Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0035412 (rhabdomyosarcoma)
 6,156 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although the t(2;13)(q35;q14) translocation has been found in most cases of the pediatric cancer alveolar rhabdomyosarcoma, several cases have been reported with a variant t(1;13)(p36;q14) translocation. Our findings indicate that this t(1;13) rearranges PAX7 on chromosome 1 and fuses it to FKHR on chromosome 13. This fusion results in a chimeric transcript consisting of 5' PAX7 and 3' FKHR regions, which is similar to the 5' PAX3-3' FKHR transcript formed by the t(2;13). The 5' PAX3 and PAX7 regions encode related DNA binding domains, and therefore we postulate that these translocations create similar chimeric transcription factors that alter expression of a common group of target genes.
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PMID:Fusion of PAX7 to FKHR by the variant t(1;13)(p36;q14) translocation in alveolar rhabdomyosarcoma. 818 70

The FKHR gene, which contains a forkhead DNA-binding motif, is fused to either PAX3 or PAX7 by the t(2;13) or t(1;13) translocation in alveolar rhabdomyosarcoma,respectively. These tumors express chimeric transcripts encoding the N-terminal portion of either PAX protein fused to the C-terminal portion of FKHR. To understand the structural basis and functional consequences of these translocations, we characterized the wild-type FKHR gene and its rearrangement in alveolar rhabdomyosarcomas. By isolating and analyzing phage, cosmid and YAC clones, we determined that FKHR consists of three exons spanning 140 kb and that several highly similar loci are present in other genomic regions. Exon 1 encodes the N-terminus of the forkhead domain and is embedded within demethylated CpG island. RNA analyses reveal FKHR transcripts initiate from a TATA-less promoter within this island. Exon 2 encodes the C-terminus of the forkhead domain and a transcription activation domain, whereas exon 3 encodes a large 3' untranslated region. The intron 1-exon 2 boundary precisely matches the FHKR fusion point in the chimeric transcripts found in alveolar rhabdomyosarcomas. Using pulsed-field and fluorescence in situ hybridization analyses, we demonstrate that the 130kb FKHR intron 1 is rearranged in t(2;13)-containing alveolar rhabdomyosarcomas. Our findings indicate that FKHR intron 1 provides a large target for DNA rearrangemnt. Rearrangement of this intron with PAX3 produces two important functional consequences: in-frame fusion of N-terminal PAX3 sequences to the FKHR transcriptional activation domain and disruption of the FKHR DNA binding domain.
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PMID:Structural characterization of the FKHR gene and its rearrangement in alveolar rhabdomyosarcoma. 863 10

In the pediatric cancer alveolar rhabdomyosarcoma, characteristic t(2;13)(q35;q14) or variant t(1;13)(p36;q14) chromosomal translocations generate PAX3-FKHR or PAX7-FKHR fusion genes. Using fluorescence in situ hybridization, reverse transcriptase-polymerase chain reaction and quantitative Southern blot analyses, we demonstrate that these fusion genes are amplified in 20% of fusion-positive tumors. In particular, we found in vivo amplification of these fusions in one of 22 PAX3-FKHR-positive cases and five of seven PAX7-FKHR-positive cases. These findings indicate that translocation and amplification can occur sequentially in a cancer to alter both the structure and copy number of a gene and thereby activate oncogenic activity by complementary mechanisms.
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PMID:In vivo amplification of the PAX3-FKHR and PAX7-FKHR fusion genes in alveolar rhabdomyosarcoma. 878 35

Alveolar rhabdomyosarcomas frequently exhibit specific translocations, resulting in the fusion of the FKHR gene at 13q14 with either the PAX3 or PAX7 gene at 2q35 and 1p36, respectively. Comparative genomic hybridization revealed amplification at 13q14 and 1p36, suggesting amplification of the PAX7-FKHR fusion gene in two cases of alveolar rhabdomyosarcoma. A PAX7-FKHR fusion transcript was demonstrated in both cases by reverse transcription-polymerase chain reaction followed by sequence analysis. In one case, amplification of the PAX7 gene and 3'-and 5'-FKHR gene sequences was demonstrated by using interphase fluorescence in situ hybridization on tumor imprints. The colocalization, variable copy number, and distribution of signals from the three cosmids was consistent with amplification of these sequences on double minutes, which were present cytogenetically. Chromatin release studies suggested that the amplified sequences correlated with amplification of the PAX7-FKHR fusion gene which resulted from the insertion of PAX7 sequences into the first intron of FKHR gene, in keeping with the absence of cytogenetic evidence for derivative chromosomes.
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PMID:Novel formation and amplification of the PAX7-FKHR fusion gene in a case of alveolar rhabdomyosarcoma. 888 1

The expression of a number of human paired box-containing (PAX) genes has been correlated with various types of tumors. Novel fusion genes encoding chimeric fusion proteins have been found in the pediatric malignant tumor alveolar rhabdomyosarcoma (RMS). They are generated by two chromosomal translocations t(2;13) and t(1;13) juxtaposing PAX3 or PAX7, respectively, with a forkhead domain gene FKHR. Here we describe that specific down-regulation of the t(2;13) translocation product in alveolar RMS cells by antisense oligonucleotides results in reduced cellular viability. Cells of embryonal RMS, the other major histiotype of this tumor, were found to express either wild type PAX3 or PAX7 at elevated levels when compared with primary human myoblasts. Treatment of corresponding embryonal RMS cells with antisense olignucleotides directed against the mRNA translational start site of either one of these two transcription factors similarly triggers cell death, which is most likely due to induction of apoptosis. Retroviral mediated ectopic expression of mouse Pax3 in a PAX7 expressing embryonal RMS cell line could partially rescue antisense induced apoptosis. These data suggest that the PAX3/FKHR fusion gene and wild-type PAX genes play a causative role in the formation of RMS and presumably other tumor types, possibly by suppressing the apoptotic program that would normally eliminate these cells.
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PMID:Induction of apoptosis in rhabdomyosarcoma cells through down-regulation of PAX proteins. 891 62

Alveolar rhabdomyosarcoma is a pediatric soft-tissue tumor that is often difficult to distinguish from other small round-cell tumors. The PAX3-FKHR and PAX7-FKHR gene fusions that result from chromosomal translocations in this tumor provide potential molecular diagnostic markers. To apply these molecular markers to commonly available archival material, we used reverse transcriptase-polymerase chain reaction and oligonucleotide hybridization methodology to develop an assay capable of identifying PAX3-FKHR and PAX7-FKHR fusion transcripts in formalin-fixed, paraffin-embedded tissue. Use of a control assay for wild-type FKHR mRNA indicated that RNA was successfully isolated, reverse-transcribed, and amplified in 15 of 16 archival cases. Comparison of assay results for the PAX3-FKHR and PAX7-FKHR fusions with standard molecular assays of paired frozen material revealed that all eight cases of known fusion-positive rhabdomyosarcoma were correctly identified and distinguished as PAX3-FKHR or PAX7-FKHR. The seven cases of known fusion-negative rhabdomyosarcoma showed no evidence of either product. These results indicate that we have developed a molecular assay that accurately identifies the fusion transcripts characteristic of alveolar rhabdomyosarcoma in archival samples. This assay will be useful for diagnosis and for retrospective clinicopathologic correlative studies.
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PMID:Detection of gene fusions in rhabdomyosarcoma by reverse transcriptase-polymerase chain reaction assay of archival samples. 909 47

Chromosomal translocations identified in hematopoietic and solid tumors result in deregulated expression of protooncogenes or creation of chimeric proteins with tumorigenic potential. In the pediatric solid tumor alveolar rhabdomyosarcoma, a consistent t(2;13)(q35;q14) or variant t(1;13)(p36;q14) translocation generates PAX3-FKHR or PAX7-FKHR fusion proteins, respectively. In this report, we demonstrate that in addition to functional alterations these translocations are associated with fusion product overexpression. Furthermore, PAX3-FKHR and PAX7-FKHR overexpression occurs by distinct mechanisms. Transcription of PAX3-FKHR is increased relative to wild-type PAX3 by a copy number-independent process. In contrast, PAX7-FKHR overexpression results from fusion gene amplification. Thus, gene-specific mechanisms were selected to overexpress PAX3-FKHR and PAX7-FKHR in alveolar rhabdomyosarcoma, presumably due to differences in regulation between the wild-type loci. We postulate that these overexpression mechanisms ensure a critical level of gene product for the oncogenic effects of these fusions.
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PMID:Fusion genes resulting from alternative chromosomal translocations are overexpressed by gene-specific mechanisms in alveolar rhabdomyosarcoma. 922 12

Characteristic chromosome aberrations and the rearranged genes resulting in chimeric fusion genes have been reported in some bone and soft tissue tumors; t(X; 18) in synovial sarcoma, t(11; 22) in Ewing's sarcoma and primitive neuroectodermal tumor, and t(2; 13) in alveolar rhabdomyosarcoma. We practically used the chromosome analysis and the reverse transcription-polymerase chain reaction (PCR) method as a tool for diagnosis and follow up. All of 10 cases of synovial sarcoma had a chimeric product of SYT/SSX gene. Eleven cases of Ewing's sarcoma and primitive neuroectodermal tumor showed 6 variants of chimeric products between EWS gene and Fli1 gene in the PCR-directed sequence analysis. Although PAX3/FKHD or PAX7/FKHD transcripts were amplified in alveolar rhabdomyosarcoma cases, MyoD1 and myogenin gene which are myogenic transcription factor were also expressed in most rhabdomyosarcomas. These findings indicate that molecular biological analysis may be a useful supplementary method for pathologic diagnosis of bone and soft tissue tumors.
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PMID:[Pathologic diagnosis on bone and soft tissue tumors by molecular biological methods]. 925 13

The PAX7 gene encodes a transcription factor that is a member of the PAX family of developmental control genes. In addition to playing a role in embryogenesis, PAX genes appear to be of importance in a number of diverse human diseases and cancers. The PAX7 gene maps to human chromosomal region 1p36 and therefore is a potential candidate for human disorders linked to this region. In particular, a rearrangement of the PAX7 gene by chromosomal translocation is frequently found in alveolar rhabdomyosarcoma tumors. Here, we cloned a cDNA containing the full coding region of the human PAX7 gene and determined its genomic organization. The gene encodes a predicted protein of 520 amino acids that is 47 amino acids longer at the carboxy end than the highly related PAX3 protein. The coding region of the gene is interrupted by seven introns, the positions and lengths of which are similar to those of the corresponding introns of the PAX3 gene. Sequence data for exon/intron boundaries of PAX7 exons 1, 5, 6, 7, and 8 were determined and, together with previously published data for exons 2, 3, and 4, provide the complete sequence information for mutation analysis of the human PAX7 gene.
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PMID:The genomic organization and the full coding region of the human PAX7 gene. 933 73

The PAX genes encode a family of transcription factors that control development within the neural, myogenic, lymphoid, and a variety of other lineages. These proteins are postulated to regulate expression of gene products that function in the control of cellular processes are fundamental to the development of cancer, and thus genetic alterations of these genes may contribute to neoplastic development within these lineages. In support of this premise, several PAX genes have been shown to be targets of consistent chromosomal translocations associated with specific tumor types. The t(2;13) and t(1;13) translocations associated with the myogenic soft tissue cancer alveolar rhabdomyosarcoma fuse portions of the PAX3 or PAX7 gene with a portion of the FKHR gene to generate novel fusion proteins. The t(9;14) translocation associated with the B cell tumor lymphoplasmacytoid lymphoma juxtaposes the PAX5 gene into the vicinity of the IGH locus to deregulate PAX5 expression. This review will examine the molecular basis of these translocations and the role of altered function or expression of paired box transcription factors in the process of tumorigenesis.
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PMID:Chromosomal translocations involving paired box transcription factors in human cancer. 957 Jan 38


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