HCT116 colorectal carcinoma cells are treated After 6 days, in p16expression is observed with Guadecitabine sodium (SGI-110 sodium) show a dose-dependent increase . In addition, a dose-dependent increase in the level of p16 protein in T24 and HCT116 cells treated with Guadecitabine sodium or 5-aza-CdR for 3 days, showing the competence of Guadecitabine sodium to inhibit DNA methylation and induce p16 at both mRNA and protein levels as well as 5-aza-CdR. Thus, Guadecitabine sodium is able to inhibit DNA methylation at 5′-region and induce the expression of the p16 gene in T24 and HCT116 cells at concentrations comparable to 5-aza-CdR, and the induction of p16 expression by both agents correlates with the demethylation at the 5′-end region of the gene in both cell lines. Guadecitabine sodium is slightly less toxic than 5-aza-CdR at the doses tested up to 1 μM concentration but displaying similar toxicity at 10 μM concentration[1].

Guadecitabine sodium(10mg/kg )is an effective dose at reducing DNA methylation and retarding tumor growth, and caused roughly the same level of toxicity as 5-Aza-CdR. Guadecitabine sodium is effective in vivo at reactivating the expression of the p16 gene, which is heavily methylated in the parent EJ6 cells. Guadecitabine sodium is effective in reducing the level of DNA methylation in vivo at the p16 promoter region. Guadecitabine sodium is better tolerated than 5-Aza-CdR in vivo[2].