These results suggest that inactivation of p16 and p15 genes is one of the most common genetic events in acute leukemia, and plays an important role for the RB/p16 pathway in the pathogenesis of acute leukemia.
The entire CpG island region of p15 was largely devoid of methylation in normal lymphocytes, but methylation of varying density was found in primary acute leukemia.
Reports on homozygous deletion of p16 and p15 genes suggest the value of larger, prospective studies with standardized treatment protocols to definitively establish the prognostic utility of p15/p16 deletions in acute leukemias.
Our results suggest that alterations of p16 and p15 genes are involved in a subset of acute leukemias with MLL gene rearrangement not only of lymphoid but also of myeloid phenotype.