ABSTRACT
There is a lack of rapid cell-based assays that read out enzymatic inhibition of the histone demethylase LSD1 (lysine-specific demethylase 1). Through transcriptome analysis of human acute myeloid leukemia THP1 cells treated with a tranylcypromine-derivative inhibitor of LSD1 active in the low nanomolar range, we identified the cell surface marker CD86 as a sensitive surrogate biomarker of LSD1 inhibition. Within 24h of enzyme inhibition, there was substantial and dose-dependent up-regulation of CD86 expression, as detected by quantitative polymerase chain reaction, flow cytometry, and enzyme-linked immunosorbent assay. Thus, the use of CD86 expression may facilitate screening of compounds with putative LSD1 inhibitory activities in cellular assays.
Subject(s)
B7-2 Antigen/antagonists & inhibitors , B7-2 Antigen/biosynthesis , Enzyme Inhibitors/pharmacology , Histone Demethylases/antagonists & inhibitors , Leukemia, Myeloid, Acute/drug therapy , Tranylcypromine/pharmacology , B7-2 Antigen/genetics , Biomarkers/metabolism , Cell Line, Tumor , Dose-Response Relationship, Drug , Enzyme Inhibitors/chemistry , Histone Demethylases/metabolism , Humans , Leukemia, Myeloid, Acute/metabolism , Leukemia, Myeloid, Acute/pathology , Structure-Activity Relationship , Tranylcypromine/chemistry , Up-Regulation/drug effectsABSTRACT
The advent of 'genomics' technology, in particular transcript profiling, has already had a measurable impact on the drug discovery process in the areas of target identification and validation. This review is concerned with the potential application of this technology to toxicology and drug safety assessment, with particular emphasis on biomarker discovery and characterization. An advantage (or possibly a drawback!) of transcript profiling is that candidate biomarkers of toxicity can be speedily identified, with the caveat that a significant amount of subsequent experimental and bioinformatic effort needs to be expended in order to evaluate and validate them. Attention is also drawn to the critical need for robust experimental design with studies of this type and to issues associated with the analysis of large data sets. In summary, while genomics technology undoubtedly offers much that can assist drug safety assessment, its potential has yet to be realized fully in this area. However, a large amount of resource continues to be applied to 'toxicogenomics'. Tangible benefits, in terms of new biomarkers of toxicity and reduced numbers of adverse drug effects, remain realistic objectives.
