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Find video protocols related to scientific articles indexed in Pubmed.
A new minimal deleted region at 11q22.3 reveals the importance of interpretation of diminished FISH signals and the choice of probe for ATM deletion screening in chronic lymphocytic leukemia.
Leuk. Res.
PUBLISHED: 06-13-2011
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Deletion of ATM detected by fluorescent in situ hybridization (FISH) in chronic lymphocytic leukemia predicts short treatment free survival and poor outcome following alkylator/purine analogue therapy. We describe five cases, with a diminished ATM FISH signal, investigated by TP53 mutation/dysfunction studies and single nucleotide polymorphism (SNP) array. The diminished signal represented loss of the ATM gene, which could have been missed were the cases not further investigated. These rare cases highlight the need for careful consideration of the choice of probe and interpretation of unusual signal patterns in FISH screening. We define a new minimal region of deletion at 11q22.3.
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Heterogeneous breakpoints in patients with acute lymphoblastic leukemia and the dic(9;20)(p11-13;q11) show recurrent involvement of genes at 20q11.21.
Haematologica
PUBLISHED: 07-07-2009
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The dic(9;20)(p11-13;q11) is a recurrent chromosomal abnormality in patients with acute lymphoblastic leukemia. Although it results in loss of material from 9p and 20q, the molecular targets on both chromosomes have not been fully elucidated. From an initial cohort of 58 with acute lymphoblastic leukemia patients with this translocation, breakpoint mapping with fluorescence in situ hybridization on 26 of them revealed breakpoint heterogeneity of both chromosomes. PAX5 has been proposed to be the target gene on 9p, while for 20q, FISH analysis implicated the involvement of the ASXL1 gene, either by a breakpoint within (n=4) or centromeric (deletion, n=12) of the gene. Molecular copy-number counting, long-distance inverse PCR and direct sequence analysis identified six dic(9;20) breakpoint sequences. In addition to the three previously reported: PAX5-ASXL1, PAX5-C20ORF112 and PAX5-KIF3B; we identified three new ones in this study: sequences 3 of PAX5 disrupting ASXL1, and ZCCHC7 disrupted by sequences 3 of FRG1B and LOC1499503. This study provides insight into the breakpoint complexity underlying dicentric chromosomal formation in acute lymphoblastic leukemia and highlights putative target gene loci.
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Array-based comparative genomic hybridization as a tool for analyzing the leukemia genome.
Methods Mol. Biol.
PUBLISHED: 03-12-2009
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Comparative genomic hybridization (CGH) is arguably the most significant technical development in the molecular cytogenetics era, and has contributed considerably to our further understanding of the cancer genome. In essence, DNA from a cancer specimen (test DNA) labeled with the fluorescence reporter molecule (or fluorochrome) is hybridized to a target genome in the presence of a differentially labeled control DNA (reference DNA). The two DNA populations compete for hybridization sites on normal metaphase chromosomes, so that the resulting fluorescence ratio is a reflection of the copy number change in the test sample. The copy number changes are mapped to their position on the chromosome template. Over recent years, the chromosomal template has been largely superseded by microarray formats (aCGH), in which changes in copy number can be mapped to the genome sequence at a high resolution. This advance allows the genome to be studied at an unbridled resolution and at a high-throughput, whilst posing several technical, statistical and interpretive challenges. It is the aim of this chapter to introduce the fundamental concepts of aCGH and to provide an overview of the steps involved in a successful aCGH processing. The materials required for BAC and oligonucleotide aCGH are included, with detailed methods and a range of refinements to improve the success rate and quality of aCGH data.
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Methylation of tumour suppressor gene promoters in the presence and absence of transcriptional silencing in high hyperdiploid acute lymphoblastic leukaemia.
Br. J. Haematol.
PUBLISHED: 01-06-2009
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Promoter methylation is a common phenomenon in tumours, including haematological malignancies. In the present study, we investigated 36 cases of high hyperdiploid (>50 chromosomes) acute lymphoblastic leukaemia (ALL) with methylation-specific multiplex ligase-dependent probe amplification to determine the extent of aberrant methylation in this subgroup. The analysis, which comprised the promoters of 35 known tumour suppressor genes, showed that 16 genes displayed abnormal methylation in at least one case each. The highest number of methylated gene promoters seen in a single case was thirteen, with all but one case displaying methylation for at least one gene. The most common targets were ESR1 (29/36 cases; 81%), CADM1 (IGSF4, TSLC1; 25/36 cases; 69%), FHIT (24/36 cases; 67%) and RARB (22/36 cases; 61%). Interestingly, quantitative reverse transcription-polymerase chain reaction showed that although methylation of the CADM1 and RARB promoters resulted in the expected pattern of downregulation of the respective genes, no difference could be detected in FHIT expression between methylation-positive and -negative cases. Furthermore, TIMP3 was not expressed regardless of methylation status, showing that aberrant methylation does not always lead to gene expression changes. Taken together, our findings suggest that aberrant methylation of tumour suppressor gene promoters is a common phenomenon in high hyperdiploid ALL.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.