Document 0506
 DOCN  M9460506
 TI    Human immunodeficiency virus 1 Tat stimulates transcription of the
       transforming growth factor alpha gene in an epidermal growth
       factor-dependent manner.
 DT    9404
 AU    Nabell LM; Raja RH; Sayeski PP; Paterson AJ; Kudlow JE; Department of
       Medicine, University of Alabama at Birmingham; 35294.
 SO    Cell Growth Differ. 1994 Jan;5(1):87-93. Unique Identifier : AIDSLINE
       MED/94169084
 AB    The human immunodeficiency virus 1 (HIV-1) tat gene encodes a protein of
       critical importance for viral transcription. In addition, Tat has been
       shown capable of entering cells, stimulating cell proliferation, and
       altering host cell gene expression. We examined the effect of Tat on the
       expression of the transforming growth factor alpha (TGF-alpha) gene in
       MDA468 human breast carcinoma cells. We showed that these cells were
       capable of supporting the activation of the HIV-1 long terminal repeat
       by Tat. Then, in cotransfection assays, in which the TGF-alpha promoter
       was linked to a luciferase reporter gene and the tat gene was expressed
       under the control of the SV40 early promoter, we showed that tat gene
       expression increased TGF-alpha-luciferase reporter function but only in
       cells stimulated with epidermal growth factor (EGF). The effects of tat
       and EGF were dose dependent. To confirm these cotransfection data, Tat
       was expressed in Escherichia coli as a fusion protein with
       glutathione-S-transferase (GST) and purified on glutathione-agarose.
       GST-Tat was introduced into the MDA468 cells either in the presence of
       chloroquine or by scrape loading. The biological activity of GST-Tat was
       tested on cells that had been stablely transfected with the HIV-1 long
       terminal repeat linked to luciferase as a reporter. GST-Tat was then
       introduced into the cells, and the level of TGF-alpha mRNA was
       determined.(ABSTRACT TRUNCATED AT 250 WORDS)
 DE    Epidermal Growth Factor-Urogastrone/*GENETICS  Female  Gene Products,
       tat/GENETICS/*PHYSIOLOGY  Genes, ras/GENETICS/PHYSIOLOGY  Genes,
       Reporter/GENETICS/PHYSIOLOGY  Human  HIV-1/*GENETICS
       Luciferase/GENETICS/METABOLISM  Plasmids  RNA, Messenger/METABOLISM
       Support, U.S. Gov't, P.H.S.  Time Factors  Transcription,
       Genetic/*GENETICS  Transforming Growth Factor alpha/*GENETICS/METABOLISM
       Tumor Cells, Cultured  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).