The THAP-zinc finger protein THAP1 regulates endothelial cell proliferation through modulation of pRB/E2F cell-cycle target genes.
We recently cloned a novel human nuclear factor (designated THAP1) from postcapillary venule endothelial cells (ECs) that contains a DNA-binding THAP domain, shared with zebrafish E2F6 and several Caenorhabditis elegans proteins interacting genetically with retinoblastoma gene product (pRB). Here, we show that THAP1 is a physiologic regulator of EC proliferation and cell-cycle progression, 2 essential processes for angiogenesis. Retroviral-mediated gene transfer of THAP1 into primary human ECs inhibited proliferation, and large-scale expression profiling with microarrays revealed that THAP1-mediated growth inhibition is due to coordinated repression of pRB/E2F cell-cycle target genes. Silencing of endogenous THAP1 through RNA interference similarly inhibited EC proliferation and G1/S cell-cycle progression, and resulted in down-regulation of several pRB/E2F cell-cycle target genes, including RRM1, a gene required for S-phase DNA synthesis. Chromatin immunoprecipitation assays in proliferating ECs showed that endogenous THAP1 associates in vivo with a consensus THAP1-binding site found in the RRM1 promoter, indicating that RRM1 is a direct transcriptional target of THAP1. The similar phenotypes observed after THAP1 overexpression and silencing suggest that an optimal range of THAP1 expression is essential for EC proliferation. Together, these data provide the first links in mammals among THAP proteins, cell proliferation, and pRB/E2F cell-cycle pathways.
Cayrol
Corinne
C
Laboratoire de Biologie Vasculaire, Equipe labellisée La Ligue 2006, Institut de Pharmacologie et de Biologie Structurale, Centre National de la Recherche Scientifique Unité mixte de recherche, Toulouse, France.
Lacroix
Chrystelle
C
Mathe
Catherine
C
Ecochard
Vincent
V
Ceribelli
Michele
M
Loreau
Emilie
E
Lazar
Vladimir
V
Dessen
Philippe
P
Mantovani
Roberto
R
Aguilar
Luc
L
Girard
Jean-Philippe
JP
D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D001483:Base Sequence; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D004247:DNA / Q000096:biosynthesis; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics; D050684:E2F Transcription Factors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D016193:G1 Phase / Q000502:physiology; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000235:genetics / Q000502:physiology*; D018816:Genes, cdc / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016160:Retinoblastoma Protein / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D012262:Ribonucleoside Diphosphate Reductase; D016196:S Phase / Q000187:drug effects / Q000502:physiology; D025521:Tumor Suppressor Proteins / Q000235:genetics
D051017:Apoptosis Regulatory Proteins; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D009687:Nuclear Proteins; D012333:RNA, Messenger; D016160:Retinoblastoma Protein; C474080:THAP1 protein, human; D025521:Tumor Suppressor Proteins; D004247:DNA; C475286:RRM1 protein, human; D012262:Ribonucleoside Diphosphate Reductase