MicroRNA-10b通过调控锌指蛋白KLF4阻滞白血病细胞分化

MicroRNA-10b Blocks the Differentiation of Leukemia Cells Through Regulating the Zinc Finger Protein KLF4

探讨microRNA-10b(miR-10b)通过调节锌指蛋白Krüppel-like factor 4(KLF4)的表达对急性白血病细胞分化的影响。Real-time PCR及Western blot分别检测不同分化程度的白血病细胞系中miR-10b与KLF4的表达;1,25-二羟基维生素D3(1,25D3)诱导人白血病细胞系HL60向单核系分化,检测此过程中miR-10b及KLF4的表达变化;利用体外合成的寡核苷酸(miR-10b mimics)转染HL60细胞,瑞氏–吉姆萨染色观察1,25D3诱导后细胞分化形态学的改变;流式细胞术检测单核细胞表面标志CD14的表达。结果显示,miR-10b在分化早期的KG-1a细胞中表达最高,在分化晚期的U937、THP-1细胞中表达最低(P<0.01),而KLF4的表达与之相反;1,25D3诱导HL60向单核系分化过程中,miR-10b表达呈时间依赖性降低,KLF4表达则逐渐增高;HL60细胞中过表达miR-10b后可抑制1,25D3诱导的细胞分化形态特征的改变及CD14的表达(P<0.05)。提示miR-10b通过负调控KLF4的表达阻滞白血病细胞HL60单核系的分化。

We aimed to explore the effect of microRNA-10b （miR-10b） on the differentiation of leukemia cells through regulating the expression of zinc finger protein Kriippel-like factor 4 （KLF4）. The expression of miR- 10b and KLF4 in leukemia cell lines at different levels of differentiation was detected by Real-time PCR and Western blot, respectively. Leukemia cell line HL60 was induced with 1,25-dihydroxy-vitamin D3 （1,25D3） to differentiate along the monocytic lineage. The expression of miR-10b and KLF4 was examined during 1,25D3-induced differentiation of HL60. The synthesized miR-10b mimics was transfected into HL60 cells. The morphological changes of cells treated with 1,25D3 were observed under light microscope following Wright-Giemsa staining, and the monocyte surface marker CD14 was analyzed by flow cytometry, miR-10b was detected at the highest levels of expression in KG-la cells displaying early differentiation phenotypes and at the lowest in more mature U937 and THP-1 cells （P〈0.01）,while the KLF4 exhibited an opposite expression pattern, miR-10b was decreased in a time-dependent manner in HL60 cells during induction with 1,25D3, whereas the KLF4 was increased. Enforced expression ofmiR-10b in HL60 cells inhibited the 1,25D3-induced morphological changes and the expression of CD14 （P〈0.05）. Our data indicate that miR-10b suppresses monocytic differentiation of ilL60 cells via targeting to KLF4.