Novel Treatment of NF-1 Associated Malignant Peripheral Nerve Sheath Tumors

描述（由申请人提供）：1型神经纤维瘤病（NF 1）患者发生称为神经纤维瘤的周围神经良性肿瘤和恶性周围神经鞘瘤（MPNST），这是一种高度侵袭性的雪旺细胞肿瘤，由神经纤维瘤引起。生长因子的不适当刺激被认为与肿瘤抑制基因如NF 1和p53的突变合作，以促进MPNST肿瘤发生。我们假设，神经调节蛋白-1（NRG-1）家族的生长和分化因子的蛋白质是促进MPNST中肿瘤性雪旺细胞增殖和/或存活的分子之一。为了验证这一假设，我们产生了在施万细胞中表达NRG-1亚型胶质生长因子-23（GGF 23）的转基因小鼠（P0-GGF 23小鼠），并发现这些动物发生了多发性神经纤维瘤和MPNST。我们还发现人神经纤维瘤和MPNST共表达多种NRG-1亚型及其erbB受体，并且用小分子erbB抑制剂PD 158780和PD 168393治疗可显著抑制人MPNST细胞系的增殖。基于这些初步研究，我们假设erbB受体的组成性激活对于人MPNST细胞的增殖和/或存活是必不可少的，并且使用PD 168393和/或4D 5（赫赛汀衍生自的抗erbB 2抗体）降低erbB活性将延缓这些细胞的增殖和存活。我们将与人MPNST细胞系、源自P0-GGF 23小鼠中产生的MPNST的小鼠系和P0-GGF 23小鼠模型合作，以严格检验以下假设：1）抑制NRG-1受体（erbB2，erbB 3和/或erbB 4）降低MPNST细胞在体内的增殖和/或存活，和2）NRG-1促进MPNST细胞在体内的增殖和/或存活。或MPNST细胞的存活通过激活特定的神经纤维蛋白调节的Ras蛋白及其下游效应物。这些研究将严格评估利用有效的现有erbB抑制剂治疗MPNST的新疗法，并将为未来开发更有效的疗法奠定坚实的基础，这些疗法精确靶向NF 1相关MPNST中关键的NRG-1调节的细胞质信号传导分子，单独或与erbB抑制剂联合使用。1型神经纤维瘤病（NF 1）患者会发生良性外周神经肿瘤（称为神经纤维瘤）和恶性外周神经鞘瘤（MPNST），这是一种高度侵袭性的雪旺细胞肿瘤，由神经纤维瘤引起。生长因子的不适当刺激被认为与肿瘤抑制基因如NF 1和p53的突变合作，以促进MPNST肿瘤发生。

DESCRIPTION (provided by applicant): Patients with neurofibromatosis type 1 (NF1) develop benign tumors of peripheral nerve known as neurofibromas and malignant peripheral nerve sheath tumors (MPNSTs), a highly aggressive form of Schwann cell neoplasm that arises from neurofibromas. Inappropriate stimulation by growth factors is thought to cooperate with mutations of tumor suppressor genes such as NF1 and p53 to promote MPNST tumorigenesis. We hypothesized that proteins from the neuregulin-1 (NRG-1) family of growth and differentiation factors are among the molecules promoting the proliferation and/or survival of neoplastic Schwann cells in MPNSTs. To test this hypothesis, we generated transgenic mice expressing the NRG-1 isoform glial growth factor-23 (GGF23) in Schwann cells (P0-GGF23 mice) and found that these animals develop multiple neurofibromas and MPNSTs. We have also found that human neurofibromas and MPNSTs coexpress multiple NRG-1 isoforms and their erbB receptors and that the proliferation of human MPNST cell lines is profoundly inhibited by treatment with the small molecular erbB inhibitors PD158780 and PD168393. Based on these preliminary studies, we hypothesize that constitutive activation of erbB receptors is essential for the proliferation and/or survival of human MPNST cells and that decreasing erbB activity with PD168393 and/or 4D5, the anti-erbB2 antibody from which Herceptin was derived, will retard the proliferation and survival of these cells. We will partner human MPNST cell lines, mouse lines derived from MPNSTs arising in P0-GGF23 mice and the P0- GGF23 mouse model to critically test the hypotheses that: 1) inhibition of the NRG-1 receptors (erbB2, erbB3 and/or erbB4) decreases the proliferation and/or survival of MPNST cells in vivo and 2) NRG-1 promotes the proliferation and/or survival of MPNST cells by activating specific neurofibromin-regulated Ras proteins and their downstream effectors. These studies will critically evaluate novel therapies for MPNSTs that utilize effective, existing erbB inhibitors and will establish a strong basis for the future development of even more effective therapies precisely targeting critical NRG-1 regulated cytoplasmic signaling molecules, alone or in combination with erbB inhibitors, in NF1-associated MPNSTs. Patients with neurofibromatosis type 1 (NF1) develop benign tumors of peripheral nerve known as neurofibromas, and malignant peripheral nerve sheath tumors (MPNSTs), a highly aggressive form of Schwann cell neoplasm that arises from neurofibromas. Inappropriate stimulation by growth factors is thought to cooperate with mutations of tumor suppressor genes such as NF1 and p53 to promote MPNST tumorigenesis.