Loss of von Hippel-Lindau protein causes cell density dependent deregulation of CyclinD1 expression through hypoxia-inducible factor.
Loss of the von Hippel-Lindau gene (VHL) expression ca-uses deregulation of contact inhibition of cell growth, which might be one of the bases of the tumor suppressor function of VHL. Here we show that this function of the VHL gene product (pVHL) depends on cell autonomous events. To identify the target gene of pVHL, which is directly involved in the contact inhibition, we compared the gene expression profile between VHL-deficient renal carcinoma 786-O cells and those infected with an adenovirus vector encoding VHL. In addition to known pVHL-regulated genes, such as vascular endothelial growth factor and carbonic anhydrase, we found cyclinD1 as a new target of pVHL at a high cell density. In VHL-expressing cells (VHL (+) cells), the cyclinD1 mRNA expression level diminishes at a high cell density, while it remains at a relatively high level in VHL-deficient cells (VHL (-) cells). The cyclinD1 expression level was also abnormally high in VHL (-) cells at a high cell density. Consequently, the phosporylation level of the retinoblastoma (Rb) protein remained high in these cells, whereas there was no phosporylated Rb in VHL (+) cells under the contact inhibition. The abnormal expression of cyclinD1 at a high cell density was observed even in VHL (+) cells under the hypoxic state. Moreover, ectopic expression of a HIF mutant resistant to pVHL-mediated proteolysis causes the abnormal cyclinD1 expression in VHL (+) cells. Taken together, these observations indicate that VHL is required for the downregulation of cyclinD1 at a high cell density through HIF.
Baba
Masaya
M
Department of Molecular Biology, Yokohama City University School of Medicine, 3-9, Fuko-ura, Kanazawaka-ku, Yokohama 236-0004, Japan.
Hirai
Syuiohi
S
Yamada-Okabe
Hisafumi
H
Hamada
Kenji
K
Tabuchi
Hisahiro
H
Kobayashi
Kazuki
K
Kondo
Keiichi
K
Yoshida
Minoru
M
Yamashita
Akio
A
Kishida
Takeshi
T
Nakaigawa
Noboru
N
Nagashima
Youji
Y
Kubota
Yoshinobu
Y
Yao
Masahiro
M
Ohno
Shigeo
S
D002256:Carbonic Anhydrases / Q000235:genetics; D002292:Carcinoma, Renal Cell; D002455:Cell Division / Q000235:genetics*; D015687:Cell Hypoxia / Q000235:genetics; D018920:Coculture Techniques; D019938:Cyclin D1 / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D016228:Endothelial Growth Factors / Q000235:genetics; D017353:Gene Deletion; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics; D007680:Kidney Neoplasms; D007700:Kinetics; D008025:Ligases / Q000172:deficiency / Q000235:genetics*; D008222:Lymphokines / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics*; D010766:Phosphorylation; D014157:Transcription Factors / Q000235:genetics; D014162:Transfection; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins; D044767:Ubiquitin-Protein Ligases; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D051794:Von Hippel-Lindau Tumor Suppressor Protein; D006623:von Hippel-Lindau Disease / Q000235:genetics*
D004268:DNA-Binding Proteins; D016228:Endothelial Growth Factors; C497442:HIF1A protein, human; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D036341:Intercellular Signaling Peptides and Proteins; D008222:Lymphokines; D009687:Nuclear Proteins; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D019938:Cyclin D1; D044767:Ubiquitin-Protein Ligases; D051794:Von Hippel-Lindau Tumor Suppressor Protein; D002256:Carbonic Anhydrases; D008025:Ligases; C497446:VHL protein, human