Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A patient with secondary acute myelomonocytic leukemia after treatment with chronic oral etoposide (VP-16) for lung cancer is reported. The leukemic cells showed a t(9;11)(p22;q23) translocation. Southern blot analysis revealed the rearrangement of the MLL (ALL-1/HRX) gene at 11q23. Reverse transcriptase-polymerase chain reaction (RT-PCR) revealed a chimeric mRNA between the MLL gene at 11q23 and LTG9 (MLLT3/AF-9) gene at 9p22. The patient was successfully treated with a VP-16 based regimen. This case is instructive in the understanding of the leukemogenesis of VP-16-related leukemias.
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PMID:Acute myelomonocytic leukemia after treatment with chronic oral etoposide: are MLL and LTG9 genes targets for etoposide? 794 64

The MLL gene involved in 11q23 translocations found in the majority of infantile leukemias and some secondary leukemias makes fusion transcripts with genes such as LTG4 (chromosome 4), LTG9 (chromosome 9), and LTG19 (chromosome 19) as a result of reciprocal translocation. We have examined 25 cases of leukemias with 11q23 abnormalities by Southern blot analysis and the reverse transcriptase-polymerase chain reaction (RT-PCR). Using various primer pairs, chimeric mRNAs could be amplified in 6 of 7 leukemias with t(4;11), 6 of 8 leukemias with t(9;11) including secondary leukemia, 8 of 9 leukemias with t(11;19), and 1 with a deletion at 11q23. The chimeric mRNAs were heterogeneous and differential usage of the MLL exons was found, irrespective of the partner chromosomes. Sensitivity studies showed that a single clone with chimeric mRNA in 10(4) to 10(5) cells could be detected. These findings show that the present RT-PCR settings provide a rapid, accurate, and sensitive tool for diagnosing leukemias with 11q23 translocations and for monitoring response to therapy in these patients.
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PMID:A reverse transcriptase-polymerase chain reaction detects heterogeneous chimeric mRNAs in leukemias with 11q23 abnormalities. 818 Mar 86

We describe a patient with acute monocytic leukemia (M5a, FAB classification) associated with a new type of variant translocation (9;11). Southern blot analysis showed the rearrangement of the MLL (ALL-1/HRX) gene at 11q23. Fluorescence in situ hybridization (FISH) with painting probes of chromosomes 9, 11, and 22 revealed the translocation as t(9;11;22) (p22;q23;q11). This is more evidence that the production of chimeric mRNA following the translocation of the LTG9 (MLLT3/AF9) gene at 9p22 to 11q is a critical event in this leukemia subtype.
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PMID:Translocation (9;11;22)(p22;q23;q11). A new type of complex variant translocation of t(9;11)(p22;q23) with MLL rearrangement. 863 Sep 74

11q23 chromosome aberrations are frequently observed in infantile as well as therapy-related leukemias. The target gene at 11q23, MLL, is disrupted by the translocation and becomes fused to various translocation partner genes such as AF4/FEL, LTG9/AF9 and LTG19/ENL. The resulting chimeric mRNAs are fused in frame and have been predicted to encode leukemia-specific chimeric proteins. In the present study, we raised antibodies against MLL, LTG9 and LTG19 and demonstrated that MLL and chimeric MLL-LTG9 and MLL-LTG19 products are synthesized in vivo and are localized in the nuclei, using immunofluorescence and cell fractionation studies. The truncated N-terminal portion of the MLL product common to the various types of 11q23 translocation was also localized in the nuclei in a similar fashion. Murine 32Dc13 cells stably expressing the truncated N-terminal MLL protein exhibited an inhibition of differentiation and a growth advantage following stimulation by granulocyte-colony stimulating factor, although the IL-3 dependency was not significantly changed in comparison to the parental cells. These results suggest that the N-terminal portion common to various MLL-chimeric products plays an important role in leukemogenesis.
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PMID:Identification of MLL and chimeric MLL gene products involved in 11q23 translocation and possible mechanisms of leukemogenesis by MLL truncation. 893 41