Dallas Nikolaos A, Gray Michael J, Xia Ling, Fan Fan, van Buren George, Gaur Puja, Samuel Shaija, Lim Sherry J, Arumugam Thiruvengadam, Ramachandran Vijaya, Wang Huamin, Ellis Lee M
Department of Surgical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77230-1402, USA.
Clin Cancer Res. 2008 Dec 15;14(24):8052-60. doi: 10.1158/1078-0432.CCR-08-1520.
Neuropilin-2 (NRP-2) is a coreceptor for vascular endothelial growth factor (VEGF) on endothelial cells. NRP-2 is overexpressed in pancreatic ductal adenocarcinoma (PDAC) cells relative to nonmalignant ductal epithelium. This study determined the role of NRP-2 in PDAC cells.
NRP-2 expression was reduced in PDAC cells with stable short-hairpin RNA (shRNA) transfection. Western blotting was done to evaluate signaling intermediates. Migration and invasion studies were carried out in Boyden chambers. Anchorage-independent growth was assessed by soft-agar colony formation. In vivo growth was evaluated using murine subcutaneous and orthotopic xenograft models. Immunohistochemical analysis evaluated in vivo proliferation and angiogenesis.
shRNA-NRP-2 decreased NRP-2 levels without affecting neuropilin-1 levels. Akt activation was decreased in clones with reduced NRP-2 (shRNA-NRP-2). shRNA-NRP-2 cells showed decreased migration, invasion, and anchorage-independent growth compared with control cells. In vitro proliferation rates were similar in control- and shRNA-transfected cells. Subcutaneous and orthotopic xenografts from shRNA-transfected cells were significantly smaller than those resulting from control-transfected cells (P < 0.05). Furthermore, shRNA-NRP-2 tumors exhibited less cellular proliferation and decreased microvascular area relative to control tumors (P < 0.05). Constitutive expression of the angiogenic mediator Jagged-1 was reduced in shRNA-NRP-2 cells, whereas vascular endothelial growth factor levels were unchanged.
Reduction of NRP-2 expression in PDAC cells decreased survival signaling, migration, invasion, and ability to grow under anchorage-independent conditions. In vivo, reduction of NRP-2 led to decreased growth of xenograft tumors and decreased vascular area, which was associated with decreased Jagged-1 levels. NRP-2 is a potential therapeutic target on PDAC cells.
神经纤毛蛋白-2（NRP-2）是内皮细胞上血管内皮生长因子（VEGF）的共受体。相对于非恶性导管上皮，NRP-2在胰腺导管腺癌（PDAC）细胞中过表达。本研究确定了NRP-2在PDAC细胞中的作用。
通过稳定的短发夹RNA（shRNA）转染降低PDAC细胞中NRP-2的表达。进行蛋白质印迹法以评估信号中间体。在博伊登小室中进行迁移和侵袭研究。通过软琼脂集落形成评估非锚定依赖性生长。使用小鼠皮下和原位异种移植模型评估体内生长。免疫组织化学分析评估体内增殖和血管生成。
shRNA-NRP-2降低了NRP-2水平，而不影响神经纤毛蛋白-1水平。在NRP-2降低的克隆（shRNA-NRP-2）中，Akt激活减少。与对照细胞相比，shRNA-NRP-2细胞显示出迁移、侵袭和非锚定依赖性生长减少。对照细胞和shRNA转染细胞的体外增殖率相似。来自shRNA转染细胞的皮下和原位异种移植物明显小于对照转染细胞产生的异种移植物（P < 0.05）。此外，相对于对照肿瘤，shRNA-NRP-2肿瘤表现出较少的细胞增殖和微血管面积减少（P < 0.05）。血管生成介质Jagged-1的组成型表达在shRNA-NRP-2细胞中降低，而血管内皮生长因子水平未改变。
PDAC细胞中NRP-2表达的降低降低了存活信号、迁移、侵袭以及在非锚定依赖性条件下生长的能力。在体内，NRP-2的降低导致异种移植肿瘤生长减少和血管面积减少，这与Jagged-1水平降低有关。NRP-2是PDAC细胞上的一个潜在治疗靶点。
