Advanced Rai Stage in Patients with Chronic Lymphocytic Leukaemia Correlates with Simultaneous Hypermethylation of Plural Tumour Suppressor Genes (chronic lymphocytic leukaemia / aberrant hypermethylation / tumour suppressor genes / Rai stage / methylation-specific polymerase chain reaction)

Hypermethylation of CpG islands within gene promoters is one of various mechanisms of gene silencing involved in the pathogenesis of human can- cer. By using methylation-specific polymerase chain reaction we explored aberrant promoter methylation of five tumour suppressor genes in 29 patients with chronic lymphocytic leukaemia. Aberrant methyla- tion of DLC1, SHP1, p15 and p16 occurred, respec- tively, in 89.7 %, 70 %, 62.1 % and 31 % of patients at diagnosis. Lamin A/C was unmethylated in all the samples. Hypermethylation of at least one gene was detected in 96.6 % of patients. Concurrent methyla- tion of two or more genes correlated with Rai stage at diagnosis.