These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Essential contribution of Ets-1 to constitutive Pim-3 expression in human pancreatic cancer cells.
    Author: Li YY, Wu Y, Tsuneyama K, Baba T, Mukaida N.
    Journal: Cancer Sci; 2009 Mar; 100(3):396-404. PubMed ID: 19154409.
    Abstract:
    We previously demonstrated that the proto-oncogene Pim-3 with serine/threonine kinase activity was aberrantly expressed in cancer cells but not in the normal cells of the pancreas. In order to elucidate the molecular mechanism underlying aberrant Pim-3 expression in pancreatic cancer cells, we constructed luciferase expression vectors linked to 5'-flanking deletion mutants of the human Pim-3 gene and transfected human pancreatic cancer cells with the resultant vectors. The region up to -264 bp was essential for constitutive Pim-3 gene expression, and the mutation in the Ets-1 binding site (between -216 and -211 bp) reduced luciferase activities. Moreover, Ets-1 mRNA and protein were constitutively expressed together with Pim-3 in human pancreatic cancer cell lines. Chromatin immunoprecipitation assay demonstrated constitutive binding of Ets-1 to the 5'-flanking region of human Pim-3 gene between -249 and -183 bp. Pim-3 promoter activity and its protein expression were induced by transfection with wild type-Ets-1 and were reduced by transfection with dominant negative-Ets-1 or Ets-1 small-interfering RNA (siRNA). Furthermore, dominant negative-Ets-1 and Ets-1 siRNA reduced the amount of Bad phosphorylated at its Ser(112) and induced apoptosis, when they were transfected into human pancreatic cancer cells. Finally, Pim-3 cDNA transfection reversed Ets-1 siRNA-induced increase in apoptosis and decrease in Bad phosphorylation at its Ser(112). These observations would indicate that the transcription factor Ets-1 can induce aberrant Pim-3 expression and subsequently prevent apoptosis in human pancreatic cancer cells.
    [Abstract] [Full Text] [Related] [New Search]