Single-cell cloning of human T-cell lines reveals clonal variation in cell death responses to chemotherapeutics

In this study, we characterize the variation in cell death of fifty clonal cell lines generated from human Jurkat and MOLT-4 T-cells edited by CRISPR-Cas9. We demonstrate a wide distribution of sensitivity to chemotherapeutics between non-edited clonal human leukemia T-cell lines, and also following CRISPR-Cas9 editing at the NLRP1 locus, or following transfection with non-targeting sgRNA controls. The cell death sensitivity profile of clonal cell lines was consistent across experiments and failed to revert to the non-clonal parental phenotype. Whole genome sequencing of two clonal cell lines edited by CRISPR-Cas9 revealed unique and shared genetic variants, which had minimal read support in the non-clonal parental population and were not suspected CRISPR-Cas9 off-target effects. These variants included genes related to cell death and drug metabolism. The variation in cell death phenotype of clonal populations of human T-cell lines may be a consequence of T-cell line genetic instability, and to a lesser extent clonal heterogeneity in the parental population or CRISPR-Cas9 off-target effects not predicted by current models. This work highlights the importance of genetic variation between clonal T-cell lines in the design, conduct, and analysis of experiments to investigate gene function after single-cell cloning.

Source: Cancer Genetics - June 12, 2019 Category: Cancer & Oncology Source Type: research