title: Down-Regulation of Ribosomal S6 kinase RPS6KA6 in Acute Myeloid Leukemia Patients.
abstract: OBJECTIVE
  Signaling pathways such as extracellular regulated kinase/mitogen activated protein kinase (ERK/MAPK) have increased activity in leukemia. Ribosomal 6 kinase (RSK4) is a factor downstream of the MAPK/ERK pathway and an important tumor suppressor which inhibits ERK trafficking. Decrease in RSK4 expression has been reported in some malignancies, which leads to an increase in growth and proliferation and eventually poor prognosis. In this study we measured RSK4 expression rate in acute myeloid leukemia (AML).
  
  
  METHODS
  This cross-sectional study was undertaken in 2013-2014 at Ghaem Hospital in Mashhad, Iran, on 40 AML patients and 10 non-AML patients as the control group. The expression rate was measured by real-time polymerase change reaction (PCR) and employing the ΔΔCT method. Data were analyzed using Mann-Whitney and Spearman tests using SPSS (version 11.5).
  
  
  RESULTS
  Expression rate of RSK4 was significantly decreased in the AML group in comparison with the non-AML group (P<0.001). There was also a significant decrease in RSK4 expression in AML with t(15;17) in comparison to other translocations (P=0.004).
  
  
  CONCLUSIONS
  We detected a down-regulation of RSK4 in AML patients. This may lead to an increase in the activity of the ERK/MPAK pathway and exacerbate leukemogenesis or the prognosis of the patients.
authors.affiliation: Hematology Lab, Imam Reza Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Rafiee
authors.affiliation: Cancer Molecular Pathology Research Center, Ghaem Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Keramati
authors.affiliation: Cancer Molecular Pathology Research Center, Ghaem Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Hosein
authors.initials: H
authors.lastname: Ayatollahi
authors.affiliation: Cancer Molecular Pathology Research Center, Ghaem Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Mohammad Hadi
authors.initials: MH
authors.lastname: Sadeghian
authors.affiliation: Hematology Lab, Imam Reza Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Mohieddin
authors.initials: M
authors.lastname: Barzegar
authors.affiliation: Hematology Lab, Imam Reza Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Asgharzadeh
authors.affiliation: Hematology Lab, Imam Reza Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Alinejad
keywords: Acute Myeloid Leukemia; Extracellular Signal-Regulated Kinase; Gene Expression; Mitogen Activated Protein Kinase; Ribosomal Protein S6 Kinase