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1.
Nucleic Acids Res ; 48(3): 1583-1598, 2020 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-31956908

RESUMO

Cyclic dimeric 3'-5' guanosine monophosphate, c-di-GMP, is a ubiquitous second messenger controlling diverse cellular processes in bacteria. In streptomycetes, c-di-GMP plays a crucial role in a complex morphological differentiation by modulating an activity of the pleiotropic regulator BldD. Here we report that c-di-GMP plays a key role in regulating secondary metabolite production in streptomycetes by altering the expression levels of bldD. Deletion of cdgB encoding a diguanylate cyclase in Streptomycesghanaensis reduced c-di-GMP levels and the production of the peptidoglycan glycosyltransferase inhibitor moenomycin A. In contrast to the cdgB mutant, inactivation of rmdB, encoding a phosphodiesterase for the c-di-GMP hydrolysis, positively correlated with the c-di-GMP and moenomycin A accumulation. Deletion of bldD adversely affected the synthesis of secondary metabolites in S. ghanaensis, including the production of moenomycin A. The bldD-deficient phenotype is partly mediated by an increase in expression of the pleiotropic regulatory gene wblA. Genetic and biochemical analyses demonstrate that a complex of c-di-GMP and BldD effectively represses transcription of wblA, thus preventing sporogenesis and sustaining antibiotic synthesis. These results show that manipulation of the expression of genes controlling c-di-GMP pool has the potential to improve antibiotic production as well as activate the expression of silent gene clusters.


Assuntos
Proteínas de Bactérias/genética , Bambermicinas/biossíntese , Produtos Biológicos/metabolismo , GMP Cíclico/análogos & derivados , Proteínas de Ligação a DNA/genética , Fatores de Transcrição/genética , Proteínas de Bactérias/antagonistas & inibidores , GMP Cíclico/genética , GMP Cíclico/metabolismo , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Escherichia coli/genética , Deleção de Genes , Regulação Bacteriana da Expressão Gênica/genética , Nucleotídeos/genética , Peptidoglicano Glicosiltransferase/antagonistas & inibidores , Fósforo-Oxigênio Liases/genética , Sistemas do Segundo Mensageiro/genética , Streptomycetaceae/genética , Streptomycetaceae/metabolismo , Fatores de Transcrição/antagonistas & inibidores
2.
Gut ; 69(2): 329-342, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31439637

RESUMO

OBJECTIVE: Facilitates Chromatin Transcription (FACT) complex is a histone chaperone participating in DNA repair-related and transcription-related chromatin dynamics. In this study, we investigated its oncogenic functions, underlying mechanisms and therapeutic implications in human hepatocellular carcinoma (HCC). DESIGN: We obtained HCC and its corresponding non-tumorous liver samples from 16 patients and identified FACT complex as the most upregulated histone chaperone by RNA-Seq. We further used CRISPR-based gene activation and knockout systems to demonstrate the functions of FACT complex in HCC growth and metastasis. Functional roles and mechanistic insights of FACT complex in oxidative stress response were investigated by ChIP assay, flow cytometry, gene expression assays and 4sU-DRB transcription elongation assay. Therapeutic effect of FACT complex inhibitor, Curaxin, was tested in both in vitro and in vivo models. RESULTS: We showed that FACT complex was remarkably upregulated in HCC and contributed to HCC progression. Importantly, we unprecedentedly revealed an indispensable role of FACT complex in NRF2-driven oxidative stress response. Oxidative stress prevented NRF2 and FACT complex from KEAP1-mediated protein ubiquitination and degradation. Stabilised NRF2 and FACT complex form a positive feedback loop; NRF2 transcriptionally activates the FACT complex, while FACT complex promotes the transcription elongation of NRF2 and its downstream antioxidant genes through facilitating rapid nucleosome disassembly for the passage of RNA polymerase. Therapeutically, Curaxin effectively suppressed HCC growth and sensitised HCC cell to sorafenib. CONCLUSION: In conclusion, our findings demonstrated that FACT complex is essential for the expeditious HCC oxidative stress response and is a potential therapeutic target for HCC treatment.


Assuntos
Carcinoma Hepatocelular/fisiopatologia , Proteínas de Ligação a DNA/fisiologia , Proteínas de Grupo de Alta Mobilidade/fisiologia , Chaperonas de Histonas/fisiologia , Neoplasias Hepáticas/fisiopatologia , Estresse Oxidativo/fisiologia , Fatores de Elongação da Transcrição/fisiologia , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Carbazóis/farmacologia , Carbazóis/uso terapêutico , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/prevenção & controle , Proteínas de Ciclo Celular/deficiência , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/fisiologia , Linhagem Celular Tumoral , Movimento Celular/genética , Movimento Celular/fisiologia , Proliferação de Células/genética , Proliferação de Células/fisiologia , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/biossíntese , Proteínas de Ligação a DNA/genética , Progressão da Doença , Regulação Neoplásica da Expressão Gênica/fisiologia , Técnicas de Inativação de Genes/métodos , Proteínas de Grupo de Alta Mobilidade/antagonistas & inibidores , Proteínas de Grupo de Alta Mobilidade/biossíntese , Proteínas de Grupo de Alta Mobilidade/genética , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas Experimentais/genética , Neoplasias Hepáticas Experimentais/patologia , Neoplasias Hepáticas Experimentais/fisiopatologia , Neoplasias Hepáticas Experimentais/prevenção & controle , Camundongos Endogâmicos BALB C , Camundongos Nus , Estresse Oxidativo/genética , Sorafenibe/farmacologia , Sorafenibe/uso terapêutico , Fatores de Transcrição/deficiência , Fatores de Transcrição/genética , Fatores de Transcrição/fisiologia , Fatores de Elongação da Transcrição/antagonistas & inibidores , Fatores de Elongação da Transcrição/biossíntese , Fatores de Elongação da Transcrição/genética , Regulação para Cima/fisiologia , Ensaios Antitumorais Modelo de Xenoenxerto
3.
Int J Cancer ; 146(2): 461-474, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31603527

RESUMO

The malignant growth of human papillomavirus (HPV)-positive cancer cells is dependent on the continuous expression of the viral E6/E7 oncogenes. Here, we examined the effects of iron deprivation on the phenotype of HPV-positive cervical cancer cells. We found that iron chelators, such as the topical antifungal agent ciclopirox (CPX), strongly repress HPV E6/E7 oncogene expression, both at the transcript and protein level. CPX efficiently blocks the proliferation of HPV-positive cancer cells by inducing cellular senescence. Although active mTOR signaling is considered to be critical for the cellular senescence response towards a variety of prosenescent agents, CPX-induced senescence occurs under conditions of severely impaired mTOR signaling. Prolonged CPX treatment leads to p53-independent Caspase-3/7 activation and induction of apoptosis. CPX also eliminates HPV-positive cancer cells under hypoxic conditions through induction of apoptosis. Taken together, these results show that iron deprivation exerts profound antiviral and antiproliferative effects in HPV-positive cancer cells and suggest that iron chelators, such as CPX, possess therapeutic potential as HPV-inhibitory, prosenescent and proapoptotic agents in both normoxic and hypoxic environments.


Assuntos
Ciclopirox/farmacologia , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas Oncogênicas Virais/antagonistas & inibidores , Proteínas E7 de Papillomavirus/antagonistas & inibidores , Infecções por Papillomavirus/tratamento farmacológico , Proteínas Repressoras/antagonistas & inibidores , Neoplasias do Colo do Útero/tratamento farmacológico , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Apoptose/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Ciclopirox/uso terapêutico , Proteínas de Ligação a DNA/metabolismo , Feminino , Células HCT116 , Células HeLa , Humanos , Quelantes de Ferro/farmacologia , Quelantes de Ferro/uso terapêutico , Proteínas Oncogênicas Virais/metabolismo , Proteínas E7 de Papillomavirus/metabolismo , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Proteínas Repressoras/metabolismo , Esferoides Celulares , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia
4.
Nat Commun ; 10(1): 4143, 2019 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-31515519

RESUMO

In pulmonary hypertension vascular remodeling leads to narrowing of distal pulmonary arterioles and increased pulmonary vascular resistance. Vascular remodeling is promoted by the survival and proliferation of pulmonary arterial vascular cells in a DNA-damaging, hostile microenvironment. Here we report that levels of Eyes Absent 3 (EYA3) are elevated in pulmonary arterial smooth muscle cells from patients with pulmonary arterial hypertension and that EYA3 tyrosine phosphatase activity promotes the survival of these cells under DNA-damaging conditions. Transgenic mice harboring an inactivating mutation in the EYA3 tyrosine phosphatase domain are significantly protected from vascular remodeling. Pharmacological inhibition of the EYA3 tyrosine phosphatase activity substantially reverses vascular remodeling in a rat model of angio-obliterative pulmonary hypertension. Together these observations establish EYA3 as a disease-modifying target whose function in the pathophysiology of pulmonary arterial hypertension can be targeted by available inhibitors.


Assuntos
Proteínas de Ligação a DNA/metabolismo , /fisiopatologia , Remodelação Vascular , Animais , Apoptose/efeitos dos fármacos , Benzobromarona/análogos & derivados , Benzobromarona/farmacologia , Cardiomegalia/complicações , Cardiomegalia/patologia , Cardiomegalia/fisiopatologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA , Reparo do DNA/efeitos dos fármacos , Proteínas de Ligação a DNA/antagonistas & inibidores , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/patologia , Hipóxia/complicações , Hipóxia/fisiopatologia , Masculino , Camundongos Transgênicos , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/metabolismo , Artéria Pulmonar/patologia , Ratos Sprague-Dawley , Remodelação Vascular/efeitos dos fármacos
5.
Gastroenterology ; 157(6): 1630-1645.e6, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31560893

RESUMO

BACKGROUND & AIMS: Intratumor heterogeneity and divergent clonal lineages within and among primary and recurrent hepatocellular carcinomas (HCCs) produce challenges to patient management. We investigated genetic and epigenetic variations within liver tumors, among hepatic lesions, and between primary and relapsing tumors. METHODS: Tumor and matched nontumor liver specimens were collected from 113 patients who underwent partial hepatectomy for primary or recurrent HCC at 2 hospitals in Hong Kong. We performed whole-genome, whole-exome, or targeted capture sequencing analyses of 356 HCC specimens collected from multiple tumor regions and matched initial and recurrent tumors. We performed parallel DNA methylation profiling analyses of 95 specimens. Genomes and epigenomes of nontumor tissues that contained areas of cirrhosis or fibrosis were analyzed. We developed liver cancer cell lines that endogenously expressed a mutant form of TP53 (R249S) or overexpressed mutant forms of STAT3 (D170Y, K348E, and Y640F) or JAK1 (S703I and L910P) and tested the abilities of pharmacologic agents to reduce activity. Cells were analyzed by immunoblotting and chromatin immunoprecipitation with quantitative polymerase chain reaction. RESULTS: We determined the monoclonal origins of individual tumors using a single sample collection approach that captured more than 90% of mutations that are detected in all regions of tumors. Phylogenetic and phylo-epigenetic analyses revealed interactions and codependence between the genomic and epigenomic features of HCCs. Methylation analysis revealed a field effect in cirrhotic liver tissues that predisposes them to tumor development. Comparisons of genetic features revealed that 52% of recurrent HCCs derive from the clonal lineage of the initial tumor. The clonal origin if recurrent HCCs allowed construction of a temporal map of genetic alterations that associated with tumor recurrence. Activation of JAK signaling to STAT was a characteristic of HCC progression via mutations that associate with response to drug sensitivity. The combination of a mutation that increases the function of TP53 and the 17p chromosome deletion might provide liver cancer cells with a replicative advantage. Chromatin immunoprecipitation analysis of TP53 with the R249S substitution revealed its interaction with genes that encode chromatin regulators (MLL1 and MLL2). We validated MLL1 and MLL2 as direct targets of TP53R249S and affirmed their association in the Cancer Genome Atlas dataset. The MLL-complex antagonists MI-2-2 (inhibitor of protein interaction) and OICR-9492 (inhibitor of activity) specifically inhibited proliferation of HCC cells that express TP53R249S at nanomolar concentrations. CONCLUSIONS: We performed a systematic evaluation of intra- and intertumor genetic heterogeneity in HCC samples and identified genetic and epigenetic changes that associate with tumor progression and recurrence. We identified chromatin regulators that are upregulated by mutant TP53 in HCC cells and inhibitors that reduce proliferation of these cells. DNA methylation patterns in cirrhotic or fibrotic liver tissues might be used to identify those at risk of HCC development.


Assuntos
Carcinoma Hepatocelular/genética , Cirrose Hepática/genética , Neoplasias Hepáticas/genética , Recidiva Local de Neoplasia/genética , Adulto , Idoso , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/terapia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Metilação de DNA , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/metabolismo , Epigênese Genética , Feminino , Seguimentos , Mutação com Ganho de Função , Heterogeneidade Genética , Hepatectomia , Histona-Lisina N-Metiltransferase/antagonistas & inibidores , Histona-Lisina N-Metiltransferase/metabolismo , Hong Kong , Humanos , Fígado/patologia , Fígado/cirurgia , Cirrose Hepática/patologia , Cirrose Hepática/cirurgia , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/terapia , Masculino , Pessoa de Meia-Idade , Proteína de Leucina Linfoide-Mieloide/antagonistas & inibidores , Proteína de Leucina Linfoide-Mieloide/metabolismo , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/metabolismo , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/terapia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Proteína Supressora de Tumor p53/genética , Sequenciamento Completo do Genoma
6.
BMC Pulm Med ; 19(1): 165, 2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31464599

RESUMO

BACKGROUND: Recent studies have highlighted the contribution of senescent mesenchymal and epithelial cells in Idiopathic Pulmonary Fibrosis (IPF), but little is known regarding the molecular mechanisms that regulate the accumulation of senescent cells in this disease. Therefore, we addressed the hypothesis that the loss of DNA repair mechanisms mediated by DNA protein kinase catalytic subunit (DNA-PKcs) in IPF, promoted the accumulation of mesenchymal progenitors and progeny, and the expression of senescent markers by these cell types. METHODS: Surgical lung biopsy samples and lung fibroblasts were obtained from patients exhibiting slowly, rapidly or unknown progressing IPF and lung samples lacking any evidence of fibrotic disease (i.e. normal; NL). The expression of DNA-Pkcs in lung tissue was assessed by quantitative immunohistochemical analysis. Chronic inhibition of DNA-PKcs kinase activity was mimicked using a highly specific small molecule inhibitor, Nu7441. Proteins involved in DNA repair (stage-specific embryonic antigen (SSEA)-4+ cells) were determined by quantitative Ingenuity Pathway Analysis of transcriptomic datasets (GSE103488). Lastly, the loss of DNA-PKc was modeled in a humanized model of pulmonary fibrosis in NSG SCID mice genetically deficient in PRKDC (the transcript for DNA-PKcs) and treated with Nu7441. RESULTS: DNA-PKcs expression was significantly reduced in IPF lung tissues. Chronic inhibition of DNA-PKcs by Nu7441 promoted the proliferation of SSEA4+ mesenchymal progenitor cells and a significant increase in the expression of senescence-associated markers in cultured lung fibroblasts. Importantly, mesenchymal progenitor cells and their fibroblast progeny derived from IPF patients showed a loss of transcripts encoding for DNA damage response and DNA repair components. Further, there was a significant reduction in transcripts encoding for PRKDC (the transcript for DNA-PKcs) in SSEA4+ mesenchymal progenitor cells from IPF patients compared with normal lung donors. In SCID mice lacking DNA-PKcs activity receiving IPF lung explant cells, treatment with Nu7441 promoted the expansion of progenitor cells, which was observed as a mass of SSEA4+ CgA+ expressing cells. CONCLUSIONS: Together, our results show that the loss of DNA-PKcs promotes the expansion of SSEA4+ mesenchymal progenitors, and the senescence of their mesenchymal progeny.


Assuntos
Senescência Celular/genética , Cromonas/farmacologia , Proteína Quinase Ativada por DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/antagonistas & inibidores , Fibrose Pulmonar Idiopática/tratamento farmacológico , Células-Tronco Mesenquimais/citologia , Morfolinas/farmacologia , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Dano ao DNA , Reparo do DNA , Proteína Quinase Ativada por DNA/deficiência , Proteínas de Ligação a DNA/deficiência , Feminino , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Humanos , Pulmão/patologia , Camundongos , Camundongos SCID
7.
Int J Oncol ; 55(2): 536-546, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31268158

RESUMO

Gastrointestinal stromal tumors (GISTs) are gastrointestinal tract sarcomas that commonly contain a mutation in the tyrosine kinases, KIT and platelet­derived growth factor receptor A (PDGFRA). Imatinib, sunitinib and regorafenib are all effective tyrosine kinase inhibitors; however, acquired resistance is inevitable. The E26 variant 1 (ETV1) pathway has been found to be a key downstream effector of KIT and is therefore a reasonable therapeutic target for this disease. In this study, we explored the potential agents targeting ETV1 in GISTs by uploading an ETV1 knockout gene signature of GIST cell lines to the pattern­matching software 'Connectivity Map'. The activity and mechanisms of identified agents were examined using an in vitro model. Four drugs were identified: Suberanilohydroxamic acid and trichostatin [two histone deacetylase inhibitors (HDACIs)] and trifluoperazine and thioridazine (two phenothiazine­class drugs). Western blot analysis demonstrated that all four drugs had ETV1­downregulating effects. As HDACIs have been previously studied in GISTs, we focused on phenothiazine. Phenothiazine was found to exert cytotoxicity and to induce apoptosis and autophagy in GISTs. Treatment with phenothiazine had little effect on the KIT/AKT/mammalian target of rapamycin (mTOR) pathway, but instead upregulated extracellular­signal­regulated kinase (ERK) activity. A combination of phenothiazine and a MEK inhibitor had a synergistic cytotoxic effect on GISTs. Western blot analysis indicated that ELK1 and early growth response 1 (EGR1) were activated/upregulated following phenothiazine treatment, and the MEK inhibitor/phenothiazine combination downregulated the ERK/ELK1/EGR1 pathway, resulting in diminished autophagy, as well as enhanced apoptosis. On the whole, the findings of this study established phenothiazine as a novel class of therapeutic agents in GIST treatment and demonstrate that a combination of phenothiazine and MEK inhibitor has great potential for use in the treatment of GISTs.


Assuntos
Biomarcadores Tumorais/genética , Conectoma , Proteínas de Ligação a DNA/antagonistas & inibidores , Neoplasias Gastrointestinais/tratamento farmacológico , Tumores do Estroma Gastrointestinal/tratamento farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Fenotiazinas/farmacologia , Fatores de Transcrição/antagonistas & inibidores , Antineoplásicos/farmacologia , Antiprotozoários/farmacologia , Apoptose , Proteínas de Ligação a DNA/genética , Neoplasias Gastrointestinais/genética , Neoplasias Gastrointestinais/patologia , Tumores do Estroma Gastrointestinal/genética , Tumores do Estroma Gastrointestinal/patologia , Perfilação da Expressão Gênica , Humanos , Prognóstico , Transdução de Sinais , Fatores de Transcrição/genética
8.
Int J Mol Sci ; 20(13)2019 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-31262091

RESUMO

The TDP-43 is originally a nuclear protein but translocates to the cytoplasm in the pathological condition. TDP-43, as an RNA-binding protein, consists of two RNA Recognition Motifs (RRM1 and RRM2). RRMs are known to involve both protein-nucleotide and protein-protein interactions and mediate the formation of stress granules. Thus, they assist the entire TDP-43 protein with participating in neurodegenerative and cancer diseases. Consequently, they are potential therapeutic targets. Protein-observed and ligand-observed nuclear magnetic resonance (NMR) spectroscopy were used to uncover the small molecule inhibitors against the tandem RRM of TDP-43. We identified three hits weakly binding the tandem RRMs using the ligand-observed NMR fragment-based screening. The binding topology of these hits is then depicted by chemical shift perturbations (CSP) of the 15N-labeled tandem RRM and RRM2, respectively, and modeled by the CSP-guided High Ambiguity Driven biomolecular DOCKing (HADDOCK). These hits mainly bind to the RRM2 domain, which suggests the druggability of the RRM2 domain of TDP-43. These hits also facilitate further studies regarding the hit-to-lead evolution against the TDP-43 RRM domain.


Assuntos
Proteínas de Ligação a DNA/antagonistas & inibidores , Simulação de Acoplamento Molecular , Bibliotecas de Moléculas Pequenas/farmacologia , Sítios de Ligação , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Humanos , Ligantes , Espectroscopia de Ressonância Magnética , Ligação Proteica , Bibliotecas de Moléculas Pequenas/química
9.
Phytomedicine ; 63: 153019, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31302317

RESUMO

BACKGROUND: Obovatol, a biphenolic chemical originating from Magnolia obovata, has been utilized as a traditional medicine for the treatment of inflammatory diseases. Inflammasome induces maturation of inflammatory cytokines in response to intracellular danger signals, and its dysregulation induces inflammatory diseases. PURPOSE: The effect of obovatol on inflammasome activation has not been reported, although its anti-inflammatory properties have been studied. STUDY DESIGN/METHODS: Obovatol was treated to macrophages with inflammasome triggers, and secretions of interleukin (IL)-1ß, IL-18, and caspase-1 were measured as readouts of inflammasome activation. In addition, Asc pyroptosome formation, caspase-1 activity, and mitochondrial reactive oxygen species (ROS) production were analyzed in mechanical studies. Anti-inflammasome properties of obovatol were confirmed in an animal model. RESULTS: Obovatol inhibited NLRP3, AIM2, and non-canonical inflammasomes through inhibition of Asc pyroptosome formation and mitochondrial ROS generation. In addition, obovatol disrupted the priming step of inflammasome activation and inhibited transcription of inflammatory cytokines. In mice, obovatol attenuated serum IL-1ß elevation in response to monosodium urate crystals. CONCLUSION: Obovatol is suggested as an inhibitor of NLRP3, AIM2, and non-canonical inflammasomes.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Compostos de Bifenilo/farmacologia , Proteínas de Ligação a DNA/antagonistas & inibidores , Inflamassomos/efeitos dos fármacos , Proteína 3 que Contém Domínio de Pirina da Família NLR/antagonistas & inibidores , Éteres Fenílicos/farmacologia , Animais , Anti-Inflamatórios não Esteroides/química , Compostos de Bifenilo/química , Caspase 1/metabolismo , Citocinas/genética , Citocinas/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Modelos Animais de Doenças , Feminino , Humanos , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos Endogâmicos C57BL , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Peritonite/tratamento farmacológico , Éteres Fenílicos/química , Espécies Reativas de Oxigênio/metabolismo , Ácido Úrico/farmacologia
10.
J Neurooncol ; 144(2): 265-273, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31280432

RESUMO

INTRODUCTION: Inflammation is a key aspect of glioblastoma multiforme (GBM) although it remains unclear how it contributes to GBM pathogenesis. Inflammasomes are intracellular multi-protein complexes that are involved in innate immunity and are activated by cellular stress, principally in macrophages. This study examined the expression of inflammasome-associated genes in GBM, particularly absent in melanoma 2 (AIM2). METHODS: Tissue samples from surgically-resected GBM tumors (n = 10) were compared to resected brain specimens from patients with epilepsy (age- and sex-matched Other Disease Controls (ODC, n=5)) by qRT-PCR, western blotting and immunofluorescence. Gene expression studies in human astrocytoma U251 cells were performed and the effects of deleting the absent in melanoma 2 (AIM2) gene using the CRISPR-Cas9 system were analyzed. RESULTS: GBM tissues showed significantly elevated expression of multiple immune (CD3E, CD163, CD68, MX1, ARG1) and inflammasome (AIM2, NLRP1, IL18, CASP1, and IL-33) genes compared to ODC tissues, without induction of IL1B, IFNG or TNFA. An insert-containing AIM2 variant transcript was highly expressed in GBM tissues and in U251 cells. AIM2 immunoreactivity was concentrated in the tumor core in the absence of PCNA immunodetection and showed a predominant 52 kDa immunoreactive band on western blot. Deletion of AIM2 resulted in significantly enhanced proliferation of U251 cells, which also displayed increased resistance to temozolomide treatment. CONCLUSIONS: GBM tumors express a distinct profile of inflammasome-associated genes in a tumor-specific manner. AIM2 expression in tumor cells suppressed cell proliferation while also conferring increased susceptibility to contemporary GBM therapy.


Assuntos
Proliferação de Células , Proteínas de Ligação a DNA/metabolismo , Glioblastoma/patologia , Inflamassomos/metabolismo , Inflamação/patologia , Biomarcadores Tumorais , Estudos de Casos e Controles , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Glioblastoma/genética , Glioblastoma/metabolismo , Humanos , Inflamassomos/genética , Inflamação/genética , Inflamação/metabolismo , RNA Interferente Pequeno/genética , Células Tumorais Cultivadas
11.
BMB Rep ; 52(7): 457-462, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31186081

RESUMO

[18F]Fluorodeoxyglucose (FDG) PET/CT imaging has been widely used in the diagnosis of malignant tumors. ATPase family AAA domain-containing protein 2 (ATAD2) plays important roles in tumor growth, invasion and metastasis. However, the relationship between [18F]FDG accumulation and ATAD2 expression remains largely unknown. This study aimed to investigate the correlation between ATAD2 expression and [18F]FDG uptake in lung adenocarcinoma (LUAD), and elucidate its underlying molecular mechanisms. The results showed that ATAD2 expression was positively correlated with maximum standardized uptake value (SUVmax), total lesion glycolysis (TLG), glucose transporter type 1 (GLUT1) expression and hexokinase2 (HK2) expression in LUAD tissues. In addition, ATAD2 knockdown significantly inhibited the proliferation, tumorigenicity, migration, [18F]FDG uptake and lactate production of LUAD cells, while, ATAD2 overexpression exhibited the opposite effects. Furthermore, ATAD2 modulated the glycometabolism of LUAD via AKT-GLUT1/HK2 pathway, as assessed using LY294002 (an inhibitor of PI3K/AKT pathway). In summary, to explore the correlation between ATAD2 expression and glycometabolism is expected to bring good news for anti-energy metabolism therapy of cancers. [BMB Reports 2019; 52(7): 457-462].


Assuntos
ATPases Associadas a Diversas Atividades Celulares/metabolismo , Adenocarcinoma de Pulmão/metabolismo , Proteínas de Ligação a DNA/metabolismo , Fluordesoxiglucose F18/farmacocinética , Neoplasias Pulmonares/metabolismo , ATPases Associadas a Diversas Atividades Celulares/antagonistas & inibidores , ATPases Associadas a Diversas Atividades Celulares/genética , Adenocarcinoma de Pulmão/tratamento farmacológico , Adenocarcinoma de Pulmão/patologia , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Cromonas/farmacologia , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Relação Dose-Resposta a Droga , Feminino , Transportador de Glucose Tipo 1/antagonistas & inibidores , Transportador de Glucose Tipo 1/metabolismo , Hexoquinase/antagonistas & inibidores , Hexoquinase/metabolismo , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Morfolinas/farmacologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo
12.
Mol Pharmacol ; 96(1): 99-108, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31036695

RESUMO

C-terminal binding proteins (CtBP1/2) are oncogenic transcriptional coregulators and dehydrogenases often overexpressed in multiple solid tumors, including breast, colon, and ovarian cancer, and associated with poor survival. CtBPs act by repressing expression of genes responsible for apoptosis (e.g., PUMA, BIK) and metastasis-associated epithelial-mesenchymal transition (e.g., CDH1), and by activating expression of genes that promote migratory and invasive properties of cancer cells (e.g., TIAM1) and genes responsible for enhanced drug resistance (e.g., MDR1). CtBP's transcriptional functions are also critically dependent on oligomerization and nucleation of transcriptional complexes. Recently, we have developed a family of CtBP dehydrogenase inhibitors, based on the parent 2-hydroxyimino-3-phenylpropanoic acid (HIPP), that specifically disrupt cancer cell viability, abrogate CtBP's transcriptional function, and block polyp formation in a mouse model of intestinal polyposis that depends on CtBP's oncogenic functions. Crystallographic analysis revealed that HIPP interacts with CtBP1/2 at a conserved active site tryptophan (W318/324; CtBP1/2) that is unique among eukaryotic D2-dehydrogenases. To better understand the mechanism of action of HIPP-class inhibitors, we investigated the contribution of W324 to CtBP2's biochemical and physiologic activities utilizing mutational analysis. Indeed, W324 was necessary for CtBP2 self-association, as shown by analytical ultracentrifugation and in vivo cross-linking. Additionally, W324 supported CtBP's association with the transcriptional corepressor CoREST, and was critical for CtBP2 induction of cell motility. Notably, the HIPP derivative 4-chloro-HIPP biochemically and biologically phenocopied mutational inactivation of CtBP2 W324. Our data support further optimization of W318/W324-interacting CtBP dehydrogenase inhibitors that are emerging as a novel class of cancer cell-specific therapeutic.


Assuntos
Oxirredutases do Álcool/química , Oxirredutases do Álcool/genética , Antineoplásicos/farmacologia , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Inibidores Enzimáticos/farmacologia , Polipose Intestinal/tratamento farmacológico , Triptofano/metabolismo , Oxirredutases do Álcool/antagonistas & inibidores , Animais , Antineoplásicos/química , Domínio Catalítico , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Proteínas de Ligação a DNA/antagonistas & inibidores , Inibidores Enzimáticos/química , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HCT116 , Humanos , Hidroxilaminas/química , Hidroxilaminas/farmacologia , Polipose Intestinal/metabolismo , Camundongos , Mutagênese Sítio-Dirigida , Fenilpropionatos/química , Fenilpropionatos/farmacologia , Multimerização Proteica/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
13.
ACS Chem Biol ; 14(6): 1110-1114, 2019 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-31091068

RESUMO

Tyrosyl DNA phosphodiesterase 2 (TDP2) facilitates the repair of topoisomerase II (TOP2)-linked DNA double-strand breaks and, as a consequence, is required for cellular resistance to TOP2 "poisons". Recently, a deazaflavin series of compounds were identified as potent inhibitors of TDP2, in vitro. Here, however, we show that while some deazaflavins can induce cellular sensitivity to the TOP2 poison etoposide, they do so independently of TDP2 status. Consistent with this, both the cellular level of etoposide-induced TOP2 cleavage complexes and the intracellular concentration of etoposide was increased by incubation with deazaflavin, suggesting an impact of these compounds on etoposide uptake/efflux. In addition, deazaflavin failed to increase the level of TOP2 cleavage complexes or sensitivity induced by m-AMSA, which is a different class of TOP2 poison to which TDP2-defective cells are also sensitive. In conclusion, while deazaflavins are potent inhibitors of TDP2 in vitro, their limited cell permeability and likely interference with etoposide influx/efflux limits their utility in cells.


Assuntos
Compostos Aza/química , Proteínas de Ligação a DNA/antagonistas & inibidores , Etoposídeo/farmacocinética , Flavinas/farmacologia , Inibidores da Topoisomerase II/farmacocinética , Animais , Transporte Biológico , Linhagem Celular , Galinhas , Flavinas/química , Flavinas/farmacocinética , Humanos , Diester Fosfórico Hidrolases , Bibliotecas de Moléculas Pequenas/farmacologia
14.
Chem Biol Interact ; 305: 148-155, 2019 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-30929997

RESUMO

Accumulating evidence has documented that ataxia-telangiectasia group D complementing gene (ATDC) is aberrantly expressed in various cancers and is associated with cancer development and progression. However, little is known about the role of ATDC in glioma tumorigenesis. In this study, we aimed to explore the biological function and regulatory mechanism of ATDC in glioma. We found that ATDC expression was highly upregulated in glioma cell lines. Knockdown of ATDC significantly inhibited the growth and invasion of glioma cells. In contrast, overexpression of ATDC markedly promoted the growth and invasion of glioma cells. Moreover, our results showed that inhibition of ATDC reduced the expression levels of Dishevelled 2 (Dvl2) and ß-catenin and impeded the activation of Wnt/ß-catenin signaling, whereas overexpression of ATDC showed the opposite effect. Knockdown of Dvl2 significantly blocked the promotion effect of ATDC overexpression on activation of Wnt/ß-catenin signaling. In addition, silencing of ß-catenin partially reversed the oncogenic effect of ATDC overexpression in glioma cells. Taken together, out study reveals an oncogenic role of ATDC that drives the growth and invasion of glioma by modulating the Wnt/Dvl2/ß-catenin signaling pathway, suggesting a potential therapeutic target for treatment of glioma.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição/metabolismo , Via de Sinalização Wnt , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Proteínas Desgrenhadas/metabolismo , Glioma/metabolismo , Glioma/patologia , Humanos , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genética , Regulação para Cima , beta Catenina/antagonistas & inibidores , beta Catenina/metabolismo
15.
J Biol Chem ; 294(22): 8760-8772, 2019 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-31010829

RESUMO

The cohesin complex regulates sister chromatid cohesion, chromosome organization, gene expression, and DNA repair. Cohesin is a ring complex composed of four core subunits and seven regulatory subunits. In an effort to comprehensively identify additional cohesin-interacting proteins, we used gene editing to introduce a dual epitope tag into the endogenous allele of each of 11 known components of cohesin in cultured human cells, and we performed MS analyses on dual-affinity purifications. In addition to reciprocally identifying all known components of cohesin, we found that cohesin interacts with a panoply of splicing factors and RNA-binding proteins (RBPs). These included diverse components of the U4/U6.U5 tri-small nuclear ribonucleoprotein complex and several splicing factors that are commonly mutated in cancer. The interaction between cohesin and splicing factors/RBPs was RNA- and DNA-independent, occurred in chromatin, was enhanced during mitosis, and required RAD21. Furthermore, cohesin-interacting splicing factors and RBPs followed the cohesin cycle and prophase pathway of cell cycle-regulated interactions with chromatin. Depletion of cohesin-interacting splicing factors and RBPs resulted in aberrant mitotic progression. These results provide a comprehensive view of the endogenous human cohesin interactome and identify splicing factors and RBPs as functionally significant cohesin-interacting proteins.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Mitose , Proteômica , Fatores de Processamento de RNA/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Cromatina/metabolismo , Proteínas Cromossômicas não Histona/genética , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Humanos , Microscopia de Fluorescência , Ligação Proteica , Mapas de Interação de Proteínas , Interferência de RNA , Fatores de Processamento de RNA/antagonistas & inibidores , Fatores de Processamento de RNA/genética , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a RNA/antagonistas & inibidores , Proteínas de Ligação a RNA/genética
16.
Nucleic Acids Res ; 47(10): 5170-5180, 2019 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-30941419

RESUMO

Homologous recombination (HR) maintains genome stability by promoting accurate DNA repair. Two recombinases, RAD51 and DMC1, are central to HR repair and form dynamic nucleoprotein filaments in vivo under tight regulation. However, the interplay between positive and negative regulators to control the dynamic assembly/disassembly of RAD51/DMC1 filaments in multicellular eukaryotes remains poorly characterized. Here, we report an antagonism between BRCA2, a well-studied positive mediator of RAD51/DMC1, and FIDGETIN-LIKE-1 (FIGL1), which we previously proposed as a negative regulator of RAD51/DMC1. Through forward genetic screen, we identified a mutation in one of the two Arabidopsis BRCA2 paralogs that suppresses the meiotic phenotypes of figl1. Consistent with the antagonistic roles of BRCA2 and FIGL1, the figl1 mutation in the brca2 background restores RAD51/DMC1 focus formation and homologous chromosome interaction at meiosis, and RAD51 focus formation in somatic cells. This study shows that BRCA2 and FIGL1 have antagonistic effects on the dynamics of RAD51/DMC1-dependent DNA transactions to promote accurate HR repair.


Assuntos
ATPases Associadas a Diversas Atividades Celulares/antagonistas & inibidores , Proteínas de Arabidopsis/antagonistas & inibidores , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ligação a DNA/antagonistas & inibidores , Epistasia Genética , Recombinação Homóloga , Proteínas Associadas aos Microtúbulos/antagonistas & inibidores , Nucleoproteínas/química , ATPases Associadas a Diversas Atividades Celulares/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/metabolismo , DNA/química , Dano ao DNA , Reparo do DNA , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Meiose , Proteínas Associadas aos Microtúbulos/metabolismo , Modelos Genéticos , Mutação , Fenótipo , Rad51 Recombinase/química , Recombinases Rec A/química , Reparo de DNA por Recombinação
17.
Genes Dev ; 33(11-12): 718-732, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30975721

RESUMO

The stationary phase promoter specificity subunit σS (RpoS) is delivered to the ClpXP machinery for degradation dependent on the adaptor RssB. This adaptor-specific degradation of σS provides a major point for regulation and transcriptional reprogramming during the general stress response. RssB is an atypical response regulator and the only known ClpXP adaptor that is inhibited by multiple but dissimilar antiadaptors (IraD, IraP, and IraM). These are induced by distinct stress signals and bind to RssB in poorly understood manners to achieve stress-specific inhibition of σS turnover. Here we present the first crystal structure of RssB bound to an antiadaptor, the DNA damage-inducible IraD. The structure reveals that RssB adopts a compact closed architecture with extensive interactions between its N-terminal and C-terminal domains. The structural data, together with mechanistic studies, suggest that RssB plasticity, conferred by an interdomain glutamate-rich flexible linker, is critical for regulation of σS degradation. Structural modulation of interdomain linkers may thus constitute a general strategy for tuning response regulators.


Assuntos
Proteínas de Bactérias/metabolismo , Proteínas de Ligação a DNA/química , Proteínas de Escherichia coli/química , Fator sigma/química , Fator sigma/metabolismo , Fatores de Transcrição/química , Proteínas de Bactérias/química , Cristalografia por Raios X , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/metabolismo , Proteínas de Escherichia coli/antagonistas & inibidores , Proteínas de Escherichia coli/metabolismo , Modelos Moleculares , Conformação Proteica , Conformação Proteica em alfa-Hélice , Domínios Proteicos , Estabilidade Proteica , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/metabolismo
18.
FEBS Open Bio ; 9(3): 490-497, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30868057

RESUMO

Neuroblastoma (NB) is an aggressive cancer that originates in the sympathetic nervous system and primarily affects children. Here, we show that high levels of RAD52 motif containing 1 (RDM1; a protein with similarities to RAD52, which is important for double-strand DNA repair) are associated with poor clinical outcomes for NB. In addition, RDM1-/- cells exhibited increased sensitivity to cisplatin, a common chemotherapy drug, and disruption of RDM1 suppressed NB cell proliferation. We also report that loss of RDM1 augmented cell apoptosis and induced cell cycle arrest, and that stable knockdown of RDM1 significantly inhibited NB tumor growth in a xenograft mouse model. Importantly, we identified that RDM1 promoted cell proliferation via the RAS-Raf-mitogen-activated protein kinase kinase (MEK)-extracellular signal-regulated kinase (ERK) signaling pathway. In conclusion, the current study demonstrates a correlation between DNA damage regulator RDM1 and the oncogenic RAS-Raf-MEK-ERK pathway in NB.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Neoplasias Pulmonares/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Neuroblastoma/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Quinases raf/metabolismo , Animais , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Neuroblastoma/tratamento farmacológico , Neuroblastoma/patologia , RNA Interferente Pequeno/farmacologia , Células Tumorais Cultivadas
19.
PLoS One ; 14(3): e0213028, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30875378

RESUMO

High-risk strains of human papillomavirus (HPV) have been identified as the etiologic agent of some anogenital tract, head, and neck cancers. Although prophylactic HPV vaccines have been approved; it is still necessary a drug-based treatment against the infection and its oncogenic effects. The E6 oncoprotein is one of the most studied therapeutic targets of HPV, it has been identified as a key factor in cell immortalization and tumor progression in HPV-positive cells. E6 can promote the degradation of p53, a tumor suppressor protein, through the interaction with the cellular ubiquitin ligase E6AP. Therefore, preventing the formation of the E6-E6AP complex is one of the main strategies to inhibit the viability and proliferation of infected cells. Herein, we propose an in silico pipeline to identify small-molecule inhibitors of the E6-E6AP interaction. Virtual screening was carried out by predicting the ADME properties of the molecules and performing ensemble-based docking simulations to E6 protein followed by binding free energy estimation through MM/PB(GB)SA methods. Finally, the top-three compounds were selected, and their stability in the E6 docked complex and their effect in the inhibition of the E6-E6AP interaction was corroborated by molecular dynamics simulation. Therefore, this pipeline and the identified molecules represent a new starting point in the development of anti-HPV drugs.


Assuntos
Antivirais/farmacologia , Proteínas de Ligação a DNA/antagonistas & inibidores , Simulação de Acoplamento Molecular , Proteínas Oncogênicas Virais/antagonistas & inibidores , Ubiquitina-Proteína Ligases/metabolismo , Antivirais/química , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Desenvolvimento de Medicamentos/métodos , Papillomavirus Humano 16/efeitos dos fármacos , Papillomavirus Humano 16/metabolismo , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/virologia , Proteínas Oncogênicas Virais/química , Proteínas Oncogênicas Virais/metabolismo , Infecções por Papillomavirus/tratamento farmacológico , Infecções por Papillomavirus/virologia , Ligação Proteica/efeitos dos fármacos , Proteólise/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo , Ubiquitina-Proteína Ligases/química
20.
Chem Asian J ; 14(9): 1570-1576, 2019 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-30843348

RESUMO

DNA damage repair through the nucleotide excision repair (NER) pathway is one of the major reasons for the decreased antitumor efficacy of platinum-based anticancer drugs that have been widely applied in the clinic. Inhibiting the intrinsic NER function may enhance the antitumor activity of cisplatin and conquer cisplatin resistance. Herein, we report the design, optimization, and application of a self-assembled lipid nanoparticle (LNP) system to simultaneously deliver a cisplatin prodrug together with siRNA targeting endonuclease xeroderma pigmentosum group F (XPF), a crucial component in the NER pathway. The LNP is able to efficiently encapsulate both the platinum prodrug and siRNA molecules with a tuned ratio. Both platinum prodrug and XPF-targeted siRNA are efficiently carried into cells and released; the former damages DNA and the latter specifically downregulates both mRNA and protein levels of XPF to potentiate the platinum drug, leading to enhanced expression levels of apoptosis markers and improved cytotoxicity in both cisplatin-sensitive and -resistant human lung cancer cells. Our results demonstrate an effective approach to utilize a multi-targeted nanoparticle system that can specifically silence an NER-related gene to promote apoptosis induced by cisplatin, especially in cisplatin-refractory tumors.


Assuntos
Antineoplásicos/química , Cisplatino/química , Proteínas de Ligação a DNA/metabolismo , Resistencia a Medicamentos Antineoplásicos , Nanopartículas/química , RNA Interferente Pequeno/química , Células A549 , Antineoplásicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/farmacologia , Cisplatino/uso terapêutico , Reparo do DNA/efeitos dos fármacos , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Portadores de Fármacos/química , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Humanos , Lipídeos/química , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Pró-Fármacos/química , Pró-Fármacos/farmacologia , Pró-Fármacos/uso terapêutico , Interferência de RNA , RNA Interferente Pequeno/metabolismo , RNA Interferente Pequeno/uso terapêutico
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