Nancy L. DiFronzo

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Glucocorticoids regulate gene expression via binding of the ligand-activated glucocorticoid receptor (GR) to glucocorticoid-responsive elements (GRE) in target gene promoters. The MUC5AC gene, which encodes the protein backbone of an abundant secreted airway mucin, has several putative GRE cis-elements in its 5' sequence. Mechanism(s) whereby(More)
The human cytomegalovirus (HCMV) UL36-38 immediate early (IE) locus encodes proteins required for its growth. The UL37 promoter drives production of an unspliced and several alternatively spliced RNAs. The UL37 exon 1 (UL37x1) unspliced RNA is abundant from IE to late times of HCMV infection, whereas the UL37 spliced RNAs are markedly less abundant.(More)
Chickens of Regional Poultry Research Laboratory (RPRL) inbred line 63 regress sarcomas induced by Bryan high-titer Rous sarcoma virus to a greater extent than chickens of line RPRL 100, although these lines are identical for the major histocompatibility B complex. They differ, however, at three independent autosomal loci: Ly-4 and Th-1 determine the(More)
We analyzed viral recombination events that occur during the preleukemic period in AKR mice. We tagged a molecular chimera between the nonleukemogenic virus Akv and the leukemogenic mink cell focus-inducing (MCF) virus MCF 247 with an amber suppressor tRNA gene, supF. We injected the supF-tagged chimeric virus that contains all of the genes of MCF 247(More)
Mink cell focus-inducing (MCF) viruses induce T-cell lymphomas in AKR/J strain mice. MCF 247, the prototype of this group of nonacute murine leukemia viruses, transforms thymocytes, in part, by insertional mutagenesis and enhancer-mediated dysregulation of cellular proto-oncogenes. The unique 3' (U3) regions in the long terminal repeats of other murine(More)
DESIGN Infection of the human promyelocytic cell line HL-60 with NL4-3, a molecularly cloned HIV-1 strain that productively infects T cells, results in adaptation of the virus and production of a variant, NL4-3(M). Unlike NL4-3, NL4-3(M) has a rapid cytopathic effect in HL-60 and other myeloid cell lines. OBJECTIVE To demonstrate that the tropism of(More)
The oncogenic potential of many nonacute retroviruses is dependent on the duplication of the enhancer sequences present in the unique 3' (U3) region of the long terminal repeat (LTR). In a molecular clone (MCF 247-W) of the murine leukemia virus MCF 247, a leukemogenic mink cell focus-inducing (MCF) virus, the U3 enhancer sequences are tandemly repeated in(More)
We report here the construction of a new packaging cell line, called MPAC, that packages defective retroviral vectors in viral particles with envelope proteins derived from a Moloney mink cell focus-inducing (MCF) polytropic virus. We characterized the tropism of MPAC-packaged retroviral vectors and show that some human cell lines can be infected with these(More)
Murine leukemia viruses (MuL V) are retroviruses that play important roles in the study of oncogenes, integration, transcriptional regulation and gene therapy. Mink cell focusinducing (MCF) viruses are polytropic MuL V s that by definition infect cells from a wide variety of species. Their ability to infect human cells and their utility as gene therapy(More)
The ability of mink cell focus-inducing (MCF) viruses to induce thymomas is determined, in part, by transcriptional enhancers in the U3 region of their long terminal repeats (LTRs). To elucidate sequence motifs important for enhancer function in vivo, we injected newborn mice with MCF 1dr (supF), a weakly pathogenic, molecularly tagged (supF) MCF virus(More)
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