Fukuda S, Pelus L M
Department of Microbiology and Immunology and the Walther Oncology Center, Indiana University School of Medicine, Indianapolis, IN, USA.
Blood. 2001 Oct 1;98(7):2091-100. doi: 10.1182/blood.v98.7.2091.
The inhibitor-of-apoptosis protein survivin is expressed in most cancers and leukemias and during fetal development, but not in most normal adult tissues. Survivin expression was analyzed in umbilical cord blood (UCB) and adult bone marrow CD34(+) cells and in the factor-dependent MO7e cell line; also investigated was whether survivin expression was regulated by hematopoietic growth factors. Survivin messsenger RNA (mRNA) and protein were expressed in fresh UCB and marrow CD34(+) cells. The combination of thrombopoietin, Flt3 ligand, and stem cell factor upregulated survivin expression in CD34(+) cells within 24 hours; survivin expression was cell-cycle related and highest during G2/M, whereas growth-factor withdrawal resulted in decreased survivin expression. Cell-cycle fractionation of UCB CD34(+) with Hoechst-33342/pyronin-Y demonstrated that survivin message was undetectable in freshly isolated G0 cells, but present in G1 cells. After cytokine stimulation, survivin mRNA and protein expression were observed in both G0 and G1 CD34(+) cells as well as in cells that had progressed to S and G2/M phase, indicating that survivin expression is regulated in all phases of the cell cycle. This contrasts with the expression of survivin predominantly during G2/M in cancer cells. In CD34(+) cells and MO7e cells, growth factor-mediated upregulation of survivin was associated with inhibition of apoptosis, and downregulation of survivin was coincident with increased apoptosis. Furthermore, an inverse correlation between survivin and active caspase-3 was observed in CD34(+) cells. These findings demonstrate that survivin is not a cancer-specific antiapoptotic protein and plays a regulatory role in normal adult hematopoiesis.
凋亡抑制蛋白survivin在大多数癌症和白血病以及胎儿发育过程中表达，但在大多数正常成人组织中不表达。对脐带血（UCB）和成人骨髓CD34(+)细胞以及因子依赖性MO7e细胞系中的survivin表达进行了分析；还研究了survivin表达是否受造血生长因子调节。Survivin信使核糖核酸（mRNA）和蛋白在新鲜UCB和骨髓CD34(+)细胞中表达。血小板生成素、Flt3配体和干细胞因子的组合在24小时内上调了CD34(+)细胞中的survivin表达；survivin表达与细胞周期相关，在G2/M期最高，而生长因子撤除导致survivin表达降低。用Hoechst-33342/派洛宁-Y对UCB CD34(+)细胞进行细胞周期分级分离显示，在新鲜分离的G0细胞中未检测到survivin信息，但在G1细胞中存在。细胞因子刺激后，在G0和G1 CD34(+)细胞以及进展到S期和G2/M期的细胞中均观察到survivin mRNA和蛋白表达，表明survivin表达在细胞周期的所有阶段均受到调节。这与癌细胞中survivin主要在G2/M期表达形成对比。在CD34(+)细胞和MO7e细胞中，生长因子介导的survivin上调与凋亡抑制相关，而survivin下调与凋亡增加一致。此外，在CD34(+)细胞中观察到survivin与活性半胱天冬酶-3呈负相关。这些发现表明，survivin不是癌症特异性抗凋亡蛋白，在正常成人造血中起调节作用。
