The expression of minichromosome maintenance protein‐2 in normal and abnormal megakaryocytes and comparison with the proliferative marker Ki‐67

The minichromosome maintenance (Mcm) and Cdc6 proteins are important regulators of eucaryotic DNA replication. In most normal tissues, a similar proportion of cells express Mcm‐2 and Ki‐67. The present study showed that in both normal and abnormal states, the proportion of megakaryocytes expressing Mcm‐2 is roughly seven times as many as those that express Ki‐67. This is likely to be related to the process of endomitosis and endoreduplication. We also demonstrated that a significantly lower proportion of megakaryocytes in myelodysplastic syndrome express Mcm‐2. These findings provide new insights into megakaryocyte biology.