Alteration of lipids and the transcription of lipid-related genes in myelodysplastic syndromes via a TP53-related pathway.

Myelodysplastic syndromes (MDS) are clonal stem cell diseases of the bone marrow characterized by abnormalities in maturation of hematopoietic cells of all lineages. MDS patients frequently have lower lipids and high rates of apoptosis and p53 (TP53) expression. An association between the reduced lipids in MDS and the expression of lipid-related genes was sought. We further evaluated whether 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGcoAR) and low-density lipoprotein receptor (LDL-R) are regulated by TP53 in vivo and in vitro. Gene expression was measured using real-time reverse transcription polymerase chain reaction on RNA extracted from bone marrow and peripheral blood from eight newly diagnosed MDS patients and eight controls and from mice livers. Serum lipid profile was measured using colorimetric enzymatic procedures. Total- and LDL cholesterol were lower in MDS patients in comparison to controls (p = 0.04 and p = 0.01, respectively). HMGcoAR messenger RNA increased in peripheral blood and bone marrow of MDS patients compared to controls (p = 0.04 and p = 0.01, respectively). LDL-R messenger RNA was higher only in the peripheral blood of MDS patients (p = 0.05). Comparable results were obtained in vivo. The transcription of these genes correlates with TP53 activation as documented by p21 messenger RNA elevation, a surrogate for TP53 activation and by using TP53 temperature-sensitive cells treated with adriamycin. To conclude, an association between reduced lipids in MDS and expression of HMGcoAR and LDL-R genes was documented. The transcription of these genes can be regulated by TP53.
(Copyright © 2012 ISEH - Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.)