RESUMO
The immediately-early response gene 5 (IER5) has been reported to be induced by γ-ray irradiation and to play a role in the induction of cell death caused by radiation. We previously identified IER5 as one of the 2,3,4-tribromo-3-methyl-1-phenylphospholane 1-oxide (TMPP)-induced transcriptional responses in AML cells, using microarrays that encompassed the entire human genome. However, the biochemical pathway and mechanisms of IER5 function in regulation of the cell cycle remain unclear. In this study, we investigated the involvement of IER5 in the cell cycle and in cell proliferation of acute myeloid leukemia (AML) cells. We found that the over-expression of IER5 in AML cell lines and in AML-derived ALDH(hi) (High Aldehyde Dehydrogenase activity)/CD34(+) cells inhibited their proliferation compared to control cells, through induction of G2/M cell cycle arrest and a decrease in Cdc25B expression. Moreover, the over-expression of IER5 reduced colony formation of AML-derived ALDH(hi)/CD34(+) cells due to a decrease in Cdc25B expression. In addition, over-expression of Cdc25B restored TMPP inhibitory effects on colony formation in IER5-suppressed AML-derived ALDH(hi)/CD34(+) cells. Furthermore, the IER5 reduced Cdc25B mRNA expression through direct binding to Cdc25B promoter and mediated its transcriptional attenuation through NF-YB and p300 transcriptinal factors. In summary, we found that transcriptional repression mediated by IER5 regulates Cdc25B expression levels via the release of NF-YB and p300 in AML-derived ALDH(hi)/CD34(+) cells, resulting in inhibition of AML progenitor cell proliferation through modulation of cell cycle. Thus, the induction of IER5 expression represents an attractive target for AML therapy.
Assuntos
Fator de Ligação a CCAAT/metabolismo , Proteína p300 Associada a E1A/metabolismo , Proteínas Imediatamente Precoces/metabolismo , Leucemia Mieloide Aguda/patologia , Células-Tronco Neoplásicas/patologia , Proteínas Nucleares/metabolismo , Transcrição Gênica , Fosfatases cdc25/genética , Antígenos CD34/metabolismo , Ciclo Celular , Proliferação de Células , Separação Celular , Regulação Leucêmica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Proteínas Imediatamente Precoces/genética , Leucemia Mieloide Aguda/genética , Proteínas Nucleares/genética , Regiões Promotoras Genéticas/genética , Ligação Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Repressoras/metabolismo , Ensaio Tumoral de Célula-TroncoRESUMO
4-Bromo-3,4-dimethyl-1-phenyl-2-phospholene 1-oxide (3c) was first synthesized from 3,4-dimethyl-1-phenyl-2-phospholene 1-oxide (2c) by a bromo-radical substitution reaction occurred at C-4 position by N-bromosuccinimide and 2,2'-azobisisobutyronitrile. The novel phospha sugar analogue 3c exerted high anti-proliferative effect on U937 cells evaluated by MTT in vitro methods and was much more efficient than that of Gleevec, which is known as a molecule targeting chemotherapeutical agent. The substitution of 2-phospholenes at C-3 and C-4 position with methyl groups as well as 4-bromo substituent suggests a good anti-proliferative effect.
Assuntos
Antineoplásicos/química , Óxidos P-Cíclicos/síntese química , Compostos Heterocíclicos/química , Compostos Organofosforados/síntese química , Fósforo/química , Antineoplásicos/síntese química , Antineoplásicos/toxicidade , Benzamidas , Linhagem Celular Tumoral , Óxidos P-Cíclicos/química , Óxidos P-Cíclicos/toxicidade , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/toxicidade , Humanos , Mesilato de Imatinib , Compostos Organofosforados/química , Compostos Organofosforados/toxicidade , Piperazinas/toxicidade , Pirimidinas/toxicidadeRESUMO
A new type of dendritic molecules Gd-DTPA-XDA-D1-Glc(OH), which work as a functionalized ligand coordinating gadolinium(III) ion at the center of their frameworks with two glucose moieties on the molecular surfaces, were readily synthesized with high yield. The structures were established by IR, (1)H, (13)C NMR, and mass spectral studies. Its bio-distribution patterns were evaluated on rats.
Assuntos
Meios de Contraste/síntese química , Gadolínio DTPA/síntese química , Glucose/síntese química , Imageamento por Ressonância Magnética , Animais , Gadolínio DTPA/análise , Glucose/análise , Neoplasias Hepáticas/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Cintilografia , RatosRESUMO
Here, we synthesized two phospha sugar derivatives, 2,3,4-tribromo-3-methyl-1-phenylphospholane 1-oxide (TMPP) and 2,3-dibromo-3-methyl-1-phenylphospholane 1-oxide (DMPP) by reacting 3-methyl-1-phenyl-2-phospholene 1-oxide with bromine, and investigated their potential as antileukemic agents in cell lines. Both agents showed inhibitory effects on leukemia cell proliferation, with mean IC(50) values of 6.25 micromol/L for TMPP and 23.7 micromol/L for DMPP, indicating that inhibition appeared to be dependent on the number of bromine atoms in the structure. Further, TMPP at 10 micromol/L and DMPP at 20 micromol/L induced G2/M cell cycle block in leukemia cells, and TMPP at 20 micromol/L induced apoptosis in these cells. TMPP treatment effected a reduction in both cell cycle progression signals (FoxM1, KIS, Cdc25B, Cyclin D1, Cyclin A, and Aurora-B) and tumor cell survival (p27(Kip1) and p21(Cip1)), as well as induced the activation of caspase-3 and -9. Further, treatment with TMPP significantly reduced the viability of AML specimens derived from AML patients, but only slightly reduced the viability of normal ALDH(hi) progenitor cells. We also observed that FoxM1 mRNA was overexpressed in AML cells, and treatment with TMPP reduced FoxM1 mRNA expression in AML cells. Here, we report on the synthesis of TMPP and DMPP and demonstrate that these agents hinder proliferation of leukemia cells by FoxM1 suppression, which leads to G2/M cell cycle block and subsequent caspase-3-dependent apoptosis in acute leukemia cells. These agents may facilitate the development of new strategies in targeted antileukemic therapy.
Assuntos
Antineoplásicos/farmacologia , Óxidos P-Cíclicos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia/tratamento farmacológico , Compostos Organofosforados/farmacologia , Adulto , Idoso , Antineoplásicos/síntese química , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Caspase 9/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Óxidos P-Cíclicos/síntese química , Óxidos P-Cíclicos/química , Proteína Forkhead Box M1 , Fatores de Transcrição Forkhead/metabolismo , Humanos , Pessoa de Meia-Idade , Compostos Organofosforados/síntese químicaRESUMO
A novel phospha sugar analogue, 2,3-dibromo-3-methyl-1-phenylphospholane 1-oxide (DBMPP), was prepared from 1-phenyl-3-methyl-2- phospholene 1-oxide and evaluated by in vitro MTT method forleukemia cells and microscopic observations forsolid tumor cells, e.g., stomach cancer cells. The evaluation revealed clearly that the synthesized phospha sugar analogue DBMPP has competent potentials and excellent anti-cancer activities that killed selectively and specifically the leukemia cells of cell lines of K562 and U937 but did not give any damages on healthy leukocyte. Moreover it was revealed that DBMPP killed solid cancer cells such as stomach cancer cells and melanoma of cell lines of MKN45 and G361. Therefore, DBMPP should exert anti-proliferative effects for different kinds of tumor cells based on the in vitro evaluations. The cell cycle analyses by flow cytometry for K562 and U937 cells clearly demonstrated that the mechanism of the anti-proliferative effect on the human tumor cells is apoptosis induced by DBMPP.
Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Neoplasias/tratamento farmacológico , Compostos Organofosforados/síntese química , Compostos Organofosforados/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , HumanosRESUMO
Quantitative evaluation of Förster-type fluorescence resonance energy transfer (FRET) was undertaken by statistical investigations on perylene-cored anthracene dendrimers.
Assuntos
Antracenos/química , Dendrímeros/química , Transferência de Energia , Perileno/química , Transferência Ressonante de Energia de FluorescênciaRESUMO
An x-ray crystallographic analysis was carried out for Boc-(Aib-DeltaZPhe)4-Aib-OMe (1: Boc = t-butoxycarbonyl; Aib = alpha-aminoisobutyric acid; DeltaZPhe = Z-alpha,beta-didehydrophenylalanine) to provide the precise conformational parameters of the octapeptide segment -(Aib-DeltaZPhe)4-. Peptide 1 adopted a typical 3(10)-helical conformation characterized by
Assuntos
Oligopeptídeos/química , Cristalografia por Raios X , Modelos Moleculares , Estrutura Molecular , Estrutura Secundária de ProteínaRESUMO
1H NMR spectroscopy of phosphorus containing hetero sugars (phospha sugars), revealed the alpha and beta configurations and chair conformations for 3-acetamido-1,4-di-O-acetyl-2,3,5-trideoxy-5-C-(isopropylphosphinyl)-alpha- and beta-D-erythro-pentopyranoses. The conformation of the title compounds was determined by 1H NMR as 1C4 in CDCl3 and the conformation was in accord with that in solid state determined by X-ray crystallographic analysis.