miRNA-196b过表达对K562细胞增殖、凋亡及survivin、Cox-2表达的影响

摘要

背景与目的：BCR-ABL融合基因是慢性粒细胞白血病发病的分子病理基础，也是诊断慢性粒细胞白血病、观察疗效、评估预后等的有效指标。miRNA-196b在急性粒细胞白血病中低表达并对疾病的发展起主要作用。在慢性粒细胞白血病中miRNA-196b的靶基因为BCR-ABL，miRNA-196b过表达抑制BCR-ABL融合基因的表达。生存素(survivin)是BCR-ABL的一个下游基因，已在多种肿瘤中发现survivin与环氧化酶-2(Cox-2)协同调节细胞的增殖凋亡。本研究旨在探讨miRNA-196b过表达对K562细胞增殖、凋亡及survivin、Cox-2 mRNA表达的影响。方法：实验分为K562-196b组、空载K562-pLV组与K562组，采用CCK-8法检测细胞增殖；采用AnnexinⅤ-PE检测细胞凋亡；采用实时荧光定量PCR法检测Cox-2、survivin mRNA的表达情况。结果：miRNA-196b过表达可以明显抑制K562细胞增殖；K562-196b组细胞凋亡率显著高于K562组(P<0.05)；miRNA-196b组中survivin基因显著低表达(P<0.05)，Cox-2基因中无明显变化(P>0.05)。结论：miRNA-196b对K562细胞的增殖抑制和诱导凋亡有显著作用；miRNA-196b过表达可下调survivin基因的表达，为miRNA-196b作为慢性粒细胞性白血病的治疗靶点提供了依据。%　　Background and purpose:BCR-ABL fusion gene is considered to be the molecular pathological basis and an effective indicator for diagnosis, observation, prognosis, and monitoring of chronic myelogenous leukemia (CML). MiRNA-196b had low expression in acute myeloid leukemia and played an important role in the development of disease. BCR-ABL is the target gene of miRNA-196b in CML, miRNA-196b overexpression leaded to BCR-ABL down-regulation or silencing. Survivin is a downstream gene of BCR-ABL signal pathways. Various studies had showed that survivin and Cox-2 cooperative regulated of cell proliferation and apoptosis in variety of tumors. The purpose of this study was to investigate the effects of miRNA-196b overexpression on proliferation, apoptosis and surviving, Cox-2 mRNA expression of K562 cells. Methods:Three groups including K562-196b, K562-pLV and K562 control groups were set up in this study. The cell proliferation and apoptosis were measured by CCK-8 assay and Annexin V-PE, respectively. The expression of Cox-2 and survivin genes at the mRNA level were detected by Q-PCR. Results:The proliferation of K562 cells could be significantly inhibited by miRNA-196b overexpression; Compared of the three groups of apoptosis rate, K562-196b group was significantly higher than K562 group (P<0.05). The expression of survivin gene in miRNA-196b was donwregulated (P<0.05), but the expression of Cox-2 gene in miRNA-196b group had no significant difference (P>0.05). Conclusion:The miRNA-196b plays an important role in K562 cells proliferation inhibition and apoptosis;Overexpression of miRNA-196b can down-regulate survivin gene expression, and provide some basis for miRNA-196b as a therapeutic target for chronic myelogenous leukemia.