汉黄芩素抗肿瘤作用的分子机制中的主要信号通路(英文)

汉黄芩素是一种从黄芩中提取的天然黄酮类化合物, 据多项研究报道汉黄芩素具有抗肿瘤作用。近期研究显示汉黄芩素可以影响多种信号通路。其抗肿瘤作用的分子信号机制主要是:上调胞内ROS水平,下调PI3K-AKT信号通路,调节MAPKs分子,上调p53信号, 抑制NF-κB活性及影响其他GSK-3β、ΔNp63等相关通路或分子。基于近年来的各体内、体外实验,本文就汉黄芩素抗肿瘤作用的分子机制尤其是汉黄芩素对重要的信号通路的影响做一综述。     

ABCG2介导的肿瘤多药耐药

ABCG2是ATP结合盒(ABC)转运超家族中的一员,其过表达被认为是限制多种化疗药物在细胞内聚集的重要机制之一.ABCG2底物范围广泛,包括多种抗肿瘤药物和环境致癌物等,与肿瘤的多药耐药(MDR)和肿瘤发展有关.以ABCG2为靶点逆转MDR受到广泛关注.     

载有柔红霉素的磁性纳米Fe2O4提高裸鼠异种移植模型中多药耐药K562白血病细胞对化疗效果

肿瘤的多药耐药是肿瘤化疗失败的主要原因,由于载有柔红霉素的磁性纳米Fe3O4颗粒在体外显示了良好的耐药逆转效果,本实验研究了载有柔红霉素的磁性纳米Fe3O4颗粒在体内对白血病多药耐药逆转效果。将裸鼠高成瘤性白血病细胞株K562-n及其相应的多药耐药株K562-n／VCR分别接种于裸鼠的两侧腹股沟皮下,以建立人类白血病移植瘤模型;将双侧成瘤裸鼠随机分为5组,A组给予生理盐水,B组给予磁性纳米Fe3O4颗粒,C组给予柔红霉素,D组给予载有柔红霉素的磁性纳米Fe3O4颗粒,E组给予载有柔红霉素的磁性纳米Fe3O4颗粒同时在肿瘤表面建立固定磁场。在实验开始后的第1,5,9,13,17,21天分别测量肿瘤体积。实验结束后,分离瘤组织并用lit-PCR,Western blot检测mdr-1的转录和表达。结果表明：D组、E组的K562．n／VCR肿瘤体积显著小于A、B、C3个组（D或E组相对于A,B或C组P〈0．05）。病理检查显示：A组、B组肿瘤细胞生长良好,未见明显细胞坏死;C组肿瘤细胞有散在细胞坏死,部分细胞出现核固缩、核碎裂等;D、E组肿瘤组织内可见细胞明显破碎、坏死、组织的纤维化。D和E组的mdr-1的转录水平明显低于A、B、C3个组,但是P．gp的表达在5个组申无差异。C组、D组、E组3个组I（562-n肿瘤平均肿瘤体积显著小于的A、B两组的平均肿瘤体积（C、D或E组相对于A或B组P〈0．05）。A组、B组肿瘤细胞生长良好,未见明显细胞坏死;在C、D、E组肿瘤组织内可见细胞明显破碎、坏死、组织的纤维化。结论：载有柔红霉素的磁性纳米Fe3O4颗粒在体内具有明显的逆转多药耐药的作用,但是相对于单用柔红霉素,载有柔红霉素的磁性纳米Fe3O4颗粒在敏感的K562-n的肿瘤中并不能进一步提高疗效;本实验中外加磁场并未增加疗效。     

脾切除治疗慢性粒细胞白血病造血干细胞移植后全血细胞减少患者三例分析

异基因外周血造血干细胞移植(allo-HSCT)是目前治愈慢性粒细胞白血病(CML)的方法之一.移植后血细胞减少是常见的并发症,通过二次移植可以治疗血细胞减少,但长期生存率不高.脾脏对移植的影响一直存在争议.动物及临床试验表明,脾脏会影响移植物功能.巨脾与植入的延迟有父.移植前脾区放疗的患者,中性粒细胞恢复较快,但移植前切脾或脾区放射对移植总生存率并无明显影响.我们对3例CML移植后全血细胞减少患者,排除其他影响造血恢复的因素后进行脾切除治疗,取得较好的效果,现报道如下.     

尼洛替尼联合5-溴汉防己甲素逆转K562/A02细胞耐药的研究

Objective To investigate the reversible effect of nilotinib,BrTet(5-bromotetrandrine)and their combination on multidrug resistance cell line K562/A02 and its mechanism.Methods Cell proliferation inhibition wag assessed by MTT method and cell apoptosis by flow cytometry(FCM).The expression of mdr1 mRNA was determined by RT-PCR,and the expression of P-gp was assessed by Western blot.Results After 48 h 5 nmol/L nilotinib or 0.5μmol/L BrTet treatment,IC50 of daunorubicin(DNR)to K562/A02 was 4.52 mg/L or 5.41 mg/L respectively;While on combinative treatment,its IC50 decreased to 2.98mg/L.Nilotinib or BrTer alone was not able to increase the DNR induced apoptosis rate of K562/A02 cell (P>0.05),while on combination treatment the apoptosis rate increased remarkably.After 48 h 5 nmol/Lnilotinib or 0.5 μmol/L BrTet treatment alone,gray-scale value of mdr1 mRNA was 0.48±0.04 or 0.64±0.01,respectively;while on combinative treatment the value decreased to 0.35±0.04.The P-gp expression level in K562/A02 cells was 0.61±0.05.or 0.52±0.02 when treated with 5 nmol/L nilotinib or 0.5 μmol/L BrTet alone for 48 h.but on combination treatment,the level decreased to 0.44±0.03.Conclusion Nilotinib or BrTet alone can partially reverse drug resistance of K562/A02 cells.The mechanism may be associated with the decrease of mdr1 mRNA and P-gp expression and increase of the apoptosis rate.And there is a synergistic action with these two agants in combination.     

Effect of hypoxia inducible factor1-α inhibitor on reversal of multidrug resistance of K562/A02 cell line

Objective To study the reversal effect of the hypoxia inducible factor( HIF)-1α inhibitor,YC-1 ,on muitidrug resistance of K562/A02 cells and its mechanism. Methods Pre- and post- incubation with adriamycin (ADM) alone or in combination with YC-1 for 48 h, the proliferation capacity of K562/A02 and K562 cells were evaluated by MTT assay. The apoptosis rate of K562/A02 cells after treated with 0,5,10 and 20 μmol/L YC-1 alone or in combination with 1 mg/L ADM and intracellular ADM concentration were analyzed by flow cytometry(FCM). The mRNA levels of HIF-1α and mdr1 genes were determined by semi-quantitative RT-PCR. The protein levels of HIF-1α and P-glycoprotein (P-gp) were detected by Western blot. Results The IC50 of ADM for K562 and K562/A02 cells were ( 1.56 ± 0.07 ) mg/L and (42.98 ±3.15) mg/L respectively. The resistance of K562/A02 cells to ADM was 27.55- fold higher of that of K562cells. After treatment with YC-1 (5μmol/L, 10μmol/L, 20 μmol/L) for 48h, the resistances of K562/A02cells to ADM were 24.63-, 16.38- and 10.71- fold increase respectively. After treatment of K562/A02 cell with YC-1(0 μmol/L, 5 μmol/L, 10 μmol/L, 20 μmoL/L) alone or in combination with 1 mg/L ADM for 48 h, the apoptotic rates were ( 1.9 ± 0. 9) %, (4.9 ± 0. 9 ) %, ( 5.8 ± 1.1 ) %, and ( 9.3 ± 1.4 ) % and(2.3 ± 0.7 ) %, (8.2 ± 1.2) %, ( 19.0 ± 1.7 ) %, and ( 34.5 ± 2.4 ) % respectively. The intracellular flucorescence intensity of ADM were 232 ±33, 1300 ±219, 1961 ±240 and 3342 ±269 in the combined treatment group. With the increase in YC-1 concentration, the levels of mdr1 mRNA reduced, while that ofHIF-1α mRNA had no obvious change.Furthermore.the expressions of HIF-1α and P-gp were also decreased in K562/A02 cells.Conclusion YC-1,as a HIF-1 inhibitor,cau reverse multidrug resistance of K562/A02cells through down-regulating HIF-1α and p-gp.     

葡萄糖神经酰胺合成酶抑制剂PDMP对K562/A02细胞柔红霉素耐药逆转的研究

本研究旨在探讨葡萄糖神经酰胺合成酶(glucosylceramide synthase,GCS)抑制剂D,L-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol(PDMP)hydrochloride对K562/A02细胞株柔红霉素(daunorubicin,DNR)耐药的逆转作用及其逆转机制。采用四甲基偶氮唑蓝(MTT)法检测不同浓度PDMP对K562细胞和K562/A02细胞的增殖抑制效应及其对K562/A02细胞DNR耐药逆转作用;用流式细胞术检测PDMP对K562/A02细胞内DNR浓度及细胞凋亡率的影响;半定量RT-PCR和Western blot方法检测K562及K562/A02细胞mdr1、GCS基因的表达以及PDMP对K562/A02细胞两种基因表达的影响。结果表明:DNR对K562和K562/A02细胞的IC50分别为0.23±0.02和7.15±0.24μg/ml,当PDMP≤20μmol/L时,对K562及K562/A02细胞株无明显生长抑制作用;20μmol/L和10μmol/L PDMP均能增加K562/A02细胞对DNR的敏感性,其耐药逆转倍数分别为2.59和1.69;两种浓度PDMP作用于耐药株48小时后能增加细胞内DNR浓度(p0.05)和细胞凋亡率(p0.01)。20μmol/L PDMP处理K562/A02细胞48小时后可在mRNA和蛋白水平下调GCS和mdr1基因的表达(p0.01)。结论:PDMP可以增强K562/A02细胞对DNR的敏感性,其机制可能与增加细胞内药物浓度及细胞凋亡率、下调GCS和mdr1基因表达有关。     

M-FISH技术在复杂核型异常的急性白血病患者的诊断、预后分析中的应用

M-FISH,即multi-coclour FISH和multiplex FISH(M-FISH),是分子细胞遗传学方面在过去的10年里最具有发展意义的代表技术之一。这项技术从最初使人类23对染色体上24种特异的荧光色彩以供核型分析,到现在已经产生了许多复杂的变化,也开始被各种不同专业的领域范围所应用。在白血病细胞遗传学上,M-FISH已被应用于下列染色体异常患者的检查:①可疑有未被发现的微小的染色体易位;②具有复杂异常核型的染色体异位(普通方法很难获得完全的染色体核型)。最终的检查结果对白血病患者的诊断、治疗及预后分析具有很大的指导作用。本文就M-FISH的技术原理和常用的探针、M-FISH在急性白血病的诊断、疗效评价及预后分析中的应用进行了综述。     

白血病干/祖细胞及靶向治疗研究进展

人类白血病是一种由造血干/祖细胞或祖细胞染色体变异或者渐进性改变的恶性克隆性疾病,耐药与复发是白血病治疗失败的两大主要原因。近年来对于白血病患者体白血病干/祖细胞（LSPC）的发现和研究,深入阐述了白血病的发生机制,并探索了针对LSPC的靶向治疗。本文简要介绍LSPC的分子生物学特性以及LSPC靶向治疗,诸如针对LSPC表面分子的靶向治疗,针对特殊分子调控机制的靶向治疗,针对干扰LSPC与骨髓微环境间相互作用的靶向治疗等的研究进展。