Placental
growth factor (PlGF), a homolog of
vascular endothelial growth factor (
VEGF), exerts pleiotropic functions in
cancer by affecting
tumor cells as well as endothelial and inflammatory cells. Moreover, PlGF expression correlates with
tumor stage, recurrence,
metastasis and patient outcome in different types of
cancer. Recently, administration of anti-PlGF
therapy reduced
tumor growth and
metastasis in preclinical
tumor models. In the present study, we evaluated the diagnostic and prognostic value of systemic and local expression of PlGF in primary
endometrial carcinomas. PlGF levels in
tumor lysates (n=128) and serum (n=88) of patients with primary
endometrial cancer were determined using ELISA. PlGF
mRNA expression in
endometrial carcinoma tissues was quantified by quantitative qRT-PCR. Results were compared to
endometrial cancer stage and grade. Systemic PlGF levels were not altered in patients with
endometrial cancer (FIGO stage I-II-III) as compared to healthy controls. Only in FIGO stage IV patients, serum PlGF levels were slightly increased. Local PlGF
mRNA and
protein expression in endometrial
tumors progressively increased with
tumor grade. In
endometrioid carcinomas, PlGF
mRNA expression was significantly increased in endometrioid grade 3
tumors as compared to normal endometrial tissue. PlGF
protein expression was significantly increased in endometrioid grade 2 and 3
carcinomas and in serous
carcinomas as compared to normal endometrial tissue. Our study showed that systemic/serum PlGF levels cannot be used as a diagnostic or prognostic marker in
endometrial cancer. However, the increased local expression of PlGF, primarily in high-grade
carcinomas, underscores the possibility for preclinical assessment of anti-PlGF
therapy in
endometrial cancer.