Park Jinkyu, Cui Gang, Hong Jiyun, Jeong Han, Han Minseok, Choi Min Seok, Lim Jeong Ah, Han Sanguk, Lee Christopher Seungkyu, Kim Min, Kim Sangwoo, Lee Junwon, Byeon Suk Ho
Department of Ophthalmology, Severance Eye Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul 03722, Republic of Korea.
Department of Biomedical Systems Informatics, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 03722, Republic of Korea.
Int J Mol Sci. 2025 Sep 5;26(17):8675. doi: 10.3390/ijms26178675.
MYCN amplification without concurrent RB1 mutations characterizes a rare yet highly aggressive subtype of retinoblastoma; however, its precise developmental origins and therapeutic vulnerabilities remain incompletely understood. Here, we modeled this subtype by lentiviral-mediated MYCN overexpression in human pluripotent stem cell-derived retinal organoids, revealing a discrete developmental window (days 70-120) during which retinal progenitors showed heightened susceptibility to transformation. Tumors arising in this period exhibited robust proliferation, expressed SOX2, and lacked CRX, consistent with origin from primitive retinal progenitors. MYCN-overexpressing organoids generated stable cell lines that reproducibly gave rise to MYCN-driven tumors when xenografted into immunodeficient mice. Transcriptomic profiling demonstrated that MYCN-overexpressing organoids closely recapitulated molecular features of patient-derived MYCN-amplified retinoblastomas, particularly through activation of MYC/E2F and mTORC1 signaling pathways. Pharmacological screening further identified distinct therapeutic vulnerabilities, demonstrating distinct subtype-specific sensitivity of MYCN-driven cells to transcriptional inhibitors (THZ1, Flavopiridol) and the cell-cycle inhibitor Volasertib, indicative of a unique oncogene-addicted state compared to RB1-deficient retinoblastoma cells. Collectively, our study elucidates the developmental and molecular mechanisms underpinning MYCN-driven retinoblastoma, establishes a robust and clinically relevant human retinal organoid platform, and highlights targeted transcriptional inhibition as a promising therapeutic approach for this aggressive pediatric cancer subtype.
MYCN扩增但无并发RB1突变是视网膜母细胞瘤一种罕见却极具侵袭性的亚型；然而，其确切的发育起源和治疗易感性仍未完全明确。在此，我们通过慢病毒介导的MYCN在人多能干细胞衍生的视网膜类器官中过表达来模拟这种亚型，揭示了一个离散的发育窗口（第70 - 120天），在此期间视网膜祖细胞对转化表现出更高的易感性。在此期间产生的肿瘤表现出强劲的增殖能力，表达SOX2且缺乏CRX，这与源自原始视网膜祖细胞一致。过表达MYCN的类器官产生了稳定的细胞系，当移植到免疫缺陷小鼠体内时可重复性地引发MYCN驱动的肿瘤。转录组分析表明，过表达MYCN的类器官紧密概括了患者来源的MYCN扩增视网膜母细胞瘤的分子特征，特别是通过激活MYC/E2F和mTORC1信号通路。药物筛选进一步确定了不同的治疗易感性，表明MYCN驱动的细胞对转录抑制剂（THZ1、氟吡汀）和细胞周期抑制剂沃拉替尼具有独特的亚型特异性敏感性，这表明与RB1缺陷的视网膜母细胞瘤细胞相比，其处于独特的癌基因成瘾状态。总体而言，我们的研究阐明了MYCN驱动的视网膜母细胞瘤的发育和分子机制，建立了一个强大且与临床相关的人视网膜类器官平台，并强调靶向转录抑制作为这种侵袭性儿科癌症亚型的一种有前景的治疗方法。
