Ação do extrato de glândulas salivares de fêmeas do carrapato Rhipicephalus sanguineus (Latreille, 1806) sobre a inibição da proliferação de células de linhagem tumoral

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito sinérgico entre a terapia fotodinâmica e a cisplatina: uma nova abordagem para o câncer de colo uterino

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Otimização do meio de transporte de oócitos bovinos destinados à produção in vitro de embriões

Pós-graduação em Medicina Veterinária - FCAV

Desenvolvimento do cultivo 3D a partir de células primarias de neoplasias mamárias caninas: estudo da apoptose sobre efeito ou não da carboplatina

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of the Paracoccidioides brasiliensis 14-3-3 and gp43 proteins on the induction of apoptosis in A549 epithelial cells

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chemical composition and antiproliferative activity of Acalypha californica

Acalypha californica Benth., is a plant in the northwestern region from Mexico, commonly known as "cancer herb" and used in traditional medicine for treating cancer. In the present study we have investigated the antiproliferative activity of methanolic extract of A. californica and its fractions in cancer cell lines and phytochemical analysis and mechanism of apoptosis of the fractions with antiproliferative activity. The antiproliferative activity of methanol extract and its fractions of solvents were evaluated by MTT assay against the M12.A(k).C3.F6, RAW 264.7, HeLa and L929 cell lines. Active fractions were fractionated by molecular exclusion chromatography, HPLC and MPLC. The identification of compounds was performed by NMR and FIA-ESI-IT-MS/MS analysis. Apoptotic mechanism was analyzed by flow cytometry, determining the reduction in the mitochondrial membrane potential (JC-1) and the activity of caspases 3,8 and 9. Cell viability assays showed that the hexane fraction of the methanol extract of the plant has significant effects against cancer lines RAW 264.7 (IC50 = 52.08 +/- 1.06 mu g/mL) and HeLa (IC50 = 46.77 +/- 1.09 mu g/mL), the residual fraction showed a selective effect on cell lines M12.A(k).C3.F6 (IC50 = 59.90 +/- 1.05 mu g/mL), RAW 264.7 (IC50 = 58.93 +/- 1.26 mu g/mL) and HeLa (IC50 = 50.11 +/- 1.135 mu g/mL) compared to the control cell line L929 (IC50 = 100.00 +/- 1.09 mu g/mL). The chemical characterization of the active fractions allowed the identification of p-sitosterol and stigmasterol in hexane fraction and some phenolic acids, proanthocyanidins and flavonoids in the residual fraction. The methanol extract and hexane fraction reduces mitochondrial membrane potential significantly and activates caspases 3, 8 and 9. Because of the antiproliferative activity observed, our results provide a rational basis for the use of extracts of A. californica in treating various types of cancer in traditional medicine from Mexico. The extracts induce apoptosis via activation of caspases. (C) 2015 Elsevier B.V. All rights reserved.

Tissue apoptosis in mice infected with Leptospira interrogans serovar Icterohaemorrhagiae

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bothropoides pauloensis venom effects on isolated perfused kidney and cultured renal tubular epithelial cells

Coordenadação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Apoptose no carcinoma de próstata

Pós-graduação em Patologia - FMB

Estratégias para minimização do estresse oxidativo em sistemas de produção in vitro de embriões bovinos destinados à vitrificação

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo da ação de derivados semi-sintéticos de curcumina em linhagens celulares de câncer humano

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Blocking of Connexin-Mediated Communication Promotes Neuroprotection during Acute Degeneration Induced by Mechanical Trauma

Accruing evidence indicates that connexin (Cx) channels in the gap junctions (GJ) are involved in neurodegeneration after injury. However, studies using KO animal models endowed apparently contradictory results in relation to the role of coupling in neuroprotection. We analyzed the role of Cx-mediated communication in a focal lesion induced by mechanical trauma of the retina, a model that allows spatial and temporal definition of the lesion with high reproducibility, permitting visualization of the focus, penumbra and adjacent areas. Cx36 and Cx43 exhibited distinct gene expression and protein levels throughout the neurodegeneration progress. Cx36 was observed close to TUNEL-positive nuclei, revealing the presence of this protein surrounding apoptotic cells. The functional role of cell coupling was assessed employing GJ blockers and openers combined with lactate dehydrogenase (LDH) assay, a direct method for evaluating cell death/viability. Carbenoxolone (CBX), a broad-spectrum GJ blocker, reduced LDH release after 4 hours, whereas quinine, a Cx36-channel specific blocker, decreased LDH release as early as 1 hour after lesion. Furthermore, analysis of dying cell distribution confirmed that the use of GJ blockers reduced apoptosis spread. Accordingly, blockade of GJ communication during neurodegeneration with quinine, but not CBX, caused downregulation of initial and effector caspases. To summarize, we observed specific changes in Cx gene expression and protein distribution during the progress of retinal degeneration, indicating the participation of these elements in acute neurodegeneration processes. More importantly, our results revealed that direct control of GJ channels permeability may take part in reliable neuroprotection strategies aimed to rapid, fast treatment of mechanical trauma in the retina.

(+)alpha-Tocopheryl succinate inhibits the mitochondrial respiratory chain complex I and is as effective as arsenic trioxide or ATRA against acute promyelocytic leukemia in vivo

The vitamin E derivative (+)alpha-tocopheryl succinate (alpha-TOS) exerts pro-apoptotic effects in a wide range of tumors and is well tolerated by normal tissues. Previous studies point to a mitochondrial involvement in the action mechanism; however, the early steps have not been fully elucidated. In a model of acute promyelocytic leukemia (APL) derived from hCG-PML-RAR alpha transgenic mice, we demonstrated that alpha-TOS is as effective as arsenic trioxide or all-trans retinoic acid, the current gold standards of therapy. We also demonstrated that alpha-TOS induces an early dissipation of the mitochondrial membrane potential in APL cells and studies with isolated mitochondria revealed that this action may result from the inhibition of mitochondrial respiratory chain complex I. Moreover, alpha-TOS promoted accumulation of reactive oxygen species hours before mitochondrial cytochrome c release and caspases activation. Therefore, an in vivo antileukemic action and a novel mitochondrial target were revealed for alpha-TOS, as well as mitochondrial respiratory complex I was highlighted as potential target for anticancer therapy. Leukemia (2012) 26, 451-460; doi:10.1038/leu.2011.216; published online 26 August 2011

Accumulation of the SET protein in HEK293T cells and mild oxidative stress: cell survival or death signaling

SET protein (I2PP2A) is an inhibitor of PP2A, which regulates the phosphorylated Akt (protein kinase B) levels. We assessed the effects of SET overexpression in HEK293T cells, both in the presence and the absence of mild oxidative stress induced by 50 mu M tert-butyl hydroperoxide. Immunoblotting assays demonstrated that SET accumulated in HEK293T cells and increased the levels of phosphorylated Akt and PTEN; in addition, SET decreased glutathione antioxidant defense of cell and increased expression of genes encoding antioxidant defense proteins. Immunofluorescence analysis demonstrated that accumulated SET was equally distributed in cytoplasm and nucleus; however, in cells that had been exposed to oxidative stress, SET was found in large aggregates in the cytoplasm. SET accumulation in HEK293T cells correlated with inhibition of basal apoptosis as evidenced by a decrease in annexin V staining and activity of caspases; under mild oxidative stress, SET accumulation correlated with caspase-independent cell death, as evidenced by increased PI and annexin V/PI double staining. The results suggest that accumulated SET could act via Akt/PTEN either as cell survival signal or as oxidative stress sensor for cell death.

SET protein accumulates in HNSCC and contributes to cell survival: Antioxidant defense, Akt phosphorylation and AVOs acidification

Objectives: Determination of the SET protein levels in head and neck squamous cell carcinoma (HNSCC) tissue samples and the SET role in cell survival and response to oxidative stress in HNSCC cell lineages. Materials and Methods: SET protein was analyzed in 372 HNSCC tissue samples by immunohistochemistry using tissue microarray and HNSCC cell lineages. Oxidative stress was induced with the pro-oxidant tert-butylhydroperoxide (50 and 250 mu M) in the HNSCC HN13 cell lineage either with (siSET) or without (siNC) SET knockdown. Cell viability was evaluated by trypan blue exclusion and annexin V/propidium iodide assays. It was assessed caspase-3 and -9, PARP-1, DNA fragmentation, NM23-H1, SET, Akt and phosphorylated Akt (p-Akt) status. Acidic vesicular organelles (AVOs) were assessed by the acridine orange assay. Glutathione levels and transcripts of antioxidant genes were assayed by fluorometry and real time PCR, respectively. Results: SET levels were up-regulated in 97% tumor tissue samples and in HNSCC cell lineages. SiSET in HN13 cells (i) promoted cell death but did not induced caspases, PARP-1 cleavage or DNA fragmentation, and (ii) decreased resistance to death induced by oxidative stress, indicating SET involvement through caspase-independent mechanism. The red fluorescence induced by siSET in HN13 cells in the acridine orange assay suggests SET-dependent prevention of AVOs acidification. NM23-H1 protein was restricted to the cytoplasm of siSET/siNC HN13 cells under oxidative stress, in association with decrease of cleaved SET levels. In the presence of oxidative stress, siNC HN13 cells showed lower GSH antioxidant defense (GSH/GSSG ratio) but higher expression of the antioxidant genes PRDX6, SOD2 and TXN compared to siSET HN13 cells. Still under oxidative stress, p-Akt levels were increased in siNC HN13 cells but not in siSET HN13, indicating its involvement in HN13 cell survival. Similar results for the main SET effects were observed in HN12 and CAL 27 cell lineages, except that HN13 cells were more resistant to death. Conclusion: SET is potential (i) marker for HNSCC associated with cancer cell resistance and (ii) new target in cancer therapy. (C) 2012 Elsevier Ltd. All rights reserved.