Guadecitabine

Guadecitabine (SGI-110) is a second-generation DNA methyltransferases (DNMT) inhibitor for research of acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS)^[1]. IC50 & Target: DNMT^[1] In Vitro: Exposure to Guadecitabine induces the expression of investigated cancer/testis antigens (CTA) in CTA-negative cancer cells. Results show that Guadecitabine induces and/or strongly up-regulates the constitutive levels of MAGE-A3- and NY-ESO-1-specific mRNA expression in neoplastic cells of all histotypes investigated. Exposure to Guadecitabine significantly (p<0.05) up-regulates the constitutive levels of expression of HLA class I antigens, HLA-A2 allospecificity, and of the co-stimulatory molecule ICAM-1, on Mel 275 melanoma cells. Results show that treatment with Guadecitabine induces a significant (p<0.01) reduction in the constitutive methylation levels of CTA promoters in investigated cancer cells. Mean values of the percentage of demethylation induced by Guadecitabine in MAGE-A1 and NY-ESO-1 promoters are 57 and 30 %, in Mel 195, and 22 and 33 % in MZ-1257 RCC cells, respectively^[2]. In Vivo: Guadecitabine (S110) is effective at retarding tumor growth. While the tumors do not shrink in size with Guadecitabine treatment, they experience very minimal growth while the tumors treated with PBS only show substantial growth. In addition, Guadecitabine induces much less toxicity as determined by mouse weight changes when given subcutaneously (SQ) compare to that with IP injections^[3].