Epigenetic Profile in Chronic Lymphocytic Leukemia using Methylation-Specific Multiplex Ligation-Dependent Probe Amplification

Abstract

To analyze the methylation status of 35 tumor suppressor genes using methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) in chronic lymphocytic leukemia (CLL). The DNA of 37 samples from patients with CLL, six healthy donors, and Jurkat and Ramos cell lines was analyzed by MS-MLPA. Our results confirm that hypermethylation is a common and not randomly distributed event in CLL, and some genes, such as WT1, CDH13, IGSF4/TSLC1, GATA5, DAPK1 and RARB, are hypermethylated in more than 25% of the analyzed samples. Importantly, MS-MLPA also detected hypermethylation of some genes not reported previously in CLL, and their methylation status was confirmed by bisulfite sequencing. These results indicate that MS-MLPA is a useful technique for the detection of methylation in CLL samples. Selecting CLL-specific methylation targets in order to generate a CLL-specific MS-MLPA probe set could enhance its usefulness as a tool in studies of risk stratification and guiding the best therapeutic decision.