RESUMEN
Prostate-specific membrane antigen (PSMA) is expressed in epithelial cells of the prostate gland and is strongly upregulated in prostatic adenocarcinoma, with elevated expression correlating with metastasis, progression, and androgen independence. Because of its specificity, PSMA is a major target of prostate cancer therapy; however, detectable levels of PSMA are also found in other tissues, especially in salivary glands and kidney, generating bystander damage of these tissues. Antibody target therapy has been used with relative success in reducing tumor growth and prostate specific antigen (PSA) levels. However, since antibodies are highly stable in plasma, they have prolonged time in circulation and accumulate in organs with an affinity for antibodies such as bone marrow. For that reason, a second generation of PSMA targeted therapeutic agents has been developed. Small molecules and minibodies have had promising clinical trial results, but concerns about their specificity had arisen with side effects due to accumulation in salivary glands and kidneys. Herein we study the specificity of small molecules and minibodies that are currently being clinically tested. We observed a high affinity of these molecules for PSMA in prostate, kidney and salivary gland, suggesting that their effect is not prostate specific. The search for specific prostate target agents must continue so as to optimally treat patients with prostate cancer, while minimizing deleterious effects in other PSMA expressing tissues.
Asunto(s)
Neoplasias de la Próstata , Masculino , Humanos , Neoplasias de la Próstata/patología , Antígenos de Superficie/metabolismo , Antígeno Prostático EspecíficoRESUMEN
In fisheries management-as in environmental governance more generally-regulatory arrangements that are thought to be helpful in some contexts frequently become panaceas or, in other words, simple formulaic policy prescriptions believed to solve a given problem in a wide range of contexts, regardless of their actual consequences. When this happens, management is likely to fail, and negative side effects are common. We focus on the case of individual transferable quotas to explore the panacea mindset, a set of factors that promote the spread and persistence of panaceas. These include conceptual narratives that make easy answers like panaceas seem plausible, power disconnects that create vested interests in panaceas, and heuristics and biases that prevent people from accurately assessing panaceas. Analysts have suggested many approaches to avoiding panaceas, but most fail to conquer the underlying panacea mindset. Here, we suggest the codevelopment of an institutional diagnostics toolkit to distill the vast amount of information on fisheries governance into an easily accessible, open, on-line database of checklists, case studies, and related resources. Toolkits like this could be used in many governance settings to challenge users' understandings of a policy's impacts and help them develop solutions better tailored to their particular context. They would not replace the more comprehensive approaches found in the literature but would rather be an intermediate step away from the problem of panaceas.
Asunto(s)
Explotaciones Pesqueras/legislación & jurisprudencia , Explotaciones Pesqueras/organización & administración , Explotaciones Pesqueras/normasRESUMEN
The ETS family of proteins consists of 28 transcription factors, many of which have been implicated in development and progression of a variety of cancers. While one family member, ERG, has been rigorously studied in the context of prostate cancer where it plays a critical role, other ETS factors keep emerging as potential hallmark oncodrivers. In recent years, numerous studies have reported initial discoveries of small molecule inhibitors of ETS proteins and opened novel avenues for ETS-directed cancer therapies. This review summarizes the state of the art data on therapeutic targeting of ETS family members and highlights the corresponding drug discovery strategies.
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Sistemas de Liberación de Medicamentos , Neoplasias/tratamiento farmacológico , Proteínas Proto-Oncogénicas c-ets/metabolismo , Secuencia de Aminoácidos , Animales , Humanos , Proteínas Proto-Oncogénicas c-ets/química , Bibliotecas de Moléculas Pequeñas/química , Bibliotecas de Moléculas Pequeñas/farmacología , Bibliotecas de Moléculas Pequeñas/uso terapéuticoRESUMEN
Despite the substantial benefit of androgen deprivation therapy (ADT) for metastatic prostate cancer, patients often progress to castration-resistant disease (CRPC) that is more difficult to treat. CRPC is associated with renewed androgen receptor activity in tumor cells and restoration of tumor androgen levels through acquired intratumoral steroidogenesis (AIS). Although prostate cancer (PCa) cells have been shown to have steroidogenic capability in vitro, we previously found that benign prostate stromal cells (PrSCs) can also synthesize testosterone (T) from an adrenal precursor, DHEA, when stimulated with a hedgehog (Hh) pathway agonist, SAG. Here, we show exposure of PrSCs to a different Smoothened (Smo) agonist, Ag1.5, or to conditioned medium from sonic hedgehog overexpressing LNCaP cells induces steroidogenic enzyme expression in PrSCs and significantly increases production of T and its precursor steroids in a Smo-dependent manner from 22-OH-cholesterol substrate. Hh agonist-/ligand-treated PrSCs produced androgens at a rate similar to or greater than that of PCa cell lines. Likewise, primary bone marrow stromal cells became more steroidogenic and produced T under the influence of Smo agonist. Treatment of mice bearing LNCaP xenografts with a Smo antagonist, TAK-441, delayed the onset of CRPC after castration and substantially reduced androgen levels in residual tumors. These outcomes support the idea that stromal cells in ADT-treated primary or metastatic prostate tumors can contribute to AIS as a consequence of a paracrine Hh signaling microenvironment. As such, Smo antagonists may be useful for targeting prostate tumor stromal cell-derived AIS and delaying the onset of CRPC after ADT.
Asunto(s)
Proteínas Hedgehog/metabolismo , Comunicación Paracrina/fisiología , Neoplasias de la Próstata Resistentes a la Castración/metabolismo , Neoplasias de la Próstata Resistentes a la Castración/patología , Microambiente Tumoral/fisiología , Andrógenos/metabolismo , Animales , Médula Ósea/metabolismo , Castración/métodos , Línea Celular Tumoral , Humanos , Masculino , Ratones , Ratones Desnudos , Receptores Androgénicos/metabolismo , Transducción de Señal/fisiología , Células del Estroma/metabolismo , Testosterona/metabolismoRESUMEN
The quantitative and qualitative analysis of circulating tumor cells (CTCs) has the potential to improve the clinical management of several cancers, including prostate cancer. As such, there is much interest in the isolation of CTCs from the peripheral blood of cancer patients. We report the design, fabrication, and proof-of-principle testing of an integrated permalloy-based microfluidic chip for immunomagnetic isolation of blood-borne prostate cancer cells using an antibody targeting prostate surface membrane antigen (PSMA). The preliminary results using spiked blood samples indicate that the proposed device is consistently capable of isolating prostate cancer cells with high sensitivity (up to 98 %) at clinically relevant low concentrations (down to 20 cells/mL) and an acceptable throughput (100 µL/min).
Asunto(s)
Separación Inmunomagnética , Dispositivos Laboratorio en un Chip , Células Neoplásicas Circulantes , Neoplasias de la Próstata/sangre , Animales , Línea Celular Tumoral , Femenino , Humanos , Separación Inmunomagnética/instrumentación , Separación Inmunomagnética/métodos , Masculino , RatasRESUMEN
BACKGROUND AND AIMS: Perforation during colonoscopy remains the most worrisome adverse event and usually requires urgent surgical rescue. The aim of this study was to evaluate the feasibility and effectiveness of endoscopic closure of full-thickness colonic perforations. METHODS: We performed a retrospective analysis of all consecutive patients with endoscopically closed colonic perforations over the past 6 years (2009-2014). Colonic perforations were closed by using endoscopic clips or an endoscopic suturing device. Most patients were admitted for treatment with intravenous antibiotics and kept on bowel rest. If their clinical condition deteriorated, urgent surgery was performed. If patients remained stable, oral feeding was resumed, and patients were discharged with subsequent clinical and endoscopic follow-up. RESULTS: Twenty-one patients had iatrogenic colonic perforations closed with an endoscopic suturing device or endoscopic clips during the study period. Primary closure of a colonic perforation was performed with endoscopic clips in 5 patients and sutured with an endoscopic suturing device in 16 patients. All 5 patients after clip closure had worsening of abdominal pain and required laparoscopy (4 patients) or rescue colonoscopy with endoscopic suturing closure (1 patient). Two patients had abdominal pain after endoscopic suturing closure, but diagnostic laparoscopy confirmed complete and adequate endoscopic closure of the perforations. The other 15 patients did not require any rescue surgery or laparoscopy after endoscopic suturing. The main limitation of our study is its retrospective, single-center design and relatively small number of patients. CONCLUSION: Endoscopic suturing closure of colonic perforations is technically feasible, eliminates the need for rescue surgery, and appears more effective than closure with hemostatic endoscopic clips.
Asunto(s)
Enfermedades del Colon/cirugía , Colonoscopía/métodos , Perforación Intestinal/cirugía , Instrumentos Quirúrgicos , Técnicas de Sutura , Adulto , Anciano , Anciano de 80 o más Años , Colon/lesiones , Colon/cirugía , Enfermedades del Colon/etiología , Colonoscopía/efectos adversos , Femenino , Humanos , Perforación Intestinal/etiología , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
The effects of six organophosphate flame retardants (OPFRs) tris(2-butoxyethyl) phosphate, tris(2-chloroethyl) phosphate, tris(1-chloro-2-propyl) phosphate, tris(methylphenyl) phosphate, tris(1,3-dichloro-2-propyl) phosphate (TDCIPP), and triethyl phosphate on the activities of androgen receptor (AR), estrogen receptor (ER), and aryl hydrocarbon receptor (AhR) were assessed in human prostate and endometrial cancer cells. OPFRs had no effect on ER or AhR target gene activation in ECC-1 cells. The effect of TDCIPP on mRNA and protein accumulation of AR target genes was examined further. AR-inducible gene and protein expression were significantly altered by TDCIPP exposure and repressed PSA levels in conditioned media of prostate cancer cells. We demonstrated that TDCIPP has no affinity for the AR ligand binding domain (AR-LBD) and exerts its antiandrogenic effects in a noncompetitive fashion. Thus, the clinical relevance of TDCIPP exposure on prostate cancer detection and progression to a therapeutically refractile state ought to be investigated further.
Asunto(s)
Disruptores Endocrinos/farmacología , Contaminantes Ambientales/farmacología , Retardadores de Llama/farmacología , Compuestos Organofosforados/farmacología , Receptores Androgénicos/genética , Transducción de Señal/efectos de los fármacos , Línea Celular Tumoral , Endometrio/citología , Endometrio/efectos de los fármacos , Endometrio/metabolismo , Células Epiteliales/citología , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Receptor alfa de Estrógeno/genética , Receptor alfa de Estrógeno/metabolismo , Femenino , Regulación de la Expresión Génica , Humanos , Calicreínas/genética , Calicreínas/metabolismo , Masculino , Organofosfatos/farmacología , Próstata/citología , Próstata/efectos de los fármacos , Próstata/metabolismo , Antígeno Prostático Específico/genética , Antígeno Prostático Específico/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores Androgénicos/metabolismo , Receptores de Hidrocarburo de Aril/genética , Receptores de Hidrocarburo de Aril/metabolismo , Transducción de Señal/genéticaRESUMEN
The effects of the organic flame retardant 1,2-Dibromo-4-(1,2-dibromoethyl) cyclohexane (TBECH) on androgen receptor target gene expression were examined in the human LNCaP prostate cancer cell line. While γ-/δ-TBECH alone led to a significant increase in prostate-specific antigen (PSA) mRNA accumulation, both the α-/-TBECH and γ-/δ-TBECH mixtures repressed androgen-inducible PSA mRNA and protein accumulation in human LNCaP cells. Thus, we hypothesize that isomeric mixtures of TBECH may act as partial agonists of the androgen receptor.
Asunto(s)
Ciclohexanos/farmacología , Disruptores Endocrinos/farmacología , Contaminantes Ambientales/farmacología , Células Epiteliales/efectos de los fármacos , Retardadores de Llama/farmacología , Receptores Androgénicos/genética , Transducción de Señal/efectos de los fármacos , Línea Celular Tumoral , Células Epiteliales/citología , Células Epiteliales/metabolismo , Regulación de la Expresión Génica , Humanos , Calicreínas/genética , Calicreínas/metabolismo , Masculino , Próstata/citología , Próstata/efectos de los fármacos , Próstata/metabolismo , Antígeno Prostático Específico/genética , Antígeno Prostático Específico/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores Androgénicos/metabolismo , Transducción de Señal/genética , EstereoisomerismoRESUMEN
Predominant forms of food and energy systems pose multiple challenges to the environment as current configurations tend to be structured around centralized one-way through-put of materials and energy. In addition, these configurations can introduce vulnerability to input material price and supply shocks as well as contribute to localized food insecurity and lost opportunities for less environmentally harmful forms of local economic development. One proposed form of system transformation involves locally integrating "unclosed" material and energy loops from food and energy systems. Such systems, which have been termed integrated food-energy systems (IFES), have existed in diverse niche forms but have not been systematically studied with respect to technological, governance, and environmental differences. As a first step in this process, we have constructed a taxonomy of IFES archetypes by using exploratory data analysis on a collection of IFES cases. We find that IFES may be classified hierarchically first by their primary purposefood or energy productionand subsequently by degree and direction of vertical supply chain coordination. We then use this taxonomy to delineate potential governance challenges and pose a research agenda aimed at understanding what role IFES may play in food and energy system transformation and ultimately what policies may encourage IFES adoption.
Asunto(s)
Conservación de los Recursos Naturales , Fuentes Generadoras de Energía , Industria de Alimentos , Agricultura , Algoritmos , Análisis por Conglomerados , Abastecimiento de Alimentos , Modelos Teóricos , Proyectos de InvestigaciónRESUMEN
BACKGROUND: In castration-resistant prostate cancer (CRPC), recent evidence has demonstrated the persistence of the intratumoral androgens. The multi-step androgen synthesis pathway originates from cholesterol, which can be obtained by cells from several major sources including intracellular synthesis through an enzyme 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR). The inhibition of this enzyme by the use of statins has been investigated in prostate cancer as a possible therapeutic target for blocking the de novo androgen synthesis resulting in decreased tumor growth. However, the effectiveness of statins in CRPC has not been investigated. METHODS: Castration-resistant C4-2 and androgen-sensitive LNCaP cells were treated with Simvastatin for 48 hours. Dose-dependent responses to Simvastatin were analyzed using cell proliferation and cytotoxicity assays. Cellular growth curve was generated using haemocytometer. HMGCR activity was assessed using 14C-acetic acid detected by thin layer chromatography, and the protein expression was quantified using western blot analysis. Intracellular cholesterol and prostate specific antigen (PSA) levels were quantified using enzyme-linked immunosorbent assays (ELISA). RESULTS: Significant decrease in cell viability and growth curve observed at 75 µM of Simvastatin compared to no treatment group in the castration-resistant C4-2 cells. HMGCR activity was significantly decreased up to 50% and 70% at 50 µM and 75 µM of Simvastatin respectively compared to the vehicle control in C4-2 cells. Simvastatin did not affect the protein expression. 80% decrease in the amount of total intracellular cholesterol levels was observed in 75 µM Simvastatin treatment group compared to vehicle control. PSA secretion levels were significantly reduced in the C4-2 cell line at 50 µM and 75 µM of Simvastatin compared to vehicle control. CONCLUSION: The inhibition of HMGCR via Simvastatin lowered the viability of castration-resistant C4-2 cells. Simvastatin's ability to limit the endogenous supply of cholesterol contributes to the effects seen in cell viability.
Asunto(s)
Antimetabolitos Antineoplásicos/farmacología , Simvastatina/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Colesterol/biosíntesis , Ensayos de Selección de Medicamentos Antitumorales , Expresión Génica/efectos de los fármacos , Humanos , Hidroximetilglutaril-CoA Reductasas/metabolismo , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Calicreínas/metabolismo , Masculino , Antígeno Prostático Específico/metabolismo , Neoplasias de la Próstata Resistentes a la CastraciónRESUMEN
Bone metastases are the most severe and prevalent consequences of prostate cancer (PC), affecting more than 80% of patients with advanced PC. PCBMs generate pain, pathological fractures, and paralysis. As modern therapies increase survival, more patients are suffering from these catastrophic consequences. Radiographically, PCBMs are predominantly osteosclerotic, but the mechanisms of abnormal bone formation and how this pathological increase in bone density is related to fractures are unclear. In this study, we conducted a comprehensive analysis on a cohort of 76 cadaveric PCBM specimens and 12 cancer-free specimens as controls. We used micro-computed tomography to determine 3D organization and quantify bone characteristics, quantitative backscattering electron microscopy to characterize mineral content and details in bone structure, nanoindentation to determine mechanical properties, and histological and immunohistochemical analysis of bone structure and composition. We define 4 PCBM phenotypes: osteolytic, mixed lytic-sclerotic, and 2 subgroups of osteosclerotic lesions-those with residual trabeculae, and others without residual trabeculae. The osteosclerotic lesions are characterized by the presence of abnormal bone accumulated on trabeculae surfaces and within intertrabecular spaces. This abnormal bone is characterized by higher lacunae density, abnormal lacunae morphology, and irregular lacunae orientation. However, mineral content, hardness, and elastic modulus at micron-scale were indistinguishable between this irregular bone and residual trabeculae. The collagen matrix of this abnormal bone presents with irregular organization and a prominent collagen III composition. These characteristics suggest that osteosclerotic PCBMs initiate new bone deposition as woven bone; however, the lack of subsequent bone remodeling, absence of lamellar bone deposition on its surface, and presence of collagen III distinguish this pathologic matrix from conventional woven bone. Although the mineralized matrix retains normal bone hardness and stiffness properties, the lack of fibril anisotropy presents a compromised trabecular structure, which may have clinical implications.
RESUMEN
Aberrant expression of the E26 transformation-specific (ETS) transcription factors characterizes numerous human malignancies. Many of these proteins, including EWS:FLI1 and EWS:ERG fusions in Ewing sarcoma (EwS) and TMPRSS2:ERG in prostate cancer (PCa), drive oncogenic programs via binding to GGAA repeats. We report here that both EWS:FLI1 and ERG bind and transcriptionally activate GGAA-rich pericentromeric heterochromatin. The respective pathogen-like HSAT2 and HSAT3 RNAs, together with LINE, SINE, ERV, and other repeat transcripts, are expressed in EwS and PCa tumors, secreted in extracellular vesicles (EVs), and are highly elevated in plasma of patients with EwS with metastatic disease. High human satellite 2 and 3 (HSAT2,3) levels in EWS:FLI1- or ERG-expressing cells and tumors were associated with induction of G2/M checkpoint, mitotic spindle, and DNA damage programs. These programs were also activated in EwS EV-treated fibroblasts, coincident with accumulation of HSAT2,3 RNAs, proinflammatory responses, mitotic defects, and senescence. Mechanistically, HSAT2,3-enriched cancer EVs induced cGAS-TBK1 innate immune signaling and formation of cytosolic granules positive for double-strand RNAs, RNA-DNA, and cGAS. Hence, aberrantly expressed ETS proteins derepress pericentromeric heterochromatin, yielding pathogenic RNAs that transmit genotoxic stress and inflammation to local and distant sites. Monitoring HSAT2,3 plasma levels and preventing their dissemination may thus improve therapeutic strategies and blood-based diagnostics.
Asunto(s)
Daño del ADN , Vesículas Extracelulares , Proteínas de Fusión Oncogénica , Proteína Proto-Oncogénica c-fli-1 , Proteína EWS de Unión a ARN , Regulador Transcripcional ERG , Humanos , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/genética , Proteínas de Fusión Oncogénica/genética , Proteínas de Fusión Oncogénica/metabolismo , Regulador Transcripcional ERG/genética , Regulador Transcripcional ERG/metabolismo , Masculino , Proteína EWS de Unión a ARN/genética , Proteína EWS de Unión a ARN/metabolismo , Proteína Proto-Oncogénica c-fli-1/genética , Proteína Proto-Oncogénica c-fli-1/metabolismo , Sarcoma de Ewing/genética , Sarcoma de Ewing/patología , Sarcoma de Ewing/metabolismo , Sarcoma de Ewing/inmunología , Línea Celular Tumoral , ARN Neoplásico/genética , ARN Neoplásico/metabolismo , Inflamación/genética , Inflamación/metabolismo , Inflamación/patología , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/metabolismo , Ratones , Animales , Heterocromatina/metabolismo , Heterocromatina/genéticaRESUMEN
Hedgehog (Hh) signaling is a highly conserved intercellular and intracellular communication mechanism that governs organogenesis and is dysregulated in cancers of numerous tissues, including prostate. Up-regulated expression of the Hh ligands, Sonic (Shh) and Desert (Dhh), has been reported in androgen-deprived and castration-resistant prostate cancer (CRPC). In a cohort of therapy naive, short- and long-term neoadjuvant hormone therapy-treated (NHT), and CRPC specimens, we observed elevated Dhh expression predominantly in long-term NHT specimens and elevated Shh expression predominantly in CRPC specimens. Together with previously demonstrated reciprocal signaling between Shh-producing prostate cancer (PCa) cells and urogenital mesenchymal fibroblasts, these results suggest that castration-induced Hh expression promotes CRPC progression through reciprocal paracrine signaling within the tumor microenvironment. We tested whether the orally available Smoothened (Smo) antagonist, TAK-441, could impair castration-resistant progression of LNCaP PCa xenografts by disrupting paracrine Hh signaling. Although TAK-441 or cyclopamine did not affect androgen withdrawal-induced Shh up-regulation or viability of LNCaP cells, castration-resistant progression of LNCaP xenografts was significantly delayed in animals treated with TAK-441. In TAK-441-treated xenografts, expression of murine orthologs of the Hh-activated genes, Gli1, Gli2 and Ptch1, was substantially suppressed, while expression of the corresponding human orthologs was unaffected. As androgen-deprived LNCaP cells up-regulate Shh expression, but are not sensitive to Smo antagonists, these studies indicate that TAK-441 leads to delayed castration-resistant progression of LNCaP xenografts by disrupting paracrine Hh signaling with the tumor stroma. Thus, paracrine Hh signaling may offer unique opportunities for prognostic biomarker development, drug targeting and therapeutic response monitoring of PCa progression.
Asunto(s)
Antineoplásicos/farmacología , Comunicación Paracrina/efectos de los fármacos , Neoplasias de la Próstata/tratamiento farmacológico , Piridinas/farmacología , Pirroles/farmacología , Receptores Acoplados a Proteínas G/antagonistas & inhibidores , Animales , Castración , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Progresión de la Enfermedad , Proteínas Hedgehog/antagonistas & inhibidores , Proteínas Hedgehog/metabolismo , Humanos , Masculino , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Neoplasias de la Próstata/metabolismo , Receptor Smoothened , Microambiente Tumoral/efectos de los fármacos , Alcaloides de Veratrum/farmacología , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Phosphorylation of the BH3 (Bcl-2 homology domain 3)-only protein BAD (Bcl-2/Bcl-X(L)-antagonist, causing cell death) can either directly disrupt its association with the pro-survival proteins Bcl-X(L) and/or Bcl-2, or cause association of BAD with 14-3-3 proteins. In the present study, we further characterize phosphorylation of BAD at Ser170, a unique site with unclear function. We provide further evidence that mutation of Ser170 to a phospho-mimetic aspartic acid residue (S170D) can have a profound inhibitory effect on the pro-apoptosis function of BAD. Furthermore, mutated BAD with an alanine substitution inhibited cell proliferation, slowing progression specifically through S-phase. We identify the kinase responsible for phosphorylation at this site as CaMKII-γ (γ isoform of Ca2+/calmodulin-dependent kinase II), but not the other three isoforms of CaMKII, revealing an extraordinary specificity among these closely related kinases. Furthermore, cytokine treatment increased BAD-Ser170-directed CaMKII-γ activity and phosphorylation of CaMKII-γ at an activating site, and CaMKII activity directed to the BAD-Ser170 site was elevated during S-phase. Treating cells with a selective inhibitor of CaMKII caused apoptosis in cells expressing BAD, but not in cells expressing the BAD-S170D mutant. The present study provides support for BAD-Ser170 phosphorylation playing a key role not only in regulating BAD's pro-apoptotic activity, but also in cell proliferation.
Asunto(s)
Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/metabolismo , Supervivencia Celular/efectos de los fármacos , Serina/metabolismo , Proteína Letal Asociada a bcl/metabolismo , Animales , Apoptosis/efectos de los fármacos , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/antagonistas & inhibidores , Línea Celular , Proliferación Celular/efectos de los fármacos , Ratones , Fosforilación , Serina/genética , Proteína Letal Asociada a bcl/genéticaRESUMEN
In cancer cells, inhibition of integrin-linked kinase (ILK) increases centrosome declustering causing mitotic arrest and cell death. Yet, not all cancer cells are susceptible to anti-ILK treatment alone. We investigate a combination drug strategy targeting ILK and another oncogenic kinase, Abelson kinase (ABL). Drug-concentration viability assays (i.e., MTT assays) indicate that ILK and ABL inhibitors in combination decreased the viability of glioblastoma cells over the ILK drug QLT-0267 alone. Combination strategies also increased aberrant mitoses and cell death over QLT-0267 alone. This was evident from an increase in mitotic arrest, apoptosis and a sub-G1 peak following FAC analysis. In vitro, ILK and ABL localized to the centrosome and the putative ILK kinase domain was important for this localization. Increased levels of cytosolic ABL are associated with its transformative abilities. ILK inhibitor effects on survival correlated with its ability to decrease cytosolic ABL levels and inhibit ABL's localization to mitotic centrosomes in glioblastoma cells. ILK inhibitor effects on ABL's centrosomal localization were reversed by the proteasomal inhibitor MG132 (a drug that inhibits ABL degradation). These results indicate that ILK regulates ABL at mitotic centrosomes and that combination treatments targeting ILK and ABL are more effective then QLT-0267 alone at decreasing the survival of dividing glioblastoma cells.
RESUMEN
Approximately half of prostate cancers (PCa) carry TMPRSS2-ERG translocations; however, the clinical impact of this genomic alteration remains enigmatic. Expression of v-ets erythroblastosis virus E26 oncogene like (avian) gene (ERG) promotes prostatic epithelial dysplasia in transgenic mice and acquisition of epithelial-to-mesenchymal transition (EMT) characteristics in human prostatic epithelial cells (PrECs). To explore whether ERG-induced EMT in PrECs was associated with therapeutically targetable transformation characteristics, we established stable populations of BPH-1, PNT1B and RWPE-1 immortalized human PrEC lines that constitutively express flag-tagged ERG3 (fERG). All fERG-expressing populations exhibited characteristics of in vitro and in vivo transformation. Microarray analysis revealed >2000 commonly dysregulated genes in the fERG-PrEC lines. Functional analysis revealed evidence that fERG cells underwent EMT and acquired invasive characteristics. The fERG-induced EMT transcript signature was exemplified by suppressed expression of E-cadherin and keratins 5, 8, 14 and 18; elevated expression of N-cadherin, N-cadherin 2 and vimentin, and of the EMT transcriptional regulators Snail, Zeb1 and Zeb2, and lymphoid enhancer-binding factor-1 (LEF-1). In BPH-1 and RWPE-1-fERG cells, fERG expression is correlated with increased expression of integrin-linked kinase (ILK) and its downstream effectors Snail and LEF-1. Interfering RNA suppression of ERG decreased expression of ILK, Snail and LEF-1, whereas small interfering RNA suppression of ILK did not alter fERG expression. Interfering RNA suppression of ERG or ILK impaired fERG-PrEC Matrigel invasion. Treating fERG-BPH-1 cells with the small molecule ILK inhibitor, QLT-0267, resulted in dose-dependent suppression of Snail and LEF-1 expression, Matrigel invasion and reversion of anchorage-independent growth. These results suggest that ILK is a therapeutically targetable mediator of ERG-induced EMT and transformation in PCa.
Asunto(s)
Neoplasias de la Próstata/patología , Proteínas Serina-Treonina Quinasas/fisiología , Transactivadores/fisiología , Animales , Compuestos Azo/farmacología , Línea Celular Tumoral , Transición Epitelial-Mesenquimal , Humanos , Factor de Unión 1 al Potenciador Linfoide/fisiología , Masculino , Ratones , Invasividad Neoplásica , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Pirazoles/farmacología , Factores de Transcripción de la Familia Snail , Factores de Transcripción/fisiología , Regulador Transcripcional ERGRESUMEN
The androgen receptor (AR) plays a central role in prostate cancer progression to the castration-resistant (CR) lethal state. L-Dopa decarboxylase (DDC) is an AR coactivator that increases in expression with disease progression and is coexpressed with the receptor in prostate adenocarcinoma cells, where it may enhance AR activity. Here, we hypothesize that the DDC enzymatic inhibitor, carbidopa, can suppress DDC-coactivation of AR and retard prostate tumor growth. Treating LNCaP prostate cancer cells with carbidopa in transcriptional assays suppressed the enhanced AR transactivation seen with DDC overexpression and decreased prostate-specific antigen (PSA) mRNA levels. Carbidopa dose-dependently inhibited cell growth and decreased survival in LNCaP cell proliferation and apoptosis assays. The inhibitory effect of carbidopa on DDC-coactivation of AR and cell growth/survival was also observed in PC3 prostate cancer cells (stably expressing AR). In vivo studies demonstrated that serum PSA velocity and tumor growth rates elevated â¼2-fold in LNCaP xenografts, inducibly overexpressing DDC, were reverted to control levels with carbidopa administration. In castrated mice, treating LNCaP tumors, expressing endogenous DDC, with carbidopa delayed progression to the CR state from 6 to 10 weeks, while serum PSA and tumor growth decreased 4.3-fold and 5.4-fold, respectively. Our study is a first time demonstration that carbidopa can abrogate DDC-coactivation of AR in prostate cancer cells and tumors, decrease serum PSA, reduce tumor growth and delay CR progression. Since carbidopa is clinically approved, it may be readily used as a novel therapeutic strategy to suppress aberrant AR activity and delay prostate cancer progression.
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Carbidopa/farmacología , Dopa-Decarboxilasa/metabolismo , Neoplasias de la Próstata/fisiopatología , Receptores Androgénicos/metabolismo , Animales , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Progresión de la Enfermedad , Regulación Neoplásica de la Expresión Génica , Masculino , Ratones , Orquiectomía , Antígeno Prostático Específico/biosíntesis , Antígeno Prostático Específico/genética , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/metabolismo , ARN Mensajero/biosíntesis , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND: Scavenger Receptor Class B Type I (SR-BI) facilitates influx of cholesterol to the cell from lipoproteins in the circulation. This influx of cholesterol may be important for many cellular functions, including synthesis of androgens. Castration-resistant prostate cancer tumors are able to synthesize androgens de novo in order to supplement the loss of exogenous sources often induced by androgen deprivation therapy. Silencing of SR-BI may impact the ability of prostate cancer cells, particularly those of castration-resistant state, to maintain the intracellular supply of androgens by removing a supply of cholesterol. METHODS: SR-BI expression was knocked down using small interfering RNA in LNCaP and C4-2 cells. The effect of down-regulation of SR-BI on PSA production, cell toxicity, and cell viability was measured in both cell types. In addition, compensatory cholesterol synthesis activity was measured using the radiolabeled precursor, (14) C-acetate. RESULTS: SR-BI protein expression is higher basally in C4-2 cells than LNCaP cells. Silencing of SR-BI expression to greater than 85% reduced PSA production in LNCaP and C4-2 SRBI-KD cells by 55% and 58% compared to negative control cells, respectively. SR-BI-KD C4-2 cells demonstrated significantly reduced cell viability (>25%) compared the NC cells. CONCLUSIONS: The down-regulation of SR-BI significantly impacts PSA production of prostate cancer cells, as well as the viability of C4-2 cells in the presence and absence of HDL. This may indicate a deficiency in cholesterol availability to the androgen synthesis pathway or may implicate a role for SR-BI in prostate cancer signal transduction pathways.
Asunto(s)
Técnicas de Silenciamiento del Gen , Antígeno Prostático Específico/antagonistas & inhibidores , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , Receptores Depuradores de Clase B/deficiencia , Receptores Depuradores de Clase B/genética , Línea Celular Tumoral , Supervivencia Celular/genética , Regulación hacia Abajo/genética , Silenciador del Gen , Humanos , Masculino , Antígeno Prostático Específico/metabolismo , Neoplasias de la Próstata/genética , Receptores Depuradores de Clase B/biosíntesisRESUMEN
BACKGROUND: The growth hormone/insulin-like growth factor I (GH/IGF-I) axis has been linked to prostate cancer (PCa) risk. Although previous studies indicate that human breast cancers and a murine PCa model develop more slowly in murine hosts homozygous for a missense mutation in the GH-releasing hormone receptor (lit/lit) whose "little" dwarfed phenotype is caused by suppressed GH and IGF-I production, the role of these two hormones remains controversial. METHODS: To assess how the GH/IGF-I axis influences androgen-responsive, castration-resistant (CR), and androgen-independent (AI) growth of human PCa, we compared xenograft growth of the androgen-responsive human PCa cells, LNCaP, and AI human PCa cells, PC3, in intact and castrate Nod/SCID lit/lit and lit/+ mice, and in vitro growth of these cell lines in lit/lit and lit/+ serum-containing media supplemented with GH or IGF-I. RESULTS: Tumor growth and PSA accumulation rates were suppressed in LNCaP tumor-bearing lit/lit mice pre- and post-castration. Growth of PC3 xenografts in lit/lit mice was also suppressed. In vitro proliferation of LNCaP and PC3 cells cultured in media containing lit/lit mouse serum was decreased as compared to growth in media containing lit/+ serum. Suppressed growth in lit/lit serum could be restored by the addition of IGF-I, and to a lesser extent, GH. Differences in growth correlated with differences in steady-state AKT and ERK1/2 activation. CONCLUSIONS: This study demonstrates that circulating GH and IGF-I can promote androgen-responsive growth, CR progression, and AI expansion of PTEN-deficient human PCa cell xenografts and indicates that IGF-I can promote PCa growth in a suppressed GH environment.
Asunto(s)
Andrógenos/fisiología , Modelos Animales de Enfermedad , Neoplasias de la Próstata/patología , Animales , Western Blotting , Peso Corporal/fisiología , Línea Celular Tumoral , Proliferación Celular , Activación Enzimática/fisiología , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Hormona de Crecimiento Humana/sangre , Hormona de Crecimiento Humana/metabolismo , Humanos , Factor I del Crecimiento Similar a la Insulina/análisis , Factor I del Crecimiento Similar a la Insulina/metabolismo , Masculino , Ratones , Ratones Endogámicos NOD , Ratones SCID , Trasplante de Neoplasias , Neoplasias Hormono-Dependientes/enzimología , Neoplasias Hormono-Dependientes/metabolismo , Neoplasias Hormono-Dependientes/patología , Proteína Oncogénica v-akt/metabolismo , Antígeno Prostático Específico/sangre , Antígeno Prostático Específico/metabolismo , Neoplasias de la Próstata/enzimología , Neoplasias de la Próstata/metabolismoRESUMEN
There have been several studies that have linked elevated scavenger receptor class b type 1 (SR-B1) expression and activity to the development and progression of castration-resistant prostate cancer (CRPC). SR-B1 facilitates the influx of cholesterol to the cell from lipoproteins in systemic circulation. This influx of cholesterol may be important for many cellular functions, including the synthesis of androgens. Castration-resistant prostate cancer tumors can synthesize androgens de novo to supplement the loss of exogenous sources often induced by androgen deprivation therapy. Silencing of SR-B1 may impact the ability of prostate cancer cells, particularly those of the castration-resistant state, to maintain the intracellular supply of androgens by removing a supply of cholesterol. SR-B1 expression is elevated in CRPC models and has been linked to poor survival of patients. The overarching belief has been that cholesterol modulation, through either synthesis or uptake inhibition, will impact essential signaling processes, impeding the proliferation of prostate cancer. The reduction in cellular cholesterol availability can impede prostate cancer proliferation through both decreased steroid synthesis and steroid-independent mechanisms, providing a potential therapeutic target for the treatment of prostate cancer. In this article, we discuss and highlight the work on SR-B1 as a potential novel drug target for CRPC management.