RESUMO
Follicular helper T (TFH) cells are a specialized subset of CD4+ T cells that essentially support germinal center responses where high-affinity and long-lived humoral immunity is generated. The regulation of TFH cell survival remains unclear. Here we report that TFH cells show intensified lipid peroxidation and altered mitochondrial morphology, resembling the features of ferroptosis, a form of programmed cell death that is driven by iron-dependent accumulation of lipid peroxidation. Glutathione peroxidase 4 (GPX4) is the major lipid peroxidation scavenger and is necessary for TFH cell survival. The deletion of GPX4 in T cells selectively abrogated TFH cells and germinal center responses in immunized mice. Selenium supplementation enhanced GPX4 expression in T cells, increased TFH cell numbers and promoted antibody responses in immunized mice and young adults after influenza vaccination. Our findings reveal the central role of the selenium-GPX4-ferroptosis axis in regulating TFH homeostasis, which can be targeted to enhance TFH cell function in infection and following vaccination.
Assuntos
Ferroptose/fisiologia , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Selênio/farmacologia , Células T Auxiliares Foliculares/fisiologia , Adolescente , Adulto , Animais , Sobrevivência Celular/imunologia , Criança , Feminino , Centro Germinativo/citologia , Centro Germinativo/imunologia , Homeostase/efeitos dos fármacos , Homeostase/genética , Humanos , Imunidade Humoral/imunologia , Vacinas contra Influenza/imunologia , Peroxidação de Lipídeos/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/fisiologia , Ovalbumina , Células T Auxiliares Foliculares/imunologia , Vacinação , Adulto JovemRESUMO
Activating KRAS mutations (KRAS*) in pancreatic ductal adenocarcinoma (PDAC) drive anabolic metabolism and support tumor maintenance. KRAS* inhibitors show initial antitumor activity followed by recurrence due to cancer cell-intrinsic and immune-mediated paracrine mechanisms. Here, we explored the potential role of cancer-associated fibroblasts (CAFs) in enabling KRAS* bypass and identified CAF-derived NRG1 activation of cancer cell ERBB2 and ERBB3 receptor tyrosine kinases as a mechanism by which KRAS*-independent growth is supported. Genetic extinction or pharmacological inhibition of KRAS* resulted in up-regulation of ERBB2 and ERBB3 expression in human and murine models, which prompted cancer cell utilization of CAF-derived NRG1 as a survival factor. Genetic depletion or pharmacological inhibition of ERBB2/3 or NRG1 abolished KRAS* bypass and synergized with KRASG12D inhibitors in combination treatments in mouse and human PDAC models. Thus, we found that CAFs can contribute to KRAS* inhibitor therapy resistance via paracrine mechanisms, providing an actionable therapeutic strategy to improve the effectiveness of KRAS* inhibitors in PDAC patients.
Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Animais , Camundongos , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proliferação de Células , Neoplasias Pancreáticas/metabolismo , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Neuregulina-1/genética , Neuregulina-1/metabolismoRESUMO
Lipid droplets are important for cancer cell growth and survival. However, the mechanism underlying the initiation of lipid droplet lipolysis is not well understood. We demonstrate here that glucose deprivation induces the binding of choline kinase (CHK) α2 to lipid droplets, which is sequentially mediated by AMPK-dependent CHKα2 S279 phosphorylation and KAT5-dependent CHKα2 K247 acetylation. Importantly, CHKα2 with altered catalytic domain conformation functions as a protein kinase and phosphorylates PLIN2 at Y232 and PLIN3 at Y251. The phosphorylated PLIN2/3 dissociate from lipid droplets and are degraded by Hsc70-mediated autophagy, thereby promoting lipid droplet lipolysis, fatty acid oxidation, and brain tumor growth. In addition, levels of CHKα2 S279 phosphorylation, CHKα2 K247 acetylation, and PLIN2/3 phosphorylation are positively correlated with one another in human glioblastoma specimens and are associated with poor prognosis in glioblastoma patients. These findings underscore the role of CHKα2 as a protein kinase in lipolysis and glioblastoma development.
Assuntos
Colina Quinase/metabolismo , Glioblastoma/enzimologia , Gotículas Lipídicas/enzimologia , Lipólise , Proteínas de Neoplasias/metabolismo , Proteínas Quinases/metabolismo , Acetilação , Linhagem Celular Tumoral , Colina Quinase/genética , Glioblastoma/genética , Humanos , Proteínas de Neoplasias/genética , Proteínas Quinases/genéticaRESUMO
Tumor-specific pyruvate kinase M2 (PKM2) is essential for the Warburg effect. In addition to its well-established role in aerobic glycolysis, PKM2 directly regulates gene transcription. However, the mechanism underlying this nonmetabolic function of PKM2 remains elusive. We show here that PKM2 directly binds to histone H3 and phosphorylates histone H3 at T11 upon EGF receptor activation. This phosphorylation is required for the dissociation of HDAC3 from the CCND1 and MYC promoter regions and subsequent acetylation of histone H3 at K9. PKM2-dependent histone H3 modifications are instrumental in EGF-induced expression of cyclin D1 and c-Myc, tumor cell proliferation, cell-cycle progression, and brain tumorigenesis. In addition, levels of histone H3 T11 phosphorylation correlate with nuclear PKM2 expression levels, glioma malignancy grades, and prognosis. These findings highlight the role of PKM2 as a protein kinase in its nonmetabolic functions of histone modification, which is essential for its epigenetic regulation of gene expression and tumorigenesis.
Assuntos
Astrocitoma/metabolismo , Proteínas de Transporte/metabolismo , Transformação Celular Neoplásica , Regulação Neoplásica da Expressão Gênica , Glioblastoma/metabolismo , Histonas/metabolismo , Proteínas de Membrana/metabolismo , Hormônios Tireóideos/metabolismo , Animais , Astrocitoma/genética , Linhagem Celular , Linhagem Celular Tumoral , Ciclina D1/genética , Ciclina D1/metabolismo , Fator de Crescimento Epidérmico/metabolismo , Epigênese Genética , Feminino , Glioblastoma/genética , Humanos , Camundongos , Camundongos Nus , Transplante de Neoplasias , Proteínas Proto-Oncogênicas c-myc/genética , Transcrição Gênica , Transplante Heterólogo , Proteínas de Ligação a Hormônio da TireoideRESUMO
Hypoxia, which occurs during tumor growth, triggers complex adaptive responses in which peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) plays a critical role in mitochondrial biogenesis and oxidative metabolism. However, how PGC-1α is regulated in response to oxygen availability remains unclear. We demonstrated that lysine demethylase 3A (KDM3A) binds to PGC-1α and demethylates monomethylated lysine (K) 224 of PGC-1α under normoxic conditions. Hypoxic stimulation inhibits KDM3A, which has a high KM of oxygen for its activity, and enhances PGC-1α K224 monomethylation. This modification decreases PGC-1α's activity required for NRF1- and NRF2-dependent transcriptional regulation of TFAM, TFB1M, and TFB2M, resulting in reduced mitochondrial biogenesis. Expression of PGC-1α K224R mutant significantly increases mitochondrial biogenesis, reactive oxygen species (ROS) production, and tumor cell apoptosis under hypoxia and inhibits brain tumor growth in mice. This study revealed that PGC-1α monomethylation, which is dependent on oxygen availability-regulated KDM3A, plays a critical role in the regulation of mitochondrial biogenesis.
Assuntos
Neoplasias Encefálicas/enzimologia , Histona Desmetilases com o Domínio Jumonji/metabolismo , Mitocôndrias/enzimologia , Biogênese de Organelas , Oxigênio/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Processamento de Proteína Pós-Traducional , Animais , Apoptose , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Células HEK293 , Células HeLa , Células Hep G2 , Humanos , Histona Desmetilases com o Domínio Jumonji/genética , Metilação , Camundongos Endogâmicos BALB C , Camundongos Nus , Mitocôndrias/patologia , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Carga Tumoral , Hipóxia Tumoral , Microambiente TumoralRESUMO
The PTEN tumor suppressor is frequently mutated or deleted in cancer and regulates glucose metabolism through the PI3K-AKT pathway. However, whether PTEN directly regulates glycolysis in tumor cells is unclear. We demonstrate here that PTEN directly interacts with phosphoglycerate kinase 1 (PGK1). PGK1 functions not only as a glycolytic enzyme but also as a protein kinase intermolecularly autophosphorylating itself at Y324 for activation. The protein phosphatase activity of PTEN dephosphorylates and inhibits autophosphorylated PGK1, thereby inhibiting glycolysis, ATP production, and brain tumor cell proliferation. In addition, knockin expression of a PGK1 Y324F mutant inhibits brain tumor formation. Analyses of human glioblastoma specimens reveals that PGK1 Y324 phosphorylation levels inversely correlate with PTEN expression status and are positively associated with poor prognosis in glioblastoma patients. This work highlights the instrumental role of PGK1 autophosphorylation in its activation and PTEN protein phosphatase activity in governing glycolysis and tumorigenesis.
Assuntos
Neoplasias Encefálicas/enzimologia , Glioblastoma/enzimologia , Glucose/metabolismo , Glicólise , PTEN Fosfo-Hidrolase/metabolismo , Fosfoglicerato Quinase/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Glioblastoma/genética , Glioblastoma/patologia , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , PTEN Fosfo-Hidrolase/genética , Fosfoglicerato Quinase/genética , Fosforilação , Prognóstico , Transdução de Sinais , Fatores de Tempo , Carga Tumoral , TirosinaRESUMO
Cancer cells increase lipogenesis for their proliferation and the activation of sterol regulatory element-binding proteins (SREBPs) has a central role in this process. SREBPs are inhibited by a complex composed of INSIG proteins, SREBP cleavage-activating protein (SCAP) and sterols in the endoplasmic reticulum. Regulation of the interaction between INSIG proteins and SCAP by sterol levels is critical for the dissociation of the SCAP-SREBP complex from the endoplasmic reticulum and the activation of SREBPs1,2. However, whether this protein interaction is regulated by a mechanism other than the abundance of sterol-and in particular, whether oncogenic signalling has a role-is unclear. Here we show that activated AKT in human hepatocellular carcinoma (HCC) cells phosphorylates cytosolic phosphoenolpyruvate carboxykinase 1 (PCK1), the rate-limiting enzyme in gluconeogenesis, at Ser90. Phosphorylated PCK1 translocates to the endoplasmic reticulum, where it uses GTP as a phosphate donor to phosphorylate INSIG1 at Ser207 and INSIG2 at Ser151. This phosphorylation reduces the binding of sterols to INSIG1 and INSIG2 and disrupts the interaction between INSIG proteins and SCAP, leading to the translocation of the SCAP-SREBP complex to the Golgi apparatus, the activation of SREBP proteins (SREBP1 or SREBP2) and the transcription of downstream lipogenesis-related genes, proliferation of tumour cells, and tumorigenesis in mice. In addition, phosphorylation of PCK1 at Ser90, INSIG1 at Ser207 and INSIG2 at Ser151 is not only positively correlated with the nuclear accumulation of SREBP1 in samples from patients with HCC, but also associated with poor HCC prognosis. Our findings highlight the importance of the protein kinase activity of PCK1 in the activation of SREBPs, lipogenesis and the development of HCC.
Assuntos
Carcinoma Hepatocelular/metabolismo , Gluconeogênese , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Lipogênese , Neoplasias Hepáticas/metabolismo , Proteínas de Membrana/metabolismo , Fosfoenolpiruvato Carboxiquinase (GTP)/metabolismo , Animais , Carcinogênese , Carcinoma Hepatocelular/patologia , Proliferação de Células , Modelos Animais de Doenças , Retículo Endoplasmático/metabolismo , Complexo de Golgi/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/química , Neoplasias Hepáticas/patologia , Masculino , Proteínas de Membrana/química , Camundongos , Camundongos Nus , Oxisteróis/metabolismo , Fosforilação , Prognóstico , Ligação Proteica , Transporte Proteico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 2/metabolismoRESUMO
DNA replication is initiated by assembly of the kinase cell division cycle 7 (CDC7) with its regulatory activation subunit, activator of S-phase kinase (ASK), to activate DNA helicase. However, the mechanism underlying regulation of CDC7-ASK complex is unclear. Here, we show that ADP generated from CDC7-mediated MCM phosphorylation binds to an allosteric region of CDC7, disrupts CDC7-ASK interaction, and inhibits CDC7-ASK activity in a feedback way. EGFR- and ERK-activated casein kinase 2α (CK2α) phosphorylates nuclear phosphoglycerate kinase (PGK) 1 at S256, resulting in interaction of PGK1 with CDC7. CDC7-bound PGK1 converts ADP to ATP, thereby abrogating the inhibitory effect of ADP on CDC7-ASK activity, promoting the recruitment of DNA helicase to replication origins, DNA replication, cell proliferation, and brain tumorigenesis. These findings reveal an instrumental self-regulatory mechanism of CDC7-ASK activity by its kinase reaction product ADP and a nonglycolytic role for PGK1 in abrogating this negative feedback in promoting tumor development.
Assuntos
Difosfato de Adenosina/metabolismo , Caseína Quinase II/metabolismo , Proteínas de Ciclo Celular/antagonistas & inibidores , Replicação do DNA , Fosfoglicerato Quinase/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Animais , Caseína Quinase II/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/fisiologia , Linhagem Celular , Linhagem Celular Tumoral , DNA Helicases/genética , DNA Helicases/metabolismo , Feminino , Xenoenxertos , Humanos , Sistema de Sinalização das MAP Quinases , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Fosfoglicerato Quinase/genética , Fosforilação , Ligação Proteica , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/fisiologia , Origem de ReplicaçãoRESUMO
EGFR activates phosphatidylinositide 3-kinase (PI3K), but the mechanism underlying this activation is not completely understood. We demonstrated here that EGFR activation resulted in lysine acetyltransferase 5 (KAT5)-mediated K395 acetylation of the platelet isoform of phosphofructokinase 1 (PFKP) and subsequent translocation of PFKP to the plasma membrane, where the PFKP was phosphorylated at Y64 by EGFR. Phosphorylated PFKP binds to the N-terminal SH2 domain of p85α, which is distinct from binding of Gab1 to the C-terminal SH2 domain of p85α, and recruited p85α to the plasma membrane resulting in PI3K activation. PI3K-dependent AKT activation results in enhanced phosphofructokinase 2 (PFK2) phosphorylation and production of fructose-2,6-bisphosphate, which in turn promotes PFK1 activation. PFKP Y64 phosphorylation-enhanced PI3K/AKT-dependent PFK1 activation and GLUT1 expression promoted the Warburg effect, tumor cell proliferation, and brain tumorigenesis. These findings underscore the instrumental role of PFKP in PI3K activation and enhanced glycolysis through PI3K/AKT-dependent positive-feedback regulation.
Assuntos
Neoplasias Encefálicas/enzimologia , Glioblastoma/enzimologia , Glicólise , Fosfatidilinositol 3-Quinases/metabolismo , Fosfofrutoquinase-1 Tipo C/metabolismo , Acetilação , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Classe Ia de Fosfatidilinositol 3-Quinase , Ativação Enzimática , Receptores ErbB/genética , Receptores ErbB/metabolismo , Retroalimentação Fisiológica , Frutosedifosfatos/metabolismo , Glioblastoma/genética , Glioblastoma/patologia , Transportador de Glucose Tipo 1/genética , Transportador de Glucose Tipo 1/metabolismo , Humanos , Lisina Acetiltransferase 5/genética , Lisina Acetiltransferase 5/metabolismo , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Fosfatidilinositol 3-Quinases/genética , Fosfofrutoquinase-1 Tipo C/genética , Fosfofrutoquinase-2/genética , Fosfofrutoquinase-2/metabolismo , Fosforilação , Ligação Proteica , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Domínios de Homologia de srcRESUMO
Native prokaryotic promoters share common sequence patterns, but are species dependent. For understudied species with limited data, it is challenging to predict the strength of existing promoters and generate novel promoters. Here, we developed PromoGen, a collection of nucleotide language models to generate species-specific functional promoters, across dozens of species in a data and parameter efficient way. Twenty-seven species-specific models in this collection were finetuned from the pretrained model which was trained on multi-species promoters. When systematically compared with native promoters, the Escherichia coli- and Bacillus subtilis-specific artificial PromoGen-generated promoters (PGPs) were demonstrated to hold all distribution patterns of native promoters. A regression model was developed to score generated either by PromoGen or by another competitive neural network, and the overall score of PGPs is higher. Encouraged by in silico analysis, we further experimentally characterized twenty-two B. subtilis PGPs, results showed that four of tested PGPs reached the strong promoter level while all were active. Furthermore, we developed a user-friendly website to generate species-specific promoters for 27 different species by PromoGen. This work presented an efficient deep-learning strategy for de novo species-specific promoter generation even with limited datasets, providing valuable promoter toolboxes especially for the metabolic engineering of understudied microorganisms.
Assuntos
Bacillus subtilis , Aprendizado Profundo , Escherichia coli , Regiões Promotoras Genéticas , Bacillus subtilis/genética , Escherichia coli/genética , Redes Neurais de Computação , Especificidade da EspécieRESUMO
Steroid receptor coactivator 3 (SRC-3) is most strongly expressed in regulatory T cells (Tregs) and B cells, suggesting that it plays an important role in the regulation of Treg function. Using an aggressive E0771 mouse breast cell line syngeneic immune-intact murine model, we observed that breast tumors were "permanently eradicated" in a genetically engineered tamoxifen-inducible Treg-cell-specific SRC-3 knockout (KO) female mouse that does not possess a systemic autoimmune pathological phenotype. A similar eradication of tumor was noted in a syngeneic model of prostate cancer. A subsequent injection of additional E0771 cancer cells into these mice showed continued resistance to tumor development without the need for tamoxifen induction to produce additional SRC-3 KO Tregs. SRC-3 KO Tregs were highly proliferative and preferentially infiltrated into breast tumors by activating the chemokine (C-C motif) ligand (Ccl) 19/Ccl21/chemokine (C-C motif) receptor (Ccr)7 signaling axis, generating antitumor immunity by enhancing the interferon-γ/C-X-C motif chemokine ligand (Cxcl) 9 signaling axis to facilitate the entrance and function of effector T cells and natural killer cells. SRC-3 KO Tregs also show a dominant effect by blocking the immune suppressive function of WT Tregs. Importantly, a single adoptive transfer of SRC-3 KO Tregs into wild-type E0771 tumor-bearing mice can completely abolish preestablished breast tumors by generating potent antitumor immunity with a durable effect that prevents tumor reoccurrence. Therefore, treatment with SRC-3-deleted Tregs represents an approach to completely block tumor growth and recurrence without the autoimmune side effects that typically accompany immune checkpoint modulators.
Assuntos
Neoplasias da Mama , Neoplasias Mamárias Animais , Coativador 3 de Receptor Nuclear , Animais , Feminino , Masculino , Camundongos , Ligantes , Camundongos Knockout , Coativador 3 de Receptor Nuclear/genética , Linfócitos T Reguladores , Tamoxifeno/farmacologiaRESUMO
GPIHBP1 plays an important role in the hydrolysis of triglyceride (TG) lipoproteins by lipoprotein lipases (LPLs). However, Gpihbp1 knockout mice did not develop hypertriglyceridemia (HTG) during the suckling period but developed severe HTG after weaning on a chow diet. It has been postulated that LPL expression in the liver of suckling mice may be involved. To determine whether hepatic LPL expression could correct severe HTG in Gpihbp1 deficiency, liver-targeted LPL expression was achieved via intravenous administration of the adeno-associated virus (AAV)-human LPL gene, and the effects of AAV-LPL on HTG and HTG-related acute pancreatitis (HTG-AP) were observed. Suckling Gpihbp1-/- mice with high hepatic LPL expression did not develop HTG, whereas Gpihbp1-/- rat pups without hepatic LPL expression developed severe HTG. AAV-mediated liver-targeted LPL expression dose-dependently decreased plasma TG levels in Gpihbp1-/- mice and rats, increased post-heparin plasma LPL mass and activity, decreased mortality in Gpihbp1-/- rat pups, and reduced the susceptibility and severity of both Gpihbp1-/- animals to HTG-AP. However, the muscle expression of AAV-LPL had no significant effect on HTG. Targeted expression of LPL in the liver showed no obvious adverse reactions. Thus, liver-targeted LPL expression may be a new therapeutic approach for HTG-AP caused by GPIHBP1 deficiency.
Assuntos
Hipertrigliceridemia , Pancreatite , Receptores de Lipoproteínas , Animais , Humanos , Camundongos , Ratos , Doença Aguda , Dependovirus/genética , Dependovirus/metabolismo , Hipertrigliceridemia/genética , Hipertrigliceridemia/terapia , Lipase Lipoproteica/genética , Lipase Lipoproteica/metabolismo , Fígado/metabolismo , Pancreatite/genética , Pancreatite/terapia , Pancreatite/metabolismo , Receptores de Lipoproteínas/genética , Receptores de Lipoproteínas/metabolismo , Triglicerídeos/metabolismoRESUMO
Autophagy is crucial for maintaining cell homeostasis. However, the precise mechanism underlying autophagy initiation remains to be defined. Here, we demonstrate that glutamine deprivation and hypoxia result in inhibition of mTOR-mediated acetyl-transferase ARD1 S228 phosphorylation, leading to ARD1-dependent phosphoglycerate kinase 1 (PGK1) K388 acetylation and subsequent PGK1-mediated Beclin1 S30 phosphorylation. This phosphorylation enhances ATG14L-associated class III phosphatidylinositol 3-kinase VPS34 activity by increasing the binding of phosphatidylinositol to VPS34. ARD1-dependent PGK1 acetylation and PGK1-mediated Beclin1 S30 phosphorylation are required for glutamine deprivation- and hypoxia-induced autophagy and brain tumorigenesis. Furthermore, PGK1 K388 acetylation levels correlate with Beclin1 S30 phosphorylation levels and poor prognosis in glioblastoma patients. Our study unearths an important mechanism underlying cellular-stress-induced autophagy initiation in which the protein kinase activity of the metabolic enzyme PGK1 plays an instrumental role and reveals the significance of the mutual regulation of autophagy and cell metabolism in maintaining cell homeostasis.
Assuntos
Autofagossomos/enzimologia , Autofagia , Proteína Beclina-1/metabolismo , Neoplasias Encefálicas/enzimologia , Glioblastoma/enzimologia , Fosfoglicerato Quinase/metabolismo , Acetilação , Animais , Autofagossomos/patologia , Proteína Beclina-1/genética , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Proliferação de Células , Classe III de Fosfatidilinositol 3-Quinases/genética , Classe III de Fosfatidilinositol 3-Quinases/metabolismo , Feminino , Glioblastoma/genética , Glioblastoma/patologia , Glutamina/deficiência , Células HEK293 , Humanos , Camundongos Nus , Acetiltransferase N-Terminal A/genética , Acetiltransferase N-Terminal A/metabolismo , Acetiltransferase N-Terminal E/genética , Acetiltransferase N-Terminal E/metabolismo , Fosfoglicerato Quinase/genética , Fosforilação , Ligação Proteica , Interferência de RNA , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Fatores de Tempo , Transfecção , Carga Tumoral , Hipóxia TumoralRESUMO
Overcoming metabolic stress is a critical step in tumor growth. Acetyl coenzyme A (acetyl-CoA) generated from glucose and acetate uptake is important for histone acetylation and gene expression. However, how acetyl-CoA is produced under nutritional stress is unclear. We demonstrate here that glucose deprivation results in AMP-activated protein kinase (AMPK)-mediated acetyl-CoA synthetase 2 (ACSS2) phosphorylation at S659, which exposed the nuclear localization signal of ACSS2 for importin α5 binding and nuclear translocation. In the nucleus, ACSS2 binds to transcription factor EB and translocates to lysosomal and autophagy gene promoter regions, where ACSS2 incorporates acetate generated from histone acetylation turnover to locally produce acetyl-CoA for histone H3 acetylation in these regions and promote lysosomal biogenesis, autophagy, cell survival, and brain tumorigenesis. In addition, ACSS2 S659 phosphorylation positively correlates with AMPK activity in glioma specimens and grades of glioma malignancy. These results underscore the significance of nuclear ACSS2-mediated histone acetylation in maintaining cell homeostasis and tumor development.
Assuntos
Acetato-CoA Ligase/metabolismo , Autofagia , Neoplasias Encefálicas/enzimologia , Núcleo Celular/enzimologia , Glioblastoma/enzimologia , Histonas/metabolismo , Lisossomos/metabolismo , Biogênese de Organelas , Transcrição Gênica , Proteínas Quinases Ativadas por AMP/metabolismo , Acetato-CoA Ligase/genética , Acetilcoenzima A/metabolismo , Acetilação , Transporte Ativo do Núcleo Celular , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Sítios de Ligação , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Núcleo Celular/patologia , Sobrevivência Celular , Metabolismo Energético , Regulação Neoplásica da Expressão Gênica , Glioblastoma/genética , Glioblastoma/patologia , Humanos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Fosforilação , Regiões Promotoras Genéticas , Ligação Proteica , Processamento de Proteína Pós-Traducional , Interferência de RNA , Estresse Fisiológico , Transfecção , alfa Carioferinas/genética , alfa Carioferinas/metabolismoRESUMO
N6-methyladenosine (m6A) is the most prevalent RNA modification in eukaryotic mRNAs. Currently available detection methods for locus-specific m6A marks rely on RT-qPCR, radioactive methods, or high-throughput sequencing. Here, we develop a non-qPCR, ultrasensitive, isothermal, and naked-eye visible method for m6A detection based on rolling circle amplification (RCA) and loop-mediated isothermal amplification (LAMP), named m6A-Rol-LAMP, to verify putative m6A sites in transcripts obtained from the high-throughput data. When padlock probes hybridize to the potential m6A sites on targets, they are converted to circular form by DNA ligase in the absence of m6A modification, while m6A modification hinders the sealing of padlock probes. Subsequently, Bst DNA polymerase-mediated RCA and LAMP allow the amplification of the circular padlock probe to achieve the locus-specific detection of m6A. Following optimization and validation, m6A-Rol-LAMP can ultra-sensitively and quantitatively determine the existence of m6A modification on a specific target site as low as 100 amol under isothermal conditions. Detections of m6A can be performed on rRNA, mRNA, lincRNA, lncRNA and pre-miRNA from biological samples with naked-eye observations after dye incubation. Together, we provide a powerful tool for locus-specific detection of m6A, which can simply, quickly, sensitively, specifically, and visually determine putative m6A modification on RNA.
Assuntos
Adenosina , Técnicas de Amplificação de Ácido Nucleico , RNA Mensageiro , Adenosina/análogos & derivados , Adenosina/análise , Adenosina/química , DNA Polimerase Dirigida por DNA/metabolismo , MicroRNAs/química , Técnicas de Amplificação de Ácido Nucleico/métodos , Reprodutibilidade dos Testes , RNA Longo não Codificante/química , RNA Mensageiro/química , RNA Ribossômico/química , DNA Ligases/metabolismoRESUMO
BACKGROUND: Triple-negative breast cancers display heterogeneity in molecular drivers and immune traits. We previously classified triple-negative breast cancers into four subtypes: luminal androgen receptor (LAR), immunomodulatory, basal-like immune-suppressed (BLIS), and mesenchymal-like (MES). Here, we aimed to evaluate the efficacy and safety of subtyping-based therapy in the first-line treatment of triple-negative breast cancer. METHODS: FUTURE-SUPER is an ongoing, open-label, randomised, controlled phase 2 trial being conducted at Fudan University Shanghai Cancer Center (FUSCC), Shanghai, China. Eligible participants were females aged 18-70 years, with an Eastern Cooperative Oncology Group performance status of 0-1, and histologically confirmed, untreated metastatic or recurrent triple-negative breast cancer. After categorising participants into five cohorts according to molecular subtype and genomic biomarkers, participants were randomly assigned (1:1) with a block size of 4, stratified by subtype, to receive, in 28-day cycles, nab-paclitaxel (100 mg/m2, intravenously on days 1, 8, and 15) alone (control group) or with a subtyping-based regimen (subtyping-based group): pyrotinib (400 mg orally daily) for the LAR-HER2mut subtype, everolimus (10 mg orally daily) for the LAR-PI3K/AKTmut and MES-PI3K/AKTmut subtypes, camrelizumab (200 mg intravenously on days 1 and 15) and famitinib (20 mg orally daily) for the immunomodulatory subtype, and bevacizumab (10 mg/kg intravenously on days 1 and 15) for the BLIS/MES-PI3K/AKTWT subtype. The primary endpoint was investigator-assessed progression-free survival for the pooled subtyping-based group versus the control group in the intention-to-treat population (all randomly assigned participants). Safety was analysed in all patients with safety records who received at least one dose of study drug. This study is registered with ClinicalTrials.gov (NCT04395989). FINDINGS: Between July 28, 2020, and Oct 16, 2022, 139 female participants were enrolled and randomly assigned to the subtyping-based group (n=69) or control group (n=70). At the data cutoff (May 31, 2023), the median follow-up was 22·5 months (IQR 15·2-29·0). Median progression-free survival was significantly longer in the pooled subtyping-based group (11·3 months [95% CI 8·6-15·2]) than in the control group (5·8 months [4·0-6·7]; hazard ratio 0·44 [95% CI 0·30-0·65]; p<0·0001). The most common grade 3-4 treatment-related adverse events were neutropenia (21 [30%] of 69 in the pooled subtyping-based group vs 16 [23%] of 70 in the control group), anaemia (five [7%] vs none), and increased alanine aminotransferase (four [6%] vs one [1%]). Treatment-related serious adverse events were reported for seven (10%) of 69 patients in the subtyping-based group and none in the control group. No treatment-related deaths were reported in either group. INTERPRETATION: These findings highlight the potential clinical benefits of using molecular subtype-based treatment optimisation in patients with triple-negative breast cancer, suggesting a path for further clinical investigation. Phase 3 randomised clinical trials assessing the efficacy of subtyping-based regimens are now underway. FUNDING: National Natural Science Foundation of China, Natural Science Foundation of Shanghai, Shanghai Hospital Development Center, and Jiangsu Hengrui Pharmaceuticals. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.
Assuntos
Neoplasias de Mama Triplo Negativas , Humanos , Feminino , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/patologia , Proteínas Proto-Oncogênicas c-akt , Fosfatidilinositol 3-Quinases/uso terapêutico , Recidiva Local de Neoplasia/tratamento farmacológico , China , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversosRESUMO
Pterodactylane is a [4]-ladderane with substituents on the central rung. Comparing the mechanochemistry of the [4]-ladderane structure when pulled from the central rung versus the end rung revealed a striking difference in the threshold force of mechanoactivation: the threshold force is dramatically lowered from 1.9 nN when pulled on the end rung to 0.7 nN when pulled on the central rung. We investigated the bicyclic products formed from the mechanochemical activation of pterodactylane experimentally and computationally, which are distinct from the mechanochemical products of ladderanes being activated from the end rung. We compared the products of pterodactylane's mechanochemical and thermal activation to reveal differences and similarities in the mechanochemical and thermal pathways of pterodactylane transformation. Interestingly, we also discovered the presence of elementary steps that are accelerated or suppressed by force within the same mechanochemical reaction of pterodactylane, suggesting rich mechanochemical manifolds of multicyclic structures. We rationalized the greatly enhanced mechanochemical reactivity of the central rung of pterodactylane and discovered force-free ground state bond length to be a good low-cost predictor of the threshold force for cyclobutane-based mechanophores. These findings advance our understanding of mechanochemical reactivities and pathways, and they will guide future designs of mechanophores with low threshold forces to facilitate their applications in force-responsive materials.
RESUMO
BACKGROUND: As a chronic inflammatory disease, diabetes mellitus (DM) contributes to the development of atherosclerosis (AS). However, how the NLRP3 inflammasome participates in diabetes-related AS remains unclear. Therefore, this study aimed to elucidate the mechanism through which NLRP3 uses high glucose (HG) levels to promote AS. METHODS: Serum and coronary artery tissues were collected from coronary artery disease (CAD) patients with and without DM, respectively. The expression of NLRP3 was detected, and the effects of this inflammasome on diabetes-associated AS were evaluated using streptozotocin (STZ)-induced diabetic apoE-/- mice injected with Adenovirus-mediated NLRP3 interference (Ad-NLRP3i). To elucidate the potential mechanism involved, ox-LDL-irritated human aortic smooth muscle cells were divided into the control, high-glucose, Si-NC, and Si-NLRP3 groups to observe the changes induced by downregulating NLRP3 expression. For up-regulating NLRP3, control and plasmid contained NLRP3 were used. TNF-α, IL-1ß, IL-6, IL-18, phosphorylated and total p38, JNK, p65, and IκBα expression levels were detected following the downregulation or upregulation of NLRP3 expression. RESULTS: Patients with comorbid CAD and DM showed higher serum levels and expression of NLRP3 in the coronary artery than those with only CAD. Moreover, mice in the Ad-NLRP3i group showed markedly smaller and more stable atherosclerotic lesions compared to those in other DM groups. These mice had decreased inflammatory cytokine production and improved glucose tolerance, which demonstrated the substantial effects of NLRP3 in the progression of diabetes-associated AS. Furthermore, using the siRNA or plasmid to downregulate or upregulate NLRP3 expression in vitro altered cytokines and the MAPK/NF-κB pathway. CONCLUSIONS: NLRP3 expression was significantly increased under hyperglycemia. Additionally, it accelerated AS by promoting inflammation via the IL/MAPK/NF-κB pathway.