Karyotype and DNA-Methylation Responses in Myelodysplastic Syndromes following Treatment with Traditional Chinese Formula Containing Arsenic

We have previously shown that arsenic-containing Chinese herbal formula, Qing-Huang powder capsule (containing tetraarsenic tetrasulfide, As(4)S(4)), is effective in the treatment of myelodysplastic syndrome (MDS); yet the underlined mechanisms remain unclear. In this study, using standard cytogenetic analysis (G-banded) and global DNA methylation method (ChIP-on-chip assays), we aimed to determine the effect of arsenic-containing Chinese herbal formula on karyotype status and the genomic methylation level in primarily diagnosed MDS patients. Correlation of aberrant DNA methylation and chromosome aberrations in MDS was also investigated. We found that the number of genes with aberrant DNA methylation was highest in MDS patients with normal karyotype, followed by trisomy 8 karyotype, and relatively low in patients with cytogenetic abnormalities other than trisomy 8. Treatment with arsenic-containing Chinese herbal formula had no effects on karyotype status, but resulted in a significant genome-wide demethylation. Our research uncovered a DNA demethylating activity of arsenic-containing Chinese herbal formula in the treatment of MDS.