Induction of Chromosomal Translocations with CRISPR-Cas9 and Other Nucleases: Understanding the Repair Mechanisms That Give Rise to Translocations

Chromosomal translocations are associated with several tumor types, including hematopoietic malignancies, sarcomas, and solid tumors of epithelial origin, due to their activation of a proto-oncogene or generation of a novel fusion protein with oncogenic potential. In many cases, the availability of suitable human models has been lacking because of the difficulty in recapitulating precise expression of the fusion protein or other reasons. Further, understanding how translocations form mechanistically has been a goal, as it may suggest ways to prevent their occurrence. Chromosomal translocations arise when DNA ends from double-strand breaks (DSBs) on two heterologous chromosomes are improperly joined. This review provides a summary of DSB repair mechanisms and their contribution to translocation formation, the various programmable nuclease platforms that have been used to generate translocations, and the successes that have been achieved in this area.