环孢菌素A逆转白血病多药耐药机制的实验研究

目的：研究环孢菌素A（CsA)持续作用7天后,K562／AO2细胞多药耐药性的变化及其变化机制,方法：细胞毒性试验采用MTTI地,细胞内柔红霉素（DNR）浓度用流式细胞术检测,多药耐药基因（mdrl)的表达水平用RT－PCR方法检测,结果：K562／AO2耐药性降低2．2倍,K562／AO2细胞内DNR浓度明显升高,mdrl表达降低,佛伯酯（TPA）可拮抗CsA升高细胞的DNR浓度的作用,结论：CsA可下调mdrl的表达和细胞内DNR浓度进而逆转MDR,其作用可能与CsA抑制蛋白激酶D（PKC）活性有关。     

Antitumor effects of cytosine deaminase and thymidine kinase fusion suicide gene under the control of mdr1 promoter in mdr1 positive leukemia cells

The multidrug resistance (mdr) mediated by P-glycoprotein (P-gp), the mdr1 gene product, is one of the major obstacles in leukemia treatment. The present study was designed to explore a suicide gene therapy approach targeting mdr1 for reversal of P-gp-mediated mdr in the mdr positive K562/A02 cells. To study targeted killing effects of cytosine deaminase (CD)-thymidine kinase (TK) fusion suicide gene on multi-drug resistant leukemia, the CD-TK fusion suicide gene expression vector driven by mdr1 promoter was constructed and transferred into K562 and K562/A02 cells using lipofectintrade mark 2000. RT-PCR was used to demonstrate that there were CD and TK genes expression in K562/A02 cells, but not in K562 cells. MTT analysis showed that, compared with that in K562/CDTK, the survival rate of K562/A02-CDTK cells decreased and at the same time the apoptotic rate increased after treatment with GCV and 5-FC (P < 0.05). In vivo studies showed that the tumor volume in the prodrug treated K562/A02-CDTK groups was significantly less than that in the NS-control and K562-CDTK groups (P < 0.05). These findings show that the CD and TK fusion suicide gene expression driven by mdr1 promoter is effective in killing multidrug resistant K562/A02 cells.     

干扰素和环孢霉素A 协同逆转K562/ ADM细胞对阿霉素的耐药性

  目的 观察干扰素(α-Interleron，α-IFN)和环孢霉素A(Cyclosporine A,CsA)对白血病K562/ADM细胞耐药性的协同逆转效应。方法 以多药耐药基因／P-糖蛋白(Muhidrug resistance gene／P-glycoprotein，mdrl／P-gp)超表达的K562／ADM细胞为靶细胞，MTT比色法检测药物的细胞毒效应；流式细胞仪检测细胞P-糖蛋白(P-glycoprotein，P-gp)表达水平；激光共聚焦显微镜观察细胞内阿霉素含量变化。结果 K562／ADM细胞对阿霉素呈高度耐药性，并与柔红霉素和鬼臼乙叉甙交叉耐药，但与CsA无交叉耐药。CsA和α-IFN单独或联合应用均对K562／ADM细胞的耐药性有较强的抑制效应。流式细胞仪和激光共聚焦显微镜分析发现α-IFN和CsA单独或联合均不能下调细胞mdrl/P-gp的表达，反而应激性地刺激耐药细胞P-gp的合成增加，但可抑制P-gp的功能、增加K562／ADM细胞内阿霉素的积聚。结论 α-IFN和CsA联合可协同逆转耐药白血病细胞的耐药性，其作用机制为抑制P-gp的功能而非下调mdrl／P-gp的表达水平。     

siRNA抑制K562/ADM细胞mdr1基因表达并逆转其耐药性

背景与目的：白血病耐药性是白血病治疗中的难点，RNAi技术具有特异、高效、毒性小的特点，可高效、特异地抑制特定基因的过度表达。本文研究小干扰RNA分子（siRNA）对白血病多药耐药K562／ADM细胞mdr1基因表达和耐药性的影响。方法：设计、筛选和合成针对mdr1基因的siRNAs（si—mdrl—1，si—mdr1—2），脂质体介导转染K562／ADM细胞；RT—PCR法检测mdr1 mRNA的转录；流式细胞术测定P-糖蛋白（P—gP）表达水平；MTT法检测K562／ADM细胞对多柔比星（阿霉素，ADM）的敏感性。结果：si—mdr1—1、si-mdr1-2转染24h和48h，si—mdr1—1的抑制率分别为55．5％和22．5％，而si—mdr1—2则分别为16．0％和57．6％。si—mdr1—1和si—mdr1—2作用72h时，P—gP的表达强度分别下降74％和85％。si—mdr1—1和si—mdr1—2均可提高K562／ADM细胞对多柔比星的敏感性、逆转其耐药性，逆转倍数分别为2．52倍和1．96倍。结论：siRNA可特异性地沉默mdr1基因的表达，逆转P—gP介导的白血病细胞耐药性。     

斑蝥酸钠逆转K562/AO2细胞多药耐药的机制初探

目的 观察斑蝥酸钠(SCA)对多药耐药的白血病细胞(K562/AO2)细胞是否有逆转作用,并初步探讨其逆转机制.方法 应用 MTT测定多柔比星(阿霉素,ADM)对K562/AO2细胞的半数抑制浓度(IC50);应用逆转录聚合酶链式反应(RT-PCR)检测K562、K562/AO2细胞表达mdr1基因水平;用流式细胞术(FCM)检测其P-gp蛋白表达的水平.结果 MTT结果显示,无毒剂量的SCA与ADM联合应用比单纯加ADM(同等剂量)对K562/AO2细胞的IC50降低了1.51倍;耐药细胞(K562/AO2)经SCA处理后mdr1基因与P-gp蛋白表达均下降(P＜0.05).结论 SCA对K562/AO2有一定的逆转作用,其机制可能与下调mdr1基因和P-gp蛋白表达有关.     

Overexpression of glucosylceramide synthase in associated with multidrug resistance of leukemia cells

Ceramide, as a second messenger, initiates one of the major signal transduction pathways in tumor apoptosis. Glucosylceramide synthase (GCS) catalyzes glycosylation of ceramide and produces glucosylceramide. Through GCS, ceramide glycosylation allows cellular escape from ceramide-induced programmed cell death. Here we investigated the expression of GCS in human leukemia cells and an association between GCS and multidrug resistance of leukemia cells. Using RT-PCR technique the level of GCS gene was detected in 65 clinical multidrug resistance/non-resistance cases with leukemia, and in K562 and K562/A02 cell lines. AlamarBlue Assay was applied to confirm the multidrug resistant of K562/A02 cells. PPMP, which is a chemical inhibitor for GCS, was used to determine the relationship between GCS and drug-resistance in K562/A02 cells. In addition, multidrug resistance gene (mdr1), Bcl-2 and Bax mRNA was also analyzed by RT-PCR. The expression of GCS and mdr1 mRNA in clinic multidrug resistance samples exhibited significantly increased compared with clinic drug sensitive group (P<0.05). There was the positive correlation both the expression of GCS and mdr1 genes in leukemia samples (P<0.01, gamma=0.7). AlamarBlue Assay showed that the K562/A02 cell line was 115-fold more resistant to adriamycin and 36-fold more resistant to vincristine compared with drug-sensitive K562 cell line. There also was significant expression difference of GCS and mdr1 genes between K562 and K562/A02 cells. Bcl-2 gene exhibited higher expressions whatever in clinic drug-resistance samples or K562/A02 cells, whereas the expressions of Bax gene were higher in drug-sensitive samples and K562 cells. PPMP increased sensitivity to adriamycin toxicity by inhibiting GCS in K562/A02 cells. Therefore, it is suggested that a high level of GCS in leukemia is possible contributed to multidrug resistance of leukemia cells. Abnormally expressions of the genes in associated with cell apoptosis might be one of the main molecular pathology mechanisms of multidrug resistance caused by GCS gene.     

硒酸酯多糖通过下调mdr1/P-gp表达逆转K562/ADM细胞凋亡抑制

目的:研究硒酸酯多糖(Kappa-selenocarrageenan,KSC)对多药耐药K562/ADM细胞的诱导凋亡效应及其分子机制。方法:以白血病多药耐药细胞K562/ADM为KSC作用的靶细胞,用MTT比色法检测细胞增殖活性,形态学、DNA片段化和流式细胞术(FCM)观察细胞凋亡;RT-PCR检测mdr1基因和Caspase-3基因mRNA的表达;FCM测定P-gp蛋白表达水平和Caspase-3活性。结果:KSC显著抑制K562/ADM细胞增殖,KSC诱导后K562/ADM细胞出现典型的凋亡形态学变化、DNA片段化和亚G1期细胞群等特征性改变。KSC下调K562/ADM细胞mdr1基因表达、抑制P-gp合成,并上调caspase-3基因表达、增强caspase-3活性。结论:KSC通过下调mdr1/P-gp表达逆转K562/ADM多药耐药细胞的凋亡抑制。     

RNAi对白血病细胞mdr-1基因和多药耐药表型的影响

目的:探讨RNA干扰技术(RNAi)对慢性粒细胞白血病急变细胞系K562/AO2细胞mdr1基因的抑制和耐药表型的逆转作用。方法:选择合成封闭mdr-1基因的小干扰序列(si-MDR1),以1个碱基突变的si-MDR1-mut为对照序列,在脂质体介导下转染至K562/AO2细胞系。RT-PCR和Western blot检测mdr1 mRNA及P-gp蛋白水平,流式细胞术分析细胞内柔红霉素(daunorubicin,DNR)积累量,并以四甲基唑蓝快速比色法(MTT)反映K562/AO2对阿霉素、长春新碱、足叶乙甙药物敏感性的变化。结果:实验证实该序列能高效封闭K562/AO2细胞内mdr-1基因表达,增加细胞内化疗药物DNR积累量,增强K562/AO2细胞对阿霉素、长春新碱、足叶乙甙的敏感性。结论:RNAi可以通过抑制mdr1基因表达,逆转K562/AO2细胞耐药表型。     

Experimental Study on the Mechanism of Reversal of Leukemia Multidrug Resistance by Proteasome Inhibitor Bortezomib

OBJECTIVE In this study, we applied multidrug resistant leukemia cell line expressing mdr1-mRNA to observe changes in mdr1-mRNA, the P-gp, cell cycle and apoptosis before and after bortezomib was used, in order to explore the mechanism of reversal of leukemia multidrug resistance by the proteasome inhibitor bortezomib.METHODS Flow cytometry (FCM) was used to detect the intracellular drug concentration, expression of P-gp, cell apoptosis and cell cycle status of K562/DNR cells before and a er treatment with different concentrations of bortezomib. Fluorescence quantitative PCR was applied to detect the mdr1-mRNA expression in K562/DNR and K562/S cells.RESULTS Bortezomib could increase the intracellular DNR content in K562/DNR cells, but showed no e. ect in K562/S cells.5-100 nmol/L bortezomib could significantly reduce the P-gp/mdr1-mRNA expression in K562/DNR cells in vitro, and showed a dose-dependent effect. There was a statistically significant di. erence (P < 0.05) between di. erent concentration groups and the control group. P-gp/mdr1-mRNA expression was negatively correlated with cell apoptosis (r = -0.912 and P < 0.01). After treatment with different concentrations of bortezomib for 24 h,K562/DNR cells in G2 + M phases were significantly increased,while cells in G0 + G1 phases and S phase were significantly decreased, accompanied by an increased apoptotic rate.CONCLUSION Bortezomib can induce G0 + G1 phase to G2 + M phase, and thereby enhance the chemosensitivity of leukemia, and may also reverse the multidrug resistance in leukemia mediated by P-gp overexpression encoded by mdr1 gene. This confi rms that bortezomib can reverse leukemia multidrug resistance at the levels of nucleic acid and protein molecules.     

维生素E琥珀酸酯下调mdr1/P-gp表达逆转K562/ADM耐药细胞的凋亡抑制

目的研究维生素E琥珀酸酯(VitaminEsuccinate,VES)诱导多药耐药K562/ADM细胞凋亡的分子机制。方法采用四氮唑蓝比色法(MTT)检测K562/ADM增殖活性;细胞形态学和AnnexinV/PI双标记法检测细胞凋亡;RT-PCR检测mdr1基因和Caspase-3基因mRNA的表达;流式细胞法(FCM)测定P-gp蛋白表达水平和Caspase-3活性。结果VES显著抑制K562/ADM细胞的增殖;经VES处理后细胞形态上出现典型的凋亡改变;AnnexinⅤ/PI双染检测凋亡细胞明显增加;mdr1mRNA表达和P-糖蛋白(P-glycoprotein,P-gp)合成明显降低,Caspase-3mRNA表达和Caspase-3活性显著增强;VES增加K562/ADM细胞对ADM的敏感性。结论VES诱导mdr1/P-gp高表达的K562/ADM耐药细胞凋亡,其主要机制为下调mdr1/P-gp表达而逆转P-gp介导的细胞凋亡抑制和耐药性。     

Comparison of idarubicin and daunorubicin regarding intracellular uptake, induction of apoptosis, and resistance

Anthracycline antibiotics are widely used as anticancer agents. Idarubicin (4-demethoxydaunorubicin; Ida), a semisynthetic derivative of daunorubicin (Dnr) is more potent than the parent compound in vitro and in vivo. The equitoxic dose of Ida in patients is about one-fourth of that of Dnr. We compared these drugs regarding cytotoxicity, apoptosis induction, and resistance mechanisms in human leukaemic cell lines. Cytotoxicity was studied by means of the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide assay and drug-induced apoptosis by means of the Annexin V-fluorescein isothiocyanate method at similar intracellular concentrations (extracellular concentrations of 0.35 microM for Ida and 1 microM for Dnr). Ida was at least twice as potent as Dnr in MOLT-4, HL60, CEM, and K562 cell lines. It took 8 h for Ida to induce approximately 20% apoptosis, but at least 22 h for Dnr to reach 20% apoptosis at identical intracellular concentration. Ida induces a faster and higher apoptosis rate compared with Dnr. The human chronic myelogenous leukaemia cell line (K562) was selected for resistance to Dnr and Ida with and without verapamil (Ver). Continuous incubation with Dnr, but not with Ida, led to an increased mdr1 gene expression as assessed by real-time PCR. The development of mdr1 gene expression in Dnr-resistant cells could be reversed by the presence of Ver. Ver also reversed the cytotoxicity to Dnr, but not to Ida, in K562/Dnr cells. The results show that Ida is more effective than Dnr in inducing apoptosis and that there are differences in resistance mechanisms between the drugs.     

Antiproliferating activity of the mitotic inhibitor pironetin against vindesine- and paclitaxel-resistant human small cell lung cancer H69 cells

Pironetin, isolated from Streptomyces sp., is a potent inhibitor of microtubule assembly and the first compound identified that covalently binds to alpha-tubulin at Lys352. We examined whether pironetin is an effective agent against human small cell lung cancer H69 cells, including two cell lines resistant to the microtubule-targeted drugs vindesine (H69/VDS) and paclitaxel (H69/Txl) that interact with beta-tubulin. Pironetin was found to be effective against these resistant cells as well as their parental cells. In addition, pironetin inhibited the growth of human leukemic K562 multidrug-resistant cells (K562/ADM), which have mdr1 gene expression, as well as the parental K562 cells. In these cell lines, including the parental and resistant cells, pironetin caused complete mitotic arrest; in addition, apoptosis inductions by 30 and 100 nM pironetin were observed. In this study, the new mitotic inhibitor, pironetin, was found to be effective not only against human tumor cell lines resistant to microtubule-targeted drugs, but also multidrug-resistant cells with mdr1 gene expression. These results suggest that pironetin is a useful agent for overcoming drug resistance in cancer chemotherapy.     

Sorcin基因和mdr1基因的相关性及临床意义

目的　探讨急性髓细胞系白血病 (AML)患者可溶性耐药相关钙结合蛋白基因 (sorcin)和多药耐药基因 (mdr1)的相关性表达及其与临床耐药和疗效的关系。方法　Northernblot检测K5 6 2 /A0 2细胞株sorcin和mdr1基因的表达 ,用半定量逆转录聚合酶链反应 (RT PCR)检测 6 5例AML患者、2 7例非白血病患者和健康人的sorcin基因和mdr1基因表达 ,并分析sorcin基因和mdr1基因表达的相关性及其临床意义。结果　AML患者中 ,sorcin和mdr1基因表达明显高于正常对照组 ,差异有非常显著性 (P <0 .0 0 1) ;在AML和对照组中 ,sorcin和mdr1基因的表达有较好的相关性 ;sorcin和mdr1基因的共表达与AML患者的临床耐药和预后具有较高的符合率。Sorcin+ 和mdr1+ 组患者临床耐药发生率为 92 .9% ,完全缓解 (CR)率为 7.1% ;sorcin-和mdr1-组患者临床耐药发生率为 8.6 % ,CR率为91.4 %。结论　白血病患者的sorcin和mdr1基因共表达与其临床耐药和预后密切相关 ,可作为检测临床耐药和判断预后的有效手段之一。     

Reversal of P-glycoprotein-mediated multidrug resistance with small interference RNA (siRNA) in leukemia cells

The multidrug resistance (MDR) mediated by P-glycoprotein (P-gp), the MDR1 gene product, is one of the major obstacles in leukemia treatment. The present study was designed to explore a MDR1-targeted small interfering RNA (si-MDR1) approach for reversal of P-gp-mediated MDR in the MDR human leukemia cell line k562/A02. It was found that si-MDR1 significantly inhibited MDR1 expression at both mRNA and protein levels. Depletion of MDR1 by si-MDR1 correlated with the increased sensitivity of the cells to cytotoxic agents and with the enhanced intracellular retention of daunorubicin (DNR). One base-pair mutated control (si-MDR1-Mut) lost the effect of si-MDR1 on both the degradation of mdr1 mRNA and the reduction of P-gp expression. These findings indicate that siRNA specifically and efficiently interferes with the expression of mdr1 and could be used as a molecularly defined therapeutic approach for MDR in the treatment of leukemia.     

Rapid up-regulation of mdr1 expression by anthracyclines in a classical multidrug-resistant cell line.

Studies were carried out in a variant human multidrug-resistant (MDR) cell line CEM/A7R, which expresses very low levels of mdr1 mRNA and P-glycoprotein (P-gp). The induction of mdr1 RNA expression by three anthracyclines, (doxorubicin, daunorubicin, epirubicin), VP-16 and two vinca alkaloids (vincristine, vinblastine) was semiquantitatively assessed by scanning Northern blots on a phosphorimager. The relative level of mdr1 expression was expressed as ratio of mdr1 to the internal RNA (actin). A significant increase (P < 0.02) in expression of mdr1 was noted within 4 hrs of exposure to 1.5 micrograms ml-1 daunorubicin or epirubicin. Neither vinblastine nor vincristine had any effect on mdr1 levels after an 8 h exposure. With increasing concentrations of daunorubicin or epirubicin in a fixed 24 h time period, mdr1 expression increased, although a biphasic response was seen. Based on MRK 16 binding, an increase in P-gp levels was seen in the CEM/A7R line after a 24 h exposure to 1 microgram ml-1 daunorubicin or epirubicin. The rapid increase in mdr1 expression after a short period of exposure to doxorubicin, daunorubicin or epirubicin suggests that induction of mdr1 expression may have an important role in the development of drug-resistant tumours.     

多药耐药基因、谷胱甘肽S-转移酶特异性siRNA逆转K562／A02细胞多药耐药.

 目的　研究多药耐药基因（mdr1）、谷胱甘肽S-转移酶（GSTπ）特异性siRNA逆转K562／A02细胞多药耐药性。方法　以mdr1 mRNA第79～99和GSTπmRNA第308～327核苷酸为作用靶点，合成针对靶区域序列的siRNA，克隆入pSilence2.1-U6 neo，克隆产物为pSilence-mdr1和pSilence-GSTπ，脂质体介导下转染K562／A02细胞。用实时荧光定量PCR检测K562／A02细胞 mdr1和GSTπ mRNA的表达；流式细胞仪检测细胞凋亡；MTT法检测多柔比星的半数抑制浓度（IC50）。结果　经酶切、测序分析表明，成功构建siRNA真核表达载体。经pSilence-mdr1转染后的K562／A02细胞株mdr1 mRNA表达量下降了71.5 %，从（2.8±1.65）×108拷贝／μg RNA下降至（3.9±2.37）×107拷贝／μg RNA（P＜0.01）；同时pSilence-GSTπ 作用后，K562／A02细胞 GSTπmRNA表达量较显示空载体pSilence2.1-U6 转染组下降了39.8 %，从（2.3±1.14）×105拷贝／μg RNA下降至（5.4±2.45）×104拷贝／μg RNA（P＜0.01）；流式细胞仪显示空载体pSilence2.1-U6 转染组细胞凋亡率为（11.65±4.06）%，pSilence-mdr1和 pSilence-GSTπ共转染组细胞凋亡率为（44.98±11.27）%（P＜0.01）；空载体转染组耐药指数为23，pSilence-mdr1和pSilence-GSTπ共转染组耐药指数降低为7，IC50值从转染前的（1.16±0.38）mmol／ml下降为（0.33±0.04）mmol／ml（P＜0.01）。结论　siRNA 真核表达载体pSilence-mdr1、pSilence-GSTπ对K562／A02细胞株多药耐药性具有明显的下调作用。     

Sorcin, an important gene associated with multidrug-resistance in human leukemia cells

Sorcin, or soluble resistance-related calcium-binding protein, is a 22kD calcium-binding protein initially identified in many mutli-drug resistant (MDR) cell lines. We previously observed by gene profiling that sorcin is significantly up-regulated in a doxorubicin-induced MDR leukemia cell line, K562/A02, over its parent cells. We have also demonstrated that the level of sorcin expression in leukemia patients correlates not only directly with that of the mdr1 gene, but also inversely with patients' response to chemotherapies and overall prognosis. In this report, we have carried out experiments to dissect out the contribution of sorcin by itself to drug resistant phenotype in K562 cells. Overexpression of sorcin protein by gene transfection in K562 cells resulted in increased drug resistance, from 4.1- to 22.5-fold, to a variety of chemotherapeutic agents, including doxorubicin, etoposide, homoharringtonine and vincristine. On the other hand, inhibition of sorcin expression in both MDR K562/A02 and the sorcin-transfected K562 cells with sorcin-targeting small interfering RNA led to varying extent of reversal of drug resistance. These results confirm that sorcin is an important gene associated with the development of MDR in leukemia cells.     

肿瘤耐药基因表达的临床意义及其逆转研究

对人白细胞病多药耐药细胞株K562／A02和人肺癌耐PDD细胞株A549PDD系统研究表明，耐药表型是多基因的，它随诱导的药物不同，肿瘤肿类，分化程度以及宿主微环境的不同而表现为一种或同种耐药同时表达，临床研究肿瘤共524例包括白血病260例，实体瘤264但目前能在临床证实跟一些肿瘤耐药相关的基础只有mdrl/P-gp。用比较敏感细菌和对应的耐药细胞cDNA阵表达水平的判别新技术发现了除已知mdrl等等耐药基因以外新的与药相关基因，这也为基因组学在耐药基因研究开辟了新的途径。开发出新的耐药逆转剂PZT11、PND和抗耐药肿新药PHⅡ-7有望在临床发挥作用。抗P－gp／抗CD3微型双功能抗体也有望成为逆转肿瘤耐药新有力工具。     

K562／Adm多药耐药细胞株生物学特性的进一步研究

采用流式细胞仪及逆转录－多聚酶链式反应技术对所建立的Ｋ５６２／Ａｄｍ细胞株生物学特性进一步研究。结果表明该耐药细胞对化疗药物的摄取能力明显降低，细胞跨膜糖蛋白Ｐ－１７０及编码该蛋白的ｍｄｒ－１ｍＲＮＡ具有过度表达。细胞酶学研究发现耐药细胞Ｇ６ＰＤ及６ＰＧＤ活性明显升高，尤以Ｇ６ＰＤ为著。该细胞为多药耐药性及其相关机制的研究提供一良好模型。     

NF-H基因参与K562/A02细胞多药耐药机制形成的研究

目的 分析K562／A02细胞多药耐药性(MDR)分子机制,寻找可能参与K562／A02细胞耐药机制的新基因。方法 通过长期逐步增加K562细胞培养液中阿霉素(ADM)的浓度,诱导出多药耐药细胞株K562／A02,利用cDNA microarray比较K562和K562／A02基因表达的筹别,从中选择NF-H基因进行RT-PCR和免疫细胞化学验证,并利用反义核酸技术和细胞内ADM浓度的测定,进一步验证该基因与K562／A02细胞多药耐药的关系。结果 通过比较发现,有12个基因可能参与了K562／A02细胞的耐药机制,其中7个基因在K562／A02中被下调,5个基因被上调。本研究结果显示,NF-H基因在K562／A02细胞中高表达,并且,将NF-H和mdrl反义核酸同时转入K562／A02细胞后,可明显提高细胞内ADM浓度,而单独转入NF-H反义核酸效果不明显。结论 K562／A02细胞耐药表型的形成是多因素的．除了P-糖蛋白(P-gp)等常见因素外,可能还有NF-H基因的参与。