Multiple myeloma (MM) is a common plasma cell malignancy, accounting for the second largest hematological malignancy. Proteasome inhibitors represented by bortezomib (BTZ) have been the main treatment for patients with newly diagnosed and relapsed or refractory myeloma in nearly two decades. Although BTZ has improved the prognosis of MM patients, MM remains incurable in most patients, mainly because MM cells become resistant to BTZ. This review is to better understand the mechanism of MM resistance to BTZ and explore possible new therapeutic strategies.
Humans ; Bortezomib/therapeutic use* ; Multiple Myeloma/pathology* ; Proteasome Inhibitors/pharmacology* ; Prognosis ; Plasma Cells/pathology* ; Drug Resistance, Neoplasm ; Antineoplastic Agents/pharmacology* ; Cell Line, Tumor

OBJECTIVE: To explore the mechanism of proteasome inhibitor MG132 in improving osteoporosis. METHODS: Total of 32 female SD rats, weighing 220 to 250 g and 8 weeks old, were selected. They were randomly divided into 4 groups(n=8). Rats of group A and group B were cut off ovaris on both sides to make model of osteoporosis, and then they were given proteasome inhibitors MG132 and dimethyl sufoxide (DMSO) respectively. Group C was a sham group and rats were given MG132. Group D was a normal group and rats were given MG132 too. The rats were killed in batches at 6 and 12 weeks after administration, and the femoral neck tissues were obtained. Relevant data were analyzed, such as pathomorphological observation, micro-CT analysis, detection of 20S proteasome activity in tissues, and expression of Wnt and β-catenin. RESULTS: Morphological observation showed that the trabecular were slightly thinner, reticulated, and occasionally interrupted in group A, while the trabecular were obviously thinner and discontinuous in group B. And the trabecular were intact and arranged reticulated in group C and D. The analysis results of bone mineral density(BMD), bone surface(BS), bone volume/total volume(BV/TV) and trabecular thickness(Tb.Th) showed that group B was worse than other groups in all parameters at different time points(P<0.05), and group A was worse than group C and group D in BS(P<0.05), there was no significant difference in all parameters between group C and group D. RFU value of 20S proteasome in group B was significantly higher than that in other groups(P<0.05). According to the results of Western blot, the gray values of Wnt protein and β-catenin protein in group A were significantly higher than those in other groups (P<0.05). CONCLUSION MG-132, a ubiquitin proteasome inhibitor, can regulate Wnt/β-catenin signaling pathway by inhibiting the degradation of β-catenin protein, and delaying the occurrence and development of osteoporosis.
Animals ; Bone Density ; Female ; Leupeptins ; Osteoporosis/drug therapy* ; Proteasome Inhibitors/pharmacology* ; Rats ; Rats, Sprague-Dawley ; Wnt Signaling Pathway ; beta Catenin/metabolism*

Ubiquitin-proteasome system (UPS) plays an essential role in eukaryotic protein cycle,the dysregulation of which can lead to tumorigenesis.Increased activities of UPS have been observed in the patients with cancers including leukemia.UPS inhibitors can kill cancer cells by affecting ubiquitin-ligating enzyme E3,deubiquitinase,and protein degradation active sites of UPS.Therefore,UPS inhibitors have emerged as an important therapy for treating hematological malignancies,while they are rarely applied in the treatment of acute myeloid leukemia.This paper summarizes the research progress in the inhibitors affecting the protein ubiquitination at different stages of acute myeloid leukemia,aiming to provide new clues for the clinical treatment of acute myeloid leukemia.
Humans ; Proteasome Inhibitors/therapeutic use* ; Ubiquitin/metabolism* ; Proteasome Endopeptidase Complex/metabolism* ; Ubiquitination ; Leukemia, Myeloid, Acute/drug therapy*

OBJECTIVES: There is less clinical data on multiple myeloma (MM) in China, and the aim of this study was to collect and analyze the clinical data of newly diagnosed multiple myeloma (NDMM) patients in Hunan Province during 1 year, to understand the real clinical features and treatment outcome for Hunan Province patients with MM, and to strengthen the understanding of the standardized diagnosis process and treatment plan of MM. METHODS: The clinical data of 529 patients with NDMM in 12 large-scale general hospitals in Hunan Province from January 1 to December 31, 2019 were collected and analyzed, including baseline data, treatment regimens, duration of treatment, and adverse reactions. The clinical characteristics, treatment, and safety of patients were analyzed by SPSS 21.0. RESULTS: Among the 529 NDMM patients, the age was 33-90 (median 64) years and the male-female ratio was 1.38꞉1. The clinical features ranged from high to low were as follows: Bone pain (77.7%), anemia (66.8%), renal insufficiency (40.6%), hypercalcemia (15.1%). Typing: IgG 46.5%, IgA 24.6%, IgD 2.6%, IgM 0.8%, light chain 15.7%, double clone 3.0%, no secretion 0.6%, absence 6.2%. Staging: Durie-Salmon stage I, II, and III were 4.5%, 10.6%, 77.3%, respectively, and 40 cases (7.6%) missed this data. International Staging System (ISS) stage I, II, and III were 10.4%, 24.4%, and 47.6%, respectively, and 93 cases (17.6%) were missing. Revised International Staging System (R-ISS) stage I, II, and III were 5.5%, 27.0%, 23.1%, respectively, and 235 cases (44.4%) missed this data. Among the 98 NDMM patients in the Third Xiangya Hospital, Central South University, Durie-Salmon (DS) stage missing 2.0%, ISS stage missing 12.3%, and R-ISS stage missing 12.3%.Treatment: Among the 529 patients,475 received treatment, the rate of treatment was 89.8%; 67.4% of the patients were able to complete four courses of chemotherapy at induction phase, 90.3% of the patients received proteasome inhibitor based combination chemotherapy regimen more than once, 67.2% received immunomodulator based regimen more than once, and 59.8% of the patients received proteasome inhibitor and immunomodulator based combination chemotherapy regimen more than once. Curative: Overall response rate (ORR) and high quality response rate (HQR) of the 4-course group were better than those of the 2-course group (ORR: 85% vs 65%, P=0.006; HQR: 68.3% vs 24.0%, P<0.001). The HQR of the standard chemotherapy group was better than that of the non-standard chemotherapy group (65.1% vs 48.2%, P=0.035). Adverse reactions during treatment included hematologic toxicity (17.5%), peripheral neuropathy (24.8%), gastrointestinal adverse events (23.8%), pulmonary infection (25.9%), herpes zoster (4.6%), and venous thrombotic events (1.7%). CONCLUSIONS In 2019, the missed diagnosis rate of MM patients was high, the medium age of diagnosis was older, and the accuracy of patient diagnosis was not high. There is a great difference among medical centers, especially in the stage and risk stratified, nearly half of NDMM patients are not diagnosed with R-ISS stage; the lack of cytogenetic data needs to be supplemented by follow-up studies. A high proportion of patients with NDMM present with bone pain and anemia.Patients received treatment have higher use of chemotherapy regimens containing proteasome inhibitors and/or immunomodulators, but there is a significant gap among different medical centers, and standardized treatment needs to be strengthened. The safety during chemotherapy is controllable.
Antineoplastic Combined Chemotherapy Protocols/therapeutic use* ; Female ; Humans ; Immunologic Factors/therapeutic use* ; Male ; Middle Aged ; Multiple Myeloma/therapy* ; Neoplasm Staging ; Pain ; Prognosis ; Proteasome Inhibitors/therapeutic use*

PURPOSE: Reduction-oxidation reaction homeostasis is vital for regulating inflammatory conditions and its dysregulation may affect the pathogenesis of chronic airway inflammatory diseases such as asthma. Peroxiredoxin-6, an important intracellular anti-oxidant molecule, is reported to be highly expressed in the airways and lungs. The aim of this study was to analyze the expression pattern of peroxiredoxin-6 in the peripheral blood mononuclear cells (PBMCs) of asthmatic patients and in bronchial epithelial cells (BECs).METHODS: The expression levels and modifications of peroxiredoxin-6 were evaluated in PBMCs from 22 asthmatic patients. Phosphorylated and acetylated peroxiredoxin-6 in hydrogen peroxide-treated human BECs was detected using immunoprecipitation analysis. The expression level of peroxiredoxin-6 was also investigated in BECs treated with hydrogen peroxide. Cycloheximide and proteasome inhibitors were used to determine whether peroxiredoxin-6 is degraded by proteasomes.RESULTS: Peroxiredoxin-6 expression was significantly reduced in the PBMCs of asthmatic patients compared to control subjects. Distinct modification patterns for peroxiredoxin-6 were observed in the PBMCs of asthmatic patients using 2-dimensional-electrophoresis. The levels of phosphorylated serine and acetylated lysine in peroxiredoxin-6 were significantly increased in the BECs following hydrogen peroxide treatment. The level of peroxiredoxin-6 expression was reduced in hydrogen peroxide-stimulated BECs, presumably due to proteasomes.CONCLUSIONS: The expression of peroxiredoxin-6, which is down-regulated in the immune cells of asthmatic patients and BECs, can be modified by oxidative stress. This phenomenon may have an effect on asthmatic airway inflammation.
Asthma ; Cycloheximide ; Epithelial Cells ; Homeostasis ; Humans ; Hydrogen ; Hydrogen Peroxide ; Immunoprecipitation ; Inflammation ; Lung ; Lysine ; Oxidative Stress ; Proteasome Inhibitors ; Protein Processing, Post-Translational ; Serine

OBJECTIVE: The study was performed to establish the purification processes of both 26S and 20S proteasomes, also to investigate the inhibitory properties and patterns of two different proteasome inhibitors on the isolated proteasomes. METHODS: The 26S and 20S proteasomes were purified respectively using liquid chromatographies and glycerol density gradient fractionation. The inhibitory patterns and kinetics of two different proteasome inhibitors were investigated using purified 26S and 20S proteasomes. RESULTS: The purity of the isolated proteasomes were determined by their biochemical properties and electrophoretic patterns. 3-nitro-4-hydroxy-5-indophenylacetyl-leucyl-leucyl-leucyl-vinylsulfone (Nip-L₃-VS) inhibited exclusively the chymotrypsin-like peptidase activities of the 26S and 20S proteasomes. On the other hand, dansyl-phenylyl-leucyl-boronic acid (DFLB) inhibited chymotrpsin-like, trypsin-like, and caspase-like peptidase activities of both proteasomes with different sensitivity. CONCLUSION: The proposed purification method provides efficient separation and isolation of the 26S and 20S proteasomes. Nip-L₃-VS and DFLB were shown to have different inhibitory effects and kinetics on the peptidase activities of the isolated proteasomes. These studies are suggested to be applied to the researches on proteasome inhibitors as therapeutic reagents for many related diseases.
Bortezomib ; Chromatography ; Glycerol ; Hand ; Indicators and Reagents ; Kinetics ; Methods ; Proteasome Endopeptidase Complex ; Proteasome Inhibitors

Objective To investigate the role of proteasome inhibitor bortezomib (BTZ) in inflammatory response in abdominal aortic aneurysm (AAA) formation induced by angiotensin Ⅱ (Ang Ⅱ). Methods Ang Ⅱ-induced ApoEmice AAA models were established. Forty male ApoEmice (8-10-week-old) were randomly and equally divided into four groups:Sham group,BTZ group,Ang Ⅱ group,and Ang Ⅱ+BTZ group.HE staining,immunohistochemical staining,and flow cytometry were used to analyze the inflammatory response. Real-time quantitative polymerase chain reaction (qPCR) was used to analyze the mRNA expression of intercellular cell adhesion molecule-1 (ICAM-1). Western blotting was used to analyze the activation of nuclear factor κB signaling (NF-κB). Results The mean maximum suprarenal aortic diameter (Dmax) of Sham group,BTZ group,Ang Ⅱ group,and Ang Ⅱ+BTZ group were (1.00±0.01),(0.99±0.01),(1.50±0.13),and (1.20±0.04)mm,respectively (F=8.959,P=0.000). The Dmax of Ang Ⅱ group was significantly larger than those of Sham group (P=0.000) and Ang Ⅱ+BTZ group (P=0.015). The incidence of AAA in Ang Ⅱ group,Ang Ⅱ+BTZ group,and Sham group were 60%,17%,and 0,respectively. HE staining revealed that the abdominal aortic wall thickening was more severe in Ang Ⅱ group than in Sham group and Ang Ⅱ+BTZ group,similar with the infiltration of inflammatory cells. Immunohistochemical staining demonstrated that the CD3T lymphocyte count was significantly higher in Ang Ⅱ group than in Sham group (107.9±15.9 vs. 0,P=0.000) and Ang Ⅱ+BTZ group (107.9±15.9 vs. 0.8±0.5,P=0.000). Flow cytometry also demonstrated that the proportion of the CD3T lymphocytes of the Ang Ⅱ group [(13.50±0.69)%] was significantly higher than that in the Ang Ⅱ+BTZ group [(10.40±0.78)%] at week 1 (t=3.009,P=0.040),and the proportion of the CD3T lymphocytes of the Ang Ⅱ group [(22.70±0.93)%] was significantly higher than that in the Ang Ⅱ+BTZ group [(15.10±0.97)%] at week 4 (t=5.654,P=0.005). The qPCR analysis showed that the mRNA expression of ICAM-1 was significantly up-regulated in Ang Ⅱ group than in Sham group (1.93±0.54 vs. 1.00±0.15,P=0.011) and Ang Ⅱ+BTZ group (1.93±0.54 vs. 0.83±0.08,P=0.009). Western blot analysis showed a lower phosphorylation level of inhibitor of NF-κB in the Ang Ⅱ group compared with the Sham group or Ang Ⅱ+BTZ group,accompanied with an increased phosphorylation level of p65. Conclusion Proteasome inhibitor BTZ can attenuate AAA formation partially by regulating T lymphocytes infiltration through regulating the mRNA expression of ICAM-1 regulated by the activation of NF-κB signaling pathway.
Angiotensin II ; adverse effects ; Animals ; Aortic Aneurysm, Abdominal ; chemically induced ; drug therapy ; Apolipoproteins E ; genetics ; Bortezomib ; pharmacology ; Intercellular Adhesion Molecule-1 ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; NF-kappa B ; metabolism ; Phosphorylation ; Proteasome Inhibitors ; pharmacology ; Random Allocation ; Signal Transduction ; T-Lymphocytes ; cytology

BACKGROUND: The ubiquitin-proteasome system (UPS) is an important pathway of proteolysis in pathologic hypertrophic cardiomyocytes. We hypothesize that MG132, a proteasome inhibitor, might prevent hypertrophic cardiomyopathy (CMP) by blocking the UPS. Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and androgen receptor (AR) have been reported to be mediators of CMP and heart failure. This study drew upon pathophysiologic studies and the analysis of NF-κB and AR to assess the cardioprotective effects of MG132 in a left ventricular hypertrophy (LVH) rat model. METHODS: We constructed a transverse aortic constriction (TAC)-induced LVH rat model with 3 groups: sham (TAC-sham, n=10), control (TAC-cont, n=10), and MG132 administration (TAC-MG132, n=10). MG-132 (0.1 mg/kg) was injected for 4 weeks in the TAC-MG132 group. Pathophysiologic evaluations were performed and the expression of AR and NF-κB was measured in the left ventricle. RESULTS: Fibrosis was prevalent in the pathologic examination of the TAC-cont model, and it was reduced in the TAC-MG132 group, although not significantly. Less expression of AR, but not NF-κB, was found in the TAC-MG132 group than in the TAC-cont group (p<0.05). CONCLUSION: MG-132 was found to suppress AR in the TAC-CMP model by blocking the UPS, which reduced fibrosis. However, NF-κB expression levels were not related to UPS function.
Animals ; Animals* ; B-Lymphocytes ; Cardiomyopathy, Hypertrophic ; Constriction ; Fibrosis ; Heart Failure ; Heart Ventricles ; Hypertrophy* ; Hypertrophy, Left Ventricular ; Models, Animal* ; Myocytes, Cardiac* ; NF-kappa B ; Proteasome Endopeptidase Complex* ; Proteasome Inhibitors* ; Proteolysis ; Rats* ; Receptors, Androgen ; Ubiquitins

The proteasome inhibitor, bortezomib, is ineffective against many solid tumors. Nutlin-3 is a potent antagonist of human homolog of murine double minute 2/p53 interaction exhibiting promising therapeutic anti-cancer activity. In this study, we show that treatment of various p53-defective bortezomib-resistant solid tumor cells with bortezomib plus nutlin-3 induces paraptosis, which is a cell death mode accompanied by dilation of the endoplasmic reticulum (ER) and mitochondria. Bortezomib alone did not markedly alter cellular morphology, and nutlin-3 alone induced only a transient mitochondrial dilation. However, bortezomib/nutlin-3 co-treatment triggered the progressive fusion of swollen ER and the formation of megamitochondria, leading to cell death. Mechanistically, proteasomal-impairment-induced ER stress, CHOP upregulation and disruption of Ca²⁺ homeostasis were found to be critically involved in the bortezomib/nutlin-3-induced dilation of the ER. Our results further suggest that mitochondrial unfolded protein stress may play an important role in the mitochondrial dilation observed during bortezomib/nutlin-3-induced cell death. Collectively, these findings suggest that bortezomib/nutlin-3 perturbs proteostasis, triggering ER/mitochondria stress and irrecoverable impairments in their structure and function, ultimately leading to paraptotic cell death.
Bortezomib* ; Cell Death ; Endoplasmic Reticulum ; Homeostasis ; Humans ; Mitochondria ; Proteasome Inhibitors ; Up-Regulation

Multiple myeloma is an incurable malignant plasma cell-originating cancer. Although its treatment outcomes have improved with the use of glucocorticoids, alkylating drugs, and novel agents, including proteasome inhibitors (bortezomib and carfilzomib) and immunomodulatory drugs (thalidomide, lenalidomide, and pomalidomide), relapse remains a serious problem. Strategies to improve outcomes following autologous stem cell transplantation and frontline treatments in non-transplant patients include consolidation to intensify therapy and improve the depth of response and maintenance therapy to achieve long-term disease control. Many clinical trials have reported increased progression-free and overall survival rates after consolidation and maintenance therapy. The role of consolidation/maintenance therapy has been assessed in patients eligible and ineligible for transplantation and is a valuable option in clinical trial settings. However, the decision to use consolidation and/or maintenance therapy needs to be guided by the individual patient situation in actual clinical practice. This review analyzes the currently available evidence from several reported clinical trials to determine the optimal consolidation and maintenance therapy in clinical practice.
Glucocorticoids ; Humans ; Immunologic Factors ; Multiple Myeloma* ; Plasma ; Proteasome Inhibitors ; Recurrence ; Stem Cell Transplantation ; Survival Rate