Search results for "Genetica"
showing 10 items of 906 documents
PTC124 derivatives as a novel approach to improve the readthrough of premature stop codons in the CFTR gene.
2011
Background Cystic fibrosis (CF) is caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR). Approximately 10% (worldwide) of patients have in-frame nonsense mutations (UAA, UAG or UGA class I mutations) in the CF trans-membrane regulator (CFTR) gene that result in premature stop codons (PTCs) in the messenger RNA (mRNA) generating truncated CFTR protein responsible for a severe CF phenotype. Pharmacological approaches have been proposed to directly overcome PTCs. Ataluren (PTC124) a small molecule that mimics the activity of aminoglycosides has been suggested to allow PTCs readthrough and to partially restore the protein function. However, des…
Methylation decrease of BECN1 gene induced by phytochemical Indicaxantin in Caco2 cells: an epigenetic hypothesis of autophagy
2014
Autophagy is a highly conserved catabolic process that degrades and recycles intracellular components through the lysosomes [1]. The role of this process in tumorigenesis and tumor progression is controversial: in the early stages, it can block tumor growth and conversely it can promote its progression in the later stages [2]. The tumor suppressor BECN1 gene, encodes the protein Beclin 1, a marker of autophagy down-regulated in several types of cancer, such as colorectal cancer [3]. There are a lot of both genetic and environmental risk factors for colorectal cancer, including diet: for this reason, in accordance with epidemiological studies, consumption of foods rich in phytochemicals is w…
Can Early Life Exposure to Permethrin lead to intergenerational effects?
2016
Pesticides are largely used in agriculture against pests and consequently are present in fruits and vegetables. The wide presence of pesticide residues in breast milk underline the risk for the population, focalizing the long-term consequence of early life pyrethroid exposure. The significant presence of pyrethroid metabolites in the urine of population over the world confirms that their presence in food is a global problem. It has been demonstrated that there is a correlation between the environmental exposure to pesticides and the development of neurodegenerative diseases. Neonatal exposure to Permethrin (PERM), a member of the family of synthetic pyrethroids, can induce neurodegeneration…
Persistent dysregulation of DNA methylation in cells with arsenic-induced genomic instability
2009
The mechanisms by which arsenic-induced genomic instability is initiated and maintained are poorly understood. In previous studies long-term progression of chromosomal instability was typified by increasing aneuploidy in Chinese hamster V79 and human keratinocyte cells treated with arsenite for a 24 hr exposure period followed by growth in arsenic-free medium for 40-120 cell generations. In the current study the role of progressive DNA methylation changes was evaluated in long-term cell cultures after brief arsenite treatments as above. We have found altered genomic methylation patterns in cells that were briefly exposed to arsenic with evidence for widespread dysregulation of CpG methylati…
Global DNA Hypomethylation following 5-aza-2'-deoxycytidine treatment induces aneuploidy in HCT-116 tumor cells.
2013
Aneuploidy, the alteration of the normal number of chromosomes, is found in most of the human solid tumors and correlated with to defects in the process of chromosome segregation (1). It was also suggested that the alteration of the 5-methylcytosine (5-mC) pattern in the chromosome pericentromeric region, generated to aneuploid cells (2, 3). To investigate the relationship between hypomethylation and whole chromosome aneuploidy, we treated HCT-116 cells, a near diploid line, with the demethylating agent 5-aza- 2'-deoxycytidine (DAC). The treatment with DAC for 24, 48 and 72 hours produced a progressive reduction of DNA methylation as shown by decrease of 5-mC signal. DNA hypomethylation res…
Antiproliferative and pro-apoptotic effects of the phytochemical Indicaxanthin on human intestinal (Caco-2) and hepatic (Ha 22T) cancer cell lines
2012
In the present study antiproliferative effects of Indicaxanthin (Ind), a highly bioavailable pigment from the fruits of Opuntia ficus-indica (1), were investigated on a number of human cancer cell lines including hepatocarcinoma cells (HepG2, Ha22T, HUH 7), breast cancer cells (MCF7), cervix epithelial carcinoma (HeLa), and colorectal carcinoma cells (Caco-2). Cytotoxicity of Ind, in a concentration range between 25 to 100 M, was evaluated by Trypan blue exclusion method and MTT assay. Ind caused a clear dose- and time-dependent decrease in the proliferation of Caco-2 and Ha 22T cells with an IC(50) of about 50 M, with minor effect on the other cell lines. Flow cytometric analysis after A…
Origine ed evoluzione dei genomi: dal brodo primordiale al DNA umano
2011
Per una migliore comprensione dell’origine e dell’evoluzione dei genomi è conveniente posizionare l’inizio e il decorso di tale processo all’interno della successione di evoluzioni che partono dall’origine dell’universo e che ancora oggi non si possono, per definizione, ritenere conclusi. Il Big Bang conclude l’evoluzione cosmica universale e dà origine all’evoluzione planetaria con la formazione dei sistemi solari ed i loro pianeti. Considerando il nostro sistema solare, e la terra in particolare, l’evoluzione geotermica, il raffreddamento del pianeta, fornisce una condizione fisica opportuna ad un’evoluzione chimica che, a conclusione, porta al brodo primordiale. Le molecole semplici poss…
Acidi nucleici: struttura e funzione
2016
Guardando il progetto di un tempio greco e quello di un moderno grattacielo, chiunque di noi trova dei tratti di similitudine e di divergenza, ma soprattutto scopre che il “linguaggio” usato per costruirlo è uguale: sia gli ingegneri di quei tempi sia quelli odierni hanno entrambi raffigurato in un progetto le fondamenta, le sopraelevazioni, i carichi da sostenere, le suddivisioni in stanze e altro. Ebbene, addentrandoci a studiare questo capitolo scopriremo che le informazioni su come generare e gestire un vivente sono contenute in un progetto fatto da macromolecole, gli acidi nucleici, scritte nel medesimo linguaggio, il codice genetico, uguale sin dai primi esseri viventi nati milioni di…
DNA Methyltransferase1 post-transcriptional silencing induces aneuploidy and cell cycle arrest in human cells.
2009
The regulation of chromatin structure is a dynamic and complex process that is modulated by epigenetic mechanisms. Malfunctioning of these processes can cause gene expression alteration and could compromise important events such as chromosome condensation and segregation. Imbalance in cytosine methylation and deregulation of DNA-methyltransferases (DNMTs), and of DNMT1 in particular, is frequent in human cancers. To investigate DNMT1 implication in the generation of aneuploidy we evaluated the effects of its depletion by RNA-interference both in primary human cells (IMR90) and in near diploid human tumor (HCT116) cells. Posttranscriptional silencing of DNMT1 induced aneuploidy, cell prolife…