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2.
J Cell Biochem ; 117(11): 2583-96, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27526954

RESUMO

We studied epigenetics, distribution pattern, kinetics, and diffusion of proteins recruited to spontaneous and γ-radiation-induced DNA lesions. We showed that PML deficiency leads to an increased number of DNA lesions, which was accompanied by changes in histone signature. In PML wt cells, we observed two mobile fractions of 53BP1 protein with distinct diffusion in spontaneous lesions. These protein fractions were not detected in PML-deficient cells, characterized by slow-diffusion of 53BP1. Single particle tracking analysis revealed limited local motion of 53BP1 foci in PML double null cells and local motion 53BP1 foci was even more reduced after γ-irradiation. However, radiation did not change co-localization between 53BP1 nuclear bodies and interchromatin granule-associated zones (IGAZs), nuclear speckles, or chromocenters. This newly observed interaction pattern imply that 53BP1 protein could be a part of not only DNA repair, but also process mediated via components accumulated in IGAZs, nuclear speckles, or paraspeckles. Together, PML deficiency affected local motion of 53BP1 nuclear bodies and changed composition and a number of irradiation-induced foci. J. Cell. Biochem. 117: 2583-2596, 2016. © 2016 Wiley Periodicals, Inc.


Assuntos
Dano ao DNA/fisiologia , Reparo do DNA/fisiologia , Raios gama/efeitos adversos , Corpos de Inclusão Intranuclear/metabolismo , Leucemia Promielocítica Aguda/metabolismo , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/metabolismo , Western Blotting , Dano ao DNA/efeitos da radiação , Reparo do DNA/efeitos da radiação , Relação Dose-Resposta à Radiação , Imunofluorescência , Humanos , Corpos de Inclusão Intranuclear/patologia , Corpos de Inclusão Intranuclear/efeitos da radiação , Leucemia Promielocítica Aguda/patologia , Leucemia Promielocítica Aguda/radioterapia , Microscopia Confocal , Células Tumorais Cultivadas
3.
Leuk Res ; 37(9): 1162-9, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23773897

RESUMO

Induction of myeloid differentiation in radioresistant HL60 cells (Res-HL60) was examined to clarify the developmental mechanism of radioresistant leukemia. Compared to wild-type HL60 cells (Wt-HL60), Res-HL60 were smaller and strongly expressed CD38. Under all-trans retinoic acid (ATRA) stimulation, Res-HL60 continued to proliferate slowly and with similar level of CD11b expression to Wt-HL60. Phorbol 12-myristate 13-acetate (PMA) strongly suppressed proliferation of Res-HL60, downregulated CD14, and affected mRNA expression. These results suggested that the specific myeloid differentiation of Res-HL60 suppressed monocyte lineage by ATRA and PMA occurred through regulation of mRNA expression.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/efeitos da radiação , Linhagem da Célula , Leucemia Promielocítica Aguda/patologia , Mutação/genética , Tolerância a Radiação/efeitos dos fármacos , Acetato de Tetradecanoilforbol/farmacologia , Antineoplásicos/farmacologia , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinógenos/farmacologia , Citometria de Fluxo , Perfilação da Expressão Gênica , Células HL-60 , Humanos , Leucemia Promielocítica Aguda/tratamento farmacológico , Leucemia Promielocítica Aguda/radioterapia , Monócitos/citologia , Monócitos/efeitos dos fármacos , Monócitos/efeitos da radiação , Análise de Sequência com Séries de Oligonucleotídeos , Tretinoína/farmacologia , Células Tumorais Cultivadas , Raios X
4.
Gen Physiol Biophys ; 29(3): 275-81, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20817951

RESUMO

In this work we evaluated changes in molecular response of human promyelocyte leukemia cells HL-60 and HL-60-IR cells (HL-60 irradiated by 10 cycles of radiation with total dose of 60 Gy, given over a period of 3 months) to irradiation by the dose of 2 and 8 Gy. Analysis of CD11b and apoptosis by flow-cytometry revealed that on 3rd day after irradiation by 8 Gy the HL-60-IR are more resistant to radiation-induced apoptosis and more differentiated (increase in CD11b in non-apoptotic cells) than regular HL-60. We found that both types of cells have high basal level of phosphorylated extracellular signal-regulated kinases Erk1/2 . Irradiation induces decrease in Erk1/2 phosphorylation after 4 and 8 h in both cell types. However, in HL-60-IR cells Erk1/2 phosphorylation is restored faster than in HL-60. Also it was found that in contrary to HL-60 cells, the HL-60-IR cells react to 2 Gy irradiation by p53 independent increase in p21(WAF1/Cip1), and not by activation of checkpoint kinase Chk-2. Therefore we concluded that relatively high dose of radiation (6 Gy) does not lead after 10 repetitive irradiations to eradication of HL-60 cells, but instead increases their radioresistance, increases the ability to differentiate, alters MAPK response, increases amount of p21(WAF1/Cip1), and decreases induction of apoptosis by ionizing radiation. p21(WAF1/Cip1) might prevent apoptosis induction and trigger permanent cell-cycle arrest, which can also contribute to regression of this leukaemia after therapy.


Assuntos
Leucemia Promielocítica Aguda/metabolismo , Leucemia Promielocítica Aguda/radioterapia , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Tolerância a Radiação/fisiologia , Apoptose/efeitos da radiação , Ciclo Celular/efeitos da radiação , Diferenciação Celular/efeitos da radiação , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Fracionamento da Dose de Radiação , Relação Dose-Resposta à Radiação , Raios gama/uso terapêutico , Células HL-60 , Humanos , Leucemia Promielocítica Aguda/patologia , Fosforilação
5.
Dermatol Online J ; 15(9): 4, 2009 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-19930991

RESUMO

A major complication following hematopoietic stem cell transplantation is graft versus host disease. Cutaneous manifestations of chronic graft versus host disease (cGVHD) are varied and this condition impacts patient outcomes and quality of life. We describe two cases of lichen sclerosus et atrophicus-like cGVHD developing in patients after hematopoietic stem cell transplantation. Both patients presented clinically with patches of pigmentary changes and scaling that displayed classic histologic features of lichen sclerosus et atrophicus. The skin is a frequent target organ of cGVHD and often the presenting location of the disease, making dermatologists key in recognition and management. It has been proposed that cutaneous cGVHD is a spectrum of disease and the lesions may evolve through various stages. Lichen sclerosus et atrophicus-like cGVHD may represent a phase in this continuum or a distinct sub-type of disease. Remaining cognizant of the potential manifestations of disease is key for prompt recognition and proper treatment.


Assuntos
Doença Enxerto-Hospedeiro/diagnóstico , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Líquen Escleroso e Atrófico/diagnóstico , Clobetasol/uso terapêutico , Terapia Combinada , Diagnóstico Diferencial , Feminino , Doença Enxerto-Hospedeiro/tratamento farmacológico , Doença Enxerto-Hospedeiro/patologia , Humanos , Hidrocortisona/uso terapêutico , Imunossupressores/uso terapêutico , Leucemia Promielocítica Aguda/radioterapia , Leucemia Promielocítica Aguda/cirurgia , Transfusão de Linfócitos/efeitos adversos , Masculino , Pessoa de Meia-Idade , Fotoferese , Leucemia-Linfoma Linfoblástico de Células Precursoras/cirurgia , Tacrolimo/uso terapêutico , Triancinolona/uso terapêutico
6.
Neoplasma ; 55(6): 519-25, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18999881

RESUMO

Valproic acid (VA) possesses anticonvulsant as well as anticancer properties of histondeacetylases inhibitor. Incubation of human promyelocytic leukemia cells HL-60 with VA leads to acetylation of nuclear histones H3 and H4. Using 2 mmol/l concentration we proved the expression of protein p21, which relates to the arrest of cell proliferation and decrease in number of cells in S phase of cell cycle. Treatment of HL-60 cells with VA causes their differentiation, proved as increase in CD11b expression. The most widely used method in cancer treatment is radiotherapy. 24 hours after irradiation by the therapeutical dose of 2 Gy, 56% of HL-60 cells are accumulated in G2 phase of cell cycle. VA had no influence on this accumulation, but 24 h-long pretreatment of cells with 1 mmol/l VA provoked higher decrease in cell number in S phase (18%) comparing with only irradiated cells (25%). The results of our work show that VA posseses radiosensitizing properties when applied 24 hours prior to irradiation and that during parallel long-term action of VA and IR the cells undergo differentiation and faster apoptosis induction. Radiosensitizing effect of VA is not caused by abrogation of G2/M cell cycle arrest, but VA induces p21 and leads to differentiation of HL-60 cells.


Assuntos
Leucemia Promielocítica Aguda/tratamento farmacológico , Leucemia Promielocítica Aguda/radioterapia , Radiossensibilizantes/farmacologia , Ácido Valproico/farmacologia , Acetilação , Apoptose , Ciclo Celular , Proliferação de Células , Terapia Combinada , Células HL-60 , Histonas/metabolismo , Humanos
7.
Bioelectromagnetics ; 25(7): 503-7, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15376245

RESUMO

The lethal response of cultured cancer cells lines K-562, U-937, DG-75, and HL-60 were measured directly after a 4 h exposure to a pulsating electromagnetic field (PEMF, sinusoidal wave form, 35 mT peak, 50 Hz) [Traitcheva et al. (2003): Bioelectromagnetics 24:148-158] and 24 h later, to determine the post-exposure effect. The results were found to depend on the medium, pH value, conductivity, and temperature. From these experiments, suitable conditions were chosen to compare the vitality between K-562 cells and normal human lymphocytes after PEMF treatment and photodynamic action. Both agents enhance necrosis synergistically for diseased as well as for healthy cells, but the lymphocytes are more resistant. The efficacy of PEMF on the destruction of cancer cells is further increased by heating (hyperthermia) of the suspension up to 44 degrees C or by lowering the pH-value (hyperacidity) to pH 6.4. Similar apoptosis and necrosis can be obtained using moderate magnetic fields (B < or = 15 mT 50/60 Hz), but this requires longer treatment of at least over a week. PEMF application combined with anticancer drugs and photodynamic therapy will be very effective.


Assuntos
Linfoma de Burkitt/patologia , Campos Eletromagnéticos , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Leucemia Promielocítica Aguda/patologia , Linfócitos/efeitos da radiação , Linfoma Difuso de Grandes Células B/patologia , Idoso , Apoptose/efeitos da radiação , Linfoma de Burkitt/radioterapia , Morte Celular/efeitos da radiação , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos da radiação , Meios de Cultura , Condutividade Elétrica , Humanos , Concentração de Íons de Hidrogênio , Hipertermia Induzida , Leucemia Mielogênica Crônica BCR-ABL Positiva/radioterapia , Leucemia Promielocítica Aguda/radioterapia , Linfócitos/patologia , Linfoma Difuso de Grandes Células B/radioterapia , Masculino , Necrose , Fotoquimioterapia , Temperatura , Fatores de Tempo
8.
J Pediatr Hematol Oncol ; 23(9): 609-11, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11902306

RESUMO

Numerous children have been treated successfully for cancer and are surviving into adulthood. As this population has aged, an increasing number of secondary malignancies has emerged. Renal cell carcinoma (RCC) is a rare tumor in childhood and has not been documented previously to occur after treatment of acute promyelocytic leukemia (APL). This report describes the clinical course of APL treated in a child in whom RCC subsequently developed during adolescence approximately 5 years after therapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carcinoma de Células Renais/etiologia , Leucemia Promielocítica Aguda/tratamento farmacológico , Segunda Neoplasia Primária/etiologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Infarto Cerebral/etiologia , Criança , Cromossomos Humanos Par 17/genética , Terapia Combinada , Irradiação Craniana , Citarabina/administração & dosagem , Daunorrubicina/administração & dosagem , Dexametasona/administração & dosagem , Etoposídeo/administração & dosagem , Humanos , Hipertensão/complicações , Falência Renal Crônica/induzido quimicamente , Leucemia Promielocítica Aguda/complicações , Leucemia Promielocítica Aguda/genética , Leucemia Promielocítica Aguda/radioterapia , Masculino , Obesidade/complicações , Indução de Remissão , Tioguanina/administração & dosagem
9.
Intern Med ; 36(7): 484-6, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9240497

RESUMO

A 54-year-old female was admitted to our hospital for gingival bleeding and was diagnosed as acute promyelocytic leukemia (APL). She received induction therapy according to the AML92 protocol of the Japan Adult Leukemia Study Group (JALSG) with all-trans retinoic acid (ATRA) plus chemotherapeutic agents. She achieved complete remission, but one year later had a relapse in her external auditory canal without leukemic cell in the bone marrow. Extramedullary disease is rare in APL. This case suggests the importance of careful observation for extramedullary relapse in patients who are treated with ATRA.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Meato Acústico Externo , Leucemia Promielocítica Aguda/patologia , Agranulocitose/induzido quimicamente , Agranulocitose/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Biomarcadores Tumorais/análise , Terapia Combinada , Citarabina/administração & dosagem , Citarabina/análogos & derivados , Daunorrubicina/administração & dosagem , Feminino , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Humanos , Idarubicina/administração & dosagem , Leucemia Promielocítica Aguda/tratamento farmacológico , Leucemia Promielocítica Aguda/radioterapia , Mercaptopurina/administração & dosagem , Pessoa de Meia-Idade , Mitoxantrona/administração & dosagem , Proteínas de Neoplasias/análise , Proteínas de Fusão Oncogênica/análise , Radioterapia , Recidiva , Indução de Remissão , Terapia de Salvação , Tretinoína/administração & dosagem , Vindesina/administração & dosagem
10.
Cancer ; 78(12): 2510-4, 1996 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-8952559

RESUMO

BACKGROUND: Extramedullary acute promyelocytic leukemia (APL) is rare, and said to be more common after treatment with all-trans retinoic acid (ATRA) than after any other treatment. METHODS: The case of a child with extramedullary relapse of APL after initial treatment with ATRA and that of an adult whose initial treatment was chemotherapy are presented, and the literature on extramedullary relapse of APL is reviewed. RESULTS: Twenty-six patients were identified, including the 2 current patients. Ethnicity could be determined in 23 patients, 17 of whom were of other than Northern European extraction. The most common sites of extramedullary disease were the skin (15 patients), central nervous system (5 patients), mediastinum (3 patients), and, curiously, gingiva (3 patients). Extramedullary leukemia developed in 19 patients: after treatment with ATRA (6 patients), cytotoxic chemotherapy (12 patients), or both (1 patient), and developed in 7 others before any treatment for leukemia was given. CONCLUSIONS: These data suggest but do not prove that extramedullary APL may occur more frequently after ATRA than other therapy, since ATRA has been available for a relatively short period of time. However, it is clear from the literature that extramedullary APL may occur after chemotherapy or before any treatment.


Assuntos
Cotovelo/patologia , Gengiva/patologia , Leucemia Promielocítica Aguda/patologia , Infiltração Leucêmica/patologia , Adulto , Pré-Escolar , Evolução Fatal , Feminino , Humanos , Leucemia Promielocítica Aguda/tratamento farmacológico , Leucemia Promielocítica Aguda/radioterapia , Infiltração Leucêmica/tratamento farmacológico , Infiltração Leucêmica/radioterapia
11.
Anticancer Drugs ; 7(2): 182-8, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8740723

RESUMO

The unique action of paclitaxel, to stabilize microtubules and block cells at the radiosensitive G2M phase of the cell cycle, suggests, it may sensitize tumors to radiotherapy. We have investigated the potential of this interaction to overcome multidrug resistance in vitro using the HL60 cell line and its P-glycoprotein expressing, multidrug resistant H/E8 subline. HL60 cells showed a modest 1.4-fold (p < 0.01) increase in sensitivity to 2 Gy radiation given 24 h after a 1 h treatment with paclitaxel. The H/E8 subline, which has increased radiation resistance and expresses an extended multidrug resistance phenotype, showed significant sensitization to radiation (up to 2.3-fold sensitization; p < 0.01) even with doses of paclitaxel which had no effect on cell viability or were associated with any G2/M block in the cell cycle. In the presence of verapamil, an inhibitor of P-glycoprotein mediated efflux, drug resistant cells could be sensitized to 2 Gy radiation by similar paclitaxel doses as the parental cell (> or = 30 nM; p < 0.01). These results indicate a therapeutic advantage may be possible in the treatment of resistant tumors by the combined use of paclitaxel with radiation.


Assuntos
Leucemia Promielocítica Aguda/tratamento farmacológico , Paclitaxel/farmacologia , Radiossensibilizantes/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/efeitos da radiação , Morte Celular/efeitos dos fármacos , Morte Celular/efeitos da radiação , Relação Dose-Resposta a Droga , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Humanos , Leucemia Promielocítica Aguda/patologia , Leucemia Promielocítica Aguda/radioterapia , Fatores de Tempo , Células Tumorais Cultivadas , Verapamil/farmacologia
12.
Blood ; 86(5): 1717-28, 1995 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-7655004

RESUMO

The Southwest Oncology Group analyzed outcome with cytotoxic chemotherapy for previously untreated acute myeloblastic leukemia (AML) from 1982 through 1986. Results with acute promyelocytic leukemia (APL) prompted comparison with patients from 1986 through 1991 and analysis of factors contributing to APL results. Patient and disease characteristics and treatment outcome were compared for all evaluable patients, with more detailed analysis of factors affecting APL treatment outcome. From 1982 through 1986, median survival and disease-free survival in 45 APL patients were 106 months and greater than 105 months, respectively, versus 6 and 14 months for 417 other AML patients. Such differences were not seen from 1986 through 1991. In the 141 APL patients from 1982 through 1991, after adjusting for significant patient and disease characteristics, higher daunomycin (DNR) doses during induction were significantly associated with higher complete remission rates (P < .0001), longer survival (P < .0001), and longer DFS (P < .0001). Cytosine arabinoside (Ara-C) induction dose, the inclusion of other chemotherapy agents in induction, postremission therapy (consolidation, maintenance, or bone marrow transplantation) other than DNR, APL subtype, and patient age did not appear to significantly affect outcome of APL, except for a significant detrimental effect of high-dose Ara-C in consolidation (P = .0042). Morphologic AML subtypes other than APL did not affect outcome. We conclude that high-dose DNR selectively increases survival in APL. This good survival is important for evaluation of combined all-trans retinoic acid (ATRA)/chemotherapy protocols and for planning future combinations of chemotherapy and ATRA. These results illustrate the need to individualize chemotherapy for subtypes of AML. Therapeutic response of APL is independent of age. Except for APL, morphologic subclassification of AML contributed little prognostic information.


Assuntos
Antineoplásicos/uso terapêutico , Leucemia Promielocítica Aguda/tratamento farmacológico , Adolescente , Adulto , Idoso , Citarabina/uso terapêutico , Relação Dose-Resposta a Droga , Feminino , Seguimentos , Humanos , Leucemia Promielocítica Aguda/mortalidade , Leucemia Promielocítica Aguda/radioterapia , Masculino , Pessoa de Meia-Idade , Indução de Remissão , Estudos Retrospectivos , Taxa de Sobrevida , Fatores de Tempo , Resultado do Tratamento , Irradiação Corporal Total
13.
Int J Radiat Oncol Biol Phys ; 30(1): 117-24, 1994 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-8083104

RESUMO

PURPOSE: Estimation of the relative biological effectiveness of electron emissions of 67Gallium for cell growth delay and inactivation. METHODS AND MATERIALS: Human myeloid HL60 cells were incubated in vitro with 0.74 MBq/mL, 1.48 MBq/mL, or 2.96 MBq/mL of 67Gallium for 4 days. Proliferation (vital cell counts and colorimetric tetrazolium assay), clonogenic survival, and cell-cycle effects were compared with responses of HL60 cells externally irradiated with 0.78, 10.37, and 13.22 Gy by an external 67Gallium source. Dosimetric calculations were performed by Monte Carlo simulations (10,000 events). RESULTS: Proliferation of cells was equally inhibited after 67Gallium incubation with 1.48 and 2.96 MBq/mL compared with 10.37 and 13.22 Gy external irradiation. Irradiation with 10.37 and 13.22 Gy caused a 81% and 89% reduction of Colony Forming Units, compared with 34%, 66%, and 80% reduction after 67Gallium incubation with 0.74, 1.48, and 2.96 MBq/mL, respectively. Peak values for G2/M accumulation were reached on day 4 for the cells externally irradiated with 10.37 and 13.22 Gy (47.5% and 56.7%) and on day 5 after 67Gallium incubation with 0.74 MBq/mL, 1.48 MBq/mL, and 2.96 MBq/mL (26.7%, 43.4%, and 58.2%). CONCLUSIONS: 67Gallium incubation exerts a significant cytotoxic effect on human HL60 cells, which, on the basis of dosimetric studies, may be mainly ascribed to conversion electrons (80 KeV) and 8 KeV Auger electrons. Low energy (< 1 keV) Auger electrons do not contribute significantly. The relative biological effectiveness of 67Gallium compared with external low dose rate gamma irradiation is about 1.0 for clonogenic survival and approximately 1.8 and 1.5 for proliferation inhibition and G2 arrest, respectively. For in vivo therapy, this might implicate that higher doses of 67Gallium than 131Iodine or 90Yttrium are necessary for the same biological effect.


Assuntos
Fase G2/efeitos da radiação , Radioisótopos de Gálio/uso terapêutico , Leucemia Promielocítica Aguda/patologia , Leucemia Promielocítica Aguda/radioterapia , Contagem de Células , Ciclo Celular/efeitos da radiação , Divisão Celular/efeitos da radiação , Células Clonais/efeitos da radiação , Ensaio de Unidades Formadoras de Colônias , Relação Dose-Resposta à Radiação , Gálio/farmacocinética , Radioisótopos de Gálio/química , Humanos , Leucemia Promielocítica Aguda/metabolismo , Doses de Radiação , Planejamento da Radioterapia Assistida por Computador , Sais de Tetrazólio , Tiazóis , Células Tumorais Cultivadas
14.
Cancer Res ; 53(13): 3186-92, 1993 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-8319228

RESUMO

The studies were aimed to detect the cell cycle-associated differences in the susceptibility of HL-60 cells to apoptosis induced by diverse agents. Exponentially growing HL-60 cells were treated with the DNA topoisomerase I inhibitor camptothecin; the DNA topoisomerase II inhibitors teniposide, m-AMSA, Mitoxantrone, or Fostriecin; the presumed tyrosine kinase inhibitor genistein; a serine/threonine kinase inhibitor H7; the protein synthesis inhibitor cycloheximide; the DNA replication inhibitor hydroxyurea; the nucleoside antimetabolites 1-beta-D-arabinofuranosylcytosine and 5-azacytidine; and the alkylating agent nitrogen mustard, cisplatin, hyperthermia, and gamma irradiation. Endonucleolysis, which accompanied apoptosis induced by these agents, was assessed by two different flow cytometric methods, one based on DNA content measurements following extraction of low molecular weight DNA, and another using exogenous terminal deoxynucleotidyl transferase to label in situ DNA strand breaks. Each method allowed for both identification of apoptotic cells and analysis of the cell cycle distribution of the unaffected cell population; the method using terminal transferase also allowed for identification of the cell cycle position of apoptotic cells. Confirmed by analysis of DNA degradation by gel electrophoresis and changes in cell morphology, apoptosis was observed as early as 3 h after administration of most drugs and for some drugs was cell cycle phase specific. Cells progressing through S phase were selectively susceptible when treated with camptothecin, teniposide, m-AMSA, Mitoxantrone, H7, hydroxyurea, and 1-beta-D-arabinofuranosylcytosine. Cells in G2-M preferentially underwent apoptosis in cultures treated with H7 or with gamma-irradiation. Cells in G1 phase were preferentially affected by 5-azacytidine, nitrogen mustard, and hyperthermia. No significant cell cycle specificity was observed in the case of Fostriecin, genistein, cycloheximide, or cisplatin. The cell cycle related difference in susceptibility to apoptosis may be a reflection of both the severity of the lesion induced by a given drug and the ability of the cells to repair that lesion; both can vary depending on the cell cycle phase.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Leucemia Promielocítica Aguda/tratamento farmacológico , Leucemia Promielocítica Aguda/patologia , Apoptose/fisiologia , Ciclo Celular/efeitos dos fármacos , Dano ao DNA , DNA de Neoplasias/análise , DNA de Neoplasias/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Eletroforese , Citometria de Fluxo , Humanos , Hipertermia Induzida , Interfase/fisiologia , Leucemia Experimental , Leucemia Promielocítica Aguda/radioterapia , Células Tumorais Cultivadas/efeitos dos fármacos
15.
Int J Radiat Biol ; 59(4): 1001-16, 1991 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1674267

RESUMO

UV radiation is known to be a potent agent for the induction of programmed cell death (apoptosis) in human skin. However, the mechanistic aspects of UV-induced apoptosis remain ill-defined. In this study the effects of varying periods of UV-irradiation on the human leukaemia HL-60 cell line and on five other human cell lines were investigated. HL-60 cells were found to rapidly undergo apoptosis en masse after short periods of UV-irradiation, whereas prolonged exposure of these cells to this form of radiation induced a more rapid form of cell death which was suggestive of necrosis, the pathological mode of cell death. Similar effects were observed on the U937 (myelomonocytic), Molt-4 (T-lymphoblastoid), and Molt-3 (T-lymphoblastoid) cell lines, whereas the K562 (pre-erythroid) and Daudi (B-lymphoblastoid) cell lines proved to be relatively resistant to the death-inducing properties of UV-irradiation by comparison. UV-induced apoptosis in cell lines was characterized by morphological changes as well as DNA fragmentation into unit multiples of approximately 200 bp, which was indicative of endogenous endonuclease activation. This DNA fragmentation pattern was not detected in cells immediately after UV-irradiation, and was therefore not the result of direct UV-induced DNA damage. UV-induced apoptosis of the HL-60 cell line was found to require extracellular calcium and to be inhibited in a dose-dependent way by zinc added to the culture medium.


Assuntos
Sobrevivência Celular/efeitos da radiação , Leucemia Promielocítica Aguda/radioterapia , Terapia Ultravioleta , Cálcio/administração & dosagem , Linhagem Celular , Meios de Cultura , DNA de Neoplasias/análise , DNA de Neoplasias/isolamento & purificação , DNA de Neoplasias/efeitos da radiação , Eletroforese em Gel de Ágar , Humanos , Células Tumorais Cultivadas/efeitos da radiação , Zinco/administração & dosagem
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