Development of a novel cell-based assay system EPISSAY for screening epigenetic drugs and liposome formulated decitabine

作者：Lim Sue Ping^*; Kumar Raman; Akkamsetty Yamini; Wang Wen; Ho Kristen; Neilsen Paul M; Walther Diego J; Suetani Rachel J; Prestidge Clive; Callen David F

来源：BMC Cancer, 2013, 13(1): 113.

DOI：10.1186/1471-2407-13-113

• Cell-based assay system
• Decitabine
• Liposomes
• Nanotechnology
• CB1954
• Nitroreductase

Background: Despite the potential of improving the delivery of epigenetic drugs, the subsequent assessment of changes in their epigenetic activity is largely dependent on the availability of a suitable and rapid screening bioassay. Here, we describe a cell-based assay system for screening gene reactivation. %26lt;br%26gt;Methods: A cell-based assay system (EPISSAY) was designed based on a silenced triple-mutated bacterial nitroreductase TMnfsB fused with Red-Fluorescent Protein (RFP) expressed in the non-malignant human breast cell line MCF10A. EPISSAY was validated using the target gene TXNIP, which has previously been shown to respond to epigenetic drugs. The potency of a epigenetic drug model, decitabine, formulated with PEGylated liposomes was also validated using this assay system. %26lt;br%26gt;Results: Following treatment with DNA methyltransferase (DNMT) and histone deacetylase (HDAC) inhibitors such as decitabine and vorinostat, increases in RFP expression were observed, indicating expression of RFP-TMnfsB. The EPISSAY system was then used to test the potency of decitabine, before and after PEGylated liposomal encapsulation. We observed a 50% higher potency of decitabine when encapsulated in PEGylated liposomes, which is likely to be due to its protection from rapid degradation. %26lt;br%26gt;Conclusions: The EPISSAY bioassay system provides a novel and rapid system to compare the efficiencies of existing and newly formulated drugs that reactivate gene expression.

• 出版日期2013-3-13