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

The WT1 gene encodes a transcription factor implicated in normal and neoplastic development. The purpose of this study was to evaluate the diagnostic utility of a commercial WT1 antibody on a variety of pediatric small round blue cell tumors (SRBCT). A mouse monoclonal antibody (clone: 6F-H2, DAKO) raised against the N-terminal amino acids 1-181 of the human WT1 protein was tested. Microscopic sections from 66 specimens were stained using an antigen retrieval protocol with trypsin. The tumors included peripheral neuroectodermal tumors (PNET/Ewing's), neuroblastomas, desmoplastic small round cell tumors (DSRCT), lymphomas, Wilms' tumors, and rhabdomyosarcomas (RMS). One RMS case was investigated by Western blot analysis and RT-PCR to confirm the antibody specificity. A strong cytoplasmic staining was demonstrated in all RMS (11/11). The Western blot analysis confirmed the WT1 protein in the tissue, and the RT-PCR confirmed the presence of WT1 mRNA in the peripheral blood and tissue of one RMS patient. The Wilms' tumors had a variable nuclear and/or cytoplasmic positivity in most (17/24) cases. All PNET/Ewing's were negative. The nuclei of two lymphoblastic lymphomas stained strongly. A weak nuclear or cytoplasmic staining was reported in a few DSRCT (3/5), lymphomas (2/10), and neuroblastomas (2/8). This is a useful antibody in the differentiation of RMS from other SRBCTs. A strong cytoplasmic staining favors an RMS, and a strong nuclear staining is suggestive of a Wilms' tumor. A role for WT1 in the pathogenesis of rhabdomyosarcomas is raised. The limited sampling precludes any conclusions regarding the value of tissue or peripheral blood analysis for WT1 mRNA in patients with rhabdomyosarcoma.
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PMID:The expression of WT1 in the differentiation of rhabdomyosarcoma from other pediatric small round blue cell tumors. 1461 59

There is increasing evidence that WT1 protein expression is found not only at nuclear, but also at cytoplasmic, level in several developing and neoplastic tissues. In order to better understand the possible role of WT1 protein in human skeletal myogenesis and oncogenesis of rhabdomyosarcoma, we assessed immunohistochemically its comparative expression in a large series of human developing, adult and neoplastic skeletal muscle tissues. The present study shows that WT1 protein is developmentally expressed in the cytoplasm of human myoblasts from the 6 weeks of gestational age. This expression was maintained in the myotubes of developing muscles of the trunk, head, neck, and extremities, while it was down-regulated in fetal skeletal fibers from 20 weeks of gestational age as well as in adult normal skeletal muscle. Notably, WT1 immunostaining disappeared from rhabdomyomas, whereas it was strongly and diffusely re-expressed in all cases (27/27) of embryonal and alveolar rhabdomyosarcoma. The comparative evaluation of the immunohistochemical findings revealed that WT1 cytoplasmic expression in rhabdomyosarcoma may represent an ontogenetic reversal, and this nuclear transcription factor can also be considered an oncofetal protein which can be exploitable as an additional, highly sensitive immunomarker, together with desmin, myogenin and MyoD1, of this tumor. Moreover, our observations support the rationale for the use of WT1 protein-based target therapy in high risk rhabdomyosarcomas in children and adolescents.
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PMID:Oncofetal expression of Wilms' tumor 1 (WT1) protein in human fetal, adult and neoplastic skeletal muscle tissues. 2580 Sep 78

Making a correct diagnosis when dealing with a small round blue cell tumor (SRBCT) of children and adolescents may be relatively straightforward if the tumor arises in the typical clinical setting and the classic pathologic features are all recognizable. However it is widely known that diagnostic difficulties may arise because of: (i) many tumors share overlapping morphological and/or immunohistochemical features; (ii) considerable clinical, pathologic, and immunohistochemical variations do exist; (iii) the increasing use of small biopsies in daily practice makes the diagnosis of these neoplasms more challenging. Accordingly, immunohistochemical analyses are currently mandatory in establishing the correct diagnosis. In this regard there is the need to identify more sensitive and specific immunomarkers useful in the distinction of the several tumor entities. Over the last decades, several markers, such as CD99, WT1 protein, desmin, myogenin, NB84, and INI1 have been identified, providing a considerable help in recognition of the most common solid tumors (ESW/pPNET, rhabdomyosarcoma, neuroblastoma, Wilms' tumor, desmoplastic small round cell tumor; malignant rhabdoid tumor) in children and adolescents. However, at the same time, their unusual, unexpected expression can result in a misinterpretation of the immunohistochemical results, especially by pathologists who are not familiar with oncologic pediatric pathology. Therefore the present review focuses on the potential immunohistochemical pitfalls which should be kept in mind by pathologists to prevent diagnostic errors when dealing with SRBCTs.
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PMID:Immunohistochemistry as potential diagnostic pitfall in the most common solid tumors of children and adolescents. 2588 77