CUDC-101 as a dual-target inhibitor of EGFR and HDAC enhances the anti-myeloma effects of bortezomib by regulating G2/M cell cycle arrest / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

CUDC-101, an effective and multi-target inhibitor of epidermal growth factor receptor (EGFR), histone deacetylase (HDAC), and human epidermal growth factor receptor 2 (HER2), has been reported to inhibit many kinds of cancers, such as acute promyelocytic leukemia and non-Hodgkin's lymphoma. However, no studies have yet investigated whether CUDC-101 is effective against myeloma. Herein, we proved that CUDC-101 effectively inhibits the proliferation of multiple myeloma (MM) cell lines and induces cell apoptosis in a time- and dose-dependent manner. Moreover, CUDC-101 markedly blocked the signaling pathway of EGFR/phosphoinositide-3-kinase (PI3K) and HDAC, and regulated the cell cycle G2/M arrest. Moreover, we revealed through in vivo experiment that CUDC-101 is a potent anti-myeloma drug. Bortezomib is one of the important drugs in MM treatment, and we investigated whether CUDC-101 has a synergistic or additive effect with bortezomib. The results showed that this drug combination had a synergistic anti-myeloma effect by inducing G2/M phase blockade. Collectively, our findings revealed that CUDC-101 could act on its own or in conjunction with bortezomib, which provides insights into exploring new strategies for MM treatment.

Effect of Celastrol Based on IRAK4/ERK/p38 Signaling Pathway on Proliferation and Apoptosis of Multiple Myeloma Cells / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of celastrol on the proliferation and apoptosis of human multiple myeloma (MM) cell lines, reveal the relationship between IRAK4/ERK/p38 signaling pathway and celastrol regulating the proliferation and apoptosis of H929 and ARP-1 cells, and explore whether celastrol combined with bortezomib has synergistic effect. @*METHODS@#CCK-8 method was used to detect the viability of MM cell lines H929 and ARP-1 treated by different concentrations of celastrol, bortezomib, and their combination, and the synergistic effect was determined by Kim's formula. The apoptosis rate of H929 cells and necrosis rate of ARP-1 were detected by Annexin V/PI method. The expression of key proteins and apoptosis proteins in IRAK4/ERK/p38 signaling pathway were detected by Western blot. @*RESULTS@#Celastrol could significantly inhibit the proliferation of H929 and ARP-1 cells (r=0.9018, r=0.9244) and induce apoptosis in a time-dependent manner. Compared with the control group, celastrol could significantly up-regulate the expression of PARP and cleaved caspase-3 while down-regulate the expression of p-IRAK4, p-ERK, and p-p38 in H929 and ARP-1 cells. Celastrol and bortezomib alone inhibited the proliferation of H929 and ARP-1 cells. Compared with celastrol and bortezomib alone, their combination had lower cell survival rate and higher apoptosis rate (P<0.05). @*CONCLUSION@#Celastrol can inhibit the proliferation and promote the apoptosis of H929 and ARP-1 cells, which may be related to inhibiting the phosphorylation of IRAK4 and blocking the activation of IRAK4/ERK/p38 signaling pathway. Celastrol combined with bortezomib has synergistic effect, which can more effectively inhibit the proliferation and induce apoptosis of H929 and ARP-1 cells.

The Inhibiting Effect of Autophagy Inhibitor ROC-325 on Multiple Myeloma / 中国实验血液学杂志

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.

PX-12 Promoting Apoptosis of Multiple Myeloma Cell Line H929 Induced by Bortezomib / 中国实验血液学杂志

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.

The Effects of Chidamide Combined with Anti-myeloma Drugs on the Proliferation and Apoptosis of Myeloma Cells / 中国实验血液学杂志

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.