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Phosphatidylinositol 3-kinase (PI3-K) signalling pathway is a crucial path in cancer for cell survival and thus represents an intriguing target for new paediatric anti-cancer drugs. However, the unique clinical toxicities of targeting this pathway (resulting in hyperglycaemia) difficulties combining with chemotherapy, rarity of mutations in childhood tumours and concomitant mutations have resulted in major barriers to clinical translation of these inhibitors in treating both adults and children. Mutations in PIK3CA predict response to PI3-K inhibitors in adult cancers. The same mutations occur in children as in adults, but they are significantly less frequent in paediatrics. In children, high-grade gliomas, especially diffuse midline gliomas (DMG), have the highest incidence of PIK3CA mutations. New mutation-specific PI3-K inhibitors reduce toxicity from on-target PI3-Kα wild-type activity. The mTOR inhibitor everolimus is approved for subependymal giant cell astrocytomas. In paediatric cancers, mTOR inhibitors have been predominantly evaluated by academia, without an overall strategy, in empiric, mutation-agnostic clinical trials with very low response rates to monotherapy. Therefore, future trials of single agent or combination strategies of mTOR inhibitors in childhood cancer should be supported by very strong biological rationale and preclinical data. Further preclinical evaluation of glycogen synthase kinase-3 beta inhibitors is required. Similarly, even where there is an AKT mutation (â¼0.1 %), the role of AKT inhibitors in paediatric cancers remains unclear. Patient advocates strongly urged analysing and conserving data from every child participating in a clinical trial. A priority is to evaluate mutation-specific, central nervous system-penetrant PI3-K inhibitors in children with DMG in a rational biological combination. The choice of combination, should be based on the genomic landscape e.g. PTEN loss and resistance mechanisms supported by preclinical data. However, in view of the very rare populations involved, innovative regulatory approaches are needed to generate data for an indication.
Assuntos
Glicogênio Sintase Quinase 3 beta , Neoplasias , Proteínas Proto-Oncogênicas c-akt , Serina-Treonina Quinases TOR , Humanos , Criança , Adolescente , Neoplasias/tratamento farmacológico , Neoplasias/genética , Glicogênio Sintase Quinase 3 beta/antagonistas & inibidores , Glicogênio Sintase Quinase 3 beta/metabolismo , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/antagonistas & inibidores , Inibidores de Fosfoinositídeo-3 Quinase/uso terapêutico , Inibidores de Fosfoinositídeo-3 Quinase/farmacologia , Inibidores de MTOR/uso terapêutico , Inibidores de MTOR/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Inibidores de Proteínas Quinases/farmacologia , Antineoplásicos/uso terapêutico , Antineoplásicos/farmacologia , Transdução de Sinais/efeitos dos fármacosRESUMO
Pediatric patients with high-risk neuroblastoma have poor survival rates and urgently need more effective treatment options with less side effects. Since novel and improved immunotherapies may fill this need, we dissect the immunoregulatory interactions in neuroblastoma by single-cell RNA-sequencing of 24 tumors (10 pre- and 14 post-chemotherapy, including 5 pairs) to identify strategies for optimizing immunotherapy efficacy. Neuroblastomas are infiltrated by natural killer (NK), T and B cells, and immunosuppressive myeloid populations. NK cells show reduced cytotoxicity and T cells have a dysfunctional profile. Interaction analysis reveals a vast immunoregulatory network and identifies NECTIN2-TIGIT as a crucial immune checkpoint. Combined blockade of TIGIT and PD-L1 significantly reduces neuroblastoma growth, with complete responses (CR) in vivo. Moreover, addition of TIGIT+PD-L1 blockade to standard relapse treatment in a chemotherapy-resistant Th-ALKF1174L/MYCN 129/SvJ syngeneic model induces CR. In conclusion, our integrative analysis provides promising targets and a rationale for immunotherapeutic combination strategies.
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Antígeno B7-H1 , Neuroblastoma , Humanos , Criança , Recidiva Local de Neoplasia , Neuroblastoma/tratamento farmacológico , Neuroblastoma/genética , Receptores Imunológicos/genética , Imunoterapia , Análise de Sequência de RNARESUMO
DNA damage response inhibitors have a potentially important therapeutic role in paediatric cancers; however, their optimal use, including patient selection and combination strategy, remains unknown. Moreover, there is an imbalance between the number of drugs with diverse mechanisms of action and the limited number of paediatric patients available to be enrolled in early-phase trials, so prioritisation and a strategy are essential. While PARP inhibitors targeting homologous recombination-deficient tumours have been used primarily in the treatment of adult cancers with BRCA1/2 mutations, BRCA1/2 mutations occur infrequently in childhood tumours, and therefore, a specific response hypothesis is required. Combinations with targeted radiotherapy, ATR inhibitors, or antibody drug conjugates with DNA topoisomerase I inhibitor-related warheads warrant evaluation. Additional monotherapy trials of PARP inhibitors with the same mechanism of action are not recommended. PARP1-specific inhibitors and PARP inhibitors with very good central nervous system penetration also deserve evaluation. ATR, ATM, DNA-PK, CHK1, WEE1, DNA polymerase theta and PKMYT1 inhibitors are early in paediatric development. There should be an overall coordinated strategy for their development. Therefore, an academia/industry consensus of the relevant biomarkers will be established and a focused meeting on ATR inhibitors (as proof of principle) held. CHK1 inhibitors have demonstrated activity in desmoplastic small round cell tumours and have a potential role in the treatment of other paediatric malignancies, such as neuroblastoma and Ewing sarcoma. Access to CHK1 inhibitors for paediatric clinical trials is a high priority. The three key elements in evaluating these inhibitors in children are (1) innovative trial design (design driven by a clear hypothesis with the intent to further investigate responders and non-responders with detailed retrospective molecular analyses to generate a revised or new hypothesis); (2) biomarker selection and (3) rational combination therapy, which is limited by overlapping toxicity. To maximally benefit children with cancer, investigators should work collaboratively to learn the lessons from the past and apply them to future studies. Plans should be based on the relevant biology, with a focus on simultaneous and parallel research in preclinical and clinical settings, and an overall integrated and collaborative strategy.
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Antineoplásicos , Neuroblastoma , Estados Unidos , Adulto , Humanos , Criança , Adolescente , Antineoplásicos/uso terapêutico , Proteína BRCA1 , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , United States Food and Drug Administration , Estudos Retrospectivos , Proteína BRCA2 , Neuroblastoma/tratamento farmacológico , Biomarcadores , Dano ao DNA , Proteínas de Membrana , Proteínas Tirosina Quinases , Proteínas Serina-Treonina QuinasesRESUMO
BACKGROUND: The MAPK pathway is an emerging target across a number of adult and pediatric tumors. Targeting the downstream effector of MAPK, MEK1, is a proposed strategy to control the growth of MAPK-dependent tumors. OBJECTIVE: iMATRIX-cobi assessed the safety, pharmacokinetics, and anti-tumor activity of cobimetinib, a highly selective MEK inhibitor, in children and young adults with relapsed/refractory solid tumors. PATIENTS AND METHODS: This multicenter Phase I/II study enrolled patients aged 6 months to < 30 years with solid tumors with known/expected MAPK pathway involvement. Patients received cobimetinib tablet or suspension formulation on Days 1-21 of a 28-day cycle. Dose escalation followed a rolling 6 design. The primary endpoint was safety; secondary endpoints were pharmacokinetics and anti-tumor activity. RESULTS: Of 56 enrolled patients (median age 9 years [range 3-29]), 18 received cobimetinib tablets and 38 cobimetinib suspension. Most common diagnoses were low-grade glioma (LGG; n = 32, including n = 12 in the expansion cohort) and plexiform neurofibroma within neurofibromatosis type 1 (n = 12). Six patients (11 %) experienced dose-limiting toxicities (including five ocular toxicity events), which established a pediatric recommended Phase II dose (RP2D) of 0.8 mg/kg tablet and 1.0 mg/kg suspension. Most frequently reported treatment-related adverse events were gastrointestinal and skin disorders. Steady state mean exposure (Cmax, AUC0-24) of cobimetinib at the RP2D (1.0 mg/kg suspension) was ~ 50 % lower than in adults receiving the approved 60 mg/day dose. Overall response rate was 5.4 % (3/56; all partial responses in patients with LGG). CONCLUSIONS: The safety profile of cobimetinib in pediatrics was similar to that reported in adults. Clinical activity was observed in LGG patients with known/suspected MAPK pathway activation. Cobimetinib combination regimens may be required to improve response rates in this pediatric population. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT02639546, registered December 24, 2015.
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Azetidinas , Neoplasias , Piperidinas , Adolescente , Adulto , Azetidinas/efeitos adversos , Azetidinas/uso terapêutico , Criança , Pré-Escolar , Inibidores Enzimáticos/uso terapêutico , Glioma/tratamento farmacológico , Humanos , Dose Máxima Tolerável , Recidiva Local de Neoplasia , Neoplasias/tratamento farmacológico , Pediatria , Piperidinas/efeitos adversos , Piperidinas/uso terapêutico , Comprimidos , Adulto JovemRESUMO
[This corrects the article DOI: 10.18632/oncotarget.24859.].
RESUMO
The MYC oncogenes and p53 have opposing yet interrelated roles in normal development and tumorigenesis. How MYCN expression alters the biology and clinical responsiveness of pediatric neuroblastoma remains poorly defined. Neuroblastoma is p53 wild type at diagnosis and repression of p53 signaling is required for tumorigenesis. Here, we tested the hypothesis that MYCN amplification alters p53 transcriptional activity in neuroblastoma. Interestingly, we found that MYCN directly binds to the tetrameric form of p53 at its C-terminal domain, and this interaction is independent of MYCN/MAX heterodimer formation. Chromatin analysis of MYCN and p53 targets reveals dramatic changes in binding, as well as co-localization of the MYCN-p53 complex at p53-REs and E-boxes of genes critical to DNA damage responses and cell cycle progression. RNA sequencing studies show that MYCN-p53 co-localization significantly modulated the expression of p53 target genes. Furthermore, MYCN-p53 interaction leads to regulation of alternative p53 targets not regulated in the presence of low MYCN levels. These novel targets include a number of genes involved in lipid metabolism, DNA repair, and apoptosis. Taken together, our findings demonstrate a novel oncogenic role of MYCN as a transcriptional co-regulator of p53 in high-risk MYCN amplified neuroblastoma. Targeting this novel oncogenic function of MYCN may enhance p53-mediated responses and sensitize MYCN amplified tumors to chemotherapy.
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Genomics has provided a detailed structural description of the cancer genome. Identifying oncogenic drivers that work primarily through dosage changes is a current challenge. Unrestrained proliferation is a critical hallmark of cancer. We constructed modular, barcoded libraries of human open reading frames (ORFs) and performed screens for proliferation regulators in multiple cell types. Approximately 10% of genes regulate proliferation, with most performing in an unexpectedly highly tissue-specific manner. Proliferation drivers in a given cell type showed specific enrichment in somatic copy number changes (SCNAs) from cognate tumors and helped predict aneuploidy patterns in those tumors, implying that tissue-type-specific genetic network architectures underlie SCNA and driver selection in different cancers. In vivo screening confirmed these results. We report a substantial contribution to the catalog of SCNA-associated cancer drivers, identifying 147 amplified and 107 deleted genes as potential drivers, and derive insights about the genetic network architecture of aneuploidy in tumors.
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Aneuploidia , Neoplasias/patologia , Animais , Linhagem Celular Tumoral , Proliferação de Células , Mapeamento Cromossômico , Cromossomos/genética , Fator de Transcrição E2F1/antagonistas & inibidores , Fator de Transcrição E2F1/genética , Fator de Transcrição E2F1/metabolismo , Feminino , Biblioteca Gênica , Genômica , Humanos , Queratinas/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Oncogenes , Fases de Leitura Aberta/genética , Interferência de RNA , RNA Interferente Pequeno/metabolismoRESUMO
Ewing sarcoma (EWS) is a highly aggressive and metabolically active malignant tumor. Metabolic activity can broadly be characterized by features of glycolytic activity and oxidative phosphorylation. We have further characterized metabolic features of EWS cells to identify potential therapeutic targets. EWS cells had significantly more glycolytic activity compared to their non-malignant counterparts. Thus, metabolic inhibitors of glycolysis such as 2-deoxy-D-glucose (2DG) and of the mitochondrial respiratory pathway, such as metformin, were evaluated as potential therapeutic agents against a panel of EWS cell lines in vitro. Results indicate that 2DG alone or in combination with metformin was effective at inducing cell death in EWS cell lines. The predominant mechanism of cell death appears to be through stimulating apoptosis leading into necrosis with concomitant activation of AMPK-α. Furthermore, we demonstrate that the use of metabolic modulators can target putative EWS stem cells, both in vitro and in vivo, and potentially overcome chemotherapeutic resistance in EWS. Based on these data, clinical strategies using drugs targeting tumor cell metabolism present a viable therapeutic modality against EWS.
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MYC (also known as c-MYC) overexpression or hyperactivation is one of the most common drivers of human cancer. Despite intensive study, the MYC oncogene remains recalcitrant to therapeutic inhibition. MYC is a transcription factor, and many of its pro-tumorigenic functions have been attributed to its ability to regulate gene expression programs. Notably, oncogenic MYC activation has also been shown to increase total RNA and protein production in many tissue and disease contexts. While such increases in RNA and protein production may endow cancer cells with pro-tumour hallmarks, this increase in synthesis may also generate new or heightened burden on MYC-driven cancer cells to process these macromolecules properly. Here we discover that the spliceosome is a new target of oncogenic stress in MYC-driven cancers. We identify BUD31 as a MYC-synthetic lethal gene in human mammary epithelial cells, and demonstrate that BUD31 is a component of the core spliceosome required for its assembly and catalytic activity. Core spliceosomal factors (such as SF3B1 and U2AF1) associated with BUD31 are also required to tolerate oncogenic MYC. Notably, MYC hyperactivation induces an increase in total precursor messenger RNA synthesis, suggesting an increased burden on the core spliceosome to process pre-mRNA. In contrast to normal cells, partial inhibition of the spliceosome in MYC-hyperactivated cells leads to global intron retention, widespread defects in pre-mRNA maturation, and deregulation of many essential cell processes. Notably, genetic or pharmacological inhibition of the spliceosome in vivo impairs survival, tumorigenicity and metastatic proclivity of MYC-dependent breast cancers. Collectively, these data suggest that oncogenic MYC confers a collateral stress on splicing, and that components of the spliceosome may be therapeutic entry points for aggressive MYC-driven cancers.
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Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Genes myc/genética , Spliceossomos/efeitos dos fármacos , Spliceossomos/metabolismo , Animais , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Transformação Celular Neoplásica/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HeLa , Humanos , Íntrons/genética , Camundongos , Camundongos Nus , Metástase Neoplásica/tratamento farmacológico , Proteínas Nucleares/metabolismo , Fosfoproteínas/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Precursores de RNA/biossíntese , Precursores de RNA/genética , Splicing de RNA/efeitos dos fármacos , Fatores de Processamento de RNA , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Ribonucleoproteína Nuclear Pequena U2/metabolismo , Ribonucleoproteínas/metabolismo , Fator de Processamento U2AF , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Myc is an oncogenic transcription factor frequently dysregulated in human cancer. To identify pathways supporting the Myc oncogenic program, we used a genome-wide RNA interference screen to search for Myc-synthetic lethal genes and uncovered a role for the SUMO-activating enzyme (SAE1/2). Loss of SAE1/2 enzymatic activity drives synthetic lethality with Myc. Inactivation of SAE2 leads to mitotic catastrophe and cell death upon Myc hyperactivation. Mechanistically, SAE2 inhibition switches a transcriptional subprogram of Myc from activated to repressed. A subset of these SUMOylation-dependent Myc switchers (SMS genes) is required for mitotic spindle function and to support the Myc oncogenic program. SAE2 is required for growth of Myc-dependent tumors in mice, and gene expression analyses of Myc-high human breast cancers suggest that low SAE1 and SAE2 abundance in the tumors correlates with longer metastasis-free survival of the patients. Thus, inhibition of SUMOylation may merit investigation as a possible therapy for Myc-driven human cancers.
Assuntos
Neoplasias da Mama/genética , Transformação Celular Neoplásica , Genes myc , Proteínas Proto-Oncogênicas c-myc/metabolismo , Transcrição Gênica , Enzimas Ativadoras de Ubiquitina/genética , Animais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Ciclo Celular , Linhagem Celular Tumoral , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Mamárias Experimentais/genética , Neoplasias Mamárias Experimentais/metabolismo , Neoplasias Mamárias Experimentais/mortalidade , Neoplasias Mamárias Experimentais/patologia , Camundongos , Camundongos Nus , Mitose , Transplante de Neoplasias , Interferência de RNA , RNA Interferente Pequeno , Fuso Acromático/fisiologia , Sumoilação , Transplante Heterólogo , Enzimas Ativadoras de Ubiquitina/antagonistas & inibidores , Enzimas Ativadoras de Ubiquitina/metabolismoRESUMO
Among breast cancers, triple-negative breast cancer (TNBC) is the most poorly understood and is refractory to current targeted therapies. Using a genetic screen, we identify the PTPN12 tyrosine phosphatase as a tumor suppressor in TNBC. PTPN12 potently suppresses mammary epithelial cell proliferation and transformation. PTPN12 is frequently compromised in human TNBCs, and we identify an upstream tumor-suppressor network that posttranscriptionally controls PTPN12. PTPN12 suppresses transformation by interacting with and inhibiting multiple oncogenic tyrosine kinases, including HER2 and EGFR. The tumorigenic and metastatic potential of PTPN12-deficient TNBC cells is severely impaired upon restoration of PTPN12 function or combined inhibition of PTPN12-regulated tyrosine kinases, suggesting that TNBCs are dependent on the proto-oncogenic tyrosine kinases constrained by PTPN12. Collectively, these data identify PTPN12 as a commonly inactivated tumor suppressor and provide a rationale for combinatorially targeting proto-oncogenic tyrosine kinases in TNBC and other cancers based on their profile of tyrosine-phosphatase activity.
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Neoplasias da Mama/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 12/genética , Proteína Tirosina Fosfatase não Receptora Tipo 12/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Transformação Celular Neoplásica , Receptores ErbB/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Sistema de Sinalização das MAP Quinases , MicroRNAs/metabolismo , Mutação , Metástase Neoplásica , Processamento de Proteína Pós-TraducionalRESUMO
The discovery of RNAi has revolutionized loss-of-function genetic studies in mammalian systems. However, significant challenges still remain to fully exploit RNAi for mammalian genetics. For instance, genetic screens and in vivo studies could be broadly improved by methods that allow inducible and uniform gene expression control. To achieve this, we built the lentiviral pINDUCER series of expression vehicles for inducible RNAi in vivo. Using a multicistronic design, pINDUCER vehicles enable tracking of viral transduction and shRNA or cDNA induction in a broad spectrum of mammalian cell types in vivo. They achieve this uniform temporal, dose-dependent, and reversible control of gene expression across heterogenous cell populations via fluorescence-based quantification of reverse tet-transactivator expression. This feature allows isolation of cell populations that exhibit a potent, inducible target knockdown in vitro and in vivo that can be used in human xenotransplantation models to examine cancer drug targets.
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Técnicas Genéticas , Vetores Genéticos/genética , Lentivirus/genética , Interferência de RNA , Animais , Neoplasias da Mama/patologia , Linhagem Celular , DNA Complementar/genética , Diagnóstico por Imagem , Feminino , Expressão Gênica , Humanos , Luminescência , Glândulas Mamárias Animais/metabolismo , Glândulas Mamárias Animais/patologia , Camundongos , RNA Interferente Pequeno/metabolismo , Reprodutibilidade dos Testes , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
PURPOSE: A phase I study of intrathecal (IT) gemcitabine was performed to define a safe dose and characterize the toxicity profile and CSF pharmacokinetics of gemcitabine and its major metabolite 2',2'-difluoro-deoxyuridine (dFdU) in patients 3 years of age and older with neoplastic meningitis. EXPERIMENTAL DESIGN: Gemcitabine was administered via Ommaya reservoir or lumbar puncture at three dose levels: 5 mg weekly, 5 mg twice-weekly, and 10 mg twice-weekly using a standard phase I dose escalation design. Serial CSF samples were obtained for pharmacokinetic studies in seven patients with Ommaya reservoirs. Serial blood samples for pharmacokinetic studies were also obtained from three patients. RESULTS: Ten patients were enrolled in this study. Significant neurological toxicities occurred in two patients including myelitis in a patient at the 5 mg twice-weekly dose level and somnolence in a patient at the 10 mg twice-weekly dose level. No complete responses were seen; however, three patients had stable disease. Gemcitabine was rapidly eliminated from the CSF with a terminal half-life of 61 +/- 50 min. No gemcitabine or dFdU was detected in plasma. CONCLUSIONS: IT gemcitabine was associated with significant neurotoxicity; therefore, its further development for IT use is not recommended.
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Antimetabólitos Antineoplásicos , Desoxicitidina/análogos & derivados , Neoplasias Meníngeas/tratamento farmacológico , Adolescente , Adulto , Antimetabólitos Antineoplásicos/administração & dosagem , Antimetabólitos Antineoplásicos/efeitos adversos , Antimetabólitos Antineoplásicos/farmacocinética , Antimetabólitos Antineoplásicos/uso terapêutico , Criança , Desoxicitidina/administração & dosagem , Desoxicitidina/efeitos adversos , Desoxicitidina/farmacocinética , Desoxicitidina/uso terapêutico , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Humanos , Injeções Espinhais , Masculino , Neoplasias Meníngeas/sangue , Neoplasias Meníngeas/líquido cefalorraquidiano , Neoplasias Meníngeas/secundário , Pessoa de Meia-Idade , GencitabinaRESUMO
We are developing a novel approach to specifically target malignant brain tumor cells for photothermal ablation using antibody-tagged, near infrared-absorbing gold-silica nanoshells, referred to as immunonanoshells. Once localized to tumor cells, these nanoshells are extremely efficient at absorbing near-infrared light and can generate sufficient heat to kill cancer cells upon exposure to laser light. In this study, we evaluated the efficacy of immunonanoshells in vitro against both medulloblastoma and high-grade glioma cell lines. We used an antibody against HER2 to target gold-silica nanoshells to medulloblastoma cells, since HER2 is frequently overexpressed in medulloblastoma. We show that treatment with HER2-targeted nanoshells, but not non-targeted nanoshells, followed by exposure to laser light, can induce cell death in the HER2-overexpressing medulloblastoma cell line Daoy.2, as well as the parental Daoy cell line, which expresses HER2 at a moderate level, but not in dermal fibroblasts that do not express HER2. In an analogous set of experiments, we conjugated gold-silica nanoshells to an antibody against interleukin-13 receptor-alpha 2 (IL13Ralpha2), an antigen that is frequently overexpressed in gliomas. We demonstrate that these immunonanoshells are capable of inducing cell death in two high-grade glioma cell lines that express IL13Ralpha2, U373 and U87, but not in A431 epidermoid carcinoma cells that do not express significant levels of IL13Ralpha2. We believe that the use of antibody-tagged gold-silica nanoshells to selectively target cancer cells presents a promising new strategy for the treatment of central nervous system tumors that will minimize the damage and resulting toxicity to the surrounding normal brain.
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Neoplasias Encefálicas/terapia , Glioma/terapia , Imunoterapia/métodos , Meduloblastoma/terapia , Nanopartículas/uso terapêutico , Fototerapia/métodos , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/metabolismo , Terapia Combinada , Sistemas de Liberação de Medicamentos/métodos , Glioma/imunologia , Glioma/metabolismo , Humanos , Hipertermia Induzida/métodos , Raios Infravermelhos , Subunidade alfa2 de Receptor de Interleucina-13/imunologia , Subunidade alfa2 de Receptor de Interleucina-13/metabolismo , Lasers , Meduloblastoma/imunologia , Meduloblastoma/metabolismo , Nanopartículas/efeitos da radiação , Radiossensibilizantes/uso terapêutico , Receptor ErbB-2/imunologia , Receptor ErbB-2/metabolismo , Células Tumorais CultivadasRESUMO
Calcitriol (1,25-dihydroxycholecalciferol), the active form of Vitamin D, is anti-proliferative in tumor cells and tumor-derived endothelial cells (TDEC). However, endothelial cells isolated from normal tissues as cell lines or freshly isolated cells or from implanted Matrigel plugs (MDEC) are relatively resistant. Both TDEC and MDEC express similar amounts of Vitamin D receptor (VDR) protein. Although the VDR from TDEC has higher binding affinity for calcitriol than those from MDEC, VDR in both cell types translocates to the nucleus and transactivates the 24-hydroxylase promoter-luciferase construct. Calcitriol selectively inhibits the growth of TDEC but not MDEC by inducing G(0)/G(1) cell cycle arrest and by promoting apoptosis. This selectivity appears to be related to 24-hydroxylase (CYP24) expression. Calcitriol significantly induced CYP24 expression in MDEC but not in TDEC and inhibition of CYP24 activity in MDEC restores their sensitivity to calcitriol. These findings indicate that the induction of CYP24 expression differs in endothelial cells isolated from different microenvironments (TDEC versus MDEC) and that this distinction contributes to selective calcitriol-mediated growth inhibition in these cell types.
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Calcitriol/farmacologia , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Animais , Proliferação de Células/efeitos dos fármacos , Humanos , Neoplasias/patologia , Receptores de Calcitriol/metabolismo , Esteroide Hidroxilases/metabolismo , Vitamina D3 24-HidroxilaseRESUMO
PURPOSE: In preclinical models, calcitriol and the tyrosine kinase inhibitor gefitinib are synergistic and modulate extracellular signal-regulated kinase (Erk) and Akt pathways. Therefore, we conducted a phase I study of calcitriol and gefitinib to determine the maximum tolerated dose (MTD) of this combination. EXPERIMENTAL DESIGN: Calcitriol was given i.v. over 1 h on weeks 1, 3, and weekly thereafter. Gefitinib was given at a fixed oral daily dose of 250 mg starting at week 2 (day 8). Escalation occurred in cohorts of three patients until the MTD was defined. Pharmacokinetic studies were done for calcitriol and gefitinib. Serial skin biopsies were done to investigate epidermal growth factor receptor (EGFR) pathway pharmacodynamic interactions. RESULTS: Thirty-two patients were treated. Dose-limiting hypercalcemia was noted in two of four patients receiving 96 mug/wk of calcitriol. One of seven patients developed dose-limiting hypercalcemia at the MTD 74 mug/wk calcitriol dose level. The relationship between calcitriol dose and peak serum calcitriol (C(max)) and systemic exposure (AUC) was linear. Mean (+/-SD) serum calcitriol C(max) at the MTD was 6.68 +/- 1.42 ng/mL. Gefitinib treatment inhibited EGFR, Akt, and Erk phosphorylation in the skin. Calcitriol did not have consistent effects on skin EGFR or its downstream elements. The combination of gefitinib and calcitriol did not modulate tumor EGFR pathway in patients with serial tumor biopsies. CONCLUSIONS: High doses of weekly i.v. calcitriol can be administered safely in combination with gefitinib. Calcitriol concentrations achieved at the MTD 74 mug calcitriol exceed in vivo concentrations associated with antitumor activity in preclinical models.
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Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Calcitriol/efeitos adversos , Calcitriol/farmacocinética , Calcitriol/farmacologia , Sinergismo Farmacológico , Receptores ErbB/metabolismo , Feminino , Gefitinibe , Humanos , Imuno-Histoquímica , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Neoplasias/enzimologia , Fosforilação , Quinazolinas/efeitos adversos , Quinazolinas/farmacocinética , Quinazolinas/farmacologiaRESUMO
1,25-Dihydroxycholecalciferol (calcitriol) is recognized widely for its effects on bone and mineral metabolism. Epidemiological data suggest that low Vitamin D levels may play a role in the genesis of prostate cancer and perhaps other tumors. Calcitriol is a potent anti-proliferative agent in a wide variety of malignant cell types. In prostate, breast, colorectal, head/neck and lung cancer as well as lymphoma, leukemia and myeloma model systems calcitriol has significant anti-tumor activity in vitro and in vivo. Calcitriol effects are associated with an increase in G0/G1 arrest, induction of apoptosis and differentiation, modulation of expression of growth factor receptors. Glucocorticoids potentiate the anti-tumor effect of calcitriol and decrease calcitriol-induced hypercalcemia. Calcitriol potentiates the antitumor effects of many cytotoxic agents and inhibits motility and invasiveness of tumor cells and formation of new blood vessels. Phase I and II trials of calcitriol either alone or in combination with carboplatin, taxanes or dexamethasone have been initiated in patients with androgen dependent and independent prostate cancer and advanced cancer. Data indicate that high-dose calcitriol is feasible on an intermittent schedule, no dose-limiting toxicity has been encountered and optimal dose and schedule are being delineated. Clinical responses have been seen with the combination of high dose calcitriol+dexamethasone in androgen independent prostate cancer (AIPC) and apparent potentiation of the antitumor effects of docetaxel have been seen in AIPC. These results demonstrate that high intermittent doses of calcitriol can be administered to patients without toxicity, that the MTD is yet to be determined and that calcitriol has potential as an anti-cancer agent.
Assuntos
Antineoplásicos/farmacologia , Calcitriol/farmacologia , Antineoplásicos/uso terapêutico , Cisplatino/farmacologia , Cisplatino/uso terapêutico , Receptores ErbB/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Glucocorticoides/farmacologia , Substâncias de Crescimento/metabolismo , Humanos , Paclitaxel/farmacologia , Paclitaxel/uso terapêutico , Receptores de Calcitriol/efeitos dos fármacos , Receptores de Calcitriol/metabolismo , Transdução de SinaisRESUMO
Epidemiologic data suggest that low exposure to vitamin D or 1alpha,25-dihydroxycholecalciferol (calcitriol) increases the risk of prostate cancer. Calcitriol, a central factor in bone and mineral metabolism, is also a potent antiproliferative agent in a wide variety of malignant cell types. We have demonstrated that calcitriol has significant antitumor activity in vitro and in vivo in prostate and squamous cell carcinoma model systems. Calcitriol, in these models, induces a significant G0/G1 arrest and modulates p21(Waf1/Cip1) and p27(Kip1), the cyclin-dependent kinase inhibitors. Calcitriol induces poly (adenosine diphosphate-ribose) polymerase cleavage, increases bax/bcl-2 ratio, reduces levels of phosphorylated mitogen-activated protein kinases (P-MAPKs; also known as extracellular signal-related kinase [ERK] 1/2) and phosphorylated Akt, induces caspase-dependent mitogen-activated protein kinase kinase (MEK) cleavage and upregulation of MEK kinase-1, all potential markers of the apoptotic pathway. We also have demonstrated that dexamethasone (dex) potentiates the antitumor effect of calcitriol through effects on the vitamin D receptor and decreases calcitriol-induced hypercalcemia. We initiated phase 1 and phase 2 trials of calcitriol, either alone or in combination with carboplatin, paclitaxel, or dex. Data from these studies indicate that high-dose calcitriol is feasible on an intermittent schedule, the maximum tolerated dose (MTD) is unclear, and dex or paclitaxel appear to ameliorate hypercalcemia. Studies continue to define the MTD of calcitriol on this intermittent schedule, either alone or with other agents, and to evaluate the mechanisms of calcitriol effects in prostate cancer models.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Calcitriol/administração & dosagem , Calcitriol/metabolismo , Neoplasias da Próstata/tratamento farmacológico , Receptores de Calcitriol/metabolismo , Animais , Ensaios Clínicos como Assunto , Dexametasona/administração & dosagem , Glucocorticoides/administração & dosagem , Humanos , Masculino , Transdução de SinaisRESUMO
Although there is abundant evidence that 1alpha,25-dihydroxyvitamin D(3) [1,25-(OH)(2)D(3)] inhibits the growth of several cancer cell types, inhibition of angiogenesis may also play a role in mediating the antitumor effects of 1,25-(OH)(2)D(3.) We examined the ability of 1,25-(OH)(2)D(3) to inhibit the growth of tumor-derived endothelial cells (TDECs) and normal endothelial cells and to modulate angiogenic signaling. 1,25-(OH)(2)D(3) inhibited the growth of TDECs from two tumor models at nanomolar concentrations, but was less potent against normal aortic or yolk sac endothelial cells. The vitamin D analogs Ro-25-6760, EB1089, and ILX23-7553 were also potent inhibitors of TDEC proliferation. Furthermore, the combination of 1,25-(OH)(2)D(3) and dexamethasone had greater activity than either agent alone. 1,25-(OH)(2)D(3) increased vitamin D receptor and p27(Kip1) protein levels in TDECs, whereas phospho-ERK1/2 and phospho-Akt levels were reduced. These changes were not observed in normal aortic endothelial cells. In squamous cell carcinoma and radiation-induced fibrosarcoma-1 cells, 1,25-(OH)(2)D(3) treatment caused a reduction in the angiogenic signaling molecule, angiopoietin-2. In conclusion, 1,25-(OH)(2)D(3) and its analogs directly inhibit TDEC proliferation at concentrations comparable to those required to inhibit tumor cells. Further, 1,25-(OH)(2)D(3) modulates cell cycle and survival signaling in TDECs and affects angiogenic signaling in cancer cells. Thus, our work supports the hypothesis that angiogenesis inhibition plays a role in the antitumor effects of 1,25-(OH)(2)D(3).