1. TOPORS E3 ligase mediates resistance to hypomethylating agent cytotoxicity in acute myeloid leukemia cells.
- Author
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Truong P, Shen S, Joshi S, Islam MI, Zhong L, Raftery MJ, Afrasiabi A, Alinejad-Rokny H, Nguyen M, Zou X, Bhuyan GS, Sarowar CH, Ghodousi ES, Stonehouse O, Mohamed S, Toscan CE, Connerty P, Kakadia PM, Bohlander SK, Michie KA, Larsson J, Lock RB, Walkley CR, Thoms JAI, Jolly CJ, and Pimanda JE
- Subjects
- Humans, Animals, Cell Line, Tumor, Mice, Sumoylation drug effects, Ubiquitin-Protein Ligases metabolism, Ubiquitin-Protein Ligases genetics, DNA Damage drug effects, DNA Methylation drug effects, Xenograft Model Antitumor Assays, DNA (Cytosine-5-)-Methyltransferase 1 metabolism, DNA (Cytosine-5-)-Methyltransferase 1 genetics, DNA (Cytosine-5-)-Methyltransferase 1 antagonists & inhibitors, Female, Leukemia, Myeloid, Acute genetics, Leukemia, Myeloid, Acute drug therapy, Leukemia, Myeloid, Acute pathology, Leukemia, Myeloid, Acute metabolism, Drug Resistance, Neoplasm genetics, Drug Resistance, Neoplasm drug effects, Myelodysplastic Syndromes drug therapy, Myelodysplastic Syndromes genetics, Myelodysplastic Syndromes pathology, Myelodysplastic Syndromes metabolism, CRISPR-Cas Systems
- Abstract
Hypomethylating agents (HMAs) are frontline therapies for Myelodysplastic Neoplasms (MDS) and Acute Myeloid Leukemia (AML). However, acquired resistance and treatment failure are commonplace. To address this, we perform a genome-wide CRISPR-Cas9 screen in a human MDS-derived cell line, MDS-L, and identify TOPORS as a loss-of-function target that synergizes with HMAs, reducing leukemic burden and improving survival in xenograft models. We demonstrate that depletion of TOPORS mediates sensitivity to HMAs by predisposing leukemic blasts to an impaired DNA damage response (DDR) accompanied by an accumulation of SUMOylated DNMT1 in HMA-treated TOPORS-depleted cells. The combination of HMAs with targeting of TOPORS does not impair healthy hematopoiesis. While inhibitors of TOPORS are unavailable, we show that inhibition of protein SUMOylation with TAK-981 partially phenocopies HMA-sensitivity and DDR impairment. Overall, our data suggest that the combination of HMAs with inhibition of SUMOylation or TOPORS is a rational treatment option for High-Risk MDS (HR-MDS) or AML., (© 2024. The Author(s).)
- Published
- 2024
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