Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery, REBIRTH - Research Center for Translational Regenerative Medicine, Hannover Medical School, 30625 Hannover, Germany, Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), Member of the German Center for Lung Research (DZL), 30625 Hannover, Germany.
Research Core Unit Genomics, Hannover Medical School, 30625 Hannover, Germany.
Mol Ther. 2021 Aug 4;29(8):2535-2553. doi: 10.1016/j.ymthe.2021.04.007. Epub 2021 Apr 6.
Cellular therapies based on induced pluripotent stem cells (iPSCs) come out of age and an increasing number of clinical trials applying iPSC-based transplants are ongoing or in preparation. Recent studies, however, demonstrated a high number of small-scale mutations in iPSCs. Although the mutational load in iPSCs seems to be largely derived from their parental cells, it is still unknown whether reprogramming may enrich for individual mutations that could lead to loss of functionality and tumor formation from iPSC derivatives. 30 hiPSC lines were analyzed by whole exome sequencing. High accuracy amplicon sequencing showed that all analyzed small-scale variants pre-existed in their parental cells and that individual mutations present in small subpopulations of parental cells become enriched among hiPSC clones during reprogramming. Among those, putatively actionable driver mutations affect genes related to cell-cycle control, cell death, and pluripotency and may confer a selective advantage during reprogramming. Finally, a short hairpin RNA (shRNA)-based experimental approach was applied to provide additional evidence for the individual impact of such genes on the reprogramming efficiency. In conclusion, we show that enriched mutations in curated onco- and tumor suppressor genes may account for an increased tumor risk and impact the clinical value of patient-derived hiPSCs.
基于诱导多能干细胞（iPSC）的细胞疗法已经问世，越来越多的应用 iPSC 移植的临床试验正在进行或准备中。然而，最近的研究表明 iPSC 中存在大量小规模突变。尽管 iPSC 中的突变负荷似乎主要来自其亲本细胞，但仍不清楚重编程是否会富集个别突变，这些突变可能导致 iPSC 衍生物失去功能和肿瘤形成。通过全外显子组测序分析了 30 条 hiPSC 系。高准确性扩增子测序表明，所有分析的小规模变体在其亲本细胞中预先存在，并且在重编程过程中，个体突变存在于亲本细胞的小亚群中富集。其中，推定的驱动突变影响与细胞周期控制、细胞死亡和多能性相关的基因，并且可能在重编程过程中赋予选择性优势。最后，应用短发夹 RNA（shRNA）的实验方法提供了额外的证据，证明这些基因对重编程效率的个别影响。总之，我们表明，在精心挑选的致癌基因和肿瘤抑制基因中富集的突变可能导致肿瘤风险增加，并影响患者来源的 hiPSC 的临床价值。
