Effect of P2 receptor on the intracellular calcium increase by cancer cells in human umbilical vein endothelial cells
Effect of P2 receptor on the intracellular calcium increase by cancer cells in human umbilical vein endothelial cells
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DOI：
10.1007/s00210-007-0259-2
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发表时间：
2008-06-01
影响因子：
3.6
通讯作者：
Shinozuka, Kazumasa
中科院分区：
文献类型：
--
作者：
Nejime, Namie;Tanaka, Naoko;Shinozuka, Kazumasa
血管内皮细胞的重要功能之一是作为血液和血管组织之间的屏障。这使我们推测癌细胞在转移过程中影响内皮细胞。在本研究中，我们研究了人纤维肉瘤细胞（HT-1080）对人脐静脉内皮细胞（HUVEC）的影响，特别是细胞内钙离子水平（[Ca2+](i)），这是已知的重要的细胞内信号转导因子。用荧光标记物处理HUVEC，然后用相衬显微镜成像测量[Ca2+](i)的荧光强度。利用荧光素-荧光素酶的化学发光和光子计数成像系统测量细胞外三磷酸腺苷（ATP）释放。发现HT-1080 （5 × 10(4)个细胞/皿）增加HUVEC中的[Ca2+](i)。U-73122（磷脂酶C抑制剂，1 μ M）和thapsigargin（钙泵抑制剂，1 μ M）显著降低了[Ca2+](i)的升高。有趣的是，P2Y受体拮抗剂pyridoxalphosphare-6-azophenyl-2', 4'-二磺酸（100 μ M）和核苷酸酶抑制剂apyrase （2 U/ml）也显著降低了HUVEC中[Ca2+](i)的升高。此外，我们观察到HT-1080的ATP释放。这些结果表明，HUVEC中的[Ca2+](i)通过磷脂酶C-IP3途径通过ATP从癌细胞释放而增加。我们以前报道过细胞外ATP通过P2Y受体增加[Ca2+](i)和增强大分子通透性。在肿瘤转移过程中，癌细胞可能利用内皮细胞层的这些调节机制。
One of the important functions of vascular endothelial cells is as a barrier between blood and vascular tissue. This led us to speculate that cancer cells affect endothelial cells during metastasis. In the present study, we investigated the influence of human fibrosarcoma cells (HT-1080) on human umbilical vein endothelial cells (HUVEC), particularly intracellular calcium ion levels ([Ca2+](i)), which are known to be an important intracellular signal transduction factor. HUVEC were treated with a fluorescent marker, and the fluorescence intensity of [Ca2+](i) was then measured by phase contrast microscopic imaging. Extracellular adenosine triphosphate (ATP) release was measured using the chemiluminescence of luciferin-luciferase and a photon counting imaging system. HT-1080 (5 x 10(4) cells per dish) was found to increase [Ca2+](i) in HUVEC. This [Ca2+](i) rise was significantly reduced by U-73122 (phospholipase C inhibitor, 1 mu M) and thapsigargin (calcium pump inhibitor, 1 mu M). Interestingly, the [Ca2+](i) rise in HUVEC was also significantly reduced by pyridoxalphosphare-6-azophenyl-2', 4'-disulfonic acid, a P2Y receptor antagonist (100 mu M) and apyrase, a nucleotidase inhibitor (2 U/ml). In addition, we observed ATP release from HT-1080. These results suggest that [Ca2+](i) in HUVEC was increased through the phospholipase C-IP3 pathway via ATP release from cancer cells. We previously reported that extracellular ATP increased [Ca2+](i) and enhanced macromolecular permeability via the P2Y receptor. In tumor metastasis, cancer cells may exploit these regulatory mechanisms in the endothelial cell layer.