REGULATION OF NORMAL AND NEOPLASTIC HEMATOPOIETIC CELL GROWTH--ROLE OF BRMS

正常和肿瘤造血细胞生长的调节——BRMS 的作用

• 批准号: 3752469
• 负责人: F W RUSCETTI
• 金额: --
• 依托单位: DIVISION OF CANCER TREATMENT
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3752469
• 关键词: biological response modifiers; cell growth regulation; cell transformation; cytokine; cytokine receptors; gene therapy; growth factor receptors; hematopoiesis; hematopoietic stem cells; human tissue; laboratory mouse; transforming growth factors

The goal of this project is to better understand the extracellular and intracellular interactions between positive and negative regulators of hematopoietic stem cells (SC) as they pertain to the mechanism(s) of malignant transformation and to the development of therapeutically useful gen therapy protocols. To initiate and maintain the growth and differentiation of primitive progenitor cells, multiple cytokine stimulation is required. This has led to the concept of "growth facto synergy". We show that such cooperativity also occurs between negative regulators of hematopoietic cell growth, and that the ability of primitive progenitors to proliferate depends on the balance of positive and negative signals the cell receives. Of several inhibitory cytokines studied only TGF-beta directly and reversibly inhibited all hematopoietic SC populations with marrow repopulating ability. TGF-B has inhibitory effects on the cell surface expression of many cytokine receptors that directly correlates with its effect on cell growth. SC factor receptor (c-kit) expression is down-regulated by TGF-beta in part by affecting c- kit mRNA stability. Also, TGF-beta prevents S phase cell cycle progression through an intracellular mechanism involving regulation of c- myb as well as c-myc. In vivo results demonstrated that TGF-beta can protect mice from both the lethal hematopoietic toxicity of 5-FU, as well as the non-hematopoiesis toxicity of DXR. The findings show that a negative regulator of hematopoiesis can be successfully used systemically to mediate chemoprotection in vivo. Several positive regulators of hematopoietic cells were used in vivo to determine their effect on myelopoiesis. The administration of rhIL-7 to mice twice a da for 7 days does not appreciably change BM cellularity, but does result in a 3-fold to 5-fold increase in the total number of leukocytes in the spleen and up to a 20-fold increase in the total number of peripheral WBC. Using our ability to regulate the growth of hematologic cells, we determined the feasibility of gene transfer under these conditions. We established that the ex-vivo transfer of the HS-tk suicide gene into T-cells before their infusion with hematopoietic SC could allow for selective in vivo depletion of these T-cells with ganciclovir (GCV) if the need subsequently arises.

该项目的目标是更好地了解细胞外和 细胞内正调节因子和负调节因子之间的相互作用 造血干细胞（SC），因为它们与造血干细胞的机制有关 恶性转化以及治疗上有用的药物的开发 基因治疗方案。 启动并维持增长 原始祖细胞分化、多种细胞因子 需要刺激。 由此产生了“增长因子”的概念。 协同作用”。我们表明这种协同作用也发生在消极之间 造血细胞生长的调节因子，并且原始细胞的能力 祖细胞的增殖取决于正负平衡 细胞接收到的信号。 仅研究了几种抑制性细胞因子 TGF-β直接且可逆地抑制所有造血SC 具有骨髓再生能力的人群。 TGF-B具有抑制作用 对细胞表面许多细胞因子受体表达的影响 与其对细胞生长的影响直接相关。 SC因子受体 (c-kit) 表达被 TGF-β 下调，部分是通过影响 c- 试剂盒 mRNA 稳定性。 此外，TGF-β 还可阻止 S 期细胞周期 通过涉及 c- 调节的细胞内机制进展 myb 以及 c-myc。 体内实验结果表明，TGF-β可以 保护小鼠免受 5-FU 的致命造血毒性，以及 DXR 的非造血毒性。 研究结果表明，一个 造血负调节剂可以成功地全身使用 介导体内化学保护。 几个积极的调节因素 在体内使用造血细胞来确定其对 骨髓生成。 给小鼠注射 rhIL-7，每天两次，持续 7 天 不会明显改变 BM 细胞结构，但会导致 BM 细胞结构增加 3 倍 脾脏中白细胞总数增加 5 倍，最多 外周血白细胞总数增加20倍。 使用我们的 调节血液细胞生长的能力，我们确定了 在这些条件下基因转移的可行性。 我们确定 将 HS-tk 自杀基因离体转移到 T 细胞中，然后再 输注造血 SC 可以选择性体内耗竭 如果随后有需要，可以用更昔洛韦 (GCV) 清除这些 T 细胞。