ALTERACIONES CROMOSOMICAS PDF

Identificación de alteraciones cromosómicas en pacientes con esquizofrenia en la población cubana / Identification of chromosomal aberrations in Cuban. Download scientific diagram | Clasificación de las alteraciones cromosómicas numéricas. from publication: The utility of cytogenetics in modern medicine. Deleciones cromosómicas, a veces conocidas como monosomías parciales, tipos de pruebas genéticas que pueden identificar alteraciones cromosómicas.

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To date, clonal chromosome aberrations have been found in all major tumor types from more than 54, patients http: The Philadelphia chromosome is the result of a reciprocal translocation, t 9;22 q For example, RNA interference screening in combination with high-resolution DNA copy-number analysis identified the REST gene as a suppressor of epithelial-cell transformation that maps to a segment of band 4q12 that is frequently deleted in colon cancer.

There is substantial evidence that these alterations are early or even initiating events in tumorigenesis. Effect of smoking habit on the frequency of micronuclei in human lymphocytes: Rearrangements leading to the expression of a chimeric protein with aberrantly increased transcriptional activity are represented by the translocation t 11;22 q However, the strategy of gene-targeted therapy has thus far had limited application, because only a fraction of the genetic lesions that are responsible for cancer development have been identified.

Genetic pathways in the pathogenesis of therapy-related myelodysplasia and acute myeloid leukemia.

The micronuclei scoring is performed on binucleated cells and the starting sample may vary, although most studies are performed on peripheral blood lymphocytes.

The telomeres “cap” the p and q arms and are important for the structural integrity of the chromosome, for complete DNA replication at the ends of the chromosome, and for the establishment of the three-dimensional architecture of the nucleus.

Causes of Chromosomal Abnormalities The cause of chromosomal abnormalities remains poorly understood. Alteracilnes Res ; The production of micronuclei from chromosome aberrations in irradiated cultures of human lymphocytes.

ALTERACIONES CROMOSOMICAS DE LOS AUTOSOMAS by Jocelyn Salgado on Prezi

Genes Chromosomes Cancer ; Although this degree of genetic complexity has hampered the delineation of the roles of individual chromosomal gains or losses in cancer, recent studies suggest that integration of genomewide analysis of gene dosage, global gene-expression profiling, and functional genomic techniques could identify functionally relevant genes within genomic xromosomicas that are affected by chromosomal imbalances.

Cancer Lett ; Many of these aberrations have emerged as prognostic and predictive markers in hematologic cancers and certain types of solid tumors. The two main groups of genes that participate in such fusions are those encoding tyrosine kinases and those encoding transcription factors.

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Until recently, chromosomal rearrangements have been linked mainly to hematologic cancers and tumors of mesenchymal origin.

This article discusses examples of two main classes of chromosomal abnormalities — balanced chromosomal rearrangements and chromosomal imbalances Figure 1 and Figure 2 — with particular focus on their functional consequences and their implications actual or potential for the development of effective anticancer therapies.

Since such aberrations involve multiple genes, the identification of their functionally relevant targets has proved to be difficult. Whether similar mechanisms are relevant to the pathogenesis of chromosomal abnormalities that are associated with sporadic cancers remains to be determined. In prostate cancer, a small interstitial deletion or cryptic insertion involving chromosome band 21q This mechanism was documented in a recent study that identified small deletions of band Xq Of particular importance for the treatment of cancer, many of the most specific drug targets, such as ABL1, ERBB2, and EGFR, undergo genetic changes that conventional cytogenetic methods or modern genomic techniques can detect.

Influence of smoking habit on the frequency of micronuclei in human lymphocytes by the cytokinesis block method. Chromosomal instability in amniocytes from fetuses of mothers who smoke. The classic approach to identifying a tumor-suppressor gene compares multiple tumors with a specific chromosomal deletion to determine the minimal genomic region that is lost in all cases.

Chromosomes are isolated at the metaphase or prometaphase stage of the cell cycle and are treated chemically e. Regardless of whether the respective disease genes have been identified, some deletions have proved to be of great value for determining the prognosis and guiding treatment decisions, as exemplified by the deletion of chromosome 5q in acute myeloid leukemia 38 ; deletions of chromosomes 11q, 13q, and 17p in chronic lymphocytic leukemia 80 ; and the concurrent ceomosomicas of chromosomes 1p and 19q in anaplastic oligodendroglioma.

One way to “filter” the genes within regions of DNA copy-number gain is to identify those that are also altered at the RNA or protein level, assuming that genes whose increased dosage translates into increased expression cromosomkcas most likely to be involved in malignant transformation.

Micronuclei in cytokinesis-blocked lymphocytes as an index of occupational exposure to alkylating cytostatic drugs. Genomic gains include complete or partial trisomies and intrachromosomal or extrachromosomal amplifications, which can be identified cytogenetically as homogeneously staining regions HSR and double-minute chromosomes dminrespectively.

A fusion protein with enhanced or aberrant transcriptional activity is present in virtually all cases of Ewing’s sarcoma, in which unique translocations — t 11;22 q The cytogenetic assay as a measure of genetic instability induced by genotoxic agents.

Sister chromatid exchange and micronucleus frequency in human lymphocytes of 1, subjects in an Italian population: In Burkitt’s lymphoma, the translocation t 8;14 q Factors contributing to chromosome damage in lymphocytes of cigarette smokers. Jpn J Cancer Res ; For many recurrent genomic losses, however, such as 1p deletions in neuroblastoma, 76 3p deletions in lung cancer, 77 and 7q deletions in myeloid cancers, 7879 the critical genes are unknown.

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The position of the in vitro micronucleus test within the battery of screening for genotoxic potential determination and the regulatory guidelines.

In the majority of cases, only one of the two fusion genes generated and not the reciprocal counterpart indicated altearciones the dashed arrows contributes to cancer pathogenesis. Effect of laboratory protocol, scoring criteria, and host factors on the frequency of micronuclei.

Inhibition of oxidative DNA damage, 8-OHdG, and carbonyl contents in smokers treated with antioxidants vitamin E, vitamin C, beta-carotene and red ginseng. Summary Cancer is caused by genetic alterations that disrupt the normal balance among cell proliferation, survival, and differentiation.

The examples described here illustrate that many of these alterations are mediated by genetic changes associated with chromosomal abnormalities. Sex chromosome loss, micronuclei, sister chromatid exchange and aging: Chromosomal rearrangements that entail aberrant transcriptional repression occur in a substantial proportion of patients with acute myeloid leukemia.

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Formation of diastereomeric benzo[a]pyrene diol epoxide-guanine adducts in p53 gene-derived DNA sequences. Zalacain 1L. Insights into molecular mechanisms underlying the formation of chromosomal aberrations have been gained from studies of rare cancer-predisposing chromosomal instability syndromes, such as the inherited bone marrow failure syndromes, 2 in which genetic changes that are associated with the development of leukemia can be followed over time.

However, it is now possible to identify focal gains by scanning cancer genomes for variations in DNA copy numbers with new high-resolution methods, such as comparative genomic hybridization CGH and single-nucleotide polymorphism SNP genotyping. As a result, binding of the chimeric transcription factors to their target genes, which include genes required for normal myeloid differentiation, causes aberrant transcriptional repression, thereby contributing to the accumulation of immature myeloid cells in acute myeloid leukemia.

The micronuclei assay is considered a practical, universally validated and technically feasible protocol which is useful to evaluate the genetic instability induced by genotoxic agents. Some of these genes encode proteins that can be specifically targeted by new anticancer agents. What do human micronuclei contain? Table 1 lists examples in these two functional categories.