Cyclin E overexpression responsible for growth of human hepatic tumors with p21WAF1/CIP1/SDI1.
We examined a relationship between p21WAF1/CIP1/SDI1 and cell-cycle-related proteins in 12 human liver tumor cell lines (JHH-1, -2, -4, -5, -6, -7; HLE; HuH-7; Hep3B; PLC/PRF/5; HuH-6; HepG2). Seven (JHH-1, -2, -5, -6, -7; Hep3B; HepG2) out of eight cell lines having p21WAF1/CIP1/SDI1 protein overexpressed cyclin E protein, although one of them (JHH-5) overexpressed a reduced size of cyclin E. The rest (HuH-6) of the 8 cell lines with p21WAF1/CIP1/SDI1 showed a decreased expression of cyclin E. Four cell lines (JHH-4; HLE; HuH-7; PLC/PRF/5) deficient of p21WAF1/CIP1/SDI1 protein did not overexpress cyclin E protein. As to expression of the other cell-cycle-related proteins, cyclin A, cyclin D1, CDK2 or CDK4, no significant difference was detected among the 12 cell lines. These findings indicate that the human liver tumor cell lines which have the p21WAF1/CIP1/SDI1-inducible barriers of the cell cycle progression can go through the G1/S checkpoint by overexpressing cyclin E.
Tsuji
T
T
Department of Cell Biology, Institute of Molecular and Cellular Biology, Okayama University Medical School.
Miyazaki
M
M
Fushimi
K
K
Mihara
K
K
Inoue
Y
Y
Ohashi
R
R
Ohtsubo
M
M
Hamazaki
K
K
Furusako
S
S
Namba
M
M
D015152:Blotting, Northern; D015139:Blotting, Southern; D015153:Blotting, Western; D042846:CDC2-CDC28 Kinases; D002453:Cell Cycle / Q000235:genetics / Q000502:physiology; D019927:Cyclin E / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D051357:Cyclin-Dependent Kinase 2; D051358:Cyclin-Dependent Kinase 4; D050759:Cyclin-Dependent Kinase Inhibitor p21; D018844:Cyclin-Dependent Kinases / Q000032:analysis / Q000378:metabolism; D016213:Cyclins / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D016158:Genes, p53 / Q000235:genetics; D006801:Humans; D007700:Kinetics; D008113:Liver Neoplasms / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000032:analysis / Q000378:metabolism; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger / Q000032:analysis; D016160:Retinoblastoma Protein / Q000378:metabolism; D014407:Tumor Cells, Cultured
C493956:CDKN1A protein, human; D019927:Cyclin E; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D016160:Retinoblastoma Protein; D017346:Protein Serine-Threonine Kinases; D042846:CDC2-CDC28 Kinases; C495894:CDK2 protein, human; C495900:CDK4 protein, human; D051357:Cyclin-Dependent Kinase 2; D051358:Cyclin-Dependent Kinase 4; D018844:Cyclin-Dependent Kinases