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)

Deletion mutants of simian immunodeficiency virus (SIVmac) which were unable to integrate into host cells were generated by removing a portion of the integrase (IN) domain of the pol gene. The resulting plasmid was transfected into HUT-78 and human rhabdomyosarcoma cells. In comparison with the parental plasmid DNA transfected in parallel, the deletion mutant was found to direct efficient production of virus in both cell systems. Viruses derived from wild-type and mutant proviral DNAs were also tested for their relative replicative abilities in HUT-78 and U937 cells, and the kinetics of virus production was found to vary between these two cell systems. Analysis of DNA from infected cell nuclei showed that the deletion mutant lacked the ability to integrate despite being able to produce infectious virus. Using the sensitive polymerase chain reaction technique, we have clearly demonstrated the absence of the IN domain in the deletion mutant after infection and replication in HUT-78 cells. Such mutants might form the basis for the development of an experimental live attenuated vaccine.
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PMID:Generation of deletion mutants of simian immunodeficiency virus incapable of proviral integration. 841 98

Human immunodeficiency virus type 1 integrase (HIV-1 IN) is thought to have several putative roles at steps prior to integration, such as reverse transcription and nuclear transport of the preintegration complex (PIC). Here, we investigated new functional aspects of HIV-1 IN in the context of the viral replication cycle through point mutagenesis of Ser, Thr, Tyr, Lys, and Arg residues conserved in IN, some of which are located at possible phosphorylation sites. Our results showed that mutations of these Ser or Thr residues had no effect on reverse transcription and nuclear transport of PIC but had a slight effect on integration. Of note, mutations in the conserved KRK motif (amino acids 186 to 189), proposed previously as a putative nuclear localization signal (NLS) of HIV-1 IN, did not affect the karyophilic property of HIV-1 IN as shown by using a green fluorescent protein fusion protein expression system. Instead, these KRK mutations resulted in an almost complete lack of viral gene expression due to the failure to complete reverse transcription. This defect was complemented by supplying wild-type IN in trans, suggesting a trans-acting function of the KRK motif of IN in reverse transcription. Mutation at the conserved Tyr 143 (Y143G) resulted in partial impairment of completion of reverse transcription in monocyte-derived macrophages (MDM) but not in rhabdomyosarcoma cells. Similar effects were obtained by introducing a stop codon in the vpr gene (DeltaVpr), and additive effects of both mutations (Y143G plus DeltaVpr) were observed. In addition, these mutants did not produce two-long terminal repeat DNA, a surrogate marker for nuclear entry, in MDM. Thus, the possible impairment of Y143G might occur during the nuclear transport of the PIC. Taken together, our results identified new functional aspects of the conserved residues in HIV-1 IN: i) the KRK motif might have a role in efficient reverse transcription in both dividing and nondividing cells but not in the NLS function; ii) Y143 might be an important residue for maintaining efficient proviral DNA formation in nondividing cells.
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PMID:Identification of critical amino acid residues in human immunodeficiency virus type 1 IN required for efficient proviral DNA formation at steps prior to integration in dividing and nondividing cells. 1077 18

Very few cases of gliosarcoma (GS) in the spinal cord with or without rhabdomyoblastic differentiation have been reported at young ages, leading to limited information on the clinical, pathological and prognosis of this type of tumors. We report a case of GS with rhabdomyoblastic differentiation in a 6-year-old girl in C1-C6 level spinal cord. This is, to the best of our knowledge, the first report of GS with rhabdomyoblastic differentiation primarily developed in spinal cord at such a young age. Histologically, GS is composed of both glioblastoma components and malignant mesenchymal components. In the present case, the mesenchymal portion displayed a typical pattern of rhabdoid morphology. The rhabdomyoblastic-differentiated cells were confirmed by desmin, MyoD1, myogenin and Vimentin immunopositivity. Loss of PTEN (phosphatase and tensin homolog) and amplification of EGFR (epidermal growth factor receptor) were not detected in both parts of GS (glioblastoma component and rhabdomyosarcoma component). Interestingly, in this case rhabdomyoblastic-differentiated cells (rhabdomyosarcoma component) were focally negative for integrase interaction 1 (INI-1) protein and glial cells (glioblastoma component) were positive, and monosomy 22 in the former and absence in the latter. The patient only received low-dose radiotherapy and survived only 6 months after diagnosis. GSs with rhabdomyoblastic differentiation have a worse prognosis than common GSs and high-dose radiotherapy is suggested to considerer.
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PMID:Spinal cord gliosarcoma with rhabdomyoblastic differentiation: a case report. 3196 62