[The methylation of CT gene in chronic myeloid leukemia]

To investigate the relationship between the abnormal methylation of the calcitonin (CT) gene and the karyotypic abnormality in predicting the disease progress in chronic myeloid leukemia (CML), we studied the abnormal methylation of the CT gene in 47 CML patients by using a sensitive PCR method. At the same time, cytogenetic study was made in the same group of patients. The abnormal methylation of CT gene was found in only 4 of 24 patients in chronic phase, but in 6 of 9 patients in accelerated phase, and in 12 of 14 patients in blast crisis. Sequential studies in one patient also showed that the gene is normally methylated during the chronic phase but turns hypermethylated as the disease progresses. Our findings indicate that abnormal methylation of the 5' region of the CT gene is regularly a marker of disease progression in CML.