BACKGROUND In recent years,many studies have shown that proteasome 26S subunit non-ATPase 6(PSMD6)plays an important role in the occurrence and development of malignant tumours.Unfortunately,there are no reports on th...BACKGROUND In recent years,many studies have shown that proteasome 26S subunit non-ATPase 6(PSMD6)plays an important role in the occurrence and development of malignant tumours.Unfortunately,there are no reports on the evaluation of the potential role of PSMD6 in hepatocellular carcinoma(HCC).AIM To comprehensively evaluate the overexpression pattern and clinical significance of PSMD6 in HCC tissues.METHODS This study integrated PSMD6 mRNA expression profiles from 4672 HCC and 3667 non-HCC tissues,along with immunohistochemical scores from 383 HCC and adjacent tissues,to assess PSMD6 overexpression in HCC.Clustered regularly interspaced short palindromic repeats knockout technology evaluated PSMD6’s essential role in HCC cell growth.Functional enrichment analysis explored the molecular mechanism of PSMD6 abnormalities in HCC.Drug sensitivity analysis and molecular docking analysed the effect of abnormal expression of PSMD6 on the drug sensitivity of HCC cells.RESULTS The results of 41 external and two internal datasets showed that PSMD6 mRNA(SMD=0.26,95%CI:0.09-0.42,P<0.05)and protein(SMD=2.85,95%CI:1.19-4.50,P<0.05)were significantly overexpressed in HCC tissues.The integrated analysis results showed that PSMD6 had a significant overexpression pattern in HCC tissues(SMD=0.40,95%CI:0.15-0.66,P<0.05).PSMD6 knockout inhibited HCC cell growth(chronos scores<-1).Functional enrichment implicated ribosome biogenesis and RNA splicing.Significant enrichment of signalling pathways such as RNA degradation,ribosomes,and chemical carcinogenesis—reactive oxygen species.Drug sensitivity analysis and a molecular docking model showed that high expression of PSMD6 was associated with the tolerance of HCC cells to drugs such as ML323,sepantronium bromide,and GDC0810.Overexpressed PSMD6 effectively distinguished HCC tissues(AUC=0.75,95%CI:0.71-0.79).CONCLUSION This study was the first to discover that PSMD6 was overexpressed in HCC tissues.PSMD6 is essential for the growth of HCC cells and may be involved in ribosome biogenesis and RNA splicing.展开更多
The proteasome,an evolutionarily conserved proteolytic complex comprising the 20S core particle and 19S regulatory particles,performs both shared and distinct functions across various tissues and organs.Spermatogenesi...The proteasome,an evolutionarily conserved proteolytic complex comprising the 20S core particle and 19S regulatory particles,performs both shared and distinct functions across various tissues and organs.Spermatogenesis,a highly complex developmental process,relies on proteasome activity at multiple stages to regulate protein turnover.In this study,we selected the 20S subunit PSMA1 and 19S regulatory subunit PSMD2 to investigate the potential functions of the proteasome in spermatogenesis.Using Psma1-EGFP and Psmd2-mCherry knock-in mouse models,we confirmed the expression of both subunits in all spermatogenic cell types,with pronounced presence in early germ cell development.To further clarify their functional significance,we specifically knocked out Psma1 and Psmd2 in germ cells.Deletion of either PSMA1 or PSMD2 led to disrupted spermatogenesis,characterized by the complete absence of sperm in the epididymis.Subsequent analysis indicated that loss of these proteasome components impaired meiotic initiation.Psma1 and Psmd2 knockout germ cells showed accumulation of DMRT1,a key regulator of mitosis-to-meiosis transition,leading to a reduction in STRA8 levels and consequent disruption of meiosis initiation.This study sheds light on the molecular mechanisms that govern meiotic initiation and identifies potential genes associated with male infertility.展开更多
Objectives:Proteasomes,multi-subunit proteases,are key actors of cellular protein catabolism and a number of regulatory processes.The detection of subtle proteasome functioning in tumors may contribute to our understa...Objectives:Proteasomes,multi-subunit proteases,are key actors of cellular protein catabolism and a number of regulatory processes.The detection of subtle proteasome functioning in tumors may contribute to our understanding of the mechanisms of cancer development.The current study aimed to identify the role of low molecular mass protein 2(LMP2),a proteasome immune subunit,in the development of mouse colon 26(C26)adenocarcinoma.Methods:The functions of the LMP2 subunit in tumor development in Balb/c mice were studied using its irreversible inhibitor KZR-504.LMP2 activity was detected by the hydrolysis of the fluorogenic substrate Ac-Pro-Ala-Leu-AMC.Western blotting and Quantitative Reverse Transcription Polymerase Chain Reaction(qRT-PCR)were used.We applied fluorescent tests for cell proliferation and apoptosis.M2 macrophages were obtained by polarization of mouse bone marrow-derived macrophages using the corresponding cytokines.Results:KZR-504 showed high specificity only for the LMP2 subunit and had no negative effect on C26 cells in culture.However,KZR-504 suppressed the formation of tumor conglomerates(by 74%,p<0.001)after C26 cell transplantation in vivo,inhibited the expression of chitinase-<3-like protein 3(Chil3)gene(by 90%,p<0.001),a key marker of immunosuppressive M2 macrophages,in the tumor<microenvironment,and reduced the tumor weight compared to the control(by 48%,p<0.01).KZR-504 also suppressed<the expression of Chil3(by 68%,p<0.05)and arginase-1(Arg1)(by 90%,p<0.001),another marker gene,in M2<<macrophages and violated M0-M2 macrophage polarization in culture.Conclusion:We discovered earlier unknown functions of the proteasome LMP2 subunit to facilitate the formation of tumor conglomerates and maintain Chil3 and Arg1 expression in immunosuppressive M2 macrophages.Our work demonstrates that the proteasome LMP2 subunit can be a target for antitumor treatment.展开更多
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
BACKGROUND Currently,intrahepatic cholangiocarcinoma(ICC)poses a continuing,significant health challenge,but the relationship has yet to be established between ICC and the proteasome 26S subunit non-ATPase 6(PSMD6).AI...BACKGROUND Currently,intrahepatic cholangiocarcinoma(ICC)poses a continuing,significant health challenge,but the relationship has yet to be established between ICC and the proteasome 26S subunit non-ATPase 6(PSMD6).AIM To investigate the protein expression and clinicopathological significance of PSMD6 in ICC.METHODS The potential impact of the PSMD6 gene on the growth of ICC cell lines was analyzed using clustered regularly interspaced short palindromic repeat knockout screening technology.Forty-two paired specimens of ICC and adjacent noncancerous tissues were collected.PSMD6 protein expression was determined by immunohistochemistry.Receiver operating characteristic curve analysis was performed to validate PSMD6 expression level,and its association with ICC patients’various clinicopathological characteristics was investigated.RESULTS The PSMD6 gene was found to be essential for the growth of ICC cell lines.PSMD6 protein was significantly overexpressed in ICC tissues(P<0.001),but showed no significant association with patient age,gender,pathological grade,or tumor-node-metastasis stage(P>0.05).CONCLUSION PSMD6 can promote the growth of ICC cells,thus playing a pro-oncogenic role.展开更多
Compound YSY-01A, a recently synthesized proteasome inhibitor, has shown potent growth-inhibitory effect on tumor cells in previous researches. However, the mechanism of its inhibitory effects, especially on cell cycl...Compound YSY-01A, a recently synthesized proteasome inhibitor, has shown potent growth-inhibitory effect on tumor cells in previous researches. However, the mechanism of its inhibitory effects, especially on cell cycle, remains largely unclear. This study aimed to evaluate the correlation between cell cycle arrest effect of YSY-01A and its anti-cancer effect, and to probe the possible molecular mechanisms for its effects on human ovarian cancer SK-OV-3 cells. The results suggested that YSY-01A significantly （P〈0.05） inhibited cellular proliferation of SK-OV-3 cells in a concentration-dependent and time-dependent manner. Furthermore, YSY-01A induced a G2/M cell cycle arrest of SK-OV-3 cells. Further investigation revealed that YSY-01A significantly （P〈0.05） changed the expression levels of a series of cell cycle related protein, such as cyclin B1, cdc2, and p-cdc2 （T14）. Meanwhile, YSY-01A could inhibit the TNF-a-induced NF-kB nuclear translocation and lead to the increase of 1kBa as well as the decrease of IKK and Gadd45a In conclusion, YSY-01A showed remarkable anti-cancer activity on SK-OV-3 cells, and its molecular mechanisms were related to G2/M cell cycle arrest.展开更多
Compound YSY-01A, a recently synthesized proteasome inhibitor, has shown potent growth-inhibitory effect on tumor cells in previous researches. However, the mechanism of its inhibitory effects, especially on cell cycl...Compound YSY-01A, a recently synthesized proteasome inhibitor, has shown potent growth-inhibitory effect on tumor cells in previous researches. However, the mechanism of its inhibitory effects, especially on cell cycle, remains largely unclear. This study aims to evaluate the correlation between cell cycle arrest effect of YSY-01A and its anti-cancer effect, and to probe the possible molecular mechanisms for its effects on human colorectal adenocarcinoma cells HT-29. The results suggested that YSY-01A significantly （P0.05） inhibited cellular proliferation of HT-29 cells in a time and concentration-dependent manner. Furthermore, YSY-01A suppressed the G 2 /M transition of HT-29 cells, whereas the mitotic inhibitor paclitaxel induced M phase accumulation. Further investigation revealed that YSY-01A significantly （P0.05） up-regulated the expression levels of a series of cell cycle related protein, such as cyclin B1, Wee1, p-cdc2 （Tyr15）, p53, p21, and p27. The HT-29 cells only exhibited typical cytotoxic symptom when YSY-01A concentration reached 0.5 μM （P0.05）, which was above the dose we used in the mechanism research. In conclusion, YSY-01A showed remarkable anti-cancer activity on HT-29 cells, and its molecular mechanisms are related to G 2 /M cell cycle transition arrest.展开更多
The proteasome is a major protein-degrading enzyme, which catalyzes degradation of oxidized and aged proteins, signal transduction factors and cleaves peptides for antigen presentation. Proteasome exists in the equili...The proteasome is a major protein-degrading enzyme, which catalyzes degradation of oxidized and aged proteins, signal transduction factors and cleaves peptides for antigen presentation. Proteasome exists in the equilibrium of 26S and 20S particles. Proteasome function is altered by ethanol metabolism, depending on oxidative stress levels： low oxidative stress induces proteasome activity, while high oxidative stress reduces it. The proposed mechanisms for modulation of proteasome activity are related to oxidative modification of proteasomal proteins with primary and secondary products derived from ethanol oxidation. Decreased proteolysis by the proteasome results in the accumulation of insoluble protein aggregates, which cannot be degraded by proteasome and which further inhibit proteasome function. Mallory bodies, a common signature of alcoholic liver diseases, are formed by liver cells, when proteasome is unable to remove cytokeratins. Proteasome inhibition by ethanol also promotes the accumulation of pro-apoptotic factors in mitochondria of ethanol-metabolizing liver cells that are normally degraded by proteasome. In addition, decreased proteasome function also induces accumulation of the negative regulators of cytokine signaling （I-~B and SOCS）, thereby blocking cytokine signal transduction. Finally, ethanol-elicited blockade of interferon type 2 and 2 signaling and decreased proteasome function impairs generation of peptides for MHC class Ⅰ-restricted antigen presentation.展开更多
Proteasome dysfunction has been repeatedly reported in alcoholic liver disease. Ethanol metabolism endproducts affect the structure of the proteasome, and, therefore, change the proteasome interaction with its regulat...Proteasome dysfunction has been repeatedly reported in alcoholic liver disease. Ethanol metabolism endproducts affect the structure of the proteasome, and, therefore, change the proteasome interaction with its regulatory complexes 19S and PA28, as well as its interacting proteins. Chronic ethanol feeding alters the ubiquitin-proteasome activity by altering the interaction between the 19S and the 20S proteasome interaction. The degradation of oxidized and damaged proteins is thus decreased and leads to accumulation of insoluble protein aggregates, such as Mallory-Denk bodies. Ethanol also affects the immunoproteasome formation. PA28a/b interactions with the 20S proteasome are decreased in the proteasome fraction isolated from the liver of rats fed ethanol chronically, thus affecting the cellular antigen presentation and defense against pathogenic agents. Recently, it has been shown that ethanol also affects the proteasome interacting proteins (PIPs). Interaction of the proteasome with Ecm29 and with deubiquitinating enzymes Rpn11, UCH37, and Usp14 has been found to decrease. However, the two UBL-ubiquitin-associated domain (UBA) PIPs p62 and valosin-containing protein are upregulated when the proteasome is inhibited. The increase of these UBL-UBA proteins, as well as the increase in Hsp70 and Hsp25 levels, compensated for the proteasome failure and helped in the unfolding/docking of misfolded proteins. Chronic alcohol feeding to rats causes a significant inhibition of the proteasome pathway and this inhibition results from a decreases of the interaction between the 20S proteasome and the regulatory complexes, PIPs, and the ubiquitin system components.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
[Objective] Using molecular biotechnology to clone the proteasome β5 gene from cotton bollworm (Helicoverpa armigera), this research aimed to provide basis for further research on the function of proteasome β5 gene ...[Objective] Using molecular biotechnology to clone the proteasome β5 gene from cotton bollworm (Helicoverpa armigera), this research aimed to provide basis for further research on the function of proteasome β5 gene in cotton bollworm. [Method] Total RNA was extracted from midgut of cotton bollworm. The full length cDNA of Habeta5 gene was cloned by using rapid amplification of cDNA ends (RACE) technology, then sequence analysis was carried out. [Result] The full length cDNA sequence was successfully cloned and isolated, named as Habeta5. It was 947 bp in length, contained an ORF (843 bp) and encoded 280 amino acid residues, with the predicted mass of 30.87 kD and isoelectric point(pI) of 9.60. In the deduced amino acid sequence, a proteasome β5 subunit domain lies between 74th to 261st amino acid residues. It has more than 62% identity to other insects such as Drosophila melanogaster. The proteasome β5 subunit conservative regions were very similar with each other. Molecular evolution by Neighbor Joining method indicated that Habeta5 was homologous with other proteasome β5 subunit of species. [Conclusion] Sequence alignment shows that the cloned fragment is a proteasome β5 subunit gene (GenBank accession number: FJ358434).展开更多
As a novel proteasome inhibitor, remarkable proliferation inhibitory effect of compound YSY-01A was shown on tumor cells in previous studies. However, few studies has reported its effect on gastric cancer and related ...As a novel proteasome inhibitor, remarkable proliferation inhibitory effect of compound YSY-01A was shown on tumor cells in previous studies. However, few studies has reported its effect on gastric cancer and related mechanism. We evaluated the anti-proliferative effect of compound YSY-01A using MGC-803 cells and its anti-tumor effect using xenograft nu-BALB/c mouse model. Cell proliferation inhibition was assessed by SRB assay. Related protein expression levels were determined by Western blot assay. We observed that the compound YSY-01A had a significant proliferation inhibitory effect on MGC-803 cells in vitro. Experiment in vivo showed that the compound YSY-01A had a remarkable growth inhibitory effect on MGC-803 cells xenograft tumor when it was used either alone or in combination with the conventional chemotherapeutic agent 5-fluorouracil （5-FU）. Furthermore, YSY-01A and 5-FU had a synergistic effect on xenograft tumor. Results of molecular experiment showed that the compound YSY-01A had a remarkable inhibitory effect on TNF-c~ and IFN induced NF-KB nuclear translocation. At the same time, the compound YSY-01A could reduce the expression of IKK-~, IL-I~ and iNOS, while it significantly enhanced the expression of COX-2 in MGC-803 ceils. Taken together, compound YSY-01A had an impressive tumor inhibitory effect, and it worked in NF-KB-related pathway, suggesting that the compound YSY-01A was an effective therapeutic drug for patients with gastric cancer. Higher tumor cell growth inhibition after the treatment in a combination with 5-FU indicated that combining YSY-01A with 5-FU might be more effective for displaying tumor cell growth inhibitory effects on gastric cancer cells.展开更多
The COP9 signalosome and the regulatory lid of the 26S proteasome are both eight-subunit protein complexes which are present in most eukaryotes. There is a one-to-one relationship between the corresponding subunits of...The COP9 signalosome and the regulatory lid of the 26S proteasome are both eight-subunit protein complexes which are present in most eukaryotes. There is a one-to-one relationship between the corresponding subunits of the two protein complexes in terms of their size and amino acid sequences. Eight groups of subunits from the COP9 signalosome and the proteasome lid complex of different organisms are collected from all the databases at the NCBI website. The corresponding subunits of COP9 signalosome and proteasome lid complex share at least 12% amino acid identity and some conserved regions, and the conserved sites spread evenly over the entire length of the subunits, suggesting that the two complexes have a common evolutionary ancestor. Phylogenetic analyses based on the amino acid sequences of the corresponding subunits of two protein complexes indicate that every tree consists of two clades. The subunits from one of the two protein complexes of different organisms are grouped into one of the two clades respectively. The sequences of single-cell organisms are always the basal groups to that of multi-cell animal and plant species. These results imply that the duplication/divergence events of COP9 signalosome and regulatory lid of the proteasome genes have occurred before the divergence of single-cell and multi-cell eukaryotes, and the genes of the two complexes are independently evolved. The analyses of dN/dS correlation show significant Pearson's correlations between 21 and 15 pairs of subunit-encoding sequences within the COP9 signalosome and the proteasome lid complex respectively, suggesting that those subunits pairs might have related functions and interacted with one another, and resulted in co-evolution.展开更多
On the basis of the Michael-addition mechanism of classical proteasome inhibitors, six dipeptide vinyl sulfonamide and dipeptide vinyl sulfonate derivatives were designed and synthesized. Moreover, an efficient method...On the basis of the Michael-addition mechanism of classical proteasome inhibitors, six dipeptide vinyl sulfonamide and dipeptide vinyl sulfonate derivatives were designed and synthesized. Moreover, an efficient method for the synthesis of g-amino vinyl sulfonamides, key intermediates to the target molecules, was developed via the Wittig-Horner reaction of peptide aldehyde with Wittig reagents derived from methanesulfonamides.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 To investigate the dynamic expression of the 20S proteasome in peripheral blood mononuclear cells(PBMCs)of type 2 diabetic patients without vascular complications.Methods PBMCs were prepared from 30 type 2 d...Objective To investigate the dynamic expression of the 20S proteasome in peripheral blood mononuclear cells(PBMCs)of type 2 diabetic patients without vascular complications.Methods PBMCs were prepared from 30 type 2 diabetic patients and 30 nondiabetic controls.The general indexes including weight,height and blood pressure were recorded.Fasting plasma glucose,fasting plasma insulin and glycosylated hemoglobin were measured.The protein level of the 20S proteasome was measured by Western blotting.The mRNA expression levels of the 20S proteasome β1,β2 and β5 subunits were detected by real-time PCR.Results Compared with that in the nondiabetic controls,the protein level of the 20S proteasome was significantly increased in the diabetic patients and was positively associated with glycosylated hemoglobin.Conclusion Type 2 diabetic patients without vascular complications have an increased 20S proteasome expression,the significance of which needs to be explored by further study.展开更多
YSY01-A, as a novel proteasome inhibitor, has shown remarkable proliferation inhibitory effect on certain types of tumor cells. However, few studies have reported its effect on non-small cell lung cancer （NSCLC）, an...YSY01-A, as a novel proteasome inhibitor, has shown remarkable proliferation inhibitory effect on certain types of tumor cells. However, few studies have reported its effect on non-small cell lung cancer （NSCLC）, and its underlying mechanism remains unknown. In our present study, we aimed to figure out the inhibitory effects as well as the mechanism of proteasome inhibitor YSY01-A against A549 cells both individually and in combination with cisplatin. A549 cell proliferation inhibition was assessed by SRB assay. Its related protein expression levels were determined by western blot assay. Moreover, the change of intracellular cisplatin accumulation was examined by ICP-MS assay. The results suggested that YSY01-A significantly （P〈0.001） inhibited the proliferation of A549 cells （IC50 was 36.2 nM for 72 h） in a concentration-dependent and time-dependent manner. Compared with the negative control group, YSY01-A （60 nM, 48 h） down-regulated PI3K/Akt pathway in A549 cells by increasing the expression level of PTEN （P〈0.01）, and decreasing the expression level of PI3K （P〈0.001） and p-Akt/Akt （P〈0.001）. When combined with cisplatin, YSY01-A of different concentrations （5, 10, 20 nM） could significantly increase the inhibition effects on A549 cells compared with the cisplatin alone treatment, showing a synergistic effect. At the same time, YSY01-A could remarkably block the cisplatin-induced down-regulation of hCTR1 in a concentration-dependent manner and increase cisplatin uptake from 2.01 to 2.47 fold （P〈0.001）. In conclusion, compound YSY01-A could significantly inhibit proliferation of NSCLC A549 cells, showing a strong synergistic effect when combined with cisplatin. Down-regulation of PI3K/Akt pathway might be the mechanism of inhibitory effect of YSY0 l-A, and the combination with cisplatin might increase the expression of CTR1 and intracellular cisplatin accumulation.展开更多
There are two degradation systems in mammalian cells, autophagy/lysosomal pathway and ubiquitin-proteasome pathway. Proteasome is consist of multiple protein subunits and plays important roles in degradation of short-...There are two degradation systems in mammalian cells, autophagy/lysosomal pathway and ubiquitin-proteasome pathway. Proteasome is consist of multiple protein subunits and plays important roles in degradation of short-lived cellular proteins. Recent studies reveal that proteasomal degradation system is also involved in signal transduction and regulation of various cellular functions. Dysfunction or dysregulation of proteasomal function may thus be an important pathogenic mechanism in certain neurological disorders. This paper reviews the biological functions of proteasome in signal transduction and its potential roles in neurodegenerative diseases.展开更多
YSY-01A has shown proliferation inhibitory activity to certain types of tumor cells by inhibiting proteasome. How- ever, its effect on autophagy, which is related with the ubiquitin proteasome pathway （UPP）, remains...YSY-01A has shown proliferation inhibitory activity to certain types of tumor cells by inhibiting proteasome. How- ever, its effect on autophagy, which is related with the ubiquitin proteasome pathway （UPP）, remains unclear. Our study aimed to find out its effect on autophagy and possible molecular mechanisms. The results suggested that YSY-0 l A significantly （P〈0.001） inhibited proliferation of PC-3M cells （IC50 was 287 nM for 48 h） in a concentration-dependent and time-dependent manner. YSY-01A （100 nM, 3 h） also induced autophagy in PC-3M ceils through increasing the expression of P53 （P〈0.001）, Beclin-1 （P〈0.001） and LC3 （P〈0.001）, and decreasing the expression of p-roTOR （P〈0.001） as compared with the negative control group. Autophagy stayed at a final stage in PC-3M cells after treated with YSY-01A （400 nM） for 12 h. Meanwhile inhibition of autophagy with chloroquine increased the sensitivity to YSY-01A in PC-3M cells. In conclusion, YSY-01A showed high proliferation inhibitory activity of PC-3M cells and it could induce autophagy in PC-3M cells. Inhibiting autophagy increased the cytotoxic activity of YSY-01A in PC-3M cells.展开更多
基金Supported by National Natural Science Foundation of China,No.82160762Guangxi Zhuang Autonomous Region Administration of Traditional Chinese Medicine Scientific Research Project,No.GXZYA20230267+2 种基金China Undergraduate Innovation and Entrepreneurship Training Program,No.S202410598060XChina Undergraduate Innovation and Entrepreneurship Training Program,No.X202410598360Future Academic Star of Guangxi Medical University,No.WLXSZX24074.
文摘BACKGROUND In recent years,many studies have shown that proteasome 26S subunit non-ATPase 6(PSMD6)plays an important role in the occurrence and development of malignant tumours.Unfortunately,there are no reports on the evaluation of the potential role of PSMD6 in hepatocellular carcinoma(HCC).AIM To comprehensively evaluate the overexpression pattern and clinical significance of PSMD6 in HCC tissues.METHODS This study integrated PSMD6 mRNA expression profiles from 4672 HCC and 3667 non-HCC tissues,along with immunohistochemical scores from 383 HCC and adjacent tissues,to assess PSMD6 overexpression in HCC.Clustered regularly interspaced short palindromic repeats knockout technology evaluated PSMD6’s essential role in HCC cell growth.Functional enrichment analysis explored the molecular mechanism of PSMD6 abnormalities in HCC.Drug sensitivity analysis and molecular docking analysed the effect of abnormal expression of PSMD6 on the drug sensitivity of HCC cells.RESULTS The results of 41 external and two internal datasets showed that PSMD6 mRNA(SMD=0.26,95%CI:0.09-0.42,P<0.05)and protein(SMD=2.85,95%CI:1.19-4.50,P<0.05)were significantly overexpressed in HCC tissues.The integrated analysis results showed that PSMD6 had a significant overexpression pattern in HCC tissues(SMD=0.40,95%CI:0.15-0.66,P<0.05).PSMD6 knockout inhibited HCC cell growth(chronos scores<-1).Functional enrichment implicated ribosome biogenesis and RNA splicing.Significant enrichment of signalling pathways such as RNA degradation,ribosomes,and chemical carcinogenesis—reactive oxygen species.Drug sensitivity analysis and a molecular docking model showed that high expression of PSMD6 was associated with the tolerance of HCC cells to drugs such as ML323,sepantronium bromide,and GDC0810.Overexpressed PSMD6 effectively distinguished HCC tissues(AUC=0.75,95%CI:0.71-0.79).CONCLUSION This study was the first to discover that PSMD6 was overexpressed in HCC tissues.PSMD6 is essential for the growth of HCC cells and may be involved in ribosome biogenesis and RNA splicing.
基金supported by the National Science Fund for Distinguished Young Scholars (81925015)Science and Technology Project of Guangzhou (2023A03J0886,2023A03J0871)National Natural Science Foundation of China (82030039,32400709)。
文摘The proteasome,an evolutionarily conserved proteolytic complex comprising the 20S core particle and 19S regulatory particles,performs both shared and distinct functions across various tissues and organs.Spermatogenesis,a highly complex developmental process,relies on proteasome activity at multiple stages to regulate protein turnover.In this study,we selected the 20S subunit PSMA1 and 19S regulatory subunit PSMD2 to investigate the potential functions of the proteasome in spermatogenesis.Using Psma1-EGFP and Psmd2-mCherry knock-in mouse models,we confirmed the expression of both subunits in all spermatogenic cell types,with pronounced presence in early germ cell development.To further clarify their functional significance,we specifically knocked out Psma1 and Psmd2 in germ cells.Deletion of either PSMA1 or PSMD2 led to disrupted spermatogenesis,characterized by the complete absence of sperm in the epididymis.Subsequent analysis indicated that loss of these proteasome components impaired meiotic initiation.Psma1 and Psmd2 knockout germ cells showed accumulation of DMRT1,a key regulator of mitosis-to-meiosis transition,leading to a reduction in STRA8 levels and consequent disruption of meiosis initiation.This study sheds light on the molecular mechanisms that govern meiotic initiation and identifies potential genes associated with male infertility.
基金funded by the Government program of basic research in Koltzov Institute of Developmental Biology of the Russian Academy of Sciences,number 0088-2024-0009the Ministry of Science and Higher Education of the Russian Federation,project number 075-15-2020-773(NPS).
文摘Objectives:Proteasomes,multi-subunit proteases,are key actors of cellular protein catabolism and a number of regulatory processes.The detection of subtle proteasome functioning in tumors may contribute to our understanding of the mechanisms of cancer development.The current study aimed to identify the role of low molecular mass protein 2(LMP2),a proteasome immune subunit,in the development of mouse colon 26(C26)adenocarcinoma.Methods:The functions of the LMP2 subunit in tumor development in Balb/c mice were studied using its irreversible inhibitor KZR-504.LMP2 activity was detected by the hydrolysis of the fluorogenic substrate Ac-Pro-Ala-Leu-AMC.Western blotting and Quantitative Reverse Transcription Polymerase Chain Reaction(qRT-PCR)were used.We applied fluorescent tests for cell proliferation and apoptosis.M2 macrophages were obtained by polarization of mouse bone marrow-derived macrophages using the corresponding cytokines.Results:KZR-504 showed high specificity only for the LMP2 subunit and had no negative effect on C26 cells in culture.However,KZR-504 suppressed the formation of tumor conglomerates(by 74%,p<0.001)after C26 cell transplantation in vivo,inhibited the expression of chitinase-<3-like protein 3(Chil3)gene(by 90%,p<0.001),a key marker of immunosuppressive M2 macrophages,in the tumor<microenvironment,and reduced the tumor weight compared to the control(by 48%,p<0.01).KZR-504 also suppressed<the expression of Chil3(by 68%,p<0.05)and arginase-1(Arg1)(by 90%,p<0.001),another marker gene,in M2<<macrophages and violated M0-M2 macrophage polarization in culture.Conclusion:We discovered earlier unknown functions of the proteasome LMP2 subunit to facilitate the formation of tumor conglomerates and maintain Chil3 and Arg1 expression in immunosuppressive M2 macrophages.Our work demonstrates that the proteasome LMP2 subunit can be a target for antitumor treatment.
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BACKGROUND Currently,intrahepatic cholangiocarcinoma(ICC)poses a continuing,significant health challenge,but the relationship has yet to be established between ICC and the proteasome 26S subunit non-ATPase 6(PSMD6).AIM To investigate the protein expression and clinicopathological significance of PSMD6 in ICC.METHODS The potential impact of the PSMD6 gene on the growth of ICC cell lines was analyzed using clustered regularly interspaced short palindromic repeat knockout screening technology.Forty-two paired specimens of ICC and adjacent noncancerous tissues were collected.PSMD6 protein expression was determined by immunohistochemistry.Receiver operating characteristic curve analysis was performed to validate PSMD6 expression level,and its association with ICC patients’various clinicopathological characteristics was investigated.RESULTS The PSMD6 gene was found to be essential for the growth of ICC cell lines.PSMD6 protein was significantly overexpressed in ICC tissues(P<0.001),but showed no significant association with patient age,gender,pathological grade,or tumor-node-metastasis stage(P>0.05).CONCLUSION PSMD6 can promote the growth of ICC cells,thus playing a pro-oncogenic role.
基金Eleventh Five-Year Plan for National Science and Technology Major Project(Grant No.2009ZX0930-010)National Science Foundation of China(Grant No.81172915)a grant from Major New Drugs Research and Development Platform of Peking University(Grant No.2009ZX09301-010)
文摘Compound YSY-01A, a recently synthesized proteasome inhibitor, has shown potent growth-inhibitory effect on tumor cells in previous researches. However, the mechanism of its inhibitory effects, especially on cell cycle, remains largely unclear. This study aimed to evaluate the correlation between cell cycle arrest effect of YSY-01A and its anti-cancer effect, and to probe the possible molecular mechanisms for its effects on human ovarian cancer SK-OV-3 cells. The results suggested that YSY-01A significantly （P〈0.05） inhibited cellular proliferation of SK-OV-3 cells in a concentration-dependent and time-dependent manner. Furthermore, YSY-01A induced a G2/M cell cycle arrest of SK-OV-3 cells. Further investigation revealed that YSY-01A significantly （P〈0.05） changed the expression levels of a series of cell cycle related protein, such as cyclin B1, cdc2, and p-cdc2 （T14）. Meanwhile, YSY-01A could inhibit the TNF-a-induced NF-kB nuclear translocation and lead to the increase of 1kBa as well as the decrease of IKK and Gadd45a In conclusion, YSY-01A showed remarkable anti-cancer activity on SK-OV-3 cells, and its molecular mechanisms were related to G2/M cell cycle arrest.
基金Eleventh Five-Year Plan for National Science and Technology Major Project (Grant No.2009ZX0930-010)National Science Foundation of China (NSFC81172915)A grant from Major New Drugs Research and Development Platform of Peking University (Grant No.2009ZX09301-010)
文摘Compound YSY-01A, a recently synthesized proteasome inhibitor, has shown potent growth-inhibitory effect on tumor cells in previous researches. However, the mechanism of its inhibitory effects, especially on cell cycle, remains largely unclear. This study aims to evaluate the correlation between cell cycle arrest effect of YSY-01A and its anti-cancer effect, and to probe the possible molecular mechanisms for its effects on human colorectal adenocarcinoma cells HT-29. The results suggested that YSY-01A significantly （P0.05） inhibited cellular proliferation of HT-29 cells in a time and concentration-dependent manner. Furthermore, YSY-01A suppressed the G 2 /M transition of HT-29 cells, whereas the mitotic inhibitor paclitaxel induced M phase accumulation. Further investigation revealed that YSY-01A significantly （P0.05） up-regulated the expression levels of a series of cell cycle related protein, such as cyclin B1, Wee1, p-cdc2 （Tyr15）, p53, p21, and p27. The HT-29 cells only exhibited typical cytotoxic symptom when YSY-01A concentration reached 0.5 μM （P0.05）, which was above the dose we used in the mechanism research. In conclusion, YSY-01A showed remarkable anti-cancer activity on HT-29 cells, and its molecular mechanisms are related to G 2 /M cell cycle transition arrest.
基金Supported by the National Institute on Alcohol Abuse and Alcoholism, grant number 5R21 AA015379-02
文摘The proteasome is a major protein-degrading enzyme, which catalyzes degradation of oxidized and aged proteins, signal transduction factors and cleaves peptides for antigen presentation. Proteasome exists in the equilibrium of 26S and 20S particles. Proteasome function is altered by ethanol metabolism, depending on oxidative stress levels： low oxidative stress induces proteasome activity, while high oxidative stress reduces it. The proposed mechanisms for modulation of proteasome activity are related to oxidative modification of proteasomal proteins with primary and secondary products derived from ethanol oxidation. Decreased proteolysis by the proteasome results in the accumulation of insoluble protein aggregates, which cannot be degraded by proteasome and which further inhibit proteasome function. Mallory bodies, a common signature of alcoholic liver diseases, are formed by liver cells, when proteasome is unable to remove cytokeratins. Proteasome inhibition by ethanol also promotes the accumulation of pro-apoptotic factors in mitochondria of ethanol-metabolizing liver cells that are normally degraded by proteasome. In addition, decreased proteasome function also induces accumulation of the negative regulators of cytokine signaling （I-~B and SOCS）, thereby blocking cytokine signal transduction. Finally, ethanol-elicited blockade of interferon type 2 and 2 signaling and decreased proteasome function impairs generation of peptides for MHC class Ⅰ-restricted antigen presentation.
基金Supported by NIH/NIAAA 8116Alcohol Center Grant on Liver and Pancreas P50-011999, Morphology Core
文摘Proteasome dysfunction has been repeatedly reported in alcoholic liver disease. Ethanol metabolism endproducts affect the structure of the proteasome, and, therefore, change the proteasome interaction with its regulatory complexes 19S and PA28, as well as its interacting proteins. Chronic ethanol feeding alters the ubiquitin-proteasome activity by altering the interaction between the 19S and the 20S proteasome interaction. The degradation of oxidized and damaged proteins is thus decreased and leads to accumulation of insoluble protein aggregates, such as Mallory-Denk bodies. Ethanol also affects the immunoproteasome formation. PA28a/b interactions with the 20S proteasome are decreased in the proteasome fraction isolated from the liver of rats fed ethanol chronically, thus affecting the cellular antigen presentation and defense against pathogenic agents. Recently, it has been shown that ethanol also affects the proteasome interacting proteins (PIPs). Interaction of the proteasome with Ecm29 and with deubiquitinating enzymes Rpn11, UCH37, and Usp14 has been found to decrease. However, the two UBL-ubiquitin-associated domain (UBA) PIPs p62 and valosin-containing protein are upregulated when the proteasome is inhibited. The increase of these UBL-UBA proteins, as well as the increase in Hsp70 and Hsp25 levels, compensated for the proteasome failure and helped in the unfolding/docking of misfolded proteins. Chronic alcohol feeding to rats causes a significant inhibition of the proteasome pathway and this inhibition results from a decreases of the interaction between the 20S proteasome and the regulatory complexes, PIPs, and the ubiquitin system components.
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.
基金Supported by National Basic Research Program of China(2005CB121005)~~
文摘[Objective] Using molecular biotechnology to clone the proteasome β5 gene from cotton bollworm (Helicoverpa armigera), this research aimed to provide basis for further research on the function of proteasome β5 gene in cotton bollworm. [Method] Total RNA was extracted from midgut of cotton bollworm. The full length cDNA of Habeta5 gene was cloned by using rapid amplification of cDNA ends (RACE) technology, then sequence analysis was carried out. [Result] The full length cDNA sequence was successfully cloned and isolated, named as Habeta5. It was 947 bp in length, contained an ORF (843 bp) and encoded 280 amino acid residues, with the predicted mass of 30.87 kD and isoelectric point(pI) of 9.60. In the deduced amino acid sequence, a proteasome β5 subunit domain lies between 74th to 261st amino acid residues. It has more than 62% identity to other insects such as Drosophila melanogaster. The proteasome β5 subunit conservative regions were very similar with each other. Molecular evolution by Neighbor Joining method indicated that Habeta5 was homologous with other proteasome β5 subunit of species. [Conclusion] Sequence alignment shows that the cloned fragment is a proteasome β5 subunit gene (GenBank accession number: FJ358434).
基金Eleventh Five-Year Plan for National Science and Technology Major Project(Grant No.2009ZX0930-010)National Science Foundation of China(Grant No.81172915)a grant from Major New Drug Research and Development Platform of PekingUniversity(Grant No.2009ZX09301-010)
文摘As a novel proteasome inhibitor, remarkable proliferation inhibitory effect of compound YSY-01A was shown on tumor cells in previous studies. However, few studies has reported its effect on gastric cancer and related mechanism. We evaluated the anti-proliferative effect of compound YSY-01A using MGC-803 cells and its anti-tumor effect using xenograft nu-BALB/c mouse model. Cell proliferation inhibition was assessed by SRB assay. Related protein expression levels were determined by Western blot assay. We observed that the compound YSY-01A had a significant proliferation inhibitory effect on MGC-803 cells in vitro. Experiment in vivo showed that the compound YSY-01A had a remarkable growth inhibitory effect on MGC-803 cells xenograft tumor when it was used either alone or in combination with the conventional chemotherapeutic agent 5-fluorouracil （5-FU）. Furthermore, YSY-01A and 5-FU had a synergistic effect on xenograft tumor. Results of molecular experiment showed that the compound YSY-01A had a remarkable inhibitory effect on TNF-c~ and IFN induced NF-KB nuclear translocation. At the same time, the compound YSY-01A could reduce the expression of IKK-~, IL-I~ and iNOS, while it significantly enhanced the expression of COX-2 in MGC-803 ceils. Taken together, compound YSY-01A had an impressive tumor inhibitory effect, and it worked in NF-KB-related pathway, suggesting that the compound YSY-01A was an effective therapeutic drug for patients with gastric cancer. Higher tumor cell growth inhibition after the treatment in a combination with 5-FU indicated that combining YSY-01A with 5-FU might be more effective for displaying tumor cell growth inhibitory effects on gastric cancer cells.
文摘The COP9 signalosome and the regulatory lid of the 26S proteasome are both eight-subunit protein complexes which are present in most eukaryotes. There is a one-to-one relationship between the corresponding subunits of the two protein complexes in terms of their size and amino acid sequences. Eight groups of subunits from the COP9 signalosome and the proteasome lid complex of different organisms are collected from all the databases at the NCBI website. The corresponding subunits of COP9 signalosome and proteasome lid complex share at least 12% amino acid identity and some conserved regions, and the conserved sites spread evenly over the entire length of the subunits, suggesting that the two complexes have a common evolutionary ancestor. Phylogenetic analyses based on the amino acid sequences of the corresponding subunits of two protein complexes indicate that every tree consists of two clades. The subunits from one of the two protein complexes of different organisms are grouped into one of the two clades respectively. The sequences of single-cell organisms are always the basal groups to that of multi-cell animal and plant species. These results imply that the duplication/divergence events of COP9 signalosome and regulatory lid of the proteasome genes have occurred before the divergence of single-cell and multi-cell eukaryotes, and the genes of the two complexes are independently evolved. The analyses of dN/dS correlation show significant Pearson's correlations between 21 and 15 pairs of subunit-encoding sequences within the COP9 signalosome and the proteasome lid complex respectively, suggesting that those subunits pairs might have related functions and interacted with one another, and resulted in co-evolution.
基金Natural Science Foundation of China for the financial support(Grant No.30772626)
文摘On the basis of the Michael-addition mechanism of classical proteasome inhibitors, six dipeptide vinyl sulfonamide and dipeptide vinyl sulfonate derivatives were designed and synthesized. Moreover, an efficient method for the synthesis of g-amino vinyl sulfonamides, key intermediates to the target molecules, was developed via the Wittig-Horner reaction of peptide aldehyde with Wittig reagents derived from methanesulfonamides.
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 To investigate the dynamic expression of the 20S proteasome in peripheral blood mononuclear cells(PBMCs)of type 2 diabetic patients without vascular complications.Methods PBMCs were prepared from 30 type 2 diabetic patients and 30 nondiabetic controls.The general indexes including weight,height and blood pressure were recorded.Fasting plasma glucose,fasting plasma insulin and glycosylated hemoglobin were measured.The protein level of the 20S proteasome was measured by Western blotting.The mRNA expression levels of the 20S proteasome β1,β2 and β5 subunits were detected by real-time PCR.Results Compared with that in the nondiabetic controls,the protein level of the 20S proteasome was significantly increased in the diabetic patients and was positively associated with glycosylated hemoglobin.Conclusion Type 2 diabetic patients without vascular complications have an increased 20S proteasome expression,the significance of which needs to be explored by further study.
基金Eleventh Five-Year Plan for National Science and Technology Major Project(Grant No.2009ZX0930010)National Science Foundation of China(Grant No.81172915)a grant from Major New Drug Research and Development Platform of Peking University(GrantNo.2009ZX09301010)
文摘YSY01-A, as a novel proteasome inhibitor, has shown remarkable proliferation inhibitory effect on certain types of tumor cells. However, few studies have reported its effect on non-small cell lung cancer （NSCLC）, and its underlying mechanism remains unknown. In our present study, we aimed to figure out the inhibitory effects as well as the mechanism of proteasome inhibitor YSY01-A against A549 cells both individually and in combination with cisplatin. A549 cell proliferation inhibition was assessed by SRB assay. Its related protein expression levels were determined by western blot assay. Moreover, the change of intracellular cisplatin accumulation was examined by ICP-MS assay. The results suggested that YSY01-A significantly （P〈0.001） inhibited the proliferation of A549 cells （IC50 was 36.2 nM for 72 h） in a concentration-dependent and time-dependent manner. Compared with the negative control group, YSY01-A （60 nM, 48 h） down-regulated PI3K/Akt pathway in A549 cells by increasing the expression level of PTEN （P〈0.01）, and decreasing the expression level of PI3K （P〈0.001） and p-Akt/Akt （P〈0.001）. When combined with cisplatin, YSY01-A of different concentrations （5, 10, 20 nM） could significantly increase the inhibition effects on A549 cells compared with the cisplatin alone treatment, showing a synergistic effect. At the same time, YSY01-A could remarkably block the cisplatin-induced down-regulation of hCTR1 in a concentration-dependent manner and increase cisplatin uptake from 2.01 to 2.47 fold （P〈0.001）. In conclusion, compound YSY01-A could significantly inhibit proliferation of NSCLC A549 cells, showing a strong synergistic effect when combined with cisplatin. Down-regulation of PI3K/Akt pathway might be the mechanism of inhibitory effect of YSY0 l-A, and the combination with cisplatin might increase the expression of CTR1 and intracellular cisplatin accumulation.
基金This work was supported by the National Natural Science Foundation of China （No. 30470587, No. 30600197）.
文摘There are two degradation systems in mammalian cells, autophagy/lysosomal pathway and ubiquitin-proteasome pathway. Proteasome is consist of multiple protein subunits and plays important roles in degradation of short-lived cellular proteins. Recent studies reveal that proteasomal degradation system is also involved in signal transduction and regulation of various cellular functions. Dysfunction or dysregulation of proteasomal function may thus be an important pathogenic mechanism in certain neurological disorders. This paper reviews the biological functions of proteasome in signal transduction and its potential roles in neurodegenerative diseases.
基金Eleventh Five-Year Plan for National Science and Technology Major Project(Grant No.2009ZX0930-010)National Science Foundation of China(Grant No.81172915)a grant from Major New Drugs Research and Development Platform of Peking University(Grant No.2009ZX09301-010)
文摘YSY-01A has shown proliferation inhibitory activity to certain types of tumor cells by inhibiting proteasome. How- ever, its effect on autophagy, which is related with the ubiquitin proteasome pathway （UPP）, remains unclear. Our study aimed to find out its effect on autophagy and possible molecular mechanisms. The results suggested that YSY-0 l A significantly （P〈0.001） inhibited proliferation of PC-3M cells （IC50 was 287 nM for 48 h） in a concentration-dependent and time-dependent manner. YSY-01A （100 nM, 3 h） also induced autophagy in PC-3M ceils through increasing the expression of P53 （P〈0.001）, Beclin-1 （P〈0.001） and LC3 （P〈0.001）, and decreasing the expression of p-roTOR （P〈0.001） as compared with the negative control group. Autophagy stayed at a final stage in PC-3M cells after treated with YSY-01A （400 nM） for 12 h. Meanwhile inhibition of autophagy with chloroquine increased the sensitivity to YSY-01A in PC-3M cells. In conclusion, YSY-01A showed high proliferation inhibitory activity of PC-3M cells and it could induce autophagy in PC-3M cells. Inhibiting autophagy increased the cytotoxic activity of YSY-01A in PC-3M cells.
