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Sample records for bax em tumores

  1. Expressão das proteínas BCL-2 e BAX em tumores astrocíticos humanos Expression of BCL-2 and BAX proteins in human astrocytic tumors

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    Mário Henrique Girão Faria

    2006-08-01

    Full Text Available INTRODUÇÃO: Os astrocitomas constituem os mais freqüentes tumores primários do sistema nervoso central (SNC. Admite-se que parte do crescimento tumoral seja resultante da inibição da morte celular programada: a apoptose. Tal fenômeno é basicamente regulado pelo equilíbrio entre moléculas antiapoptóticas (ex.: B-cell lymphoma protein 2 [BCL-2] e pró-apoptóticas (ex.: BCL-2 associated protein X [BAX]. OBJETIVO: O presente estudo objetivou avaliar a expressão de BCL-2 e BAX em tumores astrocíticos humanos. MATERIAL E MÉTODOS: Procedeu-se ao estudo imuno-histoquímico dessas proteínas utilizando-se o método da avidina-biotina-peroxidase em 55 astrocitomas (13 do grau I, 14 do II, sete do III e 21 do grau IV e cinco amostras de tecido cerebral não-tumoral (grupo controle. RESULTADOS: Os índices de positividade para BCL-2 e BAX demonstraram propensão ao acréscimo, de acordo com a gradação tumoral, com positividade geral de 43,26% e 24,67%, respectivamente. Essas proteínas não foram detectadas entre os espécimes não-tumorais. Os escores de marcação para BCL-2 apresentaram tendência ao aumento conforme a progressão histológica, enquanto os para BAX mostraram-se semelhantes nas diversas graduações. A análise conjunta dessas proteínas demonstrou significativa correlação com a gradação tumoral (p BACKGROUND: Astrocytomas represent the most frequent primary tumors of the central nervous system. Admittedly, part of tumor growth is due to inhibition of programmed cell death: the apoptosis. This phenomenon is basically regulated by the balance between anti-apoptotic (e.g.: B-cell lymphoma protein 2 [BCL-2] and pro-apoptotic (e.g.: BCL-2 associated protein X [BAX] molecules. OBJECTIVE: The present study aimed to evaluate the expression of BCL-2 and BAX in human astrocytic tumors of different histopathological grades. MATERIAL AND METHOD: An immunohistochemical study of those proteins using the avidin

  2. Bax

    National Research Council Canada - National Science Library

    Cui, Qinghua; Valentin, Mayda; Janumyan, Yelena; Yang, Elizabeth

    2009-01-01

    .... We also discovered that the cell cycle function of Bcl-2 and Bcl-xL was dependent on Bax and Bak, and in bax -/- bak -/- double knockout cells, features of G0 quiesecence were already present and p27...

  3. Activation of the Proapoptotic Bcl-2 Protein Bax by a Small Molecule Induces Tumor Cell Apoptosis

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    Zhao, Guoping; Zhu, Yanglong; Eno, Colins O.; Liu, Yanlong; DeLeeuw, Lynn; Burlison, Joseph A.; Chaires, Jonathan B.; Trent, John O.

    2014-01-01

    The proapoptotic Bcl-2 protein Bax by itself is sufficient to initiate apoptosis in almost all apoptotic paradigms. Thus, compounds that can facilitate disruptive Bax insertion into mitochondrial membranes have potential as cancer therapeutics. In our study, we have identified small-molecule compounds predicted to associate with the Bax hydrophobic groove by a virtual-screen approach. Among these, one lead compound (compound 106) promotes Bax-dependent but not Bak-dependent apoptosis. Importantly, this compound alters Bax protein stability in vitro and promotes the insertion of Bax into mitochondria, leading to Bax-dependent permeabilization of the mitochondrial outer membrane. Furthermore, as a single agent, compound 106 inhibits the growth of transplanted tumors, probably by inducing apoptosis in tumors. Our study has revealed a compound that activates Bax and induces Bax-dependent apoptosis, which may lead to the development of new therapeutic agents for cancer. PMID:24421393

  4. Quercetin induces tumor-selective apoptosis through downregulation of Mcl-1 and activation of Bax.

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    Cheng, Senping; Gao, Ning; Zhang, Zhuo; Chen, Gang; Budhraja, Amit; Ke, Zunji; Son, Young-ok; Wang, Xin; Luo, Jia; Shi, Xianglin

    2010-12-01

    To investigate the in vivo antitumor efficacy of quercetin in U937 xenografts and the functional roles of Mcl-1 and Bax in quercetin-induced apoptosis in human leukemia. Leukemia cells were treated with quercetin, after which apoptosis, Mcl-1 expression, and Bax activation and translocation were evaluated. The efficacy of quercetin as well as Mcl-1 expression and Bax activation were investigated in xenografts of U937 cells. Administration of quercetin caused pronounced apoptosis in both transformed and primary leukemia cells but not in normal blood peripheral mononuclear cells. Quercetin-induced apoptosis was accompanied by Mcl-1 downregulation and Bax conformational change and mitochondrial translocation that triggered cytochrome c release. Knockdown of Bax by siRNA reversed quercetin-induced apoptosis and abrogated the activation of caspase and apoptosis. Ectopic expression of Mcl-1 attenuated quercetin-mediated Bax activation, translocation, and cell death. Conversely, interruption of Mcl-1 by siRNA enhanced Bax activation and translocation, as well as lethality induced by quercetin. However, the absence of Bax had no effect on quercetin-mediated Mcl-1 downregulation. Furthermore, in vivo administration of quercetin attenuated tumor growth in U937 xenografts. The TUNEL-positive apoptotic cells in tumor sections increased in quercetin-treated mice as compared with controls. Mcl-1 downregulation and Bax activation were also observed in xenografts. These data suggest that quercetin may be useful for the treatment of leukemia by preferentially inducing apoptosis in leukemia versus normal hematopoietic cells through a process involving Mcl-1 downregulation, which, in turn, potentiates Bax activation and mitochondrial translocation, culminating in apoptosis. ©2010 AACR.

  5. Is Bax/Bcl-2 ratio considered as a prognostic marker with age and tumor location in colorectal cancer?

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    Khodapasand, Ehsan; Jafarzadeh, Narges; Farrokhi, Farid; Kamalidehghan, Behnam; Houshmand, Massoud

    2015-01-01

    Bax and Bcl-2 are the major members of Bcl-2 family whose play a key role in tumor progression or inhibition of intrinsic apoptotic pathway triggered by mitochondrial dysfunction. Therefore, the balance between pro- and anti-apoptotic members of this family can determine the cellular fate. In this study, the relative level of mRNA expression of Bax and Bcl-2 genes was determined using RNA extraction, cDNA synthesis and RT-qPCR technique from 22 tumoral tissues and adjacent non-tumoral tissues from adenocarcinoma colorectal cancer. The potential prognostic and predictive significance of Bax and Bcl-2 gene expression and Bax/Bcl-2 ratio were demonstrated in colorectal cancer. The significant correlation between qPCR data and different clinicopathologic parameters of colorectal carcinoma, including age, gender, tumor size, tumor stage, tumor location, and tumor differentiation was also examined. Interestingly, no significant correlation was seen between Bax and Bcl-2 expressions and clinicopathological parameters of colorectal cancer. However, Bax/Bcl-2 ratio was statistically correlated with age and tumor location. Patients with age above 50 showed decreased levels of Bax/Bcl-2 ratio. Moreover, the Bax/Bcl-2 ratio was significantly lower in tumors resected from colon compared to sigmoid colon, rectosigmoid and rectum tumors. This study indicates a significant correlation between age and tumor location with Bax/Bcl-2 expression ratio, suggesting predictive value as a potential molecular marker of colorectal cancer.

  6. Quercetin induces tumor-selective apoptosis through down-regulation of Mcl-1 and activation of Bax

    Science.gov (United States)

    Cheng, Senping; Gao, Ning; Zhang, Zhuo; Chen, Gang; Budhraja, Amit; Ke, Zunji; Son, Young-ok; Wang, Xin; Luo, Jia; Shi, Xianglin

    2010-01-01

    Purpose To investigate the in vivo antitumor efficacy of querctin in U937 xenografts and the functional role of Mcl-1 and Bax in quercetin-induced apoptosis in human leukemia cells. Experimental Design Leukemia cells were treated with quercetin, after which apoptosis, Mcl-1 expression, and Bax activation and translocation were evaluated. The efficacy of quercein, as well as Mcl-1 expression and Bax activation were investigated in xenografts of leukemia cells. Results Administration of quercetin caused pronounced apoptosis in both transformed and primary leukemia cells, but not in normal blood peripheral mononuclear cells. Quercetin-induced apoptosis was accompanied by Mcl-1 down-regulation and Bax conformational change and mitochondrial translocation which triggered cytochrome c release. Knockdown of Bax by siRNA reversed querctin-induced apoptosis. Knockout of Bax abrogated the activation of caspase and apoptosis. Ectopic expression of Mcl-1 attenuated quercetin-mediated Bax activation, translocation and cell death. Conversely, interruption of Mcl-1 by siRNA enhanced Bax activation and translocation, as well as lethality induced by quercetin. However, the absence of Bax had no effect on quercetin-mediated Mcl-1 down-regulation. Furthermore, in vivo administration of quercetin attenuated tumor growth in U937 xenografts. The TUNEL positive apoptotic cells in tumor sections increased in quercetin-treated mice as compared with controls. Mcl-1 down-regulation and Bax activation were observed in xenografts. Conclusions These data suggest that quercetin may be useful for the treatment of leukemia by preferentially inducing apoptosis in leukemia versus normal hematopoietic cells, through a process involving Mcl-1 down-regulation, which in turn potentiates Bax activation and mitochondrial translocation, culminating in apoptosis. PMID:21138867

  7. Opposite role of Bax and BCL-2 in the anti-tumoral responses of the immune system

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    Bougras Gwenola

    2004-08-01

    Full Text Available Abstract Background The relative role of anti apoptotic (i.e. Bcl-2 or pro-apoptotic (e.g. Bax proteins in tumor progression is still not completely understood. Methods The rat glioma cell line A15A5 was stably transfected with human Bcl-2 and Bax transgenes and the viability of theses cell lines was analyzed in vitro and in vivo. Results In vitro, the transfected cell lines (huBax A15A5 and huBcl-2 A15A5 exhibited different sensitivities toward apoptotic stimuli. huBax A15A5 cells were more sensitive and huBcl-2 A15A5 cells more resistant to apoptosis than mock-transfected A15A5 cells (pCMV A15A5. However, in vivo, in syngenic rat BDIX, these cell lines behaved differently, as no tumor growth was observed with huBax A15A5 cells while huBcl-2 A15A5 cells formed large tumors. The immune system appeared to be involved in the rejection of huBax A15A5 cells since i huBax A15A5 cells were tumorogenic in nude mice, ii an accumulation of CD8+ T-lymphocytes was observed at the site of injection of huBax A15A5 cells and iii BDIX rats, which had received huBax A15A5 cells developed an immune protection against pCMV A15A5 and huBcl-2 A15A5 cells. Conclusions We show that the expression of Bax and Bcl-2 controls the sensitivity of the cancer cells toward the immune system. This sensitization is most likely to be due to an increase in immune induced cell death and/or the amplification of an anti tumour immune response

  8. Killing of Brain Tumor Cells by Hypoxia-Responsive Element Mediated Expression of BAX

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    Hangjun Ruan

    1999-11-01

    Full Text Available The presence of radioresistant hypoxic cells in human brain tumors limits the overall effectiveness of conventional fractionated radiation therapy. Tumor-specific therapies that target hypoxic cells are clearly needed. We have investigated the expression of suicide genes under hypoxia by a hypoxia-responsive element (HRE, which can be activated through hypoxia-inducible factor-1 (HIF-1. We transfected plasmids containing multiple copies of HIRE into U-87 MG and U-251 MG-NCI human brain tumor cells and tested their ability to induce LacZ gene expression under anoxia. Gene expression under anoxia versus oxia was increased about 12-fold for U-87 MG cells and about fourfold for U-251 MG-NCI cells. At intermediate hypoxic conditions, increased LacZ gene expression in U-87 MG cells was induced by the plasmid that contained three HREs, but not by the plasmid with two HREs. Lastly, when we placed a suicide gene BAX under the control of HREs, cells transfected with the BAX plasmids were preferentially killed through apoptosis under anoxia. Our studies demonstrate that HRE-regulated gene expression is active in brain tumor cells, and that the amount of increased gene expression obtained is dependent on the cell line, the HIRE copy number, and the degree of hypoxia.

  9. BAX and tumor suppressor TRP53 are important in regulating mutagenesis in spermatogenic cells in mice.

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    Xu, Guogang; Vogel, Kristine S; McMahan, C Alex; Herbert, Damon C; Walter, Christi A

    2010-12-01

    During the first wave of spermatogenesis, and in response to ionizing radiation, elevated mutant frequencies are reduced to a low level by unidentified mechanisms. Apoptosis is occurring in the same time frame that the mutant frequency declines. We examined the role of apoptosis in regulating mutant frequency during spermatogenesis. Apoptosis and mutant frequencies were determined in spermatogenic cells obtained from Bax-null or Trp53-null mice. The results showed that spermatogenic lineage apoptosis was markedly decreased in Bax-null mice and was accompanied by a significantly increased spontaneous mutant frequency in seminiferous tubule cells compared to that of wild-type mice. Apoptosis profiles in the seminiferous tubules for Trp53-null were similar to control mice. Spontaneous mutant frequencies in pachytene spermatocytes and in round spermatids from Trp53-null mice were not significantly different from those of wild-type mice. However, epididymal spermatozoa from Trp53-null mice displayed a greater spontaneous mutant frequency compared to that from wild-type mice. A greater proportion of spontaneous transversions and a greater proportion of insertions/deletions 15 days after ionizing radiation were observed in Trp53-null mice compared to wild-type mice. Base excision repair activity in mixed germ cell nuclear extracts prepared from Trp53-null mice was significantly lower than that for wild-type controls. These data indicate that BAX-mediated apoptosis plays a significant role in regulating spontaneous mutagenesis in seminiferous tubule cells obtained from neonatal mice, whereas tumor suppressor TRP53 plays a significant role in regulating spontaneous mutagenesis between postmeiotic round spermatid and epididymal spermatozoon stages of spermiogenesis.

  10. Immunohistochemical expression of p53, BCL-2, BAX and VEGFR1 proteins in nephroblastomas A expressão imuno-histoquímica das proteínas p53, BCL-2, BAX e VEGFR1 em nefroblastomas

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    Ana Paula Percicote

    2013-02-01

    Full Text Available INTRODUCTION: Nephroblastoma or Wilms' tumor is the most frequent renal cancer in children. Although its prognosis is favorable for most patients, it may relapse or have a fatal outcome. The characterization of risk groups by applying immunohistochemical biomarkers aims to adapt the treatment to its corresponding group as well as to reduce relapses and fatal outcome. p53, B-cell lymphoma 2 (BCL-2, BCL-2 associated protein X (BAX and vascular endothelial growth factor receptor 1 (VEGFR1 are among the most widely studied biomarkers, which are related to the apoptotic pathway, DNA repair and neovascularization. OBJECTIVE: The objective of this study is to assess the immunohistochemical expression of p53, BCL-2, BAX and VEGFR1 in samples of human nephroblastoma and to correlate them with clinicopathological prognostic factors. MATERIAL AND METHODS: Twenty-nine surgical specimens of nephroblastoma diagnosed from 1994 to 2007 were selected from the Anatomopathological Service of two hospitals in Curitiba. The immunohistochemical analysis of tissue microarrays was performed through immunoperoxidase staining and the yielded results were compared with clinicopathological prognostic factors. RESULTS: The major immunohistochemical expression of VEGFR1 in blastema and epithelium presented positive association with the risk group. Hence this may be related to higher vascular neoplastic invasion apparently caused by the endothelial growth factor, which maximizes the chances of metastasis and ultimately changes tumor staging, risk group and clinical evolution. CONCLUSIONS: The immunohistochemical expression of VEGFR1 substantiated a directly proportional association with the nephroblastoma risk group.INTRODUÇÃO: O nefroblastoma, ou tumor de Wilms, é a neoplasia renal mais frequente na infância. Embora o prognóstico seja favorável para a maioria dos pacientes, muitos evoluem para recidiva ou óbito. A caracterização de grupos de risco por meio de

  11. Effects of erythropoietin on the expression of tumor necrosis factor-alpha and Bax after facial nerve axotomy in rats

    Institute of Scientific and Technical Information of China (English)

    Wei Zhang; Shengyu Lü; Ziying Yu; Ming Bi; Bin Sun

    2011-01-01

    This study sought to evaluate the effect of high-dose erythropoietin (EPO; 5 000 IU/kg) on the expression of tumor necrosis factor-alpha (TNF-α) and Bax in the facial nucleus after facial nerve transection in rats. A total of 42 Wistar rats of both genders were used in this study, and 40 rats were randomly divided into 2 groups: EPO group and model group. The EPO group was treated with EPO once a day for 5 days at a dose of 5 000 IU/kg body weight. The model group was treated with saline of the same amount. At day 3 after EPO (or saline) treatment, the right facial nerves of the 40 rats were transected at the level of the stylomastoid foramen, with the left sides untreated. The remaining 2 rats that did not undergo axotomy served as the control group. The surviving motor neurons in operated rats were counted in coronal paraffin sections of the facial nucleus. The expression of TNF-α and Bax in the facial nucleus was detected by immunohistochemical staining at days 3, 7, 14, 21, and 28 after axotomy. At days 14, 21, and 28 after facial nerve axotomy, a significantly greater proportion of facial motor neurons survived in the EPO group than in the model group. After axotomy, the expression of TNF-α and Bax increased in motor neurons in both the EPO and the model groups. TNF-α expression reached its peak level at day 14 after axotomy, while Bax expression reached its peak level at day 21. TNF-α expression was much lower in the EPO group than in the model group at all time points. No significant difference in Bax expression was found between the EPO and the model groups. These results indicate that high-dose EPO treatment attenuates the increase in TNF-α expression in the facial nucleus and reduces the loss of motor neurons after facial nerve transection in rats. However, high-dose EPO treatment has little effect on Bax expression.

  12. Paclitaxel-induced apoptosis is BAK-dependent, but BAX and BIM-independent in breast tumor.

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    Anna V Miller

    Full Text Available Paclitaxel (Taxol-induced cell death requires the intrinsic cell death pathway, but the specific participants and the precise mechanisms are poorly understood. Previous studies indicate that a BH3-only protein BIM (BCL-2 Interacting Mediator of cell death plays a role in paclitaxel-induced apoptosis. We show here that BIM is dispensable in apoptosis with paclitaxel treatment using bim(-/- MEFs (mouse embryonic fibroblasts, the bim(-/- mouse breast tumor model, and shRNA-mediated down-regulation of BIM in human breast cancer cells. In contrast, both bak (-/- MEFs and human breast cancer cells in which BAK was down-regulated by shRNA were more resistant to paclitaxel. However, paclitaxel sensitivity was not affected in bax(-/- MEFs or in human breast cancer cells in which BAX was down-regulated, suggesting that paclitaxel-induced apoptosis is BAK-dependent, but BAX-independent. In human breast cancer cells, paclitaxel treatment resulted in MCL-1 degradation which was prevented by a proteasome inhibitor, MG132. A Cdk inhibitor, roscovitine, blocked paclitaxel-induced MCL-1 degradation and apoptosis, suggesting that Cdk activation at mitotic arrest could induce subsequent MCL-1 degradation in a proteasome-dependent manner. BAK was associated with MCL-1 in untreated cells and became activated in concert with loss of MCL-1 expression and its release from the complex. Our data suggest that BAK is the mediator of paclitaxel-induced apoptosis and could be an alternative target for overcoming paclitaxel resistance.

  13. Cytosolic Bax

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    Vogel, Sandra; Raulf, Nina; Bregenhorn, Stephanie; Biniossek, Martin L.; Maurer, Ulrich; Czabotar, Peter; Borner, Christoph

    2012-01-01

    Bax is kept inactive in the cytosol by refolding its C-terminal transmembrane domain into the hydrophobic binding pocket. Although energetic calculations predicted this conformation to be stable, numerous Bax binding proteins were reported and suggested to further stabilize inactive Bax. Unfortunately, most of them have not been validated in a physiological context on the endogenous level. Here we use gel filtration analysis of the cytosol of primary and established cells to show that endogenous, inactive Bax runs 20–30 kDa higher than recombinant Bax, suggesting Bax dimerization or the binding of a small protein. Dimerization was excluded by a lack of interaction of differentially tagged Bax proteins and by comparing the sizes of dimerized recombinant Bax with cytosolic Bax on blue native gels. Surprisingly, when analyzing cytosolic Bax complexes by high sensitivity mass spectrometry after anti-Bax immunoprecipitation or consecutive purification by gel filtration and blue native gel electrophoresis, we detected only one protein, called p23 hsp90 co-chaperone, which consistently and specifically co-purified with Bax. However, this protein could not be validated as a crucial inhibitory Bax binding partner as its over- or underexpression did not show any apoptosis defects. By contrast, cytosolic Bax exhibits a slight molecular mass shift on SDS-PAGE as compared with recombinant Bax, which suggests a posttranslational modification and/or a structural difference between the two proteins. We propose that in most healthy cells, cytosolic endogenous Bax is a monomeric protein that does not necessarily need a binding partner to keep its pro-apoptotic activity in check. PMID:22277657

  14. Tumores em bovinos encontrados em abatedouros frigoríficos

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    Bianca Tessele

    2016-03-01

    Full Text Available Resumo: Numa pesquisa em abatedouros a procura de lesões em bovinos, realizada de janeiro de 2011 a julho de 2014, 544 foram encontradas, das quais 65 eram neoplasmas. Quarenta e dois porcento desses tumores eram de origem mesenquimal; 37% eram epiteliais; 14,5% eram derivados da crista neural; 5% eram tumores do cordão sexual; e 1,5 eram tumores originários do sistema nervoso periférico. O tumor mais frequentemente encontrado foi o linfoma (28% de todos os tumores, a maioria dos casos como parte do complexo leucose bovina enzoótica. O carcinoma de células escamosas foi o segundo tumor mais frequente (15% de todos os tumores. É chamada a atenção para a frequência desses tumores e para a sua importância no diagnóstico diferencial no abatedouro frigorífico entre eles e outras lesões importantes, incluindo as lesões granulomatosas da tuberculose. Houve uma ocorrência significativa do feocromocitoma adrenal (13% de todos os tumores. Papilomatose representou apenas 3% de todos os tumores. Como papilomas são comuns em bovinos, seu baixo número nesse estudo pode ser explicado pelo fato de que eles não são usualmente diagnosticados no exame post mortem (quando o couro já foi retirado da carcaça, mas sim no exame ante mortem, como ocorreu na maioria dos casos deste estudo. Tumores encontrados com menor frequência (cada um perfazendo entre 1.5 e 3% de todos os tumores incluíram adenocarcinoma apócrino misto da cauda, adenocarcinoma mamário, adenocarcinoma uterino, carcinoma de células renais, fibroma interdigital, hemangiossarcoma, leiomioma uterino, lipoma, lipossarcoma, mesotelioma, neurofibroma, tumor de células da granulosa, tumor estromal gastrointestinal, tumores hepáticos, tumores melanocíticos, e tumores pulmonares primários. Pretende-se que os resultados dessa pesquisa possam ajudar na identificação das lesões na inspeção oficial em matadouros frigoríficos.

  15. Hypoxia-Mediated Down-Regulation of Bid and Bax in Tumors Occurs via Hypoxia-Inducible Factor 1-Dependent and -Independent Mechanisms and Contributes to Drug Resistance

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    Erler, Janine T.; Cawthorne, Christopher J.; Williams, Kaye J.; Koritzinsky, Marianne; Wouters, Bradley G.; Wilson, Clare; Miller, Crispin; Demonacos, Costas; Stratford, Ian J.; Dive, Caroline

    2004-01-01

    Solid tumors with disorganized, insufficient blood supply contain hypoxic cells that are resistant to radiotherapy and chemotherapy. Drug resistance, an obstacle to curative treatment of solid tumors, can occur via suppression of apoptosis, a process controlled by pro- and antiapoptotic members of the Bcl-2 protein family. Oxygen deprivation of human colon cancer cells in vitro provoked decreased mRNA and protein levels of proapoptotic Bid and Bad. Hypoxia-inducible factor 1 (HIF-1) was dispensable for the down-regulation of Bad but required for that of Bid, consistent with the binding of HIF-1α to a hypoxia-responsive element (positions −8484 to −8475) in the bid promoter. Oxygen deprivation resulted in proteosome-independent decreased expression of Bax in vitro, consistent with a reduction in global translation efficiency. The physiological relevance of Bid and Bax down-regulation was confirmed in tumors in vivo. Oxygen deprivation resulted in decreased drug-induced apoptosis and clonogenic resistance to agents with different mechanisms of action. The contribution of Bid and/or Bax down-regulation to drug responsiveness was demonstrated by the relative resistance of normoxic cells that had no or reduced expression of Bid and/or Bax and by the finding that forced expression of Bid in hypoxic cells resulted in increased sensitivity to the topoisomerase II inhibitor etoposide. PMID:15024076

  16. Tumor raro em mediastino: hamartoma

    OpenAIRE

    Roberto Saad Júnior; José Donato de Próspero; Roberto Gonçalves; Jorge Henrique Rivaben; Fabiano Alves Squeff

    2013-01-01

    In the present paper we report a case of mediastinal tumor which we believe has never been reported. Since surgical treatment, the patient presented good evolution. We discuss the presentation, differential diagnosis and therapy. Finally, we stress the importance of the pathologic findings.

  17. Pituitary tumor apoplexy Apoplexia em tumor hipofisário

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    Claudia V. Chang

    2009-06-01

    Full Text Available Pituitary tumor apoplexy is a medical emergency due to acute infarction or hemorrhage in the pituitary gland. In this review, the authors discuss the sellar anatomy, the pituitary gland and adenomas' vascularization and the general aspects of the syndrome such as its ethiopatogenesis, predisposing factors, clinical features, treatment and prognosis.A apoplexia em tumor hipofisário é uma emergência médica decorrente do infarto agudo ou hemorrágico na glândula hipófise. Nesta revisão os autores discutem a anatomia da região selar, a vascularização da hipófise e adenomas hipofisários, e demais aspectos da síndrome como etiopatogenia, fatores predisponentes, quadro clínico, tratamento e prognóstico.

  18. Both p53-PUMA/NOXA-Bax-mitochondrion and p53-p21cip1 pathways are involved in the CDglyTK-mediated tumor cell suppression

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    Yu, Zhendong, E-mail: zdyu@hotmail.com [Department of Clinical laboratory, Peking University Shenzhen Hospital, Guangdong (China); Wang, Hao [Department of pathology, The Chinese University of Hong Kong, Hong Kong (China); Zhang, Libin; Tang, Aifa; Zhai, Qinna; Wen, Jianxiang; Yao, Li [Department of Clinical laboratory, Peking University Shenzhen Hospital, Guangdong (China); Li, Pengfei, E-mail: lipengfei@cuhk.edu.hk [Department of pathology, The Chinese University of Hong Kong, Hong Kong (China)

    2009-09-04

    CDglyTK fusion suicide gene has been well characterized to effectively kill tumor cells. However, the exact mechanism and downstream target genes are not fully understood. In our study, we found that CDglyTK/prodrug treatment works more efficiently in p53 wild-type (HONE1) cells than in p53 mutant (CNE1) cells. We then used adenovirus-mediated gene delivery system to either knockdown or overexpress p53 and its target genes in these cells. Consistent results showed that both p53-PUMA/NOXA/Bcl2-Bax and p53-p21 pathways contribute to the CDglyTK induced tumor cell suppression. Our work for the first time addressed the role of p53 related genes in the CDglyTK/prodrug system.

  19. Inhibition of constitutively activated Stat3 correlates with altered Bcl-2/Bax expression and induction of apoptosis in mycosis fungoides tumor cells

    DEFF Research Database (Denmark)

    Nielsen, M; Kaestel, C G; Eriksen, K W

    1999-01-01

    promotor. The decreased ability of Stat3 to bind DNA precedes dynamic alterations in the expression of anti-apoptotic Bcl-2 and pro-apoptotic Bax proteins (decreased Bcl-2 expression and increased Bax expression) and induction of apoptosis. Thus, our data suggest that the involvement of Stat3 in oncogenic...

  20. BAX supports the mitochondrial network, promoting bioenergetics in nonapoptotic cells

    Science.gov (United States)

    Boohaker, Rebecca J.; Zhang, Ge; Carlson, Adina Loosley; Nemec, Kathleen N.

    2011-01-01

    The dual functionality of the tumor suppressor BAX is implied by the nonapoptotic functions of other members of the BCL-2 family. To explore this, mitochondrial metabolism was examined in BAX-deficient HCT-116 cells as well as primary hepatocytes from BAX-deficient mice. Although mitochondrial density and mitochondrial DNA content were the same in BAX-containing and BAX-deficient cells, MitoTracker staining patterns differed, suggesting the existence of BAX-dependent functional differences in mitochondrial physiology. Oxygen consumption and cellular ATP levels were reduced in BAX-deficient cells, while glycolysis was increased. These results suggested that cells lacking BAX have a deficiency in the ability to generate ATP through cellular respiration. This conclusion was supported by detection of reduced citrate synthase activity in BAX-deficient cells. In nonapoptotic cells, a portion of BAX associated with mitochondria and a sequestered, protease-resistant form was detected. Inhibition of BAX with small interfering RNAs reduced intracellular ATP content in BAX-containing cells. Expression of either full-length or COOH-terminal-truncated BAX in BAX-deficient cells rescued ATP synthesis and oxygen consumption and reduced glycolytic activity, suggesting that this metabolic function of BAX was not dependent upon its COOH-terminal helix. Expression of BCL-2 in BAX-containing cells resulted in a subsequent loss of ATP measured, implying that, even under nonapoptotic conditions, an antagonistic interaction exists between the two proteins. These findings infer that a basal amount of BAX is necessary to maintain energy production via aerobic respiration. PMID:21289292

  1. Prognostic value of Bcl-2 and Bax tumor cell expression in patients with non muscle-invasive bladder cancer receiving bacillus Calmette-Guerin immunotherapy.

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    Ajili, Faouzia; Kaabi, Belhassen; Darouiche, Amine; Tounsi, Haifa; Kourda, Nadia; Chebil, Mohamed; Manai, Mohamed; Boubaker, Samir

    2012-02-01

    Apoptosis is the distinctive form of programmed cell death that complements cell proliferation in maintaining normal tissue homeostasis. The significance of constitutive apoptosis in the recurrence of Non Muscle Invasive Bladder Cancer has yet to be investigated. The aim of this study is to investigate the prognostic significance of Bax and Bcl-2 in terms of recurrence after BCG immunotherapy. Immunohistochemical analysis was performed on frozen biopsies to evaluate bcl-2 and Bax proteins expression in 28 cases of NMIBC. All patients with confirmed NMIBC were treated with intravesical BCG-immunotherapy. The follow up was performed for 26 months. The correlation between clinicopathological, immunohistochemical data and the response to BCG therapy was performed. Univariate analysis showed that, PT1 stage, High grade and Bax expression increased significantly the risk of recurrence (P = 0.015, P = 0.015 and P= 0.034 respectively). In addition, multivariate analysis selected the model involving stage, age, Bax and Bcl-2 expression as the best independent variables of recurrence. In conclusion, the expression of Bcl-2 and Bax in NMIBC could have a prognostic value in assessing the risk of recurrence after BCG immunotherapy. These findings require further investigations on larger cohort in order to ascertain new molecular markers of the response to BCG immunotherapy.

  2. Pro-apoptotic Bax molecules densely populate the edges of membrane pores.

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    Kuwana, Tomomi; Olson, Norman H; Kiosses, William B; Peters, Bjoern; Newmeyer, Donald D

    2016-06-03

    How the pro-apoptotic Bax protein permeabilizes the mitochondrial outer membrane is not fully understood. Previously, using cryo-electron microscopy (cryo-EM), we showed that activated Bax forms large, growing pores. Whether formed in liposomes or in mitochondrial outer membranes, Bax-induced pores exhibit the same morphology, with negative curvature flanking the edges and with no visible protein structure protruding from the membranes. Here we used cryo-EM to show that gold-labeled Bax molecules, after activation by Bid, became localized strictly at pore edges. This argues that Bax acts at short range to deform the membrane. Also, Bax molecules populated the walls of both small and large pores at the same density, implying that Bax is continuously recruited to the pores as they widen. Moreover, because all Bax molecules became oligomerized after membrane insertion, we infer that Bax oligomers are present at pore edges. We suggest that oligomerization may promote pore enlargement.

  3. Hypoxia-mediated down-regulation of Bid and Bax in tumors occurs via hypoxia-inducible factor 1-dependent and -independent mechanisms and contributes to drug resistance

    DEFF Research Database (Denmark)

    Erler, Janine Terra; Cawthorne, Christopher J; Williams, Kaye J;

    2004-01-01

    of the Bcl-2 protein family. Oxygen deprivation of human colon cancer cells in vitro provoked decreased mRNA and protein levels of proapoptotic Bid and Bad. Hypoxia-inducible factor 1 (HIF-1) was dispensable for the down-regulation of Bad but required for that of Bid, consistent with the binding of HIF-1......alpha to a hypoxia-responsive element (positions -8484 to -8475) in the bid promoter. Oxygen deprivation resulted in proteosome-independent decreased expression of Bax in vitro, consistent with a reduction in global translation efficiency. The physiological relevance of Bid and Bax down...

  4. Bax activation by Bim?

    National Research Council Canada - National Science Library

    Czabotar, P E; Colman, P M; Huang, D C S

    2009-01-01

    .... Although some data support a role for certain BH3-only proteins, such as Bim or tBid, to directly activate Bax, others have led to the conclusion that BH3-only proteins act indirectly by antagonizing...

  5. Modelo de tumor experimental em rim de ratos Experimental tumor model in rats kidney

    Directory of Open Access Journals (Sweden)

    Lúcio Flávio Gonzaga Silva

    2002-02-01

    Full Text Available O carcinossarcoma 256 de Walker tem despertado o interesse de muitos pesquisadores como modelo experimental para estudo da biologia tumoral. OBJETIVO: estabelecer um modelo de tumor renal que possa ser usado para estudar in vivo e in vitro, as alterações impostas pelas neoplasias. MÉTODOS: utilizados vinte ratos Wistar, machos, adultos, pesando entre 250-300 g, oriundos do Laboratório de Cirurgia Experimental da Universidade Federal do Ceará. Sob anestesia inalatória procedia-se uma pequena incisão supraumbilical, e com manobra delicada fazia-se a exposição do rim direito. Neste órgão eram inoculadas 3x10(5 células tumorais viáveis. Os animais então eram mantidos em gaiolas individuais com as mesmas condições ambientais e com água e dieta ad libitum. RESULTADOS: o Carcinossarcoma 256 de Walker, implantado no parênquima do rim direito de ratos Wistar apresentou índice de pega de 100%, e crescimento rápido, invadiu por contiguidade as estruturas vizinhas, porém sem apresentar metástases, no entanto, levando os animais a óbito no curso médio de 14 dias. CONCLUSÃO: o modelo de implante de tumor de Walker no parênquima do rim direito de ratos Wistar é eficiente, tem reprodutibilidade, apresentando um índice de pega de 100%, e permitindo seu uso em linhas de pesquisa.Walker carcinossarcoma 256 has a great interest as experimental model for studies on tumoral biology. OBJECTIVE: develop a kidney tumor model to be used in the evaluation of the biological behavior of neoplasms in vitro and in vivo environments. METHODS: twenty adult male Wistar rats weighting between 250-300 g were obtained from the Federal University of the Ceará Experimental Surgery Laboratory. Upon ether anesthesia, the right kidney of each animal was accessed through a supraumbelical incision and inoculated with a solution containing 3 x 10(5 tumor cells (Walker 256 carcinossarcoma tumor cells. Following anesthetic recovery the rats were returned to their

  6. Tumores do mediastino em crianças Mediastinal tumors in children

    Directory of Open Access Journals (Sweden)

    José Carlos Fraga

    2003-10-01

    Full Text Available INTRODUÇÃO: Os tumores mediastinais na criança compreendem um grupo heterogêneo de lesões com origem embrionária distinta. Podem apresentar-se como cistos benignos ou lesões malignas. OBJETIVO: Descrever os procedimentos diagnósticos, tratamento e evolução de uma série de crianças e adolescentes com tumores do mediastino. MÉTODO: Análise retrospectiva de vinte crianças com tumores de mediastino, no período de julho de 1996 a julho de 2002 no Hospital de Clínicas de Porto Alegre. Todos os pacientes foram submetidos a algum procedimento cirúrgico, seja diagnóstico, terapêutico ou ambos. RESULTADOS: Doze meninos e oito meninas foram estudados. A idade média no momento do diagnóstico foi de seis anos e oito meses, variando entre três meses e 16 anos. Quatorze tumores (70% ocorreram no mediastino anterior, sendo os mais comuns os linfomas de Hodgkin e não-Hodgkin; seis tumores (30% ocorreram no mediastino posterior, sendo o neuroblastoma o mais freqüente. Nos tumores anteriores, a abordagem cirúrgica mais comum foi a toracotomia anterior de Chamberlain; nos posteriores, a toracotomia póstero-lateral. No período de seguimento ocorreram seis óbitos, todos sem nenhuma relação com o procedimento cirúrgico. CONCLUSÃO: Os tumores mediastinais em crianças são responsáveis por morbimortalidade. No mediastino anterior foram mais comuns os linfomas; no posterior, os tumores de origem neural. A cirurgia é um passo importante no diagnóstico e tratamento dessas lesõesBACKGROUND: Mediastinal tumors in children comprise a heterogeneous group of lesions that have a range of embryonic origins. They may present as benign cysts, as well as malignant lesions. OBJECTIVE: To describe the diagnostic procedures, the treatments and outcomes of a group of children and adolescents with mediastinal tumors. METHOD: A retrospective analysis of twenty children and adolescents with mediastinal tumors who were treated at the Hospital de Cl

  7. Estudo retrospectivo de 761 tumores cutâneos em cães

    Directory of Open Access Journals (Sweden)

    Souza Tatiana Mello de

    2006-01-01

    Full Text Available Os arquivos de biópsias de cães realizadas no Laboratório de Patologia Veterinária da Universidade Federal de Santa Maria entre 1964 e 2003 foram revisados à procura de tumores cutâneos. Dos 703 registros encontrados, em 570 (81,0% estava descrito que o cão apresentava apenas um tumor na pele e, em 133 (19,0%, que o cão apresentava mais de um tumor. Seiscentos e cinqüenta e quatro (93,1% cães apresentavam apenas um tipo histológico de tumor e 41 (5,8% apresentavam dois tumores histologicamente distintos. Em sete (1,0% cães, havia três tumores diferentes e em um (0,1% cão foram diagnosticados quatro tumores não relacionados, finalizando um total de 761 tumores. Dos 761 tumores cutâneos encontrados, 673 (88,4% eram neoplásicos e 88 (11,6% eram não-neoplásicos. Os 15 tumores mais prevalentes em ordem decrescente de freqüência foram: mastocitoma, carcinoma de células escamosas, adenoma perianal, lipoma, tricoblastoma, carcinoma perianal, papiloma, cistos foliculares, hemangioma, hemangiossarcoma, melanoma, adenoma sebáceo, histiocitoma, hiperplasia sebácea nodular e fibroma.

  8. Imunolocalização da podoplanina em tumores odontogênicos benignos

    OpenAIRE

    Adriana dos Santos Caetano

    2011-01-01

    A podoplanina humana é uma glicoproteína que se expressa em várias células e tecidos normais e neoplásicos, inclusive aqueles de origem odontogênica. O objetivo deste estudo foi identificar a imunolocalização da podoplanina em tumores odontogênicos epiteliais com e sem ectomesênquima incluindo oito ameloblastomas, nove tumores odontogênicos adenomatóides, vinte tumores odontogênicos queratocísticos, cinco cistos odontogênicos ortoqueratinizados, um tumor odontogênico epitelial calcificante,...

  9. Allostery in BAX protein activation.

    Science.gov (United States)

    Jiang, Zhenyan; Zhang, Hansi; Böckmann, Rainer A

    2016-11-01

    BAX is a member of the proapoptotic BCL-2 family of proteins, which is involved in the regulation of the intrinsic pathway of apoptosis. In the process of apoptosis, BH3-only molecules activate cytosolic BAX. Activated BAX molecules insert into the mitochondrial outer membrane with their [Formula: see text]-helix and form oligomers that lead to membrane poration, resulting in the release of apoptogenic factors including cytochrome c. Recently, a novel interaction site for the binding of the BIM SAHB ligand to BAX was reported. BIM SAHB binding was shown to invoke the exposure of the 6A7 epitope (amino acids 13-19) and of the BH3 domain of BAX, followed by mobilization of the BAX [Formula: see text]-helix. However, the intramolecular pathway for signal transmission in BAX, from BIM SAHB binding to mobilization of the [Formula: see text]-helix largely remained elusive. For a molecular understanding of the activation of BAX, and thus the first steps in apoptosis, we performed microsecond atomistic molecular dynamics simulations both of the BAX protein and of the BAX:BIM SAHB complex in aqueous solution. In agreement with experiment, the 6A7 and BH3 domains adopt a more solvent-exposed conformation within the BAX:BIM SAHB complex. BIM SAHB binding was found to stabilize the secondary structure of the [Formula: see text]9-helix. A force distribution analysis revealed a force network of residue-residue interactions responsible for signal transmission from the BIM SAHB binding site predominantly via the [Formula: see text]4- and [Formula: see text]6-helices to the [Formula: see text]9-helix on the opposite site of the protein.

  10. Allosteric sensitization of proapoptotic BAX.

    Science.gov (United States)

    Pritz, Jonathan R; Wachter, Franziska; Lee, Susan; Luccarelli, James; Wales, Thomas E; Cohen, Daniel T; Coote, Paul; Heffron, Gregory J; Engen, John R; Massefski, Walter; Walensky, Loren D

    2017-09-01

    BCL-2-associated X protein (BAX) is a critical apoptotic regulator that can be transformed from a cytosolic monomer into a lethal mitochondrial oligomer, yet drug strategies to modulate it are underdeveloped due to longstanding difficulties in conducting screens on this aggregation-prone protein. Here, we overcame prior challenges and performed an NMR-based fragment screen of full-length human BAX. We identified a compound that sensitizes BAX activation by binding to a pocket formed by the junction of the α3-α4 and α5-α6 hairpins. Biochemical and structural analyses revealed that the molecule sensitizes BAX by allosterically mobilizing the α1-α2 loop and BAX BH3 helix, two motifs implicated in the activation and oligomerization of BAX, respectively. By engaging a region of core hydrophobic interactions that otherwise preserve the BAX inactive state, the identified compound reveals fundamental mechanisms for conformational regulation of BAX and provides a new opportunity to reduce the apoptotic threshold for potential therapeutic benefit.

  11. Bax-deficiency prolongs cerebellar neurogenesis, accelerates medulloblastoma formation and paradoxically increases both malignancy and differentiation

    Science.gov (United States)

    Garcia, Idoia; Crowther, Andrew J.; Gama, Vivian; Miller, C. Ryan; Deshmukh, Mohanish; Gershon, Timothy R.

    2012-01-01

    Neurogenesis requires negative regulation through differentiation of progenitors or their programmed cell death (PCD). Growth regulation is particularly important in the postnatal cerebellum, where excessive progenitor proliferation promotes medulloblastoma, the most common malignant brain tumor in children. We present evidence that PCD operates alongside differentiation to regulate cerebellar granule neuron progenitors (CGNPs) and to prevent medulloblastoma. Here we show that genetic deletion of pro-apoptotic Bax disrupts regulation of cerebellar neurogenesis and promotes medulloblastoma formation. In Bax−/− mice, the period of neurogenesis was extended into the third week of postnatal life, and ectopic neurons and progenitors collected in the molecular layer of the cerebellum and adjacent tectum. Importantly, genetic deletion of Bax in medulloblastoma-prone ND2:SmoA1 transgenic mice greatly accelerated tumorigenesis. Bax-deficient medulloblastomas exhibited strikingly distinct pathology, with reduced apoptosis, increased neural differentiation and tectal migration. Comparing Bax+/+ and Bax−/− medulloblastomas, we were able to identify up-regulation of Bcl-2 and nuclear exclusion of p27 as tumorigenic changes that are required to mitigate the tumor suppressive effect of Bax. Studies on human tumors confirmed the importance of modulating Bax in medulloblastoma pathogenesis. Our results demonstrate that Bax-dependent apoptosis regulates postnatal cerebellar neurogenesis, suppresses medulloblastoma formation, and imposes selective pressure on tumors that form. Functional resistance to Bax-mediated apoptosis, required for medulloblastoma tumorigenesis, may be a tumor-specific vulnerability to be exploited for therapeutic benefit. PMID:22710714

  12. Estudo retrospectivo de 1.647 tumores mamários em cães

    Directory of Open Access Journals (Sweden)

    José C. Oliveira Filho

    2010-02-01

    Full Text Available Tumores mamários são comuns em cães, e constituem o neoplasma mais frequente em cadelas. Este estudo tem como objetivos principais estabelecer a prevalência dos tumores mamários, e dos diferentes tipos histológicos (neoplásicos e não-neoplásicos, diagnosticados em cães no Laboratório de Patologia Veterinária da Universidade Federal de Santa Maria (LPV-UFSM. Foram avaliados 1.304 protocolos de exames histopatológicos recebidos em 1990-2008 e 132 protocolos de necropsias realizadas em 2000-2008. Deles foram obtidos a raça, o sexo e a idade dos cães, a localização do tumor na cadeia mamária, o diagnóstico morfológico e a ocorrência de metástases. Nos protocolos de exame histopatológico, foram diagnosticados 1.495 tumores, considerando que alguns cães tinham mais de um tipo de tumor, sendo 1.465 neoplásicos e 30 não-neoplásicos. Dos neoplásicos, 390 (26,6% eram benignos e 1.075 (73,3% eram malignos, estabelecendo-se uma relação benigno: maligno de 1:2,75. Das 1.125 necropsias de cães realizadas em 2000-2008, 132 (11,6% protocolos tinham descrições de tumor de mama, perfazendo 152 diagnósticos morfológicos, dos quais 150 eram neoplásicos e dois eram não-neoplásicos. Carcinoma simples foi o tipo histológico mais prevalente tanto em biópsias como em necropsias. Nas necropsias, foram observadas metástases para linfonodos em 39 casos (29,5% e para órgãos distantes em 64 casos (53,3%.Mammary gland tumors are common in dogs and are the most common type of neoplasm of female dogs. The main purposes of this study were to establish the prevalence of the mammary gland tumors, as well as of its different histologic types (neoplastic and non-neoplastic, diagnosed in the Laboratório de Patologia Veterinária of the Universidade Federal de Santa Maria. There were 1,304 biopsy reports of mammary gland tumors during 1990-2008 and 132 necropsy reports of dogs with mammary tumors in 2000-2008. Data about breed, gender, and

  13. <em>Hedyotis diffusaem> Willd Inhibits Colorectal Cancer Growth <em>in Vivoem> via Inhibition of STAT3 Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Jun Peng

    2012-05-01

    Full Text Available Signal Transducer and Activator of Transcription 3 (STAT3, a common oncogenic mediator, is constitutively activated in many types of human cancers; therefore it is a major focus in the development of novel anti-cancer agents. <em>Hedyotis diffusaem> Willd has been used as a major component in several Chinese medicine formulas for the clinical treatment of colorectal cancer (CRC. However, the precise mechanism of its anti-tumor activity remains largely unclear. Using a CRC mouse xenograft model, in the present study we evaluated the effect of the ethanol extract of<em> Hedyotis diffusaem> Willd (EEHDW on tumor growth <em>in vivoem> and investigated the underlying molecular mechanisms. We found that EEHDW reduced tumor volume and tumor weight, but had no effect on body weight gain in CRC mice, demonstrating that EEHDW can inhibit CRC growth <em>in vivoem> without apparent adverse effect. In addition, EEHDW treatment suppressed STAT3 phosphorylation in tumor tissues, which in turn resulted in the promotion of cancer cell apoptosis and inhibition of proliferation. Moreover, EEHDW treatment altered the expression pattern of several important target genes of the STAT3 signaling pathway, <em>i.e.>, decreased expression of Cyclin D1, CDK4 and Bcl-2 as well as up-regulated p21 and Bax. These results suggest that suppression of the STAT3 pathway might be one of the mechanisms by which EEHDW treats colorectal cancer.

  14. S-palmitoylation represents a novel mechanism regulating the mitochondrial targeting of BAX and initiation of apoptosis

    Science.gov (United States)

    Fröhlich, M; Dejanovic, B; Kashkar, H; Schwarz, G; Nussberger, S

    2014-01-01

    The intrinsic pathway of apoptotic cell death is mainly mediated by the BCL-2-associated X (BAX) protein through permeabilization of the mitochondrial outer membrane (MOM) and the concomitant release of cytochrome c into the cytosol. In healthy, non-apoptotic cells, BAX is predominantly localized in the cytosol and exhibits a dynamic shuttle cycle between the cytosol and the mitochondria. Thus, the initial association with mitochondria represents a critical regulatory step enabling BAX to insert into MOMs, promoting the release of cytochrome c and ultimately resulting in apoptosis. However, the molecular mode of how BAX associates with MOMs and whether a cellular regulatory mechanism governs this process is poorly understood. Here we show that in both primary tissues and cultured cells, the association with MOMs and the proapoptotic action of BAX is controlled by its S-palmitoylation at Cys-126. A lack of BAX palmitoylation reduced BAX mitochondrial translocation, BAX oligomerization, caspase activity and apoptosis. Furthermore, ectopic expression of specific palmitoyl transferases in cultured healthy cells increases BAX S-palmitoylation and accelerates apoptosis, whereas malignant tumor cells show reduced BAX S-palmitoylation consistent with their reduced BAX-mediated proapoptotic activity. Our findings suggest that S-palmitoylation of BAX at Cys126 is a key regulatory process of BAX-mediated apoptosis. PMID:24525733

  15. All-trans retinoic acid inhibits KIT activity and induces apoptosis in gastrointestinal stromal tumor GIST-T1 cell line by affecting on the expression of survivin and Bax protein

    Directory of Open Access Journals (Sweden)

    Taguchi Takahiro

    2010-12-01

    Full Text Available Abstract Background Imatinib, a selective tyrosine kinase inhibitor, has been used as a standard first-line therapy for irresectable and metastasized gastrointestinal stromal tumor (GIST patients. Unfortunately, most patients responding to imatinib will eventually exhibit imatinib-resistance, the cause of which is not fully understood. The serious clinical problem of imatinib-resistance demands alternative therapeutic strategy. This study was conducted to investigate the effect of all-trans retinoic acid (ATRA on GIST cell lines. Methods Cell proliferation was determined by trypan blue dye exclusion test. Western blot analysis was performed to test the expression of activated KIT, its downstream proteins, and apoptosis associated proteins. The cytotoxic interactions of imatinib with ATRA were evaluated using the isobologram of Steel and Peckham. Results and conclusion In this work, for the first time we have demonstrated that ATRA affected on cell proliferation of GIST-T1 and GIST-882 cell line through inhibition of cell growth in a dose dependent manner and induced apoptosis. High dose of ATRA induced morphologic change in GIST-T1 cells, rounded-up cells, and activated the caspase-3 protein. In further examination, we found that the ATRA-induced apoptosis in GIST-T1 cells was accompanied by the down-regulated expression of survivin and up-regulated expression of Bax protein. Moreover, ATRA suppressed the activity of KIT protein in GIST-T1 cells and its downstream signal, AKT activity, but not MAPK activity. We also have demonstrated that combination of ATRA with imatinib showed additive effect by isobologram, suggesting that the combination of ATRA and imatinib may be a novel potential therapeutic option for GIST treatment. Furthermore, the scracht assay result suggested that ATRA was a potential reagent to prevent the invasion or metastasis of GIST cells.

  16. Clinicopathological significance of Bcl-2 and Bax protein expression in human pancreatic cancer

    Institute of Scientific and Technical Information of China (English)

    Ming Dong; Jian-Ping Zhou; Hao Zhang; Ke-Jian Guo; Yu-Lin Tian; Yu-Ting Dong

    2005-01-01

    AIM: To assess the clinicopathological significance of the expression of the apoptosis-inhibitory Bcl-2 protein (pBcl-2) and the apoptosis-promoting Bax protein (pBax) in human invasive ductal carcinomas (IDCs) of the pancreas. METHODS: Fifty-nine surgical specimens of IDCs of the pancreas were stained immunohistochemically to detectpBcl-2 and pBax expressions whose correlation to tumor classification, staging, and prognosis was analyzed by univariate and multivariate analyses. RESULTS: The expression of pBcl-2 and pBax was detected in 21 of 59 (35.6%) and in 29 of 59 (49.2%) patients with IDCs of the pancreas, respectively. Neither pBcl-2 nor pBax alone was correlated to TNM staging and differentiation degree of IDCs of the pancreas according to univariate analysis. By Mantel-Cox test, the median survival time after surgery for pBcl-2(+) and pBcl-2(-) groups were 14.3 and 7.3 mo, respectively (χ2= 9.357, P = 0.002) and that for pBax(+) and pBax(-) groups were 12.9 and 10.2 mo, respectively (χ2= 0.285, P>0.05).Contingency coefficient between pBd-2 and pBax expression was 0.298, indicating that there was correlation between them (χ2= 5.74, P<0.05). The median survival time after surgery for pBd-2(+)pBax(+) and pBcl-2(+)pBax(-) groups were 14.3 and 14.1 mo, respectively, and that for pBcl-2 (-)pBax(+) and pBcl-2(-)pBax(-) groups were 5.9 and 9.9 mo, respectively. There was a significant difference between pBcl-2(+)pBax(+) and pBcl-2(-)pBax(+) (χ2 = 5.06,P<0.05), such was the case for pBcl-2(+)pBax(+) andpBcl-2(-)pBax(-) (χ2= 7.18, P<0.01). Cox proportional hazards model for multivariate analysis was applied, indicating that pBcl-2, TNM staging, age and pBax were high risk factors of post-surgical survival time. CONCLUSION: Both pBcl-2 and pBax have high expression in IDCs of the pancreas, indicating that co-expression of pBcl-2 and pBax is a good indicator of favorable prognosis in IDCs of the pancreas.

  17. Expression of Bcl-2 and Bax in extrahepatic biliary tract carcinoma and dysplasia

    Institute of Scientific and Technical Information of China (English)

    Sheng-Mian Li; Shu-Kun Yao; Nobuyoshi Yamamura; Toshitsugu Nakamura

    2003-01-01

    AIM: To compare the difference of expression of Bcl-2 and Bax in extrahepatic biliary tract carcinoma and dysplasia, and to analyze the role of Bcl-2 and Bax proteins in the progression from dysplasia to carcinoma and to evaluate the correlation of Bcl-2/Bax protein expression with the biological behaviors.METHODS: Expressions of Bcl-2 and Bax were examined immunohistochemically in 27 cases of extrahepatic biliary tract carcinomas (bile duct carcinoma: n=21, carcinoma of ampulla of Vater: n=6), and 10 cases of atypical dysplasia.Five cases of normal biliary epithelial tissues were used as controls. A semiquantitative scoring system was used to assess the Bcl-2 and Bax reactivity.RESULTS: The expression of Bd-2 was observed in 10 out of 27 (37.0 %) invasive carcinomas, 1 out of 10 clysplasias, none out of 5 normal epithelial tissues. Bax expression rate was 74.1% (20/27) in invasive carcinoma, 30 % (3/10) in dysplasia,and 40 % (2/5) in normal biliary epithelium. Bcl-2 and Bax activities were more intense in carcinoma than in dysplasia,with no significant difference in Bcl-2 expression (P=0.1:10),and significant difference in Bax expression (P=0.038). Level of Bax expression was higher in invasive carcinoma than in dysplasia and normal tissue (P=0.012). Bcl-2 expression was correlated to Bax expression (P=0.0059). However, Bcl-2/Bax expression had no correlation with histological subtype,grade of differentiation, or level of invasion.CONCLUSION: Increased Bcl-2/Bax expression from dysplasia to invasive tumors supports the view that this is the usual route for the development of extrahepatic biliary tract carcinoma. Bcl-2/Bax may be involved, at least in part,in the apoptotic activity in extrahepatic biliary carcinoma.

  18. Adult thoracic primitive neuroectodermal tumor - clinical, radiological and pathological features; Tumor neuroectodermico primitivo toracico em adulto

    Energy Technology Data Exchange (ETDEWEB)

    Setubal, Roger; Santos, Leynalze Lins Ramos; Georges, Silvana Habib; Souza, Ricardo Pires de [Hospital Heliopolis, Sao Paulo, SP (Brazil). Servico de Diagnostico por Imagem; Menezes, Yara de [Hospital heliopolis, Sao Paulo, SP (Brazil). Servico de Patologia; Gomes, Marcio Rogerio Alcala; Mayo, Suzete Varela; Leiro, Luis Carlos Filgueira [Hospital Heliopolis, Sao Paulo, SP (Brazil). Servico de Pneumologia e Cirurgia Toracica

    1997-03-01

    Precise diagnosis of small round cell tumors, which include the thoracic primitive neuroectodermal tumor, is often a challenge to the clinical, oncologist, radiologist and pathologist. Different terms have been used to designate these tumors, depending on their location and extent of neural differentiation. With the progress of immuno-histochemical and cytogenetic diagnosis method, some of this tumors are now classified a unique clinical entity with several locations and mode of presentation. Therefore, tumors-like peripheral neuro epithelioma, Askin`s tumor, adult neuroblastoma, and primitive neuroectodermal tumor are now named peripheral primitive neuroectodermal tumor. The most common location of peripheral primitive neuroectodermal tumor is the thorax, and the mean age are close of the adolescence. This study reports the clinical, radiological and pathological features of 5 adults (3 men and 2 women) seen at the Hospital Heliopolis, Sao Paulo, SP Brazil, between 1991 and 1995 (5 years), with diagnosis of peripheral primitive neuroectodermal tumor made by immuno-histochemical and pathological studies. The mean age of the patients was 34 years, ranged between 17 and 57 years, and the most common location was the chest wall (n=3), followed by the posterior mediastinum (n=2). All the patients were symptomatic and undergone plain films and computed tomography. (author) 12 refs., 5 figs.

  19. Apoplexia subclínica em tumores pituitários

    Directory of Open Access Journals (Sweden)

    PINHEIRO MARCELO M.

    1999-01-01

    Full Text Available Apoplexia pituitária aguda é fenômeno relativamente raro, mesmo em macroadenomas. No entanto, a presença de áreas necro-hemorrágicas intratumorais nestes tumores que não se relacionam a qualquer sintomatologia aguda parece ser bem mais frequente do que se imaginava na era da tomografia. Com o advento da ressonância magnética estas áreas podem ser facilmente diagnosticadas pré-operatoriamente. Dentre os 40 últimos macroadenomas operados e examinados com RMN, 10 possuíam áreas apopléticas subclínicas em seu interior. Sete destes tumores eram não secretores, 2 secretores de GH e um de prolactina. O quadro clínico incluiu, além daqueles correspondentes à eventual secreção endócrina, perda visual progressiva (sem história de piora abrupta ou rápida (n=8 e cefaléia (n=3. Após a remoção cirúrgica destes tumores e descompressão do aparato óptico, obtivemos melhora visual em 6 pacientes e em 2 a visão permaneceu inalterada. A cefaléia desapareceu em 2 casos. A presença de áreas apopléticas nestes macrotumores bem como sua ausência em séries de microtumores relatadas na literatura sugere que se relacionam mais ao tamanho do tumor do que ao seu caráter secretor ou não, o que é compatível com a provável natureza (insuficiência vascular da apoplexia subclínica nesses casos.

  20. Estudo retrospectivo de 207 casos de tumores mamários em gatas

    Directory of Open Access Journals (Sweden)

    Monique Togni

    2013-03-01

    Full Text Available Este estudo teve como objetivos determinar os tumores mais prevalentes em gatos e relacionar os tumores mamários a alguns de seus fatores prognósticos. Os arquivos do Laboratório de Patologia Veterinária (LPV da Universidade Federal de Santa Maria (UFSM foram revisados e um total de 1.427 protocolos de biopsias e necropsias de felinos, entre 2000 e 2011, foi encontrado. Com base nas informações dos arquivos, foi estabelecida a relação entre os tumores e alguns fatores como sexo, idade, raça, estado reprodutivo, uso de contraceptivos, número e localização das glândulas afetadas, ulcerações, tamanho do neoplasma, metástases distantes e para os linfonodos. Assim, observou-se que os tumores de mama foram o segundo diagnóstico mais prevalente, após os tumores de pele. Todos os gatos com tumores mamários eram fêmeas, sendo os sem raça definida e os idosos os mais afetados. Os neoplasmas malignos foram diagnosticados com maior frequência, seguidos pelos tumores não neoplásicos e pelos neoplasmas benignos. Os tumores menores eram, na sua maioria, carcinomas. Ulcerações estavam presentes não só em neoplasmas malignos, mas também em alterações não neoplásicas. Metástases distantes foram encontradas principalmente nos pulmões e na pele.

  1. Pin1-Induced Proline Isomerization in Cytosolic p53 Mediates BAX Activation and Apoptosis.

    Science.gov (United States)

    Follis, Ariele Viacava; Llambi, Fabien; Merritt, Parker; Chipuk, Jerry E; Green, Douglas R; Kriwacki, Richard W

    2015-08-20

    The cytosolic fraction of the tumor suppressor p53 activates the apoptotic effector protein BAX to trigger apoptosis. Here we report that p53 activates BAX through a mechanism different from that associated with activation by BH3 only proteins (BIM and BID). We observed that cis-trans isomerization of proline 47 (Pro47) within p53, an inherently rare molecular event, was required for BAX activation. The prolyl isomerase Pin1 enhanced p53-dependent BAX activation by catalyzing cis-trans interconversion of p53 Pro47. Our results reveal a signaling mechanism whereby proline cis-trans isomerization in one protein triggers conformational and functional changes in a downstream signaling partner. Activation of BAX through the concerted action of cytosolic p53 and Pin1 may integrate cell stress signals to induce a direct apoptotic response. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Overexpression of Bax sensitizes prostate cancer cells to TGF-β induced apoptosis

    Institute of Scientific and Technical Information of China (English)

    Pei Hui LIN; Zui PAN; Lin ZHENG; Na LI; David DANIELPOUR; Jian Jie MA

    2005-01-01

    NRP-154 is a tumorigenic epithelial cell line derived from the preneoplastic dorsal-lateral prostate of rats. These cells are exquisitely sensitive to TGF-β induced apoptosis. In contrast, we find that NRP-154 cells can sustain overexpression of exogenous Bax protein, which is different from non-tumor cells where Bax functions as a ubiquitous stimulator of apoptosis. NRP-154 cells stably overexpressing Bax show increased sensitivity to TGF-β induced apoptosis. The degree of TGF-β induced apoptosis displays high correlation with cleavage of Bax at the amino-terminus. Our data indicate that prostate cancer cells can host high levels of latent Bax which can be activated through post-translational modification.

  3. Parkin promotes proteasomal degradation of misregulated BAX.

    Science.gov (United States)

    Cakir, Zeynep; Funk, Kathrin; Lauterwasser, Joachim; Todt, Franziska; Zerbes, Ralf M; Oelgeklaus, Aline; Tanaka, Atsushi; van der Laan, Martin; Edlich, Frank

    2017-09-01

    The pro-apoptotic BCL-2 protein BAX commits human cells to apoptosis by permeabilizing the outer mitochondrial membrane. BAX activation has been suggested to require the separation of helix α5 from α6 - the 'latch' from the 'core' domain - among other conformational changes. Here, we show that conformational changes in this region impair BAX translocation to the mitochondria and retrotranslocation back into the cytosol, and therefore BAX inhibition, but not activation. Redirecting misregulated BAX to the mitochondria revealed an alternative mechanism of BAX inhibition. The E3 ligase parkin, which is known to trigger mitochondria-specific autophagy, ubiquitylates BAX K128 and targets the pro-apoptotic BCL-2 protein for proteasomal degradation. Retrotranslocation-deficient BAX is completely degraded in a parkin-dependent manner. Although only a minor pool of endogenous BAX escapes retrotranslocation into the cytosol, parkin-dependent targeting of misregulated BAX on the mitochondria provides substantial protection against BAX apoptotic activity. © 2017. Published by The Company of Biologists Ltd.

  4. Differential retrotranslocation of mitochondrial Bax and Bak

    Science.gov (United States)

    Todt, Franziska; Cakir, Zeynep; Reichenbach, Frank; Emschermann, Frederic; Lauterwasser, Joachim; Kaiser, Andrea; Ichim, Gabriel; Tait, Stephen WG; Frank, Stephan; Langer, Harald F; Edlich, Frank

    2015-01-01

    The Bcl-2 proteins Bax and Bak can permeabilize the outer mitochondrial membrane and commit cells to apoptosis. Pro-survival Bcl-2 proteins control Bax by constant retrotranslocation into the cytosol of healthy cells. The stabilization of cytosolic Bax raises the question whether the functionally redundant but largely mitochondrial Bak shares this level of regulation. Here we report that Bak is retrotranslocated from the mitochondria by pro-survival Bcl-2 proteins. Bak is present in the cytosol of human cells and tissues, but low shuttling rates cause predominant mitochondrial Bak localization. Interchanging the membrane anchors of Bax and Bak reverses their subcellular localization compared to the wild-type proteins. Strikingly, the reduction of Bax shuttling to the level of Bak retrotranslocation results in full Bax toxicity even in absence of apoptosis induction. Thus, fast Bax retrotranslocation is required to protect cells from commitment to programmed death. PMID:25378477

  5. Andrographolide reversed 5-FU resistance in human colorectal cancer by elevating BAX expression.

    Science.gov (United States)

    Wang, Weicheng; Guo, Wenjie; Li, Lele; Fu, Zan; Liu, Wen; Gao, Jian; Shu, Yongqian; Xu, Qiang; Sun, Yang; Gu, Yanhong

    2016-12-01

    5-FU is the first line therapy for colorectal cancer, however, treatment effect is often hampered by the development of drug resistance or toxicity at high doses. Andrographolide is a natural diterpenoid from Andrographis paniculata which has anti-bacterial, anti-antiviral and anti-inflammation activities. In the current study, we test the hypothesis that Andrographolide reverses 5-FU resistance in colorectal cancer and examine the underlying mechanism. In vitro and vivo studies indicated that Andrographolide treatment significantly re-sensitizes HCT116/5-FUR cells (HCT116 cells which are 5-FU resistant) to cytotoxicity of 5-FU. Mechanism analysis showed that Andrographolide/5-FU co-treatment elevated apoptosis level of HCT116/5-FUR cells with highly increased level of BAX. By using biotin-Andrographolide pull down and cellular thermal shift assay, we found out that Andrographolide can directly target to BAX. Andrographolide-BAX interaction prevented BAX degradation, enhancing mitochondria-mediated apoptosis thus reversed 5-FU resistance while BAX silence diminished this effect. Further, by analyzing patient samples who received 5-FU involved chemotherapy, we found that expression level of BAX is correlated with PFS. Our results here provide a novel combination treatment strategy, especially for patients with 5-FU-resistant tumors expressing low level of BAX. Meanwhile, we also proposed that BAX expression may be a predicted and prognosis marker of 5-FU involved chemotherapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Effect of Helicobacter pylori infection on Bax protein expression in patients with gastric precancerous lesions

    Institute of Scientific and Technical Information of China (English)

    Hai-Feng Liu; Wei-Wen Liu; Guo-An Wang; Xiao-Chun Teng

    2005-01-01

    AIM: To investigate the effect of Helicobacter pylori (H pylori) infection on Bax protein expression, and explore the role of H pylori in gastric carcinogenesis.METHODS: H pylori was assessed by rapid urease test and Warthin-Starry method, and expression of Bax protein was examined immunohistochemically in 72 patients with pre-malignant lesions.RESULTS: Bax protein was differently expressed in intestinal metaplasia and gastric dysplasia, and showed 63.99% positivity. The positivity of Bax protein expression in H pylori-positive gastric precancerous lesions (72.3%) was significantly higher than that in H pylori-negative gastric precancerous lesions (48.0%, χ2 = 4.191, P<0.05).H pylori infection was well correlated with the expression of Bax protein in gastric precancerous lesions (r = 0.978,P<0.01). After eradication of H pylori, the positivity of Bax protein expression significantly decreased in H pylori-positive gastric precancerous lesions (χ2= 5.506,P<0.05). In the persisting H pylori-infected patients,the positivity of Bax protein expression was not changed.CONCLUSION: H pylori infection may be involved in the upregulation of Bax gene, which might be one of the mechanisms of H pylori infection-induced gastric epithelial cell apoptosis. H pylori might act as a tumor promoter in the genesis of gastric carcinoma and eradication of H pylori could inhibit gastric carcinogenesis.

  7. Experimental model of ultrasound thermotherapy in rats inoculated with Walker-236 tumor Modelo experimental de termoterapia ultrassônica em ratos inoculados com tumor de Walker-236

    Directory of Open Access Journals (Sweden)

    José Antonio Carlos Otaviano David Morano

    2011-01-01

    Full Text Available PURPOSE: To develop a model to evaluate the effects of focal pulsed ultrasound (US waves as a source of heat for treatment of murine subcutaneous implanted Walker tumor. METHODS: An experimental, controlled, comparative study was conducted. Twenty male Wistar rats (160-300 g randomized in 2 equal groups (G-1: Control and G-2: Hyperthermia were inoculated with Walker-256 carcinosarcoma tumor. After 5 days G-2 rats were submitted to 45ºC hyperthermia. Heat was delivered directly to the tumor by an ultrasound (US equipment (3 MHz frequency, 1,5W/cm³. Tumor temperature reached 45º C in 3 minutes and was maintained at this level for 5 minutes. Tumor volume was measured on days 5, 8, 11, 14 e 17 post inoculation in both groups. Unpaired t-test was used for comparison. POBJETIVO: Desenvolver um modelo para avaliar os efeitos do ultra-som focal pulsado como fonte de calor para o tratamento de tumores de Walker subcutâneos implantados em ratos. MÉTODOS: Um estudo experimental, controlado, comparativo foi realizado. Vinte ratos Wistar machos (160-300 g divididos em dois grupos (G-1: Controle e G-2: hipertermia foram inoculados com tumor de Walker carcinossarcoma-256. Após cinco dias os ratos do grupo G-2 ratos foram submetidos a hipertermia (45ºC. O calor foi aplicado diretamente no tumor por um equipamento de ultrassonografia (3 MHz, 1,5 W/cm³. A temperatura no tumor atingiu 45ºC em 3 minutos e foi mantida nesse nível por 5 minutos. O volume do tumor foi medido nos dias 5, 8, 11, 14 e 17 após a inoculação, em ambos os grupos. Teste t não pareado foi utilizado para comparação. P <0,05 foi considerado significante. RESULTADOS: O volume do tumor foi significativamente maior no 5º dia e diminuiu nos dias 11, 14 e 17 nos ratos tratados. Animais submetidos à hipertermia sobreviveram mais tempo que os animais do grupo controle. No 29º dia após a inoculação do tumor, 40% dos ratos do grupo controle e 77,78% dos ratos tratados com

  8. Surgical treatment of primary intramedullary spinal cord tumors in adult patients Tratamento cirúrgico de tumores intramedulares primários em adultos

    Directory of Open Access Journals (Sweden)

    Mario Augusto Taricco

    2008-03-01

    Full Text Available BACKGROUND: Primary spinal cord intramedullary tumors are rare and present with insidious symptoms. Previous treatment protocols emphasized biopsy and radiation/chemotherapy but more aggressive protocols have emerged. OBJECTIVE: To report our experience. METHOD: Forty-eight patients were diagnosed with primary intramedullary tumors. The cervical cord was involved in 27% and thoracic in 42% of patients. Complete microsurgical removal was attempted whenever possible without added neurological morbidity. RESULTS: Complete resection was obtained in 33 (71% patients. Neurological function remained stable or improved in 32 patients (66.7%. Ependymoma was the most frequent tumor (66.7%. CONCLUSION: Neurological outcome is superior in patients with subtle findings; aggressive microsurgical resection should be pursued with acceptable neurological outcomes.INTRODUÇÃO: Tumores intramedulares primários são raros e apresentam-se com sintomas insidiosos. Protocolos de tratamento anteriores enfatizavam biópsia e radio/quimioterapia, mas protocolos mais agres-sivos têm surgido. OBJETIVO: Relatar nossa experiência. MÉTODO: Tumores intramedulares foram diagnosticados em 48 pacientes. O segmento cervical estava envolvido em 27% e torácico em 42% dos pacientes. Remoção completa foi tentada quando possível sem aumento da morbidade neurológica. RESULTADOS: Ressecção total foi obtida em 33 (71% pacientes. Função neurológica: permaneceu inalterada/melhorou em 32 (66,7% pacientes. O tumor mais freqüente foi ependimoma (66,7%. CONCLUSÃO: O prognóstico é melhor em pacientes oligossintomáticos; ressecção microcirúrgica agressiva deve ser tentada sempre, com resultados clínicos aceitáveis.

  9. Experimental nodel of C6 brain tumors in athymic rats Modelo experimental de tumor cerebral C6 em ratos atímicos

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    Flávio K. Miura

    2008-06-01

    Full Text Available Malignant brain tumor experimental models tend to employ cells that are immunologically compatible with the receptor animal. In this study, we have proposed an experimental model of encephalic tumor development by injecting C6 cells into athymic Rowett rats, aiming at reaching a model which more closely resembles to the human glioma tumor. In our model, we observed micro-infiltration of tumor cell clusters in the vicinity of the main tumor mass, and of more distal isolated tumor cells immersed in normal encephalic parenchyma. This degree of infiltration is superior to that usually observed in other C6 models.Modelos experimentais de tumores cerebrais malignos geralmente utilizam células imunologicamente compatíveis com o animal receptor. Neste estudo apresentamos um modelo experimental baseado na inoculação de células C6 em ratos atímicos Rowett, visando obter um tumor que se assemelhe mais àqueles observados nos seres humanos. Neste modelo observamos microinfiltração de ilhotas de células na periferia da massa tumoral principal e nas áreas mais distantes, células tumorais isoladas no tecido cerebral normal. Este grau de infiltração é superior àquele observado em outros modelos utilizando as células C6.

  10. Experimental rat lung tumor model with intrabronchial tumor cell implantation Modelo experimental de tumor de pulmão em rato por via intrabrônquica

    Directory of Open Access Journals (Sweden)

    Antero Gomes Neto

    2008-02-01

    Full Text Available PURPOSE: The objective of this study was to develop a rat lung tumor model for anticancer drug testing. METHODS: Sixty-two female Wistar rats weighing 208 ± 20 g were anesthetized intraperitoneally with 2.5% tribromoethanol (1 ml/100 g live weight, tracheotomized and intubated with an ultrafine catheter for inoculation with Walker's tumor cells. In the first step of the experiment, a technique was established for intrabronchial implantation of 10(5 to 5×10(5 tumor cells, and the tumor take rate was determined. The second stage consisted of determining tumor volume, correlating findings from high-resolution computed tomography (HRCT with findings from necropsia and determining time of survival. RESULTS: The tumor take rate was 94.7% for implants with 4×10(5 tumor cells, HRCT and necropsia findings matched closely (r=0.953; pOBJETIVO: O objetivo foi desenvolver um modelo de tumor de pulmão em rato que permita o teste de fármacos no tratamento deste câncer. MÉTODOS: Sessenta e dois ratos Wistar fêmeas, peso médio de 208±20 g, foram anestesiados com tribromo-etanol 2,5% IP (1ml/100g de rato, traqueostomizados e intubados com cateter ultrafino para injetar células do tumor de Walker. Na 1ª etapa, estabeleceu-se a técnica do implante de células tumorais por via intrabrônquica e o índice de pega tumoral, usando-se de 10(5 a 5×10(5 células. Na 2ª, avaliou-se o volume tumoral e a correlação dos achados obtidos na tomografia computadorizada de alta resolução (TCAR de tórax com os da necropsia e verificou-se a sobrevida. RESULTADOS: O índice de pega foi de 94,7, com o implante de 4×10(5 células do tumor; as medidas do tumor feitas na TCAR e comparadas com as da necropsia foram semelhantes (r=0, 953, p<0,0001; a sobrevida mediana foi de 11 dias; e a mortalidade cirúrgica de 4,8 %. CONCLUSÃO: O modelo mostrou-se viável, com alto índice de pega, mortalidade cirúrgica desprezível, de execução simples e f

  11. Expression and Prognostic Significance of EP300, TP53 and BAX in Clear Cell Renal Cell Carcinoma.

    Science.gov (United States)

    Godlewski, Janusz; Krazinski, Bartlomiej E; Kowalczyk, Anna E; Kiewisz, Jolanta; Kiezun, Jacek; Kwiatkowski, Przemyslaw; Sliwińska-Jewsiewicka, Agnieszka; Wierzbicki, Piotr W; Kmieć, Zbigniew

    2017-06-01

    Histone acetyltransferase E1A-binding protein p300 (EP300), tumor protein p53 (TP53) and B-cell lymphoma-2-associated X protein (BAX) contribute to the regulation of the cell cycle and apoptosis, cellular processes that are often impaired in cancer cells. The aim of this study was to determine the expression levels of EP300, TP53 and BAX genes and their respective proteins in clear cell renal cell carcinoma (ccRCC) and evaluate the value of these factors as prognostic factors. EP300, TP53 and BAX expression at the transcript and protein levels were determined by quantitative polymerase-chain reaction (QPCR) and immunohistochemistry (IHC) in paired tumor and kidney specimens from 31 patients with ccRCC. Levels of EP300, TP53 and BAX transcripts were found increased in tumor tissues. Immunoreactivity for TP53 was elevated in cancer cells when compared to unchanged kidney, while EP300 and BAX immunoexpression in ccRCC did not differ from that of normal renal tissue. Immunoreactivity for TP53 was positively associated with larger tumor size. In contrast, stronger BAX immunoexpression correlated with smaller tumor diameters. The average immunoreactivity for BAX was higher in localized, kidney-confined tumor than in advanced/recurrent tumors. None of the analyzed transcripts or proteins correlated with the overall survival of patients. Although TP53 and BAX immunoreactivity levels were associated with some clinicopathological parameters of the patients, the expression of EP300, TP53 and BAX did not reveal any prognostic significance in ccRCC. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  12. Bax/Bak activation in the absence of Bid, Bim, Puma, and p53.

    Science.gov (United States)

    Zhang, J; Huang, K; O'Neill, K L; Pang, X; Luo, X

    2016-06-16

    How BH3-only proteins activate Bax/Bak, the two gateway proteins of the mitochondria-dependent apoptotic pathway, remains incompletely understood. Although all pro-apoptotic BH3-only proteins are known to bind/neutralize the anti-apoptotic Bcl-2 proteins, the three most potent ones, Bid (tBid), Bim, and Puma, possess an additional activity of directly activating Bax/Bak in vitro. This latter activity has been proposed to be responsible for triggering Bax/Bak activation following apoptotic stimulation. To test this hypothesis, we generated Bid(-/)(-)Bim(-/)(-)Puma(-/)(-) (TKO), TKO/Bax(-/)(-)/Bak(-/)(-) (PentaKO), and PentaKO/Mcl-1(-/-) (HexaKO) HCT116 cells through gene editing. Surprisingly, although the TKO cells were resistant to several apoptotic stimuli, robust apoptosis was induced upon the simultaneous inactivation of Bcl-xL and Mcl-1, two anti-apoptotic Bcl-2 proteins known to suppress Bax/Bak activation and activity. Importantly, such apoptotic activity was completely abolished in the PentaKO cells. In addition, ABT-737, a BH3 mimetic that inhibits Bcl-xL/Bcl-w/Bcl-2, induced Bax activation in HexaKO cells reconstituted with endogenous level of GFP-Bax. Further, by generating TKO/p53(-/-) (QKO) cells, we demonstrated that p53, a tumor suppressor postulated to directly activate Bax, is not required for Bid/Bim/Puma-independent Bax/Bak activation. Together, these results strongly suggest that the direct activation activities of Bid (tBid), Bim, Puma, and p53 are not essential for activating Bax/Bak once the anti-apoptotic Bcl-2 proteins are neutralized.

  13. Bax-PGAM5L-Drp1 complex is required for intrinsic apoptosis execution.

    Science.gov (United States)

    Xu, Wenjuan; Jing, Linlin; Wang, Quanshi; Lin, Chung-Chih; Chen, Xiaoting; Diao, Jianxin; Liu, Yuanliang; Sun, Xuegang

    2015-10-06

    Intrinsic apoptosis eliminates cells with damaged DNA and cells with dysregulated expression of oncogene. PGAM5, a member of the phosphoglycerate mutase family, has two splicing variants: PGAM5L (the long form) and PGAM5S (the short form). It has been well established that PGAM5 is at the convergent point of multiple necrosis pathways. However, the role of PGAM5 in intrinsic apoptosis is still controversial. Here we report that the PGAM5L, but not PGAM5S is a prerequisite for the activation of Bax and dephosphorylation of Drp1 in arenobufagin and staurosporine induced intrinsic apoptosis. Knockdown of PGAM5L inhibits the translocation of Bax to the mitochondria and reduces mitochondrial fission. The interaction between PGAM5L and Drp1 was observed in both arenobufagin and staurosporine treated HCT116 cells, but not in HCT116 Bax(-/-) cells. Bax transfection rescues the formation of the triplex in both arenobufagin and staurosporine stimulated HCT116 Bax(-/-) cells. Arenobufagin shows remarkable anti-cancer effects both in orthotropic and heterotropic CRC models and demonstrates less toxic effects as compared with that of cisplatin. Bax-PGAM5L-Drp1 complex is detected in arenobufagin and staurosporine treated CRC cells in vitro and in arenobufagin and cisplatin treated tumor in vivo as well. In summary, our results demonstrate that Bax-PGAM5L-Drp1 complex is required for intrinsic apoptosis execution.

  14. Tumores cardíacos em criança: análise retrospectiva

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    Juliano Gomes Penha

    2013-02-01

    Full Text Available FUNDAMENTO: Avanço dos métodos não invasivos de imagem proporcionou o aumento no número de diagnóstico de tumores cardíacos. Apesar disso, a literatura apresenta poucos trabalhos envolvendo tumores cardíacos primários em crianças. OBJETIVO: Avaliar retrospectivamente casos de tumores cardíacos primários em crianças, considerando manifestações clínicas iniciais, exames utilizados para o diagnóstico, indicação cirúrgica, tipos histopatológicos encontrados e evolução pós-operatória imediata. MÉTODOS: O estudo foi retrospectivo, baseado na avaliação de prontuários no período de 1983 a 2011. Incluímos somente casos que foram orientados para tratamento cirúrgico no período. Avaliaram-se a idade na admissão, o diagnóstico pré-natal, a história familial, os sintomas iniciais e os resultados de exames realizados. Foram coletados, ainda, a data e indicação de cirurgia, os achados intraoperatórios, o resultado do exame histopatológico, assim como as complicações imediatas no pós-operatório. RESULTADOS: Dos 18 pacientes estudados, as manifestações clínicas mais encontradas foram dispneia e sopro cardíaco (7 e 6 pacientes, respectivamente; o método de complemento diagnóstico mais usado foi o ecocardiograma (18 pacientes; a obstrução cavitária ou do trato de entrada ou saída ventricular foi a principal indicação de cirurgia (12 casos; o perfil histológico mais encontrado foi rabdomioma (7 pacientes; a maioria dos pacientes apresentou boa evolução clínica. CONCLUSÃO: Neste estudo o diagnóstico por imagem foi basicamente ecocardiográfico, com boa correlação com os achados intraoperatórios. Os achados histopatológicos foram concordantes com a literatura, com o rabdomioma apresentando-se como o tumor mais comum em crianças. A evolução após tratamento cirúrgico mostrou-se favorável na maior parte dos casos.

  15. Tumor estromal gastrointestinal em cães: estudo clínico-anatomopatológico

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    R.M. Leandro

    2016-08-01

    Full Text Available RESUMO Os tumores estromais gastrointestinais (GIST são incomuns e apresentam elevada similaridade histológica com as neoplasias de músculo liso e de nervo periférico. Este trabalho relata e caracteriza GIST em cães do ponto de vista epidemiológico, clínico-laboratorial, anatomopatológico e imuno-histoquímico, com base na análise retrospectiva de três cães, machos, com média de idade de 10 anos, variando de porte médio a grande e peso médio de 18.5±6kg. As alterações clínicas foram progressivas e inespecíficas de quadro gastrointestinal crônico, tais como prostração, anorexia, perda de peso e melena. Anemia não regenerativa e leucocitose foram os principais achados laboratoriais. Macroscopicamente, os tumores apresentavam média de 19cm no eixo maior, localizados em jejuno e ceco, com a superfície ulcerada, e exibiam áreas de necrose. Na avaliação microscópica, os casos apresentaram proliferação de células fusiformes, arranjadas em feixes longos densamente celulares, que foram vimentina e CD117 positivas, com diferenciação neural (S100 positivo, muscular (actina e desmina positivas e anaplásica, cuja morfologia caracteriza neoplasias malignas com sobrevida de um dia a 12 meses. O GIST deve ser um dos diagnósticos diferenciais a serem considerados entre as neoplasias mesenquimais do trato gastrointestinal que acometem cães, e o diagnóstico final necessita de imuno-histoquímica.

  16. Tumorer

    DEFF Research Database (Denmark)

    Prause, J.U.; Heegaard, S.

    2005-01-01

    oftalmologi, øjenlågstumorer, conjunctivale tumorer, malignt melanom, retinoblastom, orbitale tumorer......oftalmologi, øjenlågstumorer, conjunctivale tumorer, malignt melanom, retinoblastom, orbitale tumorer...

  17. A Novel Mechanism for CTCF in the Epigenetic Regulation of Bax in Breast Cancer Cells

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    Claudia Fabiola Méndez-Catalá

    2013-08-01

    Full Text Available We previously reported the association of elevated levels of the multifunctional transcription factor, CCCTC binding factor (CTCF, in breast cancer cells with the specific anti-apoptotic function of CTCF. To understand the molecular mechanisms of this phenomenon, we investigated regulation of the human Bax gene by CTCF in breast and non-breast cells. Two CTCF binding sites (CTSs within the Bax promoter were identified. In all cells, breast and non-breast, active histone modifications were present at these CTSs, DNA harboring this region was unmethylated, and levels of Bax mRNA and protein were similar. Nevertheless, up-regulation of Bax mRNA and protein and apoptotic cell death were observed only in breast cancer cells depleted of CTCF. We proposed that increased CTCF binding to the Bax promoter in breast cancer cells, by comparison with non-breast cells, may be mechanistically linked to the specific apoptotic phenotype in CTCF-depleted breast cancer cells. In this study, we show that CTCF binding was enriched at the Bax CTSs in breast cancer cells and tumors; in contrast, binding of other transcription factors (SP1, WT1, EGR1, and c-Myc was generally increased in non-breast cells and normal breast tissues. Our findings suggest a novel mechanism for CTCF in the epigenetic regulation of Bax in breast cancer cells, whereby elevated levels of CTCF support preferential binding of CTCF to the Bax CTSs. In this context, CTCF functions as a transcriptional repressor counteracting influences of positive regulatory factors; depletion of breast cancer cells from CTCF therefore results in the activation of Bax and apoptosis.

  18. Apopotic gene Bax expression in carotid plaque

    Institute of Scientific and Technical Information of China (English)

    Bao-Zhong MEN; Ding-Biao ZHOU; Huai-Yin SHI; Xiao-Ming ZHANG

    2006-01-01

    The expression of BAX in carotid atherosclerosis and its regulation is far from defined. Objectives To investigate BAX expression in stable/fibrous and instable/vulnerable carotid plaque and its clinical significance. Methods 25 cases of carotid plaque specimens obtained from endarterectomy were divided into two groups, stable/fibrous 14 cases, vulnerable/instable 11 cases; aortic artery and its branches from hepatic transplantation donors 6 case as control. The expression of proapoptotic BAX was detected by immunohistochemistry(IHC), in situ hybridization(ISH) and in situ TdT dUTP nick end labeling (TUNEL). Results 5 cases of BAX ( + ) were detected by ICH and ISH, 4 case of TUNEL ( + ) were detected by TUNEL in stable/fibrous carotid plaque , while 10 cases were BAX ( + )by IHC(P < 0.05) , 11case by ISH and 9 case by TUNEL were detected in instable/vulnerable carotid plaque ( P < 0.01 ), respectively. The intensity of BAX ( + ) cells by IHC and ISH was 8.63 ± 2.62 and 10.32 ± 3.12 in fibrous plaques, whereas 122 ± 21.64and 152 ± 23.35 in vulnerable plaques, respectively. No expression of BAX was found in controlled group. Conclusion The higher expression of Bax in vulnerable carotid plaque may be one mechanisms in molecular pathogenesis of carotid atherosclerosis which affect plaque stability and be the cause of higher incidence of stroke than fibrous carotid plaques, the regulation of BAX expression in different stage of atherosclerosis may provide targets in gene therapy for carotid atherosclerosis.

  19. An Autoinhibited Dimeric Form of BAX Regulates the BAX Activation Pathway.

    Science.gov (United States)

    Garner, Thomas P; Reyna, Denis E; Priyadarshi, Amit; Chen, Hui-Chen; Li, Sheng; Wu, Yang; Ganesan, Yogesh Tengarai; Malashkevich, Vladimir N; Almo, Steve S; Cheng, Emily H; Gavathiotis, Evripidis

    2016-08-04

    Pro-apoptotic BAX is a cell fate regulator playing an important role in cellular homeostasis and pathological cell death. BAX is predominantly localized in the cytosol, where it has a quiescent monomer conformation. Following a pro-apoptotic trigger, cytosolic BAX is activated and translocates to the mitochondria to initiate mitochondrial dysfunction and apoptosis. Here, cellular, biochemical, and structural data unexpectedly demonstrate that cytosolic BAX also has an inactive dimer conformation that regulates its activation. The full-length crystal structure of the inactive BAX dimer revealed an asymmetric interaction consistent with inhibition of the N-terminal conformational change of one protomer and the displacement of the C-terminal helix α9 of the second protomer. This autoinhibited BAX dimer dissociates to BAX monomers before BAX can be activated. Our data support a model whereby the degree of apoptosis induction is regulated by the conformation of cytosolic BAX and identify an unprecedented mechanism of cytosolic BAX inhibition. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. ESTABELECIMENTO DE UM MODELO DE TUMOR EXPERIMENTAL PELA INOCULAÇÃO DO TUMOR DE WALKER EM ESTÔMAGO DE RATO

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    Oliveira Paulo Ferdinando de Melo

    1998-01-01

    Full Text Available A incidência de câncer gástrico espontâneo em ratos é extremamente rara. Por outro lado, embora o câncer experimental de estômago possa ser induzido por carcinógenos químicos, através da ressecção da região fúndica do estômago, pela vagotomia ou pelo refluxo, esses métodos apresentam um percentual de desenvolvimento tumoral baixo e errático. Além disso, geralmente decorre um longo período de tempo até o pleno crescimento do tumor. O presente trabalho procurou estabelecer um modelo de tumor experimental de crescimento rápido, uniforme e com elevado índice de pega, que permitisse a avaliação de novas terapêuticas para o tratamento do câncer gástrico. Para tanto, utilizou-se uma suspensão de células do carcinossarcoma 256 de Walker que foi inoculada no estômago através de uma cânula orogástrica. A implantação ocorreu na mucosa previamente lesionada por clampeadura da parede, nas regiões da junção esôfago-gástrica, pequena curvatura e grande curvatura. O crescimento tumoral ocorreu em todos os animais e, embora na junção esôfago-gástrica a incidência de pega tenha sido de apenas 20%, possivelmente em função do epitélio queratinizado, na pequena curvatura a incidência foi de 80% e na grande curvatura todos os animais apresentaram tumor. Esses dados demonstraram que é possível implantar o tumor em 100% dos animais inoculados, o que comprova a exequibilidade da técnica. A vantagem dessa metodologia sobre as outras já descritas na literatura, também usando o carcinossarcoma 256 de Walker, é que o tumor cresce a partir da mucosa, reproduzindo as condições de desenvolvimento do tumor gástrico espontâneo. A média de sobrevida dos animais inoculados é de 13,2±1,98 dias. Além disso, como o tumor se desenvolve em todos os animais inoculados, pode-se dispensar métodos radiológicos e ultra-sonográficos para evidenciar a sua presença. Trata-se, portanto, de um método simples e eficaz e que

  1. Testicular tumors in dogs: frequency and age distribution Neoplasias testiculares em cães: frequência e distribuição etária

    Directory of Open Access Journals (Sweden)

    R.L. Santos

    2000-02-01

    Full Text Available Estudaram-se a ocorrência e a predisposição etária de neoplasias testiculares em cães. Em 497 cães necropsiados, 47 apresentaram tumores testiculares, correspondendo à frequência de 9,45% (47/497. Houve aumento significativo na freqüência de tumores testiculares em animais velhos.

  2. Driving p53 Response to Bax Activation Greatly Enhances Sensitivity to Taxol by Inducing Massive Apoptosis

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    Paola De Feudis

    2000-05-01

    Full Text Available The proapoptotic gene bax is one of the downstream effectors of p53. The p53 binding site in the bax promoter is less responsive to p53 than the one in the growth arrest mediating gene p21. We introduced the bax gene under the control of 13 copies of a strong p53 responsive element into two ovarian cancer cell lines. The clones expressing bax under the control of p53 obtained from the wild-type (wt p53-expressing cell line A2780 were much more sensitive (500- to 1000-fold to the anticancer agent taxol than the parent cell line, with a higher percentage of cells undergoing apoptosis after drug treatment that was clearly p53-dependent and bax-mediated. Xenografts established in nude mice from one selected clone (A2780/C3 were more responsive to taxol than the parental line and the apoptotic response of A2780/C3 tumors was also increased after treatment. Introduction of the same plasmid into the p53 null SKOV3 cell line did not alter the sensitivity to taxol or the induction of apoptosis. In conclusion, driving the p53 response (after taxol treatment by activating the bax gene rather than the p21 gene results in induction of massive apoptosis, in vitro and in vivo, and greatly enhances sensitivity to the drug.

  3. A New Fungal Diterpene Induces VDAC1-dependent Apoptosis in Bax/Bak-deficient Cells.

    Science.gov (United States)

    Huang, Li; Han, Junjie; Ben-Hail, Danya; He, Luwei; Li, Baowei; Chen, Ziheng; Wang, Yueying; Yang, Yanlei; Liu, Lei; Zhu, Yushan; Shoshan-Barmatz, Varda; Liu, Hongwei; Chen, Quan

    2015-09-25

    The pro-apoptotic Bax and Bak proteins are considered central to apoptosis, yet apoptosis occurs in their absence. Here, we asked whether the mitochondrial protein VDAC1 mediates apoptosis independently of Bax/Bak. Upon screening a fungal secondary metabolite library for compounds inducing apoptosis in Bax/Bak-deficient mouse embryonic fibroblasts, we identified cyathin-R, a new cyathane diterpenoid compound able to activate apoptosis in the absence of Bax/Bak via promotion of the VDAC1 oligomerization that mediates cytochrome c release. Diphenylamine-2-carboxilic acid, an inhibitor of VDAC1 conductance and oligomerization, inhibited cyathin-R-induced VDAC1 oligomerization and apoptosis. Similarly, Bcl-2 overexpression conferred resistance to cyathin-R-induced apoptosis and VDAC1 oligomerization. Silencing of VDAC1 expression prevented cyathin-R-induced apoptosis. Finally, cyathin-R effectively attenuated tumor growth and induced apoptosis in Bax/Bak-deficient cells implanted into a xenograft mouse model. Hence, this study identified a new compound promoting VDAC1-dependent apoptosis as a potential therapeutic option for cancerous cells lacking or presenting inactivated Bax/Bak.

  4. A New Fungal Diterpene Induces VDAC1-dependent Apoptosis in Bax/Bak-deficient Cells*

    Science.gov (United States)

    Huang, Li; Han, Junjie; Ben-Hail, Danya; He, Luwei; Li, Baowei; Chen, Ziheng; Wang, Yueying; Yang, Yanlei; Liu, Lei; Zhu, Yushan; Shoshan-Barmatz, Varda; Liu, Hongwei; Chen, Quan

    2015-01-01

    The pro-apoptotic Bax and Bak proteins are considered central to apoptosis, yet apoptosis occurs in their absence. Here, we asked whether the mitochondrial protein VDAC1 mediates apoptosis independently of Bax/Bak. Upon screening a fungal secondary metabolite library for compounds inducing apoptosis in Bax/Bak-deficient mouse embryonic fibroblasts, we identified cyathin-R, a new cyathane diterpenoid compound able to activate apoptosis in the absence of Bax/Bak via promotion of the VDAC1 oligomerization that mediates cytochrome c release. Diphenylamine-2-carboxilic acid, an inhibitor of VDAC1 conductance and oligomerization, inhibited cyathin-R-induced VDAC1 oligomerization and apoptosis. Similarly, Bcl-2 overexpression conferred resistance to cyathin-R-induced apoptosis and VDAC1 oligomerization. Silencing of VDAC1 expression prevented cyathin-R-induced apoptosis. Finally, cyathin-R effectively attenuated tumor growth and induced apoptosis in Bax/Bak-deficient cells implanted into a xenograft mouse model. Hence, this study identified a new compound promoting VDAC1-dependent apoptosis as a potential therapeutic option for cancerous cells lacking or presenting inactivated Bax/Bak. PMID:26253170

  5. Expression of pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins in human retinoblastoma.

    Science.gov (United States)

    Singh, Lata; Pushker, Neelam; Saini, Neeru; Sen, Seema; Sharma, Anjana; Bakhshi, Sameer; Chawla, Bhavna; Kashyap, Seema

    2015-04-01

    Regulation of apoptosis is a complex process that involves a number of genes, including Bcl-2, Bcl-x, Bax and other Bcl-2 family members. The aim of the present study is to assess the expression of Bcl- 2 and Bax in retinoblastoma, and correlate them with clinical and histopathological parameters. The expression of Bcl-2 and Bax proteins were examined using immunohistochemistry, Western blotting and reverse transcriptase-polymerase chain reaction in a series of 60 prospective cases of primary retinoblastoma tissues. Immunohistochemistry showed expression of Bcl-2 in 40/60 (66.6%), whereas Bax expression was found only in 18/60 (30%) cases, and these correlated with mRNA expression. The Western blotting results also correlated well with the immunohistochemical expression of Bcl-2 (25 kDa) and Bax (21 kDa) proteins. Bcl-2 was expressed in 96% (24/25) of invasive tumours and in 45.7% (16/35) of non-invasive tumours. Expression of Bcl-2 significantly correlated with tumour invasiveness (P = 0.0274) and poor differentiation (P = 0.0163), whereas loss of Bax correlated with massive choroidal invasion and Pathological Tumor-Node-Metastasis (pTNM) (P = 0.0341). However, no correlation was found between Bax and Bcl-2 expression. Our findings suggest that these apoptotic regulatory proteins may serve as poor prognostic markers and can be used as a therapeutic target for the treatment of invasive retinoblastoma. Further functional studies are required to explore the role of Bax and Bcl-2 in retinoblastoma. © 2014 Royal Australian and New Zealand College of Ophthalmologists.

  6. Complicações oftálmicas em pacientes com tumores malignos extra-orbitários Ophthalmic complications in patients with extraorbital malignant tumors

    Directory of Open Access Journals (Sweden)

    Ana Célia Baptista

    2003-10-01

    Full Text Available OBJETIVO: Correlacionar as complicações oftálmicas, presentes em pacientes portadores de tumores malignos extra-orbitários, com o sítio de origem e diagnóstico histopatológico destas neoplasias, por meio de tomografia computadorizada. MÉTODOS: Foram estudados retrospectivamente, por tomografia computadorizada, 29 pacientes com neoplasias malignas extra-orbitárias, sem qualquer tratamento prévio do tumor, e evidência clínico-radiológica de comprometimento orbitário associado. RESULTADOS: Houve predomínio do carcinoma epidermóide (28%, seguido pelo carcinoma basocelular (14%. As complicações oftálmicas mais comumente observadas foram proptose (38%, epífora (24% e dor ocular (24%. Redução da acuidade visual foi referida em 14 % dos casos. Os sítios de origem mais comuns das neoplasias foram o seio maxilar (28%, o seio etmoidal (17% e a pele e subcutâneo da face (17%. Proptose ocular foi causada predominantemente por tumores não carcinomatosos e tumores originados no seio etmoidal, ao passo que epífora ocorreu preferencialmente nos casos de tumores carcinomatosos e de neoplasias do seio maxilar. Redução da motilidade ocular, irritação ocular e secreção no olho foram as complicações oftálmicas mais freqüentes em pacientes com tumores dos anexos oculares, ao passo que dor ocular foi a complicação oftálmica dominante nos pacientes com neoplasias originadas na pele e subcutâneo da face. CONCLUSÕES: Os autores sugerem que, diante de paciente com epífora e massa maxilo-nasal, carcinoma do seio maxilar deve ser considerado primariamente no diagnóstico diferencial da lesão. Da mesma forma, tumores não carcinomatosos, como sarcomas e linfomas, devem ser considerados, sobretudo no diagnóstico de pacientes com proptose e massa naso-etmoidal.OBJECTIVE: To correlate the ophthalmic complications in patients with extra-orbital malignant tumors with the site of origin and histopathologic diagnosis of the tumors by

  7. Modelo de tumor de pulmão em rato com o carcinossarcoma de Walker Lung tumor model in rats with Walker’s carcinosarcoma

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    Antero Gomes Neto

    2002-02-01

    Full Text Available OBJETIVO: Desenvolver um modelo de tumor pulmonar em ratos com o carcinossarcoma de Walker e verificar in vivo a presença de tumor por meio de tomografia computadorizada (TC. MÉTODOS: Ratos Wistar fêmeas (n=47 foram anestesiados com pentobarbital, intubados por traqueostomia e submetidos a toracotomia para injeção no parênquima pulmonar de células do tumor de Walker ou do veículo das mesmas. O estudo consistiu de duas etapas: na primeira desenvolveu-se a técnica de implante do tumor e estabeleceu-se o número de células necessário para um bom índice de pega tumoral. Na segunda etapa, determinou-se o volume do tumor em cm³ (Dxd²/2 através de TC e necropsia (6° dia do implante, e analizou-se a sobrevida dos animais. RESULTADOS: O índice de pega do tumor foi 93,3%, sendo 81,8% na primeira etapa e 100% na segunda. A mortalidade cirúrgica foi 17,0%. As medidas dos tumores foram semelhantes (0,099 vs. 0,111 cm³ na tomografia e na necropsia, respectivamente (r=0,993; pOBJECTIVE: To develop a lung tumor model in rats using Walker’s carcinosarcoma and to verify the presence in vivo of tumors using computerized tomography (CT. METHODS: Female Wistar rats (n=47 were anesthetized with pentobarbital, intubated through tracheostomy and submitted to thoracotomy; subsequently a 50-70 mu L volume containing Walker’s tumor cells, or the suspension of these same cells, was injected into the lung parenchyma. The study consisted of two phases: in the first a tumor implantation technique was developed and the number of cells required to attain a satisfactory tumor development rate was established. In the second phase, the tumor volume in cm³ (Dxd²/2 was determined through CT scan and necropsis, and the survival rates were analyzed. RESULTS: The overall tumor development rate was 93.3%, or rather, 81.1% in the first phase and 100% in the second. The surgical mortality rate was 17.0%. The average tumor volume was similar (0.099 vs. 0.111 cm

  8. Granulosa Cell Tumor Juvenile - Case Report-Primary Care Tumor de Celulas da Granulosa Juvenil - Relato de Caso em Atenção Primária

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    Anelise Olmos Grings

    2010-11-01

    Full Text Available

    The authors given an account of children of 2 years and 4 months with ginaecology complaints (white vaginal secretion, diffuse abdominal pain and early pseudo-puberty. Beginning investigation in Unity of Health Care PSF of Porto Alegre, are refer to the secondary levei was diagnosis ovarian tumor (Juvenile Granulosa Cell Tumor Ovary.

    Os autores relatam o caso de urna criança de 2 anos e 4 meses com queixas ginecológicas (secreção vaginal branca, dor abdominal difusa e pseudopuberdade precoce (telarca. Iniciada investigação em Unidade de Saúde PSF de Porto Alegre, sendo referenciada ao nível secundário onde foi diagnosticada neoplasia ovariana (Tumor de Células da Granulosa Juvenil.

  9. Expression of the EP300, TP53 and BAX genes in colorectal cancer: Correlations with clinicopathological parameters and survival.

    Science.gov (United States)

    Kowalczyk, Anna E; Krazinski, Bartlomiej E; Godlewski, Janusz; Kiewisz, Jolanta; Kwiatkowski, Przemyslaw; Sliwinska-Jewsiewicka, Agnieszka; Kiezun, Jacek; Sulik, Marian; Kmiec, Zbigniew

    2017-07-01

    E1A binding protein P300 (EP300), tumor protein P53 (TP53) and BCL2 associated X, apoptosis regulator (BAX) genes encode proteins which cooperate to regulate important cellular processes. The present study aimed to determine the expression levels of EP300, TP53 and BAX in colorectal cancer (CRC) and to investigate their prognostic value and association with the progression of CRC. Tumor and matched unchanged colorectal tissues were collected from 121 CRC patients. Quantitative polymerase chain reaction and immunohistochemistry were used to assess the mRNA and protein levels of the studied genes. Altered expression of the studied genes in CRC tissues was observed at both the mRNA and protein levels. The depth of invasion was associated with TP53 mRNA levels and was correlated negatively with BAX mRNA expression. Moreover, a relationship between tumor location and BAX mRNA content was noted. BAX immunoreactivity was correlated positively with the intensity of p300 immunostaining and was associated with lymph node involvement and tumor-node-metastasis (TNM) disease stage. Univariate regression analysis revealed that overexpression of p53 and BAX in CRC tissues was associated with poor patient outcome. In conclusion, dysregulation of the expression of the studied genes was found to contribute to CRC pathogenesis. The association between p300 and BAX levels suggests the existence of an interdependent regulatory mechanism of their expression. Moreover, BAX expression may be regulated alternatively, in a p53-independent manner, since the lack of correlations between expression of these factors was observed.

  10. Estudo retrospectivo de 207 casos de tumores mamários em gatas A retrospective study of 207 cases of mammary tumors in queens

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    Monique Togni

    2013-03-01

    Full Text Available Este estudo teve como objetivos determinar os tumores mais prevalentes em gatos e relacionar os tumores mamários a alguns de seus fatores prognósticos. Os arquivos do Laboratório de Patologia Veterinária (LPV da Universidade Federal de Santa Maria (UFSM foram revisados e um total de 1.427 protocolos de biopsias e necropsias de felinos, entre 2000 e 2011, foi encontrado. Com base nas informações dos arquivos, foi estabelecida a relação entre os tumores e alguns fatores como sexo, idade, raça, estado reprodutivo, uso de contraceptivos, número e localização das glândulas afetadas, ulcerações, tamanho do neoplasma, metástases distantes e para os linfonodos. Assim, observou-se que os tumores de mama foram o segundo diagnóstico mais prevalente, após os tumores de pele. Todos os gatos com tumores mamários eram fêmeas, sendo os sem raça definida e os idosos os mais afetados. Os neoplasmas malignos foram diagnosticados com maior frequência, seguidos pelos tumores não neoplásicos e pelos neoplasmas benignos. Os tumores menores eram, na sua maioria, carcinomas. Ulcerações estavam presentes não só em neoplasmas malignos, mas também em alterações não neoplásicas. Metástases distantes foram encontradas principalmente nos pulmões e na pele.This study aimed to determine the most prevalent mammary tumors in cats and associate them to some prognostic factors. The files from the Laboratório de Patologia Veterinária (LPV of the Universidade Federal de Santa Maria (UFSM were reviewed, and 1.427 feline biopsies and autopsy protocols between the years 2000 and 2011 were found. Based on the information retrieved from the files, a relationship was established among the tumors and some prognostic factors such as sex, age, breed, reproductive status, use of contraceptives, number and location of affected glands, ulcers, size of the neoplasm, distant metastases, and affected lymph nodes. Thus, it was observed that mammary cancer is the

  11. Spinal cord tumor in a patient with multiple sclerosis: case report Tumor de medula espinal em paciente com esclerose múltipla: relato de caso

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    Mario Augusto Taricco

    2002-06-01

    Full Text Available The association between multiple (MS sclerosis and cerebral gliomas has been sporadically reported in the literature, causing a long lasting discussion if these lesions occur coincidentally or if MS plaques may actually lead to the genesis of gliomas. We report a 36 year old man who developed a rapid onset of right side weakness and loss of vision, having established a diagnosis of MS which was confirmed by CSF analysis and MRI. Nine years later he developed progressive tetraparesis, leading initially to suspicion of illness relapse and a demyelinating plaque in the spinal cord. However, after MRI investigation, a spinal cord tumor was diagnosed. The patient underwent cervical spine laminotomy for microsurgical removal of the spinal cord tumor diagnosed as ependimoma. The neurological deficits improved significantly.A associação entre esclerose múltipla (EM e gliomas cerebrais foi relatada esporadicamente na literatura, levando a longa discussão quanto à possibilidade das placas de esclerose estarem envolvidas na etiologia dos gliomas ou dessas lesões ocorrerem coincidentemente. Relatamos um paciente de 36 anos que desenvolveu hemiparesia direita rapidamente progressiva e perda visual, sendo estabelecido o diagnóstico de EM após análise do LCR e imagens de RM de encéfalo. Após nove anos o paciente desenvolveu tetraparesia lentamente progressiva, levantando inicialmente a hipótese de atividade da doença e aparecimento de placa de EM na medula espinal. Contudo, após investigação com RM de coluna, um tumor medular foi diagnosticado. Foi então submetido a laminectomia cervical para ressecção microcirúrgica do tumor, que foi diagnosticado como ependimoma. Os déficits neurológicos melhoraram significativamente.

  12. Tratamento médico em tumores ósseos de células gigantes : uma nova perspectiva

    OpenAIRE

    2014-01-01

    Trabalho final de mestrado incluido em Medicina (Ortopedia), apresentado á Faculdade de Medicina da Universidade de Coimbra Introduction Giant cell tumor (GCT) is a rare, aggressive, potentially malignant primary lesion of bone that occurs in young adults, and for which surgical treatment is not always an option, sometimes resulting in severe morbidity and with the risk of recurrence. Recent studies presented denosumab as the first effective medical treatment for this type of tumo...

  13. Synthesis and Biological Evaluation of 3-Aryl-quinoxaline-2-carbonitrile 1,4-Di-<em>N>-oxide Derivatives as Hypoxic Selective Anti-tumor Agents

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    Yongzhou Hu

    2012-08-01

    Full Text Available A series of 3-aryl-2-quinoxaline-carbonitrile 1,4-di-<em>N>-oxide derivatives were designed, synthesized and evaluated for hypoxic and normoxic cytotoxic activity against human SMMC-7721, K562, KB, A549 and PC-3 cell lines. Many of these new compounds displayed more potent hypoxic cytotoxic activity compared with TX-402 and TPZ in the tumor cells based evaluation, which confirmed our hypothesis that the replacement of the 3-amine with the substituted aryl ring of TX-402 increases the hypoxic anti-tumor activity. The preliminary SAR revealed that 3-chloro was a favorable substituent in the phenyl ring for hypoxic cytotoxicity and 7-methyl or 7-methoxy substituted derivatives exhibited better hypoxic selectivity against most of the tested cell lines. The most potent compound, 7-methyl-3-(3-chlorophenyl-quinoxaline-2-carbonitrile 1,4-dioxide (9h was selected for further anti-tumor evaluation and mechanistic study. It also exhibited significant cytotoxic activity against BEL-7402, HepG2, HL-60, NCI-H460, HCT-116 and CHP126 cell lines in hypoxia with IC50 values ranging from 0.31 to 3.16 μM, and preliminary mechanism study revealed that 9h induced apoptosis in a caspase-dependent pathway.

  14. Doxorubicin Changes Bax /Bcl-xL Ratio, Caspase-8 and 9 in Breast Cancer Cells.

    Science.gov (United States)

    Sharifi, Simin; Barar, Jaleh; Hejazi, Mohammad Saeid; Samadi, Nasser

    2015-09-01

    Doxorubicin is administrated as a single agent in first-line therapy of breast cancer to induce apoptosis in tumor cells. Bax, Bcl-xL, Caspase-8 and 9 proteins are involved in induction of apoptosis. The present study describes Bax, Bcl-xL gene expression and Caspase-8 and 9 protein levels in MCF-7 cells incubated with doxorubicin at different doses an incubation times. The cytotoxic effects of doxorubicin were studied using MTT assay. MCF-7 cells were treated with three concentrations of doxorubicin (0.1, 0.5, 1 μM) and incubated for 24, 48 and 72 hours then expression levels of Bax and Bcl-xL genes were elucidated by Real-time RT-PCR technique and protein levels of caspase-8 and caspase-9 proteins were measured using ELISA method. Morphological modifications of the cells were also monitored via light microscopic images. Doxorubicin decreased the anti-apoptotic Bcl-xL and increased pro-apoptotic Bax mRNA levels. Doxorubicin induced a significant increase in Bax /Bcl-xL ratio in all doses and incubation times (pBax /Bcl-xL ratio was revealed after 48 h incubation of the cells with in all doses of doxorubicin. Doxorubicin also increased caspase-9 level in a time and dose-dependent manner, while caspase-8 level didn't follow time and dose dependency pattern. Our results confirm that doxorubicin induces mitochondrial-dependent apoptosis by down-regulation of Bcl-xL and up- regulation of Bax and caspase-9 expressions.

  15. Protocol for the anatomopathological examination of canine mammary tumors Protocolo para exame anatomopatológico de tumores mamários em cães

    Directory of Open Access Journals (Sweden)

    E. Ferreira

    2003-02-01

    Full Text Available Foi elaborado um protocolo para exame anatomopatológico de tumores de mama em cães, constituído de três partes: requisição, exame clínico e laudo histopatológico. O exame clínico contém dados sobre a descrição macroscópica da lesão. O laudo histopatológico constituiu-se de campos para descrição microscópica pormenorizada das lesões e classificação da principal lesão observada. A elaboração do protocolo tem como objetivo estabelecer critérios para estudos e pesquisas sobre neoplasias mamárias em animais e auxiliar no diagnóstico e prognóstico de lesões mamárias.

  16. Loss of BAX by miR-365 Promotes Cutaneous Squamous Cell Carcinoma Progression by Suppressing Apoptosis.

    Science.gov (United States)

    Zhou, Liang; Gao, Ruirui; Wang, Yinghui; Zhou, Meijuan; Ding, Zhenhua

    2017-05-30

    Pro-apoptotic BCL2 associated X (BAX) is traditionally thought to be regulated by anti-apoptotic BCL-2 family members, like BCL2-like 1 (BCL-XL), at the protein level. However, the posttranscriptional regulation of BAX is under explored. In this study, we identified BAX as the novel downstream target of miR-365, which is supported by gain- and loss-of-function studies of onco-miR-365. Loss of BAX by either RNA interference or highly-expressed miR-365 in cells of cutaneous squamous cell carcinoma (CSCC) enhanced the tumor resistance against apoptosis, while repressing cell proliferation, migration, and invasiveness. In vivo experiment confirmed that BAX knockdown promotes the growth of CSCC xenografts. Collectively, our results find a miR-365-BAX axis for alleviating the pro-apoptotic effects of BAX, which promotes CSCC development and may facilitate the generation of novel therapeutic regimens to the clinical treatment of CSCC.

  17. Influence of Apoptin on Up-regulation of the Expression of Bad and Bax

    Institute of Scientific and Technical Information of China (English)

    GUO Tai; YANG Qian

    2005-01-01

    The chicken anemia virus protein, apoptin, which manifests selectivity and specificity to tumor cells, induces a p53-independent and Bcl-2-insensitive type of apoptosis in various human tumor cells. In this study, the apoptin gene was cloned from the total DNA of chicken anemia virus, and the recombinant vector was constructed. We used oligonucleotide microarray to study the changes of four genes, including Bcl-2, Bcl-xL, Bad and Bax. The post-transfection with the recombinant was also studied. The pro-apoptotic genes(Bad and Bax) and anti-apoptosis genes(Bcl-2 and Bcl-xL) were up-regulated in contrast to the controls. According to the published data, either Bcl-2 or Bcl-xL can form non-functional heterodimers by Bad and Bax binding together, resulting in blocking partly the release of cytochrome c from mitochondria. However, apoptosis could be inhibited by neither the endogenous Bcl-xL nor Bcl-2 over-expression. The experiments show that the apoptin-induced apoptotic pathway is related to the up-regulation of Bad and Bax. Bad was up-regulated by apoptin; then this up-regulated product of Bad was in favor of displacing Bax from binding to Bcl-xL or Bcl-2. Consequently, Bax exerted a pro-apoptotic dysfunction to mitochondria, thereby inducing the release of cytochrome c. Finally, apoptin induced the apoptosis of HHCC cells. These results indicate that the oligonucleotide microarray can reveal the genes related to the apoptosis induced by apoptin in HHCC cells.

  18. Alterações em genes relacionados à via glicolítica em tumores de carcinoma epidermoide de esôfago

    OpenAIRE

    2013-01-01

    O carcinoma epidermoide de esôfago (CEE) representa 90% dos casos de câncer de esôfago no Brasil. O CEE tem detecção tardia, um comportamento extremamente agressivo e baixa sobrevida, sendo, portanto, um alvo interessante para o estudo dos mecanismos envolvidos em sua carcinogênese, a fim de se identificar possíveis alvos terapêuticos ou marcadores moleculares que ajudem na prática clínica. Mudanças no metabolismo energético da célula tumoral parecem ter papel de destaque na transformação mal...

  19. Tumores do tronco cerebral: estudo anatomopatológico em 35 casos de necrópsia

    Directory of Open Access Journals (Sweden)

    Carmen Lúcia Penteado Lancellotti

    1989-09-01

    Full Text Available Os tumores do tronco cerebral são raros e geralmente tratados sem diagnóstico histopatológico. Sua incidência varia na literatura entre 1,09% e 17,5% dos tumores cerebrais. O objetivo do trabalho foi relatar a casuísti desses tumores em 28500 necrópsias realizadas de 1952 a 1985 no Departamento de Anatomia Patológica da Santa Casa de São Paulo. Enfatizamos os aspectos neuropatológicos, comparamos nossos casos com os de outras séries e salientamos os tumores mais observados nessa região, com a finalidade de procurar contribuir para melhor abordagem terapêutica. Utilizamos alguns dados clínicos e, através do exame anatomopatológico, localizamos o tumor no tronco cerebral sendo o diagnóstico microscópico estabelecido segundo os critérios da Organização Mundial da Saúde. Dos 428 tumores intracranianos observados, 35 estavam localizados no tronco cerebral. Foram aqui incluídos os tumores próprios do tronco cerebral e as metástases e excluídos os tumores que infiltravam o tronco. A maior incidência ocorreu na primeira década e a causa de óbito predominante foi edema cerebral. A localização preferencial foi a ponte e o tumor mais freqüente foi o glioblas-tomia multiforme (19 casos. As metástases ficaram em segundo lugar na freqüência (9 casos, na maioria dos casos de origem pulmonar. Apesar de alguns autores se posicionarem contra a biópsia de tumor nessa região, baseando-se no alto risco cirúrgico, discordamos dessa opinião, pois acreditamos que, frente ao diagnóstico de glioma, será importante a caracterização ou não de malignidade. Ainda, não devemos deixar de considerar os diagnósticos diferenciais de processo expansivo no tronco. Enfim, com o diagnóstico anatomopatológico de glioma ou de uma das possibilidades aventadas, o procedimento terapêutico poderá ser mais adequado.

  20. Doses extracranianas em pacientes submetidos a radiocirurgia estereotáxica para tumores cerebrais

    Directory of Open Access Journals (Sweden)

    Maria da Salete Fonseca dos Santos Lundgren

    2012-04-01

    Full Text Available OBJETIVO: Estimar a dose extracraniana nos olhos, tireoide, tórax e pelve em pacientes submetidos a radiocirurgia com acelerador linear de 6 MV. MATERIAIS E MÉTODOS: Foram avaliados 11 pacientes com tumores cerebrais primários (7 pacientes e secundários (4 pacientes, sendo que dois destes apresentavam duas lesões. Para a estimativa da dose extracraniana, foram utilizados dosímetros termoluminescentes. Foram utilizados cones de 1,50 a 3,75 cm e as doses de radiação variaram de 1300 a 2000 cGy. RESULTADOS: A idade média dos pacientes foi de 52 anos, sendo 63,6% do sexo feminino e 36,4% do sexo masculino. As localizações das lesões foram: nervo acústico direito (1, frontal (2, parietal (5, occipital direito (1, cerebelar (2 e parassagitais (2. Os valores médios das doses recebidas na região entre os olhos foram de 5,1 cGy; no olho direito, de 4,8 cGy; no olho esquerdo, de 6,5 cGy; na tireoide, de 4,2 cGy; no tórax, de 1,65 cGy; e na pelve, de 0,45 cGy. CONCLUSÃO: Estes resultados mostram que embora as doses não ultrapassem os limites de tolerância para ocorrência da opacidade do cristalino, é importante que os médicos radioterapeutas considerem os riscos de dose de radiação nessas regiões durante o planejamento de procedimentos de radiocirurgia craniana.

  1. Tumor hepático experimental (VX-2 em coelho: implantação do modelo no Brasil Experimental liver tumor (VX-2 in rabbits: implantation of the model in Brazil

    Directory of Open Access Journals (Sweden)

    Rogério Saad Hossne

    2002-08-01

    Full Text Available Os estudos para a investigação de novas modalidades terapêuticas em biologia tumoral, deveriam passar por estudos experimentais prévios. Neste sentido dispõem-se hoje de uma grande variedade de modelos tumorais experimentais; em determinadas investigações faz-se necessária a adequação do modelo tumoral às necessidades biológicas, patológicas e experimentais dos estudos. Desta forma, em nosso serviço, buscávamos um modelo tumoral hepático para estudos experimentais que se adequasse às seguintes características: fácil manipulação, crescimento controlável, evolução e agressividade semelhantes aos seres humanos. Os dados da literatura nos levaram a busca do tumor hepático VX-2, em coelhos. Neste artigo discutimos as vantagens da utilização deste modelo experimental e a sua introdução em nosso país.Studies for investigation of new therapeutic modalities in tumoral biology should be based on previous experimental studies. Then, there are a great variety of tumoral experimental models today. Some investigations have been done necessary an adaptation of the tumoral model to the needing of the studies biological and pathological. So, in our laboratory, we looked for a tumoral hepatic model for experimental studies with the following characteristics: easy manipulation, control of growing, evolution and aggressiveness like to humans. Data of the literature took us the search of the hepatic tumor VX-2, in rabbits. In this article we discussed the advantages of use this experimental model and its introduction in our country. Experimental hepatic tumor (VX-2 in rabbit. Implantation of the model in Brazil.

  2. Traveling Bax and Forth from Mitochondria to Control Apoptosis

    Science.gov (United States)

    Soriano, Maria Eugenia; Scorrano, Luca

    2011-01-01

    Antiapoptotic Bcl-2 proteins on mitochondria inhibit prodeath proteins, such as Bax, which are found primarily in the cytosol. In this issue, Edlich et al., (2011) show that Bax and Bcl-xL interact on the mitochondrial surface and then retrotranslocate to the cytosol, effectively preventing Bax-induced permeabilization of mitochondria. PMID:21458662

  3. Tumores experimentais do sistema nervoso central: padronização de modelo em roedores utilizando a linhagem 9L

    Directory of Open Access Journals (Sweden)

    Custódio Michailowsky

    2003-06-01

    Full Text Available Grande variedade de modelos experimentais foram estabelecidos em neuro-oncologia durante as últimas décadas, a fim de estudar a biologia tumoral e a eficiciência de novas drogas e novos tratamentos em gliomas malignos humanos. Embora estes modelos estejam bem caracterizados e sejam facilmente reproduzíveis e aplicáveis, há limitações quanto ao seu uso e à resposta obtida, principalmente quando utilizados para monitorização de tratamentos. A proposta deste estudo é padronizar modelo de tumor cerebral glial experimental e detectar variáveis que possam influenciar o seu desenvolvimento. Células 9L foram inoculadas na substância branca do cérebro em 48 ratos machos Sprague-Dawley; destes, 25 animais receberam eletrodos corticais para realização de eletroencefalografia. Os animais eram avaliados diariamente por observação neurológica. Vinte e quatro ratos desenvolveram tumor - 10 animais morreram ou no pós-operatório imediato ou durante a evolução; 14 animais não desenvolveram tumor. Macroscopicamente, o tumor parecia bem delimitado; características de malignidade e extensa infiltração foram observadas à microscopia de luz; o diagnóstico foi o de astrocitoma maligno. A utilização de técnica estereotáxica e a infusão de pequeno volume de suspensão celular por um tempo longo de infusão foram considerados importantes para o bom desenvolvimento do tumor. Procedimentos que merecem atenção são: contagem precisa das células na câmara de Neubauer, agitação constante da suspensão de células a serem inoculadas e fixação precisa da profundidade de inoculação. O modelo experimental desenvolvido no presente trabalho mostrou ser de execução relativamente fácil, com custo razoável e reprodutível.

  4. Tumores experimentais do sistema nervoso central: padronização de modelo em roedores utilizando a linhagem 9L

    Directory of Open Access Journals (Sweden)

    Michailowsky Custódio

    2003-01-01

    Full Text Available Grande variedade de modelos experimentais foram estabelecidos em neuro-oncologia durante as últimas décadas, a fim de estudar a biologia tumoral e a eficiciência de novas drogas e novos tratamentos em gliomas malignos humanos. Embora estes modelos estejam bem caracterizados e sejam facilmente reproduzíveis e aplicáveis, há limitações quanto ao seu uso e à resposta obtida, principalmente quando utilizados para monitorização de tratamentos. A proposta deste estudo é padronizar modelo de tumor cerebral glial experimental e detectar variáveis que possam influenciar o seu desenvolvimento. Células 9L foram inoculadas na substância branca do cérebro em 48 ratos machos Sprague-Dawley; destes, 25 animais receberam eletrodos corticais para realização de eletroencefalografia. Os animais eram avaliados diariamente por observação neurológica. Vinte e quatro ratos desenvolveram tumor - 10 animais morreram ou no pós-operatório imediato ou durante a evolução; 14 animais não desenvolveram tumor. Macroscopicamente, o tumor parecia bem delimitado; características de malignidade e extensa infiltração foram observadas à microscopia de luz; o diagnóstico foi o de astrocitoma maligno. A utilização de técnica estereotáxica e a infusão de pequeno volume de suspensão celular por um tempo longo de infusão foram considerados importantes para o bom desenvolvimento do tumor. Procedimentos que merecem atenção são: contagem precisa das células na câmara de Neubauer, agitação constante da suspensão de células a serem inoculadas e fixação precisa da profundidade de inoculação. O modelo experimental desenvolvido no presente trabalho mostrou ser de execução relativamente fácil, com custo razoável e reprodutível.

  5. Small molecules reveal an alternative mechanism of Bax activation.

    Science.gov (United States)

    Brahmbhatt, Hetal; Uehling, David; Al-Awar, Rima; Leber, Brian; Andrews, David

    2016-04-15

    The pro-apoptotic protein Bax commits a cell to death by permeabilizing the mitochondrial outer membrane (MOM). To obtain small-molecule probes for elucidating the molecular mechanism(s) of Bax activation, we screened for compounds that induced Bax-mediated liposome permeabilization. We identified five structurally different small molecules that promoted both Bax targeting to and oligomerization at membranes. All five compounds initiated Bax oligomerization in the absence of membranes by a mechanism unlike Bax activation by Bcl-2 homology 3 domain (BH3) proteins. Some of the compounds induced Bax/Bak-dependent apoptosis in cells. Activation of Bax by the most active compound was poorly inhibited by the anti-apoptotic protein Bcl-XL and requires a cysteine residue at position 126 of Bax that is not required for activation by BH3 proteins. Our results reveal a novel pathway for Bax activation independent of pro-apoptotic BH3 proteins that may have important implications for the regulation of Bax activity in cells. © 2016 The Author(s).

  6. Bax Activation Initiates the Assembly of a Multimeric Catalyst that Facilitates Bax Pore Formation in Mitochondrial Outer Membranes

    Science.gov (United States)

    Kushnareva, Yulia; Andreyev, Alexander Y.; Kuwana, Tomomi; Newmeyer, Donald D.

    2012-01-01

    Bax/Bak-mediated mitochondrial outer membrane permeabilization (MOMP) is essential for “intrinsic” apoptotic cell death. Published studies used synthetic liposomes to reveal an intrinsic pore-forming activity of Bax, but it is unclear how other mitochondrial outer membrane (MOM) proteins might facilitate this function. We carefully analyzed the kinetics of Bax-mediated pore formation in isolated MOMs, with some unexpected results. Native MOMs were more sensitive than liposomes to added Bax, and MOMs displayed a lag phase not observed with liposomes. Heat-labile MOM proteins were required for this enhanced response. A two-tiered mathematical model closely fit the kinetic data: first, Bax activation promotes the assembly of a multimeric complex, which then catalyzes the second reaction, Bax-dependent pore formation. Bax insertion occurred immediately upon Bax addition, prior to the end of the lag phase. Permeabilization kinetics were affected in a reciprocal manner by [cBid] and [Bax], confirming the “hit-and-run” hypothesis of cBid-induced direct Bax activation. Surprisingly, MOMP rate constants were linearly related to [Bax], implying that Bax acts non-cooperatively. Thus, the oligomeric catalyst is distinct from Bax. Moreover, contrary to common assumption, pore formation kinetics depend on Bax monomers, not oligomers. Catalyst formation exhibited a sharp transition in activation energy at ∼28°C, suggesting a role for membrane lipid packing. Furthermore, catalyst formation was strongly inhibited by chemical antagonists of the yeast mitochondrial fission protein, Dnm1. However, the mammalian ortholog, Drp1, was undetectable in mitochondrial outer membranes. Moreover, ATP and GTP were dispensable for MOMP. Thus, the data argue that oligomerization of a catalyst protein, distinct from Bax and Drp1, facilitates MOMP, possibly through a membrane-remodeling event. PMID:23049480

  7. Conformational Heterogeneity in the Activation Mechanism of Bax.

    Science.gov (United States)

    Barnes, C Ashley; Mishra, Pushpa; Baber, James L; Strub, Marie-Paule; Tjandra, Nico

    2017-08-01

    Bax is known for its pro-apoptotic role within the mitochondrial pathway of apoptosis. However, the mechanism for transitioning Bax from cytosolic to membrane-bound oligomer remains elusive. Previous nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) studies defined monomeric Bax as conformationally homogeneous. Yet it has recently been proposed that monomeric Bax exists in equilibrium with a minor state that is distinctly different from its NMR structure. Here, we revisited the structural analysis of Bax using methods uniquely suited for unveiling "invisible" states of proteins, namely, NMR paramagnetic relaxation enhancements and EPR double electron-electron resonance (DEER). Additionally we examined the effect of glycerol, the co-solvent of choice in DEER studies, on the structure of Bax using NMR chemical-shift perturbations and residual dipolar couplings. Based on our combined NMR and EPR results, Bax is a conformationally homogeneous protein prior to its activation. Published by Elsevier Ltd.

  8. Tumor

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    2008479 Preliminary study of MR elastography in brain tumors. XU Lei(徐磊), et al.Neurosci Imaging Center, Beijing Tiantan Hosp, Capital Med Univ, Beijing 100050.Chin J Radiol 2008;42(6):605-608. Objective To investigate the potential values of magnetic resonance elastography (MRE) for evaluating the brain tumor consistency in vivo. Methods Fourteen patients with known solid brain tumor (5 male, 9 female; age range: 16-63 years)

  9. Single-cell quantification of Bax activation and mathematical modelling suggest pore formation on minimal mitochondrial Bax accumulation.

    Science.gov (United States)

    Düssmann, H; Rehm, M; Concannon, C G; Anguissola, S; Würstle, M; Kacmar, S; Völler, P; Huber, H J; Prehn, J H M

    2010-02-01

    Mitochondrial outer membrane permeabilisation (MOMP) during apoptosis is triggered by the activation and oligomerisation of Bax and Bak, but a quantification of these processes in individual cells has not yet been performed. Single-cell imaging of Bax translocation and oligomerisation in Bax-deficient DU-145 cells expressing CFP-Bax and YFP-Bax revealed that both processes started only minutes before or concomitantly with MOMP, with the majority of Bax translocation and oligomerisation occurring downstream of MOMP. Quantification of YFP-Bax concentrations at mitochondria revealed an increase of only 1.8 + or - 1.5% at MOMP onset. This was increased to 11.2 + or - 3.6% in bak-silenced cells. These data suggested that Bax activation exceeded by far the quantities required for MOMP induction, and that minimal Bax or Bak activation may be sufficient to trigger rapid pore formation. In a cellular automaton modelling approach that incorporated the quantities and movement probabilities of Bax and its inhibitors, activators and enablers in the mitochondrial membrane, we could re-model rapid pore formation kinetics at submaximal Bax activation.

  10. Expression and Significance of Bcl-2, Bax, Fas and Caspase-3 in Different Phases of Human Hemangioma

    Institute of Scientific and Technical Information of China (English)

    YANG Hong; DENG Chenguo; SHEN Shengguo; ZHANG Duanlian; YUYing

    2006-01-01

    The relationship between Bcl-2, Bax, Fas, caspase-3 and development of hemangioma and the molecular mechanism was investigated. By using immunohistochemical S-P method, proliferating cell nuclear antigen was detected. According to the classification of Mulliken in combination with PCNA expression, 27 cases were identified as proliferating hemangioma and 22 cases as involutive hemangioma. Five normal skin tissues around the tumor tissue served as controls. By using immunohistochemical technique, the expression of Bcl-2, Bax, Fax and Caspase-3 was detected. The cells expressing Bcl-2, Bax, Fax and cappase-3 were identified as hemangioma endothelia by immunohistochemical staining of Ⅷ factor. The average absorbance (A) and average positive area rate of Bcl-2, Bax, Fas and caspase-3 expression were measured by using HPIAS-2000 imaging analysis system. The results showed that the expression of Bcl-2 in the endothelia of proliferating hemangioma was significantly higher that in involutive degenerative hemangioma endothelia and vascular endothelia of normal skin tissue (P<0.01). The expression of Bax, Fas and Caspase-3 in the endothelia of involutive hemangioma was obviously higher than in the endothelia of proliferating hemangioma and normal skin tissue (P<0.01). The expression of BAx and Fas in endothelia of proliferating hemangioma was higher than in those of normal skin tissue (P<0.05). It was suggested that Bcl-2,Bax, Fas and caspase-3 might be involved in the development and involution of hemangioma. Bcl-2 could promote the growth of hemangioma by inhibiting apoptosis of endothelia. Bax, Fas and caspase-3 promote the switch of hemangioma from proliferation to involution by inducing the apoptosis of hemangioma endothelia.

  11. Metastatic primary lung tumor in three dogsTumor primário pulmonar metastático em três cães

    Directory of Open Access Journals (Sweden)

    Antônio Carlos Faria dos Reis

    2012-02-01

    Full Text Available Primary lung tumors (PLT are uncommon in dogs and occasionally metastasize to distant organs. This report describes three cases of PLT in dogs with epithelial origin, diagnosed post mortem through histopathology and immunohistochemistry. Case one presented nonspecific symptoms while the second and third cases presented respiratory alterations and radiographic exams revealed the presence of pulmonary nodule(s. Case 1 was diagnosed as a pulmonary papillary adenocarcinoma with metastasis to the mediastinal lymph nodes, liver and right adrenal gland. Case 2 was a pulmonary squamous cell carcinoma with metastasis to the heart, kidneys and perianal glan, whereas Case 3 was diagnosis as pulmonary papillary adenocarcinoma with metastasis to the pericardium and mediastinal lymph nodes. No previous report of epithelial TPP metastasis to pericardium, heart, liver, kidney and perianal gland. The three tumors showed positive immunostaining for the anti-pan-cytokeratin antibody and negative immunostaining for the anti-vimentin antibody. In dogs with PLT, the TNM clinical staging and histological classification and grading are fundamental for therapeutic planning and prognosis determination.Tumores primários pulmonares (TPP são incomuns em cães e ocasionalmente metastatizam para órgãos distantes. Relatam-se três casos de TPP com origem epitelial em cães, diagnosticados pós-morte por meio do exame histopatológico e imuno-histoquímico. O caso 1 apresentou sinais clínicos inespecíficos, os casos 2 e 3 apresentaram sinais clínicos de alterações respiratórias e no exame radiográfico visualizouse nódulo(s pulmonar. Os casos 1 e 3 foram diagnosticados como adenocarcinoma papilar pulmonar com metástase nos linfonodos mediastínicos, fígado, adrenal direita (caso 1 e, pericárdio e linfonodos mediastínicos (caso 3. O caso 2 apresentou carcinoma de células escamosas pulmonar com metástase no coração, rins e glândula perianal. Não há relatos

  12. Cystadenoma: a rare tumor originated in minor salivary gland Cistadenoma: um tumor raro em glândula salivar menor

    Directory of Open Access Journals (Sweden)

    Jean Nunes dos Santos

    2008-06-01

    Full Text Available Cystadenoma of salivary glands is an uncommon benign neoplasm that presents intraluminal papillary projections. The authors describe one case of cystadenoma located in the buccal mucosa and highlight its histomorphological features and differential diagnosis.O cistadenoma de glândula salivar é uma neoplasia benigna incomum, que exibe projeções papilíferas intraluminais. Os autores descrevem um caso de cistadenoma localizado na mucosa jugal, discutindo os aspectos histomorfológicos e o diagnóstico diferencial desse tumor.

  13. Expressão da proteína Bax no tecido mamário normal de mulheres no menacme tratadas com raloxifeno Expression of Bax protein in normal tissue of premenopausal women treated with raloxifene

    Directory of Open Access Journals (Sweden)

    Ana Maria Furtado-Veloso

    2008-04-01

    Full Text Available OBJETIVO: avaliar a expressão do antígeno Bax no epitélio mamário normal de mulheres na pré-menopausa tratadas com raloxifeno. MÉTODOS: estudo randomizado duplo-cego, envolvendo 33 mulheres pré-menopáusicas com fibroadenoma. As pacientes foram divididas em dois grupos: Placebo, (n=18 e Raloxifeno 60 mg, (n=15. A medicação foi usada durante 22 dias, começando no primeiro dia do ciclo menstrual. Uma biópsia foi realizada no 23º dia do ciclo menstrual, durante a qual uma amostra do tecido mamário normal adjacente ao fibroadenoma foi coletada e submetida a estudo imuno-histoquímico utilizando o anticorpo policlonal anti-Bax para avaliar a expressão da proteína Bax. A imunorreação para a proteína Bax foi avaliada, levando-se em consideração a intensidade e a fração de células coradas, cuja combinação resultou em um escore final de 0 a 6. Os casos com escore final >3 foram classificados como positivos para proteína Bax. O teste do c2 foi usado para análise estatística dos dados (pPURPOSE: to evaluate the expression of Bax antigen in the normal mammary epithelium of premenopausal women treated with raloxifene. METHODS: a randomized double-blind study was conducted in 33 ovulatory premenopausal women with fibroadenoma. Patients were divided into two groups: Placebo, (n=18 and Raloxifene 60 mg, (n=15. The medication was used for 22 days, beginning on the first day of the menstrual cycle. An excisional biopsy was carried out on the 23rd day of the menstrual cycle and a sample of normal breast tissue adjacent to the fibroadenoma was collected and submitted to immunohistochemical study using anti-Bax polyclonal antibody to evaluate the expression of Bax protein. Immunoreaction for Bax was evaluated taking into consideration intensity and fraction of stained cells, whose combination resulted in a final score ranging from 0 to 6. Cases with a final score >3 were classified as positive for Bax. The c2 test was used for statistical

  14. The prognostic significance of p53, Bax, Bcl-2 and cyclin E protein overexpression in colon cancer - an immunohistochemical study using the tissue microarray technique.

    Science.gov (United States)

    Melincovici, Carmen Stanca; Mihu, Carmen Mihaela; Mărginean, Mariana; Boşca, Adina Bianca; Coneac, Andrei; Moldovan, Ioana; Crişan, Maria

    2016-01-01

    In colon cancer, biological markers continue to have a limited prognostic value, the results being controversial. Studies of cell-cycle regulatory proteins and anti-apoptotic proteins aim to identify groups of patients that develop more aggressive tumors and might benefit from an individualized therapy management. The present study evaluates the prognostic role of the p53, Bax, Bcl-2 and cyclin E immunoexpression in colon cancer, using the tissue microarray (TMA) method. Tissue samples were obtained from 31 patients operated for colon cancer, embedded in TMA paraffin blocks and immunohistochemically stained for p53, Bax, Bcl-2 and cyclin E. We evaluated the relationship between the overexpression of these proteins and the clinico-pathological parameters, as well as the effect of these molecular markers on the survival rate. 65.22% of the patients were p53 positive, 39.13% Bcl-2 positive, 78.26% Bax positive and 34.78% cyclin E positive. Bcl-2(+) patients had significantly better differentiated tumors (p=0.043). Significantly poorly differentiated tumors were: Bax(+) patients (p=0.031), Bcl-2(-)÷p53(-) patients (p=0.042), Bcl-2(-)÷Bax(+) patients (p=0.029), and Bcl-2(-)÷p53(-)÷Bax(+) patients (p=0.016). The individual expression of the studied proteins did not influence the survival rate. A significantly lower survival rate was found in the following groups of patients: Bcl-2(-)÷p53(-) (40% vs. 83.3%, p=0.027), p53(-)÷Bax(+) (40% vs. 83.3%, p=0.027), Bcl-2(-)÷p53(-)÷Bax(+) (25% vs. 84.2%, p=0.003). The current study identified groups of patients with a significantly lower survival rate, which consequently are at an increased risk to develop tumors with a more aggressive biological behavior.

  15. Efeitos do reiki na evolução do granuloma induzido através da inoculação do BCG em hamsters e do tumor ascítico de Ehrlich induzido em camundongos

    OpenAIRE

    2008-01-01

    Estudaram-se os efeitos da influência do Reiki na evolução do granuloma induzido experimentalmente pela inoculação do BCG no coxim plantar de hamsters, assim como os efeitos da mesma terapia em camundongos portadores do tumor ascítico de Ehrlich in vivo e in vitro. No modelo de inflamação granulomatosa crônica, utilizou-se 40 hamsters machos, os quais após serem inoculados com BCG no dia 0 no coxim da pata posterior direita, foram separados em dois grupos contendo 20 animais em cada. Um grupo...

  16. Efeito da terapia \\"in vitro\\" com célula tronco de medula óssea em tumores mamários caninos

    OpenAIRE

    Sonia Elisabete Alves de Lima Will

    2014-01-01

    O tumor mamário é a segunda neoplasia maligna mais incidente em cães, com uma elevada taxa de mortalidade. Em cães, constituem aproximadamente 52% de todos os tumores que afetam as fêmeas, possuindo uma elevada heterogeneidade biológica e histomorfológica, sendo que 50% são malignos. As neoplasias, independentemente de suas causas primárias, apresentam distúrbios no controle do ciclo celular, o que acaba gerando um aumento na proliferação celular, perda da diferenciação e formação de massas...

  17. Cytological diagnosis of a metastatic canine mammary tumor in pleural effusion Diagnóstico citológico de tumor mamário metastático canino em derrame pleural

    Directory of Open Access Journals (Sweden)

    G.D. Cassali

    1999-08-01

    Full Text Available Descrevem-se os achados citomorfológicos de um tumor maligno de mama em uma cadela Poodle de sete anos de idade, o qual foi observado inicialmente pelo exame citológico do derrame pleural. Comparam-se os aspectos citológicos do derrame pleural e punção aspirativa com agulha fina do tumor com aqueles descritos para o câncer de mama na espécie humana.

  18. Tumor odontogênico adenomatóide em mandíbula Tumor odontógeno adenomatoide de la mandíbula Adenomatoid odontogenic tumor in mandible

    Directory of Open Access Journals (Sweden)

    Roberto de Almeida Azevedo

    2011-06-01

    Full Text Available Tumor odontogênico adenomatóide é uma lesão relativamente incomum, que acomete preferencialmente indivíduos do sexo feminino durante a segunda década de vida. Exibe como sítio de predileção a região anterior da maxila, é geralmente associado à coroa de um dente incluso. Este trabalho tem o objetivo de apresentar um caso clínico de tumor odontogênico adenomatóide. Este se apresenta localizado em região anterior da mandíbula. Pretende-se ainda abordar suas características clínicas, radiográficas e histológicas, além do tratamento cirúrgico conservador de eleição.El tumor odontógeno adenomatoide es una lesión relativamente infrecuente que afecta principalmente a las mujeres durante la segunda década de vida, porque su sitio predilecto es la región anterior de la mandíbula, con una lesión por lo general asociada con la corona del diente. Se reporta un caso de tumor odontógeno adenomatoide en la región anterior de la mandíbula junto con sus resultados clínicos, radiológicos e histológicos así como su tratamiento quirúrgico.Adenomatoid odontogenic tumor is a relatively uncommon lesion, which affects mainly individuals of the female during the second decade due, showing as a site of predilection for the anterior region of the maxilla presenting lesion usually associated with the crown of a tooth incluso. Os authors report a case of an adenomatoid odontogenic tumor in the anterior region of mandible, together with their clinical, radiographic and histological and its surgical treatment.

  19. Hyperactivity and depression-like traits in Bax KO mice.

    Science.gov (United States)

    Krahe, Thomas E; Medina, Alexandre E; Lantz, Crystal L; Filgueiras, Cláudio C

    2015-11-02

    The Bax gene is a member of the Bcl-2 gene family and its pro-apoptotic Bcl-associated X (Bax) protein is believed to be crucial in regulating apoptosis during neuronal development as well as following injury. With the advent of mouse genomics, mice lacking the pro-apoptotic Bax gene (Bax KO) have been extensively used to study how cell death helps to determine synaptic circuitry formation during neurodevelopment and disease. Surprisingly, in spite of its wide use and the association of programmed neuronal death with motor dysfunctions and depression, the effects of Bax deletion on mice spontaneous locomotor activity and depression-like traits are unknown. Here we examine the behavioral characteristics of Bax KO male mice using classical paradigms to evaluate spontaneous locomotor activity and depressive-like responses. In the open field, Bax KO animals exhibited greater locomotor activity than their control littermates. In the forced swimming test, Bax KO mice displayed greater immobility times, a behavior despair state, when compared to controls. Collectively, our findings corroborate the notion that a fine balance between cell survival and death early during development is critical for normal brain function later in life. Furthermore, it points out the importance of considering depressive-like and hyperactivity behavioral phenotypes when conducting neurodevelopmental and other studies using the Bax KO strain. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Sistema purinérgico em linhagem T24 de tumor de bexiga : identificação dos receptores e caracterização das ecto-nucleotidases

    OpenAIRE

    Joseli Stella

    2006-01-01

    Tumor de bexiga é o tipo de tumor mais comum que ocorre no trato urinário, originado a partir do epitélio estratificado da bexiga. A incidência em homens é maior do que em mulheres, está associado com a industrialização e relacionado com a origem ocupacional do paciente. Mais de 90% dos tumores de bexiga são devidos a alterações neste epitélio, sendo o principal tipo, o tumor nas células transicionais. A linhagem T24 de tumor de bexiga humana tem sido usada como modelo de tumor invasivo de be...

  1. Association of Bax Expression and Bcl2/Bax Ratio with Clinical and Molecular Prognostic Markers in Chronic Lymphocytic Leukemia.

    Science.gov (United States)

    Vucicevic, Ksenija; Jakovljevic, Vladimir; Colovic, Natasa; Tosic, Natasa; Kostic, Tatjana; Glumac, Irena; Pavlovic, Sonja; Karan-Djurasevic, Teodora; Colovic, Milica

    2016-04-01

    In chronic lymphocytic leukemia (CLL), in vivo apoptotic resistance of malignant B lymphocytes results, in part, from the intrinsic defects of their apoptotic machinery. These include genetic alterations and aberrant expression of many apoptosis regulators, among which the Bcl2 family members play a central role. The aim of this study was to investigate the association of pro-apoptotic Bax gene expression and Bcl2/Bax ratio with the clinical features of CLL patients as well as with molecular prognostic markers, namely the mutational status of rearranged immunoglobulin heavy variable (IGHV) genes and lipoprotein lipase (LPL) gene expression. We analyzed the expression of Bax mRNA and Bcl2/Bax mRNA ratio in the peripheral blood mononuclear cells of 58 unselected CLL patients and 10 healthy controls by the quantitative reverse-transcriptase polymerase chain reaction. We detected significant Bax gene overexpression in CLL samples compared to non-leukemic samples (p=0.003), as well as an elevated Bcl2/Bax ratio (p=Bax ratio showed a negative correlation to lymphocyte doubling time (r=-0.307; p=0.0451), while high-level Bax expression was associated with LPL-positive status (p=0.035). Both the expression of Bax and Bcl2/Bax ratio were higher in patients with unmutated vs. mutated IGHV rearrangements, but this difference did not reach statistical significance. Our results suggest that dysregulated expression of Bcl2 and Bax, which leads to a high Bcl2/Bax ratio in leukemic cells, contributes to the pathogenesis and clinical course of CLL.

  2. Bcl-xL retrotranslocates Bax from the mitochondria into the cytosol

    Science.gov (United States)

    Edlich, Frank; Banerjee, Soojay; Suzuki, Motoshi; Cleland, Megan M.; Arnoult, Damien; Wang, Chunxin; Neutzner, Albert; Tjandra, Nico; Youle, Richard J.

    2011-01-01

    Summary The Bcl-2 family member Bax translocates from the cytosol to mitochondria where it oligomerizes and permeabilizes the mitochondrial outer membrane to promote apoptosis. Bax activity is counteracted by pro-survival Bcl-2 proteins, but how they inhibit Bax remains controversial, because they neither co-localize nor form stable complexes with Bax. We constrained Bax in its native cytosolic conformation within cells using intramolecular disulfide tethers. Bax tethers disrupt interaction with Bcl-xL in detergents and cell free MOMP activity, but unexpectedly induce Bax accumulation on mitochondria. Fluorescence Loss in Photobleaching (FLIP) reveals constant retrotranslocation of wt Bax, but not tethered Bax, from the mitochondria into the cytoplasm of healthy cells. Bax retrotranslocation depends on pro-survival Bcl-2 family proteins and inhibition of retrotranslocation correlates with Bax accumulation on the mitochondria. We propose that Bcl-xL inhibits and maintains Bax in the cytosol by constant retrotranslocation of mitochondrial Bax. PMID:21458670

  3. Constipação intestinal em pacientes com tumores intracranianos Obstipación intestinal en pacientes com tumores intracraneanos Intestinal constipation in patients with intracranial tumors

    OpenAIRE

    Analuiza Cândido Torres; Solange Diccini

    2006-01-01

    O esforço que ocorre durante a manobra de Valsalva gera aumento da pressão intracraniana e pode descompensar pacientes com hipertensão intracraniana. Os objetivos deste estudo foram avaliar a incidência de constipação intestinal no pré-operatório de pacientes com tumores intracranianos e relacionar a constipação intestinal com a descompensação da hipertensão intracraniana. O estudo foi realizado na unidade de neurocirurgia do Hospital São Paulo, de agosto a outubro de 2003, com a avaliação de...

  4. Cytosolic Ku70 regulates Bax-mediated cell death.

    Science.gov (United States)

    Hada, Manila; Subramanian, Chitra; Andrews, Phillip C; Kwok, Roland P S

    2016-10-01

    The first known function of Ku70 is as a DNA repair factor in the nucleus. Using neuronal neuroblastoma cells as a model, we have established that cytosolic Ku70 binds to the pro-apoptotic protein Bax in the cytosol and blocks Bax's cell death activity. Ku70-Bax binding is regulated by Ku70 acetylation in that when Ku70 is acetylated Bax dissociates from Ku70, triggering cell death. We propose that Ku70 may act as a survival factor in these cells such that Ku70 depletion triggers Bax-dependent cell death. Here, we addressed two fundamental questions about this model: (1) Does all Bax, which is a cytosolic protein, bind to all cytosolic Ku70? and (2) Is Ku70 a survival factor in cells types other than neuronal neuroblastoma cells? We show here that, in neuronal neuroblastoma cells, only a small fraction of Ku70 binds to a small fraction of Bax; most Bax is monomeric. Interestingly, there is no free or monomeric Ku70 in the cytosol; most cytosolic Ku70 is in complex with other factors forming several high molecular weight complexes. A fraction of cytosolic Ku70 also binds to cytosolic Ku80, Ku70's binding partner in the nucleus. Ku70 may not be a survival factor in some cell types (Ku70-depletion less sensitive) because Ku70 depletion does not affect survival of these cells. These results indicate that, in addition to Ku70 acetylation, other factors may be involved in regulating Ku70-Bax binding in the Ku70-depletion less sensitive cells because Ku70 acetylation in these cells is not sufficient to dissociate Bax from Ku70 or to activate Bax.

  5. Eosinofilorraquia em tumor maligno: apresentação de caso

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    João Baptista dos Reis Filho

    1985-09-01

    Full Text Available A presença de granulócitos eosinófilos associados a tumores malignos que acometem o sistema nervoso tem sido raramente comunicada. O propósito deste registro é apresentar o caso de um paciente com 47 anos de idade com tumor cerebral maligno (astrocitoma grau III, cujo estudo citológico do LCR revelou quadro inflamatório com presença de elevada percentagem de granulócitos eosinófilos.

  6. Cariometria aplicada a avaliaçao da anaplasia em tumores ependimários

    OpenAIRE

    Silva, Antonio de Padua Gomes da

    1987-01-01

    Resumo: Foram realizadas 1.500 medições de volumes de núcleos, através de cariometria com ocular micrométrica simples, para comparação entre células ependimárias normais e neoplásicas, determinando-se, matematicamente, o aumento de volume que existe quando a célula normal se dediferencia em célula neoplásica.

  7. Tratamento de dor em paciente com tumor sacral inoperável: relato de caso Tratamiento de dolor en paciente con tumor sacral inoperable: relato de caso Management of pain in patient with inoperable sacral tumor: case report

    Directory of Open Access Journals (Sweden)

    Juliano Rodrigues Gasparini

    2004-04-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: Diversas técnicas podem ser utilizadas no controle de dor em pacientes oncológicos. O objetivo deste relato é mostrar o uso de algumas medidas terapêuticas empregadas para tratar um paciente com quadro doloroso importante de difícil controle. RELATO DO CASO: Paciente do sexo masculino, 70 anos, com cordoma sacral e com possibilidade terapêutica muito difícil. Apresentava quadro de dor importante associado ao tumor. São relatadas diversas técnicas utilizadas no seu tratamento e os resultados obtidos. CONCLUSÕES: Os bloqueios neurolíticos, para o controle da dor em paciente com tumores cuja possibilidade terapêutica é difícil, constituem técnica eficaz quando bem indicados e realizados dentro de critérios estabelecidos.JUSTIFICATIVA Y OBJETIVOS: Diversas técnicas pueden ser utilizadas en el control de dolor en pacientes oncológicos. El objetivo de este relato es mostrar el uso de algunas medidas terapéuticas utilizadas para tratar un paciente con cuadro doloroso importante de difícil control. RELATO DE CASO: Paciente masculino, 70 años, con cordoma sacral y con posibilidad terapéutica muy difícil. Presentaba cuadro de dolor importante asociado al tumor. Se relatan diversas técnicas utilizadas en su tratamiento y los resultados obtenidos. CONCLUSIONES: Los bloqueos neurolíticos, para el control del dolor en paciente con tumores cuja posibilidad terapéutica es difícil, constituyen técnica eficaz cuando bien indicados y realizados dentro de criterios establecidos.BACKGROUND AND OBJECTIVES: Different techniques may be used to control cancer pain. This report aimed at describing some therapeutic measures used to treat a patient with a severe and bad responsive pain. CASE REPORT: A 70-year-old male patient a sacral chordoma of very difficult therapeutic. He referred major tumor-associated pain. Several techniques used to treat pain of this patient and results obtained are reported. CONCLUSIONS

  8. INTRAOCULAR TRANSMISSIBLE VENEREAL TUMOR IN A DOG TUMOR VENÉREO TRANSMISSÍVEL INTRA-OCULAR EM CÃO

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    Geórgia Nadalini Rodrigues

    2001-02-01

    Full Text Available Canine transmissible venereal tumor (TVT is a round cell neoplasm occurring on the external genital mucosa of male and female dogs. Transmission is by cell implantation during coitus, licking, or other interaction between an affected dog and a susceptible host. Metastasis of the tumor rarely occurs. This report describes an unusual presentation of TVT with intraocular involvement and inguinal lymph nodes metastasis. The subject was a six-year-old, intact, male, Brazilian Terrier dog with a history of abnormal masses in the right eye, penis and several subcutaneous nodules in the inguinal area. Histopathological examination of the eye specimens as well as cytologic examination of penile mass and subcutaneous nodules revealed similar findings. The examination revealed round cells containing a large nuclei with prominent, central located nucleoli and a pale cytoplasm containing few small, clear round vacuoles. Histologically, the subcutaneous nodules in the inguinal area were lymph nodes. The diagnosis of TVT with intraocular involvement and lymph nodes metastasis was based on clinical, cytologic and histopathologic findings.Tumor venéreo transmissível (TVT é uma neoplasia de células redondas que acomete a mucosa genital externa de cães, machos e fêmeas. A transmissão decorre da implantação de células tumorais durante o coito, brigas ou interações entre animais portadores e susceptíveis. Existem relatos referindo-se a localizações atípicas do TVT, mas metástases raramente ocorrem. O presente relato descreve um caso incomum de TVT, com acometimento intra-ocular e metástases nos linfonodos ingüinais, num cão Terrier Brasileiro, com seis anos de idade. O animal apresentava massas anormais de tecido no olho direito, extremidade do pênis e aumento de volume de linfonodos da região ingüinal. A histopatologia do globo ocular e as citologias da massa peniana e dos nódulos subcutâneos evidenciaram aspectos citológicos semelhantes

  9. Direct Activation of Bax Protein for Cancer Therapy

    Science.gov (United States)

    Liu, Zhiqing; Ding, Ye; Ye, Na; Wild, Christopher; Chen, Haiying; Zhou, Jia

    2015-01-01

    Bax, a central cell death regulator, is an indispensable gateway to mitochondrial dysfunction and a major pro-apoptotic member of the Bcl-2 family proteins that control apoptosis in normal and cancer cells. Dysfunction of apoptosis renders the cancer cell resistant to treatment as well as promotes tumorigenesis. Bax activation induces mitochondrial membrane permeabilization, thereby leading to the release of apoptotic factor cytochrome c and consequently cancer cell death. A number of drugs in clinical use are known to indirectly activate Bax. Intriguingly, recent efforts demonstrate that Bax can serve as a promising direct target for small-molecule drug discovery. Several direct Bax activators have been identified to hold promise for cancer therapy with the advantages of specificity and the potential of overcoming chemo- and radioresistance. Further investigation of this new class of drug candidates will be needed to advance them into the clinic as a novel means to treat cancer. PMID:26395559

  10. Bax, Bak and beyond - mitochondrial performance in apoptosis.

    Science.gov (United States)

    Peña-Blanco, Aida; García-Sáez, Ana J

    2017-07-29

    Bax and Bak are members of the Bcl-2 family and core regulators of the intrinsic pathway of apoptosis. Upon apoptotic stimuli, they are activated and oligomerize at the mitochondrial outer membrane (MOM) to mediate its permeabilization, which is considered a key step in apoptosis. However, the molecular mechanism underlying Bax and Bak function has remained a key question in the field. Here, we review recent structural and biophysical evidence that has changed our understanding of how Bax and Bak promote MOM permeabilization. We also discuss how the spatial regulation of Bcl-2 family preference for binding partners contributes to regulate Bax and Bak activation. Finally, we consider the contribution of mitochondrial composition, dynamics and interaction with other organelles to apoptosis commitment. A new perspective is emerging, in which the control of apoptosis by Bax and Bak goes beyond them and is highly influenced by additional mitochondrial components. © 2017 Federation of European Biochemical Societies.

  11. Bax and Bak Pores: Are We Closing the Circle?

    Science.gov (United States)

    Cosentino, Katia; García-Sáez, Ana J

    2017-04-01

    Bax and its homolog Bak are key regulators of the mitochondrial pathway of apoptosis. On cell stress Bax and Bak accumulate at distinct foci on the mitochondrial surface where they undergo a conformational change, oligomerize, and mediate cytochrome c release, leading to cell death. The molecular mechanisms of Bax and Bak assembly and mitochondrial permeabilization have remained a longstanding question in the field. Recent structural and biophysical studies at several length scales have shed light on key aspects of Bax and Bak function that have shifted how we think this process occurs. These discoveries reveal an unexpected molecular mechanism in which Bax (and likely Bak) dimers assemble into oligomers with an even number of molecules that fully or partially delineate pores of different sizes to permeabilize the mitochondrial outer membrane (MOM) during apoptosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Constipação intestinal em pacientes com tumores intracranianos Obstipación intestinal en pacientes com tumores intracraneanos Intestinal constipation in patients with intracranial tumors

    Directory of Open Access Journals (Sweden)

    Analuiza Cândido Torres

    2006-06-01

    Full Text Available O esforço que ocorre durante a manobra de Valsalva gera aumento da pressão intracraniana e pode descompensar pacientes com hipertensão intracraniana. Os objetivos deste estudo foram avaliar a incidência de constipação intestinal no pré-operatório de pacientes com tumores intracranianos e relacionar a constipação intestinal com a descompensação da hipertensão intracraniana. O estudo foi realizado na unidade de neurocirurgia do Hospital São Paulo, de agosto a outubro de 2003, com a avaliação de 37 pacientes. O tempo médio de pré-operatório foi de 12 dias, variando de 2 a 34 dias. Durante esse período, 6 (16,2% pacientes apresentaram constipação, sendo que todos receberam dieta laxativa e lactulose, e destes, 2 (33,3% necessitaram de enema. Todos os pacientes realizaram manobra de Valsalva durante a evacuação, e não foi observada descompensação da hipertensão intracraniana nos pacientes que apresentaram ou não constipação intestinal.El esfuerzo empleado durante la maniobra de Valsalva produce aumento de la presión intracraneana, que podría llevar a descompensación de los pacientes con hipertensión intracraneana. Los objetivos del presente estudio fueron evaluar la incidencia de constipación intestinal en el preoperatorio de pacientes con tumores intracraneanos y relacionar la constipación intestinal con la descompensación de la hipertensión intracraneana. El estudio fue realizado en la unidad de neurocirugía del Hospital São Paulo, Brasil, de agosto a octubre de 2003, evaluando a 37 pacientes. El tiempo medio de preoperatorio fue 12 días, oscilando entre 2 y 34 días. Durante éste periodo 6 (16,2% pacientes presentaron constipación, considerando que todos recibieron dieta laxante y lactulosa; de estos, 2 (33,3% necesitaron de enema. Todos los pacientes hicieron maniobra de Valsalva durante la eliminación de heces; no se observó descompensación de la hipertensión intracraneana en los pacientes que

  13. Potential impact of (rs 4645878) BAX promoter -248G>A and (rs 1042522) TP53 72Arg>pro polymorphisms on epithelial ovarian cancer patients.

    Science.gov (United States)

    Dholariya, S; Mir, R; Zuberi, M; Yadav, P; Gandhi, G; Khurana, N; Saxena, A; Ray, P C

    2016-01-01

    In India, Epithelial ovarian cancer has emerged as one of the most common malignancies affecting women. Tumor protein 53 (TP53) induces expression of the B cell lymphoma 2-associated X protein (BAX) gene by directly binding to the TP53-binding element in the BAX promoter. Therefore, we hypothesized that single-nucleotide polymorphism of BAX promoter -248G>A and TP53 72Arg>Pro gene may jointly contribute to ovarian cancer risk. This study aimed at exploring the association of BAX promoter -248G>A and TP53 72Arg>Pro gene polymorphism with risk of developing EOC and its clinicopathological features and to evaluate gene-gene interaction of these two polymorphisms with risk of developing EOC. The study was conducted on 70 Epithelial ovarian cancer patients and 70 healthy controls. Genotyping of p53 codon 72 and BAX promoter gene was examined by ASO-PCR and PICA-PCR, respectively. Odds ratios and 95 % confidence intervals were calculated. We found an increased cancer risk associated with the BAX AA (ORs = 4.1, 95 %, CI = 1.23-13.97) genotype. An increased risk was also associated with the TP53 Pro/Pro (OR = 4.4, 95 % CI = 1.40-13.99) and Arg/Pro genotype (OR = 2.3, 95 % CI = 1.13-4.86). The gene-gene interaction of these polymorphisms increased EOC risk in a more than additive manner (ORs for the presence of both BAX AA and TP53 Arg/Pro genotypes = 8.7, 95 % CI = 1.66-45.48). BAX GG genotype was associated with adverse staging of cancer (P = 0.01). The findings suggest that polymorphism of BAX and TP53 genes may be potential genetic modifiers for developing ovarian cancer.

  14. CONSTRUCTION OF RECOMBINANT PLASMID PIRES-BAX-HGF%pIRES-Bax-HGF重组质粒的构建

    Institute of Scientific and Technical Information of China (English)

    黄涛; 常青; 徐平

    2011-01-01

    Objective To construct the plasmid vector of pIRES-Bax-HGF. Methods The Bax gene sequence was cloned from ovarian cancer samples, and HGF gene sequence from pBluescript Ⅱ SK+HGF plasmid derived from ATCC. Bax and HGF coding sequence were inserted into pIRES plasmid by step double enzyme digestion. Results Enzyme digestion and sequencing indicated that the construction of recombinant pIRES-Bax-HGF plasmid was successful. Conclusion Obtaining the coding genes of both Bax and HGF, and successfully creating the plasmid vector of plRES-Bax-HGF establish a foundation for further study of the effects of HGF and Bax on vascular endothelial cells, smooth muscle cells, and fibrocytes, which steps out an important step to treat post-CABG restenosis at gene level.%目的 构建pIRES-Bax-HGF质粒载体.方法 采用RT-PCR方法从卵巢癌标本中克隆Bax的基因序列,从ATCC来源的pBlueseriptⅡ SK+HGF质粒中克隆HGF的基因序列.分步双酶切插入到plRES载体质粒中.结果 酶切鉴定及测序表明,重组pIRES-Bax-HGF质粒构建成功.结论 获取HGF及Bax编码基因并成功构建重组pIRES-Bax-HGF质粒载体,为进一步研究HGF及Bax对血管内皮细胞、平滑肌细胞、纤维细胞等的影响奠定了基础,也向基因水平干预冠状动脉旁路移植术术后再狭窄的形成迈出了重要一步.

  15. The dynamics of Bax channel formation: influence of ionic strength.

    Science.gov (United States)

    Ganesan, Vidyaramanan; Walsh, Timothy; Chang, Kai-Ti; Colombini, Marco

    2012-08-08

    Mitochondrial outer membrane permeabilization (MOMP) is a complex multistep process. Studies of MOMP in vivo are limited by the stochastic variability of MOMP between cells and rapid completion of IMS protein release within single cells. In vitro models have provided useful insights into MOMP. We have investigated the dynamics of Bax-mediated MOMP in isolated mitochondria using ionic strength as a tool to control the rate of MOMP. We find that Bax can induce both transient permeabilization, detected by protein release, and more substantial long-lasting permeabilization, measured by the rate of oxidation of added cytochrome c. We found that higher ionic strength causes Bax to form small channels quickly but the expansion of these early channels is impeded. This inhibitory effect of ionic strength is independent of tBid. Channels formed under low ionic strength are not destabilized by raising the ionic strength. Increase in ionic strength also increases the ability of Bcl-xL to inhibit Bax-mediated MOMP. Ionic strength does not affect Bax insertion into mitochondria. Thus, ionic strength influences the assembly of Bax molecules already in membrane into channels. Ionic strength can be used as an effective biophysical tool to study Bax-mediated channel formation.

  16. Modulation of Bax and mTOR for Cancer Therapeutics.

    Science.gov (United States)

    Li, Rui; Ding, Chunyong; Zhang, Jun; Xie, Maohua; Park, Dongkyoo; Ding, Ye; Chen, Guo; Zhang, Guojing; Gilbert-Ross, Melissa; Zhou, Wei; Marcus, Adam I; Sun, Shi-Yong; Chen, Zhuo G; Sica, Gabriel L; Ramalingam, Suresh S; Magis, Andrew T; Fu, Haian; Khuri, Fadlo R; Curran, Walter J; Owonikoko, Taofeek K; Shin, Dong M; Zhou, Jia; Deng, Xingming

    2017-06-01

    A rationale exists for pharmacologic manipulation of the serine (S)184 phosphorylation site of the proapoptotic Bcl2 family member Bax as an anticancer strategy. Here, we report the refinement of the Bax agonist SMBA1 to generate CYD-2-11, which has characteristics of a suitable clinical lead compound. CYD-2-11 targeted the structural pocket proximal to S184 in the C-terminal region of Bax, directly activating its proapoptotic activity by inducing a conformational change enabling formation of Bax homooligomers in mitochondrial membranes. In murine models of small-cell and non-small cell lung cancers, including patient-derived xenograft and the genetically engineered mutant KRAS-driven lung cancer models, CYD-2-11 suppressed malignant growth without evident significant toxicity to normal tissues. In lung cancer patients treated with mTOR inhibitor RAD001, we observed enhanced S184 Bax phosphorylation in lung cancer cells and tissues that inactivates the propaoptotic function of Bax, contributing to rapalog resistance. Combined treatment of CYD-2-11 and RAD001 in murine lung cancer models displayed strong synergistic activity and overcame rapalog resistance in vitro and in vivo Taken together, our findings provide preclinical evidence for a pharmacologic combination of Bax activation and mTOR inhibition as a rational strategy to improve lung cancer treatment. Cancer Res; 77(11); 3001-12. ©2017 AACR. ©2017 American Association for Cancer Research.

  17. Direct and selective small-molecule activation of proapoptotic BAX

    Science.gov (United States)

    Gavathiotis, Evripidis; Reyna, Denis E; Bellairs, Joseph A; Leshchiner, Elizaveta S; Walensky, Loren D

    2013-01-01

    BCL-2 family proteins are key regulators of the apoptotic pathway. Antiapoptotic members sequester the BCL-2 homology 3 (BH3) death domains of proapoptotic members such as BAX to maintain cell survival. The antiapoptotic BH3-binding groove has been successfully targeted to reactivate apoptosis in cancer. We recently identified a geographically distinct BH3-binding groove that mediates direct BAX activation, suggesting a new strategy for inducing apoptosis by flipping BAX’s ‘on switch’. Here we applied computational screening to identify a BAX activator molecule that directly and selectively activates BAX. We demonstrate by NMR and biochemical analyses that the molecule engages the BAX trigger site and promotes the functional oligomerization of BAX. The molecule does not interact with the BH3-binding pocket of antiapoptotic proteins or proapoptotic BAK and induces cell death in a BAX-dependent fashion. To our knowledge, we report the first gain-of-function molecular modulator of a BCL-2 family protein and demonstrate a new paradigm for pharmacologic induction of apoptosis. PMID:22634637

  18. Tumor venéreo transmissível com metástases cutâneas em um cão transmissible venereal Tumor with cutaneous metastasis in a dog

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    Flávio Quaresma Moutinho

    1995-01-01

    Full Text Available O tumor venéreo transmissível é diagnosticado, na maioria das vezes, em animais jovens, sadios e sexualmente ativos. Acomete, comumente, a genitália externa. Metástases, apesar de incomuns, ocorrem. O presente trabalho relata um caso de tumor venéreo transmissível na glande peniana com disseminação para a pele das regiões abdominal e inguinal.Transmissible venereal tumor is most of the times diagnosed in young, healthy and sexually active animais. In general it affects any part of external genitalis; metastasis, although uncommon, may occur. This paper reports a case of a transmissible venereal tumor, in the glans penis of a dog with spread to the skin of abdominal and inguinal regions.

  19. Mitochondrial ceramide-rich macrodomains functionalize Bax upon irradiation.

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    Hyunmi Lee

    Full Text Available Evidence indicates that Bax functions as a "lipidic" pore to regulate mitochondrial outer membrane permeabilization (MOMP, the apoptosis commitment step, through unknown membrane elements. Here we show mitochondrial ceramide elevation facilitates MOMP-mediated cytochrome c release in HeLa cells by generating a previously-unrecognized mitochondrial ceramide-rich macrodomain (MCRM, which we visualize and isolate, into which Bax integrates.MCRMs, virtually non-existent in resting cells, form upon irradiation coupled to ceramide synthase-mediated ceramide elevation, optimizing Bax insertion/oligomerization and MOMP. MCRMs are detected by confocal microscopy in intact HeLa cells and isolated biophysically as a light membrane fraction from HeLa cell lysates. Inhibiting ceramide generation using a well-defined natural ceramide synthase inhibitor, Fumonisin B1, prevented radiation-induced Bax insertion, oligomerization and MOMP. MCRM deconstruction using purified mouse hepatic mitochondria revealed ceramide alone is non-apoptogenic. Rather Bax integrates into MCRMs, oligomerizing therein, conferring 1-2 log enhanced cytochrome c release. Consistent with this mechanism, MCRM Bax isolates as high molecular weight "pore-forming" oligomers, while non-MCRM membrane contains exclusively MOMP-incompatible monomeric Bax.Our recent studies in the C. elegans germline indicate that mitochondrial ceramide generation is obligate for radiation-induced apoptosis, although a mechanism for ceramide action was not delineated. Here we demonstrate that ceramide, generated in the mitochondrial outer membrane of mammalian cells upon irradiation, forms a platform into which Bax inserts, oligomerizes and functionalizes as a pore. We posit conceptualization of ceramide as a membrane-based stress calibrator, driving membrane macrodomain organization, which in mitochondria regulates intensity of Bax-induced MOMP, and is pharmacologically tractable in vitro and in vivo.

  20. Mitochondrial BAX Determines the Predisposition to Apoptosis in Human AML.

    Science.gov (United States)

    Reichenbach, Frank; Wiedenmann, Cornelius; Schalk, Enrico; Becker, Diana; Funk, Kathrin; Scholz-Kreisel, Peter; Todt, Franziska; Wolleschak, Denise; Döhner, Konstanze; Marquardt, Jens U; Heidel, Florian; Edlich, Frank

    2017-08-15

    Purpose: Cell-to-cell variability in apoptosis signaling contributes to heterogenic responses to cytotoxic stress in clinically heterogeneous neoplasia, such as acute myeloid leukemia (AML). The BCL-2 proteins BAX and BAK can commit mammalian cells to apoptosis and are inhibited by retrotranslocation from the mitochondria into the cytosol. The subcellular localization of BAX and BAK could determine the cellular predisposition to apoptotic death.Experimental Design: The relative localization of BAX and BAK was determined by fractionation of AML cell lines and patient samples of a test cohort and a validation cohort.Results: This study shows that relative BAX localization determines the predisposition of different AML cell lines to apoptosis. Human AML displays a surprising variety of relative BAX localizations. In a test cohort of 48 patients with AML, mitochondria-shifted BAX correlated with improved patient survival, FLT3-ITD status, and leukocytosis. Analysis of a validation cohort of 80 elderly patients treated with myelosuppressive chemotherapy confirmed that relative BAX localization correlates with probability of disease progression, FLT3-ITD status, and leukocytosis. Relative BAX localization could therefore be helpful to identify elderly or frail patients who may benefit from cytotoxic therapy.Conclusions: In this retrospective analysis of two independent AML cohorts, our data suggest that Bax localization may predict prognosis of patients with AML and cellular predisposition to apoptosis, combining the actual contribution of known and unknown factors to a final "common path." Clin Cancer Res; 23(16); 4805-16. ©2017 AACR. ©2017 American Association for Cancer Research.

  1. ATP promotes cell survival via regulation of cytosolic [Ca2+] and Bcl-2/Bax ratio in lung cancer cells.

    Science.gov (United States)

    Song, Shanshan; Jacobson, Krista N; McDermott, Kimberly M; Reddy, Sekhar P; Cress, Anne E; Tang, Haiyang; Dudek, Steven M; Black, Stephen M; Garcia, Joe G N; Makino, Ayako; Yuan, Jason X-J

    2016-01-15

    Adenosine triphosphate (ATP) is a ubiquitous extracellular messenger elevated in the tumor microenvironment. ATP regulates cell functions by acting on purinergic receptors (P2X and P2Y) and activating a series of intracellular signaling pathways. We examined ATP-induced Ca(2+) signaling and its effects on antiapoptotic (Bcl-2) and proapoptotic (Bax) proteins in normal human airway epithelial cells and lung cancer cells. Lung cancer cells exhibited two phases (transient and plateau phases) of increase in cytosolic [Ca(2+)] ([Ca(2+)]cyt) caused by ATP, while only the transient phase was observed in normal cells. Removal of extracellular Ca(2+) eliminated the plateau phase increase of [Ca(2+)]cyt in lung cancer cells, indicating that the plateau phase of [Ca(2+)]cyt increase is due to Ca(2+) influx. The distribution of P2X (P2X1-7) and P2Y (P2Y1, P2Y2, P2Y4, P2Y6, P2Y11) receptors was different between lung cancer cells and normal cells. Proapoptotic P2X7 was nearly undetectable in lung cancer cells, which may explain why lung cancer cells showed decreased cytotoxicity when treated with high concentration of ATP. The Bcl-2/Bax ratio was increased in lung cancer cells following treatment with ATP; however, the antiapoptotic protein Bcl-2 demonstrated more sensitivity to ATP than proapoptotic protein Bax. Decreasing extracellular Ca(2+) or chelating intracellular Ca(2+) with BAPTA-AM significantly inhibited ATP-induced increase in Bcl-2/Bax ratio, indicating that a rise in [Ca(2+)]cyt through Ca(2+) influx is the critical mediator for ATP-mediated increase in Bcl-2/Bax ratio. Therefore, despite high ATP levels in the tumor microenvironment, which would induce cell apoptosis in normal cells, the decreased P2X7 and elevated Bcl-2/Bax ratio in lung cancer cells may enable tumor cells to survive. Increasing the Bcl-2/Bax ratio by exposure to high extracellular ATP may, therefore, be an important selective pressure promoting transformation and cancer progression. Copyright

  2. Contaminação tumoral em trajeto de biópsia de tumores ósseos malignos primários Tumor contamination in the biopsy path of primary malignant bone tumors

    Directory of Open Access Journals (Sweden)

    Marcelo Parente Oliveira

    2012-10-01

    Full Text Available OBJETIVO: Estudar os fatores possivelmente associados à contaminação tumoral do trajeto de biópsia de tumores ósseos malignos primários. MÉTODO: Foram estudados, retrospectivamente, 35 pacientes submetidos a tratamento cirúrgico com diagnóstico de osteossarcoma, tumor de Ewing e condrossarcoma. A amostra foi analisada para caracterização quanto à técnica de biópsia empregada, tipo histológico do tumor, realização de quimioterapia neoadjuvante, ocorrência de recidiva local e contaminação tumoral no trajeto da biópsia. RESULTADOS: Nos 35 pacientes avaliados ocorreram quatro contaminações (11,43%. Um caso era de osteossarcoma, dois casos de tumor de Ewing e um caso de condrossarcoma, não se observando associação entre o tipo de tumor e a presença de contaminação tumoral no trajeto da biópsia (p = 0,65. Também não se observou associação entre a presença de contaminação tumoral e a técnica de biópsia (p = 0,06. Por outro lado, observou-se associação entre a presença de contaminação tumoral e a ocorrência de recidiva local (p = 0,01 e entre a presença de contaminação e a não realização de quimioterapia neoadjuvante (p = 0,02. CONCLUSÃO: A contaminação tumoral no trajeto de biópsia de tumores ósseos malignos primários esteve associada à ocorrência de recidiva local. Por outro lado, não mostrou ser influenciada pelo tipo de biópsia realizada e pelo tipo histológico de tumor estudado. A quimioterapia neoadjuvante mostrou um efeito protetor contra esta complicação. A despeito desses achados, a contaminação tumoral é uma complicação que deve sempre ser considerada, sendo recomendada a remoção do trajeto da biópsia na cirurgia de ressecção do tumor.OBJECTIVE: To study factors possibly associated with tumor contamination in the biopsy path of primary malignant bone tumors. METHOD: Thirty-five patients who underwent surgical treatment with diagnoses of osteosarcoma, Ewing's tumor and

  3. Glioma supratentorial de baixo grau em adulto: experiência com 23 pacientes operados Supratentorial low grade tumors in adults: an experience with 23 surgical cases

    Directory of Open Access Journals (Sweden)

    José Carlos Lynch

    2004-06-01

    Full Text Available Os astrocitomas e oligodendrogliomas supratentoriais dos adultos são tumores infrequentes. Analisamos retrospectivamente 23 pacientes com este tipo de neoplasia que foram operados entre 1986 e 2002. Não ocorreu nenhum óbito no pós-operatório. A sobrevida de 5 e 10 anos de todo o grupo foi 67 e 30% respectivamente, semelhante a outras experiências. Em 14 pacientes obtivemos a remoção completa da lesão (60,8% e em 9 (39,2% ocorreu remoção parcial do tumor. No subgrupo da ressecção total do tumor, 89% sobreviveram 5 anos e 45% alcançaram 10 anos de sobrevida, em contraste com o subgrupo da remoção parcial em que somente 35% alcançaram os 5 anos de sobrevida e nenhum, 10 anos. Devido aos efeitos deletérios da radioterapia, nós preferimos prescrevê-la apenas nos casos de recorrência tumoral.Low-grade supratentorial astrocytomas and oligodendrogliomas in adults are uncommon tumors of the central nervous system. We analyzed retrospectively 23 patients with this type of neoplasia, who were operated on between 1986 and 2002. There were no post-operative deaths. The survival rate at 5 and 10 years post-surgery for the entire sample was 67 and 30% respectively, similar to other outcomes. With 14 patients we achieved a complete removal of the lesion (60.8% and with 9 (39.2% partial removal of the tumor. In the sub-group which underwent total resection of the tumor, 89% survived 5 years and 45% attained 10 years of survival, in contrast with the sub-group that underwent partial removal in which only 35% attained 5 years of survival and none 10 years. Due to the deleterious effects of radiation therapy, we preferred to prescribe it only in cases of tumor recurrence.

  4. Meningiomas and hormonal receptors: immunohistochemical study in typical and non-typical tumors Meningiomas e receptores hormonais: estudo imuno-histoquímico em tumores típicos e não típicos

    Directory of Open Access Journals (Sweden)

    ARLETE HILBIG

    1998-06-01

    Full Text Available The authors assessed 116 cases of meningiomas classified as typical, atypical and anaplastic and they used an immunohistochemical technique for estrogen and progesterone receptors attempting to determine if there is any difference between typical and non-typical tumors in relation to hormone receptors. The immunohistochemical technique to estrogen receptors was negative in all meningiomas studied. Progesterone receptors were detected in 58.3% of typical, and in 48.2% of non-typical meningiomas. This difference was not statistically significant. However, individually considering the criteria used for selection of non-typical tumours, those that concurrently displayed brain invasion and increased mitotic activity or necrosis, as well as the summation of those three features, were predominantly negative for progesterone receptors (respectively p=0.038; p=0.001; and p=0.044. The authors conclude that estrogen receptors were not present in meningiomas; that progesterone receptors in isolation are not enough to predict a higher tumoral malignancy but can be useful associated with other histological features.Os autores avaliam 116 meningiomas classificados em típicos, atípicos ou anaplásicos usando técnica imuno-histoquímica para receptores de estrógeno (ER e progesterona (PR com o objetivo de determinar se existe diferença entre tumores típicos e não típicos em relação aos receptores hormonais. Todos os tumores estudados foram negativos para ER. Os receptores de progesterona foram detectados em 58,3% dos meningiomas típicos e em 48,2% dos tumores não-típicos. Essa diferença não foi estatisticamente significativa. Entretanto, considerando os critérios utilizados para seleção dos não-típicos, os tumores que apresentavam, de forma concomitante, invasão do sistema nervoso central e aumento da taxa mitótica ou necrose, bem como a soma das três características, foram predominantemente negativos para PR (p=0,038; 0,01 e 0

  5. Prevalência de cistos e tumores odontogênicos em pacientes atendidos na Fundação Assistencial da Paraíba: estudo retrospectivo

    OpenAIRE

    Pereira, Jozinete Vieira; Figueirêdo, Danillo Urquiza de; Souza, Emmanuel Albuquerque; Holmes, Tatiana Stuart Vieira; Gomes, Daliana Queiroga de Castro; Cavalcanti, Alessandro Leite

    2016-01-01

    Avaliar a prevalência de cistos e tumores odontogênicos em pacientes atendidos na Fundação Assistencial da Paraíba (FAP). Foi realizado um estudo observacional, epidemiológico e retrospectivo, por meio da análise de 2.268 prontuários odontológicos de pacientes atendidos no período de janeiro de 1999 a dezembro de 2008. Os dados foram coletados por um único examinador e registrados em ficha específica, sendo analisadas as variáveis: gênero, faixa etária, tipo de lesão (cisto ou tumor) e locali...

  6. A nonapoptotic role for BAX and BAK in eicosanoid metabolism.

    Science.gov (United States)

    Zhang, Tejia; Walensky, Loren D; Saghatelian, Alan

    2015-06-19

    BCL-2 proteins are key regulators of programmed cell death. The interplay between pro and antiapoptotic BCL-2 members has important roles in many cancers. In addition to their apoptotic function, recent evidence supports key nonapoptotic roles for several BCL-2 proteins. We used an unbiased lipidomics strategy to reveal that the proapoptotic proteins BAX, and to a lesser extent BAK, regulate the cellular inflammatory response by mediating COX-2 expression and prostaglandin biosynthesis. COX-2 upregulation in response to the bacterial endotoxin lipopolysaccharide is blunted in the absence of BAX, and Bax(-/-) mouse embryonic fibroblasts display altered kinetics of NFκB and MAPK signaling following endotoxin treatment. Our approach uncovers a novel, nonapoptotic function for BAX in regulation of the cellular inflammatory response and suggests that inflammation and apoptosis are more tightly connected than previously anticipated.

  7. Bax and Bak expression in cervical smears of women with low-and high-risk HPV types: A study of 120 cases.

    Science.gov (United States)

    Klapsinou, Eirini; Argyri, Elena; Panotopoulou, Efstathia; Daskalopoulou, Dimitra; Patsouris, Efstratios; Nonni, Afroditi; Lazaris, Andreas C; Thomopoulou, Georgia-Heleni

    2015-01-01

    Human papillomavirus (HPV) is known to be involved in the carcinogenesis of squamous cells in uterine cervix cancer, mostly by binding and inactivating the p53 and pRb tumor suppressor genes. Lately, evidence has emerged suggesting that HPV oncoproteins may interact with proteins involved in cellular apoptosis as well. This study aimed to investigate the expression of proapoptotic proteins Bax and Bak in women with low-risk and high-risk HPV types as opposed to HPV-negative women, and in women with normal pap smear compared to women with abnormal Papanicolau test (Pap) smear. A total of 120 liquid-based cervical samples were subtyped for HPV types with microarray hybridization and then stained and evaluated immunocytochemically for Bax and Bak expression. Statistical analysis was performed on the Bax and Bak scores (percentage of positive cells × staining intensity), the overall percentage of positive cells, and the most prevalent staining intensity group found in each sample. A weak association between negative Bax staining and cytologically normal Pap smears was discovered, whereas cytologically abnormal samples tended to stain weakly or moderately positive. No other statistically significant difference was found in the other analyzed parameters. Cytologically normal pap smears seem to have a slight tendency to stain negative for Bax as opposed to cytologically abnormal pap smears. Although the association is weak, it is an indication that there might be a connection between the expression of Bax and the development of cervical intraepithelial dysplasia, which warrants further investigation in larger-scale studies.

  8. Structural studies of the protein endostatin in fusion with BAX BH3 death domain, a hybrid that presents enhanced antitumoral activity.

    Science.gov (United States)

    Chura-Chambi, Rosa Maria; Arcuri, Helen Andrade; Lino, Felipe; Versati, Natan; Palma, Mario Sergio; Favaro, Denize C; Morganti, Ligia

    2017-05-01

    Endostatin (ES) is an antiangiogenic protein that exhibits antitumor activity in animal models. However, the activity observed in animals was not observed in human clinical trials. ES-BAX is a fusion protein composed of two functional domains: ES, which presents specificity and is internalized by activated endothelial cells and the proapoptotic BH3 domain of the protein BAX, a peptide inductor of cellular death when internalized. We have previously shown (Chura-Chambi et al., Cell Death Dis, 5, e1371, 2014) that ES-BAX presents improved antitumor activity in relation to wild-type ES. Secondary and tertiary structures of ES-BAX are similar to ES, as indicated by homology-modeling studies and molecular dynamics simulations. Tryptophan intrinsic fluorescence and circular dichroism spectroscopy corroborate these data. (15) N HSQC NMR indicates that ES-BAX is structured, but some ES residues have suffered chemical shift perturbations, suggesting that the BH3 peptide interacts with some parts of the ES protein. ES and ES-BAX present similar stability to thermal denaturation. The production of stable hybrid proteins can be a new approach to the development of therapeutic agents presenting specificity for tumoral endothelium and improved antitumor effect. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

  9. The Dynamics of Bax Channel Formation: Influence of Ionic Strength

    OpenAIRE

    Ganesan, Vidyaramanan; Walsh, Timothy; Chang, Kai-Ti; Colombini, Marco

    2012-01-01

    Mitochondrial outer membrane permeabilization (MOMP) is a complex multistep process. Studies of MOMP in vivo are limited by the stochastic variability of MOMP between cells and rapid completion of IMS protein release within single cells. In vitro models have provided useful insights into MOMP. We have investigated the dynamics of Bax-mediated MOMP in isolated mitochondria using ionic strength as a tool to control the rate of MOMP. We find that Bax can induce both transient permeabilization, d...

  10. Sindrome de russel tumor diencefálico em uma criança

    Directory of Open Access Journals (Sweden)

    Luiz A. C. Roxo da Motta

    1990-03-01

    Full Text Available Apresenta-se o caso de criança do sexo masculino com síndrome de Russel devida a astrocitoma pilocítico localizado na região diencefálica. O diagnóstico foi realizado aos 16 meses de idade, mas sua sintomatologia se iniciou aos 4 meses, com emagrecimento progressivo. À internação apresentava-se com peso de 6150g e 74cm de estatura, emaciada, sem panículo adiposo, irritadica e com sinais de hipertensão intracraniana. Existia estrabismo convergente, nistagmo vertical do olho esquerdo e papiledema bilateral. Os reflexos tendinosos eram exaltados e tinha tetraparesia espástica. A avaliação endócrina demonstrou aumento basal do GH (23 ng/ml, do TSH (6,2 mUI/l e da prolactina (26 ng/ml. Os dois primeiros hormônios não responderam ao teste agudo com o TRH, enquanto a prolactina teve resposta pobre. Foi submetida a radioterapia com acelerador linear (dose total de 4000 rads e a cirurgia, na qual não se conseguiu extirpar todo o tumor, devido a seu tamanho. Nove meses após, a criança encontra-se bem, com apreciável ganho ponderai (2500g.

  11. Reconstitution of the anti-apoptotic Bcl-2 protein into lipid membranes and biophysical evidence for its detergent-driven association with the pro-apoptotic Bax protein.

    Directory of Open Access Journals (Sweden)

    Marcus Wallgren

    Full Text Available The anti-apoptotic B-cell CLL/lymphoma-2 (Bcl-2 protein and its counterpart, the pro-apoptotic Bcl-2-associated X protein (Bax, are key players in the regulation of the mitochondrial pathway of apoptosis. However, how they interact at the mitochondrial outer membrane (MOM and there determine whether the cell will live or be sentenced to death remains unknown. Competing models have been presented that describe how Bcl-2 inhibits the cell-killing activity of Bax, which is common in treatment-resistant tumors where Bcl-2 is overexpressed. Some studies suggest that Bcl-2 binds directly to and sequesters Bax, while others suggest an indirect process whereby Bcl-2 blocks BH3-only proteins and prevents them from activating Bax. Here we present the results of a biophysical study in which we investigated the putative interaction of solubilized full-length human Bcl-2 with Bax and the scope for incorporating the former into a native-like lipid environment. Far-UV circular dichroism (CD spectroscopy was used to detect direct Bcl-2-Bax-interactions in the presence of polyoxyethylene-(23-lauryl-ether (Brij-35 detergent at a level below its critical micelle concentration (CMC. Additional surface plasmon resonance (SPR measurements confirmed this observation and revealed a high affinity between the Bax and Bcl-2 proteins. Upon formation of this protein-protein complex, Bax also prevented the binding of antimycin A2 (a known inhibitory ligand of Bcl-2 to the Bcl-2 protein, as fluorescence spectroscopy experiments showed. In addition, Bcl-2 was able to form mixed micelles with Triton X-100 solubilized neutral phospholipids in the presence of high concentrations of Brij-35 (above its CMC. Following detergent removal, the integral membrane protein was found to have been fully reconstituted into a native-like membrane environment, as confirmed by ultracentrifugation and subsequent SDS-PAGE experiments.

  12. Association of Bax and Bak homo-oligomers in mitochondria. Bax requirement for Bak reorganization and cytochrome c release

    National Research Council Canada - National Science Library

    Mikhailov, Valery; Mikhailova, Margarita; Degenhardt, Kurt; Venkatachalam, Manjeri A; White, Eileen; Saikumar, Pothana

    2003-01-01

    ATP depletion induced by hypoxia or mitochondrial inhibitors results in Bax translocation from cytosol to mitochondria and release of cytochrome c from mitochondria into cytosol in cultured rat proximal tubule cells...

  13. Avaliação textural por ressonância magnética dos tumores da fossa posterior em crianças Magnetic resonance imaging textural evaluation of posterior cranial fossa tumors in childhood

    Directory of Open Access Journals (Sweden)

    Joelson Alves dos Santos

    2004-08-01

    Full Text Available OBJETIVO: Possibilitar a distinção entre tecidos sãos e patológicos em pacientes da faixa etária pediátrica portadores de tumores da fossa posterior, por meio da análise de parâmetros texturais calculados a partir de imagens de ressonância magnética. MATERIAIS E MÉTODOS: Foram analisados 14 pacientes da faixa etária pediátrica, portadores de tumores da fossa posterior, através da definição dos valores texturais das regiões de interesse representando tecidos sãos e patológicos, com base em imagens de ressonância magnética pesadas em T2 pelo "software" MaZda. RESULTADOS: Houve diferença estatisticamente significativa entre os tecidos normal e tumoral, bem como entre os tecidos presumidamente normais adjacentes e distantes da lesão. Não foi possível a distinção entre edema e tumor. CONCLUSÃO: A avaliação textural por ressonância magnética é uma técnica útil para a determinação de diferenças entre diversos tipos de tecidos, inclusive entre áreas de tecidos presumidamente normais à análise visual.OBJECTIVE: To distinguish healthy from pathological tissues in pediatric patients with posterior cranial fossa tumors using calculated textural parameters from magnetic resonance images. MATERIALS AND METHODS: We evaluated 14 pediatric patients with posterior cranial fossa tumors using the software MaZda to define the texture parameters in selected regions of interest representing healthy and pathological tissues based on T2-weighted magnetic resonance images. RESULTS: There was a statistically significant difference between normal and tumoral tissues as well as between supposedly normal tissues adjacent and distant from the tumoral lesion. CONCLUSION: Magnetic resonance textural evaluation is an useful tool for determining differences among various tissues, including tissues that appear apparently normal on visual analysis.

  14. Grape Seed Proanthocyanidins Induce Apoptosis through p53, Bax, and Caspase 3 Pathways1

    Science.gov (United States)

    Roy, Anshu M; Baliga, Manjeshwar S; Elmets, Craig A; Katiyar, Santosh K

    2005-01-01

    Abstract Grape seed proanthocyanidins (GSP) have been shown to inhibit skin chemical carcinogenesis and photocarcinogenesis in mice. The mechanisms responsible for the anticarcinogenic effects of GSP are not clearly understood. Here, we report that treatment of JB6 C141 cells (a well-developed cell culture model for studying tumor promotion in keratinocytes) and p53+/+ fibroblasts with GSP resulted in a dose-dependent induction of apoptosis. GSP-induced (20–80 g/ml) apoptosis was observed by using immunofluorescence (27–90% apoptosis) and flow cytometry (18–87% apoptosis). The induction of apoptosis by GSP was p53-dependent because it occurred mainly in cells expressing wild-type p53 (p53+/+; 15–80%) to a much greater extent than in p53-deficient cells (p53-/-; 6–20%). GSP-induced apoptosis in JB6 C141 cells was associated with increased expression of the tumor-suppressor protein, p53, and its phosphorylation at Ser15. The antiapoptotic proteins, Bcl-2 and Bcl-xl, were downregulated by GSP, whereas the expression of the pro-apoptotic protein, Bax, and the levels of cytochrome c release, Apaf-1, caspase-9, and cleaved caspase 3 (p19 and p17) were markedly increased in JB6 C141 cells. The downregulation of Bcl-2 and upregulation of Bax were also observed in wild-type p53 (p53+/+) fibroblasts but was not observed in their p53-deficient counterparts. These data clearly demonstrate that GSP-induced apoptosis is p53-dependent and mediated through the Bcl-2, Bax, and caspase 3 pathways. PMID:15720815

  15. Molecular and immunohistochemical expression of apoptotic proteins Bax, Bcl-2 and Caspase 3 in infantile hemangioma tissues as an effect of propranolol treatment.

    Science.gov (United States)

    Wnęk, Aneta; Andrzejewska, Ewa; Kobos, Józef; Taran, Katarzyna; Przewratil, Przemysław

    2017-05-01

    Infantile hemangiomas (IHs) are the most common benign tumors of childhood. They are characterized by a unique clinical course with two phases, proliferation and involution, which are followed by regression. The therapy of infantile hemangiomas was revolutionized in 2008 by the introduction of propranolol, however, the mechanism of its influence on hemangiomas remains unclear. The study included 71 patients with IHs, 27 of whom were treated with propranolol while the remaining 44 were used as a comparative group. The expression of Bcl-2, Bax and Caspase3 was determined with immunohistochemistry and mRNA of Bax, Bcl-2 and Caspase3 were assessed with the use of RT-PCR. Both methods revealed a statistically significant decrease in Bcl-2 expression and an increase in Bax in IHs tissues after propranolol treatment. The results obtained for Bax and Bcl-2 proteins may indicate a link between the effect of propranolol and apoptosis. Higher Bax and lower Bcl-2 expression in the propranolol treated group indicates a strong pro- apoptotic action countering any anti-apoptotic activity; apoptosis was indicted in IH tissue as a potential result of propranolol treatment, with potential clinical impact in other tumors. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

  16. Mode of cell death induced by the HSP90 inhibitor 17-AAG (tanespimycin) is dependent on the expression of pro-apoptotic BAX

    Science.gov (United States)

    Powers, Marissa V; Valenti, Melanie; Miranda, Susana; Maloney, Alison; Eccles, Suzanne A.; Thomas, George; Clarke, Paul A; Workman, Paul

    2013-01-01

    Inhibitors of the molecular chaperone heat shock protein 90 (HSP90) are of considerable current interest as targeted cancer therapeutic agents because of the ability to destabilize multiple oncogenic client proteins. Despite their resulting pleiotropic effects on multiple oncogenic pathways and hallmark traits of cancer, resistance to HSP90 inhibitors is possible and their ability to induce apoptosis is less than might be expected. Using an isogenic model for BAX knockout in HCT116 human colon carcinoma cells, we demonstrate the induction of BAX-dependent apoptosis at pharmacologically relevant concentrations of the HSP90 inhibitor 17-AAG both in vitro and in tumor xenografts in vivo. Removal of BAX expression by homologous recombination reduces apoptosis in vitro and in vivo but allows a lower level of cell death via a predominantly necrotic mechanism. Despite reducing apoptosis, the loss of BAX does not alter the overall sensitivity to 17-AAG in vitro or in vivo. The results indicate that 17-AAG acts predominantly to cause a cytostatic antiproliferative effect rather than cell death and further suggest that BAX status may not alter the overall clinical response to HSP90 inhibitors. Other agents may be required in combination to enhance tumor-selective killing by these promising drugs. In addition, there are implications for the use of apoptotic endpoints in the assessment of the activity of molecularly targeted agents. PMID:24185264

  17. Assessment of cell proliferation and prognostic factors in canine mammary gland tumors Avaliação da proliferação celular e fatores prognósticos em tumores mamários caninos

    Directory of Open Access Journals (Sweden)

    A.P. Dutra

    2008-12-01

    Full Text Available Three methods for the analysis of cell proliferation, mitotic index/10 high-power fields (10 HPF, mitotic index/four sets of 10 HPF (40 HPF, and MIB-1 index were evaluated in a series of canine mammary gland tumors, as well as the possible correlation between them. Fifty-six canine mammary gland tumors, including 23 benign and 33 malignant, were studied. In addition, the prognostic impact of mitotic index/10 HPF, and histological malignancy grade were evaluated in 17 malignant tumors, being seven ductal and 10 metaplastic carcinomas. The three methods used to evaluate cell proliferation were correlated with the prognostic impact of mitotic index/10 HPF and histological malignancy grade. The results showed a strong association between mitotic figure counts and MIB-1 index (PAvaliaram-se três métodos de proliferação celular, índice mitótico/10 campos de grande aumento (10 CGA, quatro vezes 10 CGA (40 CGA e índice de marcação por MIB-1, em uma série de tumores mamários caninos, e as possíveis correlações entre estes métodos. Foram estudados 56 tumores mamários caninos, 23 benignos e 33 malignos. Foi também avaliado o impacto prognóstico do índice mitótico (10 CGA e o grau histológico maligno em 17 tumores malignos, sete carcinomas ductais e 10 carcinomas metaplásicos. A correlação entre os três métodos para avaliar a proliferação celular e o impacto prognóstico do índice mitótico por 10 CGA e o grau histológico maligno foi realizada. Os resultados mostraram que existe uma forte associação entre contagem de mitose e o índice de marcação por MIB-1(P<0,0001 e correlação entre contagem de mitoses em 40 CGA e índice de marcação por MIB-1 e entre índice mitótico em 10 CGA e 40 CGA (P<0,05. Observou-se correlação entre os três métodos de avaliação da proliferação celular e os fatores prognósticos semelhante aos estudos de câncer de mama humano.

  18. BAX channel activity mediates lysosomal disruption linked to Parkinson disease.

    Science.gov (United States)

    Bové, Jordi; Martínez-Vicente, Marta; Dehay, Benjamin; Perier, Celine; Recasens, Ariadna; Bombrun, Agnes; Antonsson, Bruno; Vila, Miquel

    2014-05-01

    Lysosomal disruption is increasingly regarded as a major pathogenic event in Parkinson disease (PD). A reduced number of intraneuronal lysosomes, decreased levels of lysosomal-associated proteins and accumulation of undegraded autophagosomes (AP) are observed in PD-derived samples, including fibroblasts, induced pluripotent stem cell-derived dopaminergic neurons, and post-mortem brain tissue. Mechanistic studies in toxic and genetic rodent PD models attribute PD-related lysosomal breakdown to abnormal lysosomal membrane permeabilization (LMP). However, the molecular mechanisms underlying PD-linked LMP and subsequent lysosomal defects remain virtually unknown, thereby precluding their potential therapeutic targeting. Here we show that the pro-apoptotic protein BAX (BCL2-associated X protein), which permeabilizes mitochondrial membranes in PD models and is activated in PD patients, translocates and internalizes into lysosomal membranes early following treatment with the parkinsonian neurotoxin MPTP, both in vitro and in vivo, within a time-frame correlating with LMP, lysosomal disruption, and autophagosome accumulation and preceding mitochondrial permeabilization and dopaminergic neurodegeneration. Supporting a direct permeabilizing effect of BAX on lysosomal membranes, recombinant BAX is able to induce LMP in purified mouse brain lysosomes and the latter can be prevented by pharmacological blockade of BAX channel activity. Furthermore, pharmacological BAX channel inhibition is able to prevent LMP, restore lysosomal levels, reverse AP accumulation, and attenuate mitochondrial permeabilization and overall nigrostriatal degeneration caused by MPTP, both in vitro and in vivo. Overall, our results reveal that PD-linked lysosomal impairment relies on BAX-induced LMP, and point to small molecules able to block BAX channel activity as potentially beneficial to attenuate both lysosomal defects and neurodegeneration occurring in PD.

  19. CO-EXPRESSIONS OF SURVIVIN GENE,BCL-2 AND BAX PROTEINS IN OVARIAN CARCINOMA

    Institute of Scientific and Technical Information of China (English)

    林蓓; 张淑兰; 赵长清

    2004-01-01

    Objective To characterize the cellular properties of ovarian cancer, we examined the correlation between the expression of apoptosis-related gene survivin and those of Bcl-2 and Bar proteins. Methods Expressions of survivin mRNA, and Bcl-2 and Bax proteins in 35 cases of ovarian carcinoma, 10 cases of borderline carcinoma, 10 cases of benign tumors and 10 cases of normal tissue were evaluated by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry SABC method, respectively. Results Expression of survivin gene was detected in a significantly greater proportion in ovarian carcinoma and borderline carcinoma than those in benign tumors and normal tissues. Although there was no relationship between expression of survivin gene and FIGO stage, histologic grade, pathological type and lymphatic metastasis, expressions of Bcl-2 and Bar proteins were positively and negatively correlated with that of survivin gene, respectively. Conclusion Survivin may play an important role in pathogenesis of ovarian carcinoma, with a synergistic role of apoptosis-related gene Bcl-2protein and an antagonistic role of Bax protein in formation and progression of ovarian carcinoma.

  20. Colectomia direita associada à gastroduodenopancreatectomia em bloco por tumor infiltrativo de cólon: relato de caso Right colectomy associated to gastroduodenopancreatectomy in bloc for infiltrative colon tumor: case report

    Directory of Open Access Journals (Sweden)

    Maria Auxiliadora Prolungatti Cesar

    2009-09-01

    Full Text Available INTRODUÇÃO: A eficácia da ressecção em bloco duodenopancreático para tumores infiltrativos não periampulares ainda não está bem definida³, mas sabe-se que em tumores colorretais localmente avançados, a ressecção multivisceral é, na maioria das vezes, a chance de melhor qualidade de vida4. OBJETIVO: apresentar um caso de neoplasia de cólon direito com invasão duodenopancreática tratado com gastroduodenopancreatectomia. RELATO DE CASO: Paciente de 73 anos, branco, que há oito meses apresentava astenia, adinamia e emagrecimento de aproximadamente 20 kg. Ao exame físico: IMC: 20,3, descorado ++/4. Abdome com massa palpável em flanco direito de aproximadamente 15cm. A colonoscopia demonstrou tumor de cólon direito e o anátomo-patológico evidenciou adenocarcinoma moderadamente diferenciado. A Tomografia computadorizada demonstrou os vasos mesentéricos livres de invasão. No intra-operatório se observou massa tumoral envolvendo cólon ascendente até ângulo hepático invadindo segunda para terceira porção duodenal. Foi realizada colectomia direita associadaà gastroduodenopancreatectomia em bloco. O anátomo-patológico da peça revelou adenocarcinoma moderadamente diferenciado de intestino grosso com metástases em tecido duodenal e pancreático com infiltração angio-linfática. O paciente sobreviveu por 8 meses. CONCLUSÃO: A gastroduodenopancreatectomia deve ser considerada para tumores não periampulares na ausência de metástases à distância e quando a condição clinica do paciente permitir e foi a conduta adequada para este paciente.INTRODUCTION: The effectiveness of duodenopancreatic ressection in block for infiltrative periampolar tumors are not yet know, but it is known that in local advanced colorretais tumors, the multivisceral ressection is, most of the time, the possibility of better quality of life. OBJECTIVE: To present a case of right colon neoplasm with duodenopancreatic invasion treated with

  1. Nerve sheath tumors of the head and neck - a radiological review; Tumores da bainha nervosa em cabeca e pescoco - estudo revisional

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Ricardo Pires de; Carramao, Cintia Fernandes; Soares, Aldemir Humberto [Hospital Heliopolis, Sao Paulo, SP (Brazil). Servico de Diagnostico por Imagem; Chacra Junior, Jose; Rapoport, Abrao [Hospital Heliopolis, Sao Paulo, SP (Brazil). Servico de Cirurgia de Cabeca e Pescoco

    1997-01-01

    Peripheral nerve sheath tumors of the head and neck - a review. Peripheral nerve sheath tumors are derived from neural crest and rare classified as neuroectodermal in origin. They can be divided into neurofibroma, schwannoma and neurogenic sarcoma. Neurofifromas are benign well circumscribed, nonencapsulated tumors which involve all elements of normal peripheral nerves. Schwannomas are beginning encapsulated tumors composed fundamentally by Schwann cells. Neurogenic sarcomas are malignant tumors which can be de novo or arise from preexisting neurofibroma or schwannoma. Peripheral nerve sheath tumors can arise from any nerve that contain myelin sheath, but are more frequent in extremities and trunk, being rare on cervical region. neurogenic tumors of head and neck can arise from cranial nerves, especially vagus nerve, brachial plexus and other small nervous plexus. Computed tomography and magnetic resonance imaging are the methods of choice in the evaluation of those tumors and can demonstrate lesions with several patterns. Areas of cystic degeneration are frequent in schwannomas, while neurofibromas are usually homogeneous. About 1/3 of those tumors are hyper vascularized and those who arise nervous spinal; roots can have an aspect of dumbbell which contain cervical and intravertebral components. (author) 51 refs., 5 figs.

  2. The effect of octreotide and bromocriptine on expression of a pro-apoptotic Bax protein in rat prolactinoma.

    Directory of Open Access Journals (Sweden)

    Jolanta Kunert-Radek

    2004-03-01

    Full Text Available It is well established that disruption of apoptosis may lead to tumor initiation, progression or metastasis. It is also well documented that many anticancer drugs induce apoptosis. In the earlier studies, the dopamine D2 receptor agonist bromocriptine (BC and somatostatin analog octreotide (OCT were found to inhibit the growth of the estrogen-induced rat prolactinoma. Our previous investigations, applying the TUNEL method showed the involvement of the pro-apoptotic effect in the action of BC, and to a lesser degree, in the action of OCT. The aim of the present study was to investigate whether the pro-apoptotic action of these drugs involves the increased expression of Bax--a member of Bcl-2 protein family which is known to play an important role in the regulation of apoptosis. Male four-week Fisher 344 rats were used in the experiment. Capsules containing diethylstilboestrol (DES were implanted subcutaneously. Six weeks after the implantation the rats were given OCT (2 x 25 microg/animal/24, BC (3 mg/kg b.w./24 h or OCT and BC at the above doses for 10 days. Bax expression was detected by immunohistochemistry. Prolactin (PRL in blood serum was measured by radioimmunoassay (RIA. It has been found that both OCT and BC, alone or in combination, significantly reduce the tumor weight. Both OCT and BC suppressed PRL levels, but the inhibitory effect of BC was stronger than that of OCT. It has been found that the treatment with OCT and BC, alone or in combination, causes a significant increase in Bax expression in the rat prolactinoma cells. Our findings indicate that anti-tumoral action of bromocriptine and to some extent the action of octreotide in the experimental rat prolactinoma is connected with the induction of apoptosis and is associated with increased Bax expression.

  3. Análise imuno-histoquímica das citoqueratinas em ameloblastoma e tumor odontogênico adenomatóide Immunohistochemical analysis of cytokeratins in ameloblastoma and adenomatoid odontogenic tumor

    Directory of Open Access Journals (Sweden)

    Fernanda Ferreira Lopes

    2005-12-01

    Full Text Available OBJETIVO: O presente trabalho teve por objetivo traçar o perfil das citoqueratinas (CKs 7, 8, 10, 13, 14, 18 e 19 em ameloblastomas e tumor odontogênico adenomatóide (TOA visando contribuir para o entendimento da histogênese desses tumores e somar com os resultados já relatados na literatura. MATERIAL E MÉTODO: do arquivo do Laboratório de Anatomia Patológica do Departamento de Odontologia da Universidade Federal do Rio Grande do Norte (UFRN foi selecionada uma amostra com dez casos de ameloblastomas e oito de TOA para o estudo imuno-histoquímico, utilizando-se anticorpos anti-CKs pelo método da estreptoavidina-biotina. RESULTADOS: Observou-se que nos ameloblastomas a CK 14 esteve presente em todos os casos, enquanto a CK 19 foi observada nas células periféricas (oito casos e nas centrais (cinco casos. Para os TOA, observou-se imunopositividade para a CK 14 em todos os casos, enquanto a CK 19 esteve marcada predominantemente nas células ductais (seis casos. CONCLUSÃO: As citoqueratinas são expressas de forma variada nos ameloblastomas e nos TOA, os quais preservam CK típicas do germe dental em estágios avançados do desenvolvimento, confirmando sua origem exclusiva a partir do epitélio odontogênico e não se evidenciando CK características do epitélio escamoso.OBJECTIVES: The aim of the present study was to describe the immunohistochemical expression of cytokeratins (CKs 7, 8, 10,13, 14, 18 and 19 in the epithelial components of ameloblastomas and adenomatoid odontogenic tumor (AOT. The results were compared and histogenesis discussed. MATERIAL AND METHOD: Specimens of ten ameloblastomas and eight adenomatoid odontogenic tumors were examined by immunohistochemistry using streptavidin-biotin-peroxidase complex method and anti-CKs antibody. The sample was obtained from Department of Oral Pathology, Federal University of Rio Grande do Norte. RESULTS: Immunohistochemical reactivity for CK14 was detected in all cases of

  4. EGR-1 forms a complex with YAP-1 and upregulates Bax expression in irradiated prostate carcinoma cells.

    Science.gov (United States)

    Zagurovskaya, M; Shareef, M M; Das, A; Reeves, A; Gupta, S; Sudol, M; Bedford, M T; Prichard, J; Mohiuddin, M; Ahmed, M M

    2009-02-26

    In this study, we investigated the functional role of early growth response-1 (Egr1 gene) in the regulation of radiation-induced clonogenic inhibition and apoptosis in p53 wild-type and mutant prostate cancer cells 22Rv1 and DU145, respectively. 22Rv1 cells were more sensitive to irradiation compared with DU145 cells, and the sensitivity was enhanced by overexpression of EGR-1 in both cells. Dominant-negative EGR-1 mutant (dnEGR-1) or repressor of EGR-1, NGFIA binding protein 1 (NAB1), increased radioresistance of these cells. Significant activation of caspases 3 and 9 and Bcl2-associated X (Bax) with increased poly(ADP-ribose) polymerase (PARP) cleavage and cytochrome c release was observed in radiation-exposed EGR-1 overexpressing cells. Gel shift analysis and chloramphenicol acetyl transferase (CAT) reporter assays indicate that EGR-1 transactivates the promoter of the Bax gene. Interaction of EGR-1 and Yes kinase-associated protein 1 (YAP-1) through the WW domain of YAP-1 enhances the transcriptional activity of EGR-1 on the Bax promoter as shown by chromatin immunoprecipitation and reporter assays. Irradiation of PC3 cell xenografts that were treated with adenoviral EGR-1 showed significant regression in tumor volume. These findings establish the radiation-induced pro-apoptotic action of EGR-1, in a p53-independent manner, by directly transactivating Bax, and prove that alters the B-cell CLL/lymphoma 2 (Bcl-2)/Bax ratio as one of the mechanisms resulting in significant activation of caspases, leading to cell death through the novel interaction of EGR-1 with YAP-1.

  5. Fraction from Wax Apple [<em>Syzygium samarangenseem> (Blume Merrill and Perry] Fruit Extract Ameliorates Insulin Resistance via Modulating Insulin Signaling and Inflammation Pathway in Tumor Necrosis Factor α-Treated FL83B Mouse Hepatocytes

    Directory of Open Access Journals (Sweden)

    Szu-Chuan Shen

    2012-07-01

    Full Text Available Inflammation is associated with the development of insulin resistance in Type 2 diabetes mellitus. In the present study, mouse FL83B cells were treated with tumor necrosis factor-alpha (TNF-α to induce insulin resistance, and then co-incubated with a fraction from wax apple fruit extract (FWFE. This fraction significantly increased the uptake of the nonradioactive fluorescent indicator 2-[<em>N>-(7-nitrobenz-2-oxa-1,3-diazol-4-yl amino]-2-deoxy-d-glucose (2-NBDG in insulin resistant cells. Western blot analysis revealed that, compared with the TNF-α-treated control group, FWFE increased the expression of the insulin receptor (IR, insulin receptor substrate-1 (IRS-1, protein kinase B (Akt/PKB, phosphatidylinositol-3 kinase (PI3K, and glucose transporter 2 (GLUT-2, and increased IR tyrosyl phosporylation, in insulin resistant FL83B cells. However, FWFE decreased phosphorylation of c-Jun <em>N>-terminal kinases (JNK, but not the expression of the intercellular signal-regulated kinases (ERK, in the same cells. These results suggest that FWFE might alleviate insulin resistance in TNF-α-treated FL83B cells by activating PI3K-Akt/PKB signaling and inhibiting inflammatory response via suppression of JNK, rather than ERK, activation.

  6. Neoplasias mamárias em cadelas: influência hormonal e efeitos da ovario-histerectomia como terapia adjuvante Canine mammary tumors: hormonal influence and effects of ovariohiysterectomy as an adjuvant therapy

    Directory of Open Access Journals (Sweden)

    Cláudia Sampaio Fonseca

    2000-08-01

    Full Text Available As neoplasias mamarias constituem aproximadamente 50% dos tumores diagnosticados em cadelas. Apesar dosharmónios sexuais femininos desempenharem papel fundamental no desenvolvimento desses tumores em mamíferos, o valor da supressão hormonal pela ovário-histerectomia como auxiliar no tratamento do tumor de mama em caninos permanece controverso. Discute-se ainda se a realização da ovário-histerectomia após o diagnóstico influencia ou não o crescimento e progressão do tumor na glândula afetada ou em outras glândulas mamarias. O objetivo desta revisão é discutir alguns aspectos relacionados à influência hormonal na etiologia de tumores mamarias em cadelas, assim como o valor terapêutico da castração, quando realizada no momento da mastectomia.The mammary neoplasms comprises aproximatel 50% ofthe diagnosed tumor s m the bitch. Although female sexual honnones play a fundamental role in the development of these tumors in mammals, the value of the suppression hormonal (ovariohysterectomy as an adjuvam treatment remains controversial. There are still arguments on whether the ovariohysterectomy after diagnosis of the tumor possesses influences lhe growth and progression of the tumor on the affected gland or on other mammary glands. The objective ofthis review is to discuss some aspects related to the hormonal influence in the pathogenesis of the canine tumor, as well as the therapeutic value ofspaying. when accomplished in the moment ofthe mastectomy.

  7. The C-terminal helix of Bcl-xL mediates Bax retrotranslocation from the mitochondria

    Science.gov (United States)

    Todt, F; Cakir, Z; Reichenbach, F; Youle, R J; Edlich, F

    2013-01-01

    The proapoptotic Bcl-2 protein Bax can commit a cell to apoptosis by translocation from the cytosol to the mitochondria and permeabilization of the outer mitochondrial membrane. Prosurvival Bcl-2 family members, such as Bcl-xL, control Bax activity. Bcl-xL recognizes Bax after a conformational change in the N-terminal segment of Bax on the mitochondria and retrotranslocates it back into the cytoplasm, stabilizing the inactive form of Bax. Here we show that Bax retrotranslocation depends on the C-terminal helix of Bcl-xL. Deletion or substitution of this segment reduces Bax retrotranslocation and correlates with the accumulation of GFP-tagged or endogenous Bax on the mitochondria of non-apoptotic cells. Unexpectedly, the substitution of the Bcl-xL membrane anchor by the corresponding Bax segment reverses the Bax retrotranslocation activity of Bcl-xL, but not that of Bcl-xL shuttling. Bax retrotranslocation depends on interaction to the Bcl-xL membrane anchor and interaction between the Bax BH3 domain and the Bcl-xL hydrophobic cleft. Interference with either interaction increases mitochondrial levels of endogenous Bax. In healthy cells, mitochondrial Bax does not permeabilize the outer mitochondrial membrane, but increases cell death after apoptosis induction. PMID:23079612

  8. Mortality is higher in patients with leptomeningeal metastasis in spinal cord tumors Mortalidade é mais elevada na disseminação metastática leptomeníngea em tumores da medula espinhal

    Directory of Open Access Journals (Sweden)

    Ricardo de Amoreira Gepp

    2013-01-01

    Full Text Available Spinal cord tumors are a rare neoplasm of the central nervous system (CNS. The occurrence of metastases is related to poor prognosis. The authors analyzed one series of metastasis cases and their associated mortality. METHODS: Clinical characteristics were studied in six patients with intramedullary tumors with metastases in a series of 71 surgical cases. RESULTS: Five patients had ependymomas of which two were WHO grade III. The patient with astrocytoma had a grade II histopathological classification. Two patients required shunts for hydrocephalus. The survival curve showed a higher mortality than the general group of patients with no metastases in the CNS (pTumores da medula espinhal são neoplasias raras do sistema nervoso central (SNC. A ocorrência de metástases é relacionada a pior prognóstico. Os autores analisaram uma série de casos de metástases e a mortalidade relacionada. MÉTODO: Foram estudadas as características clínicas em seis pacientes com metástases tumorais numa série de 71 casos operados. RESULTADOS: Cinco pacientes tinham ependimomas e dois dos quais foram grau III pela classificação da OMS. O paciente portador de astrocitoma tinha classificação histopatológica de grau II. Dois pacientes necessitaram de derivação devido à hidrocefalia. A curva de sobrevivência mostrou mortalidade mais elevada no grupo de pacientes com disseminação pelo SNC (p<0,0001. CONCLUSÃO: A mortalidade, além de elevada em pacientes com metástases, é maior do que em pacientes apenas com lesão primária. Os ependimomas, independentemente do seu grau de anaplasia, costumam causar mais metástases do que os astrocitomas medulares.

  9. Wavelets in quantification of liver tumors in contrasted computed tomography images; Wavelets na quantificacao de tumores de figado em exames contrastados de tomografia computadorizada

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Bruna T.; Alvarez, Matheus; Souza, Rafael T.F.; Miranda, Jose R.A., E-mail: matheus@ibb.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Instituto de Biociencias. Departamento de Fisica e Biofisica; Romeiro, Fernando G. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Fac de Mediciana. Departamento de Clinica Medica; Pina, Diana R. de; Trindade, Andre Petean [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Fac. de Medicina. Departamento de Doencas Tropicais e Diagnostico por Imagem

    2012-12-15

    This paper presents an original methodology of liver tumors segmentation, based on wavelet transform. A virtual phantom was constructed with the same mean and standard deviation of the intensity of gray presented by the measured liver tissue. The optimized algorithm had a sensitivity ranging from 0.81 to 0.83, with a specificity of 0.95 for differentiation of hepatic tumors from normal tissues. We obtained a 96% agreement between the pixels segmented by an experienced radiologist and the algorithm presented here. According to the results shown in this work, the algorithm is optimal for the beginning of the tests for quantification of liver tumors in retrospective surveys. (author)

  10. Caspase-3 feedback loop enhances Bid-induced AIF/endoG and Bak activation in Bax and p53-independent manner.

    Science.gov (United States)

    Guo, W; Zhang, Y; Ling, Z; Liu, X; Zhao, X; Yuan, Z; Nie, C; Wei, Y

    2015-10-15

    Chemoresistance in cancer has previously been attributed to gene mutations or deficiencies. Bax or p53 deficiency can lead to resistance to cancer drugs. We aimed to find an agent to overcome chemoresistance induced by Bax or p53 deficiency. Here, we used immunoblot, flow-cytometry analysis, gene interference, etc. to show that genistein, a major component of isoflavone that is known to have anti-tumor activities in a variety of models, induces Bax/p53-independent cell death in HCT116 Bax knockout (KO), HCT116 p53 KO, DU145 Bax KO, or DU145 p53 KO cells that express wild-type (WT) Bak. Bak knockdown (KD) only partially attenuated genistein-induced apoptosis. Further results indicated that the release of AIF and endoG also contributes to genistein-induced cell death, which is independent of Bak activation. Conversely, AIF and endoG knockdown had little effect on Bak activation. Knockdown of either AIF or endoG alone could not efficiently inhibit apoptosis in cells treated with genistein, whereas an AIF, endoG, and Bak triple knockdown almost completely attenuated apoptosis. Next, we found that the Akt-Bid pathway mediates Bak-induced caspase-dependent and AIF- and endoG-induced caspase-independent cell death. Moreover, downstream caspase-3 could enhance the release of AIF and endoG as well as Bak activation via a positive feedback loop. Taken together, our data elaborate the detailed mechanisms of genistein in Bax/p53-independent apoptosis and indicate that caspase-3-enhanced Bid activation initiates the cell death pathway. Our results also suggest that genistein may be an effective agent for overcoming chemoresistance in cancers with dysfunctional Bax and p53.

  11. The MUC1-C Oncoprotein Binds to the BH3 Domain of the Pro-apoptotic BAX Protein and Blocks BAX Function*

    Science.gov (United States)

    Ahmad, Rehan; Alam, Maroof; Rajabi, Hasan; Kufe, Donald

    2012-01-01

    The pro-apoptotic BAX protein contains a BH3 domain that is necessary for its dimerization and for activation of the intrinsic apoptotic pathway. The MUC1 (mucin 1) heterodimeric protein is overexpressed in diverse human carcinomas and blocks apoptosis in the response to stress. In this study, we demonstrate that the oncogenic MUC1-C subunit associates with BAX in human cancer cells. MUC1-C·BAX complexes are detectable in the cytoplasm and mitochondria and are induced by genotoxic and oxidative stress. The association between MUC1-C and BAX is supported by the demonstration that the MUC1-C cytoplasmic domain is sufficient for the interaction with BAX. The results further show that the MUC1-C cytoplasmic domain CQC motif binds directly to the BAX BH3 domain at Cys-62. Consistent with binding to the BAX BH3 domain, MUC1-C blocked BAX dimerization in response to (i) truncated BID in vitro and (ii) treatment of cancer cells with DNA-damaging agents. In concert with these results, MUC1-C attenuated localization of BAX to mitochondria and the release of cytochrome c. These findings indicate that the MUC1-C oncoprotein binds directly to the BAX BH3 domain and thereby blocks BAX function in activating the mitochondrial death pathway. PMID:22544745

  12. Grape Seed Proanthocyanidins Induce Apoptosis through p53, Bax, and Caspase 3 Pathways

    Directory of Open Access Journals (Sweden)

    Anshu M. Roy

    2005-01-01

    Full Text Available Grape seed proanthocyanidins (GSP have been shown to inhibit skin chemical carcinogenesis and photocarcinogenesis in mice. The mechanisms responsible for the anticarcinogenic effects of GSP are not clearly understood. Here, we report that treatment of JB6 C141 cells (a well-developed cell culture model for studying tumor promotion in keratinocytes and p53+/+ fibroblasts with GSP resulted in a dose-dependent induction of apoptosis. GSP-induced (20–80 g/ml apoptosis was observed by using immunofluorescence (27–90% apoptosis and flow cytometry (18–87% apoptosis. The induction of apoptosis by GSP was p53-dependent because it occurred mainly in cells expressing wild-type p53 (p53+/+; 15–80% to a much greater extent than in p53-deficient cells (p53-/-; 6–20%. GSP-induced apoptosis in JB6 C141 cells was associated with increased expression of the tumorsuppressor protein, p53, and its phosphorylation at Ser15. The antiapoptotic proteins, Bcl-2 and Bcl-xl, were downregulated by GSP, whereas the expression of the pro-apoptotic protein, Bax, and the levels of cytochrome c release, Apaf-1, caspase-9, and cleaved caspase 3 (p19 and p17 were markedly increased in JB6 C141 cells. The downregulation of Bcl-2 and upregulation of Bax were also observed in wild-type p53 (p53+/+ fibroblasts but was not observed in their p53-deficient counterparts. These data clearly demonstrate that GSP-induced apoptosis is p53-dependent and mediated through the Bcl-2, Bax, and caspase 3 pathways.

  13. A brewing understanding of the regulation of Bax function by Bcl-xL and Bcl-2.

    Science.gov (United States)

    Renault, Thibaud T; Dejean, Laurent M; Manon, Stéphen

    2017-01-01

    Bcl-2 family members form a network of protein-protein interactions that regulate apoptosis through permeabilization of the mitochondrial outer membrane. Deciphering this intricate network requires streamlined experimental models, including the heterologous expression in yeast. This approach had previously enabled researchers to identify domains and residues that underlie the conformational changes driving the translocation, the insertion and the oligomerization of the pro-apoptotic protein Bax at the level of the mitochondrial outer membrane. Recent studies that combine experiments in yeast and in mammalian cells have shown the unexpected effect of the anti-apoptotic protein Bcl-xL on the priming of Bax. As demonstrated with the BH3-mimetic molecule ABT-737, this property of Bcl-xL, and of Bcl-2, is crucial to elaborate about how apoptosis could be reactivated in tumoral cells.

  14. A novel plant glutathione S-transferase/peroxidase suppresses Bax lethality in yeast

    DEFF Research Database (Denmark)

    Kampranis, S C; Damianova, R; Atallah, M

    2000-01-01

    for the identification of plant genes, which inhibit either directly or indirectly the lethal phenotype of Bax. Using this method a number of cDNA clones were isolated, the more potent of which encodes a protein homologous to the class theta glutathione S-transferases. This Bax-inhibiting (BI) protein was expressed......The mammalian inducer of apoptosis Bax is lethal when expressed in yeast and plant cells. To identify potential inhibitors of Bax in plants we transformed yeast cells expressing Bax with a tomato cDNA library and we selected for cells surviving after the induction of Bax. This genetic screen allows...

  15. Metástases pulmonares em homem: localização incomum do tumor primário Pulmonary metastases in men: primary tumor in an unusual location

    Directory of Open Access Journals (Sweden)

    Daniel Brito de Araújo

    2007-04-01

    Full Text Available Os autores relatam caso de câncer de mama em um homem de 72 anos achado acidentalmente durante a pesquisa do tumor primário para investigação de metástases pulmonares. São abordados aspectos epidemiológicos, diagnóstico, tratamento e prognóstico desta patologia no sexo masculino.We report a case of breast cancer identified in a 72-year-old male as an accidental finding during the course of the investigation of a primary tumor and the search for pulmonary metastases. We address aspects related to the epidemiology, diagnosis, treatment and prognosis of this condition in males.

  16. Magnetic resonance imaging textural evaluation of posterior cranial fossa tumors in childhood; Avaliacao textural por ressonancia magnetica dos tumores da fossa posterior em criancas

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Joelson Alves dos; Costa, Maria Olivia Rodrigues da; Otaduy, Maria Concepcion Garcia; Lacerda, Maria Teresa Carvalho de; Leite, Claudia da Costa [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina. Dept. de Radiologia]. E-mail: joelson_alves@ig.com.br; Matsushita, Hamilton [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina. Dept. de Neurologia

    2004-08-01

    Objective: To distinguish healthy from pathological tissues in pediatric patients with posterior cranial fossa tumors using calculated textural parameters from magnetic resonance images. Materials And Methods: We evaluated 14 pediatric patients with posterior cranial fossa tumors using the software MaZda to define the texture parameters in selected regions of interest representing healthy and pathological tissues based on T2-weighted magnetic resonance images. Results: There was a statistically significant difference between normal and tumoral tissues as well as between supposedly normal tissues adjacent and distant from the tumoral lesion. Conclusion: Magnetic resonance textural evaluation is an useful tool for determining differences among various tissues, including tissues that appear apparently normal on visual analysis. (author)

  17. Bax targets mitochondria by distinct mechanisms before or during apoptotic cell death: a requirement for VDAC2 or Bak for efficient Bax apoptotic function

    Science.gov (United States)

    Ma, S B; Nguyen, T N; Tan, I; Ninnis, R; Iyer, S; Stroud, D A; Menard, M; Kluck, R M; Ryan, M T; Dewson, G

    2014-01-01

    In non-apoptotic cells, Bak constitutively resides in the mitochondrial outer membrane. In contrast, Bax is in a dynamic equilibrium between the cytosol and mitochondria, and is commonly predominant in the cytosol. In response to an apoptotic stimulus, Bax and Bak change conformation, leading to Bax accumulation at mitochondria and Bak/Bax oligomerization to form a pore in the mitochondrial outer membrane that is responsible for cell death. Using blue native-PAGE to investigate how Bax oligomerizes in the mitochondrial outer membrane, we observed that, like Bak, a proportion of Bax that constitutively resides at mitochondria associates with voltage-dependent anion channel (VDAC)2 prior to an apoptotic stimulus. During apoptosis, Bax dissociates from VDAC2 and homo-oligomerizes to form high molecular weight oligomers. In cells that lack VDAC2, constitutive mitochondrial localization of Bax and Bak was impaired, suggesting that VDAC2 has a role in Bax and Bak import to, or stability at, the mitochondrial outer membrane. However, following an apoptotic stimulus, Bak and Bax retained the ability to accumulate at VDAC2-deficient mitochondria and to mediate cell death. Silencing of Bak in VDAC2-deficient cells indicated that Bax required either VDAC2 or Bak in order to translocate to and oligomerize at the mitochondrial outer membrane to efficiently mediate apoptosis. In contrast, efficient Bak homo-oligomerization at the mitochondrial outer membrane and its pro-apoptotic function required neither VDAC2 nor Bax. Even a C-terminal mutant of Bax (S184L) that localizes to mitochondria did not constitutively target mitochondria deficient in VDAC2, but was recruited to mitochondria following an apoptotic stimulus dependent on Bak or upon over-expression of Bcl-xL. Together, our data suggest that Bax localizes to the mitochondrial outer membrane via alternate mechanisms, either constitutively via an interaction with VDAC2 or after activation via interaction with Bcl-2 family

  18. Effect of bax, bcl-2 and bcl-xL on regulating apoptosis in tissues of normal liver and hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Xiao-Zhong Guo; Xiao-Dong Shao; Min-Pei Liu; Jian-Hua Xu; Li-Nan Ren; Jia-Jun Zhao; Hong-Yu Li; Di Wang

    2002-01-01

    AIM: To investigate the expression of bax, bcl-2 and bcl-xL mRNA in the tissues of normal liver and hepatocellular carcinoma (HCC), and analyze the relationship between the expression of bax, bcl-2 and bcl-xL mRNA and clinical parameters of HCC patients.METHODS: The expression of bax, bcl-2 and bcl-xL mRNA of normal liver and HCC was measured by Northern blot. Statistical analyses were made by t test and correlation analysis.RESULTS: A very low mRNA level was indicated at bax,bcl-2 and bcl-xL in the HCC tissues in contrast to the tissues of normal liver by Northern blot analysis. The analyses of mRNA level revealed that HCC tissues exhibited a mean 7.6-fold decrease in bax, 4.2-fold in bcl-2 and 3.5-fold in bcl-xL in comparison with normal control tissues, respectively. Positive correlation was found between bax and bcl-xL (r=0.7061,P<0.01). There was no significance between the mRNA expression of these three genes and age, gender, tumor differentiation and tumor stage of HCC patients. CONCLUSION: The results are consistent with the fact that apoptosis rarely occurs in normal livers but increases in HCC, indicating that bcl-2 and bcl-xL may play a very important role in regulating the apoptosis of normal liver and HCC.

  19. Expressão de MMPs, marcadores angiogênicos e proliferação celular em tumores odontogênicos Expression of MMPs, angiogenic and proliferation cell markers in odontogenic tumors

    Directory of Open Access Journals (Sweden)

    Felipe Rodrigues de Matos

    2012-10-01

    Full Text Available INTRODUÇÃO E OBJETIVO: O conhecimento do comportamento biológico de lesões de natureza odontogênica é essencial para tornar a abordagem terapêutica adequada e estabelecer um prognóstico. A produção de metaloproteinases da matriz extracelular (MMPs, a angiogênese e a proliferação celular fornecem subsídios para o crescimento tumoral. O presente artigo tem como objetivo fazer uma revisão de literatura de pesquisas em tumores odontogênicos (TOs selecionados a partir da nova classificação da Organização Mundial da Saúde (OMS de 2005 sobre a expressão de MMPs, marcadores angiogênicos e proliferação celular e verificar, nestes estudos, a relação desses marcadores quanto ao comportamento biológico dessas lesões. RESULTADOS: Nota-se que as MMPs -1, -2, -7, -9 e -26 encontram-se mais expressas no componente epitelial e estroma e, particularmente, a -13 em estroma. Uma maior angiogênese é observada em TOs mais agressivos. CD 105 foi mais expresso no TO ceratocístico (TOC e CD34 em ameloblastomas sólidos (ASs. Relata-se elevada expressão do Ki-67 e p53 no TOC e no AS e baixo índice de proliferação celular no TO adenomatoide (TOA. CONCLUSÃO: Esses resultados mostram que as MMPs participam no processo de invasão e recorrência de algumas lesões odontogênicas, estando associadas ao comportamento biológico desses tumores. A angiogênese é fundamental para fornecer suporte à proliferação celular e esses dois eventos em conjunto estão correlacionados com diferentes níveis de comportamento biológico nos TOs, quando comparados com cistos de natureza odontogênica, o que pode sugerir o uso de inibidores angiogênicos como provável abordagem terapêutica nessas lesões.INTRODUCTION AND OBJECTIVE: The study of biological behavior of odontogenic lesions is essential to the establishment of appropriate therapeutic approach and prognosis. The production of extracellular matrix metalloproteinases (MMPs, angiogenesis and

  20. Análise matemática de um modelo para crescimento de células-tronco cancerígenas em tumores

    OpenAIRE

    2014-01-01

    Apresenta-se um modelo matemático baseado na hipótese de que o crescimento de tumores tem sua origem nas células-tronco cancerígenas (CTCs). No entanto, o próprio conceito de célula-tronco cancerígena (CTC) tem sido alvo de controvérsias na literatura e uma das questões abertas à discussão se refere à proporção de CTCs em um tumor. O modelo apresentado, baseado no comportamento do sistema hematopoiético, tem uma estrutura hierárquica composta de dois compartimentos: o de células-tronco (CT) e...

  1. The porin VDAC2 is the mitochondrial platform for Bax retrotranslocation.

    Science.gov (United States)

    Lauterwasser, Joachim; Todt, Franziska; Zerbes, Ralf M; Nguyen, Thanh Ngoc; Craigen, William; Lazarou, Michael; van der Laan, Martin; Edlich, Frank

    2016-09-13

    The pro-apoptotic Bcl-2 protein Bax can permeabilize the outer mitochondrial membrane and therefore commit human cells to apoptosis. Bax is regulated by constant translocation to the mitochondria and retrotranslocation back into the cytosol. Bax retrotranslocation depends on pro-survival Bcl-2 proteins and stabilizes inactive Bax. Here we show that Bax retrotranslocation shuttles membrane-associated and membrane-integral Bax from isolated mitochondria. We further discover the mitochondrial porin voltage-dependent anion channel 2 (VDAC2) as essential component and platform for Bax retrotranslocation. VDAC2 ensures mitochondria-specific membrane association of Bax and in the absence of VDAC2 Bax localizes towards other cell compartments. Bax retrotranslocation is also regulated by nucleotides and calcium ions, suggesting a potential role of the transport of these ions through VDAC2 in Bax retrotranslocation. Together, our results reveal the unanticipated bifunctional role of VDAC2 to target Bax specifically to the mitochondria and ensure Bax inhibition by retrotranslocation into the cytosol.

  2. Computed tomographic aspects of primary brain tumors in dogs and cats; Aspectos tomograficos de tumores cerebrais primarios em caes e gatos

    Energy Technology Data Exchange (ETDEWEB)

    Babicsak, Viviam Rocco; Zardo, Karen Maciel; Santos, Debora Rodrigues dos; Silva, Luciana Carandina da; Machado, Vania Maria de Vasconcelos; Vulcano, Luiz Carlos, E-mail: viviam.babicsak@gmail.com [Setor de Diagnostico por Imagem - FMVZ - UNESP/Botucatu, SP (Brazil)

    2011-07-01

    Over the years, the Veterinary Medicine has made great advances, enabling thus the diagnosis of many diseases. As a result of this new situation, there was an increased expectation of life of animals resulting in an increase in the number of clinical care of older animals. Thus, diseases considered unusual in the past, begin to be diagnosed more frequently, as is the case of brain damage. Recently, computed tomography has been widely used in Brazil as a tool to aid in the diagnosis of several diseases. This noninvasive imaging technique allows the identification and evaluation of lesions of central nervous tissue such as brain tumors. This provides information about the size, shape and location of the lesion, in addition to the magnitude of compression and invasion of adjacent structures by the tumor and its side effects (such as the peritumoral edema and hydrocephalus). The image obtained from computed tomography may suggest the presence of a certain type brain tumor, data of great importance for the prognosis and treatment of the animal. This review covers the computed tomography aspects of primary brain tumors such as meningiomas, astrocytomas, oligodendrogliomas, choroid plexus tumors and ependymomas. However, despite the computed tomography provide much information about the changes inside the skull; no way replace histopathological examination in determining the definitive diagnosis. (author)

  3. Antígeno nuclear de proliferação celular em tumores de adrenal Proliferating cell nuclear antigen in adrenal tumors

    Directory of Open Access Journals (Sweden)

    Rodrigo A.R. Falconi

    2000-01-01

    Full Text Available Fez-se um estudo imunohistoquímico do antígeno nuclear de proliferação celular (PCNA em 26 adenomas e 24 carcinomas de adrenal através da técnica da avidina-biotina-peroxidase. O índice de marcação (IP do PCNA, definido com o número de células marcadas/1000 contadas, foi em média de 77,4± 66,1 (mediana - 63,5 para os adenomas enquanto que para os carcinomas foi 215,8± 56,0 (mediana - 217,5 (p<0,0001. Estabelecendo-se o IP de 100 o marcador (para a discriminação de carcinomas dos adenomas o marcador exibiu sensibilidade, especificidade e valor preditivo positivo seguintes, respectivamente: 100%, 69% e 75%.

  4. 细胞凋亡调控蛋白bcl-2和bax在涎腺肿瘤中的表达及意义%Expression and significance of apoptosis regulatory protein bcl-2 and bax in tumor of salivary gland

    Institute of Scientific and Technical Information of China (English)

    齐红; 袁红民; 安文生; 杨荔琳

    2002-01-01

    目的:探讨bcl-2和bax基因蛋白在涎腺肿瘤(Salivary tumer,ST)中表达及意义.方法:SABC法观察87例ST及12例正常涎腺组织(Natural salivary tissue,NST)中bcl-2及bax表达.结果:bcl-2及bax蛋白在ST中表达明显高于NST;bcl-2在涎腺恶性肿瘤(Salivary malignacy,SM)中表达明显高于良性肿瘤;SM中bcl-2表达与其恶性程度及临床分期显著相关;bax蛋白表达与SM临床病理指标均无相关性.结论:bcl-2蛋白表达有助于SM恶性程度判断;可作为判断SM生物特性、临床分期的重要指标;bax/bcl-2比率变化参与了ST发生及发展过程.

  5. DRAM1 regulates apoptosis through increasing protein levels and lysosomal localization of BAX

    Science.gov (United States)

    Guan, J-J; Zhang, X-D; Sun, W; Qi, L; Wu, J-C; Qin, Z-H

    2015-01-01

    DRAM1 (DNA damage-regulated autophagy modulator 1) is a TP53 target gene that modulates autophagy and apoptosis. We previously found that DRAM1 increased autophagy flux by promoting lysosomal acidification and protease activation. However, the molecular mechanisms by which DRAM1 regulates apoptosis are not clearly defined. Here we report a novel pathway by which DRAM1 regulates apoptosis involving BAX and lysosomes. A549 or HeLa cells were treated with the mitochondrial complex II inhibitor, 3-nitropropionic acid (3NP), or an anticancer drug, doxorubicin. Changes in the protein and mRNA levels of BAX and DRAM1 and the role of DRAM1 in BAX induction were determined. The interaction between DRAM1 and BAX and its effect on BAX degradation, BAX lysosomal localization, the release of cathepsin B and cytochrome c by BAX and the role of BAX in 3NP- or doxorubicin-induced cell death were studied. The results showed that BAX, a proapoptotic protein, was induced by DRAM1 in a transcription-independent manner. BAX was degraded by autophagy under basal conditions; however, its degradation was inhibited when DRAM1 expression was induced. There was a protein interaction between DRAM1 and BAX and this interaction prolonged the half-life of BAX. Furthermore, upregulated DRAM1 recruited BAX to lysosomes, leading to the release of lysosomal cathepsin B and cleavage of BID (BH3-interacting domain death agonist). BAX mediated the release of mitochondrial cytochrome c, activation of caspase-3 and cell death partially through the lysosome-cathepsin B-tBid pathway. These results indicate that DRAM1 regulates apoptosis by inhibiting BAX degradation. In addition to mitochondria, lysosomes may also be involved in BAX-initiated apoptosis. PMID:25633293

  6. Live-cell imaging to measure BAX recruitment kinetics to mitochondria during apoptosis.

    Science.gov (United States)

    Maes, Margaret E; Schlamp, Cassandra L; Nickells, Robert W

    2017-01-01

    The pro-apoptotic BCL2 gene family member, BAX, plays a pivotal role in the intrinsic apoptotic pathway. Under cellular stress, BAX recruitment to the mitochondria occurs when activated BAX forms dimers, then oligomers, to initiate mitochondria outer membrane permeabilization (MOMP), a process critical for apoptotic progression. The activation and recruitment of BAX to form oligomers has been studied for two decades using fusion proteins with a fluorescent reporter attached in-frame to the BAX N-terminus. We applied high-speed live cell imaging to monitor the recruitment of BAX fusion proteins in dying cells. Data from time-lapse imaging was validated against the activity of endogenous BAX in cells, and analyzed using sigmoid mathematical functions to obtain detail of the kinetic parameters of the recruitment process at individual mitochondrial foci. BAX fusion proteins behave like endogenous BAX during apoptosis. Kinetic studies show that fusion protein recruitment is also minimally affected in cells lacking endogenous BAK or BAX genes, but that the kinetics are moderately, but significantly, different with different fluorescent tags in the fusion constructs. In experiments testing BAX recruitment in 3 different cell lines, our results show that regardless of cell type, once activated, BAX recruitment initiates simultaneously within a cell, but exhibits varying rates of recruitment at individual mitochondrial foci. Very early during BAX recruitment, pro-apoptotic molecules are released in the process of MOMP, but different molecules are released at different times and rates relative to the time of BAX recruitment initiation. These results provide a method for BAX kinetic analysis in living cells and yield greater detail of multiple characteristics of BAX-induced MOMP in living cells that were initially observed in cell free studies.

  7. Tumor de células gigantes em falange proximal com metástase pulmonar: relato de caso e revisão de literatura Giant cell tumor in proximal phalanx with pulmonary metastasis: case report and literature review

    Directory of Open Access Journals (Sweden)

    Frederico Carvalho de Medeiros

    2011-04-01

    Full Text Available Trata-se de um relato de caso de tumor de células gigantes (TCG em falange proximal de terceiro dedo da mão esquerda com metástase pulmonar. A paciente apresentava dor no dedo sem história prévia de trauma. Foram realizados exame clínico, estudo radiográfico e ressonância nuclear magnética. Feito o estudo histológico, a partir de biópsia incisional, com hipótese de TCG. Foi submetida à amputação do dedo, confirmando o diagnóstico pela microscopia da peça. A paciente foi acompanhada devido ao risco de metástase pulmonar, evidenciada em estudo radiográfico e tomografia computadorizada de tórax, sendo submetida à toracotomia. Desde então, houve melhora dos sintomas referidos no pré-operatório e ausência de recidiva local e novas metástases.This is a case report on a giant cell tumor in the proximal phalanx of the third finger of the left hand, with pulmonary metastasis. The patient presented pain in the finger without any previous history of trauma. Clinical examination, radiographic imaging and magnetic resonance imaging were carried out. A histological evaluation was done from an incisional biopsy, taking the hypothesis of giant cell tumor. The patient underwent amputation of the finger and the diagnosis was confirmed by means of microscopy on the specimen. The patient was followed up because of the risk of lung metastasis, which was shown by radiographic examination and computed tomography on the chest, and thoracotomy was performed. Since then, there has been an improvement of the symptoms that had been reported preoperatively, and no local recurrence or new metastasis has been found.

  8. Efeito do tratamento com própolis de Scaptotrigona aff. postica sobre o desenvolvimento do tumor de Ehrlich em camundongos

    Directory of Open Access Journals (Sweden)

    Maria José A. M. Araújo

    2010-09-01

    Full Text Available Neste trabalho foi investigado o efeito do extrato hidroalcoólico de própolis (EHP de Scaptotrigona aff. postica sobre o desenvolvimento do tumor de Ehrlich na forma sólida, sobre a celularidade dos órgãos linfóides dos animais portadores de tumor, bem como, sobre a produção de óxido nítrico (NO pelos macrófagos destes animais. Camundongos Swiss foram divididos em quatro grupos: controle, EHP 0,5; EHP 5 e EHP 50, os quais foram tratados por via intraperitoneal com dose única de solução salina (NaCl 0,9%; 0,5; 5 ou 50 mg de EHP/kg de animal, respectivamente. Depois de 48 h do tratamento, os animais foram inoculados com 10(5 células do tumor de Ehrlich nas patas. Os resultados mostraram que o tratamento com EHP nas doses de 5 e 50 mg/kg inibiu de forma significativa o desenvolvimento do tumor a partir do 6º dia pós-inóculo quando comparado ao controle e ao EHP 0,5. Além disso, houve aumento significativo da celularidade do baço e da medula óssea nos grupos EHP 0,5 e EHP 5 em relação ao controle. A produção de NO estimulada com concanavalina A (ConA apresentou uma significante diminuição nos grupos tratados com EHP em relação ao controle. Pode-se concluir que o tratamento com EHP apresentou efeito antitumoral quando administrado nas doses de 5 e 50 mg/kg, o que pode estar relacionado com a sua composição química e com a inibição da produção de NO.

  9. p53's mitochondrial translocation and MOMP action is independent of Puma and Bax and severely disrupts mitochondrial membrane integrity

    Institute of Scientific and Technical Information of China (English)

    Sonja Wolff; Susan Erster; Gustavo Palacios; Ute M Moll

    2008-01-01

    p53's apoptotic program consists of transcription-dependent and transcription-independent pathways. In the latter, physical interactions between mitochondrial p53 and anti-and pro-apoptotic members of the Bcl2 family of mitochondrial permeability regulators are central. Using isogenic cell systems with defined deficiencies, we characterize in detail how mitochondrial p53 contributes to mitochondrial permeabilization, to what extent its action depends on other key Bcl2 family members and define its release activity. We show that mitochondrial p53 is highly efficient in inducing the release of soluble and insoluble apoptogenic factors by severely disrupting outer and inner mitochondrial membrane integrity. This action is associated with wild-type p53-induced oligomerization of Bax, Bak and VDAC and the formation of a stress-induced endogenous complex between p53 and cyclophilin D, normally located at the inner membrane. Tumor-derived p53 mutants are deficient in activating the Bax/Bak lipid pore. These actions are independent of Puma and Bax. Importantly, the latter distinguishes the mitochondrial from the cytosolic p53 death pathway.

  10. Comparação entre o pencil beam convolution algorithm e o analytical anisotropic algorithm em tumores de mama

    OpenAIRE

    Sá, Ana Cravo; Coelho, Carina Marques; Monsanto, Fátima

    2014-01-01

    Objectivo do estudo: comparar o desempenho dos algoritmos Pencil Beam Convolution (PBC) e do Analytical Anisotropic Algorithm (AAA) no planeamento do tratamento de tumores de mama com radioterapia conformacional a 3D.

  11. Bax and Bak expression in cervical smears of women with low-and high-risk HPV types: A study of 120 cases

    Directory of Open Access Journals (Sweden)

    Eirini Klapsinou

    2015-01-01

    Full Text Available Background: Human papillomavirus (HPV is known to be involved in the carcinogenesis of squamous cells in uterine cervix cancer, mostly by binding and inactivating the p53 and pRb tumor suppressor genes. Lately, evidence has emerged suggesting that HPV oncoproteins may interact with proteins involved in cellular apoptosis as well. Aim: This study aimed to investigate the expression of proapoptotic proteins Bax and Bak in women with low-risk and high-risk HPV types as opposed to HPV-negative women, and in women with normal pap smear compared to women with abnormal Papanicolau test (Pap smear. Materials and Methods: A total of 120 liquid-based cervical samples were subtyped for HPV types with microarray hybridization and then stained and evaluated immunocytochemically for Bax and Bak expression. Statistical analysis was performed on the Bax and Bak scores (percentage of positive cells × staining intensity, the overall percentage of positive cells, and the most prevalent staining intensity group found in each sample. Results: A weak association between negative Bax staining and cytologically normal Pap smears was discovered, whereas cytologically abnormal samples tended to stain weakly or moderately positive. No other statistically significant difference was found in the other analyzed parameters. Conclusion: Cytologically normal pap smears seem to have a slight tendency to stain negative for Bax as opposed to cytologically abnormal pap smears. Although the association is weak, it is an indication that there might be a connection between the expression of Bax and the development of cervical intraepithelial dysplasia, which warrants further investigation in larger-scale studies.

  12. Bax and Bak expression in cervical smears of women with low-and high-risk HPV types: A study of 120 cases

    Science.gov (United States)

    Klapsinou, Eirini; Argyri, Elena; Panotopoulou, Efstathia; Daskalopoulou, Dimitra; Patsouris, Efstratios; Nonni, Afroditi; Lazaris, Andreas C; Thomopoulou, Georgia-Heleni

    2015-01-01

    Background: Human papillomavirus (HPV) is known to be involved in the carcinogenesis of squamous cells in uterine cervix cancer, mostly by binding and inactivating the p53 and pRb tumor suppressor genes. Lately, evidence has emerged suggesting that HPV oncoproteins may interact with proteins involved in cellular apoptosis as well. Aim: This study aimed to investigate the expression of proapoptotic proteins Bax and Bak in women with low-risk and high-risk HPV types as opposed to HPV-negative women, and in women with normal pap smear compared to women with abnormal Papanicolau test (Pap) smear. Materials and Methods: A total of 120 liquid-based cervical samples were subtyped for HPV types with microarray hybridization and then stained and evaluated immunocytochemically for Bax and Bak expression. Statistical analysis was performed on the Bax and Bak scores (percentage of positive cells × staining intensity), the overall percentage of positive cells, and the most prevalent staining intensity group found in each sample. Results: A weak association between negative Bax staining and cytologically normal Pap smears was discovered, whereas cytologically abnormal samples tended to stain weakly or moderately positive. No other statistically significant difference was found in the other analyzed parameters. Conclusion: Cytologically normal pap smears seem to have a slight tendency to stain negative for Bax as opposed to cytologically abnormal pap smears. Although the association is weak, it is an indication that there might be a connection between the expression of Bax and the development of cervical intraepithelial dysplasia, which warrants further investigation in larger-scale studies. PMID:26811568

  13. Calpains are downstream effectors of bax-dependent excitotoxic apoptosis.

    Science.gov (United States)

    D'Orsi, Beatrice; Bonner, Helena; Tuffy, Liam P; Düssmann, Heiko; Woods, Ina; Courtney, Michael J; Ward, Manus W; Prehn, Jochen H M

    2012-02-01

    Excitotoxicity resulting from excessive Ca(2+) influx through glutamate receptors contributes to neuronal injury after stroke, trauma, and seizures. Increased cytosolic Ca(2+) levels activate a family of calcium-dependent proteases with papain-like activity, the calpains. Here we investigated the role of calpain activation during NMDA-induced excitotoxic injury in embryonic (E16-E18) murine cortical neurons that (1) underwent excitotoxic necrosis, characterized by immediate deregulation of Ca(2+) homeostasis, a persistent depolarization of mitochondrial membrane potential (Δψ(m)), and insensitivity to bax-gene deletion, (2) underwent excitotoxic apoptosis, characterized by recovery of NMDA-induced cytosolic Ca(2+) increases, sensitivity to bax gene deletion, and delayed Δψ(m) depolarization and Ca(2+) deregulation, or (3) that were tolerant to excitotoxic injury. Interestingly, treatment with the calpain inhibitor calpeptin, overexpression of the endogenous calpain inhibitor calpastatin, or gene silencing of calpain protected neurons against excitotoxic apoptosis but did not influence excitotoxic necrosis. Calpeptin failed to exert a protective effect in bax-deficient neurons but protected bid-deficient neurons similarly to wild-type cells. To identify when calpains became activated during excitotoxic apoptosis, we monitored calpain activation dynamics by time-lapse fluorescence microscopy using a calpain-sensitive Förster resonance energy transfer probe. We observed a delayed calpain activation that occurred downstream of mitochondrial engagement and directly preceded neuronal death. In contrast, we could not detect significant calpain activity during excitotoxic necrosis or in neurons that were tolerant to excitotoxic injury. Oxygen/glucose deprivation-induced injury in organotypic hippocampal slice cultures confirmed that calpains were specifically activated during bax-dependent apoptosis and in this setting function as downstream cell-death executioners.

  14. BH3-Triggered Structural Reorganization Drives the Activation of Pro-apoptotic BAX

    Science.gov (United States)

    Gavathiotis, Evripidis; Reyna, Denis E.; Davis, Marguerite L.; Bird, Gregory H.; Walensky, Loren D.

    2010-01-01

    Summary BAX is a pro-apoptotic BCL-2 family member that lies dormant in the cytosol until converted into a killer protein in response to cellular stress. Having recently identified the elusive trigger site for direct BAX activation, we now delineate by NMR and biochemical methods the essential allosteric conformational changes that transform ligand-triggered BAX into a fully activated monomer capable of propagating its own activation. Upon BAX engagement by a triggering BH3 helix, the unstructured loop between α-helices 1 and 2 is displaced, the carboxy terminal helix 9 is mobilized for membrane translocation, and the exposed BAX BH3 domain propagates the death signal through an auto-activating interaction with the trigger site of inactive BAX monomers. Our structure-activity analysis of this seminal apoptotic process reveals new pharmacologic opportunities to modulate cell death by interceding at key steps of the BAX activation pathway. PMID:21070973

  15. Bax transmembrane domain interacts with prosurvival Bcl-2 proteins in biological membranes.

    Science.gov (United States)

    Andreu-Fernández, Vicente; Sancho, Mónica; Genovés, Ainhoa; Lucendo, Estefanía; Todt, Franziska; Lauterwasser, Joachim; Funk, Kathrin; Jahreis, Günther; Pérez-Payá, Enrique; Mingarro, Ismael; Edlich, Frank; Orzáez, Mar

    2017-01-10

    The Bcl-2 (B-cell lymphoma 2) protein Bax (Bcl-2 associated X, apoptosis regulator) can commit cells to apoptosis via outer mitochondrial membrane permeabilization. Bax activity is controlled in healthy cells by prosurvival Bcl-2 proteins. C-terminal Bax transmembrane domain interactions were implicated recently in Bax pore formation. Here, we show that the isolated transmembrane domains of Bax, Bcl-xL (B-cell lymphoma-extra large), and Bcl-2 can mediate interactions between Bax and prosurvival proteins inside the membrane in the absence of apoptotic stimuli. Bcl-2 protein transmembrane domains specifically homooligomerize and heterooligomerize in bacterial and mitochondrial membranes. Their interactions participate in the regulation of Bcl-2 proteins, thus modulating apoptotic activity. Our results suggest that interactions between the transmembrane domains of Bax and antiapoptotic Bcl-2 proteins represent a previously unappreciated level of apoptosis regulation.

  16. Bax assembly into rings and arcs in apoptotic mitochondria is linked to membrane pores.

    Science.gov (United States)

    Salvador-Gallego, Raquel; Mund, Markus; Cosentino, Katia; Schneider, Jale; Unsay, Joseph; Schraermeyer, Ulrich; Engelhardt, Johann; Ries, Jonas; García-Sáez, Ana J

    2016-02-15

    Bax is a key regulator of apoptosis that, under cell stress, accumulates at mitochondria, where it oligomerizes to mediate the permeabilization of the mitochondrial outer membrane leading to cytochrome c release and cell death. However, the underlying mechanism behind Bax function remains poorly understood. Here, we studied the spatial organization of Bax in apoptotic cells using dual-color single-molecule localization-based super-resolution microscopy. We show that active Bax clustered into a broad distribution of distinct architectures, including full rings, as well as linear and arc-shaped oligomeric assemblies that localized in discrete foci along mitochondria. Remarkably, both rings and arcs assemblies of Bax perforated the membrane, as revealed by atomic force microscopy in lipid bilayers. Our data identify the supramolecular organization of Bax during apoptosis and support a molecular mechanism in which Bax fully or partially delineates pores of different sizes to permeabilize the mitochondrial outer membrane. © 2016 The Authors.

  17. Occupational doses in neuroendocrine tumors by using {sup 177}Lu DOTATATE; Doses ocupacionais em tratamento de tumores neuroendocrinos utilizando {sup 17'}7Lu DOTATATE

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Gustavo Coelho Alves; Sa, Lidia Vasconcellos de, E-mail: gustavo@ird.gov.b, E-mail: lidia@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2011-10-26

    This paper investigated the treatment of neuroendocrine tumors (abdominal tumors) using of {sup 177}Lu DOTATATE radiopharmaceutical which is a type of treatment presently used in the experimental form in Brazil and, therefore, not contemplated in norms or specific use. This research studied the occupational doses of this treatment and suggested guidelines or rules of procedures viewing the radiological protection of workers involved and the public. The treatment were followed up by using two types of radiation detection, one a scintillator and a Geiger-Muller, and the measurements were performed in a public hospital at Rio de Janeiro and the other in a private hospital at Sao Paulo. It was observed that the equivalent occupational doses can variate from 160 {mu}Sv to 450 {mu}Sv, in function of operator, of stage of manipulation, and of the administration method, which can be through the use of infusion pump or manual injection. The use of infusion pump is highly recommended and the hospitalization of the patient until the dose rate measured at 1 m does not surpass 20 {mu}Sv/h

  18. Tumor odontogênico cístico calcificante com proliferação ameloblastomosa em seio maxilar Calcifying cystic odontogenic tumor with ameloblastoma proliferation in the maxillary sinus

    Directory of Open Access Journals (Sweden)

    Maria Carolina Gonçalves Carnasciali

    2012-08-01

    Full Text Available O tumor odontogênico cístico calcificante (TOCC com proliferação ameloblastomosa é uma variante rara entre os cistos maxilares. Este trabalho objetiva apresentar o relato clínico de um paciente do sexo masculino, 18 anos de idade, que apresentava aumento de volume extra e intraoral do lado esquerdo da maxila, firme à palpação, de característica normocrômica e indolor. A conduta consistiu em realização de tomografia Cone Beam, biópsia incisional, remoção completa da lesão, curetagem e fixação maxilar. O paciente encontra-se em acompanhamento clínico e radiográfico sem recidiva após doze meses. Dessa forma, ressalta-se a importância do diagnóstico precoce, a conduta clínica empregada e o acompanhamento periódico.Calcifying cystic odontogenic tumors (CCOT with proliferative ameloblastoma are a rare variant among maxillary cysts. This study aims to present a clinical report of an 18-year-old male patient with extra and intra oral swelling of the left maxilla, firm to touch, with normochromic characteristics and painless. The clinical approach comprised cone-beam tomography, incisional biopsy, complete removal of the lesion, curettage and maxilla fixation. His clinical and radiographic follow-up has revealed no relapse after 12 months. Hence, this study corroborates the importance of early diagnosis, clinical approach and periodical follow-ups.

  19. Comportamento do fator de necrose tumoral e da proteína C reativa em hepatectomia simultânea com colectomia em ratos Behavior of the tumor necrosis factor and C-reactive protein in simultaneous hepatectomy plus colectomy in rats

    Directory of Open Access Journals (Sweden)

    Hamilton Luiz Xavier Funes

    2005-04-01

    Full Text Available OBJETIVO: Observar o comportamento do fator de necrose tumoral-a (TNFalfa e da proteína C reativa (PCR em cirurgias simultâneas de fígado e intestino. MÉTODO: Para este objetivo foi desenvolvido um modelo experimental, no qual foram operados quarenta ratos da raça Wistar, divididos em quatros grupos: grupo controle, grupo 1 com ratos submetidos à hepatectomia a 70%, grupo 2 com ratos submetidos à colectomia e grupo 3 com cirurgia simultânea de hepactetomia e colectomia. Em todos os grupos foram dosados TNFalfa e PCR uma hora após o procedimento. Os animais foram mortos em seguida. RESULTADOS: Os valores encontrados mostraram alteração nas dosagens desses elementos nos diversos grupos, sendo que no grupo 3 houve aumento significativo do TNFalfa e queda de PCR. CONCLUSÃO: Quanto mais complexo se tornou o ato cirúrgico os níveis sangüíneos de TFNalfa aumentaram e os níveis sangüíneos da PCR diminuíram significativamente.BACKGROUND: The aim of this experimental study was to observe the behavior of Tumor Necrosis Factor and C-Reative Protein in simultaneous colectomy plus hepatectomy. METHODS: In this experimental model, 40 Wistar rats underwent surgery. They were divided into four groups: the control group; group 1, rats submitted to hepatectomy to 70%; group 2, rats submitted to colectomy; and group 3, rats submitted simultaneously to both procedures: hepatectomy plus colectomy. In all groups, TNF and PCR were collected one hour after the surgical procedure. The animals were killed afterwards. RESULTS: The dosage of these elements showed values with some alterations in all groups. Group three showed a significant increase of TNFalpha and decrease of PCR. CONCLUSION: The more complex became the surgical act the blood levels of TFNalpha have increased and the levels of the PCR decreased significantly.

  20. Infeção por HPV e EBV em tumores de cabeça e pescoço

    OpenAIRE

    Esteves, Marlene Duarte

    2013-01-01

    O cancro de cabeça e pescoço é o quinto com maior incidência em Portugal e representa um grave problema de saúde pública com cerca de 43 000 novos casos por ano. Adicionalmente ao tabaco e álcool, os vírus foram também associados ao desenvolvimento deste tipo de patologias, nomeadamente o Vírus do Papiloma Humano e o Vírus Epstein-Barr. Os objetivos deste estudo foram caracterizar a prevalência da infeção pelo EBV e HPV nos tumores de cabeça e pescoço; comparar a prevalência viral nas dife...

  1. Impact of the combined loss of BOK, BAX and BAK on the hematopoietic system is slightly more severe than compound loss of BAX and BAK.

    Science.gov (United States)

    Ke, F; Grabow, S; Kelly, G L; Lin, A; O'Reilly, L A; Strasser, A

    2015-10-22

    It is well established that BAX and BAK play crucial, overlapping roles in the intrinsic pathway of apoptosis. Gene targeted mice lacking both BAX and BAK have previously been generated, but the majority of these animals died perinatally. BOK is a poorly studied relative of BAX and BAK that shares extensive amino acid sequence homology to both proteins, but its function remains largely unclear to date. To determine whether BOK plays an overlapping role with BAX and BAK, we utilized a hematopoietic reconstitution model where lethally irradiated wild type mice were transplanted with Bok(-/-)Bax(-/-)Bak(-/-) triple knockout (TKO) fetal liver cells, and compared alongside mice reconstituted with a Bax(-/-)Bak(-/-) double knockout (DKO) hematopoietic compartment. We report here that mice with a TKO and DKO hematopoietic system died at a similar rate and much earlier than control animals, mostly due to severe autoimmune pathology. Both TKO and DKO reconstituted mice also had altered frequencies of various leukocyte subsets in the thymus, bone marrow and spleen, displayed leukocyte infiltrates and autoimmune pathology in multiple tissues, as well as elevated levels of anti-nuclear autoantibodies. Interestingly, the additional deletion of BOK (on top of BAX and BAK loss) led to a further increase in peripheral blood lymphocytes, as well as enhanced lymphoid infiltration in some organs. These findings suggest that BOK may have some functions that are redundant with BAX and BAK in the hematopoietic system.

  2. Qualidade de vida e sintomas de ansiedade e depressão em pacientes com tumores cerebrais primários

    Directory of Open Access Journals (Sweden)

    Marcela dos Reis Bigatão

    2014-03-01

    Full Text Available Objetivo: Avaliar a qualidade de vida e sintomas de ansiedade e depressão em pacientes com diagnóstico de meningioma e glioma de alto grau submetidos à neurocirurgia oncológica. Métodos: Para a coleta de dados, foram aplicados dois instrumentos validados no Brasil: Hospital Anxiety and Depression Scale (HAD e Item Short-Form Health Survey (SF-36. Resultados: Foram identificadas diferenças estatisticamente significativas quando comparados os dados do SF-36 de ambos os grupos tumorais, no pré e pós-operatório, nos aspectos: capacidade funcional (p = 0,043, aspecto emocional (p = 0,042 e saúde mental (p = 0,042 referente ao grupo meningioma. Quando comparados com respectivos grupos controle, houve diferenças significativas entre os grupos meningioma e controle, nos aspectos físico (p = 0,002 e emocional (p = 0,004, e entre os grupos glioma de alto grau e controle, nos aspectos capacidade funcional (p = 0,003 e físico (p = 0,003. Conclusão: A cirurgia oncológica gerou alterações de humor e na qualidade de vida em ambos os grupos, independente do tipo histológico do tumor. Apesar da relevância do tema, ainda são poucos os estudos sobre o tema.

  3. High BAX/BCL2 mRNA ratio predicts favorable prognosis in laryngeal squamous cell carcinoma, particularly in patients with negative lymph nodes at the time of diagnosis.

    Science.gov (United States)

    Giotakis, Aris I; Kontos, Christos K; Manolopoulos, Leonidas D; Sismanis, Aristides; Konstadoulakis, Manousos M; Scorilas, Andreas

    2016-08-01

    Laryngeal squamous cell carcinoma (LSCC), a common type of head and neck cancer, is associated with high rates of metastasis and recurrence. Therefore, accurate prognostic stratification of LSCC patients based on molecular prognostic tumor biomarkers would definitely lead to a better clinical management of this malignancy. The aim of this study was the investigation of the potential combinatorial prognostic value of BCL2 and BAX mRNA expression in LSCC. Total RNA was isolated from 105 cancerous laryngeal tissue specimens obtained from patients having undergone surgical treatment for primary LSCC. After cDNA preparation, a low-cost, in-house developed, sensitive and accurate real-time quantitative PCR (qPCR) methodology was applied for the quantification of BCL2 and BAX mRNA levels. Then, we carried out a biostatistical analysis to assess the prognostic value of the BAX/BCL2 mRNA expression ratio. High BAX/BCL2 mRNA expression constitutes a favorable prognosticator in LSCC, predicting significantly longer disease-free survival (P=0.011) and overall survival (P=0.014) of patients. More importantly, the significant prognostic value of the BAX/BCL2 mRNA expression appeared to be independent of the histological grade and size of the malignant laryngeal tumor as well as TNM stage, as revealed by the multivariate bootstrap Cox regression analysis. Kaplan-Meier survival analysis demonstrated also that the BAX/BCL2 ratio can stratify node-negative (N0) LSCC patients into two subgroups with significantly different DFS and OS (P=0.021 and P=0.009, respectively). The BAX/BCL2 mRNA ratio is a putative molecular tissue biomarker in CLL and hence deserves further validation in larger cohorts of LSCC patients. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  4. Traqueobroncopatia osteocondroplástica em portador de tumor de Klatskin: relato de caso e revisão da literatura Tracheopathia osteochondroplastica in a patient with Klatskin tumor: a case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Fabíola Sawaguchi Faig-Leite

    2008-12-01

    Full Text Available A traqueopatia osteocondroplástica (TO é uma desordem idiopática, incomum, caracterizada pela presença de nódulos osteocartilaginosos na submucosa das vias aéreas, causando rigidez e estreitamento da árvore respiratória. Afeta principalmente homens acima dos 50 anos com manifestações clínicas devidas à obstrução e/ou a infecções locais. Sua patogênese é desconhecida. Relatamos um caso de TO encontrada acidentalmente em autopsia de mulher com 73 anos de idade, que apresentava carcinoma ductal biliar extra hepático (tumor de Klatskin.Tracheopathia osteochondroplastica (TO is an unusual idiopathic disorder, characterized by osteocartilaginous nodules in the submucosa of the respiratory airway, which causes rigidity and narrowing of the respiratory tree. It affects mainly men over 50 and clinical manifestations are due to obstruction and/or local infections. The pathogenesis is uncertain. We report a case of TO found incidentally in an autopsy of a 73 year-old woman, who had an extrahepatic biliary ductal carcinoma (Klatskin tumor.

  5. Optimization of methods to assess mitochondrial DNA in archival paraffin-embedded tissues from mammary canine tumors Otimização dos métodos para avaliar o DNA mitocondrial obtido a partir de tumores mamários caninos incluídos em parafina

    Directory of Open Access Journals (Sweden)

    Angélica C. Bertagnolli

    2008-08-01

    Full Text Available In this study we describe the alterations used to extract and amplify mitochondrial desoxyribonucleic acid (DNA from formalin-fixed paraffin-embedded samples of canine mammary tumors. The epithelial and mesenchymal components (chondromyxoid and chondroid of each tumor, as well as the normal mammary gland tissues, were manually microdissected from 19 mixed canine mammary tumors (10 benign mixed tumors and nine carcinomas arising in mixed tumors. DNA was extracted by Invisorb® Spin Tissue Mini Kit, with protocol changes proposed by the manufacturer. A 273-bp fragment was amplified by polymerase chain reaction (PCR and submitted to automatic sequence analysis. The fragment was successfully analyzed in 100% of the samples. However, an additional lysis step, the reduction of volume in buffer solutions and PCR, a higher annealing temperature and an increase in the number of PCR cycles were required. The initial PCR products were diluted and re-amplified in six samples so that they could be successfully analyzed.A presente comunicação descreve as modificações usadas para extrair e amplificar o DNA mitocondrial obtido de amostras de tumores mamários caninos fixados em formol tamponado a 10% e incluídos em parafina. Os componentes epiteliais e mesenquimais (condromixóide e condróide, bem como a mama normal adjacente, foram microdissectados manualmente de 19 tumores mamários (10 tumores mistos benignos e nove carcinomas em tumores mistos. O DNA foi extraído utilizando-se o Invisorb® Spin Tissue Mini Kit com modificações do protocolo proposto pelo fabricante. Um fragmento de 273-pb foi amplificado por reação em cadeia da polimerase (PCR e seqüenciado em seqüenciador automático. O fragmento foi analisado em 100% das amostras, entretanto modificações como lise adicional, redução do volume das soluções de extração e PCR, aumento da temperatura de anelamento e do número de ciclos de amplificação foram necessárias. Em seis

  6. Análise da participação das proteínas Bax e Bcl-2 em células endoteliais humanas durante a evolução da infecção por taquizoítos de Toxoplasma gondii.

    OpenAIRE

    2010-01-01

    A toxoplasmose é uma zoonose amplamente distribuída que afeta mais de um terço da população mundial e de grande importância na saúde pública. A maioria das infecções em humanos por Toxoplasma gondii é assintomática. Entretanto, nos últimos anos, a toxoplasmose tem sido amplamente investigada uma vez que se apresenta como uma das doenças oportunistas que acometem pacientes portadores da Síndrome da Imunodeficiência Adquirida (AIDS) e indivíduos transplantados. A toxoplasmose congênita po...

  7. Bax function in the absence of mitochondria in the primitive protozoan Giardia lamblia.

    Directory of Open Access Journals (Sweden)

    Adrian B Hehl

    Full Text Available Bax-induced permeabilization of the mitochondrial outer membrane and release of cytochrome c are key events in apoptosis. Although Bax can compromise mitochondria in primitive unicellular organisms that lack a classical apoptotic machinery, it is still unclear if Bax alone is sufficient for this, or whether additional mitochondrial components are required. The protozoan parasite Giardia lamblia is one of the earliest branching eukaryotes and harbors highly degenerated mitochondrial remnant organelles (mitosomes that lack a genome. Here we tested whether human Bax expressed in Giardia can be used to ablate mitosomes. We demonstrate that these organelles are neither targeted, nor compromised, by Bax. However, specialized compartments of the regulated secretory pathway are completely ablated by Bax. As a consequence, maturing cyst wall proteins that are sorted into these organelles are released into the cytoplasm, causing a developmental arrest and cell death. Interestingly, this ectopic cargo release is dependent on the carboxy-terminal 22 amino acids of Bax, and can be prevented by the Bax-inhibiting peptide Ku70. A C-terminally truncated Bax variant still localizes to secretory organelles, but is unable to permeabilize these membranes, uncoupling membrane targeting and cargo release. Even though mitosomes are too diverged to be recognized by Bax, off-target membrane permeabilization appears to be conserved and leads to cell death completely independently of mitochondria.

  8. Connexin 43 enhances Bax activation via JNK activation in sunitinib-induced apoptosis in mesothelioma cells.

    Science.gov (United States)

    Uzu, Miaki; Sato, Hiromi; Shimizu, Ayaka; Shibata, Yukihiro; Ueno, Koichi; Hisaka, Akihiro

    2017-06-01

    The constituent protein of gap junctions, connexin (Cx), interacts with various proteins via its C-terminus region, including kinases, cell-adhesion proteins, and a pro-apoptotic protein, Bax. This molecular interaction may affect expression and functioning of the interacting proteins and modulate the cellular physiology. In our previous work, Cx43 was found to interact directly with Bax and in the presence of sunitinib, lead to the Bax-mediated apoptosis in mesothelioma cells. In this study, we investigated the mechanism of how Cx43 promotes Bax-mediated apoptosis using the same cell line. Treatment with sunitinib increased the expression of the active conformation of the Bax protein, which was predominantly localized at the mitochondria, only in Cx43-transfected cells. Bax oligomerization and decrease in the mitochondrial membrane potential were also observed. The involvement of c-Jun N-terminal kinase (JNK) in the interaction of Cx43 and Bax was further examined. Treatment with sunitinib increased the expression of phosphorylated (active) form of JNK only in the Cx43-transfected cells. Phosphorylated JNK and active Bax were co-localized, and the co-localization was suppressed by the knockdown of Cx43. Moreover, JNK inhibition clearly suppressed Bax activation. In conclusion, we identified a novel Cx43-JNK-Bax axis regulating the process of apoptosis for the first time. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  9. Evidence that inhibition of BAX activation by BCL-2 involves its tight and preferential interaction with the BH3 domain of BAX

    Institute of Scientific and Technical Information of China (English)

    Bonsu Ku; Chengyu Liang; Jae U Jung; Byung-Ha Oh

    2011-01-01

    Interactions between the BCL-2 family proteins determine the cell's fate to live or die. How they interact with each other to regulate apoptosis remains as an unsettled central issue. So far, the antiapoptotic Bc1-2 proteins are thought to interact with BAX weakly, but the physiological significance of this interaction has been vague.Herein, we show that recombinant BCL-2 and BCL-w interact potently with a BCL-2 homology (BH) 3 domain-containing peptide derived from BAX, exhibiting the dissociation constants of 15 and 23 nM, respectively. To clarify the basis for this strong interaction, we determined the three-dimensional structure of a complex of BCL-2 with a BAX peptide spanning its BH3 domain. It revealed that their interactions extended beyond the canonical BH3 domain and involved three nonconserved charged residues of BAX. A novel BAX variant, containing the alanine substitution of these three residues, had greatly impaired affinity for BCL-2 and BCL-w, hut was otherwise indistinguishable from wild-type BAX. Critically, the apoptotic activity of the BAX variant could not be restrained by BCL-2 and BCL-w, pointing that the observed tight interactions are critical for regulating BAX activation. We also comprehensively quantified the binding affinities between the three BCL-2 subfamily proteins. Collectively, the data show that due to the high affinity of BAX for BCL-2, BCL-w and A1, and of BAK for BCL-XL, MCL-1 and A1, only a subset of BH3-only proteins, commonly including BIM, BID and PUMA, could he expected to free BAX or BAK from the antiapoptotic BCL-2 proteins to elicit apoptosis.

  10. MiR-467a is upregulated in radiation-induced mouse thymic lymphomas and regulates apoptosis by targeting Fas and Bax.

    Science.gov (United States)

    Gao, Fu; Chen, Song; Sun, Mingjuan; Mitchel, Ronald E J; Li, Bailong; Chu, Zhiyong; Cai, Jianming; Liu, Cong

    2015-01-01

    It has been reported dysregulation of certain microRNAs (miRNAs / miRs) is involved in tumorigenesis. However, the miRNAs associated with radiocarcinogenesis remain undefined. In this study, we validated the upregulation of miR-467a in radiation-induced mouse thymic lymphoma tissues. Then, we investigated whether miR-467a functions as an oncogenic miRNA in thymic lymphoma cells. For this purpose, we assessed the biological effect of miR-467a on thymic lymphoma cells. Using miRNA microarray, we found four miRNAs (miR-467a, miR-762, miR-455 and miR-714) were among the most upregulated (>4-fold) miRNAs in tumor tissues. Bioinformatics prediction suggests miR-467a may potentially regulate apoptosis pathway via targeting Fas and Bax. Consistently, in miR-467a-transfected cells, both proliferation and colony formation ability were significantly increased with decrease of apoptosis rate, while, in miR-467a-knockdown cells, proliferation was suppressed with increase of apoptosis rate, indicating that miR-467a may be involved in the regulation of apoptosis. Furthermore, miR-467a-knockdown resulted in smaller tumors and better prognosis in an in vivo tumor-transplanted model. To explain the mechanism of apoptosis suppression by miR-467a, we explore the expression of candidate target genes (Fas and Bax) in miR-467a-transfected relative to negative control transfected cells using flow cytometry and immunoblotting. Fas and Bax were commonly downregulated in miR-467a-transfected EL4 and NIH3T3 cells, and all of the genes harbored miR-467a target sequences in the 3'UTR of their mRNA. Fas and Bax were actually downregulated in radiation-induced thymic lymphoma tissues, and therefore both were identified as possible targets of miR-467a in thymic lymphoma. To ascertain whether downregulation of Fas and / or Bax is involved in apoptosis suppression by miR-467a, we transfected vectors expressing Fas and Bax into miR-467a-upregulated EL4 cells. Then we found that both Fas- and Bax

  11. Uso da radioterapia no tumor venéreo transmissível em cães

    OpenAIRE

    Ciarlini, Luciana Del Rio Pinoti [UNESP; Koivisto,Marion Burkhardt; Fernandes,Marco Antônio Rodrigues; Soreano, Márcio; Silva, Rúbia Bueno da; Silva, Alexandre Redson Soares da

    2014-01-01

    Since the discovery of x rays, the use of radiation in oncology has advanced remarkably. In Brazil, radiation therapy in animals is limited to some isolated studies in public universities and the procedures performed is still precarious because radiation equipments are expensive and there is still a lack of skilled professionals. The transmissible venereal tumor (TVT) is a contagious neoplasm of spontaneous occurrence, commonly treated with vincristine. This paper describes the positive exper...

  12. JNK3 phosphorylates Bax protein and induces ability to form pore on bilayer lipid membrane

    Directory of Open Access Journals (Sweden)

    Rajeev Gupta

    2017-06-01

    Full Text Available Bax is a pro-apoptotic cytosolic protein. In this work native (unphosphorylated and JNK3 phosphorylated Bax proteins are studied on artificial bilayer membranes for pore formation. Phosphorylated Bax formed pore on the bilayer lipid membrane whereas native one does not. In cells undergoing apoptosis the pore formed by the phosphorylated Bax could be important in cytochrome c release from the mitochondrial intermembrane space to the cytosol. The low conductance (1.5 nS of the open state of the phosphorylated Bax pore corresponds to pore diameter of 0.9 nm which is small to release cytochrome c (∼3.4 nm. We hypothesized that JNK3 phosphorylated Bax protein can form bigger pores after forming complexes with other mitochondrial proteins like VDAC, t-Bid etc. to release cytochrome c.

  13. Bax mitochondrial relocation is linked to its phosphorylation and its interaction with Bcl-xL.

    Science.gov (United States)

    Garenne, David; Renault, Thibaud T; Manon, Stéphen

    2016-12-05

    The heterologous expression of Bax, and other Bcl-2 family members, in the yeast Saccharomyces cerevisiae, has proved to be a valuable reporter system to investigate the molecular mechanisms underlying their interaction with mitochondria. By combining the co-expression of Bax and Bcl-xL mutants with analyzes of their localization and interaction in mitochondria and post-mitochondrial supernatants, we showed that the ability of Bax and Bcl-xL to interact is dependent both on Bax phosphorylation - mimicked by a substitution S184D - and by Bax and Bcl-xL localization. This, and previous data, provide the molecular basis for a model of dynamic equilibrium for Bax localization and activation, regulated both by phosphorylation and Bcl-xL.

  14. Bax and Bif-1 proteins interact on Bilayer Lipid Membrane and form pore.

    Science.gov (United States)

    Gupta, Rajeev; Ghosh, Subhendu

    2015-08-07

    Bax and Bax interacting factor-1(Bif-1) are cytosolic proteins, which translocate towards mitochondria during mitochondria-mediated apoptosis. Bif-1 has been identified to co-immunoprecipitate with Bax in apoptotic cells. We have studied the interaction of Bax and Bif-1 on Bilayer Lipid Membrane (BLM) through electrophysiological experiments. It has been observed that Bax-Bif-1 equimolar mixture can form a pore. The pore conductance is in the range of 4.96-5.41 nS. It also displays a sub-state with a conductance of 2.6 nS. No pore activity is observed on BLM when monomeric Bax and Bif-1 proteins are tested independently. The above-mentioned pore forming activity could be relevant in mitochondria-mediated apoptosis. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. The oxidized phospholipid PazePC promotes permeabilization of mitochondrial membranes by Bax.

    Science.gov (United States)

    Lidman, Martin; Pokorná, Šárka; Dingeldein, Artur P G; Sparrman, Tobias; Wallgren, Marcus; Šachl, Radek; Hof, Martin; Gröbner, Gerhard

    2016-06-01

    Mitochondria play a crucial role in programmed cell death via the intrinsic apoptotic pathway, which is tightly regulated by the B-cell CLL/lymphoma-2 (Bcl-2) protein family. Intracellular oxidative stress causes the translocation of Bax, a pro-apoptotic family member, to the mitochondrial outer membrane (MOM) where it induces membrane permeabilization. Oxidized phospholipids (OxPls) generated in the MOM during oxidative stress directly affect the onset and progression of mitochondria-mediated apoptosis. Here we use MOM-mimicking lipid vesicles doped with varying concentrations of 1-palmitoyl-2-azelaoyl-sn-glycero-3-phosphocholine (PazePC), an OxPl species known to significantly enhance Bax-membrane association, to investigate three key aspects of Bax's action at the MOM: 1) induction of Bax pores in membranes without additional mediator proteins, 2) existence of a threshold OxPl concentration required for Bax-membrane action and 3) mechanism by which PazePC disturbs membrane organization to facilitate Bax penetration. Fluorescence leakage studies revealed that Bax-induced leakage, especially its rate, increased with the vesicles' PazePC content without any detectable threshold neither for OxPl nor Bax. Moreover, the leakage rate correlated with the Bax to lipid ratio and the PazePC content. Solid state NMR studies and calorimetric experiments on the lipid vesicles confirmed that OxPl incorporation disrupted the membrane's organization, enabling Bax to penetrate into the membrane. In addition, 15N cross polarization (CP) and insensitive nuclei enhanced by polarization transfer (INEPT) MAS NMR experiments using uniformly (15)N-labeled Bax revealed dynamically restricted helical segments of Bax embedded in the membrane, while highly flexible protein segments were located outside or at the membrane surface. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Role of Bax in death of uninfected retinal cells during murine cytomegalovirus retinitis.

    Science.gov (United States)

    Mo, Juan; Marshall, Brendan; Covar, Jason; Zhang, Nancy Y; Smith, Sylvia B; Atherton, Sally S; Zhang, Ming

    2014-10-08

    Extensive death of uninfected bystander neuronal cells is an important component of the pathogenesis of cytomegalovirus retinitis. Our previous results have shown that caspase 3-dependent and -independent pathways are involved in death of uninfected bystander cells during murine cytomegalovirus (MCMV) retinitis and also that Bcl-2, an important inhibitor of apoptosis via the Bax-mediated mitochondrial pathway, is downregulated during this process. The purpose of this study was to determine whether Bax-mediated mitochondrial damage has a significant role in the death of uninfected retinal cells. BALB/c mice, Bax(-/-) mice, or Bax(+/+) mice were immunosuppressed with methylprednisolone and infected with 5 × 10(3) plaque-forming units (PFU) of the K181 strain of MCMV via the supraciliary route. Injected eyes were analyzed by plaque assay, electron microscopy, hematoxylin and eosin (H&E) staining, TUNEL assay, Western blot (for caspase 3, caspase 12, Bax, receptor interacting protein-1 [RIP1] and receptor interacting protein-3 [RIP3]), as well as immunohistochemical staining for MCMV early antigen and cleaved caspase 3. Significantly more Bax was detected in mitochondrial fractions of MCMV-infected eyes than in mitochondrial fractions of mock-infected control eyes. Furthermore, the level of cleaved caspase 3 was significantly lower in MCMV-infected Bax(-/-) eyes than in MCMV-infected Bax(+/+) eyes. However, more caspase 3-independent cell death of uninfected bystander retinal cells and more cleaved RIP1 were observed in Bax(-/-) than in Bax(+/+) eyes. During MCMV retinitis, Bax is activated and has an important role in death of uninfected bystander retinal cells by caspase 3-dependent apoptosis. Although the exact mechanism remains to be deciphered, active Bax might also prevent death of some types of uninfected retinal cells by a caspase 3-independent pathway. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  17. Integration and oligomerization of Bax protein in lipid bilayers characterized by single molecule fluorescence study.

    Science.gov (United States)

    Luo, Lu; Yang, Jun; Liu, Dongxiang

    2014-11-14

    Bax is a pro-apoptotic Bcl-2 family protein. The activated Bax translocates to mitochondria, where it forms pore and permeabilizes the mitochondrial outer membrane. This process requires the BH3-only activator protein (i.e. tBid) and can be inhibited by anti-apoptotic Bcl-2 family proteins such as Bcl-xL. Here by using single molecule fluorescence techniques, we studied the integration and oligomerization of Bax in lipid bilayers. Our study revealed that Bax can bind to lipid membrane spontaneously in the absence of tBid. The Bax pore formation undergoes at least two steps: pre-pore formation and membrane insertion. The activated Bax triggered by tBid or BH3 domain peptide integrates on bilayers and tends to form tetramers, which are termed as pre-pore. Subsequent insertion of the pre-pore into membrane is highly dependent on the composition of cardiolipin in lipid bilayers. Bcl-xL can translocate Bax from membrane to solution and inhibit the pore formation. The study of Bax integration and oligomerization at the single molecule level provides new evidences that may help elucidate the pore formation of Bax and its regulatory mechanism in apoptosis. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. Cell death induced by 2-phenylethynesulfonamide uncovers a pro-survival function of BAX.

    Science.gov (United States)

    Mattiolo, Paolo; Barbero-Farran, Ares; Amigó, Josep; Ripamonti, Marta; Ribas, Judit; Boix, Jacint

    2014-11-01

    PES (2-phenylethynesulfonamide) was initially identified as an inhibitor of p53 translocation to mitochondria and named Pifithrin-µ. Further studies showed that PES selectively killed tumour cells and was thus a promising anticancer agent. PES-induced cell death was characterised by a non-apoptotic, autophagosome-rich phenotype. We observed this phenotype via electron microscopy in wild type (wt) and double Bax-/- Bak-/- (DKO) mouse embryonic fibroblasts (MEFs) treated with PES. We excluded the involvement of effector caspases, BAX and BAK, in causing PES-triggered cell death. Therefore, apoptosis was ruled out as the lethal mode of action of PES. Surprisingly, MEFs containing BAX were significantly protected from PES treatments. BAX overexpression in Bax-/- MEFs confirmed this pro-survival effect. Moreover, this protective effect required the ability of BAX to localise to mitochondrial membranes. Conversely, mitochondrial fusion induced by treatment with Mdivi-1 conferred increased resistance to MEFs subjected to PES treatment. The involvement of BAX in the regulation of mitochondrial dynamics has been reported. We propose the promotion of mitochondrial fusion by BAX to be the pro-survival function attributed to BAX. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  19. Bax assembles into large ring-like structures remodeling the mitochondrial outer membrane in apoptosis.

    Science.gov (United States)

    Große, Lena; Wurm, Christian A; Brüser, Christian; Neumann, Daniel; Jans, Daniel C; Jakobs, Stefan

    2016-02-15

    The Bcl-2 family proteins Bax and Bak are essential for the execution of many apoptotic programs. During apoptosis, Bax translocates to the mitochondria and mediates the permeabilization of the outer membrane, thereby facilitating the release of pro-apoptotic proteins. Yet the mechanistic details of the Bax-induced membrane permeabilization have so far remained elusive. Here, we demonstrate that activated Bax molecules, besides forming large and compact clusters, also assemble, potentially with other proteins including Bak, into ring-like structures in the mitochondrial outer membrane. STED nanoscopy indicates that the area enclosed by a Bax ring is devoid of mitochondrial outer membrane proteins such as Tom20, Tom22, and Sam50. This strongly supports the view that the Bax rings surround an opening required for mitochondrial outer membrane permeabilization (MOMP). Even though these Bax assemblies may be necessary for MOMP, we demonstrate that at least in Drp1 knockdown cells, these assemblies are not sufficient for full cytochrome c release. Together, our super-resolution data provide direct evidence in support of large Bax-delineated pores in the mitochondrial outer membrane as being crucial for Bax-mediated MOMP in cells. © 2016 The Authors. Published under the terms of the CC BY 4.0 license.

  20. Bak and Bax function to limit adenovirus replication through apoptosis induction.

    Science.gov (United States)

    Cuconati, Andrea; Degenhardt, Kurt; Sundararajan, Ramya; Anschel, Alan; White, Eileen

    2002-05-01

    Adenovirus infection and expression of E1A induces both proliferation and apoptosis, the latter of which is blocked by the adenovirus Bcl-2 homologue E1B 19K. The mechanism of apoptosis induction and the role that it plays in productive infection are not known. Unlike apoptosis mediated by death receptors, infection with proapoptotic E1B 19K mutant viruses did not induce cleavage of Bid but nonetheless induced changes in Bak and Bax conformation, Bak-Bax interaction, caspase 9 and 3 activation, and apoptosis. In wild-type-adenovirus-infected cells, in which E1B 19K inhibits apoptosis, E1B 19K was bound to Bak, precluding Bak-Bax interaction and changes in Bax conformation. Infection with E1B 19K mutant viruses induced apoptosis in wild-type and Bax- or Bak-deficient baby mouse kidney cells but not in those deficient for both Bax and Bak. Furthermore, Bax and Bak deficiency dramatically increased E1A expression and virus replication. Thus, Bax- and Bak-mediated apoptosis severely limits adenoviral replication, demonstrating that Bax and Bak function as an antiviral response at the cellular level.

  1. DETECÇÃO E GENOTIPAGEM DE PAPILOMAVÍRUS HUMANO EM TUMORES DE PÊNIS

    OpenAIRE

    Sousa, Antoniella Fernanda Mendanha

    2008-01-01

    O Câncer é uma conseqüência de alterações genéticas ou epigenéticas em uma variedade dos genes que são fundamentais ao processo de crescimento, proliferação, diferenciação e morte programada da célula. Atualmente, essa doença, configura-se um dos principais problemas da saúde mundial, e no Brasil, representa a segunda causa de óbito na população adulta. O câncer de pênis é um tipo raro de neoplasia, que acomete indivíduos de países subdesenvolvidos com baixo nível social e precários hábitos d...

  2. Expression of Bax in yeast affects not only the mitochondria but also vacuolar integrity and intracellular protein traffic

    DEFF Research Database (Denmark)

    Dimitrova, Irina; Toby, Garabet G; Tili, Esmerina

    2004-01-01

    Bax-induced lethality in yeast is accompanied by morphological changes in mitochondria, giving rise to a reduced number of swollen tubules. Although these changes are completely abolished upon coexpression of the Bax inhibitor, Bcl-2, coexpression of Bax with Bax inhibiting-glutathione S-transfer......Bax-induced lethality in yeast is accompanied by morphological changes in mitochondria, giving rise to a reduced number of swollen tubules. Although these changes are completely abolished upon coexpression of the Bax inhibitor, Bcl-2, coexpression of Bax with Bax inhibiting-glutathione S......-transferase (BI-GST) leads to aggregation, but not fusion of the mitochondria. In addition, Bax affects the integrity of yeast vacuoles, resulting in the disintegration and eventual loss of the organelles, and the disruption of intracellular protein traffic. While Bcl-2 coexpression only partially corrects...

  3. Targeted therapy of the XIAP/proteasome pathway overcomes TRAIL-resistance in carcinoma by switching apoptosis signaling to a Bax/Bak-independent 'type I' mode.

    Science.gov (United States)

    Gillissen, B; Richter, A; Richter, A; Overkamp, T; Essmann, F; Hemmati, P G; Preissner, R; Belka, C; Daniel, P T

    2013-05-23

    TRAIL is a promising anticancer agent, capable of inducing apoptosis in a wide range of treatment-resistant tumor cells. In 'type II' cells, the death signal triggered by TRAIL requires amplification via the mitochondrial apoptosis pathway. Consequently, deregulation of the intrinsic apoptosis-signaling pathway, for example, by loss of Bax and Bak, confers TRAIL-resistance and limits its application. Here, we show that despite resistance of Bax/Bak double-deficient cells, TRAIL-treatment resulted in caspase-8 activation and complete processing of the caspase-3 proenzymes. However, active caspase-3 was degraded by the proteasome and not detectable unless the XIAP/proteasome pathway was inhibited. Direct or indirect inhibition of XIAP by RNAi, Mithramycin A or by the SMAC mimetic LBW-242 as well as inhibition of the proteasome by Bortezomib overcomes TRAIL-resistance of Bax/Bak double-deficient tumor cells. Moreover, activation and stabilization of caspase-3 becomes independent of mitochondrial death signaling, demonstrating that inhibition of the XIAP/proteasome pathway overcomes resistance by converting 'type II' to 'type I' cells. Our results further demonstrate that the E3 ubiquitin ligase XIAP is a gatekeeper critical for the 'type II' phenotype. Pharmacological manipulation of XIAP therefore is a promising strategy to sensitize cells for TRAIL and to overcome TRAIL-resistance in case of central defects in the intrinsic apoptosis-signaling pathway.

  4. Ghrelin and pre-proghrelin immunoreactive cells in gastric neuroendocrine tumors associated with atrophic body gastritis Grelina e pré-progrelina em tumores neuroendócrinos do estômago associados à gastrite atrófica do corpo

    Directory of Open Access Journals (Sweden)

    Letícia Figueiredo Moreira

    2010-08-01

    ástrica. A expressão imuno-histoquímica da grelina tem sido descrita em tumores neuroendócrinos, acreditando-se que possa ter ação moduladora relacionada com o crescimento desses tumores. OBJETIVO: Estudar a presença de células imunorreativas a grelina e pré-progrelina em tumores neuroendócrinos gástricos associados à gastrite crônica atrófica do corpo. MÉTODOS: Biópsias endoscópicas de 15 pacientes portadores de tumor neuroendócrino da mucosa gástrica, associados à gastrite crônica atrófica do corpo, foram obtidas para as colorações imuno-histoquímicas, utilizando-se anticorpos contra cromogranina, grelina e pré-progrelina. A expressão imuno-histoquímica foi avaliada nas células tumorais e na hiperplasia endócrina micronodular presente na mucosa adjacente ao tumor e classificada em relação ao número de células coradas. RESULTADOS: A cromogranina foi positiva em 14 dos 15 tumores. Células imunorreativas à grelina foram detectadas em 11 (73% tumores e à pré-progrelina em 13 (87%, ocorrendo excelente concordância (kappa = 81% entre os resultados imuno-histoquímicos dos dois antígenos. A expressão de grelina e pré-progrelina foi detectada em nódulos hiperplásicos presentes na mucosa adjacente ao tumor em sete e oito casos, respectivamente, não ocorrendo concordância entre esses resultados e aqueles observados nas células neoplásicas. CONCLUSÃO: Células imunorreativas a pré-progrelina e grelina podem ser encontradas em número variável nos tumores neuroendócrinos tipo I do estômago e nas lesões hiperplásicas associadas a esses tumores. Entretanto, permanece obscuro o papel desses peptídeos em relação ao desenvolvimento desses tumores.

  5. Immunoexpression of tumor suppressor genes p53, p21WAF1/CIP1 and p27KIP1 in humam astrocystic tumors Imuno-expressão dos genes supressores tumorais p53, p21WAF1/CIP1 e p27KIP1 em tumores astrocíticos humanos

    Directory of Open Access Journals (Sweden)

    Mário Henrique Girão Faria

    2007-12-01

    Full Text Available The aim of the present study was to evaluate the tumor suppressor genes p53, p21WAF1/CIP1 and p27KIP1 expression in astrocytic tumors, correlating the findings with the histopathological grade (WHO. An immunohistochemical study of the p53, p21 and p27 proteins using the streptavidin-biotin-peroxidase method was performed in fifty-five astrocytomas (13 grade I, 14 grade II, 7 grade III and 21 grade IV and five samples of non-tumor brain tissue (negative control. p53 positive indices (PI and labeling indices (LI showed tendency to increase according to malignant progression. The nuclear expression of p27 presented similar inclination, except for the PI reduction verified in grade IV tumors. Otherwise, the cytoplasmic p27 staining was more evident between high-grade tumors (III and IV. p53 and nuclear p27 expression was correlated with the histological classification (pO presente estudo objetivou avaliar a expressão dos supressores tumorais p53, p21WAF1/CIP1 e p27KIP1 em tumores astrocíticos humanos, correlacionando os achados com a graduação histopatológica (OMS. Procedeu-se o estudo imuno-histoquímico para as proteínas p53, p21 e p27 utilizando o método da estreptavidina-biotina-peroxidase em 55 astrocitomas (13 do grau I, 14 do grau II, 7 do grau III e 21 do grau IV e 5 amostras de tecido cerebral não-tumoral (controle negativo. Os índices de positividade (PI e de marcação (LI para p53 demonstraram tendência de aumento conforme a progressão maligna. A expressão nuclear do p27 apresentou semelhante inclinação, exceto pela redução do PI verificada nos tumores do grau IV. Já a marcação citoplasmática do p27 foi mais evidente entre tumores de alto grau (III e IV. As expressões de p53 e p27 nuclear demonstraram correlação com a classificação histológica (p<0,01; teste H. Por outro lado, os índices para p21 manifestaram propensão à redução conforme a evolução maligna dos tumores astrocíticos, salvo significante

  6. Targeting Bax interaction sites reveals that only homo-oligomerization sites are essential for its activation

    Science.gov (United States)

    Peng, R; Tong, J-S; Li, H; Yue, B; Zou, F; Yu, J; Zhang, L

    2013-01-01

    Bax is a proapoptotic Bcl-2 family member that has a central role in the initiation of mitochondria-dependent apoptosis. However, the mechanism of Bax activation during apoptosis remains unsettled. It is believed that the activation of Bax is mediated by either dissociation from prosurvival Bcl-2 family members, or direct association with BH3-only members. Several interaction sites on Bax that mediate its interactions with other Bcl-2 family members, as well as its proapoptotic activity, have been identified in previous studies by other groups. To rigorously investigate the functional role of these interaction sites, we knocked in their respective mutants using HCT116 colon cancer cells, in which apoptosis induced by several stimuli is strictly Bax-dependent. Bax-mediated apoptosis was intact upon knock-in (KI) of K21E and D33A, which were shown to block the interaction of Bax with BH3-only activators. Apoptosis was partially reduced by KI of D68R, which impairs the interaction of Bax with prosurvival members, and S184V, a constitutively mitochondria-targeting mutant. In contrast, apoptosis was largely suppressed by KI of L70A/D71A, which blocks homo-oligomerization of Bax and its binding to prosurvival Bcl-2 family proteins. Collectively, our results suggest that the activation of endogenous Bax in HCT116 cells is dependent on its homo-oligomerization sites, but not those previously shown to interact with BH3-only activators or prosurvival proteins only. We therefore postulate that critical interaction sites yet to be identified, or mechanisms other than protein-protein interactions, need to be pursued to delineate the mechanism of Bax activation during apoptosis. PMID:23392123

  7. The impact of use of Glutamine on patients with head and neck tumors in radiotherapy and chemotherapy treatment; O Impacto do uso de Glutamina em pacientes com tumores de cabeca e pescoco em tratamento radioterapico e quimioterapico

    Energy Technology Data Exchange (ETDEWEB)

    Boligon, Caroline Schardong, E-mail: caronut@bol.com.b [Hospital de Caridade de Ijui, RS (Brazil); Huth, Adriane, E-mail: adriane.huth@unijui.edu.b [UNIJUI, RS (Brazil). Dept. Ciencias da Saude

    2011-07-01

    Introduction: patients with head and neck neoplasia usually show malnutrition or a nutritional risk, because of common symptoms like: dysphagia, odynophagia and xerostomia. Objective: this study aimed to verify the impact of using amino glutamine in patients with head and neck neoplasia and under radiotherapy and chemotherapy treatment concomitantly. Methods: the research was quantitative, cross-sectional, descriptive and exploratory. The data was collected from nutritional evaluation, and patients chart consultation. The patients were divided in a control group (without use of glutamine) and a test group (with use of glutamine). 16 patients, 13 of which were men and three were women, participated in the research. Results: The control group presented mucositis grades I to IV while patients who used the amino glutamine showed mucositis grades I to II only. It could be observed that the Nutritional Risk Index decreased, which represents higher nutritional risk in patients from the control group only. In patients who used glutamine, this decrease was not significant. Conclusion: these results suggest that the use of glutamine in patients with head and neck tumors and under antineoplastic therapy helps to maintain their nutritional stage and to prevent mucositis throughout their treatment, mainly grades III and IV, which prevents adequate and regular eating and nourishment. (author)

  8. The Expression of Bcl-2 and Bax in Normal,Hyperplastic,and Malignant Endometrium

    Institute of Scientific and Technical Information of China (English)

    ZHONGGang; TANLingfang; 等

    2002-01-01

    Objective:To investigate the expression of Bcl-2 and Bax proteins in normal,hyperplastic,and malignant endometrium.Methods:Endometrial tissues were obtained from 14 proliferative endometrial samples;simple(n=30)and complex hyperplasia without atypia(n=13);complex hyperplasia with atypia(n=20)and endometrial adenocarcinoma(n=17).The expression of Bcl-2and Bax proteins was detected by using immunohistochemical staining with appropriate antibodies.Results:The intensity of Bcl-2 staining was gradually increased from proliferative to simple and complex hyperplasia,but it was gradually decreased from atypia hyperplasia to endometrial adenocarcinoma(P<0.05).The intensity of Bax staining was gradually increased from proliferative endometrium to simple and complex hyperplasia,but in atypia hyperplasia it was obviously lower than simple hyperplasia,the ratio of Bco-2;Bax staining intensity was changed with the endometrium from proliferative,hyperplastic endo-metrium to endometrial adenocarcinoma.The ratio of Bcl-2;Bax staining intensity was obviously decreased in atypia hyperplasia and endometrial adenocarcinoma.Conclusion:The survival time of the cells in hyperplasia expressing Bcl-2 might be prolonged.Neoplastic cells in atypia hyperplasia and adenocarcinoma might show a decreased expression of Bcl-2 and Bax,suggesting that Bcl-2 and Bax might be important indexes and prognosis factors and the expression of Bcl-2 and Bax might be correlated with carcinogenesis in the uterine endometrium of hu-mans.

  9. Oncogenic Mutations Differentially Affect Bax Monomer, Dimer, and Oligomeric Pore Formation in the Membrane

    Science.gov (United States)

    Zhang, Mingzhen; Zheng, Jie; Nussinov, Ruth; Ma, Buyong

    2016-09-01

    Dysfunction of Bax, a pro-apoptotic regulator of cellular metabolism is implicated in neurodegenerative diseases and cancer. We have constructed the first atomistic models of the Bax oligomeric pore consisting with experimental residue-residue distances. The models are stable, capturing well double electron-electron resonance (DEER) spectroscopy measurements and provide structural details in line with the DEER data. Comparison with the latest experimental results revealed that our models agree well with both Bax and Bak pores, pointed to a converged structural arrangement for Bax and Bak pore formation. Using multi-scale molecular dynamics simulations, we probed mutational effects on Bax transformation from monomer → dimer → membrane pore formation at atomic resolution. We observe that two cancer-related mutations, G40E and S118I, allosterically destabilize the monomer and stabilize an off-pathway swapped dimer, preventing productive pore formation. This observation suggests a mechanism whereby the mutations may work mainly by over-stabilizing the monomer → dimer transformation toward an unproductive off-pathway swapped-dimer state. Our observations point to misfolded Bax states, shedding light on the molecular mechanism of Bax mutation-elicited cancer. Most importantly, the structure of the Bax pore facilitates future study of releases cytochrome C in atomic detail.

  10. [The Mechanisms by which Bax Induces the Apoptosis of Human Ovarian Cancer Cells].

    Science.gov (United States)

    Zeng, Jun; Yang, Jing; Chen, Deng-bang; Cao, Kang

    2015-09-01

    The purpose of this study was to observe the apoptosis of A2780 cells transfected with the recombinant plasmid of pcDNA-Bax and to observe the release of cytochrome C from the mitochondria. The recombinant plasmid of pcDNA-Bax was constructed and transfected into A2784 cells. The Hoechst 33258 stain method was applied to evaluate the apoptosis of the transfected cells and MTT mothod was used to test the cell viability. Western blot analysis was performed to determine the overexpression of Bax and the release of cytochrome C from the mitochondria. The recombinant plasmid of pcDNA-Bax was successfully constructed by using endonuclease digestion and the sequence analysis. The apoptosis of A2780 cells was induced after transfected with pcDNA3. 1-Bax as demonstrated with Hoechst staining. The cell viability were decreased in the pcDNA3. 1-Bax transfected group by MTT assay. The release of cytochrome C from the mitochondria was observed when using Western blotting analysis. And the caspase-9 and the caspase-3 were activated. Our data suggestted that Bax exhibited potent pro-apoptotic activity against the ovarian cancer cells. This study is a foundation for the further research in the pro-apoptotic activity of Bax.

  11. A sandwich ELISA for the conformation-specific quantification of the activated form of human Bax.

    Science.gov (United States)

    Teijido, Oscar; Ganesan, Yogesh Tengarai; Llanos, Raul; Peton, Ashley; Urtecho, Jean-Baptiste; Soprani, Adauri; Villamayor, Aimee; Antonsson, Bruno; Manon, Stéphen; Dejean, Laurent

    2016-03-15

    Bcl-2 family proteins are critical regulators of mitochondrial outer membrane permeabilization (MOMP), which represents the point of no return of apoptotic cell death. The exposure of the Bax N-terminus at the mitochondria reflects Bax activation; and this activated configuration of the Bax protein is associated with MOMP. N-terminal exposure can be detected using specific monoclonal and/or polyclonal antibodies, and the onset of activated Bax has extensively been used as an early marker of apoptosis. The protocols of immunoprecipitation and/or immunocytochemistry commonly used to detect activated Bax are long and tedious, and allow semiquantification of the antigen at best. The sandwich ELISA protocol we developed has a 5 ng/mL detection limit and is highly specific for the activated conformation of Bax. This ELISA allows a rapid quantification of activated human Bax in whole cells and isolated mitochondria protein extracts. These properties grant this assay the potential to further clarify the prognostic and diagnostic value of activated Bax in disorders associated with deregulated apoptotic pathways such as degenerative diseases or cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Quantitative assessment of BAX transcript and flow cytometric expression in acute myeloid leukemia: a prospective study.

    Science.gov (United States)

    Sharawat, Surender Kumar; Raina, Vinod; Kumar, Lalit; Sharma, Atul; Bakhshi, Radhika; Vishnubhatla, Sreenivas; Gupta, Ritu; Bakhshi, Sameer

    2014-10-01

    Quantitative assessment of BAX transcripts and protein in acute myeloid leukemia (AML). We quantitatively evaluated BAX gene transcripts by real-time polymerase chain reaction (TaqMan probe chemistry) and protein expression by flow cytometry. Consecutive 112 AML patients with a median age of 16 (1-59) years were recruited in the study. By flow cytometry, the percentage expression was in linear correlation with relative median fluorescent intensity (RMFI; R = 0.4425; P BAX with its RMFI (R = -0.0559; P = 0.586). The expression of the BAX at both protein and transcript level was significantly higher in AML patients as compared with normal control. RMFI of the BAX were higher in the cohort with lower white blood cell count (P = 0.029). None of the other baseline characteristics correlated with either the BAX transcript or the RMFI. BAX expression did not correlate with complete remission rate, event free, disease free, and overall survival. BAX gene expression in AML was evaluated first time with two different methods but did not correlate with the survival outcome.

  13. Higher expression of Bax in regulatory T cells increases vascular inflammation.

    Science.gov (United States)

    Xiong, Zeyu; Song, Jian; Yan, Yan; Huang, Yajue; Cowan, Alan; Wang, Hong; Yang, Xiao-Feng

    2008-05-01

    This study is to examine our hypothesis that CD4+CD25(high)Foxp3+ regulatory T cells (Tregs) have an interleukin-2 (IL-2) withdrawal-triggered apoptosis pathway, and modulation of Treg apoptosis pathway affects development of vascular inflammation. We found that pro-apoptotic protein Bax upregulation in Tregs is induced by IL-2 withdrawal. Treg apoptosis induced by IL-2 withdrawal is inhibited by a Bax inhibitor, suggesting that highly expressed Bax is functional. To define the role of upregulated Bax in Treg apoptosis, we established a Tregs-specific Bax transgenic mouse model. Enforced expression of Bax in Tregs promotes Treg apoptosis triggered by IL-2 withdrawal and other apoptosis stimuli, suggesting pro-apoptotic role of highly expressed Bax in wild-type Tregs. Finally, higher expression of Bax in Tregs decreases the striking threshold of vascular inflammation due to the failure of suppression of inflammatory cells resulting from Treg apoptosis. These results have demonstrated the proof of principle that the modulation of Tregs apoptosis/survival could be used as a new therapeutic approach for inflammatory cardiovascular diseases.

  14. The substitution of Proline 168 favors Bax oligomerization and stimulates its interaction with LUVs and mitochondria.

    Science.gov (United States)

    Simonyan, Lilit; Légiot, Alexandre; Lascu, Ioan; Durand, Grégory; Giraud, Marie-France; Gonzalez, Cécile; Manon, Stéphen

    2017-06-01

    Bax is a major player in the apoptotic process, being at the core of the mitochondria permeabilization events. In spite of the major recent advances in the knowledge of Bax organization within the membrane, the precise behavior of the C-terminal helix α9 remains elusive, since it was absent from the resolved structure of active Bax. The Proline 168 (P168) residue, located in the short loop between α8 and α9, has been the target of site-directed mutagenesis experiments, with conflicting results. We have produced and purified a recombinant mutant Bax-P168A, and we have compared its behavior with that of wild-type Bax in a series of tests on Large Unilamellar Vesicles (LUVs) and isolated mitochondria. We conclude that Bax-P168A had a greater ability to oligomerize and bind to membranes. Bax-P168A was not more efficient than wild-type Bax to permeabilize liposomes to small molecules but was more prone to release cytochrome c from mitochondria. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Involvement of nitric oxide signaling in mammalian Bax-induced terpenoid indole alkaloid production of Catharanthus roseus cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Bax, a mammalian pro-apoptotic member of the Bcl-2 family, has been demonstrated to be a potential regulatory factor for plant secondary metabolite biosynthesis recently. To investigate the molecular mechanism of Bax-induced secondary metabolite biosynthesis, we determined the contents of nitric oxide (NO) of the transgenic Catharanthus roseus cells overexpressing a mouse Bax protein and checked the effects of NO specific scavenger 2,4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1- oxyl-3-oxide (cPITO) on Bax-induced terpenoid indole alkaloid (TIA) production of the cells. The data showed that overexpression of the mouse Bax in C. roseus cells triggered NO generation of the cells. Treatment of cPITO not only inhibited the Bax-triggered NO burst but also suppressed the Bax-induced TIA production. The results indicated that the mouse Bax might activate the NO signaling in C. roseus cells and induce TIA production through the NO-dependent signal pathway in the cells. Furthermore, the activities of nitric oxide synthase (NOS) were significantly increased in the transgenic Bax cells as compared to those in the control cells, showing that the mouse Bax may induce NOS of C. roseus cells. Treatment of the transgenic Bax cells with NOS inhibitor PBITU blocked both Bax-induced NO generation and TIA production, which suggested that the mouse Bax might trigger NO generation and TIA production through NOS. However, the NOS-like activities and NO generation in the transgenic Bax cells did not match kinetically and the Bax-induced NOS-like activity was much later and lower than NO production. Moreover, the Bax-induced NO generation and TIA production were only partially inhibited by PBITU. Thus, our results suggested that the Bax-induced NO production and secondary metabolite biosynthesis in C. roseus cells was not entirely dependent on NOS or NOS-like enzymes.

  16. Célula tronco tumoral: novo conceito em carcinogênese colorretal Câncer stem cells: a new concept in colorectal carcinogenesis

    Directory of Open Access Journals (Sweden)

    Mauro de Souza Leite Pinho

    2009-03-01

    Full Text Available Apesar dos grandes avanços obtidos pelos estudos utilizando técnicas de biologia molecular diversas controvérsias persistem a respeito do mecanismo de carcinogênese colorretal. Ao longo do último ano, entretanto, observamos na literatura o surgimento de um novo conceito referente à existência de um conjunto de células situadas nas bases das criptas intestinais, as quais apresentam características bastante distintas do restante das células epiteliais. Estas células, denominadas como células tronco intestinais, apresentam-se de forma indiferenciada e com um ciclo de vida com duração superior a um ano. Desta forma, justifica-se assim nestas células a possibilidade da ocorrência de um acúmulo de mutações, etapa considerada essencial para o desenvolvimento do processo neoplásico, e que seria improvável de ocorrer em um colonócito normal, cujo ciclo de vida dura em média cinco dias. Outra importante evidência da participação destas células tronco no mecanismo de carcinogênese foi demonstrada por estudos capazes de reproduzir a formação de tecidos neoplásicos com a mesma característica do tumor original, a partir do implante de um reduzido número destas células em modelos experimentais, o que não se obtém através do implante de um grande número de células tumorais normais. Sabendo-se que a presença de uma mutação do gene APC é uma etapa precoce no processo de carcinogênese colorretal, acredita-se que esta exerça este papel contribuindo para a ocorrência de uma superpopulação de células tronco intestinais, levando a um desequilíbrio proliferativo na mucosa intestinal.Despite the great number of studies using molecular biology tools several questions remain about the mechanisms of colorectal carcinogenesis. A recent concept has emerged from the literature regarding the existence of a specific group of indiferentiated cells situated at the bottom of intestinal crypts with a long life cycle that may last

  17. Activation of JNK/Bim/Bax pathway in UV-induced apoptosis

    Science.gov (United States)

    Liu, Lei; Hui, Li; Zhang, Zhen-zhen

    2011-03-01

    Cell apoptosis induced by UV irradiation is a highly complex process in which different molecular signaling pathways are involved. JNK has been proposed as an important regulator in UV irradiation-induced apoptosis. However, the molecular mechanism through which JNK regulates apoptosis, especially how JNK activates Bax in response to UV irradiation is still controversial. In this study, using real-time single-cell analysis, we studied the machinery of Bax activation during UV-induced apoptosis. UV treatment resulted in a series of events: phosphorylation of JNK, mitochondrial translocation of Bim, and subsequent activation of Bax. The activation of Bim and Bax could be inhibited in the presence of SP600125 (a specific inhibitor of JNK), suggesting that UV irradiation activated the JNK/Bim/Bax pathway.

  18. BaP-induced DNA damage initiated p53-independent necroptosis via the mitochondrial pathway involving Bax and Bcl-2.

    Science.gov (United States)

    Jiang, Y; Chen, X; Yang, G; Wang, Q; Wang, J; Xiong, W; Yuan, J

    2013-12-01

    Benzo(a)pyrene (BaP), a typical environmental carcinogen, can induce cell death both by protein 53 or tumor protein 53 (p53)-independent and -dependent pathways. However, little is known about the molecular mechanisms of p53-independent pathways in BaP-induced cell death. In this study, cells with different genetic background (including p53-proficient human fetal lung fibroblast cell lines (MRC-5), p53-deficient human non-small-cell lung carcinoma cell lines (H1299), and p53-knockdown cell lines (MRC-5(p53-/-))) were used to establish models of BaP-induced cell death. The results showed that BaP (8, 16, 32, and 64 μM) induced necroptotic cell death in the cell lines. The necroptotic cell death and DNA damage were concurrently observed. In the three cell lines, at 24 h after treatment, BaP (8-64 μM) upregulated expressions of BAX, BCL-2, and cleaved caspase-3 proteins, but not their messenger RNA levels. The findings suggested that BaP-induced necroptosis was modulated by the p53-independent pathway, which was related to the induction of BAX, decreased expression of BCL-2, and activation of caspase-3.

  19. Punção aspirativa por agulha fina no diagnóstico de linfadenopatias e tumores sólidos em crianças e adolescentes

    Directory of Open Access Journals (Sweden)

    Wallace Acioli Freire de Gois

    Full Text Available OBJETIVO: Avaliar a importância diagnóstica da punção aspirativa por agulha fina (PAAF em crianças e adolescentes portadores de linfadenopatias e tumores sólidos. MÉTODOS: Análise retrospectiva dos pacientes com idade igual ou inferior a 18 anos, atendidos no Centro de Pediatria Cirúrgica do Hospital Universitário de Brasília, Universidade de Brasília, no período de julho de 2000 a julho de 2005. Foram calculados: sensibilidade, especificidade, precisão (acurácia diagnóstica, valor preditivo positivo e valor preditivo negativo. RESULTADOS: Em 50 pacientes estudados, os resultados da PAAF mostraram sensibilidade de 90,9%; especificidade de 100%, precisão diagnóstica de 95% e valores preditivos positivo e negativo de 100% e 90%, respectivamente. CONCLUSÃO: Em nossa experiência, a PAAF é um método preciso, simples e seguro, útil no diagnóstico de linfadenopatias e tumores sólidos em crianças e adolescentes.

  20. Correlação do tipo de biópsia e sua validade diagnóstica nos tumores músculo-esqueléticos em distintas topografias Correlation of the type of biopsy and its diagnostic validity in musculoskeletal tumors in different locations

    Directory of Open Access Journals (Sweden)

    Karina Levy Siqueira

    2008-02-01

    Full Text Available OBJETIVO: O propósito deste estudo foi aquilatar a precisão das biópsias por trefina de Jamshidi, realizadas no Serviço de Ortopedia Oncológica da UNIFESP/EPM, em tumores músculo-esqueléticos, em distintas topografias, tendo como objetivo propor uma classificação para categorizar as biópsias conforme a sua efetividade. MÉTODOS: Foram analisados de modo retrospectivo 107 pacientes que haviam sido biopsiados com agulha de Jamshidi e posteriormente submetidos a ressecção do tumor seguida de exame anatomopatológico da peça cirúrgica. A média de idade dos pacientes foi de 23,5 anos (2,7 a 68,7 anos. Quanto ao sexo, 40,2% eram mulheres e 50,8% homens. Desse universo, 86 apresentavam tumor ósseo (80,4% e 21, tumor de partes moles (19,6%. Quanto à localização, os tumores encontravam-se preferencialmente nos membros inferiores (72%, seguidos dos membros superiores (22,4% e pelve (5,6%. Foi proposta conjuntamente uma classificação para categorizar as biópsias conforme o seu resultado em excelente, bom, regular e mau. RESULTADOS: A análise dos dados gerais demonstrou resultados excelentes em 80,4% das biópsias, bons em 8,4%, regulares em 2,8% e ruins em 8,4%. Somando-se os resultados excelentes e bons, encontram-se 88,8% dos casos. Nos casos avaliados, encontraram-se 3,7% de complicações; em nenhum caso a biópsia contra-indicou a cirurgia conservadora com preservação do membro. CONCLUSÃO: As biópsias com agulha de Jamshidi representam método bastante eficiente de diagnóstico das lesões músculo-esqueléticas, com baixo índice de complicações e bons resultados comparáveis aos das biópsias abertas.OBJECTIVE:The purpose of this study is to evaluate trephine biopsies with Jamshidi needle performed at the Oncologic Orthopedics Service at UNIFESP/EPM, in musculoskeletal tumors in different locations, in order to propose an effectiveness classification of biopsy categories. METHODS: A retrospective analysis was made of 107

  1. Alterations caused by physical training in pulmonary edema and loss of muscle mass in rats with Walker-256 tumor Alterações promovidas pelo treinamento físico no edema pulmonar e perda de massa muscular em ratos portadores de tumor Walker-256

    Directory of Open Access Journals (Sweden)

    Rubens Cecchini

    2008-10-01

    Full Text Available Walker-256 tumor is a fast-growing tumor and has been studied under several metabolic aspects associated or not to cachexia. It was observed in our laboratory that animals with Walker-256 tumor, after spontaneous death (usually around the fifteenth day, showed significant pulmonary edema with fluid in the pleural cavity. Some studies have suggested that physical training improves the survival of animals with tumor and minimizes the effects of cachexia. The purpose of our work was to assess the pulmonary edema index as well as the cardiac and skeletal muscle mass, besides the survival of rats with Walker-256 tumor submitted previously to physical training through swimming (N. For this study male Wistar rats (200 to 220 g were used, submitted to physical training through swimming (1 hour; 5 days a week, four weeks. One day after the training, sedentary rats (C or trained ones (N were submitted to inoculation on the right flank of 8 x 107 Walker-256 tumor cells (T. Immediately after spontaneous death of these animals, the pulmonary edema index (PEI, cardiac and skeletal muscle mass (gastrocnemius and soleus were evaluated. Pulmonary edema was evaluated through the index calculated by the relation between lung and body weights of each animal, and multiplied by 100 (PP/PC x 100 (LEE et al., 2001. Muscle mass (MM index was calculated similarly. In normal animals the PEI is equal to 0,53±0,02 (n=20. In tumor-bearing rats after spontaneous death the PEI was significantly higher (2,62±0,31, n=18. After the physical training in rats without tumor, the PEI was 0,55±0,03 (n=5. Whereas in tumor-bearing rats previously trained, it was obtained a pulmonary edema index lower than that of the control group with tumor (1,46±0,16, n=5; pO tumor Walker-256 é um carcinoma de crescimento rápido e tem sido estudado sob vários aspectos metabólicos, associados ou não, à caquexia. Foi observado, em nosso laboratório, que em animais portadores de tumor Walker

  2. Human ribosomal protein L9 is a Bax suppressor that promotes cell survival in yeast.

    Science.gov (United States)

    Eid, Rawan; Sheibani, Sara; Gharib, Nada; Lapointe, Jason F; Horowitz, Avital; Vali, Hojatollah; Mandato, Craig A; Greenwood, Michael T

    2014-05-01

    The identification of a human ribosomal protein L9 (hRPL9) cDNA as a sequence capable of suppressing the lethal effects of heterologously expressed murine Bax in yeast led us to investigate its antiapoptotic potential. Using growth and viability assays, we show that yeast cells heterologously expressing hRPL9 are resistant to the growth inhibitory and lethal effects of exogenously supplied copper, indicating that it has pro-survival properties. To explore potential mechanisms, we used yeast mutants defective in all three types of programmed cell death (apoptosis, necrosis, and autophagy). The ability to retain pro-survival function in all the mutants suggests that hRPL9 may regulate a common pro-death process. In contrast, the yeast RPL9 orthologues, RPL9A and RPL9B, have opposite effects when overexpressed in yeast. In effect, instead of showing resistance to stress, RPL9A and RPL9B overexpressing cells show reduced cell growth. Further analysis indicates that the effects of overexpressed RPL9A and RPL9B are not in themselves lethal, instead, they serve to increase cell doubling time. Thus, yeast RPL9s are more representative of RPs whose extra-ribosomal function is similar to that of tumor suppressors. Taken together, our results demonstrate that RPL9 represents a species- and sequence-specific regulator of cell growth and survival.

  3. Bax monomers form dimer units in the membrane that further self-assemble into multiple oligomeric species

    Science.gov (United States)

    Subburaj, Yamunadevi; Cosentino, Katia; Axmann, Markus; Pedrueza-Villalmanzo, Esteban; Hermann, Eduard; Bleicken, Stephanie; Spatz, Joachim; García-Sáez, Ana J.

    2015-08-01

    Bax is a key regulator of apoptosis that mediates the release of cytochrome c to the cytosol via oligomerization in the outer mitochondrial membrane before pore formation. However, the molecular mechanism of Bax assembly and regulation by other Bcl-2 members remains obscure. Here, by analysing the stoichiometry of Bax oligomers at the single-molecule level, we find that Bax binds to the membrane in a monomeric state and then self-assembles in Bax does not exist in a unique oligomeric state, but as several different species based on dimer units. Moreover, we show that cBid activates Bax without affecting its assembly, while Bcl-xL induces the dissociation of Bax oligomers. On the basis of our experimental data and theoretical modelling, we propose a new mechanism for the molecular pathway of Bax assembly to form the apoptotic pore.

  4. Detection of codon 12 mutation in the k-ras oncogene in pancreatic tumors Detecção de mutação no códon 12 do oncogene K-ras em tumores pancreáticos

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    Márcia Saldanha Kubrusly

    1999-02-01

    Full Text Available Mutations at codons 12, 13, or 61 of the H-ras, K-ras, and N-ras have been detected in human neoplasias by a variety of techniques. Some of these techniques are very sensitive and can detect K-ras mutation in 90% of the cases of pancreatic adenocarcinomas. We analyzed 11 samples of pancreatic adenocarcinoma, three samples of pancreatic mucinous cystadenoma, and two samples without tumors in formalin-fixed paraffin embedded tissue sections. K-ras mutations at codon 12 were detected by a two-step PCR-enriched technique in all the samples of pancreatic adenocarcinoma, but not in cystadenoma or control samples. This technique may be useful for early detection of pancreatic cancer.Muitos dos oncogenes detectados em neoplasias malignas humanas pertencem à família do gene ras. Mutações nos códons 12, 13 ou 61 em um dos tres genes ras; H-ras, K-ras e N-ras, convertem esses genes em oncogenes ativos. Ensaios rápidos para detecção dessas mutações pontuais, tais como a reação em cadeia de polimertização têm sido desenvolvidos nas últimas décadas e usados para investigar o papel dos genes ras mutados na patogênese de tumores humanos. As mutações no gene ras podem ser encontradas numa variedade de tipos de tumores. Incidências mais altas aparecem em adenocarcinomas do pâncreas (90% e cólon (50%. Analisamos 11 amostras de tumores primários de pâncreas com diferentes metástases, três amostras de cistadenoma mucinoso e dois casos de ausência de tumor de material incluído em parafina, de onde extraímos o DNA para realização das amplificações. Os resultados mostraram que todos os casos de tumores apresentaram a banda de 135 pares de bases correspondente ao gene mutado e para os normais, a banda característica de 106 pares de bases. Nos três casos de cistadenoma mucinosos, não detectamos a banda de 135 pares de bases , apenas a banda de 106 pares de bases.

  5. Ultra-estrutura dos mastócitos de diferentes tipos histológicos de mastocitoma em cães Mast cell ultrastructure in different types of canine mast cell tumor

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    F.A.R. Sueiro

    2002-06-01

    Full Text Available Este trabalho teve por objetivo estudar as diferenças ultraestruturais de mastócitos neoplásicos de diferentes tipos histológicos de mastocitoma em cães, usando microscopia eletrônica de transmissão Os resultados mostraram que o núcleo e os grânulos citoplasmáticos são as estruturas mais indicadas para se avaliar o grau de anaplasia celular e o estádio de indiferenciação do tumor.The objective of this work was study the ultrastructural differences among the different histologic types of mast cell tumors in dogs collected in vivo. The ultrastructural analyses showed that the nuclei and cytoplasmic granules characteristics are the best structures to be appointed on evaluating the undifferentiation stage of this tumor.

  6. HCV upregulates Bim through the ROS/JNK signalling pathway, leading to Bax-mediated apoptosis.

    Science.gov (United States)

    Deng, Lin; Chen, Ming; Tanaka, Motofumi; Ku, Yonson; Itoh, Tomoo; Shoji, Ikuo; Hotta, Hak

    2015-09-01

    We previously reported that hepatitis C virus (HCV) infection induces Bax-triggered, mitochondrion-mediated apoptosis by using the HCV J6/JFH1 strain and Huh-7.5 cells. However, it was still unclear how HCV-induced Bax activation. In this study, we showed that the HCV-induced activation and mitochondrial accumulation of Bax were significantly attenuated by treatment with a general antioxidant, N-acetyl cysteine (NAC), or a specific c-Jun N-terminal kinase (JNK) inhibitor, SP600125, with the result suggesting that the reactive oxygen species (ROS)/JNK signalling pathway is upstream of Bax activation in HCV-induced apoptosis. We also demonstrated that HCV infection transcriptionally activated the gene for the pro-apoptotic protein Bim and the protein expression of three major splice variants of Bim (BimEL, BimL and BimS). The HCV-induced increase in the Bim mRNA and protein levels was significantly counteracted by treatment with NAC or SP600125, suggesting that the ROS/JNK signalling pathway is involved in Bim upregulation. Moreover, HCV infection led to a marked accumulation of Bim on the mitochondria to facilitate its interaction with Bax. On the other hand, downregulation of Bim by siRNA (small interfering RNA) significantly prevented HCV-mediated activation of Bax and caspase 3. Taken together, these observations suggest that HCV-induced ROS/JNK signalling transcriptionally activates Bim expression, which leads to Bax activation and apoptosis induction.

  7. Bax phosphorylation association with nucleus and oligomerization after neonatal hypoxia-ischemia.

    Science.gov (United States)

    Infante, Smitha Krishna; Oberhauser, Andres F; Perez-Polo, J Regino

    2013-09-01

    Neonatal hypoxia-ischemia (HI) is a common occurrence in preterm and low-birth-weight infants, and the incidence of low-birth-weight and preterm births is increasing. Characterization of brain injury after HI is of critical importance in developing new treatments that more accurately target the injury. After severe HI, neuronal cells undergo necrosis and secondary apoptosis of the surrounding cells as a result of neuroinflammation. We sought to characterize the biochemical pathways associated with cell death after HI. Bax, a cell death signaling protein, is activated after HI and translocates to the nucleus, endoplasmic reticulum, and mitochondria. The translocation patterns of Bax affect the resultant cell death phenotype (necrotic or apoptotic) observed. Although Bax is known to oligomerize once it is activated, less is known about the factors that control its translocation and oligomerization. We hypothesize that Bax kinase-specific phosphorylation determines its oligomerization and intracellular localization. Using well-established in vivo and in vitro models of neonatal HI, we characterized Bax oligomerization and multiorganelle translocation. We found that HI-dependent phosphorylation of Bax determines its oligomerization status and multiorganelle localization, and, ultimately, the cell death phenotype observed. Understanding the mechanisms of Bax translocation will aid in the rational design of therapeutic strategies that decrease the trauma resulting from HI-associated inflammation.

  8. Insights into the structural stability of Bax from molecular dynamics simulations at high temperatures

    Science.gov (United States)

    Rosas-Trigueros, Jorge Luis; Correa-Basurto, José; Guadalupe Benítez-Cardoza, Claudia; Zamorano-Carrillo, Absalom

    2011-01-01

    Bax is a member of the Bcl-2 protein family that participates in mitochondrion-mediated apoptosis. In the early stages of the apoptotic pathway, this protein migrates from the cytosol to the outer mitochondrial membrane, where it is inserted and usually oligomerizes, making cytochrome c-compatible pores. Although several cellular and structural studies have been reported, a description of the stability of Bax at the molecular level remains elusive. This article reports molecular dynamics simulations of monomeric Bax at 300, 400, and 500 K, focusing on the most relevant structural changes and relating them to biological experimental results. Bax gradually loses its α-helices when it is submitted to high temperatures, yet it maintains its globular conformation. The resistance of Bax to adopt an extended conformation could be due to several interactions that were found to be responsible for maintaining the structural stability of this protein. Among these interactions, we found salt bridges, hydrophobic interactions, and hydrogen bonds. Remarkably, salt bridges were the most relevant to prevent the elongation of the structure. In addition, the analysis of our results suggests which conformational movements are implicated in the activation/oligomerization of Bax. This atomistic description might have important implications for understanding the functionality and stability of Bax in vitro as well as within the cellular environment. PMID:21936009

  9. Bax/bcl-2: cellular modulator of apoptosis in feline skin and basal cell tumours.

    Science.gov (United States)

    Madewell, B R; Gandour-Edwards, R; Edwards, B F; Matthews, K R; Griffey, S M

    2001-01-01

    Bcl-2 and bax are two members of the BCL-2 gene family that play a prominent role in the regulation of apoptosis. Bax and bcl-2 expression were examined immunohistochemically in normal (healthy) feline skin and in 24 benign feline cutaneous basal cell tumours. The tumours were also examined for cellular proliferation by measurement of reactivity for the proliferation marker Ki-67, and for apoptosis by in-situ labelling for fragmented DNA. Bcl-2 was detected in normal basal epithelium and in 23 of 24 basal cell tumours. Bax was detected in both basal and suprabasal epithelium, but in only seven of 24 tumours. For tumours that expressed both bax and bcl-2, the bax:bcl-2 ratio was low. Neither bax nor bcl-2 expression was detected in 14 feline cutaneous squamous cell carcinomas. Basal cell tumours showed modest cellular proliferation (median, 17.5% Ki-67- reactive cells), but few (less than 1%) apoptotic cells. The slow, indolent growth of feline cutaneous basal cells in these benign skin tumours may be a response, at least in part, to opposing regulatory expressions of bcl-2 and bax.

  10. Inhibition of Pro-Apoptotic BAX by a Noncanonical Interaction Mechanism

    Science.gov (United States)

    Barclay, Lauren A.; Wales, Thomas E.; Garner, Thomas P.; Wachter, Franziska; Lee, Susan; Guerra, Rachel M.; Stewart, Michelle L.; Braun, Craig R.; Bird, Gregory H.; Gavathiotis, Evripidis; Engen, John R.; Walensky, Loren D.

    2015-01-01

    SUMMARY BCL-2 is a negative regulator of apoptosis implicated in homeostatic and pathologic cell survival. The canonical anti-apoptotic mechanism involves entrapment of activated BAX by a groove on BCL-2, preventing BAX homo-oligomerization and mitochondrial membrane poration. The BCL-2 BH4 domain also confers anti-apoptotic functionality, but the mechanism is unknown. We find that a synthetic α-helical BH4 domain binds to BAX with nanomolar affinity and independently inhibits the conformational activation of BAX. Hydrogen-deuterium exchange mass spectrometry demonstrated that the N-terminal conformational changes in BAX induced by a triggering BIM BH3 helix were suppressed by the BCL-2 BH4 helix. Structural analyses localized the BH4 interaction site to a groove formed by residues of α1, α1–α2 loop, and α2–α3 and α5–α6 hairpins on the BAX surface. These data reveal a previously unappreciated binding site for targeted inhibition of BAX and suggest that the BCL-2 BH4 domain may participate in apoptosis blockade by a noncanonical interaction mechanism. PMID:25684204

  11. Identification and expression analysis of alternatively spliced new transcript isoform of Bax gene in mouse.

    Science.gov (United States)

    Husain, Mohammed Amir; Ishqi, Hassan Mubarak; Sarwar, Tarique; Rehman, Sayeed Ur; Tabish, Mohammad

    2017-07-20

    Bax, a pro-apoptotic member of Bcl-2 family regulates apoptosis through homodimerization/heterodimerization with Bcl-2. Bax-α is the only product of the Bax gene that has been extensively studied. Bax-α exists in inactive form and several conformational changes are required during apoptosis to activate it. Here, we have identified a novel transcript variant of Bax gene in mouse which contains alternatively spliced new first exon that is different from the first exon of previously reported transcript. Conceptual translation of new transcript encodes a protein (Bax-α1), having different N-terminus. The existence of the new transcript variant was confirmed by reverse transcriptase-PCR, semi-nested PCR using primers designed for the newly identified transcript variant. The identity of PCR product obtained after semi-nested PCR was confirmed by DNA sequencing. Relative expression of new transcript variant with respect to reported transcript was also studied with the help of real time PCR. The existence of new transcript variant was further supported by the presence of clusters of overlapping ESTs from the database. Bax-α1 possibly displays heterogeneous properties as predicted by post-translational modification analysis tools. The differences in post-translational modifications might play important roles in divergent function of the new isoform. The three dimensional structure was generated by homology modelling to visualize the differences at N termini of known and newly identified variant. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Bax Exists in a Dynamic Equilibrium between the Cytosol and Mitochondria to Control Apoptotic Priming

    Science.gov (United States)

    Schellenberg, Barbara; Wang, Pengbo; Keeble, James A.; Rodriguez-Enriquez, Ricardo; Walker, Scott; Owens, Thomas W.; Foster, Fiona; Tanianis-Hughes, Jolanta; Brennan, Keith; Streuli, Charles H.; Gilmore, Andrew P.

    2013-01-01

    Summary The proapoptotic Bcl-2 protein Bax is predominantly found in the cytosol of nonapoptotic cells and is commonly thought to translocate to mitochondria following an apoptotic stimulus. The current model for Bax activation is that BH3 proteins bind to cytosolic Bax, initiating mitochondrial targeting and outer-membrane permeabilization. Here, we challenge this and show that Bax is constitutively targeted to mitochondria but in nonapoptotic cells is constantly translocated back to the cytosol. Using live-cell spinning-disk confocal imaging with a combination of FLIP, FRAP, and photoactivatable GFP-Bax, we demonstrate that disrupting adhesion-dependent survival signals slows the rate of Bax’s dissociation from mitochondria, leading to its accumulation on the outer mitochondrial membrane. The overall accumulation of mitochondrial Bax following loss of survival signaling sensitizes cells to proapoptotic BH3 proteins. Our findings show that Bax is normally in a dynamic equilibrium between cytosol and mitochondria, enabling fluctuations in survival signals to finely adjust apoptotic sensitivity. PMID:23375500

  13. Pro-apoptotic cBid and Bax exhibit distinct membrane remodeling activities: An AFM study.

    Science.gov (United States)

    Unsay, Joseph D; Cosentino, Katia; Sporbeck, Katharina; García-Sáez, Ana J

    2017-01-01

    Bcl-2 proteins are key regulators of the mitochondrial outer membrane (MOM) permeabilization that mediates apoptosis. During apoptosis, Bid is cleaved (cBid) and translocates to the MOM, where it activates Bax. Bax then oligomerizes and induces MOM permeabilization. However, little is known about how these proteins affect membrane organization aside from pore formation. In previous studies, we have shown that both cBid and Bax are able to remodel membranes and stabilize curvature. Here, we dissected the independent effects of Bax and cBid on supported lipid structures mimicking the mitochondrial composition by means of atomic force spectroscopy. We show that cBid did not permeabilize the membrane but lowered the membrane breakthrough force. On the other hand, Bax effects were dependent on its oligomeric state. Monomeric Bax did not affect the membrane properties. In contrast, oligomeric Bax lowered the breakthrough force of the membrane, which in the context of pore formation, implies a lowering of the line tension at the edge of the pore. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Deacetylation of Ku70 by SIRT6 attenuates Bax-mediated apoptosis in hepatocellular carcinoma.

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    Tao, Na-Na; Ren, Ji-Hua; Tang, Hua; Ran, Long-Kuan; Zhou, Hong-Zhong; Liu, Bo; Huang, Ai-Long; Chen, Juan

    2017-04-15

    SIRT6 is a class III histone deacetylase that has been implicated in HCC development. We previously reported that SIRT6 potentiated apoptosis evasion in hepatocellular carcinoma by inhibiting both Bax expression and mitochondrial translocalization. However, the mechanism underlying SIRT6-mediated inhibition of Bax mitochondrial localization remains elusive. In this study, we found that although SIRT6 had no effect on the expression level of Ku70, SIRT6 could interact with Ku70 and deacetylate it. The increased acetylation of Ku70 in SIRT6-depleted cells disrupt its interaction with Bax, which finally resulted in Bax mitochondrial translocalization. Furthermore, lysine K542 on Ku70 was the target for deacetylation by SIRT6. Ku70(K542Q) mutation abolished suppression of association between Ku70 and Bax and caused redistribution of Bax to the cytosol in SIRT6-depleted cells. Finally, Ku70(K542Q) mutation could reversed the inhibition of growth and apoptosis promotion mediated by SIRT6 silencing. Together, our findings revealed SIRT6 could block the mitochondrial translocation of Bax and decrease the apoptotic ratio of HCC cells by deacetylation of Ku70. SIRT6 may serve as a promising target for developing targeted therapies for HCC in the future. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Enhancing terpenoid indole alkaloid production by inducible expression of mammalian Bax in Catharanthus roseus cells

    Institute of Scientific and Technical Information of China (English)

    XU MaoJun; DONG JuFang

    2007-01-01

    Bax, a mammalian pro-apoptotic member of the Bcl-2 family, triggers hypersensitive reactions when expressed in plants. To investigate the effects of Bax on the biosynthesis of clinically important natural products in plant cells, we generate transgenic Catharanthus roseus cells overexpressing a mouse Bax protein under the β-estradiol-inducible promoter. The expression of Bax in transgenic Catharanthus roseus cells is highly dependent on β-estradiol concentrations applied. Contents of catharanthine and total terpenoid indole alkaloid of the transgenic cells treated with 30 μmol/L β-estradiol are 5.0- and 5.5-fold of the control cells. Northern and Western blotting results show that expression of mammalian Bax induces transcriptional activation of Tdc and Str, two key genes in terpenoid indole alkaloid biosynthetic pathway of Catharanthus roseus cells, and stimulates the accumulation of defense-related protein PR1 in the cells, showing that the mouse Bax triggers the defense responses of Catharanthus roseus cells and activates the terpenoid indole alkaloid biosynthetic pathway. Thus, our data suggest that the mammalian Bax might be a potential regulatory factor for secondary metabolite biosynthesis in plant cells and imply a new secondary metabolic engineering strategy for enhancing the metabolic flux to natural products by activating the whole biosynthetic pathway rather than by engineering the single structural genes within the pathways.

  16. Enhancing terpenoid indole alkaloid production by inducible expression of mammalian Bax in Catharanthus roseus cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Bax,a mammalian pro-apoptotic member of the Bcl-2 family,triggers hypersensitive reactions when expressed in plants.To investigate the effects of Bax on the biosynthesis of clinically important natural products in plant cells,we generate transgenic Catharanthus roseus cells overexpressing a mouse Bax protein under the β-estradiol-inducible promoter.The expression of Bax in transgenic Catharanthus roseus cells is highly dependent on β-estradiol concentrations applied.Contents of catharanthine and total terpenoid indole alkaloid of the transgenic cells treated with 30 μmol/L β-estradiol are 5.0-and 5.5-fold of the control cells.Northern and Western blotting results show that expression of mammalian Bax induces transcriptional activation of Tdc and Str,two key genes in terpenoid indole alkaloid bio-synthetic pathway of Catharanthus roseus cells,and stimulates the accumulation of defense-related protein PR1 in the cells,showing that the mouse Bax triggers the defense responses of Catharanthus roseus cells and activates the terpenoid indole alkaloid biosynthetic pathway.Thus,our data suggest that the mammalian Bax might be a potential regulatory factor for secondary metabolite biosynthesis in plant cells and imply a new secondary metabolic engineering strategy for enhancing the metabolic flux to natural products by activating the whole biosynthetic pathway rather than by engineering the single structural genes within the pathways.

  17. Isatin decreases Bax protein expression in the substantia nigra of a mouse model of Parkinson's disease

    Institute of Scientific and Technical Information of China (English)

    Jiguo Zhang; Fang Zhang; Yanlong Qiu; Wang Yue

    2011-01-01

    The present study observed the action of 1H-indole-2, 3-dione (isatin) on Bax protein expression in the substantia nigra of a Parkinson's disease animal model. Parkinson's disease-like behaviors were induced in C57BL/6J mice treated with 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP). Bax protein expression was significantly reduced in isatin (100, 200 mg/kg)-pretreated mice. Results demonstrate that isatin plays a neuroprotective role in mice treated with MPTP by down-regulating Bax protein expression.

  18. Bcl-2/Bax protein and mRNA expression in yak (Bos grunniens) placentomes.

    Science.gov (United States)

    Fan, JiangFeng; Yu, SiJiu; Cui, Yan; Xu, Gengquan; Wang, Libin; Pan, Yangyang; He, Honghong

    2017-07-29

    Placental function is complex and influenced by various factors; furthermore, it depends on a delicate balance between cell proliferation, cell differentiation, and cell death. Bcl-2 and Bax proteins are key apoptosis regulators and are considered to play an important role in the maintenance of both dynamic balance and integrity of many tissues. Changes in Bcl-2 and Bax expressions have been described during different developmental stages in normal human placentas. Studies furthermore indicated several pathological placental changes to be related to abnormal Bcl-2 and Bax expressions. In the present study, we investigated both expression and distribution of Bcl-2 and Bax in yak placentas. For this, we collected placentas of 35 yaks at different stages of pregnancy as well as cotyledonary villi of four postpartum yaks. Protein and mRNA expressions of both Bcl-2 and Bax were investigated via immunohistochemistry, Western blot, and real-time PCR. Immunoreactive Bcl-2 protein was mainly localized near the fetal villous trophoblast at various gestational stages and post-partum. The Positive Index (PI) of Bcl-2 protein expression significantly decreased with increasing gestational age. Early during pregnancy (≤2 months), the Bax protein was widely distributed in the fetal villous trophoblast layer, the maternal caruncular crypt epithelium, and the stroma. Subsequently, the Bax protein distribution gradually concentrated in the fetal villous trophoblast layer. The staining intensity of Bax increased from the 3rd month to the prepartum of gestation. The PI reached a minimum of 9.4 ± 2.2 in fetal chorionic villi (FCV) and 1.3 ± 0.8 in maternal caruncular crypts (MCC) of the three months group. Both Bcl-2 and Bax had maximum immunoreactivity in the fetal villous trophoblast layer of placentas collected form postpartum yaks (with PIs of 36.6 ± 5.7 and 38.2 ± 4.8, respectively). Protein and mRNA expression of Bcl-2 and Bax investigated via Western blot and real

  19. Punção aspirativa por agulha fina no diagnóstico de linfadenopatias e tumores sólidos em crianças e adolescentes Fine needle aspiration biopsy in the diagnosis of lymphadenopathies and solid tumors in children and adolescents

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    Wallace Acioli Freire de Gois

    2008-02-01

    Full Text Available OBJETIVO: Avaliar a importância diagnóstica da punção aspirativa por agulha fina (PAAF em crianças e adolescentes portadores de linfadenopatias e tumores sólidos. MÉTODOS: Análise retrospectiva dos pacientes com idade igual ou inferior a 18 anos, atendidos no Centro de Pediatria Cirúrgica do Hospital Universitário de Brasília, Universidade de Brasília, no período de julho de 2000 a julho de 2005. Foram calculados: sensibilidade, especificidade, precisão (acurácia diagnóstica, valor preditivo positivo e valor preditivo negativo. RESULTADOS: Em 50 pacientes estudados, os resultados da PAAF mostraram sensibilidade de 90,9%; especificidade de 100%, precisão diagnóstica de 95% e valores preditivos positivo e negativo de 100% e 90%, respectivamente. CONCLUSÃO: Em nossa experiência, a PAAF é um método preciso, simples e seguro, útil no diagnóstico de linfadenopatias e tumores sólidos em crianças e adolescentes.BACKGROUND: To evaluate the diagnostic value of the fine needle aspiration biopsy in children and adolescents with solid tumors or lymphadenopathy. METHODS: 18 years old or less patients were observed since July 2000 to July 2005. We observed: sensibility, specificity, diagnostic accuracy and predictive value. RESULTS: In 50 studied patients the fine needle aspiration biopsy we found 90.9% sensibility, 100% specificity, 95% diagnostic accuracy, 100% positive predictive value and 90% negative predictive value. CONCLUSION: The fine needle aspiration biopsy is a easy, safe and accurate diagnostic method for solid tumors and lymphadenopathies.

  20. Mangiferin attenuates contusive spinal cord injury in rats through the regulation of oxidative stress, inflammation and the Bcl‑2 and Bax pathway.

    Science.gov (United States)

    Luo, Yang; Fu, Changfeng; Wang, Zhenyu; Zhang, Zhuo; Wang, Hongxia; Liu, Yi

    2015-11-01

    Mangiferin has antioxidant, antiviral, apoptosis regulating, anti‑inflammatory, antitumor and antidiabetic effects, which can also inhibit osteoclast formation and bone resorption. However, whether mangiferin ameliorates the neurological pain of spinal cord injury (SCI) in ratS remains to be elucidated. The present study investigated the therapeutic effects of mangiferin on neurological function, the water content of spinal cord, oxidative stress, the expression of inflammatory cytokines and the protein expression of Bcl‑2/Bax in a SCI rat model. In the present study, the Basso, Beattie and Bresnahan scores, and the water content of the spinal cord were used to analyze the therapeutic effects of mangiferin on neurological pain in the SCI rat. The concentrations of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and the serum levels of glutathione peroxidase (GSH‑PX), nuclear factor‑κB p65 unit, tumor necrosis factor‑α, interleukin (IL)‑1β, IL‑6 and caspase‑3/9 were detected using commercial kits. The expression levels of Bcl‑2 and Bax were measured using western blot analysis. The results demonstrated that administrating mangiferin began to ameliorate neurological function and the water content of the spinal cord in the SCI rat. The mangiferin‑treated group were found to have lower oxidative stress activity and lower expression levels of inflammatory cytokines, compared with the SCI rat. In addition, mangiferin significantly reduced the protein expression of Bax and promoted the protein expression of Bcl-2 in the SCI rat model. Finally, mangiferin markedly suppressed the expression of caspase‑3/9, indicating that the protective action of mangiferin may be associated with anti‑apoptosis activation. In conclusion, mangiferin attenuated contusive SCI in the rats through regulating oxidative stress, inflammation and the Bcl‑2 and Bax pathway.

  1. <em>In Vitro em>and <em>in em>Vivo> Antitumor Effect of Trachylobane-360, a Diterpene from<em> Xylopia langsdorffianaem>

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    João Carlos Lima Rodrigues Pita

    2012-08-01

    Full Text Available Trachylobane-360 (<em>ent>-7α-acetoxytrachyloban-18-oic acid was isolated from <em>Xylopia langsdorffianaem>. Studies have shown that it has weak cytotoxic activity against tumor and non-tumor cells. This study investigated the <em>in vitroem>> em>and <em>in vivoem> antitumor effects of trachylobane-360, as well as its cytotoxicity in mouse erythrocytes. In order to evaluate the <em>in vivoem> toxicological aspects related to trachylobane-360 administration, hematological, biochemical and histopathological analyses of the treated animals were performed. The compound exhibited a concentration-dependent effect in inducing hemolysis with HC50 of 273.6 µM, and a moderate <em>in vitroem>> em>concentration-dependent inhibitory effect on the proliferation of sarcoma 180 cells with IC50 values of 150.8 µM and 150.4 µM, evaluated by the trypan blue exclusion test and MTT reduction assay, respectively. The <em>in vivoem> inhibition rates of sarcoma 180 tumor development were 45.60, 71.99 and 80.06% at doses of 12.5 and 25 mg/kg of trachylobane-360 and 25 mg/kg of 5-FU, respectively. Biochemical parameters were not altered. Leukopenia was observed after 5-FU treatment, but this effect was not seen with trachylobane-360 treatment. The histopathological analysis of liver and kidney showed that both organs were mildly affected by trachylobane-360 treatment. Trachylobane-360 showed no immunosuppressive effect. In conclusion, these data reinforce the anticancer potential of this natural diterpene.

  2. Matrine inhibits diethylnitrosamine-induced HCC proliferation in rats through inducing apoptosis via p53, Bax-dependent caspase-3 activation pathway and down-regulating MLCK overexpression

    Science.gov (United States)

    Zhang, Xiaolin; Yu, Hao

    2016-01-01

    The proliferation of hepatocellular carcinoma (HCC) cells is one of the leading causes of liver cancer mortality in humans. The inhibiting effects of matrine on HCC cell proliferation have been studied, but the mechanism of that inhibition has not been fully elucidated. Since, apoptosis plays an important role in HCC cell proliferation. We examined the apoptosis-inducing effect of matrine on tumor cells. Western blot analysis of p53, Bax, cleaved caspase-3 and myosin light chain kinase (MLCK) revealed that matrine induced tumor cell apoptosis by controlling anoikis. It activated p53, Bax-dependent caspase-3 and blocked the ECM-integrin mediated cell survival pathway through down-regulating MLCK over-expression in the liver of rats with diethyl nitrosamine (DENA)-induced HCC. Our results suggest that matrine can inhibit the proliferation of HCC cells through inducing tumor cell apoptosis via activation of the p53 pathway and inhibition of MLCK overexpression. Matrine may thus be used as a potentially promising reagent to inhibit HCC cell proliferation and MLCK may be a novel target for the treatment of HCC. PMID:27642320

  3. Matrine inhibits diethylnitrosamine-induced HCC proliferation in rats through inducing apoptosis via p53, Bax-dependent caspase-3 activation pathway and down-regulating MLCK overexpression.

    Science.gov (United States)

    Zhang, Xiaolin; Yu, Hao

    2016-01-01

    The proliferation of hepatocellular carcinoma (HCC) cells is one of the leading causes of liver cancer mortality in humans. The inhibiting effects of matrine on HCC cell proliferation have been studied, but the mechanism of that inhibition has not been fully elucidated. Since, apoptosis plays an important role in HCC cell proliferation. We examined the apoptosis-inducing effect of matrine on tumor cells. Western blot analysis of p53, Bax, cleaved caspase-3 and myosin light chain kinase (MLCK) revealed that matrine induced tumor cell apoptosis by controlling anoikis. It activated p53, Bax-dependent caspase-3 and blocked the ECM-integrin mediated cell survival pathway through down-regulating MLCK over-expression in the liver of rats with diethyl nitrosamine (DENA)-induced HCC. Our results suggest that matrine can inhibit the proliferation of HCC cells through inducing tumor cell apoptosis via activation of the p53 pathway and inhibition of MLCK overexpression. Matrine may thus be used as a potentially promising reagent to inhibit HCC cell proliferation and MLCK may be a novel target for the treatment of HCC.

  4. The presence of bilobar tumor should be considered as a new limit for transplantation beyond the Milan criteria? A presença de tumor bilobar deve ser considerado novo limite para exclusão de transplante em pacientes que excedem os critérios de Milão?

    Directory of Open Access Journals (Sweden)

    Raul Carlos Wahle

    2010-03-01

    de 1996 ou critérios semelhantes no período anterior a esta data. Inicialmente todas as variáveis foram analisadas descritivamente, e as quantitativas através da observação dos valores mínimos e máximos, e do cálculo de médias e desvios-padrão e medianas. Para as variáveis qualitativas calcularam-se frequências absolutas e relativas. Realizou-se a regressão logística com ajuste pelo modelo de Cox para avaliar a sobrevida e os fatores relacionados à recidiva tumoral e invasão microvascular. RESULTADOS: A sobrevida da amostra foi de 64%, 59% e 45% para 1, 3 e 5 anos, respectivamente. Em 13% dos casos, a recidiva tumoral foi verificada. A análise multivariada identificou a chance de um paciente com nódulo bilobar sofrer invasão microvascular é 3,67 vezes maior em relação a um paciente com nódulo unilobar e a presença de um tumor unilobar representar um significativo efeito protetor em relação à invasão microvascular (p = 0,048. CONCLUSÕES: A identificação de um tumor bilobar no estadiamento tumoral é fator preditivo independente de maior risco de invasão microvascular e é necessário ainda confirmar se a presença de tumor bilobar deve ser adicionada aos critérios de Milão para melhor indicação de transplante de fígado em pacientes cirróticos com carcinoma hepatocelular.

  5. Kanglaite combined Gemcitabine inhibits growth of nude mouse subcutaneous transplantation tumor of human PC-3 pancreatic cancer cell

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; JIN Jian-guang; QIN Zhao-yin

    2005-01-01

    Objective:To study the mechanisms of pancreatic cancer treatment with Kanglaite combined Gemcitabine by investigating the relationship between the apoptosis and the expression of bcl-2, Bax and VEGF in pancreatic cancer cells.Methods:Nude mouse subcutaneous transplantation tumor model of Human PC-3 pancreatic cancer was established; the expressions of bcl-2, Bax and VEGF of transplantation tumor cell were determined; the earlier apoptosis rate of pancreatic cancer cell and the gross tumor volume were determined. Results:Kanglaite combined Gemcitabine remarkably decreased the protein expression of bcl-2,raised the expression of Bax,increased the apoptosis rate of the pancreatic cancer and contract the gross tumor volume. Kanglaite greatly decreased the protein expression of VEGF of the tumor cell. Conclusion:Therapeutic efficacy of Kanglaite combined Gemcitabine is far better than separate use of the two medicines in the pancreatic cancer transplantation tumor treatment.

  6. Interaction of caveolin-1 with Ku70 inhibits Bax-mediated apoptosis.

    Directory of Open Access Journals (Sweden)

    Huafei Zou

    Full Text Available Caveolin-1, the structural protein component of caveolae, acts as a scaffolding protein that functionally regulates signaling molecules. We show that knockdown of caveolin-1 protein expression enhances chemotherapeutic drug-induced apoptosis and inhibits long-term survival of colon cancer cells. In vitro studies demonstrate that caveolin-1 is a novel Ku70-binding protein, as shown by the binding of the scaffolding domain of caveolin-1 (amino acids 82-101 to the caveolin-binding domain (CBD of Ku70 (amino acids 471-478. Cell culture data show that caveolin-1 binds Ku70 after treatment with chemotherapeutic drugs. Mechanistically, we found that binding of caveolin-1 to Ku70 inhibits the chemotherapeutic drug-induced release of Bax from Ku70, activation of Bax, translocation of Bax to mitochondria and apoptosis. Potentiation of apoptosis by knockdown of caveolin-1 protein expression is greatly reduced in the absence of Bax expression. Finally, we found that overexpression of wild type Ku70, but not a mutant form of Ku70 that cannot bind to caveolin-1 (Ku70 Φ→A, limits the chemotherapeutic drug-induced Ku70/Bax dissociation and apoptosis. Thus, caveolin-1 acts as an anti-apoptotic protein in colon cancer cells by binding to Ku70 and inhibiting Bax-dependent cell death.

  7. THE EXPRESSION AND CLINICAL VALUE OF APOPTOSIS CONTROL GENE Bcl-2 AND Bax IN BREAST CANCER

    Institute of Scientific and Technical Information of China (English)

    ZHENG Jun; YAO Zhen-xiang; ZHANG Jing

    1999-01-01

    Objective: To study the expression and clinical value of apoptosis control gene bcl-2 and bax in breast cancer.Methods: Protein bax and bcl-2 in 41 breast cancers obtained from operations in our hospital in 1996 were detected using ABC immunohistochemical stain assay and compared with 10 cases with normal breast tissues.Results: The positive rate of bax in normal breast tissue was 90% and in breast cancer was 59%, with a significant statistical difference between them (P<0.05), but there was no statistical difference in bcl-2 protein expression. Among the 41 breast cancer, the group with lymph node metastasis (21 cases) had obviously low bax expression (43%) and high bcl-2 expression (76%), showing significant difference to the group without lymph node metastasis (P<0.05).Conclusion: The antiapoptosis function of bcl-2 was stronger than bax in breast cancer. Protein bax and bcl-2 assay may be useful in understanding the biological behaviors of breast cancer.

  8. PATZ1 expression correlates positively with BAX and negatively with BCL6 and survival in human diffuse large B cell lymphomas

    Science.gov (United States)

    Valentino, Elena; Vitiello, Michela; Luciano, Antonio; Palma, Giuseppe; Arra, Claudio; Mantia, Elvira La; Panico, Luigi; Tenneriello, Valentina; Pinto, Antonello; Frigeri, Ferdinando; Capobianco, Gaetana; Botti, Gerardo; Cerchia, Laura; De Chiara, Annarosaria; Fedele, Monica

    2016-01-01

    Non-Hodgkin lymphomas (NHLs) include a heterogeneous group of diseases, which differ in both cellular origin and clinical behavior. Among the aggressive malignancies of this group, the diffuse large B-cell lymphomas (DLBCLs) are the most frequently observed. They are themselves clinically and molecularly heterogeneous and have been further sub-divided in three sub-types according to different cell of origin, mechanisms of oncogenesis and clinical outcome. Among them, the germinal center B-cell-like (GCB) derives from the germinal center and expresses the BCL6 oncogene. We have previously shown that Patz1-knockout mice develop B-cell neoplasias, suggesting a tumor suppressor role for PATZ1 in human NHLs. Here, by immunohistochemical analysis of a tissue-microarray including 170 NHLs, we found that PATZ1 nuclear expression is down-regulated in follicular lymphomas and DLBCLs. Moreover, consistent with our previous results showing a PATZ1-dependent regulation of BCL6 and BAX transcription, we show that low PATZ1 nuclear expression significantly correlates with high BCL6 expression, mainly in DLBCLs, and with low BAX expression, also considering separately follicular lymphomas and DLBCLs. Finally, by analyzing overall and progression-free survival in DLBCL patients that underwent rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy, low levels of PATZ1 were significantly associated to a worst outcome and demonstrated an independent prognostic factor in multivariate analysis, including known prognostic factors of DLBCL, IPI score and cell of origin (GCB/non-GCB). Therefore, we propose PATZ1 as a new prognostic marker of DLBCLs, which may act as a tumor suppressor by enhancing apoptosis through inhibiting and enhancing transcription of BCL6 and BAX, respectively. PMID:27494852

  9. Dynamin-related protein Drp1 is required for Bax translocation to mitochondria in response to irradiation-induced apoptosis.

    Science.gov (United States)

    Wang, Ping; Wang, Peiguo; Liu, Becky; Zhao, Jing; Pang, Qingsong; Agrawal, Samir G; Jia, Li; Liu, Feng-Ting

    2015-09-08

    Translocation of the pro-apoptotic protein Bax from the cytosol to the mitochondria is a crucial step in DNA damage-mediated apoptosis, and is also found to be involved in mitochondrial fragmentation. Irradiation-induced cytochrome c release and apoptosis was associated with Bax activation, but not mitochondrial fragmentation. Both Bax and Drp1 translocated from the cytosol to the mitochondria in response to irradiation. However, Drp1 mitochondrial translocation and oligomerization did not require Bax, and failed to induce apoptosis in Bax deficient diffuse large B-cell lymphoma (DLBCL) cells. Using fluorescent microscopy and the intensity correlation analysis, we demonstrated that Bax and Drp1 were colocalized and the levels of colocalization were increased by UV irradiation. Using co-immuno-precipitation, we confirmed that Bax and Drp1 were binding partners. Irradiation induced a time-associated increase in the interaction between active Bax and Drp1. Knocking down Drp1 using siRNA blocked UV irradiation-mediated Bax mitochondrial translocation. In conclusion, our findings demonstrate for the first time, that Drp1 is required for Bax mitochondrial translocation, but Drp1-induced mitochondrial fragmentation alone is not sufficient to induce apoptosis in DLBCL cells.

  10. Bcl-xS and Bax induce different apoptotic pathways in PC12 cells.

    Science.gov (United States)

    Lindenboim, L; Yuan, J; Stein, R

    2000-03-30

    Apoptosis is regulated by the action of the Bcl-2 family of proteins, which includes anti- and pro-apoptotic members such as Bcl-xS and Bax. These proteins may differ from each other in structure, mechanism of action and interactions with anti-apoptotic signaling. The mechanism whereby Bax induces cell death has been studied in some cellular systems, but the mechanism of Bcl-xS-induced apoptosis is largely unknown. In this study we investigated and compared the apoptotic effects of Bcl-xS and Bax in the pheochromocytoma cell line, PC12 (a useful model system for studying neuronal apoptosis), and the extent to which they are protected by the survival factor, nerve growth factor (NGF). PC12 cells express endogenous Bcl-xS, Bax and Bcl-xL proteins. Subcellular fractionation revealed that Bax is presented mainly in the cytosolic and the heavy membrane fractions, Bcl-xS is present only in the cytosol, and the anti-apoptotic protein Bcl-xL is located mainly in the heavy membrane fraction. In contrast to the cytosolic localization of endogenous Bcl-xS, the exogenously overexpressed Bcl-xS is localized to the mitochondria. Overexpression of Bcl-xS or Bax induces cell death in the transfected cells. The cell death induced by overexpression of Bcl-xS was inhibited by coexpression of Bcl-xS with Bcl-2 or Bcl-xL, or by treatment with the broad-spectrum caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp-fluoro-methylketone (Z-VAD-FMK) or with NGF. The Bcl-2 mutants deltaC22, which lacks the transmembrane domain, and G145A (mI-3) were able to inhibit the death-inducing effect of Bcl-xS. These results therefore suggest that the apoptotic pathway induced by overexpression of Bcl-xS in PC12 cells can be controlled by Bcl-2 and Bcl-xL, is mediated by caspases, and can be inhibited by the NGF signaling pathway. The Bax-induced cell death was inhibited by co-expression of Bax with Bcl-2 or Bcl-xL, but was not inhibited by Z-VAD-FMK, NGF, or the Bcl-2 ml-3 or deltaC22 mutants. These

  11. Eficácia da craniotomia com paciente plenamente acordado para ressecção de tumores supratentoriais primários em área eloqüente

    OpenAIRE

    Pereira, Luiz Cláudio Modesto

    2011-01-01

    Introdução: Os Tumores Cerebrais Primários (TCP) causam importante impacto social econômico e psicológico. O tratamento ideal dos TCP permanece controverso. Os objetivos principais da ressecção cirúrgica de TCP são o da máxima redução do volume de células tumorais e o alívio dos sintomas neurológicos, alcançados por descompressão. Neste aspecto, tumores localizados em áreas eloqüentes oferecem grande desafio, maior risco e possivelmente menor possibilidade de ressecção. Técnicas modernas de i...

  12. Ablação por radiofrequência de tumores hepáticos primários e metastáticos: experiência em 113 casos

    OpenAIRE

    Ribeiro Jr,Marcelo Augusto Fontenelle; Colaneri,Renata Potonyacz; Nunes,Bárbara dos Santos; Chaib, Eleazar; D'Ipolitto,Giuseppe; Gama-Rodrigues, Joaquim José; Saad, William Abrão; Cecconello,Ivan

    2007-01-01

    RACIONAL: A ablação por radiofreqüência de tumores hepáticos primários e metastáticos é método efetivo para o tratamento paliativo de tais neoplasias. Pode ser utilizada em nódulos com até 3-4 cm de diâmetro e não mais do que três lesões a serem tratadas. É procedimento passível de execução via laparotômia, laparoscópica e percutânea. Freqüentemente vem sendo aplicado como ponte para o transplante, assim como método alternativo nos tumores recorrentes após ressecção. OBJETIVO: Apresentar a ex...

  13. BAX insertion, oligomerization, and outer membrane permeabilization in brain mitochondria: role of permeability transition and SH-redox regulation

    Science.gov (United States)

    Brustovetsky, Tatiana; Li, Tsyregma; Yang, Youyun; Zhang, Jiang-Ting; Antonsson, Bruno; Brustovetsky, Nickolay

    2010-01-01

    BAX cooperates with truncated BID (tBID) and Ca2+ in permeabilizing the outer mitochondrial membrane (OMM) and releasing mitochondrial apoptogenic proteins. The mechanisms of this cooperation are still unclear. Here we show that in isolated brain mitochondria, recombinant BAX readily self-integrates/oligomerizes in the OMM but produces only a minuscule release of cytochrome c, indicating that BAX insertion/oligomerization in the OMM does not always lead to massive OMM permeabilization. Ca2+ in a mitochondrial permeability transition (mPT)-dependent and recombinant tBID in an mPT-independent manner promoted BAX insertion/oligomerization in the OMM and augmented cytochrome c release. Neither tBID nor Ca2+ induced BAX oligomerization in the solution without mitochondria, suggesting that BAX oligomerization required interaction with the organelles and followed rather than preceded BAX insertion in the OMM. Recombinant Bcl-xL failed to prevent BAX insertion/oligomerization in the OMM but strongly attenuated cytochrome c release. On the other hand, a reducing agent, dithiothreitol (DTT), inhibited BAX insertion/oligomerization augmented by tBID or Ca2+ and suppressed the BAX-mediated release of cytochrome c and Smac/DIABLO but failed to inhibit Ca2+-induced swelling. Altogether, these data suggest that in brain mitochondria, BAX insertion/oligomerization can be dissociated from OMM permeabilization and that tBID and Ca2+ stimulate BAX insertion/oligomerization and BAX-mediated OMM permeabilization by different mechanisms involving mPT induction and modulation of the SH-redox state. PMID:20655869

  14. Clinical significance of bax/bcl-2 ratio in chronic lymphocytic leukemia.

    Science.gov (United States)

    Del Principe, Maria Ilaria; Dal Bo, Michele; Bittolo, Tamara; Buccisano, Francesco; Rossi, Francesca Maria; Zucchetto, Antonella; Rossi, Davide; Bomben, Riccardo; Maurillo, Luca; Cefalo, Mariagiovanna; De Santis, Giovanna; Venditti, Adriano; Gaidano, Gianluca; Amadori, Sergio; de Fabritiis, Paolo; Gattei, Valter; Del Poeta, Giovanni

    2016-01-01

    In chronic lymphocytic leukemia the balance between the pro-apoptotic and anti-apoptotic members of the bcl-2 family is involved in the pathogenesis, chemorefractoriness and clinical outcome. Moreover, the recently proposed anti-bcl-2 molecules, such as ABT-199, have emphasized the potential role of of bcl-2 family proteins in the context of target therapies. We investigated bax/bcl-2 ratio by flow cytometry in 502 patients and identified a cut off of 1.50 to correlate bax/bcl-2 ratio with well-established clinical and biological prognosticators. Bax/bcl-2 was 1.50 or over in 263 patients (52%) with chronic lymphocytic leukemia. Higher bax/bcl-2 was associated with low Rai stage, lymphocyte doubling time over 12 months, beta-2 microglobulin less than 2.2 mg/dL, soluble CD23 less than 70 U/mL and a low risk cytogenetic profile (Pbax/bcl-2 was correlated with unmutated IGHV (Pbax/bcl-2 (Pbax/bcl-2 identified cases with significant longer PFS (P=0.00002 and P=0.039). In multivariate analysis of progression-free survival and overall survival, bax/bcl-2 was an independent prognostic factor (P=0.0002 and P=0.002). In conclusion, we defined the prognostic power of bax/bcl-2 ratio, as determined by a flow cytometric approach, and highlighted a correlation with chemoresistance and outcome in chronic lymphocytic leukemia. Finally, the recently proposed new therapies employing bcl-2 inhibitors prompted the potential use of bax/bcl-2 ratio to identify patients putatively resistant to these molecules. Copyright© Ferrata Storti Foundation.

  15. Effect of β Radiation on Bcl-2 and Bax Expressions in Benign Prostate Hyperplasia Tissues

    Institute of Scientific and Technical Information of China (English)

    MA Qing-jie; GAO Shi; ZHAO Jie; GU Xin-quan; CAI Shan-yu; ZHAO Guo-qing

    2008-01-01

    The authors chose specimens from nine normal prostate tissues(NP group),15 benign prostate hyperplasia(BPH) prostates(BPH group),and 35 BPH prostates that had been treated with 90Sr/90Y Prostatic Hyperplasia Applicator(exposure group),The expressions of bcl-2 and bax in stroma and epithelia of prostate tissues were demonstrated by means of immunohistochemical staining,and the staining positive rate was semiquantatively determined,so as to observe the expression of bcl-2 and bax genes in the prostate tissues of normal individuals and BPH patients,before and after β radiation,and to evaluate the influence of β radiation on bcl-2 and bax expressions,The expressions of gene bcl-2 in the prostate epithelia of NP and BPH are significantly higher than those in the prostate stroma(P<0.01),However,the expressions of bcl-2 in the prostate epithelia and stroma of the BPH group are obviously higher than those in the NP group(P<0.01),The expression of gene bax in the prostate epithelia of the NP group is higher than that in the BPH group(P<0.05),However,bcl-2 expressions in the prostate epithelia and stroma of the BPH group are significantly higher than the bax expressions(P<0.01),Compared with those of the NP group,the expressions of bcl-2 in the prostate epithelia and stroma of the exposure group decrease remarkably,even as the expressions of the bax notably increase(P<0.01),Thus,the administration of β radiation can remarkably affect bcl-2 and bax gene expressions,to regulate cell apoptosis,in the prostate tissues of BPH.

  16. The BH3 α-Helical Mimic BH3-M6 Disrupts Bcl-XL, Bcl-2, and MCL-1 Protein-Protein Interactions with Bax, Bak, Bad, or Bim and Induces Apoptosis in a Bax- and Bim-dependent Manner*

    Science.gov (United States)

    Kazi, Aslamuzzaman; Sun, Jiazhi; Doi, Kenichiro; Sung, Shen-Shu; Takahashi, Yoshinori; Yin, Hang; Rodriguez, Johanna M.; Becerril, Jorge; Berndt, Norbert; Hamilton, Andrew D.; Wang, Hong-Gang; Sebti, Saïd M.

    2011-01-01

    A critical hallmark of cancer cell survival is evasion of apoptosis. This is commonly due to overexpression of anti-apoptotic proteins such as Bcl-2, Bcl-XL, and Mcl-1, which bind to the BH3 α-helical domain of pro-apoptotic proteins such as Bax, Bak, Bad, and Bim, and inhibit their function. We designed a BH3 α-helical mimetic BH3-M6 that binds to Bcl-XL and Mcl-1 and prevents their binding to fluorescently labeled Bak- or Bim-BH3 peptides in vitro. Using several approaches, we demonstrate that BH3-M6 is a pan-Bcl-2 antagonist that inhibits the binding of Bcl-XL, Bcl-2, and Mcl-1 to multi-domain Bax or Bak, or BH3-only Bim or Bad in cell-free systems and in intact human cancer cells, freeing up pro-apoptotic proteins to induce apoptosis. BH3-M6 disruption of these protein-protein interactions is associated with cytochrome c release from mitochondria, caspase-3 activation and PARP cleavage. Using caspase inhibitors and Bax and Bak siRNAs, we demonstrate that BH3-M6-induced apoptosis is caspase- and Bax-, but not Bak-dependent. Furthermore, BH3-M6 disrupts Bcl-XL/Bim, Bcl-2/Bim, and Mcl-1/Bim protein-protein interactions and frees up Bim to induce apoptosis in human cancer cells that depend for tumor survival on the neutralization of Bim with Bcl-XL, Bcl-2, or Mcl-1. Finally, BH3-M6 sensitizes cells to apoptosis induced by the proteasome inhibitor CEP-1612. PMID:21148306

  17. Comparison of immunoexpression of VEGF, TGF-β and MMP-9 in ameloblastoma and adenomatoid odontogenic tumor = Comparação da imunoexpressão de VEGF, TGF-β e MMP-9 em ameloblastoma e tumor odontogênico adenomatóide

    Directory of Open Access Journals (Sweden)

    Ferreira, Stefânia Jeronimo

    2015-01-01

    Full Text Available Objetivo: Estudos sobre tumores odontogênicos têm identificado várias disfunções moleculares envolvidas no seu desenvolvimento, e alguns mecanismos como a angiogênese e modulação da matriz são objetos úteis para investigar as diferenças no comportamento biológico destes tumores. Alguns marcadores importantes para identificar a agressividade do tumor por imunoistoquímica são as proteínas VEGF, TGF-ß e MMP-9. Este estudo teve como objetivo comparar a expressão imunoistoquímica de VEGF, TGF-ß e MMP-9 entre ameloblastoma e tumor odontogênico adenomatoide (TOA. Métodos: Imunoexpressão de VEGF, TGF-ß e MMP-9 foi estudada em 15 ameloblastomas sólidos e 15 TOA. Uma análise semiquantitativa das células imunomarcadas foi realizada e a análise estatística foi feita usando o teste não paramétrico de Mann-Whitney e o teste de correlação de Spearman, com nível de significância de 0,05 (P0. 05. Conclusão: Os resultados sugerem o envolvimento da angiogênese na progressão tumoral de ameloblastomas e o efeito indutor de células estromais em TOA, portanto, justificando o seu potencial de crescimento mais baixo

  18. Oral tumors in dogs: clinical aspects, exfoliative cytology and histopathology Neoplasias orais em cães: avaliação dos aspectos clínicos, histopatologia e citologia esfoliativa

    Directory of Open Access Journals (Sweden)

    Cláudia Ronca Felizzola

    1999-09-01

    Full Text Available In order to establish the diagnosis and prognosis of tumors of the oral cavity, a comparative study was carried out in 130 dogs considering age, sex, breed, clinical aspects, exfoliative cytology as well as histopathology. Exfoliative cytology revealed: 100% negative for benign non-odontogenic tumors, 97.91% negative benign odontogenic tumors and 77.92% positive for malignant tumors. Histopathology showed: 59.23% malignant tumors (33.08% malignant melanoma, 9.23% squamous cell carcinoma, 5.38% osteosarcoma, 2.31% fibrosarcoma, 2.31% angiosarcoma, 1.54% malignant mesenchymal tumors, 1.54% malignant fibrohistiocytoma, 1.54% lymphoma, 0.77% leyomyosarcoma, 0.77%% epithelioid sarcoma and 0.77% angiofibrosarcoma; 36.92% benign odontogenic tumors (25.38% peripheral odontogenic fibroma, 10.0% ossifyng fibroma and 1.54% odontoma in addition to 3.85% benign non-odontogenic tumors (1.54% fibroma, 0.77% plasmocytoma, 0.77% pilomatrixoma and 0.77% giant tumor cells. These results permit us to conclude that exfoliative cytology was an efficient, safe, quick and noninvasive method and could be used for early evaluation of oral cancer.Objetivou-se o estudo comparativo em tumores de cavidade bucal de animais de espécie canina de acordo com sexo, faixa etária, raça, aspectos clínicos, citologia esfoliativa e histopatologia, para estabelecer diagnóstico dessas neoplasias, tendo sido utilizados 130 cães, encaminhados ao Hospital Veterinário (HOVET da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo. Os resultados obtidos na citologia esfoliativa foram: 100% de negativos para neoplasias benignas não odontogênicas; 97,91% de negativos para neoplasias benignas odontôgenicas e 77,92% de positivos para neoplasias malignas. Obtiveram-se os seguintes resultados no exame histopatológico: neoplasias malignas - 59,23% (melanoma 33,08%, carcinoma epidermóide 9,23%, osteossarcoma 5,38%, fibrossarcoma 2,31%, angiossarcoma 2

  19. Prostaglandin E2 reduces radiation-induced epithelial apoptosis through a mechanism involving AKT activation and bax translocation.

    Science.gov (United States)

    Tessner, Teresa G; Muhale, Filipe; Riehl, Terrence E; Anant, Shrikant; Stenson, William F

    2004-12-01

    Prostaglandin E2 (PGE2) synthesis modulates the response to radiation injury in the mouse intestinal epithelium through effects on crypt survival and apoptosis; however, the downstream signaling events have not been elucidated. WT mice receiving 16,16-dimethyl PGE2 (dmPGE2) had fewer apoptotic cells per crypt than untreated mice. Apoptosis in Bax(-/-) mice receiving 12 Gy was approximately 50% less than in WT mice, and the ability of dmPGE2 to attenuate apoptosis was lost in Bax(-/-) mice. Positional analysis revealed that apoptosis in the Bax(-/-) mice was diminished only in the bax-expressing cells of the lower crypts and that in WT mice, dmPGE2 decreased apoptosis only in the bax-expressing cells. The HCT-116 intestinal cell line and Bax(-/-) HCT-116 recapitulated the apoptotic response of the mouse small intestine with regard to irradiation and dmPGE2. Irradiation of HCT-116 cells resulted in phosphorylation of AKT that was enhanced by dmPGE2 through transactivation of the EGFR. Inhibition of AKT phosphorylation prevented the reduction of apoptosis by dmPGE2 following radiation. Transfection of HCT-116 cells with a constitutively active AKT reduced apoptosis in irradiated cells to the same extent as in nontransfected cells treated with dmPGE2. Treatment with dmPGE2 did not alter bax or bcl-x expression but suppressed bax translocation to the mitochondrial membrane. Our in vivo studies indicate that there are bax-dependent and bax-independent radiation-induced apoptosis in the intestine but that only the bax-dependent apoptosis is reduced by dmPGE2. The in vitro studies indicate that dmPGE2, most likely by signaling through the E prostaglandin receptor EP2, reduces radiation-induced apoptosis through transactivation of the EGFR and enhanced activation of AKT and that this results in reduced bax translocation to the mitochondria.

  20. Identification of Bax-Interacting Proteins in Oligodendrocyte Progenitors during Glutamate Excitotoxicity and Perinatal Hypoxia–Ischemia

    Directory of Open Access Journals (Sweden)

    Sopio Simonishvili

    2013-11-01

    Full Text Available OPC (oligodendrocyte progenitor cell death contributes significantly to the pathology and functional deficits following hypoxic-ischemic injury in the immature brain and to deficits resulting from demyelinating diseases, trauma and degenerative disorders in the adult CNS. Glutamate toxicity is a major cause of oligodendroglial death in diverse CNS disorders, and previous studies have demonstrated that AMPA/kainate receptors require the pro-apoptotic protein Bax in OPCs undergoing apoptosis. The goal of the present study was to define the pro-apoptotic and anti-apoptotic effectors that regulate Bax in healthy OPCs and after exposure to excess glutamate in vitro and following H–I (hypoxia–ischemia in the immature rat brain. We show that Bax associates with a truncated form of Bid, a BH3-only domain protein, subsequent to glutamate treatment. Furthermore, glutamate exposure reduces Bax association with the anti-apoptotic Bcl family member, Bcl-xL. Cell fractionation studies demonstrated that both Bax and Bid translocate from the cytoplasm to mitochondria during the early stages of cell death consistent with a role for Bid as an activator, whereas Bcl-xL, which normally complexes with both Bax and Bid, disassociates from these complexes when OPCs are exposed to excess glutamate. Bax remained unactivated in the presence of insulin-like growth factor-1, and the Bcl-xL complexes were protected. Our data similarly demonstrate loss of Bcl-xL–Bax association in white matter following H–I and implicate active Bad in Bax-mediated OPC death. To identify other Bax-binding partners, we used proteomics and identified cofilin as a Bax-associated protein in OPCs. Cofilin and Bax associated in healthy OPCs, whereas the Bax–cofilin association was disrupted during glutamate-induced OPC apoptosis.

  1. Identification of Bax-interacting proteins in oligodendrocyte progenitors during glutamate excitotoxicity and perinatal hypoxia–ischemia

    Directory of Open Access Journals (Sweden)

    Sopio Simonishvili

    2013-12-01

    Full Text Available OPC (oligodendrocyte progenitor cell death contributes significantly to the pathology and functional deficits following hypoxic-ischemic injury in the immature brain and to deficits resulting from demyelinating diseases, trauma and degenerative disorders in the adult CNS. Glutamate toxicity is a major cause of oligodendroglial death in diverse CNS disorders, and previous studies have demonstrated that AMPA/kainate receptors require the pro-apoptotic protein Bax in OPCs undergoing apoptosis. The goal of the present study was to define the pro-apoptotic and anti-apoptotic effectors that regulate Bax in healthy OPCs and after exposure to excess glutamate in vitro and following H–I (hypoxia–ischemia in the immature rat brain. We show that Bax associates with a truncated form of Bid, a BH3-only domain protein, subsequent to glutamate treatment. Furthermore, glutamate exposure reduces Bax association with the anti-apoptotic Bcl family member, Bcl-xL. Cell fractionation studies demonstrated that both Bax and Bid translocate from the cytoplasm to mitochondria during the early stages of cell death consistent with a role for Bid as an activator, whereas Bcl-xL, which normally complexes with both Bax and Bid, disassociates from these complexes when OPCs are exposed to excess glutamate. Bax remained unactivated in the presence of insulin-like growth factor-1, and the Bcl-xL complexes were protected. Our data similarly demonstrate loss of Bcl-xL–Bax association in white matter following H–I and implicate active Bad in Bax-mediated OPC death. To identify other Bax-binding partners, we used proteomics and identified cofilin as a Bax-associated protein in OPCs. Cofilin and Bax associated in healthy OPCs, whereas the Bax–cofilin association was disrupted during glutamate-induced OPC apoptosis.

  2. BAX OVEREXPRESSION ENHANCES APOPTOSIS INDUCED BY ADRIAMYCIN IN HCC-9204 CELLS

    Institute of Scientific and Technical Information of China (English)

    郑建勇; 李江; 李开宗; 王文亮; 王为忠

    2004-01-01

    Objective: To investigate the effect of overexpression of Bax to the sensitivity of human HCC-9204 cells to adriamycin (ADR). Methods: Human cultured hepatocellular carcinoma cell line HCC-9204 was exposed in vitro to adriamycin for various time. An inducible vector containing Bax gene, with ZnSO4 as external inducer was constructed. Cell apoptosis was ascertained by morphological criteria, detection of apoptotic DNA fragmentation by TUNEL assay and flow cytometry. Tetrazolium blue (MTT) assay was used to evaluate the differences in drug sensitivity of HCC-9204 cells after Bax-transfection. Results: HCC-9204 cells treated with adriamycin at 20μmol/L showed extensive cell death. TUNEL assay showed nucleus fragmentation. And apoptotic peak was also shown by flow cytometry. FACS analyses showed a significant sub-G1 peak and apoptosis in 31% cells at 24h after treatment. Furthermore, the time-course of cell viability following exposure of HCC-9204/Bax cells to adriamycin showed that Bax was able to significantly decrease cell survival following exposure to adriamycin.

  3. Immunohistochemical localization of Bcl-2 and Bax proteins in in situ and invasive duct breast carcinomas.

    Science.gov (United States)

    Kapucuoglu, N; Losi, L; Eusebi, V

    1997-01-01

    Bcl-2 and Bax proteins are coded by a family of genes that take part in the manteinance of the balance between cell proliferation rate and programmed cell death in multicellular organisms. The Bax gene acts as promoter of cell death by opposing the death protector effect of the Bcl-2 gene. Expression of the Bcl-2 and Bax proteins has been investigated in 58 cases of duct carcinoma in situ (DCIS) and duct invasive and invasive lobular carcinomas (IC) of the breast. While both proteins were expressed at the same time in normal and benign epithelium, different staining patterns were observed according to the degree of differentiation of the neoplastic epithelium. In well-differentiated DCIS and grade I IC there was a predominance of Bcl-2 protein staining. Grade II lesions co-expressed both proteins. Poorly differentiated DCIS displayed a predominantly Bax protein staining pattern. Therefore, it appears that Bax protein expression, especially in DCIS, relates to more aggressive neoplasms while Bcl-2 protein expression is associated with less aggressive malignant lesions.

  4. Effects of cadmium on Bcl-2/ Bax expression ratio in rat cortex brain and hippocampus.

    Science.gov (United States)

    Mahdavi, S; Khodarahmi, P; Roodbari, N H

    2017-01-01

    To investigate the underlying mechanism of neurotoxicity of cadmium, we examined the effects of intraperitoneal injection of cadmium on messenger RNA (mRNA) expression of Bcl-2 (B-cell lymphoma 2) and Bax (Bcl2-associated x) genes and caspase-3/7 activation in rat hippocampus and frontal cortex. Twenty-eight male Wistar rats weighing 200-250 g were randomly divided into four groups. Control group received saline and three other groups received cadmium at doses of 1, 2 and 4 mg/kg (body weight) for 15 successive days. One day after the last injection, the hippocampus and frontal cortex were dissected and removed and then the expression of Bcl-2 and Bax genes was evaluated using real-time polymerase chain reaction and apoptotic studies was done using caspase-3/7 activation assay. Cadmium reduced the mRNA level of Bcl-2 in the control group at doses of 1 ( p Bax increased significantly compared to the control group at the doses of 1 ( p Bax was increased significantly compared to the control group at the doses of 2 and 4 mg/kg ( p Bax mRNA ratio induces cell apoptosis. Apoptotic effect of cadmium may be through the mitochondrial pathway by the activation of caspase-3/7.

  5. Bax Activation Blocks Self-Renewal and Induces Apoptosis of Human Glioblastoma Stem Cells.

    Science.gov (United States)

    Daniele, Simona; Pietrobono, Deborah; Costa, Barbara; Giustiniano, Mariateresa; La Pietra, Valeria; Giacomelli, Chiara; La Regina, Giuseppe; Silvestri, Romano; Taliani, Sabrina; Trincavelli, Maria Letizia; Da Settimo, Federico; Novellino, Ettore; Martini, Claudia; Marinelli, Luciana

    2017-04-11

    Glioblastoma (GBM) is characterized by a poor response to conventional chemotherapeutic agents, attributed to the insurgence of drug resistance mechanisms and to the presence of a subpopulation of glioma stem cells (GSCs). GBM cells and GSCs present, among others, an overexpression of antiapoptotic proteins and an inhibition of pro-apoptotic ones, which help to escape apoptosis. Among pro-apoptotic inducers, the Bcl-2 family protein Bax has recently emerged as a promising new target in cancer therapy along with first BAX activators (BAM7, Compound 106, and SMBA1). Herein, a derivative of BAM-7, named BTC-8, was employed to explore the effects of Bax activation in different human GBM cells and in their stem cell subpopulation. BTC-8 inhibited GBM cell proliferation, arrested the cell cycle, and induced apoptosis through the induction of mitochondrial membrane permeabilization. Most importantly, BTC-8 blocked proliferation and self-renewal of GSCs and induced their apoptosis. Notably, BTC-8 was demonstrated to sensitize both GBM cells and GSCs to the alkylating agent Temozolomide. Overall, our findings shed light on the effects and the relative molecular mechanisms related to Bax activation in GBM, and they suggest Bax-targeting compounds as promising therapeutic tools against the GSC reservoir.

  6. Eucommia ulmoides cortex, geniposide and aucubin regulate lipotoxicity through the inhibition of lysosomal BAX.

    Science.gov (United States)

    Lee, Geum-Hwa; Lee, Mi-Rin; Lee, Hwa-Young; Kim, Seung Hyun; Kim, Hye-Kyung; Kim, Hyung-Ryong; Chae, Han-Jung

    2014-01-01

    In this study we examined the inhibition of hepatic dyslipidemia by Eucommia ulmoides extract (EUE). Using a screening assay for BAX inhibition we determined that EUE regulates BAX-induced cell death. Among various cell death stimuli tested EUE regulated palmitate-induced cell death, which involves lysosomal BAX translocation. EUE rescued palmitate-induced inhibition of lysosomal V-ATPase, α-galactosidase, α-mannosidase, and acid phosphatase, and this effect was reversed by bafilomycin, a lysosomal V-ATPase inhibitor. The active components of EUE, aucubin and geniposide, showed similar inhibition of palmitate-induced cell death to that of EUE through enhancement of lysosome activity. Consistent with these in vitro findings, EUE inhibited the dyslipidemic condition in a high-fat diet animal model by regulating the lysosomal localization of BAX. This study demonstrates that EUE regulates lipotoxicity through a novel mechanism of enhanced lysosomal activity leading to the regulation of lysosomal BAX activation and cell death. Our findings further indicate that geniposide and aucubin, active components of EUE, may be therapeutic candidates for non-alcoholic fatty liver disease.

  7. Bax Inhibitor-1 down-regulation in the progression of chronic liver diseases

    Directory of Open Access Journals (Sweden)

    Burra Patrizia

    2010-04-01

    Full Text Available Abstract Background Bax inhibitor-1 (BI-1 is an evolutionary conserved endoplasmic reticulum protein that, when overexpressed in mammalian cells, suppresses the apoptosis induced by Bax, a pro-apoptotic member of the Bcl-2 family. The aims of this study were: (1 to clarify the role of intrinsic anti- and pro-apoptotic mediators, evaluating Bax and BI-1 mRNA and protein expressions in liver tissues from patients with different degrees of liver damage; (2 to determine whether HCV and HBV infections modulate said expression. Methods We examined 62 patients: 39 with chronic hepatitis (CH (31 HCV-related and 8 HBV-related; 7 with cirrhosis (6 HCV-related and 1 HBV-related; 13 with hepatocellular carcinoma (HCC [7 in viral cirrhosis (6 HCV- and 1 HBV-related, 6 in non-viral cirrhosis]; and 3 controls. Bax and BI-1 mRNAs were quantified by real-time PCR, and BI-1 protein expression by Western blot. Results CH tissues expressed significantly higher BI-1 mRNA levels than cirrhotic tissues surrounding HCC (P Conclusions BI-1 expression is down-regulated as liver damage progresses. The high BI-1 mRNAs levels observed in early liver disease may protect virus-infected cells against apoptosis, while their progressive downregulation may facilitate hepatocellular carcinogenesis. HCV genotype seems to have a relevant role in Bax transcript expression.

  8. THE EXPRESSION OF BCL-2 AND BAX PROTEINS IN GASTRIC CARCINOMA AND PRECANCEROUS LESIONS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective To investigate the variance of expression of bcl-2 and bax genes in the genesis of gastric carcinoma as well as their relationship. Methods Thirty-five cases of early-stage gastric carcinoma and Twenty-four cases of chronic atrophic gastritis were studied by immunohistochemical method. Results There were no statistical differences of bcl-2 expression levels between gastric carcinoma and atypical hyperplasia or paracancerous intestinalepithelial metaplasia(IEM)(P>0. 05). There were statistical differences of bcl-2 expression between normal epithelial tissues (or non-cancerous IEM) and the other three groups (P<0.05),but no statistical difference between the normal epithelial and the non-cancerous IEM group was observed (P>0. 05). The expressions of bax protein were found in the normal epithelial and the other groups in varying degrees,but there were no statistical differences between either two of the groups (P>0.05). The bcl-2/bax ratio was higher in early-stage gastric carcinoma,atypical hyperplasia and paracancerous intestinai-metaplasia than in the non-cancerous intestinal-metaplasia (P<0. 05) and normal epithelial tissues(P<0. 01). Conclusion The abnormal expression of bcl-2 protein and bax protein ,especially the increased bcl-2/bax ratio, probably play an important role in the course of carcinogenesis of gastric carcinoma.

  9. Assessment of cell proliferation and prognostic factors in canine mammary gland tumors Avaliação da proliferação celular e fatores prognósticos em tumores mamários caninos

    OpenAIRE

    A.P. Dutra; G.M. Azevedo Júnior; Schmitt, F. C.; G.D. Cassali

    2008-01-01

    Three methods for the analysis of cell proliferation, mitotic index/10 high-power fields (10 HPF), mitotic index/four sets of 10 HPF (40 HPF), and MIB-1 index were evaluated in a series of canine mammary gland tumors, as well as the possible correlation between them. Fifty-six canine mammary gland tumors, including 23 benign and 33 malignant, were studied. In addition, the prognostic impact of mitotic index/10 HPF, and histological malignancy grade were evaluated in 17 malignant tumors, being...

  10. The morphological changes in transplanted tumors in rats at plasmonic photothermal therapy

    Science.gov (United States)

    Bucharskaya, Alla B.; Maslyakova, Galina N.; Navolokin, Nikita A.; Dikht, Nataliya I.; Terentyuk, Georgy S.; Bashkatov, Alexey N.; Genina, Elina A.; Khlebtsov, Boris N.; Khlebtsov, Nikolai G.; Tuchin, Valery V.

    2016-04-01

    The aim of work was to study the morphological changes in transplanted liver tumors of rats after plasmonic photothermal therapy (PPTT). The gold nanorods functionalized with thiolated polyethylene glycol were injected intravenously to rats with transplanted liver cancer PC-1. A day after injection the tumors were irradiated by the infrared 808-nm diode laser. The withdrawal of the animals from the experiment and sampling of tumor tissue for morphological study were performed 24 hours after the laser exposure. The standard histological and immunohistochemical staining with antibodies to proliferation marker Ki-67 and apoptosis marker BAX were used for morphological study of transplanted tumors. The plasmonic photothermal therapy had pronounced damaging effect in rats with transplanted liver tumors expressed in degenerative and necrotic changes in the tumor cells. The decrease of proliferation marker Ki-67 and increase of expression of apoptosis marker BAX were observed in tumor cells after PPTT.

  11. Bax is not involved in the resveratrol-induced apoptosis in human lung adenocarcinoma cells

    Science.gov (United States)

    Zhang, Wei-wei; Wang, Zhi-ping; Chen, Tong-sheng

    2010-02-01

    Resveratrol (RV) is a natural plant polyphenol widely present in foods such as grapes, wine, and peanuts. Previous studies indicate that RV has an ability to inhibit various stages of carcinogenesis and eliminate preneoplastic cells in vitro and in vivo. However, little is known about the molecular mechanism of RV-induced apoptosis in human lung adenocarcinoma (ASTC-a-1) cell. In this report, we analyzed whether Bax translocation from cytoplasm to mitochondria during RV-induced apoptosis in single living cell using onfocal microscopey. Cells were transfected with GFP-Bax plasmid. Cell counting kit (CCK-8) assay was used to assess the inhibition of RV on the cells viability. Apoptotic activity of RV was detected by Hoechst 33258 and propidium iodide (PI) staining. Our results showed that RV induced a dose-dependent apoptosis in which Bax did not translocate to mitochondrias.

  12. A non-apoptotic role for BAX and BAK in eicosanoid metabolism

    Science.gov (United States)

    Zhang, Tejia; Walensky, Loren D.; Saghatelian, Alan

    2015-01-01

    BCL-2 proteins are key regulators of programmed cell death. The interplay between pro- and anti-apoptotic BCL-2 members has important roles in many cancers. In addition to their apoptotic function, recent evidence supports key non-apoptotic roles for several BCL-2 proteins. We used an unbiased lipidomics strategy to reveal that the pro-apoptotic proteins BAX, and to a lesser extent BAK, regulate the cellular inflammatory response by mediating COX-2 expression and prostaglandin biosynthesis. COX-2 upregulation in response to the bacterial endotoxin lipopolysaccharide is blunted in the absence of BAX, and Bax−/− mouse embryonic fibroblasts display altered kinetics of NFκB and MAPK signaling following endotoxin treatment. Our approach uncovers a novel, non-apoptotic function for BAX in regulation of the cellular inflammatory response and suggests that inflammation and apoptosis are more tightly connected than previously anticipated. PMID:25815636

  13. Tomografia computadorizada na análise dos padrões de calcificações nos tumores ósseos da bacia em pediatria: nova abordagem Computed tomography in the analysis of calcification patterns in pediatric bone tumors of the hip: a new approach

    Directory of Open Access Journals (Sweden)

    Gabriel Antônio de Oliveira

    2006-12-01

    Full Text Available OBJETIVO: No grupo pediátrico, o diagnóstico radiológico dos tumores dos ossos ilíacos, ísquios e púbis apresenta dificuldades e peculiaridades próprias, mas a literatura revisada não trata especificamente desse tema. Este trabalho pretende investigar a existência de padrões radiológicos confiáveis para o diagnóstico diferencial desses tumores. MATERIAIS E MÉTODOS: Foram revistos os achados radiológicos de tumores dos ossos do quadril em dez pacientes com idades entre 8 e 19 anos. RESULTADOS: Reação óssea (esclerose ou lise, reação periosteal (lamelar em camada única, múltiplas camadas ou radial, extensão do tumor no osso e grau de invasão das partes moles revelaram baixa especificidade. As calcificações nas partes moles, consideradas em conjunto, foram inespecíficas. Contudo, separando as próximas do osso comprometido, que apresentam formas e tamanhos variados - padrão I -, daquelas afastadas do osso, finas e amorfas - padrão II -, observamos que o padrão I foi totalmente inespecífico e o padrão II foi identificado nos três casos de osteossarcoma (100% e em apenas um dos casos de Ewing (16,6%. CONCLUSÃO: Neste material, as calcificações padrão II revelaram sensibilidade de 100% e especificidade de 90% para osteossarcoma. Contudo, sua importância pode não se limitar ao diagnóstico radiológico. As calcificações padrão II indicam, provavelmente, os sítios ideais para biópsia.OBJECTIVE: In the pediatric group, the radiological diagnosis of bone tumors of the hip is difficult and presents some peculiarities, but reviewed literature does not approach this specific problem. The objective of the present study was to investigate the existence of reliable radiological patterns for the differential diagnosis of these tumors. MATERIALS AND METHODS: Radiological findings of bone tumors of the hip in ten patients in the age range between 8 and 19 years have been reviewed. RESULTS: Bone reaction (sclerosis or

  14. Formononetin Induces Apoptosis of Human Osteosarcoma Cell Line U2OS by Regulating the Expression of Bcl-2, Bax and MiR-375 In Vitro and In Vivo

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    Wei Hu

    2015-09-01

    Full Text Available Background/Aims: Phytoestrogens are known to prevent tumor progression by inhibiting proliferation and inducing apoptosis in cancer cells. Formononetin is one of the main components of red clover plants, and is considered as a typical phytoestrogen. This study investigates formononetin induction of apoptosis of human osteosarcoma cell line U2OS by regulating Bcl-2 and Bax expression in vitro and in vivo. Methods: U2OS cells were treated with different concentrations of formononetin and the proliferation of the cells was measured using an MTT assay. Cell apoptosis was examined by flow cytometry. The levels of miR-375, Bax and Bcl-2 protein expression in treated cells were determined by Western blot and RT-PCR. The antitumor activity of formononetin was also evaluated in vivo in nude mice bearing orthotopic tumor implants. Results: High concentrations of formononetin significantly suppress the proliferation of U2OS cells and induce cell apoptosis. Moreover, compared to control group the expression of Bcl-2 and miR-375 decreases with formononetin in the U2OS cells, while Bax increases. Conclusion: Formononetin has inhibitory effects on the proliferation of U2SO cells, both in vitro and in vivo. This antitumor effect is directly correlated with formononetin concentration.

  15. bax和p53基因共转染对人舌癌细胞增 殖和凋亡的影晌%Effect on Proliferation and Apoptosis of Human Lingual Carc inoma Cells Cotransfected by bax and p53 Genes

    Institute of Scientific and Technical Information of China (English)

    马英红; 杨绍华; 陈俊杰; 高家让; 彭文珍; 王若菡

    2001-01-01

    Objective To investigate th e effects on prolife ration andapoptosis of human cancerous cells cotransfected by bax apoptosis-in ducing gene and p53 tumor suppressor gene. Methods The chi meric gene pSV-CIP-bax -CAT was constructed in which bax gene was flanked upstream by a 217bp fragment (+822~+1093) of the first intron and a 317bp promoter fragment of human a 1(Ⅰ) colla gen gene . Human lingual carcinoma cell line Tca 8113 (LCC) in culture was respe ctively transfected with pSV-CIP-bax-CAT, and cotransfected with pSV-p53-CA T and pSV-CIP-bax-CAT by using the transfection reagent DOSPER. Res ults Immuno- slot blot and ELISA demonstrated that the expression of bax and p53 genes incr eased remarkably in the transfected and cotransfected LCC, compared with the con trols(LCC transfected with pSV-CIP-CAT and LCC).MTT colorimetric assay,TUNE L fluorecence microscopy and flow cytometry showed that foreign bax or p53 gene inhibited the LCC growth and induced apoptosis(23.9% and 26.1% of inhibitory ra te by bax gene and p53 plus bax genes respectively). Conclusion The ectopic expression of the bax gene in the LCC promoted by the cis-act ing elements of human a1(Ⅰ)collagen gene has obviously synergistic effect on th e proliferation and apoptosis of the LCC cotransfected with p53 gene plus bax gene for 48 hours.%目的 探讨诱导凋亡的bax基因和p53抑癌基因共转染对人癌细胞增殖和凋亡的作用。方法 构建pSV-CIP-bax-CAT嵌合基因。在其bax基因上游含人a1(Ⅰ)型胶原基因的第一内含子217bp片段(+822~+1093)和317bp启动子片段。经阳离子转染试剂DOSPER介导,分别用pSV-CIP-bax-CAT转染、pSV-CIP-bax-CAT和pSV-p53-CAT共转染培养的人舌癌Tca8113细胞系(LCC)。结果 免疫狭缝印迹和ELISA检测证实,转染组和共转染组比对照的bax和p53基因表达量明显增加。MTT显色分析、TUNEL荧光显微镜和流式细胞仪监测结果显示,bax基因或p53基因均具抑

  16. Diagnosis and evaluation of surveying examination by intracranial tumor in dogs CT; Diagnostico e avaliacao topografica de neoplasias intracranianas pelo exame de TC em caes

    Energy Technology Data Exchange (ETDEWEB)

    Romaldini, Andre Fonseca; Santos, Debora Rodrigues dos; Oliveira, Juliana Messias; Abreu, Felipe Andrei Suarez; Wallace, Verena; Pacheco, Eduardo Nelson da Silva, E-mail: andreromaldini@gmail.com [Hospital Santa Ines de Sao Paulo, Santana, SP (Brazil)

    2012-07-01

    The use of computed tomography (CT) revolutionized image diagnostic in veterinary medicine and currently can be considered one of the most useful tools for the imaging evaluation of intracranial tumor in dogs. Computed tomography of the brain in small animals allows visualization of intracranial tumor, compression of adjacent structures such as cerebral parenchyma, falx or lateral ventricles, and evaluate secondary hemorrhages and edema. The CT imaging provides essential information to indicate the surgical approach for a possible tumor resection or biopsy, including the correct location and boundaries structures involved, and also can be used to monitor the clinical treatment. However, only histopathological examination is able to confirm the final diagnosis. (author)

  17. Oclusão arterial aguda de membros inferiores por êmbolo tumoral em paciente com neoplasia de pulmão Acute arterial occlusion of lower limbs caused by tumor embolism in a patient with lung neoplasia

    Directory of Open Access Journals (Sweden)

    Viviane Queli Macedo de Alcântara

    2012-12-01

    Full Text Available A embolia arterial periférica originada de tumores malignos é considerada uma manifestação rara da doença neoplásica, podendo se originar de vários sítios, incluindo coração, aorta e veias pulmonares, sendo estas últimas, fontes massivas de embolia por trombo ou tumores com erosão para seu lúmen. Apesar de infrequente, a neoplasia pulmonar deve ser considerada como uma fonte de êmbolos para as extremidades, principalmente quando há invasão neoplásica para as veias pulmonares. Apresentamos o caso de um paciente do sexo masculino submetido à pneumectomia por neoplasia pulmonar, que evoluiu com oclusão arterial aguda de membros inferiores por êmbolo tumoral " a cavaleiro".Peripheral arterial embolism (PAE caused by malignant tumors is a rare manifestation of cancer. PAE may originate from several sites, including heart, aorta, and pulmonary veins. Such veins are a major source of thrombotic embolism or tumors with vascular erosion. Although uncommon, lung cancer should be regarded as a source of emboli in the extremities, especially when there is neoplastic invasion of the pulmonary veins. We report on a case of a male patient who underwent pneumonectomy for lung cancer who developed acute arterial occlusion of the lower extremities caused by saddle tumor embolus.

  18. Differential expression of Bcl-2 and Bax during gastric ischemia-reperfusion of rats

    Institute of Scientific and Technical Information of China (English)

    Wei-Li Qiao; Guang-Ming Wang; Yue Shi; Jin-Xia Wu; You-Jian Qi; Jian-Fu Zhang; Hong Sun; Chang-Dong Yan

    2011-01-01

    AIM: To investigate expression of Bcl-2 and Bax in gastric ischemia-reperfusion (GI-R) and involvement of extracellular signal-regulated kinase (ERK) 1/2 activation.METHODS: The GI-R model was established by ligature of the celiac artery for 30 min and reperfusion in Sprague-Dawley rats. Rats were assigned to groups in accordancewith their evaluation period: control, 0, 0.5, 1, 3, 6, 24,48, and 72 h. Expression and distribution of Bcl-2 and Bax proteins were analyzed by immunohistochemistry and western blotting in gastric tissue samples after sacrifice.RESULTS: Compared with controls, the percentage of positive cells and protein levels of Bcl-2 decreased in the early phases of reperfusion, reached its minimumat 1 h (P < 0.05); it then increased, reaching its peak at 24 h of reperfusion (P < 0.05). The pattern of Bax expression was opposite to that of Bcl-2. Bax expressionincreased after reperfusion, with its peak at 1 h of reperfusion (P < 0.05), and then it decreased gradually to a minimum at 24 h after reperfusion (P < 0.05).On the other hand, inhibition of activation of ERK1/2 induced by PD98059, a specific upstream MEK inhibitor,had significant effects on Bcl-2 and Bax in GI-R.Compared with GI-R treatment only at 3 h of reperfusion,PD98059 reduced the number of Bcl-2 positive cells (0.58% of R3h group, P < 0.05) and Bcl-2 proteinlevel (74% of R3h group, P < 0.05) but increased the number of Bax-positive cells (1.33-fold vs R3h group, P< 0.05) and Bax protein level (1.35-fold of R3h group,P < 0.05).CONCLUSION: These results indicated that the Bcl-2 and Bax played a pivotal role in the gastric mucosal I-R injury and repair by activation of ERK1/2.

  19. Detecção, por hibridização genomica comparativa, de anormalidades genéticas em tumores primários de mama e em metástases nos linfonodos sentinela correspondentes /

    OpenAIRE

    Santos, Savana Camilla de Lima

    2007-01-01

    Orientador : Iglenir João Cavalli Co-orientadores : Enilze M.S.F. Ribeiro e Luciane Regina Cavalli Tese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Genética. Defesa: Curitiba, 2007 Inclui bibliografia

  20. Dexamethasone protected human glioblastoma U87MG cells from temozolomide induced apoptosis by maintaining Bax:Bcl-2 ratio and preventing proteolytic activities

    Directory of Open Access Journals (Sweden)

    Patel Sunil J

    2004-12-01

    Full Text Available Abstract Background Glioblastoma is the deadliest and most prevalent brain tumor. Dexamethasone (DXM is a commonly used steroid for treating glioblastoma patients for alleviation of vasogenic edema and pain prior to treatment with chemotherapeutic drugs. Temozolomide (TMZ, an alkylating agent, has recently been introduced in clinical trials for treating glioblastoma. Here, we evaluated the modulatory effect of DXM on TMZ induced apoptosis in human glioblastoma U87MG cells. Results Freshly grown cells were treated with different doses of DXM or TMZ for 6 h followed by incubation in a drug-free medium for 48 h. Wright staining and ApopTag assay showed no apoptosis in cells treated with 40 μM DXM but considerable amounts of apoptosis in cells treated with 100 μM TMZ. Apoptosis in TMZ treated cells was associated with an increase in intracellular free [Ca2+], as determined by fura-2 assay. Western blot analyses showed alternations in the levels of Bax (pro-apoptotic and Bcl-2 (anti-apoptotic proteins resulting in increased Bax:Bcl-2 ratio in TMZ treated cells. Western blot analyses also detected overexpression of calpain and caspase-3, which cleaved 270 kD α-spectrin at specific sites for generation of 145 and 120 kD spectrin break down products (SBDPs, respectively. However, 1-h pretreatment of cells with 40 μM DXM dramatically decreased TMZ induced apoptosis, decreasing Bax:Bcl-2 ratio and SBDPs. Conclusion Our results revealed an antagonistic effect of DXM on TMZ induced apoptosis in human glioblastoma U87MG cells, implying that treatment of glioblastoma patients with DXM prior to chemotherapy with TMZ might result in an undesirable clinical outcome.

  1. Involvement of Bcl-2 and Bax in photodynamic therapy-mediated apoptosis. Antisense Bcl-2 oligonucleotide sensitizes RIF 1 cells to photodynamic therapy apoptosis.

    Science.gov (United States)

    Srivastava, M; Ahmad, N; Gupta, S; Mukhtar, H

    2001-05-04

    Photodynamic therapy (PDT), a promising treatment modality, is an oxidative stress that induces apoptosis in many cancer cells in vitro and tumors in vivo. Understanding the mechanism(s) involved in PDT-mediated apoptosis may improve its therapeutic efficacy. Although studies suggest the involvement of multiple pathways, the triggering event(s) responsible for PDT-mediated apoptotic response is(are) not clear. To investigate the role of Bcl-2 in PDT-mediated apoptosis, we employed Bcl-2-antisense and -overexpression approaches in two cell types differing in their responses toward PDT apoptosis. In the first approach, we treated radiation-induced fibrosarcoma (RIF 1) cells, which are resistant to silicon phthalocyanine (Pc 4)-PDT apoptosis, with Bcl-2-antisense oligonucleotide. This treatment resulted in sensitization of RIF 1 cells to PDT-mediated apoptosis as demonstrated by i) cleavage of poly(ADP-ribose) polymerase, ii) DNA ladder formation, iii) terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive cells, and iv) DEVDase activity. This treatment also resulted in oligonucleotide concentration-dependent decrease in cell viability and down-regulation of Bcl-2 protein with a concomitant increase in apoptosis. However, the level of Bax, a pro-apoptotic member of Bcl-2 family, remained unaltered. In the second approach, an overexpression of Bcl-2 in PDT apoptosis-sensitive human epidermoid carcinoma (A431) cells resulted in enhanced apoptosis and up-regulation of Bax following PDT. In both the approaches, the increased Bax/Bcl-2 ratio was associated with an increased apoptotic response of PDT. Our data also demonstrated that PDT results in modulation of other Bcl-2 family members in a way that the overall ratio of pro-apoptotic and anti-apoptotic member proteins favors apoptosis.

  2. ACOMPANHAMENTO CLINICO NUM TUMOR DE CÉLULAS DA GRANULOSA DIAGNOSTICADO EM UMA ÉGUA ATRAVÉS DO ULTRA-SOM

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    Karin Erica Brass

    1994-01-01

    Full Text Available RESUMO Descreve-se o acompanhamento clínico de um caso de tumor de células da granulosa na égua através da ultra-sonografia. Foi constatada uma evolução rápida durante 18 dias para o tumor confirmado, pelo exame macroscópico e histopatológico, após remoção cirúrgica.

  3. 杏仁核点燃鼠海马不同亚区Bax mRNA的表达%The expression of Bax mRNA in the hippocampus-subareas in amygdala-kindled rats

    Institute of Scientific and Technical Information of China (English)

    梁代义; 伍国锋; 庞成

    2006-01-01

    目的:观察细胞凋亡调控基因Bax mRNA在癫(癎)鼠海马不同亚区的表达.方法:利用电极植入鼠脑杏仁核的方法建立点燃癫(癎)模型,采用原位杂交法检测鼠脑海马CA1、CA2、CA3及齿状回(DGL)区Bax mRNA的表达.结果:正常大鼠海马各区少见Bax mRNA阳性细胞表达,杏仁核植入电极大鼠及其点燃后海马各区Bax mRNA表达阳性细胞数增多,点燃鼠Bax mRNA阳性细胞平均光密度高于仅仅植入电极鼠,海马不同亚区Bax mRNA阳性细胞平均光密度值不同.结论:杏仁核点燃癫(癎)模型鼠的海马不同亚区均存在Bax mRNA表达增强,但不同亚区对Bax mRNA表达敏感性不同,以DGL区为最高.

  4. DMFC (3,5-dimethyl-(7)H-furo[3,2-g]chromen-7-one) regulates Bim to trigger Bax and Bak activation to suppress drug-resistant human hepatoma.

    Science.gov (United States)

    Xiang, Jun; Wang, Zhe; Liu, Qianqian; Li, Xia; Sun, Jianguo; Fung, Kwok-Pui; Liu, Feiyan

    2017-03-01

    3,5-Dimethyl-(7)H-furo[3,2-g]chromen-7-one (DMFC) is a coumarin derivative with anti-cancer activity against human hepatoma cells, but the mechanisms underlying DMFC function in cancer suppression is unknown. In this study, we aimed at elucidating the molecular mechanisms underlying DMFC anti-cancer activity and determining whether DMFC is effective in suppression of drug-resistant human hepatocellular carcinoma. We show here that DMFC effectively suppresses both the parent and the multidrug-resistant hepatoma cell growth in vitro and DMFC suppresses hepatoma cell growth at least in part through inducing tumor cell apoptosis. In the molecular level, we observed that DMFC treatment decreases Bcl-2 level by a post-transcriptional mechanism and activates Bim transcription to increase Bim mRNA and protein level in hepatoma cells. Furthermore, co-immunoprecipitation studies revealed that DMFC-induced Bim interrupts interactions between Bcl-2 and Bax and between Mcl-1 and Bak, resulting in dissociation of Bax from Bcl-2 and Bak from Mcl-1 and subsequent activation of both Bax and Bak. Activation of Bax and Bak leads to mitochondrial outer membrane permeabilization and cytochrome c release. Consistent with its potent apoptosis-inducing activity, DMFC exhibited potent activity against the multidrug-resistant hepatoma xenograft growth in vivo. Therefore, we determine that DMFC suppresses hepatoma growth through decreasing Bcl-2 and increasing Bim to induce tumor cell apoptosis and hold great promise for further development as a therapeutic agent to treat chemoresistant hepatoma.

  5. Classificação dos tumores hematopoéticos e linfoides de acordo com a OMS: padronização da nomenclatura em língua portuguesa, 4ª edição Classification of haematopoietic and lymphoid tumors: WHO, standardization of nomenclature in Portuguese, 4th edition

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    Maria Cláudia Nogueira Zerbini

    2011-12-01

    Full Text Available INTRODUÇÃO: A classificação da Organização Mundial da Saúde (OMS para os tumores do tecido hematopoético e linfoide (4ª edição, 2008 representa uma revisão atualização da 3ª edição publicada em 2001. A tradução da nomenclatura utilizada para identificar as entidades descritas deve ser clara, precisa e uniforme no sentido de reproduzir de forma correta as diversas entidades clinicopatológicas para clínicos, patologistas e pesquisadores envolvidos na área da onco-hematopatologia. OBJETIVO: Os autores apresentam uma proposta de atualização e padronização terminológica em língua portuguesa, com base na OMS/2008INTRODUCTION: The World Health Organization (WHO classification of hematopoietic and lymphoid tissue (4th edition, 2008 tumors constitutes an updated review of the 3rd edition published in 2001. The translation of the nomenclature used to describe the entities should be clear, precise and uniform so that clinicians, pathologists and researchers involved in the onco-hematopathological area may identify them accurately. OBJECTIVE: With this purpose, the authors present an updated proposal and a terminological standardization in Portuguese based on WHO/2008

  6. NDV-induced apoptosis in absence of Bax; evidence of involvement of apoptotic proteins upstream of mitochondria

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    Molouki Aidin

    2012-08-01

    Full Text Available Abstract Background Recently it was shown that following infection of HeLa cells with Newcastle disease virus (NDV, the matrix (M protein binds to Bax and subsequently the intrinsic pathway of apoptosis is activated. Moreover, there was very little alteration on mRNA and protein levels of Bax and Bcl-2 after infection with NDV. Finding In order to further investigate the role of members of the Bcl-2 family, Bax-knockout and wild-type HCT116 cells were infected with NDV strain AF2240. Although both cells underwent apoptosis through the activation of the intrinsic pathway and the release of cytochrome c from mitochondria, the percentage of dead Bax-knockout cells was significantly lower than wt cells (more than 10% at 48 h post-infection. In a parallel experiment, the effect of NDV on HT29 cells, that are originally Bcl-2-free, was studied. Apoptosis in HT29 cells was associated with Bax redistribution from cytoplasm to mitochondria, similar to that of HeLa and wt HCT116 cells. Conclusion Although the presence of Bax during NDV-induced apoptosis contributes to a faster cell death, it was concluded that other apoptotic protein(s upstream of mitochondria are also involved since cancer cells die whether in the presence or absence of Bax. Therefore, the classic Bax/Bcl-2 ratio may not be a major determinant in NDV-induced apoptosis.

  7. Imbalanced expression of Bcl-xL and Bax in platelets treated with plasma from immune thrombocytopenia.

    Science.gov (United States)

    Qiao, Jianlin; Liu, Yun; Li, Depeng; Wu, Yulu; Li, Xiaoqian; Yao, Yao; Niu, Mingshan; Fu, Chunling; Li, Hongchun; Ma, Ping; Li, Zhenyu; Xu, Kailin; Zeng, Lingyu

    2016-04-01

    Immune thrombocytopenia is a heterogeneous autoimmune disease, characterized by accelerated platelet destruction and impaired platelet production. Bcl-xL and Bax play an opposite role in the regulation of apoptotic process with Bcl-xL for cell survival and Bax for cell apoptosis. Given the critical roles in the regulation of platelet apoptosis, whether Bcl-xL or Bax was involved in the pathogenesis of ITP remains unknown. The aim of this study is to evaluate the expression profile of Bcl-xL and Bax in platelets treated with ITP plasma. Normal washed platelets were treated with plasma from 20 active ITP patients or 10 age and gender-matched control to mimic the ITP in vivo environment. Mitochondrial depolarization, platelet apoptosis and activation were measured by flow cytometry. Expression of Bcl-xL, Bax and caspase-3 were also measured by quantitative real-time PCR and western blot. Our results demonstrated increased mitochondrial depolarization, platelet apoptosis and activation in platelets after treated with ITP plasma in comparison to control. In addition, decreased expression of Bcl-xL, increased expression of Bax and activity of caspase-3 were also observed. Furthermore, a negative correlation of Bcl-xL with Bax was found in platelets treated with ITP plasma. In conclusion, imbalanced expression of Bcl-xL and Bax might be associated with platelet apoptosis in ITP and therapeutically targeting them might be a novel approach in the treatment of ITP.

  8. Cycloheximide Can Induce Bax/Bak Dependent Myeloid Cell Death Independently of Multiple BH3-Only Proteins.

    Science.gov (United States)

    Goodall, Katharine J; Finch-Edmondson, Megan L; van Vuuren, Joanne; Yeoh, George C; Gentle, Ian E; Vince, James E; Ekert, Paul G; Vaux, David L; Callus, Bernard A

    2016-01-01

    Apoptosis mediated by Bax or Bak is usually thought to be triggered by BH3-only members of the Bcl-2 protein family. BH3-only proteins can directly bind to and activate Bax or Bak, or indirectly activate them by binding to anti-apoptotic Bcl-2 family members, thereby relieving their inhibition of Bax and Bak. Here we describe a third way of activation of Bax/Bak dependent apoptosis that does not require triggering by multiple BH3-only proteins. In factor dependent myeloid (FDM) cell lines, cycloheximide induced apoptosis by a Bax/Bak dependent mechanism, because Bax-/-Bak-/- lines were profoundly resistant, whereas FDM lines lacking one or more genes for BH3-only proteins remained highly sensitive. Addition of cycloheximide led to the rapid loss of Mcl-1 but did not affect the expression of other Bcl-2 family proteins. In support of these findings, similar results were observed by treating FDM cells with the CDK inhibitor, roscovitine. Roscovitine reduced Mcl-1 abundance and caused Bax/Bak dependent cell death, yet FDM lines lacking one or more genes for BH3-only proteins remained highly sensitive. Therefore Bax/Bak dependent apoptosis can be regulated by the abundance of anti-apoptotic Bcl-2 family members such as Mcl-1, independently of several known BH3-only proteins.

  9. A Small-Molecule Inhibitor of Bax and Bak Oligomerization Prevents Genotoxic Cell Death and Promotes Neuroprotection.

    Science.gov (United States)

    Niu, Xin; Brahmbhatt, Hetal; Mergenthaler, Philipp; Zhang, Zhi; Sang, Jing; Daude, Michael; Ehlert, Fabian G R; Diederich, Wibke E; Wong, Eve; Zhu, Weijia; Pogmore, Justin; Nandy, Jyoti P; Satyanarayana, Maragani; Jimmidi, Ravi K; Arya, Prabhat; Leber, Brian; Lin, Jialing; Culmsee, Carsten; Yi, Jing; Andrews, David W

    2017-04-20

    Aberrant apoptosis can lead to acute or chronic degenerative diseases. Mitochondrial outer membrane permeabilization (MOMP) triggered by the oligomerization of the Bcl-2 family proteins Bax/Bak is an irreversible step leading to execution of apoptosis. Here, we describe the discovery of small-molecule inhibitors of Bax/Bak oligomerization that prevent MOMP. We demonstrate that these molecules disrupt multiple, but not all, interactions between Bax dimer interfaces thereby interfering with the formation of higher-order oligomers in the MOM, but not recruitment of Bax to the MOM. Small-molecule inhibition of Bax/Bak oligomerization allowed cells to evade apoptotic stimuli and rescued neurons from death after excitotoxicity, demonstrating that oligomerization of Bax is essential for MOMP. Our discovery of small-molecule Bax/Bak inhibitors provides novel tools for the investigation of the mechanisms leading to MOMP and will ultimately facilitate development of compounds inhibiting Bax/Bak in acute and chronic degenerative diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Bone tumor

    Science.gov (United States)

    Tumor - bone; Bone cancer; Primary bone tumor; Secondary bone tumor; Bone tumor - benign ... The cause of bone tumors is unknown. They often occur in areas of the bone that grow rapidly. Possible causes include: Genetic defects ...

  11. Estudos in vitro e in vivo de análogo da timidina marcada com complexo organometálico de tecnécio-99m para potencial uso em diagnóstico tumoral Studies in vitro and in vivo of thymidine analog labeled with organometalic complex of technetium-99m for potential use in tumor diagnosis

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    Rodrigo Luis Silva Ribeiro Santos

    2008-03-01

    Full Text Available Análogos da timidina têm sido marcados com diferentes radioisótopos devido ao seu potencial em monitorar a proliferação incontrolável de células. Considerando que o radioisótopo tecnécio-99m ainda mantém uma posição privilegiada devido às suas propriedades químicas e nucleares, este trabalho constituiu-se no desenvolvimento da marcação da timidina com o 99mTc, mediante o emprego de compostos organometálicos. Os objetivos principais foram a síntese do precursor carbonil-tecnécio-99m, marcação da timidina com este precursor, estudo da estabilidade, e avaliações radioquímicas e biológicas com animais sadios e portadores de tumor. A síntese do precursor organometálico e a marcação da timidina com este precursor foi realizada com > 97% e > 94% de pureza radioquímica, respectivamente, obtendo-se também uma boa estabilidade em até 6 h em temperatura ambiente. A transquelação frente aos aminoácidos cisteína e histidina apresentou perdas entre 8 e 11% para concentrações de até 300 mM. Os ensaios de biodistribuição em camundongos sadios indicaram que o complexo radiomarcado apresentou um rápido depuramento sangüíneo e baixa captação nos demais órgãos, com predominância de excreção da droga pelo sistema urinário e hepatobiliar. A captação tumoral foi de 0,28 e 0,18 %DI/g para tumor de pulmão e mama, respectivamente. Os resultados obtidos sugerem maiores investigações em outros análogos da timidina.Thymidine analogs have been labeled with different radioisotopes due to their potential in monitoring the uncontrollable cell proliferation. Considering that the radioisotope technetium-99m still keeps a privileged position as a marker due to its chemical and nuclear properties, this work was designed to develop a new technique of labeling of thymidine analog with 99mTc, by means of the organometallic compounds. The aims of this research were: synthesis of the organometallic precursor technetium-99m

  12. Canine malignant peripheral nerve sheath tumor involving nerve roots of the third lumbar spinal cord segmentTumor maligno da bainha de nervo periférico envolvendo raízes nervosas do terceiro segmento medular lombar em um cão

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    Elisângela Olegário da Silva

    2012-12-01

    Full Text Available Malignant peripheral nerve sheath tumors (MPNST involving spinal nerve roots are uncommon in dogs. A nine-year old, intact, mixed-breed dog, demonstrated clinical signs of incoordination in the pelvic limbs and micturition for approximately one week. Clinical examination revealed proprioceptive deficits and bilateral patellar hyperreflexia. During exploratory celiotomy a mass was observed adhered to the lumbar vertebral segments. Medical therapy was initiated, but neurological signs were progressive, and the owner opted for euthanasia. Gross examination showed that the mass in the abdominal cavity was attached to the lumbar segments L3 and L4, causing bone lysis in L3, but showed no tumor invasion into the spinal canal. Microscopic features were characterized by prominent proliferation of ovoid and fusiform cells with poorly defined cytoplasm arranged in interlacing bundles and concentric whorls. The cells were embedded in a delicate to moderate collagenous stroma and moderate anisokariose and high mitotic activity were noted. The immunohistochemical assay showed positive staining for GFAP, S-100 protein and vimentin, and negative staining for factor VIII, ?-actin and citokeratine. The definitive diagnosis of malignant peripheral nerve sheath tumor was made on the basis of the histological and immunohistochemical findings. Tumores malignos da bainha de nervo periférico (TMBNP em raízes nervosas espinhais são incomuns em cães. Relata-se o caso de um cão, sem raça definida, nove anos de idade, não castrado, com histórico de incoordenação em membros pélvicos e retenção urinária há aproximadamente uma semana. Ao exame clínico constatou-se déficit proprioceptivo e hiperreflexia patelar bilaterais. Durante a celiotomia exploratória constatou-se uma massa intensamente vascularizada e aderida aos segmentos vertebrais lombares. Estabeleceu-se plano terapêutico e o animal foi tratado com fluidoterapia, anti-inflamatório e analg

  13. A BAX/BAK and cyclophilin D-independent intrinsic apoptosis pathway.

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    Sebastián Zamorano

    Full Text Available Most intrinsic death signals converge into the activation of pro-apoptotic BCL-2 family members BAX and BAK at the mitochondria, resulting in the release of cytochrome c and apoptosome activation. Chronic endoplasmic reticulum (ER stress leads to apoptosis through the upregulation of a subset of pro-apoptotic BH3-only proteins, activating BAX and BAK at the mitochondria. Here we provide evidence indicating that the full resistance of BAX and BAK double deficient (DKO cells to ER stress is reverted by stimulation in combination with mild serum withdrawal. Cell death under these conditions was characterized by the appearance of classical apoptosis markers, caspase-9 activation, release of cytochrome c, and was inhibited by knocking down caspase-9, but insensitive to BCL-X(L overexpression. Similarly, the resistance of BIM and PUMA double deficient cells to ER stress was reverted by mild serum withdrawal. Surprisingly, BAX/BAK-independent cell death did not require Cyclophilin D (CypD expression, an important regulator of the mitochondrial permeability transition pore. Our results suggest the existence of an alternative intrinsic apoptosis pathway emerging from a cross talk between the ER and the mitochondria.

  14. Label-Free Classification of Bax/Bak Expressing vs. Double-Knockout Cells.

    Science.gov (United States)

    Naser, Mohammad; Graham, Michelle T; Pierre, Kamau; Boustany, Nada N

    2016-11-01

    We combine optical scatter imaging with principal component analysis (PCA) to classify apoptosis-competent Bax/Bak-expressing, and apoptosis resistant Bax/Bak-null immortalized baby mouse kidney cells. We apply PCA to 100 stacks each containing 236 dark-field cell images filtered with an optically implemented Gabor filter with period between 0.3 and 2.9 μm. Each stack yields an "eigencell" image corresponding to the first principal component obtained at one of the 100 Gabor filter periods used. At each filter period, each cell image is multiplied by (projected onto) the eigencell image. A Feature Matrix consisting of 236 × 100 scalar values is thus constructed with significantly reduced dimension compared to the initial dataset. Utilizing this Feature Matrix, we implement a supervised linear discriminant analysis and classify successfully the Bax/Bak-expressing and Bax/Bak-null cells with 94.7% accuracy and an area under the curve (AUC) of 0.993. Applying a feature selection algorithm further reveals that the Gabor filter period ranges most significant for the classification correspond to both large (likely nuclear) features as well as small sized features (likely organelles present in the cytoplasm). Our results suggest that cells with a genetic defect in their apoptosis pathway can be differentiated from their normal counterparts by label-free multi-parametric optical scatter data.

  15. Conformational Rearrangements in the Pro-apoptotic Protein, Bax, as It Inserts into Mitochondria

    Science.gov (United States)

    Gahl, Robert F.; He, Yi; Yu, Shiqin; Tjandra, Nico

    2014-01-01

    The B-cell lymphoma 2 (Bcl-2) family of proteins regulates the activation of apoptosis through the mitochondria pathway. Pro- and anti-apoptotic members of this family keep each other in check until the correct time to commit to apoptosis. The point of no return for this commitment is the permeabilization of the outer mitochondrial membrane. Translocation of the pro-apoptotic member, Bax, from the cytosol to the mitochondria is the molecular signature of this event. We employed a novel method to reliably detect Förster resonance energy transfer (FRET) between pairs of fluorophores to identify intra-molecular conformational changes and inter-molecular contacts in Bax as this translocation occurs in live cells. In the cytosol, our FRET measurement indicated that the C-terminal helix is exposed instead of tucked away in the core of the protein. In addition fluorescence correlation spectroscopy (FCS) showed that cytosolic Bax diffuses much slower than expected, suggesting possible complex formation or transient membrane interaction. Cross-linking the C-terminal helix (α9) to helix α4 reduced the potential of those interactions to occur. After translocation, our FRET measurements showed that Bax molecules form homo-oligomers in the mitochondria through two distinct interfaces involving the BH3 domain (helix α2) and the C-terminal helix. These findings have implications for possible contacts with other Bcl-2 proteins necessary for the regulation of apoptosis. PMID:25315775

  16. Wheat BAX inhibitor-1 contributes to wheat resistance to Puccinia striiformis

    Science.gov (United States)

    BAX inhibitor-1 (BI-1) is proposed to be a cell death suppressor conserved in both animals and plants. The ability of BI-1 genes to inhibit programmed cell death (PCD) has been well studied in animals, but the physiological importance of BI-1 in plant-microbe interactions remains unclear. This study...

  17. cBid, Bax and Bcl-xL exhibit opposite membrane remodeling activities

    Science.gov (United States)

    Bleicken, S; Hofhaus, G; Ugarte-Uribe, B; Schröder, R; García-Sáez, A J

    2016-01-01

    The proteins of the Bcl-2 family have a crucial role in mitochondrial outer membrane permeabilization during apoptosis and in the regulation of mitochondrial dynamics. Current models consider that Bax forms toroidal pores at mitochondria that are responsible for the release of cytochrome c, whereas Bcl-xL inhibits pore formation. However, how Bcl-2 proteins regulate mitochondrial fission and fusion remains poorly understood. By using a systematic analysis at the single vesicle level, we found that cBid, Bax and Bcl-xL are able to remodel membranes in different ways. cBid and Bax induced a reduction in vesicle size likely related to membrane tethering, budding and fission, besides membrane permeabilization. Moreover, they are preferentially located at highly curved membranes. In contrast, Bcl-xL not only counterbalanced pore formation but also membrane budding and fission. Our findings support a mechanism of action by which cBid and Bax induce or stabilize highly curved membranes including non-lamellar structures. This molecular activity reduces the energy for membrane remodeling, which is a necessary step in toroidal pore formation, as well as membrane fission and fusion, and provides a common mechanism that links the two main functions of Bcl-2 proteins. PMID:26913610

  18. [Influence of TIEG1 on apoptosis of HL-60 cells and expression of Bcl-2/Bax].

    Science.gov (United States)

    Yao, Kun; Yang, Ying; Hu, Rong; Miao, Miao; Liao, Ai-Jun; Yang, Wei; Liu, Zhuo-Gang

    2013-06-01

    This study was aimed to investigate the influence of TIEG1 on apoptosis of HL-60 cells and the expression of Bcl-2/Bax. Different concentration of TIEG1 were used to treat HL-60 cells, the cell growth inhibition rate was detected by MTT method. After treating HL-60 cells with 12.03 ng/ml TIEG1, cell apoptosis was detected with flow cytometry. Bcl-2 and Bax was detected with RT-PCR. The results showed that TIEG1 had inhibitory effect on HL-60 cell proliferation, and in time-and dose-dependent manners. The more obvious inhibitory effect was observed in HL-60 cells treated with TIEG1 of 12.03 ng/ml. During the course of cell apoptosis, Bax expression increased, but Bcl-2 expression decreased (P HL-60 cell proliferation and induces apoptosis in time and dose-dependent manners. During the course of HL-60 cells apoptosis induced by TIEG1, Bcl-2/Bax are associated with HL-60 cell apoptosis induced by TIEG1.

  19. Inotodiol inhabits proliferation and induces apoptosis through modulating expression of cyclinE, p27, bcl-2, and bax in human cervical cancer HeLa cells.

    Science.gov (United States)

    Zhao, Li-Wei; Zhong, Xiu-Hong; Yang, Shu-Yan; Zhang, Yi-Zhong; Yang, Ning-Jiang

    2014-01-01

    Inonotus obliquus is a medicinal mushroom that has been used as an effective agent to treat various diseases such as diabetes, tuberculosis and cancer. Inotodiol, an included triterpenoid shows significant anti-tumor effect. However, the mechanisms have not been well documented. In this study, we aimed to explore the effect of inotodiol on proliferation and apoptosis in human cervical cancer HeLa cells and investigated the underlying molecular mechanisms. HeLa cells were treated with different concentrations of inotodiol. The MTT assay was used to evaluate cell proliferating ability, flow cytometry (FCM) was employed for cell cycle analysis and cell apoptosis, while expression of cyclinE, p27, bcl-2 and bax was detected by immunocytochemistry. Proliferation of HeLa cells was inhibited by inotodiolin a dose-dependent manner at 24h (r=0.9999, pHeLa cells was detected after treatment and the apoptosis rate with the concentration and longer incubation time (r=1.0, pHeLa cells and induced apoptosis in vitro. The mechanisms may be related to promoting apoptosis through increasing the expression of bax and cutting bcl-2 and affecting the cell cycle by down-regulation the expression of cyclin E and up-regulation of p27. The results further indicate the potential value of inotodiol for treatment of human cervical cancer.

  20. Computed tomography of mast cell tumors in dogs: assessment before and after chemotherapy; Tomografia computadorizada de mastocitomas em caes: avaliacao pre e pos-tratamento quimioterapico

    Energy Technology Data Exchange (ETDEWEB)

    Lorigados, Carla A.B.; Matera, Julia Maria; Pinto, Ana Carolina B.C.F.; Macedo, Thais R., E-mail: clorigados@usp.br [Universidade de Sao Paulo (FMVZ/USP), SP (Brazil). Fac. de Medicina Veterinaria e Zootecnia. Dept. de Cirurgia; Coppi, Antonio A.; Ladd, Fernando V.L. [Universidade de Sao Paulo (LSSCA/USP), SP (Brazil). Fac. de Medicina Veterinaria e Zootecnia. Lab. de Estereologia Estocastica e Anatomia Quimica; Souza, Vanessa A.F. de [Faculdades Metropolitanas Unidas (FMU), Sao Paulo, SP (Brazil). Curso de Medicina Veterinaria

    2013-11-15

    Nineteen dogs with mast cell tumors treated with chemotherapy were evaluated by computed tomography (CT). Were evaluated aspects related to contours, attenuation, postcontrast enhancement and presence of cleavage with adjacent structures. The RECIST criteria and volumetric measurement of lesions were performed to assess the response to treatment. The mast cell tumors presented a homogeneous or heterogeneous attenuation, presented more frequently a well delineated and regular contours and moderate enhancement after intravenous administration of the iodinated contrast media. The methods RECIST and volumetric measurements showed an excellent agreement to the classification of therapeutic response, providing a good parameter of the response to treatment. The CT examination proved to be useful in the delimitation of the tumor and an important tool for planning of surgical margins. (author)

  1. Influência dos níveis de prolactina e tamanho tumoral na função hipofisária pós-operatória em macroadenomas hipofisários clinicamente não-funcionantes Influence of hyperprolactinemia and tumoral size in the postoperative pituitary function in clinically nonfuncioning pituitary macroadenomas

    Directory of Open Access Journals (Sweden)

    Ana Luiza Vidal Fonseca

    2002-09-01

    Full Text Available OBJETIVO: Estudar a influência da hiperprolactinemia e de tamanho tumoral na função hipofisária em macroadenomas hipofisários clinicamente não funcionantes. MÉTODOS: Foram analisados 23 pacientes com macroadenomas hipofisários clinicamente não funcionantes, com exames de imagem (tomografia computadorizada ou ressonância magnética e dosagens hormonais basais; 16 tinham provas de função hipotálamo-hipofisária (megateste pré-operatórios. Todos os tumores tiveram diagnóstico histológico e em 17 foi realizado também estudo imuno-histoquímico para os hormônios adeno-hipofisários. A análise estatística foi feita por meio dos testes t de Student, qui-quadrado, exato de Fisher e de Mc Neman. O nível de significância adotado foi 5% (pOBJECTIVE: To study the influence of hyperprolactinemia and tumoral size in the pituitary function in clinically nonfuncioning pituitary macroadenomas. METHODS: Twenty three patients with clinically nonfuncioning pituitary macroadenomas were evaluated by image studies (computed tomography or magnetic resonance and basal hormonal level; 16 had preoperative hypothalamus-hypophysial function tests (megatests. All tumors had histological diagnosis and in seventeen immunohistochemical study for adenohypophysial hormones was also performed. Student's t test, chi square test, exact test of Fisher and Mc Neman test were used for the statistics analysis . The level of significance adopted was 5% (p<0.05. RESULTS: Tumoral diameter varied of 1.1 to 4.7 cm (average=2.99 cm ± 1.04. In the preoperative, 5 (21.7% patients did not show laboratorial hormonal deficit, 9 (39.1% developed hyperprolactinemia, 13 (56,5% normal levels of prolactin (PRL and 1 (4.3% subnormal; 18 (78.3% patients developed hypopituitarism (4 pan-hypopituitarism. Nineteen patients (82.6% underwent transsfenoidal approach, 3 (13% craniotomy and 1 (4.4% combined access. Only 6 patients had total tumoral resection. Of the 17 immunohistochemical

  2. Estratégias para aumentar a ressecabilidade em pacientes com metástases hepáticas de tumores colorretais Strategies to increase resected liver metastases in patients with colorectal tumors

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    Marcos Vinicius Perini

    2011-12-01

    Full Text Available INTRODUÇÃO: Atualmente, as ressecções hepáticas podem ser realizadas com taxas aceitáveis de morbimortalidade. Em centros especializados, mortalidade ao redor de 1% pode ser alcançada, mesmo em fígados previamente submetidos à quimioterapia por longo prazo. Com o objetivo de reduzir essas taxas, novas estratégias têm sido empregadas, como a embolização portal, ablação por radiofrequência, re-hepatectomias ressecções vasculares com reconstrução e hepatectomias em dois tempos. MÉTODO: Foi realizada revisão de literatura nos sites de pesquisa PubMed, Bireme e Scielo, com os descritores "hepatectomias parciais, metástases, neoplasia colorretal, radiofrequência e embolização". Selecionaram-se, principalmente, os estudos de aplicação de técnicas e procedimentos cirúrgicos no tratamento das metástases hepáticas. CONCLUSÃO: Sobrevida ao redor de 50% em cinco anos podem ser conseguidas em casos selecionados quando equipe multidisciplinar está envolvida no tratamento. Com a melhora na técnica operatória, poupando-se parênquima hepático, e com o advento de novos agentes quimioterápicos, lesões metastáticas hepáticas irressecáveis podem se tornar ressecáveis e a sobrevida a longo prazo pode ser alcançada.INTRODUCTION: Nowadays, liver resections can be performed with acceptable morbi-mortality rates. In specialized centers, mortality as low as 1% can be achieved, even with the advent of new hepatotoxic chemotherapy regimens. In order to reduce morbidity and mortality, newer strategies can be undertaken, such as portal vein embolization, radiofrequency ablation techniques, re-hepatectomies, major vascular resections and two stages hepatectomies. METHOD: Literature review was conducted on sites search PubMed, BIREME, SciELO, with the headings "partial hepatectomy, hepatic metastases, colorectal cancer, radiofrequency and embolization". Were selected mainly studies with the application of techniques and surgical

  3. A Single Nucleotide Polymorphism in the Bax Gene Promoter Affects Transcription and Influences Retinal Ganglion Cell Death

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    Sheila J Semaan

    2010-03-01

    Full Text Available Pro-apoptotic Bax is essential for RGC (retinal ganglion cell death. Gene dosage experiments in mice, yielding a single wild-type Bax allele, indicated that genetic background was able to influence the cell death phenotype. DBA/2J Bax+/− mice exhibited complete resistance to nerve damage after 2 weeks (similar to Bax −/− mice, but 129B6 Bax+/− mice exhibited significant cell loss (similar to wild-type mice. The different cell death phenotype was associated with the level of Bax expression, where 129B6 neurons had twice the level of endogenous Bax mRNA and protein as DBA/2J neurons. Sequence analysis of the Bax promoters between these strains revealed a single nucleotide polymorphism (T129B6 to CDBA/2J at position −515. A 1.5- to 2.5-fold increase in transcriptional activity was observed from the 129B6 promoter in transient transfection assays in a variety of cell types, including RGC5 cells derived from rat RGCs. Since this polymorphism occurred in a p53 half-site, we investigated the requirement of p53 for the differential transcriptional activity. Differential transcriptional activity from either 129B6 or DBA/2J Bax promoters were unaffected in p53−/− cells, and addition of exogenous p53 had no further effect on this difference, thus a role for p53 was excluded. Competitive electrophoretic mobility-shift assays identified two DNA-protein complexes that interacted with the polymorphic region. Those forming Complex 1 bound with higher affinity to the 129B6 polymorphic site, suggesting that these proteins probably comprised a transcriptional activator complex. These studies implicated quantitative expression of the Bax gene as playing a possible role in neuronal susceptibility to damaging stimuli.

  4. Computed tomography in the analysis of calcification patterns in pediatric bone tumors of the hip: a new approach; Tomografia computadorizada na analise dos padroes de calcificacoes nos tumores osseos da bacia em pediatria: nova abordagem

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Gabriel Antonio de; Werlang, Henrique Zambenedetti; Bergoli, Pedro Martins [Hospital Universitario Cassiano Antonio de Morais/Hospital Infantil Nossa Senhora da Gloria, Vitoria, ES (Brazil). Centro de Diagnostico por Imagem]. E-mail: hzwerlang@gmail.com; Frechiani, Madalena; Oliveira, Fernao [Hospital Infantil Nossa Senhora da Gloria, Vitoria, ES (Brazil)

    2006-11-15

    Objective: In the pediatric group, the radiological diagnosis of bone tumors of the hip is difficult and presents some peculiarities, but reviewed literature does not approach this specific problem. The objective of the present study was to investigate the existence of reliable radiological patterns for the differential diagnosis of these tumors. Materials And Methods: Radiological findings of bone tumors of the hip in ten patients in the age range between 8 and 19 years have been reviewed. Results: Bone reaction (sclerosis or lysis), periosteal reaction (lamellar with single or multiple layers, or radial), tumor extent in the bone and level of soft tissues invasion have presented low specificity. Soft tissue calcifications, when considered as a whole, were non-specific. However, when those calcifications with varied shapes and sizes, nearby the affected bone (pattern I) were separated from those, thin and amorphous, away from the bone (pattern II), we have observed that the pattern I was totally non-specific, and the pattern II was found in the three cases of osteosarcoma (100%) and in only one case of Ewing's sarcoma (16.6%). Conclusion: In the present study, pattern II calcifications have shown a 100% sensitivity and 90% specificity for osteosarcoma. However, their importance may be not limited to the radiological diagnosis. Pattern II calcifications indicate probably ideal sites for biopsy. (author)

  5. Galectina-3 em tumores de próstata: imuno-histoquímica e análise digital de imagens Galectin-3 in prostatic tumours: immunohistochemistry and digital image analysis

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    Jorge Luiz Silva Araújo-Filho

    2006-12-01

    Full Text Available A imuno-histoquímica é uma técnica de grande ajuda no diagnóstico de doenças da próstata, incluindo os tumores. De igual importância, a análise digital de imagens vem sendo cada vez mais utilizada em estudos de alterações na próstata. O presente estudo teve como objetivo quantificar morfometricamente a expressão da galectina-3 através da imuno-histoquímica em tecidos de próstata normal (PN, hiperplasia benigna da próstata (HPB e adenocarcinoma prostático (AP. Fragmentos cirúrgicos de tecido prostático com AP (n = 10, HPB (n = 12 e PN (n = 10 foram fixados em formalina, submetidos à rotina histológica e embebidos em parafina. Foram feitos cortes histológicos (4µm montados em lâminas e corados com hematoxilina e eosina (HE para confirmar o diagnóstico. As amostras teciduais selecionadas foram incubadas com anticorpo monoclonal antigalectina-3 por uma hora em temperatura ambiente (37ºC e então incubadas com um anticorpo secundário. A revelação foi realizada após incubação com diaminobenzidina (DAB e peróxido de hidrogênio. A análise morfométrica foi realizada mediante uma estação de análise digital de imagens, que consiste num microscópio óptico acoplado a uma câmera digital ligada a um computador equipado com o software de análise OPTIMAS®. Nas células de adenocarcinoma foi observada diminuição significativa na marcação (p Immunohistochemistry helps pathologists in the diagnosis of prostatic diseases, mainly carcinomas. Equally important, digital image analysis is being increasingly used to study alterations in the prostate. The present work aims to morphometrically quantify the immunostain of galectin-3 expressed in normal prostate (NP, benign hyperplasia (BH and prostatic adenocarcinoma (PA in humans. Immunohistochemistry was developed using monoclonal anti-galectin-3 antibody. Surgical specimens from different patients with BH (n = 12, PA (n = 10 and NP (n = 10 were fixed in formalin, processed

  6. Effect of Bcl-2 and Bax on survival of side population cells from hepatocellular carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To understand the role and significance of side population (SP) cells from hepatocellular carcinoma (HCC) in hepatocarcinogenesis, development, relapse and metastasis, we simulated the denutrition conditions that cancer cells experience in clinical therapy, observed the different anti-apoptosis ability of SP cells and non-SP cells under such conditions, and established the possible effects of P53, Bcl-2 and Bax on survival of SP cells.METHODS: We used flow cytometry to analyze and sort the SP and non-SP cells in established HCC lines MHCC97and hHCC. We evaluated cell proliferation by methyl thiazolyl tetrazolium (MTT) assay and investigated the expression of p53, bd-2 and bax genes during denutrition,by RT-PCR and immunofluorescence staining.RESULTS: The percentage of SP cells in the two established HCC lines was 0.25% and 0.5%, respectively.SP cells had greater anti-apoptosis and proliferation ability than non-SP cells. Expression of Bcl-2 and Bax in SP and non-SP cells differed during denutrition. The former was up-regulated in SP cells, and the latter was up-regulated in non-SP cells.CONCLUSION: It may be that different upstream molecules acted and led to different expression levels of Bcl-2 and Bax in these two cell lines. There was a direct relationship between up-regulation of Bcl-2 and down-regulation of Bax and higher anti-apoptosis ability in SP cells. It may be that the existence and activity of SP cells are partly responsible for some of the clinical phenomena which are seen in HCC, such as relapse or metastasis. Further research on SP cells may have potential applications in the field of anticancer therapy.

  7. WNT signaling controls expression of pro-apoptotic BOK and BAX in intestinal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zeilstra, Jurrit; Joosten, Sander P.J. [Department of Pathology, Academic Medical Center, University of Amsterdam (Netherlands); Wensveen, Felix M. [Department of Experimental Immunology, Academic Medical Center, Amsterdam (Netherlands); Dessing, Mark C.; Schuetze, Denise M. [Department of Pathology, Academic Medical Center, University of Amsterdam (Netherlands); Eldering, Eric [Department of Experimental Immunology, Academic Medical Center, Amsterdam (Netherlands); Spaargaren, Marcel [Department of Pathology, Academic Medical Center, University of Amsterdam (Netherlands); Pals, Steven T., E-mail: s.t.pals@amc.uva.nl [Department of Pathology, Academic Medical Center, University of Amsterdam (Netherlands)

    2011-03-04

    Research highlights: {yields} Intestinal adenomas initiated by aberrant activation of the WNT pathway displayed an increased sensitivity to apoptosis. {yields} Expression profiling of apoptosis-related genes in Apc{sup Min/+} mice revealed the differential expression of pro-apoptotic Bok and Bax. {yields} APC-mutant adenomatous crypts in FAP patients showed strongly increased BAX immunoreactivity. {yields} Blocking of {beta}-catenin/TCF-4-mediated signaling in colon cancer cells reduced the expression of BOK and BAX. -- Abstract: In a majority of cases, colorectal cancer is initiated by aberrant activation of the WNT signaling pathway. Mutation of the genes encoding the WNT signaling components adenomatous polyposis coli or {beta}-catenin causes constitutively active {beta}-catenin/TCF-mediated transcription, driving the transformation of intestinal crypts to cancer precursor lesions, called dysplastic aberrant crypt foci. Deregulated apoptosis is a hallmark of adenomatous colon tissue. However, the contribution of WNT signaling to this process is not fully understood. We addressed this role by analyzing the rate of epithelial apoptosis in aberrant crypts and adenomas of the Apc{sup Min/+} mouse model. In comparison with normal crypts and adenomas, aberrant crypts displayed a dramatically increased rate of apoptotic cell death. Expression profiling of apoptosis-related genes along the crypt-villus axis and in Apc mutant adenomas revealed increased expression of two pro-apoptotic Bcl-2 family members in intestinal adenomas, Bok and Bax. Analysis of the colon of familial adenomatous polyposis (FAP) patients along the crypt-to-surface axis, and of dysplastic crypts, corroborated this expression pattern. Disruption of {beta}-catenin/TCF-4-mediated signaling in the colorectal cancer cell line Ls174T significantly decreased BOK and BAX expression, confirming WNT-dependent regulation in intestinal epithelial cells. Our results suggest a feedback mechanism by which

  8. Bax and Bcl-2 are focally overexpressed in the normal epithelium of cancerous prostates.

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    Tolonen, Teemu T; Tommola, Satu; Jokinen, Samuli; Parviainen, Tiina; Martikainen, Paula M

    2007-01-01

    Development of prostate cancer is connected with a disturbance of apoptosis. Prostate cancer is multifocal, suggesting that the control of apoptosis is impaired at multiple foci. We wanted to know whether apoptosis is generally disturbed in cancerous prostates and if changes in apoptotic control could be detected even in the absence of any morphologically visible changes. Therefore, we compared expression of two common apoptotic markers, Bax and Bcl-2, in normal epithelium of cancerous prostates and controls. We also evaluated the expression of these proteins in hyperplasia, prostatic intraepithelial neoplasia (PIN), carcinomas of different Gleason grades and capsular perineural invasion. The tissue material was obtained from radical prostatectomies, transurethral resection chips and autopsies. Individual tissue arrays were done for each patient. The intensity of Bax and Bcl-2 immunostaining was estimated semiquantitatively. The data were analyzed using a linear mixed-models analysis as well as dichotomized staining indices. Normal epithelium of cancerous prostates contained foci with high expression of Bax and Bcl-2. The expression of Bax in Gleason grades 3-5 carcinoma was significantly higher than that in Gleason grade 2, and was highest in foci with perineural invasion. The expression of Bcl-2 was strongest in PIN foci. Expression of Bax and Bcl-2 in normal epithelium of cancerous prostates suggests that increases in these indirect markers may reflect altered apoptotic control in these foci. Further studies are needed to show whether these changes represent the earliest step of the multifocal carcinogenetic process. Control of apoptosis seems to be involved and modulated during local progression of prostate cancer.

  9. Zerumbone induced apoptosis in liver cancer cells via modulation of Bax/Bcl-2 ratio

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    Azimahtol Hawariah LP

    2007-04-01

    Full Text Available Abstract Background Zerumbone is a cytotoxic component isolated from Zingiber zerumbet Smith, a herbal plant which is also known as lempoyang. This new anticancer bioactive compound from Z. zerumbet was investigated for its activity and mechanism in human liver cancer cell lines. Results Zerumbone significantly showed an antiproliferative activity upon HepG2 cells with an IC50 of 3.45 ± 0.026 μg/ml. Zerumbone was also found to inhibit the proliferation of non-malignant Chang Liver and MDBK cell lines. However the IC50 obtained was higher compared to the IC50 for HepG2 cells (> 10 μg/ml. The extent of DNA fragmentation was evaluated by the Tdt-mediated dUTP nick end labelling assay which showed that, zerumbone significantly increased apoptosis in HepG2 cells in a time-course manner. In detail, the apoptotic process triggered by zerumbone involved the up-regulation of pro-apoptotic Bax protein and the suppression of anti-apoptotic Bcl-2 protein expression. The changes that occurred in the levels of this antagonistic proteins Bax/Bcl-2, was independent of p53 since zerumbone did not affect the levels of p53 although this protein exists in a functional form. Western blotting analysis for Bax protein was further confirmed qualitatively with an immunoassay that showed the distribution of Bax protein in zerumbone-treated cells. Conclusion Therefore, zerumbone was found to induce the apoptotic process in HepG2 cells through the up and down regulation of Bax/Bcl-2 protein independently of functional p53 activity.

  10. Apoptosis through Bcl-2/Bax and Cleaved Caspase Up-Regulation in Melanoma Treated by Boron Neutron Capture Therapy

    Science.gov (United States)

    Faião-Flores, Fernanda; Coelho, Paulo Rogério Pinto; Toledo Arruda-Neto, João Dias; Maria-Engler, Silvya Stuchi; Tiago, Manoela; Capelozzi, Vera Luiza; Giorgi, Ricardo Rodrigues; Maria, Durvanei Augusto

    2013-01-01

    Boron neutron capture therapy (BNCT) is a binary treatment involving selective accumulation of boron carriers in a tumor followed by irradiation with a thermal or epithermal neutron beam. The neutron capture reaction with a boron-10 nucleus yields high linear energy transfer (LET) particles, alpha and 7Li, with a range of 5 to 9 µm. These particles can only travel very short distances and release their damaging energy directly into the cells containing the boron compound. We aimed to evaluate proliferation, apoptosis and extracellular matrix (ECM) modifications of B16F10 melanoma and normal human melanocytes after BNCT. The amounts of soluble collagen and Hsp47, indicating collagen synthesis in the ECM, as well as the cellular markers of apoptosis, were investigated. BNCT decreased proliferation, altered the ECM by decreasing collagen synthesis and induced apoptosis by regulating Bcl-2/Bax in melanoma. Additionally, BNCT also increased the levels of TNF receptor and the cleaved caspases 3, 7, 8 and 9 in melanoma. These results suggest that multiple pathways related to cell death and cell cycle arrest are involved in the treatment of melanoma by BNCT. PMID:23527236

  11. Apoptosis through Bcl-2/Bax and cleaved caspase up-regulation in melanoma treated by boron neutron capture therapy.

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    Fernanda Faião-Flores

    Full Text Available Boron neutron capture therapy (BNCT is a binary treatment involving selective accumulation of boron carriers in a tumor followed by irradiation with a thermal or epithermal neutron beam. The neutron capture reaction with a boron-10 nucleus yields high linear energy transfer (LET particles, alpha and (7Li, with a range of 5 to 9 µm. These particles can only travel very short distances and release their damaging energy directly into the cells containing the boron compound. We aimed to evaluate proliferation, apoptosis and extracellular matrix (ECM modifications of B16F10 melanoma and normal human melanocytes after BNCT. The amounts of soluble collagen and Hsp47, indicating collagen synthesis in the ECM, as well as the cellular markers of apoptosis, were investigated. BNCT decreased proliferation, altered the ECM by decreasing collagen synthesis and induced apoptosis by regulating Bcl-2/Bax in melanoma. Additionally, BNCT also increased the levels of TNF receptor and the cleaved caspases 3, 7, 8 and 9 in melanoma. These results suggest that multiple pathways related to cell death and cell cycle arrest are involved in the treatment of melanoma by BNCT.

  12. Mutações no gene TP53 em tumores malignos de mama: associação com fatores de risco e características clínico-patológicas, inclusive risco de óbito, em pacientes residentes no Rio de Janeiro TP53 mutation in malignant breast tumors: association with risk factors and clinical-pathological characteristics, including risk of death, in patients from Rio de Janeiro

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    Claudia Vitória de Moura-Gallo

    2004-06-01

    Full Text Available No Brasil, o câncer de mama é a primeira causa de óbito por câncer entre mulheres, sendo o Rio de Janeiro o Estado que apresenta o maior coeficiente de mortalidade do país. Estudos que avaliam a sobrevida por câncer de mama têm indicado que vários fatores de ordem genética e molecular podem influenciar a evolução dos casos. O objetivo deste trabalho foi descrever mutações no gene TP53 em 120 pacientes com diagnóstico de carcinoma invasivo de mama, recrutadas no Instituto Nacional de Câncer (INCA, Rio de Janeiro, entre 1995 a 1997, e analisar as possíveis associações entre fatores de risco e presença de mutação e entre características do tumor, incluindo estas mutações e o risco de óbito. A análise molecular detectou 24 mutações no gene TP53 em 22 casos (18,3%, sendo que 2 casos apresentaram 2 mutações cada e, em um caso observamos o polimorfismo no éxon 6. As mutações encontradas eram: 14 com troca de sentido; 2 sem sentido; 2 silenciosas; 2 deleções; 1 inserção e 3 localizadas em íntron. Em relação aos fatores de risco estudados em associação à presença de mutação, observou-se que apenas o consumo de tabaco mostrou associação negativa (OR ajustado= 0,24 (0,06-0,88. A análise multivariada utilizada para avaliar as características tumorais associadas ao risco de óbito mostrou que apenas a agressividade do tumor apresentou OR indicativo de risco (3,98, IC 95% 1,25-12,72. Estes resultados corroboram outros estudos que mostram que a mutação no gene TP53 pode ser um indicador de tumores de mama biologicamente mais agressivos, apesar de não ser o único parâmetro a ser considerado.Breast cancer is the leading cause of death due to cancer among women in Brazil and, the State of Rio de Janeiro presents the highest mortality coefficient of this disease in the country. Studies have shown that many genetic and molecular factors may be related to the outcome of cases. The aim of this study was to

  13. Influência da localização do tumor na expressão tecidual da proteína p53 em doentes com câncer colorretal: estudo de 100 casos

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    Carlos Augusto Real Martinez

    Full Text Available OBJETIVO: O objetivo do presente estudo foi verificar, se existem diferenças na expressão tecidual da proteína p53 segundo a localização do tumor em doentes com câncer colorretal. MÉTODO: Foram estudados 100 doentes (54 mulheres, com média de idade de 59,8 anos com adenocarcinoma colorretal. A expressão da proteína p53 foi analisada por imunoistoquímica, com anticorpo monoclonal anti-p53 pela técnica da estreptavidina-biotina-peroxidase. A expressão tecidual da proteína p53 foi relacionada às variáveis: gênero, idade, grau histológico, tipo histológico, tamanho do tumor, estadiamento TNM, profundidade de invasão da parede intestinal, comprometimento linfonodal, invasão angiolinfática, localização do tumor no intestino grosso em relação à flexura esplênica. Na avaliação estatística da relação entre expressão da proteína p53 e as variáveis consideradas empregou-se o teste qui-quadrado, estabelecendo-se nível de significância de 5% (p<0,05. RESULTADOS: A proteína p53 foi positiva em 77% dos casos. Com relação as diferentes variáveis consideradas verificou-se maior tendência de expressão da proteína mutante quando se considerava a idade (p=0,001, grau histológico (p=0,001, tipo histológico (p=0,001, estádios tardios da classificação TNM (p=0,001, maior profundidade de invasão na parede cólica (p=0,001, comprometimento linfonodal (p=0,001, invasão angiolinfática (p=0,02, localização após a flexura esplênica (p=0,001, não se encontrando relação com gênero (p=0,49 e tamanho do tumor (p=0,08. CONCLUSÃO: Os resultados do presente estudo permitem concluir que a expressão da proteína p53 mutante ocorre com maior freqüência nos tumores localizados a partir da flexura esplênica.

  14. Tumores neuroendócrinos do pulmão: principais achados radiológicos em uma série de 22 casos com confirmação anatomopatológica

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    Marcel Koenigkam Santos

    2012-08-01

    Full Text Available OBJETIVO: Descrever os principais achados de imagem em uma série de casos de tumores neuroendócrinos primários do pulmão (TNPs, destacando as alterações na tomografia computadorizada. MATERIAIS E MÉTODOS: Exames de 22 pacientes (12 homens, idade média de 60 anos avaliados nos últimos cinco anos em nosso serviço, com confirmação histopatológica, foram retrospectivamente revistos por dois médicos radiologistas e os achados foram descritos em consenso, focando as alterações tomográficas. RESULTADOS: Descrevemos 5 carcinoides típicos, 3 carcinoides atípicos, 3 carcinomas neuroendócrinos de grandes células (CNGCs e 11 cânceres pulmonares de pequenas células (CPPCs. Apenas um carcinoide típico apresentou aspecto característico de nódulo endobrônquico central com atelectasia pulmonar distal, enquanto os demais foram nódulos ou massas pulmonares. Os carcinoides atípicos eram massas pulmonares periféricas e heterogêneas. Um CNGC era massa periférica delimitada e homogênea, enquanto os demais eram mal delimitados e heterogêneos. Os 11 CPPCs eram massas centrais, infiltrativas e heterogêneas, com alterações pleuropulmonares secundárias. Calcificações estavam ausentes nos CNGCs e CPPCs. Metástases foram vistas inicialmente ou no seguimento de todos os CNGCs e CPPCs. CONCLUSÃO: Apesar de alguns aspectos semelhantes nos exames de imagem, os achados radiológicos, quando integrados às informações clínicas, podem constituir critérios importantes na diferenciação dos tipos histológicos de TNPs.

  15. Gene expression and MR diffusion-weighted imaging after chemoembolization in rabbit liver VX-2 tumor model

    Institute of Scientific and Technical Information of China (English)

    You-Hong Yuan; En-Hua Xiao; Jian-Bin Liu; Zhong He; Ke Jin; Cong Ma; Jun Xiang; Jian-Hua Xiao; Wei-Jian Chen

    2008-01-01

    AIM: To investigate the dynamic characteristics and the correlation between PCNA, Bax, nm23, E-cadherin expression and apparent diffusion coefficient (ADC)on MR diffusion-weighted imaging (DWI) after chemoembolization in rabbit liver VX-2 tumor model. METHODS: Forty New Zealand rabbit liver VX-2 tumor models were included in the study. DWI was carried out periodically after chemoembolization. All VX-2 tumor samples in each group were examined by histopathology and StTept Avidin-Biotin Complex (SABC)immunohistochemical staining. RESULTS" The PCNA expression index in VX-2 tumors was higher than in the normal parenchyma around the tumor (P<0. 001). Nm23, Bax or E-caderin expression index in VX-2 tumors were lower than in the normal parenchyma around the tumor (all P<0. 001). PCNA and nm23 expression in the VX-2 tumor periphery first increased and then decreased (P<0. 001 and P=0. 03, respectively), while the expression of Bax and E-cadherin before and after chemoembolization was insignificant. When b-value was 100 s/mm2, there was a linear correlation between PCNA expression and ADC in the area of VX-2 tumor periphery (P<0. 001), and PCNA expression in VX-2 tumor periphery influenced the ADC. CONCLUSION: The potential of VX-2 tumor infiltrating and metastasizing decreases, while its ability to proliferate increases for a short time after chemoembolization. To some degree, the ADC value indirectly reflects the proliferation of VX-2 tumor cells.

  16. Percutaneous endoscopic gastrostomy in advanced head and neck cancer Gastrostomia endoscópica percutânea em pacientes com tumores avançados de cabeça e pescoço

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    Paulo Moacir de Oliveira Campoli

    2007-06-01

    Full Text Available BACKGROUND: Percutaneous endoscopic gastrostomy performed as proposed by Gauderer et al. in 1980, has been used quite frequently in patients with head and neck tumors. Some authors believe that this so-called pull technique would be associated to the risk of a tumor implantation in the wound as well as high levels of peristomal wound infection. Although some alternative techniques provide better results, doubts about their technical applicability in daily practice still persists. AIM: To assess the feasibility, safety and morbidity of percutaneous endoscopic gastrostomy performed through a well-defined and standardized technique in patients with nonresectable or advanced head and neck cancer. METHODS: A consecutive series of patients who had either nonresectable or advanced tumors and were unable to be fed orally were submitted to an oncologic-hospital-based tertiary-referral endoscopy practice. Tubes were implanted through an introducer technique comprised of two main stages. The first consisted of the application of two stitches aiming to fixate the anterior gastric wall to the abdominal wall, and the second being the inserting of the gastrostomy tube. RESULTS: Between February 2003 and May 2004, 129 percutaneous endoscopic gastrostomies were performed. This study included 60 patients. They were all able to receive food on the same day. Operative morbidity was observed in six patients (10% and one procedure-related mortality was also observed (1.6%. CONCLUSION: Percutaneous endoscopic gastrostomy is both feasible and safe, associated to low morbidity, and to acceptable mortality rates.RACIONAL: A gastrostomia endoscópica percutânea executada conforme a técnica proposta por Gauderer et al., em 1980, tem sido freqüentemente utilizada em pacientes com tumores de cabeça e pescoço. Diversos autores relatam que ela, conhecida como técnica de “puxar”, está associada a risco de implante de tumor na parede abdominal assim como risco

  17. Proapoptotic protein Smac mediates apoptosis in cisplatin-resistant ovarian cancer cells when treated with the anti-tumor agent AT101.

    Science.gov (United States)

    Hu, Wenbin; Wang, Fang; Tang, Jingsheng; Liu, Xinyu; Yuan, Zhu; Nie, Chunlai; Wei, Yuquan

    2012-01-02

    Chemoresistance of ovarian cancer has been previously attributed to the expression and activation of Bcl-2 family proteins. BH3-mimetic molecules possessing potential anticancer activity are able to inhibit antiapoptotic Bcl-2 family proteins. AT101 (R-(-)-gossypol), a natural BH3-mimetic molecule, has shown anti-tumor activity as a single agent and in combination with standard anticancer therapies in a variety of tumor models. Here, we report the effect of AT101 on apoptosis in cisplatin-resistant ovarian cancer cells and identify the major molecular events that determine sensitivity. AT101 induced cell apoptosis by activating Bax through a conformational change, translocation, and oligomerization. The inhibition of Bax expression only partially prevented caspase-3 cleavage. However, the gene silencing of Bax had no effect on mitochondrial Smac release. Further experiments demonstrated that Smac reduction inhibited caspase-3 activation and attenuated cell apoptosis. More importantly, the inhibition of Smac or overexpression of XIAP attenuated Bax activation in ovarian cells. Furthermore, our data indicate that the Akt-p53 pathway is involved in the regulation of Smac release. Taken together, our data demonstrate the role of Smac and the molecular mechanisms of AT101-induced apoptosis of chemoresistant ovarian cancer cells. Our findings suggest that AT101 not only triggers Bax activation but also induces mitochondrial Smac release. Activated Smac can enhance Bax-mediated cellular apoptosis. Therefore, Smac mediates Bax activation to determine the threshold for overcoming cisplatin resistance in ovarian cancer cells.

  18. Significance and expression of Bax, Survivin and p53 in gastric carcinoma and precancerous lesions using tissue microarray%利用组织芯片技术研究胃癌及其癌前病变中Bax、p53、Survivin表达的关系及意义

    Institute of Scientific and Technical Information of China (English)

    Yuping Xiao; Zhi Lin; Lili Mao; Dongying Wu; Yujia Gao; Hongwei Sun; Yan Xin

    2007-01-01

    Objective: To explore the relationship between expressions of apoptosis-related protein Bax, Survivin and p53 and the molecular mechanisms of carcinogenesis and progression of gastric carcinoma. Methods: Tissue microarray and immunohistochemistry were used in this study. Results: The positive rate of Bax protein in gastric cancer (17.7%, 17/96) was significantly lower than those in adjacent normal mucosa (51%), intestinal metaplasia (69.2%) and dysplasia (75%), P < 0.01.The positive rate of Survivin expression in gastric cancer (80.6%, 89/98) was significantly higher than that in adjacent normal mucosa (3.9%), P < 0.01. The positive rates of Survivin expression in tumors with different organ metastases (in lymph node metastasis 86.2%, liver 100% and ovarian 100%) were statistically higher than in tumors without metastasis (64.3%), P <0.05. Bax expression was correlated with Survivin but not with mp53 that was closely related to Survivin expression (P < 0.05)in gastric cancer. Conclusion: The abnormal expressions of Bax, Survivin and mp53 were correlated with the tumorigenesis and progression of gastric carcinoma. P53 and Survivin genes may share the similar mechanism in regulating cell apoptosis,and because of the mutation, p53 gene may lower its down-regulation to Survivin expression.

  19. Frequency of tumors in dogs based on cytological diagnosis: a retrospective study in a veterinary teaching hospital / Frequência de neoplasmas em cães diagnosticados por exame citológico: estudo retrospectivo em um hospital-escola

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    Ana Paula Frederico Rodrigues Loureiro Bracarense

    2009-07-01

    Full Text Available Cytological examination is considered a very important method to diagnose neoplasms in pets and can be performed in many clinical situations. The aim of this study was to determine the prevalence of neoplasms diagnosed by cytological examination in dogs from the region of Londrina, and to evaluate epidemiological aspects as age, breed, sex predisposition, biological behaviour and anatomical localization. The data were obtained from the Animal Pathology Laboratory of Universidade Estadual de Londrina. 3378 cases of cytological examinations from the routine service of the laboratory were evaluated, from January 1996 to December 2006. From these, 1019 cases were diagnosed as neoplasms. Round cell tumors represented 44% of the diagnosis, followed by epithelial and mesenchymal neoplasms with 36.7% and 16%, respectively. Undifferentiated neoplasms totalized 3.3% of the cytological diagnosis. Malignant behaviour were more frequent in epithelial than mesenchymal neoplasms. Mast cell tumor, transmissible venereal tumor and lymphoma were the neoplasms more frequently diagnosed within round cell tumors. Pure breeds were more prevalent than mongrel dogs. Boxers, poodles and German shepherds were the most affected by neoplasms. The average age was 7.94 ± 3.55 years. There was no sex predisposition. Perineum was the most affected site in benign epithelial neoplasms and transmissible venereal tumors, whereas benign mesenchymal neoplasms were often located in thorax. Malignant epithelial and mesenchymal neoplasms, melanoma and histiocytoma were located mainly in the head. Mast cell tumors were observed mainly in trunk and limbs. The most common clinical sign in lymphoma was lymphadenomegaly.O exame citológico é um importante método de diagnóstico de neoplasias em animais de companhia e pode ser realizado em diversas situações clínicas. O objetivo do presente estudo foi determinar a prevalência dos neoplasmas diagnosticados pelo exame citológico em c

  20. Altered mitochondrial morphology and defective protein import reveal novel roles for Bax and/or Bak in skeletal muscle.

    Science.gov (United States)

    Zhang, Yuan; Iqbal, Sobia; O'Leary, Michael F N; Menzies, Keir J; Saleem, Ayesha; Ding, Shuzhe; Hood, David A

    2013-09-01

    The function Bax and/or Bak in constituting a gateway for mitochondrial apoptosis in response to apoptotic stimuli has been unequivocally demonstrated. However, recent work has suggested that Bax/Bak may have unrecognized nonapoptotic functions related to mitochondrial function in nonstressful environments. Wild-type (WT) and Bax/Bak double knockout (DKO) mice were used to determine alternative roles for Bax and Bak in mitochondrial morphology and protein import in skeletal muscle. The absence of Bax and/or Bak altered mitochondrial dynamics by regulating protein components of the organelle fission and fusion machinery. Moreover, DKO mice exhibited defective mitochondrial protein import, both into the matrix and outer membrane compartments, which was consistent with our observations of impaired membrane potential and attenuated expression of protein import machinery (PIM) components in intermyofibrillar mitochondria. Furthermore, the cytosolic chaperones heat-shock protein 90 (Hsp90) and binding immunoglobulin protein (BiP) were markedly increased with the deletion of Bax/Bak, indicating that the cytosolic environment related to protein folding may be changed in DKO mice. Interestingly, endurance training fully restored the deficiency of protein import in DKO mice, likely via the upregulation of PIM components and through improved cytosolic chaperone protein expression. Thus our results emphasize novel roles for Bax and/or Bak in mitochondrial function and provide evidence, for the first time, of a curative function of exercise training in ameliorating a condition of defective mitochondrial protein import.

  1. Ghrelin Administration Increases the Bax/Bcl-2 Gene Expression Ratio in the Heart of Chronic Hypoxic Rats.

    Science.gov (United States)

    Aliparasti, Mohammad Reza; Alipour, Mohammad Reza; Almasi, Shohreh; Feizi, Hadi

    2015-06-01

    Programmed cell death or apoptosis, is a biochemical procedure that initiates due to some conditions, including hypoxia. Bax and Bcl-2 are among the agents that regulate apoptosis. The amplification of the first one triggers the initiation of apoptosis, and the second one prevents it. Ghrelin is an endogenous peptide that antiapoptosis is its new effect. The aim of this study is to examine the effect of ghrelin on the Bax/Bcl-2 ratio. Twenty four wistar rats were divided randomly in three groups; control, hypoxic + saline and hypoxic + ghrelin. Hypoxic animals lived in O2 11% for 2 weeks and received either saline or ghrelin subcutaneously daily. The bax and Bcl-2 gene expression were measured by Real-Time RT-PCR. Chronic hypoxia increased the Bax gene expression significantly compared with normal animals (P = 0.008), but the Bcl-2 was not affected by hypoxia. The Bax/Bcl-2 ratio also amplified significantly (P=0.005). Ghrelin administration significantly increased the Bax/Bcl-2 ratio in the hypoxic animals compared to the hypoxic + saline and normal groups (p=0.042 and P= 0.001, respectively). In the present study, animals' treatment with ghrelin leads to an increment of Bax/Bcl-2 ratio, which indicates a controversy related to cardioprotection of ghrelin.

  2. Ghrelin Administration Increases the Bax/Bcl-2 Gene Expression Ratio in the Heart of Chronic Hypoxic Rats

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    Mohammad Reza Aliparasti

    2015-06-01

    Full Text Available Purpose: Programmed cell death or apoptosis, is a biochemical procedure that initiates due to some conditions, including hypoxia. Bax and Bcl-2 are among the agents that regulate apoptosis. The amplification of the first one triggers the initiation of apoptosis, and the second one prevents it. Ghrelin is an endogenous peptide that antiapoptosis is its new effect. The aim of this study is to examine the effect of ghrelin on the Bax/Bcl-2 ratio. Methods: Twenty four wistar rats were divided randomly in three groups; control, hypoxic + saline and hypoxic + ghrelin. Hypoxic animals lived in O2 11% for 2 weeks and received either saline or ghrelin subcutaneously daily. The bax and Bcl-2 gene expression were measured by Real-Time RT-PCR. Results: Chronic hypoxia increased the Bax gene expression significantly compared with normal animals (P = 0.008, but the Bcl-2 was not affected by hypoxia. The Bax/Bcl-2 ratio also amplified significantly (P=0.005. Ghrelin administration significantly increased the Bax/Bcl-2 ratio in the hypoxic animals compared to the hypoxic + saline and normal groups (p=0.042 and P= 0.001, respectively. Conclusion: In the present study, animals’ treatment with ghrelin leads to an increment of Bax/Bcl-2 ratio, which indicates a controversy related to cardioprotection of ghrelin.

  3. Ghrelin Administration Increases the Bax/Bcl-2 Gene Expression Ratio in the Heart of Chronic Hypoxic Rats

    Science.gov (United States)

    Aliparasti, Mohammad Reza; Alipour, Mohammad Reza; Almasi, Shohreh; Feizi, Hadi

    2015-01-01

    Purpose: Programmed cell death or apoptosis, is a biochemical procedure that initiates due to some conditions, including hypoxia. Bax and Bcl-2 are among the agents that regulate apoptosis. The amplification of the first one triggers the initiation of apoptosis, and the second one prevents it. Ghrelin is an endogenous peptide that antiapoptosis is its new effect. The aim of this study is to examine the effect of ghrelin on the Bax/Bcl-2 ratio. Methods: Twenty four wistar rats were divided randomly in three groups; control, hypoxic + saline and hypoxic + ghrelin. Hypoxic animals lived in O2 11% for 2 weeks and received either saline or ghrelin subcutaneously daily. The bax and Bcl-2 gene expression were measured by Real-Time RT-PCR. Results: Chronic hypoxia increased the Bax gene expression significantly compared with normal animals (P = 0.008), but the Bcl-2 was not affected by hypoxia. The Bax/Bcl-2 ratio also amplified significantly (P=0.005). Ghrelin administration significantly increased the Bax/Bcl-2 ratio in the hypoxic animals compared to the hypoxic + saline and normal groups (p=0.042 and P= 0.001, respectively). Conclusion: In the present study, animals’ treatment with ghrelin leads to an increment of Bax/Bcl-2 ratio, which indicates a controversy related to cardioprotection of ghrelin. PMID:26236657

  4. Cisplatin-induced apoptosis in non-small-cell lung cancer cells is dependent on Bax- and Bak-induction pathway and synergistically activated by BH3-mimetic ABT-263 in p53 wild-type and mutant cells.

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    Matsumoto, Masaru; Nakajima, Wataru; Seike, Masahiro; Gemma, Akihiko; Tanaka, Nobuyuki

    2016-04-29

    Cisplatin is a highly effective anticancer drug for treatment of various tumors including non-small-cell lung cancer (NSCLC), and is especially useful in cases nonresponsive to molecular-targeted drugs. Accumulating evidence has shown that cisplatin activates the p53-dependent apoptotic pathway, but it also induces apoptosis in p53-mutated cancer cells. Here we demonstrated that DNA-damage inducible proapoptotic BH3 (Bcl-2 homology region 3)-only Bcl-2 family members, Noxa, Puma, Bim and Bid, are not involved in cisplatin-induced apoptosis in human NSCLC cell lines. In contrast, the expression of proapoptotic multidomain Bcl-2-family members, Bak and Bax, was induced by cisplatin in p53-dependent and -independent manners, respectively. Moreover, in wild-type p53-expressing cells, cisplatin mainly used the Bak-dependent apoptotic pathway, but this apoptotic pathway shifted to the Bax-dependent pathway by loss-of-function of p53. Furthermore, both Bak- and Bax-induced apoptosis was enhanced by the antiapoptotic Bcl-2 family member, Bcl-XL knockdown, but not by Mcl-1 knockdown. From this result, we tested the effect of ABT-263 (Navitoclax), the specific inhibitor of Bcl-2 and Bcl-XL, but not Mcl-1, and found that ABT-263 synergistically enhanced cisplatin-induced apoptosis in NSCLC cells in the presence or absence of p53. These results indicate a novel regulatory system in cisplatin-induced NSCLC cell apoptosis, and a candidate efficient combination chemotherapy method against lung cancers.

  5. Bax-induced apoptosis in Leber's congenital amaurosis: a dual role in rod and cone degeneration.

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    Séverine Hamann

    Full Text Available Pathogenesis in the Rpe65(-/- mouse model of Leber's congenital amaurosis (LCA is characterized by a slow and progressive degeneration of the rod photoreceptors. On the opposite, cones degenerate rapidly at early ages. Retinal degeneration in Rpe65(-/- mice, showing a null mutation in the gene encoding the retinal pigment epithelium 65-kDa protein (Rpe65, was previously reported to depend on continuous activation of a residual transduction cascade by unliganded opsin. However, the mechanisms of apoptotic signals triggered by abnormal phototransduction remain elusive. We previously reported that activation of a Bcl-2-dependent pathway was associated with apoptosis of rod photoreceptors in Rpe65(-/- mice during the course of the disease. In this study we first assessed whether activation of Bcl-2-mediated apoptotic pathway was dependent on constitutive activation of the visual cascade through opsin apoprotein. We then challenged the direct role of pro-apoptotic Bax protein in triggering apoptosis of rod and cone photoreceptors.Quantitative PCR analysis showed that increased expression of pro-apoptotic Bax and decreased level of anti-apoptotic Bcl-2 were restored in Rpe65(-/-/Gnat1(-/- mice lacking the Gnat1 gene encoding rod transducin. Moreover, photoreceptor apoptosis was prevented as assessed by TUNEL assay. These data indicate that abnormal activity of opsin apoprotein induces retinal cell apoptosis through the Bcl-2-mediated pathway. Following immunohistological and real-time PCR analyses, we further observed that decreased expression of rod genes in Rpe65-deficient mice was rescued in Rpe65(-/-/Bax(-/- mice. Histological and TUNEL studies confirmed that rod cell demise and apoptosis in diseased Rpe65(-/- mice were dependent on Bax-induced pathway. Surprisingly, early loss of cones was not prevented in Rpe65(-/-/Bax(-/- mice, indicating that pro-apoptotic Bax was not involved in the pathogenesis of cone cell death in Rpe65-deficient mice

  6. Estudo de associação genética entre fator de necrose tumoral alfa e sepse e choque séptico em pacientes pediátricos tailandeses

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    Suwannee Phumeetham

    2012-10-01

    Full Text Available OBJETIVOS: Avaliar a associação entre o polimorfismo genético do fator de necrose tumoral alfa (TNF-α e o desenvolvimento de sepse e choque séptico em pacientes pediátricos tailandeses e investigar o impacto clínico de polimorfismos do TNF-α nessa população. MÉTODOS: Para a realização deste estudo de associação genética, foram analisados prospectivamente pacientes pediátricos (idade < 18 anos com sepse clínica/choque séptico. Todos os dados foram coletados por especialistas em terapia intensiva pediátrica e as análises genéticas foram realizadas em um laboratório central. Um polimorfismo de nucleotídeo único [single nucleotide polymorphism (SNP], localizado na região promotora 5' na posição -308, foi genotipado e os resultados foram associados a fenótipos clínicos. RESULTADOS: Foram investigados 167 indivíduos tailandeses, dos quais 66 eram pacientes pediátricos com sepse/choque séptico e 101 eram controles saudáveis. Curiosamente, não foi possível identificar associação entre sepse e o polimorfismo -308 (G→A, um dos principais SNPs anteriormente associado à sepse em várias populações caucasianas, visto que não houve diferença de frequência entre casos e controles. CONCLUSÕES: Neste estudo, o principal polimorfismo do TNF-α -308 não esteve associado à sepse clínica/choque séptico na população tailandesa. Essa informação é importante para futuras análises que busquem identificar a função do TNF-α como risco genético para o desenvolvimento de imunopatologia subjacente a várias doenças no continente asiático.

  7. The Proapoptotic Bcl-2 Protein Bax Plays an Important Role in the Pathogenesis of Reovirus Encephalitis ▿

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    Berens, Heather M.; Tyler, Kenneth L.

    2011-01-01

    Encephalitis induced by reovirus serotype 3 (T3) strains results from the apoptotic death of infected neurons. Extrinsic apoptotic signaling is activated in reovirus-infected neurons in vitro and in vivo, but the role of intrinsic apoptosis signaling during encephalitis is largely unknown. Bax plays a key role in intrinsic apoptotic signaling in neurons by allowing the release of mitochondrial cytochrome c. We found Bax activation and cytochrome c release in neurons following infection of neonatal mice with T3 reoviruses. Bax−/− mice infected with T3 Abney (T3A) have reduced central nervous system (CNS) tissue injury and decreased apoptosis, despite viral replication that is similar to that in wild-type (WT) Bax+/+ mice. In contrast, in the heart, T3A-infected Bax−/− mice have viral growth, caspase activation, and injury comparable to those in WT mice, indicating that the role of Bax in pathogenesis is organ specific. Nonmyocarditic T3 Dearing (T3D)-infected Bax−/− mice had delayed disease and enhanced survival compared to WT mice. T3D-infected Bax−/− mice had significantly lower viral titers and levels of activated caspase 3 in the brain despite unaffected transneuronal spread of virus. Cytochrome c and Smac release occurred in some reovirus-infected neurons in the absence of Bax; however, this was clearly reduced compared to levels seen in Bax+/+ wild-type mice, indicating that Bax is necessary for efficient activation of proapoptotic mitochondrial signaling in infected neurons. Our studies suggest that Bax is important for reovirus growth and pathogenesis in neurons and that the intrinsic pathway of apoptosis, mediated by Bax, is important for full expression of disease, CNS tissue injury, apoptosis, and viral growth in the CNS of reovirus-infected mice. PMID:21307199

  8. Low levels of Bax inhibitor-1 gene expression increase tunicamycin-induced apoptosis in human neuroblastoma SY5Y cells

    Institute of Scientific and Technical Information of China (English)

    Dan Wu; Peirong Wang; Shiyao Wang

    2012-01-01

    A human SH-SY5Y neuroblastoma cell line with a low level of Bax inhibitor-1 expression was established by lentivirus-mediated RNA interference and fluorescence-activated cell sorting. In control SH-SY5Y cells, tunicamycin treatment induced endoplasmic reticulum stress-mediated apoptosis; however, after Bax inhibitor-1 gene knockdown, cell survival rates were significantly decreased and the degree of apoptosis was significantly increased following tunicamycin treatment. In addition, chromatin condensation and apparent apoptotic phenomena, such as marginalization and cytoplasmic vesicles, were observed. Our findings indicate that Bax inhibitor-1 can delay apoptosis induced by endoplasmic reticulum stress.

  9. Tumor's other immune targets: dendritic cells.

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    Esche, C; Lokshin, A; Shurin, G V; Gastman, B R; Rabinowich, H; Watkins, S C; Lotze, M T; Shurin, M R

    1999-08-01

    The induction of apoptosis in T cells is one of several mechanisms by which tumors escape immune recognition. We have investigated whether tumors induce apoptosis in dendritic cells (DC) by co-culture of murine or human DC with different tumor cell lines for 4-48 h. Analysis of DC morphological features, JAM assay, TUNEL, caspase-3-like and transglutaminase activity, Annexin V binding, and DNA fragmentation assays revealed a time- and dose-dependent induction of apoptosis in DC by tumor-derived factors. This finding is both effector and target specific. The mechanism of tumor-induced DC apoptosis involved regulation of Bcl-2 and Bax expression. Double staining of both murine and human tumor tissues confirmed that tumor-associated DC undergo apoptotic death in vivo. DC isolated from tumor tissue showed significantly higher levels of apoptosis as determined by TUNEL assay when compared with DC isolated from spleen. These findings demonstrate that tumors induce apoptosis in DC and suggest a new mechanism of tumor escape from immune recognition. DC protection from apoptosis will lead to improvement of DC-based immunotherapies for cancer and other immune diseases.

  10. Functional Mechanism of Resveratrol in Inhabiting Growth of Cells ls174t and Its Mechanism in Subcutaneously Transplanted Tumor of Nude Mice

    Institute of Scientific and Technical Information of China (English)

    CHEN Jie; DONG Xin-shu; GUO Xing-gang

    2008-01-01

    To explore the functional mechanism of Resveratrol against colon cancer cells Is174t and the growth of colon cancer tissue of tumor-bearing mice,MTT method was used to observe the functions of resveratrol for inhibition against cells ls174t in vitro.Transmission electron microscope was used to observe the cell apoptosis.FCM assay was performed to measure the change of the cell apoptosis rate and of cell cycle,RT-PCR method was used to detect the expressions of bc1-2 and bax mRNA.Western blot method was used to detect the expressions of bc1-2 and bax protein.Cells isi74t were transplanted subcutaneously to nude mice to observe the effect of resveratrol on the growth of subcutaneously transplanted tumor.RT-PCR method was used to detect the expressions of bc1-2 and bax mRNA in the tumor tissue.Western blot method was used to detect the expressions of bc1-2 and bax protein in the tumor tissue.Resveratrol has an effect of inhibiting proliferation of cells ls174t in vitro(P<0.01).It is able to induce the apoptosis of cells Is174t,causing the decrease in the expression of bc1-2 and the increase in the expression of bax.Resveratrol could inhibit the growth of subcutaneously transplanted tumor of nude mice(P<0.05),causing the decrease in the expression of bc1-2 and the increase in the expression of bax.Resveratrol can inhibit the growth of cells 174t and the growth of subcutaneously transplanted tumor.The mechanism is possibly related to the induction of the cell apoptosis and the regulation of bc1-2/bax expression.

  11. Perimetria computadorizada e manual em pacientes com defeitos perimétricos temporais avançados causados por tumores supra-selares Computerized and manual perimetry in patientes with severe temporal visual field defects due to supraselar tumors

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    Andrea Pereira

    2005-10-01

    Full Text Available OBJETIVO: Estudar, ao perímetro de Goldmann, um grupo de pacientes com hemianopsia completa ao perímetro Humphrey (24-2 full threshold test, e verificar em quantos casos a perimetria computadorizada deixou de identificar a presença de campo visual periférico residual. MÉTODOS: Dezenove pacientes com defeitos campimétricos por compressão quiasmática foram estudados prospectivamente por meio das perimetrias manual e computadorizada. Vinte e cinco olhos com hemianopsia temporal completa pelo programa 24-2 do Humphrey Field Analyzer foram selecionados e estudados pela perimetria manual de Goldmann para avaliar a presença de campo visual periférico residual. De acordo com os resultados ao perímetro de Goldmann, os olhos foram divididos em 2 grupos: grupo 1, os portadores de hemianopsia temporal completa ao Goldmann e grupo 2, os portadores de campo visual temporal periférico residual. Foi calculada a média do "mean deviation" fornecido pelo aparelho nos dois grupos e o resultado foi comparado pelo teste t de Student. RESULTADOS: A perimetria computadorizada deixou de identificar a presença de campo visual periférico residual em 17 dos 25 olhos (68%. Os valores médios do "mean deviation" no grupo 1 e grupo 2 foram respectivamente -15,43 e -15,93. O estudo estatístico não mostrou diferença significativa entre os dois valores. CONCLUSÕES: A perimetria computadorizada Humphrey com o programa 24-2 threshold test deixa de identificar remanescentes temporais de campo visual em grande porcentagem de pacientes com compressão quiasmática grave. A análise do "mean deviation" fornecido pelo aparelho não permite identificar estes casos. Pacientes estudados ao perímetro automático e apresentando hemianopsia temporal completa, devem complementar sua avaliação perimétrica com a pesquisa por áreas remanescentes no campo visual temporal.PURPOSE: To study, on Goldmann perimetry, a group of patients with complete temporal hemianopia on

  12. Effect of morin-5'-sulfonic acid sodium salt on the expression of apoptosis related proteins caspase 3, Bax and Bcl 2 due to the mercury induced oxidative stress in albino rats.

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    Venkatesan, Rantham Subramaniam; Sadiq, Abdul Majeeth Mohamed

    2017-01-01

    Many environmental contaminants have been reported to disturb the pro-oxidant or antioxidant balance of the cells by inducing oxidative stress. Oxidative stress mediated by the HgCl2 induces DNA, protein and lipid oxidation resulted in necrosis or apoptosis, or both. Currently flavonoids are being emerging topic and reported to have antiviral, anti-inflammatory, anti- tumor and antioxidant activities. Morin is one of the flavonoid protects the cells from oxygen free radical damage and scavenges the free radicals and metals and also heals the injured cells commercially. Morin hydrate is sparingly soluble in water. Hence, the water soluble morin -5'- sulfonic acid sodium salt (NaMSA) was selected and synthesized. Aim of the present study was to analyze the effect of morin-5'-sulfonic acid sodium salt on the expression of apoptosis related proteins caspase 3, Bax and Bcl 2 due to the mercury induced oxidative stress in albino rats.. The experimental rats were exposed to sub lethal concentration of mercuric chloride (1.25mg/kg) and the ameliorating effect of NaMSA was studied by using apoptotic protein markers Bax and caspase-3 and Bcl-2. The obtained results were analyzed using one way analysis of variance by the Duncan's Multiple comparison test to determine the level of significance (p) and pBax and caspase-3 and a decreased expression was noted in the Bcl-2 level compared with control bands significantly (pBax, Caspase-3 and Bcl-2 levels compared with control rats. Hence, the membrane damage was protected, stopped the cell death and apoptosis. This could be due to the morin-5'-sulfonic acid sodium salt effective chelation action on the HgCl2 generated free radicals. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  13. Quercetin inhibits human breast cancer cell proliferation and induces apoptosis via Bcl-2 and Bax regulation.

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    Duo, Jian; Ying, Guo-Guang; Wang, Guo-Wen; Zhang, Li

    2012-06-01

    Breast cancer is a disease in which cancer cells form in the tissues of the breast. The present study aimed to explore the effect of the flavonoid compound quercetin on the growth and apoptosis of human breast cancer cells. Varying concentrations (12.5, 25, 50, 100, 200 µM) of quercetin were applied to cultured MCF-7 human breast cancer cells for defined lengths of time. At 50 to 200 µM doses, quercetin significantly inhibited the proliferation of MCF-7 cells assessed by MTT colorimetry, in both dose- and time-dependent manners (Papoptosis after 48 h of exposure (Pquercetin treatment Bcl-2 expression decreased significantly while Bax expression increased significantly (Pquercetin inhibits cell growth and induces apoptosis in MCF-7 human breast cancer cells. The mechanisms behind these effects may stem from the downregulation of Bcl-2 protein expression and upregulation of Bax expression.

  14. The Bax Inhibitor-1 (BI-1) family in apoptosis and tumorigenesis.

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    Reimers, Kerstin; Choi, Claudia Y U; Bucan, Vesna; Vogt, Peter M

    2008-03-01

    The signaling pathways that determine the fate of a cell regarding death or survival depend on a large number of regulatory proteins. The Bax Inhibitor-1 (BI-1) family is a highly preserved family of small transmembrane proteins located mostly in the endoplasmic reticulum (ER). Although most members of this family are still not characterized an antiapoptotic effect has been described for BI-1, Lifeguard (LFG), and the Golgi anti-apoptotic protein (GAAP). The cytoprotective activity has been associated to the control of ion homeostasis and ER stress but includes other cell death stimuli as well. Recent data describes multiple interactions between the proteins of the BI-1 family and the Bcl-2 family either stimulating the antiapoptotic function of Bcl-2 or inhibiting the proapoptotic effect of Bax. The potent cell death suppression makes this protein family an interesting target for the development of new drugs and gene therapeutic approaches for diseases caused by apoptotic dysregulation, such as cancer.

  15. Kazrin F is involved in apoptosis and interacts with BAX and ARC

    Institute of Scientific and Technical Information of China (English)

    Qiong Wang; Min Liu; Xin Li; Lu Chen; Hua Tang

    2009-01-01

    Kazrin has recently been identified as a functional protein that is involved in cell-cell junctions and in signal transduction. Here, we identified a new isoform, Kazrin F, which is 518 aa in length and has 97 aa unique at the N-terminus. Knockdown of Kazrin F using siRNA caused cell apoptosis and a marked decrease in cell viability measured by MTT and TUNEL assays. Co-immunoprecipitation analysis revealed that Kazrin F interacts with ARC (apoptosis repressor with caspase recruitment domain) and Bas (Bcl-2-associated X protein). Co-localization of Kazriin F with ARC and Bax in the cytoplasm was determined by immunofluorescence analysis. These results suggested that Kazrin F might play an important role in regulating cellular apoptosis by interacting with ARC and Bax.

  16. Conformational Heterogeneity of Bax Helix 9 Dimer for Apoptotic Pore Formation

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    Liao, Chenyi; Zhang, Zhi; Kale, Justin; Andrews, David W.; Lin, Jialing; Li, Jianing

    2016-07-01

    Helix α9 of Bax protein can dimerize in the mitochondrial outer membrane (MOM) and lead to apoptotic pores. However, it remains unclear how different conformations of the dimer contribute to the pore formation on the molecular level. Thus we have investigated various conformational states of the α9 dimer in a MOM model — using computer simulations supplemented with site-specific mutagenesis and crosslinking of the α9 helices. Our data not only confirmed the critical membrane environment for the α9 stability and dimerization, but also revealed the distinct lipid-binding preference of the dimer in different conformational states. In our proposed pathway, a crucial iso-parallel dimer that mediates the conformational transition was discovered computationally and validated experimentally. The corroborating evidence from simulations and experiments suggests that, helix α9 assists Bax activation via the dimer heterogeneity and interactions with specific MOM lipids, which eventually facilitate proteolipidic pore formation in apoptosis regulation.

  17. Building blocks of the apoptotic pore: how Bax and Bak are activated and oligomerize during apoptosis

    Science.gov (United States)

    Westphal, D; Kluck, R M; Dewson, G

    2014-01-01

    The central role of the Bcl-2 family in regulating apoptotic cell death was first identified in the 1980s. Since then, significant in-roads have been made in identifying the multiple members of this family, characterizing their form and function and understanding how their interactions determine whether a cell lives or dies. In this review we focus on the recent progress made in characterizing the proapoptotic Bcl-2 family members, Bax and Bak. This progress has resolved longstanding controversies, but has also challenged established theories in the apoptosis field. We will discuss different models of how these two proteins become activated and different ‘modes' by which they are inhibited by other Bcl-2 family members. We will also discuss novel conformation changes leading to Bak and Bax oligomerization and speculate how these oligomers might permeabilize the mitochondrial outer membrane. PMID:24162660

  18. Tumor suppression by resistant maltodextrin, Fibersol-2.

    Science.gov (United States)

    So, Eui Young; Ouchi, Mutsuko; Cuesta-Sancho, Sara; Olson, Susan Losee; Reif, Dirk; Shimomura, Kazuhiro; Ouchi, Toru

    2015-01-01

    Resistant maltodextrin Fibersol-2 is a soluble and fermentable dietary fiber that is Generally Recognized As Safe (GRAS) in the United States. We tested whether Fibersol-2 contains anti-tumor activity. Human colorectal cancer cell line, HCT116, and its isogenic cells were treated with FIbersol-2. Tumor growth and tumorigenesis were studied in vitro and in vivo. Apoptotic pathway and generation of reactive oxygen species (ROS) were investigated. We discovered that Fibersol-2 significantly inhibits tumor growth of HCT116 cells by inducing apoptosis. Fibersol-2 strongly induces mitochondrial ROS and Bax-dependent cleavage of caspase 3 and 9, which is shown by isogenic HCT116 variants. Fibersol-2 induces phosphorylation of Akt, mTOR in parental HCT116 cells, but not in HCT116 deficient for Bax or p53. It prevents growth of tumor xenograft without any apparent signs of toxicity in vivo. These results identify Fibersol-2 as a mechanism-based dietary supplement agent that could prevent colorectal cancer development.

  19. Synergistic Effect of Subtoxic-dose Cisplatin and TRAIL to Mediate Apoptosis by Down-regulating Decoy Receptor 2 and Up-regulating Caspase-8, Caspase-9 and Bax Expression on NCI-H460 and A549 Cells

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    Xiaoyan Zhang

    2013-05-01

    Full Text Available Objective(s: Although tumor necrosis factor-related apoptosis-inducing ligand (TRAIL can selectively induce apoptosis in tumor cells, more than half of tumors including non-small cell lung cancer (NSCLC exhibit TRAIL-resistance. The purpose of this study was to determine whether subtoxic-dose cisplatin and TRAIL could synergistically enhance apoptosis on NSCLC cells and investigate its underlying mechanisms. Materials and Methods:NCI-H460 and A549 cells were treated with TRAIL alone, cisplatin alone or combination treatment in this study. The cytotoxicity was evaluated according to Sulforhodamine B assay, and apoptosis was examined using Hoechst 33342 staining and flow cytometry. The mRNA and protein levels of TRAIL receptors and apoptotic proteins including caspase-8, caspase-9, Bcl-2 and Bax were determined by RT-PCR and Western blotting, respectively. Results:Our results showed that NCI-H460 cells were sensitive to TRAIL, whereas A549 cells were resistant. However, subtoxic-dose cisplatin could enhance the both cells to TRAIL-mediated cell proliferation inhibition and apoptosis. The underlying mechanisms might be associated with the down-regulation of DcR2 and up-regulation of Caspase-8, Caspase-9 and Bax. Conclusion:Subtoxic-dose cisplatin could enhance both TRAIL- sensitive and TRAIL- resistant NSCLC cells to TRAIL-mediated apoptosis. These findings motivated further studies to evaluate such a combinatory therapeutic strategy against NSCLC in the animal models.

  20. Influence of neurotrophin-3 on Bcl-2 and Bax expressions in spinal cord injury of rats

    Institute of Scientific and Technical Information of China (English)

    GUO Shu-zhang; JIANG Tao; REN Xian-jun

    2007-01-01

    Objective:To study the protective mechanisms of neurotrophin-3 (NT-3) on the spinal cord injury.Methods:Totally 105 SD rats were randomly divided into 3 groups:control group,experimental group and sham operation group.Rats from the former 2 groups were inflicted to animal model of acute spinal cord injury according to Allen's (WD) by situating a thin plastic tube in the subarachnoid space below the injury level for perfusion.Rats in experimental group received 20μl NT-3 (200 ng) from the tube at 0,4,8,12,24 h and 3,7 d after injury,and those in control group got an equal volume of normal saline at the same time.The animals in sham operation group only received opening vertebral plate and tube was put in subarachnoid space.The rats were sacrificed at 4,8,12,24 h and 3,7,14 d post injury (n=5).The expression levels of Bcl-2 and Bax proteins in spinal cord of rats were detected by immunohistochemistry assay.Results:The level of Bax protein in control group significantly increased as compared with those in sham operation group, and the peak reached at 8 h after spinal cord injury.The Bcl-2 proteins were always weakly positive.The Bax proteins in NT-3 group significantly decreased but the Bcl-2 proteins obviously increased as compared with those in control group.Conclusion:NT-3 can protect spinal cord from injury in vivo.One of the mechanisms is that NT-3 can inhibit abnormal expression of Bax protein,and increase the expression of Bcl-2 protein,then inhibit apoptosis after spinal cord injury.

  1. Reação granulomatosa do tipo corpo estranho simulando tumor de parede torácica em cicatriz de toracotomia prévia

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    MACEDO NETO AMARÍLIO VIEIRA DE

    2000-01-01

    Full Text Available Paciente apresentando tumoração indolor, de crescimento lento, em local correspondente à cicatriz de toracotomia para correção de coarctação de aorta realizada 15 anos antes. Tomografia computadorizada de tórax mostrou lesões tumorais de contornos relativamente bem definidos e osteólise dos arcos costais adjacentes. Realizada ressecção e reconstrução de parede torácica. O anatomopatológico demonstrou reação de histiócitos granulares e reação granulomatosa de corpo estranho a material necro-hemorrágico. Este é um evento raro na prática médica, tendo-se realizado revisão da literatura pertinente.

  2. DuPont Qualicon BAX System assay for genus Listeria 24E.

    Science.gov (United States)

    Wallace, F Morgan; Fallon, Dawn; DeMarco, Daniel; Varkey, Stephen

    2011-01-01

    The new BAX System PCR Assay for Genus Listeria 24E was evaluated for detecting Listeria spp. in frankfurters, spinach, cooked shrimp, queso fresco cheese, and on stainless steel surfaces with a single-stage enrichment in BAX System 24 Listeria Enrichment Broth (24 LEB). Method comparison studies performed on samples with low-level inoculates showed that the BAX System demonstrates a sensitivity equivalent or superior to the U.S. Food and Drug Administration's Bacteriological Analytical Manual and the U.S. Department of Agriculture-Food Safety and Inspection Service culture methods, but with a significantly shorter time to result. Tests to evaluate inclusivity and exclusivity returned no false-negative and no false-positive results on a diverse panel of isolates, and tests for lot-to-lot variability and tablet stability demonstrated consistent performance. Ruggedness studies determined that none of the factors examined, within the range of deviations from specified parameters examined, affect the performance of the assay.

  3. Expanded polyglutamine embedded in the endoplasmic reticulum causes membrane distortion and coincides with Bax insertion

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, Masashi; Li, Shimo; Itoh, Masanori; Wang, Miao-xing; Hayakawa, Miki; Islam, Saiful; Tana; Nakagawa, Kiyomi [Department of Neurobiology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194 (Japan); Chen, Huayue [Department of Anatomy, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194 (Japan); Nakagawa, Toshiyuki, E-mail: tnakagaw@gifu-u.ac.jp [Department of Neurobiology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194 (Japan)

    2016-05-27

    The endoplasmic reticulum (ER) is important in various cellular functions, such as secretary and membrane protein biosynthesis, lipid synthesis, and calcium storage. ER stress, including membrane distortion, is associated with many diseases such as Huntington's disease. In particular, nuclear envelope distortion is related to neuronal cell death associated with polyglutamine. However, the mechanism by which polyglutamine causes ER membrane distortion remains unclear. We used electron microscopy, fluorescence protease protection assay, and alkaline treatment to analyze the localization of polyglutamine in cells. We characterized polyglutamine embedded in the ER membrane and noted an effect on morphology, including the dilation of ER luminal space and elongation of ER-mitochondria contact sites, in addition to the distortion of the nuclear envelope. The polyglutamine embedded in the ER membrane was observed at the same time as Bax insertion. These results demonstrated that the ER membrane may be a target of polyglutamine, which triggers cell death through Bax. -- Highlights: •We characterized polyglutamine embedded in the ER membrane. •The polyglutamine embedded in the ER membrane was observed at the same time as Bax insertion. •The ER membrane may be a target of polyglutamine, which triggers cell death.

  4. The Octyl Ester of Ginsenoside Rh2 Induces Lysosomal Membrane Permeabilization via Bax Translocation.

    Science.gov (United States)

    Chen, Fang; Zhang, Bing; Sun, Yong; Xiong, Zeng-Xing; Peng, Han; Deng, Ze-Yuan; Hu, Jiang-Ning

    2016-04-25

    Ginsenoside Rh2 is a potential pharmacologically active metabolite of ginseng. Previously, we have reported that an octyl ester derivative of ginsenoside Rh2 (Rh2-O), has been confirmed to possess higher bioavailability and anticancer effect than Rh2 in vitro. In order to better assess the possibility that Rh2-O could be used as an anticancer compound, the underlying mechanism was investigated in this study. The present results revealed that lysosomal destabilization was involved in the early stage of cell apoptosis in HepG2 cells induced by Rh2-O. Rh2-O could induce an early lysosomal membrane permeabilization with the release of lysosomal protease cathepsins to the cytosol in HepG2 cells. The Cat B inhibitor (leu) and Cat D inhibitor (pepA) inhibited Rh2-O-induced HepG2 apoptosis as well as tBid production and Δφm depolarization, indicating that lysosomal permeabilization occurred upstream of mitochondrial dysfunction. In addition, Rh2-O induced a significant increase in the protein levels of DRAM1 and Bax (p lysosomes of HepG2 cells. Knockdown of Bax partially inhibited Rh2-O-induced Cat D release from lysosomes. Thus it was concluded that Rh2-O induced apoptosis of HepG2 cells through activation of the lysosomal-mitochondrial apoptotic pathway involving the translocation of Bax to the lysosome.

  5. Enterovirus 71 2B Induces Cell Apoptosis by Directly Inducing the Conformational Activation of the Proapoptotic Protein Bax.

    Science.gov (United States)

    Cong, Haolong; Du, Ning; Yang, Yang; Song, Lei; Zhang, Wenliang; Tien, Po

    2016-11-01

    To survive and replicate within a host, many viruses have evolved strategies that target crucial components within the apoptotic cascade, leading to either inhibition or induction of cell apoptosis. Enterovirus 71 (EV71) infections have been demonstrated to impact the mitochondrial apoptotic pathway and induce apoptosis in many cell lines. However, the detailed mechanism of EV71-induced apoptosis remains to be elucidated. In this study, we report that EV71 2B protein (2B) localized to the mitochondria and induced cell apoptosis by interacting directly with and activating the proapoptotic protein Bax. 2B recruited Bax to the mitochondria and induced Bax conformational activation. In addition, mitochondria isolated from 2B-expressing cells that were treated with a recombinant Bax showed increased Bax interaction and cytochrome c (Cyt c) release. Importantly, apoptosis in cells with either EV71 infection or 2B expression was dramatically reduced in Bax knockdown cells but not in Bak knockdown cells, suggesting that Bax played a pivotal role in EV71- or 2B-induced apoptosis. Further studies indicate that a hydrophobic region of 18 amino acids (aa) in the C-terminal region of 2B (aa 63 to 80) was responsible for the location of 2B in the mitochondria. A hydrophilic region of 14 aa in the N-terminal region of 2B was functional in Bax interaction and its subsequent activation. Moreover, overexpression of the antiapoptotic protein Bcl-XL abrogates 2B-induced release of Cyt c and caspase activation. Therefore, this study provides direct evidence that EV71 2B induces cell apoptosis and impacts the mitochondrial apoptotic pathway by directly modulating the redistribution and activation of proapoptotic protein Bax. EV71 infections are usually accompanied by severe neurological complications. It has also been postulated that the induction of cell apoptosis resulting from tissue damage is a possible process of EV71-related pathogenesis. In this study, we report that EV71 2B

  6. Bax-induced apoptosis shortens the life span of DNA repair defect Ku70-knockout mice by inducing emphysema.

    Science.gov (United States)

    Matsuyama, Shigemi; Palmer, James; Bates, Adam; Poventud-Fuentes, Izmarie; Wong, Kelvin; Ngo, Justine; Matsuyama, Mieko

    2016-06-01

    Cells with DNA damage undergo apoptosis or cellular senescence if the damage cannot be repaired. Recent studies highlight that cellular senescence plays a major role in aging. However, age-associated diseases, including emphysema and neurodegenerative disorders, are caused by apoptosis of lung alveolar epithelial cells and neurons, respectively. Therefore, enhanced apoptosis also promotes aging and shortens the life span depending on the cell type. Recently, we reported that ku70(-) (/) (-)bax(-) (/) (-) and ku70(-) (/) (-)bax(+/) (-) mice showed significantly extended life span in comparison with ku70(-) (/) (-)bax(+/+) mice. Ku70 is essential for non-homologous end joining pathway for DNA double strand break repair, and Bax plays an important role in apoptosis. Our study suggests that Bax-induced apoptosis has a significant impact on shortening the life span of ku70(-) (/) (-) mice, which are defective in one of DNA repair pathways. The lung alveolar space gradually enlarges during aging, both in mouse and human, and this age-dependent change results in the decrease of respiration capacity during aging that can lead to emphysema in more severe cases. We found that emphysema occurred in ku70(-) (/) (-) mice at the age of three-months old, and that Bax deficiency was able to suppress it. These results suggest that Bax-mediated apoptosis induces emphysema in ku70(-) (/) (-) mice. We also found that the number of cells, including bronchiolar epithelial cells and type 2 alveolar epithelial cells, shows a higher DNA double strand break damage response in ku70 KO mouse lung than in wild type. Recent studies suggest that non-homologous end joining activity decreases with increased age in mouse and rat model. Together, we hypothesize that the decline of Ku70-dependent DNA repair activity in lung alveolar epithelial cells is one of the causes of age-dependent decline of lung function resulting from excess Bax-mediated apoptosis of lung alveolar epithelial cells (and their

  7. EGR-1/Bax pathway plays a role in vitamin E δ-tocotrienol-induced apoptosis in pancreatic cancer cells.

    Science.gov (United States)

    Wang, Chen; Husain, Kazim; Zhang, Anying; Centeno, Barbara A; Chen, Dung-Tsa; Tong, Zhongsheng; Sebti, Säid M; Malafa, Mokenge P

    2015-08-01

    The anticancer activity of δ-tocotrienol, a bioactive vitamin E present in whole grain cereals, annatto beans and palm fruit, is strongly dependent on its effect on the induction of apoptosis. δ-Tocotrienol-induced apoptosis is associated with consistent induction in the expression of the proapoptotic protein Bcl-2-associated X protein (Bax). The molecular mechanism by which δ-tocotrienol regulates Bax expression is unknown. We carried out a DNA microarray study that identified δ-tocotrienol induction of the zinc finger transcription factor EGR-1 in pancreatic cancer cells. Here, we provide evidence linking δ-tocotrienol-induced apoptosis in pancreatic cancer cells to EGR-1 regulation of Bax expression. Forced expression of EGR-1 induces Bax expression and apoptosis in pancreatic cancer cells. In contrast, knockdown of δ-tocotrienol-induced EGR-1 by small interfering RNA attenuated δ-tocotrienol-induced Bax expression and reduced δ-tocotrienol-induced apoptosis. Further analyses showed that de novo protein synthesis was not required for δ-tocotrienol-induced EGR-1 expression, suggesting a direct effect of δ-tocotrienol on EGR-1 expression. Furthermore, a chromatin immunoprecipitation assay demonstrated that EGR-1 binds to the Bax gene promoter. Finally, δ-tocotrienol treatment induced Bax expression and activated EGR-1 in the pancreatic neoplastic cells of the PDX-Cre Kras genetically engineered model of pancreatic cancer. Our study provides the first evidence for EGR-1 as a direct target of vitamin E δ-tocotrienol, suggesting that EGR-1 may act as a proapoptotic factor in pancreatic cancer cells via induction of Bax. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. MAC inhibitors antagonize the pro-apoptotic effects of tBid and disassemble Bax / Bak oligomers.

    Science.gov (United States)

    Peixoto, Pablo M; Teijido, Oscar; Mirzalieva, Oygul; Dejean, Laurent M; Pavlov, Evgeny V; Antonsson, Bruno; Kinnally, Kathleen W

    2017-02-01

    Mitochondrial Apoptotic Channel inhibitors or iMACs are di-bromocarbazole derivatives with anti-apoptotic function which have been tested and validated in several mouse models of brain injury and neurodegeneration. Owing to the increased therapeutic potential of these compounds, we sought to expand our knowledge of their mechanism of action. We investigated the kinetics of MAC inhibition in mitochondria from wild type, Bak, and Bax knockout cell lines using patch clamp electrophysiology, fluorescence microscopy, ELISA, and semiquantitative western blot analyses. Our results show that iMACs work through at least two mechanisms: 1) by blocking relocation of the cytoplasmic Bax protein to mitochondria and 2) by disassembling Bax and Bak oligomers in the mitochondrial outer membrane. iMACs exert comparable effects on channel conductance of Bax or Bak and similarly affect cytochrome c release from Bax or Bak-containing mitochondria. Interestingly, wild type mitochondria were more susceptible to inhibition than the Bak or Bax knockouts. Western blot analysis showed that wild type mitochondria had lower steady state levels of Bak in the absence of apoptotic stimulation.

  9. Tricolemoma em coelho Tricholemmoma in a rabbit

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    Krishna Duro de Oliveira

    1999-06-01

    Full Text Available Tricolemoma é um raro tumor benigno, composto por células epiteliais claras derivadas da bainha externa da raiz do folículo piloso. Esses tumores têm sido descritos no homem e raramente em cães. No presente relato, descreve-se a ocorrência de um tricolemoma, de 1cm de diâmetro em um coelho adulto, cujas características histológicas são muito semelhantes às descritas para esses tumores em cães.Tricholemmoma is a rare benign tumor composed of clear epithelial cells derived from the outer root sheath of the hair follicle. The tumor has been described in man and rarely in dogs. This report deals with the occurrence of a tricholemmoma , with a diemeter of 1cm, in an adult rabbit. The histologic features are similar to those described in such tumors in dogs.

  10. Poliarterite nodosa localizada em membros inferiores simulando tumoração de panturrilhas Localized polyarteritis nodosa resembling tumoral masses on lower extremities

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    Mauro Goldfarb

    2007-04-01

    Full Text Available É apresentado um caso inusitado de poliarterite nodosa em uma mulher de 57 anos, que se manifestou por aumento progressivo das panturrilhas, com discreta manifestação sintomática local. Entretanto, o achado resultou numa investigação laboratorial e imagenológica, mas que só teve o diagnóstico esclarecido após a realização de estudo histopatológico de biópsia muscular da panturrilha, que demonstrou tratar-se de caso de poliarterite nodosa localizada, sem nenhuma manifestação sistêmica. Revisão da literatura é apresentada.An unusual case of polyarteritis nodosa is presented in a 57 year-old woman. Progressive enlargement of her calf muscles with no significant complaints was the clinical presentation. Laboratorial and radiological investigations were not diagnostic. Unexpectedly, the histopathological study was compatible with localized polyarteritis nodosa of her calfs. Literature review is presented.

  11. AVALIAÇÃO BIOQUÍMICA DO ÁCIDO SIÁLICO COMO BIOMARCADOR TUMORAL EM NOVILHAS CRIADAS EM PROPRIEDADE ENDÊMICA PARA HEMATÚRIA ENZOÓTICA DOS BOVINOS

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    MARCOS COELHO DE CARVALHO

    2011-06-01

    Full Text Available Pteridium aquilinum (bracken fern is one of the most concerning toxic vegetables in many countries in the world. Therefore, science aims to find ways for the epidemiological control of bovine intoxication with the purpose of making early diagnoses of Bovine Enzootic Hematuriae. Researches have shown a high correlation between the excessive production of mucoprotein by animals with Bovine Enzootic Hematuriae and sialic acid, proving that this acid acts as an inflammatorybiochemical marker associated to bladder tumor development. Based on this information, serum sialic acid levels of clinically healthy Nellore heifers (control group were statistically compared to Nellore heifers raised in bracken fern endemic properties (experimental group. The average level of serum sialic acid of the control groups was not different from the sialic acid level of the affected group (0.611 ± 0.225 g/L and 0.615 ± 0.258 g/L, respectively. Results obtained in the present study demonstrate no differences of the sialic acid average levels between the groups. Therefore, measurement ofsialic acid serum levels was not effective as a neoplasic biochemical marker in Nellore heifers continuously fed with bracken fern.

  12. Wilms Tumor

    Science.gov (United States)

    Wilms tumor is a rare type of kidney cancer. It causes a tumor on one or both kidneys. It usually affects ... are at risk should be screened for Wilms tumor every three months until they turn eight. Symptoms ...

  13. Resveratrol ameliorates hypoxia/ischemia-induced brain injury in the neonatal rat via the miR-96/Bax axis.

    Science.gov (United States)

    Bian, Hongen; Shan, Haijun; Chen, Tuanying

    2017-07-18

    This study was aimed to investigate the mechanism of resveratrol on amelioration of hypoxia/ischemia (H/I)-induced brain injury. The RT-PCR and western blot were used to detect the mRNA and protein expressions, respectively. The PC12 cell induced by OGD/R was as in vitro H/I brain injury model. The luciferase reporter assay was used to prove the relationship between Bax and miR-96, and the cell apoptosis was detected by MTT assay. The loss of MBP+ area in neonatal rats analyzed by immunohistochemistry was to evaluate the extent of brain injury. The miR-96 expression was decreased in the hippocampus and cerebral cortex of neonatal rats with H/I brain injury and the oxygenglucose deprivation/re-oxygenation (OGD/R)-induced PC12 cell, while Bax expression was opposite. And then the H/I rats and OGD/R-induced PC12 cell were treated with resveratrol (RSV); the results showed that the RSV could reverse the miR-96 and Bax expressions. Next, the luciferase reporter assay proved that Bax was a target of miR-96. We used the miR-96 inhibitor to suppress miR-96 expression in OGD/R-induced PC12 cell, and found that RSV regulated Bax expression and prevented OGD/R-induced PC12 cell apoptosis via miR-96. In addition, the immunohistochemistry was used to analyze the loss of MBP+ area in neonatal rats, and the result showed that the RSV significantly reduced the brain damage, increased miR-96 expression, and decreased Bax expression, while inhibition of miR-96 aggravated the brain damage and reversed the effect of RSV. Resveratrol ameliorates hypoxia/ischemia-induced brain injury in neonatal rat via the miR-96/ Bax axis.

  14. Germ cell apoptosis and expression of Bcl-2 and Bax in porcine testis under normal and heat stress conditions.

    Science.gov (United States)

    Fan, Xiaorui; Xi, Huaming; Zhang, Zhen; Liang, Yajun; Li, Qinghong; He, Junping

    2017-04-01

    The aim of this study was to examine whether an elevated ambient temperature (37-40°C) had an effect on the apoptosis of germ cells and the expression of Bcl-2 and Bax in porcine testis. Six boars were used. Three boars were subjected to an elevated ambient temperature (37-40°C, 7days, 3h per day) as a heat stress (HS) group. The other 3 boars were kept in a room temperature house (20-27°C) as a control group. All boars were castrated and the testes were harvested. TUNEL assay was used for the detection of apoptotic cells. Immunohistochemistry, Western blotting and quantitative real-time PCR were used to analyze protein and mRNA levels of Bcl-2 and Bax in response to heat treatment. The results showed that apoptotic signals increased under heat stress conditions compared with the control (PBax protein and mRNA did not show significant changes between the control and experimental group. Low to moderate Bax immunoreactivity staining was observed in all kinds of germ cells in the control group. Strong staining was observed in spermatogonia, and low to moderate Bax staining was observed in spermatocytes and spermatids. A redistribution of Bax from a cytoplasmic to perinuclear or nuclear localization could be observed in the spermatogonia, spermatocytes and spermatids obtained in the heat treated group. These results showed that elevated ambient temperatures induced germ cell apoptosis. In response to heat stress, the expression of Bcl-2 increased and a redistribution of Bax from a cytoplasmic to a perinuclear or nuclear localization. This indicates that Bcl-2 and Bax may be involved in regulation of germ cell apoptosis induced by heat stress in boars. Copyright © 2016. Published by Elsevier GmbH.

  15. Enhancing survival of mouse oocytes following chemotherapy or aging by targeting Bax and Rad51.

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    Loro L Kujjo

    Full Text Available BACKGROUND: Therapeutic approaches to preserve fertility in females undergoing cancer treatments are currently ineffective. This is partly due to limited knowledge of the molecular mechanisms that injured germ cells elicit to repair damage and survive or to abort repair and activate biochemical pathways leading to death. So far, we know that following spontaneously occurring or drug-induced DNA damage, the efficiency of DNA repair is a critical determinant of the cell's fate. The protein encoded by the Rad51 gene is one of several components recruited for homologous recombination-dependent DNA double-strand break repair in both somatic cells and germ cells. Recently, we showed that microinjection of recombinant Rad51 into AKR/J mouse oocytes decreased the extent of spontaneous DNA double-strand breaks, suppressed apoptosis, and restored the developmental competence in AKR/J embryos. Herein we characterized the nature of chemotherapy-induced lesions in oocytes, and the associated individual components of the DNA damage sensor and repair apparatus. For comparison, we also assessed parallel spontaneous changes in aging oocytes. METHODS: Data collected were derived from: analysis of apoptosis; immunodepletion; oocyte microinjections; immunocytochemistry; immunofluorescence; and CHIP-like assays. RESULTS: Our data show that: (i DNA damage in oocytes can be induced by both chemotherapy and spontaneously by the aging process; (ii oocytes possess the machinery and capability for repairing such DNA damage; (iii Rad51 is a critical player in the repair of both chemotherapy-induced and spontaneously-sustained DNA damage; and (iv in response to damage, oocytes exhibit an inverse functional relationship between presence of Bax and activity of Rad51. CONCLUSION/SIGNIFICANCE: Our results establish Rad51 and/or Bax as potential candidates that can be targeted for development of individualized chemotherapeutic interventions that are effective, but minimal in

  16. Regulation of hydrogen peroxide production by brain mitochondria by calcium and Bax.

    Science.gov (United States)

    Starkov, Anatoly A; Polster, Brian M; Fiskum, Gary

    2002-10-01

    Abnormal accumulation of Ca2+ and exposure to pro-apoptotic proteins, such as Bax, is believed to stimulate mitochondrial generation of reactive oxygen species (ROS) and contribute to neural cell death during acute ischemic and traumatic brain injury, and in neurodegenerative diseases, e.g. Parkinson's disease. However, the mechanism by which Ca2+ or apoptotic proteins stimulate mitochondrial ROS production is unclear. We used a sensitive fluorescent probe to compare the effects of Ca2+ on H2O2 emission by isolated rat brain mitochondria in the presence of physiological concentrations of ATP and Mg2+ and different respiratory substrates. In the absence of respiratory chain inhibitors, Ca2+ suppressed H2O2 generation and reduced the membrane potential of mitochondria oxidizing succinate, or glutamate plus malate. In the presence of the respiratory chain Complex I inhibitor rotenone, accumulation of Ca2+ stimulated H2O2 production by mitochondria oxidizing succinate, and this stimulation was associated with release of mitochondrial cytochrome c. In the presence of glutamate plus malate, or succinate, cytochrome c release and H2O2 formation were stimulated by human recombinant full-length Bax in the presence of a BH3 cell death domain peptide. These results indicate that in the presence of ATP and Mg2+, Ca2+ accumulation either inhibits or stimulates mitochondrial H2O2 production, depending on the respiratory substrate and the effect of Ca2+ on the mitochondrial membrane potential. Bax plus a BH3 domain peptide stimulate H2O2 production by brain mitochondria due to release of cytochrome c and this stimulation is insensitive to changes in membrane potential.

  17. Influence of Stress on the Expression of bcl-2/bax Protein in Spontaneously Hypertensive Rats

    Institute of Scientific and Technical Information of China (English)

    刘巍; 李为民; 孙宁玲; 陈源源; 任哲; 虞有智

    2002-01-01

    Objective To explore the influence of stress-induced increased sympathetic nerve activity on cardiomyocyte apoptosis and on the development of congestive heart failure. Methods 45male, 16-week-old spontaneously hypertensive rats (SHRs) were studied, in which 6 as controls. After the 6 controlled SHRs were examined by echocardiography, they were anesthetized and killed by decapitation.The other 39 were divided into the stress group ( n =20) and the control group ( n = 19), and both groups were observed from 16-week-old to 36-week-old. In the stress group, binding- stress model was used. Till 36week, all animals were echocardiographied, weighed and killed as described above. Cardiac bcl-2 and bax protein were quantified by western blot. Circulating catecholamine and angiotensin II (Ang II) were detected by radioimmunoasssy. Results Left ventricular volume ( P < 0.05), left ventricular mass ( P<0.05) and the ratio of ventricular mass to body weight were higher in 36 week than those of the 16 week SHRs, whereas the volumes of eject fraction (EF)manifested the trend of decline, P< 0.05, bindingstress for 20 weeks made this trend significantly, P<0.05. With the increase of age, the serum nore pinephrine (NE), epinephrine (E) and Ang Ⅱ in creased, suggesting that the binding- stress triggered the activity of central sympathetic nerve system. The cardiac bcl-2 protein was higher in 36 week than 16week, P >0.05, whereas the bax protein increased significantly with the increase of age, P < 0.05, and so was the ratio of bax to bcl-2, P < 0.05. Conclusions The model of binding-stress can effectivelyactivate central sympathetic system, thus and mimic the neuroendocrine states. From 16 to 36 week, the process of cardiac apoptosis aggravated and the increased sympathetic activity would exacerbate rather than relieve this trend.

  18. Expression of Ki-67, Bcl-2 and Bax in the First Trimester Abortion Materials

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    Ender DÜZCAN

    2010-01-01

    Full Text Available Objective: The aim of this study was to investigate possible similar or different mechanisms in recurrent and spontaneous abortion by evaluating immunohistochemical correlation between proliferation marker Ki-67, and apoptosis markers Bcl-2 and Bax in the fetal trophoblasts and maternal deciduas from abortion material.Material and Method: Eighty samples of curettage materials from 65 abortion patients histopathologically diagnosed “decidua showing Arias-Stella reaction and chorionic villi” or only “decidua showing Arias-Stella reaction” were included in the study. Hematoxylin&Eosin stained sections from all cases were re-evaluated and further stained immunohistochemically using antibodies against Ki-67, Bcl-2 and Bax.Results: Proliferation rate evaluated by Ki-67 expression both in the cytotrophoblastic cells and decidua was found to be significantly lower in spontaneous and recurrent abortions compared to evacuation abortion. The extent of Bcl-2 expression in syncytiotrophoblastic cells covering villous stroma was also decreased in spontaneous abortion. There were no significant differences between spontaneous and recurrent abortions in terms of Bcl-2 expression in syncytiotrophoblasts and Ki-67 proliferation index in cytotrophoblastic cells or decidua. Bax staining showed minimal decidual expression in a few spontaneous and recurrent abortions.Conclusion: We concluded that proliferation rate was decreased in fetal villous cytotrophoblasts and maternal deciduas in spontaneous and recurrent abortions. We also proposed that loss of Bcl-2 expression in syncytiotrophoblasts may cause abortion in a subset of cases. However, the data from spontaneous and recurrent abortions did not not support the presence of different mechanisms in both groups.

  19. Complicações das endopróteses em pacientes com tumores ósseos do joelho Endoprostheses-related complications in patients with bone tumors of the knee

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    Vinicius Ynoe de Moraes

    2011-01-01

    Full Text Available As endopróteses não convencionais (ENC são frequentemente utilizadas na ortopedia oncológica. As complicações do procedimento é motivo de pesquisa, pois há a instituição deste em população jovem e com grande potencial de sobrevida. Nós conduzimos uma revisão da literatura com o objetivo de buscar a melhor evidência científica relativa ao tema. A pesquisa englobou as bases: MEDLINE, EMBASE, CINAHL e o Registro Central Cochrane de ensaios clínicos randomizados (ECR, objetivando identificar estudos reportando complicações, e a substituição ou não da superfície articular da patela. Os estudos foram selecionados de acordo com a melhor qualidade metodológica existente para o assunto. Cento e quarenta e seis (146 estudos foram avaliados. Nenhum ERC foi encontrado. Realizamos uma avaliação qualitativa e quantitativa dos trabalhos encontrados (níveis de evidência IV e V. Utilizou-se o teste de U de Mann-Whitney para a análise estatística. Os resultados apontam para a necessidade de produção de novos estudos, para que se possa chegar a uma conclusão mais sólida. Pode-se considerar altas as taxas de complicações pós ENC, a despeito da baixa qualidade dos estudos, conforme demonstra os estudos existentes na literatura.Non-conventional endoprostheses (NCE are frequently used in orthopedic oncology. The complications associated with this procedure have prompted research, due to the fact that it is commonly performed on young patients, with a higher survival rate. We conducted a systematic review of the literature, searching for the best scientific evidence on the subject. The research was carried out in the following databases: MEDLINE, EMBASE, CINAHL and the Cochrane Central Register of randomized controlled trials (CCTR, seeking to identify studies that report complications, and compare patellar resurfacing versus retention. The studies were selected according to the best methodological quality that exists for the

  20. Effect of Flunarizine on the Expression of Bax mRNA in Hippocampus of Amygdala Kindling Seizures Rat%氟桂利嗪对杏仁核点燃鼠海马Bax mRNA表达的影响

    Institute of Scientific and Technical Information of China (English)

    梁代义; 伍国锋; 董佑忠; 庞成

    2005-01-01

    目的:观察氟桂利嗪对杏仁核点燃鼠癎性发作及海马促凋亡基因Bax mRNA表达的影响.方法:建立杏仁核点燃模型,予不同剂量氟桂利嗪灌喂点燃鼠.原位杂交法检测鼠脑海马Bax mRNA表达,图像分析软件测量阳性细胞平均吸光度.结果:正常大鼠海马存在少量Bax mRNA表达阳性细胞,点燃鼠海马各区Bax mRNA表达阳性细胞数及平均吸光度增加,氟桂利嗪处理后平均吸光度下降与剂量有关.结论:氟桂利嗪具有抗癫癎效应和拮抗点燃鼠海马Bax mRNA表达的作用.

  1. Bcl-2/Bax protein ratio predicts 5-fluorouracil sensitivity independently of p53 status

    OpenAIRE

    Mirjolet, J-F; Barberi-Heyob, M; Didelot, C; Peyrat, J-P; Abecassis, J; Millon, R.; Merlin, J-L

    2000-01-01

    p53 tumour-suppressor gene is involved in cell growth control, arrest and apoptosis. Nevertheless cell cycle arrest and apoptosis induction can be observed in p53-defective cells after exposure to DNA-damaging agents such as 5-fluorouracil (5-FU) suggesting the importance of alternative pathways via p53-independent mechanisms. In order to establish relationship between p53 status, cell cycle arrest, Bcl-2/Bax regulation and 5-FU sensitivity, we examined p53 mRNA and protein expression and p53...

  2. NFAT2 mediates high glucose-induced glomerular podocyte apoptosis through increased Bax expression

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ruizhao, E-mail: liruizhao1979@126.com [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Zhang, Li, E-mail: Zhanglichangde@163.com [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Southern Medical University, Guangzhou, Guangdong (China); Shi, Wei, E-mail: shiwei.gd@139.com [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Zhang, Bin, E-mail: zhangbinyes@yahoo.com.cn [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Liang, Xinling, E-mail: xinlingliang@yahoo.com [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Liu, Shuangxin, E-mail: mplsxi@yahoo.com.cn [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China); Wang, Wenjian, E-mail: wwjph@yahoo.com [Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan No. 2 Road, Guangzhou, 510080 (China)

    2013-04-15

    Background: Hyperglycemia promotes podocyte apoptosis and plays a key role in the pathogenesis of diabetic nephropathy. However, the mechanisms that mediate hyperglycemia-induced podocyte apoptosis is still far from being fully understood. Recent studies reported that high glucose activate nuclear factor of activated T cells (NFAT) in vascular smooth muscle or pancreatic β-cells. Here, we sought to determine if hyperglycemia activates NFAT2 in cultured podocyte and whether this leads to podocyte apoptosis. Meanwhile, we also further explore the mechanisms of NFAT2 activation and NFAT2 mediates high glucose-induced podocyte apoptosis. Methods: Immortalized mouse podocytes were cultured in media containing normal glucose (NG), or high glucose (HG) or HG plus cyclosporine A (a pharmacological inhibitor of calcinerin) or 11R-VIVIT (a special inhibitor of NFAT2). The activation of NFAT2 in podocytes was detected by western blotting and immunofluorescence assay. The role of NFAT2 in hyperglycemia-induced podocyte apoptosis was further evaluated by observing the inhibition of NFAT2 activation by 11R-VIVIT using flow cytometer. Intracellular Ca{sup 2+} was monitored in HG-treated podcocytes using Fluo-3/AM. The mRNA and protein expression of apoptosis gene Bax were measured by real time-qPCR and western blotting. Results: HG stimulation activated NFAT2 in a time- and dose-dependent manner in cultured podocytes. Pretreatment with cyclosporine A (500 nM) or 11R-VIVIT (100 nM) completely blocked NFAT2 nuclear accumulation. Meanwhile, the apoptosis effects induced by HG were also abrogated by concomitant treatment with 11R-VIVIT in cultured podocytes. We further found that HG also increased [Ca{sup 2+}]i, leading to activation of calcineurin, and subsequent increased nuclear accumulation of NFAT2 and Bax expression in cultured podocytes. Conclusion: Our results identify a new finding that HG-induced podocyte apoptosis is mediated by calcineurin/NFAT2/Bax signaling pathway

  3. Robotic assistance for performing vocational rehabilitation activities using BaxBot.

    Science.gov (United States)

    Ashley, Kyle; Alqasemi, Redwan; Dubey, Rajiv

    2017-07-01

    Activities of Daily Living (ADL's) refer to tasks that people do on a daily basis, such as self-feeding, cleaning the house, or bathing. These activities often require a degree of functional mobility that may be outside the ability of a person suffering from cognitive or physical impairment. This work describes methods of performing ADL's with a mobile robotic system. We examined the needs of potential users and caregivers through surveys to determine the most needed applications for robotic assistance. Using this information, we extended the functionality of our BaxBot mobile robotic system to provide meaningful, autonomous assistance in performing three specific ADL's with minimal user interaction.

  4. Pristimerin, a Triterpenoid, Inhibits Tumor Angiogenesis by Targeting VEGFR2 Activation

    Directory of Open Access Journals (Sweden)

    Luyong Zhang

    2012-06-01

    Full Text Available Pristimerin is a triterpenoid isolated from <em>Celastrus em>and <em>Maytenus spp.em>> em>that> em>has been shown to possess a variety of biological activities, including anti-cancer activity. However, little is known about pristimerin’s effects on tumor angiogenesis. In this study, we examined the function and the mechanism of this compound in tumor angiogenesis<em> em>using multiple angiogenesis assays. We found that pristimerin significantly reduced both the volume and weight of solid tumors and decreased angiogenesis in a xenograft mouse tumor model<em> in vivoem>. Pristimerin significantly inhibited the neovascularization of chicken chorioallantoic membrane (CAM<em> in vivoem>> em>and abrogated vascular endothelial growth factor (VEGF-induced microvessel sprouting in an<em> ex vivoem> rat aortic ring assay. Furthermore, pristimerin inhibited the VEGF-induced proliferation, migration and capillary-like structure formation of human umbilical vascular endothelial cells (HUVECs in a concentration-dependent manner. Mechanistic studies revealed that pristimerin suppressed the VEGF-induced phosphorylation of VEGF receptor 2 kinase (KDR/Flk-1 and the activity of AKT, ERK1/2, mTOR, and ribosomal protein S6 kinase. Taken together, our results provide evidence for the first time that pristimerin potently suppresses angiogenesis by targeting VEGFR2 activation. These results provide a novel mechanism of action for pristimerin which may be important in the treatment of cancer.

  5. E2F is involved in radioresistance of carbon ion induced apoptosis via Bax/caspase 3 signal pathway in human hepatoma cell.

    Science.gov (United States)

    Xie, Yi; Si, Jing; Wang, Yu-Pei; Li, Hong-Yan; Di, Cui-Xia; Yan, Jun-Fang; Ye, Yan-Cheng; Zhang, Yan-Shan; Zhang, Hong

    2017-05-13

    Deletion of p53, most common genetic alteration, is observed in human tumors and reported to lead to improve in cell radioresistance. Heavy-ion irradiation (IR) could induce p53(-/-) cancer cells apoptosis. However, little is known regarding the molecular mechanism in this type of cell apoptosis. The present studies have focused on mechanisms state of signaling pathways as an activator of the cell fate decisions induced by heavy ion IR without p53. Carbon ion IR could induce up-regulation of E2F1 expression in cancer cells. This phenomenon was not observed in X-ray IR group. Up-regulation of E2F1 could cause a higher reduction in clonogenic survival, low level of cellular activity, G2 /M phase arrest, promotion of apoptosis rate, up-regulation of phosphor-Rb, Bax, and cleaved-caspase 3 proteins expressions without p53. Changes of E2F1 expressions could partly alter radioresistance in cancer cells. The results were suggested that heavy ion IR could induce p53(-/-) cancer cells apoptosis via E2F1 signal pathway. Our study provides a scientific rationale for the clinical use of heavy ion as radiotherapy in patients with p53-deficient tumors, which are often resistant to radiotherapy. © 2017 Wiley Periodicals, Inc.

  6. Reconstrução de ponte nasal com tela de titânio após exérese tumoral em um cão Nasal bridge reconstruction with titanium mesh after tumor excision in a dog

    Directory of Open Access Journals (Sweden)

    Renan Marcel Krüger

    2011-03-01

    Full Text Available O presente trabalho relata o uso de tela de titânio como alternativa para reconstrução do defeito ósseo criado pela ressecção agressiva de carcinoma de células escamosas da ponte nasal em cão. Após o tratamento quimioterápico com 5-fluorouracil tópico e sistêmico associado à piroxicam para a redução da massa tumoral, foi realizada a ressecção cirúrgica da região comprometida e reparo do defeito ósseo com tela de titânio e posterior recobrimento com retalho músculo-cutâneo unipediculado de avanço. A principal complicação no período pós-operatório foi a formação de enfisema subcutâneo, controlado em três dias com drenagem do ar e aplicação de bandagens compressivas. O animal permaneceu sem sinais de recidiva por oito meses. No décimo mês pós-operatório, o paciente apresentou miíase no local da recidiva e a proprietária optou pela eutanásia. Com esse caso, foi possível concluir que a tela de titânio foi um material adequado para a reconstrução da ponte nasal, tendo como principal complicação a ocorrência de enfisema subcutâneo.This paper describes the use of titanium mesh as an alternative for reconstruction of bone defect created by resection of aggressive squamous cell carcinoma of the nasal bridge in a dog. After chemotherapy with topic and systemic 5-fluorouracil associated with piroxicam for the tumor mass reduction, it was performed a surgical resection of the affected region, repair of bone defects with titanium mesh and subsequent closing of the wound with musculocutaneous single pedicle advancement flap. The main complication in the postoperative period was the formation of subcutaneous emphysema, which was controlled in three days with air drainage and application of compression bandages. The animal remained without signs of recurrence for eight months. In the tenth month postoperatively, the patient presented myiasis in local recurrence and the owner opted for euthanasia. In this case, it

  7. NOXA-induced alterations in the Bax/Smac axis enhance sensitivity of ovarian cancer cells to cisplatin.

    Directory of Open Access Journals (Sweden)

    Chao Lin

    Full Text Available Ovarian cancer is the most common cause of death from gynecologic malignancy. Deregulation of p53 and/or p73-associated apoptotic pathways contribute to the platinum-based resistance in ovarian cancer. NOXA, a pro-apoptotic BH3-only protein, is identified as a transcription target of p53 and/or p73. In this study, we found that genetic variants of Bcl-2 proteins exist among cisplatin-sensitive and -resistant ovarian cancer cells, and the responses of NOXA and Bax to cisplatin are regulated mainly by p53. We further evaluated the effect of NOXA on cisplatin. NOXA induced apoptosis and sensitized A2780s and SKOV3 cells to cisplatin in vitro and in vivo. The effects were mediated by elevated Bax expression, enhanced caspase activation, release of Cyt C and Smac into the cytosol. Furthermore, gene silencing of Bax or Smac significantly attenuated NOXA and/or cisplatin-induced apoptosis in chemosensitive A2780s cells, whereas overexpression of Bax or addition of Smac-N7 peptide significantly increased NOXA and/or cisplatin-induced apoptosis in chemoresistant SKOV3 cells. To our knowledge, these data suggest a new mechanism by which NOXA chemosensitized ovarian cancer cells to cisplatin by inducing alterations in the Bax/Smac axis. Taken together, our findings show that NOXA is potentially useful as a chemosensitizer in ovarian cancer therapy.

  8. NOXA-induced alterations in the Bax/Smac axis enhance sensitivity of ovarian cancer cells to cisplatin.

    Science.gov (United States)

    Lin, Chao; Zhao, Xin-yu; Li, Lei; Liu, Huan-yi; Cao, Kang; Wan, Yang; Liu, Xin-yu; Nie, Chun-lai; Liu, Lei; Tong, Ai-ping; Deng, Hong-xin; Li, Jiong; Yuan, Zhu; Wei, Yu-quan

    2012-01-01

    Ovarian cancer is the most common cause of death from gynecologic malignancy. Deregulation of p53 and/or p73-associated apoptotic pathways contribute to the platinum-based resistance in ovarian cancer. NOXA, a pro-apoptotic BH3-only protein, is identified as a transcription target of p53 and/or p73. In this study, we found that genetic variants of Bcl-2 proteins exist among cisplatin-sensitive and -resistant ovarian cancer cells, and the responses of NOXA and Bax to cisplatin are regulated mainly by p53. We further evaluated the effect of NOXA on cisplatin. NOXA induced apoptosis and sensitized A2780s and SKOV3 cells to cisplatin in vitro and in vivo. The effects were mediated by elevated Bax expression, enhanced caspase activation, release of Cyt C and Smac into the cytosol. Furthermore, gene silencing of Bax or Smac significantly attenuated NOXA and/or cisplatin-induced apoptosis in chemosensitive A2780s cells, whereas overexpression of Bax or addition of Smac-N7 peptide significantly increased NOXA and/or cisplatin-induced apoptosis in chemoresistant SKOV3 cells. To our knowledge, these data suggest a new mechanism by which NOXA chemosensitized ovarian cancer cells to cisplatin by inducing alterations in the Bax/Smac axis. Taken together, our findings show that NOXA is potentially useful as a chemosensitizer in ovarian cancer therapy.

  9. Cytosolic BNIP3 Dimer Interacts with Mitochondrial BAX Forming Heterodimers in the Mitochondrial Outer Membrane under Basal Conditions.

    Science.gov (United States)

    Hendgen-Cotta, Ulrike B; Esfeld, Sonja; Rudi, Katharina; Miinalainen, Ilkka; Klare, Johann P; Rassaf, Tienush

    2017-03-23

    The primary function of mitochondria is energy production, a task of particular importance especially for cells with a high energy demand like cardiomyocytes. The B-cell lymphoma (BCL-2) family member BCL-2 adenovirus E1B 19 kDa-interacting protein 3 (BNIP3) is linked to mitochondrial targeting after homodimerization, where it functions in inner membrane depolarization and permeabilization of the mitochondrial outer membrane (MOM) mediating cell death. We investigated the basal distribution of cardiac BNIP3 in vivo and its physical interaction with the pro-death protein BCL2 associated X, apoptosis regulator (BAX) and with mitochondria using immunoblot analysis, co-immunoprecipitation, and continuous wave and pulsed electron paramagnetic resonance spectroscopy techniques. We found that BNIP3 is present as a dimer in the cytosol and in the outer membrane of cardiac mitochondria under basal conditions. It forms disulfide-bridged, but mainly non-covalent dimers in the cytosol. Heterodimers with BAX are formed exclusively in the MOM. Furthermore, our results suggest that BNIP3 interacts with the MOM directly via mitochondrial BAX. However, the physical interactions with BAX and the MOM did not affect the membrane potential and cell viability. These findings suggest that another stimulus other than the mere existence of the BNIP3/BAX dimer in the MOM is required to promote BNIP3 cell-death activity; this could be a potential disturbance of the BNIP3 distribution homeostasis, namely in the direction of the mitochondria.

  10. BH3 domains of BH3-only proteins differentially regulate Bax-mediated mitochondrial membrane permeabilization both directly and indirectly.

    Science.gov (United States)

    Kuwana, Tomomi; Bouchier-Hayes, Lisa; Chipuk, Jerry E; Bonzon, Christine; Sullivan, Barbara A; Green, Douglas R; Newmeyer, Donald D

    2005-02-18

    Using a Bax-dependent membrane-permeabilization assay, we show that peptides corresponding to the BH3 domains of Bcl-2 family "BH3-only" proteins have dual functions. Several BH3 peptides relieved the inhibition of Bax caused by the antiapoptotic Bcl-x(L) and/or Mcl-1 proteins, some displaying a specificity for either Bcl-x(L) or Mcl-1. Besides having this derepression function, the Bid and Bim peptides activated Bax directly and were the only BH3 peptides tested that could potently induce cytochrome c release from mitochondria in cultured cells. Furthermore, Bax activator molecules (cleaved Bid protein and the Bim BH3 peptide) synergistically induced cytochrome c release when introduced into cells along with derepressor BH3 peptides. These observations support a unified model of BH3 domain function, encompassing both positive and negative regulation of other Bcl-2 family members. In this model, the simple inhibition of antiapoptotic functions is insufficient to induce apoptosis unless a direct activator of Bax or Bak is present.

  11. Deregulated expression of A1, Bcl-2, Bcl-xL, and Mcl-1 antiapoptotic proteins and Bid, Bad, and Bax proapoptotic genes in polycythemia vera patients

    Directory of Open Access Journals (Sweden)

    Elainy Patricia Lino Gasparotto

    2011-12-01

    Full Text Available Apoptosis deregulation might have a role in the pathophysiology of polycythemia vera (PV. This study evaluated Bcl-2 molecule expression in CD34+ cells and leukocytes in 12 PV patients. Gene expression was investigated by real time PCR using SybrGreen Quantitect kit and protein expression was evaluated by western-blotting. JAK2 V617F mutation was detected according to Baxter et al (2005. CD34+ cells from PV patients presented higher levels of A1 and Mcl-1 expression (median: 22.6 and 5.2, respectively in comparison with controls (0.9 and 0.5, p=0.004 and p=0.020; while Bcl-2 and Bcl-xL expression decreased in PV patients (0.18 and 1.19 compared with controls (1.39 and 2.01, p=0.006 and p=0.020. CD34+ cells in PV patients showed an elevated Bid expression (14.4 in comparison with healthy subjects (1.0; p=0.002. Patients' leukocytes showed an A1 augmentation (7.41, p=0.001 and a reduced expression of Bax (0.19; p=0.040 and Bad (0.2; p=0.030. There was no correlation between JAK2 V617F allele burden and molecular expression. PV patients showed alterations in Bcl-2 members' expression, which may interfere with control of apoptotic machinery and contribute to disease pathogenesis.A desregulação da apoptose parece participar da fisiopatologia da policitemia vera (PV. Este estudo avaliou a expressão das moléculas da família Bcl-2 em células hematopoéticas CD34 + e leucócitos de 12 pacientes com PV. Foram realizados: a quantificação da expressão gênica por PCR em tempo real utilizando kit Sybrgreen Quantitect, avaliação da expressão de proteínas por western-blot e detecção da mutação JAK2 V617F segundo Baxter et al. (2005. Células CD34 + dos pacientes com PV apresentaram maior expressão de A1 e Mcl-1 (mediana: 22,6 e 5,2, respectivamente em comparação com controles (0,9 e 0,5, p = 0,004 e p = 0,020 e expressão de Bcl-2 e Bcl-xL diminuída nestes pacientes (0,18 e 1,19 em relação aos controles (1,39 e 2,01, p = 0,006 e p = 0

  12. Pituitary Tumors

    Science.gov (United States)

    ... institutes of the National Institutes of Health (NIH) conduct research related to brain tumors, including pituitary tumors, in their laboratories at ... institutes of the National Institutes of Health (NIH) conduct research related to brain tumors, including pituitary tumors, in their laboratories at ...

  13. The Effect of Atorvastatin and Nicorandil on Bcl-2 and Bax in Isolated and Reperfusion Rabbit Hearts%阿托伐他汀和尼可地尔后处理对兔心肌缺血再灌注心功能及 Bcl-2、Bax 的影响

    Institute of Scientific and Technical Information of China (English)

    李艳芳; 费丽萍; 常志红

    2016-01-01

    Objective:To observe the heart function and Bcl-2,Bax of Atorvastat in and Nicorandil on ischemia and reperfusion induced injury in rabbit heart.Methods:50 rabbits were randomly divided into 5 groups,and the myocardial ischemia-reperfusion were generated by two sutures and two knots,then administrated in accordance with the experimental design,monitoring ECG and left ventricular pressure,testing CK,cTnI in serum,observing the changes of myocardial structure,testing Bcl-2 and Bax by RT-PCR.Results:The LVSP and ± dp/dt max levels of group C-E were significantly higher than that of group B(P <0.05).On the contrary,the LVEDP was lower than that of group B(P <0.01).The CK and cTnI levels of group C-E were lower than B(P <0.01).The injury of group B was worse than C-E of the cellular structure under EM.The BCL-2 and Bax mRNA levels of group B-E were significantly higher than that of group A(P <0.05 ),and BCL-2 C-E higher than B,The contrary,however,the bax was lower than that of group B.Conclusion:Myocardial isehemic postconditioning of Atorvastatin and Nicorandil induced cardio protection on ischemia reperfusion injury in rabbits.They can improve myocardial systolic and diastolic function,maybe through reducing cell apoptosis.%目的::建立缺血再灌注模型,观察阿托伐他汀和尼可地尔后处理对兔心肌缺血再灌注心功能及 Bcl-2、Bax 的影响。方法:50只大白兔随机分成5组[假手术组(A)、对照组(B)、阿托伐他汀组(C)、尼可地尔组(D)、联合后处理组(E)],采用“二线二结法”建立缺血再灌注模型。各组按照实验设计方案给药,记录心电图、血流动力学指标。采集血液标本,试剂盒检测 CK、cTnI。电镜下观察各组心肌细胞超微结构变化。双色实时荧光定量 PCR 检测 Bcl-2、Bax。结果:(1)再灌注2 h,C~E 组 LVSP 高于 B 组(P <0.05),±dp/dt max 高于 B 组(P <0.01),而 LVEDP 低于 B 组(P <0.01)。其中,C、D 组无显著性差异, E 组 LVSP

  14. PUMA promotes Bax translocation in FOXO3a-dependent pathway during STS-induced apoptosis

    Science.gov (United States)

    Zhang, Yingjie; Chen, Qun

    2009-08-01

    PUMA (p53 up-regulated modulator of apoptosis, also called Bbc3) was first identified as a BH3-only Bcl-2 family protein that is transcriptionally up-regulated by p53 and activated upon p53-dependent apoptotic stimuli, such as treatment with DNA-damaging drugs or UV irradiation. Recently studies have been shown that Puma is also up-regulated in response to certain p53-independent apoptotic stimuli, such as growth factor deprivation or treatment with glucocorticoids or STS (staurosporine). However, the molecular mechanisms of PUMA up-regulation and how PUMA functions in response to p53-independent apoptotic stimuli remain poorly understood. In this study, based on real-time single cell analysis, flow cytometry and western blotting technique, we investigated the function of PUMA in living human lung adenocarcinoma cells (ASTC-a-1) after STS treatment. Our results show that FOXO3a was activated by STS stimulation and then translocated from cytosol to nucleus. The expression of PUMA was up-regulated via a FOXO3a-dependent manner after STS treatment, while p53 had little function in this process. Moreover, cell apoptosis and Bax translocation induced by STS were not blocked by Pifithrin-α (p53 inhibitor), which suggested that p53 was not involved in this signaling pathway. Taken together, these results indicate that PUMA promoted Bax translocation in a FOXO3a-dependment pathway during STS-induced apoptosis, while p53 was dispensable in this process.

  15. Bz-423 superoxide signals B cell apoptosis via Mcl-1, Bak, and Bax.

    Science.gov (United States)

    Blatt, Neal B; Boitano, Anthony E; Lyssiotis, Costas A; Opipari, Anthony W; Glick, Gary D

    2009-10-15

    Bz-423 is a pro-apoptotic 1,4-benzodiazepine with therapeutic properties in murine models of lupus demonstrating selectivity for autoreactive lymphocytes. Bz-423 modulates the F(1)F(0)-ATPase, inducing the formation of superoxide within the mitochondrial respiratory chain, which then functions as a second messenger initiating apoptosis. In order to understand some of the features that contribute to the increased sensitivity of lymphocytes, we report the signaling pathway engaged by Bz-423 in a Burkitt lymphoma cell line (Ramos). Following the generation of superoxide, Bz-423-induced apoptosis requires the activation of Bax and Bak to induce mitochondrial outer membrane permeabilization and cytochrome c release. Knockdown of the BH3-only proteins Bad, Bim, Bik, and Puma inhibits Bz-423 apoptosis, suggesting that these proteins serve as upstream sensors of the oxidant stress induced by Bz-423. Treatment with Bz-423 results in superoxide-dependent Mcl-1 degradation, implicating this protein as the link between Bz-423-induced superoxide and Bax and Bak activation. In contrast to fibroblasts, B cell death induced by Bz-423 is independent of c-Jun N-terminal kinase. These results demonstrate that superoxide generated from the mitochondrial respiratory chain as a consequence of a respiratory transition can signal a specific apoptotic response that differs across cell types.

  16. Bz-423 superoxide signals apoptosis via selective activation of JNK, Bak, and Bax.

    Science.gov (United States)

    Blatt, Neal B; Boitano, Anthony E; Lyssiotis, Costas A; Opipari, Anthony W; Glick, Gary D

    2008-11-01

    Bz-423 is a proapoptotic 1,4-benzodiazepine with potent therapeutic properties in murine models of lupus and psoriasis. Bz-423 modulates the F(1)F(0)-ATPase, inducing the formation of superoxide within the mitochondrial respiratory chain, which then functions as a second messenger initiating apoptosis. Herein, we report the signaling pathway activated by Bz-423 in mouse embryonic fibroblasts containing knockouts of key apoptotic proteins. Bz-423-induced superoxide activates cytosolic ASK1 and its release from thioredoxin. A mitogen-activated protein kinase cascade follows, leading to the specific phosphorylation of JNK. JNK signals activation of Bax and Bak which then induces mitochondrial outer membrane permeabilization to cause the release of cytochrome c and a commitment to apoptosis. The response of these cells to Bz-423 is critically dependent on both superoxide and JNK activation as antioxidants and the JNK inhibitor SP600125 prevents Bax translocation, cytochrome c release, and cell death. These results demonstrate that superoxide generated from the mitochondrial respiratory chain as a consequence of a respiratory transition can signal a sequential and specific apoptotic response. Collectively, these data suggest that the selectivity of Bz-423 observed in vivo results from cell-type specific differences in redox balance and signaling by ASK1 and Bcl-2 proteins.

  17. Frequência de anticorpos aos agentes etiológicos da síndrome da imunodeficiência adquirida, sífilis, hepatites virais B e C e doença de Chagas em pacientes reumatológicos em tratamento com antifator de necrose tumoral (Tumor Necrosis Factor - TNF Frequency of antibodies against the etiologic agents of acquired imunodeficiency syndrome, syphilis, hepatitis B and C, and Chagas' disease in patients with rheumatic diseases treated with anti-tumor necrosis factor

    Directory of Open Access Journals (Sweden)

    Bárbara Santos Pires da Silva

    2009-10-01

    Full Text Available INTRODUÇÃO: Os pacientes reumatológicos em terapia com antifator de necrose tumoral (anti-TNF, Tumor Necrosis Factor são considerados imunodeprimidos. Neste sentido, a pesquisa de doenças infecciosas nesta população é imperiosa devido à alta morbidade e, por vezes, mortalidade associada a este quadro. OBJETIVOS: O presente trabalho teve por objetivo avaliar a frequência de soropositividade para os seguintes agentes infecciosos: Treponema pallidum (sífilis, Trypanosoma cruzii (doença de Chagas, vírus da imunodeficiência humana adquirida (Human imunnodeficiency Virus - HIV e hepatites B e C (HBV e HCV, respectivamente em pacientes recebendo terapia anti-TNF. PACIENTES E MÉTODOS: Foram avaliados 143 pacientes reumatológicos em um estudo observacional, com artrite reumatoide, espondilite anquilosante, artrite psoriásica e outras doenças, em uso de terapia anti-TNF (adalimumabe, etanercepte e infliximabe no período de setembro de 2007 a novembro de 2008. Foram coletados dados clínicos e demográficos, bem como uma amostra de sangue para a análise da presença de anticorpos contra os agentes infecciosos HIV (Aids, HBV e HCV (hepatites B e C, respectivamente, Treponema pallidum (sífilis e Trypanosoma cruzii (doença de Chagas. RESULTADOS: A média de idade da população estudada foi de 45,78 ± 12,7 anos, sendo 60,1% do sexo feminino e 76,9% de cor branca. Treze (9% dos pacientes apresentaram pelo menos uma sorologia positiva. Nenhum dos pacientes apresentou sorologia positiva para o Trypanosoma cruzii (doença de Chagas, bem como para HIV. Somente dois (1,4% indivíduos apresentaram positividade para o Treponema pallidum (sífilis (ELISA positivo e VDRL negativo. A frequência de anti-HBc total foi de 5% (7/140, sendo que todos estes foram positivos também para anti-HBs. O HBsAg foi negativo em todos os pacientes. Quatro pacientes tiveram HCV positivo, sendo que dois deles tinham PCR negativo para o vírus e os outros dois

  18. Wilms' tumor suppressor gene (WT1) suppresses apoptosis by transcriptionally downregulating BAX expression in immature rat granulosa cells

    National Research Council Canada - National Science Library

    Park, Minji; Choi, Yuri; Choi, Hyeonhae; Roh, Jaesook

    2014-01-01

    The important role of WT1 in early folliculogenesis was evident from its restricted expression pattern in immature follicles and from its involvement in transcriptional control of inhibin-α and FSH receptor...

  19. Ionic conduction in BaxCe0.8Pr0.2O3-

    Institute of Scientific and Technical Information of China (English)

    WANG; Maoyuan

    2009-01-01

    [1]Iwahara H,Yajima T,Ushida H.Effect of ionic radii of dopants on mixed ionic conductions (H++O2) in BaCeO3-based electrolytes.SolidState Ionics,1994,70/71:267.[2]Taniguchi N,Yasumoto E,Nakagiri Y,Gamo T.Sensing properties of an oxygen sensor using BaCe0.8Gd0.2O3-a ceram-ics as electrolytes.J.Electrochem.Soc.,1998,145(5):1744.[3]de Arcllano-Lopez A R,Goretta K C,Park E T,Dorris S E,Balchandran U,Routbort J L.High-temperature deformation of a BaCe0.8Y0.2O3-y+Ni composite.J.Fur.Ceram.Soc.,2002,22:2555.[4]Ma G L,Shimura T,Iwahara H.Ionic conduction and non-stoichiometry in BaxCe0.90Y0.10O3-a.Solid State lonics,1998,110:103.[5]Ma G L,Matsumoto H,Iwahara H.Ionic conduction and non-stoichiometry in non-doped BaxCeO3-a.Solid State Ionics,1999,122:237.[6]Ma Guilin,Qiu Ligan,Chen Rong.Performance of the solid oxide fuel cell based on BaxCe0.8Sm0.2O3-a.Acta Chimica Sinica (in Chin.),2002,60(12):2135.[7]Ma G L,Qiu L G,Tao W H,Zhou L,Chen R.Ionic conduc-tion in BaxCe0.8Sm0.2O3-a solid electrolyte.J.Chin.Rare Earths Soc.(in Chin.),2003,21(2):236.[8]Qiu L G,Ma G L,Wen D J.Study on preparation and electri-cal properties of Ba1.03Ce0.8Eu0.2O3-a solid electrolyte.J.Rare Earths,2004,22(5):678.[9]Qiu L G,Ma G L,Wen D J.Ionic conduction in BaxCe0.8Er0.2O3-a.Solid State lonics,2004,166:69.[10]Wang M Y,Qin L G.Mixed conduction in BaCe0.8Pr0.2O3-a ceramic.Chin.J.Chem.Phys.,2008,21:286.[11]Bonanos N.Transport properties and conduction mechanism in high-temperature protonic conductots.Solid State Ionics,1992,53-56:967.[12]Ma G L,Shimura T,Iwahara H.Simultaneous doping with La3+ and y3+ for Ba2+-and Ce4+-sites in BaCeO3 and the ionic conduction.Solid State Ionics,1999,120:51.[13]Shima D,Halle S M.The influence of cation non-stoichiome-try on the properties of undoped and gadolinia-doped barium ceres.Solid State Ionics,1997,97:443.

  20. Oral tumors in dogs: clinical aspects, exfoliative cytology and histopathology Neoplasias orais em cães: avaliação dos aspectos clínicos, histopatologia e citologia esfoliativa

    OpenAIRE

    Cláudia Ronca Felizzola; Angelo João Stopiglia; Ney Soares de Araújo

    1999-01-01

    In order to establish the diagnosis and prognosis of tumors of the oral cavity, a comparative study was carried out in 130 dogs considering age, sex, breed, clinical aspects, exfoliative cytology as well as histopathology. Exfoliative cytology revealed: 100% negative for benign non-odontogenic tumors, 97.91% negative benign odontogenic tumors and 77.92% positive for malignant tumors. Histopathology showed: 59.23% malignant tumors (33.08% malignant melanoma, 9.23% squamous cell carcinoma, 5.38...

  1. BAX and BAK1 are dispensable for ABT-737-induced dissociation of the BCL2-BECN1 complex and autophagy.

    Science.gov (United States)

    Pedro, Jose Manuel Bravo-San; Wei, Yongjie; Sica, Valentina; Maiuri, Maria Chiara; Zou, Zhongju; Kroemer, Guido; Levine, Beth

    2015-01-01

    Disruption of the complex of BECN1 with BCL2 or BCL2L1/BCL-XL is an essential switch that turns on cellular autophagy in response to environmental stress or treatment with BH3 peptidomimetics. Recently, it has been proposed that BCL2 and BCL2L1/BCL-XL may inhibit autophagy indirectly through a mechanism dependent on the proapoptotic BCL2 family members, BAX and BAK1. Here we report that the BH3 mimetic, ABT-737, induces autophagy in parallel with disruption of BCL2-BECN1 binding in 2 different apoptosis-deficient cell types lacking BAX and BAK1, namely in mouse embryonic fibroblasts cells and in human colon cancer HCT116 cells. We conclude that the BH3 mimetic ABT-737 induces autophagy through a BAX and BAK1-independent mechanism that likely involves disruption of BECN1 binding to antiapoptotic BCL2 family members.

  2. Exhaustive Training Increases Uncoupling Protein 2 Expression and Decreases Bcl-2/Bax Ratio in Rat Skeletal Muscle

    Directory of Open Access Journals (Sweden)

    W. Y. Liu

    2013-01-01

    Full Text Available This work investigates the effects of oxidative stress due to exhaustive training on uncoupling protein 2 (UCP2 and Bcl-2/Bax in rat skeletal muscles. A total of 18 Sprague-Dawley female rats were randomly divided into three groups: the control group (CON, the trained control group (TC, and the exhaustive trained group (ET. Malondialdehyde (MDA, superoxide dismutase (SOD, xanthine oxidase (XOD, ATPase, UCP2, and Bcl-2/Bax ratio in red gastrocnemius muscles were measured. Exhaustive training induced ROS increase in red gastrocnemius muscles, which led to a decrease in the cell antiapoptotic ability (Bcl-2/Bax ratio. An increase in UCP2 expression can reduce ROS production and affect mitochondrial energy production. Thus, oxidative stress plays a significant role in overtraining.

  3. Effects of curcumin on hippocampal Bax and Bcl-2 expression and cognitive function of a rat model of Alzheimer's disease

    Institute of Scientific and Technical Information of China (English)

    Yunliang Wang; Honglei Yin; Jiyu Lou; Bing Han; Xinyue Qin; Fanchao Meng; Shuang Geng; Yajun Liu

    2011-01-01

    We tested the effects of curcumin treatment on a rat model of Alzheimer's disease induced by beta-amlyoid (Aβ1-40) expression. We investigated alterations in the expression of the apoptosis-related genes Bax and Bcl-2 in the hippocampus, as well as changes in the spatial memory and cognitive function of the rats. Reverse transcription-polymerase chain reaction and immunohistochemistry results showed that Bax expression was remarkably decreased and Bcl-2 expression was increased in the rat Alzheimer's disease model after curcumin treatment. Morris water maze results showed that the average time of escape latency was shortened in the curcumin treated model rats. Our study shows that curcumin can significantly improve spatial learning and memory functions in rats with Aβ1-40-induced Alzheimer's disease by modulating Bax and Bcl-2 expression.

  4. Inhibition of autophagy by 3-MA potentiates purvalanol-induced apoptosis in Bax deficient HCT 116 colon cancer cells.

    Science.gov (United States)

    Coker-Gurkan, Ajda; Arisan, Elif Damla; Obakan, Pinar; Guvenir, Esin; Unsal, Narcin Palavan

    2014-10-15

    The purine-derived analogs, roscovitine and purvalanol are selective synthetic inhibitors of cyclin-dependent kinases (CDKs) induced cell cycle arrest and lead to apoptotic cell death in various cancer cells. Although a number of studies investigated the molecular mechanism of each CDK inhibitor on apoptotic cell death mechanism with their therapeutic potential, their regulatory role on autophagy is not clarified yet. In this paper, our aim was to investigate molecular mechanism of CDK inhibitors on autophagy and apoptosis in wild type (wt) and Bax deficient HCT 116 cells. Exposure of HCT 116 wt and Bax(-/-) cells to roscovitine or purvalanol for 24h decreased cell viability in dose-dependent manner. However, Bax deficient HCT 116 cells were found more resistant against purvalanol treatment compared to wt cells. We also established that both CDK inhibitors induced apoptosis through activating mitochondria-mediated pathway in caspase-dependent manner regardless of Bax expression in HCT 116 colon cancer cells. Concomitantly, we determined that purvalanol was also effective on autophagy in HCT 116 colon cancer cells. Inhibition of autophagy by 3-MA treatment enhanced the purvalanol induced apoptotic cell death in HCT 116 Bax(-/-) cells. Our results revealed that mechanistic action of each CDK inhibitor on cell death mechanism differs. While purvalanol treatment activated apoptosis and autophagy in HCT 116 cells, roscovitine was only effective on caspase-dependent apoptotic pathway. Another important difference between two CDK inhibitors, although roscovitine treatment overcame Bax-mediated drug resistance in HCT 116 cells, purvalanol did not exert same effect. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Apigenin induces apoptosis by targeting inhibitor of apoptosis proteins and Ku70-Bax interaction in prostate cancer.

    Science.gov (United States)

    Shukla, Sanjeev; Fu, Pingfu; Gupta, Sanjay

    2014-05-01

    Dysfunction of the apoptotic pathway in prostate cancer cells confers apoptosis resistance towards various therapies. A novel strategy to overcome resistance is to directly target the apoptotic pathway in cancer cells. Apigenin, an anticancer agent, selectively toxic to cancer cells induces cell cycle arrest and apoptosis through mechanisms which are not fully explored. In the present study we provide novel insight into the mechanisms of apoptosis induction by apigenin. Treatment of androgen-refractory human prostate cancer PC-3 and DU145 cells with apigenin resulted in dose-dependent suppression of XIAP, c-IAP1, c-IAP2 and survivin protein levels. Apigenin treatment resulted in significant decrease in cell viability and apoptosis induction with the increase of cytochrome C in time-dependent manner. These effects of apigenin were accompanied by decrease in Bcl-xL and Bcl-2 and increase in the active form of Bax protein. The apigenin-mediated increase in Bax was due to dissociation of Bax from Ku70 which is essential for apoptotic activity of Bax. Apigenin treatment resulted in the inhibition of class I histone deacetylases and HDAC1 protein expression, thereby increasing the acetylation of Ku70 and the dissociation of Bax resulting in apoptosis of cancer cells. Furthermore, apigenin significantly reduced HDAC1 occupancy at the XIAP promoter, suggesting that histone deacetylation might be critical for XIAP downregulation. These results suggest that apigenin targets inhibitor of apoptosis proteins and Ku70-Bax interaction in the induction of apoptosis in prostate cancer cells and in athymic nude mouse xenograft model endorsing its in vivo efficacy.

  6. Safe switching from a pdFIX (Immunine®) to a rFIX (Bax326).

    Science.gov (United States)

    Solano Trujillo, M H; Stasyshyn, O; Rusen, L; Serban, M; Lamas, J L; Perina, F G; Urasinski, T; Oh, M; Knowlton, W B; Valenta-Singer, B; Pavlova, B G; Abbuehl, B

    2014-09-01

    The ability to switch between coagulation factors safely is of common interest to haemophilia patients and treating physicians. This is the first formal prospective comparative evaluation of safety, efficacy and incremental recovery of a plasma-derived FIX (pdFIX) and a recombinant FIX (rFIX) in the same haemophilia B patients following a switch from pdFIX Immunine® to a recently developed rFIX Bax326 product. Patients (aged <65 years) who completed a pretreatment study which prospectively documented the exposure to Immunine® and monitored FIX inhibitors while receiving prophylactic treatment were transitioned into pivotal (patients aged 12-65 years) and paediatric (patients aged <12 years) clinical studies investigating prophylaxis and treatment of bleeding episodes with Bax326. None of the 44 patients developed inhibitory or specific binding anti-FIX antibodies during the course of the studies. A total of 38 unrelated adverse events (AEs) were occurred in 20/44 (45.5%) subjects during the Immunine® study. Following a switch to Bax326, 51 AEs were reported in 25/44 (56.8%) subjects. The incidence of AEs related to Bax326 treatment (two episodes of dysgeusia in one patient) was low (2.3%); there were no serious adverse reactions. The comparison between Immunine® and Bax326 demonstrated analogous haemostatic characteristics and annualized bleeding rates. Overall, there is direct evidence indicating a safe and clinically effective transition from a pdFIX (Immunine®) to a newly developed rFIX (Bax326(1) ) for prophylaxis and treatment of bleeding in previously treated patients of all age cohorts with severe or moderately severe haemophilia B.

  7. Apigenin induces apoptosis by targeting inhibitor of apoptosis proteins and Ku70–Bax interaction in prostate cancer

    Science.gov (United States)

    Shukla, Sanjeev; Fu, Pingfu; Gupta, Sanjay

    2014-01-01

    Dysfunction of the apoptotic pathway in prostate cancer cells confers apoptosis resistance towards various therapies. A novel strategy to overcome resistance is to directly target the apoptotic pathway in cancer cells. Apigenin, an anticancer agent, selectively toxic to cancer cells induces cell cycle arrest and apoptosis through mechanisms which are not fully explored. In the present study we provide novel insight into the mechanisms of apoptosis induction by apigenin. Treatment of androgen-refractory human prostate cancer PC-3 and DU145 cells with apigenin resulted in dose-dependent suppression of XIAP, c-IAP1, c-IAP2 and survivin protein levels. Apigenin treatment resulted in significant decrease in cell viability and apoptosis induction with the increase of cytochrome C in time-dependent manner. These effects of apigenin were accompanied by decrease in Bcl-xL and Bcl-2 and increase in the active form of Bax protein. The apigenin-mediated increase in Bax was due to dissociation of Bax from Ku70 which is essential for apoptotic activity of Bax. Apigenin treatment resulted in the inhibition of class I histone deacetylases and HDAC1 protein expression, thereby increasing the acetylation of Ku70 and the dissociation of Bax resulting in apoptosis of cancer cells. Furthermore, apigenin significantly reduced HDAC1 occupancy at the XIAP promoter, suggesting that histone deacetylation might be critical for XIAP downregulation. These results suggest that apigenin targets inhibitor of apoptosis proteins and Ku70–Bax interaction in the induction of apoptosis in prostate cancer cells and in athymic nude mouse xenograft model endorsing its in vivo efficacy. PMID:24563225

  8. Recombinant factor IX (BAX326) in previously treated paediatric patients with haemophilia B: a prospective clinical trial.

    Science.gov (United States)

    Urasinski, T; Stasyshyn, O; Andreeva, T; Rusen, L; Perina, F G; Oh, M S; Chapman, M; Pavlova, B G; Valenta-Singer, B; Abbuehl, B E

    2015-03-01

    A newly developed recombinant factor IX (BAX326(1) ) was investigated for prophylactic use in paediatric patients aged 96% of bleeds (100% of minor, 88.9% of moderate and 100% of major bleeds); the majority (88.5%) resolved after 1-2 infusions. Longer T1/2 and lower IR were observed in younger children (<6 years) compared to those aged 6 to 12 years. BAX326 administered as prophylactic treatment as well as for controlling bleeds is efficacious and safe in paediatric patients aged <12 years with haemophilia B.

  9. Clinicopathological aspects and their relation to prognosis in adult-type granulosa cell tumor of the ovary Aspectos clinicopatológicos e sua relação com o prognóstico em tumor de células da granulosa do tipo adulto do ovário

    Directory of Open Access Journals (Sweden)

    Maurício De Angelo Andrade

    2009-10-01

    Full Text Available INTRODUCTION AND OBJECTIVE: The adult granulosa cell tumors (AGCT correspond to less than 5% of ovarian neoplasias. They are considered low malignant potential tumors and may recur after many years. The differential diagnosis must be made with other primary or metastatic ovarian neoplasias. The aim was to analyze clinical and pathological aspects of AGCT and relate them to its evolution. METHOD: in a 10- year (1995-2004 review of the files from University of Campinas Clinical Hospital, Brazil, 20 AGCT cases were found. The clinical records and slides were reviewed and age, symptoms, macro and microscopic aspects, diagnostic staging and recurrence were considered. When there was intraoperative biopsy, its accuracy was evaluated. RESULTS: Age ranged from 27 to 79 years (mean: 53 and the follow-up from 12 to 96 months (mean: 42. The main symptoms were post-menopause bleeding (45%, abdominal pain (35% and palpable mass (25%. Most tumors were yellowish (60% and the solid aspect (40% was more common than the cystic or solid-cystic. The histological patterns were 40% solid, 15% macrofollicular and 45% combined forms. All of them with low mitotic index. Only three out of nine intraoperative frozen sections were accurately diagnosed. The clinical staging was 13 cases in Ia (65%, one case Ic and 6 IIIc. In three out of 14 hysterectomies there was simple endometrial hyperplasia with no atypia. Only the disease staging was significantly associated with recurrence (p INTRODUÇÃO E OBJETIVO: O tumor de células da granulosa tipo adulto (TCGA corresponde a menos de 5% das neoplasias ovarianas. São de baixo potencial de malignidade, podem recorrer depois de muitos anos, e o diferencial deve ser feito com outras neoplasias primárias ou metastáticas. Analisamos os aspectos clínicos e patológicos do tumor, relacionando-os à evolução. MÉTODOS: Na revisão de 10 anos dos arquivos do laboratório de Anatomia Patológica do Hospital das Clínicas da

  10. Wilms Tumor

    Science.gov (United States)

    ... Wilms tumor is 1 pound at diagnosis. Some children also may have nausea, stomach pain, high blood pressure (hypertension), blood in the urine, loss of appetite, or fever. Even though Wilms tumors often are ...

  11. Hypothalamic tumor

    Science.gov (United States)

    Complications of brain surgery may include: Bleeding Brain damage Death (rarely) Infection Seizures can result from the tumor or from any surgical procedure on the brain. Hydrocephalus can occur with some tumors and ...

  12. THE EXPRESSION OF APOPTOSIC GENES BCL-2,BAX AND FAS IN ENDOMETRIOSIS%凋亡调节基因bcl-2,bax和fas在子宫内膜异位症中的表达

    Institute of Scientific and Technical Information of China (English)

    王云霞; 李亚里; 黄靖香

    2001-01-01

    应用免疫组化法检测凋亡调节蛋白bcl-2,bax和fas在无异位症妇女的正常子宫内膜、腹腔液巨噬细胞与卵巢子宫内膜异位症患者在位子宫内膜、异位子宫内膜及腹腔液巨噬细胞中的表达。同时,用TUNEL法测出各种细胞的调亡率。结果表明,bcl-2在异位症患者在位、异位内膜及腹腔液巨噬细胞中的表达较无异位症者增强,差异有显著性意义(P<0.01)。bax在异位症中的表达较低,差异有显著性意义(P<0.05)。fas在异位症患者在位及异位内膜中的表达较低,差异有显著性意义(P<0.05)。结果提示,子宫内膜异位症患者在位、异位内膜及腹腔液巨噬细胞中凋亡基因的表达与无异位症者不同,其凋亡率低,对凋亡的接受性降低,有利于异位内膜的种植、生存和发展。%We examined eutopic,ectopic endometria and peritoneal fluid macrophages from 22 patients with endometriosis(EMS) and 14 women without EMS.To obtain evidence for the induction of programmed cell death,apoptotic cells were identified using a modified terminal deixynucleotidyltransferasebiotin nick end-labeling method(TUNEL).To evaluate cell death repressor activity,bcl-2,bax and fas genes expression was examined using immunohistochemical staining. The results showed that bcl-2 expression in eutopic,ectopic endometrium and peritoneal fluid macrophages with EMS was significantly increased compared with no EMS(P<0.01).Bax expression in eutopic,ectopic and peritoneal fluid macrophages with EMS was significantly decreased compared with no EMS(P<0.05). Fas expression in eutopic,ectopic endometrium was decreased compared with no EMS(P<0.05). The expression of apoptotic genes were different in eutopic,ectopic endometrium and peritoneal fluid macrophages from EMS and no EMS.Apoptotic rate in EMS was lower than no EMS,and its acceptance was decreased,which could bear implications for the growth and survival of

  13. Stripe order in La2-xBaxCuO4 in high magnetic fields

    Science.gov (United States)

    Huecker, M.; von Zimmermann, M.; Xu, Z. J.; Wen, J. S.; Gu, G. D.; Zaliznyak, I. A.; Chung, J.-H.; Choi, E. S.; Tranquada, J. M.

    2012-02-01

    The observation of enhanced spin stripe order in the vortex cores of La2-xSrxCuO4 has been a landmark experiment that revealed the intimate connection between superconductivity and incommensurate antiferromagnetism. Only recently we have observed a corresponding field dependence of the spin and, more importantly, of the charge stripe order in La2-xBaxCuO4. Here we present our recent results from neutron diffraction, x-ray diffraction, and torque measurements in high magnetic fields. These helped us to establish the field versus temperature and doping phase diagrams for spin and charge order, and to further corroborate the stripe model as the more appropriate description than for example spiral and vortex states.

  14. Immortalization of mouse myogenic cells can occur without loss of p16INK4a, p19ARF, or p53 and is accelerated by inactivation of Bax

    Directory of Open Access Journals (Sweden)

    Kravetz Amanda J

    2004-01-01

    Full Text Available Abstract Background Upon serial passaging of mouse skeletal muscle cells, a small number of cells will spontaneously develop the ability to proliferate indefinitely while retaining the ability to differentiate into multinucleate myotubes. Possible gene changes that could underlie myogenic cell immortalization and their possible effects on myogenesis had not been examined. Results We found that immortalization occurred earlier and more frequently when the myogenic cells lacked the pro-apoptotic protein Bax. Furthermore, myogenesis was altered by Bax inactivation as Bax-null cells produced muscle colonies with more nuclei than wild-type cells, though a lower percentage of the Bax-null nuclei were incorporated into multinucleate myotubes. In vivo, both the fast and slow myofibers in Bax-null muscles had smaller cross-sectional areas than those in wild-type muscles. After immortalization, both Bax-null and Bax-positive myogenic cells expressed desmin, retained the capacity to form multinucleate myotubes, expressed p19ARF protein, and retained p53 functions. Expression of p16INK4a, however, was found in only about half of the immortalized myogenic cell lines. Conclusions Mouse myogenic cells can undergo spontaneous immortalization via a mechanism that can include, but does not require, loss of p16INK4a, and also does not require inactivation of p19ARF or p53. Furthermore, loss of Bax, which appears to be a downstream effector of p53, accelerates immortalization of myogenic cells and alters myogenesis.

  15. Comparison of automated BAX polymerase chain reaction and standard culture methods for detection of Listeria monocyogenes in blue crab meat (Callinectus sapidus) and blue crab processing plants

    Science.gov (United States)

    This study compared the BAX Polymerase Chain Reaction method (BAX PCR) with the Standard Culture Method (SCM) for detection of L. monocytogenes in blue crab meat and crab processing plants. The aim of this study was to address this data gap. Raw crabs, finished products and environmental sponge samp...

  16. DuPont Qualicon BAX System polymerase chain reaction assay. Performance Tested Method 100201.

    Science.gov (United States)

    Tice, George; Andaloro, Bridget; Fallon, Dawn; Wallace, F Morgan

    2009-01-01

    A recent outbreak of Salmonella in peanut butter has highlighted the need for validation of rapid detection methods. A multilaboratory study for detecting Salmonella in peanut butter was conducted as part of the AOAC Research Institute Emergency Response Validation program for methods that detect outbreak threats to food safety. Three sites tested spiked samples from the same master mix according to the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA-BAM) method and the BAX System method. Salmonella Typhimurium (ATCC 14028) was grown in brain heart infusion for 24 h at 37 degrees C, then diluted to appropriate levels for sample inoculation. Master samples of peanut butter were spiked at high and low target levels, mixed, and allowed to equilibrate at room temperature for 2 weeks. Spike levels were low [1.08 most probable number (MPN)/25 g]; high (11.5 MPN/25 g) and unspiked to serve as negative controls. Each master sample was divided into 25 g portions and coded to blind the samples. Twenty portions of each spiked master sample and five portions of the unspiked sample were tested at each site. At each testing site, samples were blended in 25 g portions with 225 mL prewarmed lactose broth until thoroughly homogenized, then allowed to remain at room temperature for 55-65 min. Samples were adjusted to a pH of 6.8 +/- 0.2, if necessary, and incubated for 22-26 h at 35 degrees C. Across the three reporting laboratories, the BAX System detected Salmonella in 10/60 low-spike samples and 58/60 high-spike samples. The reference FDA-BAM method yielded positive results for 11/60 low-spike and 58/60 high-spike samples. Neither method demonstrated positive results for any of the 15 unspiked samples.

  17. Urogenital tumors

    Energy Technology Data Exchange (ETDEWEB)

    Weller, R.E.

    1994-03-01

    An overview is provided for veterinary care of urogenital tumors in companion animals, especially the dog. Neoplasms discussed include tumors of the kidney, urinary bladder, prostate, testis, ovary, vagina, vulva and the canine transmissible venereal tumor. Topics addressed include description, diagnosis and treatment.

  18. Brain Tumors

    Science.gov (United States)

    A brain tumor is a growth of abnormal cells in the tissues of the brain. Brain tumors can be benign, with no cancer cells, ... cancer cells that grow quickly. Some are primary brain tumors, which start in the brain. Others are ...

  19. Odontogenic Tumors

    OpenAIRE

    TAHSİNOĞLU, Melih

    2013-01-01

    DefinitionThe neoplasms that consist of the cells considered specialized for odontogenesis, and their product (dentin, enamel, cementum) are called odontogenic tumors.ClassificationTo initiate odontogenesis, epithelium is a must. Same rule holds for the odontogenic tumors: without odontogenic epithelium, odontogenic tumors cannot be, without the induction of odontogenic epithelium odontogenic mesenchyme cannot develop.

  20. Tumor cerebral e gravidez Brain tumors and pregnancy

    Directory of Open Access Journals (Sweden)

    José Carlos Lynch

    2007-12-01

    Full Text Available O diagnóstico de um tumor cerebral durante a gravidez é um fato raro que coloca a mãe e o concepto em risco de vida. OBJETIVO: Avaliar a melhor forma de conduzir uma paciente grávida portadora de um tumor cerebral. MÉTODO: Realizamos análise retrospectiva dos prontuários e imagens de seis pacientes grávidas portadoras de tumor cerebral. RESULTADOS: Vários tipos histológicos de tumor cerebral podem estar associados à gravidez. O meningioma é o mais freqüente. Nessa série não observamos óbito cirúrgico materno. Em duas pacientes, o parto ocorreu antes da craniotomia e em outras quatro o parto foi realizado após a neurocirurgia. CONCLUSÃO: O momento mais adequado para a realização da craniotomia para remoção tumoral irá depender da gravidade do quadro neurológico, do tipo histológico presumível da lesão, e da idade gestacional do embrião.BACKGROUND: Despite not being a common fact, the occurrence of brain tumors during pregnancy poses a risk to both the mother and infant. AIM: To identify the best medical procedure to be followed for a pregnant patient harboring a brain tumor. METHOD: The records of 6 patients with brain tumors, diagnosed during pregnancy were examined. RESULTS: Several types of brain tumors have been associated with pregnancy, but the meningioma is, by far, the most frequent. It seems that pregnancy aggravates the clinical course of intracranial tumors. There were no operative mortality in these series. In 2 patients the labor occurred before the craniotomy and in others, the delivery occurred after the surgery. CONCLUSION: The best moment to recommend the craniotomy and the neurosurgical removal of the tumor will depend of the mother’s neurological condition, the tumor histological type as well as the gestational age.

  1. ISCHEMIC PRECONDITIONING RELIEVES ISCHEMIA/REPERFUSION INJURY OF HIPPOCAMPUS NEURONS IN RAT BY INHIBITING p53 AND BAX EXPRESSIONSA

    Institute of Scientific and Technical Information of China (English)

    Hui-min Liu; Jing-xin Li; Lian-bi Chen

    2007-01-01

    Objective To examine whether ischemic preconditioning (IPC) can protect neuron against delayed death in CA1 subfield of hippocampus following reperfusion of a lethal ischemia in rats, and explore the role of p53 and bax in this process.Methods We examined the effect of IPC on delayed neuron death, neuron apoptosis, expressions of p53 and bax gene in the CA1 area of hippocampus in the rats using HE staining, flow cytometry, RT-PCR, and immunohistochemis-try technique.Results IPC enhanced the quantity of survival cells in the CA1 region of hippocampus (216 ±9 cells/0. 72 mm2 vs. 30 ±5 cells/0. 72 mm2, P<0. 01), decreased the percentages of apoptotic neurons of hippocampus caused by is-chemia/reperfusion (2. 06% ±0.21% vs. 4.27% ±0. 08% , P<0. 01), and weakened the expressions of p53 and bax gene of hippocampus compared with ischemia/reperrusion without IPC.Conclusion IPC can protect the neurons in the CA1 region of hippocampus against apoptosis caused by ischemia/reperfusion, and this process may be related to the reduced expressions of p53 and bax.

  2. Apoptosis and Bax expression are increased by coal dust in the polycyclic aromatic hydrocarbon-exposed lung

    Energy Technology Data Exchange (ETDEWEB)

    Ghanem, M.M.; Battelli, L.A.; Mercer, R.R.; Scabilloni, J.F.; Kashon, M.L.; Ma, J.Y.C.; Nath, J.; Hubbs, A.F.

    2006-09-15

    Miners inhaling respirable coal dust (CD) frequently develop coal workers' pneumoconiosis. Many coal miners are also exposed to polycyclic aromatic hydrocarbon (PAH) components of diesel engine exhaust and cigarette smoke, which may contribute to lung disease in these workers. Recently, apoptosis was reported to play a critical role in the development of another pneumoconiosis of miners, silicosis. In addition, CID was reported to suppress cytochrome P450 1A1 (CYP1A1) induction by PAHs. We exposed rats intratracheally to 0.0, 2.5, 10.0, 20.0, or 40.0 mg/rat CD and, 11 days later, to intraperitoneal P-naphthoflavone (BNF), a PAH. In another group of rats exposed to CD and BNF, caspase activity was inhibited by injection of the pan-caspase inhibitor Q-VD-OPH (quinoline-Val-Asp (OMe)-CH{sub 2}-OPH). In rats exposed to BNF, CD exposure increased alveolar expression of the proapoptotic mediator Bax but decreased CYP1A1 induction relative to BNF exposure alone. Pan-caspase inhibition decreased CD-associated Bax expression and apoptosis but did not restore CYP1A1 activity. Further, CD-induced lung inflammation and alveolar epithelial cell hypertrophy and hyperplasia were not suppressed by caspase inhibition. It is concluded that combined BNF and CD exposure increased Bax expression and apoptosis in the lung, but Bax and apoptosis were not the major determinants of early lung injury in this model.

  3. Immunohistochemical study of epidermal and dermal expression of Bcl-X, Bcl-2 and bax in psoriasis.

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To investigate the regulation of cell proliferation and apoptosis in psoriasis. Methods: The expressions of Bcl-X, Bcl-2 and Bax were studied with immunohistochemical technique (SP) in the lesional and non-lesional psoriatic skin. Results: There were significant overexpressions of Bcl-X in all layers of epidermis, inflammatory cells and vascular endothelia in dermis;

  4. Relationship between expression of Bax and Bcl-2 proteins and apoptosis in radiation compound wound healing of rats

    Institute of Scientific and Technical Information of China (English)

    崔玉芳; 夏国伟; 付小兵; 杨红; 彭瑞云; 张莹; 谷庆阳; 高亚兵; 崔雪梅; 胡文华

    2003-01-01

    Objective: To study the relationship between the expression of Bax, Bcl-2 proteins, and apoptosis in radiation compound wound healing of rats.Methods: Apoptosis, Bax and Bcl-2 proteins were estimated by in situ terminal labeling (TUNEL) and immunohistochemical methods. Results: (1) Changes of the apoptosis in wound healing showed three typical characteristics: early occurrence, high frequency and delayed disappearance after radiation to rats when compared with those of simple wound group, which might be an important reason for radiation-induced delayed wound healing. (2) The expression of Bax protein increased evidently with the increment of apoptosis and showed a good corresponding relationship with the apoptotic frequency in the process of wound healing. While the expression of Bcl-2 protein decreased obviously as the apoptosis reached a maximum and showed increasing tendency up to normal level when the apoptosis decreased distinctively. Conclusions: Bax and Bcl-2 proteins play an important role in the apoptotic regulation of radiation compound wound healing in rats.

  5. EXPRESSION OF BAX AND BCL-2 IN MOUSE OFFSPRING BRAIN AFTER MATERNAL ORAL ADMINIS TRATION OF MONOSODIUM GLUTAMATE

    Institute of Scientific and Technical Information of China (English)

    徐磊; 赵晏; 展淑琴; 王会生; 史文春

    2002-01-01

    Objective To analyze the excitotoxicity of monoso dium glutamate (MSG) in the offspring cerebral cortex and hippocampal subregions after maternal oral administration of MSG. Methods Kunming mi ce were given per os MSG ( 4.0 g/kg ) at 17~21 days of pregnancy and their offs pring behaviors were studied at 10, 20 , 30 days postnatally. By using immunohis tochemical means, the involvement of Bcl-2 and Bax in the glutamate-induced c ell death in cortical and hippocampal neur ons were examined. Cell damage was assessed by direct cell counting. Res ults Administration of monosodium glutamate during the fetal period in mice resulted in a moderate increase in the expression of Bax in principal neuro ns in CA1, CA2, CA3, CA4 and in the cerebral cortex at postpartum 10, 20, 30 day s in the offspring mice, whereas Bcl-2 protein expressions were reduced signif icantly in the same regions as compared with those of controls. Conclusi on These findings suggest that glutamate toxicity results in cellular d eath via an apoptotic mechanism in which the Bcl-2/Bax-alpha molecular comple x may be involved. The glutamate-induced apoptosis appears to be related to the modulation of Bcl-2 family gene products such as Bcl-2 and Bax.

  6. EXPRESSION OF BAX AND BCL-2 IN MOUSE OFFSPRING BRAIN AFIER MATERNAL ORAL ADMINISTRATION OF MONOSODIUM GLUTAMATE

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objective:To analyze the excitotoxicity of monosodium glutamate(MSG)in the offspring crebral cortex and hippocampal subresions after maternal oral administration of MSG.Methods:Kunming mice were given per os MSG(4.0g/kg)at 17-21 days of pregnancy and their offspring behaviors were studied at 10,20,30days postnatally.By using inmunohistochemical means,the involvment of Bcl-2 and bax in the glutamate-induced cell death in cortical and hippocampal neurons were examined.Cell damage was assessed by direct cell counting.Results:administration of monosodium glutamate during the fetal period in mice resulted in a moderate increase in the expression of Bax in principal neurons in CA1,CA2,CA3,CA4 and in the cerebral cortex at postpartum 10,20,30 days in the offspring mice,whereas Bcl-2 protein expressions were reduced significantly in the same regions as compared with those of controls.Conclusion:These findings suggest that glutamate toxicity results in cellular death via an apoptotic mechanism in which the Bcl-2/Bax-alpha molecular complex may be involved.The glutamate-induced apoptosis appears to be related to the modulation of Bcl-2 family gene products such as Bcl-2 and Bax.

  7. p38(MAPK)/p53-Mediated Bax induction contributes to neurons degeneration in rotenone-induced cellular and rat models of Parkinson's disease.

    Science.gov (United States)

    Wu, Feng; Wang, Zhong; Gu, Jin-Hua; Ge, Jian-Bin; Liang, Zhong-Qin; Qin, Zheng-Hong

    2013-09-01

    Rotenone is an environmental neurotoxin that induces degeneration of dopaminergic (DA) neurons in substantia nigra pars compacta (SNpc), which ultimately results in parkinsonism, but the molecular mechanisms of selective degeneration of nigral DA neurons are not fully understood. In the present study, we investigated the induction of p38(MAPK)/p53 and Bax in SNpc of Lewis rats after chronic treatment with rotenone and the contribution of Bax to rotenone-induced apoptotic commitment of differentiated PC12 cells. Lewis rats were subcutaneously treated with rotenone (1.5mg/kg) twice a day for 50days and the loss of tyrosine hydroxylase (THase), motor function impairment, and expression of p38(MAPK), P-p38(MAPK), p53, and Bax were assessed. After differentiated PC cells were treated with rotenone (500nM) for 6-36h, protein levels of p38(MAPK) and P-p38(MAPK), p53 nuclear translocation, Bax induction and cell death were measured. The results showed that rotenone administration significantly reduced motor activity and caused a loss of THase immunoreactivity in SNpc of Lewis rats. The degeneration of nigral DA neurons was accompanied by the increases in p38(MAPK), P-p38(MAPK), p53, and Bax protein levels. In cultured PC12 cells, rotenone also induced an upregulation of p38(MAPK), P-p38(MAPK), p53 and Bax. Pharmacological inhibition of p38(MAPK) with SB203580 (25μM) blunted rotenone-induced cell apoptosis. Treatment with SB203580 prevented the p53 nuclear translocation and upregulation of Bax. Inhibition of p53 with pifthrin-alpha or Bax with siRNAs significantly reduced rotenone-induced Bax induction and apoptotic cell death. These results suggest that the p38(MAPK)/p53-dependent induction of Bax contributes to rotenone's neurotoxicity in PD models.

  8. After Embedding in Membranes Antiapoptotic Bcl-XL Protein Binds Both Bcl-2 Homology Region 3 and Helix 1 of Proapoptotic Bax Protein to Inhibit Apoptotic Mitochondrial Permeabilization*

    Science.gov (United States)

    Ding, Jingzhen; Mooers, Blaine H. M.; Zhang, Zhi; Kale, Justin; Falcone, Domina; McNichol, Jamie; Huang, Bo; Zhang, Xuejun C.; Xing, Chengguo; Andrews, David W.; Lin, Jialing

    2014-01-01

    Bcl-XL binds to Bax, inhibiting Bax oligomerization required for mitochondrial outer membrane permeabilization (MOMP) during apoptosis. How Bcl-XL binds to Bax in the membrane is not known. Here, we investigated the structural organization of Bcl-XL·Bax complexes formed in the MOM, including the binding interface and membrane topology, using site-specific cross-linking, compartment-specific labeling, and computational modeling. We found that one heterodimer interface is formed by a specific interaction between the Bcl-2 homology 1–3 (BH1–3) groove of Bcl-XL and the BH3 helix of Bax, as defined previously by the crystal structure of a truncated Bcl-XL protein and a Bax BH3 peptide (Protein Data Bank entry 3PL7). We also discovered a novel interface in the heterodimer formed by equivalent interactions between the helix 1 regions of Bcl-XL and Bax when their helical axes are oriented either in parallel or antiparallel. The two interfaces are located on the cytosolic side of the MOM, whereas helix 9 of Bcl-XL is embedded in the membrane together with helices 5, 6, and 9 of Bax. Formation of the helix 1·helix 1 interface partially depends on the formation of the groove·BH3 interface because point mutations in the latter interface and the addition of ABT-737, a groove-binding BH3 mimetic, blocked the formation of both interfaces. The mutations and ABT-737 also prevented Bcl-XL from inhibiting Bax oligomerization and subsequent MOMP, suggesting that the structural organization in which interactions at both interfaces contribute to the overall stability and functionality of the complex represents antiapoptotic Bcl-XL·Bax complexes in the MOM. PMID:24616095

  9. BAX, a novel cell pro-apoptotic protein, involved in hemocytes early antiviral immune response in fresh water crayfish, Procambarus clarkii.

    Science.gov (United States)

    du, Zhi-Qiang

    2016-08-01

    Apoptosis plays an important role in various biological processes and acts as a host defending mechanism by which infected cells are eliminated to restrict the virus propagation scale. Bax is a crucial pro-apoptotic protein, which mediates the release of cytochrome c from mitochondrion to cytosol in mammalian. However, its role in invertebrate is still obscure. Here, a novel pro-apoptotic protein gene was identified from hemocytes of red swamp crayfish. There was a Bcl-2 domain in the C-terminus of Pc-Bax, which possessed 497 amino acids residues. And an important transmembrane region existed in the C-terminus of Pc-Bax, which implied that Pc-Bax located in mitochondrial membrane. Besides, Pc-Bax was expressed at a relative high level in hemocytes, and a relative low expression levels in hepatopancreas, gills, and intestine. In hemocytes, Pc-Bax transcript was rapidly up-regulated from 12 h to 36 h after WSSV infection. And there was the same trend for Pc-Bax protein expression level in hemocytes after WSSV infection. Results of qRT-PCR testing for VP28 gene showed WSSV replication was obviously enhanced after Pc-Bax knockdown. Meantime, hemocytes apoptosis was suppressed in Pc-Bax knockdown crayfish after WSSV injection, compared with the dsGFP injection group and normal group. Taken together, these results revealed that crayfish hemocytes apoptosis scale was enhanced to suppress WSSV replication by up-regulating Bax protein expression level after WSSV infection. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. BH3-only proteins are tail-anchored in the outer mitochondrial membrane and can initiate the activation of Bax.

    Science.gov (United States)

    Wilfling, F; Weber, A; Potthoff, S; Vögtle, F-N; Meisinger, C; Paschen, S A; Häcker, G

    2012-08-01

    During mitochondrial apoptosis, pro-apoptotic BH3-only proteins cause the translocation of cytosolic Bcl-2-associated X protein (Bax) to the outer mitochondrial membrane (OMM) where it is activated to release cytochrome c from the mitochondrial intermembrane space, but the mechanism is under dispute. We show that most BH3-only proteins are mitochondrial proteins that are imported into the OMM via a C-terminal tail-anchor domain in isolated yeast mitochondria, independently of binding to anti-apoptotic Bcl-2 proteins. This C-terminal domain acted as a classical mitochondrial targeting signal and was sufficient to direct green fluorescent protein to mitochondria in human cells. When expressed in mouse fibroblasts, these BH3-only proteins localised to mitochondria and were inserted in the OMM. The BH3-only proteins Bcl-2-interacting mediator of cell death (Bim), tBid and p53-upregulated modulator of apoptosis sensitised isolated mitochondria from Bax/Bcl-2 homologous antagonist/killer-deficient fibroblasts to cytochrome c-release by recombinant, extramitochondrial Bax. For Bim, this activity is shown to require the C-terminal-targeting signal and to be independent of binding capacity to and presence of anti-apoptotic Bcl-2 proteins. Bim further enhanced Bax-dependent killing in yeast. A model is proposed where OMM-tail-anchored BH3-only proteins permit passive 'recruitment' and catalysis-like activation of extra-mitochondrial Bax. The recognition of C-terminal membrane-insertion of BH3-only proteins will permit the development of a more detailed concept of the initiation of mitochondrial apoptosis.

  11. Calpain and reactive oxygen species targets Bax for mitochondrial permeabilisation and caspase activation in zerumbone induced apoptosis.

    Directory of Open Access Journals (Sweden)

    Praveen K Sobhan

    Full Text Available Fluorescent protein based signaling probes are emerging as valuable tools to study cell signaling because of their ability to provide spatio- temporal information in non invasive live cell mode. Previously, multiple fluorescent protein probes were employed to characterize key events of apoptosis in diverse experimental systems. We have employed a live cell image based approach to visualize the key events of apoptosis signaling induced by zerumbone, the active principle from ginger Zingiber zerumbet, in cancer cells that enabled us to analyze prominent apoptotic changes in a hierarchical manner with temporal resolution. Our studies substantiate that mitochondrial permeabilisation and cytochrome c dependent caspase activation dominate in zerumbone induced cell death. Bax activation, the essential and early event of cell death, is independently activated by reactive oxygen species as well as calpains. Zerumbone failed to induce apoptosis or mitochondrial permeabilisation in Bax knockout cells and over-expression of Bax enhanced cell death induced by zerumbone confirming the essential role of Bax for mitochondrial permeabilsation. Simultaneous inhibition of reactive oxygen species and calpain is required for preventing Bax activation and cell death. However, apoptosis induced by zerumbone was prevented in Bcl 2 and Bcl-XL over-expressing cells, whereas more protection was afforded by Bcl 2 specifically targeted to endoplasmic reticulum. Even though zerumbone treatment down-regulated survival proteins such as XIAP, Survivin and Akt, it failed to affect the pro-apoptotic proteins such as PUMA and BIM. Multiple normal diploid cell lines were employed to address cytotoxic activity of zerumbone and, in general, mammary epithelial cells, endothelial progenitor cells and smooth muscle cells were relatively resistant to zerumbone induced cell death with lesser ROS accumulation than cancer cells.

  12. The human septin7 and the yeast CDC10 septin prevent Bax and copper mediated cell death in yeast.

    Science.gov (United States)

    Horowitz, Avital; Lapointe, Jason F; Eid, Rawan; Sheibani, Sara; Gharib, Nada; Jones, Natalie K; Vali, Hojatollah; Mandato, Craig A; Greenwood, Michael T

    2013-12-01

    The mechanisms of programmed cell death activate genetically encoded intracellular programs in a controlled manner, the most common form being apoptosis. Apoptosis is carried out through a cascade of caspase mediated proteolytic cleavages initiated by the oligomerization of Bax, a cardinal regulator of mitochondrial-mediated apoptosis. Heterologous expression of Bax in yeast causes cell death that shares a number of similarities to processes that occur in mammalian apoptosis. A screen of a cardiac cDNA library for suppressors of Bax-mediated apoptosis identified human septin7, a protein that belongs to the septin superfamily of conserved GTP-binding proteins that share a conserved cdc/septin domain. Analysis of the amino acid sequence deduced from the septin7 clone as well as the corresponding human septin7 gene revealed that a novel alternatively spliced transcript called septin7 variant4 (v4) was uncovered. Yeast cells overexpressing the human septin7 v4 cDNA were also capable of resisting copper-mediated cell death suggesting that it is not only a Bax suppressor but also an anti-apoptotic sequence. Analysis of septin7 function in a MCA1Δ yeast strain suggests that septin7 inhibits apoptosis in a caspase independent pathway. Overexpression of the yeast septin7 ortholog CDC10 also conferred resistance to the negative effects of copper as well as protecting cells from the overexpression of Bax. In contrast, septin7 was unable to prevent the increase in cell size associated with mutants lacking the endogenous yeast CDC10 gene. Taken together, our analysis suggests that anti-apoptosis is a novel yet evolutionarily conserved property of the septin7 sub-family of septins.

  13. Erythropoietin can promote survival of cerebral cells by downregulating Bax gene after traumatic brain injury in rats

    Directory of Open Access Journals (Sweden)

    Liao Z

    2009-01-01

    Full Text Available Background : Traumatic brain injury (TBI is an important cause of adult mortality and morbidity. Erythropoietin (Epo has been shown to promote the viability of cerebral cells by upregulating Bcl-2 gene; however, Epo may exert its antiapoptotic effect via the differential regulation of the expression of genes involved in the apoptotic process. Aim : The present study examined the neuroprotective effect of Epo as a survival factor through the regulation of the Bax. Materials and Methods : Wistar rats were randomly divided into three groups: Recombinant human EPO treated (rhEPO TBI, vehicle-treated TBI, and sham-operated. Traumatic brain injury was induced by the Feeney free-falling model. Rats were killed 5, 12, 24, 72, 120, or 168 h after TBI. Regulation of Bcl-2 was detected by reverse transcription-polymerase chain reaction (RT-PCR, western blotting and immunofluorescence. Results : Bax mRNA and protein levels were lower in the rhEPO-treated rat brains than in the vehicle-treated rat brains. Induction of Bax expression peaked at 24 h and remained stable for 72-120 h in vehicle-treated rat brains, whereas induction of Bax expression was only slightly elevated in rhEPO-treated rat brains. The number of TdT-mediated dUTP Nick-End Labeling(TUNEL-positive cells in the rhEPO-treated rat brains was far fewer than in the vehicle-treated rat brains. Conclusions : Epo exerts neuroprotective effect against traumatic brain injury via reducing Bax gene expression involved in inhibiting TBI-induced neuronal cell death.

  14. Evaluation of Antioxidant and Immunity-Enhancing Activities of <em>Sargassum pallidumem> Aqueous Extract in Gastric Cancer Rats

    Directory of Open Access Journals (Sweden)

    Shen-Kang Zhou

    2012-07-01

    Full Text Available The effect of <em>Sargassum pallidumem> (brown seaweed aqueous extract on the immunity function and antioxidant activities in was studied gastric cancer rats. Treatment with <em>Sargassum pallidumem> aqueous extract at oral doses 400, 600 or 800 mg/kg body weight was found to provide a dose-dependent protection against <em>Nem>-methyl-N′-nitro-N>-nitrosoguanidine (MNNG-induced immunity damage and oxidative injury by enhancing serum interleukin-2 (IL-2, interleukin-4 (IL-4, interleukin-10 (IL-10 levels, decreasing interleukin-6 (IL-6, interleukin-1β (IL-1β, tumor necrosis factor-alpha (TNF-α levels, preserving normal antioxidant enzymes activities, and by inhibiting lipid peroxidation in gastric mucosa. It can be concluded that <em>Sargassum pallidumem> aqueous extract may enhance the immunity and antioxidant activities in gastric cancer rats.

  15. Synthesis, analysis, purification and biodistribution in an animal model of radiopharmaceutical {sup 177}Lu{sup 3+} -dotatato for diagnostic and therapeutic use in neuroendocrine tumors; Sintese, analise, purificacao e biodistribuicao em modelo animal do radiofarmaco {sup 177}Lu{sup 3+} -dotatato para uso diagnostico e terapeutico em tumores neuroendocrinos

    Energy Technology Data Exchange (ETDEWEB)

    Caldeira Filho, Jose de Souza

    2009-07-01

    The aim of this work was to propose rationalization in the synthesis, analysis and purification of radiopharmaceutical {sup 177} Lu{sup 3+} - DOTATATO for diagnostic and therapeutic use in neuroendocrine tumors, as well as for evaluation g biodistribution of this radiopharmaceutical an animal-mode. The complexation reaction for the synthesis of radiopharmaceutical was carried out in ammonium acetate buffer 0.5 M, p H 7.0, for 30 minutes at 95 deg C. The radiochemical purity was > 95%, according to analysis by chromatography in ITLC-SG, when using the sodium citrate buffer 0,1 M, p H 5.0, as the mobile phase. The molar-limit ratio {sup 177}Lu{sup 3+}:DOTATATO, in ammonium acetate buffer 0.5 M, p H 7.0, for 30 minutes at 95 deg C, was dependent on the specific activity and origin of the radioisotope, this being 1:3.5 (370 MBq : 26{mu}g) for that from the Oak Ridge National Laboratory /USA, and 1:16 (370 MBq: 11.8 {mu}g) for that from Nuclear Analytical and Medical Services/Holland, when considering a decay of five days from the production date of te radioisotopes. This rationalization in the synthesis of radiopharmaceutical {sup 177}Lu{sup 3+} - DOTATATO permits high economy in production costs. Chemical studies on the synthesis of radiopharmaceuticals also placed in evidence the interference of {sup 177}Hf{sup 4+}, the decay product of {sup 177}Lu{sup 3=}, as the {sup 177} Lu{sup 3=} competitor for DOTATATO. Radiopharmaceutical preparation proved to be stable during 24 hours, at an activity rate of 2775 MBq, with the addition of 0.6 mg/mL of gentisic acid and when kept in dry ice. In biodistribution studies on Swiss and Nuce mice, the specificity of radiopharmaceutical for somatostatin positive-receptor tissues, such as the pancreas, stomach, lungs, adrenal glands, kidneys and the cell tumor AR42J was demonstrated. (author)

  16. Effects of acetylsalicylic acid and acetic acid solutions on VX2 liver carcinoma in rabbits: in vivo analysis Efeitos das soluções de aspirina e de ácido acético em fígado de coelhos portadores de tumor hepático VX2: análise in vivo

    Directory of Open Access Journals (Sweden)

    Rogério Saad-Hossne

    2007-08-01

    Full Text Available PURPOSE: To analyze, in vitro, the effects of acetylsalicylic acid (aspirin and acetic acid solutions on VX2 carcinoma cells in the liver of rabbits with VX2 hepatic tumors; to determine the histolytic and anatomopathological characteristics of the solutions; and to evaluate the eventual biochemical and hepatic changes. METHODS: A total of 48 rabbits were evaluated. The animals were randomized into two groups, protocol 3 (study group and protocol 4 (controls, and each group was then subdivided into 3 subgroups. Four days after implantation of the tumor in the liver, median laparotomy was performed with a 0.4-ml injection of a solution of either aspirin (5.0%, acetic acid (5.0% or saline. The animals were sacrificed after 24 hours (protocol 3 or after 11 days (protocol 4. Body weight, clinical evolution and biochemical levels, as well as the abdominal and thoracic cavities, were evaluated, and liver microscopy was performed. RESULTS: No changes in clinical evolution, body weight or biochemical levels were reported. However, an increase in alkaline phosphatase was observed in protocol 4 (controls. The tumor was eliminated in both protocols. CONCLUSION: Acetylsalicylic acid and acetic acid solutions cause the destruction of experimental hepatic tumors.OBJETIVO: Analisar os efeitos das soluções de aspirina e de ácido acético, in vivo, em fígado de coelhos portadores de tumor hepático VX2, verificando o efeito histolítico e anatomo-patológico das soluções e eventuais alterações bioquímicas hepáticas. MÉTODOS: Utilizou-se 48 coelhos, divididos em 2 protocolos experimentais(3 e 4, subdivididos em 3 grupos cada. Após 4 dias da implantação do tumor no fígado, procedeu-se a laparotomia mediana, com injeção de 0,4 ml da solução de aspirina (5,0%, de ácido acético (5,0% e solução salina; o sacrifício ocorreu apos 24 horas (protocolo 3 e 11 dias (protocolo 4; avaliou-se o peso, evolução clinica, dosagens bioquímicas, cavidade

  17. A Novel Apoptosis Correlated Molecule: Expression and Characterization of Protein Latcripin-1 from <em>Lentinula em>edodes> C91–3

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    Min Huang

    2012-05-01

    Full Text Available An apoptosis correlated molecule—protein Latcripin-1 of <em>Lentinula> edodesem> C91-3—was expressed and characterized in <em>Pichia pastorisem> GS115. The total RNA was obtained from <em>Lentinula edodesem> C91–3. According to the transcriptome, the full-length gene of Latcripin-1 was isolated with 3'-Full Rapid Amplification of cDNA Ends (RACE and 5'-Full RACE methods. The full-length gene was inserted into the secretory expression vector pPIC9K. The protein Latcripin-1 was expressed in <em>Pichia pastorisem> GS115 and analyzed by Sodium Dodecylsulfonate Polyacrylate Gel Electrophoresis (SDS-PAGE and Western blot. The Western blot showed that the protein was expressed successfully. The biological function of protein Latcripin-1 on A549 cells was studied with flow cytometry and the 3-(4,5-Dimethylthiazol-2-yl-2,5-Diphenyl-tetrazolium Bromide (MTT method. The toxic effect of protein Latcripin-1 was detected with the MTT method by co-culturing the characterized protein with chick embryo fibroblasts. The MTT assay results showed that there was a great difference between protein Latcripin-1 groups and the control group (<em>p em>< 0.05. There was no toxic effect of the characterized protein on chick embryo fibroblasts. The flow cytometry showed that there was a significant difference between the protein groups of interest and the control group according to apoptosis function (<em>p em>< 0.05. At the same time, cell ultrastructure observed by transmission electron microscopy supported the results of flow cytometry. The work demonstrates that protein Latcripin-1 can induce apoptosis of human lung cancer cells A549 and brings new insights into and advantages to finding anti-tumor proteins.

  18. BIM (BCL-2 interacting mediator of cell death) SAHB (stabilized α helix of BCL2) not always convinces BAX (BCL-2-associated X protein) for apoptosis.

    Science.gov (United States)

    Verma, Sharad; Goyal, Sukriti; Tyagi, Chetna; Jamal, Salma; Singh, Aditi; Grover, Abhinav

    2016-06-01

    The interaction of BAX (BCL-2-associated X protein) with BIM (BCL-2 interacting mediator of cell death) SAHB (stabilized α helix of BCL2) directly initiates BAX-mediated mitochondrial apoptosis. This molecular dynamics study reveals that BIM SAHB forms a stable complex with BAX but it remains in a non-functional conformation. N terminal of BAX folds towards the core which has been reported exposed in the functional monomer. The α1-α2 loop, which has been reported in open conformation in functional BAX, acquires a closed conformation during the simulation. BH3/α2 remains less exposed as compared to initial structure. The hydrophobic residues of BIM accommodates in the rear pocket of BAX during the simulation. A steep decrease in radius of gyration and solvent accessible surface area (SASA) indicates the complex folding to acquire a more stable but inactive conformation. Further the covariance matrix reveals that the backbone atoms' motions favour the inactive conformation of the complex. This is the first report on the non-functional BAX-BIM SAHB complex by molecular dynamics simulation in the best of our knowledge.

  19. Modification of the BAX Salmonella test kit to include a hot start functionality (modification of AOAC Official Method 2003.09).

    Science.gov (United States)

    Wallace, F Morgan; DiCosimo, Deana; Farnum, Andrew; Tice, George; Andaloro, Bridget; Davis, Eugene; Burns, Frank R

    2011-01-01

    In 2010, the BAX System PCR assay for Salmonella was modified to include a hot start functionality designed to keep the reaction enzyme inactive until PCR begins. To validate the assay's Official Methods of Analysis status to include this procedure modification, an evaluation was conducted on four food types that were simultaneously analyzed with the BAX System and either the U.S. Food and Drug Administration's Bacteriological Analytical Manual or the U.S. Department of Agriculture-Food Safety and Inspection Service Microbiology Laboratory Guidebook reference method for detecting Salmonella. Identical performance between the BAX System method and the reference methods was observed. Additionally, lysates were analyzed using both the BAX System Classic and BAX System Q7 instruments with identical results using both platforms for all samples tested. Of the 100 samples analyzed, 34 samples were positive for both the BAX System and reference methods, and 66 samples were negative by both the BAX System and reference methods, demonstrating 100% correlation. No instrument platform variation was observed. Additional inclusivity and exclusivity testing using the modified test kit demonstrated the test kit to be 100% accurate in evaluation of test panels of 352 Salmonella strains and 46 non-Salmonella strains.

  20. Modification of the BAX System PCR assay for detecting Salmonella in beef, produce, and soy protein isolate. Performance Tested Method 100201.

    Science.gov (United States)

    Peng, Linda X; Wallace, Morgan; Andaloro, Bridget; Fallon, Dawn; Fleck, Lois; Delduco, Dan; Tice, George

    2011-01-01

    The BAX System PCR assay for Salmonella detection in foods was previously validated as AOAC Research Institute (RI) Performance Tested Method (PTM) 100201. New studies were conducted on beef and produce using the same media and protocol currently approved for the BAX System PCR assay for E. coli O157:H7 multiplex (MP). Additionally, soy protein isolate was tested for matrix extension using the U.S. Food and Drug Administration-Bacteriological Analytical Manual (FDA-BAM) enrichment protocols. The studies compared the BAX System method to the U.S. Department of Agriculture culture method for detecting Salmonella in beef and the FDA-BAM culture method for detecting Salmonella in produce and soy protein isolate. Method comparison studies on low-level inoculates showed that the BAX System assay for Salmonella performed as well as or better than the reference method for detecting Salmonella in beef and produce in 8-24 h enrichment when the BAX System E. coli O157:H7 MP media was used, and soy protein isolate in 20 h enrichment with lactose broth followed by 3 h regrowth in brain heart infusion broth. An inclusivity panel of 104 Salmonella strains with diverse serotypes was tested by the BAX System using the proprietary BAX System media and returned all positive results. Ruggedness factors involved in the enrichment phase were also evaluated by testing outside the specified parameters, and none of the factors examined affected the performance of the assay.

  1. Benzo(a)pyrene-7,8-diol-9,10-epoxide induced p53-independent necrosis via the mitochondria-associated pathway involving Bax and Bak activation.

    Science.gov (United States)

    Zhang, W; Liu, N; Wang, X; Jin, X; Du, H; Peng, G; Xue, J

    2015-02-01

    Benzo(a)pyrene-7,8-diol-9,10-epoxide (BPDE) is a highly reactive DNA damage agent and can induce cell death through both p53-independent and -dependent pathways. However, little is known about the molecular mechanisms of p53-independent pathways in BPDE-induced cell death. To understand the p53-independent mechanisms, we have now examined BPDE-induced cytotoxicity in p53-deficient baby mouse kidney (BMK) cells. The results showed that BPDE could induce Bax and Bak activation, cytochrome c release, caspases activation, and necrotic cell death in the BMK cells. Bax and Bak, two key molecules of mitochondrial permeability transition pore, were interdependently activated by BPDE, with Bax and Bak translocation to and Bax/Bak homo-oligomerization in mitochondria, release of cytochrome c was induced. Importantly, cytochrome c release and necrotic cell death were diminished in BMK cells (Bax(-/-)), BMK cells (Bak(-/-)), and BMK cells (Bax(-/-)/Bak(-/-)). Furthermore, overexpression of Bcl-2 could ameliorate BPDE-induced cytochrome c release and necrosis. Together the findings suggested that BPDE-induced necrosis was modulated by the p53-independent pathway, which was related to the translocation of Bax and Bak to mitochondria, release of cytochrome c, and activation of caspases. © The Author(s) 2015.

  2. Boron neutron capture therapy induces apoptosis of glioma cells through Bcl-2/Bax

    Directory of Open Access Journals (Sweden)

    Mao Xinggang

    2010-12-01

    Full Text Available Abstract Background Boron neutron capture therapy (BNCT is an alternative treatment modality for patients with glioma. The aim of this study was to determine whether induction of apoptosis contributes to the main therapeutic efficacy of BNCT and to compare the relative biological effect (RBE of BNCT, γ-ray and reactor neutron irradiation. Methods The neutron beam was obtained from the Xi'an Pulsed Reactor (XAPR and γ-rays were obtained from [60Co] γ source of the Fourth Military Medical University (FMMU in China. Human glioma cells (the U87, U251, and SHG44 cell lines were irradiated by neutron beams at the XAPR or [60Co] γ-rays at the FMMU with different protocols: Group A included control nonirradiated cells; Group B included cells treated with 4 Gy of [60Co] γ-rays; Group C included cells treated with 8 Gy of [60Co] γ-rays; Group D included cells treated with 4 Gy BPA (p-borono-phenylalanine-BNCT; Group E included cells treated with 8 Gy BPA-BNCT; Group F included cells irradiated in the reactor for the same treatment period as used for Group D; Group G included cells irradiated in the reactor for the same treatment period as used for Group E; Group H included cells irradiated with 4 Gy in the reactor; and Group I included cells irradiated with 8 Gy in the reactor. Cell survival was determined using the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium (MTT cytotoxicity assay. The morphology of cells was detected by Hoechst33342 staining and transmission electron microscope (TEM. The apoptosis rate was detected by flow cytometer (FCM. The level of Bcl-2 and Bax protein was measured by western blot analysis. Results Proliferation of U87, U251, and SHG44 cells was much more strongly inhibited by BPA-BNCT than by irradiation with [60Co] γ-rays (P 60Co] γ-rays (P P Conclusions Compared with ��-ray and reactor neutron irradiation, a higher RBE can be achieved upon treatment of glioma cells with BNCT. Glioma cell apoptosis induced by

  3. Titanium dioxide induces apoptotic cell death through reactive oxygen species-mediated Fas upregulation and Bax activation

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    Yoon TH

    2012-03-01

    Full Text Available Ki-Chun Yoo1, Chang-Hwan Yoon1, Dongwook Kwon2, Kyung-Hwan Hyun1, Soo Jung Woo1, Rae-Kwon Kim1, Eun-Jung Lim1, Yongjoon Suh1, Min-Jung Kim1, Tae Hyun Yoon2, Su-Jae Lee11Laboratory of Molecular Biochemistry, 2Laboratory of Nanoscale Characterization and Environmental Chemistry, Department of Chemistry, Hanyang University, Seoul, Republic of KoreaBackground: Titanium dioxide (TiO2 has been widely used in many areas, including biomedicine, cosmetics, and environmental engineering. Recently, it has become evident that some TiO2 particles have a considerable cytotoxic effect in normal human cells. However, the molecular basis for the cytotoxicity of TiO2 has yet to be defined.Methods and results: In this study, we demonstrated that combined treatment with TiO2 nanoparticles sized less than 100 nm and ultraviolet A irradiation induces apoptotic cell death through reactive oxygen species-dependent upregulation of Fas and conformational activation of Bax in normal human cells. Treatment with P25 TiO2 nanoparticles with a hydrodynamic size distribution centered around 70 nm (TiO2P25–70 together with ultraviolet A irradiation-induced caspase-dependent apoptotic cell death, accompanied by transcriptional upregulation of the death receptor, Fas, and conformational activation of Bax. In line with these results, knockdown of either Fas or Bax with specific siRNA significantly inhibited TiO2-induced apoptotic cell death. Moreover, inhibition of reactive oxygen species with an antioxidant, N-acetyl-L-cysteine, clearly suppressed upregulation of Fas, conformational activation of Bax, and subsequent apoptotic cell death in response to combination treatment using TiO2P25–70 and ultraviolet A irradiation.Conclusion: These results indicate that sub-100 nm sized TiO2 treatment under ultraviolet A irradiation induces apoptotic cell death through reactive oxygen species-mediated upregulation of the death receptor, Fas, and activation of the preapoptotic protein

  4. Downregulation of uPAR and cathepsin B induces apoptosis via regulation of Bcl-2 and Bax and inhibition of the PI3K/Akt pathway in gliomas.

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    Ramarao Malla

    Full Text Available BACKGROUND: Glioma is the most commonly diagnosed primary brain tumor and is characterized by invasive and infiltrative behavior. uPAR and cathepsin B are known to be overexpressed in high-grade gliomas and are strongly correlated with invasive cancer phenotypes. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we observed that simultaneous downregulation of uPAR and cathepsin B induces upregulation of some pro-apoptotic genes and suppression of anti-apoptotic genes in human glioma cells. uPAR and cathepsin B (pCU-downregulated cells exhibited decreases in the Bcl-2/Bax ratio and initiated the collapse of mitochondrial membrane potential. We also observed that the broad caspase inhibitor, Z-Asp-2, 6-dichlorobenzoylmethylketone rescued pCU-induced apoptosis in U251 cells but not in 5310 cells. Immunoblot analysis of caspase-9 immunoprecipitates for Apaf-1 showed that uPAR and cathepsin B knockdown activated apoptosome complex formation in U251 cells. Downregulation of uPAR and cathepsin B also retarded nuclear translocation and interfered with DNA binding activity of CREB in both U251 and 5310 cells. Further western blotting analysis demonstrated that downregulation of uPAR and cathepsin B significantly decreased expression of the signaling molecules p-PDGFR-β, p-PI3K and p-Akt. An increase in the number of TUNEL-positive cells, increased Bax expression, and decreased Bcl-2 expression in nude mice brain tumor sections and brain tissue lysates confirm our in vitro results. CONCLUSIONS/SIGNIFICANCE: In conclusion, RNAi-mediated downregulation of uPAR and cathepsin B initiates caspase-dependent mitochondrial apoptosis in U251 cells and caspase-independent mitochondrial apoptosis in 5310 cells. Thus, targeting uPAR and cathepsin B-mediated signaling using siRNA may serve as a novel therapeutic strategy for the treatment of gliomas.

  5. Methylglyoxal reduces mitochondrial potential and activates Bax and caspase-3 in neurons: Implications for Alzheimer's disease.

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    Tajes, Marta; Eraso-Pichot, Abel; Rubio-Moscardó, Fanny; Guivernau, Biuse; Bosch-Morató, Mònica; Valls-Comamala, Victòria; Muñoz, Francisco J

    2014-09-19

    Alzheimer's disease (AD) is characterized by the oxidative stress generated from amyloid β-peptide (Aβ) aggregates. It produces protein nitrotyrosination, after the reaction with nitric oxide to form peroxynitrite, being triosephosphate isomerase (TPI) one of the most affected proteins. TPI is a glycolytic enzyme that catalyzes the interconversion between glyceraldehyde 3-phosphate (GAP) and dihydroxyacetone phosphate (DHAP). Methylglyoxal (MG) is a by-product of TPI activity whose production is triggered when TPI is nitrotyrosinated. MG is harmful to cells because it glycates proteins. Here we found protein glycation when human neuroblastoma cells were treated with Aβ. Moreover glycation was also observed when neuroblastoma cells overexpressed mutated TPI where Tyr165 or Tyr209, the two tyrosines close to the catalytic center, were changed by Phe in order to mimic the effect of nitrotyrosination. The pathological relevance of these findings was studied by challenging cells with Aβ oligomers and MG. A significant decrease in mitochondrial transmembrane potential, one of the first apoptotic events, was obtained. Therefore, increasing concentrations of MG were assayed searching for MG effect in neuronal apoptosis. We found a decrease of the protective Bcl2 and an increase of the proapoptotic caspase-3 and Bax levels. Our results suggest that MG is triggering apoptosis in neurons and it would play a key role in AD neurodegeneration.

  6. Direct proof of static charge stripe correlations in La2-xBaxCuO4

    Science.gov (United States)

    Chen, X. M.; Thampy, V.; Mazzoli, C.; Barbour, A.; Gu, G.; Hill, J. P.; Tranquada, J. M.; Dean, M. P. M.; Wilkins, S. B.

    The nature of charge stripe order in the cuprates, and in particular whether the stripes are static or dynamic, is a key issue in understanding the relationship between stripes and superconductivity. In La2-xBaxCuO4 (LBCO) a low temperature structural distortion is widely believed to pin stripes into fixed, static domains, but such an assertion has never been directly verified. We performed resonant soft x-ray photon correlation spectroscopy (XPCS) to probe the charge order Bragg peak of 1/8 doped LBCO. At low temperatures, we observe time-independent x-ray speckle patterns persisting for more than three hours, proving the static nature of the stripes and we go on to discuss how stripe order melts with increasing temperature. Our results demonstrate that the combination of XPCS with diffraction limited light sources such as the National Synchrotron Light Source II can probe the dynamics of even subtle order parameters such as stripes in the cuprates. Work performed at Brookhaven National Laboratory was supported by the US Department of Energy, Division of Materials Science, under Contract No. DE-AC02-98CH10886. Use of the National Synchrotron Light Source II was supported under Contract No. DE-SC0012704.

  7. Stripe order in La2-xBaxCuO4 at ambient and high pressure.

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    Huecker, M.; Wen, J. S.; Xu, Z. J.; Gu, G. D.; Tranquada, J. M.; Zimmermann, M. V.

    2009-03-01

    The pronounced stability of the charge and spin stripe order in La2-xBaxCuO4 at x=1/8 doping still is a poorly understood peculiarity. A combination of electronic and structural interactions is likely, however it has been difficult to clearly separate the involved mechanisms. One approach is to explore how stripe order fades away for dopings x !=1/8. We have performed high energy (100 keV) x-ray diffraction and static magnetization experiments on single crystals between x=0.095 and 0.155. To our surprise, at ambient pressure stripes exist in a much broader range of doping around x=1/8 than expected. In the underdoped region charge stripe order always coincides with a structural transition associated with a rotation of the octahedral tilt axis. However, for x=1/8 and high pressure we have been able to show that stripe order also occurs in the absence of this structural phase, which motivates us to discuss stripes in terms of an electronic liquid crystal phase.

  8. Infrared Spectra of La0.65BaxMnO3-δ Oxides

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The infrared spectra of La0.65BaxMnO3-d (x = 0.35, 0.33 and 0.30) were investigated experimentally. The result shows that the sample La0.65Ba0.33MnO3-d has the largest Curie temperature and the smallest resistivity and wave number of the stretching vibration mode of MnO6 octahedron at 300 K among the investigated samples. However, the absorption strength for the stretching vibration mode of MnO6 octahedron in La0.65Ba0.35MnO3-d is stronger for paramagnetic phase than that for ferromagnetic phase, which may be connected with the reducing of the dynamic incoherent Jahn-Teller distortion below Curie temperature. In addition, the large shift of wave number for the stretching mode at the temperatures from 293 to 423 K has been observed in La0.65Ba0.35MnO3-d, which may be due to the increase of the Mn-O bond length with temperature increasing.

  9. Integration of BaxSr1-xTiO3 thin film for DRAM application

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    Kashihara, Keiichiro; Okudaira, Tomonori; Tsunemine, Yoshikazu; Ohno, Yoshikazu; Itoh, Hiromi; Nishimura, Tadashi; Hirayama, Makoto; Horikawa, Tsuyoshi; Shibano, Teruo; Horie, Kazuo

    1995-09-01

    This paper presents a newly developed process technology to integrate the BaxSr1-xTiO3(BST) thin film prepared by an rf magnetron sputtering. Evaluations of the integrated BST capacitors on a test element group (TEG) structure revealed some of key issues for a successful integration. A two-step sputtering method comprising the first step to form a nucleation layer and the second step to form the main part of the BST film was found to be useful for preventing the dielectric properties of the integrated BST thin film from the degradation. A careful control of the shape of the lower structures such as the edge of the bottom electrode or the poly Si plug of the storage node turned to be indispensable to obtain the reliable capacitor and this recommends the extensive use of the process that can provide a flush surface such as the Chemical Mechanical Polishing (CMP) in the future integration. The interlevel dielectrics over the BST capacitor was shown to seriously affect the leakage characteristics and an undoped SiO2 film was most suitable for the integrity, implying the needs for another planarization technique instead of the glass reflow. Finally, a preliminary evaluation of the reliability and the normal bit function of a 4 Mbits DRAM, made of fully flat BST stacked capacitors, demonstrated the utility of the developed integration technology.

  10. Pindborg tumor

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    Caliaperoumal, Santhosh Kumar; Gowri, S.; Dinakar, J.

    2016-01-01

    Calcifying epithelial odontogenic tumor (CEOT), also known as Pindborg tumor, is a rare odontogenic epithelial neoplasm. So far, nearly 200 cases have been reported in the literature. We are reporting a case of CEOT in a 42-year-old male patient with painless bony swelling in the mandible. The clinical, radiographic, and histopathologic features are discussed with relevant references. PMID:27041911

  11. Pindborg tumor

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    Santhosh Kumar Caliaperoumal

    2016-01-01

    Full Text Available Calcifying epithelial odontogenic tumor (CEOT, also known as Pindborg tumor, is a rare odontogenic epithelial neoplasm. So far, nearly 200 cases have been reported in the literature. We are reporting a case of CEOT in a 42-year-old male patient with painless bony swelling in the mandible. The clinical, radiographic, and histopathologic features are discussed with relevant references.

  12. Two-Dimensional Superconducting Fluctuations in Stripe-Ordered La2-xBaxCuO4

    Science.gov (United States)

    Li, Qiang; Hucker, Markus; Gu, Genda; Tsvelik, Alexei; Tranquada, John

    2008-03-01

    Recent spectroscopic observations of a d-wave-like gap in stripe-ordered La2-xBaxCuO4 with x=1/8 have led us to critically analyze the anisotropic transport and magnetization properties of this material. The data suggest that concomitant with the spin ordering is an electronic decoupling of the CuO2 planes. We observe a transition (or crossover) to a state of two-dimensional (2D) fluctuating superconductivity. Thus, it appears that the stripe order in La2-xBaxCuO4 frustrates three-dimensional superconducting phase order, but is fully compatible with 2D superconductivity and an enhanced Tc --[Ref. Q. Li, et al., PRL 99, 067001 (2007)

  13. Double knockout of Bax and Bak from kidney proximal tubules reduces unilateral urethral obstruction associated apoptosis and renal interstitial fibrosis

    Science.gov (United States)

    Mei, Shuqin; Li, Lin; Wei, Qingqing; Hao, Jielu; Su, Yunchao; Mei, Changlin; Dong, Zheng

    2017-01-01

    Interstitial fibrosis, a common pathological feature of chronic kidney diseases, is often associated with apoptosis in renal tissues. To determine the associated apoptotic pathway and its role in renal interstitial fibrosis, we established a mouse model in which Bax and Bak, two critical genes in the intrinsic pathway of apoptosis, were deleted specifically from kidney proximal tubules and used this model to examine renal apoptosis and interstitial fibrosis following unilateral urethral obstruction (UUO). It was shown that double knockout of Bax and Bak from proximal tubules attenuated renal tubular cell apoptosis and suppressed renal interstitial fibrosis in UUO. The results indicate that the intrinsic pathway of apoptosis contributes significantly to the tubular apoptosis and renal interstitial fibrosis in kidney diseases. PMID:28317867

  14. Interaction between Hsp60 and Bax in normal human myocardium and in myocardium affected by dilated cardiomyopathy

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    Tykhonkova I. O.

    2009-04-01

    Full Text Available The main functional compartments of molecular chaperone Hsp60 are mitochondria and cytoplasm. Up to 30 % of Hsp60 are located in cytoplasm of cardiomyocytes. The interaction between molecular chaperone Hsp60 and proapoptotic Bax protein in the cytoplasmic fraction from normal human heart tissue has been revealed by co-immunoprecipitation in contrast to myocardium affected by dilated cardiomyopathy, where this interaction has not been observed

  15. Enhanced Superconductivity in Close Proximity to the Structural Phase Transition of Sr1-xBaxNi2P2

    Science.gov (United States)

    Kudo, Kazutaka; Kitahama, Yutaka; Iba, Keita; Takasuga, Masaya; Nohara, Minoru

    2017-03-01

    The structural evolution and superconductivity of a 122-type solid solution Sr1-xBaxNi2P2 were studied. We found that an orthorhombic-tetragonal structural phase transition takes place at x = 0.5, and is characterized by the P-P dimers breaking. The superconducting transition temperature exhibited its highest value of 2.85 K at x = 0.4.

  16. Preparation and Photocatalytic Properties of Sr2−xBaxTa3O10−yNz Nanosheets

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    Tatsumi Ishihara

    2013-01-01

    Full Text Available Sr2−xBaxTa3O10−yNz (x = 0.0, 0.5, 1.0 nanosheets were prepared by exfoliating layered perovskite compounds (CsSr2−xBaxTa3O10−yNz. The Sr1.5Ba0.5Ta3O9.7N0.2 nanosheet showed the highest photocatalytic activity for H2 production from the water/methanol system among the Sr2−xBaxTa3O9.7N0.2 nanosheets prepared. In addition, Rh-loaded Sr1.5Ba0.5Ta3O9.6N0.3 nanosheet showed the photocatalytic activity for oxygen and hydrogen production from water. The ratio of hydrogen to oxygen evolved was around two. These results indicate that the Rh-loaded Sr1.5Ba0.5Ta3O9.6N0.3 nanosheet is a potential catalyst for photocatalytic water splitting.

  17. Emodin inhibits LOVO colorectal cancer cell proliferation via the regulation of the Bcl-2/Bax ratio and cytochrome c.

    Science.gov (United States)

    Ma, Liang; Li, Wusheng

    2014-10-01

    In this study, the effect of emodin and its mechanism of action were investigated in LOVO colorectal cancer cells. Cell growth was determined using a Cell Counting kit-8 assay, and the results demonstrated that emodin significantly inhibited the growth of LOVO cells in a concentration-dependent manner. In order to investigate the anticancer mechanism of emodin, reverse transcription polymerase chain reaction assays were performed to determine the B-cell lymphoma-2 (Bcl-2)/Bcl-2-associated X protein (Bax) expression ratio in LOVO colorectal cancer cells following treatment with emodin. The results showed that emodin induced a significant increase in the Bax expression level and a marked reduction of the Bcl-2 expression level in LOVO cells. In addition, emodin was found to have an inhibitory effect on the mitochondrial membrane potential and the results from the western blot analysis revealed that cytochrome c was released from the mitochondria to the cytoplasm. In combination, these results suggest that emodin inhibits cancer cell growth via the regulation of the Bcl-2/Bax ratio and by its effect on the mitochondrial apoptosis pathway.

  18. Associations of NF-kappaB and Bax with Apoptosis in Varicose Veins of Women of Different Age Groups

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    Helle Evi Simovart

    2011-01-01

    Full Text Available The study aimed at detecting apoptotic endothelial cells (ECs and smooth muscle cells (SMCs together with determining expression of NF-kappaB (p105/p50 and Bax in varicose vein walls. Women (n=35 undergoing the excision of varicose veins were divided into 3 groups: younger than 35 years (I, 36–50 years (II, and older than 50 years (III. Apoptosis was determined by the TUNEL method, NF-kappaB and Bax expression by immunohistochemistry. The percentage of apoptotic ECs and SMCs in the layers of varicose vein wall increased in groups II and III. NF-kappaB expression had the lowest level in Group II with particularly low level in the media. Contrariwise, Bax expression levels in Group II were increased. The study revealed that in varicose veins ECs and SMCs apoptosis increased with advancing age. If increase in apoptosis during earlier stages of varicosities is probably regulated by intrinsic pathway, then in older patients other signaling pathways may be involved.

  19. Expression of apoptosis-Related genes bcl-2 and bax in rat brain hippocampus, followed by intraperitoneal injection of nanosilver

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    Maryam Ghoshcian

    2016-05-01

    Full Text Available Background: Silver nanoparticles are small scale substance (<100 nm used in food technology and medical industry. The data suggest that nanosilver may produce neurotoxicity by generating free radical-induced oxidative stress and by altering gene expression producing apoptosis and neurotoxicity. In this study, the apoptotic effects of Nano silver on apoptosis- related genes expression bcl-2 and bax on rat hippocampus, which is involved in memory and learning, was investigated. Materials & Methods: 28 male Wistar rats were divided into four groups of control and three groups of the treatment. The control group received saline and the treatment groups received intraperitoneal injections of silver nanoparticles at doses of 100, 200 and 400ppm. Ten days after the last injection, the hippocampal region was dissected and removed and then the expression of bcl-2 and bax genes was evaluated using semi-qualitative RT-PCR and Densitometry assay. Results: The expression of anti- apoptotic b-cl2 gene was reduced in the treatment groups compared to the control group. In comparison, the expression of pro- apoptotic bax gene was increased in the treatment groups compared to the control group. This apoptotic affects was increased at higher doses. Conclusion: The data suggest that silver nanoparticles may produce apoptosis by altering apoptosis- related genes expression, in rat brain hippocampus cells.

  20. Schiff Base Metal Derivatives Enhance the Expression of HSP70 and Suppress BAX Proteins in Prevention of Acute Gastric Lesion

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    Shahram Golbabapour

    2013-01-01

    Full Text Available Schiff base complexes have appeared to be promising in the treatment of different diseases and disorders and have drawn a lot of attention to their biological activities. This study was conducted to evaluate the regulatory effect of Schiff base metal derivatives on the expression of heat shock proteins (HSP 70 and BAX in protection against acute haemorrhagic gastric ulcer in rats. Rats were assigned to 6 groups of 6 rats: the normal control (Tween 20 5% v/v, 5 mL/kg, the positive control (Tween 20 5% v/v, 5 mL/kg, and four Schiff base derivative groups named Schiff_1, Schiff_2, Schiff_3, and Schiff_4 (25 mg/kg. After 1 h, all of the groups received ethanol 95% (5 mL/kg but the normal control received Tween 20 (Tween 20 5% v/v, 5 mL/kg. The animals were euthanized after 60 min and the stomachs were dissected for histology (H&E, immunohistochemistry, and western blot analysis against HSP70 and BAX proteins. The results showed that the Schiff base metal derivatives enhanced the expression of HSP70 and suppressed the expression of BAX proteins during their gastroprotection against ethanol-induced gastric lesion in rats.

  1. Virosecurinine induces apoptosis by affecting Bcl-2 and Bax expression in human colon cancer SW480 cells.

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    Chen, Chuan-Rong; Xia, Yong-Hui; Yao, Shu-Yan; Zhang, Qing; Wang, Ying; Ji, Zhao-Ning

    2012-04-01

    Virosecurinine, the major alkaloid isolated from Securinega suffruticosa Pall Rehd was found to exhibit growth inhibition and cytotoxicity against huaman colon cancer SW480 cells via the microculture tetrazolium (MTT) assay. Due to its greater cytotoxic potency and selectivity towards SW480 cells, flow cytometry was used to analyze the cell cycle distribution of control and treated SW480 cells whereas Annexin V-FITC/PI flow cytometry analysis was carried out to confirm apoptosis induced by virosecurinine in SW480 cells. Apoptotic regulatory genes were determined by RT-PCR analysis. Virosecurinine was found to induce G1/S cell cycle arrest which led to predominantly apoptotic mode of cell death. Mechanistically, virosecurinine was found to up-regulated the Bax gene expression and down-regulated the Bcl-2 expression in SW480, The ratio of Bcl-2 to Bax was significantly decreased. Hence, we suggest that virosecurinine induced apoptosis in SW480 cells by affecting the expression of bcl-2 and bax.

  2. Melatonin restores normal Bax and Bcl-2 protein expression in the subgranular zone of the dentate gyrus in pinealectomized rats

    Institute of Scientific and Technical Information of China (English)

    Shengchang Zhang; Shuang Zhao; Lu Bai; Mingming Guan; Jielin Mo; Ling Lan

    2011-01-01

    In this study, we sought to elucidate the effects of melatonin on learning and memory as well as apoptosis and expression of the Bax or Bcl-2 proteins in the subgranular zone of the dentate gyrus in pinealectomized rats. Using the Morris water maze and the olfactory memory tests, we found that the average escape latency in pinealectomized rats was clearly increased compared with sham-operated rats. Moreover, the average escape latency in the melatonin-treated and pinealectomized rats was longer than that in the sham-operated rats and shorter than that in the pinealectomized and untreated rats. Immunohistochemistry and terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) showed that there were fewer Bax immunoreactive cells and TUNEL-positive (apoptotic) cells but more Bcl-2 immunoreactive cells in the melatonin-treated rats compared with the pinealectomized rats. The sham-operated rats showed numbers of these cells similar to the melatonin-treated rats. These experimental findings demonstrate that melatonin treatment may reduce abnormal apoptosis by promoting gene expression of