Campbell C L, Savarese D M, Quesenberry P J, Savarese T M
Cytokine/Cytokine Receptor Laboratory, LINK Laboratories, Cancer Center, University of Massachusetts Medical Center, Worcester 01655, USA.
Int J Cancer. 1999 Mar 15;80(6):868-74. doi: 10.1002/(sici)1097-0215(19990315)80:6<868::aid-ijc12>3.0.co;2-1.
The cytokines that regulate angiogenesis in normal and malignant prostate tissue are not well studied. Using an RT-PCR-based screen, we observed that cultured, low-passage normal human prostate epithelial cells (PrECs) express a variety of cytokines which have been shown to have angiogenic and/or endothelial cell-activating properties in various systems. These include vascular endothelial growth factor (VEGF), basic fibroblastic growth factor (bFGF), transforming growth factor-alpha (TGF-alpha), transforming growth factor-beta (TGF-beta), interleukin-8 (IL-8), tumor necrosis factor-alpha (TNF-alpha), granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF). Expression of VEGF, bFGF, GM-CSF, G-CSF, TGF-alpha and TNF-alpha in these cells was confirmed by immunohistochemistry. Culture medium conditioned by normal human PrECs for periods of up to 96 hr were found to contain VEGF, GM-CSF, G-CSF, IL-8, TGF-beta1 and TGF-beta2 but not TNF-alpha or bFGF, as determined by ELISA. Of these, VEGF was by far the most prominently expressed angiogenic cytokine (approx. 2,500 pg/ml conditioned medium at 96 hr vs. 30 to 100 pg/ml conditioned medium for the other cytokines). PrEC-conditioned medium induced an approximately 2-fold stimulation of [3H]-thymidine incorporation in cultured human umbilical cord endothelial cells (HUVECs) deprived of the endothelial growth factors VEGF and bFGF; this stimulation was abolished by neutralizing antibodies directed against VEGF but not bFGF, IL-8, GM-CSF or TNF-alpha. VEGF expression by PrECs was not markedly altered by administration or deprivation of other angiogenic cytokines for which these cells have receptors, suggesting that there is not a hierarchy of cytokines controlling its expression; however, retinoic acid, a component of PrEC growth medium, was found to modestly suppress VEGF at physiological concentrations (0.1 ng/ml). These data suggest that normal PrECs express a variety of angiogenic cytokines, most prominently VEGF, to recruit a supporting vasculature, even in culture. Our data also suggest that the ability of malignant PrECs to stimulate angiogenesis may be intrinsic and does not need to be acquired during oncogenesis.
在正常和恶性前列腺组织中调节血管生成的细胞因子尚未得到充分研究。通过基于逆转录聚合酶链反应（RT-PCR）的筛选，我们观察到培养的低传代正常人前列腺上皮细胞（PrECs）表达多种细胞因子，这些细胞因子在各种系统中已被证明具有血管生成和/或内皮细胞激活特性。这些细胞因子包括血管内皮生长因子（VEGF）、碱性成纤维细胞生长因子（bFGF）、转化生长因子-α（TGF-α）、转化生长因子-β（TGF-β）、白细胞介素-8（IL-8）、肿瘤坏死因子-α（TNF-α）、粒细胞-巨噬细胞集落刺激因子（GM-CSF）和粒细胞集落刺激因子（G-CSF）。通过免疫组织化学证实了这些细胞中VEGF、bFGF、GM-CSF、G-CSF、TGF-α和TNF-α的表达。通过酶联免疫吸附测定（ELISA）确定，正常人PrECs培养长达96小时的条件培养基中含有VEGF、GM-CSF、G-CSF、IL-8、TGF-β1和TGF-β2，但不含有TNF-α或bFGF。其中，VEGF是迄今为止表达最显著的血管生成细胞因子（96小时时条件培养基中约为2500 pg/ml，而其他细胞因子的条件培养基中为30至100 pg/ml）。PrEC条件培养基在缺乏内皮生长因子VEGF和bFGF的培养人脐静脉内皮细胞（HUVECs）中诱导了约2倍的[3H]-胸苷掺入刺激；这种刺激被针对VEGF的中和抗体消除，但未被针对bFGF、IL-8、GM-CSF或TNF-α的中和抗体消除。PrECs对VEGF的表达不会因给予或剥夺这些细胞具有受体的其他血管生成细胞因子而发生明显改变，这表明不存在控制其表达的细胞因子等级制度；然而，发现视黄酸（PrEC生长培养基的一种成分）在生理浓度（0.1 ng/ml）下适度抑制VEGF。这些数据表明，即使在培养中，正常PrECs也表达多种血管生成细胞因子，其中最显著的是VEGF，以募集支持性脉管系统。我们的数据还表明，恶性PrECs刺激血管生成的能力可能是内在的，不需要在肿瘤发生过程中获得。
