Expression of Lipoprotein Lipase and SORL1 Genes in Patients with Chronic Lymphocytic Leukemia

Introduction. Leukemic cells of patients with chronic lymphocytic leukemia (CLL) are characterized by high expression of the lipoprotein lipase (LPL) gene in unmutated (UM) status of the variable region of the immunoglobulin heavy chain (IGHV) genes and low expression of the SORL1 gene. SORL1 protein promotes the degradation of LPL in nervous cells in vitro that has been previously shown. Objective: to study SORL1 gene expression in CLL patients depending on LPL gene expression and mutational status of IGHV genes. Materials and methods. Analysis was performed in the group of 61 CLL patients. The IGHV gene mutational status was studied by polymerase chain reaction (PCR) followed by direct sequencing. LPL and SORL1 expression was evaluated by Quantitative Real-time PCR. Results. Relative LPL expression levels in CLL samples ranged from 0.5 to 119.5 (mean 23.65 ± 5.19) and correlated with IGHV mutational status (p < 0.01). The average relative SORL1 expression level was 1.71 ± 0.55. No association between SORL1 expression and IGHV mutational status was found (p = 0.358). Among unmutated IGHV cases, negative correlation between LPL and SORL1 gene expression levels was identified (r = -0.764; p = 0.036). Conclusion. The obtained data support the involvement of SORL1 in the post-translational regulation of LPL levels in leukemic cells in CLL. Ketwords: chronic lymphocytic leukemia, lipoprotein lipase, SORL1.