Relationship between BH3 mimetic S1 and expression of BCL-2 family members in acute myeloid leukemia / 中国实验血液学杂志

<p><b>OBJECTIVE</b>This study was to investigate the molecular biomarkers of apoptosis induced by BH3 mimetic S1 in human primary AML cells.</p><p><b>METHODS</b>Mononuclear cells were isolated from 27 newly diagnosed AML samples. Apoptosis was analyzed by flow cytometry. IC(50) value of S1 on these samples was determined by XTT assay. The expression level of BCL-2 family members and phosphorylated BCL-2 were assessed by Western blot with subsequent semi-quantitatively densitometric analysis. XTT assay was performed to determine the cell viability of the combined use of S1 and MEK/ERK inhibitor PD98059. The interactions between BCL-2 and pro-apoptosis proteins were tested by co-immunoprecipitation.</p><p><b>RESULTS</b>The flow-cytometry detection showed that S1 induced the apoptosis of primary AML cells. Based on the responses, 27 primary samples could be classified into three groups: (1) a sensitive group (12 of 27 cases) with IC(50)<14 µmol/L, (2) an intermediate group (8 of 27 cases) with IC(50) of 14-30 µmol/L and (3) a resistant group (7 of 27 cases) with IC(50)>30 µmol/L. The ratio of pBCL-2/(BCL-2+MCL-1) showed a good linear correlation with the IC(50) values. (R(2) = 0.71, P < 0.0001). PD98059 suppressed BCL-2 phosphorylation. When PD98059 suppressed BCL-2 phosphorylation, the apoptotic rate of drug-resistant cells induced by S1 increased from 9.8% to 64.5% (combination index, CI = 0.4), accompanied by more dissociation of BCL-2 heterodimers.</p><p><b>CONCLUSION</b>The combination of S1 with PD98059 decrease pBCL-2 level of AML patients and inhibits of the anti-apoptotic function of BCL-2 through enhancing the dissociation of BCL-2 heterodimers.</p>

Differentiation and increase of dendritic cells from umbilical cord blood in vitro / 中国实验血液学杂志

The aims of this study were to analyze the composition of umbilical cord blood cells (UCBC), to examine the characteristics of dendritic cells (DC) before and after culture, to search the method of differentiation and increase of DC in vitro and to appraise surface antigen from UCBC. Twelve units of umbilical cord blood were collected from May 2002 to September 2002. Peripheral blood mononuclear cells of 9 cases were collected from healthy adult donors. The nature of UCBC was freshly determined and then UCBC were cultured for 1, 2, 3 and 4 weeks with granulocyte-monocyte colony-stimulating factor (GM-CSF), interleukin 3 (IL-3), recombinant human stem cell factor (SCF) and EPO. Method of flow cytometry was used to determine the number of DC and cell surface antigens before and after culture by using monoclonal antibodies. The monoclonal antibodies included CD4, CD8, CD19, CD34, CD38, CD83, CD1a, CD11c and CDw123. The results showed that amounts of CD34+ progenitors in peripheral blood cells were 0.02 x 10(5)/ml, and amounts of CD34+ progenitors in human UCBC were 0.22 x 10(5)/ml. UCBC cultured for 1, 2, 3 and 4 weeks with GM-CSF, IL-3, EPO and SCF were shown to differentiate into CD1a+ CD11c+ CD83+ CDw123+ DC. Numbers of DC from UCBC remarkably generated in 2-4 weeks and then decreased in number. By culture with cytokines DC increased up to (10.6 - 28.2) x 10(5)/ml in actual numbers. It is concluded that the mononuclear cells of UCB are able to differentiate into CD1a+, CD83+, CD11c+ and CDw123+ DC when UCBC are cultured with proper cytokines of GM-CSF, SCF, EPO and IL-3 for 2-4 weeks. These DCs as antigen presenting cells are possibly effective in cancer immunotherapy.