The present disclosure provides novel compositions and methods suitable for specifically eliminating target cells (e.g., cancer cells) without affecting non-target cells (e.g., non-cancer cells). For example, CR-ISPR system and the compositions of the present disclosure can be employed to specifically introduce a suicidal gene into a cancer cell in the loci of a cancer-specific target sequence, which as a result of chromosomal re-arrangement or translocation in a cancer cell presents a cancer specific sequence for a guide RNA and CAS to be recognized and such sequence is absent in a non-cancer cell. Consequently, the specific introduction of the composition(s) to cancer-specific site(s) and integration of suicide gene in the target genome, which is inapplicable to normal cells for lack of the site(s), leads to selective elimination of cancer cells but not non-cancer cells, and therefore render novel therapeutic methods and compositions for cancer treatment.
