Mouse beta-globin DNA-binding protein B1 is identical to a proto-oncogene, the transcription factor Spi-1/PU.1, and is restricted in expression to hematopoietic cells and the testis

The hematopoietic-specific DNA-binding protein B1 binds to the DNA consensus sequence AAAGRGGAARYG located twice in intervening sequence 2 of both of the mouse beta-globin genes (D. L. Galson and D.E. Housman, Mol. Cell. Biol. 8:381-392, 1988). B1 was cloned by expression of a murine erythroleukemia (MEL) cell cDNA library in transfected COS cells and screening by electrophoretic mobility shift analysis. B1 is identical to the proto-oncogene Spi-1/PU.1 (Spi-1), an ets family member. Protein-DNA contacts are shown to resemble those of the helix-turn-helix homeodomain proteins. By Northern (RNA) analysis, we found that Spi-1 mRNA is present at low levels during murine CFU-E maturation and is at least 20-fold higher in uninduced MEL, a transformed proerythroblast-like cell line which contains an activating/transforming insertion of spleen focus-forming virus at the Spi-1 locus. Dimethyl sulfoxide-induced MEL cell differentiation decreases Spi-1 mRNA to approximately 20% of the uninduced level before commitment occurs. In addition to erythroid cells, Spi-1 mRNA is present in B cells, myelomonocytes, and mast cells but not in T cells and nonhematopoietic cell types. In situ hybridization demonstrated Spi-1 mRNA expression in bone marrow, spleen, interstitial nonhepatocytes of the liver, and interstitial nontubular cells of the testis. The Spi-1 locus was mapped on human chromosome 11 to the same interval as ACP2 (lysosomal acid phosphatase), between the anonymous DNA markers D11S33 and D11S14. This region has not yet been found to be associated with a human malignancy.     

Protein kinase C activation increases binding of transcription factor PU.1 in murine tissue macrophages

The Vitek GNI card was used to identify 212 isolates of 10 Yersinia species. Identification was correct for 96.3% of the isolates (156 of 162) to the genus level and for 57.4% of the isolates (93 of 162) to the species level for Yersinia spp. listed in the Vitek database. We recommend additional identification methods for isolates assigned to the genus Yersinia by the Vitek system.     

The role of transcription factor PU.1 in the activity of the intronic enhancer of the eosinophil-derived neurotoxin (RNS2) gene

PURPOSE: To evaluate the therapeutic significance of cisplatin, vincristine, doxorubicin, and etoposide (CODE) plus granulocyte colony-stimulating factor (G-CSF) compared with cyclophosphamide, doxorubicin, and vincristine, alternating with cisplatin and etoposide (CAV/PE) for extensive-disease (ED) small-cell lung cancer (SCLC). PATIENTS AND METHODS: Two hundred twenty-seven patients were randomized. CODE consisted of cisplatin 25 mg/m2 weekly for 9 weeks; vincristine 1 mg/m2 on weeks 1, 2, 4, and 6; and doxorubicin 40 mg/m2 and etoposide 80 mg/m2 for 3 days on weeks 1, 3, 5, 7, and 9. G-CSF 50 micrograms/m2 was administered on the days when chemotherapy was not administered. CAV/PE consisted of cyclophosphamide 800 mg/m2; doxorubicin 50 mg/m2; and vincristine 1.4 mg/m2 on day 1, which alternated every 3 weeks with cisplatin 80 mg/m2 on day 1 and etoposide 100 mg/m2 on days 1 to 3. RESULTS: Overall response rates were 77% for the CAV/PE arm and 84% for the CODE arm respectively (15% complete response in both arms). The median survival times were 10.9 months in the CAV/PE arm and 11.6 months in the CODE arm (P = .1034). The achieved dose-intensity for CODE was approximately twice that for CAV/PE for those drugs common to both arms. The incidence of leukopenia did not differ between the two arms, but anemia and thrombocytopenia had a significantly higher incidence in the CODE arm. Four treatment-related deaths from neutropenic fever occurred in the CODE arm. CONCLUSION: The CODE group had a similar median survival to the CAV/PE group. It does not appear that CODE is a useful approach to improve survival in ED SCLC.