AIMS To establish whether the MYB protein expressed in HL-60 variant cells, which are cells resistant to 12-O-tetradecanoylphorbol-13-acetate (TPA) induced differentiation, is able to bind MYB recognition elements (MREs) involved in the transcriptional regulation of myb target genes. In addition, to determine whether alterations in the binding of the MYB protein to MREs affects HL-60 cell proli...

PURPOSE Adult T-cell leukemia/lymphoma (ATLL) is an aggressive human T-cell malignancy induced by human T-lymphotrophic virus-1 (HTLV-1) infection. The genetic alterations in infected cells that lead to transformation have not been completely elucidated, thus hindering the identification of effective therapeutic targets for ATL. Here, we present the first assessment of MYB proto-oncogene dysreg...

The c-Myb transcription factor is required for normal adult hematopoiesis. However, the embryonic lethality of Myb-null mutations has been an impediment to identifying roles for c-Myb during lymphocyte development. We have used tissue-specific inactivation of the Myb locus in early progenitor cells to demonstrate that c-Myb is absolutely required for the differentiation of CD19(+) B-lineage cel...

The c-myb promoter contains multiple GGA repeats beginning 17 bp downstream of the transcription initiation site. GGA repeats have been previously shown to form unusual DNA structures in solution. Results from chemical footprinting, circular dichroism and RNA and DNA polymerase arrest assays on oligonucleotides representing the GGA repeat region of the c-myb promoter demonstrate that the elemen...

Hematopoietic tissues and some leukemic cell lines express elevated levels of c-myb transcripts. We have separated a subpopulation of chicken embryo yolk sac cells that represents about 5% of the yolk sac hematopoietic cells and appears to contain all of the detectable c-myb transcripts. The level of myb expression in this cell population is higher than previously reported for any normal cell p...

B-Myb, a highly conserved member of the Myb transcription factor family, is expressed ubiquitously in proliferating cells and controls the cell cycle dependent transcription of G2/M-phase genes. Deregulation of B-Myb has been implicated in oncogenesis and loss of genomic stability. We have identified B-Myb as a novel interaction partner of the Mre11-Rad50-Nbs1 (MRN) complex, a key player in the...

PURPOSE The objectives of this study were to determine the incidence of the MYB-NFIB fusion in salivary adenoid cystic carcinoma (ACC), to establish the clinicopathologic significance of the fusion, and to analyze the expression of MYB in ACCs in the context of the MYB-NFIB fusion. EXPERIMENTAL DESIGN We did an extensive analysis involving 123 cancers of the salivary gland, including primary ...

The cellular c-myb gene encodes a transcription factor composed of a DNA-binding domain, a transactivating domain and a regulatory domain located at its carboxy (C-) terminus. The latter one is deleted in the transforming viral protein v-Myb. Here we show that deletion of the C-terminus of c-Myb increases the transcriptional transactivation activity of c-Myb defining it as cis-acting negative r...

BACKGROUND Cyclins and their catalytic partners, the cyclin-dependent kinases (Cdks), function as key regulators of the eukaryotic cell cycle. Specific cyclin-Cdk complexes are active at successive stages during the cell cycle and control cell-cycle progression by phosphorylating specific target proteins, most of which have not yet been identified. B-Myb, a conserved member of the Myb oncoprote...

The transcription factor gene MYB was identified recently as an oncogene that is rearranged/duplicated in some human leukemias. Here we describe a new mechanism of activation of MYB in human cancer involving gene fusion. We show that the t(6;9)(q22-23;p23-24) translocation in adenoid cystic carcinomas (ACC) of the breast and head and neck consistently results in fusions encoding chimeric transc...