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。     

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。     

酪氨酸激酶抑制剂逆转K562/A02细胞多药耐药的研究

本研究旨在比较酪氨酸激酶抑制剂伊马替尼(Imatinib)、尼洛替尼(Nilotinib)对K562/A02细胞多药耐药的逆转作用。用RT-PCR法检测各组mdr-1mRNA、bcr-abl mRNA表达;用Western blot法检测各组P-gp、P210蛋白表达;用流式细胞术检测各组细胞内柔红霉素(DNR)的蓄积。结果表明:0.0625μmol/L伊马替尼、5nmol/L尼洛替尼对K562/A02细胞无明显细胞毒性,伊马替尼和尼洛替尼上述剂量单独作用48小时均下调mdr-1mRNA、bcr-abl mRNA、P-gp、P210蛋白的表达,且尼洛替尼较伊马替尼作用更强。荧光强度检测显示,K562/A02细胞经伊马替尼、尼洛替尼单独处理48小时后,其细胞内DNR浓度分别为K562细胞中的7.85%、12.02%。结论:酪氨酸激酶抑制剂具有很好的逆转细胞耐药作用,且尼洛替尼较伊马替尼逆转作用更强。     

新型口服铁螯合剂——地拉罗司的研究进展

地拉罗司是一种新型口服铁螯合剂,它是美国FDA批准的第一个能够常规使用的口服驱铁剂,获准在≥2岁、输血造成的慢性铁负荷过多的患者中使用,在欧洲它被推荐作为6岁以上地中海贫血铁过载患者的一线用药,国内目前正在进行临床研究。本文主要就近年来有关地拉罗司的相关研究及最新进展进行介绍。Ⅱ、Ⅲ期临床试验及药代动力学研究均表明,地拉罗司具有良好的安全性和耐受性,且显著降低心脏、肝脏铁负荷,易于被患者接受。地拉罗司常见不良反应为胃肠道症状及皮疹,但近年来报道了一些罕见不良反应事件,应引起我们的重视,尤其是针对特殊人群应谨慎用药。地拉罗司治疗适应证有所放宽,包括接受auto-SCT治疗的患者以及由Fanconi综合症所致的可逆性肾功能不全的患者。地拉罗司常用剂量并非绝对适用于每个患者,临床医师应根据实际病情及相关指标调整用药剂量;铁蛋白并不是一项唯一且可靠的监测铁螯合剂疗效及调整DFS剂量的指标。另外,本文还介绍了地拉罗司的一些新特性,例如抗真菌、抗细胞增殖等作用。     

CD3AK细胞对耐药白血病细胞的体外杀伤作用

肿瘤生物治疗是近年来肿瘤治疗中的重要进展之一 ,其中采用免疫效应细胞 ,如ＬＡＫ细胞、ＴＩＬ、ＣＤ3 ＡＫ、ＣＩＫ、ＣＴＬ等进行的过继免疫治疗在某些肿瘤的治疗中取得了一定疗效。ＣＤ3 ＡＫ细胞是由抗ＣＤ3 单抗联合小剂量ＩＬ 2激活的Ｔ细胞 ,增殖能力和杀伤力较强。我们在实验中观察了ＣＤ3 ＡＫ细胞对耐药的白血病细胞株及慢性髓系白血病 (ＣＭＬ)急变患者原代肿瘤细胞的体外杀伤作用。材料和方法1　材料　正常人外周血由健康男性提供 ;ＣＭＬ急变患者骨髓由附属医院血液科提供。Ｋ5 6 2、ＨＬ 6 0、Ｋ5 6 2 ＶＣＲ细胞系由上海血…     

2-甲氧基雌二醇抑制骨髓增生异常综合征SKM-1细胞增殖和诱导细胞凋亡

目的 探讨2-甲氧基雌二醇(2-ME)对骨髓增生异常综合征SKM-1细胞增殖和细胞凋亡的影响.方法 常规培养的SKM-1细胞分为2-ME处理组与非处理对照组,SKM-1细胞分别与不同浓度2-ME(1、2、4和8 μmol/L)和对照组共同培养,MTT法检测2-ME对SKM-1细胞增殖抑制作用;光学显微镜观察瑞氏-姬姆萨染色后的细胞形态;流式细胞术分析细胞周期和凋亡;荧光探针JC-1检测细胞线粒体膜电位(△Ψm).结果 2-ME对SKM-1细胞的生长抑制作用具有浓度和时间依赖性;光学显微镜下可见典型的凋亡细胞形态特征;SKM-1细胞被阻滞于G2/M期,表现为Go/G期细胞和S期细胞逐渐减少,G2/M期细胞逐渐增多(P＜0.05＝;2-ME降低细胞△Ψm具有时间依赖性(P＜0.05＝.结论 2-ME对人骨髓增生异常综合征SKM-1细胞的增殖具有显著的抑制作用并可诱导细胞凋亡.其机制可能与细胞G2/M期阻滞和△Ψm下调有关.     

急性白血病不同病期端粒酶活性及其预后意义初探

目的：观察急性白血病（AL）不同病期端粒酶活性及其与AL预后的关系。方法：用端粒重复扩增酶联免疫法进行端粒酶活性半定量测定。结果：（1）初发AL端粒酶活性与首次完全缓解（CR）期无显著差异而与CR期超3个月者差异显著；（2）CR3个月后持续高端粒酶活性提示缓解期短，预后不佳。结论：CR3个月后端粒酶活性可作为预后判定指标之一，而发病前端端酶活性与预后无关。