9 research outputs found

    Cytoskeletal rearrangement and cell death induced by Bothrops alternatus snake venom in cultured Madin-Darby canine kidney cells

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    Bothrops snake venoms cause renal damage, with renal failure being the main cause of death in humans bitten by these snakes. In this work, we investigated the cytoskeletal rearrangement and cytotoxicity caused by Bothrops alternatus venom in cultured Madin-Darby canine kidney (MDCK) cells. Incubation with venom (10 and 100 mu g/mL) significantly (p <0.05) decreased the cellular uptake of neutral red dye after 1 and 3 h. Venom (100 mu g/mL) also markedly decreased the transepithelial electrical resistance (R-T) across MDCK monolayers. Staining with rhodamine-conjugated phalloidin revealed disarray of the cytoskeleton that involved the stress fibers at the basal cell surface and focal adhesion-associated F-actin in the cell-matrix contact region. Feulgen staining showed a significant decrease in the number of cells undergoing mitosis and an increase in the frequency of altered nuclei. Scanning electron microscopy revealed a decrease in the number of microvilli and the presence of cells with a fusiform format. Flow cytometry with annexin V and propidium iodide showed that cell death occurred by necrosis, with little apoptosis, a conclusion supported by the lack of DNA fragmentation characteristic of apoptosis. Pretreating the cells with catalase significantly attenuated the venom-induced loss of viability, indicating a possible involvement of H2O2 in the cellular damage; less protection was observed with superoxide dismutase or N-w-nitro-L-arginine methyl ester. These results indicate that Bothrops alternatus venom is cytotoxic to cultured MDCK cells, possibly via the action of reactive oxygen species. This cytotoxicity could contribute to nephrotoxicity after envenoming by this species.85559160

    Prognostic significance of WT1 gene expression in pediatric acute myeloid leukemia

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    Background. The Wilms Tumor gene (WT1) encodes a transcription factor involved in kidney development and malignancy. WT1 expression in a subpopulation of early CD34+ cells has suggested its involvement in hematopoiesis. WT1 is aberrantly expressed in leukemias. High expression of WT1 at diagnosis has been associated With unfavourable prognosis in adult acute myeloid leukemia (AML). The prognostic relevance of WT1 expression in pediatric AML was evaluated in only one study, including 47 patients, which Showed that very low levels of WT1 at presentation were associated with an excellent outcome. To test the validity of these findings we measured levels of WT1 in 41 newly diagnosed pediatric AML of the non-M3 FAB subtype. Procedure. Patients were treated according to an AML-BFM 83-based protocol in a single institution. Mononucleated cells, obtained from presentation BM aspirates were cryopreserved and later thawed and used for total RNA extraction and cDNA synthesis. The quantitative assessment of WT1 transcripts was made by real-time PCR (RQ-PCR). WT1 transcripts values were normalized with respect to the number of ABL transcripts. Results. WT1 levels were significantly higher in patients bearing favorable chromosome abnormalities, t(8;21) and inv(16) (P = 0.002). Higher levels of WT1 expression were Unexpectedly associated with a higher probability of overall survival by Cox regression analysis (P = 0.002). Multivariate regression analysis could not discriminate between the effects of WT1 and cytogenetics on survival. Conclusions. Higher WT1 expression was associated with favorable cytogenetics subtypes and accordingly with better outcome in children with AML in this study.49213313

    Evaluation of the anti-proliferative effect the extracts of Allamanda blanchetti and A-schottii on the growth of leukemic and endothelial cells

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    PURPOSE. To investigate the anti-proliferative effect of A. blanchetti and A. schottii extracts. METHODS. The anti-proliferative effect of A. blanchetti and A. schottii ethanolic extracts on K562 leukemic cells as well as on BMEC and HUVEC were evaluated. Phytochemical analysis to identify the possible active components was carried out. RESULTS. The root extract of A. schottii was the most active of them. At 80 mu g/mL, the root extracts showed a cytostatic effect on K562, whereas at 400 mu g/mL, there was a strong cytotoxic effect. Similar cytostatic and cytotoxic effects were seen in the endothelial cells, but at lower doses. The effect of A. schottii root extract on endothelial cells was seen at concentrations ten times lower (8 mu g/mL) than the effect of the A. blanchetti root extract (80 mu g/mL). Phytochemical investigation of different fractions and parts of the plant led to the isolation of several known compounds, some of which are described for the first time in the genus Allamanda, and with previous evidence of anticancer and antitumoral properties. CONCLUSIONS. Our results suggest that both plants studied exhibit cytostatic and cytotoxic activity, but the most active compounds are located in the roots.9220020

    Essential Oil from the Leaves of Campomanesia guaviroba (DC.) Kiaersk. (Myrtaceae): Chemical Composition, Antioxidant and Cytotoxic Activity

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The essential oil from the leaves of Campomanesia guaviroba (DC.) Kiaersk., obtained by hydrodistillation, was analyzed by GC and GC/MS. Sixteen compounds could be identified, representing around 94% of the total oil. The major components were myrtenal (27.0%), myrtenol (24.7%) and trans-pinocarveol (15.7%). The essential oil was also evaluated for DPPH radical-scavenging activity by TLC autographic assay, antioxidant capacity by ORAC-FL assay and antiproliferative activity against leukemic cells lines.235SI3437Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAEPEX-UNICAMPFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Cytotoxic non-aromatic B-ring flavanones from Piper carniconnectivum C. DC.

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The EtOAc extract from the leaves of Piper carniconnectivum C. DC. was subjected to chromatographic separation to afford two non-aromatic B-ring flavanone compounds: 5-hydroxy-2-(1'-hydroxy-4'-oxo-cyclohex-2'-en-1'-yl)-6,7-dimethoxy-2,3-dihydro-4H-chromen-4-one (1) and 5-hydroxy-2-(1',2'-dihydroxy-4'-oxo-cyclohexyl)-6,7-dimethoxy-2,3-dihydro-4H-chromen-4-one (2). The absolute configuration of (+)-1 was unambiguously determined as 2S,1'R by electronic circular dichroism (ECD) spectroscopy and comparison to simulated spectra that were calculated using time-dependent density functional theory (TDDFT). This methodology allowed the assignment of the absolute configuration of (+)-2 also as 2S,1'R, except for the stereogenic center at C-2', which was assigned as R because of the evidence drawn from high resolution NMR experiments. The cytotoxic activity of both compounds and 3 (hydrogenated B-ring derivative of 1) was evaluated on twelve human leukemia cell lines, and the IC50 values (<10 mu M) indicated the activity of 1 against seven cell lines. (C) 2013 Elsevier Ltd. All rights reserved.978187Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)NSF [DEB 1145609]University of Sao Paulo [2012.1.17646.1.8][2008/58658-3][2008/58717-0][2011/22339-4]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2009/51850-9]NSF [DEB 1145609]University of Sao Paulo [2012.1.17646.1.8][2008/58658-3][2008/58717-0][2011/22339-4

    Cytotoxic, Antitumour and Antimetastatic Activity of Two New Polyacetylenes Isolated from Vernonia scorpioides (Lam.) Pers

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    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Vernonia scorpioides (Lam.) Pers., popularly known as Enxuga, Erva-de-SAo SimAo and Piraca, has been used in folk medicine for its anti-inflammatory, wound healing and antimicrobial properties. Two polyacetylenes, 5-octa-2,4,6-triynyl-furan-2(5H)-one (1) and 8-hydroxy 3-4 dihydrovernoniyne (2), were isolated from the dichloromethane extract fraction of V.scorpioides. In this study, polyacetylene 1 demonstrated a more potent cytotoxic activity than 2 in the tumour cell lines examined, and cytotoxicity was found to be comparable to a commercial drug (p>0.05) in melanoma cells. No significant cytotoxic effect was observed in normal cell lines. Furthermore, polyacetylene 1 induced an in vitro increase in caspase-3 activity in B16F10 cells. When polyacetylene 1 was administered intraperitoneally (i.p.) in mice, a reduction in solid tumour volume and metastasis was observed in mice injected with B16F10 cells. An increase in locomotor activity was also observed in mice with solid tumours, and an inhibition of mechanical hypersensitivity was observed in a mouse model of metastasis. Notably, no significant morphological change was observed in several organs harvested from the treated mice. In conclusion, in vitro and in vivo anticancer activity of polyacetylene 1 was consistently observed and involved the induction of apoptosis by the activation of caspase-3. The anticancer activity demonstrated by polyacetylene 1, together with the absence of preliminary toxicological effects, represents a new and interesting option for the management of neoplastic disease.1135307315Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundacao de Apoio a Pesquisa Cientofica e Tecnologica do Estado de Santa Catarina (FAPESC)Pro-Reitoria de Pesquisa, Pos-Graduacao, Extensao e Cultura of the Universidade do Vale do Itajai (ProP-PEC/UNIVALI), BrazilConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

    ANKHD1, a novel component of the Hippo signaling pathway, promotes YAP1 activation and cell cycle progression in prostate cancer cells

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    ANKHD1 is a multiple ankyrin repeat containing protein, recently identified as a novel member of the Hippo signaling pathway. The present study aimed to investigate the role of ANKHDI in DU145 and LNCaP prostate cancer cells. ANKHD1 and YAP1 were found to be highly expressed in prostate cancer cells, and ANKHD1 silencing decreased cell growth, delayed cell cycle progression at the S phase, and reduced tumor xenograft growth. Moreover, ANKHD1 knockdown down-regulated YAP1 expression and activation, and reduced the expression of CCNA2, a YAP1 target gene. These findings indicate that ANKHD1 is a positive regulator of YAP1 and promotes cell growth and cell cycle progression through Cyclin A upregulation. (C) 2014 Elsevier Inc. All rights reserved.324213714
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