Adriamycin Sensitizes Adriamycin-Resistant HL-60/ADR Cells to TRAIL-Mediated Apoptosis

OBJECTIVE To study whether an adriamycin-resistant cell line(HL-60/ADR) can be sensitized by adriamycin(ADR) to TRAIL-mediated apoptosis.METHODS The mRNA levels of the TRAIL receptor and apoptosis-related signaling molecules involved in the TRAIL-mediated apoptotic pathway were measured by RT-PCR.The protein levels of apoptotic-related signaling molecules involved in the TRAIL-mediated apoptotic pathway and processed caspase-3,caspase-9,and caspase-8 were measured by Western blots.Apoptosis was assessed by flow cytometry.Mitochondrial membrane potential was analyzed by DiOC6(3) staining.Cytotoxicity was determined by the colorimetric MTT viability/ proliferation assay.RESULTS Treatment with a combination of TRAIL and subtoxic concentrations of ADR resulted in synergistic cytotoxicity and apoptosis for both the parental HL-60 and the HL-60/ADR cells.For HL-60,there was a 5-fold potentiation and synergy in cytotoxicity for TRAIL and for HL-60/ADR,cytotoxicity to TRAIL was potentiated 6-fold with ADR.Adriamycin treatment modestly up-regulated TRAIL-R2(DR5),but had no effect on the expression of Fas-associated death domain,c-FLIP,Bcl-2,Bcl-xL,Bax,and IAP family members(cIAP-1,cIAP-2,XIAP,and survivin).The protein levels of pro-caspase-8 and pro-caspase-3 were not affected by ADR,whereas pro-caspase-9 and Apaf-1 were up-regulated.Combined treatment with TRAIL and ADR resulted in activation of caspase-9 and caspase-3,but there was no detectable processing of caspase-8 beyond the background levels.There was signif icant depolarization of the mitochondrial membrane by the combined treatment of both cell lines and it was more pronounced in the parental HL-60 cell line.The combined treatment with TRAIL and ADR resulted in 42.6% of the HL-60/ADR cells undergoing DNA fragmentation,whereas treatment with either ADR or TRAIL alone resulted in 5.46% and 21.3% DNA fragmented cells,respectively.Similar results were obtained with the HL-60 cells.CONCLUSION These fi ndings demonstrate that ADR can still signal ADR-resistant tumor cells,resulting in the modifi cation of the TRAIL-mediated signaling pathway and apoptosis.

Antileukemic activity of jaspolide B,an isomalabaricane-type triterpene from marine sponge Jaspis sp. on human promyeloleukemic HL-60 cells

The antiproliferative activity and underlying mechanisms of jaspolide B, an isomalabaricane-type triterpene, isolated from the sponge Jaspis sp., were investigated using human promyeloleukemic HL-60 cells. Jaspolide B arrested HL-60 cells in the G2/M phase of the cell cycle and induced apoptosis of HL-60 cells in a dose- and time-dependent manner. Moreover, the poly （ADP-ribose） polymerase （PARP） protein was cleaved by jaspolide in a dose- and time-dependent way. Jaspolide B with an ICs0 value of 0.61 μmol/L was found to be comparable efficacy as that of paclitaxel （IC50：0.78 μmol/L）. These results implicate the potential ofjaspolide B as a promising anticancer agent in chemotherapy of leukemia by arresting cell cycle progression at G2/M phase and triggering apoptosis.

Polymethylenebis [acetamides] Analogues.Synthesis and Differentiation-Inducing Activity on HL-60 Cells

报导了一系列多亚甲基双［酰胺］类化合物的合成，由－摩尔多亚甲基二甲酰氯分别和二摩尔２－氨基噻唑啉及５－氨基－１－甲基吡啶酮反应制得。测定了其体外对ＨＬ－６０人早幼粒白血病细胞的分化诱导活性，初步结果表明：Ｎ，Ｎ｀－双吡啶酮基六二甲酰胺和Ｎ，Ｎ｀－双噻唑啉基八亚甲基二甲酰胺分别在０．１ｍｍｏｌ／Ｌ和０．５ｍｍｏｌ／Ｌ浓度时，诱导分化百分率可达６０％。此浓度下细胞存活率分别为２６％及２２％，其有效诱导浓度比ＨＭＢＡ低十倍。

ARSENIC TRIOXIDE DOWNREGULATES TELOMERASE ACTIVITY IN HL-60 CELLS

Objective: To evaluate whether arsenic trioxide (AS2O3) could downregulate human telomerase reverse transcriptase (hTERT) gene expression and telomerase activity during induction of apoptosis of HL-60 cells. Methods: Apoptosis was detected by morphological observation and flow cytomertric cell cycle analysis. The expression of hTERT at mRNA and protein levels was analyzed by reverse transcriptase polymerase chain reaction (RT-PCR) and immunofluorescence using fluoresce isothiocyanate (FITC) label, respectively. Telomerase activity was determined by polymerase chain reaction enzyme-linked immunoassay (PCR-ELISA). Results: Treatment of 2 μmol/L at As2O3 could induce apoptosis of HL-60 cells. hTERT was decreased at both mRNA and protein levels during apoptosis of HL-60 cells. Telomerase activity of HL-60 cells was significantly inhibited. Conclusion: It is suggested that telomerase activity of HL-60 cells might be specifically inhibited by AS2O3 through the downregulation of hTERT gene expression.

The Influence of Curcumin on the Cell Cycle of HL-60 Cells and Contrast Study

The mechanisms of curcumin inhibiting the proliferation of HL-60 cells were investigated. Acute myeloid leukemic cell line HL-60 was studied by using cell culture, NBT reduction, SABC method measuring BrdU incorporation rate, FCM measuring DNA contents and TUNEL method determining apoptotic cell percentage. Curcumin inhibited proliferation of HL-60 cells in a dose- and time-dependent manner. When the HL-60 cells were treated with 25 μmol/L curcumin for 48 h, the inhibitory rate was 60. 71 % ± 1. 20 %. The study on BrdU incorporation rate and the distribution of DNA content and NBT reduction indicated that curcumin arrested. the cells in G2/M phase of cell cy cle at first, then in G0/G1 phase, the whole cell cycle progression was slowed down and DNA synthesis activities was halted. The arrested cells went to apoptosis instead of differentiation. The comparative study indicated that the ability of curcumin regulating the cell cycle of HL-60 cells was stronger than As2O3 and the acting points of curcumin were not completely consistent with those of VP-16. It was suggested that curcumin was able to regulate, to some extent, the G1/S and G2/M transmit checkpoints and disturb the HL-60 cell cycle to induce apoptosis.

Altered expression of nuclear matrix proteins in etoposide induced apoptosis in HL-60 cells

The events of cell death and the expression of nuclear matrix protein (NMP) have been investigated in a promyelocytic leukemic cell line HL-60 induced with etoposide. By means of TUNEL assay, the nuclei displayed a characteristic morphology change, and the amount of apoptotic cells increased early and reached maximun about 39% after treatment with etoposide for 2 h. Nucleosomal DNA fragmentation was observed after treatment for 4 h. The morphological change of HL-60 cells, thus, occurred earlier than the appearance of DNA ladder. Total nuclear matrix proteins were analyzed by 2-dimensional gel electrophoresis. Differential expression of 59 nuclear matrix proteins was found in 4 h etoposide treated cells. Western blotting was then performed on three nuclear matrix acssociated proteins, PML, HSC70 and NuMA. The expression of the suppressor PML protein and heat shock protein HSC70 were significantly upregulated after etoposide treatment, while NuMA, a nuclear mitotic apparatus protein, was down regulated. These results demonstrate that significant biochemical alterations in nuclear matrix proteins take place during the apoptotic process.

Pyrrolidine Dithiocarbamate (PDTC) Attenuates Luteolin-Induced Apoptosis in Human Leukemia HL-60 Cells

Studies have indicated that flavonoid luteolin is a potential inhibitor of tumor cell proliferation and may function as an anticarcinogenic agent. Pyrrolidine dithiocarbamate (PDTC), a synthetic compound, may exhibit biphasic effects on apoptosis depending on the experimental context. Previously, we found that luteolin induced the activation of the proapoptotic proteins, such as Bad, Bid, and Bax, in HL-60 human leukemia cells. We also explored the modulatory effects and molecular mechanisms of PDTC on the cytotoxicity of luteolin in HL-60 cells;PDTC could interfere with luteolin’s ability to cleave poly(ADP-ribose)-polymerase (PARP) and DNA fragmentation of factor-45 (DFF-45). In the current study, we further investigated the effect of PDTC on the luteolin-induced death-receptor pathway and the cleavage of the Bcl-2 family members. We found that the combination of luteolin and PDTC increased the survival of the HL-60 cells such that PDTC inhibited both extrinsic and intrinsic pathways in luteolin-induced apoptosis.

Apoptosis of human leukemic HL-60 cells induced to differentiate by treatment with RA or DMSO

In present study we studied the effect of all-trans retinoic acid(ATRA) and dimethylsulfoxide (DMSO) on the induction of apoptosis in HL-60 cell line. Based on morphological changes by Hochest 33342 staining and identification of internucleosomal DNA cleavage by gel electrophoresis, we observed aberrant nuclear chromatin eondensation and ladder-like pattern of DNA degradation. Using Flow Cytometric method, we found sub-G1 peak in RA-treated HL-60 cells starting 5 to 6 d after the initiation of the treatment. However, such an obvious apoptotic peak was not identified in DMSO-differentiated cells. Combining the research accomplished before, our study approves further that apoptosis could be a common mode of death of terminally differentiated HL-60 cells.

Effect of Concurrent Use of rh-IL-3 and rh-GM-CSFon Apoptosis of HL-60 Cells Induced by Ara-C

The myeloid leukemic cell line HL-60 was studied by using DNA gel electrophoresis, flow cytomery, McAb C-myc, McAb Bc1-2 and CFU-L. From zero to 36 h,the apoptosis rates of 8 different phases and other indexes were observed. The results showed that with the prolonged time of drug incubation,apoptosis of HL-60 cells increased progressively. This effect can be enhanced obviously by rh-IL-3 and rh-GM-CSF. At the same time,the killed rate of leukemic cells by Ara-C induction was increased. C-myc expression was decreased and Bc1-2 expression did not display apparent change. Interestingly, the normal hemopoietic cells were not affected by these two kinds of cytokine. The theoretical basis was provided for concurrent use of rh-IL-3, rh-GM-CSF and cytotoxic drugs whose purpose is to elevate remission rate during the phase of induced remission of leukemia.

Effects of Concurrent Use of rh-IFN-γ and Curcumin on the Anti-proliferative Capacity of HL-60 Cells

To understand the effect of rh-IFN-γ on the ability of curcumin to kill HL-60 cells in vitro, the myeloid leukemic cell line HL-60 was studied by using cell culture. BrdU incorporation rate was examined by SABC, DNA content was determined by flow cytometry and apoptotic cell percentage was determined by TUNEL method. The results showed that curcumin inhibited proliferation of leukemic cells in a dose-dependent manner. When HL-60 cells were treated with 25 μmol curcumin for 24 h, the proliferative inhibitory rate was 43. 75±2. 00 %.This effect could be enhanced obviously by IFN-γ, the combined proliferative inhibitory rate increased to over 80 %. The 5-BrdU incorportion rate and the distribution of DNA content indicated that curcumin could arrest cells in the G1/G0 and G2/M phase of cell cycle. At the same time, the sub-G1 peak (apoptotic peak) appeared. After IFN-γ combined with curcumin, DNA synthesis rate decreased further. It showed a significant difference when compared with single drug group (Pr< 0. 05). Meanwhile, sub-G1 peak also increased. The percentage of TUNEL positive cells was aslo increased. It is concluded that IFN-γ can enhance the antiproliferative ability of curcumin against HL-60 cells.

Regulation of Histone Acetylation and Apoptosis by Trichostatin in HL-60 Cells

Summary: In order to examine the strong anticancer action and low toxicity of Trichostatin A (TSA), the effect of TSA was examined on the growth inhibition, acetylation of histone H_3 and apoptosis in HL-60 cells by employing MTT, immunocytochemical techniques, and Annexin-V-FITC/PI assay. Our results showed that TSA could inhibit proliferation of HL-60 cells in a time-and dose-dependent manner, and the IC_~50 at the 36th h was 100 ng/ml. The apoptosis-inducing effect of TSA on HL-60 cells was also time-and dose-dependent. But it didn't demonstrate apparent apoptosis induction in NPBMNCs within specific dose and time range. Both of the acetylation of histone H_3 in HL-60 cells and NPBMNCs increased significantly (P<0.05) after treated with 100 ng/ml TSA for 4 h. However, there was no significant differences between the two groups (P>0.05). It is concluded that TSA can inhibit growth and induce apoptosis of HL-60 cells in a time-and dose-dependent manner, and is able to selectively induce apoptosis in HL-60 cells but does not respond in NPBMNCs under the same conditions. The difference of TSA between HL-60 cells and NPBMNCs can't be explained by the regulation of histone acetylation.

EFFECTS OF ANTISENSE OLIGODEOXYNUCLEOTIDES ON EXPRESSION OF CASPASE-3 IN Γ-RADIATION INDUCED APOPTOTIC HL-60 CELLS

Objective To study the inhibitory effects of caspase-3 mRNA antisense oligodeoxynucleotides (ASODN) on expressions of caspase-3 and it's mRNA in γ-radiation induced apoptotic HL-60 cells, and screen the effective ASODN. Methods ASODN-1 and ASODN-2 targeting 5′-noncoding region and initial translation region of caspase-3 mRNA were respectively designed, synthesized and introduced into HL-60 cells by means of liposome-mediated transfection followed by 10Gy γ-radiation exposures. TUNEL assay was conducted to investigate the morphologic change and apoptotic percentage of HL-60 cells 18 h later. Immunocytochemical staining and one step RT-PCR were respectively performed to detect the expressions of caspase-3 and it's mRNA. Mismatched oligodeoxynucleotide (MODN) transfected and un-transfected HL-60 cells were taken as control. Results TUNEL assay found that the apoptotic percentages in ASODN-1 and ASODN-2 groups were significantly reduced compared with the control groups (P<0.01) when the final concentration of both ASODNs was ≥3μmol/L. Immunocytochemistry showed that caspase-3 positive cell percentages were reduced but the average gray values increased significantly compared with the control groups (P<0.01). RT-PCR showed expressions of caspase-3 mRNA was decreased after ASODN transfection. Furthermore, ASODN-1 proved more effective in inhibiting HL-60 cell apoptosis than ASODN-2 (P<0.01). Conclusion Caspase-3 mRNA ASODNs can prevent HL-60 cells from apoptosis induced by γ-radiation and reduce expression of caspase-3 and its mRNA. These effects are dose dependent in a certain range.

EFFECTS OF THE HYPERTHERMIA AND HARRINGTONINE ON TELOMERASE ACTIVITY OF HL-60 CELLS

Objective To understand the mechanism of the hyperthermia and harringtonine in purging of leukemia cells In Vitro. telomerase activity of HL-60 cells treated by hyperthermia ( 42℃ for one hour) and different concentrations of Harringtonine were investigated.Methods Using Telomeric Repeats Amplification Protocol (TRAP) and ELISA techniques to analyze the telomerase activity of HL-60 cells. Results Our results showed that harringtonine inhibited the telomerase activity of HL-60 cells in a dosage related manner. Moreover, the telomerase activity of HL-60 cells was significantly decreased after the hyperthermia treatment as compared with untreated cells.Conclusion The effect of the hyperthermia and Harringtonine on purging leukemia cells In Vitro may be mediated by down regulation of telomerase activity of tumor cells.

EFFECTS OF S86019, AN ACTIVE COMPONENT FROM PURALIA LOB AT A, ON CELL DIFFERENTIATION AND CELL CYCLE TRAVERSE OF HL-60 CELLS

The effects of S86019, an active component from Puralia lobata, on the induction of cell differentiation and cell cycle traverse of HL-60 cells were described. It was shown that cell proliferation of HL-60 cells was inhibited by S86019 in vitro. Under the action of S86019 the HL-60 cells were induced to differentiate into metamyelocytes, myelocytes and much matured cells with banded or segmented nucleus. Flow cytometry demonstrated that the cell population of HL-60 cells was blocked at G1 phase which resulted in the elevation of percentage of G1 cells and decrease of percentage of cells in S phase. Experimental results demonstrated that S86019 is an active inducer of cell differentiation in HL-60 cells.

Antioxidant attenuation of ROS-involved cytotoxicity induced by Paraquat on HL-60 cells

The cytotoxic effects of Paraquat, an herbicide refractory to treatment after intentional or accidental contact, were investigated on the human leukemia HL-60 cells. With the establishment of Paraquat injury model of HL-60 cells, trypan blue exclusion assaying was performed to have determined the effects of Paraquat-induced cytotoxicity on HL-60 cells in a concentration- dependent manner. Upon treatment with various concentrations of Paraquat, pronounced increase on the levels of intracellular production of O2?- and H2O2 was detected with employment of fluorescent probes. Indicative of the oxidative stress, levels of MDA and T-AOC were quantitated to have determined the causal role for Paraquat in subjecting HL-60 cells to oxidative damage. Based on this finding, effects of antioxidant enzymes including GSH, NAC, CAT and SOD on attenuating the Paraquat-induced oxidative damage on HL-60 cells were examined, aiming to identify the most effective antioxidant enzyme for alleviating the cytotoxicity induced by Paraquat. In conjunction with the determination of cytotoxicity exerted by all the antioxidant enzymes on HL-60 cells, GSH-with its least inherent cytotoxicity on HL-60 cells-was identified as a promising candidate ingredient for extenuating the Paraquat-induced cytotoxicity.

Effect of N’-Acetylindirubin on Proliferation, Apoptosis and Cell Cycle in Acute Myeloid Leukemia HL-60 Cells

Acute promyelocytic leukemia (APL) is a severe type of acute leukemia and the prognosis of patients was poor. Indirubin is the active constituent of the traditional Chinese medicine qingdai and an indoline anti-tumor drug. N’-Acetylindirubin is a novel indirubin derivative with better curative effect and less side effect. In this study, the effects of N’-Acetylindirubin on proliferation, apoptosis and cell cycle of acute myeloid leukemia cell line HL-60 was examined. The results demonstrated that N’-Acetylindirubin significantly induced apoptotic cell death in a dose and time-dependent manner and arrested cell cycle in G2/M in HL-60 cells. N’-Acetylindirubin also suppressed cyclin D1. This study suggests that N’-Acetylindirubin may serves as a potential chemopreventive agent for acute promyelocytic leukemia.

1-Chloromethyl-6,7-dimethoxy-3,4-dihydro-1H-isoquinoline-2-sulfonic acid amide, a derivative of tetrahydroisoquinoline, induces granulocytic differentiation of the human leukemic HL-60 cells via G0/G1 phase arrest

Tetrahydroisoquinolines are known to have various biological effects, including antitumor activity. This study investigated the effect of 1-chloromethyl-6, 7-dimethoxy-3, 4-dihydro-1H-isoquinoline-2-sulfonic acid amide (CDST), a newly synthesized anticancer agent, on cellular differentiation and proliferation in HL-60 cells. Differentiation and proliferation of HL-60 cells were determined through expression of CD11b and CD14 surface antigens using flow cytometry and nitroblue tetrazolium (NBT) assay, and through analysis of cell cycle using propidium iodide staining, western blot analysis and immunoprecipitation, respectively. CDST induced the differentiation of HL-60, as shown by increased expression of differentiation surface antigen CD11b (but no significant change in CD14 expression) and increased NBT-reducing functional activity. DNA flow cytometry analysis indicated that CDST markedly induced a G0/G1 phase arrest of HL-60 cells. Subsequently, we examined the expre-ssion of G0/G1 phase cell cycle-related proteins, including cyclin-dependent kinases (CDKs), cyclins and cyclin dependent kinase inhibitors (CKIs), during the differentiation of HL-60. The levels of CDK2, CDK6, cyclin E and cyclin A were decreased, whereas steady-state levels of CDK4 and cyclin D1 were unaffected. The expression of the p27Kip1 was markedly increased by CDST, but not p21WAF1/Cip1. Moreover, CDST markedly enhanced the binding of p27Kip1 with CDK2 and CDK6, resulting in the reduced activity of both kinases. Taken together, these results demonstrate that CDST is capable of inducing cellular differentiation and growth inhibition through p27Kip1 protein-related G0/G1 phase arrest in HL-60 cells.

大黄素对HL-60/ADR耐药细胞多药耐药逆转作用的研究

本研究旨在探讨大黄素(emodin)对人急性白血病HL-60/ADR耐药细胞多药耐药(multidrug resistance,MDR)逆转作用及其相应的作用机制。采用MTT法检测HL-60/ADR细胞对大黄素以及8种临床常用化疗药物的耐药性,比较大黄素联合化疗药物后对HL-60/ADR细胞耐药逆转效果,应用DNA倍体和DNA Ladder分析检测大黄素与阿霉素联合用药后细胞凋亡改变,RT-PCR和Western blot分别检测耐药相关基因和蛋白表达变化,流式细胞术检测大黄素处理后HL-60/ADR细胞内阿霉素荧光阳性率和柔红霉素平均荧光强度(MFI),激光共聚焦显微镜检测细胞内柔红霉素分布变化。结果表明:大黄素对HL-60/ADR耐药株和相应HL-60细胞敏感株的IC50值接近,分别为24.09±1.72μmol/L和23.18±0.87μmol/L,对阿霉素(ADR)、柔红霉素(DNR)、依托泊苷(VP16)、长春新碱(VCR)、阿糖胞苷(Ara-C)、高三尖杉酯碱(HHT)、米托蒽醌(MTZ)和吡柔比星(THP)呈现不同程度耐药。小剂量大黄素对8种药物耐药逆转倍数介于1.58-4.12之间,其中对ADR的耐药细胞逆转效果最好。大黄素与ADR联合用药组可见明显的亚二倍体凋亡峰和典型的DNA降解梯状带形成。与单药组比较,联合用药组MRP1、TOPOⅡβ、GSTπ、BCL-2耐药相关基因mRNA和蛋白表达水平下调明显,细胞内ADR和DNR蓄积水平增加,胞浆和胞核DNR分布增加,该作用与大黄素呈浓度依赖性。结论 :大黄素具有逆转HL-60/ADR细胞多药耐药作用,其作用机制可能与下调耐药相关基因表达水平、增加细胞内化疗药物蓄积和促进细胞凋亡作用有关。

大黄素抑制HL-60/ADR耐药细胞增殖和诱导凋亡的作用

本研究探讨中药大黄素(emodin)对人白血病耐药细胞株HL-60/ADR的增殖、凋亡影响及其相应的可能作用机制。采用MTT法绘制细胞生长曲线;集落培养法观察大黄素对HL-60/ADR克隆形成的影响;细胞周期分析、线粒体跨膜电位检测、Caspase-3酶活性检测、Annexin V FITC/PI法、TdT酶介导的原位缺口末端标记法(TUNEL)分析凋亡细胞;RT-PCR及Western blot法检测大黄素作用后不同时间段bcl-2、c-myc mRNA及Bcl-2、c-Myc、Caspase-3前体蛋白表达水平的变化。结果表明,大黄素对HL-60/ADR细胞增殖具有明显的抑制作用,呈时间和浓度依赖性。较低浓度大黄素即可抑制HL-60/ADR细胞集落形成,IC50值为5.79μmol/L。细胞周期分析显示,与对照组比较,40、80μmol/L浓度组细胞被阻滞于G0/G1期比率明显增高(p<0.01),G2/M期细胞比率降低(p<0.01),而20μmol/L浓度组细胞周期改变差异不具有显著性(p>0.05),各浓度组均检测到典型的亚二倍体峰(凋亡峰)。大黄素作用12小时HL-60/ADR细胞线粒体跨膜电位降低,Annexin V FITC/PI法检测到早期凋亡细胞,作用24小时caspase-3酶活性显著升高,作用48小时TUNEL法检测到晚期凋亡细胞,细胞凋亡率呈药物浓度依赖性。大黄素作用HL-60/ADR细胞不同时间段,bcl-2、c-myc mRNA和Bcl-2、c-Myc、Caspase-3前体蛋白表达水平均有不同程度下调,并呈时间依赖性。结论:大黄素能够有效抑制HL-60/ADR细胞增殖,并诱导其凋亡,bcl-2、c-myc表达水平下调,线粒体跨膜电位水平降低和caspase-3激活可能参与了该过程。

姜黄素与阿霉素联合应用对人白血病耐药细胞株HL-60/ADR的生长抑制影响

目的：研究姜黄素与阿霉素联合应用对人白血病多药耐药细胞株HL-60／ADR的生长抑制作用。方法：采用MTT法测定药物的体外杀伤作用，应用金氏公式进行联合用药效果分析。应用流式细胞术分析细胞周期和测定细胞内药物浓度。结果：姜黄素2～16μmol／L，阿霉素0．8～6．4μmol／L同时给药对HL-60／ADR细胞可产生单纯相加至增强的协同杀伤效果，对HL-60／ADR细胞周期的影响也有协同作用。序贯给药法中，先给姜黄素后给阿霉素结果为协同作用，先给阿霉素后给姜黄素实验结果为拮抗作用。结论：姜黄素与阿霉素同时用药可产生协同作用，可有效逆转多药耐药，HL-60／ADR细胞内ADR积聚增加可能是其原因之一；序贯联合用药仅产生单向协同作用。