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1.
Int J Mol Sci ; 25(9)2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38731935

RESUMO

Cancer treatment is greatly challenged by drug resistance, highlighting the need for novel drug discoveries. Here, we investigated novel organoarsenic compounds regarding their resistance-breaking and apoptosis-inducing properties in leukemia and lymphoma. Notably, the compound (2,6-dimethylphenyl)arsonic acid (As2) demonstrated significant inhibition of cell proliferation and induction of apoptosis in leukemia and lymphoma cells while sparing healthy leukocytes. As2 reached half of its maximum activity (AC50) against leukemia cells at around 6.3 µM. Further experiments showed that As2 overcomes multidrug resistance and sensitizes drug-resistant leukemia and lymphoma cell lines to treatments with the common cytostatic drugs vincristine, daunorubicin, and cytarabine at low micromolar concentrations. Mechanistic investigations of As2-mediated apoptosis involving FADD (FAS-associated death domain)-deficient or Smac (second mitochondria-derived activator of caspases)/DIABLO (direct IAP binding protein with low pI)-overexpressing cell lines, western blot analysis of caspase-9 cleavage, and measurements of mitochondrial membrane integrity identified the mitochondrial apoptosis pathway as the main mode of action. Downregulation of XIAP (x-linked inhibitor of apoptosis protein) and apoptosis induction independent of Bcl-2 (B-cell lymphoma 2) and caspase-3 expression levels suggest the activation of additional apoptosis-promoting mechanisms. Due to the selective apoptosis induction, the synergistic effects with common anti-cancer drugs, and the ability to overcome multidrug resistance in vitro, As2 represents a promising candidate for further preclinical investigations with respect to refractory malignancies.


Assuntos
Apoptose , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Leucemia , Linfoma , Mitocôndrias , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/metabolismo , Humanos , Apoptose/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Linfoma/tratamento farmacológico , Linfoma/metabolismo , Linfoma/patologia , Leucemia/metabolismo , Leucemia/tratamento farmacológico , Leucemia/patologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Linhagem Celular Tumoral , Regulação para Baixo/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Citostáticos/farmacologia , Antineoplásicos/farmacologia
2.
Int J Mol Sci ; 24(2)2023 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-36674465

RESUMO

Ruthenium(II) complexes with N-heterocyclic carbene (NHC) ligands have recently attracted attention as novel chemotherapeutic agents. The complex HB324 was intensively studied as an apoptosis-inducing compound in resistant cell lines. HB324 induced apoptosis via mitochondrial pathways. Of particular interest is the upregulation of the Harakiri resistance protein, which inhibits the anti-apoptotic and death repressor proteins Bcl-2 (B-cell lymphoma 2) and BCL-xL (B-cell lymphoma-extra large). Moreover, HB324 showed synergistic activity with various established anticancer drugs and overcame resistance in several cell lines, such as neuroblastoma cells. In conclusion, HB324 showed promising potential as a novel anticancer agent in vitro, suggesting further investigations on this and other preclinical ruthenium drug candidates.


Assuntos
Antineoplásicos , Neuroblastoma , Rutênio , Humanos , Cisplatino/farmacologia , Rutênio/farmacologia , Regulação para Cima , Apoptose , Antineoplásicos/farmacologia , Neuroblastoma/tratamento farmacológico , Linhagem Celular Tumoral
3.
Molecules ; 27(15)2022 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-35956988

RESUMO

Isatis tinctoria and its indigo dyes have already provided highly active anti-leukaemic lead compounds, with the focus mainly being on indirubin, whereas indigo itself is inactive. There are many more indigoids to find in this plant extract, for example, quingdainone, an indigoid derived from tryptanthrin. We present here a new synthesis of hitherto neglected substituted quingdainones, which is very necessary due to their poor solubility behaviour, and a structure-dependent anti-leukaemic activity study of a number of compounds. Substituted α-phenylaminoacrylic acid was synthesised by hydrogen sulfide extrusion from an analogue mercaptoacetic acid, available from the condensation of rhodanin and a substituted tryptanthrin. It is shown that just improving water solubility does not increase anti-leukaemic activity, since a quingdainone carboxylic acid is inactive compared to dihydroxyquingdainone. The most effective compound, dihydroxyquingdainone with an AC50 of 7.5 µmole, is further characterised, revealing its ability to overcome multidrug resistance in leukaemia cells (Nalm-6/BeKa) with p-glycoprotein expression.


Assuntos
Citostáticos , Leucemia , Linfoma , Apoptose , Caspase 3 , Índigo Carmim , Leucemia/tratamento farmacológico , Folhas de Planta
4.
J Biol Inorg Chem ; 26(8): 897-907, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34617137

RESUMO

Despite high cure rates in pediatric patients with acute leukemia, development of resistance limits the efficacy of antileukemic therapy. Tris(1,10-phenanthroline)tris(thiocyanato-κN)lanthanum(III) (KP772) is an experimental antineoplastic agent to which multidrug-resistant cell models have shown hypersensitivity. Antiproliferative and apoptotic activities of KP772 were tested in leukemia, lymphoma and solid tumor cell lines as well as primary leukemia cells (isolated from the bone marrow of a child with acute myeloid leukemia (AML). The ability to overcome drug resistances was investigated in doxorubicin- and vincristine-resistant cell lines. Real-time PCR was used to gain insight into the mechanism of apoptosis induction. KP772 inhibited proliferation and induced apoptosis in various leukemia and lymphoma cell lines in a concentration-dependent manner (LC50 = 1-2.5 µM). Primary AML cells were also sensitive to KP772, whereas daunorubicin showed no significant effect. KP772 induces apoptosis independently of Bcl-2, Smac, and the CD95 receptor and is also effective in caspase 3-deficient MCF7 cells, indicating that apoptosis is partly triggered independently of caspase 3. mRNA expression profiling revealed an upregulation of the BH3-only Bcl-2 protein Harakiri in the course of KP772-induced apoptosis. Remarkably, KP772 overcame drug resistance to doxorubicin and vincristine in vitro, and the apoptotic effect in resistant cells was even superior to that in non-resistant parental cells. In combination with vincristine, doxorubicin and cytarabine, synergistic effects were observed in BJAB cells. The cytotoxic potency in vitro/ex vivo and the remarkable ability to overcome multidrug resistance propose KP772 as a promising candidate drug for antileukemic therapy, especially of drug-refractory malignancies.Graphic abstract.


Assuntos
Antineoplásicos , Leucemia , Linfoma , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose , Criança , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Humanos , Leucemia/tratamento farmacológico , Proteínas Proto-Oncogênicas c-bcl-2 , Regulação para Cima
5.
Pediatr Blood Cancer ; 68(8): e28936, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33580918

RESUMO

OBJECTIVES: Clinical studies have shown low toxicity and a favorable safety profile for sirolimus in vascular anomalies. Here, we describe severe adverse events (SAEs) observed during "off-label use" for vascular anomalies. METHODS: We performed a retrospective, multicenter chart review for SAEs during "off-label" sirolimus therapy for vascular anomalies and analyzed these cases by a predesigned workflow. RESULTS: We identified 17 SAEs in 14 patients diagnosed with generalized lymphatic anomaly (n = 4), Gorham-Stout disease (n = 2), central conducting lymphatic anomaly (n = 1), lymphatic malformation (n = 4), tufted angioma (n = 1), kaposiform hemangioendothelioma (n = 1), and venous malformation in a patient with CLOVES syndrome (n = 1). Three patients presented two SAEs each. The age at initiation of sirolimus therapy was under 2 years (n = 5), 2-6 years (n = 5), and older than 12 years (n = 4). SAEs occurred during the first 3 months of sirolimus therapy (n = 7), between 3 and 12 months (n = 7) and after 1 year of therapy (n = 3). The most frequent SAE was viral pneumonia (n = 8) resulting in one death due to a metapneumovirus infection in a 3 months old and a generalized adenovirus infection in a 28-month-old child. Sirolimus blood level at the time of SAEs ranged between 2.7 and 21 ng/L. Five patients were on antibiotic prophylaxis. CONCLUSIONS: Most SAEs are observed in the first year of sirolimus therapy; however, SAEs can also occur after a longer treatment period. SAEs are potentially life threatening, especially in early infancy. Presence of other risk factors, that is, underlying vascular anomaly or immune status, may contribute to the risk of SAEs. Sirolimus is an important therapeutic option for vascular anomalies, but patients and physicians need to be aware that adequate monitoring is necessary, especially in patients with complex lymphatic anomalies that are overrepresented in our cohort of SAEs.


Assuntos
Malformações Vasculares , Pré-Escolar , Hemangioendotelioma , Humanos , Lactente , Síndrome de Kasabach-Merritt/tratamento farmacológico , Anormalidades Linfáticas/tratamento farmacológico , Uso Off-Label , Estudos Retrospectivos , Sirolimo/efeitos adversos , Malformações Vasculares/tratamento farmacológico
6.
Biometals ; 34(2): 211-220, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33560473

RESUMO

We investigated the aluminium-salen complex MBR-8 as a potential anti-cancer agent. To see apoptotic effects induced by MBR-8, alone and in combination with common cytostatic drugs, DNA-fragmentations were studied using the flow cytometric analysis. Western blot analysis and measurement of the mitochondrial membrane potential with a JC-1 dye were employed to identify the pathway of apoptosis. An impressive overcoming of multidrug-resistance in leukemia (Nalm6) cells was observed. Additionally, solid tumor cells including Burkitt-like lymphoma (BJAB) and mamma carcinoma cells (MCF-7) are affected by MBR-8 in the same way. Western blot analysis revealed activation of caspase-3. MBR-8 showed very pronounced selectivity with regard to tumor cells and high synergistic effects in Nalm6 and daunorubicin-resistant Nalm6 cells when administered in combination with vincristine, daunorubicin and doxorubicin. The aluminium-salen complex MBR-8 showed very promising anti-cancer properties which warrant further development towards a cytostatic agent for future chemotherapy. Studies on aluminium compounds for cancer therapy are rare, and our report adds to this important body of knowledge.


Assuntos
Alumínio/farmacologia , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Complexos de Coordenação/farmacologia , Citostáticos/farmacologia , Etilenodiaminas/farmacologia , Alumínio/química , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Citostáticos/síntese química , Citostáticos/química , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Etilenodiaminas/química , Humanos
7.
Pediatr Blood Cancer ; 67(4): e28130, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31867835

RESUMO

BACKGROUND: Limited data on the prevalence and medical care of sickle cell disease (SCD) in Germany are available. Here, we make use of a patient registry to characterize the burden of disease and the treatment modalities for patients with SCD in Germany. PROCEDURE: A nationwide German registry for patients with SCD documents basic data on diagnosis and patient history retrospectively at the time of registration. A prospective annual documentation provides more details on complications and treatment of SCD. For the current analyses, data of 439 patients were available. RESULTS: Most patients had homozygous SCD (HbSS 75.1%, HbS/ß-thalassemia 13.2%, and HbSC 11.3%). The median age at diagnosis was 1.9 years (interquartile range, 0.6-4.4 years), most patients were diagnosed when characteristic symptoms occurred. Sepsis and stroke had affected 3.2% and 4.2% of patients, respectively. During the first year of observation, 48.3% of patients were admitted to a hospital and 10.1% required intensive care. Prophylactic penicillin was prescribed to 95.6% of patients with homozygous SCD or HbS/ß thalassemia below the age of six and hydroxycarbamide to 90.4% of patients above the age of two years. At least one annual transcranial Doppler ultrasound was documented for 74.8% of patients between 2 and 18 years. CONCLUSION: With an estimated number of at least 2000, the prevalence of SCD in Germany remains low. Prospectively, we expect that the quality of care for children with SCD will be further improved by an earlier diagnosis after the anticipated introduction of a newborn screening program for SCD.


Assuntos
Anemia Falciforme/epidemiologia , Adulto , Criança , Alemanha/epidemiologia , Humanos , Prevalência , Sistema de Registros
8.
Bioorg Chem ; 104: 104193, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32947134

RESUMO

A very small number of cobalt complexes is examined in oncology research. In this work, we investigate the cobalt (III) salen complex MBR-60 that turns out to be a promising anticancer drug. It induces apoptosis in Nalm6 leukemia and BJAB lymphoma cells and overcomes multidrug resistances by blocking the drug efflux pump P-glycoprotein. It further develops the apoptotic effects over the intrinsic pathway. An activation of caspase-3, caspase-8 and caspase-9 can be detected by western blot analysis. The independence of CD95 is shown by similar apoptotic inductions in BJAB and BJAB FADDdn cells. MBR-60 displays synergistic effects with daunorubicin and vincristine and has a selectivity to tumor cells. In comparison to the apoptotic effects of MBR-60 in BJAB lymphoma cells, the cobalt-free ligand 5 does not influence these cells. The research highlights that a cobalt complex has a therapeutic potential for cancer treating with a focus on drug-resistant tumors.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Cobalto/farmacologia , Complexos de Coordenação/farmacologia , Descoberta de Drogas , Etilenodiaminas/farmacologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cobalto/química , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Relação Dose-Resposta a Droga , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Etilenodiaminas/química , Humanos , Necrose Dirigida por Permeabilidade Transmembrânica da Mitocôndria/efeitos dos fármacos , Estrutura Molecular , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Relação Estrutura-Atividade , Células Tumorais Cultivadas
9.
Klin Padiatr ; 232(3): 159-165, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32176934

RESUMO

BACKGROUND: Exercise interventions in pediatric oncology include primarily traditional types of physical activity (PA) such as endurance and strength training, while there is a growing interest in recreational types of PA for pediatric cancer survivors, as well. One of these motivating and fun activities is indoor wall climbing. Therefore, this exploratory study aims to evaluate the feasibility and beneficial effects of a 10-week indoor wall climbing intervention in pediatric oncology. PATIENTS: Thirteen childhood cancer survivors aged 6-21 years were included after cessation of their inpatient medical treatment of whom eleven completed the study. METHODS: Study participants completed measurements of physical functioning at baseline (t0) and post-intervention (t1), as well as a questionnaire on program satisfaction at t1. RESULTS: Survivors participated in 57.43±31.77% of the climbing sessions and no adverse events occurred. Most study participants evaluated the climbing experience to be fun and motivational. One child stated that the climbing intervention was too exhausting/overstraining. Significant positive effects were found in terms of ankle DF-ROM and ankle DF strength. DISCUSSION: Indoor wall climbing seems feasible with childhood cancer survivors and suggests beneficial potentials on physical functioning. However, some preconditions (i. e. close supervision; slow increase of intensity; sufficient breaks) must be ensured. CONCLUSION: Indoor wall climbing could be a motivational adjunct to traditional types of exercise in pediatric oncology.


Assuntos
Sobreviventes de Câncer/psicologia , Exercício Físico , Neoplasias/reabilitação , Qualidade de Vida/psicologia , Adolescente , Adulto , Criança , Estudos de Viabilidade , Humanos , Neoplasias/psicologia , Avaliação de Resultados em Cuidados de Saúde , Adulto Jovem
10.
Klin Padiatr ; 231(3): 142-149, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30544267

RESUMO

BACKGROUND: With improved survival rates in pediatric oncology, the detection of adverse side- and late-effects is gaining increased interest. This cross-sectional study investigated walking abilities and ankle dorsiflexion function in children with cancer. PATIENTS: Study participants included 16 children with various cancers (4-20 years, patient group) after completion of the intense treatment and 16 age- and gender-matched healthy peers (comparison group). METHOD: Walking speed (10-meter-walking-test, treadmill test assessing preferred transition speed), walking capacity (2-minute-walk-test), walking balance (Timed-Up-And-Go-Test), active/passive ankle dorsiflexion range of motion (ROM) (goniometer) and ankle dorsiflexion strength (hand-held dynamometer) were comprehensively assessed. RESULTS: Significant lower values in the patient group were found for walking capacity, maximum walking speed, ankle dorsiflexion ROM and strength. No significant differences between the groups were found for preferred walking speed and walking balance. DISCUSSION: Limited walking abilities and ankle dorsiflexion dysfunctions are prominent in children with cancer; having the potential to impact children's community mobility and physical activity. CONCLUSIONS: To provide holistic care, the development of specific supportive strategies such as exercise interventions and its translation into clinical practice needs to be accelerated.


Assuntos
Articulação do Tornozelo/fisiopatologia , Tornozelo , Amplitude de Movimento Articular/fisiologia , Caminhada/fisiologia , Antineoplásicos/uso terapêutico , Criança , Estudos Transversais , Exercício Físico , Marcha/fisiologia , Humanos , Neoplasias/terapia
11.
Pediatr Phys Ther ; 30(4): 341-349, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30277971

RESUMO

PURPOSE: To assess a whole-body vibration (WBV) intervention for children after cancer treatment. METHODS: Eleven children after inpatient anticancer therapy participated in a 12-week supervised WBV intervention, which consisted of one 9- to 13-minute WBV session per week, with 5 to 9 minutes' overall vibration time. Feasibility was defined as the ability to participate in WBV training without reporting adverse events. The number of offered and completed training sessions, program acceptance, and measures of function were assessed. RESULTS: Nine participants completed the WBV intervention without any WBV-related adverse events. The adherence rate was 87.96%. Only minor side effects were reported and there was general program acceptance. We found indications that WBV has positive effects on knee extensor strength and active ankle dorsiflexion range of motion. CONCLUSIONS: WBV was feasible, safe, and well received among children after inpatient anticancer therapy. No health deteriorations were observed. Positive effects need to be confirmed in future trials.


Assuntos
Pacientes Internados , Atividade Motora/fisiologia , Força Muscular/fisiologia , Neoplasias/reabilitação , Modalidades de Fisioterapia , Adolescente , Criança , Pré-Escolar , Terapia Combinada , Feminino , Humanos , Masculino , Neoplasias/terapia , Projetos Piloto , Resultado do Tratamento , Vibração , Adulto Jovem
12.
Chemistry ; 23(8): 1869-1880, 2017 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-27865002

RESUMO

Gold complexes with N-heterocyclic carbene (NHC) ligands represent a promising class of metallodrugs for the treatment of cancer or infectious diseases. In this report, the synthesis and the biological evaluation of halogen-containing NHC-AuI -Cl complexes are described. The complexes 1 and 5 a-5 f displayed good cytotoxic activity against tumor cells, and cellular uptake studies suggested that an intact Au-NHC fragment is essential for the accumulation of high amounts of both the metal and the NHC ligand. However, the bioavailability was negatively affected by serum components of the cell culture media and was influenced by likely transformations of the complex. One example (5 d) efficiently induced apoptosis in vincristine- and daunorubicin-resistant P-glycoprotein overexpressing Nalm-6 leukemia cells. Cellular uptake studies with this compound showed that both the wild-type and resistant Nalm-6 cells accumulated comparable amounts of gold, indicating that the gold drug was not excreted by P-glycoprotein or other efflux transporters. The effective inhibition of mammalian and bacterial thioredoxin reductases (TrxR) was confirmed for all of the gold complexes. Antibacterial screening of the gold complexes showed a particularly high activity against Gram-positive strains, reflecting their high dependence on an intact Trx/TrxR system. This result is of particular interest as the inhibition of bacterial TrxR represents a relatively little explored mechanism of new anti-infectives.


Assuntos
Antibacterianos/farmacologia , Antineoplásicos/química , Proteínas de Bactérias/antagonistas & inibidores , Complexos de Coordenação/química , Ouro/química , Bactérias Gram-Positivas/efeitos dos fármacos , Tiorredoxina Dissulfeto Redutase/antagonistas & inibidores , Antibacterianos/síntese química , Antibacterianos/química , Antineoplásicos/síntese química , Antineoplásicos/toxicidade , Apoptose/efeitos dos fármacos , Proteínas de Bactérias/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Complexos de Coordenação/metabolismo , Complexos de Coordenação/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Compostos Heterocíclicos/química , Humanos , Metano/análogos & derivados , Metano/química , Testes de Sensibilidade Microbiana , Tiorredoxina Dissulfeto Redutase/metabolismo
13.
Pediatr Blood Cancer ; 63(1): 127-32, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26184456

RESUMO

BACKGROUND: Exercise interventions in pediatric oncology are feasible and safe. However, scarce data are available with regard to the effectiveness of outpatient, group-based exercise interventions. As well, the potential role of exercise to improve motor performance has not been adequately explored despite being a meaningful outcome during childhood with important implications for physical activity behavior. No study has yet demonstrated significant changes in motor performance after an exercise intervention. PROCEDURES: This explorative, prospective study was designed to evaluate the effects of a 6-month, group-based, therapeutic exercise program for a mixed childhood cancer population on motor performance, level of activity, and quality of life. After cessation of inpatient medical treatment, childhood cancer outpatients aged 4-17 years exercised once a week during a 6-month period (IG). Comparison groups included childhood cancer outpatients receiving care as usual (CG(1)), as well as healthy peers (matched to IG by age and gender) (CG(2)). RESULTS: Overall motor performance, various motor dimensions, activity in sport clubs and school sports, as well as physical and emotional well-being were significantly reduced in the IG at baseline. Significant differences between the IG and CG(1) and/or CG(2) were identified in the change of overall motor performance, single motor dimensions, overall level of activity, and emotional well-being from baseline to post-intervention. CONCLUSIONS: The exercise intervention was beneficial in terms of motor performance, level of activity, and emotional well-being. As such, this study provides support for group-based exercise as a potential strategy to improve these outcomes after inpatient medical treatment.


Assuntos
Exercício Físico , Neoplasias/terapia , Desempenho Psicomotor , Qualidade de Vida , Adolescente , Criança , Pré-Escolar , Emoções , Feminino , Processos Grupais , Humanos , Masculino , Pacientes Ambulatoriais , Estudos Prospectivos
14.
Mol Cancer ; 14: 114, 2015 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-26041471

RESUMO

BACKGROUND: Redox stress is a hallmark of the rewired metabolic phenotype of cancer. The underlying dysregulation of reactive oxygen species (ROS) is interconnected with abnormal mitochondrial biogenesis and function. In chronic lymphocytic leukemia (CLL), elevated ROS are implicated in clonal outgrowth and drug resistance. The pro-survival oncogene T-cell leukemia 1 (TCL1) is causally linked to the high threshold towards classical apoptosis in CLL. We investigated how aberrant redox characteristics and bioenergetics of CLL are impacted by TCL1 and if this is therapeutically exploitable. METHODS: Bio-organometallic chemistry provided compounds containing a cytosine nucleobase, a metal core (ferrocene, ruthenocene, Fe(CO)3), and a 5'-CH2O-TDS substituent. Four of these metal-containing nucleoside analogues (MCNA) were tested for their efficacy and mode of action in CLL patient samples, gene-targeted cell lines, and murine TCL1-transgenic splenocytes. RESULTS: The MCNA showed a marked and selective cytotoxicity towards CLL cells. MCNA activity was equally observed in high-risk disease groups, including those of del11q/del17p cytogenetics and of clinical fludarabine resistance. They overcame protective stromal cell interactions. MCNA-evoked PARP-mediated cell death was non-autophagic and non-necrotic as well as caspase- and P53-independent. This unconventional apoptosis involved early increases of ROS, which proved indispensible based on mitigation of MCNA-triggered death by various scavengers. MCNA exposure reduced mitochondrial respiration (oxygen consumption rate; OCR) and induced a rapid membrane depolarization (∆ΨM). These characteristics distinguished the MCNA from the alkylator bendamustine and from fludarabine. Higher cellular ROS and increased MCNA sensitivity were linked to TCL1 expression. The presence of TCL1 promoted a mitochondrial release of in part caspase-independent apoptotic factors (AIF, Smac, Cytochrome-c) in response to MCNA. Although basal mitochondrial respiration (OCR) and maximal respiratory capacity were not affected by TCL1 overexpression, it mediated a reduced aerobic glycolysis (lactate production) and a higher fraction of oxygen consumption coupled to ATP-synthesis. CONCLUSIONS: Redox-active substances such as organometallic nucleosides can confer specific cytotoxicity to ROS-stressed cancer cells. Their P53- and caspase-independent induction of non-classical apoptosis implicates that redox-based strategies can overcome resistance to conventional apoptotic triggers. The high TCL1-oncogenic burden of aggressive CLL cells instructs their particular dependence on mitochondrial energetic flux and renders them more susceptible towards agents interfering in mitochondrial homeostasis.


Assuntos
Leucemia Linfocítica Crônica de Células B/patologia , Mitocôndrias/metabolismo , Nucleosídeos/farmacologia , Oncogenes , Compostos Organometálicos/farmacologia , Proteínas Proto-Oncogênicas/genética , Espécies Reativas de Oxigênio/metabolismo , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Caspase 3/metabolismo , Linhagem Celular Tumoral , Metabolismo Energético/efeitos dos fármacos , Homeostase/efeitos dos fármacos , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Necrose , Nucleosídeos/química , Compostos Organometálicos/química , Fatores de Risco , Células Estromais/efeitos dos fármacos , Células Estromais/patologia , Proteína Supressora de Tumor p53/metabolismo
16.
Beilstein J Org Chem ; 10: 1630-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25161720

RESUMO

An operationally simple, convenient, and mild strategy for the synthesis of triazole-substituted titanocenes via strain-driven 1,3-dipolar cycloadditions between azide-functionalized titanocenes and cyclooctyne has been developed. It features the first synthesis of titanocenes containing azide groups. These compounds constitute 'second-generation' functionalized titanocene building blocks for further synthetic elaboration. Our synthesis is modular and large numbers of the complexes can in principle be prepared in short periods of time. Some of the triazole-substituted titanocenes display high cyctotoxic activity against BJAB cells. Comparison of the most active complexes allows the identification of structural features essential for biological activity.

17.
RSC Adv ; 14(15): 10244-10254, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38544944

RESUMO

Synthesis and characterization of the first two cyclic ethylene-bridged tetradentate NHC ligands, with an unsaturated (imidazole) and saturated backbone (2-imidazoline), are described. Complexes of both ligands containing palladium(ii) have been obtained. For platinum(ii) and gold(iii), only the unsaturated tetracarbene complexes could be isolated. The attempts to synthesize a methylene-bridged 2-imidazoline macrocycle are also described. Furthermore, a novel bisimidazolinium ligand precursor and its open-chain PdII and PtII tetracarbene complexes are obtained. Finally, it is shown that the unsaturated gold(iii) tetracarbene is able to induce apoptosis in malignant SK-N-AS neuroblastoma cells via the mitochondrial and ROS pathway and overcomes resistance to cisplatin in vitro.

18.
Chemistry ; 19(52): 17871-80, 2013 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-24243420

RESUMO

Rhodium(I) complexes bearing N-heterocyclic carbene (NHC) ligands have been widely used in catalytic chemistry, but there are very few reports of biological properties of these organometallics. A series of Rh(I)-NHC derivatives with 1,5-cyclooctadiene and CO as secondary ligands were synthesized, characterized, and biologically investigated as prospective antitumor drug candidates. Pronounced antiproliferative effects were noted for all complexes, along with moderate inhibitory activity of thioredoxin reductase (TrxR) and efficient binding to biomolecules (DNA, albumin). Biodistribution studies showed that the presence of albumin lowered the cellular uptake and confirmed the transport of rhodium into the nuclei. Changes in the mitochondrial membrane potential (MMP) were observed as well as DNA fragmentation in wild-type and daunorubicin- or vincristine-resistant Nalm-6 leukemia cells. Overall, these studies indicated that Rh(I)-NHC fragments could be used as partial structures of new antitumor agents, in particular in those drugs designed to address resistant malignant tissues.


Assuntos
Antineoplásicos/química , Metano/análogos & derivados , Ródio/química , Antineoplásicos/farmacologia , Humanos , Metano/química , Ródio/farmacologia
19.
Chemistry ; 19(39): 13017-29, 2013 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-23934861

RESUMO

The synthesis and stereochemical assignment of two classes of iron-containing nucleoside analogues, both of which contain a butadiene-Fe(CO)3 substructure, is described. The first type of compounds are Fe(CO)3-complexed 3'-alkenyl-2',3'-dideoxy-2',3'-dehydro nucleosides (2,5-dihydrofuran derivatives), from which the second class of compounds is derived by formal replacement of the ring oxygen atom by a CH2 group (carbocyclic nucleoside analogues). These compounds were prepared in a stereoselective manner through the metal-assisted introduction of the nucleobase. Whilst the furanoid intermediates were prepared from carbohydrates (such as methyl-glucopyranoside), the carbocyclic compounds were obtained by using an intramolecular Pauson-Khand reaction. Stereochemical assignments based on NMR and CD spectroscopy were confirmed by X-ray structural analysis. Biological investigations revealed that several of the complexes exhibited pronounced apoptosis-inducing properties (through an unusual caspase 3-independent but ROS-dependent pathway). Furthermore, some structure-activity relationships were identified, also as a precondition for the design and synthesis of fluorescent and biotin-labeled conjugates.


Assuntos
Biotina/síntese química , Corantes Fluorescentes/síntese química , Ferro/química , Metaloproteínas/síntese química , Metaloproteínas/farmacologia , Nucleosídeos/síntese química , Nucleosídeos/farmacologia , Apoptose/efeitos dos fármacos , Biotina/química , Corantes Fluorescentes/química , Espectroscopia de Ressonância Magnética , Metaloproteínas/química , Estrutura Molecular , Nucleosídeos/química , Relação Estrutura-Atividade , Difração de Raios X
20.
Pediatr Hematol Oncol ; 30(4): 336-47, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23495850

RESUMO

Although survival rates in childhood cancer have distinctly improved, pediatric cancer patients often experience various disease- and treatment-related side effects with long-term consequences. Despite current studies investigating inactivity and limitations in physical functioning and quality of life in pediatric cancer patients, only little information regarding specific deficits in physical functioning and quality of life has been available until now. No study has yet analyzed these parameters from a global perspective and then identified specific deficits in a mixed childhood cancer population. Within this cross-sectional pilot study, motor performance and quality of life of 26 pediatric cancer patients were assessed after inpatient medical treatment, using standardized motor test batteries (MOT 4-6; DMT 6-18) and a quality of life questionnaire (KINDL®). Reference data have been mainly provided by the German "Children and Young People Health Survey" (KiGGS). Patients achieved lower motor performance scores (p = .000) (more than 27% below the average of healthy peers). Specific deficits were identified in motor speed and motor control (4-6 years), as well as in endurance, strength and coordination under time pressure (6-17 years). In terms of quality of life, no significant differences were examined compared to healthy children of the same age. The results of this study confirm that children with oncological diseases frequently have specific motor problems. Future research in pediatric oncology must investigate the impact of targeted, individualized exercise interventions addressing these specific deficits.


Assuntos
Atividade Motora , Neoplasias/fisiopatologia , Neoplasias/psicologia , Qualidade de Vida , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Masculino , Projetos Piloto , Leucemia-Linfoma Linfoblástico de Células Precursoras/psicologia
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