Search results for "Neoplastic"
showing 10 items of 2901 documents
Topoisomerase II inhibition and high yield of endoreduplication induced by the flavonoids luteolin and quercetin
2006
Luteolin and quercetin are widely distributed plant flavonoids that possess a variety of chemical and biological activities, including free-radical scavenging and antioxidant activity. Recently, both flavonoids have been reported to inhibit DNA topoisomerases I and II (topo I and topo II), a property that, together with their ability to induce DNA and chromosome damage, has made them candidate anticancer compounds. In the present study, we confirmed that both compounds are topo II inhibitors by conducting a comparative study of their effect on topo II activity from Chinese hamster ovary AA8 cells. Because interference with the function of topo II to resolve DNA entanglement at the end of re…
Chemotherapy-induced cardiotoxicity: role of the conventional echocardiography and the tissue Doppler.
2011
Aim. The cardiotoxicity of anticancer drugs is an emerging problem and only an identification of the early signs of cardiotoxicity by conventional echocardiography and not (tissue Doppler imaging, TDI), will limit and contain the long-term cardiotoxicity effects. The aim of this study was to identify, through conventional echocardiography and TDI, parameters to use as early "signs" of cardiotoxicity. Methods. A prospective study was performed using patients with breast cancer (72 women, median age 57+/-12) treated with anticancer drugs (adjuvant chemotherapy). All patients underwent a careful cardiological evaluation before starting treatment (T0) and during follow-up at 3 months (T1), 6 mo…
Inhibitory effect of resveratrol on the proliferation of human and rat hepatic derived cell lines.
2000
Resveratrol is a polyphenolic compound especially produced by grapevine and consequently found in wine. Based on epidemiological studies resveratrol may act as a cancer chemopreventive compound. The ability of resveratrol to inhibit cell proliferation was studied in rat hepatoma Fao cell line and human hepatoblastoma HepG2 cell line. The results show that resveratrol strongly inhibits cell proliferation at the micromolar range in a time- and dose-dependent manner. Concentrations higher than 50 microM become toxic. Fao cells are more sensitive than HepG2 cells. Interestingly, the presence of ethanol lowers the threshold of resveratrol effect. Resveratrol appears to prevent or to delay the en…
Molecular analysis on the chemopreventive properties of resveratrol, a plant polyphenol microcomponent.
2002
As a plant microcomponent, resveratrol is a polyphenolic compound produced by several species and found especially in Polygonum roots, peanuts seeds, berries and also grape and therefore can be present in human diet or beverages (red wine, for instance). Traditional chinese medicine and more recent epidemiological studies strongly suggested that resveratrol may act as a cancer chemopreventive compound. The biochemical mechanism by which resveratrol inhibits cell proliferation was provided by studies in numerous human cell lines including our work in hepatoblastoma HepG2 and colorectal tumor SW480 cells. The results show that resveratrol strongly inhibits cell proliferation at the micromolar…
Immunohistochemical Study as a Tool in Differential Diagnosis of Pediatric Malignant Rhabdoid Tumor
2010
Malignant rhabdoid tumors (MRTs) are aggressive childhood neoplasms, occurring mainly in the kidney and brain. We describe 2 unusual cases of extrarenal and noncranial location (liver and soft tissue with dissemination) mimicking hepatoblastoma, neuroblastoma or Ewing sarcoma. Both cases revealed a polyphenotypic profile, combined with cytokeratin, vimentin, and CD99 expression. INI1/BAF-47 showed negative protein nuclear expression in both cases, suggesting a diagnosis of MRT. An extensive immunohistochemical panel was performed to exclude pediatric tumors reminiscent of MRT. The genetic studies failed to detected MYCN amplification, 11q23 deletion, and EWS break-apart positivity. No alter…
Effects of BRCA2 cis-regulation in normal breast and cancer risk amongst BRCA2 mutation carriers
2012
Introduction: Cis-acting regulatory single nucleotide polymorphisms (SNPs) at specific loci may modulate penetrance of germline mutations at the same loci by introducing different levels of expression of the wild-type allele. We have previously reported that BRCA2 shows differential allelic expression and we hypothesize that the known variable penetrance of BRCA2 mutations might be associated with this mechanism. Methods: We combined haplotype analysis and differential allelic expression of BRCA2 in breast tissue to identify expression haplotypes and candidate cis-regulatory variants. These candidate variants underwent selection based on in silico predictions for regulatory potential and di…
Genetic Determined Downregulation of Both Type 1 and Type 2 Cytokine Pathways Might Be Protective against Pancreatic Cancer
2009
Many cytokine polymorphisms have been studied for associations with susceptibility to breast, gastric, liver, lung, prostate, and ovarian cancer without conclusive results. The cytokine network, indeed, is characterized by complex interactions, and the final biological effect of a single genetic variation depends on the balance among different molecular signals. As is well known, Th1/Th2 cytokine unbalanced production might predispose to different pathologies, cancer included. In general, a prolonged type 1 inflammatory response might allow that cells accumulating enough "genetic hits" are promoted to neoplastic transformation. On the other hand, IL-13-producing cells through the IL-13/IL-4…
Astrocytes give rise to new neurons in the adult mammalian hippocampus
2001
Neurogenesis in the dentate gyrus of the hippocampus persists throughout life in many vertebrates, including humans. The progenitors of these new neurons reside in the subgranular layer (SGL) of the dentate gyrus. Although stem cells that can self-renew and generate new neurons and glia have been cultured from the adult mammalian hippocampus, the in vivo primary precursors for the formation of new neurons have not been identified. Here we show that SGL cells, which express glial fibrillary acidic protein and have the characteristics of astrocytes, divide and generate new neurons under normal conditions or after the chemical removal of actively dividing cells. We also describe a population o…
Dissection of keratin dynamics: different contributions of the actin and microtubule systems.
2005
It has only recently been recognized that intermediate filaments (IFs) and their assembly intermediates are highly motile cytoskeletal components with cell-type- and isotype-specific characteristics. To elucidate the cell-type-independent contribution of actin filaments and microtubules to these motile properties, fluorescent epithelial IF keratin polypeptides were introduced into non-epithelial, adrenal cortex-derived SW13 cells. Time-lapse fluorescence microscopy of stably transfected SW13 cell lines synthesizing fluorescent human keratin 8 and 18 chimeras HK8-CFP and HK18-YFP revealed extended filament networks that are entirely composed of transgene products and exhibit the same dynamic…
Mutant p53 gain of function can be at the root of dedifferentiation of human osteosarcoma MG63 cells into 3AB-OS cancer stem cells
2014
Osteosarcoma is a highly metastatic tumor affecting adolescents, for which there is no second-line chemotherapy. As suggested for most tumors, its capability to overgrow is probably driven by cancer stem cells (CSCs), and finding new targets to kill CSCs may be critical for improving patient survival. TP53 is the most frequently mutated tumor suppressor gene in cancers and mutant p53 protein (mutp53) can acquire gain of function (GOF) strongly contributing to malignancy. Studies thus far have not shown p53-GOF in osteosarcoma. Here, we investigated TP53 gene status/role in 3AB-OS cells-a highly aggressive CSC line previously selected from human osteosarcoma MG63 cells-to evaluate its involv…