透过斑马鱼直接观察肿瘤细胞变化
将人类肿瘤细胞植入免疫缺陷小鼠，已经成为评定癌症治疗药物临床前有效性的金标准，但是直接观察小鼠的肿瘤细胞显然非常困难。
2019年4月25日，全球自然科学三大旗舰期刊之一、美国《细胞》正刊在线发表麻省总医院、哈佛大学、波士顿施赖纳斯儿童医院、布莱根医院和波士顿妇女医院、霍华德休斯医学研究所、杜克大学的研究报告，发现一种免疫缺陷型透明斑马鱼可以在37℃下植入多种人类肿瘤（包括乳腺癌、白血病、淋巴瘤、黑色素瘤、胶质母细胞瘤、肉瘤、肾细胞癌）并且可以动态观察单个植入细胞。
此类斑马鱼的DNA依赖型蛋白激酶催化亚基（DNA-PKCS）编码基因（PRKDC）和白介素2受体γ亚基A（IL2RGA）编码基因均缺失，故缺乏适应性（又称后天性、获得性、特异性）免疫力和自然杀伤细胞。例如，通过荧光细胞谱系追踪，可以观察人类肿瘤细胞的转移和繁殖状态。此外，该研究还探讨了PARP抑制剂奥拉帕利联合DNA损伤剂替莫唑胺治疗肿瘤的临床前有效性，并且通过四色荧光泛素化细胞有丝分裂周期指示剂（FUCCI4）观察治疗效果，确定了联合治疗诱导肿瘤细胞凋亡之前将细胞有丝分裂周期阻滞于DNA合成后期（G2）。
因此，该研究结果表明，患者来源异种移植物可以植入该模型，为将来研发个体化治疗方法开辟了多快好省的新途径。
Cell. 2019 Apr 25. [Epub ahead of print]
Visualizing Engrafted Human Cancer and Therapy Responses in Immunodeficient Zebrafish.
Chuan Yan, Dalton C. Brunson, Qin Tang, Daniel Do, Nicolae A. Iftimia, John C. Moore, Madeline N. Hayes, Alessandra M. Welker, Elaine G. Garcia, Taronish D. Dubash, Xin Hong, Benjamin J. Drapkin, David T. Myers, Sarah Phat, Angela Volorio, Dieuwke L. Marvin, Matteo Ligorio, Lyle Dershowitz, Karin M. McCarthy, Murat N. Karabacak, Jonathan A. Fletcher, Dennis C. Sgroi, John A. Iafrate, Shyamala Maheswaran, Nick J. Dyson, Daniel A. Haber, John F. Rawls, David M. Langenau.
Massachusetts General Hospital Research Institute, Charlestown, MA, USA; Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA, USA; Massachusetts General Hospital, Boston, MA, USA; Harvard Stem Cell Institute, Cambridge, MA, USA; Shriners Hospitals for Children, Boston, MA, USA; Harvard Medical School, Boston, MA, USA; Brigham and Women's Hospital, Boston, MA, USA; Howard Hughes Medical Institute, Bethesda, MD, USA; Duke University School of Medicine, Durham, NC, USA.
HIGHLIGHTS
prkdc -/-, il2rga -/- zebrafish reared at 37°C engraft a wide array of human cancers
Growth and therapy responses can be dynamically visualized at single-cell resolution
Combination olaparib and temozolomide kill xenografted human rhabdomyosarcoma
Engrafting patient-derived cancers opens new avenues for personalized therapy
Xenograft cell transplantation into immunodeficient mice has become the gold standard for assessing pre-clinical efficacy of cancer drugs, yet direct visualization of single-cell phenotypes is difficult. Here, we report an optically-clear prkdc -/-, il2rga -/- zebrafish that lacks adaptive and natural killer immune cells, can engraft a wide array of human cancers at 37°C, and permits the dynamic visualization of single engrafted cells. For example, photoconversion cell-lineage tracing identified migratory and proliferative cell states in human rhabdomyosarcoma, a pediatric cancer of muscle. Additional experiments identified the preclinical efficacy of combination olaparib PARP inhibitor and temozolomide DNA-damaging agent as an effective therapy for rhabdomyosarcoma and visualized therapeutic responses using a four-color FUCCI cell-cycle fluorescent reporter. These experiments identified that combination treatment arrested rhabdomyosarcoma cells in the G2 cell cycle prior to induction of apoptosis. Finally, patient-derived xenografts could be engrafted into our model, opening new avenues for developing personalized therapeutic approaches in the future.
KEYWORDS: zebrafish; rhabdomyosarcoma; melanoma; breast cancer; immune deficient; xenograft; il2rg; prkdc; SCID
DOI: 10.1016/j.cell.2019.04.004