KIS induces proliferation and the cell cycle progression through the phosphorylation of p27Kip1 in leukemia cells.
CEM, MOLT4 and SUP-B15 cells were transduced with lentivirus-mediated siRNA KIS gene. The mRNA expressions of KIS were successfully reduced in all cell lines. On the other hand, the mRNA expressions of p27(Kip1) in CEM, MOLT4 and SUP-B15 cells were not affected by the transduction with siRNA KIS gene. We showed that KIS protein directly interacted with p27(Kip1) protein, and reduction of KIS inhibited the S10 phosphorylation of p27(Kip1) in leukemia cells. On these cells transfected with siRNA KIS, the inhibition of S10 phosphorylation of p27(Kip1) was strongly suppressed cell proliferation in a time-dependent manner. Moreover, the inhibition of S10 phosphorylation of p27(Kip1) increased a significant population in G0/G1 fraction. These data demonstrated that the KIS activity was induced during G0/G1, and it promotes cell cycle progression by phosphorylation of S10 on p27(Kip1). We showed that KIS mRNA expression was increased in primary leukemia specimens (acute myelogenous leukemia (AML); 37, myelodysplastic syndrome (MDS); 72, acute lymphoblastic leukemia (ALL); 23), and the mean ratios of KIS to G3PDH in AML, MDS and ALL specimens were 3.62+/-0.68, 3.27+/-0.73 and 3.17+/-0.58, respectively. Moreover, we found that KIS protein was overexpressed in all 132 adults cases of various leukemias, including 37 AML (8 M1, 12 M2, 2 M3, 7 M4, 8 M5), 72 MDS (42 RAEB-I, 30 REAB-II) and 23 ALL (23 L2). This study demonstrates that the elevated levels of KIS protein in leukemia cells promote the cell cycle progression in leukemia cells.
Nakamura
Satoki
S
Department of Internal Medicine III, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka 431-3192, Japan. satonaka@hama-med.ac.jp
Okinaka
Keiji
K
Hirano
Isao
I
Ono
Takaaki
T
Sugimoto
Yuya
Y
Shigeno
Kazuyuki
K
Fujisawa
Shinya
S
Shinjo
Kaori
K
Ohnishi
Kazunori
K
D000328:Adult; D000368:Aged; D015153:Blotting, Western; D001853:Bone Marrow / Q000378:metabolism / Q000473:pathology; D002453:Cell Cycle / Q000502:physiology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D050760:Cyclin-Dependent Kinase Inhibitor p27; D006801:Humans; D047468:Immunoprecipitation; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D015470:Leukemia, Myeloid, Acute / Q000235:genetics / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000378:metabolism / Q000473:pathology; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction
C436291:CDKN1B protein, human; D047908:Intracellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D050760:Cyclin-Dependent Kinase Inhibitor p27; D017346:Protein Serine-Threonine Kinases; C530658:UHMK1 protein, human