Prabhakar Shilpa, Beauchamp Roberta L, Cheah Pike See, Yoshinaga Akiko, Haidar Edwina Abou, Lule Sevda, Mani Gayathri, Maalouf Katia, Stemmer-Rachamimov Anat, Jung David H, Welling D Bradley, Giovannini Marco, Plotkin Scott R, Maguire Casey A, Ramesh Vijaya, Breakefield Xandra O
Department of Neurology and Center for Molecular Imaging Research, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.
Mol Ther Methods Clin Dev. 2022 Jun 22;26:169-180. doi: 10.1016/j.omtm.2022.06.012. eCollection 2022 Sep 8.
Loss of function of the neurofibromatosis type 2 (NF2) tumor suppressor gene leads to the formation of schwannomas, meningiomas, and ependymomas, comprising ∼50% of all sporadic cases of primary nervous system tumors. NF2 syndrome is an autosomal dominant condition, with bi-allelic inactivation of germline and somatic alleles resulting in loss of function of the encoded protein merlin and activation of mammalian target of rapamycin (mTOR) pathway signaling in -deficient cells. Here we describe a gene replacement approach through direct intratumoral injection of an adeno-associated virus vector expressing merlin in a novel human schwannoma model in nude mice. In culture, the introduction of an AAV1 vector encoding merlin into CRISPR-modified human -null arachnoidal cells (ACs) or Schwann cells (SCs) was associated with decreased size and mTORC1 pathway activation consistent with restored merlin activity. , a single injection of AAV1-merlin directly into human -null SC-derived tumors growing in the sciatic nerve of nude mice led to regression of tumors over a 10-week period, associated with a decrease in dividing cells and an increase in apoptosis, in comparison with vehicle. These studies establish that merlin re-expression via gene replacement in -null schwannomas is sufficient to cause tumor regression, thereby potentially providing an effective treatment for NF2.
神经纤维瘤病2型（NF2）肿瘤抑制基因功能丧失会导致神经鞘瘤、脑膜瘤和室管膜瘤的形成，约占所有原发性神经系统肿瘤散发病例的50%。NF2综合征是一种常染色体显性疾病，种系和体细胞等位基因的双等位基因失活导致编码蛋白默林功能丧失，并在缺乏默林的细胞中激活哺乳动物雷帕霉素靶蛋白（mTOR）信号通路。在此，我们在裸鼠的一种新型人神经鞘瘤模型中，描述了一种通过直接瘤内注射表达默林的腺相关病毒载体的基因替代方法。在培养过程中，将编码默林的AAV1载体导入经CRISPR修饰的人默林缺失的蛛网膜细胞（ACs）或雪旺细胞（SCs），与细胞大小减小和mTORC1信号通路激活降低相关，这与默林活性恢复一致。此外，单次将AAV1-默林直接注射到在裸鼠坐骨神经中生长的人默林缺失的SC衍生肿瘤中，导致肿瘤在10周内消退，与注射媒介物相比，这与分裂细胞减少和细胞凋亡增加相关。这些研究表明，在默林缺失的神经鞘瘤中通过基因替代重新表达默林足以导致肿瘤消退，从而可能为NF2提供一种有效的治疗方法。
