Impact of iron overload by transfusion on survival and leukemia transformation of myelodysplastic syndromes in a single center of China

GSH exhaustion via inhibition of xCT-GSH-GPX4 pathway synergistically enhanced DSF/Cu-induced cuproptosis in myelodysplastic syndromes

The clinical application of the therapeutic approach in myelodysplastic syndromes (MDS) remains an insurmountable challenge for the high propensity for progressing to acute myeloid leukemia and predominantly affecting elderly individuals. Thus, the discovery of molecular mechanisms underlying the regulatory network of different programmed cell death holds great promise for the identification of therapeutic targets and provides insights into new therapeutic avenues. Herein, we found that disulfiram/copper (DSF/Cu) significantly repressed the cell viability, increased reactive oxygen species (ROS) accumulation, destroyed mitochondrial morphology, and altered oxygen consumption rate. Further studies verified that DSF/Cu induces cuproptosis, as evidenced by the depletion of glutathione (GSH), aggregation of lipoylated DLAT, and induced loss of Fe-S cluster-containing proteins, which could be rescued by tetrathiomolybdate and knockdown of ferredoxin 1 (FDX1). Additionally, GSH contributed to the tolerance of DSF/Cu-mediated cuproptosis, while pharmacological chelation of GSH triggered ROS accumulation and sensitized cell death. The xCT-GSH-GPX4 axis is the ideal downstream component of ferroptosis that exerts a powerful protective mechanism. Notably, classical xCT inhibitors were capable of leading to the catastrophic accumulation of ROS and exerting synergistic cell death, while xCT overexpression restored these phenomena. Simvastatin, an inhibitor of HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase, has beneficial effects in repurposing for inhibiting GPX4. Similarly, the combination treatment of DSF/Cu and simvastatin dramatically decreased the expression of GPX4 and Fe-S proteins, ultimately accelerating cell death. Moreover, we identified that the combination treatment of DSF/Cu and simvastatin also had a synergistic antitumor effect in the MDS mouse model, with the reduced GPX4, increased COX-2 and accumulated lipid peroxides. Overall, our study provided insight into developing a novel synergistic strategy to sensitize MDS therapy by targeting ferroptosis and cuproptosis.

Iron Overload in Children With Leukemia; Identification of a Cutoff Value for Serum Ferritin Level

OBJECTIVE

To determine the prevalence of iron overload in children with acute lymphoblastic leukemia (ALL) after treatment cessation and establish a cutoff value for serum ferritin level as an indicator of iron overload.

BACKGROUND

Early detection and monitoring of iron overload in patients with leukemia is crucial.

METHODS

In this prospective cohort study, 66 pediatric patients with ALL who were treated at a tertiary referral center affiliated with Shiraz University of Medical Sciences in Shiraz, Southern Iran, were investigated from July 2020 to December 2022. Serum ferritin levels were measured 6 months after treatment completion. T2* magnetic resonance imaging of the liver and heart was done for all patients. The receiver operating characteristic curve was used to illustrate the area under the receiver operating characteristic curve to assess the diagnostic value of serum ferritin level and total transfusion volume.

RESULTS

A total of 24 patients (36.4%) had iron overload in the heart or liver based on T2 magnetic resonance imaging findings. Serum ferritin level was a highly accurate diagnostic marker for iron overload in pediatric patients with ALL, with a sensitivity of 95.8%, and specificity of 85.7% for a cutoff value of 238.5 ng/mL. Also, blood transfusion was a good predictor of iron overload a sensitivity of 75% and specificity of 81% for a cutoff value of 28.3 mL/kg.

CONCLUSION

We identified specific cutoff values for serum ferritin and blood transfusion volume to predict iron overload with high sensitivity and specificity. These markers offer a cost-effective and accessible approach for periodic screening of iron deposition, particularly in resource-constrained settings.

Clinical view versus guideline adherence in ferritin monitoring and initiating iron chelation therapy in patients with myelodysplastic syndromes

OBJECTIVES

In patients with myelodysplastic syndromes (MDS) with >20 transfusions and ferritin levels >1000 μg/L, international guidelines recommend iron chelation therapy (ICT). The study's objective was to determine guideline adherence and the intensity of ferritin monitoring in clinical practice.

METHODS

We performed an observational population-based study using the HemoBase Registry, which contains data of all MDS patients diagnosed since 2005 in Friesland, the Netherlands. Clinical information on transfusions, ferritin measurements, ICT, and clinical performance as defined by age ≤ 80 years, Charlson Comorbidity Index <2 and lower-risk MDS was collected from health records.

RESULTS

Two hundred and thirty seven of 292 patients (81.1%) received ≥1 transfusion, and 121 (41.4%) received >20 transfusions. In 57 of these 121 patients (47.1%), ferritin measurements were performed at least once. Clinical performance was significantly associated with monitoring ferritin around the 20th transfusion (RR: 2.49, p = .016). Clinical performance was also associated with initiating ICT (RR: 5.99, p < .001). ICT was offered to 22.3% (n = 25) of eligible patients.

CONCLUSIONS

In this population-based study, ferritin levels were measured in <50% of MDS patients who received >20 transfusions, and clinical performance was significantly associated with measuring ferritin. Our study suggests that in heavily transfused MDS patients, ferritin monitoring is primarily based on patients' clinical performance rather than guideline recommendations.