DNA methylation analysis of the tumor suppressor gene CDKN2B in Brazilian leukemia patients

The aim of this work was to evaluate the methylation profile of the p15 (CDKN2B) gene in Brazilian patients with leukemia and to correlate the CDKN2B gene expression with the percentage of methylated CpG dinucleotides in its promoter region. Thirty-one samples from six patients with acute lymphocytic leukemia (ALL), four with chronic myeloid leukemia (CML), and 21 with acute myeloid leukemia (AML) were evaluated by MSP (Methylation-Specific PCR). The CDKN2B gene was found to be methylated in four (67%) of the six ALL samples and in 16 (76%) of the 21 AML samples, but in none of the four CML samples analyzed. We observed a correlation between the CDKN2B mRNA expression (RT-PCR) and the percentage of methylated CpG dinucleotides. Therefore, this study in Brazilian patients confirms that the CDKN2B gene is methylated in the majority of leukemia patients.