OBJECTIVETo investigate the effect of bortezomib (Bor) alone or in combination with As(2)O(3) (ATO) and/or dexamethasone (DXM) on proliferation and apoptosis in KM3 human multiple myeloma cell line KM3.

METHODSKM3 cells were cultured with different concentrations of Bor and ATO and/or DXM in combination or Bor, ATO, DXM alone for different times. Cell proliferation was assayed by MTT assay, and IC(50) was calculated. Cell morphology was observed with light and electric microscopy. The agarose gel electrophoresis was used to evaluate DNA content, and the flow cytometry was used to exam Annexin V-FITC/PI stain.

RESULTSBor, ATO and DXM inhibited KM3 cell proliferation in a time-and dose-dependent manner with the IC(50) of 0.27, 3.10 and 8.01 micromol/L, respectively. The inhibition rate of KM3 cells by Bor plus ATO and DXM was significantly higher than Bor plus ATO or DXM \[(34.51 +/- 0.51)% vs (25.39 +/- 0.90)% and (34.51 +/- 0.51)% vs (23.80 +/- 0.78)% respectively\]. Typical morphology for apoptosis and DNA ladder were observed in KM3 cell treated with 0.25 micromol/L Bor for 48 h, by Annexin V positivity. The apoptosis rate induced by Bor plus both ATO and DXM was higher than that induced by Bor plus DXM.

CONCLUSIONBor can inhibit the proliferation and induce apoptosis of KM3 cells. Bor enhances the inhibitory effect of ATO and DXM on the growth of KM3 cell. ATO enhances the apoptosis effects of Bor and DXM on KM3 cells.

Apoptosis ; drug effects ; Boronic Acids ; pharmacology ; Bortezomib ; Cell Line, Tumor ; Dexamethasone ; pharmacology ; Humans ; Multiple Myeloma ; metabolism

OBJECTIVETo investigate the effect of bortezomib (Bor) alone and in combination with arabinoside (Ara-C) on proliferation and apoptosis of leukemia cell line K562.

METHODSK562 cells were treated with 20 nmol/L Bor and 0.2 microg/ml Ara-C alone and in combination for 48 h. MTT was used to study the inhibitory effects on cell growth and the apoptosis rate was analysed by flow cytometry. After K562 cells treated with 20 nmol/L Bor or 0.2 microg/ml Ara-C for 6 h, the activity of NF-kappaB was analyzed by SP immunohistochemistry and cell cycle by flow cytometry.

RESULTSThe inhibition and apoptosis rates of K562 cells in combination groups were higher than those in the two single treatment groups (P < 0.01), especially in the combined treatment group in which K562 cells were treated first with Ara-C for 6 h then with Bor combined,the inhibition and apoptosis rates were the highest [(81.5 +/- 4.0)% and (29.2 +/- 3.1)%, respectively] (P < 0.01). In the other two combined groups in which the cells were treated with Bor for 6 h then with Ara-C combined, or treated with the two drugs simultaneously, the inhibition and apoptosis rates were (54.1 +/- 4.2)% and (18.7 +/- 3.5)%, and (66.2 +/- 2.8)% and (21.1 +/- 2.2)%, respectively. Treatment of K562 cells with 20 nmol/L Bor for 6 h, the activity of NF-kappaB was decreased significantly, and the cells were apparently arrested in G(2)/M phase, and treatment with 0.2 microg/ml Ara-C in the same manner, the activity of NF-kappaB was increased significantly, and the cells were apparently arrested in G(1) phase.

CONCLUSIONSBor can effectively inhibit K562 cell proliferation, and induced its apoptosis. This effect was enhanced significantly when in combination with Ara-C. Pretreatment of K562 cells with Ara-C lead to the increased activity of NF-kappaB and the fraction of G(1) phase cells.

Apoptosis ; drug effects ; Boronic Acids ; pharmacology ; Bortezomib ; Cell Proliferation ; drug effects ; Humans ; K562 Cells ; Pyrazines ; pharmacology

OBJECTIVETo investigate the synergistic anti-multiple myeloma (MM) effect of 2-methoxyestradiol (2-ME2) and bortezomib, and explore the relationship between this effect and blockade of aggresomes formation by 2-ME2.

METHODSFour MM cell lines RPMI-8226, NCI-H929, U266 and SKO-007 were used for study. Immunoflourescent anti-ubiquitin and Hoechst 33342 staining were used to examine aggresome-positive cells and apoptotic cells, respectively. Isobolographic analysis was used for determination of synergy.

RESULTS(1) Quantitative assay showed that in the absence of bortezomib, only 6.6% - 8.9% of MM cells were aggresome-positive, but the percentage was increased to 71.9%-83.4% after treatment with bortezomib at IC(20) concentration for 24 h. Aggresome-positive cells with immunoreactivity to anti-ubiquitin were detected in almost all non-apoptotic cells, but not in apoptotic cells. (2) Treatment in a definite range of concentrations bortezomib plus 2-ME2 led to MM cell apoptosis compared with each agent alone and the significantly synergistic effect confirmed by isobolographic analysis. (3) Combination of bortezomib and 2-ME2 increased the apoptotic cells aggresome-negative cells (ANK) and decreased the non-apoptotic cells in aggresome positive cells (APC). In RPMI8226 and U266 cells, the apoptotic cells in ANC increased from (14.5 +/- 2.0)% and (20.1 +/- 2.9)% to (80.7 +/- 6.9)% and (71.6 +/- 6.2)%, and the non-apoptotic cells in APC decreased from (75.3 +/- 5.7)% and (69.1 +/- 8.6)% to (13.8 +/- 3.8)% and (19.5 +/- 4.2)%, respectively, in combined group and bortezomib alone group.

CONCLUSIONBortezomib-induced aggresomes have a protective function for MM cells and combination of bortezomib with 2-ME2 induced a synergistic cytotoxicity to the cells.

Apoptosis ; drug effects ; Boronic Acids ; pharmacology ; Bortezomib ; Cell Line, Tumor ; Humans ; Multiple Myeloma ; metabolism ; Pyrazines ; pharmacology

OBJECTIVETo explore the effects of BTZ plus HHT on proliferation and apoptosis of K562 cells, and to clarify the relationship between the mechanism inderlying the effect of BTZ plus HHT on K562 cells and BCL-2, BAX, MCL-1 proteins.

METHODSThe K562 cells were divided into 4 groups by different treatment: BTZ(20 nmol/L), HHT(40 ng/ml), BTZ(20 nmol/L)+HHT(40 ng/ml) and control. The proliferation inhibition rates of K562 cells in each group were detected by using MTT, and the early apoptosis rates of K562 cells in each group were assayed by using flow cytometry with Annexin V-FITC/PI staining. The proteins level of BCL-2, BAX and MCL-1 in each group were examined by using Western blot.

RESULTSThe inhibition rate of K562 cell proliferation in combined group was higher than that in BTZ, HHT alone group(P<0.01). The early apoptosis rate of K562 cells in combined group was increased significantly in comparison with BTZ and HHT alone group(P<0.05). The BCL-2 protein level of K562 cells in combined group was significantly lower than that in BTZ and HHT alone group(P<0.05). BAX protein level of K562 cells in combined group was higher than that in BTZ and HHT alone group(P<0.05). The Orders of the MCL-1 protein level of K562 cells in 4 groups were BTZ>Control>BTZ plus HHT>HHT(P<0.05 ).

CONCLUSIONThe combination of BTZ and HHT exerts the synergistic effect of anti-proliferative activity and induces apoptosis against K562 cells in vitro. The combination can induce apoptosis of K562 cells via suppression of BCL-2 protein and up-regulation of BAX protein. HHT can increase the sensitivity of K562 cells to BTZ by down-regulating the expression of MCL-1 protein.

Apoptosis ; Bortezomib ; pharmacology ; Cell Proliferation ; Harringtonines ; pharmacology ; Homoharringtonine ; Humans ; K562 Cells

This study was aimed to explore the effect of bortezomib and low concentration cytarabine (Ara-C) on proliferation and apoptosis in U937 cell line and its mechanism. The proliferation and apoptosis of U937 cells treated with bortezomib (10 nmol/L) and(or) Ara-C (50 nmol/L) were observed by cell count, cell morphology, flow cytometry and Western blot. The results showed that bortezomib and Ara-C alone inhibited U937 cell proliferation. The inhibitory effect was enhanced by combination of these two drugs, the inhibitory rates of U937 cell proliferation were (55.00 ± 2.81)% and (70.02 ± 3.33)% after treatment for 24 h and 48 h, respectively. Bortezomib and Ara-C synergistically induced apoptosis and decreased mitochondrial membrane potential in U937 cells. The percentage of Rhodamin123 positive cells was (38.70 ± 1.54)%. Bortezomib and Ara-C also synergistically induced activation of caspase-9, caspase-8 and caspase-3. It is concluded that the bortezomib and low concentration Ara-C synergistically induced apoptosis in U937 cells, mainly through mitochondrial pathway, and possibly through death receptor pathway.
Apoptosis ; drug effects ; Boronic Acids ; pharmacology ; Bortezomib ; Cell Cycle ; drug effects ; Cytarabine ; pharmacology ; Humans ; Pyrazines ; pharmacology ; U937 Cells

Apoptosis ; drug effects ; Boronic Acids ; pharmacology ; Bortezomib ; Hepatic Stellate Cells ; cytology ; drug effects ; Protease Inhibitors ; pharmacology ; Pyrazines ; pharmacology

OBJECTIVE: To investigate the effects of chidamide combined with anti-myeloma drugs on the proliferation and apoptosis of myeloma cells. METHODS: The proliferation inhibition of the cells was detected by CCK-8 method, and flow cytometry was used to detected the apoptosis of the cells. RESULTS: Chidamide could inhibit the proliferation of myeloma cells and promote the apoptosis of primary myeloma plasma cells in a time- and dose-dependent manner (P<0.05). In NCI-H929 cell line, chidamide combined with low-dose bortezomib and lenalidomide showed synergistic effect, while combined with dexamethasone and pomalidomide showed additive effect. In MM.1s cell line, chidamide combined with bortezomib, dexamethasone, lenalidomide and pomalidomide all showed synergistic effects. CONCLUSION Chidamide inhibits proliferation of myeloma cells in a time- and dose-dependent manner and promotes apoptosis of primary myeloma plasma cells. Furthermore, it can enhance the inhibitory effect of anti-myeloma drugs.
Aminopyridines ; Apoptosis ; Benzamides ; Bortezomib/pharmacology* ; Cell Line, Tumor ; Cell Proliferation ; Humans ; Multiple Myeloma ; Pharmaceutical Preparations

OBJECTIVETo investigate the growth inhibitory effect of Imatinib derivative TEB-415 on various multiple myeloma (MM) cell lines, such as U226, H929, RPMI8226, MM1R and MM1S.

METHODSTEB-415, a derivative of Imatinib was synthesized by modifying the chemical structure of Imatinib. MM cell lines (U226, H929, RPMI8226, MM1R and MM1S) were treated with TEB-415, Imatini and Bortezomib of various concentrations. Cells were grown for 72 hours and the growth rate was measured by CCK-8 method, cell morphology was observed and the IC50 was calculated.

RESULTSTEB-415 could inhibit H929 and RPMI8226 growth significantly. When the concentration of TEB-415 was <0.1 nmol/L, >50% H929 cells died. The IC50 of Imatinib was 0.123 mol/L while the IC50 of Bortezomib was 0.03 nmol/L. In RPMI8226 cell line, when the concentration of TEB-415 was 11.9 mol/L, more than 50% of cells died. In contrast, when RPMI8266 were treated with Imatinib of the concentration of 12.8 mol/L, cells grew normally.

CONCLUSIONIn comparison to Imatinib, TEB-415, a derivative of Imatinib, can kill H929 MM cells much effectively, its effecacy is only inferior to Bortezomib. RPMI8226, an MM cell line is insensitive to Imatinib, but still sensitive to TEB-415 and its growth can be inhibited by TEB-415.

Apoptosis ; Bortezomib ; Cell Line, Tumor ; drug effects ; Humans ; Imatinib Mesylate ; analogs & derivatives ; pharmacology ; Multiple Myeloma ; pathology

OBJECTIVE: To study the effect of PX-12 on apoptosis of multiple myeloma (MM) cell line induced by bortezomib. METHODS: MM cell line H929 cells were divided into PX-12 group, bortezomib group, combination group, and control group. 5.0 μmol/L PX-12, 20 nmol/L bortezomib, combination of the two drugs, and DMSO were given to the above mentioned group, respectively. After culture for 24, 48, and 72 hours, the changes of cell viability were observed, the MM cell activity was detected by MTT method, and the cell cycle distribution and apoptosis of each group was detected by flow cytometry. The intracellular ROS level was measured by H RESULTS: MTT assay showed that after culture for 72 hours, the activity of H929 cells in PX-12 group (P<0.05) and bortezomib group (P<0.01) was significantly lower than that in the control group, while that in the combination group was decreased most significantly (P<0.01). After culture for 48 hours, cells in G1 phase in PX-12 group was decreased to 40%, while cells in S phase and G CONCLUSION PX-12 can increase the apoptosis of MM cell line H929 induced by bortezomib, which may be caused by increasing of ROS level.
Apoptosis ; Bortezomib/pharmacology* ; Cell Line, Tumor ; Cell Proliferation ; Humans ; Multiple Myeloma

OBJECTIVE: To investigate the effects of autophagy inhibitor ROC-325 and its combination with bortezomib on the proliferation, apoptosis and autophagy of multiple myeloma cell lines. METHODS: Multiple myeloma cells were treated with ROC-325 at different concentration. The cell proliferation was detected by CCK-8. Apoptosis was determined by Caspase-3/7 and Caspase-9 activity assays. Autophagy was detected by monodansylcadaverine staining. The apoptosis-related proteins (PARP and Caspase-3) and autophagy-related proteins (P62, Beclin-1, and LC3A/B) were analyzed by Western blot. The combined effect with bortezomib on bortezomib-resistant cell line was detected by CCK-8. RESULTS: ROC-325 inhibited the proliferation of RPMI 8226, RPMI 8226-BTZ100, U266 and IM9 cells in a dose-dependent manner (r=-0.8275, r=-0.9079, r=-0.9422, r=-0.9305), the 72 h IC CONCLUSION ROC-325 can inhibit the proliferation, induce the apoptosis of myeloma cells through the mitochondrial pathway, inhibit the autophagy of myeloma cells by affecting the fusion of autophagosomes and lysosomes, and overcome bortezomib resistance by the combination of ROC-325 with bortezomib.
Apoptosis ; Autophagy ; Bortezomib/pharmacology* ; Cell Line, Tumor ; Cell Proliferation ; Humans ; Hydroxychloroquine/analogs & derivatives* ; Multiple Myeloma