RESUMEN
Overwhelming evidence identifies the microenvironment as a critical factor in the development and progression of chronic lymphocytic leukemia, underlining the importance of developing suitable translational models to study the pathogenesis of the disease. We previously established that stable expression of kinase dead protein kinase C alpha in hematopoietic progenitor cells resulted in the development of a chronic lymphocytic leukemia-like disease in mice. Here we demonstrate that this chronic lymphocytic leukemia model resembles the more aggressive subset of chronic lymphocytic leukemia, expressing predominantly unmutated immunoglobulin heavy chain genes, with upregulated tyrosine kinase ZAP-70 expression and elevated ERK-MAPK-mTor signaling, resulting in enhanced proliferation and increased tumor load in lymphoid organs. Reduced function of PKCα leads to an up-regulation of PKCßII expression, which is also associated with a poor prognostic subset of human chronic lymphocytic leukemia samples. Treatment of chronic lymphocytic leukemia-like cells with the selective PKCß inhibitor enzastaurin caused cell cycle arrest and apoptosis both in vitro and in vivo, and a reduction in the leukemic burden in vivo. These results demonstrate the importance of PKCßII in chronic lymphocytic leukemia-like disease progression and suggest a role for PKCα subversion in creating permissive conditions for leukemogenesis.
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Linfocitos B/metabolismo , Regulación Leucémica de la Expresión Génica , Leucemia Linfocítica Crónica de Células B/genética , Leucemia Linfocítica Crónica de Células B/metabolismo , Proteína Quinasa C beta/genética , Proteína Quinasa C-alfa/genética , Animales , Linfocitos B/patología , Proliferación Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Trasplante de Células Madre Hematopoyéticas , Células Madre Hematopoyéticas/metabolismo , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Región Variable de Inmunoglobulina/genética , Leucemia Linfocítica Crónica de Células B/mortalidad , Leucemia Linfocítica Crónica de Células B/patología , Leucemia Linfocítica Crónica de Células B/terapia , Infiltración Leucémica/patología , Tejido Linfoide/patología , Ratones , Ratones Noqueados , Pronóstico , Proteína Quinasa C beta/antagonistas & inhibidores , Proteína Quinasa C beta/metabolismo , Proteína Quinasa C-alfa/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Transducción Genética , Carga Tumoral/efectos de los fármacos , Proteína Tirosina Quinasa ZAP-70/genética , Proteína Tirosina Quinasa ZAP-70/metabolismoRESUMEN
During hematopoietic lineage development, hematopoietic stem cells sequentially commit toward myeloid or lymphoid lineages in a tightly regulated manner, which under normal circumstances is irreversible. However, studies have established that targeted deletion of the B-lineage specific transcription factor, paired box gene 5 (Pax5), enables B cells to differentiate toward other hematopoietic lineages, in addition to generating progenitor B-cell lymphomas. Our previous studies showed that subversion of protein kinase C (PKC)-α in developing B cells transformed B-lineage cells. Here, we demonstrate that PKC-α modulation in committed CD19(+) B lymphocytes also promoted lineage conversion toward myeloid, NK-, and T-cell lineages upon Notch ligation. This occurred via a reduction in Pax5 expression resulting from a downregulation of E47, a product of the E2A gene. T-cell lineage commitment was indicated by the expression of T-cell associated genes Ptcra, Cd3e, and gene rearrangement at the Tcrb gene locus. Importantly, the lineage-converted T cells carried Igh gene rearrangements reminiscent of their B-cell origin. Our findings suggest that modulation of PKC-α induces hematopoietic-lineage plasticity in committed B-lineage cells by perturbing expression of critical B-lineage transcription factors, and deregulation of PKC-α activity/expression represents a potential mechanism for lineage trans-differentiation during malignancies.
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Linfocitos B/inmunología , Desdiferenciación Celular/inmunología , Células Progenitoras Linfoides/inmunología , Células Progenitoras Mieloides/inmunología , Factor de Transcripción PAX5/inmunología , Proteína Quinasa C-alfa/inmunología , Animales , Linfocitos B/enzimología , Desdiferenciación Celular/genética , Línea Celular , Transformación Celular Neoplásica/inmunología , Transformación Celular Neoplásica/metabolismo , Femenino , Reordenamiento Génico de Linfocito B/genética , Reordenamiento Génico de Linfocito B/inmunología , Cadenas Pesadas de Inmunoglobulina/genética , Cadenas Pesadas de Inmunoglobulina/inmunología , Cadenas Pesadas de Inmunoglobulina/metabolismo , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/metabolismo , Células Progenitoras Linfoides/enzimología , Linfoma de Células B/enzimología , Linfoma de Células B/inmunología , Masculino , Ratones , Ratones Endogámicos ICR , Células Progenitoras Mieloides/enzimología , Factor de Transcripción PAX5/genética , Factor de Transcripción PAX5/metabolismo , Proteína Quinasa C-alfa/genética , Proteína Quinasa C-alfa/metabolismo , Receptores Notch/genética , Receptores Notch/inmunología , Receptores Notch/metabolismo , Linfocitos T/inmunología , Linfocitos T/metabolismoRESUMEN
Introduction We report the results of a phase I clinical trial NCT03790072 of an adoptive transfer of γδ T lymphocytes from haploidentical donors in patients with refractory/relapsed acute myeloid leukemia after lymphodepletion regimen. Patients and methods Healthy donor mononuclear cells collected by leukapheresis were consistently expanded to generate products of 109 to 1010 γδ T cells. Seven patients received donor-derived T cell product at doses of 106/kg (n = 3), 107/kg (n = 3), and 108/kg (n = 1). Results Four patients had bone marrow evaluation at day 28. One patient had a complete remission, one was classified as morphologic leukemia-free state, one had stable disease and one had no evidence of response. In one patient, there was evidence of disease control with repeat infusions up to 100 days after first dosing. There were no treatment-related serious adverse events or treatment-related Common Terminology Criteria for Adverse Events grade 3 or greater toxicities at any dose level. Allogeneic Vγ9Vδ2 T cell infusion was shown to be safe and feasible up to a cell dose of 108/kg. Discussion In agreement with previously published studies, the infusion of allogeneic Vγ9Vδ2 cells was safe. The contribution of lymphodepleting chemotherapy to responses seen cannot be ruled out. Main limitation of the study is the low number of patients and interruption due to COVID-19 pandemic. Conclusion These positive Phase 1 results support progression to phase II clinical trials.
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COVID-19 , Trasplante de Células Madre Hematopoyéticas , Leucemia Mieloide Aguda , Humanos , Pandemias , Resultado del Tratamiento , Leucemia Mieloide Aguda/terapia , Linfocitos T , Trasplante de Células Madre Hematopoyéticas/métodosRESUMEN
As antigenic stimulation of the B cell antigen receptor (BCR) is key to chronic lymphocytic leukaemia (CLL) pathogenesis, targeting dysregulated kinases involved in BCR signalling is an attractive therapeutic approach. We studied the effects of the Src/c-Abl tyrosine kinase inhibitor dasatinib on BCR signal transduction in CLL cells. Treatment of CLL cells with 100 nmol/l dasatinib induced apoptosis by an average reduction in viability of 33·7% at 48 h, with dasatinib sensitivity correlating with inhibition of Syk(Y348) phosphorylation. Dasatinib inhibited calcium flux, phosphatidylinositol-3-kinase and mitogen-activated protein kinase activation following BCR crosslinking, and blocked the Mcl-1-dependent increase in CLL cell survival on prolonged BCR stimulation. However, the pro-apoptotic effect of dasatinib was abrogated by stromal cell contact alone or in the presence of CD154 and interleukin (IL)-4 (CD154L/IL-4 system). Whilst dasatinib retained the ability to sensitize CLL cells in stromal co-culture to both fludarabine and chlorambucil, the addition of CD154 and IL-4 rendered cells resistant to these drug combinations. We demonstrate that the HSP90 inhibitor 17-DMAG exhibited synergy with dasatinib in vitro, and moreover, induced apoptosis of CLL cells in the CD154L/IL-4 system. Our data provide evidence that dasatinib would be most clinically effective in combination with agents able to target antigen-independent microenvironmental signals.
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Linfocitos B/metabolismo , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/farmacología , Pirimidinas/farmacología , Receptores de Antígenos de Linfocitos B/metabolismo , Transducción de Señal/efectos de los fármacos , Tiazoles/farmacología , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Apoptosis/efectos de los fármacos , Linfocitos B/patología , Benzoquinonas/agonistas , Benzoquinonas/farmacología , Benzoquinonas/uso terapéutico , Ligando de CD40/metabolismo , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Dasatinib , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Femenino , Proteínas HSP90 de Choque Térmico/antagonistas & inhibidores , Proteínas HSP90 de Choque Térmico/metabolismo , Humanos , Interleucina-4/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Lactamas Macrocíclicas/agonistas , Lactamas Macrocíclicas/farmacología , Lactamas Macrocíclicas/uso terapéutico , Leucemia Linfocítica Crónica de Células B/metabolismo , Leucemia Linfocítica Crónica de Células B/patología , Masculino , Persona de Mediana Edad , Proteína 1 de la Secuencia de Leucemia de Células Mieloides , Fosfatidilinositol 3-Quinasas/metabolismo , Fosforilación/efectos de los fármacos , Inhibidores de Proteínas Quinasas/agonistas , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Tirosina Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Pirimidinas/agonistas , Pirimidinas/uso terapéutico , Células del Estroma/metabolismo , Células del Estroma/patología , Quinasa Syk , Tiazoles/agonistas , Tiazoles/uso terapéutico , Factores de TiempoRESUMEN
Reelin is a secreted, signaling protein associated with neuronal cell positioning and migration. Recently, reelin was found to be epigenetically silenced in gastric and pancreatic cancers in which down-regulation was associated with increased migratory ability and reduced survival. Here we analyzed reelin expression by immunohistochemistry in 17 normal breast tissue samples from reduction mammoplasties and in two independent tissue microarrays of 136 and more than 2000 breast cancer biopsy samples, respectively. Results were analyzed with regard to clinical parameters, including BRE (Bloom, Richardson, Elston) grade, nodal status, estrogen receptor and HER2 status, and overall survival. Reelin was expressed in the luminal epithelium and myoepithelium of the normal human breast but not in cancerous breasts. Loss of reelin protein expression correlated significantly with decreased survival (P=0.01) and positive lymph node status (P<0.001). By measuring reelin expression and promoter methylation status in 39 primary breast tumors, as well as in breast cancer-derived cell lines before and after decitabine treatment, we established that reelin expression levels correlated inversely with promoter methylation status, whereas demethylation increased reelin mRNA expression in vitro. Reelin overexpression in MDA-MB231 cells, as well as incubation with recombinant reelin, suppressed cell migration, invadopodia formation, and invasiveness in vitro. We conclude that reelin may play an important role in controlling invasiveness and metastatic potential of breast cancer cells and that its expression is controlled by promoter methylation.
Asunto(s)
Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Moléculas de Adhesión Celular Neuronal/metabolismo , Epigénesis Genética , Proteínas de la Matriz Extracelular/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Serina Endopeptidasas/metabolismo , Moléculas de Adhesión Celular Neuronal/genética , Línea Celular Tumoral , Movimiento Celular , Colágeno Tipo I/metabolismo , Proteínas de la Matriz Extracelular/genética , Femenino , Células HEK293 , Humanos , Invasividad Neoplásica , Proteínas del Tejido Nervioso/genética , Pronóstico , Regiones Promotoras Genéticas , Proteína Reelina , Serina Endopeptidasas/genéticaRESUMEN
PURPOSE: To determine whether inhibition of mTOR kinase-mediated signaling represents a valid therapeutic approach for chronic lymphocytic leukemia (CLL). EXPERIMENTAL DESIGN: Stratification of mTOR activity was carried out in patients with primary CLL samples and an aggressive CLL-like mouse model. The potency of dual mTOR inhibitor AZD8055 to induce apoptosis in primary CLL cells was assessed in the presence/absence of B-cell receptor (BCR) ligation. Furthermore, we addressed the molecular and functional impact of dual mTOR inhibition in combination with BTK inhibitor ibrutinib. RESULTS: Differential regulation of basal mTORC1 activity was observed in poor prognostic CLL samples, with elevated p4EBP1T37/46 and decreased p70S6 kinase activity, suggesting that dual mTORC1/2 inhibitors may exhibit improved response in poor prognostic CLL compared with rapalogs. AZD8055 treatment of primary CLL cells significantly reduced CLL survival in vitro compared with rapamycin, preferentially targeting poor prognostic subsets and overcoming BCR-mediated survival advantages. Furthermore, AZD8055, and clinical analog AZD2014, significantly reduced CLL tumor load in mice. AKT substrate FOXO1, while overexpressed in CLL cells of poor prognostic patients in LN biopsies, peripheral CLL cells, and mouse-derived CLL-like cells, appeared to be inactive. AZD8055 treatment partially reversed FOXO1 inactivation downstream of BCR crosslinking, significantly inhibiting FOXO1T24 phosphorylation in an mTORC2-AKT-dependent manner, to promote FOXO1 nuclear localization, activity, and FOXO1-mediated gene regulation. FOXO1 activity was further significantly enhanced on combining AZD8055 with ibrutinib. CONCLUSIONS: Our studies demonstrate that dual mTOR inhibitors show promise as future CLL therapies, particularly in combination with ibrutinib.
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Proteína Forkhead Box O1/metabolismo , Leucemia Linfocítica Crónica de Células B/metabolismo , Leucemia Linfocítica Crónica de Células B/mortalidad , Diana Mecanicista del Complejo 2 de la Rapamicina/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Receptores de Antígenos de Linfocitos B/metabolismo , Animales , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Sinergismo Farmacológico , Femenino , Proteína Forkhead Box O1/genética , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Leucemia Linfocítica Crónica de Células B/genética , Masculino , Diana Mecanicista del Complejo 2 de la Rapamicina/metabolismo , Ratones , Ratones Transgénicos , Pronóstico , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/efectos de los fármacos , Resultado del Tratamiento , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
PURPOSE: Both [(131)I]meta-iodobenzylguanidine ([(131)I]MIBG) and the topoisomerase I inhibitor topotecan are effective as single-agent treatments of neuroblastoma. The aim of this study was to investigate the efficacy of [(131)I]MIBG in combination with topotecan in vitro and in vivo. EXPERIMENTAL DESIGN: The cell lines used were SK-N-BE(2c) (human neuroblastoma) and UVW/NAT (glioma cell line transfected with the noradrenaline transporter gene). Three different treatment schedules were assessed: topotecan given before (schedule 1), after (schedule 2), or simultaneously (schedule 3) with [(131)I]MIBG. DNA strand breakage was evaluated by comet assay, and cytotoxicity was determined by clonogenic survival. Efficacy was also measured by growth delay of tumor xenografts in nude mice. RESULTS: Combination schedules 2 and 3 caused more cytotoxicity than schedule 1. Similarly, significant DNA damage was observed following treatment schedules 2 and 3 (P < 0.005) but not schedule 1. The mean number of days for a doubling in volume of SK-N-BE(2c) tumors and a 10-fold increase in volume of UVW/NAT tumors were 10.4 and 18.6 (untreated), 19.7 and 25.3 (topotecan alone), 22.8 and 31.9 ([(131)I]MIBG alone), 26.3 and 37.1 (combination schedule 1), 34.3 and 49.7 (combination schedule 2), and 53.2 and >71 (combination schedule 3), respectively. The highest rate of cure of both xenografts was observed following treatment with combination schedule 3. CONCLUSIONS: The combination of topotecan and [(131)I]MIBG compared with either treatment alone gave rise to greater than additive DNA damage, clonogenic cell kill, and tumor growth delay. These effects were dependent on the scheduling of the two agents.
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3-Yodobencilguanidina/uso terapéutico , Antineoplásicos/uso terapéutico , Radioisótopos de Yodo/metabolismo , Neoplasias/tratamiento farmacológico , Proteínas de Transporte de Noradrenalina a través de la Membrana Plasmática/metabolismo , Topotecan/uso terapéutico , Animales , Bovinos , Línea Celular Tumoral , Ensayo Cometa , Daño del ADN , Fragmentación del ADN , ADN Complementario/metabolismo , Glioma/patología , Humanos , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Neuroblastoma/tratamiento farmacológico , Factores de Tiempo , TransfecciónRESUMEN
The goal of targeted radionuclide therapy is the deposition in malignant cells of sterilizing doses of radiation without damaging normal tissue. The radiopharmaceutical [(131)I]meta-iodobenzylguanidine ([(131)I]MIBG) is an effective single agent for the treatment of neuroblastoma. However, uptake of the drug in malignant sites is insufficient to cure disease. A growing body of experimental evidence indicates exciting possibilities for the integration of gene transfer with [(131)I]MIBG-targeted radiotherapy.
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3-Yodobencilguanidina/uso terapéutico , Marcación de Gen/métodos , Terapia Genética/métodos , Neuroblastoma/genética , Neuroblastoma/radioterapia , Proteínas de Transporte de Noradrenalina a través de la Membrana Plasmática/genética , Radioterapia/métodos , Animales , Sistemas de Liberación de Medicamentos/métodos , Humanos , Radiofármacos/uso terapéuticoRESUMEN
Neuroblastoma (NB) is the most common neuroectoderma derived solid tumour of paediatric age. Since conventional treatments are often inefficient, novel therapeutic interventions are required. Among these, the use of antisense oligonucleotides (asODNs) as therapeutic antineoplastic agents has been recently investigated. Oligonucleotide in vivo applicability is impaired from their high sensitivity to cellular nuclease degradation. Encapsulating them within liposomes could nevertheless increase their stability. C-myb gene expression has been reported in several solid tumours of different embryonic origin, including NB, where it is linked to cell proliferation and/or differentiation. We performed a new technique to encapsulate c-myb antisense oligonucleotides within lipid particles. Liposomes resulting from this technique were called coated cationic liposomes (CCLs), since they were made up of a central core of a cationic phospholipid bound to myb-asODNs, and an outer shell of neutral lipids. A monoclonal antibody (mAb) specific for the neuroectoderma antigen disialoganglioside GD(2), has been covalently coupled to their external surface. The resulting anti-GD(2)-targeted CCLs showed high loading efficiency for the asODNs, small particle size and good stability. In vitro, they were able to deliver myb-asODNs selectively to GD(2)-positive NB cell lines more efficiently than non-targeted liposomes or free asODNs. Consequently, targeted formulations showed greater inhibition of cell proliferation than non-targeted formulations or free asODNs. Furthermore, we demonstrated that the inhibition of cell proliferation was dependent on the down-modulation of c-myb protein expression. Pharmacokinetic studies showed that these targeted liposomal formulations were long circulating in blood. Biodistribution studies presented differences between the free and the encapsulated myb-as ODN profiles, as well. While free myb-as ODNs are widely distributed (mainly liver, kidney and spleen) even after 30 min post-injection, myb-as ODN entrapped into CCL or anti-GD(2)-CCL presents only an accumulation in the spleen after 24 h. Future studies will be performed to evaluate the antitumour efficacy of the above formulations in animal models.
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Neuroblastoma/tratamiento farmacológico , Oligodesoxirribonucleótidos Antisentido/uso terapéutico , Proteínas Proto-Oncogénicas c-myb/antagonistas & inhibidores , Anticuerpos Monoclonales/inmunología , Sistemas de Liberación de Medicamentos , Gangliósidos/inmunología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Liposomas , Proteínas Proto-Oncogénicas c-myb/genética , Células Tumorales CultivadasRESUMEN
Angiogenesis is a critical event in the progression of human neuroblastoma. This mini-review summarizes our literature and experimental data concerning the use of anti-angiogenic molecules, such as TNP-470 and fenretinide, in neuroblastoma treatment.
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Inhibidores de la Angiogénesis/uso terapéutico , Antineoplásicos/uso terapéutico , Fenretinida/uso terapéutico , Neovascularización Patológica/prevención & control , Neuroblastoma/irrigación sanguínea , Humanos , Neuroblastoma/tratamiento farmacológicoRESUMEN
PURPOSE: Chronic lymphocytic leukemia (CLL) is currently incurable with standard chemotherapeutic agents, highlighting the need for novel therapies. Overcoming proliferative and cytoprotective signals generated within the microenvironment of lymphoid organs is essential for limiting CLL progression and ultimately developing a cure. EXPERIMENTAL DESIGN: We assessed the potency of cyclin-dependent kinase (CDK) inhibitor CR8, a roscovitine analog, to induce apoptosis in primary CLL from distinct prognostic subsets using flow cytometry-based assays. CLL cells were cultured in in vitro prosurvival and proproliferative conditions to mimic microenvironmental signals in the lymphoid organs, to elucidate the mechanism of action of CR8 in quiescent and proliferating CLL cells using flow cytometry, Western blotting, and quantitative real-time PCR. RESULTS: CR8 was 100-fold more potent at inducing apoptosis in primary CLL cells than roscovitine, both in isolated culture and stromal-coculture conditions. Importantly, CR8 induced apoptosis in CD40-ligated CLL cells and preferentially targeted actively proliferating cells within these cultures. CR8 treatment induced downregulation of the antiapoptotic proteins Mcl-1 and XIAP, through inhibition of RNA polymerase II, and inhibition of NF-κB signaling at the transcriptional level and through inhibition of the inhibitor of IκB kinase (IKK) complex, resulting in stabilization of IκBα expression. CONCLUSIONS: CR8 is a potent CDK inhibitor that subverts pivotal prosurvival and proproliferative signals present in the tumor microenvironment of CLL patient lymphoid organs. Our data support the clinical development of selective CDK inhibitors as novel therapies for CLL.
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Antineoplásicos/farmacología , Apoptosis , Supervivencia Celular/efectos de los fármacos , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , FN-kappa B/metabolismo , Purinas/farmacología , Piridinas/farmacología , Adulto , Anciano , Ligando de CD40/fisiología , Puntos de Control del Ciclo Celular/efectos de los fármacos , Proliferación Celular , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Quinasas Ciclina-Dependientes/metabolismo , Evaluación Preclínica de Medicamentos , Femenino , Regulación Leucémica de la Expresión Génica/efectos de los fármacos , Humanos , Concentración 50 Inhibidora , Interleucina-4/fisiología , Masculino , Persona de Mediana Edad , Proteína 1 de la Secuencia de Leucemia de Células Mieloides , FN-kappa B/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , ARN Polimerasa II/antagonistas & inhibidores , Roscovitina , Transducción de Señal/efectos de los fármacos , Células Tumorales Cultivadas/efectos de los fármacos , Proteína Inhibidora de la Apoptosis Ligada a X/genética , Proteína Inhibidora de la Apoptosis Ligada a X/metabolismoRESUMEN
Chemokines and their ligands play a critical role in enabling chronic lymphocytic leukaemia (CLL) cells access to protective microenvironmental niches within tissues, ultimately resulting in chemoresistance and relapse: disruption of these signaling pathways has become a novel therapeutic approach in CLL. The tyrosine kinase inhibitor dasatinib inhibits migration of several cell lines from solid-organ tumours, but effects on CLL cells have not been reported. We studied the effect of clinically achievable concentrations of dasatinib on signaling induced by the chemokine CXCL12 through its' receptor CXCR4, which is highly expressed on CLL cells. Dasatinib pre-treatment inhibited Akt and ERK phosphorylation in CLL cells upon stimulation with CXCL12. Dasatinib also significantly diminished the rapid increase in actin polymerisation observed in CLL cells following CXCL12 stimulation. Moreover, the drug significantly inhibited chemotaxis in a transwell assay, and reduced the percentage of cells able to migrate beneath a CXCL12-expressing murine stromal cell line. Dasatinib also abrogated the anti-apoptotic effect of prolonged CXCL12 stimulation on cultured CLL cells. These data suggest that dasatinib, akin to other small molecule kinase inhibitors targeting the B-cell receptor signaling pathway, may redistribute CLL cells from protective tissue niches to the peripheral blood, and support the investigation of dasatinib in combination strategies.
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Quimiocina CXCL12/metabolismo , Regulación Leucémica de la Expresión Génica , Pirimidinas/farmacología , Receptores CXCR4/metabolismo , Tiazoles/farmacología , Actinas/química , Adulto , Anciano , Animales , Apoptosis , Movimiento Celular , Dasatinib , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Femenino , Humanos , Ligandos , Masculino , Ratones , Persona de Mediana Edad , Fosforilación , Inhibidores de Proteínas Quinasas/farmacología , Transducción de SeñalRESUMEN
Neuroblastoma (NB) is the most common extracranial solid tumor of childhood. In advanced disease stages, prognosis is poor and treatments have limited efficacy, thus novel strategies are warranted. The synthetic retinoid Fenretinide (HPR) induces apoptosis in NB and melanoma cell lines. We reported an in vitro potentiation of HPR effects on melanoma cells when the drug is incorporated into GD2-targeted immunoliposomes (anti-GD2-SIL-HPR). We investigated the antitumor activity of anti-GD2-SIL-HPR against NB cells, both in vitro and in vivo. Anti-GD2-SIL showed specific, competitive binding to and uptake by, various NB cell lines. In in vitro cytotoxicity studies, NB cells, incubated with 30 microM HPR entrapped in anti-GD2-immunoliposomes, showed a significant reduction in cellular growth compared to free HPR, HPR entrapped in Ab-free liposomes or anti-GD2 empty liposomes. In an in vivo NB metastatic model, we demonstrated that anti-GD2-SIL-HPR completely inhibited the development of macroscopic and microscopic metastases in comparison to controls. Similar, but significantly less potent, antitumor effect was observed also in mice treated with anti-GD2 immunoliposomes without HPR (anti-GD2-SIL-blank) or anti-GD2 MAb alone (p = 0.0297 and p = 0.0294, respectively, vs. anti-GD2-SIL-HPR). Moreover, our results clearly demonstrated that although anti-GD2 MAb had a strong antitumor effect in this in vivo NB model, 100% curability was obtained only after treatment with anti-GD2-SIL-HPR (p < 0.0001). Anti-GD2 liposomal HPR should receive clinical evaluation as adjuvant therapy of neuroblastoma.