Tissue inhibitor of metalloproteinases-3 interacts with angiotensin II type 2 receptor and additively inhibits angiogenesis.
OBJECTIVE
The tissue inhibitors of metalloproteinases (TIMPs) are complex molecules with both pro- and anti-tumour effects. Thus, their diverse expression could be because of their multifunctional properties with respect to tumour growth, angiogenesis, apoptosis, and other biological functions. Previous data have shown that TIMPs bind tightly to most matrix metalloproteinases, although the pathway that mediates angiostatic activity has not been fully established.


RESULTS
As an initial step to elucidate the mechanism that regulates TIMP-3, we used a yeast two-hybrid system to screen a human ovary cDNA library for a novel TIMP-3-interacting partner. Here, we identified human angiotensin II type 2 receptor (AGTR2) as such a partner, which is well known to be a regulator of cardiovascular homoeostasis. In this present study, we investigated whether AGTR2-mediated apoptotic activity can inhibit the growth of ovarian cancer in an experimental model system. AGTR2 treatment was found to be more effective in inhibiting ovarian cancer growth than the treatment with TIMP-3 in parallel experiments. Subsequently, the efficacy of the combined treatment with TIMP-3 and AGTR2 was investigated. In the presence of both of these proteins, vascular endothelial growth factor-induced human umbilical vein endothelial cell proliferation was additively inhibited, and the inhibition of Akt and endothelial NO synthase phosphorylation was blocked.


CONCLUSIONS
These combined results suggest that two angiostatic molecules may have an important biological role in regulating potent anti-angiogenic effects and possibly may have a role in anti-tumour therapy.
Kang
Kyo-Hwa
KH
Molecular Therapy Research Center, Sungkyunkwan University, Samsung Medical Center Annex 8F, 50, Ilwon-Dong, Seoul 135-710, Republic of Korea.
Park
Sang-Yoon
SY
Rho
Seung Bae
SB
Lee
Je-Ho
JH
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002478:Cells, Cultured; D002642:Chick Embryo; D005260:Female; D006801:Humans; D009389:Neovascularization, Pathologic / Q000378:metabolism*; D018919:Neovascularization, Physiologic / Q000502:physiology*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D010051:Ovarian Neoplasms / Q000098:blood supply / Q000378:metabolism / Q000473:pathology; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D044139:Receptor, Angiotensin, Type 2 / Q000378:metabolism*; D019717:Tissue Inhibitor of Metalloproteinase-3 / Q000502:physiology*; D014471:Umbilical Veins / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism / Q000494:pharmacology
D044139:Receptor, Angiotensin, Type 2; D019717:Tissue Inhibitor of Metalloproteinase-3; D042461:Vascular Endothelial Growth Factor A; D052250:Nitric Oxide Synthase Type III; D051057:Proto-Oncogene Proteins c-akt