Selenium and glutathione peroxidase status in adult Egyptian patients with acute myeloid leukemia

Therapeutic Benefits of Selenium in Hematological Malignancies

Supplementing chemotherapy and radiotherapy with selenium has been shown to have benefits against various cancers. This approach has also been shown to alleviate the side effects associated with standard cancer therapies and improve the quality of life in patients. In addition, selenium levels in patients have been correlated with various cancers and have served as a diagnostic marker to track the efficiency of treatments or to determine whether these selenium levels cause or are a result of the disease. This concise review presents a survey of the selenium-based literature, with a focus on hematological malignancies, to demonstrate the significant impact of selenium in different cancers. The anti-cancer mechanisms and signaling pathways regulated by selenium, which impart its efficacious properties, are discussed. An outlook into the relationship between selenium and cancer is highlighted to guide future cancer therapy development.

Implications of Glutathione Peroxidase 3 Expression in a Cohort of Egyptian Patients with Acute Myeloid Leukemia

Background:

The impact of low expression of Glutathione peroxidase 3 (GPX3) on the clinical course of acute myeloid leukemia (AML) is poorly investigated.

Aims:

To explore the status of GPX3 expression and analyze its clinical characteristics and prognosis in a cohort of Egyptian patients with AML.

Methods:

GPX3 mRNA level was assessed by RT-q PCR in 40 newly diagnosed AML patients and 10 healthy controls.

Results:

The gene expression level was significantly lower in AML patients than the control group (P < 0.001). A cut off value (0.1223) for the discrimination between AML and controls was obtained by ROC curve. According to this cutoff value; the patients were reassigned into 2 groups; 28 patients with lower GPX3 expression and 12 patients with high GPX3 expression. GPX3^low expression was significantly associated with higher incidence of induction death (P= 0.037) and lower CR rate (P=0.048). Moreover, GPX3^low expression was significantly associated with shorter cumulative 1-year overall survival (OS) (P = 0.001) and disease-free survival (DFS) (P=0.028).

Conclusion:

GPX3^low expression status is considered a poor prognostic factor in AML predicting shorter OS and DFS. The study highlights the importance of targeting glutathione metabolism as a central component of the anti-leukemia therapy.

Selenium suppresses leukemia through the action of endogenous eicosanoids

Eradicating cancer stem-like cells (CSC) may be essential to fully eradicate cancer. Metabolic changes in CSC could hold a key to their targeting. Here, we report that the dietary micronutrient selenium can trigger apoptosis of CSC derived from chronic or acute myelogenous leukemias when administered at supraphysiologic but nontoxic doses. In leukemia CSC, selenium treatment activated ATM-p53-dependent apoptosis accompanied by increased intracellular levels of reactive oxygen species. Importantly, the same treatment did not trigger apoptosis in hematopoietic stem cells. Serial transplantation studies with BCR-ABL-expressing CSC revealed that the selenium status in mice was a key determinant of CSC survival. Selenium action relied upon the endogenous production of the cyclooxygenase-derived prostaglandins Δ(12)-PGJ2 and 15d-PGJ2. Accordingly, nonsteroidal anti-inflammatory drugs and NADPH oxidase inhibitors abrogated the ability of selenium to trigger apoptosis in leukemia CSC. Our results reveal how selenium-dependent modulation of arachidonic acid metabolism can be directed to trigger apoptosis of primary human and murine CSC in leukemia.