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1.
J Cancer Res Clin Oncol ; 146(6): 1523-1532, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32285256

RESUMO

PURPOSE: APOBEC3A and APOBEC3B cytidine deaminases have been implicated in the pathogenesis of multiple cancers, including breast cancer (BC). A germline deletion linking APOBEC3A and APOBEC3B loci (A3A/B) has been associated with higher APOBEC-mediated mutational burden, but its association with BC risk have been controversial. Therefore, this study investigated the association between A3A/B and BC susceptibility and clinical presentation in a Brazilian cohort. METHODS: A3A/B deletion was evaluated through allele-specific PCR in 341 BC patients and 397 women without familial or personal history of neoplasia from Brazil and associations with susceptibility to BC subtypes were tested through age-adjusted logistic models while correlations with clinicopathological parameters were tested using Kendall's tests. RESULTS: No association was found between A3A/B and BC susceptibility; however, in Luminal-A BCs, it was positively correlated with tumor size (Tau-c = 0.125) and Ki67 (Tau-c = 0.116) and negatively correlated with lymph node metastasis (LNM) (Tau-c = - 0.162). The negative association between A3A/B with LNM in Luminal-A BCs remained significant even after adjusting for tumor size and Ki67 in logistic models (OR = 0.22; p = 0.008). CONCLUSION: These results show that although A3A/B may not modify BC susceptibility in Brazilian population, it may affect clinicopathological features in BC subtypes, promoting tumor cell proliferation while being negatively associated with LNM in Luminal-A BCs.


Assuntos
Neoplasias da Mama/genética , Citidina Desaminase/genética , Deleção de Genes , Mutação em Linhagem Germinativa , Antígenos de Histocompatibilidade Menor/genética , Adulto , Idoso , Brasil , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Humanos , Pessoa de Meia-Idade
2.
PLoS One ; 15(3): e0230261, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32176735

RESUMO

BACKGROUND: We aimed to evaluate the expression of APOBEC3A (A3A), 3B (A3B) mRNA, and germline APOBEC3A/B deletion polymorphism in patients with breast cancers and to investigate the correlation between their expressions and clinicopathological characteristics. METHODS: RNA and DNA samples were extracted from 138 breast cancer tissues and adjacent normal breast tissues. The levels of A3A and A3B mRNA transcripts were determined using quantitative real-time polymerase chain reaction. Insertion and deletion PCR assays were performed to detect the A3B deletion allele. The serum concentrations of soluble programmed death-ligand 1 (sPD-L1) and interferon gamma were determined using enzyme-linked immunosorbent assays. RESULTS: A3B mRNA expression levels were significantly higher in triple-negative breast cancers compared to hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancers. Older age of the patient and high ki-67 expression were associated with increased expression levels of A3A and A3B mRNA. Advanced tumor stage, presence of lymph node involvement, and high histological grade were associated with increased expression levels of A3A mRNA. The APOBEC3A/B deletion allele was found in 77 (55.8%) patients. TP53 and PIK3CA mutations were detected in 62 (44.9%) and 31 (22.5%) patients, respectively. The presence of a PIK3CA mutation was associated with lower A3A mRNA expression levels. There was a weak positive relationship between A3A mRNA expression levels and serum sPD-L1 levels. CONCLUSIONS: There was a difference in A3B mRNA expression levels according to breast cancer subtypes, and high levels of A3A and A3B mRNA expressions were associated with an aggressive phenotype. There was a high incidence of APOBEC3A/B deletion allele. Further studies are needed to identify the clinical significance of APOBEC in Asian patients with breast cancer.


Assuntos
Neoplasias da Mama/genética , Citidina Desaminase/genética , Regulação Neoplásica da Expressão Gênica , Antígenos de Histocompatibilidade Menor/genética , Proteínas/genética , Antígeno B7-H1/sangue , Neoplasias da Mama/sangue , Neoplasias da Mama/classificação , Classe I de Fosfatidilinositol 3-Quinases/genética , Feminino , Predisposição Genética para Doença , Humanos , Interferon gama/sangue , Pessoa de Meia-Idade , Polimorfismo Genético , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Deleção de Sequência , Proteína Supressora de Tumor p53/genética
4.
Emerg Microbes Infect ; 9(1): 366-377, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32056513

RESUMO

Hepatitis B virus (HBV) is a partially double-stranded DNA virus that replicates by reverse transcription. We previously demonstrated that the host restriction factor-APOBEC3B (A3B) inhibited HBV replication which was dependent on its deaminase activity during reverse transcription. However, the host factors involved in the process of regulating the anti-HBV function of A3B are less known. In this research, to obtain a comprehensive understanding of the interaction networks of A3B, we conducted coimmunoprecipitation and mass spectrometry to identify A3B-interacting proteins in the presence of HBV. By this approach, we determined that DExD/H-box helicase 9 (DHX9) suppressed the anti-HBV effect of A3B, and this suppression was dependent on their interaction. Although DHX9 did not affect the deamination activity of A3B in vitro assay or the viral DNA editing of A3B in HepG2-NTCP cells that support HBV infection, it inhibited the binding of A3B with pgRNA. These data suggest that DHX9 can interact with A3B and attenuate the anti-HBV efficacy of A3B.Abbreviations: 3D-PCR: differential DNA denaturation PCR; APOBEC3: apolipoprotein B mRNA-editing catalytic polypeptide 3; cccDNA: covalently closed circular DNA; co-IP: coimmunoprecipitation; DDX: DExD-box RNA helicases; HBc: HBV core protein; HBV: hepatitis B virus; HepAD38: HepG2 cell line stably transfected with HBV DNA; HepG2-NTCP: HepG2 cell line stably transfected with Na+/taurocholate cotransporter polypeptide; Huh7: human hepatoma cell line; pgRNA: pregenomic RNA; PPI: protein-protein interactions; RC DNA: relaxed circular DNA.


Assuntos
Citidina Desaminase/metabolismo , RNA Helicases DEAD-box/metabolismo , Hepatite B/metabolismo , Antígenos de Histocompatibilidade Menor/metabolismo , Proteínas de Neoplasias/metabolismo , Células HEK293 , Células Hep G2 , Vírus da Hepatite B/fisiologia , Humanos , Ligação Proteica , Mapeamento de Interação de Proteínas , RNA Viral , Replicação Viral
5.
Nat Cell Biol ; 22(2): 167-174, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32029896

RESUMO

Branched-chain amino acid (BCAA) metabolism is potentially linked with development of pancreatic ductal adenocarcinoma (PDAC)1-4. BCAA transaminase 2 (BCAT2) was essential for the collateral lethality conferred by deletion of malic enzymes in PDAC and the BCAA-BCAT metabolic pathway contributed to non-small-cell lung carcinomas (NSCLCs) other than PDAC3,4. However, the underlying mechanism remains undefined. Here we reveal that BCAT2 is elevated in mouse models and in human PDAC. Furthermore, pancreatic tissue-specific knockout of Bcat2 impedes progression of pancreatic intraepithelial neoplasia (PanIN) in LSL-KrasG12D/+; Pdx1-Cre (KC) mice. Functionally, BCAT2 enhances BCAA uptake to sustain BCAA catabolism and mitochondrial respiration. Notably, BCAA enhances growth of pancreatic ductal organoids from KC mice in a dose-dependent manner, whereas addition of branched-chain α-keto acid (BCKA) and nucleobases rescues growth of KC organoids that is suppressed by BCAT2 inhibitor. Moreover, KRAS stabilizes BCAT2, which is mediated by spleen tyrosine kinase (SYK) and E3 ligase tripartite-motif-containing protein 21 (TRIM21). In addition, BCAT2 inhibitor ameliorates PanIN formation in KC mice. Of note, a lower-BCAA diet also impedes PDAC development in mouse models of PDAC. Thus, BCAT2-mediated BCAA catabolism is critical for development of PDAC harbouring KRAS mutations. Targeting BCAT2 or lowering dietary BCAA may have translational significance.


Assuntos
Adenocarcinoma/genética , Aminoácidos de Cadeia Ramificada/metabolismo , Carcinoma Ductal Pancreático/genética , Regulação Neoplásica da Expressão Gênica , Antígenos de Histocompatibilidade Menor/genética , Neoplasias Pancreáticas/genética , Proteínas da Gravidez/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Transaminases/genética , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Adulto , Aminoácidos de Cadeia Ramificada/farmacologia , Animais , Carcinogênese/genética , Carcinogênese/metabolismo , Carcinogênese/patologia , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Progressão da Doença , Feminino , Xenoenxertos , Humanos , Isoenzimas/genética , Isoenzimas/metabolismo , Cetoácidos/metabolismo , Cetoácidos/farmacologia , Masculino , Camundongos , Camundongos Transgênicos , Pessoa de Meia-Idade , Antígenos de Histocompatibilidade Menor/metabolismo , Organoides/efeitos dos fármacos , Organoides/metabolismo , Organoides/patologia , Ductos Pancreáticos/efeitos dos fármacos , Ductos Pancreáticos/metabolismo , Ductos Pancreáticos/patologia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Proteínas da Gravidez/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Ribonucleoproteínas/genética , Ribonucleoproteínas/metabolismo , Transdução de Sinais , Quinase Syk/genética , Quinase Syk/metabolismo , Transaminases/metabolismo
6.
Nat Commun ; 11(1): 790, 2020 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-32034147

RESUMO

APOBEC3B, an anti-viral cytidine deaminase which induces DNA mutations, has been implicated as a mediator of cancer evolution and therapeutic resistance. Mutational plasticity also drives generation of neoepitopes, which prime anti-tumor T cells. Here, we show that overexpression of APOBEC3B in tumors increases resistance to chemotherapy, but simultaneously heightens sensitivity to immune checkpoint blockade in a murine model of melanoma. However, in the vaccine setting, APOBEC3B-mediated mutations reproducibly generate heteroclitic neoepitopes in vaccine cells which activate de novo T cell responses. These cross react against parental, unmodified tumors and lead to a high rate of cures in both subcutaneous and intra-cranial tumor models. Heteroclitic Epitope Activated Therapy (HEAT) dispenses with the need to identify patient specific neoepitopes and tumor reactive T cells ex vivo. Thus, actively driving a high mutational load in tumor cell vaccines increases their immunogenicity to drive anti-tumor therapy in combination with immune checkpoint blockade.


Assuntos
Vacinas Anticâncer/farmacologia , Citidina Desaminase/imunologia , Imunoterapia/métodos , Antígenos de Histocompatibilidade Menor/imunologia , Linfócitos T/imunologia , Animais , Linhagem Celular Tumoral , Citidina Desaminase/genética , Citidina Desaminase/metabolismo , Resistencia a Medicamentos Antineoplásicos , Epitopos/imunologia , Feminino , Humanos , Células Matadoras Naturais/imunologia , Melanoma/imunologia , Melanoma/terapia , Melanoma Experimental/imunologia , Melanoma Experimental/terapia , Camundongos Endogâmicos C57BL , Antígenos de Histocompatibilidade Menor/genética , Antígenos de Histocompatibilidade Menor/metabolismo , Mutação , Evasão Tumoral/efeitos dos fármacos
8.
PLoS Negl Trop Dis ; 14(2): e0008080, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32078636

RESUMO

Schistosoma mansoni adaptive success is related to regulation of replication, transcription and translation inside and outside the intermediate and definitive host. We hypothesize that S. mansoni alters its epigenetic state in response to the mammalian host immune system, reprogramming gene expression and altering the number of eggs. In response, a change in the DNA methylation profile of hepatocytes could occurs, modulating the extent of hepatic granuloma. To investigate this hypothesis, we used the EBi3-/- murine (Mus musculus) model of S. mansoni infection and evaluated changes in new and maintenance DNA methylation profiles in the liver after 55 days of infection. We evaluated expression of epigenetic genes and genes linked to histone deubiquitination in male and female S. mansoni worms. Comparing TET expression with DNMT expression indicated that DNA demethylation exceeds methylation in knockout infected and uninfected mice and in wild-type infected and uninfected mice. S. mansoni infection provokes activation of demethylation in EBi3-/-I mice (knockout infected). EBi3-/-C (knockout uninfected) mice present intrinsically higher DNA methylation than WTC (control uninfected) mice. EBi3-/-I mice show decreased hepatic damage considering volume and reduced number of granulomas compared to WTI mice; the absence of IL27 and IL35 pathways decreases the Th1 response resulting in minor liver damage. S. mansoni males and females recovered from EBi3-/-I mice have reduced expression of a deubiquitinating enzyme gene, orthologs of which target histones and affect chromatin state. SmMBD and SmHDAC1 expression levels are downregulated in male and female parasites recovered from EBi3-/-, leading to epigenetic gene downregulation in S. mansoni. Changes to the immunological background thus induce epigenetic changes in hepatic tissues and alterations in S. mansoni gene expression, which attenuate liver symptoms in the acute phase of schistosomiasis.


Assuntos
Epigênese Genética , Antígenos de Histocompatibilidade Menor/genética , Receptores de Citocinas/genética , Esquistossomose mansoni/imunologia , Animais , Metilação de DNA , Feminino , Regulação da Expressão Gênica/imunologia , Fígado/metabolismo , Fígado/parasitologia , Masculino , Camundongos , Camundongos Knockout , MicroRNAs , RNA de Helmintos/genética , RNA de Helmintos/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Schistosoma mansoni/imunologia , Esquistossomose mansoni/parasitologia
9.
PLoS One ; 15(2): e0227997, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32023277

RESUMO

BACKGROUND: Behçet's disease (BD) is a chronic multi-systemic vasculitis with a considerable prevalence in Asian countries. There are many genes associated with a higher risk of developing BD, one of which is endoplasmic reticulum aminopeptidase-1 (ERAP1). In this study, we aimed to investigate the interactions of ERAP1 single nucleotide polymorphisms (SNPs) using a novel data mining method called Model-based multifactor dimensionality reduction (MB-MDR). METHODS: We have included 748 BD patients and 776 healthy controls. A peripheral blood sample was collected, and eleven SNPs were assessed. Furthermore, we have applied the MB-MDR method to evaluate the interactions of ERAP1 gene polymorphisms. RESULTS: The TT genotype of rs1065407 had a synergistic effect on BD susceptibility, considering the significant main effect. In the second order of interactions, CC genotype of rs2287987 and GG genotype of rs1065407 had the most prominent synergistic effect (ß = 12.74). The mentioned genotypes also had significant interactions with CC genotype of rs26653 and TT genotype of rs30187 in the third-order (ß = 12.74 and ß = 12.73, respectively). CONCLUSION: To the best of our knowledge, this is the first study investigating the interaction of a particular gene's SNPs in BD patients by applying a novel data mining method. However, future studies investigating the interactions of various genes could clarify this issue.


Assuntos
Algoritmos , Aminopeptidases/genética , Síndrome de Behçet/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Antígenos de Histocompatibilidade Menor/genética , Modelos Genéticos , Redução Dimensional com Múltiplos Fatores , Polimorfismo de Nucleotídeo Único/genética , Adulto , Entropia , Feminino , Frequência do Gene/genética , Redes Reguladoras de Genes , Humanos , Irã (Geográfico) , Masculino
10.
PLoS One ; 15(1): e0223463, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31914134

RESUMO

Apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like (APOBEC) DNA cytosine deaminase 3B (A3B) is a DNA editing enzyme which induces genomic DNA mutations in multiple myeloma and in various other cancers. APOBEC family proteins are highly homologous so it is especially difficult to investigate the biology of specifically A3B in cancer cells. To easily and comprehensively investigate A3B function in myeloma cells, we used CRISPR/Cas9 to generate A3B reporter cells that contain 3×FLAG tag and IRES-EGFP sequences integrated at the end of the A3B gene. These reporter cells stably express 3xFLAG tagged A3B and the reporter EGFP and this expression is enhanced by known stimuli, such as PMA. Conversely, shRNA knockdown of A3B decreased EGFP fluorescence and 3xFLAG tagged A3B protein levels. We screened a series of anticancer treatments using these cell lines and identified that most conventional therapies, such as antimetabolites or radiation, exacerbated endogenous A3B expression, but recent molecular targeted therapeutics, including bortezomib, lenalidomide and elotuzumab, did not. Furthermore, chemical inhibition of ATM, ATR and DNA-PK suppressed EGFP expression upon treatment with antimetabolites. These results suggest that DNA damage triggers A3B expression through ATM, ATR and DNA-PK signaling.


Assuntos
Citidina Desaminase/genética , Dano ao DNA/genética , Antígenos de Histocompatibilidade Menor/genética , Mieloma Múltiplo/genética , Anticorpos Monoclonais Humanizados/farmacologia , Bortezomib/farmacologia , Sistemas CRISPR-Cas/genética , Linhagem Celular Tumoral , Núcleo Celular/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Proteínas de Fluorescência Verde/genética , Humanos , Lenalidomida/farmacologia , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/patologia , Mieloma Múltiplo/radioterapia , Mutação/genética , Fosforilcolina/análogos & derivados , Fosforilcolina/farmacologia , Ácidos Polimetacrílicos/farmacologia , RNA Interferente Pequeno/genética , Radiação , Transdução de Sinais/efeitos dos fármacos
11.
Nat Immunol ; 21(2): 178-185, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31959982

RESUMO

Human leukocyte antigen (HLA)-independent, T cell-mediated targeting of cancer cells would allow immune destruction of malignancies in all individuals. Here, we use genome-wide CRISPR-Cas9 screening to establish that a T cell receptor (TCR) recognized and killed most human cancer types via the monomorphic MHC class I-related protein, MR1, while remaining inert to noncancerous cells. Unlike mucosal-associated invariant T cells, recognition of target cells by the TCR was independent of bacterial loading. Furthermore, concentration-dependent addition of vitamin B-related metabolite ligands of MR1 reduced TCR recognition of cancer cells, suggesting that recognition occurred via sensing of the cancer metabolome. An MR1-restricted T cell clone mediated in vivo regression of leukemia and conferred enhanced survival of NSG mice. TCR transfer to T cells of patients enabled killing of autologous and nonautologous melanoma. These findings offer opportunities for HLA-independent, pan-cancer, pan-population immunotherapies.


Assuntos
Citotoxicidade Imunológica/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Menor/imunologia , Neoplasias/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Subpopulações de Linfócitos T/imunologia , Animais , Sistemas CRISPR-Cas , Estudo de Associação Genômica Ampla , Humanos , Imunoterapia/métodos , Ativação Linfocitária/imunologia , Camundongos
12.
Acta Crystallogr F Struct Biol Commun ; 76(Pt 1): 14-19, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31929181

RESUMO

This study presents the crystal structure of a thiol variant of the human mitochondrial branched-chain aminotransferase protein. Human branched-chain aminotransferase (hBCAT) catalyzes the transamination of the branched-chain amino acids leucine, valine and isoleucine and α-ketoglutarate to their respective α-keto acids and glutamate. hBCAT activity is regulated by a CXXC center located approximately 10 Šfrom the active site. This redox-active center facilitates recycling between the reduced and oxidized states, representing hBCAT in its active and inactive forms, respectively. Site-directed mutagenesis of the redox sensor (Cys315) results in a significant loss of activity, with no loss of activity reported on the mutation of the resolving cysteine (Cys318), which allows the reversible formation of a disulfide bond between Cys315 and Cys318. The crystal structure of the oxidized form of the C318A variant was used to better understand the contributions of the individual cysteines and their oxidation states. The structure reveals the modified CXXC center in a conformation similar to that in the oxidized wild type, supporting the notion that its regulatory mechanism depends on switching the Cys315 side chain between active and inactive conformations. Moreover, the structure reveals conformational differences in the N-terminal and inter-domain region that may correlate with the inactivated state of the CXXC center.


Assuntos
Cisteína/química , Cisteína/genética , Antígenos de Histocompatibilidade Menor/química , Mitocôndrias/enzimologia , Proteínas da Gravidez/química , Transaminases/química , Sequência de Aminoácidos , Catálise , Domínio Catalítico/genética , Cristalografia por Raios X , Cisteína/metabolismo , Escherichia coli , Expressão Gênica/genética , Humanos , Antígenos de Histocompatibilidade Menor/genética , Modelos Moleculares , Mutação , Oxirredução , Proteínas da Gravidez/genética , Domínios Proteicos/genética , Transaminases/genética
13.
Mol Immunol ; 117: 155-159, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31790864

RESUMO

INTRODUCTION: ERAP1 has been recently proposed as risk marker of Behçet syndrome (BS). Gene single nucleotide polymorphisms (SNPs) could affect the enzymatic activity and the conserved active site is pivotal for the aminopeptidase function. This study aims to characterize the ERAP1 active site in a cohort of BS patients vs healthy controls (HC) integrating genomics, transcriptomics and bioinformatics approach. MATERIALS AND METHODS: We recruited 109 consecutive Italian BS patients (63M:46 F; mean age: 45.07 ± 12.28 years) and 106 matched HC (55M:51 F; mean age: 42.57 ± 12.29 years). DNA was isolated and amplified using PCR with home made-primer pairs. PCR products were directly sequenced and computational analyses were performed to search active site SNPs (NCBI-BlastN tool), to predict SNPs functional effect (PolyPhen-2 software) and to obtain protein 3D modelling (Protean3D software). In a second phase of analysis, RNA was extracted and reverse transcribed. Quantitative Real-Time PCR (qPCR) was performed to assess ERAP1 mRNA level in presence (target) and in absence (control) of gene polymorphisms. The Fold change was calculated for the relative quantification of gene expression. RESULTS: A novel coding variation (NG_027839.1:g.25637 T > G; NP_057526.3:p.Phe360Cys, HGSV nomenclature) was found in heterozygosity state in 5/109 BS patients (4.59 % of cases) and none of HC. It was recognized in association with rs2287987, rs30187, rs17482078, and rs27044 BS-related polymorphisms for 4 out of 5 patients. All patients carrying the novel SNP were HLA-B*51-positive. The novel SNP was released in GenBank database with MK140632.1 ID. The SNP was predicted to be damaging and resides within the Zn-binding HEXXH(X)18E region of the active site, changing the structurally conserved region for the amminopeptidase function. In fact, the change in energy (ΔE) score between wild-type and SNP-containing protein showed a less stable protein in presence of p.Cys360 (ΔE:3.584) (Protean3D prediction). Preliminary qPCR results underlined a significant difference in fold change value when target and control values were compared (p < 0.05), suggesting a reduced expression of ERAP1 mRNA in presence of the novel SNP. CONCLUSIONS: Our study strengthens the association between ERAP1 and BS. The most significant point was the localization of the novel p.Phe360Cys SNP within the Zn-binding region of protein active site that was predicted to affect its function, causing protein destabilization. Our findings need to be tested in larger genetic studies.


Assuntos
Aminopeptidases/química , Aminopeptidases/genética , Síndrome de Behçet/genética , Antígenos de Histocompatibilidade Menor/química , Antígenos de Histocompatibilidade Menor/genética , Adulto , Domínio Catalítico/fisiologia , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Relação Estrutura-Atividade
15.
APMIS ; 128(4): 326-334, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31863490

RESUMO

Hepatitis C is a global public health problem, and Pakistan is the second largest country in the globe with highest prevalence rate of hepatitis C virus (HCV). Until 2014, pegylated interferon (PEG-IFN) plus ribavirin (RBV) has been the standard therapy for HCV, however, owing to its adverse side effects and very low sustained virologic response (SVR) rates therapeutics trend is shifted toward direct-acting antivirals. Tripartite motif containing 22 (TRIM22) is a dynamic antiviral protein that can inhibit multiple viruses in vivo. Expression of TRIM22 mRNA has been linked to outcome of PEG-IFN and ribavirin therapy, where its higher expression leads to rapid virus clearance. However, in terms of therapy with direct-acting antiviral (DAA) or double DAA, impact of TRIM22 expression is largely unknown. These new drugs show more than 90% of SVR rates and lesser side effects and have proven to be better than IFN therapy. Endogenous IFN system suppresses various pathogens through the induction of antiviral effectors termed as interferon-stimulating genes (ISGs). We have studied the expression levels of one of these antiviral effectors, TRIM22 in response to sofosbuvir (SOF) and daclatasvir (DAC) in combination with RBV, using quantitative PCR in the peripheral blood mononuclear cells (PBMCs) of HCV-infected patients. We have observed sustained virus clearance in more than 90% of patients treated with DAA and double DAA and have seen the expression of TRIM22 to be higher in patients who attained SVR as compared to the untreated patients. We have also observed downregulation of TRIM22 in patients who failed to attain rapid virus clearance, and upregulation in those who achieved rapid clearance of virus. Genetic factors that determine the lower TRIM22 expression in these patients are needed to be explored that may also play a role in lower response to anti-HCV therapy. Endogenous IFN system and effects of antiviral proteins in response to DAA therapy is needed to be studied in order to better understand the host response toward these drugs to make them more effective.


Assuntos
Antivirais/uso terapêutico , Hepacivirus/efeitos dos fármacos , Hepatite C Crônica/etiologia , Hepatite C Crônica/metabolismo , Antígenos de Histocompatibilidade Menor/metabolismo , RNA Mensageiro/metabolismo , Proteínas Repressoras/metabolismo , Proteínas com Motivo Tripartido/metabolismo , Adulto , Células Cultivadas , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Quimioterapia Combinada/métodos , Feminino , Hepatite C Crônica/virologia , Humanos , Interferon-alfa/uso terapêutico , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/virologia , Masculino , Resposta Viral Sustentada , Resultado do Tratamento
16.
J Med Chem ; 63(1): 103-121, 2020 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-31841350

RESUMO

ERAP1 is an endoplasmic reticulum-resident zinc aminopeptidase that plays an important role in the immune system by trimming peptides for loading onto major histocompatibility complex proteins. Here, we report discovery of the first inhibitors selective for ERAP1 over its paralogues ERAP2 and IRAP. Compound 1 (N-(N-(2-(1H-indol-3-yl)ethyl)carbamimidoyl)-2,5-difluorobenzenesulfonamide) and compound 2 (1-(1-(4-acetylpiperazine-1-carbonyl)cyclohexyl)-3-(p-tolyl)urea) are competitive inhibitors of ERAP1 aminopeptidase activity. Compound 3 (4-methoxy-3-(N-(2-(piperidin-1-yl)-5-(trifluoromethyl)phenyl)sulfamoyl)benzoic acid) allosterically activates ERAP1's hydrolysis of fluorogenic and chromogenic amino acid substrates but competitively inhibits its activity toward a nonamer peptide representative of physiological substrates. Compounds 2 and 3 inhibit antigen presentation in a cellular assay. Compound 3 displays higher potency for an ERAP1 variant associated with increased risk of autoimmune disease. These inhibitors provide mechanistic insights into the determinants of specificity for ERAP1, ERAP2, and IRAP and offer a new therapeutic approach of specifically inhibiting ERAP1 activity in vivo.


Assuntos
Aminopeptidases/antagonistas & inibidores , Compostos de Fenilureia/farmacologia , Inibidores de Proteases/farmacologia , Sulfonamidas/farmacologia , Triptaminas/farmacologia , Aminopeptidases/genética , Aminopeptidases/metabolismo , Domínio Catalítico/genética , Descoberta de Drogas , Células HeLa , Humanos , Antígenos de Histocompatibilidade Menor/genética , Antígenos de Histocompatibilidade Menor/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Compostos de Fenilureia/síntese química , Compostos de Fenilureia/metabolismo , Polimorfismo de Nucleotídeo Único , Inibidores de Proteases/síntese química , Inibidores de Proteases/metabolismo , Ligação Proteica , Relação Estrutura-Atividade , Sulfonamidas/síntese química , Sulfonamidas/metabolismo , Triptaminas/síntese química , Triptaminas/metabolismo
17.
Toxicol In Vitro ; 62: 104679, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31676337

RESUMO

Ruthenium complexes are being considered as novel chemotherapeutic alternatives for cancer treatment. In our study, we assessed the antitumoral activities of novel ruthenium complexes coupled to the amino acids proline (RuPro) and threonine (RuThr) in prostate tumor cell lines (DU145) and breast (MCF7), and normal cell lines of the lung fibroblast (GM07492A). Our results revealed that the EC50 of the complexes for DU145 and MCF7 was two times lower than that GM07492A. Moreover, RuPro and RuThr were not able to induce significant genomic instability, cell cycle arrest or cell death in GM07492A, but could induce DNA damage, arrest in G2/M and apoptosis in DU145 and MCF7. Furthermore, BAX, TP53 and ATM were found to be upregulated in DU145 and MCF7 treated with RuPro and RuThr, in which, a higher ASCT2 gene expression was also observed. Using molecular docking, RuPro and RuThr interact with ASCT2, suggesting that this transporter might have a pivotal role in the execution of their activities. Hence, our results with RuPro and RuThr are capable of selectively inducing genetic damage, cell cycle arrest and apoptosis in DU145 and MCF7. We suggest that the selective action of the RuPro and RuThr complexes is related to the higher expression of ASCT2 in the tumor cells.


Assuntos
Apoptose/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Quelantes/farmacologia , Instabilidade Genômica/efeitos dos fármacos , Prolina/química , Neoplasias da Próstata/tratamento farmacológico , Compostos de Rutênio/farmacologia , Treonina/química , Sistema ASC de Transporte de Aminoácidos/efeitos dos fármacos , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Dano ao DNA/efeitos dos fármacos , Feminino , Humanos , Ligantes , Masculino , Antígenos de Histocompatibilidade Menor/efeitos dos fármacos , Simulação de Acoplamento Molecular , Neoplasias da Próstata/patologia
18.
PLoS Comput Biol ; 15(12): e1007485, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31825969

RESUMO

Apoptosis is an essential defensive mechanism against tumorigenesis. Proteins of the B-cell lymphoma-2 (Bcl-2) family regulate programmed cell death by the mitochondrial apoptosis pathway. In response to intracellular stress, the apoptotic balance is governed by interactions of three distinct subgroups of proteins; the activator/sensitizer BH3 (Bcl-2 homology 3)-only proteins, the pro-survival, and the pro-apoptotic executioner proteins. Changes in expression levels, stability, and functional impairment of pro-survival proteins can lead to an imbalance in tissue homeostasis. Their overexpression or hyperactivation can result in oncogenic effects. Pro-survival Bcl-2 family members carry out their function by binding the BH3 short linear motif of pro-apoptotic proteins in a modular way, creating a complex network of protein-protein interactions. Their dysfunction enables cancer cells to evade cell death. The critical role of Bcl-2 proteins in homeostasis and tumorigenesis, coupled with mounting insight in their structural properties, make them therapeutic targets of interest. A better understanding of gene expression, mutational profile, and molecular mechanisms of pro-survival Bcl-2 proteins in different cancer types, could help to clarify their role in cancer development and may guide advancement in drug discovery. Here, we shed light on the pro-survival Bcl-2 proteins in breast cancer using different bioinformatic approaches, linking -omics with structural data. We analyzed the changes in the expression of the Bcl-2 proteins and their BH3-containing interactors in breast cancer samples. We then studied, at the structural level, a selection of interactions, accounting for effects induced by mutations found in the breast cancer samples. We find two complexes between the up-regulated Bcl2A1 and two down-regulated BH3-only candidates (i.e., Hrk and Nr4a1) as targets associated with reduced apoptosis in breast cancer samples for future experimental validation. Furthermore, we predict L99R, M75R as damaging mutations altering protein stability, and Y120C as a possible allosteric mutation from an exposed surface to the BH3-binding site.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Genes bcl-2 , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Apoptose/genética , Proteínas Reguladoras de Apoptose/química , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/química , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/genética , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/metabolismo , Neoplasias da Mama/patologia , Biologia Computacional , Feminino , Humanos , Antígenos de Histocompatibilidade Menor/química , Antígenos de Histocompatibilidade Menor/genética , Antígenos de Histocompatibilidade Menor/metabolismo , Modelos Moleculares , Mutação , Domínios e Motivos de Interação entre Proteínas , Mapas de Interação de Proteínas , Estabilidade Proteica , Proteínas Proto-Oncogênicas c-bcl-2/química , Transcrição Genética
19.
Nat Genet ; 51(12): 1723-1731, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31784729

RESUMO

WNT signaling activates MYC expression in cancer cells. Here we report that this involves an oncogenic super-enhancer-mediated tethering of active MYC alleles to nuclear pores to increase transcript export rates. As the decay of MYC transcripts is more rapid in the nucleus than in the cytoplasm, the oncogenic super-enhancer-facilitated export of nuclear MYC transcripts expedites their escape from the nuclear degradation system in colon cancer cells. The net sum of this process, as supported by computer modeling, is greater cytoplasmic MYC messenger RNA levels in colon cancer cells than in wild type cells. The cancer-cell-specific gating of MYC is regulated by AHCTF1 (also known as ELYS), which connects nucleoporins to the oncogenic super-enhancer via ß-catenin. We conclude that WNT signaling collaborates with chromatin architecture to post-transcriptionally dysregulate the expression of a canonical cancer driver.


Assuntos
Proteínas de Ligação a DNA/genética , Elementos Facilitadores Genéticos , Genes myc , Fatores de Transcrição/genética , Via de Sinalização Wnt/genética , Colo/citologia , Proteínas de Ligação a DNA/metabolismo , Células Epiteliais/fisiologia , Regulação Neoplásica da Expressão Gênica , Células HCT116 , Humanos , Antígenos de Histocompatibilidade Menor/genética , Antígenos de Histocompatibilidade Menor/metabolismo , Complexo de Proteínas Formadoras de Poros Nucleares/genética , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Transporte Proteico , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Processamento Pós-Transcricional do RNA , Fatores de Transcrição/metabolismo , beta Catenina/genética , beta Catenina/metabolismo
20.
PLoS Genet ; 15(12): e1008545, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31841499

RESUMO

APOBEC cytidine deaminases are the second-most prominent source of mutagenesis in sequenced tumors. Previous studies have proposed that APOBEC3B (A3B) is the major source of mutagenesis in breast cancer (BRCA). We show that APOBEC3A (A3A) is the only APOBEC whose expression correlates with APOBEC-induced mutation load and that A3A expression is responsible for cytidine deamination in multiple BRCA cell lines. Comparative analysis of A3A and A3B expression by qRT-PCR, RSEM-normalized RNA-seq, and unambiguous RNA-seq validated the use of RNA-seq to measure APOBEC expression, which indicates that A3A is the primary correlate with APOBEC-mutation load in primary BRCA tumors. We also demonstrate that A3A has >100-fold more cytidine deamination activity than A3B in the presence of cellular RNA, likely explaining why higher levels of A3B expression contributes less to mutagenesis in BRCA. Our findings identify A3A as a major source of cytidine deaminase activity in breast cancer cells and possibly a prominent contributor to the APOBEC mutation signature.


Assuntos
Neoplasias da Mama/genética , Citidina Desaminase/genética , Citidina Desaminase/metabolismo , Proteínas/genética , Proteínas/metabolismo , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Antígenos de Histocompatibilidade Menor/genética , Antígenos de Histocompatibilidade Menor/metabolismo , Mutação , Análise de Sequência de RNA
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