A more efficient method for generating glioblastoma-multiforme model in mice using genome editing technology.

The elucidation of the properties of malignant glioma and development of therapeutic methods require glioblastoma-multiforme mice model with characteristics such as invasiveness, multinuclearity, and ability for mitosis. A previous study has shown that overexpression of active HRas (HRasL61) in neural stem/progenitor cells (NSCs) isolated from p53 knockout (KO) mice could induce glioma-initiating cells (GICs). The orthotopically transplantation of 10 cells into the forebrain of immunodeficient mice resulted in the development of glioblastoma multiforme-like malignant brain tumors. In this study, we successfully induced GICs from wild-type fetal NSCs. Using CRISPR/Cas9, we obtained p53 KO NSCs. HRasL61 was additionally overexpressed in p53 KO NSCs. p53-/HRasL61+ cells were cloned and then transplanted into immunodeficient mice. p53-/HRasL61+ cells formed glioblastoma multiforme-like tumors. Further, GIC markers were strongly expressed in p53-/HRasL61+ cells. Therefore, p53-/HRasL61+ cell is an induced GIC. A CRISPR/Cas9-based method for inducing GIC is much more efficient than a KO mice-based method. This study provides a promising framework for easily creating glioblastoma model in mice.