A hypoxic response induced in MatLyLu cells by cobalt chloride results in an enhanced angiogenic response by the chick chorioallantoic membrane.
Hypoxia is an important regulator of hypoxia inducible factor-1alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF) expression. Using Dunning rat prostate tumour cells (MatLyLu) we examined the induction of HIF-1alpha and VEGF by hypoxia and if the induction of these proteins would lead to angiogenesis in the chick chorioallantoic membrane (CAM). MatLyLu cells were exposed to 1% O2, in 5.25% CO2 and 94.75% N2, or treated with 100 mM CoCl2 to simulate hypoxia. Conditioned medium was analyzed using Western blots for HIF-1alpha or VEGF. VEGF levels were quantified using ELISA. Hypoxia significantly increased both HIF-1alpha and VEGF protein production. MatLyLu cells (1x10(6) viable cells in 50 microl of medium) grown under normoxic conditions induced in angiogenesis in the CAM, evaluated by the formation of a spoke wheel, and in cross sections by the number of blood vessels, following 5-day culture. This response was significantly increased using CoCl2-treated cells. Culture medium alone with or without CoCl2 was not angiogenic. These results provide direct evidence for the role of hypoxia in the induction of HIF-1alpha and VEGF which act as key angiogenic signals.
Van Lieshout
T
T
Department of Pathology and Molecular Medicine, McMaster University, Hamilton Regional Cancer Centre, Hamilton, Ontario L8V 5C2, Canada.
Stanisz
J
J
Espiritu
V
V
Richardson
M
M
Singh
G
G
D000818:Animals; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002642:Chick Embryo; D002823:Chorion / Q000378:metabolism*; D003035:Cobalt / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay; D000860:Hypoxia; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D008297:Male; D018715:Microscopy, Video; D009389:Neovascularization, Pathologic; D011471:Prostatic Neoplasms / Q000473:pathology; D051381:Rats; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis / Q000378:metabolism
D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; D042461:Vascular Endothelial Growth Factor A; D003035:Cobalt; C018021:cobaltous chloride