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)

Development of primary cultured chicken myogenic cells were studied using living cell micro-morphoanalysis, muscle specific protein immunofluorescent double staining, image projection analysis and 3H-TdR incorporation autoradiography methods. Changes in single, normal newborn myoblasts from the time of their last mitosis until 22 hr old were followed. All +/- 4 hr myoblasts were desmin+ and most were positive for alpha-actinin, zeugmatin, troponin-I (TnI), alpha-actin. titin, nebulin and myosin heavy chain (MHC). There was no obligatory temporal or spatial sequence in the order of the appearance of the major myofibrillar proteins. Nascent sister myoblasts assumed an exceptionally elongated bipolar morphology that is as singular to mononucleated postmitotic myoblasts as is their capacity to transcribe myofibrillar genes. The assembly of non-striated myofibrils (NSMFs) was evident in all 6-8 hr cells and was initiated in the absence of myomesin and C-protein. Myomesin first appeared along NSMFs in 10-14 hr old cells. C-protein was only found localized to transverse doublets bisecting 1.6 microns wide A-bands of assembled sarcomeres. Each newly assembled sarcomere presented the same invariant distribution of proteins that is found in adult sarcomeres. There is a lag of 16 or more hours between the first appearance of most of the major myofibrillar proteins and their assembly into NSMFs and the first appearance of striated myofibrils (SMFs). The observations indicated that the majority of normal myoblasts up-regulate the synthesis of myofibrillar proteins prior to, not after, fusion. In brief, new-born +/- 4 hr myoblasts expressed their differentiation program in the process as (1) withdrawal from the cell cycle: (2) initiation of synthesis and accumulation of desmin and 7 early myofibrillar proteins: (3) cellular elongation and assembly of NSMFs and SMFs: (4) acquisition of a fusion-competent sarcolemma. The expression of this cell autonomous myogenic differentiation program is distorted or blocked in rhabdomyosarcoma RD cells. The majority of RD cells expressed desmin (50-90%): among these desmin+ cells, 10-20% incorporated 3H-TdR. In addition, 60-78% of the mitotic cells were desmin+. Most desmin+ cells were myofibrillar protein negative. Only a small number of tumor cells (5-10%) expressed MHC, titin, alpha-actinin and s-alpha-actin. 3H-TdR positive nuclei were observed in these myofibrillar protein+ cells: 11-12% in titin+ or nebulin+ cells and 4% in MHC+ cells. But none of the mitotic cells were myofibrillar protein+.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Expression of myogenic differentiation program in cultured normal postmitotic mononucleated myoblasts and the aberrant differentiation in rhabdomyosarcoma cells]. 804 10

The microfilament-associated protein vinculin is a major constituent of muscle tissue localized in costameres and Z-discs of the sarcomeric apparatus, where it is thought to play a pivotal role in the alignment of sarcomeric myofibrils and the transduction of mechanical force between the internal contractile machinery and the extracellular environment. In order to investigate whether anti-vinculin antibodies are helpful in confirming the commitment of rhabdomyosarcomas to the myogenic pathway, we studied immunohistochemically the expression pattern of vinculin in a series of 7 human rhabdomyosarcomas including those of embryonal, botryoid, and pleomorphic subtypes. Using monoclonal antibody from clone hVIN-1 by APAAP techniques on formalin-fixed, paraffin-embedded tissue, all but one tumor, which was a primitive embryonal rhabdomyosarcoma, demonstrated a significant positive vinculin staining. Vinculin expression was most prominent in differentiated tumors with a focal staining pattern showing a high degree of correlation with rhabdomyoblasts, whereas a diffuse staining was observed in areas in which small, poorly differentiated tumor cells alone were present. Since vinculin immunoreactivity could also be demonstrated in cases of leiomyosarcoma, the positive immunohistochemical detection of vinculin was not exclusively restricted to mesenchymal tumors derived from sarcomeric muscle tissue. Immunodetectable amounts of nebulin could be revealed only in two embryonal rhabdomyosarcomas. Our results suggested that the positive identification of rhabdomyosarcoma achieved by using antibodies against vinculin in addition to other known myogenic markers may be particularly useful in the differential diagnosis of anaplastic, poorly differentiated sarcomas.
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PMID:Immunohistochemical detection of vinculin in human rhabdomyosarcomas. 906 83