In acute myeloid leukemias, aberrant DNA methylation of promoter-associated CpG islands represents an important mechanism in leukemogenesis. Hypermethylation of promoters blocks transcriptional activity of genes associated with tumor suppression and cell cycle control. In this study, we evaluate the promoter methylation status of genes CDKN2A and MLH1 in a small sample of Puertorrican patients with acute myeloid leukemia.

Methods: Peripheral blood was obtained from 6 patients with acute myeloid leukemia at the time of their diagnosis. Mononuclear cells were isolated by density gradient technique. DNA was isolated and further modified with sodium bisulfite. Methylation-specific polymerase (MSP) chain reaction was performed to detect the aberrant promoter methylation of CDKN2A and MLH1 genes in 6 patients with acute myeloid leukemia.

Results: A total of 6 samples were analyzed. The mean age was 44 years (24-66) and most of the patients were female (5/6,83%). Four of the patients had diploid cytogenetics, one patient had t(8;21) and one had-7q cytogenetics. WBC counts at presentation were 5.35/uL (0.8-13.8). Hypermethylation of CDKN2A and MLH1 was not detected in any of the samples.

Conclusions: Hypermethylation of CDKN2Aand MLH1 was not seen in the first six samples analyzed in this cohort of Puertorrican patients. Collection of more patient's samples and correlation with clinical data is ongoing.

Citation Information: Cancer Epidemiol Biomarkers Prev 2010;19(10 Suppl):A92.