RESUMO
AIM: To study the effect of platelet factor 4 (PF4) on murine bone marrow cell apoptosis after irradiation with 5.0 Gy (60)COgamma and explore its potential mechanism. METHODS: 30 male BALB/c mice were randomly divided into three groups: namely normal control group (n = 6), PF4 treatment group (n=12) and irradiation (IR) group (n = 12). The mice in PF4 treatment group were administrated intraperitoneally PF4 40 microg/kg at 26 h and 20 h respectively before total-body irradiation with 5.0 Gy (60)COgamma ray. At 4 h and 20 h after irradiation the apoptosis of bone marrow cells were detected by flow cytometry (FCM) and the expression of Bax protein was identified by Western blot. RESULTS: At 4 h and 20 h after irradiation the apoptosis of bone marrow cells in PF4 treatment group was significantly lower than that in IR group (P < 0.01), the expression of Bax protein in the PF4 group was lower than that in the IR group (P < 0.05). CONCLUSION: PF4 can protect bone marrow cells from radiation-induced apoptosis, which is partly due to the down-regulation of proapoptotic protein Bax expression.
Assuntos
Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Células da Medula Óssea/patologia , Raios gama/efeitos adversos , Fator Plaquetário 4/farmacologia , Animais , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Células da Medula Óssea/efeitos da radiação , Radioisótopos de Cobalto/efeitos adversos , Citometria de Fluxo , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Proteína X Associada a bcl-2/metabolismoRESUMO
<p><b>OBJECTIVE</b>To investigate the effect of short hairpin RNA (shRNA) targeting hypoxia-inducible factor-1 alpha (HIF-1 alpha) on the human breast carcinoma MCF-7 cell line.</p><p><b>METHODS</b>The hypoxia environment was achieved by treating cells with cobalt chloride. The shRNA eukaryotic expression vector targeting HIF-1 alpha was constructed, and transfected into MCF-7 cells through lipofectamine 2000. Semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to study the expression of vascular endothelial growth factor (VEGF). The mRNA and protein level of HIF-1 alpha were detected by real-time PCR and Western blot. Sub-G1 apoptotic population analysis, Annexin V/PI binding assay, and DNA ladder analysis were applied to investigate the cell apoptosis. The cell cycle was detected by flow cytometry.</p><p><b>RESULTS</b>The mRNA and protein level of HIF-1 alpha increased after exposure of MCF-7 cells to hypoxia (P < 0.01). However, apoptosis was lower in hypoxia compared with normoxia (P < 0.05). The HIF-1 level of MCF-7 transfected with HIF-1 alpha shRNA decreased approximately 91.63% (P < 0.01). When the cells were treated with or without apoptosis inducer Ara-C, the apoptosis of MCF-7 cells transfected with HIF-1 alpha shRNA increased by 1.75 times (P < 0.01) and 61. 31 times (P < 0.01), respectively. The expression of VEGF in MCF-7 cells transfected with HIF-1 alpha shRNA decreased 66.8% compared with untransfected cells (P < 0.05). Cell cycle progression was inhibited when the MCF-7 cells were transfected with HIF-1 alpha shRNA.</p><p><b>CONCLUSIONS</b>HIF-1 alpha plays an anti-apoptotic role in human breast carcinoma MCF-7 cell line. The shRNA we designed targeting HIF-1 alpha in MCF-7 can promote cell apoptosis, inhibit the expression of VEGF, and delay cell cycle progression.</p>
Assuntos
Feminino , Humanos , Apoptose , Neoplasias da Mama , Genética , Metabolismo , Patologia , Ciclo Celular , Linhagem Celular Tumoral , Regulação para Baixo , Subunidade alfa do Fator 1 Induzível por Hipóxia , Genética , Interferência de RNA , RNA Mensageiro , Genética , RNA Interferente Pequeno , Genética , Transfecção , Fator A de Crescimento do Endotélio Vascular , MetabolismoRESUMO
<p><b>OBJECTIVE</b>To explore the effect of hemangiopoietin (HAPO) on the adhesive properties of human umbilical vein endothelial cells (HUVEC).</p><p><b>METHODS</b>The adhesion of HUVEC and the expressions of CD54, CD102, CD106, CD31, CD62E, and CD62P were measured by adhesion assay, flow cytometry, and semi-quantitative RT-PCR.</p><p><b>RESULTS</b>HAPO enhanced the total adherence of HUVEC in a concentration-dependent manner. Flow cytometry analysis revealed that the treatment of HAPO resulted in a significantly increased expression of CD106 and CD62E on HUVEC in a time-dependent manner. When HUVEC were incubated with HAPO for 6 h, the percentage of CD106 + HUVEC and CD62E HUVEC increased about 2.10 folds and 5.84 folds, respectively, compared with control. The time-course of adhesive molecules mRNA expression indicated that the expression of CD106 and CD62E reached at the maximum 1.86 folds and 6.16 folds, respectively, compared with control.</p><p><b>CONCLUSION</b>HAPO may facilitate the homing of hematopoietic stem/progenitor cells.</p>