Growing vascular endothelial cells express somatostatin subtype 2 receptors.
We hypothesized that non-proliferating (quiescent) human vascular endothelial cells would not express somatostatin receptor subtype 2 (sst 2) and that this receptor would be expressed when the endothelial cells begin to grow. To test this hypothesis, placental veins were harvested from 6 human placentas and 2 mm vein disks were cultured in 0.3% fibrin gels. Morphometric analysis confirmed that 50-75% of cultured vein disks developed radial capillary growth within 15 days. Sst 2 gene expression was determined by reverse transcription-polymerase chain reaction (RT-PCR) analysis of the RNA from veins before culture and from tissue-matched vein disks that exhibited an angiogenic response. The sst 2 gene was expressed in the proliferating angiogenic sprouts of human vascular endothelium. The presence of sst 2 receptors on proliferating angiogenic vessels was confirmed by immunohistochemical staining and in vivo scintigraphy. These results suggest that sst 2 may be a unique target for antiangiogenic therapy with sst 2 preferring somatostatin analogues conjugated to radioisotopes or cytotoxic agents.
Watson
J C
JC
Departments of Surgery, Ophthalmology, Radiology, The Stanley S. Scott Cancer Center, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, USA.
Balster
D A
DA
Gebhardt
B M
BM
O'Dorisio
T M
TM
O'Dorisio
M S
MS
Espenan
G D
GD
Drouant
G J
GJ
Woltering
E A
EA
D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D046508:Culture Techniques; D017931:DNA Primers; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D008819:Mice, Nude; D018919:Neovascularization, Physiologic; D017481:Receptors, Somatostatin / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D017931:DNA Primers; D017481:Receptors, Somatostatin; C093733:somatostatin receptor 2