Background: In this study, the effect of clofarabine, a new generation 2'-deoxyadenosine analogue, on promoter methylation and transcriptional activity of selected genes (PTEN, APC, RARB2, ZAP70) in K562 cells was assessed.
Materials and methods: Promoter methylation was estimated using methylation-sensitive restriction analysis. The mRNA level of the genes was measured with real-time PCR.
Results: The inhibitory cytostatic index (IG(50)) for clofarabine in K562 cells cultured for 72 (or 96) h was 8 nM. The drug (20 nM) caused: (i) potent diminution in methylation of PTEN promoter, moderate methylation reduction of APC and RARB2 promoters, and complete methylation of ZAP70 promoter; (ii) significant stimulation of PTEN, APC, RARB, and p21 mRNA expression and (iii) decline in mRNA level of ZAP70 and DNMT1 genes.
Conclusion: The results indicated that clofarabine is involved in epigenetic regulation of transcriptional activity of the tested tumour suppressor genes and genes encoding proteins involved in DNA methylation process.