Spontaneous ATM Gene Reversion in A-T iPSC to Produce an Isogenic Cell Line

• Main Authors: Lucy Lin, Mavis R. Swerdel, Michael P. Lazaropoulos, Gary S. Hoffman, Alana J. Toro-Ramos, Jennifer Wright, Howard Lederman, Jianmin Chen, Jennifer C. Moore, Ronald P. Hart
• Format: Article
• Language: English
• Published: Elsevier 2015-12-01
• Series: Stem Cell Reports
• Online Access: http://www.sciencedirect.com/science/article/pii/S2213671115003070

A spontaneously reverted iPSC line was identified from an A-T subject with heterozygous ATM truncation mutations. The reverted iPSC line expressed ATM protein and was capable of radiation-induced phosphorylation of CHK2 and H2A.X. Genome-wide SNP analysis confirmed a match to source T cells and also to a distinct, non-reverted iPSC line from the same subject. Rearranged T cell receptor sequences predict that the iPSC culture originated as several independently reprogrammed cells that resolved into a single major clone, suggesting that gene correction likely occurred early in the reprogramming process. Gene expression analysis comparing ATM−/− iPSC lines to unrelated ATM+/− cells identifies a large number of differences, but comparing only the isogenic pair of A-T iPSC lines reveals that the primary pathway affected by loss of ATM is a diminished expression of p53-related mRNAs. Gene reversion in culture, although likely a rare event, provided a novel, reverted cell line for studying ATM function.