Phosphorylation of signaling proteins in factor-independent myeloid leukemia cell lines

  • Authors:
    • S Tohda
    • N Nara
  • View Affiliations

  • Published online on: October 1, 1997     https://doi.org/10.3892/ijo.11.4.843
  • Pages: 843-847
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Abstract

We investigated the mechanisms of factor-independent growth of four human myeloid leukemia cell lines. The autocrine mechanisms were ruled out by RT-PCR method examining growth factor mRNA. The immunoblotting method showed that many proteins were tyrosine phosphorylated irrespective of the stimulation with growth factors (G-CSF and GM-CSF) in factor-independent cell lines while the phosphorylation was induced stimulation dependently in a factor-dependent cell line. MAP kinase was constitutively phosphorylated in factor-independent cell lines. JAK2 protein was not tyrosine phosphorylated before the stimulation. It was significantly phosphorylated after the stimulation in three factor-independent cell lines although the stimulation did not affect their growth. JAK1 protein was not phosphorylated either before or after the stimulation. In conclusion, constitutive phosphorylation of signaling proteins seemed to be related to factor-independent growth. MAP kinase was involved in the phosphorylation, while JAK1 and JAK2 were not.

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October 1997
Volume 11 Issue 4

Print ISSN: 1019-6439
Online ISSN:1791-2423

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Spandidos Publications style
Tohda S and Tohda S: Phosphorylation of signaling proteins in factor-independent myeloid leukemia cell lines. Int J Oncol 11: 843-847, 1997
APA
Tohda, S., & Tohda, S. (1997). Phosphorylation of signaling proteins in factor-independent myeloid leukemia cell lines. International Journal of Oncology, 11, 843-847. https://doi.org/10.3892/ijo.11.4.843
MLA
Tohda, S., Nara, N."Phosphorylation of signaling proteins in factor-independent myeloid leukemia cell lines". International Journal of Oncology 11.4 (1997): 843-847.
Chicago
Tohda, S., Nara, N."Phosphorylation of signaling proteins in factor-independent myeloid leukemia cell lines". International Journal of Oncology 11, no. 4 (1997): 843-847. https://doi.org/10.3892/ijo.11.4.843