A PDE Model for Imatinib-Treated Chronic Myelogenous Leukemia

We derive a model for describing the dynamics of imatinib-treated chronic myelogenous leukemia (CML). This model is a continuous extension of the agent-based CML model of Roeder et al. (Nat. Med. 12(10), 1181–1184, 2006) and of its recent formulation as a system of difference equations (Kim et al. in Bull. Math. Biol. 70(3), 728–744, 2008). The new model is formulated as a system of partial differential equations that describe various stages of differentiation and maturation of normal hematopoietic cells and of leukemic cells. An imatinib treatment is also incorporated into the model. The simulations of the new PDE model are shown to qualitatively agree with the results that were obtained with the discrete-time (difference equation and agent-based) models. At the same time, for a quantitative agreement, it is necessary to adjust the values of certain parameters, such as the rates of imatinib-induced inhibition and degradation.     

伊马替尼血药浓度监测指导慢性粒细胞白血病患者的研究

目的 观察是否可以通过对伊马替尼(Imatinib,IM)进行血药浓度监测提高疗效,减少药物不良反应。方法 选取2013~2018年就诊于我院的慢性粒细胞白血病(chronic myelogenous leukemia, CML)患者,分为试验组(药物监测组),对照组(常规经验治疗组)。对服药3个月、6个月、12个月、18个月,进行疗效及不良反应评估及比较。结果 共有51人入选此次临床试验。其中试验组35人,对照组16人。结果 服用伊马替尼400mg/d时,血药浓度568.00~3 989.66ng/ml,均数(标准差):1 716.46ng/ml(788.96);服用伊马替尼300mg/d时,血药浓度720.89~1 497.11ng/ml,均数(标准差):971.67ng/ml(204.02)。达到主要分子学反应(major molecular response, MMR)的伊马替尼血药浓度高于未达到稳态时的伊马替尼血药浓度。两组不良反应评级有统计学差异。试验组III级及以上不良反应发生率明显小于对照组。结论 伊马替尼的稳态血浆药物谷浓度存在较大个体差异,这种个体差异与疗效和不良反应存在相关性。通过治疗药物监测(therapeutic drug monitoring, TDM)可以在确保疗效的同时,减少伊马替尼在治疗慢性粒细胞白血病中的不良反应。结果尚需大样本临床试验进一步验证。伊马替尼药物代谢个体差异的原因需要大样本遗传药理学研究进一步探讨。     

慢性髓细胞性白血病病人骨髓单个核细胞中差异表达基因的筛选

目的:筛选慢性髓细胞性白血病(CML)病人骨髓单个核细胞与正常人的差异表达基因,探讨CML的发病机制.方法:提取正常人和CML病人单个核细胞的RNA,逆转录成cDNA并用地高辛标记,应用全基因组表达谱基因芯片对差异表达基因进行研究,采用Jubilant病理/疾病分类法对CML相关差异表达基因进行分析.结果:共筛选出CM...     

Imatinib reduces the fertility of male mice by penetrating the blood-testis barrier and inducing spermatogonia apoptosis

Imatinib, the first generation of tyrosine kinase inhibitor, is used to treat and improve the prognosis of chronic myelogenous leukemia (CML). Clinical data suggest that imatinib could cross the blood-testis barrier and reduces the fertility of patients with CML-chronic phase. However, its exact molecular mechanism has not been fully elucidated. In this study, adult male Kunming mice were treated with different doses of imatinib for 8 weeks. The fertility was evaluated, and the sex hormone levels in the blood were detected by enzyme-linked immunosorbent assay. Histological changes were detected by hematoxylin and eosin staining. The concentration of imatinib in semen and blood was detected by liquid chromatography-mass spectrometry. The ultrastructure of blood-testis barrier and apoptotic bodies were observed by transmission electron microscope. The expression of blood-testis barrier function-regulating protein, Mfsd2a, and apoptosis-associated proteins in testis tissue was detected by immunohistochemistry and Western blot. The results indicated that the fertility of male mice was significantly decreased in a dose-dependent manner after imatinib treatment. Certain hormones in the serum were increased in imatinib treatment groups. Sperm morphology and testicular tissue showed various changes after imatinib treatment. The blood-testis barrier was destroyed and the concentration of imatinib in semen was similar to that in blood after imatinib treatment. Apoptosis was significantly increased in testis tissue after imatinib treatment. Collectively, these results suggest that imatinib can alter blood-testis barrier function, induce apoptosis of spermatogonia, and adversely affect fertility by reducing the number of spermatozoa, decreasing sperm motility and increasing the deformity rate.     

三七总皂甙对人急性髓系白血病细胞株U937 的抑制增殖及诱导凋亡作用

目的:观察三七总皂甙(panax notoginsenosides,PNS)对人急性髓系白血病细胞株U937凋亡的影响,并探讨PNS对Bax和Bcl-2蛋白表达的影响。方法:将处于对数生长期的U937细胞分为5组:正常对照组及PNS组(5 mg/L、10 mg/L、20 mg/L、40mg/L),药物作用12 h、24 h、48 h后,CCK-8比色法检测PNS对肿瘤细胞的相对细胞活力的影响;流式细胞术检测PNS促进细胞凋亡的能力;RT-PCR和Western blot法分别检测不同浓度的PNS对Bax和Bcl-2蛋白表达的影响。结果:CCK-8分析显示,PNS在低浓度(≤40 mg/L)能明显抑制肿瘤细胞的活力,40 mg/L处理组较正常对照组细胞活力在3个时间点分别下降47%、72%、85%;与对照组相比,处理组的凋亡率显著增加,10 mg/L、20 mg/L、40 mg/L实验组凋亡率分别上升7%、10%、43%;PNS能明显增加细胞内Bax mRNA及蛋白的表达,抑制Bcl-2 mRNA及蛋白的表达。结论:PNS具有抑制人急性髓系白血病细胞株U937的增殖抑制及凋亡诱导作用,并能影响Bax和Bcl-2蛋白的表达。文章探讨了PNS抑制肿瘤发展可能存在的作用机制,为将来进一步研发PNS作为白血病治疗药物奠定基础。     

Use of moving optical gradient fields for analysis of apoptotic cellular responses in a chronic myeloid leukemia cell model

To facilitate quantitation of cellular apoptotic responses to various antineoplastic agents, a laser-based technology, Optophoresis, has been developed to provide analysis of cells without any need for labeling or cell processing. Optophoresis is defined as the analysis of the motion of cells, where the motion is either induced or modified by a moving optical gradient field, which produces radiation pressure forces on the cells in an aqueous suspension. Quantitation of the induced motion provides a basis for distinguishing one population of cells from another. One Optophoretic technique, Fast Scan, measures the distribution of distances traversed by a population of cells when exposed to a fast-moving optical gradient. Fast Scan was validated using a cell-based model of chronic myeloid leukemia treated with Gleevec, a specific inhibitor of aberrant Bcr-Abl protein kinase. The Optophoretic measurements were quantitatively comparable to reference assays with regard to drug selectivity and potency and to target specificity, demonstrating the suitability of this technology for pharmaceutical and clinical applications.     

胆固醇对K562及耐药株K562G细胞增殖及伊马替尼敏感性的影响

目的:探讨胆固醇对K562及耐药株K562G细胞增殖及伊马替尼(Imatinib,IM)敏感性的影响。方法:通过qRT-PCR方法检测K562和K562G细胞的胆固醇代谢途径相关蛋白的表达;以不同药物组合处理K562细胞、K562G细胞,采用CCK-8方法检测细胞增殖情况。结果:耐药K562G细胞胆固醇合成酶(人角鲨烯单加氧酶SQLE,细胞色素P450酶家族51亚家族A1 CYP51A1,固醇C5去饱和酶SC5D)表达下降、而低密度脂蛋白受体LDLR、固醇酰基转移酶SOAT1、ATP结合盒转运体A1 ABCA1表达量增加;0.5μg/m L、0.75μg/m L胆固醇处理K562细胞,其增殖率比对照组K562细胞分别增加(9.51±2.84)%和(19.88±3.00)%;使用阿托伐他汀(20μM)、GW3965 (20μM)、MβCD (10 m M)降低K562G细胞胆固醇使其增殖抑制率分别为(50.73±2.34)%,(49.42±1.13)%,(76.54±1.48)%;两种浓度胆固醇使IM处理的K562细胞增殖抑制率分别减少51.59%及53.80%;MβCD联合IM使K562及K562G细胞存活率分别降低至6.89%及23.34%。结论:IM抵抗的K562G细胞与IM敏感的K562细胞相比胆固醇代谢增强;增加胆固醇能够促进K562细胞增殖,降低细胞对IM的敏感性;MβCD可能通过降低胆固醇增强K562、K562G细胞对IM敏感性。     

慢性粒细胞白血病小鼠动物模型建立的研究进展*

慢性粒细胞白血病(chronic myeloid leukemia,CML)是造血干细胞(hematopoietic stem cells,HSC)恶性克隆性增殖引起的一种血液系统疾病。动物模型是研究CML发病机制及药物靶向治疗的重要载体和工具。研究表明,CML小鼠模型可以通过逆转录病毒介导、转基因和白血病细胞移植的方法建立。三种方法建立的CML小鼠模型均可用于CML发病机制及药物疗效评估研究。实验动物模型进一步通过血常规、血涂片和骨髓涂片、免疫学、分子生物学及病理学等检测手段,判断模型是否建立成功。本文就近年来CML小鼠模型的建立、鉴定及研究应用进展进行综述。     

Characterization of miRNomes in Acute and Chronic Myeloid Leukemia Cell Lines

Myeloid leukemias are highly diverse diseases and have been shown to be associated with microRNA（miRNA） expression aberrations. The present study involved an in-depth miRNome analysis of two human acute myeloid leukemia（AML） cell lines, HL-60 and THP-1, and one human chronic myeloid leukemia（CML） cell line, K562, via massively parallel signature sequencing. mRNA expression profiles of these cell lines that were established previously in our lab facilitated an integrative analysis of miRNA and mRNA expression patterns. miRNA expression profiling followed by differential expression analysis and target prediction suggested numerous miRNA signatures in AML and CML cell lines. Some miRNAs may act as either tumor suppressors or oncomiRs in AML and CML by targeting key genes in AML and CML pathways. Expression patterns of cell type-specific miRNAs could partially reflect the characteristics of K562, HL-60 and THP-1 cell lines, such as actin filament-based processes, responsiveness to stimulus and phagocytic activity. miRNAs may also regulate myeloid differentiation, since they usually suppress differentiation regulators. Our study provides a resource to further investigate the employment of miRNAs in human leukemia subtyping, leukemogenesis and myeloid development. In addition, the distinctive miRNA signatures may be potential candidates for the clinical diagnosis, prognosis and treatment of myeloid leukemias.     

Post-transplantation dynamics of the immune response to chronic myelogenous leukemia

We model the immune dynamics between T cells and cancer cells in leukemia patients after bone marrow transplants, using a system of six delay differential equations to track the various cell-populations. Our approach incorporates time delays and accounts for the progression of cells through different modes of behavior. We explore possible mechanisms behind a successful cure, whether mediated by a blood-restricted immune response or a cancer-specific graft-versus-leukemia (GVL) effect. Characteristic features of this model include sustained proliferation of T cells after initial stimulation, saturated T cell proliferation rate, and the possible elimination of cancer cells, independent of fixed-point stability. In addition, we use numerical simulations to examine the effects of varying initial cell concentrations on the likelihood of a successful transplant. Among the observed trends, we note that higher initial concentrations of donor-derived, anti-host T cells slightly favor the chance of success, while higher initial concentrations of general host blood cells more significantly favor the chance of success. These observations lead to the hypothesis that anti-host T cells benefit from stimulation by general host blood cells, which induce them to proliferate to sufficient levels to eliminate cancer.     

54例慢性淋巴细胞白血病的临床回顾性分析

目的：本研究旨在探讨慢性淋巴细胞白血病（CLL）的实验室检查特点及特征性临床表现。方法：利用血细胞分析仪、流式细胞术、骨髓形态分析及R显带技术等对我院2002年4月．2012年4月收治的54例慢性淋巴细胞白血病患者的相关临床资料如血细胞计数、骨髓形态、染色体及免疫表型等进行检测并对结果进行回顾性分析。结果：CLL多发于老年患者,男性多见,中位年龄65岁（45．82岁）。大部分患者初诊时可出现典型的临床表现,37例（68％）患者初诊时淋巴结大,49例（91％）初诊时白细胞≥10×109、L,淋巴细胞绝对值≥5×109／L。13例（24％）初诊时肝脾或者脾大,17例（31％）初诊时乏力、消瘦。34（63％）例患者可见典型的CLL免疫表型,CD5、CDl9．CD23、CD20的阳性率分别为90％、87％、72％、67％。32例患者染色体检测结果表明：13q-2例,17p．2例,11q-1例,＋12有1例,6q-1例,t（14,16）1例。2例患者发生了自身免疫性溶血性贫血（AIHA）。1例患者发生了Richter转化,肿大淋巴结活检显示部分区域为弥漫性大B细胞淋巴瘤,其高表达CD20、CDl9、CD22。结论：慢性淋巴细胞白血病具有其典型的临床表现、免疫表型及遗传学改变,并且对诊断及治疗有重要意义。     

BCR-ABL Gene Expression Is Required for Its Mutations in a Novel KCL-22 Cell Culture Model for Acquired Resistance of Chronic Myelogenous Leukemia

Acquired resistance through genetic mutations is a common phenomenon in several cancer therapies using molecularly targeted drugs, best exemplified by the BCR-ABL inhibitor imatinib in treating chronic myelogenous leukemia (CML). Overcoming acquired resistance is a daunting therapeutic challenge, and little is known about how these mutations evolve. To facilitate understanding the resistance mechanisms, we developed a novel culture model for CML acquired resistance in which the CML cell line KCL-22, following initial response to imatinib, develops resistant T315I BCR-ABL mutation. We demonstrate that the emergence of BCR-ABL mutations do not require pre-existing BCR-ABL mutations derived from the original patient as the subclones of KCL-22 cells can form various BCR-ABL mutations upon imatinib treatment. BCR-ABL mutation rates vary from cell clone to clone and passages, in contrast to the relatively stable mutation rate of the hypoxanthine-guanine phosphoribosyltransferase gene. Strikingly, development of BCR-ABL mutations depends on its gene expression because BCR-ABL knockdown completely blocks KCL-22 cell relapse on imatinib and acquisition of mutations. We further show that the endogenous BCR-ABL locus has significantly higher mutagenesis potential than the transduced randomly integrated BCR-ABL cDNA. Our study suggests important roles of BCR-ABL gene expression and its native chromosomal locus for acquisition of BCR-ABL mutations and provides a new tool for further studying resistance mechanisms.     

错配修复基因hMSH2与慢性粒细胞白血病相关性研究

目的:通过对慢性粒细胞白血病(chronic myeloid leukemia,CML)患者骨髓细胞中错配修复基因(mismatch repair,MMR)h MSH2的表达水平及其调控机制的分析,探讨h MSH2与慢性粒细胞白血病疾病进展的联系。方法:用实时定量PCR方法检测10例对照,27例CML患者(包括慢性期9例,进展期8例,急变期10例)骨髓中4个MMR基因(h MSH2、h MSH6、h MLHl、h PMS2)m RNA的表达;用MSP方法检测MMR基因启动子区甲基化水平;用Western blot方法观察MMR蛋白水平在各组之间的差异。结果:与正常对照比较,CML患者的h MSH2的表达明显降低(P0.05),其表达随疾病恶化而下降,依次为急变期加速期慢性期,而h MLHl、h PMS2、h MSH6的表达却未见异常;27例CML患者中出现3例h MSH2启动子区高甲基化。结论:CML患者的h MSH2表达水平比正常人显著降低,且随着疾病恶化其表达水平逐下降,提示h MSH2可能与CML疾病进展相关。     

Hybridization biosensor using 2-nitroacridone as electrochemical indicator for detection of short DNA species of Chronic Myelogenous Leukemia

A new acridone derivative 2-nitroacridone (NAD) was synthesized in this paper, and it was found that NAD had excellent electrochemical activity on the glassy carbon electrode (GCE) with a couple reversible redox peaks at 0.051 V and 0.103 V, respectively. Voltammetry was used to investigate the electrochemical behavior of NAD and the interaction between NAD and salmon sperm DNA. In pH 4.0 phosphate buffer solution, the binding ratio between NAD and salmon sperm DNA was calculated to be 2:1 and the binding constant was 3.19 × 10⁵ L/mol. A Chronic Myelogenous Leukemia (CML, Type b₃a₂) DNA biosensor was developed by immobilizing covalently single-stranded CML DNA fragments to a modified GCE. The surface hybridization of the immobilized single-stranded CML DNA fragment with its complementary DNA fragment was evidenced by electrochemical methods using NAD as a novel electrochemical indicator, with a detection limit of 6.7 × 10⁻⁹ M and a linear response range of 1.8 × 10⁻⁸ M to 9.1 × 10⁻⁸ M for CML DNA. Selective determination of complementary ssDNA was achieved using differential pulse voltammetry (DPV).     

慢性充血性心力衰竭大鼠模型的建立

目的：探讨建立慢性充血性心力衰竭大鼠模型的方法。方法：采用腹主动脉缩窄法制备CHF大鼠模型。于右肾动脉分支处上方缩窄腹主动脉至0.6mm,同时设立假手术组及正常对照组。12周后行一般情况观察,超声心动图及血液动力学检测心脏结构和功能、计算心脏肥厚指数,HE及Masson染色检测心肌病理改变,综合评价CHF大鼠心功能。结果：与假手术及正常对照组比较,CHF模型组术后12周均出现进食减少、精神萎靡、少动、被毛无光;IVS、LVPW、LVM、LVEDD、LVESD、SV显著增加,EF、FS显著降低;HR显著增加;VSP、＋dP/dtmax显著降低,T-dP/dtmax显著延长;LVEDP显著升高,-dP/dtmax绝对值显著降低;心脏湿重及心脏肥厚指数均增加;病理结果表明CHF模型组心肌细胞肥大、排列紊乱、心肌胶原纤维增多。结论：应用腹主动脉缩窄术可成功制备CHF大鼠模型。     

慢性髓细胞白血病急变期MICM分型回顾性分析

目的：探讨慢性髓细胞白血病急变期（CML-Be）患者的细胞形态学（M）、免疫学（I）、细胞遗传学（C）和分子生物学（M）的特征及应用价值。方法：对38例CML．BC患者的MICM分型进行回顾性分析。结果：以FAB分型为基础的形态学确诊率达94．7％;免疫分型结果为：38例CML-BC中CML-AML占71．0％,其中37．0％伴淋系表达;CML-ALL占23．7％,均为B细胞性,其中66．67％伴髓系表达;CML-MAL（混合性白血病）占5．3％,均为B系和髓系混合表达;CD34＋26例（68．4％）,cD7＋10例（26．3％）,均与CD34共表达。细胞遗传学结果显示：CML特征性Ph染色体检出率为94．3％（36／38）,附加异常染色体检出率为60．5％（23／38）,发生频率较高的类型是＋Ph、＋8和i（17q）;FISH检测BCR／ABL融合基因阳性率为100％,der（9）缺失占14．7％。RT—PCR检测20例患者BCR／ABL融合基因均为阳性,其中b2a2型（12／20）,b3a2型（8／20）,1例（1／20）,b2a2和b3a2双阳性（1／20）。结论：CML—BC是造血干细胞疾病,原始细胞分化阻滞在早期阶段,预后差。MICM分型对CML-BC的诊断、治疗和预后判断均有重要价值。     

SHIP2 overexpression strongly reduces the proliferation rate of K562 erythroleukemia cell line

SHIP2 belongs to the inositol 5-phosphatase family and is characterized by a phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5)P(3)) 5-phosphatase activity. Evidence based on mice lacking the SHIP2 gene has demonstrated its predominant role in the control of insulin sensitivity. However, SHIP2 expression in both hematopoietic and non-hematopoietic cells suggests additional functions. SHIP2 was previously identified in chronic myelogenous progenitor cells, in which its constitutive tyrosine phosphorylation was reported by Wisniewski et al., [Blood 93 (1999) 2707-2720]. Here, we further investigated the function of SHIP2 in this hematopoietic and malignant context. A detailed analysis of the substrate specificity of SHIP2 indicated that this phosphatase is primarily directed towards PI(3,4,5)P(3) both in vitro and in K562 chronic myeloid leukemia cells. The SHIP2-mediated decrease in PI(3,4,5)P(3) levels and increase in phosphatidylinositol 3,4-bisphosphate (PI(3,4)P(2)) was accompanied by a reduction of cell proliferation, characterized by an accumulation of the cells in the G2/M phase of the cell cycle. Thus, in addition to its role in the control of insulin sensitivity, SHIP2 may also play a role in cell proliferation, at least in chronic myelogenous progenitor cells.     

Using Agent-Based Models to Aid Reef Restoration: Enhancing Coral Cover and Topographic Complexity through the Spatial Arrangement of Coral Transplants

High coral cover and topographic complexity are favorable qualities of a healthy coral reef. Because coral reef restoration is expensive and coral growth is naturally slow, there is a need to strategically arrange coral transplants to maximize coral cover and topographic complexity. Similarly, it is important to understand how differences in the life history characteristics of coral transplants can influence changes in the structural attributes of coral reefs. This study utilizes agent‐based computer modeling to explore the different spatial scenarios of coral transplantation using corals with contrasting r‐ and K‐selected life histories. Spatial indexes are used to compare coral cover and topographic complexity at incremental time scales, within which disturbance events are of minor importance in spatial structuring. The outcomes of the model suggest that even‐spaced grided transplanting arrangements provide the fastest increase in coral cover and three‐dimensional habitat space (topographic complexity) across large temporal scales (<30 years) for corals with r‐selected life history strategies.     

CDA基因沉默对人慢性髓系白血病细胞增殖和凋亡的影响

目的:探讨胞苷脱氨酶(CDA)基因沉默在治疗人慢性髓系白血病(CML)中的潜在价值。方法:通过RT-PCR和Western blot检测CML患者和造血干细胞移植供体的骨髓单个核细胞中的CDA表达。对CML KCL-22细胞系转染shRNA和过表达CDA的p BS/U6-Neo质粒来诱导CDA基因沉默或过表达。通过细胞计数试剂盒8(CCK-8)测定和细胞集落形成实验评价细胞增殖,通过流式细胞仪检测细胞凋亡。此外,将0.2 m L不同处理的细胞悬浮液(106个细胞/m L)注射到裸鼠中建立裸鼠肿瘤异种移植模型。结果:与造血干细胞移植供体相比,CML患者的骨髓单个核细胞中的CDA m RNA和蛋白表达显著升高(P 0.05)。转染shRNA-CDA显著降低了KCL-22细胞的细胞活力和细胞集落数(P0.05)。与对照组(4.32%)相比,shRNA-CDA组(13.45%)的细胞凋亡率显著升高(P0.05)。与对照组相比,shRNA-CDA组的BCL-2蛋白表达水平显著降低,而cleaved caspase-3显著升高(P0.05)。与对照组相比,shRNA-CDA组的PI3K蛋白表达水平和Akt磷酸化水平显著降低(P0.05)。接种30 d后,与对照组相比,shRNA-CDA组裸鼠的肿瘤重量和肿瘤体积均显著降低(P0.05)。结论:CDA在人慢性髓系白血病中高表达,CDA基因沉默可在体内和体外抑制肿瘤细胞的生长。其机制与抑制PI3K/Akt信号通路的激活有关。     

Stochastic modeling of cellular colonies with quiescence: an application to drug resistance in cancer

Several cancers are thought to be driven by cells with stem cell like properties. An important characteristic of stem cells, which also applies to primitive tumor cells, is the ability to undergo quiescence, where cells can temporarily stop the cell cycle. Cellular quiescence can affect the kinetics of tumor growth, and the susceptibility of the cells to therapy. To study how quiescence affects treatment, we formulate a stochastic birth-death process with quiescence, on a combinatorial cellular mutation network, and consider the pre-treatment (growth) and treatment (decay) regimes. We find that, in the absence of mutations, treatment (if sufficiently strong) will proceed as a biphasic decline with the first (faster) phase driven by the elimination of the cycling cells and the second (slower) phase limited by the process of cell awakening. Other regimes are possible for weaker treatments. We also describe how the process of mutant generation is influenced by quiescence. Interestingly, for single-drug treatments, the probability to have resistance at start of treatment is independent of quiescence. For two or more drugs, the probability to have generated resistant mutants before treatment grows with quiescence. Finally, we study the influence of quiescence on the treatment phase. Starting from a given composition of mutants, the chances of treatment success are not influenced by the presence of quiescence.