Malignant ascites fluid (MAF), including ovarian-cancer-associated MAF, contains angiostatin and other factor(s) which inhibit angiogenesis.
OBJECTIVE
The aim was to determine whether human malignant ascites fluid (MAF) associated with abdominal cancer, including ovarian cancer, contained factors which inhibit angiogenesis as well as others which stimulate this process.


METHODS
MAF was collected from six patients, four with ovarian cancer, one with gastric cancer, and one with liver metastases. Using the chick chorioallantoic membrane (CAM) the effect of MAF on 7-day-old CAM capillaries was examined for 48 h. Vascular endothelial growth factor (VEGF) was evaluated by ELISA. Five samples of MAF were fractionated by lysine-Sepharose chromatography and the lysine-bound and -unbound fractions were eluted by epsilon-amino-n-hexanoic acid. Whole MAF, the lysine-bound and -unbound fractions, and human angiostatin were subjected to SDS-PAGE/Western blot analysis and immunostained after exposure to anti-human plasminogen. Human plasminogen was exposed to conditioned medium from ovarian epithelial cancer (HEY) cells and subjected to similar Western blot analysis.


RESULTS
Despite containing VEGF, each MAF sample examined caused a loss of capillaries from the CAM; a similar response was seen using purified human angiostatin. Whole MAF and the lysine-bound fraction contained plasminogen (90 kDa) and a 55-kDa protein which migrated in a similar manner to human angiostatin on Western blot. Both the lysine-bound and -unbound fractions caused a loss of capillaries in the CAM. Human plasminogen exposed to conditioned medium from HEY cells yielded a fragment which was similar in size to angiostatin.


CONCLUSIONS
MAF from patients with various clinical presentations contains angiostatin and VEGF as well as other factors which are capable of inhibiting angiogenesis.
Richardson
M
M
Cancer Care Ontario, Hamilton Regional Cancer Centre, 699 Concession Street, Hamilton, Ontario L8V 5C2, Canada.
Gunawan
J
J
Hatton
M W C
MW
Seidlitz
E
E
Hirte
H W
HW
Singh
G
G
D000328:Adult; D000368:Aged; D000482:Allantois / Q000098:blood supply / Q000187:drug effects; D020533:Angiogenesis Inhibitors / Q000032:analysis* / Q000378:metabolism / Q000494:pharmacology; D043168:Angiostatins; D000818:Animals; D001202:Ascitic Fluid / Q000737:chemistry* / Q000201:enzymology / Q000378:metabolism; D015153:Blotting, Western; D002642:Chick Embryo; D002823:Chorion / Q000098:blood supply / Q000187:drug effects; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000032:analysis / Q000378:metabolism; D016228:Endothelial Growth Factors / Q000032:analysis; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism / Q000556:secondary; D008222:Lymphokines / Q000032:analysis; D008875:Middle Aged; D018919:Neovascularization, Physiologic / Q000187:drug effects; D010051:Ovarian Neoplasms / Q000378:metabolism*; D010446:Peptide Fragments / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D010958:Plasminogen / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D013274:Stomach Neoplasms / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D020533:Angiogenesis Inhibitors; D016228:Endothelial Growth Factors; D008222:Lymphokines; D010446:Peptide Fragments; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D043168:Angiostatins; D010958:Plasminogen; D010450:Endopeptidases