RESUMO
Antineoplastic therapy has been associated with pain syndrome development characterized by acute and chronic pain. The chemotherapeutic agent dacarbazine, used mainly to treat metastatic melanoma, is reported to cause painful symptoms, compromising patient quality of life. Evidence has proposed that transient receptor potential ankyrin 1 (TRPA1) plays a critical role in chemotherapy-induced pain syndrome. Here, we investigated whether dacarbazine causes painful hypersensitivity in naive or melanoma-bearing mice and the involvement of TRPA1 in these models. Mouse dorsal root ganglion (DRG) neurons and human TRPA1-transfected HEK293 (hTRPA1-HEK293) cells were used to evaluate the TRPA1-mediated calcium response evoked by dacarbazine. Mechanical and cold allodynia were evaluated after acute or repeated dacarbazine administration in naive mice or after inoculation of B16-F10 melanoma cells in C57BL/6 mice. TRPA1 involvement was investigated by using pharmacological and genetic tools (selective antagonist or antisense oligonucleotide treatment and Trpa1 knockout mice). Dacarbazine directly activated TRPA1 in hTRPA1-HEK293 cells and mouse DRG neurons and appears to sensitize TRPA1 indirectly by generating oxidative stress products. Moreover, dacarbazine caused mechanical and cold allodynia in naive but not Trpa1 knockout mice. Also, dacarbazine-induced nociception was reduced by the pharmacological TRPA1 blockade (antagonism), antioxidants, and by ablation of TRPA1 expression. TRPA1 pharmacological blockade also reduced dacarbazine-induced nociception in a tumor-associated pain model. Thus, dacarbazine causes nociception by TRPA1 activation, indicating that this receptor may represent a pharmacological target for treating chemotherapy-induced pain syndrome in cancer patients submitted to antineoplastic treatment with dacarbazine.
Assuntos
Antineoplásicos Alquilantes/toxicidade , Dacarbazina/toxicidade , Hiperalgesia/induzido quimicamente , Melanoma Experimental , Canal de Cátion TRPA1/efeitos dos fármacos , Animais , Células HEK293 , Humanos , Hiperalgesia/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Canal de Cátion TRPA1/metabolismoRESUMO
BACKGROUND/AIMS: Glioblastoma (GBM) is a malignant brain tumor with a poor prognosis. Proteasome subunit beta type-4 (PSMB4) is an essential subunit that contributes to the assembly of the 20S proteasome complex. However, the role of PSMB4 in glioblastomas remains to be clarified. The aim of this study was to investigate the role of PSMB4 in GBM tumor progression. METHODS: We first analyzed the PSMB4 protein and mRNA expression in 80 clinical brain specimens and 77 datasets from the National Center for Biotechnology Information (NCBI) Gene Expression Omnibus (GEO) database. Next, we inhibited the PSMB4 expression by siRNA in cellular and animal models to explore PSMB4's underlying mechanisms. The cell survival after siPSMB4 transfection was assayed by MTT assay. Annexin V and propidium iodide staining was used to monitor the apoptosis by flow cytometric analysis. Moreover, the migration and invasion were evaluated by wound healing and Transwell assays. The expression of migration-related and invasion-related proteins after PSMB4 inhibition was detected by Western blotting. In addition, an orthotropic xenograft mouse model was used to assay the effect of PSMB4 knockdown in the in vivo study. RESULTS: Basis on the results of bioinformatics study, glioma patients with higher PSMB4 expression had a shorter survival time than those with lower PSMB4 expression. The staining of clinical brain tissues showed elevated PSMB4 expression in GBM tissues compared with normal brain tissues. The PSMB4 inhibition decreased proliferation, migration and invasion abilities in human GBM cells. Downregulated PSMB4 resulted in cell cycle arrest and apoptosis in vitro. In an orthotropic xenograft mouse model, the glioma tumors progression was reduced when PSMB4 was down-regulated. The decreased PSMB4 enhanced the anti-tumor effect of temozolomide (TMZ) on tumor growth. In addition, the absence of PSMB4 decreased the expression of phosphorylated focal adhesion kinase and matrix metallopeptidase 9 in vivo. CONCLUSION: PSMB4 inhibition in combination with TMZ may exert an anti-tumor effect by decreasing cell proliferation and invasion as well as by promoting apoptosis in human glioblastoma cells. This research may improve the therapeutic efficacy of glioblastoma treatment.
Assuntos
Complexo de Endopeptidases do Proteassoma/metabolismo , Animais , Apoptose/efeitos dos fármacos , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Catepsina B/metabolismo , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Dacarbazina/análogos & derivados , Dacarbazina/uso terapêutico , Dacarbazina/toxicidade , Bases de Dados Factuais , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Antígeno Ki-67/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Gradação de Tumores , Complexo de Endopeptidases do Proteassoma/química , Complexo de Endopeptidases do Proteassoma/genética , Interferência de RNA , TemozolomidaRESUMO
AIM: Glioblastoma (GBM) is one of the lethal central nervous system tumors. One of the widely used chemical agents for the treatment of glioblastoma is temozolomide. It is an orally administered, deoxyribonucleic acid (DNA) alkylating agent. DNA alkylation triggers the death of tumor cells. However, some tumor cells are able to repair this type of DNA damage and thus lower the therapeutic effect of temozolomide. Laboratory and clinical studies indicate that temozolomide"s anticancer effects might be strengthened when combined with other chemotherapeutic agents like etoposide or antioxidant agents like ascorbic acid. In this study, we aimed to evaluate the cytotoxic and oxidative stress effects of ascorbic acid (1000 ?M), temozolomide (100 ?M) and etoposide (25 ?M) agents alone and in dual and triple combinations in a glioblastoma U87 MG cell culture. MATERIAL AND METHODS: The cytotoxic and oxidative stress effects were investigated by the 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) and liquid chromatography tandem-mass spectrometry (LC-MS/MS) analysis methods. RESULTS: Cytotoxicity tests showed that etoposide, temozolomide, "etoposide+ascorbic acid", "temozolomide+ascorbic acid", "temozolomide+etoposide" and "temozolomide+etoposide+ascorbic acid" combinations have anti-proliferative effects. The maximum anti-proliferation response was observed in the "temozolomide+etoposide+ascorbic acid"-added group. Similarly LCMS/ MS analyses showed that minimum oxidative DNA damage occurred in the "temozolomide+etoposide+ascorbic acid"-added group. CONCLUSION: Ascorbic acid decreases the cytotoxic and genotoxic effect of etoposide and etoposide-temozolomide combination but it has no meaningful effect on temozolomide"s toxicity.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/toxicidade , Ácido Ascórbico/toxicidade , Dano ao DNA/efeitos dos fármacos , Dacarbazina/análogos & derivados , Etoposídeo/toxicidade , Glioblastoma/patologia , Antineoplásicos Alquilantes/administração & dosagem , Antineoplásicos Alquilantes/toxicidade , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Ácido Ascórbico/administração & dosagem , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Neoplasias do Sistema Nervoso Central/tratamento farmacológico , Neoplasias do Sistema Nervoso Central/patologia , Dano ao DNA/fisiologia , Dacarbazina/administração & dosagem , Dacarbazina/toxicidade , Sinergismo Farmacológico , Etoposídeo/administração & dosagem , Glioblastoma/tratamento farmacológico , Humanos , TemozolomidaRESUMO
A metastatic melanoma obtained from the right chest wall of a patient was previously established orthotopically in the right chest wall of nude mice as a patient-derived orthotopic xenograft (PDOX) model. We previously showed that the combination of tumor-targeting Salmonella typhimurium A1-R (S. typhimurium A1-R) and chemotherapy was highly effective against the melanoma PDOX. In the present study, we investigated the mechanism of the high efficacy of this combination. Two weeks after implantation, 40 PDOX mouse models were randomized into 4 groups of 10 mice each: untreated control (n = 10); treated with S. typhimurium A1-R (5 × 107 CFU/100 µl, i.v., once a week for 2 weeks, n = 10); treated with temozolomide (TEM) (25 mg/kg, p.o. for 14 consecutive days) combined with S. typhimurium A1-R (5 × 107 CFU/100 µl, i.v., once a week for 2 weeks, n = 10); treated with vemurafenib (VEM) (30 mg/kg, p.o., for 14 consecutive days) combined with S. typhimurium A1-R (5 × 107 CFU/100 µl, i.v., once a week for 2 weeks) (n = 10). On day 14 from initiation, all treatments significantly inhibited tumor growth compared with untreated control (S. typhimurium A1-R: p < 0.01; TEM combined with S. typhimurium A1-R: p < 0.01; VEM combined with S. typhimurium A1-R: p < 0.01). Combination therapy with S. typhimurium A1-R was significantly more effective on tumor growth than S. typhimurium A1-R alone (with TEM: p < 0.01; with VEM: p < 0.01). Combination therapy significantly increased S. typhimurium A1-R tumor targeting alone (S. typhimurium A1-R + TEM: p < 0.01, S. typhimurium A1-R + VEM: p < 0.01), relative to S. typhimurium A1-R alone, respectively. In conclusion, chemotherapy drugs promoted targeting of S. typhimurium A1-R of melanoma, thereby enhancing efficacy against the melanoma PDOX.
Assuntos
Antineoplásicos/uso terapêutico , Dacarbazina/análogos & derivados , Indóis/uso terapêutico , Melanoma/terapia , Proteínas Proto-Oncogênicas B-raf/genética , Salmonella typhimurium/fisiologia , Sulfonamidas/uso terapêutico , Idoso , Animais , Antineoplásicos/toxicidade , Dacarbazina/uso terapêutico , Dacarbazina/toxicidade , Modelos Animais de Doenças , Esquema de Medicação , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Xenoenxertos , Humanos , Indóis/toxicidade , Melanoma/tratamento farmacológico , Melanoma/patologia , Camundongos , Camundongos Nus , Microscopia Confocal , Sulfonamidas/toxicidade , Temozolomida , VemurafenibRESUMO
Glioblastoma multiforme (GBM) is the most malignant brain cancer that causes high mortality in humans. It responds poorly to the most common cancer treatments, such as surgery, chemo- and radiation therapy. Temozolomide (TMZ) is an alkylating agent that has been widely used to treat GBM; resistance to this drug is often found. One unexplored possibility for overcoming this resistance is a treatment based on concomitant exposure to electromagnetic fields (EMF) and TMZ. Indeed, many evidences show that EMF affects cancer cells and drug performance. In this study, we evaluated the potential synergistic effect of 100µM TMZ and EMF (100Hz, 100G) on two human glioma cells line, i.e., U87 and T98G above single treatments, TMZ or EMF. Co-treatment synergistically enhanced apoptosis in U87 and T98G cells, by increasing the expression of P53, Bax, and Caspase-3 and decreasing that of Bcl-2 and Cyclin-D1. We also observed an increase in reactive oxygen species (ROS) production and the overexpression of the heme oxygenase-1 (HO-1) gene in comparison to controls. In conclusion, since EMF enhanced the apoptotic effect of TMZ, possibly through a redox regulation mechanism, the TMZ/EMF combination may be effective for glioma cancer treating. Further studies are needed to reveal the action mechanism of this possible novel therapeutic approach.
Assuntos
Antineoplásicos Alquilantes/toxicidade , Citotoxinas/toxicidade , Dacarbazina/análogos & derivados , Campos Eletromagnéticos/efeitos adversos , Glioblastoma/tratamento farmacológico , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Dacarbazina/toxicidade , Glioblastoma/patologia , Humanos , Magnetoterapia/métodos , TemozolomidaRESUMO
Sleeping sickness is an infectious disease that is caused by the protozoan parasite Trypanosoma brucei. The second stage of the disease is characterised by the parasites entering the brain. It is therefore important that sleeping sickness therapies are able to cross the blood-brain barrier. At present, only three medications for chemotherapy of the second stage of the disease are available. As these trypanocides have serious side effects and are difficult to administer, new and safe anti-trypanosomal brain-penetrating drugs are needed. For these reasons, the anti-glioblastoma drug temozolomide was tested in vitro for activity against bloodstream forms of T. brucei. The concentration of the drug required to reduce the growth rate of the parasites by 50% was 29.1 µM and to kill all trypanosomes was 125 µM. Importantly, temozolomide did not affect the growth of human HL-60 cells up to a concentration of 300 µM. Cell cycle analysis revealed that temozolomide induced DNA damage and subsequent cell cycle arrest in trypanosomes exposed to the compound. As drug combination regimes often achieve greater therapeutic efficacy than monotherapies, the interactions of temozolomide with the trypanocides eflornithine and melarsoprol, respectively, was determined. Both combinations were found to produce an additive effect. In conclusion, these results together with well-established pharmacokinetic data provide the basis for in vivo studies and potentially for clinical trials of temozolomide in the treatment of T. brucei infections and a rationale for its use in combination therapy, particularly with eflornithine or melarsoprol.
Assuntos
Dacarbazina/análogos & derivados , Eflornitina/farmacologia , Melarsoprol/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma brucei brucei/efeitos dos fármacos , Antineoplásicos Alquilantes/farmacologia , Antineoplásicos Alquilantes/uso terapêutico , Antineoplásicos Alquilantes/toxicidade , Neoplasias Encefálicas/tratamento farmacológico , Dacarbazina/farmacologia , Dacarbazina/uso terapêutico , Dacarbazina/toxicidade , Quimioterapia Combinada , Eflornitina/uso terapêutico , Glioblastoma/tratamento farmacológico , Células HL-60 , Humanos , Melarsoprol/uso terapêutico , Temozolomida , Tripanossomicidas/uso terapêutico , Tripanossomicidas/toxicidade , Tripanossomíase Africana/tratamento farmacológicoRESUMO
Glioblastoma multiforme (GBM) is the high-grade primary glioma in adults. Temozolomide (TMZ), an alkylating agent of the imidazotetrazine series, is a first-line chemotherapeutic drug for clinical therapy. However, the expense of TMZ therapy and increasing drug resistance to TMZ decreases its therapeutic effects. Therefore, our aim was to investigate the detailed molecular mechanisms of TMZ-mediated cytotoxicity to enhance the efficacy of TMZ in clinical GBM therapy. First, TMZ-mediated gene expression profiles and networks in U87-MG cells were identified by transcriptome microarray and bioinformatic analyses. Cation transport regulator-like protein 1 (CHAC1) was the most highly TMZ-upregulated gene. Overexpression and knockdown of CHAC1 expression significantly influenced TMZ-mediated cell viability, apoptosis, caspase-3 activation, and poly(ADP ribose) polymerase (PARP) degradation. The c-Jun N-terminal kinase (JNK)1/c-JUN pathway was identified to participate in TMZ-upregulated CHAC1 expression via transcriptional control. Furthermore, CHAC1 levels were significantly decreased in GBM cell lines, TCGA array data, and tumor tissues. Overexpression of CHAC1 enhanced glioma apoptotic death via caspase-3/9 activation, PARP degradation, autophagy formation, reactive oxygen species generation, increased intracellular calcium, and loss of the mitochondria membrane potential. Finally, we also identified that TMZ significantly reduced Notch3 levels, which are upregulated in gliomas. TMZ also induced CHAC1 to bind to the Notch3 protein and inhibit Notch3 activation, resulting in attenuation of Notch3-mediated downstream signaling pathways. These results emphasize that CHAC1-inhibited Notch3 signaling can influence TMZ-mediated cytotoxicity. Our findings may provide novel therapeutic strategies for future glioblastoma therapy.
Assuntos
Antineoplásicos Alquilantes/farmacologia , Dacarbazina/análogos & derivados , Glioma/tratamento farmacológico , Receptor Notch3/metabolismo , gama-Glutamilciclotransferase/farmacologia , Antineoplásicos Alquilantes/toxicidade , Autofagia/efeitos dos fármacos , Autofagia/fisiologia , Cálcio/metabolismo , Caspase 3/metabolismo , Caspase 9/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Dacarbazina/farmacologia , Dacarbazina/toxicidade , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioma/metabolismo , Glioma/patologia , Humanos , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Potencial da Membrana Mitocondrial/fisiologia , Proteína Quinase 8 Ativada por Mitógeno/metabolismo , Proteínas Proto-Oncogênicas c-jun/metabolismo , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Temozolomida , gama-Glutamilciclotransferase/toxicidadeRESUMO
Glioblastomas (GBL) are the most common and aggressive brain tumors. They are distinguished by high resistance to radiation and chemotherapy. To find novel approaches for GBL classification, we obtained 16 primary GBL cell cultures and tested them with real-time PCR for mRNA expression of several genes (YB-1, MGMT, MELK, MVP, MDR1, BCRP) involved in controlling cell proliferation and drug resistance. The primary GBL cultures differed in terms of proliferation rate, wherein a group of GBL cell cultures with low proliferation rate demonstrated higher resistance to temozolomide. We found that GBL primary cell cultures characterized by high proliferation rate and lower resistance to temozolomide expressed higher mRNA level of the YB-1 and MDR1 genes, whereas upregulated expression of MVP/LRP mRNA was a marker in the group of GBL with low proliferation rate and high resistance. A moderate correlation between expression of YB-1 and MELK as well as YB-1 and MDR1 was found. In the case of YB-1 and MGMT expression, no correlation was found. A significant negative correlation was revealed between mRNA expression of MVP/LRP and MELK, MDR1, and BCRP. No correlation in expression of YB-1 and MVP/LRP genes was observed. It seems that mRNA expression of YB-1 and MVP/LRP may serve as a marker for GBL cell cultures belonging to distinct groups, each of which is characterized by a unique pattern of gene activity.
Assuntos
Antineoplásicos Alquilantes/toxicidade , Proliferação de Células/efeitos dos fármacos , Dacarbazina/análogos & derivados , Partículas de Ribonucleoproteínas em Forma de Abóbada/metabolismo , Proteína 1 de Ligação a Y-Box/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Dacarbazina/toxicidade , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Imuno-Histoquímica , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Temozolomida , Células Tumorais Cultivadas , Partículas de Ribonucleoproteínas em Forma de Abóbada/genética , Proteína 1 de Ligação a Y-Box/genéticaRESUMO
A series of novel 5-fluorine-benzimidazole-4-carboxamide analogs were designed and synthesized. All target compounds were evaluated for their PARP-1 inhibitory activity. Compounds possessed high intrinsic PARP-1 inhibitory potency have been evaluated in vitro cellular assays to measure the potentiation effect of cytotoxic agents against cancer cell line. These efforts led to the identification of compound 10f, which displayed strong inhibition against the PARP-1 enzyme with an IC50 of 43.7nM, excellent cell inhibitory activity in HCT116 cells (IC50=7.4µM) and potentiation of temozolomide cytotoxicity in cancer cell line A549 (PF50=1.6).
Assuntos
Amidas/química , Antineoplásicos/síntese química , Benzimidazóis/química , Benzimidazóis/síntese química , Desenho de Fármacos , Inibidores Enzimáticos/síntese química , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Células A549 , Amidas/síntese química , Amidas/toxicidade , Antineoplásicos/química , Antineoplásicos/toxicidade , Benzimidazóis/toxicidade , Sítios de Ligação , Sobrevivência Celular/efeitos dos fármacos , Dacarbazina/análogos & derivados , Dacarbazina/toxicidade , Inibidores Enzimáticos/química , Inibidores Enzimáticos/toxicidade , Células HCT116 , Humanos , Simulação de Acoplamento Molecular , Poli(ADP-Ribose) Polimerase-1/metabolismo , Ligação Proteica , Estrutura Terciária de Proteína , Relação Estrutura-Atividade , TemozolomidaRESUMO
BACKGROUND: Temozolomide (TMZ), an oral alkylator of the imidazotetrazine family, is used to treat glioma. Whether this drug has any ionic effects in glioma cells remains largely unclear. METHODS: With the aid of patch-clamp technology, we investigated the effects of TMZ on the ionic currents in U373 glioma cells. The mRNA expression of KCNN4 (KCa3.1) in U373 glioma cells and TMZ's effect on K+ currents in these KCNN4 siRNA-transfected U373 cells were investigated. RESULTS: In whole-cell recordings, TMZ decreased the amplitude of voltage-dependent K+ currents (IK) in U373 cells. TMZ-induced IK inhibition was reversed by ionomycin or 1-ethyl-2-benzimidazolinone (1-EBIO). In cell-attached configuration, TMZ concentration-dependently reduced the activity of intermediate-conductance Ca2+-activated K+ (IKCa) channels with an IC50 value of 9.2 µM. Chlorzoxazone or 1-EBIO counteracted the TMZ-induced inhibition of IKCa channels. Although TMZ was unable to modify single-channel conductance, its inhibition of IKCa channels was weakly voltage-dependent and accompanied by a significant prolongation in the slow component of mean closed time. However, neitherlarge-conductance Ca2+-activated (BKCa) nor inwardly rectifying K+ (Kir) channels were affected by TMZ. In current-clamp mode, TMZ depolarized the cell membrane and 1-EBIO reversed TMZ-induced depolarization. TMZ had no effect on IK in KCNN4 siRNA-transfected U373 cells. CONCLUSION: In addition to the DNA damage it does, its inhibitory effect on IKCa channels accompanied by membrane depolarization could be an important mechanism underlying TMZ-induced antineoplastic actions.
Assuntos
Alquilantes/toxicidade , Dano ao DNA/efeitos dos fármacos , Dacarbazina/análogos & derivados , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/metabolismo , Benzimidazóis/farmacologia , Linhagem Celular Tumoral , Dacarbazina/toxicidade , Glioma , Humanos , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/antagonistas & inibidores , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/genética , Ionomicina/farmacologia , Canais de Potássio Ativados por Cálcio de Condutância Alta/metabolismo , Potenciais da Membrana/efeitos dos fármacos , Técnicas de Patch-Clamp , Canais de Potássio Corretores do Fluxo de Internalização/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , TemozolomidaRESUMO
BACKGROUND: The primary aim of this Phase I study was to determine the maximum tolerated dose (MTD) of TPI 287 and the safety and tolerability of TPI 287 alone and in combination with temozolomide (TMZ) in pediatric patients with refractory or recurrent neuroblastoma or medulloblastoma. The secondary aims were to evaluate the pharmacokinetics of TPI 287 and the treatment responses. PROCEDURE: Eighteen patients were enrolled to a phase I dose escalation trial of weekly intravenous infusion of TPI 287 for two 28-day cycles with toxicity monitoring to determine the MTD, followed by two cycles of TPI 287 in combination with TMZ. Samples were collected to determine the pharmacokinetic parameters C(max), AUC(0-24), t(1/2), CL, and Vd on day 1 of cycles 1 (TPI 287 alone) and 3 (TPI 287 + TMZ) following TPI 287 infusion. Treatment response was evaluated by radiographic (CT or MRI) and radionuclide (MIBG) imaging for neuroblastoma. RESULTS: We determined the MTD of TPI 287 alone and in combination with temozolomide to be 125 mg/m(2). The non-dose-limiting toxicities at this dose were mainly anorexia and pain. The dose-limiting toxicities (DLTs) of two patients at 135 mg/m(2) were grade 3 hemorrhagic cystitis and grade 3 sensory neuropathy. CONCLUSIONS: Overall, TPI 287 was well tolerated by pediatric patients with refractory and relapsed neuroblastoma and medulloblastoma at a dose of 125 mg/m(2) IV on days 1, 8, and 15 of a 28 day cycle.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Dacarbazina/análogos & derivados , Meduloblastoma/tratamento farmacológico , Neuroblastoma/tratamento farmacológico , Taxoides/administração & dosagem , Taxoides/uso terapêutico , Adolescente , Adulto , Criança , Pré-Escolar , Dacarbazina/administração & dosagem , Dacarbazina/farmacocinética , Dacarbazina/toxicidade , Feminino , Humanos , Infusões Intravenosas , Masculino , Dose Máxima Tolerável , Recidiva Local de Neoplasia , Taxoides/farmacocinética , Taxoides/toxicidade , TemozolomidaRESUMO
Histone deacetylase inhibitors (HDACi) have been evaluated in patients with Ewing sarcoma (EWS) but demonstrated limited activity. To better understand the potential for HDACi in EWS, we evaluated the combination of the HDACi vorinostat, with DNA damaging agents SN-38 (the active metabolite of irinotecan and topoisomerase 1 inhibitor) plus the alkylating agent temozolomide (ST). Drugs were evaluated in sequential and simultaneous combinations in two EWS cell lines. Results demonstrate that cell viability, DNA damage and reactive oxygen species (ROS) production are dependent on the sequence of drug administration. Enhanced cytotoxicity is exhibited in vitro in EWS cell lines treated with ST administered before vorinostat, which was modestly higher than concomitant treatment and superior to vorinostat administered before ST. Drug combinations downregulate cyclin D1 to induce G0/G1 arrest and promote apoptosis by cleavage of caspase-3 and PARP. When ST is administered before or concomitantly with vorinostat there is activation of STAT3, MAPK and the p53 pathway. In contrast, when vorinostat is administered before ST, there is DNA repair, increased AKT phosphorylation and reduced H2B acetylation. Inhibition of AKT using the small molecule inhibitor MK-2206 did not restore H2B acetylation. Combining ST with the dual ALK and IGF-1R inhibitor, AZD3463 simultaneously inhibited STAT3 and AKT to enhance the cytotoxic effects of ST and further reduce cell growth suggesting that STAT3 and AKT activation were in part mediated by ALK and IGF-1R signaling. In summary, potent antiproliferative and proapoptotic activity were demonstrated for ST induced DNA damage before or simultaneous with HDAC inhibition and cell death was mediated through the p53 pathway. These observations may aid in designing new protocols for treating pediatric patients with high-risk EWS.
Assuntos
Antineoplásicos/toxicidade , Apoptose/efeitos dos fármacos , Camptotecina/análogos & derivados , Dacarbazina/análogos & derivados , Inibidores de Histona Desacetilases/toxicidade , Ácidos Hidroxâmicos/toxicidade , Transdução de Sinais/efeitos dos fármacos , Acetilação/efeitos dos fármacos , Camptotecina/toxicidade , Caspase 3/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Dacarbazina/toxicidade , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Compostos Heterocíclicos com 3 Anéis/farmacologia , Humanos , Irinotecano , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fator de Transcrição STAT3/antagonistas & inibidores , Fator de Transcrição STAT3/metabolismo , Sarcoma de Ewing/metabolismo , Sarcoma de Ewing/patologia , Temozolomida , Proteína Supressora de Tumor p53/metabolismo , VorinostatRESUMO
Although temozolomide (TMZ) is the current first-line chemotherapy for glioblastoma multiforme (GBM), most patients either do not respond or ultimately fail TMZ treatment. Both intrinsic tumor resistance and limited access of TMZ to brain tumors as a result of the blood-brain barrier (BBB) contribute to poor response and ultimately to poor prognosis for GBM patients. We have developed a "dual-targeting" nanomedicine that both actively crosses the BBB and actively targets cancer cells once in the brain parenchyma. This nanomedicine (termed scL-TMZ) is sized ~40 nm and comprised of a cationic liposome (DOTAP:DOPE) encapsulating TMZ. The surface of liposome is decorated with anti-transferrin receptor single-chain antibody fragments to facilitate the crossing of the BBB by the scL-TMZ in addition to targeting GBM in the brain. This novel formulation was found to be markedly more effective than standard TMZ in both TMZ-resistant and TMZ-sensitive GBM. Encapsulation of TMZ also markedly enhanced its efficacy in killing a variety of non-GBM tumor cells. The scL-TMZ nanocomplex was shown to target cancer stem cells, which have been linked to both drug resistance and recurrence in GBM. Most significantly, systemically administered scL-TMZ significantly prolonged survival in mice bearing intracranial GBM tumors. The improved efficacy of scL-TMZ compared to standard TMZ was accompanied by reduced toxicity, so we conclude that the scL-TMZ nanomedicine holds great promise as a more effective therapy for GBM and other tumor types.
Assuntos
Antineoplásicos/administração & dosagem , Neoplasias Encefálicas/tratamento farmacológico , Dacarbazina/análogos & derivados , Glioblastoma/tratamento farmacológico , Nanocápsulas/administração & dosagem , Animais , Antineoplásicos/toxicidade , Apoptose , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Sobrevivência Celular , Dacarbazina/administração & dosagem , Dacarbazina/toxicidade , Feminino , Glioblastoma/patologia , Humanos , Camundongos Nus , Nanocápsulas/toxicidade , Temozolomida , Resultado do Tratamento , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Alkylating agents, such as streptozocin and dacarbazine, have been reported as active in neuroendocrine neoplasms (NENs). Temozolomide (TMZ) is an oral, potentially less toxic derivative of dacarbazine, which has shown activity both as a single agent and in combination with other drugs. Nevertheless, its role in NENs has not been well defined. Several retrospective and prospective phase I-II studies have been published describing its use in a variety of NENs. In a retrospective series, the combination of capecitabine and TMZ was reported to be associated with a particularly high tumour response in pancreatic NENs as a first-line treatment. Although in NENs, determination of the O6-methylguanine-DNA methyltransferase (MGMT) status has been suggested as a predictive biomarker of response, its role still remains investigational, awaiting validation along with the establishment of the optimal detection method. Metronomic schedules have been reported to potentially overcome MGMT-related drug resistance. Toxicity is manageable if well monitored. We reviewed the literature regarding pharmacological and clinical aspects of TMZ, focusing on specific settings of NENs, different schedules, toxicity and safety profiles, and potential predictive biomarkers of response.
Assuntos
Antineoplásicos Alquilantes/uso terapêutico , Dacarbazina/análogos & derivados , Tumores Neuroendócrinos/tratamento farmacológico , Antineoplásicos Alquilantes/farmacocinética , Antineoplásicos Alquilantes/farmacologia , Antineoplásicos Alquilantes/toxicidade , Dacarbazina/farmacocinética , Dacarbazina/farmacologia , Dacarbazina/uso terapêutico , Dacarbazina/toxicidade , Humanos , TemozolomidaRESUMO
The alkylating agent temozolomide (TMZ) represents an important component of current melanoma therapy, but overexpression of O6-methyl-guanine DNA methyltransferase (MGMT) in tumor cells confers resistance to TMZ and impairs therapeutic outcome. We investigated a novel perillyl alcohol (POH)-conjugated analog of TMZ, NEO212, for its ability to exert anticancer activity against MGMT-positive melanoma cells. Human melanoma cells with variable MGMT expression levels were treated with NEO212, TMZ, or perillyl alcohol in vitro and in vivo, and markers of DNA damage and apoptosis, and tumor cell growth were investigated. NEO212 displayed substantially greater anticancer activity than any of the other treatments. It reduced colony formation of MGMT-positive cells up to eight times more effectively than TMZ, and much more potently induced DNA damage and cell death. In a nude mouse tumor model, NEO212 showed significant activity against MGMT-positive melanoma, whereas TMZ, or a mix of TMZ plus POH, was ineffective. At the same time, NEO212 was well tolerated. NEO212 may have potential as a more effective therapy for advanced melanoma, and should become particularly suitable for the treatment of patients with MGMT-positive tumors.
Assuntos
Antineoplásicos Alquilantes/farmacologia , Dacarbazina/análogos & derivados , Melanoma/metabolismo , Melanoma/patologia , O(6)-Metilguanina-DNA Metiltransferase/metabolismo , Animais , Antineoplásicos Alquilantes/administração & dosagem , Antineoplásicos Alquilantes/toxicidade , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Metilação de DNA/efeitos dos fármacos , Dacarbazina/administração & dosagem , Dacarbazina/farmacologia , Dacarbazina/toxicidade , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Humanos , Concentração Inibidora 50 , Melanoma/tratamento farmacológico , Camundongos , Temozolomida , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: 3-bromopyruvate (3-BrPA) and dichloroacetate (DCA) are inhibitors of cancer-cell specific aerobic glycolysis. Their application in glioma is limited by 3-BrPA's inability to cross the blood-brain-barrier and DCA's dose-limiting toxicity. The safety and efficacy of intracranial delivery of these compounds were assessed. METHODS: Cytotoxicity of 3-BrPA and DCA were analyzed in U87, 9L, and F98 glioma cell lines. 3-BrPA and DCA were incorporated into biodegradable pCPP:SA wafers, and the maximally tolerated dose was determined in F344 rats. Efficacies of the intracranial 3-BrPA wafer and DCA wafer were assessed in a rodent allograft model of high-grade glioma, both as a monotherapy and in combination with temozolomide (TMZ) and radiation therapy (XRT). RESULTS: 3-BrPA and DCA were found to have similar IC50 values across the 3 glioma cell lines. 5% 3-BrPA wafer-treated animals had significantly increased survival compared with controls (P = .0027). The median survival of rats with the 50% DCA wafer increased significantly compared with both the oral DCA group (P = .050) and the controls (P = .02). Rats implanted on day 0 with a 5% 3-BrPA wafer in combination with TMZ had significantly increased survival over either therapy alone. No statistical difference in survival was noted when the wafers were added to the combination therapy of TMZ and XRT, but the 5% 3-BrPA wafer given on day 0 in combination with TMZ and XRT resulted in long-term survivorship of 30%. CONCLUSION: Intracranial delivery of 3-BrPA and DCA polymer was safe and significantly increased survival in an animal model of glioma, a potential novel therapeutic approach. The combination of intracranial 3-BrPA and TMZ provided a synergistic effect.
Assuntos
Antineoplásicos/administração & dosagem , Neoplasias Encefálicas/metabolismo , Ácido Dicloroacético/administração & dosagem , Glioblastoma/metabolismo , Glicólise/efeitos dos fármacos , Piruvatos/administração & dosagem , Implantes Absorvíveis , Animais , Antineoplásicos/toxicidade , Antineoplásicos Alquilantes/administração & dosagem , Antineoplásicos Alquilantes/toxicidade , Neoplasias Encefálicas/prevenção & controle , Neoplasias Encefálicas/radioterapia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Terapia Combinada , Dacarbazina/administração & dosagem , Dacarbazina/análogos & derivados , Dacarbazina/toxicidade , Ácido Dicloroacético/toxicidade , Vias de Administração de Medicamentos , Combinação de Medicamentos , Sistemas de Liberação de Medicamentos , Feminino , Glioblastoma/prevenção & controle , Glioblastoma/radioterapia , Humanos , Estimativa de Kaplan-Meier , Polímeros , Piruvatos/toxicidade , Ratos , Ratos Endogâmicos F344 , TemozolomidaRESUMO
Glioblastoma (formally glioblastoma multiforme, GBM) represents both the most common and most malignant variant among numerous of primary brain tumors. Temozolomide (TMZ) has been used for the treatment of glioblastoma. However, less than 1/3 of glioblastomas respond to TMZ-based therapies. Therefore, strategies to enhance the effect of TMZ are needed for more effective targeted therapeutics. Stress-activated protein kinases (SAPKs) JNK and p38 MAPK have been known to have apoptotic or anti-apoptotic effects depending on cell type and condition. On the other hand, Akt is a key regulator of cellular survival and has direct effects on the apoptosis machinery. In addition, it was discovered that Akt activation is primed by the activity of JNK. We, therefore, examined whether inhibition of JNK or p38 potentiates TMZ-induced apoptosis in U87MG cells via inhibition of Akt activation. TMZ significantly induced Akt activation as well as JNK or p38 activation. Inhibition of JNK suppressed Akt activation and potentiated TMZ-induced cytotoxicity. The phosphorylation of GSK-3ß and Bad, the downstream mediators of Akt, was also suppressed by the inhibition of JNK. The present data strongly suggest that there may be a crosstalk between JNK pathway and Akt pathway in glioblastoma and that further investigation based on the present data may provide a valuable approach for enhancing TMZ-induced cytotoxicity in glioblastoma.
Assuntos
Antineoplásicos Alquilantes/farmacologia , Dacarbazina/análogos & derivados , Glioblastoma/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Antineoplásicos Alquilantes/toxicidade , Linhagem Celular Tumoral , Dacarbazina/farmacologia , Dacarbazina/toxicidade , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Humanos , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Temozolomida , Proteína de Morte Celular Associada a bcl/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
BACKGROUND & AIMS: Lynch syndrome, a nonpolyposis form of hereditary colorectal cancer, is caused by inherited defects in DNA mismatch repair (MMR) genes. Most patients carry a germline mutation in 1 allele of the MMR genes MSH2 or MLH1. With spontaneous loss of the wild-type allele, cells with defects in MMR exist among MMR-proficient cells, as observed in healthy intestinal tissues from patients with Lynch syndrome. We aimed to create a mouse model of this situation to aid in identification of environmental factors that affect MMR-defective cells and their propensity for oncogenic transformation. METHODS: We created mice in which the MMR gene Msh2 can be inactivated in a defined fraction of crypt base columnar stem cells to generate MSH2-deficient intestinal crypts among an excess of wild-type crypts (Lgr5-CreERT2;Msh2(flox/-) mice). Intestinal tissues were collected; immunohistochemical analyses were performed for MSH2, along with allele-specific PCR assays. We traced the fate of MSH2-deficient crypts under the influence of different external factors. RESULTS: Lgr5-CreERT2;Msh2(flox/-) mice developed more adenomas and adenocarcinomas than control mice; all tumors were MSH2 deficient. Exposure of Lgr5-CreERT2;Msh2(flox/-) mice to the methylating agent temozolomide caused MSH2-deficient intestinal stem cells to proliferate more rapidly than wild-type stem cells. The MSH2-deficient intestinal stem cells were able to colonize the intestinal epithelium and many underwent oncogenic transformation, forming intestinal neoplasias. CONCLUSIONS: We developed a mouse model of Lynch syndrome (Lgr5-CreERT2;Msh2(flox/-) mice) and found that environmental factors can modify the number and mutability of the MMR-deficient stem cells. These findings provide evidence that environmental factors can promote development of neoplasias and tumors in patients with Lynch syndrome.
Assuntos
Adenocarcinoma/induzido quimicamente , Adenocarcinoma/genética , Adenoma/induzido quimicamente , Adenoma/genética , Neoplasias Colorretais Hereditárias sem Polipose/induzido quimicamente , Neoplasias Colorretais Hereditárias sem Polipose/genética , Reparo de Erro de Pareamento de DNA/efeitos dos fármacos , Dacarbazina/análogos & derivados , Intestinos/efeitos dos fármacos , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Adenoma/metabolismo , Adenoma/patologia , Animais , Proliferação de Células/efeitos dos fármacos , Transformação Celular Neoplásica/induzido quimicamente , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Neoplasias Colorretais Hereditárias sem Polipose/metabolismo , Neoplasias Colorretais Hereditárias sem Polipose/patologia , Dacarbazina/toxicidade , Modelos Animais de Doenças , Feminino , Mucosa Intestinal/metabolismo , Intestinos/patologia , Masculino , Camundongos Knockout , Proteína 2 Homóloga a MutS/deficiência , Proteína 2 Homóloga a MutS/genética , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Fatores de Risco , Temozolomida , Fatores de TempoRESUMO
This study evaluated the toxicity profiles of temozolomide in the treatment of malignant glioma as either concurrent or adjuvant chemotherapy. We retrospectively reviewed the medical records of 300 malignant glioma patients treated with temozolomide in two medical institutions in Korea between 2004 and 2010. Two hundred nine patients experienced a total of 618 toxicities during temozolomide therapy. A total of 84.8% of the 618 toxicities were Common Terminology Criteria for Adverse Events (CTCAE) grade 1 or 2, while 15.2% were grade 3 or 4. Among the hematologic toxicities, thrombocytopenia (13.7%), anemia (11.0%), and AST/ALT increases (7.0%) were common. Among the non-hematologic toxicities, nausea (44.3%), vomiting (37.0%), and anorexia (14.3%) were the three most common toxicities. There was no mortality due to temozolomide. Although temozolomide showed many types of toxicities, the majority of the toxicities were tolerable and of lower grade. Gastrointestinal troubles are the most common toxicities in Korean patients treated with temozolomide.
Assuntos
Antineoplásicos Alquilantes/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Dacarbazina/análogos & derivados , Glioma/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anorexia/etiologia , Antineoplásicos Alquilantes/efeitos adversos , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/radioterapia , Dacarbazina/efeitos adversos , Dacarbazina/uso terapêutico , Dacarbazina/toxicidade , Feminino , Glioma/patologia , Glioma/radioterapia , Doenças Hematológicas/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Náusea/tratamento farmacológico , Náusea/etiologia , Estadiamento de Neoplasias , República da Coreia , Estudos Retrospectivos , Índice de Gravidade de Doença , Fatores Sexuais , Temozolomida , Vômito/tratamento farmacológico , Vômito/etiologia , Adulto JovemRESUMO
Functional DNA mismatch repair (MMR) is essential for maintaining the fidelity of DNA replication and genetic stability. In hematopoiesis, loss of MMR results in methylating agent resistance and a hematopoietic stem cell (HSC) repopulation defect. Additionally MMR failure is associated with a variety of human malignancies, notably Lynch syndrome. We focus on the 5'â3' exonuclease Exo1, the primary enzyme excising the nicked strand during MMR, preceding polymerase synthesis. We found that nuclease dead Exo1 mutant cells are sensitive to the O6-methylguanine alkylating agent temozolomide when given with the MGMT inactivator, O6benzylguanine (BG). Additionally we used an MMR reporter plasmid to verify that Exo1(mut) MEFs were able to repair G:T base mismatches in vitro. We showed that unlike other MMR deficient mouse models, Exo1(mut) mouse HSC did not gain a competitive survival advantage post temozolomide/BG treatment in vivo. To determine potential nucleases implicated in MMR in the absence of Exo1 nuclease activity, but in the presence of the inactive protein, we performed gene expression analyses of several mammalian nucleases in WT and Exo1(mut) MEFs before and after temozolomide treatment and identified upregulation of Artemis, Fan1, and Mre11. Partial shRNA mediated silencing of each of these in Exo1(mut) cells resulted in decreased MMR capacity and increased resistance to temozolomide/BG. We propose that nuclease function is required for fully functional MMR, but a portfolio of nucleases is able to compensate for loss of Exo1 nuclease activity to maintain proficiency.