Chronic myeloid leukemia （CML） is a clonal myeloprolif- erative disorder characterized by a chromosome translocation that generates the Bcr-Abl oncogene en- coding a constitutive kinase activity. Despite remarkable ...Chronic myeloid leukemia （CML） is a clonal myeloprolif- erative disorder characterized by a chromosome translocation that generates the Bcr-Abl oncogene en- coding a constitutive kinase activity. Despite remarkable success in controlling CML at chronic phase by Bcr-Abl tyrosine kinase inhibitors （TKIs）, a significant proportion of CML patients treated with TKIs develop drug resis- tance due to the inability of TKIs to kill leukemia stem cells （LSCs） that are responsible for initiation, drug re- sistance, and relapse of CML. Therefore, there is an ur- gent need for more potent and safer therapies against leukemia stem cells for curing CML. A number of LSC- associated targets and corresponding signaling path- ways, including CaMKII-y, a critical molecular switch for co-activating mu｜tipte LSC-associated signaling path- ways, have been identified over the past decades and various small inhibitors targeting LSC are also under development. Increasing evidence shows that leukemia stem cells are the root of CML and targeting LSC may offer a curable treatment option for CML patients. This review summarizes the molecular biology of LSC and its- associated targets, and the potential clinical application in chronic myeloid leukemia.展开更多
在多种肿瘤中,生长阻滞特异性转录因子5(growth-arrest specific transcript 5,GAS5)高表达与患者的良好生存期相关。GAS5存在多种剪接变异体,本研究探讨GAS5部分剪接变异体在髓系白血病细胞系中的表达模式。并基于对凋亡诱导敏感的慢...在多种肿瘤中,生长阻滞特异性转录因子5(growth-arrest specific transcript 5,GAS5)高表达与患者的良好生存期相关。GAS5存在多种剪接变异体,本研究探讨GAS5部分剪接变异体在髓系白血病细胞系中的表达模式。并基于对凋亡诱导敏感的慢性髓系白血病(chronic myeloid leukemia,CML)细胞系K562,研究GAS5部分剪接变异体对K562细胞自身增殖、凋亡以及对靶向药物伊马替尼(imatinib,IM)的敏感性的影响。反转录PCR结果显示,GAS5剪接模式在髓系白血病细胞系HL-60、K562、NB4和KASUMI-1之间未见明显差异。相较于指数增长期,GAS5_AE表达水平在细胞密度引起的生长停滞期有一定程度的累积。通过核转染,将GAS5剪接变异体(pcDNA3-GAS5_1B、-GAS5_2B、-GAS5_3A、-GAS5_4A、-GAS5_O1或-GAS5_AE)转入K562细胞的单克隆株中。通过台盼蓝染色、吖啶橙染色后进行细胞计数,克隆形成实验检测细胞集落形成能力。结果与对照组相比,瞬时转染GAS5剪接变异体并无抑制细胞的基础增殖或增强细胞对药物的敏感性。建立GAS5_O1的稳定转染株,延长培养时程并计算倍增时间,发现GAS5_O1的表达水平和倍增时间成正比(R^(2)=0.5692)。在稳转株O1-C8中观察到GAS5_O1可促进IM引起的细胞生长抑制(56.94%±2.84%vs.36.07%±2.32%,P<0.05)和凋亡(29.33%±1.30%vs.52.00%±2.52%,P<0.05)。上述结果表明,GAS5_O1的上调可能增加CML细胞的倍增时间,并使CML细胞对IM处理敏感。展开更多
基金We apologize to the scientists who made contributions to the field, but have not been cited due to the space limitations. This work was sup- ported in part by the National Natural Science Foundation of China （Grant Nos. 81270601, 81328016, and 81470306） and Leukemia Research Innovative Team of Zhejiang Province （2011 R50015）.
文摘Chronic myeloid leukemia （CML） is a clonal myeloprolif- erative disorder characterized by a chromosome translocation that generates the Bcr-Abl oncogene en- coding a constitutive kinase activity. Despite remarkable success in controlling CML at chronic phase by Bcr-Abl tyrosine kinase inhibitors （TKIs）, a significant proportion of CML patients treated with TKIs develop drug resis- tance due to the inability of TKIs to kill leukemia stem cells （LSCs） that are responsible for initiation, drug re- sistance, and relapse of CML. Therefore, there is an ur- gent need for more potent and safer therapies against leukemia stem cells for curing CML. A number of LSC- associated targets and corresponding signaling path- ways, including CaMKII-y, a critical molecular switch for co-activating mu｜tipte LSC-associated signaling path- ways, have been identified over the past decades and various small inhibitors targeting LSC are also under development. Increasing evidence shows that leukemia stem cells are the root of CML and targeting LSC may offer a curable treatment option for CML patients. This review summarizes the molecular biology of LSC and its- associated targets, and the potential clinical application in chronic myeloid leukemia.
