RESUMO
Despite advancements in chemotherapy and the availability of novel therapies, the outcome of adult patients with B-cell acute lymphoblastic leukemia (B-ALL) remains unsatisfactory. Therefore, it is necessary to understand the molecular mechanisms underlying the progression of B-ALL. Brahma-related gene 1 (BRG1) is a poor prognostic factor for multiple cancers. Here, the expression of BRG1 was found to be higher in patients with B-ALL, irrespective of the molecular subtype, than in healthy individuals, and its overexpression was associated with a poor prognosis. Upregulation of BRG1 accelerated cell cycle progression into the S phase, resulting in increased cell proliferation, whereas its downregulation facilitated the apoptosis of B-ALL cells. Mechanistically, BRG1 occupies the transcriptional activation site of PPP2R1A, thereby inhibiting its expression and activating the PI3K/AKT signaling pathway to regulate the proto-oncogenes c-Myc and BCL-2. Consistently, silencing of BRG1 and administration of PFI-3 (a specific inhibitor targeting BRG1) significantly inhibited the progression of leukemia and effectively prolonged survival in cell-derived xenograft mouse models of B-ALL. Altogether, this study demonstrates that BRG1-induced overactivation of the PPP2R1A/PI3K/AKT signaling pathway plays an important role in promoting the progression of B-ALL. Therefore, targeting BRG1 represents a promising strategy for the treatment of B-ALL in adults.
Assuntos
DNA Helicases , Progressão da Doença , Proteínas Nucleares , Proteína Fosfatase 2 , Fatores de Transcrição , Animais , Feminino , Humanos , Masculino , Camundongos , Apoptose/efeitos dos fármacos , Apoptose/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , DNA Helicases/metabolismo , DNA Helicases/genética , Proteínas Nucleares/metabolismo , Proteínas Nucleares/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Proteína Fosfatase 2/metabolismo , Proteína Fosfatase 2/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Transcrição Gênica/efeitos dos fármacosRESUMO
Objective To analyze the relationship between protein phosphatase 2A catalytic subunit alpha (PPP2CA) expression and prognosis and immune infiltration in colorectal cancer (CRC) patients, and further explore the mechanism about the development and progression of CRC. Methods The differences in PPP2CA expression levels between CRC tissues and normal tissues were analyzed using the gene chip database Oncomine and The Tumor Immune Estimation Resource (TIMER) database. The impact of PPP2CA expression levels on the prognosis of CRC patients was analyzed using The University of Alabama at Birmingham Cancer data analysis portal (UALCAN) and Gene Expression Profiling Interactive Analysis (GEPIA) databases. To further understand the role of PPP2CA in CRC, the co-expression network of PPP2CA was constructed using LinkedOmics platform, followed by Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Besides, the correlation between PPP2CA and immune infiltration was analyzed using TIMER and GEPIA databases. The gene mutation of PPP2CA in colon adenocarcinoma (COAD) were analyzed using c-BioPortal platform. Results PPP2CA was down-regulated in CRC tissues compared with normal tissues, and higher PPP2CA expression indicated better Overall Survival (OS) and Progression-Free Survival (PFS). In COAD, the expression level of PPP2CA was positively correlated with immune infiltrating cells including CD8+ T cells, neutrophils and dendritic cells. However, certain immune cell markers including CD19 and CD38 in B cells, NOS2 in M1 macrophages, Arginase 1 (ARG1) and Mannose Receptor C-Type 1 (MRC1) in M2 macrophages, Human Leukocyte Antigen G (HLA-G) and CD80 in Tumor Associated Macrophage (TAM) and CD14 and Fc Gamma Receptor 3A (FCGR3A) in monocytes, showed a different pattern of PPP2CA-associated immune infiltration. In other words, PPP2CA expression level was significantly associated with B cells, macrophages, monocytes, TAM, Th1 cells, Th2 cells, regulatory T cells, exhausted T cells and neutrophils in both COAD and rectum adenocarcinoma (READ). Conclusion PPP2CA is down-regulated in CRC tissues and closely correlated with immune infiltration.
Assuntos
Neoplasias Colorretais , Biologia Computacional , Proteína Fosfatase 2 , Humanos , Neoplasias Colorretais/genética , Neoplasias Colorretais/imunologia , Proteína Fosfatase 2/genética , Prognóstico , Regulação Neoplásica da Expressão Gênica , Linfócitos do Interstício Tumoral/imunologia , Perfilação da Expressão GênicaRESUMO
BACKGROUND: Approximately 25-30% of patients with acute myeloid leukemia (AML) have FMS-like receptor tyrosine kinase-3 (FLT3) mutations that contribute to disease progression and poor prognosis. Prolonged exposure to FLT3 tyrosine kinase inhibitors (TKIs) often results in limited clinical responses due to diverse compensatory survival signals. Therefore, there is an urgent need to elucidate the mechanisms underlying FLT3 TKI resistance. Dysregulated sphingolipid metabolism frequently contributes to cancer progression and a poor therapeutic response. However, its relationship with TKI sensitivity in FLT3-mutated AML remains unknown. Thus, we aimed to assess mechanisms of FLT3 TKI resistance in AML. METHODS: We performed lipidomics profiling, RNA-seq, qRT-PCR, and enzyme-linked immunosorbent assays to determine potential drivers of sorafenib resistance. FLT3 signaling was inhibited by sorafenib or quizartinib, and SPHK1 was inhibited by using an antagonist or via knockdown. Cell growth and apoptosis were assessed in FLT3-mutated and wild-type AML cell lines via Cell counting kit-8, PI staining, and Annexin-V/7AAD assays. Western blotting and immunofluorescence assays were employed to explore the underlying molecular mechanisms through rescue experiments using SPHK1 overexpression and exogenous S1P, as well as inhibitors of S1P2, ß-catenin, PP2A, and GSK3ß. Xenograft murine model, patient samples, and publicly available data were analyzed to corroborate our in vitro results. RESULTS: We demonstrate that long-term sorafenib treatment upregulates SPHK1/sphingosine-1-phosphate (S1P) signaling, which in turn positively modulates ß-catenin signaling to counteract TKI-mediated suppression of FLT3-mutated AML cells via the S1P2 receptor. Genetic or pharmacological inhibition of SPHK1 potently enhanced the TKI-mediated inhibition of proliferation and apoptosis induction in FLT3-mutated AML cells in vitro. SPHK1 knockdown enhanced sorafenib efficacy and improved survival of AML-xenografted mice. Mechanistically, targeting the SPHK1/S1P/S1P2 signaling synergizes with FLT3 TKIs to inhibit ß-catenin activity by activating the protein phosphatase 2 A (PP2A)-glycogen synthase kinase 3ß (GSK3ß) pathway. CONCLUSIONS: These findings establish the sphingolipid metabolic enzyme SPHK1 as a regulator of TKI sensitivity and suggest that combining SPHK1 inhibition with TKIs could be an effective approach for treating FLT3-mutated AML.
Assuntos
Glicogênio Sintase Quinase 3 beta , Leucemia Mieloide Aguda , Fosfotransferases (Aceptor do Grupo Álcool) , Proteína Fosfatase 2 , beta Catenina , Tirosina Quinase 3 Semelhante a fms , Tirosina Quinase 3 Semelhante a fms/genética , Tirosina Quinase 3 Semelhante a fms/metabolismo , Tirosina Quinase 3 Semelhante a fms/antagonistas & inibidores , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/patologia , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Glicogênio Sintase Quinase 3 beta/genética , beta Catenina/metabolismo , beta Catenina/genética , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Fosfotransferases (Aceptor do Grupo Álcool)/antagonistas & inibidores , Animais , Camundongos , Proteína Fosfatase 2/metabolismo , Proteína Fosfatase 2/genética , Proteína Fosfatase 2/antagonistas & inibidores , Linhagem Celular Tumoral , Sorafenibe/farmacologia , Apoptose/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Transdução de Sinais/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sinergismo Farmacológico , Ensaios Antitumorais Modelo de Xenoenxerto , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genéticaRESUMO
BACKGROUND: Abdominal obesity increases the risk for non-alcoholic fatty liver disease (NAFLD), now known as metabolic dysfunction-associated steatotic liver disease (MASLD). METHODS: To elucidate the directional cell-type level biological mechanisms underlying the association between abdominal obesity and MASLD, we integrated adipose and liver single nucleus RNA-sequencing and bulk cis-expression quantitative trait locus (eQTL) data with the UK Biobank genome-wide association study (GWAS) data using colocalization. Then we used colocalized cis-eQTL variants as instrumental variables in Mendelian randomization (MR) analyses, followed by functional validation experiments on the target genes of the cis-eQTL variants. FINDINGS: We identified 17 colocalized abdominal obesity GWAS variants, regulating 17 adipose cell-type marker genes. Incorporating these 17 variants into MR discovers a putative tissue-of-origin, cell-type-aware causal effect of abdominal obesity on MASLD consistently with multiple MR methods without significant evidence for pleiotropy or heterogeneity. Single cell data confirm the adipocyte-enriched mean expression of the 17 genes. Our cellular experiments across human adipogenesis identify risk variant -specific epigenetic and transcriptional mechanisms. Knocking down two of the 17 genes, PPP2R5A and SH3PXD2B, shows a marked decrease in adipocyte lipidation and significantly alters adipocyte function and adipogenesis regulator genes, including DGAT2, LPL, ADIPOQ, PPARG, and SREBF1. Furthermore, the 17 genes capture a characteristic MASLD expression signature in subcutaneous adipose tissue. INTERPRETATION: Overall, we discover a significant cell-type level effect of abdominal obesity on MASLD and trace its biological effect to adipogenesis. FUNDING: NIH grants R01HG010505, R01DK132775, and R01HL170604; the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (Grant No. 802825), Academy of Finland (Grants Nos. 333021), the Finnish Foundation for Cardiovascular Research the Sigrid Jusélius Foundation and the Jane and Aatos Erkko Foundation; American Association for the Study of Liver Diseases (AASLD) Advanced Transplant Hepatology award and NIH/NIDDK (P30DK41301) Pilot and Feasibility award; NIH/NIEHS F32 award (F32ES034668); Finnish Diabetes Research Foundation, Kuopio University Hospital Project grant (EVO/VTR grants 2005-2021), the Academy of Finland grant (Contract no. 138006); Academy of Finland (Grant Nos 335443, 314383, 272376 and 266286), Sigrid Jusélius Foundation, Finnish Medical Foundation, Finnish Diabetes Research Foundation, Novo Nordisk Foundation (#NNF20OC0060547, NNF17OC0027232, NNF10OC1013354) and Government Research Funds to Helsinki University Hospital; Orion Research Foundation, Maud Kuistila Foundation, Finish Medical Foundation, and University of Helsinki.
Assuntos
Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Obesidade Abdominal , Locos de Características Quantitativas , Humanos , Obesidade Abdominal/genética , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/patologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Polimorfismo de Nucleotídeo Único , Análise de Sequência de RNA , Proteína Fosfatase 2/genética , Proteína Fosfatase 2/metabolismo , Núcleo Celular/metabolismo , Núcleo Celular/genética , Adipogenia/genética , Análise de Célula Única , Regulação da Expressão GênicaRESUMO
Prostate cancer exhibits high prevalence and accounts for a high number of cancer-related deaths. The discovery and characterization of molecular determinants of aggressive prostate cancer represents an active area of research. The Immediate Early Response (IER) family of genes, which regulate Protein Phosphatase 2A (PP2A) activity, has emerged among the factors that influence cancer biology. Here, we show that the less studied member of this family, Immediate Early Response 5 like (IER5L), is upregulated in aggressive prostate cancer. Interestingly, the upregulation of IER5L expression exhibits a robust association with metastatic disease in prostate and is recapitulated in other cancer types. In line with this observation, IER5L silencing reduces foci formation, migration and invasion ability in a variety of human and murine prostate cancer cell lines. In vivo, using zebrafish and immunocompromised mouse models, we demonstrate that IER5L-silencing reduces prostate cancer tumor growth, dissemination, and metastasis. Mechanistically, we characterize the transcriptomic and proteomic landscapes of IER5L-silenced cells. This approach allowed us to identify DNA replication and monomeric G protein regulators as downstream programs of IER5L through a pathway that is consistent with the regulation of PP2A. In sum, we report the alteration of IER5L in prostate cancer and beyond and provide biological and molecular evidence of its contribution to tumor aggressiveness.
Assuntos
Progressão da Doença , Neoplasias da Próstata , Proteína Fosfatase 2 , Masculino , Neoplasias da Próstata/patologia , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Humanos , Proteína Fosfatase 2/metabolismo , Proteína Fosfatase 2/genética , Animais , Camundongos , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Peixe-Zebra , Movimento Celular/genética , Proliferação de CélulasRESUMO
Helicobacter pylori (HP) infection initiates and promotes gastric carcinogenesis. ONECUT2 shows promise for tumor diagnosis, prognosis, and treatment. This study explored ONECUT2's role and the specific mechanism underlying HP infection-associated gastric carcinogenesis to suggest a basis for targeting ONECUT2 as a therapeutic strategy for gastric cancer (GC). Multidimensional data supported an association between ONECUT2, HP infection, and GC pathogenesis. HP infection upregulated ONECUT2 transcriptional activity via NFκB. In vitro and in vivo experiments demonstrated that ONECUT2 increased the stemness of GC cells. ONECUT2 was also shown to inhibit PPP2R4 transcription, resulting in reduced PP2A activity, which in turn increased AKT/ß-catenin phosphorylation. AKT/ß-catenin phosphorylation facilitates ß-catenin translocation to the nucleus, initiating transcription of downstream stemness-associated genes in GC cells. HP infection upregulated the reduction of AKT and ß-catenin phosphorylation triggered by ONECUT2 downregulation via ONECUT2 induction. Clinical survival analysis indicated that high ONECUT2 expression may indicate poor prognosis in GC. This study highlights a critical role played by ONECUT2 in promoting HP infection-associated GC by enhancing cell stemness through the PPP2R4/AKT/ß-catenin signaling pathway. These findings suggest promising therapeutic strategies and potential targets for GC treatment.
Assuntos
Infecções por Helicobacter , Helicobacter pylori , Células-Tronco Neoplásicas , Proteínas Proto-Oncogênicas c-akt , Neoplasias Gástricas , Animais , Feminino , Humanos , Masculino , Camundongos , beta Catenina/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Infecções por Helicobacter/metabolismo , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/complicações , Infecções por Helicobacter/patologia , Camundongos Endogâmicos BALB C , Camundongos Nus , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Fosforilação , Proteína Fosfatase 2/metabolismo , Proteína Fosfatase 2/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Neoplasias Gástricas/patologia , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/genéticaRESUMO
PP2A B55α, encoded by PPP2R2A, acts as a regulatory subunit of the serine/threonine phosphatase PP2A. Despite a frequent loss of heterozygosity of PPP2R2A in cases of non-small cell lung cancer (NSCLC), research on PP2A B55α's functions remains limited and controversial. To investigate the biological roles of PP2A B55α, we conducted bulk RNA-sequencing to assess the impact of PPP2R2A knockdown using two shRNAs in a NSCLC cell line. Gene set enrichment analysis (GSEA) of the RNA-sequencing data revealed significant enrichment of the epithelial-mesenchymal transition (EMT) pathway, with SNAI2 (the gene encoding Slug) emerging as one of the top candidates. Our findings demonstrate that PP2A B55α suppresses EMT, as PPP2R2A deficiency through knockdown or homozygous or hemizygous depletion promotes EMT and metastatic behavior in NSCLC cells, as evidenced by changes in EMT biomarkers, invasion and migration abilities, as well as metastasis in a tail vein assay. Mechanistically, PP2A B55α inhibits EMT by downregulating SNAI2 expression via the GSK3ß-ß-catenin pathway. Importantly, PPP2R2A deficiency also slows cell proliferation by disrupting DNA replication, particularly in PPP2R2A-/- cells. Furthermore, PPP2R2A deficiency, especially PPP2R2A-/- cells, leads to an increase in the cancer stem cell population, which correlates with enhanced resistance to chemotherapy. Overall, the decrease in PP2A B55α levels due to hemizygous/homozygous depletion heightens EMT and the metastatic or stemness/drug resistance potential of NSCLC cells despite their proliferation disadvantage. Our study highlights the significance of PP2A B55α in EMT and metastasis and suggests that targeting EMT/stemness could be a potential therapeutic strategy for treating PPP2R2A-deficient NSCLC.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares , Proteína Fosfatase 2 , Fatores de Transcrição da Família Snail , Transição Epitelial-Mesenquimal/genética , Humanos , Fatores de Transcrição da Família Snail/genética , Fatores de Transcrição da Família Snail/metabolismo , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Proteína Fosfatase 2/genética , Proteína Fosfatase 2/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/metabolismo , Animais , Movimento Celular , Linhagem Celular Tumoral , Glicogênio Sintase Quinase 3 beta/metabolismo , Glicogênio Sintase Quinase 3 beta/genética , Células A549 , Camundongos , Invasividade NeoplásicaRESUMO
The Ser/Thr protein phosphatase 2 A (PP2A) regulates the dephosphorylation of many phosphoproteins. Substrate recognition are mediated by B regulatory subunits. Here, we report the identification of a substrate conserved motif [RK]-V-x-x-[VI]-R in FAM122A, an inhibitor of B55α/PP2A. This motif is necessary for FAM122A binding to B55α, and computational structure prediction suggests the motif, which is helical, blocks substrate docking to the same site. In this model, FAM122A also spatially constrains substrate access by occluding the catalytic subunit. Consistently, FAM122A functions as a competitive inhibitor as it prevents substrate binding and dephosphorylation of CDK substrates by B55α/PP2A in cell lysates. FAM122A deficiency in human cell lines reduces the proliferation rate, cell cycle progression, and hinders G1/S and intra-S phase cell cycle checkpoints. FAM122A-KO in HEK293 cells attenuates CHK1 and CHK2 activation in response to replication stress. Overall, these data strongly suggest that FAM122A is a short helical motif (SHeM)-dependent, substrate-competitive inhibitor of B55α/PP2A that suppresses multiple functions of B55α in the DNA damage response and in timely progression through the cell cycle interphase.
Assuntos
Motivos de Aminoácidos , Interfase , Proteína Fosfatase 2 , Humanos , Pontos de Checagem do Ciclo Celular/genética , Proliferação de Células , Quinase 1 do Ponto de Checagem/metabolismo , Quinase 1 do Ponto de Checagem/genética , Quinase do Ponto de Checagem 2/metabolismo , Quinase do Ponto de Checagem 2/genética , Células HEK293 , Fosforilação , Ligação Proteica , Proteína Fosfatase 2/metabolismo , Proteína Fosfatase 2/genéticaRESUMO
Cell cycle progression is regulated by the orderly balance between kinase and phosphatase activities. PP2A phosphatase holoenzymes containing the B55 family of regulatory B subunits function as major CDK1-counteracting phosphatases during mitotic exit in mammals. However, the identification of the specific mitotic roles of these PP2A-B55 complexes has been hindered by the existence of multiple B55 isoforms. Here, through the generation of loss-of-function genetic mouse models for the two ubiquitous B55 isoforms (B55α and B55δ), we report that PP2A-B55α and PP2A-B55δ complexes display overlapping roles in controlling the dynamics of proper chromosome individualization and clustering during mitosis. In the absence of PP2A-B55 activity, mitotic cells display increased chromosome individualization in the presence of enhanced phosphorylation and perichromosomal loading of Ki-67. These data provide experimental evidence for a regulatory mechanism by which the balance between kinase and PP2A-B55 phosphatase activity controls the Ki-67-mediated spatial organization of the mass of chromosomes during mitosis.
Assuntos
Antígeno Ki-67 , Mitose , Proteína Fosfatase 2 , Animais , Proteína Fosfatase 2/metabolismo , Proteína Fosfatase 2/genética , Camundongos , Antígeno Ki-67/metabolismo , Fosforilação , Cromossomos de Mamíferos/metabolismo , Cromossomos de Mamíferos/genética , Cromossomos/metabolismoRESUMO
Cisplatin resistance is a major challenge for systemic therapy against advanced bladder cancer (BC). Little information is available on the regulation of cisplatin resistance and the underlying mechanisms require elucidation. Here, we detected that downregulation of the tumor suppressor, PPP2R2B (a serine/threonine protein phosphatase 2 A regulatory subunit), in BC promoted cell proliferation and migration. What's more, low PPP2R2B expression was correlated with cisplatin resistance. In vitro and in vivo experiments verified that PPP2R2B could promote BC sensitivity to cisplatin. In terms of mechanism, we identified a novel function of PPP2R2B as a nucleocytoplasmic transport molecule. PPP2R2B promoted ISG15 entry into the nucleus by mediating binding of IPO5 with ISG15. Nuclear translocation of ISG15 inhibited DNA repair, further increasing ISG15 expression through activation of the STING pathway. Besides, PPP2R2B was down-regulated by SUV39H1-mediated histone 3 lysine 9 trimethylation, which could be restored by the SUV39H1-specific inhibitor, chaetocin. Our data suggest that PPP2R2B expression level is a potential biomarker for chemotherapy response and that chemotherapy in combination with chaetocin may be a feasible treatment strategy for patients with BC.
Assuntos
Cisplatino , Citocinas , Resistencia a Medicamentos Antineoplásicos , Proteína Fosfatase 2 , Ubiquitinas , Neoplasias da Bexiga Urinária , Neoplasias da Bexiga Urinária/tratamento farmacológico , Neoplasias da Bexiga Urinária/metabolismo , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia , Proteína Fosfatase 2/metabolismo , Proteína Fosfatase 2/genética , Humanos , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Ubiquitinas/metabolismo , Ubiquitinas/genética , Citocinas/metabolismo , Animais , Linhagem Celular Tumoral , Camundongos , Proliferação de Células/efeitos dos fármacos , Camundongos Nus , Núcleo Celular/metabolismo , Antineoplásicos/farmacologia , Camundongos Endogâmicos BALB C , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Feminino , Proteínas do Tecido NervosoRESUMO
Tumor angiogenesis, the formation of new blood vessels to support tumor growth and metastasis, is a complex process regulated by a multitude of signaling pathways. Dysregulation of signaling pathways involving protein kinases has been extensively studied, but the role of protein phosphatases in angiogenesis within the tumor microenvironment remains less explored. However, among angiogenic pathways, protein phosphatases play critical roles in modulating signaling cascades. This review provides a comprehensive overview of the involvement of protein phosphatases in tumor angiogenesis, highlighting their diverse functions and mechanisms of action. Protein phosphatases are key regulators of cellular signaling pathways by catalyzing the dephosphorylation of proteins, thereby modulating their activity and function. This review aims to assess the activity of the protein tyrosine phosphatases and serine/threonine phosphatases. These phosphatases exert their effects on angiogenic signaling pathways through various mechanisms, including direct dephosphorylation of angiogenic receptors and downstream signaling molecules. Moreover, protein phosphatases also crosstalk with other signaling pathways involved in angiogenesis, further emphasizing their significance in regulating tumor vascularization, including endothelial cell survival, sprouting, and vessel maturation. In conclusion, this review underscores the pivotal role of protein phosphatases in tumor angiogenesis and accentuate their potential as therapeutic targets for anti-angiogenic therapy in cancer.
Assuntos
Neoplasias , Neovascularização Patológica , Fosfoproteínas Fosfatases , Transdução de Sinais , Humanos , Neovascularização Patológica/metabolismo , Neoplasias/irrigação sanguínea , Neoplasias/metabolismo , Neoplasias/patologia , Animais , Fosfoproteínas Fosfatases/metabolismo , Proteína Fosfatase 2/metabolismo , Microambiente Tumoral , Fosforilação , AngiogêneseRESUMO
BACKGROUND: Cantharidin (CTD), a natural toxic compound from blister beetle Mylabris, has been used for cancer treatment for millenary. CTD and its analogs have become mainstream adjuvant drugs with radiotherapy and chemotherapy in clinical applications. However, the detailed pharmacology mechanism of CTD was not fully elucidated. METHODS: Publications of CTD were collected from the Web of Science Core Collection database from 1991 to 2023 using CiteSpace, VOSviewer, and Scimago Graphica software. RESULTS: A total of 1,611 publications of CTD were mainly published in China and the United States. The University of Newcastle has published the most researches. Mcclusey, Adam, Sakoff, Jennette, and Zhang, Yalin had the most CTD publications with higher H. Notably, CTD researches were mainly published in Bioorganic & Medicinal Chemistry Letters and the Journal of Biological Chemistry. Cluster profile results revealed that protein phosphatase 2A (PP2A), human gallbladder carcinoma, Aidi injection, and cell apoptosis were the hotspots. Concentration on the pharmacology function of PP2A subunit regulation, hepatotoxicity, nephrotoxicity, and cardiotoxicity mechanism should be strengthened in the future. CONCLUSION: Bibliometric analysis combined with a systemic review of CTD research first revealed that PP2A and CTD analogs were the knowledge base of CTD, and PP2A subunit regulation and toxic mechanism could be the frontiers of CTD.
Assuntos
Bibliometria , Cantaridina , Cantaridina/uso terapêutico , Humanos , Animais , Proteína Fosfatase 2/antagonistas & inibidores , Proteína Fosfatase 2/metabolismo , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacosRESUMO
Post-translational modification, mitochondrial abruptions, neuroinflammation, and α-synuclein (α-Syn) aggregation are considered as major causes of Parkinson's disease (PD) pathogenesis. The recent literature highlights neuroimmune cross talk and the negative role of immune effector T (Teff) and positive regulation by regulatory T (Treg) cells in PD treatment. Herein, a strategy to endow Treg action paves the path for development of PD treatment. Thus, we explored the neuroprotective efficiency of the immunomodulator and PP2A (protein phosphatase 2) activator, FTY720 nanoparticles in in vivo experimental PD models. Repurposing of FTY720 for PD is known due to its protective effect by reducing PD and its camouflaged role in endowing EZH2-mediated epigenetic regulation of PD. EZH2-FOXP3 interaction is necessary for the neuroprotective Treg cell activity. Therefore, we synthesized FTY720 nanoparticles to improve FTY720 protective efficacy in an in vivo PD model to explore the PP2A mediated signaling. We confirmed the formation of FTY720NPs, and the results of the behavioral and protein expression study showed the significant neuroprotective efficiency of our nanoformulations. In the exploration of neuroprotective mechanism, several lines of evidence confirmed FTY720NPs mediated induction of PP2A/EZH2/FOXP3 signaling in the induction of Treg cells effect in in vivo PD treatment. In summary, our nanoformulations have novel potential to alleviate PD by inducing PP2A-induced epigenetic regulation-mediated neuroimmunomodulation at the clinical setup.
Assuntos
Cloridrato de Fingolimode , Nanopartículas , Fármacos Neuroprotetores , Linfócitos T Reguladores , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Animais , Nanopartículas/química , Camundongos , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/química , Cloridrato de Fingolimode/farmacologia , Cloridrato de Fingolimode/química , Cloridrato de Fingolimode/uso terapêutico , Camundongos Endogâmicos C57BL , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/antagonistas & inibidores , Proteína Fosfatase 2/metabolismo , Agentes de Imunomodulação/farmacologia , Agentes de Imunomodulação/química , Masculino , Fatores Imunológicos/farmacologia , Fatores Imunológicos/química , Fatores de Transcrição Forkhead/metabolismo , Humanos , Transtornos Parkinsonianos/tratamento farmacológicoRESUMO
Chronic obstructive pulmonary disease (COPD) is a common disease with high global morbidity and mortality. Macrophages release IL-1ß and orchestrate airway inflammation in COPD. Previously, we explored the role of a new lncRNA, LincR-PPP2R5C, in regulating Th2 cells in asthma. Here, we established a murine model of COPD and explored the roles and mechanisms by which LincR-PPP2R5C regulates IL-1ß in macrophages. LincR-PPP2R5C was highly expressed in pulmonary macrophages from COPD-like mice. LincR-PPP2R5C deficiency ameliorated emphysema and pulmonary inflammation, as characterized by reduced IL-1ß in macrophages. Unexpectedly, in both lung tissues and macrophages, LincR-PPP2R5C deficiency decreased the expression of the IL-1ß protein but not the IL-1ß mRNA. Furthermore, we found that LincR-PPP2R5C deficiency increased the level of ubiquitinated IL-1ß in macrophages, which was mediated by PP2A activity. Targeting PP2A with FTY720 decreased IL-1ß and improved COPD. In conclusion, LincR-PPP2R5C regulates IL-1ß ubiquitination by affecting PP2A activity in macrophages, contributing to the airway inflammation and emphysema in a murine model of COPD. PP2A and IL-1ß ubiquitination in macrophages might be new therapeutic avenues for COPD therapy.
Assuntos
Modelos Animais de Doenças , Interleucina-1beta , Camundongos Endogâmicos C57BL , Doença Pulmonar Obstrutiva Crônica , RNA Longo não Codificante , Ubiquitinação , Animais , Doença Pulmonar Obstrutiva Crônica/imunologia , Doença Pulmonar Obstrutiva Crônica/metabolismo , Interleucina-1beta/metabolismo , Camundongos , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Proteína Fosfatase 2/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Humanos , Masculino , Enfisema Pulmonar/metabolismo , Enfisema Pulmonar/imunologia , Enfisema Pulmonar/patologia , Enfisema Pulmonar/genética , Pulmão/patologia , Pulmão/imunologia , Camundongos KnockoutRESUMO
BACKGROUND: Abnormally elevated homocysteine (Hcy) is recognized as a biomarker and risk factor for Alzheimer's disease (AD). However, the underlying mechanisms by which Hcy affects AD are still unclear. OBJECTIVES: This study aimed to elucidate the effects and mechanisms by which Hcy affects AD-like pathological changes in the hippocampus through in vivo and in vitro experiments, and to investigate whether folic acid (FA) and S-adenosylmethionine (SAM) supplementation could improve neurodegenerative injuries. METHODS: In vitro experiments hippocampal neurons of rat were treated with Hcy, FA or SAM for 24 h; while the hyperhomocysteinemia (HHcy) in Wistar rats was established by intraperitoneal injection of Hcy, and FA was added to feed. The expression of ß-amyloid (Aß), phosphorylated tau protein, presenilin 1 (PS1) at the protein level and the activity of protein phosphatase 2A (PP2A) were detected, the immunopositive cells for Aß and phosphorylated tau protein in the rat hippocampus were also evaluated by immunohistochemical staining. RESULTS: FA and SAM significantly repressed Hcy-induced AD-like pathological changes in the hippocampus, including the increased tau protein phosphorylation at Ser214, Ser396 and the expression of Aß42. In addition, Hcy-induced PS1 expression increased at the protein level and PP2A activity decreased, while FA and SAM were able to retard that. CONCLUSIONS: The increase in PS1 expression and decrease in PP2A activity may be the mechanisms underlying the Hcy-induced AD-like pathology. FA and SAM significantly repressed the Hcy-induced neurodegenerative injury by modulating PS1 and PP2A methylation levels.
Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Ácido Fólico , Hipocampo , Homocisteína , Presenilina-1 , Proteína Fosfatase 2 , Ratos Wistar , S-Adenosilmetionina , Proteínas tau , Animais , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Hipocampo/patologia , Proteína Fosfatase 2/metabolismo , S-Adenosilmetionina/farmacologia , Doença de Alzheimer/patologia , Doença de Alzheimer/metabolismo , Doença de Alzheimer/induzido quimicamente , Homocisteína/farmacologia , Homocisteína/toxicidade , Ácido Fólico/farmacologia , Ratos , Masculino , Presenilina-1/genética , Proteínas tau/metabolismo , Peptídeos beta-Amiloides/metabolismo , Metilação/efeitos dos fármacos , Hiper-Homocisteinemia/metabolismo , Hiper-Homocisteinemia/induzido quimicamente , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Fosforilação/efeitos dos fármacos , Modelos Animais de DoençasRESUMO
Merkel Cell Carcinoma (MCC) is a rare neuroendocrine skin cancer. In our previous work, we decoded genes specifically deregulated by MCPyV early genes as opposed to other polyomaviruses and established functional importance of NDRG1 in inhibiting cellular proliferation and migration in MCC. In the present work, we found the SET protein, (I2PP2A, intrinsic inhibitor of PP2A) upstream of NDRG1 which was modulated by MCPyV early genes, both in hTERT-HK-MCPyV and MCPyV-positive (+) MCC cell lines. Additionally, MCC dermal tumour nodule tissues showed strong SET expression. Inhibition of the SET-PP2A interaction in hTERT-HK-MCPyV using the small molecule inhibitor, FTY720, increased NDRG1 expression and inhibited cell cycle regulators, cyclinD1 and CDK2. SET inhibition by shRNA and FTY720 also decreased cell proliferation and colony formation in MCPyV(+) MCC cells. Overall, these results pave a path for use of drugs targeting SET protein for the treatment of MCC.
Assuntos
Carcinoma de Célula de Merkel , Movimento Celular , Proliferação de Células , Poliomavírus das Células de Merkel , Proteína Fosfatase 2 , Humanos , Poliomavírus das Células de Merkel/fisiologia , Poliomavírus das Células de Merkel/genética , Proteína Fosfatase 2/metabolismo , Proteína Fosfatase 2/genética , Carcinoma de Célula de Merkel/virologia , Carcinoma de Célula de Merkel/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Cloridrato de Fingolimode/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Linhagem Celular Tumoral , Chaperonas de Histonas/metabolismo , Chaperonas de Histonas/genética , Infecções por Polyomavirus/virologia , Neoplasias Cutâneas/virologia , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/metabolismo , Quinase 2 Dependente de Ciclina/metabolismo , Quinase 2 Dependente de Ciclina/genéticaRESUMO
Many organisms utilize an actin- and myosin-based cytokinetic ring (CR) to help complete cytokinesis. In Schizosaccharomyces pombe, the Septation Initiation Network (SIN) promotes proper CR function and stability. The SIN is a conserved and essential signaling network consisting of a GTPase and a cascade of kinases assembled at the spindle pole body (SPB). The PP2A SIN inhibitory phosphatase (SIP) complex related to the STRIPAK phosphatase complex is one inhibitor of SIN signaling. The SIP consists of Csc1, Csc2, Csc3, Csc4, Paa1, and the phosphatase subunit Ppa3. Here, we determine that the SIP is anchored at the SPB via the Csc1 FHA domain and that constitutive SPB localization of the SIP is lethal due to persistent SIN inhibition. Disrupting SIP docking at the SPB with a point mutation within the FHA domain or eliminating phosphatase activity by introducing a point mutation within Ppa3 resulted in intact SIP complexes without SIN inhibitory function. Lastly, we defined the unique features of Ppa3 that allow it, but not two other PP2A catalytic subunits, to incorporate into the SIP. Overall, we provide insight into how the SIP complex assembles, localizes, and functions to counteract the SIN with spatiotemporal precision during cytokinesis.
Assuntos
Citocinese , Mitose , Proteína Fosfatase 2 , Proteínas de Schizosaccharomyces pombe , Schizosaccharomyces , Corpos Polares do Fuso , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Proteína Fosfatase 2/metabolismo , Citocinese/fisiologia , Corpos Polares do Fuso/metabolismo , Domínios Proteicos , Transdução de Sinais , Fuso Acromático/metabolismoRESUMO
Phosphorylation of cardiac myosin binding protein-C (cMyBP-C) is a determinant of cardiac myofilament function. Although cMyBP-C phosphorylation by various protein kinases has been extensively studied, the influence of protein phosphatases on cMyBP-C's multiple phosphorylation sites has remained largely obscure. Here we provide a detailed biochemical characterization of cMyBP-C dephosphorylation by protein phosphatases 1 and 2 A (PP1 and PP2A), and develop an integrated kinetic model for cMyBP-C phosphorylation using data for both PP1, PP2A and various protein kinases known to phosphorylate cMyBP-C. We find strong site-specificity and a hierarchical mechanism for both phosphatases, proceeding in the opposite direction of sequential phosphorylation by potein kinase A. The model is consistent with published data from human patients and predicts complex non-linear cMyBP-C phosphorylation patterns that are validated experimentally. Our results suggest non-redundant roles for PP1 and PP2A under both physiological and heart failure conditions, and emphasize the importance of phosphatases for cMyBP-C regulation.
Assuntos
Proteínas de Transporte , Miocárdio , Proteína Fosfatase 1 , Proteína Fosfatase 2 , Fosforilação , Humanos , Proteína Fosfatase 1/metabolismo , Proteínas de Transporte/metabolismo , Animais , Proteína Fosfatase 2/metabolismo , Miocárdio/metabolismo , Proteínas Quinases/metabolismo , CinéticaRESUMO
Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by multi-organ involvement and autoantibody production. Patients with SLE face a substantial risk of developing lupus nephritis (LN), which imposes a substantial burden on both patients and their families. Protein phosphatase 2A (PP2A) is a widely distributed serine/threonine phosphatase that participates in regulating multiple signaling pathways. Inhibition of PP2A has been implicated in the treatment of various diseases. LB-100, a small molecule inhibitor of PP2A, has demonstrated anti-tumor therapeutic effects and high safety profile in preclinical experiments. However, the role of PP2A and its inhibitor has been insufficiently studied in LN. In this study, we assessed the potential effects of LB-100 in both MRL/lpr mice and R848-induced BALB/c mice. Our findings indicated that LB-100 administration led to reduced spleen enlargement, decreased deposition of immune complexes, ameliorated renal damage, and improved kidney function in both spontaneous and R848-induced lupus mouse models. Importantly, we observed the formation of tertiary lymphoid structures (TLSs) in the kidneys of two distinct lupus mouse models. The levels of signature genes of TLS were elevated in the kidneys of lupus mice, whereas LB-100 mitigated chemokine production and inhibited TLS formation. In addition, we confirmed that inhibition or knockdown of PP2A reduced the production of T cell-related chemokines by renal tubular epithelial cells (RTEC). In summary, our study highlighted the renal protective potential of the PP2A inhibitor LB-100 in two distinct lupus mouse models, suggesting its potential as a novel strategy for treating LN and other autoimmune diseases.
Assuntos
Nefrite Lúpica , Camundongos Endogâmicos BALB C , Proteína Fosfatase 2 , Estruturas Linfoides Terciárias , Animais , Proteína Fosfatase 2/antagonistas & inibidores , Proteína Fosfatase 2/metabolismo , Nefrite Lúpica/tratamento farmacológico , Nefrite Lúpica/patologia , Camundongos , Estruturas Linfoides Terciárias/patologia , Feminino , Camundongos Endogâmicos MRL lpr , Rim/efeitos dos fármacos , Rim/patologia , Rim/metabolismo , Modelos Animais de Doenças , Baço/efeitos dos fármacos , Baço/patologia , Baço/imunologia , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , PiperazinasRESUMO
Resveratrol is a polyphenol known to have metabolic as well as circadian effects. However, there is little information regarding the metabolic and circadian effect of resveratrol on muscle cells. We sought to investigate the metabolic impact of resveratrol throughout the circadian cycle to clarify the associated signaling pathways. C2C12 myotubes were incubated with resveratrol in the presence of increasing concentrations of glucose, and metabolic and clock proteins were measured for 24 h. Resveratrol led to SIRT1, AMPK and PP2A activation. Myotubes treated with increasing glucose concentrations showed higher activation of the mTOR signaling pathway. However, resveratrol did not activate the mTOR signaling pathway, except for P70S6K and S6. In accordance with the reduced mTOR activity, resveratrol led to advanced circadian rhythms and reduced levels of pBMAL1 and CRY1. Resveratrol increased myogenin expression and advanced its rhythms. In conclusion, resveratrol activates the SIRT1-AMPK-PP2A axis, advances circadian rhythms and induces muscle development.