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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
20
pubmed:dateCreated
2001-6-22
pubmed:abstractText
Activated phosphoinositide 3-kinase (PI3K) and its downstream target Akt are essential for the fibroblast transformation induced by many viral products. Tax, encoded by human T-cell leukemia virus type I (HTLV-I), has been demonstrated to induce the transformation of rat fibroblast Rat-1 cell through NF-kappaB activation. By stable transfection of Rat-1 cells with expressing constructs of Tax and its mutant M47, which is defective in HTLV-I LTR transactivation, we selected their transformed clones, which have characteristics of NF-kappaB activation and colony formation beyond the cell monolayer (a malignant phenotype). However, these two characteristics in the transformed clones of Tax and M47 disappear after these cells have been treated with wortmannin, a specific inhibitor of PI3K. Further, increased activity of the PI3K/Akt is observed in the transformed clones of Tax and M47 as compared to the clones of empty vector Neo and the M148, which is defective in NF-kappaB activation and cell transformation. Increased activity of PI5K is present in the transformed clones of both Tax and M47 and in the M148 clone as compared to that in the Neo cell. It is known that the efficiency of Tax-induced cell transformation is not high; a minority of Tax-expressing clones show transformation, although the majority of Tax-expressing clones show activated NF-kappaB. A Tax-expressing, nontransformed clone after transfection with an active form of the catalytic subunit of PI3K, p110alpha, becomes transformed. Consistent with these results, a Tax highly-expressing human T-cell line MT2 exhibits both higher polyphosphoinositide turnover and higher activities of PI3K and PI5K than those of Jurkat or MT1 and HTLV-I-negative and a Tax-unexpressing cell line, respectively. These results demonstrate that the activation of the PI3K/Akt signaling pathway, excepting for the NF-kappaB, is also required for the cell transformation induced by Tax.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/AKT1 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Akt1 protein, rat, http://linkedlifedata.com/resource/pubmed/chemical/Androstadienes, http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Gene Products, tax, http://linkedlifedata.com/resource/pubmed/chemical/NF-kappa B, http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylinositol 3-Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylinositol Phosphates, http://linkedlifedata.com/resource/pubmed/chemical/Protein-Serine-Threonine Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Proto-Oncogene Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Proto-Oncogene Proteins c-akt, http://linkedlifedata.com/resource/pubmed/chemical/wortmannin
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0950-9232
pubmed:author
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
20
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2514-26
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:11420661-Androstadienes, pubmed-meshheading:11420661-Animals, pubmed-meshheading:11420661-Cell Line, pubmed-meshheading:11420661-Cell Transformation, Viral, pubmed-meshheading:11420661-Chromatography, High Pressure Liquid, pubmed-meshheading:11420661-Enzyme Activation, pubmed-meshheading:11420661-Enzyme Inhibitors, pubmed-meshheading:11420661-Fibroblasts, pubmed-meshheading:11420661-Gene Products, tax, pubmed-meshheading:11420661-Human T-lymphotropic virus 1, pubmed-meshheading:11420661-Humans, pubmed-meshheading:11420661-NF-kappa B, pubmed-meshheading:11420661-Phosphatidylinositol 3-Kinases, pubmed-meshheading:11420661-Phosphatidylinositol Phosphates, pubmed-meshheading:11420661-Protein-Serine-Threonine Kinases, pubmed-meshheading:11420661-Proto-Oncogene Proteins, pubmed-meshheading:11420661-Proto-Oncogene Proteins c-akt, pubmed-meshheading:11420661-Rats, pubmed-meshheading:11420661-Signal Transduction, pubmed-meshheading:11420661-Transfection
pubmed:year
2001
pubmed:articleTitle
Phosphoinositide-3 kinase-PKB/Akt pathway activation is involved in fibroblast Rat-1 transformation by human T-cell leukemia virus type I tax.
pubmed:affiliation
Department of Laboratory and Molecular Medicine, Faculty of Medicine, Kagoshima University, 8-35-1 Sakuragaka, Kagoshima, 890-8520, Japan.
pubmed:publicationType
Journal Article