31 research outputs found
An aqueous olive leaf extract ({OLE}) ameliorates parameters of oxidative stress associated with lipid accumulation and induces lipophagy in human hepatic cells
Fatty liver is a disease characterized by a buildup of lipids in the liver, often resulting from excessive consumption of high-fat-containing foods. Fatty liver can degenerate, over time, into more severe forms of liver diseases, especially when oxidative stress occurs. Olive leaf extract (OLE) is a reliable source of polyphenols with antioxidant and hypolipidemic properties that have been successfully used in medicine, cosmetics, and pharmaceutical products. Using "green" solvents with minimal impact on the environment and human health, which simultaneously preserves the extract's beneficial properties, represents one of the major challenges of biomedical research. In the present study, we assayed the potential antioxidant and lipid-lowering effect of a "green" OLE obtained by a water ultrasound-assisted extraction procedure, on the human hepatic HuH7 cell line, treated with a high concentration of free fatty acids (FFA). We found that high FFA concentration induced lipid accumulation and oxidative stress, as measured by increased hydrogen peroxide levels. Moreover, the activity of antioxidant enzymes, catalase, superoxide dismutase, and glutathione peroxidase, was reduced upon FFA treatment. Coincubation of high FFA with OLE reduced lipid and H2O2 accumulation and increased the activity of peroxide-detoxifying enzymes. OLE ameliorated mitochondrial membrane potential, and hepatic parameters by restoring the expression of enzymes involved in insulin signaling and lipid metabolism. Electron microscopy revealed an increased autophagosome formation in both FFA- and FFA + OLE-treated cells. The study of the autophagic pathway indicated OLE's probable role in activating lipophagy
Topoisomerase II alpha gene copy loss has adverse prognostic significance in ERBB2-amplified breast cancer: a retrospective study of paraffin-embedded tumor specimens and medical charts
<p>Abstract</p> <p>Background</p> <p>Amplification of the <it>ERBB2 </it>(<it>Her-2/neu</it>) oncogene, which occurs in approximately 25% of breast carcinomas, is a known negative prognostic factor. Available data indicate that a variable number of nearby genes on chromosome 17q may be co-amplified or deleted, forming a continuous amplicon of variable size. In approximately 25% of these patients, the amplicon extends to the gene for <it>topoisomerase II alpha </it>(<it>TOP2A</it>), a target for anthracyclines. We sought to understand the significance of these associated genomic changes for breast cancer prognosis and predicting response to therapy.</p> <p>Methods and patients</p> <p>Archival tissue samples from 63 breast cancer patients with <it>ERBB2 </it>amplification, stages 0–IV, were previously analyzed with FISH probes for genes located near <it>ERBB2</it>. In the present study, the clinical outcome data were determined for all patients presenting at stages I–III for whom adequate clinical follow up was available.</p> <p>Results</p> <p>Four amplicon patterns (Classes) were identified. These were significantly associated with the clinical outcome, specifically, recurrence of breast cancer. The Amplicon class IV with deleted <it>TOP2A </it>had 67% (6/9) cases with recurrence, whereas the other three classes combined had only 12% (3/25) cases (p-value = 0.004) at the time of last follow-up. <it>TOP2A </it>deletion was also significantly associated with time to recurrence (p-value = 0.0002). After adjusting for age in Cox regression analysis, the association between <it>TOP2A </it>deletion and time to recurrence remains strongly significant (p-value = 0.002) whereas the association with survival is marginally significant (p-value = 0.06).</p> <p>Conclusion</p> <p><it>TOP2A </it>deletion is associated with poor prognosis in <it>ERBB2</it>-amplified breast carcinomas. Clarification of the mechanism of this association will require additional study.</p
Rootstock–scion interaction affecting citrus response to CTV infection: a proteomic view
Citrus tristeza virus (CTV) is the causal agent of various diseases with dramatic
effects on citrus crops worldwide. Most Citrus species, grown on their
own roots, are symptomless hosts for many CTV isolates. However, depending
on different scion\u2013rootstock combination, CTV infection should result in
distinct syndromes, being \u2018tristeza\u2019 the more severe one, leading to a complete
decline of the susceptible plants in a few weeks. Transcriptomic analyses
revealed several genes involved either in defense response, or systemic
acquired resistance, as well as transcription factors and components of the
phosphorylation cascades, to be differentially regulated during CTV infection
in Citrus aurantifolia species. To date little is known about the molecular
mechanism of this host\u2013pathogen interaction, and about the rootstock
effect on citrus response to CTV infection. In this work, the response to CTV
infection has been investigated in tolerant and susceptible scion\u2013rootstock
combinations by two-dimensional gel electrophoresis (2DE). A total of 125
protein spots have been found to be differently accumulated and/or phosphorylated
between the two rootstock combinations. Downregulation in tolerant
plants upon CTV infection was detected for proteins involved in reactive oxygen
species (ROS) scavenging and defense response, suggesting a probable
acclimation response able to minimize the systemic effects of virus infection.
Some of these proteins resulted to be modulated also in absence of virus
infection, revealing a rootstock effect on scion proteome modulation. Moreover,
the phospho-modulation of proteins involved in ROS scavenging and
defense response, further supports their involvement either in scion\u2013rootstock
crosstalk or in the establishment of tolerance/susceptibility to CTV infection
Morphological and molecular responses induced by microalgae extracts in Beta vulgaris L.
Root morphological and molecular responses induced by microalgae extracts in sugar beet (Beta vulgaris L.)
The different dermoscopic features of the yellow background in Langerhans and non-Langerhans cells histiocytosis
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Maspin influences response to doxorubicin by changing the tumor microenvironment organization
Altered degradation and deposition of extracellular matrix are hallmarks of tumor progression and response to therapy. From a microarray supervised analysis on a dataset of chemotherapy-treated breast carcinoma patients, maspin, a member of the serpin protease inhibitor family, has been the foremost variable identified in non-responsive versus responsive tumors. Accordingly, in a series of 52 human breast carcinomas, we detected high maspin expression in tumors that progressed under doxorubicin (DXR)-based chemotherapy. Our analysis of the role of maspin in response to chemotherapy in human MCF7 and MDAMB231 breast and SKOV3 ovarian carcinoma cells transfected to overexpress maspin and injected into mice showed that maspin overexpression led to DXR resistance through the maspin-induced collagen-enriched microenvironment and that an anti-maspin neutralizing monoclonal antibody reversed the collagen-dependent DXR resistance. Impaired diffusion and decreased DXR activity were also found in tumors derived from Matrigel-embedded cells, where abundant collagen fibers characterize the tumor matrix. Conversely, liposome-based DXR reached maspin-overexpressing tumor cells despite the abundant extracellular matrix and was more efficient in reducing tumor growth. Our results identify maspin-induced accumulation of collagen fibers as a cause of disease progression under DXR chemotherapy for breast cancer. Use of a more hydrophilic DXR formulation or of a maspin inhibitor in combination with chemotherapy holds the promise of more consistent responses to maspin-overexpressing tumors and dense-matrix tumors in general. What's new? Alterations in the extracellular matrix can cause resistance of tumors to chemotherapeutic drugs. Here, the authors identify the serpin-like serine protease inhibitor maspin as a gene upregulated in its expression in breast tumors that progress despite doxorubicin treatment. In mice xenografted with maspin-overexpressing tumor cells, enhanced collagen fiber accumulation and decreased diffusion of the chemotherapeutic drug was observed. The study indicates that more hydrophilic doxorubicin formulations or the combination with a maspin inhibitor could be useful in the treatment of drug-resistant, dense matrix breast tumors