The Gln223Arg polymorphism of the leptin receptor gene and peripheral blood-bone marrow leptin level in leukemic children

Leptin is an adipocyte-derived hormone regulating energy homeostasis and body weight. Leptin also plays a role in hematopoesis, cell cycle regulation, and in oncogenesis. The leptin receptor is a single transmembrane protein belonging to the superfamily of cytokine receptors, structurally related to the hemopoietin receptor family. The aim of the study was to evaluate bone marrow and peripheral blood leptin level and frequency of distribution of leptin receptor gene polymorphism Gln223Arg in children with acute leukemia. The examined group included 92 children with acute leukemia (83 ALL and 9 AML) and 39 non-leukemic control children. Leptin level was measured by ELISA method at the day of leukemia diagnosis. Genomic DNA was isolated with the use of a column method and the genotyping of DNA sequence variation was carried out by the restriction enzyme analysis of PCR – amplified DNA. The samples were then electrophoresed on 2.5% agarose gel. Leptin level in leukemic children was lower than in healthy children. Bone marrow leptin level was significantly lower than that in the blood in leukemic children with ALL-T and AML. An analysis of frequency distribution of the Gln233Arg polymorphism in the leptin receptor gene in leukemic children showed lack of differences between the patients and controls. There was no difference in the genotype frequencies between the leukemic AML and ALL groups either. The results indicate a possible relation between the leptin level and leukemia development in children. The effectory effect of the hormone seems not related to Gln223Arg polymorphism of its receptor.