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Cancer Biology & Therapy Dec 2023Osteosarcoma is a highly metastatic malignant bone tumor, necessitating the development of new treatments to target its metastasis. Recent studies have revealed the...
Osteosarcoma is a highly metastatic malignant bone tumor, necessitating the development of new treatments to target its metastasis. Recent studies have revealed the significance of VAMP8 in regulating various signaling pathways in various types of cancer. However, the specific functional role of VAMP8 in osteosarcoma progression remains unclear. In this study, we observed a significant downregulation of VAMP8 in osteosarcoma cells and tissues. Low levels of VAMP8 in osteosarcoma tissues were associated with patients' poor prognosis. VAMP8 inhibited the migration and invasion capability of osteosarcoma cells. Mechanically, we identified DDX5 as a novel interacting partner of VAMP8, and the conjunction of VAMP8 and DDX5 promoted the degradation of DDX5 via the ubiquitin-proteasome system. Moreover, reduced levels of DDX5 led to the downregulation of β-catenin, thereby suppressing the epithelial-mesenchymal transition (EMT). Additionally, VAMP8 promoted autophagy flux, which may contribute to the suppression of osteosarcoma metastasis. In conclusion, our study anticipated that VAMP8 inhibits osteosarcoma metastasis by promoting the proteasomal degradation of DDX5, consequently inhibiting WNT/β-catenin signaling and EMT. Dysregulation of autophagy by VAMP8 is also implicated as a potential mechanism. These findings provide new insights into the biological nature driving osteosarcoma metastasis and highlight the modulation of VAMP8 as a potential therapeutic strategy for targeting osteosarcoma metastasis.
Topics: Humans; beta Catenin; Cell Line, Tumor; Wnt Signaling Pathway; Osteosarcoma; Bone Neoplasms; Epithelial-Mesenchymal Transition; Gene Expression Regulation, Neoplastic; Cell Movement; Cell Proliferation; R-SNARE Proteins
PubMed: 37405957
DOI: 10.1080/15384047.2023.2230641 -
Current Oncology (Toronto, Ont.) Nov 2023Proteasome inhibitors are moieties targeting the proteolytic activity of a proteasome, with demonstrated efficacy in certain hematological malignancies and candidate... (Review)
Review
Proteasome Inhibitors against Glioblastoma-Overview of Molecular Mechanisms of Cytotoxicity, Progress in Clinical Trials, and Perspective for Use in Personalized Medicine.
Proteasome inhibitors are moieties targeting the proteolytic activity of a proteasome, with demonstrated efficacy in certain hematological malignancies and candidate drugs in other types of cancer, including glioblastoma (GBM). They disturb the levels of proteasome-regulated proteins and lead to the cell cycle inhibition and apoptosis of GBM cells. The accumulation of cell cycle inhibitors p21 and p27, and decreased levels of prosurvival molecules NFKB, survivin, and MGMT, underlie proteasome inhibitors' cytotoxicity when used alone or in combination with the anti-GBM cytostatic drug temozolomide (TMZ). The evidence gathered in preclinical studies substantiated the design of clinical trials that employed the two most promising proteasome inhibitors, bortezomib and marizomib. The drug safety profile, maximum tolerated dose, and interaction with other drugs were initially evaluated, mainly in recurrent GBM patients. A phase III study on newly diagnosed GBM patients who received marizomib as an adjuvant to the Stupp protocol was designed and completed in 2021, with the Stupp protocol receiving patients as a parallel control arm. The data from this phase III study indicate that marizomib does not improve the PFS and OS of GBM patients; however, further analysis of the genetic and epigenetic background of each patient tumor may shed some light on the sensitivity of individual patients to proteasome inhibition. The mutational and epigenetic makeup of GBM cells, like genetic alterations to and , or promoter methylation levels may actually determine the response to proteasome inhibition.
Topics: Humans; Glioblastoma; Proteasome Inhibitors; Proteasome Endopeptidase Complex; Precision Medicine; Neoplasm Recurrence, Local
PubMed: 37999122
DOI: 10.3390/curroncol30110702 -
Redox Biology Aug 2023Oxidative stress due to abnormal accumulation of reactive oxygen species (ROS) is an initiator of a large number of human diseases, and thus, the elimination and...
Oxidative stress due to abnormal accumulation of reactive oxygen species (ROS) is an initiator of a large number of human diseases, and thus, the elimination and prevention of excessive ROS are important aspects of preventing the development of such diseases. Nuclear factor erythroid 2-related factor 2 (NRF2) is an essential transcription factor that defends against oxidative stress, and its function is negatively controlled by Kelch-like ECH-associated protein 1 (KEAP1). Therefore, activating NRF2 by inhibiting KEAP1 is viewed as a strategy for combating oxidative stress-related diseases. Here, we generated a cereblon (CRBN)-based proteolysis-targeting chimera (PROTAC), which we named SD2267, that induces the proteasomal degradation of KEAP1 and leads to NRF2 activation. As was intended, SD2267 bound to KEAP1, recruited CRBN, and induced the degradation of KEAP1. Furthermore, the KEAP1 degradation efficacy of SD2267 was diminished by MG132 (a proteasomal degradation inhibitor) but not by chloroquine (an autophagy inhibitor), which suggested that KEAP1 degradation by SD2267 was proteasomal degradation-dependent and autophagy-independent. Following KEAP1 degradation, SD2267 induced the nuclear translocation of NRF2, which led to the expression of NRF2 target genes and attenuated ROS accumulation induced by acetaminophen (APAP) in hepatocytes. Based on in vivo pharmacokinetic study, SD2267 was injected intraperitoneally at 1 or 3 mg/kg in APAP-induced liver injury mouse model. We observed that SD2267 degraded hepatic KEAP1 and attenuated APAP-induced liver damage. Summarizing, we described the synthesis of a KEAP1-targeting PROTAC (SD2267) and its efficacy and mode of action in vitro and in vivo. The results obtained suggest that SD2267 could be used to treat hepatic diseases related to oxidative stress.
Topics: Mice; Animals; Humans; Antioxidants; Kelch-Like ECH-Associated Protein 1; Reactive Oxygen Species; Proteolysis; Acetaminophen; NF-E2-Related Factor 2; Oxidative Stress
PubMed: 37348157
DOI: 10.1016/j.redox.2023.102783 -
ACS Chemical Biology Jan 2024Targeted protein degradation has arisen as a powerful therapeutic modality for eliminating proteins. Thus far, most heterobifunctional proteolysis targeting chimeras...
Targeted protein degradation has arisen as a powerful therapeutic modality for eliminating proteins. Thus far, most heterobifunctional proteolysis targeting chimeras (PROTACs) have utilized recruiters against substrate receptors of Cullin RING E3 ubiquitin ligases, such as cereblon and VHL. However, previous studies have surprisingly uncovered molecular glue degraders that exploit a CUL4 adaptor protein DDB1 to degrade neosubstrate proteins. Here, we sought to investigate whether DDB1 recruiters can be discovered that can be exploited for PROTAC applications. We utilized activity-based protein profiling and cysteine chemoproteomic screening to identify a covalent recruiter that targets C173 on DDB1 and exploited this recruiter to develop PROTACs against BRD4 and androgen receptor (AR). We demonstrated that the BRD4 PROTAC results in selective degradation of the short BRD4 isoform over the long isoform in a proteasome, NEDDylation, and DDB1-dependent manner. We also demonstrated degradation of AR with the AR PROTAC in prostate cancer cells. Our study demonstrated that covalent chemoproteomic approaches can be used to discover recruiters against Cullin RING adapter proteins and that these recruiters can be used for PROTAC applications to degrade neo-substrates.
Topics: Proteolysis; Cullin Proteins; Transcription Factors; Nuclear Proteins; Ubiquitin-Protein Ligases; Adaptor Proteins, Signal Transducing; Proteasome Endopeptidase Complex; Protein Isoforms
PubMed: 38192078
DOI: 10.1021/acschembio.3c00487 -
Expert Reviews in Molecular Medicine Mar 2024Deubiquitinases are a group of proteins that identify and digest monoubiquitin chains or polyubiquitin chains attached to substrate proteins, preventing the substrate... (Review)
Review
Deubiquitinases are a group of proteins that identify and digest monoubiquitin chains or polyubiquitin chains attached to substrate proteins, preventing the substrate protein from being degraded by the ubiquitin-proteasome system. Deubiquitinases regulate cellular autophagy, metabolism and oxidative stress by acting on different substrate proteins. Recent studies have revealed that deubiquitinases act as a critical regulator in various cardiac diseases, and control the onset and progression of cardiac disease through a board range of mechanism. This review summarizes the function of different deubiquitinases in cardiac disease, including cardiac hypertrophy, myocardial infarction and diabetes mellitus-related cardiac disease. Besides, this review briefly recapitulates the role of deubiquitinases modulators in cardiac disease, providing the potential therapeutic targets in the future.
Topics: Humans; Ubiquitin; Polyubiquitin; Proteasome Endopeptidase Complex; Myocardial Infarction; Deubiquitinating Enzymes
PubMed: 38525836
DOI: 10.1017/erm.2024.2 -
Gene Nov 2023The role of histone deacetylases (HDACs) in the tumor immune microenvironment of gynecologic tumors remains unexplored. We integrated data from The Cancer Genome Atlas...
The role of histone deacetylases (HDACs) in the tumor immune microenvironment of gynecologic tumors remains unexplored. We integrated data from The Cancer Genome Atlas and Human Protein Atlas to examine HDAC expression in breast, cervical, ovarian, and endometrial cancers. Elevated HDAC expression correlated with poor prognosis and highly malignant cancer subtypes. Gene Set Enrichment Analysis revealed positive associations between HDAC expression and tumor proliferation signature, while negative associations were found with tumor inflammation signature. Increased HDAC expression was linked to reduced infiltration of natural killer (NK), NKT, and CD8 T cells, along with negative associations with the expression of PSMB10, NKG7, CCL5, CD27, HLA-DQA1, and HLA-DQB1. In a murine 4T1 breast cancer model, treatment with suberoylanilide hydroxamic acid (SAHA; HDAC inhibitor) and PD-1 antibody significantly inhibited tumor growth and infiltration of CD3 and CD8 T cells. Real-time polymerase chain reaction revealed upregulated expressions of Psmb10, Nkg7, Ccl5, Cd8a, Cxcr6, and Cxcl9 genes, while Ctnnb1 and Myc genes were inhibited, indicating tumor suppression and immune microenvironment activation. Our study revealed that HDACs play tumor-promoting and immunosuppressive roles in gynecologic cancers, suggesting HDAC inhibitors as potential therapeutic agents for these cancers.
Topics: Female; Humans; Animals; Mice; Histone Deacetylases; Genital Neoplasms, Female; Hydroxamic Acids; CD8-Positive T-Lymphocytes; Vorinostat; Histone Deacetylase Inhibitors; Tumor Microenvironment; Membrane Proteins; Proteasome Endopeptidase Complex
PubMed: 37572797
DOI: 10.1016/j.gene.2023.147704 -
Science Advances Oct 2023Endoplasmic reticulum-associated degradation (ERAD) maintains protein homeostasis by retrieving misfolded proteins from the endoplasmic reticulum (ER) lumen into the...
Endoplasmic reticulum-associated degradation (ERAD) maintains protein homeostasis by retrieving misfolded proteins from the endoplasmic reticulum (ER) lumen into the cytosol for degradation. The retrotranslocation of misfolded proteins across the ER membrane is an energy-consuming process, with the detailed transportation mechanism still needing clarification. We determined the cryo-EM structures of the hetero-decameric complex formed by the Derlin-1 tetramer and the p97 hexamer. It showed an intriguing asymmetric complex and a putative coordinated squeezing movement in Derlin-1 and p97 parts. With the conformational changes of p97 induced by its ATP hydrolysis activities, the Derlin-1 channel could be torn into a "U" shape with a large opening to the lipidic environment, thereby forming an entry for the substrates in the ER membrane. The EM analysis showed that p97 formed a functional protein complex with Derlin-1, revealing the coupling mechanism between the ERAD retrotranslocation and the ATP hydrolysis activities.
Topics: Humans; Endoplasmic Reticulum-Associated Degradation; Cryoelectron Microscopy; Proteasome Endopeptidase Complex; Membrane Proteins; Adenosine Triphosphatases; Adenosine Triphosphate
PubMed: 37831771
DOI: 10.1126/sciadv.adi5656 -
The Journal of Cell Biology Feb 2024Cytoplasmic aggregation of TDP-43 in neurons is a pathological feature common to amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). We...
Cytoplasmic aggregation of TDP-43 in neurons is a pathological feature common to amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). We demonstrate that the IκB kinase (IKK) complex promotes the degradation of cytoplasmic TDP-43 through proteasomes. While IKKβ is a major factor in TDP-43 degradation, IKKα acts as a cofactor, and NEMO functions as a scaffold for the recruitment of TDP-43 to the IKK complex. Furthermore, we identified IKKβ-induced phosphorylation sites of TDP-43 and found that phosphorylation at Thr8 and Ser92 is important for the reduction of TDP-43 by IKK. TDP-43 phosphorylation at Ser92 was detected in a pattern different from that of C-terminal phosphorylation in the pathological inclusion of ALS. IKKβ was also found to significantly reduce the expression level and toxicity of the disease-causing TDP-43 mutation. Finally, the favorable effect of IKKβ on TDP-43 aggregation was confirmed in the hippocampus of mice. IKK and the N-terminal phosphorylation of TDP-43 are potential therapeutic targets for ALS and FTLD.
Topics: Animals; Mice; Amyotrophic Lateral Sclerosis; Disease Models, Animal; DNA-Binding Proteins; Frontotemporal Dementia; Frontotemporal Lobar Degeneration; I-kappa B Kinase; Proteasome Endopeptidase Complex; Humans
PubMed: 38197897
DOI: 10.1083/jcb.202302048 -
Genetics in Medicine : Official Journal... Jun 2024Imbalances in protein homeostasis affect human brain development, with the ubiquitin-proteasome system (UPS) and autophagy playing crucial roles in neurodevelopmental...
PURPOSE
Imbalances in protein homeostasis affect human brain development, with the ubiquitin-proteasome system (UPS) and autophagy playing crucial roles in neurodevelopmental disorders (NDD). This study explores the impact of biallelic USP14 variants on neurodevelopment, focusing on its role as a key hub connecting UPS and autophagy.
METHODS
Here, we identified biallelic USP14 variants in 4 individuals from 3 unrelated families: 1 fetus, a newborn with a syndromic NDD and 2 siblings affected by a progressive neurological disease. Specifically, the 2 siblings from the latter family carried 2 compound heterozygous variants c.8T>C p.(Leu3Pro) and c.988C>T p.(Arg330∗), whereas the fetus had a homozygous frameshift c.899_902del p.(Lys300Serfs∗24) variant, and the newborn patient harbored a homozygous frameshift c.233_236del p.(Leu78Glnfs∗11) variant. Functional studies were conducted using sodium dodecyl-sulfate polyacrylamide gel electrophoresis, western blotting, and mass spectrometry analyses in both patient-derived and CRISPR-Cas9-generated cells.
RESULTS
Our investigations indicated that the USP14 variants correlated with reduced N-terminal methionine excision, along with profound alterations in proteasome, autophagy, and mitophagy activities.
CONCLUSION
Biallelic USP14 variants in NDD patients perturbed protein degradation pathways, potentially contributing to disorder etiology. Altered UPS, autophagy, and mitophagy activities underscore the intricate interplay, elucidating their significance in maintaining proper protein homeostasis during brain development.
Topics: Humans; Neurodevelopmental Disorders; Female; Male; Alleles; Autophagy; Ubiquitin Thiolesterase; Infant, Newborn; Proteasome Endopeptidase Complex; Pedigree; Homozygote; Genetic Predisposition to Disease; Mutation
PubMed: 38469793
DOI: 10.1016/j.gim.2024.101120 -
Life Science Alliance Aug 2023The interaction of the 19S regulatory particle of the 26S proteasome with ubiquitylated proteins leads to gate opening of the 20S core particle and increases its...
The interaction of the 19S regulatory particle of the 26S proteasome with ubiquitylated proteins leads to gate opening of the 20S core particle and increases its proteolytic activity by binding of the ubiquitin chain to the inhibitory deubiquitylation enzyme USP14 on the 19S regulatory subunit RPN1. Covalent modification of proteins with the cytokine inducible ubiquitin-like modifier FAT10 is an alternative signal for proteasomal degradation. Here, we report that FAT10 and its interaction partner NUB1L facilitate the gate opening of the 20S proteasome in an ubiquitin- and USP14-independent manner. We also show that FAT10 is capable to activate all peptidolytic activities of the 26S proteasome, however only together with NUB1L, by binding to the UBA domains of NUB1L and thereby interfering with NUB1L dimerization. The binding of FAT10 to NUB1L leads to an increased affinity of NUB1L for the subunit RPN1. In conclusion, the herein described cooperation of FAT10 and NUB1L is a substrate-induced mechanism to activate the 26S proteasome.
Topics: Humans; Mice; Proteasome Endopeptidase Complex; Proteolysis; Ubiquitin; Ubiquitins; Animals
PubMed: 37188463
DOI: 10.26508/lsa.202201463