Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.6 (RNA polymerase)
 34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

As a result of the t(11;22)(q24;q12) chromosomal translocation characterizing the Ewing family of tumors (ET), the amino terminal portion of EWS, an RNA binding protein of unknown function, is fused to the DNA-binding domain of the ets transcription factor Fli1. The hybrid EWS-Fli1 protein acts as a strong transcriptional activator and, in contrast to wildtype Fli1, is a potent transforming agent. Similar rearrangements involving EWS or the highly homologous TLS with various transcription factors have been found in several types of human tumors. Employing yeast two-hybrid cloning we isolated the seventh largest subunit of human RNA polymerase II (hsRPB7) as a protein that specifically interacts with the amino terminus of EWS. This association was confirmed by in vitro immunocoprecipitation. In nuclear extracts, hsRPB7 was found to copurify with EWS-Fli1 but not with Fli1. Overexpression of recombinant hsRPB7 specifically increased gene activation by EWS-chimeric transcription factors. Replacement of the EWS portion by hsRPB7 in the oncogenic fusion protein restored the transactivating potential of the chimera. Our results suggest that the interaction of the amino terminus of EWS with hsRPB7 contributes to the transactivation function of EWS-Fli1 and, since hsRPB7 has characteristics of a regulatory subunit of RNA polymerase II, may influence promoter selectivity.
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PMID:Oncogenic EWS-Fli1 interacts with hsRPB7, a subunit of human RNA polymerase II. 970 26

Reverse transcriptase polymerase chain reaction (RT-PCR) was applied to evaluate the frequency of tumour cells in PBPC products from 15 high risk Ewing tumour (ET) patients who were treated according to EICESS 92 with high-dose chemotherapy (HDC) and stem cell rescue. Initial tumour cell contamination of the bone marrow (BM) detected by light microscopy was found in five and by RT-PCR in eight cases. RT-PCR was performed on each PBPC sample repeatedly at a sensitivity comparable to 20-100 highly EWS-Fli1 expressing tumour cells per 10 ml of fresh blood. Irrespective of the extent of BM involvement at diagnosis, all BM samples obtained before harvest were RT-PCR negative. Among 12 of 35 analysed apheresis products with single positive RT-PCR results only one sample tested reproducibly positive for tumour cell contamination in independent determinations. These preliminary data suggest that tumour cell contamination of PBPC is rarely found in patients with ET.
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PMID:Low incidence of molecular evidence for tumour in PBPC harvests from patients with high risk Ewing tumours. 1046 30