Triptolide modulates the sensitivity of K562/A02 cells to adriamycin by regulating miR-21 expression

Context: Multidrug-resistance is a serious obstacle encountered in leukemia treatment. Recent studies have shown microRNA-21 (miR-21) is overexpressed in several types of cancer and contributes to tumor resistance to chemotherapy. In our previous studies, we found triptolide (TPL) could enhance adriamycin-induced cytotoxicity and apoptosis in K562/A02 cells.

Objective: In the present study, we investigated the mechanism of TPL on the sensitivity of K562/A02 cells to adriamycin.

Materials and methods: Cell viability was assessed by methyl thiazolyl tetrazolium (MTT) assay. Expression of mature miR-21 was determined by SYBER green PCR. The miR-21 mimics and inhibitors were chemically synthesized and transfected into K562 cells or K562/A02 cells. PTEN protein levels was determined by western blots. PTEN promoter activity was measured by luciferase assays.

Results: TPL (5 nmol/L) increased the sensitivity of K562/A02 to adriamycin. When adriamycin was combined with 5 nmol/L TPL, the mean apoptotic population of K562/A02 cells was increased from 4.3 to 18.5%, respectively. K562/A02 cells showed a significant reduction in miR-21 and phosphatase and tensin homolog deleted on chromosome ten (PTEN) expressions after TPL treatment. K562/A02 cells that were transfected with the miR-21 inhibitor had a significantly higher PTEN protein level than the control. K562 cells that were pre-treated with PTEN siRNA had increased survival rate compared to the control group.

Discussion and conclusion: Our findings indicated that triptolide modulates the sensitivity of K562/A02 cells to adriamycin by regulating miR-21 expression. Triptolide inhibited miR-21 expression and enhanced PTEN levels in K562/A02 cells.     

木香烃内酯对K562/A02细胞阿霉素耐药的逆转作用研究

目的探索木香烃内酯对白血病耐药细胞系K562/A02阿霉素耐药的逆转作用。方法将木香烃内酯与K562/A02细胞共培养72 h后,采用MTT法检测木香烃内酯对细胞生长的抑制作用。不同浓度木香烃内酯处理K562/A02细胞24 h后,采用Annexin V和PI双染法检测木香烃内酯对细胞的凋亡。不同浓度木香烃内酯与阿霉素共培养72 h后采用MTT法检测木香烃内酯对K562/A02细胞的耐药逆转情况。采用流式细胞仪检测木香烃内酯处理24 h之后K562/A02细胞阿霉素蓄积以及细胞膜表面P-糖蛋白(P-gp)的表达。结果木香烃内酯对K562/A02细胞的生长具有明显抑制作用,呈显著的剂量相关性。与对照组比较,2.5~50μmol/L木香烃内酯组K562/A02细胞存活率显著降低(P0.05、0.01、0.001)。随着木香烃内酯浓度的增加,凋亡细胞的比例明显增加。与对照组比较,不同浓度木香烃内酯组细胞凋亡比例显著升高(P0.05、0.01、0.001)。加入5μmol/L木香烃内酯后,使K562/A02细胞对阿霉素的敏感性提高12倍。木香烃内酯处理后K562/A02细胞内部阿霉素的蓄积明显增加,呈浓度相关性。与对照组比较,5、10μmol/L木香烃内酯组K562/A02细胞内部阿霉素的蓄积增加显著升高(P0.05)。细胞表面的P-gp的表达并无显著影响。结论木香烃内酯能够抑制K562/A02细胞增殖,诱导K562/A02细胞凋亡,增强阿霉素的化疗敏感性,逆转阿霉素耐药。     

miR- 221 表达与K 562/A 02 细胞耐药关系的探讨

目的观察miR-221表达与K562/A02细胞耐药的关系。方法常规培养K562/A02细胞株作为对照组,选择通过反义寡核苷酸特异性抑制K562/A02细胞中miR-221表达细胞株作为实验组,应用实时荧光定量RT-PCR方法检测两组细胞中miR-221表达情况。采用MTT法比较两组细胞对化疗药物的敏感性。结果荧光定量RT-PCR结果显示,实验组细胞中miR-221表达较对照组明显降低,（P〈0.05）,两组比较差异倍数均值为-8.43±2.18。阿霉素对实验组细胞的IC50为0.0375mg·L-1,阿霉素对对照组细胞的IC50为4.32mg·L-1,后者的耐药倍数是实验组的115倍。结论反义寡核苷酸能够抑制K562/A02细胞中miR-221的表达,这种抑制作用能够逆转K562/A02细胞对阿霉素的耐药性。miR-221表达与K562/A02细胞耐药性密切相关。     

Reversal effect of a macrocyclic bisbibenzyl plagiochin E on multidrug resistance in adriamycin-resistant K562/A02 cells

Plagiochin E is a new macrocyclic bisbibenzyl compound isolated from Marchantia polymorpha. In the previous studies, we reported that when combined with fluconazole, plagiochin E had synergetic effects against the resistant strain of Candida albicans. Herein, we examined the reversal effect of plagiochin E on multidrug resistance in adriamycin-induced resistant K562/A02 cells and the parental K562 cells. Its cytotoxicity and reversal effects on multidrug resistance were assessed by MTT (3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl-tetrazolium bromide) assay. Apoptosis percentage of cells was obtained from Annexin V/fluorescein isothiocyanate (FITC) and propridium iodide (PI) double-staining. The effects of plagiochin E on P-glycoprotein activity were evaluated by measuring rhodamine 123 (Rh123)-associated mean fluorescence intensity and P-glycoprotein expression on the basis of the flow cytometric technology, respectively. The results showed that plagiochin E ranging from 2 to 12 mug/ml had little cytotoxicity against K562/A02 cells. When combined with adriamycin, it significantly promoted the sensitivity of K562/A02 cells toward adriamycin through increasing intracellular accumulation of adriamycin in a dose-dependent manner. Further study demonstrated that the inhibitory effect of plagiochin E on P-glycoprotein activity was the major cause of increased stagnation of adriamycin inside K562/A02 cells, indicating that plagiochin E, as a new class of mutidrug resistance inhibitor, may effectively reverse the multidrug resistance in K562/A02 cells via inhibiting expression and drug-transport function of P-glycoprotein.     

Sorcin过表达——白血病多药耐药的一种新机制

目的研究sorcin基因与白血病多药耐药的相关性。方法用NorthernBlot和WesternBlot方法,检测人白血病耐药细胞株K562/A02及其野生型细胞株K562中sorcin基因和蛋白表达水平的差异。设计针对sorcin基因的反义寡核苷酸,通过脂质体将其导入K562/A02细胞,通过WesternBlot方法检测转染前后细胞内sorcin蛋白表达的变化,运用MTT方法检测转染反义寡核苷酸后细胞对阿霉素敏感性的变化。结果NorthernBlot和WesternBlot结果表明,K562/A02细胞中sorcin表达水平明显高于K562敏感细胞。将sorcin基因反义寡核苷酸转入K562/A02细胞后,细胞内sorcin蛋白表达明显下降,对阿霉素的敏感性提高。结论作为一种耐药相关基因,sorcin参与了白血病多药耐药细胞耐药表型的形成,有望成为今后白血病耐药诊断和治疗的新靶点。     

AGEs与其受体相互作用与K562及K562/A02细胞耐药性

目的观察晚期糖基化终末产物(AGEs)与其受体相互作用是否与K562及K562/A02细胞对阿霉素(ADM)耐药性相关。方法用流式细胞术检测K562及K562/A02细胞晚期糖基化终末产物受体(RAGE)及P-糖蛋白(P-gp)的表达和细胞凋亡率,CCK-8法观察AGEs对K562及K562/A02细胞增殖的影响,计算AGEs作用下两种细胞对ADM的半抑制浓度(IC50)值,用半定量RT-PCR检测mdr1mRNA相对表达水平。结果 K562与K562/A02细胞RAGE表达比较差异无统计学意义。AGEs可呈浓度和依赖性促进K562及K562/A02细胞增殖(P<0.05);AGEs作用K562及K562/A02细胞48h后,K562细胞mdr1mRNA及P-gp的表达均为阴性,K562/A02细胞mdr1mRNA及P-gp的表达与不加AGEs组比较差异均无统计学意义。结论 AGEs不能改变K562细胞对ADM的敏感性,同时亦不能改变K562/A02细胞对ADM的耐药性;AGEs与其受体相互作用与K562及K562/A02细胞耐药性无关。     

新的肿瘤耐药相关基因ERGIC-53的研究

目的:研究ERGIC-53基因表达与肿瘤细胞耐药的关系,寻找肿瘤耐药逆转可能的新靶点。方法:采用Northern Blot检测ERGIC-53基因在K562和K562/A02中的表达差异;应用逆转录聚合酶链反应(RT-PCR)检测11种肿瘤敏感及耐药细胞系中ERGIC-53基因的表达;设计合成针对ERGIC-53基因的siRNAs,用脂质体法转染K562和K562/A02细胞,用MTT比色法和流式细胞仪检测其干扰耐药细胞中ERGIC-53基因表达后的细胞对阿霉素的敏感性。结果:ERGIC-53在K562/A02细胞中的表达明显高于亲代K562细胞(P<0.05);6种耐药细胞株中ERGIC-53基因表达的平均值约为亲代敏感细胞的2倍。siRNA转染组与对照组相比,K562/A02细胞对阿霉素的敏感性均有不同程度的提高,且在转染后72h时细胞内阿霉素积累接近其亲代敏感细胞水平。结论:ERGIC-53基因与肿瘤细胞耐药相关,明确该基因参与耐药肿瘤细胞表型的形成。     

Ligustrazine derivate DLJ14 reduces multidrug resistance of K562/A02 cells by modulating GSTπ activity

Multidrug resistance (MDR) of tumor cells is a major obstacle in chemotherapeutic cancer treatment. Over-expression of glutathione S-transferase π (GSTπ) is one of the mechanisms contributing to MDR. In this study, we investigated the reversal of MDR by DLJ14, a ligustrazine derivate, in adriamycin (Adr) resistant human myelogenous leukemia (K562/A02) cells by modulating the expression of GSTπ and the activity of GST-related enzymes. In the MTT test, DLJ14 showed a weak inhibition on proliferation of both K562/A02 and K562 cells, while verapamil at the same concentration showed a much stronger inhibition. The sensitivity of K562/A02 cells to cytotoxic killing by Adr was enhanced by incubation with DLJ14 as a result of the increased intracellular accumulation of Adr. The accumulation of Adr induced by DLJ14 may due to down regulation of GST-related enzyme activity. Western blot analysis and RT-PCR showed that DLJ14 was able to inhibit the protein expression and mRNA expression of GSTπ in K562/A02 cells. Moreover, DLJ14 increased the expression of cellular c-Jun NH₂-terminal kinase (JNK) in K562/A02 cells exposure to Adr. This is consistent with the inhibition of GSTπ. These results demonstrate that DLJ14 may be an attractive new agent for the chemosensitization of cancer cells.     

半夏水提取液逆转多药耐药细胞系K562/A02耐药性的研究

目的观察非细胞毒性浓度半夏水提取液对耐阿霉素的人白血病细胞系K562/A02多药耐药性的逆转作用,并探讨其逆转机制.方法采用MTT法测定半夏水提取液的细胞毒性及其对K562/A02细胞敏感性的影响,用流式细胞仪检测非细胞毒性浓度的半夏水提取液处理后K562/A02细胞膜表面糖蛋白P170表达的变化.结果半夏水提取液对K562/A02细胞有一定的细胞毒作用,非细胞毒性浓度半夏水提取液可显著降低阿霉素对K562/A02细胞的IC50,显著降低细胞膜糖蛋白P170的表达.结论半夏水提取液可部分逆转多药耐药细胞系K562/A02细胞对阿霉素的耐药性.     

姜黄素通过调节miR-21干预伊马替尼耐药K562/IM细胞的化疗敏感性

目的 研究姜黄素对伊马替尼耐药的K562细胞(K562/IM)多药耐药性的逆转作用,并探讨其机制。方法 采用MTT法分析姜黄素对于K562/IM细胞的增殖抑制作用,并选取非毒性浓度姜黄素联合伊马替尼作用于K562/IM,分析其增殖抑制效应;流式细胞术检测其协同诱导细胞凋亡的作用;实时荧光定量PCR和Western blot法检测姜黄素对于miR-21和Bcl-2蛋白表达水平的改变;并采用microRNA转染技术,观察miR-21对细胞增殖抑制和Bcl-2 蛋白表达的影响。结果 非毒性浓度(25 μmol·L^-1)姜黄素能显著增强K562/IM细胞对伊马替尼的敏感性,并能增强伊马替尼诱导细胞凋亡的作用,使K562/IM细胞平均凋亡率由6.3%提高到23.6%(P<0.05);姜黄素作用后,miR-21和Bcl-2蛋白水平显著降低;miR-21抑制剂转染K562/IM细胞后,可显著降低Bcl-2表达,提高K562/IM细胞对伊马替尼的敏感性。结论 姜黄素可增强K562/IM细胞对伊马替尼的敏感性,并诱导其凋亡,其作用机制可能与下调miR-21表达水平、抑制靶基因Bcl-2 蛋白表达有关。     

α-干扰素增强耐药性白血病K562/ADM细胞及其白血病干细胞对阿霉素的敏感性

目的研究α-干扰素(interferon alpha,IFN-α)对白血病多药耐药K562/ADM群体细胞及其白血病干细胞(LSC)对细胞周期特异性药物阿霉素敏感性的影响。方法以K562/ADM耐药细胞为靶细胞,采用噻唑蓝(MTT)比色法检测细胞增殖活性;流式细胞术碘化丙啶(PI)染色和AnnexinV/PI双染色分别测定细胞周期分布和细胞凋亡;抗CD34、CD38和CD123抗体以及Annexin V共染色检测群体细胞中LSC的含量及凋亡率。结果 IFN-α作用后K562/ADM细胞周期分布发生改变,G0/G1期细胞比例减少,S期细胞比例增高。IFN-α与阿霉素联合作用,明显增强阿霉素对K562/ADM细胞的增殖抑制作用,细胞凋亡率增高。IFN-α可提高K562/ADM细胞群体中LSC的含量(比例),且增加LSC对阿霉素的敏感性,凋亡的LSC数量增高。结论 IFN-α促进K562/ADM群体细胞及其LSC进入细胞增殖周期而提高对细胞周期特异性抗癌药物阿霉素的敏感性。     

阿霉素纳米粒对白血病多药耐药细胞株K562/ADR耐药性的逆转作用

目的:研究阿霉素纳米粒对人白血病多药耐药细胞株K562/ADR耐药性的逆转作用.方法:采用MTT法测定药物的体外杀伤作用,应用流式细胞术测定细胞内药物浓度.结果:阿霉素纳米粒和阿霉素对K562细胞细胞毒作用相似,K562/ADR对阿霉素纳米粒较阿霉素敏感2.63倍,细胞内阿霉素浓度显著增加可能是关键因素.结论:阿霉素纳米粒通过增加耐药细胞内阿霉素浓度有效逆转多药耐药.     

2-氯脱氧腺苷对多药耐药白血病细胞的毒性实验研究

目的　探讨 2 -氯脱氧腺苷 (2 - CDA)对多药耐药白血病细胞 (K5 6 2 / A0 2 )的毒性作用。方法　细胞毒实验采用 MTT法 ,二药合用时细胞毒性作用采用 Chou- Talalay联合指数法分析。结果　 2 - CDA对 K5 6 2和K5 6 2 / A0 2的 IC50 分别为 (2 3.9± 2 .4) nmol/ L 和 (137.6± 12 .7) nm ol/ L(P<0 .0 5 )。 2 - CDA与柔红霉素 (DNR)联合应用时 ,对 K5 6 2细胞的联合指数分别是 1.0 ,对 K5 6 2 / A0 2细胞为 5 .1。结论　 2 - CDA对敏感白血病细胞具有明显细胞毒性作用。多药耐药白血病细胞对 2 - CDA不敏感。2 - CDA与 DNR联合应用时 ,对敏感白血病细胞的毒性为相加作用 ,对多药耐药白血病细胞的毒性为拮抗作用。     

抗多药耐药基因肽核酸与反义寡脱氧核苷酸增强K562／ADM细胞的敏感性和促进凋亡

AIM: To investigate the reversal effect and apoptosis enhancement of peptide nucleic acid (PNA) and antisenseoligodeoxyribonucleotide (ASODN) targeted to multidrug resistance gene (mdrl) on human multidrug resistantleukemia K562/ADM cells. METHODS: A 15-mer PNA and the same sequence of ASODN, complementary to the5' end of the AUG initiator codon-containing region of mdrl messenger RNA (MDR1-PNA, MDR1-ASODN), weredesigned and synthesized. Proliferation and sensitivity to adriamycin of K562/ADM cells treated with MDRI-PNAand MDR1-ASODN were analyzed with a MTT colorimetric assay. Apoptotic morphologies, P-glycoprotein (P-gp)expression, intracellular adriamycin accumulation, and cell cycle were measured. RESULTS: MDRI-PNA 1 to 10μmol/L and MDR1-ASODN 2 to 20 μmol/L alone had no inhibitory effects on the proliferation of K562/ADM cells,but significantly inhibited the growth of K562/ADM cells cultured in adriamycin-containing medium. After treatment with MDRI-PNA and MDRI-ASODN, intracellular adriamycin accumulation in K562/ADM cells increasedgreatly and P-gp synthesis was strikingly reduced. The resistance to adriamycin of the drug-resistant cells waspartly reversed and the cells were induced to apoptosis by adriamycin. The reversal efficacy of MDR1-PNA was3.1-fold higher than that of the same sequence of MDR-ASODN, but neither MDRI-PNA nor MDRI-ASODNcould completely block the mdrllP-gp expression. CONCLUSION: Sequence-special PNA targeted to mdr1 genemore effectively than the same sequence of MDR1-ASODN inhibited the expression of P-glycoprotein to overcomethe drug-resistance.     

屈洛苷芬对K562耐阿霉素细胞株耐药性的逆转作用

目的：研究屈洛昔芬（DRO）对耐阿霉素（ADR）K562细胞株（K562／A02)多药耐药性（MDR）的逆转作用及逆转机制。方法：用DRO分别处理K562／A02和K562敏感株。MTT法观察DRO影响K562／A02对ADR化学敏感性的变化。DRO 10μmol/L处理K562／A02前后,通过RT－PCR和免疫细胞化学染色,分析MDR1、GSTπ基因表达的变化,采用流式细胞技术测定细胞内ADR浓度的变化。结果：DRO显著逆转K562／A02的MDR,在20,10和5μmol/L浓度时,对ADR的化学敏感性分别增加到14、13和4倍,逆转活性与维拉帕米相当。MDR1和GSTπ的mRNA和蛋白表达在DRO 10μmol/L处理后第2天开始下降,第5天明显降低。用20、10和5μmol/L浓度的DRO处理两株细胞,K562／A02细胞内ADR积累分别增加到2．9、2．3和1．5倍。但DRO不能明显增加K562细胞内的ADR的浓度。结论：DRO对K562／A02的MDR有较强的逆转活性,逆转强度与维拉帕米相当,其逆转机制有多种不同的途径。     

自噬水平与白血病K562/ADM细胞耐药的关系研究

目的采用阿霉素(adriamycin,ADM)“逐步提高药物浓度+间歇性诱导”的方式体外诱导建立稳定耐受15μmol·L^-1 ADM的白血病K562/ADM细胞,观察该细胞对其它化疗药物的敏感性以及细胞自噬水平与耐药的关系。方法MTT法检测细胞对几种化疗药物的敏感性;用透射电镜、荧光显微镜观察细胞自噬形态学改变;Annexin-V/PI双染流式细胞仪检测细胞凋亡;Western blot检测自噬和耐药相关蛋白的表达水平。结果K562/ADM细胞除了对ADM产生明显耐药外,还对多种化疗药物如:吡柔比星、柔红霉素、5-FU和长春新碱等有交叉耐药,但对三氧化二砷较敏感。K562/ADM细胞内自噬体数量、MDC荧光强度以及LC3Ⅰ/Ⅱ、Beclin-1蛋白表达水平均高于亲本细胞。用3-MA抑制自噬可明显增加K562/ADM细胞对ADM的敏感性,同时也能有效抑制K562/ADM细胞内耐药相关蛋白的表达。结论K562/ADM细胞出现多药耐药现象,且耐药性与细胞自噬水平有密切关系。     

FAT对K562/A02细胞内GSH含量的影响

目的：探讨FAT对K562/A02细胞内谷胱甘肽（GSH）含量的影响,及其对白血病细胞代谢解毒系统介导的多药耐药（MDR）的逆转效果。方法：采用生化DTNB法测定细胞内谷胱甘肽水平。结果：K562/A02细胞内GSH含量（231.54μmol/106细胞）高于K562细胞内GSH含量（58.03μmol/106细胞）,为K562细胞的3.99倍;VRP（10μmol/L）、FAT（0.01、0.02、0.04、0.08mg/ml）作用48h后,K562/A02细胞内GSH含量从231.54μmol/106细胞分别减少到96.95μmol/106细胞、212.89μmol/106细胞、161.00μmol/106细胞、122.35μmol/106细胞。结论：细胞内GSH含量增加是K562/A02细胞产生MDR的机制之一;FAT降低K562/A02细胞内GSH的含量是FAT逆转MDR的机制之一。     

微小RNA-21调控同源性磷酸酶-张力蛋白基因表达在子痫前期发病中的作用机制

目的 探究微小RNA-21(miR-21)在子痫前期(PE)病人发病中的表达变化及可能作用机制.方法 收集2016年8月至2019年10月郑州市妇幼保健院收治的45例PE病人及45例匹配正常孕妇胎盘组织,采用实时定量PCR(RT-qPCR)法检测miR-21相对表达水平.体外培养人滋养层细胞系HTR-8/SVneo,转...     

Hsa-miR-203联合伊马替尼对慢性粒细胞白血病K562细胞的作用

目的探讨hsa-miR-203联合甲磺酸伊马替尼（mesylate imatinibMI）对人慢性粒细胞白血病K562细胞的影响。方法体外培养K562细胞,利用Lipofectamine^TM2000将has-miR-203模拟物转染至K562细胞,MT＇F法检测使用miR-203、MI以及两者联合使用对细胞增殖的抑制率,流式细胞术检测对细胞早期凋亡率的影响。结果miR-203转染至K562细胞（24、48、72h）后,联合MI显著抑制K562细胞增殖,抑制效果较各单独使用组作用明显增强。单用miR-203浓度为50μmol·L^-1时的抑制率分别为19．69％、25．62％、35．21％。而联合不同浓度（0．5、1、2、3、4μmol·L^-1）的伊马替尼,抑制率随着作用时间增加,呈时间一依赖效应。单用hsa-miR-203、伊马替尼及两者联合作用于K562细胞48h后,早期凋亡率分别为7．8％、8．9％、12．5％。结论当一定浓度的hsa-miR-203与不同浓度的伊马替尼联合之后,对K562细胞的增殖抑制作用增强,hsa．miR-203提高了K562细胞对伊马替尼的敏感性,其机制可能为共同促进K562细胞早期凋亡有关,并为白血病的治疗提供新的依据。     

Reversal of p-glycoprotein-mediated multidrug resistance by macrocyclic bisbibenzyl derivatives in adriamycin-resistant human myelogenous leukemia (K562/A02) cells

Macrocyclic bisbibenzyls, a class of characteristic natural molecules derived from liverworts, have diverse biological significances. Dihydroptychantol A (DHA) was identified to be an antifungal active macrocyclic bisbibenzyl from liverwort Asterella angusta. In an attempt to understand other biological activities of this compound, the chemical synthesized DHA and its analogues (compounds 1–3) were employed to test this possibility by using adriamycin-resistant K562/A02 cells. Among the tested compounds (1–4), DHA showed the strongest potency to increase adriamycin cytotoxicity toward K562/A02 cells by MTT assays and its reversal fold is 8.18 (20 μM). Mechanisms of DHA on p-glycoprotein (P-gp)-mediated multidrug resistance (MDR) were further investigated. Based on the flow cytometry, we detected the significant increase of adriamycin and rhodamine123 accumulation in K562/A02 cells exposed to various concentrations of DHA, meanwhile, notable decrease of rhodamine123 efflux was also observed, which revealed DHA caused a decline of P-gp activity. Furthermore, P-gp expression was analyzed by the flow cytometry and RT-PCR. Dose-dependent reduction of P-gp expression was measured in K562/A02 cells pretreated with DHA for 24 h. No such results were found in parental K562 cells. These results demonstrated DHA reversed effectively MDR by blocking the drugs to be pumped out via inhibiting P-gp function and expression pathway.