NEGATIVE CONTROL OF MIGRATION BY 24 KD FGF-2

24 KD FGF-2 对迁移的阴性控制

• 批准号: 6042131
• 负责人: EUGENE G LEVIN
• 金额: $ 22.77万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-12-15 至 2000-09-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6042131
• 关键词: MCF7 cell; angiogenesis; cell migration; estrogen receptors; fibroblast growth factor; growth factor receptors; receptor binding; tissue /cell culture

Angiogenesis is a process that involves the recruitment, replication and migration of endothelial cells and is pivotal for the survival of the surrounding tissue during development, would healing, reproductive cycles and tumor development. One grown factor that plays a pivotal role in these events is basic fibroblast growth factor (FGF-2). FGF-2 is synthesized as 24, 22.5, 22(hmwFGF-2), and 18 kD forms with the 24 kD FGF-2 containing a 55 amino acid extension at the amino terminal end (ATE) of 18 kD FGF-2. While 18 kD FGF-2 stimulates endothelial cell migration, we have found that hmwFGF-2 inhibits is. This inhibitory activity is effective in the presence of 18 kD FGF-2 and VEGF, another stimulus of enhanced migration. HmwFGF-2 also inhibits migration of mammary carcinoma cells (MCF-7) responding to insulin-like growth factor 1. Antibodies generated against an 12 amino acid fragment of the ATE block the inhibition of migration but antibodies to the 18 kD FGF-2 have no effect. HmwFGF-2 stimulates proliferation of MCF-7 cells but this activity is not blocked by the antibodies against the ATE but is reversed by anti-18 kD FGF-2 antibodies. Thus, the inhibition of migration is a function of the ATE while the effect on growth rate is promoted by the carboxy terminal 18 kD FGF-2. In addition, studies examining the intracellular mechanism that mediates hmwFGF-2 inhibition of migration clearly show that the estrogen receptor (ER) is involved; elimination of the ER from either endothelial or MCF-7 cells abrogates the inhibitory response (without affecting the growth stimulatory effect) and treatment with hmwFGF-2 leads to enhanced phosphorylation of the ER. Thus, we propose that the ER plays a pivotal role in this process. This grant proposal will address the mechanism by which hmwFGF-2 (presumably the ATE region) inhibits migration of endothelial and breast tumor cells. The hypothesis states that hmwFGF-2 binds to FGF receptors distince from 18kD FGF-2 binding, that this effect is mediated exclusively through the ATE region of hmwFGF-2, and is mediated intracellularly through an ER- dependent pathway. The experiments will examine the mechanism by which hmwFGF-2 inhibits mitogen-stimulated migration considering receptor binding and activation, intracellular pathways, as well as cytoskeletal arrangement. This study addresses a novel and unique role for FGF-2 in tumor development and possibly metastasis, the regulation of cell migration by hmwFGF-2.

血管生成是一个涉及内皮细胞的募集、复制和迁移的过程，在发育、愈合、生殖周期和肿瘤发展过程中对周围组织的生存至关重要。在这些事件中起关键作用的一个生长因子是碱性成纤维细胞生长因子(FGF-2)。成纤维细胞生长因子-2合成为24、22.5、22(hmwFGF-2)和18kD形式，其中24kD的成纤维细胞生长因子-2在18kD的氨基末端含有55个氨基酸的延伸。在18kD的成纤维细胞生长因子-2刺激内皮细胞迁移的同时，我们发现hmw成纤维细胞生长因子-2抑制血管内皮细胞的迁移。这种抑制活性在18kD的成纤维细胞生长因子-2和血管内皮生长因子的存在下是有效的，血管内皮生长因子是促进迁移的另一种刺激。HmwFGF-2还抑制对胰岛素样生长因子1反应的乳腺癌细胞(MCF-7)的迁移。针对ATE的12个氨基酸片段产生的抗体可阻断这种抑制迁移，但针对18kD的成纤维细胞生长因子-2的抗体没有作用。HmwFGF-2促进MCF-7细胞的增殖，但这种活性不被ATE抗体所阻断，而被抗18 kD的FGF-2抗体逆转。因此，迁移的抑制是ATE的功能，而对生长速度的影响是由18kD的羧基末端的FGF-2促进的。此外，对hmwFGF-2抑制迁移的细胞内机制的研究清楚地表明，雌激素受体(ER)参与其中；从内皮细胞或MCF-7细胞中消除ER会消除抑制反应(不影响生长刺激效应)，而hmwFGF-2处理会增强ER的磷酸化。因此，我们认为内质网在这一过程中起着关键作用。这项拨款提案将解决hmwFGF-2(可能是ATE区域)抑制血管内皮细胞和乳腺肿瘤细胞迁移的机制。该假说认为hmwFGF-2与成纤维细胞生长因子受体结合不同于与18kD的成纤维细胞生长因子2结合，这种作用仅通过hmwFGF-2的ATE区域介导，并通过内质网依赖的途径在细胞内介导。这些实验将从受体结合和激活、细胞内途径以及细胞骨架排列的角度来研究hmwFGF-2抑制丝裂原刺激的迁移的机制。本研究探讨了成纤维细胞生长因子-2在肿瘤发生和可能的转移中的独特作用，即hmwFGF-2对细胞迁移的调控。