Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2009-3-2
pubmed:abstractText
The successful treatment of paediatric malignancies by multimodal therapy has improved outcomes for children with cancer, especially those with acute lymphoblastic leukaemia (ALL). Second malignant neoplasms, however, represent a serious complication after treatment. Depending on dosage, 2-12% of patients treated with topoisomerase II inhibitors and/or alkylating agents develop treatment-related acute myeloid leukaemia characterized by translocations at 11q23. Our goal was to study MLL rearrangements in peripheral lymphocytes using cytogenetic and molecular methods in order to evaluate the late effects of cancer therapy in patients previously treated for childhood ALL. Chromosomal rearrangements at 11q23 were analysed in cytogenetic preparations from 49 long-term ALL survivors and 49 control individuals. Patients were subdivided depending on the inclusion or omission of topoisomerase II inhibitors (VP-16 and/or VM-26) in their treatment protocol. The statistical analysis showed significant (P = 0.007) differences between the frequency of translocations observed for the groups of patients and controls. These differences were also significant (P = 0.006) when the groups of patients (independent of the inclusion of topoisomerase II inhibitors) and controls were compared (P = 0.006). The frequencies of extra signals, however, did not differ between groups of patients and controls. Several MLL translocations were detected and identified by inverse polymerase chain reaction, followed by cloning and sequencing. Thirty-five patients (81%) presented putative translocations; among those, 91% corresponded with t(4;11) (q21;q23), while the other 9% corresponded with t(11;X), t(8;11)(q23;q23) and t(11;16). Our results indicate an increase in MLL aberrations in childhood ALL survivors years after completion of therapy. The higher frequency in this cohort might be associated with therapy using anti-tumoural drugs, independent of the inclusion of topoisomerase II inhibitors. Even though the biological significance of these rearrangements needs further investigation, they demonstrate a degree of genome instability, indicating the relevance of cytogenetic and molecular studies during the follow-up of patients in complete clinical remission.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1464-3804
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
24
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
153-60
pubmed:meshHeading
pubmed-meshheading:19028982-Adolescent, pubmed-meshheading:19028982-Adult, pubmed-meshheading:19028982-Base Sequence, pubmed-meshheading:19028982-Case-Control Studies, pubmed-meshheading:19028982-Child, pubmed-meshheading:19028982-Child, Preschool, pubmed-meshheading:19028982-Chromosomes, Human, Pair 11, pubmed-meshheading:19028982-Cytogenetic Analysis, pubmed-meshheading:19028982-Etoposide, pubmed-meshheading:19028982-Gene Rearrangement, pubmed-meshheading:19028982-Humans, pubmed-meshheading:19028982-Molecular Sequence Data, pubmed-meshheading:19028982-Myeloid-Lymphoid Leukemia Protein, pubmed-meshheading:19028982-Polymerase Chain Reaction, pubmed-meshheading:19028982-Precursor Cell Lymphoblastic Leukemia-Lymphoma, pubmed-meshheading:19028982-Survivors, pubmed-meshheading:19028982-Teniposide, pubmed-meshheading:19028982-Translocation, Genetic
pubmed:year
2009
pubmed:articleTitle
Cytogenetic and molecular analysis of MLL rearrangements in acute lymphoblastic leukaemia survivors.
pubmed:affiliation
Departamento de Genética, Faculdade de Medicina de Ribeirão Preto-USP, Universidade de São Paulo, São Paulo, Brazil. marsol@rge.fmrp.usp.br
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't