NEGATIVE CONTROL OF MIGRATION BY 24 KD FGF-2

24 KD FGF-2 对迁移的阴性控制

• 批准号: 6624691
• 负责人: EUGENE G LEVIN
• 金额: $ 44.48万
• 依托单位: LA JOLLA INST FOR MOLECULAR MEDICINE
• 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 2004-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6624691
• 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募集、复制和迁移的过程，对于周围组织在发育、愈合、生殖周期和肿瘤发展过程中的存活至关重要。在这些事件中起关键作用的一种生长因子是碱性成纤维细胞生长因子（FGF-2）。FGF-2合成为24,22.5,22(hmwFGF-2)， 18kd与24kd FGF-2形成，其中18kd FGF-2在18kd FGF-2的氨基末端（ATE）含有55个氨基酸延伸。虽然18kd FGF-2刺激内皮细胞迁移，但我们发现hmwFGF-2抑制内皮细胞迁移。这种抑制活性在18kd FGF-2和VEGF存在时有效，这是另一种增强迁移的刺激。HmwFGF-2还能抑制响应胰岛素样生长因子1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阻断了对迁移的抑制，但针对18kd FGF-2的抗体没有作用。HmwFGF-2刺激MCF-7细胞的增殖，但这种活性不被针对ATE的抗体阻断，而是被抗18kd FGF-2抗体逆转。因此，对迁移的抑制是ATE的功能，而对生长速度的影响是由羧基末端18kd FGF-2促进的。此外，对介导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细胞中消除内质网会消除抑制反应（不影响生长刺激作用），用hmwFGF-2处理会导致内质网磷酸化增强。因此，我们认为急诊室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）抑制内皮细胞和乳腺肿瘤细胞迁移的机制。该假设认为，hmwFGF-2与FGF受体的结合不同于18kD FGF-2的结合，这种作用完全通过hmwFGF-2的ATE区域介导，并通过内质网依赖性途径在细胞内介导。实验将研究hmwFGF-2抑制丝裂原刺激的迁移的机制，考虑受体结合和激活、细胞内途径以及细胞骨架排列。这项研究揭示了FGF-2在肿瘤发展和可能的转移中的一个新颖而独特的作用，即通过hmwFGF-2调节细胞迁移。