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Triple-negative breast cancer (TNBC) is a subtype of breast cancer with aggressive behavior and poor prognosis. Current therapeutic options available for TNBC patients are primarily chemotherapy. With our evolving understanding of this disease, novel targeted therapies, including poly ADP-ribose polymerase (PARP) inhibitors, antibody-drug conjugates, and immune-checkpoint inhibitors, have been developed for clinical use. Previous reports have demonstrated the essential role of estrogen receptor ß (ERß) in TNBC, but the detailed molecular mechanisms downstream ERß activation in TNBC are still far from elucidated. In this study, we demonstrated that a specific ERß agonist, LY500307, potently induces R-loop formation and DNA damage in TNBC cells. Subsequent interactome experiments indicated that the residues 151 to 165 of U2 small nuclear RNA auxiliary factor 1 (U2AF1) and the Trp439 and Lys443 of ERß were critical for the binding between U2AF1 and ERß. Combined RNA sequencing and ribosome sequencing analysis demonstrated that U2AF1-regulated downstream RNA splicing of 5-oxoprolinase (OPLAH) could affect its enzymatic activity and is essential for ERß-induced R-loop formation and DNA damage. In clinical samples including 115 patients from The Cancer Genome Atlas (TCGA) and 32 patients from an in-house cohort, we found a close correlation in the expression of ESR2 and U2AF1 in TNBC patients. Collectively, our study has unraveled the molecular mechanisms that explain the therapeutic effects of ERß activation in TNBC, which provides rationale for ERß activation-based single or combined therapy for patients with TNBC.
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Empalme Alternativo , Benzopiranos , Receptor beta de Estrógeno , Estructuras R-Loop , Factor de Empalme U2AF , Neoplasias de la Mama Triple Negativas , Humanos , Receptor beta de Estrógeno/agonistas , Receptor beta de Estrógeno/metabolismo , Factor de Empalme U2AF/química , Factor de Empalme U2AF/genética , Factor de Empalme U2AF/metabolismo , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/metabolismo , Terapia Combinada , Células MDA-MB-231 , Empalme Alternativo/efectos de los fármacos , Benzopiranos/farmacología , Benzopiranos/uso terapéutico , Unión Proteica , Sitios de UniónRESUMEN
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes a respiratory disease called coronavirus disease 2019 (COVID-19), the spread of which has led to a pandemic. An effective preventive vaccine against this virus is urgently needed. As an essential step during infection, SARS-CoV-2 uses the receptor-binding domain (RBD) of the spike protein to engage with the receptor angiotensin-converting enzyme 2 (ACE2) on host cells1,2. Here we show that a recombinant vaccine that comprises residues 319-545 of the RBD of the spike protein induces a potent functional antibody response in immunized mice, rabbits and non-human primates (Macaca mulatta) as early as 7 or 14 days after the injection of a single vaccine dose. The sera from the immunized animals blocked the binding of the RBD to ACE2, which is expressed on the cell surface, and neutralized infection with a SARS-CoV-2 pseudovirus and live SARS-CoV-2 in vitro. Notably, vaccination also provided protection in non-human primates to an in vivo challenge with SARS-CoV-2. We found increased levels of RBD-specific antibodies in the sera of patients with COVID-19. We show that several immune pathways and CD4 T lymphocytes are involved in the induction of the vaccine antibody response. Our findings highlight the importance of the RBD domain in the design of SARS-CoV-2 vaccines and provide a rationale for the development of a protective vaccine through the induction of antibodies against the RBD domain.
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Anticuerpos Antivirales/inmunología , Betacoronavirus/inmunología , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/prevención & control , Pandemias/prevención & control , Neumonía Viral/inmunología , Neumonía Viral/prevención & control , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/inmunología , Vacunas Virales/inmunología , Animales , Anticuerpos Neutralizantes/inmunología , COVID-19 , Vacunas contra la COVID-19 , Humanos , Macaca mulatta/inmunología , Macaca mulatta/virología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Modelos Animales , Modelos Moleculares , Dominios Proteicos , SARS-CoV-2 , Suero/inmunología , Bazo/citología , Bazo/inmunología , Linfocitos T/inmunología , VacunaciónRESUMEN
Liver cancer is one of the most prevalent malignant tumors worldwide. According to the staging criteria of Barcelona Clinic Liver Cancer, clinical guidelines provide tutorials to clinical management of liver cancer at their individual stages. However, most patients diagnosed with liver cancer are at advanced stage, thereby, many researchers conduct investigations on targeted therapy, aiming to improve the overall survival of these patients. To date, small molecule-based targeted therapies are highly recommended (fist-line: Sorafenib and Lenvatinib; second-line: Regorafenib and Cabozantinib) by current clinical guidelines of American Society of Clinical Oncology, European Society for Medical Oncology, and National Comprehensive Cancer Network. Herein, we summarize the small molecule-based targeted therapies in liver cancer, including the approved and preclinical therapies as well as the therapies under clinical trials, and introduce their history of discovery, clinical trials, indications, and molecular mechanisms. For drug resistance, the revealed mechanisms of action and the combination therapies are also discussed. In fact, the known small molecule-based therapies still have limited clinical benefits to liver cancer patients. Therefore, we analyze the current status and give our ideas for the urgent issues and future directions in this field, suggesting the clues for novel techniques in liver cancer treatment.
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GSK3α and GSK3ß are two GSK3 isoforms with 84% overall identity and 98% identity in their catalytic domains. GSK3ß plays important roles in the pathogenesis of cancer, while GSK3α has long been considered a functionally redundant protein of GSK3ß. Few studies have specifically investigated the functions of GSK3α. In this study, unexpectedly, we found that the expression of GSK3α, but not GSK3ß, was significantly correlated with the overall survival of colon cancer patients in 4 independent cohorts. To decipher the roles of GSK3α in colon cancer, we profiled the phosphorylation substrates of GSK3α and uncovered 156 phosphosites from 130 proteins specifically regulated by GSK3α. A number of these GSK3α-mediated phosphosites have never been reported before or have been incorrectly identified as substrates of GSK3ß. Among them, the levels of HSF1S303p, CANXS583p, MCM2S41p, POGZS425p, SRRM2T983p, and PRPF4BS431p were significantly correlated with the overall survival of colon cancer patients. Further pull-down assays identified 23 proteins, such as THRAP3, BCLAF1, and STAU1, showing strong binding affinity to GSK3α. The interaction between THRAP3 and GSK3α was verified by biochemical experiments. Notably, among the 18 phosphosites of THRAP3, phosphorylation at S248, S253, and S682 is specifically mediated by GSK3α. Mutation of S248 to D (S248D), which mimics the effect of phosphorylation, obviously increased cancer cell migration and the binding affinity to proteins related to DNA damage repair. Collectively, this work not only discloses the specific function of GSK3α as a kinase but also suggests GSK3α as a promising therapeutic target for colon cancer.
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Relevancia Clínica , Neoplasias del Colon , Humanos , Proteínas del Citoesqueleto , Glucógeno Sintasa Quinasa 3 beta , Fosforilación , Isoformas de Proteínas , Proteínas Serina-Treonina Quinasas , Proteómica , Proteínas de Unión al ARNRESUMEN
The occurrence and prevalence of colorectal cancer (CRC) is closely associated with age. More than 90% of patients with CRC are diagnosed after 50 years of age. However, CRC incidence of young individuals has been increasing since 1990s, whereas the overall CRC frequency is declining. Distinct overall survival rates between young and aged patients with CRC have been established. Tremendous efforts have been made to clarify the underlying mechanisms of age-dependent clinical differences, but it still remains elusive. Here, we performed proteomic profiling of 50 patients with CRC and revealed proteomic signatures of CRC across age groups. Gene set enrichment analysis showed that distinct age-dependent clinical outcomes might mainly attribute to varied MYC targets V1/V2, E2F targets and G2M checkpoint gene sets, which were associated with cancer cell proliferation, cell apoptosis, tumor growth, and tumor metastasis. Multiple linear regression analysis revealed a large number of functional proteins, such as NOP2, CSE1L, NHP2, NOC2L and CDK1, with adjusted expression significantly correlated with age (p < 0.05). Among them, NHP2 is a core component of the telomerase complex associated with age. High NHP2 expression predicted poor overall survival, with a more significant correlation in aged patients with CRC. Knockdown of NHP2 significantly suppressed cancer cell proliferation. In addition, we revealed some age-related potential clinically actionable targets, such as PSEN1, TSPO, and CDK1, which might be more suitable for patients with late-onset CRC. Collectively, this study identifies age-associated proteomic signatures and potential therapeutic targets of CRC and may help make a precise decision on CRC treatment.
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Envejecimiento/metabolismo , Neoplasias Colorrectales/metabolismo , Adulto , Envejecimiento/genética , Proteína Quinasa CDC2/metabolismo , Línea Celular Tumoral , Proteína de Susceptibilidad a Apoptosis Celular/metabolismo , Neoplasias Colorrectales/genética , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Presenilina-1/metabolismo , Proteómica , Receptores de GABA/metabolismo , Proteínas Represoras/metabolismo , Ribonucleoproteínas Nucleares Pequeñas/genética , Ribonucleoproteínas Nucleares Pequeñas/metabolismo , ARNt Metiltransferasas/genética , ARNt Metiltransferasas/metabolismoRESUMEN
The rate-limiting serine biogenesis enzyme PHGDH is overexpressed in cancers. Both serine withdrawal and genetic/pharmacological inhibition of PHGDH have demonstrated promising tumor-suppressing activities. However, the enzyme properties of PHGDH are not well understood and the discovery of PHGDH inhibitors is still in its infancy. Here, oridonin was identified from a natural product library as a new PHGDH inhibitor. The crystal structure of PHGDH in complex with oridonin revealed a new allosteric site. The binding of oridonin to this site reduced the activity of the enzyme by relocating R54, a residue involved in substrate binding. Mutagenesis studies showed that PHGDH activity was very sensitive to cysteine mutations, especially those in the substrate binding domain. Conjugation of oridonin and other reported covalent PHGDH inhibitors to these sites will therefore inhibit PHGDH. In addition to being inhibited enzymatically, PHGDH can also be inhibited by protein aggregation and proteasome-mediated degradation. Several tested PHGDH cancer mutants showed altered enzymatic activity, which can be explained by protein structure and stability. Overall, the above studies present new biophysical and biochemical insights into PHGDH and may facilitate the future design of PHGDH inhibitors.
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Fenómenos Biofísicos , Inhibidores Enzimáticos/farmacología , Fosfoglicerato-Deshidrogenasa/antagonistas & inhibidores , Productos Biológicos/química , Productos Biológicos/farmacología , Línea Celular Tumoral , Cristalografía por Rayos X , Cisteína/genética , Cisteína/metabolismo , Diterpenos de Tipo Kaurano/química , Diterpenos de Tipo Kaurano/farmacología , Inhibidores Enzimáticos/química , Ácidos Glicéricos/metabolismo , Humanos , Mutación/genética , NAD/metabolismo , Fosfoglicerato-Deshidrogenasa/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Agregado de Proteínas , Proteolisis/efectos de los fármacos , Especificidad por Sustrato/efectos de los fármacosRESUMEN
Here we report a nonenzymatic glycosylation reaction that builds axial S-glycosidic bonds under biorelevant conditions. This strategy is enabled by the design and use of allyl glycosyl sulfones as precursors to glycosyl radicals and exploits the exceptional functional group tolerance of radical processes. Our method introduces a variety of unprotected glycosyl units to the cysteine residues of peptides in a highly selective fashion. Through developing the second-generation protocol, we applied our method in the direct glycosylation of complex polypeptides and proteins. Computational studies were performed to elucidate the reaction mechanism.
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Péptidos/síntesis química , Proteínas/síntesis química , Glicosilación , Estructura Molecular , Péptidos/química , Proteínas/química , EstereoisomerismoRESUMEN
BACKGROUND AND AIMS: Tumor metastasis is a major factor of high recurrence and mortality in hepatocellular carcinoma (HCC), but its underlying mechanism remains elusive. We report that PDZ and LIM domain protein 1 (PDLIM1) is significantly down-regulated in metastatic human HCC tissues, which predicts unfavorable prognosis, suggesting that PDLIM1 may play an important inhibitory role during HCC metastasis. APPROACH AND RESULTS: Functional studies indicate that PDLIM1 knockdown induces epithelial-to-mesenchymal transition (EMT) of HCC cells, elevates their invasive capacity, and promotes metastasis in vitro and in vivo, whereas overexpression of PDLIM1 exhibits opposite phenotypes. Mechanistically, PDLIM1 competitively binds to the cytoskeleton cross-linking protein alpha-actinin 4 (ACTN4), leading to the disassociation of ACTN4 from F-actin, thus preventing F-actin overgrowth. In contrast, loss of PDLIM1 induces excessive F-actin formation, resulting in dephosphorylation of large tumor suppressor kinase 1 and activation of Yes-associated protein, thereby promoting HCC metastasis. Moreover, Asn145 (N145) of PDLIM1 is critical for its interaction with ACTN4, and N145A mutation abolishes its regulatory function in Hippo signaling and HCC metastasis. CONCLUSIONS: Our findings indicate that PDLIM1 suppresses HCC metastasis by modulating Hippo signaling, suggesting that PDLIM1 may be a potential prognostic marker for metastatic HCC.
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Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/secundario , Proteínas con Dominio LIM/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Factores de Transcripción/metabolismo , Actinina/metabolismo , Actinas/metabolismo , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Carcinoma Hepatocelular/genética , Línea Celular Tumoral , Transición Epitelial-Mesenquimal , Vía de Señalización Hippo , Humanos , Proteínas con Dominio LIM/genética , Neoplasias Hepáticas/genética , Metástasis de la Neoplasia , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal , Factores de Transcripción/genética , Proteínas Señalizadoras YAPRESUMEN
Gastrointestinal stromal tumor (GIST) is a common sarcoma of gastrointestinal tract (GIT) with high metastatic and recurrence rates, but the proteomic features are still less understood. Here we performed systematic quantitative proteome profiling of GIST from 13 patients classified into very low/low, intermediate and high risk subgroups. An extended cohort of GIST (n = 131) was used for immunohistochemical validation of proteins of interest. In total, 9177 proteins were quantified, covering 55.9% of the GIT transcriptome from The Human Protein Altas. Out of the 9177 quantified proteins, 4930 proteins were observed in all 13 cases with 517 upregulated and 187 downregulated proteins in tumorous tissues independent of risk stage. Pathway analysis showed that the downregulated proteins were mostly enriched in metabolic pathway, whereas the upregulated proteins mainly belonged to spliceosome pathway. In addition, 131 proteins showed differentially expressed patterns among GIST subgroups with statistical significance. The 13 GIST cases were classified into 3 subgroups perfectly based on the expression of these proteins. The intensive comparison of molecular phenotypes and possible functions of quantified oncoproteins, tumor suppressors, phosphatases and kinases between GIST subgroups was carried out. Immunohistochemical analysis of the phosphatase PTPN1 (n = 117) revealed that the GIST patients with high PTPN1 expression had low chances of developing metastasis. Collectively, this work provides valuable information for understanding the inherent biology and evolution of GIST.
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Tumores del Estroma Gastrointestinal/metabolismo , Proteómica , Adulto , Anciano , Femenino , Tumores del Estroma Gastrointestinal/patología , Humanos , Masculino , Persona de Mediana Edad , Proteínas de Neoplasias/metabolismo , Proteoma/metabolismo , Proteínas Supresoras de Tumor/metabolismoRESUMEN
Constitutive activation of signal transducer and activator of transcription 3 (STAT3) occurs in â¼70% of human cancers, and STAT3 is regarded as one of the most promising targets for cancer therapy. However, specific direct STAT3 inhibitors remain to be developed. Oridonin is an ent-kaurane plant-derived diterpenoid with anti-cancer and anti-inflammatory activities. Here, using an array of cell-based and biochemical approaches, including cell proliferation and apoptosis assays, pulldown and reporter gene assays, site-directed mutagenesis, and molecular dynamics analyses, we report that a thiazole-derived oridonin analogue, CYD0618, potently and directly inhibits STAT3. We found that CYD0618 covalently binds to Cys-542 in STAT3 and suppresses its activity through an allosteric effect, effectively reducing STAT3 dimerization and nuclear translocation, as well as decreasing expression of STAT3-targeted oncogenes. Remarkably, CYD0618 not only strongly inhibited growth of multiple cancer cell lines that harbor constitutive STAT3 activation, but it also suppressed in vivo tumor growth via STAT3 inhibition. Taken together, our findings suggest Cys-542 as a druggable site for selectively inhibiting STAT3 and indicate that CYD0618 represents a promising lead compound for developing therapeutic agents against STAT3-driven diseases.
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Antineoplásicos/farmacología , Diterpenos de Tipo Kaurano/farmacología , Neoplasias/tratamiento farmacológico , Factor de Transcripción STAT3/antagonistas & inhibidores , Regulación Alostérica/efectos de los fármacos , Animales , Antineoplásicos/química , Antineoplásicos/uso terapéutico , Línea Celular Tumoral , Diterpenos de Tipo Kaurano/química , Diterpenos de Tipo Kaurano/uso terapéutico , Femenino , Humanos , Ratones Endogámicos BALB C , Modelos Moleculares , Neoplasias/metabolismo , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/metabolismo , Factor de Transcripción STAT3/metabolismo , Tiazoles/química , Tiazoles/farmacología , Tiazoles/uso terapéuticoRESUMEN
Activity-based chemical proteomics approaches used for identifying cellular targets of drugs are mainly dependent on the availability of probes derived from drugs. However, all chemical probes are structurally different from the drugs themselves and cannot fully mimic the real actions of drugs in cells. Here we present a concise and unbiased immunoaffinity-based strategy for identifying covalent drug targets in vivo. By using the specific antibody, we not only confirm the well-known ibrutinib-binding target BTK, but also identify some previously undescribed strongly binding proteins, such as CKAP4 in human cell lines and TAP1 in mouse organs. The observed target profiles between species may partially explain why certain drug candidates are very effective in mice but not in humans. This approach avoids the chemical modification of drugs, eliminates the nonspecific bindings of chemical probes, and allows to unbiasedly decode the underlying mechanisms of action of covalent drugs.
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Agammaglobulinemia Tirosina Quinasa/metabolismo , Péptidos/química , Proteómica , Pirazoles/química , Pirimidinas/química , Transportador de Casetes de Unión a ATP, Subfamilia B, Miembro 2/química , Transportador de Casetes de Unión a ATP, Subfamilia B, Miembro 2/metabolismo , Adenina/análogos & derivados , Agammaglobulinemia Tirosina Quinasa/antagonistas & inhibidores , Secuencia de Aminoácidos , Animales , Anticuerpos/inmunología , Línea Celular , Humanos , Hígado/química , Hígado/metabolismo , Hígado/patología , Proteínas de la Membrana/química , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Microscopía Fluorescente , Péptidos/análisis , Piperidinas , Unión Proteica , Pirazoles/inmunología , Pirazoles/metabolismo , Pirimidinas/inmunología , Pirimidinas/metabolismo , Bazo/química , Bazo/metabolismo , Bazo/patologíaRESUMEN
STK19 was originally identified as a manganese-dependent serine/threonine-specific protein kinase, but its function has been highly debated. Here, the crystal structure of STK19 revealed that it does not contain a kinase domain, but three intimately packed winged helix (WH) domains. The third WH domain mediated homodimerization and double-stranded DNA binding, both being important for its nuclear localization. STK19 participated in the nucleotide excision repair (NER) and mismatch repair (MMR) pathways by recruiting damage repair factors such as RPA2 and PCNA. STK19 also bound double-stranded RNA through the DNA-binding interface and regulated the expression levels of many mRNAs. Furthermore, STK19 knockdown cells exhibited very slow cell proliferation, which cannot be rescued by dimerization or DNA-binding mutants. Therefore, this work concludes that STK19 is highly unlikely to be a kinase but a DNA/RNA-binding protein critical for DNA damage repair (DDR) and cell proliferation. To prevent further confusions, we renamed this protein as TWH19 (Tandem Winged Helix protein formerly known as STK19).
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Proliferación Celular , Reparación del ADN , Proteínas Nucleares , Procesamiento Proteico-Postraduccional , Proteínas Serina-Treonina Quinasas , Daño del ADN , Fosforilación , Humanos , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Nucleares/metabolismo , Estructura Terciaria de ProteínaRESUMEN
Magnesium (Mg) deficiency is associated with increased risk and malignancy in colorectal cancer (CRC), yet the underlying mechanisms remain elusive. Here, we used genomic, proteomic, and phosphoproteomic data to elucidate the impact of Mg deficiency on CRC. Genomic analysis identified 160 genes with higher mutation frequencies in Low-Mg tumors, including key driver genes such as KMT2C and ERBB3. Unexpectedly, initiation driver genes of CRC, such as TP53 and APC, displayed higher mutation frequencies in High-Mg tumors. Additionally, proteomic and phosphoproteomic data indicated that low Mg content in tumors may activate epithelial-mesenchymal transition (EMT) by modulating inflammation or remodeling the phosphoproteome of cancer cells. Notably, we observed a negative correlation between the phosphorylation of DBN1 at S142 (DBN1S142p) and Mg content. A mutation in S142 to D (DBN1S142D) mimicking DBN1S142p upregulated MMP2 and enhanced cell migration, while treatment with MgCl2 reduced DBN1S142p, thereby reversing this phenotype. Mechanistically, Mg2+ attenuated the DBN1-ACTN4 interaction by decreasing DBN1S142p, which in turn enhanced the binding of ACTN4 to F-actin and promoted F-actin polymerization, ultimately reducing MMP2 expression. These findings shed new light on the crucial role of Mg deficiency in CRC progression and suggest that Mg supplementation may be a promising preventive and therapeutic strategy for CRC.
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The incidence of intestinal diseases increases with age, yet the mechanisms governing gut aging and its link to diseases, such as colorectal cancer (CRC), remain elusive. In this study, while considering age, sex and proximal-distal variations, we used a multi-omics approach in non-human primates (Macaca fascicularis) to shed light on the heterogeneity of intestinal aging and identify potential regulators of gut aging. We explored the roles of several regulators, including those from tryptophan metabolism, in intestinal function and lifespan in Caenorhabditis elegans. Suggesting conservation of region specificity, tryptophan metabolism via the kynurenine and serotonin (5-HT) pathways varied between the proximal and distal colon, and, using a mouse colitis model, we observed that distal colitis was more sensitive to 5-HT treatment. Additionally, using proteomics analysis of human CRC samples, we identified links between gut aging and CRC, with high HPX levels predicting poor prognosis in older patients with CRC. Together, this work provides potential targets for preventing gut aging and associated diseases.
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Colitis , Serotonina , Animales , Humanos , Anciano , Serotonina/metabolismo , Triptófano/metabolismo , Multiómica , Colitis/metabolismo , Envejecimiento/genética , Caenorhabditis elegans/metabolismo , Primates/metabolismoRESUMEN
The ubiquitination-dependent processing of NF-κB2 (also known as p100) is a critical step in the activation of the noncanonical NF-κB pathway. We investigated the molecular mechanisms regulating this process and showed that TRIM55 was the E3 ubiquitin ligase that mediated the ubiquitination of p100 and coordinated its processing. TRIM55 deficiency impaired noncanonical NF-κB activation and B cell function. Mice with a B cell-specific Trim55 deficiency exhibited reduced germinal center formation and antibody production. These mice showed less severe symptoms than those of control mice upon the induction of a systemic lupus-like disease, suggesting B cell-intrinsic functions of TRIM55 in humoral immune responses and autoimmunity. Mechanistically, the ubiquitination of p100 mediated by TRIM55 was crucial for p100 processing by VCP, an ATPase that mediates ubiquitin-dependent protein degradation by the proteasome. Furthermore, we found that TRIM55 facilitated the interaction between TRIM21 and VCP as well as TRIM21-mediated K63-ubiquitination of VCP, both of which were indispensable for the formation of the VCP-UFD1-NPL4 complex and p100 processing. Together, our results reveal a mechanism by which TRIM55 fine-tunes p100 processing and regulates B cell-dependent immune responses in vivo, highlighting TRIM55 as a potential therapeutic target for lupus-like disease.
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FN-kappa B , Transducción de Señal , Animales , Ratones , Inmunidad , FN-kappa B/genética , FN-kappa B/metabolismo , Subunidad p52 de NF-kappa B/genética , Subunidad p52 de NF-kappa B/metabolismo , UbiquitinaciónRESUMEN
Glioblastoma (GBM) constitutes the most lethal primary brain tumor for which immunotherapy has provided limited benefit. The unique brain immune landscape is reflected in a complex tumor immune microenvironment (TIME) in GBM. Here, single-cell sequencing of the GBM TIME revealed that microglia were under severe oxidative stress, which induced nuclear receptor subfamily 4 group A member 2 (NR4A2)-dependent transcriptional activity in microglia. Heterozygous Nr4a2 (Nr4a2+/-) or CX3CR1+ myeloid cell-specific Nr4a2 (Nr4a2fl/flCx3cr1Cre) genetic targeting reshaped microglia plasticity in vivo by reducing alternatively activated microglia and enhancing antigen presentation capacity for CD8+ T cells in GBM. In microglia, NR4A2 activated squalene monooxygenase (SQLE) to dysregulate cholesterol homeostasis. Pharmacologic NR4A2 inhibition attenuated the protumorigenic TIME, and targeting the NR4A2 or SQLE enhanced the therapeutic efficacy of immune-checkpoint blockade in vivo. Collectively, oxidative stress promotes tumor growth through NR4A2-SQLE activity in microglia, informing novel immune therapy paradigms in brain cancer. SIGNIFICANCE: Metabolic reprogramming of microglia in GBM informs synergistic vulnerabilities for immune-checkpoint blockade therapy in this immunologically cold brain tumor. This article is highlighted in the In This Issue feature, p. 799.
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Neoplasias Encefálicas , Glioblastoma , Humanos , Glioblastoma/tratamiento farmacológico , Glioblastoma/genética , Microglía , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Macrófagos , Encéfalo/patología , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/genética , Microambiente Tumoral/fisiologíaRESUMEN
Development of safe and efficient vaccines is still necessary to deal with the COVID-19 pandemic. Herein, we reported that yeast-expressed recombinant RBD proteins either from wild-type or Delta SARS-CoV-2 were able to elicit immune responses against SARS-CoV-2 and its variants. The wild-type RBD (wtRBD) protein was overexpressed in Pichia pastoris, and the purified protein was used as the antigen to immunize mice after formulating an aluminium hydroxide (Alum) adjuvant. Three immunization programs with different intervals were compared. It was found that the immunization with an interval of 28 days exhibited the strongest immune response to SARS-CoV-2 than the one with an interval of 14 or 42 days based on binding antibody and the neutralizing antibody (NAb) analyses. The antisera from the mice immunized with wtRBD were able to neutralize the Beta variant with a similar efficiency but the Delta variant with 2~2.5-fold decreased efficiency. However, more NAbs to the Delta variant were produced when the Delta RBD protein was used to immunize mice. Interestingly, the NAbs may cross react with the Omicron variant. To increase the production of NAbs, the adjuvant combination of Alum and CpG oligonucleotides was used. Compared with the Alum adjuvant alone, the NAbs elicited by the combined adjuvants exhibited an approximate 10-fold increase for the Delta and a more than 53-fold increase for the Omicron variant. This study suggested that yeast-derived Delta RBD is a scalable and an effective vaccine candidate for SARS-CoV-2 and its variants.
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COVID-19 , Vacunas Virales , Ratones , Humanos , Animales , SARS-CoV-2 , Saccharomyces cerevisiae , Vacunas contra la COVID-19 , Pandemias , Ratones Endogámicos BALB C , COVID-19/prevención & control , Adyuvantes Inmunológicos , Proteínas Recombinantes , InmunidadRESUMEN
Glycyrrhetinic acid (GA) is a natural product of licorice with mitochondria targeting properties and shows broad anticancer activities, but its targets and underlying mechanisms remain elusive. Here, we identified the mitochondrial enzyme serine hydroxymethyltransferase 2 (SHMT2) as a target of GA by using chemical proteomics. Binding to and inhibiting the activity of SHMT2 by GA were validated in vitro and in vivo. Knockout of SHMT2 or inhibiting SHMT2 with GA restricts mitochondrial energy supplies by downregulating mitochondrial oxidative phosphorylation (OXPHOS) and fatty acid ß-oxidation, and consequently suppresses cancer cell proliferation and tumor growth. Crystal structures of GA derivatives indicate that GA occupies SHMT2 folate-binding pocket and regulates SHMT2 activity. Modifications at GA carboxylic group with diamines significantly improved its anticancer potency, demonstrating GA as a decent structural template for SHMT2 inhibitor development.
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BACKGROUND & AIMS: Latent metastasis of colorectal cancer (CRC) frequently develops months or years after primary surgery, followed by adjuvant therapies, and may progress rapidly even with targeted therapy administered, but the underlying mechanism remains unclear. Here, we aim to explore the molecular basis for the aggressive behavior of latent metastasis in CRC. METHODS: Transcriptional profiling and pathway enrichment analysis of paired primary and metastatic tumor samples were performed. The underlying mechanisms of pleckstrin homology-like domain, family B, member 2 (PHLDB2) in CRC were investigated by RNA immunoprecipitation assay, immunohistochemistry, mass spectrometry analysis, and Duolink in situ proximity ligation assay (Sigma-Aldrich, Shanghai, China). The efficacy of targeting PHLDB2 in cetuximab treatment was elucidated in CRC cell lines and mouse models. RESULTS: Based on the transcriptional profile of paired primary and metastatic tumor samples, we identified PHLDB2 as a potential regulator in latent liver metastasis. A detailed mechanistic study showed that chemotherapeutic agent-induced oxidative stress promotes methyltransferase-like 14 (METTL14)-mediated N6-methyladenosine modification of PHLDB2 messenger RNA, facilitating its protein expression. Up-regulated PHLDB2 stabilizes epidermal growth factor receptor (EGFR) and promotes its nuclear translocation, which in turn results in EGFR signaling activation and consequent cetuximab resistance. Moreover, Arg1163 (R1163) of PHLDB2 is crucial for interaction with EGFR, and the R1163A mutation abrogates its regulatory function in EGFR signaling. CONCLUSIONS: PHLDB2 plays a crucial role in cetuximab resistance and is proposed to be a potential target for the treatment of CRC.