OBJECTIVE: To investigate the mechanism of circular RNA RAD18 (CircRAD18 ) in regulating daunorubicin (DNR) resistance in acute myeloid leukemia (AML) cells through the miR-185-5p/hepatoma-derived growth factor ( HDGF) axis. METHODS: Real-time fluorescence quantitative PCR and immunoblotting were applied to detect the expression of CircRAD18 , miR-185-5p, and HDGF in human AML cell lines HL-60, U937, and human AML drug-resistant cell line KG1a. KG1a cells were cultured in vitro and randomly divided into control group, DNR group, DNR+negative control group, DNR+CircRAD18 knockdown group, and DNR+CircRAD18 knockdown+miR-185-5p inhibitor group. After transfection, real-time fluorescence quantitative PCR and immunoblotting were applied to detect the expression of CircRAD18 , miR-185-5p, and HDGF of cells, CCK-8 method and Ki-67 immunofluorescence staining were applied to detect cell proliferation, flow cytometry was applied to detect cell apoptosis, and immunoblotting was applied to detect the expression of cell proliferation, apoptosis and drug resistance related proteins in each group. The double luciferase reporter gene experiment was applied to detect the targeting regulation of CircRAD18 on miR-185-5p, and miR-185-5p on HDGF in KG1a cells. RESULTS: Compared with HL-60 and U937 cells, the expression of CircRAD18 , and HDGF mRNA and protein in KG1a cells increased (all P <0.05), while miR-185-5p decreased ( P <0.05). Compared with the control group, the CircRAD18 expression, HDGF mRNA and protein expression, cell viability, proliferation rate, and PCNA, Bcl-2, BCRP, and P-gp protein expression in the DNR+CircRAD18 knockdown group decreased (all P <0.05), while miR-185-5p expression, apoptosis rate, and Bax protein expression increased (all P <0.05). There were no obvious changes in all indicators of cells in the DNR group compared with control group ( P >0.05). Compared with the DNR group, the CircRAD18 expression, HDGF mRNA and protein expression, cell viability, proliferation rate, PCNA, Bcl-2, BCRP, and P-gp protein expression in the DNR+CircRAD18 knockdown group decreased (all P < 0.05), while miR-185-5p expression, apoptosis rate, and Bax protein expression increased (all P < 0.05). There were no obvious changes in all indicators of cells in the DNR+negative control group compared with DNR group (P >0.05). Compared with the DNR+CircRAD18 knockdown group, the HDGF mRNA and protein expression, cell viability, proliferation rate, PCNA, Bcl-2, BCRP, and P-gp protein expression in the DNR+CircRAD18 knockdown+miR-185-5p inhibitor group increased (all P < 0.05), while miR-185-5p expression, apoptosis rate, and Bax protein expression decreased (all P < 0.05). CircRAD18 was able to target and down-regulate the expression of miR-185-5p in KG1a cells, and miR-185-5p was able to target and down-regulate the HDGF expression. CONCLUSION Knocking down CircRAD18 can reduce HDGF expression by up-regulating miR-185-5p, thereby weakening DNR resistance in AML cells, inhibiting KG1a cell proliferation under DNR treatment, and promoting apoptosis.
Humans ; MicroRNAs/metabolism* ; Leukemia, Myeloid, Acute ; Daunorubicin/pharmacology* ; Drug Resistance, Neoplasm ; Apoptosis ; RNA, Circular ; Intercellular Signaling Peptides and Proteins/metabolism* ; Cell Proliferation ; HL-60 Cells ; Cell Line, Tumor

OBJECTIVE: To investigate the effect and mechanism of artesunate (ARTS) combined with cytarabine(Ara-C) and/or daunorubicin (DNR) on the proliferation and apoptosis of MV4-11 human mixed-lineage leukemia rearranged（MLL-r） acute myeloid leukemia (AML) cell line. METHODS: CCK-8 assay was used to detect the proliferation effect of individual or in combination of ARTS, DNR, Ara-C on MV4-11 cells. The IC₅₀ of ARTS, DNR and Ara-C was calculated separately. The cell apoptosis and expression of receptors DR4 and DR5 were detected by flow cytometry. Western blot was used to detect the expression of Caspase-3 and Caspase-9 in each groups. RESULTS: The inhibition effect of ARTS, Ara-C and DNR on the proliferation of MV4-11 were all dose-dependently (r=0.99, 0.90 and 0.97, respectively). The IC₅₀ of ARTS, Ara-C and DNR on MV4-11 for 48 hours were 0.31 μg/ml, 1.43 μmol/L and 22.47 nmol/L, respectively. At the dose of ARTS 0.3 μg/ml， Ara-C 1.0 μmol/L and DNR 15 nmol/L, the proliferation rate for 48 hours of the tri-combination treatment was significantly lower than that of the bi-combination treatment, while both were significantly lower than that of the individual treatment (all P＜0.05). In terms of bi-combination treatment, the cells proliferation rate for 48 hours of the ARTS+Ara-C group was significantly lower than that of the ARTS+DNR group, while both were significantly lower than that of the Ara-C+DNR group (all P＜0.05). The cooperativity index (CI) of bi- and tri-combination treatment were all less than 1. After 48 hours of drug action, the cell apoptosis rate of the ARTS+DNR+Ara-C group was significantly higher than that of the Ara-C+DNR group, while both were significantly higher than that of the ARTS+DNR group (all P＜0.05). Meanwhile, the was no statistical difference between the cells apoptotic rate of the ARTS+DNR+Ara-C group and the ARTS+Ara-C group (P>0.05). The expression of DR4 and DR5 also showed no difference between control group and drug group. Compared with the DNR+Ara-C group, the expressions of Caspase-3 were significantly down-regulated in both the ARTS+DNR+Ara-C group and the ARTS+Ara-C group (all P＜0.05). The down-regulation of Caspase-3 expression was the most significantly in the combination group of three drugs, while the Caspase-9 expressions in different groups showed no apparent change. CONCLUSION The in vitro study showed that tri-combination of ARTS+Ara-C+DNR and bi-combination of ARTS+Ara-C could inhibit the proliferation and promote apoptosis of MV4-11 cell line. The inhibition effect of these two combinations were significantly superior to that of the traditional Ara-C+DNR treatment. The mechanism underlying this finding may be identified by the down regulation of Caspase-3, while no altered expression was observed of Caspase-9, DR4 and DR5.
Humans ; Cytarabine/pharmacology* ; Daunorubicin/pharmacology* ; Caspase 3 ; Caspase 9 ; Artesunate/pharmacology* ; Leukemia, Myeloid, Acute ; Apoptosis ; Cell Line

OBJECTIVETo investigate the protect effects of sodium ferulate (SF) on the daunormbicin(DNR-induced cardiotoxicity in juvenile rats.

METHODSForty male juvenile SD rats were randomly divided into control group (Control), daunorubicin group (DNR), sodium ferudate treatment group (DNR + SF), sodium ferudate group (SF) (n = 10) . Juvenile rats were intraperitoneally treated with DNR (2.5 mg/kg every week for a cumulative dose of 10 mg/kg) preparation immature myocardial injury model in presence with SF (60 mg/kg) oral treat- ment for 25 days. The left ventricular pressure and its response to isoproterenol were measured using left ventricular catheter. Rat myocardium myocardial pathology specimens and ultrastructure changes were also observed. The expression of cardiac Troponin I (cTNI) was detected by Western blot and RT-PCR. Results: SF treatment could inhibit the decreasing of heart rates induced by DNR damage (P < 0.05); it could increase the left ventrivular end diastolic pressure(LVEDP), heart rate, the maximal left ventrivular systolic speed(LVP + dp/dtmax) and the maximal left ventrivular diastolic speed (LVP-dp/dtmax) responding to isoproterenol stimulation(P < 0.01); SF also could improve the myocardial ultrastructure injuries and inhibit the decreasing of cTNI expression caused by DNR damages (P < 0.05).

CONCLUSIONSF treatment could alleviate the decreasing of cardiac reservation induced by DNR damages in juvenile rats, which might be related to its reversing the effects on the cardiac systolic and diastolic function injuries and its inhibiting effects on the decreasing of cTNI expression caused by DNR. The mechanism of SF preventing daunorubicin-induced cardiotoxicity in juvenile rats is relevant to inhabited cardiac Troponin I expression.

Animals ; Blood Pressure ; Cardiotoxicity ; drug therapy ; Coumaric Acids ; pharmacology ; Daunorubicin ; toxicity ; Heart ; physiopathology ; Heart Rate ; Isoproterenol ; Male ; Myocardium ; pathology ; Protective Agents ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Troponin I ; metabolism

The aim of this study was to observe the inhibitory effect of daunorubicin on KG1a cells and the expression of Eps8 which is a novel tumor-associated antigen with its full name epidermal growth factor receptor pathway substrate 8 (Eps8), and to explore the effect of daunorubicin on Eps8 expression in KG1a cells at mRNA and protein levels. The KG1a cells were treated with different concentration of daunorubicin for 24, 48, 72 h, then trypan blue staining was used to detect the inhibitory rate of KGla cells, RQ-PCR and Western blot were used to detect Eps8 mRNA and Eps8 protein expression. The results showed that daunorubicin inhibited the proliferation of KG1a cells in a dose and time dependent manner (r = 0.983, P < 0.01). Daunorubicin could reduce the mRNA and protein levels of Eps8 expression in dose and time dependent manners in KG1a cells (r = 0.979, P < 0.05). It is concluded that with the increasing of concentration and time of daunorubicin acting on KG1a cells, the cell proliferative inhibitory effect increased and the expression of Eps8 decreased, suggesting that the inhibitory effect of daunorubicin on KG1a cell proliferation is realized through downregulation of Eps8 expression.
Adaptor Proteins, Signal Transducing ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Daunorubicin ; pharmacology ; Humans

Azacitidine ; administration & dosage ; analogs & derivatives ; pharmacology ; Cell Proliferation ; drug effects ; Daunorubicin ; administration & dosage ; pharmacology ; HL-60 Cells ; Humans ; PTEN Phosphohydrolase ; metabolism

The purpose of this study was to investigate the effect of magnetic nanoparticle of Fe3O4 combined with daunorubicin on lymphoma cell line Raji. The Raji cells were cultured with Fe3O4-magnetic nanoparticle and daunorubicin polymerized by means of mechanical absorption, the cell viability was detected by MTT and trypan-blue exclusion; the apoptosis was detected by flow cytometry, the expressions of P53 and P65 are measured by Western blot. The results showed that raji cell proliferation rate was dramatically inhibited by daunorubicin and MNP-Fe3O4-DNR in concentration-and time-dependent manners, there was significant difference in OD (p < 0.05) between these 2 groups. The apoptotic rate was correlated with time and there was significantly different between these 2 groups (p = 0.05).Western blot showed that the grey value in daunorubicin and MNP-Fe3O4-DNR were 2.52 ± 0.32, 2.08 ± 0.39 in P65 and 0.685 ± 0.144, 0.870 ± 0.091 in P53 respectively (p < 0.05). It is concluded that the combination treatment of MNP-Fe3O4 and daunorubicin efficiently inhibits growth and induces apoptosis in Raji cell line, while the activation of P53 and down-regulation of NF-κB may play important roles.
Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Daunorubicin ; pharmacology ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; Ferric Compounds ; pharmacology ; Gene Expression Regulation, Neoplastic ; Humans ; Magnetics ; Nanoparticles ; Transcription Factor RelA ; metabolism ; Tumor Suppressor Protein p53 ; metabolism

This study was aimed to investigate the relevance of nilotinib in combination with tetrandrine (Tet) on reversing multidrug resistance and inducing apoptosis of K562/A02 cell line and its mechanism. Methyl-thiazol tetrazolium (MTT) assay was employed to examine the pharmacological effect of nilotinib or Tet alone on K562/A02 cell line, the IC(50) of daunorubicin (DNR) on K562/A02 cell line treated with nilotinib and Tet was calculated; the flow cytometry (FCM) was employed to detect the apoptosis rate of K562/A02. The expression of bax/survivin mRNA was determined by RT-PCR, and the expression of bax/survivin protein was assayed by Western blot. The results showed that after being treated by 5 nmol/L nilotinib or 1.0 µml/L Tet for 48 hours, IC(50) of DNR to K562/A02 was 5.71 ± 0.72 mg/L or 6.52 ± 0.43 mg/L, respectively, while in their combined treatment, IC(50) decreased to 3.12 ± 0.13 mg/L. Nilotinib or Tet alone could increase DNR-inducing apoptosis rate of K562/A02 cell, while the apoptosis rate of K562/A02 increased remarkably in combination treatment of nilotinib with Tet. After being treated with 5 nmol/L nilotinib or 1.0 µml/L Tet alone for 48 hours, the expressions of bax mRNA and BAX protein was up-regulated, while both effects were more obvious in combination treatment of nilotinib with Tet. Treatment with 5 nmol/L nilotinib or 1.0 µmol/L Tet alone for 48 hours down-regulated the expression of survivin mRNA and its protein, while treatment of nilotinib in combination with Tet had more significant effect on down-regulation of their expression. It is concluded that the K562/A02 cells are resistant to DNR, nilotinib or Tet alone both can partially reverse resistance of K562/A02 cells to DNR, increase the apoptosis rate of K562/A02 cells. Combination of nilotinib with Tet shows obvious synergistic action, mechanism of which may associate with up-regulation of bax mRNA and BAX protein expressions and down-regulation of survivin mRNA and its protein expressions.
Apoptosis ; drug effects ; Benzylisoquinolines ; administration & dosage ; pharmacology ; Daunorubicin ; pharmacology ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; Gene Expression Regulation, Leukemic ; Humans ; Inhibitor of Apoptosis Proteins ; genetics ; K562 Cells ; Pyrimidines ; administration & dosage ; pharmacology ; bcl-2-Associated X Protein ; genetics

The aim of this study was to investigate the potential benefit of combination therapy with 5-bromotetrandrine (5-BrTet) and daunorubicin (DNR) on chronic leukemia. The apoptosis of K562/A02 cells treated by DNA, BrTet and BrTet combined with DNR for 48 hours was detected by flow cytometry; the expressions levels of survivin mRNA and protein K562/A02 cells treated by DNR, BrTet and BrTet combined with DNR and in untreated K562 cells for 48 hours were measured by RT-PCR and Western blot respectively. The results showed that the combination of BrTet with DNR increased apoptotic rate of K562/A02, down-regulated the expression levels of survivin mRNA and protein in K562/A02 cells as compared with blank control and cells treated by BrTet or DNR alone, the survivin expression in K562/A02 cells was higher than that in K562 cells. It is concluded that the combination of BrTet with DNR can effectively reverse the multidrug resistance of K562/A02 cells, promote the apoptosis of K562/A02 cells, the mechanism of which may be related with down-regulation of survivin expression. Survivin may be a target for the treatment of MDR in hematopoietic malignancies.
Apoptosis ; drug effects ; genetics ; Benzylisoquinolines ; pharmacology ; Daunorubicin ; pharmacology ; Drug Resistance, Multiple ; genetics ; Drug Resistance, Neoplasm ; genetics ; Gene Expression Regulation, Leukemic ; Humans ; Inhibitor of Apoptosis Proteins ; genetics ; K562 Cells

The aim of this study was to investigate the effect of sorafenib combined with daunorubicin on leukemic k562 cell line. The inhibitory effect of sorafenib alone and its combination with daunorubicin on K562 cell proliferation was detected by MTT method; the synergistic effect was measured by CDI (coefficient of drug interaction); the apoptosis of K562 cells was observed by flow cytometry with Hoechst 33258 staining. The results showed that the sorafenib alone or its combination with daunorubicin could significantly inhibit K562 cell proliferation and the combination of both drugs displayed synergistic effect on K562 cells, meanwhile the apoptotic cells increased. It is concluded that the combination of sorafenib and daunorubicin has a obviously synergistic inhibitory effect on leukemic cell line K562.
Apoptosis ; drug effects ; Benzenesulfonates ; pharmacology ; Daunorubicin ; pharmacology ; Drug Synergism ; Humans ; K562 Cells ; Niacinamide ; analogs & derivatives ; Phenylurea Compounds ; Pyridines ; pharmacology

Mesenchymal stem cells (MSC) are important cellular component of the bone marrow microenvironment in supporting hemopoiesis. Li J et al reported previously that MSCs are resistant to chemotherapy commonly used in hematologic malignancies but are relatively sensitive to anti-microtubule agents. However, the response of MSCs to other chemotherapeutic agents commonly used in solid tumour settings remains unknown. This study was purposed to evaluate the acute direct effects of 4 individual chemotherapeutic agents on human MSCs (hMSC), including cisplatin, topotecan, daunorubicin and hydroxyurea. Using an in vitro culture system, the chemosensitivity of hMSC was determined by XTT assay and compared with NB-4 cells and normal peripheral blood mononuclear cells (PBMNC). The recovery of cell numbers following exposure to chemotherapeutic agents and apoptosis induced by chemotherapy in hMSC were evaluated. The results showed that although hMSCs were more resistant to the 4 agents above mentioned than NB-4 cells, they were sensitive to topotecan, cisplatin and daunorubicin than PBMNCs. The IC₅₀ values of hMSCs for topotecan, cisplatin, hydroxyurea and daunorubicin were 636, 24.8, > 20 and 2.4 times of those of NB-4 cells respectively. The IC₅₀ values of human PBMNCs for topotecan, cisplatin and daunorubicin were > 27, 1.9 and 1.4 times of those of hMSCs respectively. Reduction of cell number was observed in hMSCs treated with the 4 drugs in clinically relative concentrations. Sustained suppression in hMSCs was observed following 3 days exposure to the 4 agents. It is concluded that the cisplatin, topotecan, daunorubicin and hydroxyurea alone can induce apoptosis of hMSCs and exert persistent suppressive effect on the proliferation of hMSCs even with short term exposure.
Antineoplastic Agents ; pharmacology ; Bone Marrow Cells ; cytology ; drug effects ; Cells, Cultured ; Cisplatin ; pharmacology ; Daunorubicin ; pharmacology ; Humans ; Hydroxyurea ; pharmacology ; Inhibitory Concentration 50 ; Mesenchymal Stromal Cells ; cytology ; drug effects ; Topotecan ; pharmacology