Background: Several studies showed that aberrant DNA methylation is involved in leukemia and cancer pathogenesis. Protein tyrosine phosphatase receptor gamma (PTPRG) expression is a natural inhibitory mechanism that is downregulated in chronic myeloid leukemia (CML) disease. The mechanism behind its downregulation has not been fully elucidated yet.
Aim: This study aimed to investigate the CpG methylation status at the PTPRG locus in CML patients.
Methods: Peripheral blood samples from CML patients at time of diagnosis [no tyrosine kinase inhibitors (TKIs)] (n = 13), failure to (TKIs) treatment (n = 13) and healthy controls (n = 6) were collected. DNA was extracted and treated with bisulfite treatment, followed by PCR, sequencing of 25 CpG sites in the promoter region and 26 CpG sites in intron-1 region of PTPRG. The bisulfite sequencing technique was employed as a high-resolution method.
Results: CML groups (new diagnosed and failed treatment) showed significantly higher methylation levels in the promoter and intron-1 regions of PTPRG compared to the healthy group. There were also significant differences in methylation levels of CpG sites in the promoter and intron-1 regions amongst the groups.
Conclusion: Aberrant methylation of PTPRG is potentially one of the possible mechanisms of PTPRG downregulation detected in CML.
Keywords: CML; PTPRG; Qatar; aberrant DNA; cancer; epigenetics; methylation.
© 2020 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.