复方苦参注射液影响HL-60细胞迁移的机制研究

目的探讨复方苦参注射液(CKI)影响HL-60细胞迁移的机制。方法选取HL-60细胞株作为研究对象,根据不同加药方案分为粒细胞集落刺激因子(G-CSF)组(40ng/mL)、CKI组(0.5ng/mL)、G-CSF和CKI联合加药组和空白对照组,共培养48h后采用蛋白质印迹法(WB)和逆转录聚合酶链反应(RT-PCR)分别检测微小RNA-146a(miR-146a)、趋化因子CXC受体4(CXCR4)等信使RNA(mRNA)、CXCR4蛋白表达变化情况;同时采用Transwell小室检测CKI、G-CSF作用前后细胞迁移率变化情况。结果 (1)与空白对照组相比,基质细胞衍生因子-1α(SDF-1α)能促进HL-60细胞的迁移[(2.01±0.13)比(1.05±0.10),P0.05],而CKI组、G-CSF组、CKI联合GCSF组均能阻断HL-60细胞向SDF-1α迁移[(1.50±0.04)、(1.68±0.08)、(1.27±0.02)比(2.01±0.13),P0.05]。(2)与空白对照组相比,CKI、G-CSF处理HL60细胞后,CXCR4的mRNA、蛋白表达均受抑[(0.75±0.10)、(0.47±0.09)比(1.00±0.08),P0.05];与CKI组、G-CSF组相比,CIK联合GCSF组CXCR4的mRNA蛋白表达受抑更明显[(0.24±0.04)比(0.47±0.09)、(0.75±0.10),P0.05]。(3)与空白对照组比较,G-CSF、CKI处理HL-60细胞后,miR-146a表达显著上调[(5.59±0.46)、(3.53±0.39)比(1.03±0.11),P0.01];而联合加药组上调更明显[(6.76±0.54)比(5.59±0.46)、(3.53±0.39),P0.05]。结论 CKI能协同G-CSF上调miR-146a表达,通过降低HL-60细胞表面的CXCR4表达而阻断CXCR4/SDF-1α信号轴,最终导致HL-60细胞体外迁移能力明显下降。     

Epigenetic inactivation of INK4/CDK/RB cell cycle pathway in acute leukemias

Dysregulation of cell cycle is important in oncogenesis. We analyzed the inactivation of the INK4 family CKI/CDK/RB pathway by gene promoter hypermethylation in leukemogenesis. The methylation-specific polymerase chain reaction (MSP) with primers for methylated (M-MSP) and unmethylated (U-MSP) alleles of the p15, p16, p18, and RB genes was used to study five leukemic cell lines, 50 acute myeloid leukemia (AML) and 25 acute lymphoblastic leukemia (ALL) samples. None of the leukemic cell lines showed p18 and RB methylation. p15 was methylated in Raji, while p16 was methylated in U937 and Raji. In NB4 and Jurkat, both alleles of p15 and p16 appeared to be deleted. At diagnosis, p15 methylation occurred in 29 (58%) AML patients, and 10 (40.0%) ALL patients. p16 methylation occurred in two (4%) AML and two (8%) ALL patients. Only one each of AML and ALL patients had concurrent p15 and p16 methylation. None of the patients had methylation of p18 or RB. In AML, p15 methylation was associated with M2 subtype (p=0.018). Patients with and without p15 methylation had similar complete remission (CR) rates and projected 5-year overall survival (OS) or disease-free survival (DFS). Therefore, methylation inactivation of the INK4/CDK/RB pathway in leukemia involved primarily p15 and occasionally p16, but not p18 or RB. In AML, p15 gene methylation was associated with the M2 subtype, but was not prognostic for CR, OS, or DFS.