| Title | Mechanism for the decrease in the FIP1L1-PDGFRalpha protein level in EoL-1 cells by histone deacetylase inhibitors. | | Author(s) | Ishihara K, Kaneko M, Kitamura H, Takahashi A, Hong JJ, Seyama T, Iida K, Wada H, Hirasawa N, Ohuchi K | | Institution | Laboratory of Pathophysiological Biochemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan. ishihara@wadalab.mech.tohoku.ac.jp | | Source | Int Arch Allergy Immunol 2008.:7-10. | | Abstract | BACKGROUND: Acetylation and deacetylation of proteins occur in cells in response to various stimuli, and are reversibly catalyzed by histone acetyltransferase and histone deacetylase (HDAC), respectively. EoL-1 cells have an FIP1L1-PDGFRA fusion gene that causes transformation of eosinophilic precursor cells into leukemia cells. The HDAC inhibitors apicidin and n-butyrate suppress the proliferation of EoL-1 cells and induce differentiation into eosinophils by a decrease in the protein level of FIP1L1-PDGFRalpha without affecting the mRNA level for FIP1L1-PDGFRA. In this study, we analyzed the mechanism by which the protein level of FIP1L1-PDGFRalpha is decreased by apicidin and n-butyrate.
METHODS: EoL-1 cells were incubated in the presence of the HDAC inhibitors apicidin, trichostatin A or n-butyrate. The protein levels of FIP1L1-PDGFRalpha and phosphorylated eIF-2alpha were determined by Western blotting. Actinomycin D and cycloheximide were used to block RNA synthesis and protein synthesis, respectively, in the chasing experiment of the amount of FIP1L1-PDGFRalpha protein.
RESULTS: When apicidin- and n-butyrate-treated EoL-1 cells were incubated in the presence of actinomycin D, the decrease in the protein level of FIP1L1-PDGFRalpha was significantly enhanced when compared with controls. In contrast, the protein levels were not changed by cycloheximide among these groups. Apicidin and n-butyrate induced the continuous phosphorylation of eIF-2alpha for up to 8 days.
CONCLUSIONS: The decrease in the level of FIP1L1-PDGFRalpha protein by continuous inhibition of HDAC may be due to the decrease in the translation rate of FIP1L1-PDGFRA. | | Language | eng | | Pub Type(s) | Journal Article
Research Support, Non-U.S. Gov't
| | PubMed ID | 18504399 |
|
