Zhang Shu-Qin, Wang Guang-Ping, Zhu Ping, Liang Jia-Jia, Xu Ya-Jing, Peng Min-Yuan, Chen Yan, Tan San-Qin, Chen Fang-Ping
Department of Hematology, Central South University Xiangya Hospital, Changsha 410008, Hunan Province, China.
Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2011 Jun;19(3):561-5.
A little is known about the specific marker on the surface of acute leukemia cells, leading to the lack of the specific diagnosis method for acute leukemia. Therefore, in this study, cell-systematic evolution of ligands by exponential enrichment (cSELEX) was performed to screen the aptamers binding to CD33(+)/CD34(+) cells from the patients with acute myeloblastic leukemia (AML) of M(2) subtype (AML-M₂) so as to provide the basis for finding the specific marker on the surface of AML-M(2) CD33(+)/CD34(+) cells. Firstly, AML-M₂ CD33(+)/CD34(+) cells were sorted and used as targeted cells, and normal CD33(+)/CD34(+)cells were used as counter-targeted cells; the aptamers binding to CD33(+)/CD34(+) cells from patients with AML-M₂ were screened from the single strand deoxyribonucleic acid (ssDNA) library by cSELEX. Subsequently, each aptamer structure was analyzed after cloning and sequencing. The results indicated that after 13 round of screenings, the enrichment of aptamers in the ssDNA library was ranged from 0.7% to 52.9%, and reached steady state at 13th round screening. Sequence analysis for 30 aptamers showed that most of the aptamers born one of the three conserved sequences of CCCCT, CTCTC, and CTCAC. Secondary structure analysis indicated that three different secondary structures existed in these aptamers. It is concluded that the aptamers binding to the AML-M(2) CD33(+)/CD34(+) cells are successfully screened, which lay the basis for further looking for the specific marker on the surface of AML-M₂ CD33(+)/CD34(+) cells, and the molecular diagnosis of the AML-M₂ leukemia.
关于急性白血病细胞表面的特异性标志物知之甚少，这导致缺乏针对急性白血病的特异性诊断方法。因此，在本研究中，通过指数富集系统进化配体技术（cSELEX）进行筛选，以从M₂亚型急性髓细胞白血病（AML-M₂）患者中筛选出与CD33(+)/CD34(+)细胞结合的适体，从而为寻找AML-M₂ CD33(+)/CD34(+)细胞表面的特异性标志物提供依据。首先，分选AML-M₂ CD33(+)/CD34(+)细胞作为靶细胞，正常CD33(+)/CD34(+)细胞作为反靶细胞；通过cSELEX从单链脱氧核糖核酸（ssDNA）文库中筛选与AML-M₂患者CD33(+)/CD34(+)细胞结合的适体。随后，对每个适体结构进行克隆和测序分析。结果表明，经过13轮筛选后，ssDNA文库中适体的富集率在0.7%至52.9%之间，并在第13轮筛选时达到稳定状态。对30个适体的序列分析表明，大多数适体含有CCCCT、CTCTC和CTCAC这三个保守序列之一。二级结构分析表明，这些适体存在三种不同的二级结构。结论是成功筛选出了与AML-M₂ CD33(+)/CD34(+)细胞结合的适体，这为进一步寻找AML-M₂ CD33(+)/CD34(+)细胞表面的特异性标志物以及AML-M₂白血病的分子诊断奠定了基础。
