Screening of a heptamer-type sgRNA library for potential therapeutic agents against hematological malignancies.

tRNase-Z(L)-utilizing efficacious (TRUE) gene silencing is an RNA-mediated gene expression control technology that has therapeutic potential. This technology is based on the property of tRNase Z(L) that it can cleave any target RNA at any desired site under the direction of an appropriate artificial small guide RNA (sgRNA). To search for novel potential therapeutic sgRNAs for hematological malignancies, we screened a library composed of 156 sgRNAs, and found that 20 sgRNAs can efficiently induce apoptosis in leukemia and/or myeloma cells. Furthermore, we demonstrated that 4 of the 20 sgRNAs can reduce growth rates of HL60 cells in mouse xenograft models.