TP53 Expression Status Alters Hemoglobinization and Ferroptosis Sensitivity in K-562 Cells

Area of Science:

• Molecular Biology
• Cell Biology
• Biochemistry

Background:

• TP53 signaling is crucial for erythroid development.
• Pathologic TP53 activation in Diamond-Blackfan anemia (DBA) and myelodysplastic syndrome (MDS) impairs erythroid precursor expansion.
• TP53 is implicated in DBA and MDS pathogenesis via ferroptosis, an iron-mediated cell death.

Purpose of the Study:

• To investigate how TP53 gene overexpression and mutation affect lipid composition, erythroid differentiation, and ferroptosis sensitivity.
• To utilize K-562 cells as an in vitro model for erythropoiesis studies.
• To understand the specific roles of wild-type (WT) and mutant TP53 (R175H, R282W) in these cellular processes.

Main Methods:

• Generated four isogenic K-562 cell lines: TP53 null, WT TP53, R175H mutant TP53, and R282W mutant TP53.
• Employed non-targeted lipidomics to analyze lipid species changes.
• Assessed gene expression (qPCR), ferroptosis sensitivity (CCK-8 assay), and hemoglobinization (o-dianisidine staining).

Main Results:

• WT TP53 induction altered 337 lipid species compared to TP53 null cells; only 17 differed between WT and mutant TP53.
• Cells expressing WT or mutant TP53 showed remarkable resistance to ferroptosis, unlike TP53 null cells.
• R175H mutant TP53 significantly impaired terminal differentiation and hemoglobinization.

Conclusions:

• TP53 plays a significant role in regulating lipid metabolism during erythropoiesis.
• Mutant TP53, particularly R175H, profoundly affects erythroid terminal differentiation and hemoglobinization.
• This study provides novel insights into TP53's function in lipid metabolism and erythropoiesis, relevant to ribosomopathies.