Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rhabdomyosarcoma (RMS) is an uncommon malignant soft tissue sarcoma whose cause is largely unknown. Reported risk factors include genetic alterations (e.g., p53 mutations, a defective gene at 11p15.5, or specific chromosomal translocation of t(2:13)), and parents' use of drugs around the time of conception. We present results from a national, case-control study of 249 RMS cases (170 males and 79 females) and 302 controls (196 males and 106 females). The cases, aged 0-20 years at diagnosis, were identified via the Intergroup RMS Study-III during 1982-1988. Controls were selected by random digit telephone dialing. As a supplement to the original study, information on genetic diseases and birth defects (BD) was collected from the subjects' parents by telephone interview. Fifty-six (22.5%) cases and 55 (18.2%) controls were reported to have genetic diseases or BD (odds ratio [OR] = 1.30,95% confidence interval [CI] = 0.85-2.02, P = .21). The case group had a significantly higher frequency of neurofibromatosis type I (NF1) than did the control group, i.e., five cases (2.0%) had NF1 vs. zero controls (P = .02). The case group also had a higher frequency of major BDs than did the control group (6.0% vs. 2.6%, OR = 2.36, 95% CI = 0.92-6.52, P = .05). However, this excess was only observed in males (7.6% vs. 2.6%, OR = 3.16, 95% CI = 1.02-10.41, P = .02). Among the 15 cases having both RMS and major BDs, six (40.0%) had both conditions in the same regional anatomic site: Two (13.3%) had both in the extremities, two (13.3%) in the genitourinary system, and two in the head and neck. These findings suggest that common genetic mechanisms or in utero exposures may be involved in the development of many childhood tumors and congenital abnormalities.
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PMID:Association of childhood rhabdomyosarcoma with neurofibromatosis type I and birth defects. 855 79

We recently reported that rhabdomyosarcoma cell lines express and secrete interleukin 15 (IL-15), a tightly regulated cytokine with IL-2-like activity. To test whether the p53-impaired function that is frequently found in this tumour type could play a role in the IL-15 production, wild-type p53 gene was transduced in the human rhabdomyosarcoma cell line RD (which harbours a mutated p53 gene), and its effect on proliferation and expression of IL-15 was studied. Arrest of proliferation was induced by wild-type p53; increased proportions of G1-arrested cells and of apoptotic cells were observed. A marked down-modulation of IL-15 expression, at both the mRNA and protein level, was found in p53-transduced cells. Because a direct effect of IL-15 on normal muscle cells has been reported, the presence of IL-15 membrane receptors was studied by cytofluorometric analysis. Rhabdomyosarcoma cells showed IL-15 membrane receptors, which are down-modulated by wild-type p53 transfected gene. In conclusion, wild-type p53 transduction in human rhabdomyosarcoma cells induces the down-modulation of both IL-15 production and IL-15 receptor expression.
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PMID:Wild-type p53-mediated down-modulation of interleukin 15 and interleukin 15 receptors in human rhabdomyosarcoma cells. 986 62

A comparative genomic hybridization (CGH) approach provides identification of genomic gains and losses in a tumor specimen in a single experiment. Only 11 embryonal rhabdomyosarcomas (E-RMS) have previously been subjected to CGH. The underlying genetic events in this histologic subtype are not well defined. In this investigation, 12 E-RMS specimens from 10 patients entered into Intergroup Rhabdomyosarcoma Study (IRS) I-IV and two local patients were analyzed by CGH and fluorescence in situ hybridization (FISH). Gains of chromosomes or chromosomal regions 2 (50%), 7 (42%), 8 (67%), 11 (42%), 12 (58%), 13q21 (33%), and 20 (33%) and losses of 1p35-36.3 (42%), 6 (33%), 9q22 (33%), 14q21-32 (25%), and 17 (25%) were most prominent. Chromosomal regions 1p35-36.3 and 9q22 represent novel regions of loss. Importantly, loss of 9q22 corresponds to the locus of a putative tumor suppressor gene (PTCH), which has been shown to play a role in rhabdomyosarcoma in a mouse model of Gorlin syndrome. Loss of 1p36 corresponds to the locus for PAX7, a paired box containing gene characteristically altered in alveolar rhabdomyosarcoma. Moreover, loss of 1p36 is prominent in another common pediatric soft tissue tumor, neuroblastoma. Gains of 2, 7, 8, 12, and 13 and loss of 14 were seen in the sole prior E-RMS CGH series; thus, these data provide important confirmatory results. In contrast to this previous study, however loss, not gain, of chromosome 17 was observed in the current study. Chromosome 17 loss correlates well with previous descriptions of frequent allelic loss of 17p (TP53) in E-RMS. In summary, CGH and FISH analyses of 12 E-RMS specimens revealed novel genomic imbalances that may be useful in directing further molecular studies for the determination of E-RMS critically involved genes.
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PMID:Novel genomic imbalances in embryonal rhabdomyosarcoma revealed by comparative genomic hybridization and fluorescence in situ hybridization: an intergroup rhabdomyosarcoma study. 1071 62

Rhabdomyosarcoma (RMS) is a family of soft tissue tumors that are associated with the skeletal muscle lineage and generally occur in the pediatric population. Based on histopathologic features, two subtypes, embryonal (ERMS) and alveolar (ARMS), were identified and associated with distinct clinical characteristics and genetic alterations. ARMS is associated with 2;13 or 1;13 chromosomal translocations, which generate PAX3-FKHR and PAX7-FKHR fusion products, respectively. These translocations result in altered expression, function, and subcellular localization of the fusion products relative to the wild-type proteins, and ultimately contribute to oncogenic behavior by modifying growth, differentiation, and apoptosis pathways. In contrast to the specific translocations found in ARMS, most ERMS cases have allelic loss at chromosome 11p15.5. Chromosome fragment transfer studies demonstrated that this region represses tumor cell growth, suggesting the presence of tumor suppressor gene(s) in this region. In both ERMS and ARMS, there is evidence of collaborating alterations that affect common targets, such as the p53 and RB pathways. One mechanism for perturbing these pathways involves amplification of genes such as MDM2 and CDK4; these amplification events occur frequently in ARMS but only rarely in ERMS. Therefore, despite similarities in the downstream targets of these genetic alterations, the striking cytogenetic and molecular differences between ARMS and ERMS indicate distinct molecular etiologies in these two subtypes.
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PMID:Molecular pathogenesis of rhabdomyosarcoma. 1217 Jul 81

Rhabdomyosarcoma (RMS) cell lines were transduced with an adenoviral vector containing the wild-type p53 (wtp53) cDNA (Ad-p53) and then exposed to four cytotoxic agents: actinomycin D, vincristine, 5-fluorouracil and bleomycin. Potentiation of cytotoxicity following wild-type p53 expression varied from 0- to 20-fold for different drugs and between cell lines. It appeared that alveolar RMS cells (n = 2) were more susceptible to p53-mediated chemosensitization than embryonal RMS cells (n = 3), although this was independent of pax3-FKHR expression. Overall, cells that were most chemosensitive prior to Ad-p53 exposure were those that were most susceptible to p53 potentiation of cytotoxicity. The different results obtained with these RMS cell lines does not appear to be related to expression of pax3-FKHR, p21, Bax or Bcl-2 but may in part be due to differential regulation of p53 target genes, such as MDM2. In conclusion, exogenous wild-type expression selectively chemosensitizes RMS cells to cytotoxic agents. However, expression of transcriptionally active wtp53 does not predict a chemosensitive phenotype.
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PMID:Selective chemosensitization of rhabdomyosarcoma cell lines following wild-type p53 adenoviral transduction. 1239 75

Rhabdomyosarcoma is the most commonly occurring soft-tissue sarcoma in children. Some reports have discussed the altered expression and molecular abnormalities of cell-cycle-regulatory proteins in rhabdomyosarcoma; however, variable frequencies of occurrence have been noted. In the current study, among 72 cases of rhabdomyosarcoma, the authors evaluated for the expression of p53, MDM2, p16, p21/WAF1, p27, cyclin D1, cyclin E, pRb and E2F-1 protein immunohistochemically and assessed for proliferative activities using MIB-1. We also analyzed the mutation of the p53 gene in 45 cases, the amplification of the MDM2 gene in 18 cases and the mutation of the H-ras gene in 29 cases, using formalin-fixed paraffin-embedded materials. Furthermore, we assessed the correlation between clinicopathologic factors and the results of both immunohistochemical and molecular analyses. Alveolar type affected older patients, and it had a significantly higher mitotic rate compared with the embryonal type (P=0.0226). p53 overexpression was detected in 22 (30.6%) of 72 cases, and 10 (22.2%) of 45 cases had p53 gene abnormalities. As for MDM2, its overexpression was found in nine (12.5%) of 72 cases, and three (16.7%) of 18 cases showed MDM2 amplification. A statistically significant association was observed between immunoreaction for MDM2 and p53 overexpression (P=0.0002), and p53 and MDM2 overexpression was significantly correlated with high MIB-1 labeling indices. E2F-1 labeling indices showed a significantly higher score in alveolar type compared with that seen in embryonal type (P=0.0334), but MIB-1 did not. In conclusion, our study suggests that p53 overexpression may be related to tumor progression because tumors with p53 overexpression have a high proliferative activity in the current study. Alveolar type had a significantly higher both mitotic rate and E2F-1 labeling indices when compared with the embryonal type. The current study is the first report of the correlation of E2F-1 with alveolar rhabdomyosarcoma.
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PMID:Altered expression and molecular abnormalities of cell-cycle-regulatory proteins in rhabdomyosarcoma. 1509 8

Rhabdomyosarcoma (RMS) is a highly malignant tumor that is histologically related to skeletal muscle, yet genetic and molecular lesions underlying its genesis and progression remain largely unknown. In this study we have compared the molecular profiles of two different mouse models of RMS, each associated with a defined primary genetic defect known to play a role in rhabdomyosarcomagenesis in man. We report that RMS of heterozygous Patched1 (Ptch1) mice show less aggressive growth and a greater degree of differentiation than RMS of heterozygous p53 mice. By means of cDNA microarray analysis we demonstrate that RMS in Ptch1 mutants predominantly express a number of myogenic markers, including myogenic differentiation 1, myosin heavy chain, actin, troponin and tropomyosin, as well as genes associated with Hedgehog/Patched signaling like insulin-like growth factor 2, forkhead box gene Foxf1 and the growth arrest and DNA-damage-inducible gene Gadd45a. In sharp contrast, RMS in p53 mutants display higher expression levels of cell cycle-associated genes like cyclin B1, cyclin-dependent kinase 4 and the proliferation marker Ki-67. These results demonstrate that different causative mutations lead to distinct gene expression profiles in RMS, which appear to reflect their different biological characteristics. Our results provide a first step towards a molecular classification of different forms of RMS. If the described differences can be confirmed in human RMS our results will contribute to a new molecular taxonomy of this cancer, which will be critical for gene mutation- and expression-specific therapy.
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PMID:Profiling the molecular difference between Patched- and p53-dependent rhabdomyosarcoma. 1548 Apr 23

Rhabdomyosarcoma (RMS) is the most common soft tissue neoplasm of children, and those metastatic at presentation have a poor prognosis. RMS development is related to defective skeletal muscle differentiation, involving a variety of cell signaling and transcriptional control pathways, including aberrant hedgehog signaling. Here we evaluate Fem1a, a gene highly expressed in skeletal muscle, as a candidate for involvement in RMS. Fem1a is a homolog of fem-1, which controls cell fate decisions in the sex determination pathway of Caenorhabditis elegans, a pathway with homology to mammalian hedgehog signaling. We show that Fem1a expression is activated during myocyte differentiation of C2C12 myoblasts, and this expression is largely confined to the terminally differentiating pool, not to the satellite-cell-like quiescent reserve cell pool. We find that the human homolog, FEM1A, is downregulated in all of 8 different human RMS cell lines, including those derived from embryonal and alveolar RMS. Using mouse genetic models of RMS development, we further show that Fem1a is consistently downregulated in primary RMS from Ptch1+/- mice, from p53-/- mice, from p53+/-; Ptch1+/- mice, and from HGF/SF-Ink4a/Arf-/- mice. Therefore, Fem1a downregulation may be involved in, and/or a marker of, an early cell fate defect fundamental to RMS pathogenesis.
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PMID:The Fem1a gene is downregulated in Rhabdomyosarcoma. 1625 58

Rhabdomyosarcoma is the most common soft tissue sarcoma in children, yet the genetic changes causing this disease are poorly understood. The Fos protein, a major component of the AP-1 transcription factor, is essential for osteoclast differentiation, acts as an oncogene, potentiates transforming signals and controls invasive growth and angiogenesis during tumor progression. To genetically investigate a potential interaction between the p53 and Fos pathways, Trp53/Fos double knock-out mice were generated. These mice develop highly proliferative and invasive rhabdomyosarcomas of the facial and orbital regions with more than 90% penetrance at 6 months of age. Expression of Fos in Trp53/Fos mutant rhabdomyosarcoma cell lines established from primary tumors is associated with enhanced apoptosis and downregulation of Pax7 expression. Our results show that Trp53/Fos double knock-out mice recapitulate major aspects of human rhabdomyosarcoma development and therefore provide a mouse model for the human disease. Furthermore, this study identifies a novel and unexpected tumor suppressive function of the Fos proto-oncogene.
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PMID:[Rhabdomyosarcoma development in Trp53/fos mutant mice: tumor suppressor functions of the Fos protooncogene]. 1689 56

Rhabdomyosarcoma is the most common soft tissue sarcoma of childhood and adolescence. Historically, rhabdomyosarcoma has been studied by the manipulation of human cell lines derived from primary rhabdomyosarcoma tumor tissue adapted to grow in culture. Recently, mouse models have been added to the arsenal of tools to study this disease in vivo. However, given the emerging understanding of the genetic variability and mutability of human tumor-derived cell lines, and the existing differences between human and murine tumorigenesis, we sought to uniformly dissect the genetic events required to generate rhabdomyosarcoma from primary human skeletal muscle precursors. To this end, primary human skeletal muscle cells were transformed with defined genetic elements to corrupt the p53, Rb, Myc, telomerase, and Ras pathways, resulting in cells that, when assayed as subcutaneous xenografts in immunocompromised mice, formed tumors indistinguishable at the immunohistochemical level from the embryonal histologic variant of rhabdomyosarcoma. This chapter will discuss the techniques used to transform primary human skeletal muscle cells, the assays used to verify expression of the ectopically expressed genetic elements, and the methods used to evaluate the tumorigenic capacity of the resulting cell lines.
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PMID:Genetic modeling of Ras-induced human rhabdomyosarcoma. 1841 64


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