Arsenic Trioxide Combine with G-CSF Triggers Distinct TP53 Mutations Acute Myeloid Leukemia Cells Ferroptosis through TP53-SLC7A11-GPX4 Pathway

Abstract ：

Background ：

Acute myeloid leukemia (AML) is a complex disease with diverse molecular subtypes. Approximately 8% of AML patients carry the TP53 mutation, which is associated with an aggressive disease course and dismal survival rates. Arsenic trioxide (ATO) has been remarkably effective in treating acute promyelocytic leukemia (APL), but its clinical activity in other AML subtypes remains limited. Recent evidence indicates that ATO demonstrates potential in rescuing multiple TP53 mutations effectively, offering promise as an individualized therapeutic strategy targeting mutant TP53 in leukemic cells. Our previous study showed that the upregulation of AQP9 by G-CSF enhanced the effect of ATO in non-APL AML cells. This demonstrates that ATO holds therapeutic promise in AML cases harboring distinct TP53 mutations.

Methods ：

We conducted a comprehensive analysis of TP53 mutations in the Analysis of Whole Genomes cohort, encompassing patients from the TCGA and OHSU databases. The frequency and distribution of TP53 mutations were determined. Median overall survival (OS) was calculated using the Kaplan-Meier method.

To functionally assess the effect of TP53 mutation on AML phenotype, various cell lines harboring distinct TP53 mutation types were used for this study, including KASUMI-1 ^{TP53 R248Q} THP-1 ^{TP53frameshift_del}HL-60 ^{TP53 deletion}MOLM13 ^{TP53 wild-type}. The cellular lipid oxidation levels were measured by a C11 BODIPY flow cytometry assay and it was also observed by fluorescence microscopy. Additionally, the RNA and protein expressions of GPX4 and SLC7A11 were analyzed by real-time quantitative Polymerase Chain Reaction (QRT-PCR) and Western Blot.

Results ：

In the OHSU cohort and TCGALAML database, including 1005 newly diagnosed patients with 120 TP53 mutations, we found that missense mutations are the most common TP53 mutations and R248Q has the highest mutation frequency. Furthermore, TP53 mutationwas significantly associated with lower survival ( P <0.001).

ATO potently induced cell death in each cell line. The KASUMI-1 ^R248Q cell line was the most sensitive to ATO (IC50=0.3607) and showed the most pronounced change in the IC50 of ATO with the addition of ferrostatin-1(Fer-1, ferroptosis inhibitor). ATO induced cell death was prevented by the addition of lipophilic antioxidant ferrostatin-1, supporting the hypothesis that ATO induced cell death occurred by ferroptosis.

In KASUMI-1 ^R248Q cell line, ATO increases the lipid oxidation levels (observed by C11 BODIPY flow cytometry assay and fluorescence microscopy), MDA levels and decreases the expression of GPX4 and SLC7A11 (including RNA level and protein level). Whereas, in MOLM13 ^{TP53 wildtype} cell line, ATO increases the lipid oxidation levels but cannot prevented by Fer-1. THP-1 ^{TP53 frameshift_del} and HL-60 ^{TP53 deletion} only decrease the RNA expression of GPX4 and SLC7A11, nothing else changed in ferroptosis. These suggest that ATO has a more pronounced effect on missense mutations such as TP53 R248Q. In KASUMI-1 ^R248Q cell line, associated with G-CSF can further promote lipid oxidation levels (observed by C11 BODIPY flow cytometry assay and fluorescence microscopy) and further reduce the expression of GPX4 and SLC7A11. These results suggest that G-CSF promotes ATO-induced ferroptosis in KASUMI-1 ^R248Q cell line.

Conclusion:

We have demonstrated that ATO induces AML with distinct TP53 mutation cell death by ferroptosis resulting from depletion of GPX4 and SLC7A11. ATO associated with G-CSF may be able to be a new therapeutic strategy for the treatment of AML with distinct TP53 mutation.