The reduction in pigment epithelium-derived factor is a sign of malignancy in ovarian cancer expressing low-level of vascular endothelial growth factor.
BACKGROUND
Angiogenesis is a critical factor in the progression of solid tumors and metastasis. The aim of this study was to characterise the roles of angiogenic and anti-angiogenic factors on ovarian cancer.


METHODS
The expression levels of vascular endothelial growth factor (VEGF, angiogenic factor) and pigment epithelial growth factor (PEDF, anti-angiogenic factor) were measured by real-time polymerase chain reaction and Western blotting in ovarian tumors. Microvessel density (MVD) was evaluated by the total microvessel length in high-power field of tumor tissue preparations.


RESULTS
MVD correlated with tumor malignancy. The tissues with the highest expression levels of VEGF (VEGF-H) were malignant tumors. The VEGF expression levels in some malignant tumors (VEGF-L) were as low as that in benign tumors. Therefore, the expression of PEDF was examined. The PEDF expression levels in VEGF-L malignant tumors were significantly lower than those in benign tumors. On the other hand, the PEDF expression levels in VEGF-H malignant tumor tissues were not significantly different from those in benign tumors.


CONCLUSIONS
The reduction in PEDF expression levels may be, in part, responsible for tumor malignancy in VEGF-L ovarian tumors. Furthermore, PEDF may be a useful marker of malignancy in VEGF-L ovarian tumors.
Tsuchiya
Takehiko
T
Department of Cellular Physiological Chemistry, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
Nakahama
Ken-Ichi
K
Asakawa
Yasuyuki
Y
Maemura
Toshimitu
T
Tanaka
Masanobu
M
Takeda
Satoru
S
Morita
Mineto
M
Morita
Ikuo
I
D018262:Adenocarcinoma, Clear Cell / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology; D002288:Adenocarcinoma, Mucinous / Q000098:blood supply / Q000473:pathology* / Q000503:physiopathology*; D014408:Biomarkers, Tumor / Q000378:metabolism; D015153:Blotting, Western; D018269:Carcinoma, Endometrioid / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology; D005136:Eye Proteins / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008833:Microcirculation / Q000502:physiology; D009369:Neoplasms / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology; D009389:Neovascularization, Pathologic / Q000378:metabolism / Q000473:pathology; D009414:Nerve Growth Factors / Q000235:genetics* / Q000378:metabolism; D010051:Ovarian Neoplasms / Q000098:blood supply / Q000473:pathology* / Q000503:physiopathology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015843:Serpins / Q000235:genetics* / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics* / Q000378:metabolism; D000099174:Pigment Epithelium-Derived Factor
D014408:Biomarkers, Tumor; D005136:Eye Proteins; D009414:Nerve Growth Factors; D015843:Serpins; D042461:Vascular Endothelial Growth Factor A; D000099174:Pigment Epithelium-Derived Factor; C467484:VEGFA protein, human