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1.
Hum Vaccin Immunother ; : 1-5, 2021 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-34844524

RESUMO

There is experimental and clinical data to indicate the contribution of immune-escape mechanisms in relapsed/refractory pediatric leukemia. Studies have shown the accumulation of mutations that translate to peptides containing tumor-specific epitopes (neoantigens). The effectiveness of neoantigen-based vaccines has been shown in several clinical trials in adults. Though the initial results are encouraging, this knowledge must be developed to account for the uniqueness of pediatric cancer biology. We have completed the initial proof-of-concept analysis on a high-risk pediatric leukemia specimen and identified usable neoantigen sequences. We describe this approach, including the bioinformatics method and experimental model to verify their function that can be further broadened for personalized neoantigen prediction and testing for the generation of anticancer vaccines against high-risk pediatric leukemias.

2.
Eur J Cancer ; 159: 259-274, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34798454

RESUMO

BACKGROUND: Efficacy and safety data of COVID-19 vaccines among cancer populations have been limited; however, preliminary data from recent studies have emerged regarding their immunogenicity and safety in this population. In this review, we examined current peer-reviewed publications containing serological and safety data after COVID-19 vaccination of patients with cancer. METHODS: This analysis examined 21 studies with a total of 5012 patients with cancer, of which 2676 (53%) had haematological malignancies, 2309 (46%) had solid cancers and 739 were healthy controls. Serological responses by anti-SARS-CoV-2 spike protein S1/S2 immunoglobulin G antibody levels and post-vaccination patient questionnaires regarding vaccine-related side-effects after the first and second dose were collected and analysed. RESULTS: In general, a single dose of the COVID-19 vaccine yields weaker and heterogeneous serological responses in both patients with haematological and solid malignancies. On receiving a second dose, serological response rates indicate a substantial increase in seropositivity to the SARS-CoV-2 spike protein in all cancer cohorts, but antibody titres remain reduced in comparison with healthy controls. Furthermore, seroconversion in patients with haematological malignancies was significantly lower than that in patients with solid tumours. COVID-19 vaccines are safe and well-tolerated in patients with cancer based on current data of local and systemic effects. CONCLUSION: Together, these data support the prioritisation of patients with cancer to receive their first and second doses to minimise the risk of COVID-19 infection and severe complications in this vulnerable population. Additional prophylactic measures must be considered for high-risk patients where current vaccination programs may not mount sufficient protection against SARS-CoV-2 infection.

3.
Curr Eye Res ; : 1-10, 2021 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-34674590

RESUMO

PURPOSE: Retinoblastoma is the most frequent intraocular cancer in children. It is also one of the most common causes for enucleation and carries a significant morbidity rate in affected individuals. Hence, studies on its pathophysiological and growth regulatory mechanisms are urgently needed to identify more effective novel therapeutics. METHODS: Using the Y79 retinoblastoma cell line, we investigated the electrophysiological and functional activities of the T-type voltage-gated calcium channel Cav3.1, that is constitutively expressed in these cells. We also analyzed the Akt and MAPK signaling pathways downstream of the epidermal growth factor receptor (EGFR) to understand the mechanism responsible for the inhibition of Cav3.1. RESULTS: We demonstrate that the EGFR inhibitor Afatinib significantly reduced cell viability and Cav3.1 mRNA expression and electrophysiological activity. At low concentrations (1 µM), Afatinib reduced the amplitude of Cav3.1 current density, whereas at a high concentration (10 µM), it completely abolished the voltage-gated calcium current. Our results show that inhibition of the MAPK pathway by a specific inhibitor VX-11e affected the Cav3.1 current in a dose-dependent manner. VX-11e (50 nM-1 µM) treatment reduced Cav3.1 current densities in Y79 cells, with complete abolishment of Cav3.1 current at higher concentrations (5 µM). We also demonstrate that the specific inhibition of the Akt kinase (using MK-2206) had no effect on the Cav3.1 currents. CONCLUSION: Our study provides a functional relationship between the MAPK pathway and EGFR signaling and indicates that the MAPK signaling pathway mediates the control of Cav3.1 by EGFR in retinoblastoma.

4.
Artigo em Inglês | MEDLINE | ID: mdl-33949932

RESUMO

BACKGROUND: Most children with recurrent metastatic solid tumors have high mortality rates. Recent studies have shown that proteasome inhibition leads to effective tumor killing in cells that have acquired treatment resistance and metastatic properties. OBJECTIVE: The purpose of this study was to test the potential of Carfilzomib (CFZ), a proteasome inhibitor, in refractory pediatric solid tumors, which is currently unknown. METHODS: A panel of pediatric solid tumor cell lines, including neuroblastoma, Ewing's sarcoma, osteosarcoma, rhabdomyosarcoma, and atypical teratoid rhabdoid tumor (ATRT), was used to evaluate the cytotoxic and proteasomal inhibitory effects of CFZ. A drug scheduling experiment was performed to determine the optimal dose and time to obtain effective cell killing. Combination studies of CFZ with chemotherapeutic drugs of different classes were performed to determine the extent of synergy. RESULTS: CFZ showed effective cytotoxicity against all cell lines tested (mean IC50 = 7nM, range = 1-20nM) and activity in a fluorophore-tagged cell-based proteasome assay. Drug scheduling experiments showed that the minimum exposure of 4-8 hours/day is needed for effective cumulative killing. CFZ, when combined with chemotherapeutic drugs of different classes, synergistically enhanced the extent of cell death. CONCLUSIONS: CFZ showed cytotoxic activity against all the solid pediatric cancer cell lines tested. This study provides initial in vitro data on the potential of CFZ to treat pediatric solid tumors and supports further investigations into the components of drug scheduling, biological correlates, and drug combinations for future early phase clinical trials in children.

5.
Cancer Biol Ther ; 22(4): 333-344, 2021 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-33978549

RESUMO

Enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase and a catalytic subunit of the polycomb repressive complex 2 (PRC2) that catalyzes the mono-, di-, and tri-methylation of histone H3 at Lys 27 (H3K27me3) to facilitate chromatin-remodeling and gene-silencing functions. Previous reports showed a significant association of EZH2 aberrations in pediatric cancers, such as soft tissue sarcomas and glioblastoma. Recent reports in human subjects and animal models have also suggested a central role of EZH2 in the induction and progression of acute myeloid leukemia. In this study, we aimed to investigate the molecular status of EZH in cell lines derived from distinct pediatric leukemia to assess the efficacy of targeting EZH2 to suppress cancer cell survival and proliferation. Our results showed that EZH2 protein is overexpressed in the pediatric monocytic cell-line THP-1, but not in other leukemia-derived cell lines MV4;11 and SEM. Screening a panel of methyltransferase inhibitors revealed that three inhibitors; GSK126, UNC1999 and EPZ-5687 are the most potent inhibitors that suppressed EZH2 activity selectively on lysine 27 which resulted in increased apoptosis and inhibition of AKT and ERK protein phosphorylation in THP-1 cells. Our data demonstrated a significant increase in apoptosis in cells treated with drug combination (EZH2i and selinexor) compared to EZH2i inhibitors alone. Taken together, our data provide initial evidence that targeting EZH2 is a promising therapeutic strategy for the treatment of subtypes of pediatric AML. Also, combining EZH2 inhibitors with selinexor may increase the treatment efficacy in these patients.

6.
Curr Oncol ; 28(1): 346-366, 2021 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-33435412

RESUMO

Neurotrophic tyrosine receptor kinase gene fusions (NTRK) are oncogenic drivers present at a low frequency in most tumour types (<5%), and at a higher frequency (>80%) in a small number of rare tumours (e.g., infantile fibrosarcoma [IFS]) and considered mutually exclusive with other common oncogenic drivers. Health Canada recently approved two tyrosine receptor kinase (TRK) inhibitors, larotrectinib (for adults and children) and entrectinib (for adults), for the treatment of solid tumours harbouring NTRK gene fusions. In Phase I/II trials, these TRK inhibitors have demonstrated promising overall response rates and tolerability in patients with TRK fusion cancer who have exhausted other treatment options. In these studies, children appear to have similar responses and tolerability to adults. In this report, we provide a Canadian consensus on when and how to test for NTRK gene fusions and when to consider treatment with a TRK inhibitor for pediatric patients with solid tumours. We focus on three pediatric tumour types: non-rhabdomyosarcoma soft tissue sarcoma/unspecified spindle cell tumours including IFS, differentiated thyroid carcinoma, and glioma. We also propose a tumour-agnostic consensus based on the probability of the tumour harbouring an NTRK gene fusion. For children with locally advanced or metastatic TRK fusion cancer who have either failed upfront therapy or lack satisfactory treatment options, TRK inhibitor therapy should be considered.


Assuntos
Neoplasias , Receptor trkA , Biomarcadores , Canadá , Criança , Consenso , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/genética , Proteínas de Fusão Oncogênica/genética , Receptor trkA/genética
8.
Cancer Gene Ther ; 28(7-8): 739-744, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-32678303

RESUMO

Central nervous system (CNS) atypical teratoid/rhabdoid tumor (AT/RT) is a rare, aggressive tumor that most often affects very young children. The common decisive molecular defect in AT/RT has been shown to be a single genetic alteration, i.e., the loss of hSNF5 gene that encodes for a subunit of the SWI/SNF complex that modulates chromatin remodeling activities. As a result, AT/RT cells display unregulated cell proliferation due to the dysfunction of an important epigenetic control. We have previously demonstrated the preclinical efficacy of the oncolytic double-deleted vaccinia virus (VVDD) against AT/RT. Here we report the establishment of a modified VVDD engineered to express wild type hSNF5 gene. We show that this reconstructed vaccinia virus retains comparable infectivity and in vitro cytotoxicity of the parent strain. However, in addition, hSNF5-arming of VVDD results in a decreased cell cycle S phase population and down-regulation of cyclin D1. These findings suggest that hSNF5-arming of VVDD may increase the efficacy in the treatment of AT/RT and validates, as a proof-of-concept, an experimental approach to enhance the effective use of novel modified oncolytic viruses in the treatment of tumors with loss of a tumor suppressor gene function.

9.
Haematologica ; Online ahead of print2020 12 30.
Artigo em Inglês | MEDLINE | ID: mdl-33375775

RESUMO

Mutations in the gene CBL were first identified in adults with various myeloid malignancies. Some patients with juvenile myelomonocytic leukemia (JMML) were also noted to harbor mutations in CBL, but were found to have generally less aggressive disease courses compared to other forms of Ras pathway-mutant JMML. Importantly, and in contrast to most reports in adults, the majority of CBL mutations in JMML patients are germline with acquired uniparental disomy occurring in affected marrow cells. Here, we systematically studied a large cohort of 33 JMML patients with CBL mutations and found this disease to be highly diverse in presentation and overall outcome. Moreover, we discovered somatically-acquired CBL mutations in 15% of pediatric patients who presented with more aggressive disease. Neither clinical features nor methylation profiling were able to distinguish somatic CBL patients from germline CBL patients, highlighting the need for germline testing. Overall, we demonstrate that disease courses are quite heterogeneous even among germline CBL patients. Prospective clinical trials are warranted to find ideal treatment strategies for this diverse cohort of patients.


Assuntos
Leucemia Mielomonocítica Juvenil , Adulto , Criança , Humanos , Leucemia Mielomonocítica Juvenil/genética , Mutação , Estudos Prospectivos , Proteínas Proto-Oncogênicas c-cbl/genética
10.
Neurology ; 95(9): e1163-e1173, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32727836

RESUMO

OBJECTIVE: To examine the relationship between neonatal inflammatory cytokines and perinatal stroke using a systems biology approach analyzing serum and blood-spot cytokines from 47 patients. METHODS: This was a population-based, controlled cohort study with prospective and retrospective case ascertainment. Participants were recruited through the Alberta Perinatal Stroke Project. Stroke was classified as neonatal arterial ischemic stroke (NAIS), arterial presumed perinatal ischemic stroke (APPIS), or periventricular venous infarction (PVI). Biosamples were stored blood spots (retrospective) and acute serum (prospective). Controls had comparable gestational and maternal ages. Sixty-five cytokines were measured (Luminex). Hierarchical clustering analysis was performed to create heat maps. The Fisher linear discriminant analysis was used to create projection models to determine discriminatory boundaries between stroke types and controls. RESULTS: A total of 197 participants were analyzed (27 with NAIS, 8 with APPIS, 12 with PVI, 150 controls). Cytokines were quantifiable with quality control measures satisfied (standards testing, decay analysis). Linear discriminant analysis had high accuracy in using cytokine profiles to separate groups. Profiles in participants with PVI and controls were similar. NAIS separation was accurate (sensitivity 77%, specificity 97%). APPIS mapping was also distinguishable from NAIS (sensitivity 86%, specificity 99%). Classification tree analysis generated similar diagnostic accuracy. CONCLUSIONS: Unique inflammatory biomarker signatures are associated with specific perinatal stroke diseases. Findings support an acquired pathophysiology and suggest the possibility that at-risk pregnancies might be identified to develop prevention strategies. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that differences in acute neonatal serum cytokine profiles can discriminate between patients with specific perinatal stroke diseases and controls.


Assuntos
Isquemia Encefálica/imunologia , Citocinas/imunologia , Inflamação/imunologia , Acidente Vascular Cerebral/imunologia , Adulto , Idade de Início , Infarto Encefálico/classificação , Infarto Encefálico/diagnóstico por imagem , Infarto Encefálico/imunologia , Infarto Encefálico/fisiopatologia , Isquemia Encefálica/classificação , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/fisiopatologia , Análise por Conglomerados , Análise Discriminante , Teste em Amostras de Sangue Seco , Feminino , Humanos , Recém-Nascido , Infarto da Artéria Cerebral Média/classificação , Infarto da Artéria Cerebral Média/diagnóstico por imagem , Infarto da Artéria Cerebral Média/imunologia , Infarto da Artéria Cerebral Média/fisiopatologia , Doenças Arteriais Intracranianas/classificação , Doenças Arteriais Intracranianas/diagnóstico por imagem , Doenças Arteriais Intracranianas/imunologia , Doenças Arteriais Intracranianas/fisiopatologia , Modelos Lineares , Imageamento por Ressonância Magnética , Masculino , Idade Materna , Paresia/fisiopatologia , Pré-Eclâmpsia/epidemiologia , Gravidez , Convulsões/fisiopatologia , Fumar/epidemiologia , Acidente Vascular Cerebral/classificação , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/fisiopatologia , Substância Branca/diagnóstico por imagem , Adulto Jovem
11.
Curr Cancer Drug Targets ; 20(4): 295-305, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31713485

RESUMO

BACKGROUND: Atypical teratoid rhabdoid tumor of the central nervous system (CNS ATRT) is a malignancy that commonly affects young children. The biological mechanisms contributing to tumor aggressiveness and resistance to conventional therapies in ATRT are unknown. Previous studies have shown the activity of insulin like growth factor-I receptor (IGF-1R) in ATRT tumor specimens and cell lines. IGF-1R has been shown to cross-talk with other receptor tyrosine kinases (RTKs) in a number of cancer types, leading to enhanced cell proliferation. OBJECTIVE: This study aims to evaluate the role of IGF-1 receptor cross-talk in ATRT biology and the potential for therapeutic targeting. METHODS: Cell lines derived from CNS ATRT specimens were analyzed for IGF-1 mediated cell proliferation. A comprehensive receptor tyrosine kinase (RTK) screen was conducted following IGF-1 stimulation. Bioinformatic analysis of publicly available cancer growth inhibition data to identify correlation between IC50 of a VEGFR inhibitor and IGF-1R expression. RESULTS: Comprehensive RTK screen identified VEGFR-2 cross-activation following IGF-1 stimulation. Bioinformatics analysis demonstrated a positive correlation between IC50 values of VEGFR inhibitor Axitinib and IGF-1R expression, supporting the critical influence of IGF-1R in modulating response to anti-angiogenic therapies. CONCLUSION: Overall, our data present a novel experimental framework to evaluate and utilize receptor cross-talk mechanisms to select effective drugs and combinations for future therapeutic trials in ATRT.


Assuntos
Neoplasias do Sistema Nervoso Central/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Receptor Cross-Talk/efeitos dos fármacos , Receptor IGF Tipo 1/antagonistas & inibidores , Tumor Rabdoide/tratamento farmacológico , Teratoma/tratamento farmacológico , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Axitinibe/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias do Sistema Nervoso Central/metabolismo , Neoplasias do Sistema Nervoso Central/patologia , Humanos , Técnicas In Vitro , Fator de Crescimento Insulin-Like I/farmacologia , Terapia de Alvo Molecular/métodos , Receptor IGF Tipo 1/metabolismo , Tumor Rabdoide/metabolismo , Tumor Rabdoide/patologia , Transdução de Sinais/efeitos dos fármacos , Teratoma/metabolismo , Teratoma/patologia , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo
12.
Invest New Drugs ; 38(3): 690-699, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31264069

RESUMO

High-risk, relapsed and refractory neuroblastoma are associated with poor 5-years survival rates, demonstrating the need for investigational therapeutic agents to treat this disease. Taurolidine is derived from the aminosulfoacid taurine and has known anti-microbial and anti-inflammatory properties. Taurolidine has also demonstrated anti-neoplastic effects in a range of cancers, providing the rationale to investigate the activity of taurolidine against neuroblastoma in preclinical studies. We investigated the in vitro activity of taurolidine against neuroblastoma using the alamar blue cytotoxicity assay, phase-contrast light microscopy, western blotting and analysis of global gene expression by RNA-Seq. In vivo activity of taurolidine was evaluated using mouse xenograft models. In vitro pre-clinical data show that taurolidine is cytotoxic to neuroblastoma cell lines, inducing cell death by apoptosis. Analysis of global gene expression and determination of signaling pathway activation scores using the in silico Pathway Activation Network Decomposition Analysis (iPANDA) platform indicates that taurolidine has an effect on the Notch, mitogen-activated protein kinase (MAPK) and interleukin-10 (IL-10) signaling pathways. In vivo experiments in xenograft mouse models show that taurolidine decreases tumor growth and improves survival. These results provide supportive pre-clinical data on the activity of taurolidine against neuroblastoma. The findings support the rationale for further evaluation of taurolidine for the treatment of relapsed/refractory neuroblastoma patients in an early phase clinical trial.


Assuntos
Anti-Infecciosos/farmacologia , Antineoplásicos/farmacologia , Neuroblastoma/tratamento farmacológico , Taurina/análogos & derivados , Tiadiazinas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Expressão Gênica/efeitos dos fármacos , Xenoenxertos/efeitos dos fármacos , Xenoenxertos/metabolismo , Humanos , Camundongos , Camundongos SCID , Neuroblastoma/metabolismo , Transdução de Sinais/efeitos dos fármacos , Taurina/farmacologia
13.
Stem Cells Dev ; 28(19): 1277-1287, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31364487

RESUMO

Although treatment strategies for pediatric leukemia have improved overall survival rates in the recent past, relapse rates in certain subgroups such as infant leukemia remain unacceptably high. Despite undergoing extensive chemotherapy designed to target the rapidly proliferating leukemia cells, many of these children experience relapse. In refractory leukemia, the existence of cell populations with stemness characteristics, termed leukemia stem cells (LSCs), which remain quiescent and subsequently replenish the blast population, has been described. A significant body of evidence exists, derived largely from xenograft models of adult acute myeloid leukemia, to support the idea that LSCs may play a fundamental role in refractory disease. In addition, clinical studies have also linked LSCs with increased minimal residual disease, higher relapse rate, and decreased survival rates in these patients. Recently, a number of reports have addressed effective ways to utilize new-generation genomic sequencing and transcriptomic analyses to identify targeted therapeutic agents aimed at LSCs, while sparing normal hematopoietic stem cells. These data underscore the value of timely translation of knowledge from adult studies to the unique molecular and physiological characteristics seen in pediatric leukemia. We aim to summarize this article in the rapidly expanding field of stem cell biology in hematopoietic malignancies, focusing particularly on relevant preclinical models and novel targeted therapeutics, and their applicability to childhood leukemia.


Assuntos
Antineoplásicos/uso terapêutico , Epigênese Genética/efeitos dos fármacos , Leucemia Mieloide Aguda/terapia , Células-Tronco Neoplásicas/efeitos dos fármacos , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Adulto , Aldeído Desidrogenase/genética , Aldeído Desidrogenase/metabolismo , Animais , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Criança , Metilação de DNA/efeitos dos fármacos , Modelos Animais de Doenças , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/metabolismo , Humanos , Lactente , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/mortalidade , Leucemia Mieloide Aguda/patologia , Terapia de Alvo Molecular , Neoplasia Residual , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Recidiva , Análise de Sobrevida
14.
J Cancer Res Clin Oncol ; 145(6): 1461-1469, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31006845

RESUMO

BACKGROUND: Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma in children. Pathogenesis of RMS is associated with aggressive growth pattern and increased risk of morbidity and mortality. There are two main subtypes or RMS: embryonal and alveolar. The embryonal type is characterized by distinct molecular aberrations, including alterations in the activity of certain protein kinases. Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that plays a vital role in focal adhesion (FA) assembly to promote cytoskeleton dynamics and regulation of cell motility. It is regulated by multiple phosphorylation sites: tyrosine 397, Tyr 576/577, and Tyr 925. Tyrosine 397 is the autophosphorylation site that regulates FAK localization at the cell periphery to facilitate the assembly and formation of the FA complex. The kinase activity of FAK is mediated by the phosphorylation of Tyr 576/577 within the kinase domain activation loop. Aberrations of FAK phosphorylation have been linked to the pathogenesis of different types of cancers. In this regard, pY397 upregulation is linked to increase ERMS cell motility, invasion, and tumorigenesis. METHODS: In this study, we have used an established human embryonal muscle rhabdomyosarcoma cell line RD as a model to examine FAK phosphorylation profiles to characterize its role in the pathogenies of RMS. RESULTS: Our findings revealed a significant increase of FAK phosphorylation at pY397 in RD cells compared to control cells (hTERT). On the other hand, Tyr 576/577 phosphorylation levels in RD cells displayed a pronounced reduction. Our data showed that Y925 residue exhibited no detectable change. The in vitro analysis showed that the FAK inhibitor, PF-562271 led to G1 cell-cycle arrest induced cell death (IC50, ~ 12 µM) compared to controls. Importantly, immunostaining analyses displayed a noticeable reduction of Y397 phosphorylation following PF-562271 treatment. Our data also showed that PF-562271 suppressed RD cell migration in a dose-dependent manner associated with a reduction in Y397 phosphorylation. CONCLUSIONS: The data presented herein indicate that targeting FAK phosphorylation at distinct sites is a promising strategy in future treatment approaches for defined subgroups of rhabdomyosarcoma.


Assuntos
Quinase 1 de Adesão Focal/metabolismo , Rabdomiossarcoma Embrionário/enzimologia , Rabdomiossarcoma Embrionário/patologia , Western Blotting , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Sobrevivência Celular/fisiologia , Criança , Inibidores Enzimáticos/farmacologia , Feminino , Quinase 1 de Adesão Focal/antagonistas & inibidores , Humanos , Imuno-Histoquímica , Indóis/farmacologia , Fosforilação , Rabdomiossarcoma Embrionário/tratamento farmacológico , Sulfonamidas/farmacologia
15.
Onco Targets Ther ; 12: 1293-1307, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30863096

RESUMO

Purpose: Neuroblastoma is the most common extracranial cancer in children. Although the prognosis for low-risk neuroblastoma patients is good, the 5-year survival rates for high-risk and relapsed patients are low. The poor survival rates for these patients demonstrate the need for novel therapeutic approaches to treat this disease. PV-10 is a sterile 10% solution of Rose Bengal that has previously been shown to induce cell death in a range of adult cancers, providing the rationale for studying the activity of PV-10 against neuroblastoma in preclinical studies. Methods: The effects of PV-10 on neuroblastoma were investigated in vitro. Cytotoxicity assays were performed using the alamar blue assay on the following cell lines: SK-N-AS, SK-N-BE(2), IMR5, LAN1, SHEP, and SK-N-SH neuroblastoma cells, SK-N-MC neuroepithelioma cells, and normal primary, BJ, and WI38 fibroblasts. Phase-contrast, fluorescence, and time-lapse video microscopy; flow cytometry; and Western blotting were used to investigate the effects of PV-10 on SK-N-AS and IMR5 cells. Synergy with commonly used anticancer drugs was determined by calculation of combination indices in SK-N-AS and IMR5 cells. Mouse xenograft models of SK-N-AS and IMR5 tumors were also used to evaluate the efficacy of PV-10 in vivo. Results: In vitro preclinical data demonstrate that pharmacologically relevant concentrations of PV-10 are cytotoxic to neuroblastoma cell lines. Studies to investigate target modulation in neuroblastoma cell lines show that PV-10 disrupts lysosomes, decreases the percentage of cells in S phase, and induces apoptosis in a concentration-, time-, and cell-line-dependent manner, and we also identify agents that are synergistic with PV-10. Furthermore, experiments in xenograft mouse models show that PV-10 induces tumor regression in vivo. Conclusion: Our study provides preclinical data on the efficacy of PV-10 against neuroblastoma and provides rationale for the development of an early phase clinical trial of this agent in relapsed and refractory neuroblastoma patients.

16.
Curr Cancer Drug Targets ; 19(10): 828-837, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30914027

RESUMO

BACKGROUND: GDC-0980 is a selective small molecule inhibitor of class I PI3K and mTOR pathway with a potent anti-proliferative activity. OBJECTIVE: We set out to evaluate the efficacy of GDC-0980, in pre-clinical studies, against pediatric leukemia cells. METHODS: The anti-neoplastic activity of GDC-0980 was evaluated in vitro using five different pediatric leukemia cells. RESULTS: Our data show that GDC-0980 significantly inhibited the proliferation of leukemia cell lines, KOPN8 (IC50, 532 nM), SEM (IC50,720 nM), MOLM-13 (IC50,346 nM), MV4;11 (IC50,199 nM), and TIB-202 (IC50, 848 nM), compared to normal control cells (1.23 µM). This antiproliferative activity was associated with activation of cellular apoptotic mechanism characterized by a decrease in Bcl-2 protein phosphorylation and enhanced PARP cleavage. Western blot analyses of GDC-0980 treated cells also showed decreased phosphorylation levels of mTOR, Akt and S6, but not ERK1/2. Notably, FLT3 phosphorylation was decreased in Molm-13 and MV4;11 cells following the application of GDC-0980. We further examined cellular viability of GDC-0980-treated primary leukemia cells isolated from pediatric leukemia patients. This study revealed a potential therapeutic effect of GDC-0980 on two ALL patients (IC50's, 1.23 and 0.625 µM, respectively). Drug combination analyses of GDC-0980 demonstrated a synergistic activity with the MEK inhibitor Cobimetinib (MV4-11; 11, CI, 0.25, SEM, CI, 0.32, and TIB-202, CI, 0.55) and the targeted FLT3 inhibitor, Crenolanib (MV4-11; 11, CI, 0.25, SEM, CI, 0.7, and TIB-202, CI, 0.42). CONCLUSION: These findings provide initial proof-of-concept data and rationale for further investigation of GDC-0980 in selected subgroups of pediatric leukemia patients.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Pirimidinas/farmacologia , Transdução de Sinais , Serina-Treonina Quinases TOR/antagonistas & inibidores , Fatores de Transcrição/antagonistas & inibidores , Tirosina Quinase 3 Semelhante a fms/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular , Criança , Humanos , Leucemia Mieloide Aguda/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Tirosina Quinase 3 Semelhante a fms/genética
17.
J Pediatr Hematol Oncol ; 41(6): e359-e370, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30702467

RESUMO

BACKGROUND: Recent studies have shown that cell cycle events are tightly controlled by complex and shared activities of a select group of kinases. Among these, polo-like kinases (Plks) are regulatory mitotic proteins that are overexpressed in several types of cancer and are associated with poor prognosis. MATERIALS AND METHODS: We have evaluated, in preclinical in vitro studies, the activity of a panel of Plk inhibitors against cell lines derived from refractory pediatric leukemia, as well as primary leukemia cells, in culture. Through in vitro growth inhibition studies, Western blot analysis for the expression and activation of key regulators of cell growth and survival and gene silencing studies, we specifically examined the ability of these agents to induce cytotoxicity through the activation of apoptosis and their capacity to interact and modulate the expression and phosphorylation of Aurora kinases. RESULTS: Our findings show that the various Plk-1 inhibitors in development show potential utility for the treatment of pediatric leukemia and exhibit a wide range of phosphorylation and target modulatory capabilities. Finally, we provide evidence for a complex interregulatory relationship between Plk-1 and Aurora kinases enabling the identification of synergy and biologic correlates of drug combinations targeting the 2 distinct enzyme systems. DISCUSSION: This information provide the rationale for the evaluation of Plk-1 as an effective target for therapeutics in refractory pediatric leukemia and indicate compensatory activities between Plk-1 and Aurora kinases, providing insight into some of the complex mechanisms involved in the process of cell division.


Assuntos
Apoptose , Aurora Quinases/antagonistas & inibidores , Azepinas/farmacologia , Proteínas de Ciclo Celular/antagonistas & inibidores , Leucemia/patologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Pteridinas/farmacologia , Pirimidinas/farmacologia , Proliferação de Células , Humanos , Leucemia/tratamento farmacológico , Leucemia/enzimologia , Células Tumorais Cultivadas
18.
Pediatr Blood Cancer ; 66(6): e27676, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30786157

RESUMO

BACKGROUND: Melatonin is a natural health product used for sleep disturbances. In preliminary studies of adults with advanced cancer, 20 mg of melatonin daily was associated with reduction in anorexia and weight loss-symptoms that also impact pediatric oncology patients. High doses of melatonin have not been studied in pediatrics. METHODS: This was a multicenter single-arm phase I dose-escalation study utilizing a 3 + 3 design to determine the safety and tolerability of escalating doses of melatonin in pediatric oncology patients with relapsed solid tumors. Melatonin was given for 8 weeks at three dose levels-0.075 mg/kg (maximum 5 mg), 0.15 mg/kg (maximum 10 mg), and 0.3 mg/kg (maximum 20 mg). RESULTS: Melatonin was well tolerated at all three dose levels with no significant adverse events or dose-limiting toxicities. The only grade 3/4 toxicities were myelosuppression, which was attributed to the concomitant chemotherapy and occurred at all dose levels. Weight gain occurred in seven of nine patients, with a median increase of 1.1 kg (range -3.3 to 4.5) or 3.4% (range -10.2 to 8.7), with two patients losing weight (one in dose level 1 and one level 3). CONCLUSIONS: Melatonin is well tolerated at a dose of 0.3 mg/kg (maximum 20 mg), in the pediatric population. This study provides the background for further study of high-dose melatonin in pediatric oncology patients.


Assuntos
Anorexia/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Antioxidantes/uso terapêutico , Melatonina/uso terapêutico , Neoplasias/tratamento farmacológico , Transtornos do Sono-Vigília/tratamento farmacológico , Perda de Peso/efeitos dos fármacos , Adolescente , Anorexia/induzido quimicamente , Anorexia/diagnóstico , Criança , Pré-Escolar , Relação Dose-Resposta a Droga , Feminino , Seguimentos , Humanos , Masculino , Dose Máxima Tolerável , Neoplasias/patologia , Prognóstico , Transtornos do Sono-Vigília/induzido quimicamente , Transtornos do Sono-Vigília/diagnóstico
19.
Cancer Biother Radiopharm ; 34(4): 252-257, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30724592

RESUMO

Background: Neuroblastoma (NB) is one of the most aggressive and common solid tumors in pediatrics. Development of effective new therapeutics for NB is in progress to help reduce mortality and morbidity of the disease, particularly in relapsed patients. The tumor suppressor protein p53 plays a critical role in multiple signaling pathways to maintain cellular hemostasis. Dysregulation of p53 protein and/or molecular aberrations have been associated with multiple human malignancies. p53 stability and protein activity is negatively regulated by the E3 ubiquitin ligase (MDM2). Thus, targeting p53-MDM2 protein-protein interaction is a feasible and promising therapeutic strategy to restore the physiological function of p53 in cancer cells. RG7112 is a highly potent and selective small molecule inhibitor, which target a unique structure located within p53 binding motif of MDM2. Methods: The efficacy of RG7112 in vitro using NB cell lines was examined. Two wild-type (WT)-p53 NB cell lines IMR5 and LAN-5, a mutant p53 cell line SK-N-BE(2), and a WT-p53/p14 deleted cell line SH-EP were employed. Results: Data showed that RG7112 significantly reduced cellular viability of IMR5 (IC50, 562 nM) and LAN-5 (IC50, 430 nM), but not SK-N-BE(2) and SH-EP cells. Further, RG7112 restores p53 and p21 protein levels in IMR5 and LAN-5 in a dose-dependent manner. RG7112 induces cell cycle arresting (60% G1 arresting) in WT-p53 cells (IMR5), but no pronounced effect observed in SK-N-BE(2). In this study, 15 different drugs in combination with RG7112 in IMR5 cell line and identified venetoclax (Bcl-2/Bcl-xL inhibitor) as a promising candidate were evaluated. Conclusions: Taken together, these findings provide initial proof-of-concept data for further investigations of RG7112 in selected subgroups of NB patients.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Imidazolinas/farmacologia , Neuroblastoma/tratamento farmacológico , Proteínas Proto-Oncogênicas c-mdm2/antagonistas & inibidores , Proteína Supressora de Tumor p53/metabolismo , Motivos de Aminoácidos/efeitos dos fármacos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Sinergismo Farmacológico , Humanos , Imidazolinas/uso terapêutico , Concentração Inibidora 50 , Neuroblastoma/genética , Neuroblastoma/patologia , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/genética , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sulfonamidas/farmacologia , Sulfonamidas/uso terapêutico , Proteína Supressora de Tumor p53/genética
20.
Target Oncol ; 13(6): 779-793, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30446871

RESUMO

BACKGROUND: Leukemia accounts for 30% of all childhood cancers and although the survival rate for pediatric leukemia has greatly improved, relapse is a major cause of treatment failure. Therefore, the development and introduction of novel therapeutics to treat relapsed pediatric leukemia is urgently needed. The proteasome inhibitor bortezomib has been shown to be effective against adult hematological malignancies such as multiple myeloma and lymphoma, but is frequently associated with the development of resistance. Carfilzomib is a next-generation proteasome inhibitor that has shown promising results against refractory adult hematological malignancies. OBJECTIVE: Carfilzomib has been extensively studied in adult hematological malignancies, providing the rationale for evaluating proof-of-concept activity of carfilzomib in pediatric leukemia. METHODS: The effects of carfilzomib on pediatric leukemia cell lines and primary pediatric leukemia patient samples were investigated in vitro using the alamar blue cytotoxicity assay, western blotting, and a proteasome activity assay. Synergy with commonly used anticancer drugs was determined by calculation of combination indices. RESULTS: In vitro preclinical data show pharmacologically relevant concentrations of carfilzomib are cytotoxic to pediatric leukemia cell lines and primary pediatric leukemia cells. Target modulation studies validate the effective inhibition of the proteasome and induction of apoptosis. We also identify agents that have effective synergy with carfilzomib in these cells. CONCLUSIONS: Our data provide pre-clinical information that can be incorporated into future early-phase clinical trials for the assessment of carfilzomib as a treatment for children with refractory hematological malignancies.


Assuntos
Leucemia/tratamento farmacológico , Oligopeptídeos/farmacologia , Inibidores de Proteassoma/farmacologia , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Bortezomib/farmacologia , Processos de Crescimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Criança , Sinergismo Farmacológico , Feminino , Humanos , Lactente , Leucemia/metabolismo , Leucemia/patologia , Masculino , Terapia de Alvo Molecular , Oligopeptídeos/administração & dosagem
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