IFNγ联合全反式维甲酸对白血病细胞株NB4、MR2增殖和分化的影响

背景与目的:全反式维甲酸(all-transretinoicacid,ATRA)的应用,使90%以上的急性早幼粒细胞白血病(acutepromyelocyticleukemia,APL)患者获得了完全缓解,但维甲酸耐药的快速发生成为ATRA治疗APL的一大缺憾。许多研究表明ATRA耐药与缺乏干扰素合成的某些蛋白质有一定的关系,本研究拟探讨干扰素联合ATRA作用抑制ATRA耐药APL细胞增殖和分化的可能性及其机制。方法:γ干扰素(interferonγ,IFNγ)、ATRA单独或联合作用于ATRA敏感细胞株(NB4)及ATRA耐药细胞株(MR2)后,采用MTT法检测细胞的增殖,用光镜观察和NBT还原实验检测细胞的分化,间接免疫荧光法观察早幼粒细胞白血病(promyelocyticleukemia,PML)蛋白表达的情况。结果:第8天时,IFNγ组、ATRA组和(IFNγ ATRA)组NB4细胞的生长抑制率依次为68.0%、85.0%和95.2%;MR2细胞的生长抑制率依次为24.1%、4.3%和51.5%。联合用药组NB4细胞、MR2细胞的生长抑制率明显高于单独用药组(P<0.05)。第3天时,IFNγ组、ATRA组和(IFNγ ATRA)组NB4细胞的NBT阳性率依次为19.3%、74.7%和93.3%,MR2细胞的NBT阳性率依次为16.8%、5.2%和31.5%,联合用药组NB4细胞、MR2细胞的NBT阳性率明显高于单独用药组(P<0.05)。IFNγ作用后,NB4细胞和MR2细胞核内的荧光颗粒较对照组明显增多。结论:IFNγ与ATRA具有协同作用,二者联合应用不仅能够增强ATRA对NB4细胞和MR2细胞的增殖抑制作用,而且能够部分诱导对ATRA耐药的MR2细胞发生分化。     

维甲酸逆转人宫颈癌耐药细胞株耐药性的实验研究

目的 :本研究旨在探讨全反式维甲酸 (ATRA)逆转人宫颈癌Hela/MMC耐药株对MMC的耐药作用。方法 :观察ATRA作用下Hela/MMC细胞的增殖 ,采用MTT法观察ATRA对Hela/MMC药物敏感性的影响 ,半定量RT PCR检测mdrI基因的表达情况。结果 :ATRA能提高MMC对Hela/MMC细胞的杀伤作用 ,上调细胞mdr1mRNA的表达。结论 :ATRA能逆转Hela/MMC对MMC的耐药性 ,但这种作用与mdrl基因表达无关     

维甲酸逆转人宫颈癌耐药细胞株耐药性的实验研究

目的：本研究旨在探讨全反式维甲酸(ATRA)逆转入宫颈癌Hela／MMc耐药株对MMc的耐药作用。方法：观察ATRA作用下Hela／MMC细胞的增殖，采用MTT法观察ATRA对Hela／MMC药物敏感性的影响，半定量RT-PCR检测mdr I基因的表达情况。结果：ATRA能提高MMC对Hela／MMC细胞的杀伤作用，上调细胞mdr l mRNA的表达。结论：ATRA能逆转Hela／MMc对MMc的耐药性，但这种作用与mdfl基因表达无关。     

水杨酸钠对HL-60/VCR细胞多药耐药的部分逆转

目的 :研究水杨酸钠 (Na Sal)对HL 6 0 VCR细胞多药耐药的部分逆转作用。方法 :采用噻唑蓝(MTT)法、流式细胞术等方法 ,观察非甾体抗炎药Na Sal对HL 6 0 VCR细胞多药耐药的部分逆转作用。结果 :Na Sal对HL 6 0 VCR细胞的生长具有抑制作用并表现出剂量依赖性 ,1mmol L的非细胞毒剂量的Na Sal和化疗药物联合应用可以提高多种化疗药物的细胞毒性作用 ,逆转倍数为 1 0 1～ 3 2 6 ,相对逆转效率为 0 5 2 %～ 73 6 2 %。流式细胞仪测定细胞内柔红霉素 (DNR)浓度发现 ,Na Sal并不增加HL 6 0 VCR细胞内DNR浓度。结论 :Na Sal能有效地部分逆转HL 6 0 VCR细胞的多药耐药性     

急性早幼粒细胞白血病耐药机制的研究进展

全反式维甲酸(ATRA)与三氧化二砷(As2O3)作为一线药物治疗急性早幼粒细胞白血病(APL)以来,APL患者的治愈率得到显著提高.但ATRA和(或)As2O3耐药的出现成为一个严重问题.现就近年来新提出的一些耐药机制如融合基因突变、细胞信号通路异常、染色质重构复合物异常、凋亡调控异常、骨髓微环境介导耐药等方面进行综述.     

全反式维甲酸联合三氧化二砷治疗急性早幼粒细胞白血病29例观察

目的　观察全反式维甲酸 (ATRA)联合三氧化二砷 (As2 O3 )治疗急性早幼粒细胞白血病 (APL)的临床疗效、作用特点及毒副作用。方法　As2 O3 注射液 0 .16mg/ (kg·d) ,ATRA 2 5mg/ (m2 ·d)联合治疗初治APL 2 9例 ,根据外周血白细胞计数、维甲酸综合征以及肝功能变化调整ATRA和As2 O3 的剂量。治疗过程中每周检查血象、骨髓像 ,随机检查凝血纤溶指标和肝、肾功能、心电图。结果　治疗初治APL 2 9例 ,1例因并发颅内出血而早期死亡 ,其余 2 8例均达到CR ,完全缓解率 96.6% ,平均缓解时间 ( 2 6.3± 4.1)天。结论　As2 O3 联合ATRA治疗APL的CR率高 ,达CR时间缩短 ,不良反应少。     

他米巴罗汀治疗难治性急性早幼粒细胞白血病的进展

0 引言 急性早幼粒细胞白血病(acute promyelocytic leukemia,APL)是急性髓细胞白血病的一种亚型,FAB分型为M3型,占10％～15％,极易并发严重的出血与凝血功能障碍而引起患者早期死亡.自从上世纪八十年代使用全反式维甲酸(all trans retinoic acid,ATRA)诱导分化治疗,APL的治疗进入一个全新阶段.但维甲酸使用过程中的不良反应及严重诱导分化综合征使部分患者不能耐受;三氧化二砷(arsenic trioxide,As2O3)的应用使部分ATRA耐药患者获得再次缓解,但其累积毒性应引起关注;还存在一部分对这两种药物耐药与治疗后复发患者,这部分患者使用ATRA及As2O3很难再次得到缓解.     

亚砷酸、全反式维甲酸联合化疗治疗儿童急性早幼粒细胞白血病八例

目的 观察亚砷酸(As2O3)、全反式维甲酸(ATRA)联合化疗治疗儿童急性早幼粒细胞白血病(APL)的疗效.方法 8例APL患儿采用ATRA及柔红霉素(DNR)联合进行诱导、巩固及维持治疗,并定期检测PML-RARα融合基因.结果 完全缓解(CR)率为87.5%,达CR中位时间为26 d,并于巩固治疗期间采用As2O3与ATRA及蒽环类药物交替进行,并予以维持治疗,总疗程为3.5年.目前1例已停药,6例处于维持治疗阶段.7例患儿每3个月检测PML-RARα融合基因均为(-),仅1例患儿未达CR死亡.结论 As2O3与ATRA联合化疗治疗儿童APL的疗效较满意.     

亚砷酸、全反式维甲酸联合化疗治疗儿童急性早幼粒细胞白血病八例

目的 观察亚砷酸(As2O3)、全反式维甲酸(ATRA)联合化疗治疗儿童急性早幼粒细胞白血病(APL)的疗效.方法 8例APL患儿采用ATRA及柔红霉素(DNR)联合进行诱导、巩固及维持治疗,并定期检测PML-RARα融合基因.结果 完全缓解(CR)率为87.5%,达CR中位时间为26 d,并于巩固治疗期间采用As2O3与ATRA及蒽环类药物交替进行,并予以维持治疗,总疗程为3.5年.目前1例已停药,6例处于维持治疗阶段.7例患儿每3个月检测PML-RARα融合基因均为(-),仅1例患儿未达CR死亡.结论 As2O3与ATRA联合化疗治疗儿童APL的疗效较满意.     

亚砷酸、全反式维甲酸联合化疗治疗儿童急性早幼粒细胞白血病八例

目的 观察亚砷酸(As2O3)、全反式维甲酸(ATRA)联合化疗治疗儿童急性早幼粒细胞白血病(APL)的疗效.方法 8例APL患儿采用ATRA及柔红霉素(DNR)联合进行诱导、巩固及维持治疗,并定期检测PML-RARα融合基因.结果 完全缓解(CR)率为87.5%,达CR中位时间为26 d,并于巩固治疗期间采用As2O3与ATRA及蒽环类药物交替进行,并予以维持治疗,总疗程为3.5年.目前1例已停药,6例处于维持治疗阶段.7例患儿每3个月检测PML-RARα融合基因均为(-),仅1例患儿未达CR死亡.结论 As2O3与ATRA联合化疗治疗儿童APL的疗效较满意.     

Effect of arsenic trioxide or ATRA on primary APL cell or HL-60 cells and their value analysis in hyperleukocytosis

We have done a lots of works to detect the mechanism of hyperleukocytosis in patients with acute promyelocytic leukemia (APL) after treatment with all trans retinoic acid (ATRA). The early results of study showed that some important factors are related to the hyperleukocytosis, for example, the relationship between serum G-CSF and variation of promyelocytes or more matured granulocytes[1,2]. The further study also indicated that effect of G-CSF on leukemia cells was related to the variat…     

Arsenic trioxide-induced apoptosis and differentiation are associated respectively with mitochondrial transmembrane potential collapse and retinoic acid signaling pathways in acute promyelocytic leukemia.

Recent studies showed that arsenic trioxide (As2O3) could induce apoptosis and partial differentiation of leukemic promyelocytes. Here, we addressed the possible mechanisms underlying these two different effects. 1.0 microM As2O3-induced apoptosis was associated with condensation of the mitochondrial matrix, disruption of mitochondrial transmembrane potentials (DeltaPsim) and activation of caspase-3 in acute promyelocytic leukemia (APL) cells regardless of their sensitivity to all-trans retinoic acid (ATRA). All these effects were inhibited by dithiothreitol (DTT) and enhanced by buthionine sulfoximine (BSO). Furthermore, BSO could also render HL60 and U937 cells, which had the higher cellular catalase activity, sensitive to As2O3-induced apoptosis. Surprisingly, 1.0 microM As2O3 did not induce the DeltaPsim collapse and apoptosis, while 0.1 microM As2O3 induced partial differentiation of fresh BM cells from a de novo APL patient. In this study, we also showed that 0.2 mM DTT did not block low-dose As2O3-induced NB4 cell differentiation, and 0. 10.5 microM As2O3 did not induce differentiation of ATRA-resistant NB4-derived sublines, which were confirmed by cytomorphology, expression of CD11b, CD33 and CD14 as well as NBT reduction. Another interesting finding was that 0.10.5 microM As2O3 could also induce differentiation-related changes in ATRA-sensitive HL60 cells. However, the differentiation-inducing effect could not be seen in ATRA-resistant HL60 sublines with RARalpha mutation. Moreover, low-dose As2O3 and ATRA yielded similar gene expression profiles in APL cells. These results encouraged us to hypothesize that As2O3 induces APL cell differentiation through direct or indirect activation of retinoic acid receptor-related signaling pathway(s), while DeltaPsim collapse is the common mechanism of As2O3-induced apoptosis.     

Efficacy of gemtuzumab ozogamicin on ATRA- and arsenic-resistant acute promyelocytic leukemia (APL) cells.

Acute promyelocytic leukemia (APL) cells express a considerable level of CD33, which is a target of gemtuzumab ozogamicin (GO), and a significantly lower level of P-glycoprotein (P-gp). In this study, we examined whether GO was effective on all-trans retinoic acid (ATRA)- or arsenic trioxide (ATO)-resistant APL cells. Cells used were an APL cell line in which P-gp was undetectable (NB4), ATRA-resistant NB4 (NB4/RA), NB4 and NB4/RA that had been transfected with MDR-1 cDNA (NB4/MDR and NB4/RA/MDR, respectively), ATO-resistant NB4 (NB4/As) and blast cells from eight patients with clinically ATRA-resistant APL including two patients with ATRA- and ATO-resistant APL. The efficacy of GO was analyzed by (3)H-thymidine incorporation, the dye exclusion test and cell cycle distribution. GO suppressed the growth of NB4, NB4/RA and NB4/As cells in a dose-dependent manner. GO increased the percentage of hypodiploid cells significantly in NB4, NB4/RA and NB4/As cells, and by a limited degree in NB4/MDR and NB4/RA/MDR cells. Similar results were obtained using blast cells from the patients with APL. GO is effective against ATRA- or ATO-resistant APL cells that do not express P-gp, and the mechanism of resistance to GO is not related to the mechanism of resistance to ATRA or ATO in APL cells.Leukemia (2005) 19, 1306-1311. doi:10.1038/sj.leu.2403807; published online 26 May 2005.     

WEB-2086 and WEB-2170 trigger apoptosis in both ATRA-sensitive and -resistant promyelocytic leukemia cells and greatly enhance ATRA differentiation potential.

PAF-receptor antagonists WEB-2086 and WEB-2170 (WEBs) have been previously shown to induce differentiation in murine and human leukemia cells. The present study describes the apoptotic-differentiative effect of WEBs in all-trans-retinoic acid (ATRA)-sensitive (NB4) and -resistant (NB4-007-6 and NB4-MR4) acute promyelocytic leukemia (APL) cell lines as well as blasts from patients with t(15;17) APL. NB4 cells exposed to 0.5-1 mM WEBs underwent striking growth arrest and massive apoptosis without appreciable differentiation; IC50 values after 3-day treatment of NB4 were 0.4 and 0.25 mM for WEB-2086 and WEB-2170, respectively. WEBs induced apoptosis also in the two ATRA-resistant NB4-007-6 and NB4-MR4 cell lines and in blasts from patients with t(15;17) APL. Moreover, subapoptotic WEBs acted synergistically with low-dose (0.025-0.05 microM) ATRA; this allowed to increase ATRA differentiation potential up to 40-fold and to improve both number and intensity of NBT-positive NB4 cells at definitely higher levels than with 1 muM ATRA alone. The powerful antiproliferative-apoptotic activities of WEBs in vitro on ATRA-sensitive, ATRA-resistant APL cells and blasts from patients with APL as well as drug capabilities to enhance ATRA differentiation potential suggested that these agents also due to their recognized tolerability in vivo might improve, alone or in combination, clinical treatment of APL.     

Relationship between G-CSF and hyperleukocytosis in patients with APL after treatment with all-trans retinoic acid

Thepatientswithacutepromyelocyticleukemia(APL)oftendiedfromearlyinfectionorcoagulationdisorders.lllCompleteremission(CR)ratesof50%-60%duringthechemotherapywerereportedinrecentyears.Studiesinvitrohaveshownthatall-transretinoicacid(ATRA)wascapableoflettingAPLcellstodifferentiateatsomelowconcentrations.ThispropertyhasbeenappliedinvivoinnewlydiagnosedandinrelapsingAPL.Otherwise,withlesscoagulationofdisordersandbonemarrowaplasia.DevelopmentofATRAtreatmenthasresultedinincreasingCRratestoabo…     

Retinoid/arsenic combination therapy of promyelocytic leukemia: induction of telomerase-dependent cell death.

Acute promyelocytic leukemia (APL) is efficiently treated with a cell differentiation inducer, all-trans retinoic acid (ATRA). However, a significant percentage of patients still develop resistance to this treatment. Recently, arsenic trioxide (As2O3), alone or in combination with ATRA, has been identified as an alternative therapy in patients with both ATRA-sensitive and ATRA-resistant APL. Previous investigations restricted the mechanism of this synergism to the modulation and/or degradation of PML-RARalpha oncoprotein through distinct pathways. In this study, using several ATRA maturation-resistant APL cell lines, we demonstrate in vitro that the success of ATRA/As2O3 treatment in APL pathology can be explained, at least in part, by a synergistic effect of these two drugs in triggering downregulation of telomerase efficient enough to cause telomere shortening and subsequent cell death. Such long-term low-dose combinatorial therapy strategies, developed also to avoid acute side effects, reinforce the notion that the antitelomerase strategy, based on a combination of active agents, should now be considered and evaluated not only in APL but also in other malignancies.     

Apoptosis induction by (+)α-tocopheryl succinate in the absence or presence of all-trans retinoic acid and arsenic trioxide in NB4, NB4-R2 and primary APL cells

We analyzed the effect of (+)α-tocopheryl succinate (α-TOS) alone or associated with arsenic trioxide (ATO) or all-trans retinoid acid (ATRA) in acute promyelocytic leukemia (APL). α-TOS-induced apoptosis in APL clinical samples and in ATRA-sensitive (NB4) and ATRA-resistant (NB4-R2) APL cell lines. The effective dose 50% (ED-50) was calculated to be 71 and 58 μM, for NB4 and NB4-R2, respectively. α-TOS neither induced nor modified ATRA-induced differentiation of APL cells, and did not affect the proliferation and differentiation of normal CD34⁺ hematopoietic progenitors in methylcellulose assays. α-TOS exerted a moderate antagonistic effect to ATO-induced apoptosis when treatment was done simultaneously but when α-TOS was added 24 h after ATO, an additive effect was observed. Our results support the concept of α-TOS as an anti-leukemic compound which spares normal hematopoiesis.