A new ELISA for use in a 3-ELISA system to assess concentrations of VEGF splice variants and VEGF(110) in ovarian cancer tumors.
BACKGROUND
Vascular endothelial growth factor (VEGF), which affects tumor angiogenesis, is expressed as different splice variants, including the major isoforms VEGF(165) and VEGF(121), and can be cleaved by plasmin to generate VEGF(110). The amount of VEGF(121) and VEGF(110) in biological samples has not been well studied.


METHODS
We developed an ELISA that detects VEGF(165) and VEGF(121) equally, but does not detect VEGF(110). We used this ELISA together with 2 other ELISAs, one detecting VEGF(165) and the other detecting VEGF(165), VEGF(121), and VEGF(110) equally, to assess the concentrations of VEGF(121) and VEGF(110) in ovarian cancer tumors.


RESULTS
The median concentrations in ovarian cancer tumor lysates were 0.61 (range <0.055-74) fmol/mg protein for VEGF(165), 1.4 (range <0.20-500) fmol/mg protein for VEGF(165) plus VEGF(121), and 2.3 (range <0.079-520) fmol/mg protein for total VEGF including VEGF(110) (n = 248). VEGF concentrations measured by the 3 ELISAs were highly correlated (r = 0.91-0.94). Median estimated VEGF(121) and VEGF(110) concentrations were 0.77 and 0.58 fmol/mg protein, respectively. In lysates with measurable VEGF(165) and total VEGF concentrations, mean VEGF(165) was approximately 31% (SD 23%) of the total VEGF (n = 217). In contrast, VEGF(165) constituted approximately half of the total circulating VEGF.


CONCLUSIONS
VEGF(165), VEGF(121), and VEGF(110) may be present at significant amounts in ovarian cancer tumors.
Gutierrez
Johnny
J
Department of Assay and Automation Technology, Genentech Inc., South San Francisco, CA 94080, USA.
Konecny
Gottfried E
GE
Hong
Kyu
K
Burges
Alexander
A
Henry
Timothy D
TD
Lambiase
Pier D
PD
Lee Wong
Wai
W
Meng
Y Gloria
YG
D017398:Alternative Splicing; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D010051:Ovarian Neoplasms / Q000235:genetics*; D012680:Sensitivity and Specificity; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics*
D042461:Vascular Endothelial Growth Factor A