Homologous Recombination DNA Repair Genes Play a Critical Role in Reprogramming to a Pluripotent State
Federico González,
Daniela Georgieva,
Fabio Vanoli,
Zhong-Dong Shi,
Matthias Stadtfeld,
Thomas Ludwig,
Maria Jasin,
Danwei Huangfu
Affiliations
Federico González
Developmental Biology Program, Sloan-Kettering Institute, 1275 York Avenue, New York, NY 10065, USA
Daniela Georgieva
Developmental Biology Program, Sloan-Kettering Institute, 1275 York Avenue, New York, NY 10065, USA
Fabio Vanoli
Developmental Biology Program, Sloan-Kettering Institute, 1275 York Avenue, New York, NY 10065, USA
Zhong-Dong Shi
Developmental Biology Program, Sloan-Kettering Institute, 1275 York Avenue, New York, NY 10065, USA
Matthias Stadtfeld
Developmental Genetics Program, Skirball Institute of Biomolecular Medicine, Department of Cell Biology, New York University School of Medicine, 540 1st Avenue, New York, NY 10016, USA
Thomas Ludwig
The Ohio State University Wexner Medical Center, The James Comprehensive Cancer Center, 596 Biomedical Research Tower, 460 West 12th Avenue, Columbus, OH 43210, USA
Maria Jasin
Developmental Biology Program, Sloan-Kettering Institute, 1275 York Avenue, New York, NY 10065, USA
Danwei Huangfu
Developmental Biology Program, Sloan-Kettering Institute, 1275 York Avenue, New York, NY 10065, USA
Induced pluripotent stem cells (iPSCs) hold great promise for personalized regenerative medicine. However, recent studies show that iPSC lines carry genetic abnormalities, suggesting that reprogramming may be mutagenic. Here, we show that the ectopic expression of reprogramming factors increases the level of phosphorylated histone H2AX, one of the earliest cellular responses to DNA double-strand breaks (DSBs). Additional mechanistic studies uncover a direct role of the homologous recombination (HR) pathway, a pathway essential for error-free repair of DNA DSBs, in reprogramming. This role is independent of the use of integrative or nonintegrative methods in introducing reprogramming factors, despite the latter being considered a safer approach that circumvents genetic modifications. Finally, deletion of the tumor suppressor p53 rescues the reprogramming phenotype in HR-deficient cells primarily through the restoration of reprogramming-dependent defects in cell proliferation and apoptosis. These mechanistic insights have important implications for the design of safer approaches to creating iPSCs.