Home About us Contact | |||
Cluster Genes (cluster + gene)
Selected AbstractsThe chromosome translocation t(7;11)(p15;p15) in acute myeloid leukemia results in fusion of the NUP98 gene with a HOXA cluster gene, HOXA13, but not HOXA9GENES, CHROMOSOMES AND CANCER, Issue 4 2002Takeshi Taketani The nucleoporin gene NUP98 has been reported to be fused to 9 partner genes in hematologic malignancies with 11p15 translocations. The NUP98-HOXA9 fusion gene has been identified in acute myeloid leukemia (AML) and chronic myelogenous leukemia with t(7;11)(p15;p15). We report here a novel NUP98 partner gene, HOXA13, in a patient with de novo AML having t(7;11)(p15;p15). The HOXA13 gene is part of the HOXA cluster genes and contains 2 exons, encoding a protein of 338 amino acids with a homeodomain. The NUP98-HOXA13 fusion protein consists of the N-terminal phenylalanine-glycine repeat motif of NUP98 and the C-terminal homeodomain of HOXA13, similar to the NUP98-HOXA9 fusion protein. Reverse transcriptase,polymerase chain reaction (RT-PCR) analysis in various leukemic cell lines showed that the HOXA13 gene was expressed significantly more frequently in acute monocytic leukemic cell lines than in other leukemic cell lines (P = 0.039). HOXA13 and three HOXA cluster genes (A9, A10, A11) located at the 5, end of the HOXA9 gene were frequently expressed in myeloid leukemic cell lines. Our results revealed that t(7;11)(p15;p15) was not a single chromosomal abnormality at the molecular level. The protein encoded by the NUP98-HOXA13 fusion gene is similar to that encoded by NUP98-HOXA9, and the expression pattern of the HOXA13 gene in leukemic cell lines is similar to that of the HOXA9 gene, suggesting that the NUP98-HOXA13 fusion protein may play a role in leukemogenesis through a mechanism similar to that of the NUP98-HOXA9 fusion protein. © 2002 Wiley-Liss, Inc. [source] Tracking the origins of the bilaterian Hox patterning system: insights from the acoel flatworm Symsagittifera roscoffensisEVOLUTION AND DEVELOPMENT, Issue 5 2009Eduardo Moreno SUMMARY Genes of the Hox cluster encode for transcriptional regulators that show collinear expression along the anteroposterior (AP) body axis in all bilateral animals. However, it is still unclear when in the evolutionary history of bilaterians the Hox system first conferred positional identity along the AP-axis. Recent molecular phylogenies have convincingly shown that the acoel flatworms, traditionally classified within the Platyhelminthes, are the sister group of the remaining Bilateria, branching out before the common ancestor of protostomes, and deuterostomes (the so-called PDA). This key phylogenetic position offers the opportunity to search for the presence and early role of Hox cluster genes to pattern the AP axis in acoels. Here, we report on the cloning, genomic arrangement, and expression domains of Hox genes in Symsagittifera roscoffensis. Three Hox genes were detected: one from each of the major groups of Hox genes, which are anterior, central, and posterior. In bacterial artificial chromosome cloning, sequencing, and chromosomal fluorescence in situ hybridization, Hox genes were not observed as being clustered in a unique genomic region. Nevertheless, despite its dispersion within the genome, Hox genes are expressed in nested domains along the AP axis in the juvenile worm. The basic set of Hox genes in acoels and their coarse nested spatial deployment might be the first indicators of the role of Hox genes in the evolution of bilateral symmetry and AP positional identity from a hypothetical radial ancestor. [source] Human homeobox gene HOXC13 is the partner of NUP98 in adult acute myeloid leukemia with t(11;12)(p15;q13)GENES, CHROMOSOMES AND CANCER, Issue 4 2003Roberta La Starza The chimeric gene NUP98/HOXC13 was detected in a patient with a de novo acute myeloid leukemia and a t(11;12)(p15;q13). Fluorescence in situ hybridization with PAC1173K1 identified the breakpoint on 11p15, indicating that the NUP98 gene was involved in the translocation. At 12q13, the breakpoint fell within BAC 578A18, selected for the homeobox C (HOXC) cluster genes. RACE-PCR showed that HOXC13 was the partner gene of NUP98. To date, HOXC13 is the eighth homeobox gene that, as the result of a reciprocal translocation, fuses with NUP98 in myeloid malignancies. © 2003 Wiley-Liss, Inc. [source] The chromosome translocation t(7;11)(p15;p15) in acute myeloid leukemia results in fusion of the NUP98 gene with a HOXA cluster gene, HOXA13, but not HOXA9GENES, CHROMOSOMES AND CANCER, Issue 4 2002Takeshi Taketani The nucleoporin gene NUP98 has been reported to be fused to 9 partner genes in hematologic malignancies with 11p15 translocations. The NUP98-HOXA9 fusion gene has been identified in acute myeloid leukemia (AML) and chronic myelogenous leukemia with t(7;11)(p15;p15). We report here a novel NUP98 partner gene, HOXA13, in a patient with de novo AML having t(7;11)(p15;p15). The HOXA13 gene is part of the HOXA cluster genes and contains 2 exons, encoding a protein of 338 amino acids with a homeodomain. The NUP98-HOXA13 fusion protein consists of the N-terminal phenylalanine-glycine repeat motif of NUP98 and the C-terminal homeodomain of HOXA13, similar to the NUP98-HOXA9 fusion protein. Reverse transcriptase,polymerase chain reaction (RT-PCR) analysis in various leukemic cell lines showed that the HOXA13 gene was expressed significantly more frequently in acute monocytic leukemic cell lines than in other leukemic cell lines (P = 0.039). HOXA13 and three HOXA cluster genes (A9, A10, A11) located at the 5, end of the HOXA9 gene were frequently expressed in myeloid leukemic cell lines. Our results revealed that t(7;11)(p15;p15) was not a single chromosomal abnormality at the molecular level. The protein encoded by the NUP98-HOXA13 fusion gene is similar to that encoded by NUP98-HOXA9, and the expression pattern of the HOXA13 gene in leukemic cell lines is similar to that of the HOXA9 gene, suggesting that the NUP98-HOXA13 fusion protein may play a role in leukemogenesis through a mechanism similar to that of the NUP98-HOXA9 fusion protein. © 2002 Wiley-Liss, Inc. [source] The Ustilago maydis Cys2His2 -type zinc finger transcription factor Mzr1 regulates fungal gene expression during the biotrophic growth stageMOLECULAR MICROBIOLOGY, Issue 6 2008Yan Zheng§ Summary The smut fungus Ustilago maydis establishes a biotrophic relationship with its host plant maize to progress through sexual development. Here, we report the identification and characterization of the Cys2His2 -type zinc finger protein Mzr1 that functions as a transcriptional activator during host colonization. Expression of the U. maydis mig2 cluster genes is tightly linked to this phase. Upon conditional overexpression, Mzr1 confers induction of a subset of mig2 genes during vegetative growth and this requires the same promoter elements that confer inducible expression in planta. Furthermore, expression of the mig2-4 and mig2-5 genes during biotrophic growth is strongly reduced in cells deleted in mzr1. DNA-array analysis led to the identification of additional Mzr1-induced genes. Some of these genes show a mig2 -like plant-specific expression pattern and Mzr1 is responsible for their high-level expression during pathogenesis. Mzr1 function requires the b -dependently regulated Cys2His2 -type cell cycle regulator Biz1, indicating that two stage-specific regulators mediate gene expression during host colonization. In spite of a role as transcriptional activator during biotrophic growth, mzr1 is not essential for pathogenesis; however, conditional overexpression interfered with proliferation during vegetative growth and mating ability, caused a cell separation defect, and triggered filamentous growth. We discuss the implications of these findings. [source] Proliferative drive and liver carcinogenesis: Too much of a good thing?JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 12 2009Narci C Teoh Abstract There have been innumerable studies published in the attempt to identify gene expression signatures in hepatocellular carcinoma (HCC). When all the regulators and targets of the differentially expressed genes are analyzed from larger studies, the most striking theme is upregulation of mitosis-promoting and cell proliferation genes in HCC compared with ,liver-specific gene clusters' in non-tumorous tissue. A major limitation of expression profiling is that it only provides a ,snapshot' of what is an evolving process and thus cannot distinguish the differences in gene expression that are primary effectors of dysregulated growth from those that represent downstream consequences. The development of HCC in a chronically diseased liver, often referred to as hepatocarcinogenesis, is a multistep process characterized by the progressive accumulation and interplay of genetic alterations causing aberrant growth, malignant transformation of liver parenchymal cells, followed by vascular invasion and metastasis. This review will discuss HCC precursor lesions, draw on the ,proliferation cluster' genes highlighted from HCC expression profiling studies, relate them to a selection of regulatory networks important in liver regeneration, cell cycle control and their potential significance in the pathogenesis of HCC or primary liver cancer. [source] |