RESUMO
Human immunodeficiency virus-1 (HIV-1) infection can cause chronic activation, exhaustion, and anergy of the immune system. Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) is an immune checkpoint molecule, which plays an important role in immune homeostasis and disease. CTLA-4 expression is elevated in HIV-1-infected patients and is associated with disease progression. However, the mechanism controlling expression of CTLA-4 in HIV-1 infection is poorly characterized. In this study, we used a SIV-infected Chinese rhesus macaque (ChRM) model to explore CTLA-4 expression in SIV infection. Results showed that SIV infection significantly increased CTLA-4 expression in all T cell subsets, especially central memory T cells. CTLA-4+CD4+ T cell frequency was significantly associated with disease progression markers. Activation of the cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) signaling pathway regulated CTLA-4 expression in CD4+T cells, as confirmed by stimulation with dibutyryl cyclic adenosine monophosphate, forskolin, and 3-isobutyl-1-methylxanthine, and inhibition with H-89 ex vivo. Simultaneously, cAMP concentration in PBMCs and PKA activity in both PBMCs and CD4+ T cells were increased in acute SIV-infected ChRMs, accompanied by an increase in adenylate cyclase 6 expression and a decrease in cAMP-phosphodiesterase 3A (PDE3A), PDE4B, and PDE5A expression in PBMCs. In addition, selective inhibition of PDE4B and PDE5A activity enhanced CTLA-4 expression in CD4+ T cells. These results suggest that SIV infection alters cAMP metabolism and increases cAMP-PKA signaling pathway activation, which up-regulates the expression of CTLA-4 in acute SIVmac239-infected ChRMs. Thus, regulation of the cAMP-PKA signaling pathway may be a potential strategy for the restoration of T cell function and therapy for AIDS.
Assuntos
Infecções por HIV , Síndrome de Imunodeficiência Adquirida dos Símios , Vírus da Imunodeficiência Símia , Animais , Humanos , Linfócitos T CD4-Positivos , Macaca mulatta , Vírus da Imunodeficiência Símia/fisiologia , Antígeno CTLA-4/genética , Regulação para Cima , Progressão da Doença , Transdução de Sinais , Monofosfato de AdenosinaRESUMO
A majority of cancers fail to respond to immunotherapy due to the immunosuppressive tumor microenvironment (TME), and metabolic regulation of the TME has been a promising strategy to improve immunotherapy. Lactate is a key metabolic player in tumor immune response since its excess secretion aggravates tumor immune escape by favoring the polarization of tumor-associated macrophages (TAMs) to an immunosuppressive phenotype meanwhile impeding the tumor infiltration of the cytotoxic T lymphocyte. Here, we proposed a metabolic reprogramming mechanism to ameliorate tumor immunosuppression by using lonidamine and syrosingopine incorporated liposomes (L@S/L) to regulate lactate production and efflux. Concretely, lonidamine reduced lactate production by affecting the glycolytic metabolic pathway while syrosingopine decreased lactate efflux by inhibiting the key protein expression of the lactate transporter MCT-4. Consequently, both the drugs synergistically normalize the pH of the TME to overcome the tumor immunosuppressive microenvironment. In vivo studies demonstrated that the decreased extracellular lactate preferentially polarized TAMs to the M1 phenotype, simultaneously increased the proportion of NK cells and reduced the number of Treg cells. These results validated an efficient tumor immunotherapy in the breast cancer model. This new strategy of lactic acid metabolism regulation is proposed to operate in concert with immune modulation in the TME, which shows great potential for immunotherapy of immunologically "cold" tumors.
Assuntos
Nanopartículas , Neoplasias , Humanos , Fatores Imunológicos , Imunoterapia/métodos , Ácido Láctico , Nanopartículas/uso terapêutico , Neoplasias/patologia , Microambiente TumoralRESUMO
ABSTRACT: The association between high-dose or low-dose sodium-glucose cotransporter 2 (SGLT2) inhibitors and various cardiovascular and respiratory serious adverse events (SAE) is unclear. Our meta-analysis aimed to define the association between high-dose or low-dose SGLT2 inhibitors and 86 kinds of cardiovascular SAE and 58 kinds of respiratory SAE. We included large cardiorenal outcome trials of SGLT2 inhibitors. Meta-analysis was conducted and stratified by the dose of SGLT2 inhibitors (high dose or low dose) to synthesize risk ratio (RR) and 95% confidence interval (CI). We included 9 trials. Compared with placebo, SGLT2 inhibitors used at high dose or low dose were associated with the decreased risks of 6 kinds of cardiovascular SAE [eg, bradycardia (RR, 0.60; 95% CI, 0.41-0.89), atrial fibrillation (RR, 0.79; 95% CI, 0.69-0.92), and hypertensive emergency (RR, 0.34; 95% CI, 0.15-0.78)] and 6 kinds of respiratory SAE [eg, asthma (RR, 0.59; 95% CI, 0.37-0.93), chronic obstructive pulmonary disease (RR 0.77, 95% CI 0.62-0.96), and sleep apnea syndrome (RR 0.37, 95% CI 0.17-0.81)]. SGLT2 inhibitors used at high dose or low dose did not show significant associations with 132 other cardiopulmonary SAE. For any outcome of interest, the subgroup difference according to the dose of SGLT2 inhibitors was not significant (Psubgroup > 0.05). SGLT2 inhibitors used at whether high dose or low dose are associated with the decreased risks of 12 cardiopulmonary disorders (eg, bradycardia, atrial fibrillation, hypertensive emergency, asthma, chronic obstructive pulmonary disease, and sleep apnea syndrome). These findings may suggest the potential efficacy of high- or low-dose SGLT2 inhibitors for the prevention and treatment of these cardiopulmonary disorders.
Assuntos
Asma , Fibrilação Atrial , Diabetes Mellitus Tipo 2 , Doença Pulmonar Obstrutiva Crônica , Síndromes da Apneia do Sono , Inibidores do Transportador 2 de Sódio-Glicose , Asma/induzido quimicamente , Asma/complicações , Asma/tratamento farmacológico , Fibrilação Atrial/tratamento farmacológico , Bradicardia/induzido quimicamente , Bradicardia/diagnóstico , Bradicardia/epidemiologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Humanos , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Síndromes da Apneia do Sono/induzido quimicamente , Síndromes da Apneia do Sono/complicações , Síndromes da Apneia do Sono/tratamento farmacológico , Inibidores do Transportador 2 de Sódio-Glicose/efeitos adversosRESUMO
Preschool-aged children are in a critical period of developing fundamental movement skills (FMS). FMS have a close link with physical activity (PA). This study aimed to systematically review the associations between FMS and PA in preschool-aged children. Searching Cochrane Library, Web of Science, PubMed, ScienceDirect, and EBSCO (including SPORTDiscus, ERIC, and Academic Search Premier) was utilized to conduct a systematic review of the available literature. Studies were included if they examined associations between FMS and PA among typically developing children aged 3-6 years, published between January 2000 and April 2020. A total of 26 studies met the inclusion criteria, including 24 cross-sectional studies and two cohort studies. There was a strong level of evidence to support low to moderate associations between moderate to vigorous physical activity and components of FMS, specifically, the total FMS (r = 0.11-0.48, R2 = 16%-19%) and object control skill (r = 0.16-0.46, ß = 0.28-0.49, R2 = 10.4%-16.9%). Similar associations were also found between the total physical activity and components of FMS, specifically, the total FMS (r = 0.10-0.45, R2 = 16%), locomotor skills (r = 0.14-0.46, R2 = 21.3%), and objective control skills (r = 0.16-0.44, ß = 0.47, R2 = 19.2%). There was strong evidence that there is no significant association between light physical activity and FMS, specifically, total FMS and locomotor skills. The associations, including "stability skills-PA" and "locomotor skills-moderate to vigorous PA", were uncertain due to insufficient evidence. Our findings provide strong evidence of associations between specific FMS components and a specific PA intensity. Future studies should consider using a longitudinal study design in order to explore the causal relationship between specific-intensity PA and the FMS subdomain.
Assuntos
Exercício Físico , Destreza Motora , Criança , Desenvolvimento Infantil , Pré-Escolar , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Estudos Longitudinais , MasculinoRESUMO
The anti-cancer activities of curcumin (CUR), a polyphenol derived from the plant Curcuma longa, has been extensively studied. In the present study, we found that CUR displayed anti-multidrug-resistant (MDR) activity in K562/A02 cells. A short-time treatment with CUR sufficiently and equally induced DNA damage, decreased cell viability, and triggered apoptosis in parent K562 and MDR K562/A02 cells. The short-time treatment with CUR also caused decrease of pro-caspase 3 in both cell lines and decrease of pro-caspase 9, increase of PARP cleavage and the ratio of Bax/Bcl-xL in MDR K562/A02 cells. Further experiment revealed that CUR was capable of down-regulating P-glycoprotein in MDR K562/A02 cells. Moreover, we observed that Cu(2+) enhanced CUR-mediated apoptosis which was blocked by antioxidants N-acetyl-cysteine and catalase. In summary, the short-time treatment with CUR sufficiently induced DNA damage, decreased cell viability and triggered apoptosis in MDR K562/A02 cells and Cu(2+) enhanced CUR-mediated apoptosis which due to reactive oxygen species generation.
Assuntos
Antineoplásicos/farmacologia , Apoptose , Sobrevivência Celular/efeitos dos fármacos , Sulfato de Cobre/farmacologia , Curcumina/farmacologia , Resistencia a Medicamentos Antineoplásicos , Linhagem Celular Tumoral , Ensaio Cometa , Dano ao DNA , Regulação para Baixo/efeitos dos fármacos , Sinergismo Farmacológico , Glicoproteínas/genética , Glicoproteínas/metabolismo , Humanos , Concentração Inibidora 50RESUMO
Curcumin (CUR), a polyphenol derived from the plant Curcuma longa, displays potential anti-cancer activity. One of the mechanisms stems from its ability to elicit cell cycle arrest followed by suppression of cell proliferation. Herein, we reported that CUR significantly induced DNA damage and mediated S and G2/M phase arrest in colorectal carcinoma HCT116 cells. Unlike etoposide, a classical topoisomerase II inhibitor, CUR-triggered G2/M phase arrest was hardly reversed by caffeine (CAFF) which is an inhibitor of activated ataxia-telangiectasia-mutated (ATM)/ATM- and Rad3-related (ATR), indicating that ATM and ATR signaling pathways may be not involved in CUR-mediated S and G2/M phase arrest in HCT116 cells. Furthermore, we demonstrated that CUR caused mitosis arrest in HCT116 cells by using mitotic protein monoclonal antibody-2 as a mitosis marker and the surface plasmon resonance assay. The findings provide new mechanisms of cell proliferation inhibition triggered by CUR in HCT116 cells.
Assuntos
Antineoplásicos/farmacologia , Cafeína/farmacologia , Curcumina/farmacologia , Dano ao DNA , Fase G2 , Inibidores de Fosfodiesterase/farmacologia , Fase S , Neoplasias Colorretais , Células HCT116 , Humanos , Mitose , Tubulina (Proteína)/metabolismoRESUMO
Naphthalimides, particularly amonafide and 2-(2-dimethylamino)-6-thia-2-aza-benzo[def]chrysene-1,3-diones (R16), have been identified to possess anticancer activities and to induce G(2)-M arrest through inhibiting topoisomerase II accompanied by Chk1 degradation. The current study was designed to precisely dissect the signaling pathway(s) responsible for the naphthalimide-induced cell cycle arrest in human colon carcinoma HCT116 cells. Using phosphorylated histone H3 and mitotic protein monoclonal 2 as mitosis markers, we first specified the G(2) arrest elicited by the R16 and amonafide. Then, R16 and amonafide were revealed to induce phosphorylation of the DNA damage sensor ataxia telangiectasia-mutated (ATM) responding to DNA double-strand breaks (DSBs). Inhibition of ATM by both the pharmacological inhibitor caffeine and the specific small interference RNA (siRNA) rescued the G(2) arrest elicited by R16, indicating its ATM-dependent characteristic. Furthermore, depletion of Chk2, but not Chk1 with their corresponding siRNA, statistically significantly reversed the R16- and amonafide-triggered G(2) arrest. Moreover, the naphthalimides phosphorylated Chk2 in an ATM-dependent manner but induced Chk1 degradation. These data indicate that R16 and amonafide preferentially used Chk2 as evidenced by the differential ATM-executed phosphorylation of Chk1 and Chk2. Thus, a clear signaling pathway can be established, in which ATM relays the DNA DSBs signaling triggered by the naphthalimides to the checkpoint kinases, predominantly to Chk2,which finally elicits G(2) arrest. The mechanistic elucidation not only favors the development of the naphthalimides as anticancer agents but also provides an alternative strategy of Chk2 inhibition to potentiate the anticancer activities of these agents.
Assuntos
Antineoplásicos/farmacologia , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ligação a DNA/metabolismo , Fase G2/efeitos dos fármacos , Naftalimidas/farmacologia , Proteínas Serina-Treonina Quinases/metabolismo , Tiofenos/farmacologia , Proteínas Supressoras de Tumor/metabolismo , Adenina , Proteínas Mutadas de Ataxia Telangiectasia , Western Blotting , Quinase do Ponto de Checagem 2 , Quebras de DNA de Cadeia Dupla , Citometria de Fluxo , Imunofluorescência , Células HCT116 , Humanos , Organofosfonatos , RNA Interferente Pequeno , Transdução de Sinais/fisiologia , TransfecçãoRESUMO
Resveratrol is a well-known natural antioxidant and cancer chemopreventive agent that has attracted much interest in the past decade. Resveratrol-directed compounds were synthesized, and their antioxidant effects against reactive oxygen species (ROS)-induced DNA damage, their prooxidant effects on DNA damage in the presence cupric ions, and their cytotoxic and apoptosis-inducing effects on human promyelocytic leukemia (HL-60) cells were investigated in vitro. It was found that the compounds bearing o-diphenoxyl groups exhibited remarkably higher activities in inhibiting ROS-induced DNA damage, accelerating DNA damage in the presence cupric ions, and inducing apoptosis of HL-60 cells compared with the ones bearing no such groups. The detail mechanism of the structure-activity relationship was also studied by the oxidative product analysis of resveratrol and its analogues with galvinoxyl radical or cupric ions and UV-visible spectra change in the presence cupric ions. This study reveals a good and interesting correlation between antioxidant and prooxidant activity, as well as cytotoxicity and apoptosis-inducing activity against HL-60 cells, and provides an idea for designing antioxidant-based cancer chemoprevention agents.
Assuntos
Anticarcinógenos/síntese química , Antioxidantes/síntese química , Estilbenos/síntese química , Animais , Anticarcinógenos/química , Anticarcinógenos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Apoptose , Cátions Bivalentes , Sobrevivência Celular/efeitos dos fármacos , Cobre/farmacologia , Dano ao DNA , Células HL-60 , Humanos , Peróxido de Hidrogênio/farmacologia , Técnicas In Vitro , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Oxidantes/síntese química , Oxidantes/química , Oxidantes/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Resveratrol , Estilbenos/química , Estilbenos/farmacologia , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacosRESUMO
Camptothecins (CPT) activate S or G(2)-M arrest and the homologous recombination (HR) repair pathway in tumor cells. In this process, both checkpoint kinases 1 and 2 (Chk1 and Chk2, respectively) are activated, but their differential roles, especially in the coordination of checkpoint and repair control, and potential clinic relevance remain to be fully elucidated. In this study, the repairable double-strand breaks were induced in human colon cancer HCT116 cells by 1-h exposure to 25 or 100 nmol/L CPT and its novel derivative chimmitecan. The cellular disposal of double-strand breaks was reflected as the progressive dispersal of gamma-H2AX foci, reduction of "comet" tails, dynamic activation of RAD51-mediated HR repair, and reversible G(2)-M arrest. In this model, the differential kinetics of Chk1 and Chk2 activation was characterized by the progressively increased phosphorylation of Chk2 until 72 h, the degradation of Chk1, and the disappearance of phosphorylated Chk1 48 h after drug removal. Using RNA interference, we further showed that Chk2 was essential to G(2)-M arrest, whereas Chk1 was mainly required for HR repair in CPT-treated HCT116 cells. Moreover, Chk2, rather than Chk1, predominated over the control of cell survival in this model. The differential roles of Chk1 and Chk2 in regulating HR repair and G(2)-M phase arrest were also confirmed in HT-29 colon cancer cells. Together, these findings systematically dissect the differential roles of Chk1 and Chk2 in a favorable model pursuing CPT-driven DNA damage responses, providing critical evidence to further explore checkpoint modulation, especially Chk2 inhibition as a therapeutic strategy in combination with CPT.
Assuntos
Camptotecina/farmacologia , Ciclo Celular/efeitos dos fármacos , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Recombinação Genética/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Camptotecina/análogos & derivados , Sobrevivência Celular/efeitos dos fármacos , Quinase 1 do Ponto de Checagem , Quinase do Ponto de Checagem 2 , Ativação Enzimática/efeitos dos fármacos , Fase G2/efeitos dos fármacos , Células HCT116 , Células HT29 , Humanos , Cinética , Mitose/efeitos dos fármacos , Rad51 Recombinase/metabolismoRESUMO
Glutathione (GSH), as the major small-molecule antioxidant in cells, has been implicated in the regulation of cell proliferation and apoptosis. Salvicine (SAL), a novel diterpenoid quinone compound, exhibits potent antitumor activities both in vitro and in vivo by poisoning topoisomerase II (Topo II) and has entered Phase II clinical trials for cancer therapy. Herein, we provide further evidence that SAL-induced DNA double-strand breaks (DSBs) and apoptosis by GSH depletion drives H2O2 generation and Topo II inhibition. Our data reveal that treatment with SAL results in a pronounced increase in intracellular H2O2 and is accompanied by the occurrence of DNA DSBs and apoptosis in epithelial HeLa cells. Furthermore, SAL was also noted to trigger a dramatic depletion of intracellular GSH via its direct reaction with GSH. Importantly, the introduction of GSH and overexpression of catalase antagonized SAL-mediated DNA DSBs and apoptosis, and the GSH synthesis inhibitor dl-buthionine-[S,R]-sulfoximine reduced SAL-mediated H2O2 generation, indicating that SAL-mediated H2O2 generation is derived from intracellular GSH depletion. Notably, SAL-mediated Topo II inhibition was also concentration-dependently reversed by GSH. Furthermore, we found that Topo II-defective HL-60/MX2 cells were almost completely resistant to SAL-induced DNA DSBs, suggesting that, in addition to its direct inhibitory effect on Topo II, SAL-mediated H2O2 generation may also trigger DNA DSBs via poisoning of Topo II. All these findings together suggest that GSH-depletion-driven H2O2 generation and Topo II inhibition are both critical for SAL-induced DNA DSBs and apoptosis.
Assuntos
Apoptose/efeitos dos fármacos , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Glutationa/metabolismo , Peróxido de Hidrogênio/metabolismo , Naftoquinonas/farmacologia , Inibidores da Topoisomerase II , Linhagem Celular Tumoral , DNA Topoisomerases Tipo II/metabolismo , HumanosRESUMO
Dihydroartemisinin (DHA), the main active metabolite of artemisinin derivatives, is one of the most effective anti-malarial analogs of artemisinin. In the current study, we found that DHA inhibited the proliferation of a panel of tumor cells originated from different tissue types. DHA effectively induced apoptosis in human promyelocytic leukemia HL-60 cells, which was accompanied with mitochondrial dysfunction and caspases activation. Further studies indicated that DHA-induced apoptosis was iron-dependent. Though DHA slightly elicited superoxide anion, these reactive oxygen species (ROS) contribute little to DHA-induced apoptosis in HL-60 cells. Moreover, DHA time-dependently activated mitogen-activeted protein kinases (MAPKs) and specific inhibition of p38 MAPK, but not c-Jun-NH2-terminal kinase (JNK) or extracellular signal-regulated kinase (ERK), abolished DHA-induced apoptosis, indicating that activation of p38 MAPK is required for DHA-induced apoptosis in HL-60 cells. Altogether, our data uncover that DHA induces apoptosis is dependent of iron and p38 MAPK activation but not ROS in HL-60 cells.
Assuntos
Apoptose , Artemisininas/farmacologia , Ferro/metabolismo , Espécies Reativas de Oxigênio , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Ativação Enzimática , Células HL-60 , Células HeLa , Humanos , Concentração Inibidora 50 , Células K562 , Potenciais da Membrana , Sais de Tetrazólio/farmacologia , Tiazóis/farmacologiaRESUMO
Pseudolaric acid B (PAB), discovered as a promising angiogensis inhibitor, was served as the anticancer drug lead, and a series of its derivatives were synthesized. Among them, some derivatives, such as 13c- 13k, exhibited potent inhibition on the HMEC-1 cell proliferation and strong cytotoxic activities against the tested six tumor cell lines. The PAB derivatives 13c- 13k also showed significant and specific inhibition on HMEC-1 cell migration in vitro, and only 13d expressed moderate activity against HMEC-1 cell tube formation. The in vitro anticancer tests of the selected natural PAB analogs and the structurally modified PAB derivatives have led to the establishment of a clear structure-activity relationship.
Assuntos
Inibidores da Angiogênese/química , Diterpenos/química , Inibidores da Angiogênese/farmacologia , Linhagem Celular , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Diterpenos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Células Endoteliais/efeitos dos fármacos , Humanos , Microcirculação/citologia , Relação Estrutura-AtividadeRESUMO
14-Ethyl-2,5,11-trimethyl-4,13,19,20-tetraoxa-tricyclo[14.2.1.1(7,10)]eicosane-3,12-dione (MFTZ-1), a new macrolide compound isolated from Streptomyces sp. Is9131, displayed wide cytotoxicity in human tumor cell lines with an average IC(50) of 0.905 micromol/L. Notably, MFTZ-1 showed significant cytotoxicity in the three multidrug resistance cell lines with an average resistance factor of 2.08. The in vivo experiments showed that MFTZ-1 had inhibitory effects on the human ovarian carcinoma HO-8910 cell line xenotransplanted in nude mice. Further studies showed that MFTZ-1 induced DNA double-strand breaks and triggered mitochondria-dependent apoptosis in human leukemia HL-60 cells. Using a yeast genetic system, we found that topoisomerase (Topo) II rather than Topo I was the primary cellular target of MFTZ-1. Most importantly, MFTZ-1 functions as a novel nonintercalative Topo II poison via binding to ATPase of Topo II, characterized by its strong inhibition on the decatenation and relaxation of Topo II. The capacity of MFTZ-1 to stabilize Topo II-DNA covalent complexes was comparable with that of the classic Topo II poison, etoposide. Moreover, using a Topo II catalytic inhibitor aclarubicin and Topo II-deficient HL-60/MX2 cells, we further showed that MFTZ-1-triggered DNA double-strand breaks and apoptosis occurred in a Topo II-dependent manner. Together, the well-defined Topo II-poisoning function and the potent antitumor activity, with the appreciable anti-multidrug resistance action in particular, promises MFTZ-1 as a novel potential Topo II-targeted agent, which merits further research and development.
Assuntos
Actinobacteria/química , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Eicosanoides/isolamento & purificação , Eicosanoides/farmacologia , Macrolídeos/isolamento & purificação , Macrolídeos/farmacologia , Inibidores da Topoisomerase II , Adenosina Trifosfatases/metabolismo , Animais , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , DNA/metabolismo , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , DNA Topoisomerases Tipo I/metabolismo , Eicosanoides/química , Feminino , Humanos , Substâncias Intercalantes/farmacologia , Macrolídeos/química , Camundongos , Mitocôndrias/efeitos dos fármacos , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/enzimologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Amonafide, a naphthalimide derivative, although selected for exploratory clinical trials for its potent anticancer activity, has long been challenged by its unpredictable side effects. In the present study, a novel amonafide analogue, 2-(2-dimethylamino)-6-thia-2-aza-benzo-[def]-chrysene-1,3-diones (R16) was synthesized by substituting 5'-NH(2) of the naphthyl with a heterocyclic group to amonafide, with additional introduction of a thiol group. In a panel of various human tumor cell lines, R16 was more cytotoxic than its parent compound amonafide. It was also effective against multidrug-resistant cells. Importantly, the i.p. administration of R16 inhibited tumor growth in mice implanted with S-180 sarcoma and H(22) hepatoma. The molecular and cellular machinery studies showed that the R16 functions as a topoisomerase II (topo II) poison via binding to the ATPase domain of human topo IIalpha. The superior cytotoxicity of R16 to amonafide was ascribed to its potent effects on trapping topo II-DNA cleavage complexes. Moreover, using a topo II catalytic inhibitor aclarubicin, ataxia-telangiectasia-mutated (ATM)/ATM- and Rad3-related (ATR) kinase inhibitor caffeine and topo II-deficient HL-60/MX2 cells, we further showed that R16-triggered DNA double-strand breaks, tumor cell cycle arrest, and apoptosis were in a topo II-dependent manner. Taken together, R16 stood out by its improved anticancer activity, appreciable anti-multidrug resistance activities, and well-defined topo II poisoning mechanisms, as comparable with the parent compound amonafide. All these collectively promise the potential value of R16 as an anticancer drug candidate, which deserves further development.
Assuntos
Apoptose/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Fase G2/efeitos dos fármacos , Imidas/farmacologia , Isoquinolinas/farmacologia , Naftalimidas/farmacologia , Tiofenos/farmacologia , Inibidores da Topoisomerase II , Adenina , Animais , Antineoplásicos/farmacologia , Caspases/metabolismo , Proliferação de Células/efeitos dos fármacos , Citocromos c/metabolismo , DNA Topoisomerases Tipo II/metabolismo , Inibidores Enzimáticos/farmacologia , Feminino , Citometria de Fluxo , Humanos , Imidas/química , Marcação In Situ das Extremidades Cortadas , Isoquinolinas/química , Neoplasias Hepáticas Experimentais/tratamento farmacológico , Neoplasias Hepáticas Experimentais/enzimologia , Neoplasias Hepáticas Experimentais/patologia , Camundongos , Camundongos Endogâmicos , Naftalimidas/química , Organofosfonatos , Poli(ADP-Ribose) Polimerases/metabolismo , Sarcoma Experimental/tratamento farmacológico , Sarcoma Experimental/enzimologia , Sarcoma Experimental/patologia , Células Tumorais Cultivadas/efeitos dos fármacosRESUMO
The prooxidant effect of resveratrol (3,5,4'-trihydroxy-trans-stibene) and its synthetic analogues (ArOH), that is, 3,4,4'-trihydroxy-trans-stibene (3,4,4'-THS), 3,4,5-trihydroxy-trans-stibene (3,4,5-THS), 3,4-dihydroxy-trans-stibene (3,4-DHS), 4,4'-dihydroxy-trans-stibene (4,4'-DHS), 2,4-dihydroxy-trans-stilbene (2,4-DHS), 3,5-dihydroxy-trans-stilbene (3,5-DHS) and 3,5,4'-trimethoxy-trans-stibene (3,5,4'-TMS), on supercoiled pBR322 plasmid DNA strand breakage and calf thymus DNA damage in the presence of Cu (II) ions has been studied. It was found that the compounds bearing ortho-dihydroxyl groups (3,4-DHS, 3,4,4'-THS, and 3,4,5-THS) or bearing 4-hydroxyl groups (2,4-DHS, 4,4'-DHS, and resveratrol) exhibit remarkably higher activity in the DNA damage than the ones bearing no such functionalities. Kinetic analysis by UV-visible spectra demonstrates that the formation of ArOH-Cu (II) complexes, the stabilization of oxidative intermediate derived from ArOH and Cu (II)/Cu (I) redox cycles, might be responsible for the DNA damage. This study also reveals a good correlation between antioxidant and prooxidant activity, as well as cytotoxicity against human leukemia (HL-60 and Jurkat) cell lines. The mechanisms and implications of these observations are discussed.
Assuntos
Cobre/farmacologia , Dano ao DNA/efeitos dos fármacos , Estilbenos/farmacologia , DNA/efeitos dos fármacos , Células HL-60 , Humanos , Células Jurkat , Modelos Biológicos , Plasmídeos/efeitos dos fármacos , Espécies Reativas de Oxigênio/farmacologia , Resveratrol , Espectrofotometria Ultravioleta , Estilbenos/agonistas , Estilbenos/química , Relação Estrutura-AtividadeRESUMO
Two ent-kaurene type diterpenoids, diterpenoids A (1) and B (2) were isolated from the Chinese herb Caryopteris terniflora and defined as ent-7beta, 11alpha,14-trihydroxy-18-aldehyde-11beta-20-epoxy-kaur-16-en15-one and ent-7beta,14-dihydroxy-11alpha-methoxy-18-aldehyde-11beta-20-epoxy-kaur-16-en-15-one respectively. Compounds 1 and 2 showed significant antibacterial and antitumour activity.
Assuntos
Antibacterianos/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Diterpenos/farmacologia , Verbenaceae/química , Bactérias/efeitos dos fármacos , Linhagem Celular Tumoral , Diterpenos/química , Humanos , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Espectrofotometria InfravermelhoRESUMO
Ginger is one of the most widely used spices and has been used in traditional oriental medicines for long time. Its extract and major pungent principles have been shown to exhibit a variety of biological activities. In order to find more active constituents and evaluate their structure-activity relationship (SAR) we isolated from the rhizomes of Chinese ginger (Zingiber officinale Roscoe) five new diarylheptanoids along with 20 known diarylheptanoids and gingerol-related compounds and studied their cytotoxic and apoptotic activities against human promyelocytic leukemia (HL-60) cells. It was found that compounds 1a, 2a, 5, 6a, 6b and 7 possess significant cytotoxicity against HL-60 cells (IC(50)<50 microM) and that the cytotoxic activity is associated with the cell apoptosis. SAR analysis demonstrates that the following structural determinants contribute critically to the enhancement of the activity: (i) acetoxyl groups at 3- and/or 5-positions of the side chain; (ii) the appropriate longer alkyl side-chain length; (iii) the ortho-diphenoxyl functionality on the aromatic ring; (iv) the alpha,beta-unsaturated ketone moiety in the side chain. These provide useful information for potential chemopreventive drug design.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Diarileptanoides/farmacologia , Álcoois Graxos/farmacologia , Rizoma/química , Zingiber officinale/química , Catecóis , Proliferação de Células/efeitos dos fármacos , Fragmentação do DNA/efeitos dos fármacos , Citometria de Fluxo , Células HL-60 , Humanos , Relação Estrutura-AtividadeRESUMO
Reactive oxygen species (ROS) are produced by all aerobic cells and have been implicated in the regulation of diverse cellular functions, including intracellular signaling, transcription activation, proliferation, and apoptosis. Salvicine, a novel diterpenoid quinone compound, demonstrates a broad spectrum of antitumor activities. Although salvicine is known to trap the DNA-topoisomerase II (Topo II) complex and induce DNA double-strand breaks (DSBs), its precise antitumor mechanisms remain to be clarified. In this study, we investigated whether salvicine altered the levels of ROS in breast cancer MCF-7 cells and whether these ROS contributed to the observed antitumoral activity. Our data revealed that salvicine stimulated intracellular ROS production and subsequently elicited notable DSBs. The addition of N-acetyl cysteine (NAC), an antioxidant, effectively attenuated the salvicine-induced ROS enhancement and subsequent DNA DSBs. Heat treatment reversed the accumulation of DNA DSBs, and the addition of NAC attenuated the Topo II-DNA cleavable complexes formation and the growth inhibition of salvicine-treated JN394top2-4 yeast cells, collectively indicating that Topo II is a target of the salvicine-induced ROS. On the other hand, when examining the impact of salvicine on DNA repair pathways, we unexpectedly observed that salvicine selectively down-regulated the catalytic subunit of DNA-dependent protein kinase (DNA-PK(CS)) protein levels and repressed DNA-PK kinase activity; both of these effects were attenuated by NAC pretreatment of MCF-7 cells. Finally and most importantly, NAC attenuated salvicine-induced apoptosis and cytotoxicity in MCF-7 cells. These results indicate that apart from its direct actions, salvicine generates ROS that modulate DNA damage and repair, contributing to the comprehensive biological consequences of salvicine treatment, such as DNA DSBs, apoptosis, and cytotoxicity in tumor cells. The finding of salvicine-induced ROS provides new evidence for the molecular mechanisms of this compound. Moreover, the effects of salvicine-induced ROS on Topo II and DNA-PK give new insights into the diverse biological activities of ROS.