RESUMEN
Previous studies have established a role of vascular-disrupting agents as anti- cancer agents. Plinabulin is a novel vascular-disrupting agent that exhibits potent interruption of tumor blood flow because of the disruption of tumor vascular endothelial cells, resulting in tumor necrosis. In addition, plinabulin exerts a direct action on tumor cells, resulting in apoptosis. In the present study, we examined the anti-multiple myeloma (MM) activity of plinabulin. We show that low concentrations of plinabulin exhibit a potent antiangiogenic action on vascular endothelial cells. Importantly, plinabulin also induces apoptotic cell death in MM cell lines and tumor cells from patients with MM, associated with mitotic growth arrest. Plinabulin-induced apoptosis is mediated through activation of caspase-3, caspase-8, caspase-9, and poly(ADP-ribose) polymerase cleavage. Moreover, plinabulin triggered phosphorylation of stress response protein JNK, as a primary target, whereas blockade of JNK with a biochemical inhibitor or small interfering RNA strategy abrogated plinabulin-induced mitotic block or MM cell death. Finally, in vivo studies show that plinabulin was well tolerated and significantly inhibited tumor growth and prolonged survival in a human MM.1S plasmacytoma murine xenograft model. Our study therefore provides the rationale for clinical evaluation of plinabulin to improve patient outcome in MM.
Asunto(s)
Inhibidores de la Angiogénesis/farmacología , Apoptosis/efectos de los fármacos , Imidazoles/farmacología , Proteína Quinasa 8 Activada por Mitógenos/metabolismo , Mieloma Múltiple/irrigación sanguínea , Mieloma Múltiple/tratamiento farmacológico , Neovascularización Patológica/prevención & control , Piperazinas/farmacología , Animales , Western Blotting , Proliferación Celular/efectos de los fármacos , Dicetopiperazinas , Técnica del Anticuerpo Fluorescente , Humanos , Masculino , Ratones , Ratones SCID , Proteína Quinasa 8 Activada por Mitógenos/antagonistas & inhibidores , Proteína Quinasa 8 Activada por Mitógenos/genética , ARN Interferente Pequeño/genética , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Our recent study demonstrated that a novel proteasome inhibitor NPI-0052 is distinct from bortezomib (Velcade) and, importantly, triggers apoptosis in multiple myeloma (MM) cells resistant to bortezomib. Here we demonstrate that combining NPI-0052 and lenalidomide (Revlimid) induces synergistic anti-MM activity in vitro using MM-cell lines or patient MM cells. NPI-0052 plus lenalidomide-induced apoptosis is associated with (1) activation of caspase-8, caspase-9, caspase-12, caspase-3, and poly(ADP) ribose polymerase; (2) activation of BH-3 protein BIM; (3) translocation of BIM to endoplasmic reticulum; (4) inhibition of migration of MM cells and angiogenesis; and (5) suppression of chymotrypsin-like, caspase-like, and trypsin-like proteasome activities. Importantly, blockade of BIM using siRNA significantly abrogates NPI-0052 plus lenalidomide-induced apoptosis. Furthermore, studies using biochemical inhibitors of caspase-8 versus caspase-9 demonstrate that NPI-0052 plus lenalidomide-triggered apoptosis is primarily dependent on caspase-8 signaling. In animal tumor model studies, low-dose combination of NPI-0052 and lenalidomide is well tolerated, significantly inhibits tumor growth, and prolongs survival. Taken together, our study provides the preclinical rationale for clinical protocols evaluating lenalidomide together with NPI-0052 to improve patient outcome in MM.
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Antineoplásicos/farmacología , Lactonas/farmacología , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/patología , Pirroles/farmacología , Talidomida/análogos & derivados , Animales , Apoptosis/efectos de los fármacos , División Celular/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Resistencia a Antineoplásicos , Sinergismo Farmacológico , Humanos , Técnicas In Vitro , Lenalidomida , Ratones , Ratones SCID , Inhibidores de Proteasoma , Talidomida/farmacología , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Bortezomib therapy has proven successful for the treatment of relapsed, relapsed/refractory, and newly diagnosed multiple myeloma (MM). At present, bortezomib is available as an intravenous injection, and its prolonged treatment is associated with toxicity and development of drug resistance. Here we show that the novel proteasome inhibitor ONX 0912, a tripeptide epoxyketone, inhibits growth and induces apoptosis in MM cells resistant to conventional and bortezomib therapies. The anti-MM activity of ONX-0912 is associated with activation of caspase-8, caspase-9, caspase-3, and poly(ADP) ribose polymerase, as well as inhibition of migration of MM cells and angiogenesis. ONX 0912, like bortezomib, predominantly inhibits chymotrypsin-like activity of the proteasome and is distinct from bortezomib in its chemical structure. Importantly, ONX 0912 is orally bioactive. In animal tumor model studies, ONX 0912 significantly reduced tumor progression and prolonged survival. Immununostaining of MM tumors from ONX 0912-treated mice showed growth inhibition, apoptosis, and a decrease in associated angiogenesis. Finally, ONX 0912 enhances anti-MM activity of bortezomib, lenalidomide dexamethasone, or pan-histone deacetylase inhibitor. Taken together, our study provides the rationale for clinical protocols evaluating ONX 0912, either alone or in combination, to improve patient outcome in MM.
Asunto(s)
Antineoplásicos/farmacología , Mieloma Múltiple/tratamiento farmacológico , Oligopéptidos/farmacología , Complejo de la Endopetidasa Proteasomal/efectos de los fármacos , Animales , Antineoplásicos/química , Apoptosis/efectos de los fármacos , Western Blotting , Caspasas/efectos de los fármacos , Caspasas/metabolismo , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Humanos , Ratones , Ratones SCID , Oligopéptidos/química , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
PR-924 is an LMP-7-selective tripeptide epoxyketone proteasome inhibitor that covalently modifies proteasomal N-terminal threonine active sites. In the present study, we show that PR-924 inhibits growth and triggers apoptosis in multiple myeloma (MM) cell lines and primary patient MM cells, without significantly affecting normal peripheral blood mononuclear cells. PR-924-induced apoptosis in MM cells is associated with activation of caspase-3, caspase-8, caspase-9, BID, PARP and cytochrome-c release. In vivo administration of PR-924 inhibits tumour growth in human plasmacytoma xenografts. Results from SCID-hu model show a significant reduction in the shIL-6R levels in mice treated with PR-924 versus vehicle-control. PR-924 treatment was well tolerated as evidenced by the lack of weight loss. Importantly, treatment of tumour-bearing mice with PR-924, but not vehicle alone, prolonged survival. Our preclinical findings therefore validate immunoproteasome LMP-7 subunit as a novel therapeutic target in MM.
Asunto(s)
Antineoplásicos/farmacología , Mieloma Múltiple/patología , Oligopéptidos/farmacología , Inhibidores de Proteasoma , Animales , Antineoplásicos/uso terapéutico , Apoptosis/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Evaluación Preclínica de Medicamentos/métodos , Humanos , Ratones , Ratones SCID , Mieloma Múltiple/metabolismo , Proteínas de Neoplasias/antagonistas & inhibidores , Proteínas de Neoplasias/metabolismo , Oligopéptidos/uso terapéutico , Plasmacitoma/tratamiento farmacológico , Plasmacitoma/patología , Complejo de la Endopetidasa Proteasomal/metabolismo , Análisis de Supervivencia , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
SIRT1 belongs to the silent information regulator 2 (Sir2) protein family of enzymes and functions as a NAD(+) -dependent class III histone deacetylase. Here, we examined the anti-multiple myeloma (MM) activity of a novel oral agent, SRT1720, which targets SIRT1. Treatment of MM cells with SRT1720 inhibited growth and induced apoptosis in MM cells resistant to conventional and bortezomib therapies without significantly affecting the viability of normal cells. Mechanistic studies showed that anti-MM activity of SRT1720 is associated with: (i) activation of caspase-8, caspase-9, caspase-3, poly(ADP) ribose polymerase; (ii) increase in reactive oxygen species; (iii) induction of phosphorylated ataxia telangiectasia mutated/checkpoint kinase 2 signalling; (iv) decrease in vascular endothelial growth factor-induced migration of MM cells and associated angiogenesis; and (v) inhibition of nuclear factor-κB. Blockade of ATM attenuated SRT1720-induced MM cell death. In animal tumour model studies, SRT1720 inhibited MM tumour growth. Finally, SRT1720 enhanced the cytotoxic activity of bortezomib or dexamethasone. Our preclinical studies provide the rationale for novel therapeutics targeting SIRT1 in MM.
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Compuestos Heterocíclicos de 4 o más Anillos/farmacología , Mieloma Múltiple/tratamiento farmacológico , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Ácidos Borónicos/administración & dosificación , Bortezomib , Línea Celular Tumoral , Dexametasona/administración & dosificación , Femenino , Compuestos Heterocíclicos de 4 o más Anillos/administración & dosificación , Compuestos Heterocíclicos de 4 o más Anillos/química , Humanos , Inmunohistoquímica , Ratones , Mieloma Múltiple/metabolismo , Mieloma Múltiple/patología , Pirazinas/administración & dosificación , Distribución Aleatoria , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND: Cancer patients in the North East Region (NER) of India have poorer survival rates compared with the rest of India. This is due to late stage at presentation related to poor awareness, risk factors such as use of tobacco, alcohol consumption and less physical activity, This study aims to determine the association between socio-demographic characters and use of tobacco, alcohol consumption and physical activity among people in the NER. METHODS: A cross-sectional study of 1400 participants was conducted across Assam, Nagaland and Meghalaya in the NER. A questionnaire was developed to study the socio-demographic profile and factors such as use of tobacco, alcohol consumption and physical activity among participants. Multivariate analysis was performed to understand tobacco and alcohol use and physical activity and a logistic regression analysis was performed to understand the association of different independent variables with lifestyle practice. RESULTS: Use of tobacco and alcohol consumption was highest amongst males, 25-44 years age range and middle income group as defined in this study. The main reasons given for quitting tobacco and alcohol were becoming aware of the harmful effects of using tobacco, pressure from family and friends, and noticing a deterioration in health. Over 90 % of tobacco users and consumers of alcohol initiated this between 10-30 years of age. In all, 62 % of participants rarely or never engaged in any physical recreational activity. CONCLUSION: Patterns of use of tobacco and consumption of alcohol and recreational physical activity undertaken in the NER show a strong relationship with gender, age and household income. POLICY IMPLICATIONS: The paper finds a close association of different pattern of modifiable habits which are the risk factors for cancer in the Northeast Region. The limited awareness about the risk factors strengthen the case of context specific prevention strategies and constant reinforcement of behavior communication strategies by using multipronged approach.
Asunto(s)
Consumo de Bebidas Alcohólicas , Nicotiana , Consumo de Bebidas Alcohólicas/epidemiología , Estudios Transversales , Ejercicio Físico , Humanos , India/epidemiología , Masculino , PrevalenciaRESUMEN
BACKGROUND: Adolescence is an influential stage in students' lives when lifelong behaviours such as tobacco use are formed. During these years, school teachers are important role models for tobacco control among students. A study was conducted among school personnel and administrators to understand the key drivers for implementing an evidence-based school tobacco control program. METHODOLOGY: A cross-sectional, mixed-method study was conducted in five districts of Assam, India. The quantitative study was conducted among 565 school personnel across 40 Government-aided schools. Data was collected by means of an anonymous, self-administered questionnaire. Qualitative data was generated from 15 focus group discussions (FGDs) among 146 participants - District Program Officers, Block Education Officers, Cluster Coordinators, Headmasters and Teachers. RESULTS: While the prevalence of smoked tobacco was low (3%), the use of smokeless tobacco was higher (40%), and the prevalence of use of areca nut without tobacco (65%) was still higher among school personnel. They were aware of the school policies prohibiting the use of tobacco among students within or outside school buildings or during school-sponsored activities (81%); they had rather limited knowledge about policy for themselves (58%). There was lack of access to training materials about prevention of tobacco use among youth. The FGDs amongst school personnel resulted in several constructive suggestions on tobacco control in schools mainly in training school teachers, monitoring the program and incentives for execution of the program. However, there was a reluctance to implement a smokeless tobacco control programme since many were current users of smokeless tobacco and areca nut. CONCLUSION: Tobacco control policies as well as training school personnel in schools need to improve and further measures must be taken to prohibit use of areca nut, which contains carcinogens. The existing system of the education department can be utilised to implement tobacco control programmes effectively.
Asunto(s)
Instituciones Académicas , Prevención del Hábito de Fumar/organización & administración , Uso de Tabaco/prevención & control , Adolescente , Adulto , Niño , Estudios Transversales , Humanos , India , Persona de Mediana Edad , Fumar/epidemiología , Encuestas y Cuestionarios , Productos de Tabaco , Uso de Tabaco/epidemiología , Adulto JovenRESUMEN
Our previous study showed that the novel proteasome inhibitor NPI-0052 induces apoptosis in multiple myeloma (MM) cells resistant to conventional and bortezomib (Velcade, Takeda, Boston, MA, USA) therapies. In vivo studies using human MM-xenografts demonstrated that NPI-0052 is well tolerated, prolongs survival, and reduces tumour recurrence. These preclinical studies provided the basis for an ongoing phase-1 clinical trial of NPI-0052 in relapsed/refractory MM patients. Here we performed pharmacodynamic (PD) studies of NPI-0052 using human MM xenograft murine model. Our results showed that NPI-0052: (i) rapidly left the vascular compartment in an active form after intravenous (i.v.) administration, (ii) inhibited 20S proteasome chymotrypsin-like (CT-L, beta5), trypsin-like (T-L, beta2), and caspase-like (C-L, beta1) activities in extra-vascular tumours, packed whole blood (PWB), lung, liver, spleen, and kidney, but not brain and (iii) triggered a more sustained (>24 h) proteasome inhibition in tumours and PWB than in other organs (<24 h). Tissue distribution analysis of radiolabeled compound (3H-NPI-0052) in mice demonstrated that NPI-0052 left the vascular space and entered organs as the parent compound. Importantly, treatment of MM.1S-bearing mice with NPI-0052 showed reduced tumour growth without significant toxicity, which was associated with prolonged inhibition of proteasome activity in tumours and PWB but not normal tissues.
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Antineoplásicos/uso terapéutico , Lactonas/uso terapéutico , Plasmacitoma/tratamiento farmacológico , Pirroles/uso terapéutico , Animales , Antineoplásicos/farmacocinética , Antineoplásicos/farmacología , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos/métodos , Humanos , Riñón/metabolismo , Lactonas/farmacocinética , Lactonas/farmacología , Masculino , Ratones , Plasmacitoma/metabolismo , Plasmacitoma/patología , Inhibidores de Proteasoma , Pirroles/farmacocinética , Pirroles/farmacología , Ratas , Ratas Sprague-Dawley , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
A role of dietary bioactive components in bladder cancer prevention is biologically plausible because most substances or metabolites are excreted through the urinary tract and are consequently in direct contact with the mucosa of the bladder. We first determined antigrowth activity of genistein against poorly differentiated 253J B-V human bladder cancer cells in vitro. Genistein inhibited the cell growth in a time- and dose-dependent manner via G(2)-M arrest, down-regulation of nuclear factor kappaB (NF-kappaB), and induction of apoptosis. We also evaluated both genistin, which is a natural form of genistein, and the isoflavone-rich soy phytochemical concentrate (SPC) on the growth and metastasis of 253J B-V tumors in an orthotopic tumor model. Mice treated with genistin and SPC had reduced final tumor weights by 56% (P < 0.05) and 52% (P < 0.05), respectively, associated with induction of tumor cell apoptosis and inhibition of tumor angiogenesis in vivo. In addition, SPC treatment, but not genistin treatment, significantly inhibited lung metastases by 95% (P < 0.01) associated with significant down-regulation of NF-kappaB expression in tumor tissues and reduction of circulating insulin-like growth factor-I levels, suggesting that SPC may contain other bioactive ingredients that have antimetastatic activity. The results from our studies suggest that further clinical investigation should be warranted to apply soy phytochemicals, such as SPC, as a potent prevention regimen for bladder cancer progression. This orthotopic human bladder tumor model also provides a clinically relevant experimental tool for assessing potential preventive activity of other dietary components against bladder tumor growth and metastasis.
Asunto(s)
Apoptosis/efectos de los fármacos , Genisteína/farmacología , Glycine max , Isoflavonas/farmacología , Fitoterapia/métodos , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Animales , Ciclo Celular/efectos de los fármacos , Procesos de Crecimiento Celular/efectos de los fármacos , Línea Celular Tumoral , Femenino , Factor 2 de Crecimiento de Fibroblastos/sangre , Humanos , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Factor I del Crecimiento Similar a la Insulina/metabolismo , Isoflavonas/farmacocinética , Isoflavonas/orina , Ratones , Ratones SCID , FN-kappa B/biosíntesis , FN-kappa B/metabolismo , Neovascularización Patológica/tratamiento farmacológico , Neovascularización Patológica/patología , Neoplasias de la Vejiga Urinaria/irrigación sanguínea , Neoplasias de la Vejiga Urinaria/metabolismo , Neoplasias de la Vejiga Urinaria/patología , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
The radioprotective potential of alcoholic extract of root of R. cordifolia, was studied by survival, hemopoietic cell protection and micronucleus assay. The LD50 value for the alcoholic root extract was found to be 1200 mg/kg body weight at 72 hr post irradiation. A significant radiation protection (67%) as assessed by increased animal survival was observed when R. cordifolia (RC) extract was administered intraperitoneally, 90 min. before the radiation exposure. Besides, the extract also inhibited radiation induced lipid peroxidation measured by the inhibition of thiobarbituric acid reactive substance (TBARS). The RC extract at a selected dose of 460 mg/kg body weight was effective in protecting the radiation induced suppression of endogenous colony forming units in spleen. A significant inhibition of radiation (2 Gy) induced micronuclei formation was observed when RC extract was administered 90 min prior to irradiation. Thus, it appears that the alcoholic root extract of R. cordifolia provides significant protection against radiation induced lipid peroxidation, hemopoietic injury and genotoxicity. The mechanism of action of RC extract appears to be through its anti-oxidant, metal chelation and anti-inflammatory property.
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Extractos Vegetales/farmacología , Protección Radiológica , Protectores contra Radiación/farmacología , Rubia/metabolismo , Alcoholes/metabolismo , Animales , Antiinflamatorios/farmacología , Antioxidantes/metabolismo , Peso Corporal , Células Madre Hematopoyéticas/citología , Peroxidación de Lípido , Ratones , Pruebas de Micronúcleos/métodos , Raíces de Plantas/metabolismo , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismoRESUMEN
OBJECTIVES: The impact of simvastatin (SMV), a cholesterol lowering drug, on bone metabolism appears to involve complex interaction with cholesterol metabolites, hormones, inflammatory mediators and growth factors, thus having direct influence on extent and severity of periodontitis. The present study aims to evaluate the in vivo effect of subgingivally delivered SMV gel (1.2 mg) as a local drug-delivery agent on clinical parameters and on interleukin-6 (IL-6), interleukin-8 (IL-8) and interleukin-10 (IL-10) levels in gingival crevicular fluid (GCF) of chronic periodontitis patients. MATERIALS AND METHODS: 50 patients were selected and categorized into two treatment groups: control (scaling and root planing) and test group (scaling and root planing with SMV gel). At initial appointment, clinical parameters were measured. Biochemical analysis of GCF samples was done to evaluate the amount of IL-6, IL-8 and IL-10. GCF sampling and clinical parameters were repeated at one and three months for both the groups. RESULTS: SMV has an inhibitory effect on pro-inflammatory cytokines (IL-6, IL-8) and stimulatory effect on anti-inflammatory cytokines (IL-10) in GCF of periodontitis patients and has significantly positive effect on all clinical parameters except relative attachment level (RAL). The addition of SMV, thereby, further alters the levels of cytokine that reflect enhanced antibacterial host defence activity at that site. CONCLUSION: Topical SMV has a beneficial effect on periodontal health. Removal of the bacterial plaque and subgingival delivery of SMV significantly modulates the chemokines present in GCF. To summarize, SMV shows promising role in the management of periodontitis.
RESUMEN
Temporomandibular joint (TMJ) disc derangement is defined as a malpositioning of the articular disc relative to the condyle and eminence. Arthrocentesis of the TMJ is a minimally invasive chair side procedure for the patients with TMJ internal derangement. This case report presents convincing results to keep arthrocentesis as an imperative procedure to relieve such patients of their acute symptoms. TMJ dynamics has also been discussed for an in-depth understanding of the pathology in cases with internal derangement.
RESUMEN
Free radicals are implicated in various chronic diseases. There has always been a search for new antioxidants. In this paper we have investigated Tamra bhasma, a metallic ayurvedic preparation. It is a time-tested medicine in Ayurveda and is in clinical use for various ailments specifically the free radical mediated diseases. Our results show that Tamra bhasma inhibits lipid peroxidation (LPO), prevents the rate of aerial oxidation of reduced glutathione (GSH) content and induces the activity of superoxide dismutase (SOD) in rat liver homogenate in the bi-phasic manner. The drug was orally given for 7, 15 and 30 days in different doses. Best protective response was found at the dose of 0.5mg/100g body weight in albino rats, although it showed some histopathological changes at the dose of 20mg/100g body weight. The results suggest that this Ayurvedic preparation is not merely a source of copper metal, but it is a strong anti-oxidant with no detectable adverse effect in lower doses of therapeutic range.
RESUMEN
Multiple myeloma (MM) remains incurable despite novel therapies, suggesting the need for further identification of factors mediating tumorigenesis and drug resistance. Using both in vitro and in vivo MM xenograft models, we show that plasmacytoid dendritic cells (pDCs) in the bone marrow (BM) microenvironment both mediate immune deficiency characteristic of MM and promote MM cell growth, survival, and drug resistance. Microarray, cell signaling, cytokine profile, and immunohistochemical analysis delineate the mechanisms mediating these sequelae. Although pDCs are resistant to novel therapies, targeting toll-like receptors with CpG oligodeoxynucleotides both restores pDC immune function and abrogates pDC-induced MM cell growth. Our study therefore validates targeting pDC-MM interactions as a therapeutic strategy to overcome drug resistance in MM.
Asunto(s)
Células de la Médula Ósea/inmunología , Comunicación Celular , Células Dendríticas/inmunología , Resistencia a Antineoplásicos , Mieloma Múltiple/inmunología , Transducción de Señal , Animales , Antineoplásicos/farmacología , Apoptosis , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/patología , Ácidos Borónicos/farmacología , Bortezomib , Estudios de Casos y Controles , Comunicación Celular/efectos de los fármacos , Proliferación Celular , Supervivencia Celular , Quimiotaxis , Técnicas de Cocultivo , Citocinas/metabolismo , Células Dendríticas/efectos de los fármacos , Células Dendríticas/patología , Regulación Neoplásica de la Expresión Génica , Humanos , Inmunofenotipificación , Ratones , Ratones SCID , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/genética , Mieloma Múltiple/patología , Oligodesoxirribonucleótidos/farmacología , Inhibidores de Proteasas/farmacología , Complejo de la Endopetidasa Proteasomal/metabolismo , Pirazinas/farmacología , Receptores Inmunológicos/metabolismo , Transducción de Señal/efectos de los fármacos , Linfocitos T/inmunología , Factores de Tiempo , Receptores Toll-Like/efectos de los fármacos , Receptores Toll-Like/metabolismo , Trasplante Heterólogo , Células Tumorales CultivadasRESUMEN
Our recent study demonstrated that a novel proteasome inhibitor NPI-0052 triggers apoptosis in multiple myeloma (MM) cells, and importantly, that is distinct from bortezomib (Velcade) in its chemical structure, effects on proteasome activities, and mechanisms of action. Here, we demonstrate that combining NPI-0052 and bortezomb induces synergistic anti-MM activity both in vitro using MM cell lines or patient CD138(+) MM cells and in vivo in a human plasmacytoma xenograft mouse model. NPI-0052 plus bortezomib-induced synergistic apoptosis is associated with: (1) activation of caspase-8, caspase-9, caspase-3, and PARP; (2) induction of endoplasmic reticulum (ER) stress response and JNK; (3) inhibition of migration of MM cells and angiogenesis; (4) suppression of chymotrypsin-like (CT-L), caspase-like (C-L), and trypsin-like (T-L) proteolytic activities; and (5) blockade of NF-kappaB signaling. Studies in a xenograft model show that low dose combination of NPI-0052 and bortezomib is well tolerated and triggers synergistic inhibition of tumor growth and CT-L, C-L, and T-L proteasome activities in tumor cells. Immununostaining of MM tumors from NPI-0052 plus bortezomib-treated mice showed growth inhibition, apoptosis, and a decrease in associated angiogenesis. Taken together, our study provides the preclinical rationale for clinical protocols evaluating bortezomib together with NPI-0052 to improve patient outcome in MM.
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Ácidos Borónicos/toxicidad , Lactonas/toxicidad , Mieloma Múltiple/enzimología , Mieloma Múltiple/patología , Inhibidores de Proteasas/toxicidad , Complejo de la Endopetidasa Proteasomal/metabolismo , Pirazinas/toxicidad , Pirroles/toxicidad , Animales , Bortezomib , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Retículo Endoplásmico/metabolismo , Proteínas de Choque Térmico/metabolismo , Humanos , Ratones , Mieloma Múltiple/irrigación sanguínea , FN-kappa B/metabolismo , Neovascularización Patológica , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Sulforaphane (SFN), a constituent of cruciferous vegetables, is highly effective in affording protection against chemically induced cancers in animal models. Here, we report that SFN inhibited proliferation of cultured PC-3 human prostate cancer cells by inducing apoptosis that was characterized by appearance of cells with sub-G0/G1 DNA content, formation of cytoplasmic histone associated DNA fragments and cleavage of poly(ADP-ribose)polymerase (PARP). SFN-induced apoptosis was associated with up-regulation of Bax, down-regulation of Bcl-2 and activation of caspases-3, -9 and -8. SFN-induced apoptosis, and cleavage of procaspase-3 and PARP were blocked upon pre-treatment of cells with pan caspase inhibitor z-VADfmk, and specific inhibitors of caspase-9 (z-LEHDfmk) and caspase-8 (z-IETDfmk) suggesting involvement of both caspase-9 and caspase-8 pathways in SFN-induced cell death. Oral administration of SFN (5.6 micro mol, 3 times/week) significantly inhibited growth of PC-3 xenografts in nude mice. For instance, 10 days after starting therapy, the average tumor volumes in control and SFN-treated mice were 170 +/- 13 and 80 +/- 14 mm3, respectively, reflecting a >50% reduction in tumor volume due to SFN administration. To the best of our knowledge, the present study is the first published report to document in vivo anticancer activity of SFN in a tumor xenograft model.
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Anticarcinógenos/farmacología , Apoptosis/efectos de los fármacos , Caspasas/fisiología , Neoplasias de la Próstata/prevención & control , Tiocianatos/farmacología , Animales , División Celular/efectos de los fármacos , Línea Celular Tumoral , Femenino , Humanos , Isotiocianatos , Masculino , Ratones , Ratones Desnudos , Neoplasias de la Próstata/patología , Proteínas Proto-Oncogénicas/análisis , Proteínas Proto-Oncogénicas c-bcl-2/análisis , Sulfóxidos , Trasplante Heterólogo , Proteína X Asociada a bcl-2RESUMEN
Previously, we showed that sulforaphane (SFN), a naturally occurring cancer chemopreventive agent, effectively inhibits proliferation of PC-3 human prostate cancer cells by causing caspase-9- and caspase-8-mediated apoptosis. Here, we demonstrate that SFN treatment causes an irreversible arrest in the G(2)/M phase of the cell cycle. Cell cycle arrest induced by SFN was associated with a significant decrease in protein levels of cyclin B1, cell division cycle (Cdc) 25B, and Cdc25C, leading to accumulation of Tyr-15-phosphorylated (inactive) cyclin-dependent kinase 1. The SFN-induced decline in Cdc25C protein level was blocked in the presence of proteasome inhibitor lactacystin, but lactacystin did not confer protection against cell cycle arrest. Interestingly, SFN treatment also resulted in a rapid and sustained phosphorylation of Cdc25C at Ser-216, leading to its translocation from the nucleus to the cytoplasm because of increased binding with 14-3-3beta. Increased Ser-216 phosphorylation of Cdc25C upon treatment with SFN was the result of activation of checkpoint kinase 2 (Chk2), which was associated with Ser-1981 phosphorylation of ataxia telangiectasia-mutated, generation of reactive oxygen species, and Ser-139 phosphorylation of histone H2A.X, a sensitive marker for the presence of DNA double-strand breaks. Transient transfection of PC-3 cells with Chk2-specific small interfering RNA duplexes significantly attenuated SFN-induced G(2)/M arrest. HCT116 human colon cancer-derived Chk2(-/-) cells were significantly more resistant to G(2)/M arrest by SFN compared with the wild type HCT116 cells. These findings indicate that Chk2-mediated phosphorylation of Cdc25C plays a major role in irreversible G(2)/M arrest by SFN. Activation of Chk2 in response to DNA damage is well documented, but the present study is the first published report to link Chk2 activation to cell cycle arrest by an isothiocyanate.