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1.
J Dig Dis ; 25(1): 61-69, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38408848

RESUMO

OBJECTIVES: Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease that affects the quality of life (QoL) of patients. This study aimed to evaluate the differences in perceptions of PBC among physicians from different hospital departments and patients with PBC. METHODS: An online survey regarding the general knowledge, diagnosis, and management of PBC was completed by physicians and patients. RESULTS: A total of 239 patients with PBC and 239 physicians from eight hospital departments (gastroenterology, infectious diseases, rheumatology, hepatobiliary surgery, pathology, clinical laboratory, ultrasound, and radiology) completed the survey. The results showed that physicians from departments other than gastroenterologists and rheumatologists lacked knowledge of PBC, and that junior gastroenterologists were uncertain about the diagnostic and treatment pathways of PBC. Importantly, the lack of knowledge significantly impacted the QoL of patients, especially the emotional scores of PBC-40 (odds ratio -2.556, 95% confidence interval -3.852 to -1.260, P < 0.001). In addition, there was a perceived knowledge gap between patients and gastroenterologists. CONCLUSIONS: Physicians must improve their awareness of PBC. Patient education and patient-physician communication are important for improving the patient's QoL.


Assuntos
Doenças Autoimunes , Colangite , Gastroenterologistas , Cirrose Hepática Biliar , Humanos , Cirrose Hepática Biliar/diagnóstico , Qualidade de Vida , Inquéritos e Questionários
2.
Molecules ; 23(11)2018 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-30453532

RESUMO

A great deal of attention has been focused on the secondary metabolites produced by marine endophytic fungi, which can be better alternatives to chemicals, such as biopesticides, for control of polyphagous pests. On the basis of its novel biocontrol attributes, chemical investigation of a marine alga-derived endophytic fungus, Acremonium vitellinum, resulted in the isolation of three chloramphenicol derivatives (compounds 1⁻3). Their chemical structures were elucidated by detailed analysis of their nuclear magnetic resonance spectra, high-resolution electrospray ionization mass spectrometry, and by comparison with the data available in the literature. In this paper, compound 2 was firstly reported as the natural origin of these fungal secondary metabolites. The insecticidal activities of compounds 1⁻3 against the cotton bollworm, Helicoverpa armigera, were evaluated. The natural compound 2 presented considerable activity against H. armigera, with an LC50 value of 0.56 ± 0.03 mg/mL (compared to matrine with an LC50 value of 0.24 ± 0.01 mg/mL). Transcriptome sequencing was used to evaluate the molecular mechanism of the insecticidal activities. The results presented in this study should be useful for developing compound 2 as a novel, ecofriendly and safe biopesticide.


Assuntos
Acremonium/fisiologia , Cloranfenicol/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Inseticidas/farmacologia , Larva/crescimento & desenvolvimento , Lepidópteros/crescimento & desenvolvimento , Controle Biológico de Vetores , Animais , Cloranfenicol/química , Cloranfenicol/isolamento & purificação , Proteínas de Insetos/genética , Inseticidas/química , Inseticidas/isolamento & purificação , Larva/efeitos dos fármacos , Larva/genética , Lepidópteros/efeitos dos fármacos , Lepidópteros/genética
3.
Molecules ; 23(9)2018 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-30227613

RESUMO

Considerable attention has been paid to marine derived endophytic fungi, owing to their capacity to produce novel secondary metabolites with potent bioactivities. In this study, two new compounds with a prenylated diphenyl ether structure-diorcinol L (1) and (R)-diorcinol B (2)-were isolated from the marine algal-derived endophytic fungus Aspergillus tennesseensis, along with seven known compounds: (S)-diorcinol B (3), 9-acetyldiorcinol B (4), diorcinol C (5), diorcinol D (6), diorcinol E (7), diorcinol J (8), and a dihydrobenzofuran derivative 9. Their structures were elucidated by extensive NMR spectroscopy studies. Compound 2 represents the first example of an R-configuration in the prenylated moiety. All these isolated compounds were examined for antimicrobial and cytotoxic activities. Compounds 1⁻9 exhibited antimicrobial activities against some human- and plant-pathogenic microbes with MIC values ranging from 2 to 64 µg/mL. Moreover, compound 9 displayed considerable inhibitory activity against the THP-1 cell line in vitro, with an IC50 value of 7.0 µg/mL.


Assuntos
Organismos Aquáticos/microbiologia , Aspergillus/química , Endófitos/química , Éteres Fenílicos/isolamento & purificação , Prenilação , Bactérias/efeitos dos fármacos , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Linhagem Celular Tumoral , Humanos , Testes de Sensibilidade Microbiana , Éteres Fenílicos/química , Espectroscopia de Prótons por Ressonância Magnética
4.
Zhongguo Dang Dai Er Ke Za Zhi ; 19(1): 104-110, 2017 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-28100332

RESUMO

OBJECTIVE: To study the expression and significance of the mammalian target of rapamycin (mTOR)/eukaryote initiating factor 4E binding protein 1(4EBP1)/hypoxia inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) signaling pathway in asthmatic mice. METHODS: Forty SPF level 6-8 week-old female Balb/C mice were randomly divided into control, asthma, budesonide and mTOR inhibitor (rapamycin) intervention groups (n=10 each). The asthmatic mouse model was prepared via OVA induction and challenge test. The intervention groups were administered with rapamycin at the dosage of 3 mg/kg by an intraperitoneal injection or budesonide suspension at the dosage of l mg by aerosol inhalation respectively 30 minutes before the OVA challenge. The control and asthma groups were treated with normal saline instead. The concentrations of HIF-1α and VEGF in bronchoalveolar lavage fluid (BALF) were examined using ELISA 24 hours after the last challenge. The pathological changes of lung tissue were observed by hematoxylin-eosin (HE) staining. The p-mTOR and p-4EBP1 from the lung tissues were detected by immunohistochemistry and Western blot. Pearson analysis was used to study the correlation between p-mTOR, p-4EBP1, HIF-1α, and VEGF expression. RESULTS: Compared with the control group, inflammatory cell infiltration and secretions in the trachea increased in the asthma group. The levels of HIF-1α and VEGF in BALF and p-mTOR and p-4EBP1 expression in lung tissues also increased (P<0.01). Compared with the asthma group, inflammatory cell infiltration and secretions in the trachea were reduced in the two intervention groups, and the levels of HIF-1α and VEGF in BALF and p-mTOR and p-4EBP1 expression in lung tissues were also reduced (P<0.01). There were no significant differences in the above changes between the two intervention groups and control group (P>0.05). In the asthma group, there was a pairwise positive correlation between lung p-mTOR and p-4EBP1 expression and HIF-1α and VEGF levels in BALF (P<0.05). However, there were no correlations in the above indexes in the intervention groups and control group. CONCLUSIONS: p-mTOR, p-4EBP1, HIF-1α and VEGF together are involved in the pathogenesis of asthma. Rapamycin treatment can block this signaling pathway, suggesting that this pathway can be used as a novel target for asthma treatment.


Assuntos
Asma/metabolismo , Proteínas de Transporte/fisiologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Pulmão/química , Fosfoproteínas/fisiologia , Transdução de Sinais/fisiologia , Serina-Treonina Quinases TOR/fisiologia , Fator A de Crescimento do Endotélio Vascular/fisiologia , Proteínas Adaptadoras de Transdução de Sinal , Animais , Asma/tratamento farmacológico , Proteínas de Transporte/análise , Proteínas de Ciclo Celular , Fatores de Iniciação em Eucariotos , Feminino , Subunidade alfa do Fator 1 Induzível por Hipóxia/análise , Pulmão/patologia , Camundongos , Camundongos Endogâmicos BALB C , Fosfoproteínas/análise , Serina-Treonina Quinases TOR/análise , Fator A de Crescimento do Endotélio Vascular/análise
5.
Zhongguo Dang Dai Er Ke Za Zhi ; 15(12): 1116-8, 2013 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-24342211

RESUMO

OBJECTIVE: To study myeloid-derived suppressor cells (MDSC) levels in peripheral blood of infants with recurrent wheezing, and the role of MDSC in the development of recurrent wheezing. METHODS: Thirty-one infants with recurrent wheezing at wheezing attacks were randomly enrolled in the study. Twenty-seven infants with bronchopneumonia and 27 preoperative infants (hernia or renal calculus), without infectious or neoplastic diseases, were selected as controls. The proportion of MDSC in peripheral blood mononuclear cells (PBMC) was measured by flow cytometry. RESULTS: The proportion of MDSC in PBMC in infants with wheezing was significantly higher than in those with bronchopneumonia and preoperative infants (P<0.05). CONCLUSIONS: MDSC levels increase in infants with recurrent wheezing, suggesting that MDSC may play a crucial role in the development of this disorder.


Assuntos
Leucócitos Mononucleares/imunologia , Células Mieloides/imunologia , Sons Respiratórios/imunologia , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Recidiva
6.
Cell Biochem Biophys ; 67(2): 657-68, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23516093

RESUMO

Esophageal squamous cell carcinoma (ESCC) is the leading malignancy in Huaian, China. Recently, emerging studies have suggested that an aberrant microRNA (miRNA) expression signature exists in ESCC. However, there is discordant information available on specific miRNA expression in patients from different regions. In this study, we identified 12 miRNAs that are differentially expressed in patients with ESCC from Huaian, China. Among these miRNAs that displayed unique miRNA expression signatures, miR-1, miR-29c, miR-100, miR-133a, miR-133b, miR-143, miR-145, and miR-195 were downregulated, and miR-7, miR-21, miR-223, and miR-1246 were upregulated in cancerous tissue compared with the adjacent normal tissue. Bioinformatics analyses identified the major biological processes and signaling pathways that are targeted by these differentially expressed miRNAs. Accordingly, miR-29c, miR-100, miR-133a, and miR-133b were found to be involved in invasion and metastasis of ESCC, and miR-7 and miR-21 were found to be related to the differentiation of ESCC. Thus, our data present new evidence for the important roles of miRNAs in ESCC.


Assuntos
Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Diferenciação Celular/genética , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patologia , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Idoso , Linhagem Celular Tumoral , Movimento Celular/genética , China , Feminino , Ontologia Genética , Redes Reguladoras de Genes , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica
7.
J Med Case Rep ; 7: 30, 2013 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-23347569

RESUMO

INTRODUCTION: Malignant fibrous histiocytoma is a very common subtype of soft-tissue sarcoma in middle and late adulthood. However, malignant fibrous histiocytoma of the testis is very rare in adolescents. CASE PRESENTATION: We report here the case of a 14-year-old Han Chinese boy, who presented with left scrotal mass lasting for 20 days along with distending pain for 5 days. A physical examination revealed a chicken egg-sized, firm, well-defined mass and unclear epididymis. A B-scan ultrasonography of the left scrotum displayed a 9.0×5.2×4.5cm medium- or low-echoic lobulated mass, which suggested a left testicular neoplasm. A fine needle aspiration cytology examination revealed that the cells obtained from the patient's testicular neoplasm were composed of myxoid spindle, and ovoid cells with nuclear atypia and mitotic activity, and arranged in a whirlpool or storiform pattern. Under histological examination, the tumor cells were arranged in a storiform pattern, which displayed mucoid matrix degeneration, and grew invasively. Consequently, a histopathological diagnosis suggested myxofibrosarcoma (or myxoid malignant fibrous histiocytoma). CONCLUSIONS: An ultrasonic examination combined with fine needle aspiration cytology should be helpful for the initial differential diagnosis of testicular malignant fibrous histiocytoma. However, the final confirmation relies on histopathological examination. To the best of our knowledge, this is the first reported case of malignant fibrous histiocytoma of the testis in an adolescent.

8.
Yi Chuan ; 34(1): 113-9, 2012 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-22306880

RESUMO

SV40 PolyA (Simian virus 40 PolyA, also called PolyA) sequence is DNA sequence (240 bp) that possesses the activity of transcription termination and can add PolyA tail to mRNA. PolyA contains AATAAA hexanucleotide polyadenylation signal. Fourteen copies of Alu in sense orientation (Alu14) were inserted downstream of GFP in pEGFP-C1 to construct pAlu14 plasmid, and then HeLa cells were transiently transfected with pAlu14. Northern blot and fluorescence microscope were used to observe GFP RNA and protein expressions. Our results found that Alu tandem sequence inhibited remarkably GFP gene expression, but produced higher-molecular-mass GFP fusion RNA. PolyA and its sequence that was deleted AATAAA signal in sense or antisense orientation were inserted between GFP and Alu tandem sequence in pAlu14. The results showed that all the inserted PolyA sequences partly eliminated the inhibition induced by Alu14. PolyA sequences without AATAAA signal in sense or antisense orientation still induced transcription termination. Antisense PolyA (PolyAas) was divided into four fragments that all are 60 bp long and the middle two fragments were named 2F2R and 3F3R. 2F2R or 3F3R was inserted upstream of Alu tandem sequence in pAlu14. The molecular mass of GFP fusion RNA increased when the copy number of 2F2R increased. 2F2R can support transcription elongation when 2F2R is located upstream of other 2F2R. Nevertheless, 2F2R located upstream of Alu tandem sequence can induce transcription termination. Inserting one copy or 64 copies of 3F3R in upstream of Alu tandem sequence caused the production of lower-molecular-mass GFP RNA.


Assuntos
Expressão Gênica , Proteínas de Fluorescência Verde/genética , Poli A/metabolismo , Vírus 40 dos Símios/genética , Transcrição Gênica , Elementos Alu , Códon de Terminação , Proteínas de Fluorescência Verde/metabolismo , Células HeLa , Humanos , Poli A/genética , Vírus 40 dos Símios/metabolismo , Transfecção
9.
Acta Pharmacol Sin ; 31(12): 1604-10, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21127496

RESUMO

AIM: to study the molecular mechanisms underlying α-tocopheryl succinate (α-TOS)-induced apoptosis in erbB2-positive breast cancer cells and to determine whether α-TOS and the human recombinant TNF-related apoptosis-inducing ligand (hrTRAIL) act synergically to induce cell death of erbB2-expressing breast cancer cells. METHODS: the annexin V binding method was used to measure apoptosis induced by α-TOS and/or hrTRAIL. RT-PCR and Western blotting were performed to detect gene and protein expression. A colorimetric assay was performed to detect caspase activity. The TransAM(TM) NF-κB p65 kit was used to assess NF-κB activation. RESULTS: α-TOS (100 µmol/L) significantly inhibited NF-κB nuclear translocation in erbB2-expressing breast cancer cells; this inhibition is expected to result in the inactivation of NF-κB. α-TOS (50 and 100 µmol/L) inhibited the expression of Flice-like inhibitory protein (FLIP) and cellular inhibitor of apoptosis protein 1 (c-IAP1) in erbB2-positive cells. α-TOS (100 µmol/L) inhibited Akt activation and augmented the activity of caspase 3 and caspase 8 in breast cancer cells expressing erbB2. α-TOS (50 µmol/L) and hrTRAIL (30 mg/mL) acted synergically to induce apoptosis in breast cancer cells. α-TOS also decreased the hrTRAIL-induced transient activation of NF-κB . CONCLUSION: our results suggest that α-TOS mediates the apoptosis of erbB2-positive breast cancer cells and acts synergically with hrTRAIL via the NF-κB pathway.


Assuntos
Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , NF-kappa B/fisiologia , Receptor ErbB-2/metabolismo , alfa-Tocoferol/farmacologia , Neoplasias da Mama , Caspases/genética , Caspases/metabolismo , Linhagem Celular Tumoral , Feminino , Humanos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
10.
Toxicol Appl Pharmacol ; 237(3): 249-57, 2009 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-19480910

RESUMO

The vitamin E analogue alpha-tocopheryl succinate (alpha-TOS) is an efficient anti-cancer drug. Improved efficacy was achieved through the synthesis of alpha-tocopheryl maleamide (alpha-TAM), an esterase-resistant analogue of alpha-tocopheryl maleate. In vitro tests demonstrated significantly higher cytotoxicity of alpha-TAM towards cancer cells (MCF-7, B16F10) compared to alpha-TOS and other analogues prone to esterase-catalyzed hydrolysis. However, in vitro models demonstrated that alpha-TAM was cytotoxic to non-malignant cells (e.g. lymphocytes and bone marrow progenitors). Thus we developed lyophilized liposomal formulations of both alpha-TOS and alpha-TAM to solve the problem with cytotoxicity of free alpha-TAM (neurotoxicity and anaphylaxis), as well as the low solubility of both drugs. Remarkably, neither acute toxicity nor immunotoxicity implicated by in vitro tests was detected in vivo after application of liposomal alpha-TAM, which significantly reduced the growth of cancer cells in hollow fiber implants. Moreover, liposomal formulation of alpha-TAM and alpha-TOS each prevented the growth of tumours in transgenic FVB/N c-neu mice bearing spontaneous breast carcinomas. Liposomal formulation of alpha-TAM demonstrated anti-cancer activity at levels 10-fold lower than those of alpha-TOS. Thus, the liposomal formulation of alpha-TAM preserved its strong anti-cancer efficacy while eliminating the in vivo toxicity found of the free drug applied in DMSO. Liposome-based targeted delivery systems for analogues of vitamin E are of interest for further development of efficient and safe drug formulations for clinical trials.


Assuntos
Antineoplásicos/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Melanoma Experimental/tratamento farmacológico , alfa-Tocoferol/análogos & derivados , alfa-Tocoferol/administração & dosagem , Animais , Antineoplásicos/farmacologia , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Química Farmacêutica , Feminino , Humanos , Lipossomos , Maleimidas/administração & dosagem , Maleimidas/farmacologia , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/farmacologia , Vitamina E/administração & dosagem , Vitamina E/análogos & derivados , Vitamina E/farmacologia , alfa-Tocoferol/farmacologia
11.
Genet. mol. biol ; 32(4): 688-696, 2009. ilus, tab
Artigo em Inglês | LILACS | ID: lil-531810

RESUMO

The retrotransposon known as long interspersed nuclear element-1 (L1) is 6 kb long, although most L1s in mammalian and other eukaryotic cells are truncated. L1 contains two open reading frames, ORF1 and ORF2, that code for an RNA-binding protein and a protein with endonuclease and reverse transcriptase activities, respectively. In this work, we examined the effects of full length L1-ORF2 and ORF2 fragments on green fluorescent protein gene (GFP) expression when inserted into the pEGFP-C1 vector downstream of GFP. All of the ORF2 fragments in sense orientation inhibited GFP expression more than when in antisense orientation, which suggests that small ORF2 fragments contribute to the distinct inhibitory effects of this ORF on gene expression. These results provide the first evidence that different 280-bp fragments have distinct effects on the termination of gene transcription, and that when inserted in the antisense direction, fragment 280-9 (the 3' end fragment of ORF2) induces premature termination of transcription that is consistent with the effect of ORF2.

12.
Cancer Res ; 67(24): 11906-13, 2007 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-18089821

RESUMO

"Mitocans" from the vitamin E group of selective anticancer drugs, alpha-tocopheryl succinate (alpha-TOS) and its ether analogue alpha-TEA, triggered apoptosis in proliferating but not arrested endothelial cells. Angiogenic endothelial cells exposed to the vitamin E analogues, unlike their arrested counterparts, readily accumulated reactive oxygen species (ROS) by interfering with the mitochondrial redox chain and activating the intrinsic apoptotic pathway. The vitamin E analogues inhibited angiogenesis in vitro as assessed using the "wound-healing" and "tube-forming" models. Endothelial cells deficient in mitochondrial DNA (mtDNA) were resistant to the vitamin E analogues, both in ROS accumulation and apoptosis induction, maintaining their angiogenic potential. alpha-TOS inhibited angiogenesis in a mouse cancer model, as documented by ultrasound imaging. We conclude that vitamin E analogues selectively kill angiogenic endothelial cells, suppressing tumor growth, which has intriguing clinical implications.


Assuntos
Antineoplásicos/uso terapêutico , Mitocôndrias/fisiologia , Neovascularização Patológica/prevenção & controle , Estresse Oxidativo/fisiologia , Vitamina E/análogos & derivados , Vitamina E/uso terapêutico , Inibidores da Angiogênese/uso terapêutico , Apoptose/efeitos dos fármacos , DNA Mitocondrial/genética , Resistência a Medicamentos , Endotélio Vascular , Humanos , Mitocôndrias/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos
13.
FEBS Lett ; 581(24): 4611-5, 2007 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-17825301

RESUMO

Malignant mesothelioma (MM) cells enhanced proliferation of endothelial cells (ECs) as well as their angiogenesis in vitro by secretion of fibroblast growth factor-2 (FGF2). This effect was suppressed by pre-treating MM cells with alpha-tocopheryl succinate (alpha-TOS), which inhibited FGF2 secretion by inducing mitochondria-dependent generation of reactive oxygen species. The role of FGF2 was confirmed by its down-regulation by treating MM cells with siRNA, abolishing EC proliferation and wound healing enhancement afforded by MM cells. We conclude that alpha-TOS disrupts angiogenesis mediated by MM cells by inhibiting FGF2 paracrine signalling.


Assuntos
Fator 2 de Crescimento de Fibroblastos/metabolismo , Comunicação Parácrina/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Vitamina E/análogos & derivados , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Técnicas de Cocultura , Regulação para Baixo/efeitos dos fármacos , Humanos , Mesotelioma/irrigação sanguínea , Mesotelioma/metabolismo , Mesotelioma/patologia , Tocoferóis , Vitamina E/farmacologia
14.
Redox Rep ; 12(3): 148-62, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17623522

RESUMO

Ischemia-reperfusion (I/R) is a condition leading to serious complications due to death of cardiac myocytes. We used the cardiomyocyte-like cell line H9c2 to study the mechanism underlying cell damage. Exposure of the cells to simulated I/R lead to their apoptosis. Over-expression of Bcl-2 and Bcl-x(L) protected the cells from apoptosis while over-expression of Bax sensitized them to programmed cell death induction. Mitochondria-targeted coenzyme Q (mitoQ) and superoxide dismutase both inhibited accumulation of reactive oxygen species (ROS) and apoptosis induction. Notably, mtDNA-deficient cells responded to I/R by decreased ROS generation and apoptosis. Using both in situ and in vivo approaches, it was found that apoptosis occurred during reperfusion following ischemia, and recovery was enhanced when hearts from mice were supplemented with mitoQ. In conclusion, I/R results in apoptosis in cultured cardiac myocytes and heart tissue largely via generation of mitochondria-derived superoxide, with ensuing apoptosis during the reperfusion phase.


Assuntos
Apoptose/fisiologia , Mitocôndrias/metabolismo , Miócitos Cardíacos/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Traumatismo por Reperfusão/metabolismo , Transdução de Sinais/fisiologia , Animais , Caspase 3/metabolismo , Linhagem Celular , DNA Mitocondrial/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/ultraestrutura , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Superóxido Dismutase/metabolismo , Ubiquinona/metabolismo , Proteína X Associada a bcl-2/metabolismo , Proteína bcl-X/metabolismo
15.
Mol Aspects Med ; 28(5-6): 607-45, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17499351

RESUMO

Mitochondria have recently emerged as new and promising targets for cancer prevention and therapy. One of the reasons for this is that mitochondria are instrumental to many types of cell death and often lie downstream from the initial actions of anti-cancer drugs. Unlike the tumour suppressor gene encoding p53 that is notoriously prone to inactivating mutations but whose function is essential for induction of apoptosis by DNA-targeting agents (such as doxorubicin or 5-fluorouracil), mitochondria present targets that are not so compromised by genetic mutation and whose targeting overcomes problems with mutations of upstream targets such as p53. We have recently proposed a novel class of anti-cancer agents, mitocans that exert their anti-cancer activity by destabilising mitochondria, promoting the selective induction of apoptotic death in tumour cells. In this communication, we review recent findings on mitocans and propose a common basis for their mode of action in inducing apoptosis of cancer cells. We use as an example the analogues of vitamin E that are proving to be cancer cell-specific and may soon be developed into efficient anti-cancer drugs.


Assuntos
Antineoplásicos/farmacologia , Mitocôndrias/efeitos dos fármacos , Vitamina E/análogos & derivados , Animais , Apoptose/efeitos dos fármacos , Humanos , Transdução de Sinais/efeitos dos fármacos
16.
Cancer Res ; 67(7): 3337-44, 2007 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-17409443

RESUMO

Overexpression of erbB2 is associated with resistance to apoptosis. We explored whether high level of erbB2 expression by cancer cells allows their targeting using an erbB2-binding peptide (LTVSPWY) attached to the proapoptotic alpha-tocopheryl succinate (alpha-TOS). Treating erbB2-low or erbB2-high cells with alpha-TOS induced similar levels of apoptosis, whereas alpha-TOS-LTVSPWY induced greater levels of apoptosis in erbB2-high cells. alpha-TOS rapidly accumulated in erbB2-high cells exposed to alpha-TOS-LTVSPWY. The extent of apoptosis induced in erbB2-high cells by alpha-TOS-LTVSPWY was suppressed by erbB2 RNA interference as well as by inhibition of either endocytotic or lysosomal function. alpha-TOS-LTVSPWY reduced erbB2-high breast carcinomas in FVB/N c-neu transgenic mice. We conclude that a conjugate of a peptide targeting alpha-TOS to erbB2-overexpressing cancer cells induces rapid apoptosis and efficiently suppresses erbB2-positive breast tumors.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Oligopeptídeos/farmacocinética , Receptor ErbB-2/biossíntese , Vitamina E/análogos & derivados , Neoplasias da Mama/enzimologia , Linhagem Celular Tumoral , Humanos , Oligopeptídeos/administração & dosagem , Ligação Proteica , Receptor ErbB-2/metabolismo , Tocoferóis , Vitamina E/administração & dosagem , Vitamina E/farmacocinética
17.
J Bioenerg Biomembr ; 39(1): 65-72, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17294131

RESUMO

Recently mitochondria in cancer cells have emerged as the Achilles heel for tumour destruction. Anti-cancer agents specifically targeting cancer cell mitochondria are referred to as 'mitocans'. These compounds act by destabilising these organelles, unleashing their apoptogenic potential, resulting in the efficient death of malignant cells and suppression of tumour growth. Importantly, at least some mitocans are selective for cancer cells, and these are represented by the group of redox-silent vitamin E analogues, epitomised by alpha-tocopheryl succinate (alpha-TOS). This compound has proven itself in pre-clinical models to be an efficient anti-cancer agent, targeting complex II of the respiratory chain to displace ubiquinone binding. We propose that disrupting the electron flow of mitochondrial complex II results in generation of superoxide, triggering mitochondrial destabilisation and initiation of apoptotic pathways. Moreover, alpha-TOS is selective for cancer cells with their reduced anti-oxidant defenses and lower esterase activity than the normal (non-malignant) counterparts. In this mini-review we discuss the emerging significance of mitocans, as exemplified by alpha-TOS.


Assuntos
Antineoplásicos/farmacologia , Complexo II de Transporte de Elétrons/metabolismo , Mitocôndrias/fisiologia , Modelos Moleculares , Vitamina E/farmacologia , Animais , Antineoplásicos/uso terapêutico , Complexo II de Transporte de Elétrons/efeitos dos fármacos , Humanos , Mitocôndrias/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Espécies Reativas de Oxigênio/metabolismo , Superóxidos/metabolismo , Vitamina E/análogos & derivados , Vitamina E/uso terapêutico
18.
Mol Pharmacol ; 71(5): 1185-99, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17220355

RESUMO

The search for a selective and efficient anticancer agent for treating all neoplastic disease has yet to deliver a universally suitable compound(s). The majority of established anticancer drugs either are nonselective or lose their efficacy because of the constant mutational changes of malignant cells. Until recently, a largely neglected target for potential anticancer agents was the mitochondrion, showing a considerable promise for future clinical applications. Vitamin E (VE) analogs, epitomized by alpha-tocopheryl succinate, belong to the group of "mitocans" (mitochondrially targeted anticancer drugs). They are selective for malignant cells, cause destabilization of their mitochondria, and suppress cancer in preclinical models. This review focuses on our current understanding of VE analogs in the context of their proapoptotic/anticancer efficacy and suggests that their effect on mitochondria may be amplified by modulation of alternative pathways operating in parallel. We show here that the analogs of VE that cause apoptosis (which translates into their anticancer efficacy) generally do not possess antioxidant (redox) activity and are prototypical of the mitocan group of anticancer compounds. Therefore, by analogy to Oscar Wilde's play The Importance of Being Earnest, we use the motto in the title "the importance of being redox-silent" to emphasize an essentially novel paradigm for cancer therapy, in which redox-silence is a prerequisite property for most of the anticancer activities described in this communication.


Assuntos
Antineoplásicos/farmacologia , Mitocôndrias/efeitos dos fármacos , Vitamina E/análogos & derivados , Vitamina E/farmacologia , Animais , Apoptose/efeitos dos fármacos , Humanos , Oxirredução/efeitos dos fármacos , Relação Estrutura-Atividade , Vitamina E/química
19.
FEBS Lett ; 580(22): 5125-9, 2006 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-16979626

RESUMO

Mitochondria have emerged recently as effective targets for novel anti-cancer drugs referred to as 'mitocans'. We propose that the molecular mechanism of induction of apoptosis by mitocans, as exemplified by the drug alpha-tocopheryl succinate, involves generation of reactive oxygen species (ROS). ROS then mediate the formation of disufide bridges between cytosolic Bax monomers, resulting in the formation of mitochondrial outer membrane channels. ROS also cause oxidation of cardiolipin, triggering the release of cytochrome c and its translocation via the activated Bax channels. This model may provide a general mechanism for the action of inducers of apoptosis and anticancer drugs, mitocans, targeting mitochondria via ROS production.


Assuntos
Antineoplásicos/metabolismo , Apoptose/efeitos dos fármacos , Membranas Mitocondriais/metabolismo , Neoplasias/metabolismo , Vitamina E/análogos & derivados , Proteína X Associada a bcl-2/metabolismo , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Cardiolipinas/metabolismo , Citocromos c/metabolismo , Humanos , Mitocôndrias/metabolismo , Neoplasias/tratamento farmacológico , Oxirredução/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Espécies Reativas de Oxigênio , Tocoferóis , Vitamina E/metabolismo , Vitamina E/farmacologia , Vitamina E/uso terapêutico
20.
Mol Nutr Food Res ; 50(8): 675-85, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16835868

RESUMO

The new millennium has witnessed considerable decrease in a number of previously fatal pathologies, largely due to the advancement in molecular medicine and modern approaches to treatment. In spite of this success, neoplastic disease remains a serious problem due to several reasons. These include an exceedingly high variability of cancer cells even within the same type of tumour. Cancer cells, albeit of clonal origin, mutate so that they escape established treatments, resulting in the fatal outcome of current therapies. Moreover, there are types of cancer, such as mesotheliomas, that cannot be treated at present. A novel group of clinically interesting anticancer drugs has been a recent focus in the literature that hold substantial promise as selective anticancer drugs. These compounds, epitomised by alpha-tocopheryl succinate, comprise redox-silent analogues of vitamin E that have been shown to suppress several types of cancer in animal models, including breast, colon and lung cancer as well as mesotheliomas and melanomas, while being nontoxic to normal cells and tissues. It is now proven that the strong anticancer effect of vitamin E analogues stems from their propensity to induce selective apoptosis in malignant cells. The results point to the novel group of vitamin E analogues as promising agents applicable to different types of tumours.


Assuntos
Antineoplásicos , Vitamina E/análogos & derivados , Animais , Apoptose/efeitos dos fármacos , Homeostase/efeitos dos fármacos , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/fisiologia , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Neoplasias Experimentais/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade , Tocoferóis , Vitamina E/química , Vitamina E/uso terapêutico
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