Yi Juan, Chen Jing, Sun Jing, Wei Hu-Lai
Laboratory Center for Medical Science, School of Medicine, Lanzhou University, Lanzhou, China.
Zhonghua Yi Xue Za Zhi. 2009 Jul 7;89(25):1741-4.
To investigate the drug resistance, proportion of leukemia stem cells (LSC) and expression of P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) in drug-sensitive and multidrug-resistant leukemia cell population.
The multidrug-resistant leukemia K562/ADM cell and its parental K562 cell were used as the model cells. The drug sensitivity was tested with a MTT assay. Flow cytometry was employed to detect the immunophenotype of stem cells and the expression of P-gp and BCRP. The self-renewal and proliferating potential were examined with methylcellulose colony-forming unit assay.
K562/ADM cells were highly resistant to adriamycin, daunorubicin and etoposide. The amount of CD34+, CD123+ and CD34+ CD38- cells in K562/ADM cells was much higher than that in K562 cells, and the proportion of CD34+ CD38- CD123+ cells (LSC) in K562/ADM cells was (5.23 +/- 0.21)% versus (1.27 + 0.17)% in K562 cells, which was 4.12-fold higher than that in K562 cells. Both P-gp and BCRP were overexpressed in K562/ADM cells relative to K562 cells, and the K562/ADM cells coexpressing P-gp and BCRP were 11.25-fold higher over K562 cells. The proportion of CD34+ CD38- CD123+ BCRP+ and CD34+ CD38- P-gp+ BCRP+ cells in K562/ADM cells were (4.13 +/- 0.40)% and (5.80 +/- 1.19)% respectively, which were 3.66- and 11.37-fold higher than the same cells in K562 cells [(1.13 +/- 0.15)% and (0.51 +/- 0.01)%]. Furthermore, drug-resistant K562/ADM cells displayed 4.17-time greater colony-forming ability over the parent K562 cells, corresponding to the proportion of LSCs in K562/ADM cells.
The ABC transporters-overexpressing LSC population exists in drug-resistant leukemic K562/ADM cells relative to drug-sensitive K562 cells, and the drug-resistant LSCs may be the source of chemotherapeutic resistance of leukemia.
研究药物敏感及多药耐药白血病细胞群体中的耐药性、白血病干细胞（LSC）比例以及P-糖蛋白（P-gp）和乳腺癌耐药蛋白（BCRP）的表达情况。
以多药耐药白血病K562/ADM细胞及其亲本K562细胞作为模型细胞。采用MTT法检测药物敏感性。运用流式细胞术检测干细胞免疫表型以及P-gp和BCRP的表达。通过甲基纤维素集落形成单位试验检测自我更新和增殖潜能。
K562/ADM细胞对阿霉素、柔红霉素和依托泊苷高度耐药。K562/ADM细胞中CD34 +、CD123 +和CD34 + CD38 -细胞的数量远高于K562细胞，K562/ADM细胞中CD34 + CD38 - CD123 +细胞（LSC）的比例为（5.23±0.21）%，而K562细胞中为（1.27 + 0.17）%，比K562细胞高4.12倍。相对于K562细胞，K562/ADM细胞中P-gp和BCRP均过度表达，同时表达P-gp和BCRP的K562/ADM细胞比K562细胞高11.25倍。K562/ADM细胞中CD34 + CD38 - CD123 + BCRP +和CD34 + CD38 - P-gp + BCRP +细胞的比例分别为（4.13±0.40）%和（5.80±1.19）%，分别比K562细胞中相同细胞高3.66倍和11.37倍[（1.13±0.15）%和（0.51±0.01）%]。此外，耐药的K562/ADM细胞的集落形成能力比亲本K562细胞高4.17倍，与K562/ADM细胞中LSC的比例相对应。
与药物敏感的K562细胞相比，耐药白血病K562/ADM细胞中存在过表达ABC转运蛋白的LSC群体，耐药LSC可能是白血病化疗耐药的根源。
