TDP1 splice-site mutation causes HAP1 cell hypersensitivity to topoisomerase I inhibition.

ABSTRACT: HAP1 is a near-haploid human cell line commonly used for mutagenesis and genome editing studies due to its hemizygous nature. We noticed an unusual hypersensitivity of HAP1 to camptothecin, an antineoplastic drug that stabilizes topoisomerase I cleavage complexes (TOP1ccs). We have attributed this hypersensitivity to a deficiency of TDP1, a key phosphodiesterase involved in resolving abortive TOP1ccs. Through whole-exome sequencing and subsequent restoration of TDP1 protein via CRISPR-Cas9 endogenous genome editing, we demonstrate that TDP1 deficiency and camptothecin hypersensitivity in HAP1 cells are a result of a splice-site mutation (TDP1 c.660-1G > A) that causes exon skipping and TDP1 loss of function. The lack of TDP1 in HAP1 cells should be considered when studying topoisomerase-as

SUBMITTER: Goh CG 

PROVIDER: S-EPMC11754736 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature