Highly metastatic human prostate cancer growing within the prostate of athymic mice overexpresses vascular endothelial growth factor.
Angiogenesis is essential for tumor progression and metastasis. It is mediated by the release of angiogenic factors by the tumor or host. We analyzed the expression of angiogenic factors by the prostate cancer cell line LNCaP and two derived variants, in vitro and in vivo, to determine whether metastatic cell lines express higher levels of these factors. The production of three angiogenic factors, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and interleukin 8 (IL-8), by LNCaP and its variants, LNCaP-LN3 (highly metastatic) and LNCaP-Pro5 (slightly metastatic), was measured by ELISA. VEGF, bFGF, and IL-8 mRNA expression was determined in vitro by Northern blot analysis. VEGF mRNA expression was determined in vivo by in situ hybridization. VEGF and flk-1 protein expression and microvessel density of LNCaP cell tumors were quantified by immunohistochemistry. In vitro, VEGF production by LNCaP-LN3 (3.15+/-0.04 pg/ml/10(3) cells) was significantly higher than those of both LNCaP (2.38+/-0.34 pg/ml/10(3) cells) and LNCaP-Pro5 (1.67+/-0.37 pg/ml/10(3) cells; P = 0.049 and 0.001, respectively). None of the three cell lines produced detectable levels of bFGF or IL-8 in vitro. In vivo, LNCaP-LN3 tumors exhibited higher levels of VEGF mRNA and protein (152.2+/-28.5 and 200.5+/-28.3) and of flk-1 protein (156.5+/-20.6) and had higher microvessel density (16.4+/-4.2) than either LNCaP tumors (89+/-17.5, 173.3+/-23.0, 124.6+/-21.6, and 12.4+/-3.5, respectively) or LNCaP-Pro5 tumors (63+/-14.7, 141.2+/-38.1, 126.1+/-20, and 5.8+/-2.2, respectively). In conclusion, metastatic human prostate cancer cells exhibited enhanced VEGF production and tumor vascularity compared with prostate cancer cells of lower metastatic potential. Thus, VEGF may play an important role in prostate cancer metastasis.
Balbay
M D
MD
Department of Urology, The University of Texas M.D. Anderson Cancer Center, Houston 77030, USA.
Pettaway
C A
CA
Kuniyasu
H
H
Inoue
K
K
Ramirez
E
E
Li
E
E
Fidler
I J
IJ
Dinney
C P
CP
D000818:Animals; D002277:Carcinoma / Q000098:blood supply / Q000378:metabolism*; D016228:Endothelial Growth Factors / Q000096:biosynthesis*; D016222:Fibroblast Growth Factor 2 / Q000096:biosynthesis; D006801:Humans; D017403:In Situ Hybridization; D016209:Interleukin-8 / Q000096:biosynthesis; D008222:Lymphokines / Q000096:biosynthesis*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008833:Microcirculation; D009362:Neoplasm Metastasis; D009368:Neoplasm Transplantation; D011471:Prostatic Neoplasms / Q000098:blood supply / Q000378:metabolism*; D020794:Receptor Protein-Tyrosine Kinases / Q000096:biosynthesis; D017978:Receptors, Growth Factor / Q000096:biosynthesis; D040262:Receptors, Vascular Endothelial Growth Factor; D014407:Tumor Cells, Cultured; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D016228:Endothelial Growth Factors; D016209:Interleukin-8; D008222:Lymphokines; D017978:Receptors, Growth Factor; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D016222:Fibroblast Growth Factor 2; D020794:Receptor Protein-Tyrosine Kinases; D040262:Receptors, Vascular Endothelial Growth Factor