data are consistent with SERBP1 interacting selectively with RACK1, mediated by an extensive interaction surface on both proteins.
Asunto(s)
Mapas de Interacción de Proteínas/genética , Proteína-Arginina N-Metiltransferasas/genética , Proteínas de Unión al ARN/genética , Receptores de Cinasa C Activada/genética , Proteínas Represoras/genética , Sustitución de Aminoácidos , Sitios de Unión , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/genética , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/metabolismo , Humanos , Unión Proteica , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteína-Arginina N-Metiltransferasas/metabolismo , Empalme del ARN/genética , Proteínas de Unión al ARN/metabolismo , Receptores de Cinasa C Activada/metabolismo , Proteínas Represoras/metabolismo , Transducción de Señal/genética , Especificidad por SustratoRESUMEN
PDE4 cyclic nucleotide phosphodiesterases regulate cAMP abundance in cells and therefore regulate numerous processes, including cell growth and differentiation. The rat PDE4A5 isoform (human homolog PDE4A4) interacts with the AIP protein (also called XAP2 or ARA-9). Germline mutations in AIP occur in approximately 20% of patients with Familial Isolated Pituitary Adenoma (FIPA) and 20% of childhood-onset simplex somatotroph adenomas. We therefore examined the protein expression of PDE4A4 and the closely related isoform PDE4A8 in normal human pituitary tissue and in pituitary adenomas. PDE4A4 had low expression in normal pituitary but was significantly overexpressed in somatotroph, lactotroph, corticotroph and clinically nonfunctioning gonadotroph adenomas (P<0.0001 for all subtypes). Likewise, PDE4A8 was expressed in normal pituitary and was also significantly overexpressed in the adenoma subtypes (P<0.0001 for all). Among the different adenoma subtypes, corticotroph and lactotroph adenomas were the highest and lowest expressed for PDE4A4, respectively, whereas the opposite was observed for PDE4A8. Naturally occurring oncogenic variants in AIP were shown by a two-hybrid assay to disrupt the ability of AIP to interact with PDE4A5. A reverse two-hybrid screen identified numerous additional variants in the tetratricopeptide repeat (TPR) region of AIP that also disrupted its ability to interact with PDE4A5. The expression of PDE4A4 and PDE4A8 in normal pituitary, their increased expression in adenomatous pituitary cells where AIP is meant to participate, and the disruption of the PDE4A4-AIP interaction by AIP mutants may play a role in pituitary tumorigenesis.
Asunto(s)
Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Hipófisis/metabolismo , Neoplasias Hipofisarias/metabolismo , Animales , Células COS , Chlorocebus aethiops , AMP Cíclico/metabolismo , HumanosRESUMEN
PDE4 family cAMP-selective cyclic nucleotide phosphodiesterases are important in the regulation of cAMP abundance in numerous systems, and thereby play an important role in the regulation of PKA and EPAC activity and the phosphorylation of CREB. We have used the yeast 2-hybrid system to demonstrate recently that long PDE4 isoforms form homodimers, consistent with data obtained recently by structural studies. The long PDE4 isoform PDE4D5 interacts selectively with ß-arrestin2, implicated in the regulation of G-protein-coupled receptors and other cell signaling components, and also with the ß-propeller protein RACK1. In the present study, we use 2-hybrid approaches to demonstrate that RACK1 and ß-arrestin2 inhibit the dimerization of PDE4D5. We also show that serine-to-alanine mutations at PKA and ERK1/2 phosphorylation sites on PDE4D5 detectably ablate dimerization. Conversely, phospho-mimic serine-to-aspartate mutations at the MK2 and oxidative stress kinase sites ablate dimerization. Analysis of PDE4D5 that is locked into the dimeric configuration by the formation of a trans disulfide bond between Ser261 and Ser602 shows that RACK1 interacts strongly with both the monomeric and dimeric forms, but that ß-arrestin2 interacts exclusively with the monomeric form. This is consistent with the concept that ß-arrestin2 can preferentially recruit the monomeric, or "open," form of PDE4D5 to ß2-adrenergic receptors, where it can regulate cAMP signaling.
Asunto(s)
Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/metabolismo , Proteínas de Unión al GTP/metabolismo , Proteínas de Neoplasias/metabolismo , Multimerización de Proteína , Receptores de Superficie Celular/metabolismo , Arrestina beta 2/metabolismo , Supervivencia Celular , Humanos , Proteínas Mutantes/metabolismo , Mutación/genética , Fosforilación , Unión Proteica , Dominios Proteicos , Receptores de Cinasa C Activada , beta-Galactosidasa/metabolismoRESUMEN
Germ cell tumors (GCTs) account for 95% of testicular cancers. Testicular GCTs constitute the most common solid tumor in men between the ages of 20 and 34 years, and the incidence of testicular GCTs has been increasing in the past 2 decades. Testicular GCTs are classified into 2 broad groups--pure seminoma and nonseminoma--which are treated differently. Pure seminomas, unlike nonseminomas, are more likely to be localized to the testis at presentation. Nonseminoma is the more clinically aggressive tumor associated with elevated serum concentrations of alphafetoprotein (AFP). The diagnosis of a seminoma is restricted to pure seminoma histology and a normal serum concentration of AFP. When both seminoma and elements of a nonseminoma are present, management follows that for a nonseminoma. The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Testicular Cancer outline the diagnosis, workup, risk assessment, treatment, and follow-up schedules for patients with both pure seminoma and nonseminoma.
Asunto(s)
Seminoma/terapia , Neoplasias Testiculares/terapia , Terapia Combinada , Manejo de la Enfermedad , Humanos , Masculino , Estadificación de Neoplasias , Guías de Práctica Clínica como Asunto , Seminoma/diagnóstico , Neoplasias Testiculares/diagnósticoRESUMEN
BACKGROUND: African-American race appears to be associated with higher stages of urothelial carcinoma of the bladder (UCB) at presentation and poorer survival. However, the independent effect of African-American race on objective tumor recurrence after radical cystectomy (RC) after controlling for clinical and pathologic variables is unknown. PATIENTS AND METHODS: The data from consecutive patients with UCB who underwent RC with curative intent at a single institution (University of Alabama, Birmingham) from 2001 to 2012 with or without perioperative chemotherapy or chemoradiation were reviewed. The patient demographics, risk factors, clinical course, pathologic characteristics, and long-term outcomes were collected. Descriptive statistics were performed. Cox regression analysis was performed for key clinical, demographic, and pathologic variables, including race, stratified as African American versus white. RESULTS: A total of 215 patients, 163 men (76%) and 52 women (24%), with a mean age at RC of 65.6 years, were identified and reviewed. A total of 186 patients (87%) were white and 28 (13%) were African American. The median follow-up period after RC was 17.6 months. On conventional multivariate analysis, African-American race nearly attained statistical significance (hazard ratio [HR], 2.48; 95% confidence interval [CI], 0.98-6.29; P = .055). In a stepwise regression model, race was significantly associated with tumor recurrence (HR, 3.11; 95% CI, 1.2-7.4; P < .011). CONCLUSION: African-American race appears to be independently associated with a greater risk of tumor recurrence after RC for UCB. The effect of host genetics on tumor biology needs to be characterized at the genomic level to develop precision medicine.
Asunto(s)
Negro o Afroamericano , Recurrencia Local de Neoplasia/epidemiología , Neoplasias de la Vejiga Urinaria/etnología , Neoplasias de la Vejiga Urinaria/cirugía , Adulto , Negro o Afroamericano/estadística & datos numéricos , Anciano , Anciano de 80 o más Años , Cistectomía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Estados Unidos/etnología , Neoplasias de la Vejiga Urinaria/patologíaRESUMEN
The NCCN Guidelines for Kidney Cancer provide multidisciplinary recommendations for the clinical management of patients with clear cell and non-clear cell renal carcinoma. These NCCN Guidelines Insights highlight the recent updates/changes in these guidelines, and updates include axitinib as first-line treatment option for patients with clear cell renal carcinoma, new data to support pazopanib as subsequent therapy for patients with clear cell carcinoma after first-line treatment with another tyrosine kinase inhibitor, and guidelines for follow-up of patients with renal cell carcinoma.
Asunto(s)
Carcinoma de Células Renales/tratamiento farmacológico , Neoplasias Renales/tratamiento farmacológico , Axitinib , Carcinoma de Células Renales/diagnóstico , Humanos , Imidazoles/uso terapéutico , Indazoles/uso terapéutico , Neoplasias Renales/diagnóstico , Inhibidores de Proteínas Quinasas/uso terapéutico , Pirimidinas/uso terapéutico , Sulfonamidas/uso terapéuticoRESUMEN
PDE4 family cAMP phosphodiesterases play a pivotal role in determining compartmentalised cAMP signalling through targeted cAMP breakdown. Expressing the widely found PDE4D5 isoform, as both bait and prey in a yeast 2-hybrid system, we demonstrated interaction consistent with the notion that long PDE4 isoforms form dimers. Four potential dimerization sites were uncovered using a scanning peptide array approach, where a recombinant purified PDE4D5 fusion protein was used to probe a 25-mer library of overlapping peptides covering the entire PDE4D5 sequence. Key residues involved in PDE4D5 dimerization were defined using a site-directed mutagenesis programme directed by an alanine scanning peptide array approach. Critical residues stabilising PDE4D5 dimerization were defined within the regulatory UCR1 region found in long, but not short, PDE4 isoforms, namely the Arg(173), Asn(174) and Asn(175) (DD1) cluster. Disruption of the DD1 cluster was not sufficient, in itself, to destabilise PDE4D5 homodimers. Instead, disruption of an additional interface, located on the PDE4 catalytic unit, was also required to convert PDE4D5 into a monomeric form. This second dimerization site on the conserved PDE4 catalytic unit is dependent upon a critical ion pair interaction. This involves Asp(463) and Arg(499) in PDE4D5, which interact in a trans fashion involving the two PDE4D5 molecules participating in the homodimer. PDE4 long isoforms adopt a dimeric state in living cells that is underpinned by two key contributory interactions, one involving the UCR modules and one involving an interface on the core catalytic domain. We propose that short forms do not adopt a dimeric configuration because, in the absence of the UCR1 module, residual engagement of the remaining core catalytic domain interface provides insufficient free energy to drive dimerization. The functioning of PDE4 long and short forms is thus poised to be inherently distinct due to this difference in quaternary structure.
Asunto(s)
Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/química , Multimerización de Proteína , Secuencia de Aminoácidos , Dominio Catalítico , AMP Cíclico/metabolismo , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/genética , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/metabolismo , Células HEK293 , Humanos , Modelos Moleculares , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Péptidos/química , Péptidos/metabolismo , Conformación Proteica , Estructura Terciaria de ProteínaRESUMEN
These NCCN Guidelines Insights highlight treatment recommendations and updates specific to the management of patients with advanced non-clear cell carcinoma included in the 2014 version of the NCCN Clinical Practice Guidelines in Oncology for Kidney Cancer.
Asunto(s)
Antineoplásicos/uso terapéutico , Neoplasias Renales/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/uso terapéutico , Humanos , Neoplasias Renales/diagnóstico , Terapia Molecular DirigidaRESUMEN
BACKGROUND: Prognostic factors in men with penile squamous cell carcinoma (PSCC) receiving systemic therapy are unknown. A prognostic classification system in this disease may facilitate interpretation of outcomes and guide rational drug development. We performed a retrospective analysis to identify prognostic factors in men with PSCC receiving first-line systemic therapy for advanced disease. PATIENTS AND METHODS: Individual patient level data were obtained from 13 institutions to study prognostic factors in the context of first-line systemic therapy for advanced PSCC. Cox proportional hazards regression analysis was conducted to examine the prognostic effect of these candidate factors on progression-free survival (PFS) and overall survival (OS): age, stage, hemoglobin, neutrophil count, lymphocyte count, albumin, site of metastasis (visceral or nonvisceral), smoking, circumcision, regimen, ECOG performance status (PS), lymphovascular invasion, precancerous lesion, and surgery following chemotherapy. The effect of different treatments was then evaluated adjusting for factors in the prognostic model. RESULTS: The study included 140 eligible men. Mean age across all men was 57.0 years. Among them, 8.6%, 21.4%, and 70.0% of patients had stage 2, 3, and 4 diseases, respectively; 40.7% had ECOG PS ≥ 1, 47.4% had visceral metastases, and 73.6% received cisplatin-based chemotherapy. The multivariate model of poor prognostic factors included visceral metastases (P<0.001) and ECOG PS ≥ 1 (P<0.001) for both PFS and OS. A risk stratification model constructed with 0, 1, and both poor prognostic factors was internally validated and demonstrated moderate discriminatory ability (c-statistic of 0.657 and 0.677 for OS and PFS, respectively). The median OS for the entire population was 9 months. Median OS was not reached, 8, and 7 months for those with 0, 1, and both risk factors, respectively. Cisplatin-based regimens were associated with better OS (P = 0.017) but not PFS (P = 0.37) compared with noncisplatin-based regimens after adjusting for the 2 prognostic factors. CONCLUSIONS: In men with advanced PSCC receiving first-line systemic therapy, visceral metastases and ECOG PS ≥ 1 were poor prognostic factors. A prognostic model including these factors exhibited moderate discriminatory ability for outcomes and warrants external validation. Patients receiving cisplatin-based regimens exhibited better outcomes compared with noncisplatin-based regimens after adjusting for prognostic factors.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Células Escamosas/tratamiento farmacológico , Neoplasias del Pene/tratamiento farmacológico , Medicina de Precisión , Medición de Riesgo/métodos , Carcinoma de Células Escamosas/mortalidad , Carcinoma de Células Escamosas/secundario , Terapia Combinada , Estudios de Seguimiento , Humanos , Metástasis Linfática , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Neoplasias del Pene/mortalidad , Neoplasias del Pene/patología , Pronóstico , Estudios Retrospectivos , Tasa de SupervivenciaRESUMEN
Cigarette smoking causes acquired cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction and is associated with delayed mucociliary clearance and chronic bronchitis. Roflumilast is a clinically approved phosphodiesterase 4 inhibitor that improves lung function in patients with chronic bronchitis. We hypothesized that its therapeutic benefit was related in part to activation of CFTR. Primary human bronchial epithelial (HBE) cells, Calu-3, and T84 monolayers were exposed to whole cigarette smoke (WCS) or air with or without roflumilast treatment. CFTR-dependent ion transport was measured in modified Ussing chambers. Airway surface liquid (ASL) was determined by confocal microscopy. Intestinal fluid secretion of ligated murine intestine was monitored ex vivo. Roflumilast activated CFTR-dependent anion transport in normal HBE cells with a half maximal effective concentration of 2.9 nM. Roflumilast partially restored CFTR activity in WCS-exposed HBE cells (5.3 ± 1.1 µA/cm(2) vs. 1.2 ± 0.2 µA/cm(2) [control]; P < 0.05) and was additive with ivacaftor, a specific CFTR potentiator approved for the treatment of CF. Roflumilast improved the depleted ASL depth of HBE monolayers exposed to WCS (9.0 ± 3.1 µm vs. 5.6 ± 2.0 µm [control]; P < 0.05), achieving 79% of that observed in air controls. CFTR activation by roflumilast also induced CFTR-dependent fluid secretion in murine intestine, increasing the wet:dry ratio and the diameter of ligated murine segments. Roflumilast activates CFTR-mediated anion transport in airway and intestinal epithelia via a cyclic adenosine monophosphate-dependent pathway and partially reverses the deleterious effects of WCS, resulting in augmented ASL depth. Roflumilast may benefit patients with chronic obstructive pulmonary disease with chronic bronchitis by activating CFTR, which may also underlie noninfectious diarrhea caused by roflumilast.