Generation of mouse-induced pluripotent stem cells by transient expression of a single nonviral polycistronic vector

TLDR

Induced pluripotent stem cells, derived from diverse cell types, are promising for regenerative medicine but are typically generated with integrating viral vectors that pose risks of insertional mutagenesis and oncogenesis. The study aims to produce iPS cells devoid of integrated transgenes to meet safety requirements for therapeutic applications. Using nucleofection, the authors introduced a nonviral polycistronic vector encoding Oct4, Sox2, Klf4, and c‑Myc into mouse embryonic fibroblasts, generating iPS lines without detectable vector integration.

Abstract

Induced pluripotent stem (iPS) cells have generated keen interest due to their potential use in regenerative medicine. They have been obtained from various cell types of both mice and humans by exogenous delivery of different combinations of Oct4, Sox2, Klf4, c-Myc, Nanog, and Lin28. The delivery of these transcription factors has mostly entailed the use of integrating viral vectors (retroviruses or lentiviruses), carrying the risk of both insertional mutagenesis and oncogenesis due to misexpression of these exogenous factors. Therefore, obtaining iPS cells that do not carry integrated transgene sequences is an important prerequisite for their eventual therapeutic use. Here we report the generation of iPS cell lines from mouse embryonic fibroblasts with no evidence of integration of the reprogramming vector in their genome, achieved by nucleofection of a polycistronic construct coexpressing Oct4, Sox2, Klf4, and c-Myc.