Department of Advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, Beijing, China.
J Cell Mol Med. 2013 Jun;17(6):782-91. doi: 10.1111/jcmm.12062. Epub 2013 May 26.
Induced pluripotent stem cell (iPSC) provides a promising seeding cell for regenerative medicine. However, iPSC has the potential to form teratomas after transplantation. Therefore, it is necessary to evaluate the tumorigenic risks of iPSC and all its differentiated derivates prior to use in a clinical setting. Here, murine iPSCs were transduced with dual reporter gene consisting of monomeric red fluorescent protein (mRFP) and firefly luciferase (Fluc). Undifferentiated iPSCs, iPSC derivates from induced differentiation (iPSC-derivates), iPSC-derivated cardiomyocyte (iPSC-CMs) were subcutaneously injected into the back of nude mice. Non-invasive bioluminescence imaging (BLI) was longitudinally performed at day 1, 7, 14 and 28 after transplantation to track the survival and proliferation of transplanted cells. At day 28, mice were killed and grafts were explanted to detect teratoma formation. The results demonstrated that transplanted iPSCs, iPSC-derivates and iPSC-CMs survived in receipts. Both iPSCs and iPSC-derivates proliferated dramatically after transplantation, while only slight increase in BLI signals was observed in iPSC-CM transplanted mice. At day 28, teratomas were detected in both iPSCs and iPSC-derivates transplanted mice, but not in iPSC-CM transplanted ones. In vitro study showed the long-term existence of pluripotent cells during iPSC differentiation. Furthermore, when these cells were passaged in feeder layers as undifferentiated iPSCs, they would recover iPSC-like colonies, indicating the cause for differentiated iPSC's tumourigenicity. Our study indicates that exclusion of tumorigenic cells by screening in addition to lineage-specific differentiation is necessary prior to therapeutic use of iPSCs.
诱导多能干细胞（iPSC）为再生医学提供了一种很有前途的种子细胞。然而，iPSC 移植后有形成畸胎瘤的潜力。因此，在临床应用之前，有必要评估 iPSC 及其所有分化衍生物的致瘤风险。在这里，我们使用由单体红色荧光蛋白（mRFP）和萤火虫荧光素酶（Fluc）组成的双报告基因转导小鼠 iPSCs。未分化的 iPSCs、诱导分化的 iPSC 衍生物（iPSC-derivates）、iPSC 衍生的心肌细胞（iPSC-CMs）被皮下注射到裸鼠的背部。在移植后第 1、7、14 和 28 天进行非侵入性生物发光成像（BLI），以跟踪移植细胞的存活和增殖。在第 28 天，处死小鼠并取出移植物以检测畸胎瘤的形成。结果表明，移植的 iPSCs、iPSC-derivates 和 iPSC-CMs 在受体中存活。移植后 iPSCs 和 iPSC-derivates 均显著增殖，而在 iPSC-CM 移植小鼠中仅观察到 BLI 信号的轻微增加。在第 28 天，在移植了 iPSCs 和 iPSC-derivates 的小鼠中均检测到畸胎瘤，但在移植了 iPSC-CM 的小鼠中未检测到。体外研究表明，在 iPSC 分化过程中多能细胞长期存在。此外，当这些细胞在饲养层中作为未分化的 iPSCs 传代时，它们会恢复 iPSC 样集落，这表明分化的 iPSC 致瘤性的原因。我们的研究表明，在将 iPSCs 用于治疗之前，除了谱系特异性分化之外，通过筛选排除致瘤细胞是必要的。
