Lymphocyte transformation by Pim-2 is dependent on nuclear factor-kappaB activation

Cancer Res. 2004 Nov 15;64(22):8341-8. doi: 10.1158/0008-5472.CAN-04-2284.

Abstract

Pim-2 is a transcriptionally regulated oncogenic kinase that promotes cell survival in response to a wide variety of proliferative signals. Deregulation of Pim-2 expression has been documented in several human malignancies, including leukemia, lymphoma, and multiple myeloma. Here, we show that the ability of Pim-2 to promote survival of cells is dependent on nuclear factor (NF)-kappaB activation. Pim-2 activates NF-kappaB-dependent gene expression by inducing phosphorylation of the oncogenic serine/threonine kinase Cot, leading to both augmentation of IkappaB kinase activity and a shift in nuclear NF-kappaB from predominantly p50 homodimers to p50/p65 heterodimers. Blockade of NF-kappaB function eliminates Pim-2-mediated survival in both cell lines and primary cells, and both Cot phosphorylation and expression are required for the prosurvival effects of Pim-2. Although Pim-2 cooperates with Myc to promote growth factor-independent cell proliferation, this feature is abrogated by NF-kappaB blockade. The ability of Pim-2 to serve as an oncogene in vivo depends on sustained NF-kappaB activity. Thus, the transcriptional induction of Pim-2 initiates a novel NF-kappaB activation pathway that regulates cell survival.

MeSH terms

  • Animals
  • Base Sequence
  • DNA Primers
  • Electrophoretic Mobility Shift Assay
  • Humans
  • Hydrolysis
  • I-kappa B Proteins / metabolism
  • Jurkat Cells
  • Lymphocyte Activation / physiology*
  • Mice
  • Mice, Transgenic
  • NF-kappa B / metabolism*
  • Phosphorylation
  • Protein Serine-Threonine Kinases / physiology*
  • Proto-Oncogene Proteins / physiology*

Substances

  • DNA Primers
  • I-kappa B Proteins
  • NF-kappa B
  • Pim2 protein, mouse
  • Proto-Oncogene Proteins
  • Protein Serine-Threonine Kinases