HEX acts as a negative regulator of angiogenesis by modulating the expression of angiogenesis-related gene in endothelial cells in vitro.
OBJECTIVE
The hematopoietically expressed homeobox (HEX) is transiently expressed in endothelial cells (ECs) during vascular formation in embryo. Here, we investigated whether HEX played any role in angiogenesis-related properties of ECs in vitro.


RESULTS
We transiently overexpressed HEX in human umbilical vein ECs (HUVECs). To our surprise, HEX completely abrogated the response of HUVECs to vascular endothelial growth factor (VEGF) with regard to proliferation, migration, and invasion and abolished network formation by HUVECs on Matrigel. cDNA microarray analysis and quantitative real-time reverse transcription-polymerase chain reaction combined with Western blotting revealed that HEX significantly repressed the expression of VEGF receptor-1, VEGF receptor-2, neuropilin-1, tyrosine kinase with Ig and EGF homology domains (TIE)-1, TIE-2, and the integrin alpha(v) subunit, whereas it augmented the expression of endoglin in HUVECs. We established murine embryonic stem cells that were stably transfected with HEX sense cDNA or antisense cDNA, and we examined the in vitro differentiation to ECs. Although the expression of VEGF receptor-2 was decreased in sense transfectants, the number of cells expressing VE-cadherin, a specific marker of ECs, was not altered.


CONCLUSIONS
Our present results suggest that HEX may not affect the differentiation of ECs but acts as a negative regulator of angiogenesis.
Nakagawa
Tomowaki
T
Department of Vascular Biology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.
Abe
Mayumi
M
Yamazaki
Tohru
T
Miyashita
Hiroki
H
Niwa
Hitoshi
H
Kokubun
Shoichi
S
Sato
Yasufumi
Y
D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D002460:Cell Line; D002465:Cell Movement / Q000235:genetics; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000737:chemistry / Q000166:cytology* / Q000378:metabolism; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D005796:Genes / Q000235:genetics; D005801:Genes, Homeobox / Q000502:physiology; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D008565:Membrane Proteins / Q000276:immunology / Q000378:metabolism; D051379:Mice; D018919:Neovascularization, Physiologic / Q000235:genetics* / Q000502:physiology*; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology; D014471:Umbilical Veins / Q000737:chemistry / Q000166:cytology / Q000378:metabolism
D018398:Homeodomain Proteins; D008565:Membrane Proteins; D012333:RNA, Messenger; D014157:Transcription Factors