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1.
G3 (Bethesda) ; 11(9)2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34544118

RESUMO

DNA topoisomerase I (Top1) maintains chromatin conformation during transcription. While Top1 is not essential in simple eukaryotic organisms such as yeast, it is required for the development of multicellular organisms. In fact, tissue and cell-type-specific functions of Top1 have been suggested in the fruit fly Drosophila. A better understanding of Top1's function in the context of development is important as Top1 inhibitors are among the most widely used anticancer drugs. As a step toward such a better understanding, we studied its localization in live cells of Drosophila. Consistent with prior results, Top1 is highly enriched at the nucleolus in transcriptionally active polyploid cells, and this enrichment responds to perturbation of transcription. In diploid cells, we uncovered evidence for Top1 foci formation at genomic regions not limited to the active rDNA locus, suggestive of novel regulation of Top1 recruitment. In the male germline, Top1 is highly enriched at the paired rDNA loci on sex chromosomes suggesting that it might participate in regulating their segregation during meiosis. Results from RNAi-mediated Top1 knockdown lend support to this hypothesis. Our study has provided one of the most comprehensive descriptions of Top1 localization during animal development.


Assuntos
DNA Topoisomerases Tipo I , Drosophila , Animais , DNA Topoisomerases Tipo I/genética , DNA Topoisomerases Tipo I/metabolismo , DNA Ribossômico/genética , Drosophila/genética , Drosophila/metabolismo , Meiose , Saccharomyces cerevisiae/genética , Inibidores da Topoisomerase I
2.
Inorg Chem ; 60(18): 14174-14189, 2021 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-34477373

RESUMO

Ruthenium(II) complexes (Ru1-Ru5), with the general formula [Ru(N-S)(dppe)2]PF6, bearing two 1,2-bis(diphenylphosphino)ethane (dppe) ligands and a series of mercapto ligands (N-S), have been developed. The combination of these ligands in the complexes endowed hydrophobic species with high cytotoxic activity against five cancer cell lines. For the A549 (lung) and MDA-MB-231 (breast) cancer cell lines, the IC50 values of the complexes were 288- to 14-fold lower when compared to cisplatin. Furthermore, the complexes were selective for the A549 and MDA-MB-231 cancer cell lines compared to the MRC-5 nontumor cell line. The multitarget character of the complexes was investigated by using calf thymus DNA (CT DNA), human serum albumin, and human topoisomerase IB (hTopIB). The complexes potently inhibited hTopIB. In particular, complex [Ru(dmp)(dppe)2]PF6 (Ru3), bearing the 4,6-diamino-2-mercaptopyrimidine (dmp) ligand, effectively inhibited hTopIB by acting on both the cleavage and religation steps of the catalytic cycle of this enzyme. Molecular docking showed that the Ru1-Ru5 complexes have binding affinity by active sites on the hTopI and hTopI-DNA, mainly via π-alkyl and alkyl hydrophobic interactions, as well as through hydrogen bonds. Complex Ru3 displayed significant antitumor activity against murine melanoma in mouse xenograph models, but this complex did not damage DNA, as revealed by Ames and micronucleus tests.


Assuntos
Antineoplásicos/farmacologia , Complexos de Coordenação/farmacologia , DNA Topoisomerases Tipo I/metabolismo , Fosfinas/farmacologia , Rutênio/farmacologia , Inibidores da Topoisomerase I/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Ligantes , Fosfinas/química , Rutênio/química , Inibidores da Topoisomerase I/síntese química , Inibidores da Topoisomerase I/química , Células Tumorais Cultivadas
3.
Nat Commun ; 12(1): 5010, 2021 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-34408146

RESUMO

Poly(ADP)-ribosylation (PARylation) regulates chromatin structure and recruits DNA repair proteins. Using single-molecule fluorescence microscopy to track topoisomerase I (TOP1) in live cells, we found that sustained PARylation blocked the repair of TOP1 DNA-protein crosslinks (TOP1-DPCs) in a similar fashion as inhibition of the ubiquitin-proteasome system (UPS). PARylation of TOP1-DPC was readily revealed by inhibiting poly(ADP-ribose) glycohydrolase (PARG), indicating the otherwise transient and reversible PARylation of the DPCs. As the UPS is a key repair mechanism for TOP1-DPCs, we investigated the impact of TOP1-DPC PARylation on the proteasome and found that the proteasome is unable to associate with and digest PARylated TOP1-DPCs. In addition, PARylation recruits the deubiquitylating enzyme USP7 to reverse the ubiquitylation of PARylated TOP1-DPCs. Our work identifies PARG as repair factor for TOP1-DPCs by enabling the proteasomal digestion of TOP1-DPCs. It also suggests the potential regulatory role of PARylation for the repair of a broad range of DPCs.


Assuntos
DNA Topoisomerases Tipo I/metabolismo , DNA/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , DNA/química , DNA/metabolismo , Dano ao DNA , Reparo do DNA , DNA Topoisomerases Tipo I/química , DNA Topoisomerases Tipo I/genética , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Células HEK293 , Humanos , Poli ADP Ribosilação , Complexo de Endopeptidases do Proteassoma/química , Complexo de Endopeptidases do Proteassoma/genética , Proteólise , Ubiquitinação
4.
Nucleic Acids Res ; 49(15): 8573-8591, 2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34329467

RESUMO

R-loops, which consist of a DNA/RNA hybrid and a displaced single-stranded DNA (ssDNA), are increasingly recognized as critical regulators of chromatin biology. R-loops are particularly enriched at gene promoters, where they play important roles in regulating gene expression. However, the molecular mechanisms that control promoter-associated R-loops remain unclear. The epigenetic 'reader' Tudor domain-containing protein 3 (TDRD3), which recognizes methylarginine marks on histones and on the C-terminal domain of RNA polymerase II, was previously shown to recruit DNA topoisomerase 3B (TOP3B) to relax negatively supercoiled DNA and prevent R-loop formation. Here, we further characterize the function of TDRD3 in R-loop metabolism and introduce the DExH-box helicase 9 (DHX9) as a novel interaction partner of the TDRD3/TOP3B complex. TDRD3 directly interacts with DHX9 via its Tudor domain. This interaction is important for recruiting DHX9 to target gene promoters, where it resolves R-loops in a helicase activity-dependent manner to facilitate gene expression. Additionally, TDRD3 also stimulates the helicase activity of DHX9. This stimulation relies on the OB-fold of TDRD3, which likely binds the ssDNA in the R-loop structure. Thus, DHX9 functions together with TOP3B to suppress promoter-associated R-loops. Collectively, these findings reveal new functions of TDRD3 and provide important mechanistic insights into the regulation of R-loop metabolism.


Assuntos
RNA Helicases DEAD-box/metabolismo , Proteínas de Neoplasias/metabolismo , Regiões Promotoras Genéticas , Proteínas/metabolismo , Estruturas R-Loop , Cromatina , DNA Topoisomerases Tipo I/metabolismo , Células HEK293 , Humanos , Células MCF-7 , Domínios e Motivos de Interação entre Proteínas , Proteínas/química , Transcrição Genética
5.
Mol Cell ; 81(15): 3065-3081.e12, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34297911

RESUMO

The chromatin fiber folds into loops, but the mechanisms controlling loop extrusion are still poorly understood. Using super-resolution microscopy, we visualize that loops in intact nuclei are formed by a scaffold of cohesin complexes from which the DNA protrudes. RNA polymerase II decorates the top of the loops and is physically segregated from cohesin. Augmented looping upon increased loading of cohesin on chromosomes causes disruption of Lamin at the nuclear rim and chromatin blending, a homogeneous distribution of chromatin within the nucleus. Altering supercoiling via either transcription or topoisomerase inhibition counteracts chromatin blending, increases chromatin condensation, disrupts loop formation, and leads to altered cohesin distribution and mobility on chromatin. Overall, negative supercoiling generated by transcription is an important regulator of loop formation in vivo.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Cromatina/química , Cromatina/genética , Proteínas Cromossômicas não Histona/metabolismo , Transcrição Genética/fisiologia , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/genética , Linhagem Celular , Núcleo Celular/genética , Proteoglicanas de Sulfatos de Condroitina/genética , Proteoglicanas de Sulfatos de Condroitina/metabolismo , Cromatina/metabolismo , Proteínas Cromossômicas não Histona/química , Proteínas Cromossômicas não Histona/genética , DNA Topoisomerases Tipo I/genética , DNA Topoisomerases Tipo I/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Feminino , Humanos , Laminas/genética , Laminas/metabolismo , RNA Polimerase II/metabolismo , Imagem Individual de Molécula/métodos
6.
Nat Commun ; 12(1): 4373, 2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34272385

RESUMO

Although homologous recombination (HR) is indicated as a high-fidelity repair mechanism, break-induced replication (BIR), a subtype of HR, is a mutagenic mechanism that leads to chromosome rearrangements. It remains poorly understood how cells suppress mutagenic BIR. Trapping of Topoisomerase 1 by camptothecin (CPT) in a cleavage complex on the DNA can be transformed into single-ended double-strand breaks (seDSBs) upon DNA replication or colliding with transcriptional machinery. Here, we demonstrate a role of Abraxas in limiting seDSBs undergoing BIR-dependent mitotic DNA synthesis. Through counteracting K63-linked ubiquitin modification, Abraxas restricts SLX4/Mus81 recruitment to CPT damage sites for cleavage and subsequent resection processed by MRE11 endonuclease, CtIP, and DNA2/BLM. Uncontrolled SLX4/MUS81 loading and excessive end resection due to Abraxas-deficiency leads to increased mitotic DNA synthesis via RAD52- and POLD3- dependent, RAD51-independent BIR and extensive chromosome aberrations. Our work implicates Abraxas/BRCA1-A complex as a critical regulator that restrains BIR for protection of genome stability.


Assuntos
Proteínas de Transporte/metabolismo , Cromatina/metabolismo , Dano ao DNA/efeitos dos fármacos , DNA Topoisomerases Tipo I/metabolismo , Proteínas de Ligação a DNA/metabolismo , Endonucleases/metabolismo , Recombinases/metabolismo , Animais , Camptotecina/farmacologia , Proteínas de Transporte/genética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Cromatina/genética , Quebras de DNA de Cadeia Dupla , Dano ao DNA/genética , DNA Polimerase III/metabolismo , Replicação do DNA/genética , Proteínas de Ligação a DNA/genética , Endonucleases/genética , Recombinação Homóloga , Humanos , Proteína Homóloga a MRE11/metabolismo , Camundongos , RNA Interferente Pequeno , Proteína Rad52 de Recombinação e Reparo de DNA/genética , Proteína Rad52 de Recombinação e Reparo de DNA/metabolismo , Recombinases/genética , Inibidores da Topoisomerase I/farmacologia , Ubiquitinação
7.
Int J Mol Sci ; 22(14)2021 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-34299074

RESUMO

Human DNA topoisomerase IB controls the topological state of supercoiled DNA through a complex catalytic cycle that consists of cleavage and religation reactions, allowing the progression of fundamental DNA metabolism. The catalytic steps of human DNA topoisomerase IB were analyzed in the presence of a drug, obtained by the open-access drug bank Medicines for Malaria Venture. The experiments indicate that the compound strongly and irreversibly inhibits the cleavage step of the enzyme reaction and reduces the cell viability of three different cancer cell lines. Molecular docking and molecular dynamics simulations suggest that the drug binds to the human DNA topoisomerase IB-DNA complex sitting inside the catalytic site of the enzyme, providing a molecular explanation for the cleavage-inhibition effect. For all these reasons, the aforementioned drug could be a possible lead compound for the development of an efficient anti-tumor molecule targeting human DNA topoisomerase IB.


Assuntos
Antimaláricos/farmacologia , Antineoplásicos/farmacologia , Simulação por Computador , DNA Topoisomerases Tipo I/química , DNA/metabolismo , Inibidores da Topoisomerase I/farmacologia , Catálise , Domínio Catalítico , DNA/química , DNA/efeitos dos fármacos , DNA Topoisomerases Tipo I/metabolismo , Humanos , Técnicas In Vitro , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Conformação de Ácido Nucleico , Conformação Proteica
8.
Int J Mol Sci ; 22(14)2021 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-34299090

RESUMO

The compounds 7-ethyl-9-(N-methylamino)methyl-10-hydroxycamptothecin (2) and 7-ethyl-9-(N-morpholino)methyl-10-hydroxycamptothecin (3) are potential topoisomerase I poisons. Moreover, they were shown to have favorable anti-neoplastic effects on several tumor cell lines. Due to these properties, the compounds are being considered for advancement to the preclinical development stage. To gain better insights into the molecular mechanism with the biological target, here, we conducted an investigation into their interactions with model nicked DNA (1) using different techniques. In this work, we observed the complexity of the mechanism of action of the compounds 2 and 3, in addition to their decomposition products: compound 4 and SN38. Using DOSY experiments, evidence of the formation of strongly bonded molecular complexes of SN38 derivatives with DNA duplexes was provided. The molecular modeling based on cross-peaks from the NOESY spectrum also allowed us to assign the geometry of a molecular complex of DNA with compound 2. Confirmation of the alkylation reaction of both compounds was obtained using MALDI-MS. Additionally, in the case of 3, alkylation was confirmed in the recording of cross-peaks in the 1H/13C HSQC spectrum of 13C-enriched compound 3. In this work, we showed that the studied compounds-parent compounds 2 and 3, and their potential metabolite 4 and SN38-interact inside the nick of 1, either forming the molecular complex or alkylating the DNA nitrogen bases. In order to confirm the influence of the studied compounds on the topoisomerase I relaxation activity of supercoiled DNA, the test was performed based upon the measurement of the fluorescence of DNA stain which can differentiate between supercoiled and relaxed DNA. The presented results confirmed that studied SN38 derivatives effectively block DNA relaxation mediated by Topo I, which means that they stop the machinery of Topo I activity.


Assuntos
Camptotecina/análogos & derivados , Camptotecina/metabolismo , Quebras de DNA de Cadeia Simples , DNA Topoisomerases Tipo I/química , DNA Topoisomerases Tipo I/metabolismo , DNA Super-Helicoidal , Inibidores da Topoisomerase II/farmacologia , Alquilação , Humanos
9.
Sensors (Basel) ; 21(14)2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34300575

RESUMO

DNA sensors can be used as robust tools for high-throughput drug screening of small molecules with the potential to inhibit specific enzymes. As enzymes work in complex biological pathways, it is important to screen for both desired and undesired inhibitory effects. We here report a screening system utilizing specific sensors for tyrosyl-DNA phosphodiesterase 1 (TDP1) and topoisomerase 1 (TOP1) activity to screen in vitro for drugs inhibiting TDP1 without affecting TOP1. As the main function of TDP1 is repair of TOP1 cleavage-induced DNA damage, inhibition of TOP1 cleavage could thus reduce the biological effect of the TDP1 drugs. We identified three new drug candidates of the 1,5-naphthyridine and 1,2,3,4-tetrahydroquinolinylphosphine sulfide families. All three TDP1 inhibitors had no effect on TOP1 activity and acted synergistically with the TOP1 poison SN-38 to increase the amount of TOP1 cleavage-induced DNA damage. Further, they promoted cell death even with low dose SN-38, thereby establishing two new classes of TDP1 inhibitors with clinical potential. Thus, we here report a dual-sensor screening approach for in vitro selection of TDP1 drugs and three new TDP1 drug candidates that act synergistically with TOP1 poisons.


Assuntos
DNA Topoisomerases Tipo I , Inibidores de Fosfodiesterase/farmacologia , Diester Fosfórico Hidrolases , DNA , Dano ao DNA , DNA Topoisomerases Tipo I/metabolismo , Ensaios de Triagem em Larga Escala , Humanos , Diester Fosfórico Hidrolases/genética , Diester Fosfórico Hidrolases/metabolismo
10.
Cell Chem Biol ; 28(6): 743-745, 2021 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-34143956

RESUMO

Topoisomerase I is the target for a number of widely prescribed anticancer drugs that are based on camptothecin. In this issue of Cell Chemical Biology, Flor et al. (2020) demonstrate that the cellular response to camptothecin is mediated by lipid-derived electrophiles that are generated as a result of drug-induced oxidative stress.


Assuntos
DNA Topoisomerases Tipo I , Venenos , Camptotecina/farmacologia , DNA Topoisomerases Tipo I/metabolismo , Inibidores da Topoisomerase I
11.
Anticancer Res ; 41(6): 2773-2779, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34083267

RESUMO

Head and neck carcinoma (HNC) comprises a variety of pathological entities. Among them, squamous cell carcinoma (SCC) is histo-pathologically prominent. Specific malignancies, such as nasopharyngeal carcinoma (NPC) arise also from the same anatomical region. In all of them, genomic instability (GI) is implicated not only in the early stages of epithelial malignant transformation, but also in the aggressiveness of the corresponding phenotypes. Among the molecules that are frequently deregulated in solid malignancies including HNCs, topoisomerases (Topo) are of increased significance due to their involvement in DNA topological, structural, and functional stability. The main members are Topo I (20q11), Topo II alpha (17q21) and Topo IIb (3p24). In the current article, we describe the mechanisms of Topo I and Topo IIa deregulation leading to GI in a variety of HNCs. Furthermore, novel data regarding the corresponding targeted therapeutic strategies are presented.


Assuntos
DNA Topoisomerases Tipo I/metabolismo , Instabilidade Genômica , Neoplasias de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/enzimologia , DNA Topoisomerases Tipo I/genética , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia
12.
J Mol Evol ; 89(6): 384-395, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33999213

RESUMO

DNA topoisomerase III beta (TOP3B) is unique by operating on both DNA and RNA substrates to regulate gene expression and genomic stability. Mutations in human TOP3B are linked to neurodevelopmental and cognitive disorders, highlighting its relevance for human health. Despite the emerging importance of TOP3B, its precise cellular functions and evolutionary history remain poorly understood. Here, we show that TOP3B is conserved across main metazoan groups and evolved under strong purifying selection. Subdomain IV was identified as the most conserved TOP3B region, in agreement with its role in providing the structural foundation of the protein. On the contrary, subdomain II is the less conserved, possibly because it is the most structurally flexible region of all TOP3B regions. Interestingly, TOP3B residue at position 472, previously associated with schizophrenia, is highly variable across animals, suggesting a more specific role in humans and related species. Finally, we show that all TOP3B CXXC zinc finger motifs previously identified at the protein C-terminal region are retained across metazoans. We also found that the two major methylation sites known to regulate TOP3B activity are located in the most conserved region of the C-terminal arginine-glycine-glycine (RGG) box, suggesting that a similar regulatory mechanism may operate throughout animals. Overall, our results provide a better understanding of the evolution and functional roles of TOP3B.


Assuntos
DNA Topoisomerases Tipo I , Evolução Molecular , Animais , DNA Topoisomerases Tipo I/genética , DNA Topoisomerases Tipo I/metabolismo , Humanos , Mutação , Proteínas/metabolismo
13.
J Med Chem ; 64(10): 6720-6729, 2021 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-33961424

RESUMO

As c-MYC is one of the central players in triple-negative breast cancer (TNBC) oncogenesis, inhibiting c-MYC expression would be an effective anticancer strategy. Transcription-induced negative supercoiling is crucial in the regulation of c-MYC transcription, which facilitates the formation of a G4 structure in NHE III1 that can silence the transcription. However, topoisomerase 1 (Topo1) can dissipate this negative supercoiling, leading to continuous activation of c-MYC transcription. Thus, dual ligands targeting both Topo1 and c-MYC G4 appear to be significant in cancer therapy. In this study, a series of new dibenzoquinoxaline derivatives were designed, synthesized, and evaluated for both Topo1 and c-MYC inhibition. Among them, 5 was identified as the most promising dual ligand, which could effectively inhibit Topo1 activity and strongly stabilize c-MYC G4, thereby inhibiting cancer cell growth. Accordingly, this work suggests that this dual-targeting strategy may be effective in cancer therapy.


Assuntos
Antineoplásicos/farmacologia , DNA Topoisomerases Tipo I/química , Quadruplex G/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-myc/genética , Quinoxalinas/química , Animais , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , DNA Topoisomerases Tipo I/metabolismo , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Desenho de Fármacos , Feminino , Humanos , Ligantes , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Proto-Oncogênicas c-myc/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-myc/metabolismo , Quinoxalinas/farmacologia , Quinoxalinas/uso terapêutico , Transplante Heterólogo , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/patologia
14.
J Med Chem ; 64(11): 7617-7629, 2021 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-34008967

RESUMO

As a recently discovered DNA repair enzyme, tyrosyl-DNA phosphodiesterase 1 (TDP1) removes topoisomerase IB (TOP1)-mediated DNA protein cross-links. Inhibiting TDP1 can potentiate the cytotoxicity of TOP1 inhibitors and overcome cancer cell resistance to TOP1 inhibitors. On the basis of our previous study, herein we report the synthesis of benzophenanthridinone derivatives as TOP1 and TDP1 inhibitors. Seven compounds (C2, C4, C5, C7, C8, C12, and C14) showed a robust TOP1 inhibitory activity (+++ or ++++), and four compounds (A13, C12, C13, and C26) showed a TDP1 inhibition (half-maximal inhibitory concentration values of 15 or 19 µM). We also show that the dual TOP1 and TDP1 inhibitor C12 induces both cellular TOP1cc, TDP1cc formation and DNA damage, resulting in cancer cell apoptosis at a sub-micromolar concentration. In addition, C12 showed an enhanced activity in drug-resistant MCF-7/TDP1 cancer cells and was synergistic with topotecan in both MCF-7 and MCF-7/TDP1 cells.


Assuntos
Benzofenantridinas/química , DNA Topoisomerases Tipo I/metabolismo , Inibidores de Fosfodiesterase/síntese química , Diester Fosfórico Hidrolases/metabolismo , Inibidores da Topoisomerase I/síntese química , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Benzofenantridinas/metabolismo , Benzofenantridinas/farmacologia , Benzofenantridinas/uso terapêutico , Sítios de Ligação , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , DNA Topoisomerases Tipo I/química , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Simulação de Dinâmica Molecular , Neoplasias/tratamento farmacológico , Inibidores de Fosfodiesterase/metabolismo , Inibidores de Fosfodiesterase/farmacologia , Inibidores de Fosfodiesterase/uso terapêutico , Diester Fosfórico Hidrolases/química , Relação Estrutura-Atividade , Inibidores da Topoisomerase I/metabolismo , Inibidores da Topoisomerase I/farmacologia , Inibidores da Topoisomerase I/uso terapêutico
15.
Eur J Med Chem ; 220: 113544, 2021 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-34052678

RESUMO

10-Hydroxyevodiamine is a multitargeting antitumor lead compound with excellent in vitro activity. However, its in vivo antitumor potency is rather limited, which has hampered its further clinical development. To overcome this obstacle, a series of novel water-soluble derivatives of 10-hydroxyevodiamine were designed and synthesized. Most of them exhibited good to excellent antitumor activities against several cancer cell lines. In particular, phosphate derivative 9 was orally active and showed improved in vivo antitumor efficacy in HCT116 xenograft models. Further antitumor mechanism studies indicated that compound 9 acted by triple Top1/Top2/tubulin inhibition and induced apoptosis with G2/M cell cycle arrest. Taken together, this study extended the structure-activity relationship of evodiamine and identified phosphate derivative 9 as a promising antitumor lead compound.


Assuntos
Antineoplásicos/farmacologia , Descoberta de Drogas , Fosfatos/farmacologia , Quinazolinas/farmacologia , Administração Oral , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , DNA Topoisomerases Tipo I/metabolismo , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Células HCT116 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Fosfatos/administração & dosagem , Fosfatos/química , Quinazolinas/administração & dosagem , Quinazolinas/química , Solubilidade , Relação Estrutura-Atividade , Água/química
16.
J Cell Biol ; 220(6)2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-33798260

RESUMO

An important quality control mechanism eliminates meiocytes that have experienced recombination failure during meiosis. The culling of defective oocytes in Caenorhabditis elegans meiosis resembles late oocyte elimination in female mammals. Here we show that topoisomerase 3 depletion generates DNA lesions in both germline mitotic and meiotic compartments that are less capable of triggering p53 (cep-1)-dependent apoptosis, despite the activation of DNA damage and apoptosis signaling. Elimination of nonhomologous, alternative end joining and single strand annealing repair factors (CKU-70, CKU-80, POLQ-1, and XPF-1) can alleviate the apoptosis block. Remarkably, the ability of single mutants in the other members of the Bloom helicase-topoisomerase-RMI1 complex to elicit apoptosis is not compromised, and depletion of Bloom helicase in topoisomerase 3 mutants restores an effective apoptotic response. Therefore, uncontrolled Bloom helicase activity seems to direct DNA repair toward normally not used repair pathways, and this counteracts efficient apoptosis. This implicates an as-yet undescribed requirement for topoisomerase 3 in mounting an effective apoptotic response to ensure germ cell quality control.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , DNA Topoisomerases Tipo I/metabolismo , Células Germinativas/citologia , Meiose , Controle de Qualidade , Animais , Apoptose , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/genética , Dano ao DNA , Reparo do DNA , DNA Topoisomerases Tipo I/genética , Células Germinativas/metabolismo , Oócitos/citologia , Oócitos/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
17.
Cell ; 184(10): 2618-2632.e17, 2021 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-33836156

RESUMO

The ongoing pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently affecting millions of lives worldwide. Large retrospective studies indicate that an elevated level of inflammatory cytokines and pro-inflammatory factors are associated with both increased disease severity and mortality. Here, using multidimensional epigenetic, transcriptional, in vitro, and in vivo analyses, we report that topoisomerase 1 (TOP1) inhibition suppresses lethal inflammation induced by SARS-CoV-2. Therapeutic treatment with two doses of topotecan (TPT), an FDA-approved TOP1 inhibitor, suppresses infection-induced inflammation in hamsters. TPT treatment as late as 4 days post-infection reduces morbidity and rescues mortality in a transgenic mouse model. These results support the potential of TOP1 inhibition as an effective host-directed therapy against severe SARS-CoV-2 infection. TPT and its derivatives are inexpensive clinical-grade inhibitors available in most countries. Clinical trials are needed to evaluate the efficacy of repurposing TOP1 inhibitors for severe coronavirus disease 2019 (COVID-19) in humans.


Assuntos
COVID-19/tratamento farmacológico , DNA Topoisomerases Tipo I/metabolismo , SARS-CoV-2/metabolismo , Inibidores da Topoisomerase I/farmacologia , Topotecan/farmacologia , Animais , COVID-19/enzimologia , COVID-19/patologia , Chlorocebus aethiops , Humanos , Inflamação/tratamento farmacológico , Inflamação/enzimologia , Inflamação/patologia , Inflamação/virologia , Mesocricetus , Camundongos , Camundongos Transgênicos , Células THP-1 , Células Vero
18.
Bioorg Med Chem Lett ; 41: 127998, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33794318

RESUMO

A facile one-pot synthesis of C-ring substituted angular luotonins has been realized via a methanesulfonic acid mediated aza-Nazarov-Friedlander condensation sequence on quinazolinonyl enones. Topoisomerase I (topo-I) inhibition studies revealed that the angular luotonin library (7a-7l) and their regioisomeric analogs (linear luotonins, 8a-8l) are weak negative modulators, compared to camptothecin. These results would fare well for the design of topo-I-inert luotonins for non-oncological applications such as anti-fungal and insecticide lead developments. Surprisingly, the tricyclic vasicinones (9h, 9i, and 9j) showed better topo-I inhibition compared to pentacyclic C-aryl luotonins providing a novel pharmacophore for further explorations.


Assuntos
Alcaloides/farmacologia , DNA Topoisomerases Tipo I/metabolismo , Desenho de Fármacos , Pirróis/farmacologia , Quinonas/farmacologia , Inibidores da Topoisomerase I/farmacologia , Alcaloides/síntese química , Alcaloides/química , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Pirróis/síntese química , Pirróis/química , Quinonas/síntese química , Quinonas/química , Relação Estrutura-Atividade , Inibidores da Topoisomerase I/síntese química , Inibidores da Topoisomerase I/química
19.
Int J Mol Sci ; 22(9)2021 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-33925940

RESUMO

Antimony is a toxic metalloid with poorly understood mechanisms of toxicity and uncertain carcinogenic properties. By using a combination of genetic, biochemical and DNA damage assays, we investigated the genotoxic potential of trivalent antimony in the model organism Saccharomyces cerevisiae. We found that low doses of Sb(III) generate various forms of DNA damage including replication and topoisomerase I-dependent DNA lesions as well as oxidative stress and replication-independent DNA breaks accompanied by activation of DNA damage checkpoints and formation of recombination repair centers. At higher concentrations of Sb(III), moderately increased oxidative DNA damage is also observed. Consistently, base excision, DNA damage tolerance and homologous recombination repair pathways contribute to Sb(III) tolerance. In addition, we provided evidence suggesting that Sb(III) causes telomere dysfunction. Finally, we showed that Sb(III) negatively effects repair of double-strand DNA breaks and distorts actin and microtubule cytoskeleton. In sum, our results indicate that Sb(III) exhibits a significant genotoxic activity in budding yeast.


Assuntos
Antimônio/toxicidade , Dano ao DNA/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , DNA/metabolismo , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Dano ao DNA/genética , Reparo do DNA/efeitos dos fármacos , DNA Topoisomerases Tipo I/metabolismo , Estresse Oxidativo/genética , Recombinação Genética/efeitos dos fármacos , Recombinação Genética/genética , Reparo de DNA por Recombinação/efeitos dos fármacos , Reparo de DNA por Recombinação/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomycetales/genética , Saccharomycetales/metabolismo , Telômero/metabolismo
20.
Int J Mol Sci ; 22(8)2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33923641

RESUMO

Natural products are widely used as source for drugs development. An interesting example is represented by natural drugs developed against human topoisomerase IB, a ubiquitous enzyme involved in many cellular processes where several topological problems occur due the formation of supercoiled DNA. Human topoisomerase IB, involved in the solution of such problems relaxing the DNA cleaving and religating a single DNA strand, represents an important target in anticancer therapy. Several natural compounds inhibiting or poisoning this enzyme are under investigation as possible new drugs. This review summarizes the natural products that target human topoisomerase IB that may be used as the lead compounds to develop new anticancer drugs. Moreover, the natural compounds and their derivatives that are in clinical trial are also commented on.


Assuntos
Antineoplásicos/farmacologia , Produtos Biológicos/farmacologia , Neoplasias/tratamento farmacológico , Inibidores da Topoisomerase I/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Produtos Biológicos/química , Produtos Biológicos/uso terapêutico , Ensaios Clínicos como Assunto , DNA Topoisomerases Tipo I/química , DNA Topoisomerases Tipo I/metabolismo , Humanos , Inibidores da Topoisomerase I/química , Inibidores da Topoisomerase I/uso terapêutico
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