Promoter methylation of p16 was detected in 85% of acute lymphocytic leukemia (ALL), 83% in acute myeloid leukemia (AML) whereas no methylation was detected in chronic myeloid leukemia (CML) in blast crisis.
p16 gene methylation was detected in 6 of 55 patients (10.9%), who were 1 patient with M2a, 1 patient with M5a, 2 patients with chronic myelogenous leukemia (CML) in blast crisis, 1 patient with progressing multiple myeloma (MM), 1 with non-Hodgkin's lymphoma (NHL) accompanied by B-ALL, respectively. p16 gene methylation correlates with adverse prognostic features.
In order to determine whether these genes are more widely involved in haematological malignancies, we have investigated a total of 84 samples that did not have homozygous p16 or p15 deletions from patients with acute lymphoid leukaemia (n=13), acute myeloid leukaemia (n=24) and chronic myeloid leukaemia in blast crisis (n=43) as well as four haemopoietic cell lines. p15 and p16 exon 1 and exon 2 were amplified by polymerase chain reaction (PCR), analysed by single-stranded conformation polymorphism (SSCP) and subsequently by sequencing.