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)

Eight rhabdomyosarcomas were examined by indirect Coons method using rabbit antisera to myosin of human striated and smooth muscles. Positive immunofluorescence with the antiserum to striated muscle myosin was observed in 6 out of 8 tumors. In the preparations treated with the antiserum to smooth muscle myosin, fluorescence of smooth muscles of the blood vessels was observed. Immunofluorescence was absent in 1 embryonal and 1 pleomorphic rhabdomyosarcomas. The tumors with positive fluorescence included 2 embryonal, 1 alveolar rhabdomyosarcomas, 1 metastasis of testicular rhabdomyosarcoma into the lymph nodes, 1 rhabdomyosarcoma of undifferentiated type, and 1 rhabdomyosarcoma with signs of therapeutic pathomorphosis. The high resolving capacity of the method allows its use for specification ppf histological diagnosis of tumors with different levels of cytodifferentiation.
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PMID:[Immunomorphological method in the diagnosis of rhabdomyosarcomas]. 703 96

Histological and ultrastructural studies have been undertaken on a perineal rhabdomyosarcoma from a newborn child. The spontaneous tumour has the typical feature of mesenchymoma. The recurrent tumour, however, displays some rhabdopoietic characteristics. The myosin of the recurrent tumour has been extracted and compared with human fetal myosin. These two myosins are identical in their synthetic filaments and their light-chain composition. Nevertheless, whereas the ATPase activity of fetal myosin can be stimulated considerably by increasing the ca2+ concentration, that of tumoral myosin remains very low. These results show that there are isoenzymes of myosins and there must be differences in the myosin heavy chains, particularly in the active sites. These findings are identical with those seen in experimental rhabdomyosarcoma.
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PMID:Perineal rhabdomyosarcoma in a newborn child: pathological and biochemical studies with emphasis on contractile proteins. 743 Mar 94

Human skeletal muscle differentiation and maturation follows a precise sequence of events. To investigate whether and to what extent rhabdomyosarcoma (RMS) cells follow a comparable sequence, 29 fresh frozen specimens of RMS (14 primary and 15 relapses) were immunostained with antibodies directed against developmentally regulated myosin heavy chains (MHC), ie, fetal, fast, and slow MHC, in addition to desmin and vimentin. Four distinct patterns of expression were observed: I) RMS cells expressing exclusively vimentin and desmin (n = 7), II) in addition to expression of vimentin and desmin, a minority of neoplastic cells were immunoreactive with fetal MHC (n = 6), III) in addition to pattern II, fast MHC was expressed (n = 7), and IV) RMS cells simultaneously expressing vimentin, desmin, fetal, fast, and slow MHC (n = 9). Accordingly, the proportion of the MHC immunoreactive RMS cells increased gradually along with the four patterns of expression evolving from less than 25% up to 75% for fetal MHC, from less than 25% up to 50% for fast MHC, and up to 25% for slow MHC in the last category. Vimentin and desmin were coexpressed by almost all RMS cells. Double immunostaining revealed that comparable with the myogenic cells in the developing fetal skeletal muscle, expression of fetal MHC could be demonstrated in the same neoplastic cells either in conjunction with fast or slow MHC. In contrast, only in RMS, slow MHC expression in conjunction with fast MHC could be observed in the neoplastic cells. Neither the shape or size of neoplastic RMS cells, nor the histopathological types, nor tumor localization were related to the expression pattern of developmentally regulated MHC (fetal, fast, and slow MHC). These results confirm the commitment of the RMS cells to the myogenic pathway and demonstrate a restricted and aberrant differentiation pattern of the neoplastic cells in RMS compared with normal myogenesis, independent of histopathological types of RMS.
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PMID:Expression of developmentally regulated muscle proteins in rhabdomyosarcomas. 752 32

Human rhabdomyosarcoma RD cells express the myogenic regulatory factors MyoD and myogenin but differentiate spontaneously very poorly. Prolonged treatment of RD cells with the protein kinase C (PKC) activator 12-O-tetradecanoylphorbol-13-acetate (TPA) induces growth arrest and myogenic differentiation as shown by the accumulation of alpha-actin and myosin light and heavy chains, without affecting the expression of MyoD and myogenin. In this study, we show that short-term phorbol ester treatment of the cultures is sufficient to trigger myogenic differentiation but not growth arrest. Furthermore, PKC inhibitors, such as staurosporine or calphostin C, prevent TPA-induced differentiation but not cell growth arrest. These data suggest that the two events are mediated by different pathways; a possible interpretation is that the activation of one or more PKC isoforms mediates the induction of differentiation, whereas the down-regulation of the same or different isoforms mediates the growth arrest. To address the mechanism whereby TPA affects cell growth and differentiation in RD cells, we first analyzed PKC isoenzyme distribution. We found that RD cells express the alpha, beta 1, gamma, and sigma PKC isoenzymes. Only the alpha isoform is exclusively found in the soluble fraction, but it translocates to the membrane fraction within 5 min of TPA treatment and is completely down-regulated after 6 h. The other isoenzymes are found associated to both the soluble and the particulate fractions and are down-regulated after long-term TPA treatment. By immunofluorescence analysis, we show that the PKC alpha down-regulation is specific for those cells that respond to TPA by activating the muscle phenotype. We propose that TPA-induced differentiation in RD cells is mediated by the transient activation of PKC alpha, which activates some of the intracellular events that are necessary for MyoD and myogenin transacting activity and for the induction of terminal differentiation of RD cells. By contrast, the constitutively active beta 1 and sigma are responsible for the maintenance of cell growth, and their down-regulation is responsible for long-term TPA-induced cell growth arrest.
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PMID:Rapid activation and down-regulation of protein kinase C alpha in 12-O-Tetradecanoylphorbol-13-acetate-induced differentiation of human rhabdomyosarcoma cells. 754 6

Three human rhabdomyosarcoma cell lines were used to investigate the presence of autocrine loops based on the production of insulin-like growth factor (IGF)-II, basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF)/transforming growth factor (TGF)-alpha and of their corresponding receptors, and whether these loops affect cell proliferation and myogenic differentiation. Two cell lines, RD/18 and CCA, deriving from tumours of the embryonal histotype, showed the presence of both growth factors and receptors which make possible three different autocrine loops, while the alveolar RMZ-RC2 cell line lacked that based on the EGF receptor. Culture of rhabdomyosarcoma cells in the presence of specific blocking antibodies, directed to a component of single autocrine loops, inhibited cell proliferation (up to 50%), without inducing myogenic differentiation. Suramin, a drug which non-selectively interferes with the binding of growth factors to their cellular receptors, was used to block all the autocrine loops simultaneously. In CCA and RMZ-RC2 cells suramin was able to induce a significant increase (up to 3-fold) in the proportion of myosin-positive cells over control cultures. Therefore rhabdomyosarcoma cells of embryonal and alveolar histotype can show a redundancy of growth-sustaining autocrine loops. Suramin could interfere with them by acting on both growth inhibition and induction of myogenic differentiation.
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PMID:Redundancy of autocrine loops in human rhabdomyosarcoma cells: induction of differentiation by suramin. 757 72

The effects of aphidicolin, a specific inhibitor of DNA polymerase alpha, on cell growth, DNA synthesis and myogenic differentiation in the human alveolar rhabdomyosarcoma cell line KFR were studied. The treatment with aphidicolin at 5 x 10(-6) M concentration, which completely inhibited DNA synthesis and cell growth, induced morphological differentiation of small mononuclear cells to elongated, multinucleated (myotube-like) structures. The morphological differentiation was accompanied by the expression of skeletal muscle myosin; about 30% myosin-positive cells were observed after 14 days of treatment, compared to 2.3% in untreated cultures. The results showed that aphidicolin induces differentiation of human rhabdomyosarcoma cells and that multinucleated myotube-like elements may develop simply by cell fusion without cell division and DNA synthesis.
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PMID:Aphidicolin induces myogenic differentiation in the human rhabdomyosarcoma cell line KFR. 804 42

Sodium phenylacetate (NaPA) at concentrations ranging from 2 to 10 mM promoted myogenic differentiation of the human alveolar rhabdomyosarcoma cell line KFR. These concentrations inhibited DNA synthesis of the cells in a dose-dependent manner without significant effect on cell viability. The morphological differentiation of small mononuclear elements to terminal, elongated multinuclear structures resembling myotubes was accompanied by the expression of skeletal muscle myosin. The proportion of differentiated myosin-positive cells which was around 0.8-1.7% in control cultures 12 days after seeding was increased by NaPA treatment up to 47%. In the cytoplasm of differentiated cells, features of sarcomerogenesis were observed. These results suggest that NaPA is an effective inducer of rhabdomyosarcoma cell differentiation at concentrations that have been achieved in humans with no significant adverse effects.
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PMID:Induction of myogenic differentiation in a human rhabdomyosarcoma cell line by phenylacetate. 818 Sep 67

Currently, pleomorphic rhabdomyosarcoma (RMS) in adults is considered to be extremely rare or nonexistent. The authors have identified 11 cases of pleomorphic RMS using the following criteria: pleomorphic sarcoma occurring within voluntary muscle, large polygonal or strap-like cells with copious eosinophilic cytoplasm, desmin and myoglobin immunoreactivity, or ultrastructural evidence of sarcomeric differentiation. Ten patients were male, the median age at presentation was 56 years (range, 27-84), and the thigh (seven cases) was the most common site. Of eight cases with clinical follow-up, one patient is alive at 20 months, and seven died 2 to 28 months following diagnosis. The tumors were generally patternless, but several had storiform areas. Cross-striations were not identified. Immunostaining for muscle-related antigens was positive as follows: desmin (in 10 of 11 cases), myoglobin (in 10 of 11 cases), actin HHF-35 (in all 11 cases), smooth-muscle actin (in six of eight cases), sarcomeric actin (in six of nine cases), and fast myosin (in five of five cases). Staining for S-100 protein was negative in all cases. On electron microscopy (six cases), two tumors had well-differentiated rhabdomyoblasts with sarcomeres, Z-disks, and hexagonal arrays of myofilaments; three were poorly differentiated; and one contained immature mesenchymal cells only. Pleomorphic RMS can be distinguished from other pleomorphic sarcomas provided that well-fixed tumor tissue is available for immunohistochemical staining and electron microscopy. We consider that this distinction is important in view of the poor prognosis associated with pleomorphic RMS in this series.
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PMID:Pleomorphic rhabdomyosarcoma in adulthood. Analysis of 11 cases with definition of diagnostic criteria. 833 59

Cell lines from rhabdomyosarcomas, which are tumors of muscle origin, have been used as models of CD4-independent HIV infection. These cell lines can be induced to differentiate in vitro. We report here that the vpr gene of HIV1 is sufficient for the differentiation of the human rhabdomyosarcoma cell line TE671. Differentiated cells are characterized by great enlargement, altered morphology, lack of replication, and high level expression of the muscle-specific protein myosin. We have also observed the morphological differentiation and inhibition of proliferation of two other transformed cell lines. vpr-transfected cells remain fully viable in culture for extended periods. These observations elucidate a potential role for vpr in the virus life cycle and raise the possibility that some aspects of HIV-induced pathologies may be caused by a disturbance of cells by vpr.
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PMID:Induction of cell differentiation by human immunodeficiency virus 1 vpr. 844 20

The effects of dexamethasone, a synthetic glucocorticoid, and of N,N-dimethylformamide on in vitro growth and differentiation and on proto-oncogene expression of human rhabdomyosarcoma cells were studied. RD/18 clone cells (derived from the embryonal rhabdomyosarcoma cell line RD) treated with 100 nM dexamethasone showed an almost complete block of differentiation: about 5% myosin-positive cells were observed after 2 weeks of culture in dexamethasone-supplemented differentiation medium, compared to 20% of untreated cultures. Dexamethasone also induced a 20-30% growth inhibition and a more flattened morphology. The treatment with N,N-dimethylformamide induced a significantly increased proportion of myosin-positive cells (reaching about 30%) and a 40% growth inhibition. Induction of differentiation inversely correlated with the levels of c-myc proto-oncogene expression: after a 2 week culture dexamethasone-treated cells showed the highest c-myc expression and N,N-dimethylformamide-treated cells the lowest. Culture conditions per se down-modulated c-erbB1 and up-regulated c-jun expression, with no relationship to the differentiation pattern. Other proto-oncogenes were not expressed (c-sis, N-myc, c-mos, c-myb) or were not modulated (c-fos, c-raf). Therefore dexamethasone and N,N-dimethylformamide, both causing a decreased growth rate, showed opposing actions on myogenic differentiation and on c-myc proto-oncogene expression of human rhabdomyosarcoma cells.
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PMID:Uncoupling of growth inhibition and differentiation in dexamethasone-treated human rhabdomyosarcoma cells. 847 24


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