title: Identification of apoptotic tyrosine-phosphorylated proteins after etoposide or retinoic acid treatment.
abstract: A main shortcoming of using HL-60 cells as a model of granulocyte-macrophage differentiation is that some cells in the differentiating population undergo apoptosis. To address this issue, we have identified which tyrosine-phosphorylated proteins are involved in apoptosis and differentiation, respectively. HL-60 cells were induced specifically to undergo apoptosis with 68 microM etoposide, and to undergo granulocytic differentiation with 1 microM retinoic acid (RA). The corresponding two-dimensional electrophoretic maps of tyrosine-phosphorylated proteins from treated cells were compared. In the 8 h etoposide-treated HL-60 cell population, 83% of the cells were apoptotic. In the 120 h RA-treated cells, 50% of the cells were apoptotic. Eighteen cytosolic and nuclear tyrosine-phosphorylated proteins were found in both the 8 h etoposide- and the 120 h RA-treated cells, but not in the proliferating HL-60 cell population. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry analyses suggested that some of the proteins may be involved in signal transduction pathways (NFkappaB, GTP-binding protein, protein disulfide isomerase, Cyclophilin A), others in cell transcriptional and translational control (hnRNP H, hnRNP L, Hsp60, Hp1, Hcc-1, 26S proteasome beta-subunit, ATP synthase beta-chain), and a third group in cell cytoskeleton organization and receptor cycling (profilin, caveolin-1). An understanding of signal transduction in apoptosis initiation by screening for tyrosine-phosphorylated proteins associated with apoptosis may provide new targets for the treatment of leukemia.
authors.affiliation: Department of Developmental Biology, Institute of Biochemistry, Vilnius, Lithuania. ruta.navakauskiene@bchi.lt
authors.forename: Ruta
authors.initials: R
authors.lastname: Navakauskiene
authors.forename: Grazina
authors.initials: G
authors.lastname: Treigyte
authors.forename: Arunas
authors.initials: A
authors.lastname: Gineitis
authors.forename: Karl-Eric
authors.initials: KE
authors.lastname: Magnusson
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects*; D003599:Cytoskeleton / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D005047:Etoposide / Q000494:pharmacology*; D006098:Granulocytes / Q000166:cytology / Q000378:metabolism; D018922:HL-60 Cells; D006801:Humans; D008264:Macrophages / Q000166:cytology / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects*; D019000:Phosphotyrosine / Q000378:metabolism; D020543:Proteome; D015398:Signal Transduction / Q000187:drug effects; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014212:Tretinoin / Q000494:pharmacology*
chemical_list: D020543:Proteome; D019000:Phosphotyrosine; D014212:Tretinoin; D005047:Etoposide