In this editorial we comment on the article by Tang et al published in the recent issue of World Journal of Hepatology.Drug therapy of intrahepatic cholangiocarcinoma(iCCA)poses an enormous challenge since only a smal...In this editorial we comment on the article by Tang et al published in the recent issue of World Journal of Hepatology.Drug therapy of intrahepatic cholangiocarcinoma(iCCA)poses an enormous challenge since only a small proportion of patients demonstrate beneficial responses to therapeutic agents.Thus,there has been a sustained search for novel molecular targets for iCCA.The study by Tang et al evaluated the role of 26S proteasome non-ATPase regulatory subunit 6(PSMD6),a 19S regulatory subunit of the proteasome,in human iCCA cells and specimens.The authors employed clustered regularly interspaced short palindromic repeat(CRISPR)knockout screening technology integrated with the computational CERES algorithm,and analyzed the human protein atlas(THPA)database and tissue microarrays.The results show that PSMD6 is a gene essential for the proliferation of 17 iCCA cell lines,and PSMD6 protein was overexpressed in iCCA tissues without a significant correlation with the clinicopathological parameters.The authors conclude that PSMD6 may play a promoting role in iCCA.The major limitations and defects of this study are the lack of detailed information of CRISPR knockout screening,in vivo experiments,and a discussion of plausible mechanistic cues,which,therefore,dampen the significance of the results.Further studies are required to verify PSMD6 as a molecular target for developing novel therapeutics for iCCA.In addition,the editorial article summarizes the latest advances in molecular targeted drugs and recently emerging immunotherapy in the clinical management of iCCA,development of proteasome inhibitors for cancer therapy,and advantages of CRISPR screening technology,computational methods,and THPA database as experimental tools for fighting cancer.We hope that these comments may provide some clues for those engaged in the field of basic and clinical research into iCCA.展开更多
Multiple myeloma(MM) is a cancer caused by uncontrolled proliferation of antibody-secreting plasma cells in bone marrow, which represents the second most common hematological malignancy. MM is a highly heterogeneous d...Multiple myeloma(MM) is a cancer caused by uncontrolled proliferation of antibody-secreting plasma cells in bone marrow, which represents the second most common hematological malignancy. MM is a highly heterogeneous disease and can be classified into a spectrum of subgroups based on their molecular and cytogenetic abnormalities. In the past decade, novel therapies, especially, the first-in-class proteasome inhibitor bortezomib, have been revolutionary for the treatment of MM patients. Despite these remarkable achievements, myeloma remains incurable with a high frequency of patients suffering from a relapse, due to drug resistance. Mutation in the proteasome β5-subunit(PSMB5) was found in a bortezomib-resistant cell line generated via long-term coculture with increasing concentrations of bortezomib in 2008, but their actual implication in drug resistance in the clinic has not been reported until recently. A recent study discovered four resistance-inducing PSMB5 mutations from a relapsed MM patient receiving prolonged bortezomib treatment. Analysis of the dynamic clonal evolution revealed that two subclones existed at the onset of disease, while the other two subclones were induced. Protein structural modeling and functional assays demonstrated that all four mutations impaired the binding of bortezomib to the 20 S proteasome, conferring different degrees of resistance. The authors further demonstrated two potential approaches to overcome drug resistance by using combination therapy for targeting proteolysis machinery independent of the 20 S proteasome.展开更多
Oxidative stress, generated by chronic ethanol consumption, is a major cause of hepatotoxicity and liver injury. Increased production of oxygen-derived free radicals due to ethanol metabolism by CYP2E1 is principally ...Oxidative stress, generated by chronic ethanol consumption, is a major cause of hepatotoxicity and liver injury. Increased production of oxygen-derived free radicals due to ethanol metabolism by CYP2E1 is principally located in the cytoplasm and in the mitochondria, which does not only injure liver cells, but also other vital organs, such as the heart and the brain. Therefore, there is a need for better treatment to enhance the antioxidant response elements. To date, there is no established treatment to attenuate high levels of oxidative stress in the liver of alcoholic patients. To block this oxidative stress, proteasome inhibitor treatment has been found to significantly enhance the antioxidant response elements of hepatocytes exposed to ethanol. Recent studies have shown in an experimental model of alcoholic liver disease that proteasome inhibitor treatment at low dose has cytoprotective effects against ethanol-induced oxidative stress and liver steatosis. The beneficial effects of proteasome inhibitor treatment against oxidative stress occurred because antioxidant response elements （glutathione peroxidase 2, superoxide dismutase 2, glutathione synthetase, glutathione reductase, and GCLC） were upregulated when rats fed alcohol were treated with a low dose of PS-34Z （Bortezomib, Velcade）. This is an important finding because proteasome inhibitor treatment up-regulated reactive oxygen species removal and glutathione recycling enzymes, while ethanol feeding alone down-regulated these antioxidant elements. For the first time, it was shown that proteasome inhibition by a highly specific and reversible inhibitor is different from the chronic ethanol feeding-induced proteasome inhibition. As previously shown by our group, chronic ethanol feeding causes a complex dysfunction in the ubiquitin proteasome pathway, which affects the proteasome system, as well as the ubiquitination system. The beneficial effects of proteasome inhibitor treatment in alcoholic liver disease are related to proteasome inhibitor reversibility and the rebound of proteasome activity 72 h post PS-341 administration.展开更多
Ubiquitin-proteasome pathway mediates the degradation of cell protein, and cell cycle, gene translation and expression, antigen presentation and inflammatory development. Proteasome inhibitor can inhibit growth and pr...Ubiquitin-proteasome pathway mediates the degradation of cell protein, and cell cycle, gene translation and expression, antigen presentation and inflammatory development. Proteasome inhibitor can inhibit growth and proliferation of tumor cell, induce apoptosis and reverse multipledrug resistance of tumor cell, increase the sensitivity of other chemotherapeutic drugs and radiotherapy, and is a novel class of potent anti-tumor agents.展开更多
To investigate the effect of proteasome inhibitor MG132 on the apoptosis of bovine lens epithelial cells （BLECs）, the cells were treated with MG132 at different concentrations for12, 24 and 36 h. The cell viability ...To investigate the effect of proteasome inhibitor MG132 on the apoptosis of bovine lens epithelial cells （BLECs）, the cells were treated with MG132 at different concentrations for12, 24 and 36 h. The cell viability was analyzed by MTT assay and the effect of MG132 on the apoptosis of BLECs was assessed by flow cytometry （FCM）. The results showed that after treatment for the same period, the inhibitory effect of MG132 on BLECs proliferation was enhanced with the increment of the concentration of MG132 （0, 2, 5, 10, μmol/L） （P〈0.05）. The 50% inhibiting concentration （IC50） was 2.03 μmol/L when the BLECs were treated with MG132 for 36 h. MG132 also induced the apop- tosis of BLECs obviously. FCM showed that the apoptosis index of the cells treated by MG132 at 2 μmol/L for 12 h was （20.24±1.51）%, and that of the control was （0.98±0.20）% respectively （P〈0.01, n=3）. It was concluded that MG132 could lead to apoptosis of BLECs. The decrease of proteasome activity may play an important role in the formation and development of cataract.展开更多
OBJECTIVE In this study, we applied multidrug resistant leukemia cell line expressing mdr1-mRNA to observe changes in mdr1-mRNA, the P-gp, cell cycle and apoptosis before and after bortezomib was used, in order to exp...OBJECTIVE In this study, we applied multidrug resistant leukemia cell line expressing mdr1-mRNA to observe changes in mdr1-mRNA, the P-gp, cell cycle and apoptosis before and after bortezomib was used, in order to explore the mechanism of reversal of leukemia multidrug resistance by the proteasome inhibitor bortezomib.METHODS Flow cytometry （FCM） was used to detect the intracellular drug concentration, expression of P-gp, cell apoptosis and cell cycle status of K562/DNR cells before and a er treatment with different concentrations of bortezomib. Fluorescence quantitative PCR was applied to detect the mdr1-mRNA expression in K562/DNR and K562/S cells.RESULTS Bortezomib could increase the intracellular DNR content in K562/DNR cells, but showed no e. ect in K562/S cells.5-100 nmol/L bortezomib could significantly reduce the P-gp/mdr1-mRNA expression in K562/DNR cells in vitro, and showed a dose-dependent effect. There was a statistically significant di. erence （P 〈 0.05） between di. erent concentration groups and the control group. P-gp/mdr1-mRNA expression was negatively correlated with cell apoptosis （r = -0.912 and P 〈 0.01）. After treatment with different concentrations of bortezomib for 24 h,K562/DNR cells in G2 ＋ M phases were significantly increased,while cells in G0 ＋ G1 phases and S phase were significantly decreased, accompanied by an increased apoptotic rate.CONCLUSION Bortezomib can induce G0 ＋ G1 phase to G2 ＋ M phase, and thereby enhance the chemosensitivity of leukemia, and may also reverse the multidrug resistance in leukemia mediated by P-gp overexpression encoded by mdr1 gene. This confi rms that bortezomib can reverse leukemia multidrug resistance at the levels of nucleic acid and protein molecules.展开更多
Dexamethasone (Dex), a ligand for transcriptional enhancement of tyrosine aminotransferase (TAT) and tryptophan 2,3-dioxygenase (TO) genes, (100 nM) maximally increased these mRNA levels at 12 h and 7 h in primary cul...Dexamethasone (Dex), a ligand for transcriptional enhancement of tyrosine aminotransferase (TAT) and tryptophan 2,3-dioxygenase (TO) genes, (100 nM) maximally increased these mRNA levels at 12 h and 7 h in primary cultured rat hepatocytes and the nuclear fraction, respectively. Lactacystin (5 μM) and epoxomicin (0.5 μM), 26S proteasome inhibitors, significantly suppressed the Dex-dependent maximum increase of TAT and TO mRNA levels in the cells and the nuclear fraction. Electrophoretic mobility shift assay demonstrated that lactacystin did not affect binding of glucocorticoid receptor to glucocorticoid responsive element. Furthermore, lactacystin did not affect the activation of GRE luciferase reporter by Dex transfected to the cells. The results demonstrate that 26S proteasome is positively involved in the Dex-dependent increase of TAT and TO mRNA levels in the cells and suggest that the mechanism of action of 26S proteasome may be degradation of some RNase(s), which breaks down TAT and TO mRNAs.展开更多
Proteasome dysfunction during dopaminergic degeneration induces proteolytic stress, and is a contributing factor for the onset and formation of Lewy bodies. Results from our previous studies showed that synthetic prot...Proteasome dysfunction during dopaminergic degeneration induces proteolytic stress, and is a contributing factor for the onset and formation of Lewy bodies. Results from our previous studies showed that synthetic proteasome inhibitor-induced inclusions in PC12 cells contained six subunits in the 26S proteasome. In the present study, mass spectrometry analysis of single protein spots resolved by two-dimensional gel electrophoresis and identified by bioinformatic analysis of peptide mass fingerprint （PMF） data were performed to comprehensively characterize the proteomic profile of the proteasome subunits. Results showed that six subunits in the 26S proteasome were characterized through accurate assignment by PMF data-specific protein identification in protein databases. Additionally, identification of one of the proteasome subunits was further confirmed using a subunit-specific antibody against non-adenosine triphosphatase subunit 11 of the 19S regulatory particle. Results suggest that the potential proteomic profile of six subunits in the 26S proteasome could be established from proteasome inhibitor-induced inclusions in PC12 cells.展开更多
Objective:Fluzoparib(SHR3162)is a novel,potent poly(ADP-ribose)polymerases(PARP)1,2 inhibitor that showed anti-tumor activity in xenograft models.We conducted a phaseⅠ,first-in-human,dose-escalation and expansion(D-E...Objective:Fluzoparib(SHR3162)is a novel,potent poly(ADP-ribose)polymerases(PARP)1,2 inhibitor that showed anti-tumor activity in xenograft models.We conducted a phaseⅠ,first-in-human,dose-escalation and expansion(D-Esc and D-Ex)trial in patients with advanced solid cancer.Methods:This was a 3+3 phaseⅠD-Esc trial with a 3-level D-Ex at 5 hospitals in China.Eligible patients for DEsc had advanced solid tumors refractory to standard therapies,and D-Ex enrolled patients with ovarian cancer(OC).Fluzoparib was administered orally once or twice daily(bid)at 11 dose levels from 10 to 400 mg/d.Endpoints included dose-finding,safety,pharmacokinetics,and antitumor activity.Results:Seventy-nine patients were enrolled from March,2015 to January,2018[OC(47,59.5%);breast cancer(BC)(16,20.3%);colorectal cancer(8,10.1%),other tumors(8,10.1%)];48 patients were treated in the D-Esc arm and 31 in the D-Ex arm.The maximum tolerated dose(MTD)was 150 mg bid,with a half-life of 9.14 h.Grade 3/4 adverse events included anemia(7.6%)and neutropenia(5.1%).The objective response rate(ORR)was 30%(3/10)in patients with platinum-sensitive OC and 7.7%(1/13)in patients with BC.Among patients treated with fluzoparib≥120 mg/d,median progression-free survival(m PFS)was 7.2[95%confidence interval(95%CI),1.8-9.3]months in OC,9.3(95%CI,7.2-9.3)months in platinum-sensitive OC,and 3.5(range,2.0-28.0)months in BC.In patients with germline BC susceptibility gene mutation(g BRCAMut)(11/43 OC;2/16 BC),m PFS was 8.9 months for OC(range,1.0-23.2;95%CI,1.0-16.8)and 14 and 28 months for BC(those two patients both also had somatic BRCAMut).Conclusions:The MTD of fluzoparib was 150 mg bid in advanced solid malignancies.Fluzoparib demonstrated single-agent antitumor activity in BC and OC,particularly in BRCAMut and platinum-sensitive OC.展开更多
BRAF has been recognized as a promising target for cancer therapy. A number of crystal structures have been published. Molecular docking is one of the most effective techniques in the field of computer-aided drug des...BRAF has been recognized as a promising target for cancer therapy. A number of crystal structures have been published. Molecular docking is one of the most effective techniques in the field of computer-aided drug design（CADD）. Appropriate protein conformation and docking method are essential for the successful virtual screening experiments. One approach considering protein flexibility and multiple docking methods was proposed in this study. Six DFG-in/αC-helix-out crystal structures of BRAF, three docking programs（Glide, GOLD and Ligand Fit） and 12 scoring functions were applied for the best combination by judging from the results of pose prediction and retrospective virtual screening（VS）. The most accurate results（mean RMSD of about 0.6 A） of pose prediction were obtained with two complex structures（PDB： 3 C4 C and 3 SKC） using Glide SP. From the retrospective VS, the most active compounds were identified by using the complex structure of 3 SKC, indicated by a ROC/AUC score of 0.998 and an EF of 20.6 at 5% of the database screen with Glide-SP. On the whole, PDB 3 SKC could achieve a higher rate of correct reproduction, a better enrichment and more diverse compounds. A comparison of 3 SKC and the other X-ray crystal structures led to a rationale for the docking results. PDB 3 SKC could achieve a broad range of sulfonamide substitutions through an expanded hydrophobic pocket formed by a further shift of the αC-helix. Our study emphasized the necessity and significance of protein flexibility and scoring functions in both ligand docking and virtual screening.展开更多
目的:探讨蛋白酶体抑制剂(PI)相关血栓性微血管病(TMA)的发生规律和临床特点,为临床安全用药提供参考。方法:检索中国知网、万方数据库、维普数据库、PubMed、Web of Science等数据库中收录的PI相关TMA的案例报道,检索时间为建库至2023...目的:探讨蛋白酶体抑制剂(PI)相关血栓性微血管病(TMA)的发生规律和临床特点,为临床安全用药提供参考。方法:检索中国知网、万方数据库、维普数据库、PubMed、Web of Science等数据库中收录的PI相关TMA的案例报道,检索时间为建库至2023年4月30日。对患者基本信息、用药情况、TMA的临床表现、实验室检查、治疗及预后进行汇总分析。结果:纳入文献37篇,涉及患者92例,其中男性46例(占50.00%),女性29例(占31.52%),性别不详17例(占18.48%);平均年龄为(61±13)岁。TMA的中位发病时间为64 d,临床表现以发热、乏力、恶心/呕吐、少尿/无尿为主。因1例患者出现2次TMA,则合计93例次TMA,患者血小板计数明显降低,中位值为19.5×10^(9)/L,其中0~50×10^(9)/L的患者最多(52例次,占55.91%);64例次患者(占68.82%)的血清肌酐水平升高,其中>177~445μmol/L的患者最多(32例次,占34.41%)。停药和支持治疗后(共93例次),76例次患者(占81.72%)痊愈/好转,6例次(占6.45%)有后遗症,5例次(占5.38%)死亡。PI相关TMA中,主要涉及的药物为卡非佐米(67例次,占72.04%)。结论:应重视PI所致TMA,应用PI时应考虑患者性别、药物种类等因素;根据临床表现及实验室检查结果,尽早识别不良反应,保障患者用药安全。展开更多
基金Supported by The National Key Research and Development Program of China,No.2017YFC1308602The Research Funds by the Fifth Affiliated Hospital of Harbin Medical University,No.2022-002 and No.2023-001.
文摘In this editorial we comment on the article by Tang et al published in the recent issue of World Journal of Hepatology.Drug therapy of intrahepatic cholangiocarcinoma(iCCA)poses an enormous challenge since only a small proportion of patients demonstrate beneficial responses to therapeutic agents.Thus,there has been a sustained search for novel molecular targets for iCCA.The study by Tang et al evaluated the role of 26S proteasome non-ATPase regulatory subunit 6(PSMD6),a 19S regulatory subunit of the proteasome,in human iCCA cells and specimens.The authors employed clustered regularly interspaced short palindromic repeat(CRISPR)knockout screening technology integrated with the computational CERES algorithm,and analyzed the human protein atlas(THPA)database and tissue microarrays.The results show that PSMD6 is a gene essential for the proliferation of 17 iCCA cell lines,and PSMD6 protein was overexpressed in iCCA tissues without a significant correlation with the clinicopathological parameters.The authors conclude that PSMD6 may play a promoting role in iCCA.The major limitations and defects of this study are the lack of detailed information of CRISPR knockout screening,in vivo experiments,and a discussion of plausible mechanistic cues,which,therefore,dampen the significance of the results.Further studies are required to verify PSMD6 as a molecular target for developing novel therapeutics for iCCA.In addition,the editorial article summarizes the latest advances in molecular targeted drugs and recently emerging immunotherapy in the clinical management of iCCA,development of proteasome inhibitors for cancer therapy,and advantages of CRISPR screening technology,computational methods,and THPA database as experimental tools for fighting cancer.We hope that these comments may provide some clues for those engaged in the field of basic and clinical research into iCCA.
文摘Multiple myeloma(MM) is a cancer caused by uncontrolled proliferation of antibody-secreting plasma cells in bone marrow, which represents the second most common hematological malignancy. MM is a highly heterogeneous disease and can be classified into a spectrum of subgroups based on their molecular and cytogenetic abnormalities. In the past decade, novel therapies, especially, the first-in-class proteasome inhibitor bortezomib, have been revolutionary for the treatment of MM patients. Despite these remarkable achievements, myeloma remains incurable with a high frequency of patients suffering from a relapse, due to drug resistance. Mutation in the proteasome β5-subunit(PSMB5) was found in a bortezomib-resistant cell line generated via long-term coculture with increasing concentrations of bortezomib in 2008, but their actual implication in drug resistance in the clinic has not been reported until recently. A recent study discovered four resistance-inducing PSMB5 mutations from a relapsed MM patient receiving prolonged bortezomib treatment. Analysis of the dynamic clonal evolution revealed that two subclones existed at the onset of disease, while the other two subclones were induced. Protein structural modeling and functional assays demonstrated that all four mutations impaired the binding of bortezomib to the 20 S proteasome, conferring different degrees of resistance. The authors further demonstrated two potential approaches to overcome drug resistance by using combination therapy for targeting proteolysis machinery independent of the 20 S proteasome.
基金Supported by NIH/NIAAA 8116 and by a Pilot Project Funding from the Alcohol Center Grant on Liver and Pancreas P50-011999
文摘Oxidative stress, generated by chronic ethanol consumption, is a major cause of hepatotoxicity and liver injury. Increased production of oxygen-derived free radicals due to ethanol metabolism by CYP2E1 is principally located in the cytoplasm and in the mitochondria, which does not only injure liver cells, but also other vital organs, such as the heart and the brain. Therefore, there is a need for better treatment to enhance the antioxidant response elements. To date, there is no established treatment to attenuate high levels of oxidative stress in the liver of alcoholic patients. To block this oxidative stress, proteasome inhibitor treatment has been found to significantly enhance the antioxidant response elements of hepatocytes exposed to ethanol. Recent studies have shown in an experimental model of alcoholic liver disease that proteasome inhibitor treatment at low dose has cytoprotective effects against ethanol-induced oxidative stress and liver steatosis. The beneficial effects of proteasome inhibitor treatment against oxidative stress occurred because antioxidant response elements （glutathione peroxidase 2, superoxide dismutase 2, glutathione synthetase, glutathione reductase, and GCLC） were upregulated when rats fed alcohol were treated with a low dose of PS-34Z （Bortezomib, Velcade）. This is an important finding because proteasome inhibitor treatment up-regulated reactive oxygen species removal and glutathione recycling enzymes, while ethanol feeding alone down-regulated these antioxidant elements. For the first time, it was shown that proteasome inhibition by a highly specific and reversible inhibitor is different from the chronic ethanol feeding-induced proteasome inhibition. As previously shown by our group, chronic ethanol feeding causes a complex dysfunction in the ubiquitin proteasome pathway, which affects the proteasome system, as well as the ubiquitination system. The beneficial effects of proteasome inhibitor treatment in alcoholic liver disease are related to proteasome inhibitor reversibility and the rebound of proteasome activity 72 h post PS-341 administration.
基金the National Outstanding Youth Scientists Foundation of china(No.30225038) and the Youth and Middle-Age Scientists Science and Research Found of the Affiliated Hospital,Wuhan University of Science and Technology.
文摘Ubiquitin-proteasome pathway mediates the degradation of cell protein, and cell cycle, gene translation and expression, antigen presentation and inflammatory development. Proteasome inhibitor can inhibit growth and proliferation of tumor cell, induce apoptosis and reverse multipledrug resistance of tumor cell, increase the sensitivity of other chemotherapeutic drugs and radiotherapy, and is a novel class of potent anti-tumor agents.
文摘To investigate the effect of proteasome inhibitor MG132 on the apoptosis of bovine lens epithelial cells （BLECs）, the cells were treated with MG132 at different concentrations for12, 24 and 36 h. The cell viability was analyzed by MTT assay and the effect of MG132 on the apoptosis of BLECs was assessed by flow cytometry （FCM）. The results showed that after treatment for the same period, the inhibitory effect of MG132 on BLECs proliferation was enhanced with the increment of the concentration of MG132 （0, 2, 5, 10, μmol/L） （P〈0.05）. The 50% inhibiting concentration （IC50） was 2.03 μmol/L when the BLECs were treated with MG132 for 36 h. MG132 also induced the apop- tosis of BLECs obviously. FCM showed that the apoptosis index of the cells treated by MG132 at 2 μmol/L for 12 h was （20.24±1.51）%, and that of the control was （0.98±0.20）% respectively （P〈0.01, n=3）. It was concluded that MG132 could lead to apoptosis of BLECs. The decrease of proteasome activity may play an important role in the formation and development of cataract.
文摘OBJECTIVE In this study, we applied multidrug resistant leukemia cell line expressing mdr1-mRNA to observe changes in mdr1-mRNA, the P-gp, cell cycle and apoptosis before and after bortezomib was used, in order to explore the mechanism of reversal of leukemia multidrug resistance by the proteasome inhibitor bortezomib.METHODS Flow cytometry （FCM） was used to detect the intracellular drug concentration, expression of P-gp, cell apoptosis and cell cycle status of K562/DNR cells before and a er treatment with different concentrations of bortezomib. Fluorescence quantitative PCR was applied to detect the mdr1-mRNA expression in K562/DNR and K562/S cells.RESULTS Bortezomib could increase the intracellular DNR content in K562/DNR cells, but showed no e. ect in K562/S cells.5-100 nmol/L bortezomib could significantly reduce the P-gp/mdr1-mRNA expression in K562/DNR cells in vitro, and showed a dose-dependent effect. There was a statistically significant di. erence （P 〈 0.05） between di. erent concentration groups and the control group. P-gp/mdr1-mRNA expression was negatively correlated with cell apoptosis （r = -0.912 and P 〈 0.01）. After treatment with different concentrations of bortezomib for 24 h,K562/DNR cells in G2 ＋ M phases were significantly increased,while cells in G0 ＋ G1 phases and S phase were significantly decreased, accompanied by an increased apoptotic rate.CONCLUSION Bortezomib can induce G0 ＋ G1 phase to G2 ＋ M phase, and thereby enhance the chemosensitivity of leukemia, and may also reverse the multidrug resistance in leukemia mediated by P-gp overexpression encoded by mdr1 gene. This confi rms that bortezomib can reverse leukemia multidrug resistance at the levels of nucleic acid and protein molecules.
文摘Dexamethasone (Dex), a ligand for transcriptional enhancement of tyrosine aminotransferase (TAT) and tryptophan 2,3-dioxygenase (TO) genes, (100 nM) maximally increased these mRNA levels at 12 h and 7 h in primary cultured rat hepatocytes and the nuclear fraction, respectively. Lactacystin (5 μM) and epoxomicin (0.5 μM), 26S proteasome inhibitors, significantly suppressed the Dex-dependent maximum increase of TAT and TO mRNA levels in the cells and the nuclear fraction. Electrophoretic mobility shift assay demonstrated that lactacystin did not affect binding of glucocorticoid receptor to glucocorticoid responsive element. Furthermore, lactacystin did not affect the activation of GRE luciferase reporter by Dex transfected to the cells. The results demonstrate that 26S proteasome is positively involved in the Dex-dependent increase of TAT and TO mRNA levels in the cells and suggest that the mechanism of action of 26S proteasome may be degradation of some RNase(s), which breaks down TAT and TO mRNAs.
基金the Science and Technology Commission Foundation of Jilin Province,No.200505200the Distinguished Professor Foundation of Jilin University,No.450011011204
文摘Proteasome dysfunction during dopaminergic degeneration induces proteolytic stress, and is a contributing factor for the onset and formation of Lewy bodies. Results from our previous studies showed that synthetic proteasome inhibitor-induced inclusions in PC12 cells contained six subunits in the 26S proteasome. In the present study, mass spectrometry analysis of single protein spots resolved by two-dimensional gel electrophoresis and identified by bioinformatic analysis of peptide mass fingerprint （PMF） data were performed to comprehensively characterize the proteomic profile of the proteasome subunits. Results showed that six subunits in the 26S proteasome were characterized through accurate assignment by PMF data-specific protein identification in protein databases. Additionally, identification of one of the proteasome subunits was further confirmed using a subunit-specific antibody against non-adenosine triphosphatase subunit 11 of the 19S regulatory particle. Results suggest that the potential proteomic profile of six subunits in the 26S proteasome could be established from proteasome inhibitor-induced inclusions in PC12 cells.
文摘Objective:Fluzoparib(SHR3162)is a novel,potent poly(ADP-ribose)polymerases(PARP)1,2 inhibitor that showed anti-tumor activity in xenograft models.We conducted a phaseⅠ,first-in-human,dose-escalation and expansion(D-Esc and D-Ex)trial in patients with advanced solid cancer.Methods:This was a 3+3 phaseⅠD-Esc trial with a 3-level D-Ex at 5 hospitals in China.Eligible patients for DEsc had advanced solid tumors refractory to standard therapies,and D-Ex enrolled patients with ovarian cancer(OC).Fluzoparib was administered orally once or twice daily(bid)at 11 dose levels from 10 to 400 mg/d.Endpoints included dose-finding,safety,pharmacokinetics,and antitumor activity.Results:Seventy-nine patients were enrolled from March,2015 to January,2018[OC(47,59.5%);breast cancer(BC)(16,20.3%);colorectal cancer(8,10.1%),other tumors(8,10.1%)];48 patients were treated in the D-Esc arm and 31 in the D-Ex arm.The maximum tolerated dose(MTD)was 150 mg bid,with a half-life of 9.14 h.Grade 3/4 adverse events included anemia(7.6%)and neutropenia(5.1%).The objective response rate(ORR)was 30%(3/10)in patients with platinum-sensitive OC and 7.7%(1/13)in patients with BC.Among patients treated with fluzoparib≥120 mg/d,median progression-free survival(m PFS)was 7.2[95%confidence interval(95%CI),1.8-9.3]months in OC,9.3(95%CI,7.2-9.3)months in platinum-sensitive OC,and 3.5(range,2.0-28.0)months in BC.In patients with germline BC susceptibility gene mutation(g BRCAMut)(11/43 OC;2/16 BC),m PFS was 8.9 months for OC(range,1.0-23.2;95%CI,1.0-16.8)and 14 and 28 months for BC(those two patients both also had somatic BRCAMut).Conclusions:The MTD of fluzoparib was 150 mg bid in advanced solid malignancies.Fluzoparib demonstrated single-agent antitumor activity in BC and OC,particularly in BRCAMut and platinum-sensitive OC.
基金supported by the National Natural Science Foundation of China(21102181,81302634 and 21572273)
文摘BRAF has been recognized as a promising target for cancer therapy. A number of crystal structures have been published. Molecular docking is one of the most effective techniques in the field of computer-aided drug design（CADD）. Appropriate protein conformation and docking method are essential for the successful virtual screening experiments. One approach considering protein flexibility and multiple docking methods was proposed in this study. Six DFG-in/αC-helix-out crystal structures of BRAF, three docking programs（Glide, GOLD and Ligand Fit） and 12 scoring functions were applied for the best combination by judging from the results of pose prediction and retrospective virtual screening（VS）. The most accurate results（mean RMSD of about 0.6 A） of pose prediction were obtained with two complex structures（PDB： 3 C4 C and 3 SKC） using Glide SP. From the retrospective VS, the most active compounds were identified by using the complex structure of 3 SKC, indicated by a ROC/AUC score of 0.998 and an EF of 20.6 at 5% of the database screen with Glide-SP. On the whole, PDB 3 SKC could achieve a higher rate of correct reproduction, a better enrichment and more diverse compounds. A comparison of 3 SKC and the other X-ray crystal structures led to a rationale for the docking results. PDB 3 SKC could achieve a broad range of sulfonamide substitutions through an expanded hydrophobic pocket formed by a further shift of the αC-helix. Our study emphasized the necessity and significance of protein flexibility and scoring functions in both ligand docking and virtual screening.
文摘目的:探讨蛋白酶体抑制剂(PI)相关血栓性微血管病(TMA)的发生规律和临床特点,为临床安全用药提供参考。方法:检索中国知网、万方数据库、维普数据库、PubMed、Web of Science等数据库中收录的PI相关TMA的案例报道,检索时间为建库至2023年4月30日。对患者基本信息、用药情况、TMA的临床表现、实验室检查、治疗及预后进行汇总分析。结果:纳入文献37篇,涉及患者92例,其中男性46例(占50.00%),女性29例(占31.52%),性别不详17例(占18.48%);平均年龄为(61±13)岁。TMA的中位发病时间为64 d,临床表现以发热、乏力、恶心/呕吐、少尿/无尿为主。因1例患者出现2次TMA,则合计93例次TMA,患者血小板计数明显降低,中位值为19.5×10^(9)/L,其中0~50×10^(9)/L的患者最多(52例次,占55.91%);64例次患者(占68.82%)的血清肌酐水平升高,其中>177~445μmol/L的患者最多(32例次,占34.41%)。停药和支持治疗后(共93例次),76例次患者(占81.72%)痊愈/好转,6例次(占6.45%)有后遗症,5例次(占5.38%)死亡。PI相关TMA中,主要涉及的药物为卡非佐米(67例次,占72.04%)。结论:应重视PI所致TMA,应用PI时应考虑患者性别、药物种类等因素;根据临床表现及实验室检查结果,尽早识别不良反应,保障患者用药安全。
