RESUMO
CONTEXT: We have previously reported that benznidazole (BZL), known for its trypanocidal action, has anti-proliferative activity against different cell lines like HeLa and Raw 264.7 among others. At the moment, it has not been reported if the anti-proliferative effect of BZL is similar for non-adherent hematopoietic cells like was reported for adherent cancer cell lines. OBJECTIVE: We aimed to investigate the efficacy of BZL on the growth of the leukemic cell lines THP-1 and OCI/AML3. MATERIALS AND METHODS: We evaluated cell proliferation by [³H]-thymidine incorporation and MTT reduction as well as cell death by lactate dehydrogenase (LDH) activity. We assessed apoptosis by flow cytometry for detection of annexin V-positive and propidium iodide-negative cells, along with nuclear morphology by diamidino-2-phenolindole (DAPI) staining. Western blot studies were performed to evaluate changes in cell cycle proteins in BZL-treated cells. RESULTS: BZL significantly reduced proliferation of both cell lines without inducing cell death. Likewise it produced no significant differences in apoptosis between treated cells and controls. In addition, flow cytometry analysis indicated that BZL caused a larger number of THP-1 cells in G0/G1 phase and a smaller number of cells in S phase than controls. This was accompanied with an increase in the expression of the CDK inhibitor p27 and of cyclin D1, with no significant differences in the protein levels of CDK1, CDK2, CDK4, cyclins E, A and B as compared to controls. CONCLUSION: BZL inhibits the proliferation of leukemic non-adherent cells by controlling cell cycle at G0/G1 cell phase through up-regulation of p27.
Assuntos
Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Leucemia Monocítica Aguda/metabolismo , Nitroimidazóis/farmacologia , Tripanossomicidas/farmacologia , Morte Celular/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p27/biossíntese , Quinases Ciclina-Dependentes/biossíntese , Ciclinas/biossíntese , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Células HeLa , Humanos , Leucemia Monocítica Aguda/patologia , Proteínas de Neoplasias/biossínteseRESUMO
Hypocholesterolemia is a common finding in patients with acute leukemia (AL). The aim of this study is to investigate if blast myeloid and lynfoid cells take up more high density lipoprotein (HDL) cholesteryl esters than normal cells of the same origin. The HDL-cholesteryl ester uptake followed a kinetic saturation process. Higher maximal velocity rates were found in lymphoblasts and myeloblasts compared to normal cells (Vmax=3.51+/-0.30/3.61+/-0.16 and 2.54+/-0.12/2.28+/-0.12 microg/mg, respectively). High density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) and total cholesterol were significantly lower in AL patients (p<0.05); no differences were observed in triglyceride or VLDL-C levels. In conclusion, low HDL-C levels observed in AL may be related to an overexpression of a selective HDL-cholesteryl ester putative site.
Assuntos
Ésteres do Colesterol/metabolismo , Ésteres do Colesterol/farmacocinética , HDL-Colesterol/metabolismo , Leucemia Monocítica Aguda/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Adulto , Radioisótopos de Carbono , Colesterol/metabolismo , HDL-Colesterol/sangue , LDL-Colesterol/sangue , LDL-Colesterol/metabolismo , Feminino , Humanos , Leucemia Monocítica Aguda/sangue , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/sangue , Células Tumorais CultivadasRESUMO
BACKGROUND: Apoptosis is an essential form of cell death, the failure of which can lead to cancer development. Cancer including leukemia is usually treated with chemotherapeutic drugs that can be effective, but frequently problems are encountered that impair the success of the treatment. Butyrate is a short-chain fatty acid that can have many effects on different cells, including apoptosis. METHODS: The effect of a combination treatment with butyrate and antineoplastic agents Ara-C, etoposide and vincristine is evaluate on the leukemic cell line THP-1. RESULTS: We show that butyrate increased apoptosis induced by the three agents as seen by measurement of DNA content, annexin exposure and morphological characteristics. We also demonstrate that the process of apoptosis induced by butyrate and chemotherapeutic drugs involves the participation of caspases and induced activation of caspase-3, -8 and -9. CONCLUSIONS: We believe that butyrate could be a promising therapeutic agent for the treatment of leukemia in combination with other antineoplastic drugs.
Assuntos
Antineoplásicos/farmacologia , Butiratos/farmacologia , Sinergismo Farmacológico , Leucemia Monocítica Aguda/tratamento farmacológico , Leucemia Monocítica Aguda/patologia , Clorometilcetonas de Aminoácidos/farmacologia , Clorometilcetonas de Aminoácidos/uso terapêutico , Antineoplásicos/classificação , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Western Blotting , Butiratos/química , Butiratos/uso terapêutico , Inibidores de Caspase , Caspases/metabolismo , Caspases/uso terapêutico , Linhagem Celular Tumoral , Citarabina/farmacologia , Citarabina/uso terapêutico , Replicação do DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Quimioterapia Combinada , Etoposídeo/farmacologia , Etoposídeo/uso terapêutico , Humanos , Leucemia Monocítica Aguda/metabolismo , Vincristina/farmacologia , Vincristina/uso terapêuticoRESUMO
Cell-cell interaction is important in the expansion of leukemic cells and of solid tumors. Steel factor (SF) or Kit ligand is produced as a membrane-bound form (mSF) and a soluble form. Because both primary gynecological tumors and primary leukemic cells from patients with acute myeloblastic leukemia (AML) have been shown to coexpress c-Kit and SF, we addressed the question of whether mSF could contribute to cell interaction in these cancers. Investigations on primary cervical carcinomas have been hindered by the fact that the cells do not grow in culture. We report herein the establishment of two cervical carcinoma cell lines, CALO and INBL, that reproduce the pattern of SF/c-Kit expression observed in primary tumor samples. In addition, these cells exhibit marked density-dependent growth much in the same way as AML blasts. Using an antisense strategy with phosphorothioate-modified oligonucleotides that specifically target SF without affecting other surface markers, we provide direct evidence for a role of mSF and c-Kit in cell interaction and cell survival in these gynecological tumor cell lines as well as in primary AML blasts. Finally, our study defines the importance of juxtacrine stimulation, which may be as important, if not more, than autocrine stimulation in cancers.