Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recently, the MLL gene at 11q23 was found to be involved in a subset of leukemias with an 11q23 abnormality. In the present study, we isolated chimeric cDNAs between the MLL and a gene designated MLLT3 at 9p22 from a cDNA library of an IMS-M1 cell line with a t(9;11)(p22;q23) translocation, a representative karyotypic abnormality seen in acute monocytic leukemia. We also isolated a normal MLLT3 cDNA and found an open reading frame encoding at least 318 amino acids with high serine/proline content (24.8%). The chimeric mRNAs were demonstrated to be fused to MLL in frame, as found in t(11;19) and t(4;11) leukemias. The predicted MLLT3 protein demonstrated a significant homology to that of the MLLT1 gene at 19p13 involved in t(11;19) leukemia. The highest homology, up to 74.1%, was found in 86 amino acids of the C-terminus, suggesting that this region is of particular importance for leukemogenesis in t(9;11) leukemia. Northern blot analysis with the MLLT3 cDNA probe against normal tissues revealed multiple transcripts in lymphoid organs. A survey of hematopoietic cell lines demonstrated relatively stronger signals in cells belonging to megakaryocytic and erythroid lineages. As previously found in t(11;19) leukemia, heterogeneous MLL-MLLT3 chimeric mRNAs could be detected by the reverse transcriptase-polymerase chain reaction (RT-PCR) in t(9;11) leukemia samples.
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PMID:MLLT3 gene on 9p22 involved in t(9;11) leukemia encodes a serine/proline rich protein homologous to MLLT1 on 19p13. 841 10

Unusual MLL gene rearrangements were found in bone marrow cells of four patients with acute myeloid leukemia. A combination of conventional and molecular cytogenetic methods were used to describe translocations t(9;12;11)(p22;p13;q23), t(11;19)(q23;p13.3), and t(10;11)(p12;23) and inverted insertion ins(10;11)(p12;q23.3q23.1). Partial nontandem duplication of the MLL gene was identified by reverse transcriptase-polymerase chain reaction in all cases. The duplication, which included MLL exons 2 through 8-9, was interrupted by a cryptic insertion of one or two exons from the respective MLL partner gene: MLLT10, MLLT3, or MLLT1.
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PMID:A partial nontandem duplication of the MLL gene in four patients with acute myeloid leukemia. 1996 15

MLL is involved in fusion genes with more than 100 partner genes, approximately 80 of which have been characterized at the molecular level. MLL fusion genes are often found in infants (60-80% of acute lymphoblastic leukemia (ALL) cases and 40-50% of acute myeloblastic leukemia (AML) cases) and are appreciably rarer (8-10%) in children older than 1 year of age. MLL rearrangements are important markers in diagnosis and treatment choice. To identify the partner gene is of primary importance for prognosis and minimal residual disease monitoring. The structure of the fusion gene, including localization of the MLL breakpoints, is also informative. A method was developed to examine the fusion transcripts in order to identify the partner gene among the six most common ones and to establish the exon structure of the rearranged MLL. The method includes a multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) to amplify and to fluorescently label a fusion transcript fragment and subsequent hybridization of the product on a biological microchip with immobilized oligonucleotides complementary to exons of MLL and its partner genes AFF1, MLLT1, MLLT3, MLLT4, MLLT10, and ELL. Hybridization results were verified by sequencing the RT-PCR products and, in some cases, performing long-distance inverse PCR (LDI-PCR). The study involved 38 bone marrow samples from ALL patients (including 33 children younger than 1 year of age) and 15 samples from AML patients (including 10 from children younger than 1 year of age). The main partner genes were AFF1 (49%), MLLT1 (27%), MLLT3 (12%), and MLLT10 (12%) in ALL and MLLT3 (80%), MLLT10 (10%), and MLLT4 (10%) in AML. Fusion gene transcripts most commonly included MLL exon 11 (58% of ALL cases and 50% of AML cases), suggesting a breakpoint in MLL intron 11.
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PMID:[Biological microchip for establishing the structure of fusion transcripts involving MLL in children with acute leukemia]. 2806 13