二乙酰己二胺治疗高危型骨髓增生异常综合征的研究

本研究探讨癌细胞诱导分化剂二乙酰己二胺(CAHB)对高危型骨髓增生异常综合征(MDS)的疗效,查明其在体外对HL-60细胞的作用及可能机制.高危型MDS患者8例,给予CAHB治疗2个疗程,用药前后计数骨髓原幼粒细胞和单核细胞的比例.在体外试验中用MTT法检测CAHB对HL-60细胞增殖的抑制作用,流式细胞术(FCM)检测CAHB时HL-60细胞表面CD11b和CD14分化抗原表达的影响,Annexin V/PI双染色法检测CAHB诱导HL-60细胞凋亡的作用,FCM检测CAHB对HL-60细胞周期分布的影响.结果表明,8例患者用CAHB治疗后.骨髓的原幼粒细胞和单核细胞比例有不同程度的下降,造血系统毒副反应主要是血小板减少.MTT检测发现,HL-60细胞经1、2、3、4 mmol/L CAHB作用72小时后,HL-60细胞的增殖受到抑制,并且该作用随药物浓度的增加而增强.HL-60细胞分别经1、2、3、4 mmol/L CAHB作用72小时后,CDIlb的阳性表达率为(22.39±3.97)%、(33.12±4.46)%、(49.25±5.27)%和(78.05±5.66)%,与空白对照组的(5.89±2.94)%比较,差异有统计学意义(p＜0.01).而CD14的表达在各组细胞中均为阴性,这表明CAHB可诱导HL-60细胞向成熟粒细胞系分化,并且该作用随药物浓度的增加而增强.HL-60细胞经1、2、3、4 mmol/L CAHB作用72小时后,其凋亡率(Annexin /PI-)仅较空白对照组略有增加.此结果提示在1-4 mmol/L浓度下,CAHB诱导HL-60细胞凋亡的作用很微弱.HL-60细胞经1、2、3、4 mmol/L CAHB作用72小时后,随药物浓度的增加,G0/G1期细胞的比例逐渐增加,而S期和G2/M期细胞的比例相应地逐渐减少,这表明CAHB能阻滞HL-60细胞于G0/G1期,并且该作用随药物浓度的增加而增强.结论CAHB对MDS有减少原幼粒细胞和单核细胞的作用,该治疗作用可能主要是通过诱导分化实现的,在治疗浓度时无诱导凋亡的作用,细胞周期的阻滞作用可能是CAHB诱导分化的基础.用药后血小板减少的副作用可能与CAHB的抑制造血相关.

Efficacy of Diacetyl Hexamethylene Diamine in Treatment of Patients with High Risk Myelodysplastic Syndrome

The aim of this study was to investigate the efficacy of diacetyl hexamethylene diamine (CAHB) for patients with high risk myelodysplastic syndrome (MDS), and to explore the effect of CAHB on HL-60 cells in vitro and its possible mechanism. 8 patients with high risk MDS were treated with CAHB by continuous intravenous infusion for 10 days, and repeated once after an interval of 28 days. The count of the granulo- and mono-blasts in bone marrow (BM) aspirate was measured before and after treatment. HL-60 cells were treated with different concentrations of CAHB for 72 hours in vitro. The inhibitory effect of CAHB on proliferation of HL-60 cells in vitro was measured by MTT assay. Differentiation of HL-60 cells was detected by the changes of CD11b and CD14 expression on cell surface. Apoptosis of HL-60 cells was detected by double staining of Annexin V and PI. The cell cycle distribution change of HL-60 cells was analyzed by flow-cytometry. The results indicated that the granulo- and mono-blasts in BM decreased in all the 8 patients after CAHB treatment. The main side effect of CAHB on hematological system was thrombocytopenia. After being treated with 1, 2, 3, 4 mmol/L CAHB for 72 hours in vitro, the result of MTT assay showed the inhibitory effect of CAHB on the proliferation of HL-60 cells in dose-dependent manner. After being treated manner 1, 2, 3, 4 mmol/L CAHB for 72 hours, the CD11b positive HL-60 cells were 22.39+/-3.97%, 33.12+/-4.46%, 49.25+/-5.27%, 78.05+/-5.66%, respectively, which were significantly different from the control group (CD11b positive HL-60 cells was 5.89+/-2.94%) (p<0.01). The CD14 expression was negative in all the 5 groups. These results suggested that CAHB could induce HL-60 cells to differentiate into mature granulocytes, and the effect of CAHB appeared in dose-dependent manner. After being treated for 72 hours by 1, 2, 3, 4 mmol/L CAHB, the apoptotic cells (Annexin V(+)/PI(-) cells) increased mildly, which suggested that CAHB only weakly induces HL-60 cells to apoptosis at the concentration of 1 to 4 mmol/L. Along with the concentration increase of CAHB, the ratio of cells in G(0)/G(1) phase increased, and ratio of cells in S phase and G(2)/M phase decreased correspondingly, it indicated that CAHB could arrest HL-60 cells in G(0)/G(1) phase in a dose-dependent manner. It is concluded that induction of cell differentiation may be the primary effect of CAHB on MDS. Cell cycle arrest may be essential to the effect of CAHB as well. Side effect of CAHB on platelet count may correlated with its inhibitory effect on hematopoiesis.